Physical Layer Secret-Key Generation Scheme for Transportation Security Sensor Network.

PubMed

Yang, Bin; Zhang, Jianfeng

2017-06-28

Wireless Sensor Networks (WSNs) are widely used in different disciplines, including transportation systems, agriculture field environment monitoring, healthcare systems, and industrial monitoring. The security challenge of the wireless communication link between sensor nodes is critical in WSNs. In this paper, we propose a new physical layer secret-key generation scheme for transportation security sensor network. The scheme is based on the cooperation of all the sensor nodes, thus avoiding the key distribution process, which increases the security of the system. Different passive and active attack models are analyzed in this paper. We also prove that when the cooperative node number is large enough, even when the eavesdropper is equipped with multiple antennas, the secret-key is still secure. Numerical results are performed to show the efficiency of the proposed scheme.

Hybrid monitoring scheme for end-to-end performance enhancement of multicast-based real-time media

NASA Astrophysics Data System (ADS)

Park, Ju-Won; Kim, JongWon

2004-10-01

As real-time media applications based on IP multicast networks spread widely, end-to-end QoS (quality of service) provisioning for these applications have become very important. To guarantee the end-to-end QoS of multi-party media applications, it is essential to monitor the time-varying status of both network metrics (i.e., delay, jitter and loss) and system metrics (i.e., CPU and memory utilization). In this paper, targeting the multicast-enabled AG (Access Grid) a next-generation group collaboration tool based on multi-party media services, the applicability of hybrid monitoring scheme that combines active and passive monitoring is investigated. The active monitoring measures network-layer metrics (i.e., network condition) with probe packets while the passive monitoring checks both application-layer metrics (i.e., user traffic condition by analyzing RTCP packets) and system metrics. By comparing these hybrid results, we attempt to pinpoint the causes of performance degradation and explore corresponding reactions to improve the end-to-end performance. The experimental results show that the proposed hybrid monitoring can provide useful information to coordinate the performance improvement of multi-party real-time media applications.

Development of smart piezoelectric transducer self-sensing, self-diagnosis and tuning schemes for structural health monitoring applications

NASA Astrophysics Data System (ADS)

Lee, Sang Jun

Autonomous structural health monitoring (SHM) systems using active sensing devices have been studied extensively to diagnose the current state of aerospace, civil infrastructure and mechanical systems in near real-time and aims to eventually reduce life-cycle costs by replacing current schedule-based maintenance with condition-based maintenance. This research develops four schemes for SHM applications: (1) a simple and reliable PZT transducer self-sensing scheme; (2) a smart PZT self-diagnosis scheme; (3) an instantaneous reciprocity-based PZT diagnosis scheme; and (4) an effective PZT transducer tuning scheme. First, this research develops a PZT transducer self-sensing scheme, which is a necessary condition to accomplish a PZT transducer self-diagnosis. Main advantages of the proposed self-sensing approach are its simplicity and adaptability. The necessary hardware is only an additional self-sensing circuit which includes a minimum of electric components. With this circuit, the self-sensing parameters can be calibrated instantaneously in the presence of changing operational and environmental conditions of the system. In particular, this self-sensing scheme focuses on estimating the mechanical response in the time domain for the subsequent applications of the PZT transducer self-diagnosis and tuning with guided wave propagation. The most significant challenge of this self-sensing comes from the fact that the magnitude of the mechanical response is generally several orders of magnitude smaller than that of the input signal. The proposed self-sensing scheme fully takes advantage of the fact that any user-defined input signals can be applied to a host structure and the input waveform is known. The performance of the proposed self-sensing scheme is demonstrated by theoretical analysis, numerical simulations and various experiments. Second, this research proposes a smart PZT transducer self-diagnosis scheme based on the developed self-sensing scheme. Conventionally, the capacitance change of the PZT wafer is monitored to identify the abnormal PZT condition because the capacitance of the PZT wafer is linearly proportional to its size and also related to the bonding condition. However, temperature variation is another primary factor that affects the PZT capacitance. To ensure the reliable transducer self-diagnosis, two different self-diagnosis features are proposed to differentiate two main PZT wafer defects, i.e., PZT debonding and PZT cracking, from temperature variations and structural damages. The PZT debonding is identified using two indices based on time reversal process (TRP) without any baseline data. Also, the PZT cracking is identified by monitoring the change of the generated Lamb wave power ratio index with respect to the driving frequency. The uniqueness of this self-diagnosis scheme is that the self-diagnosis features can differentiate the PZT defects from environmental variations and structural damages. Therefore, it is expected to minimize false-alarms which are induced by operational or environmental variations as well as structural damages. The applicability of the proposed self-diagnosis scheme is verified by theoretical analysis, numerical simulations, and experimental tests. Third, a new methodology of guided wave-based PZT transducer diagnosis is developed to identify PZT transducer defects without using prior baseline data. This methodology can be applied when a number of same-size PZT transducers are attached to a target structure to form a sensor network. The advantage of the proposed technique is that abnormal PZT transducers among intact PZT transducers can be detected even when the system being monitored is subjected to varying operational and environmental conditions or changing structural conditions. To achieve this goal, the proposed diagnosis technique utilizes the linear reciprocity of guided wave propagation between a pair of surface-bonded PZT transducers. Finally, a PZT transducer tuning scheme is being developed for selective Lamb wave excitation and sensing. This is useful for structural damage detection based on Lamb wave propagation because the proper transducer size and the corresponding input frequency can be is crucial for selective Lamb wave excitation and sensing. The circular PZT response model is derived, and the energy balance is included for a better prediction of the PZT responses because the existing PZT response models do not consider any energy balance between Lamb wave modes. In addition, two calibration methods are also suggested in order to model the PZT responses more accurately by considering a bonding layer effect. (Abstract shortened by UMI.)

A Temporal Credential-Based Mutual Authentication with Multiple-Password Scheme for Wireless Sensor Networks

PubMed Central

Zhang, Ruisheng; Liu, Qidong

2017-01-01

Wireless sensor networks (WSNs), which consist of a large number of sensor nodes, have become among the most important technologies in numerous fields, such as environmental monitoring, military surveillance, control systems in nuclear reactors, vehicle safety systems, and medical monitoring. The most serious drawback for the widespread application of WSNs is the lack of security. Given the resource limitation of WSNs, traditional security schemes are unsuitable. Approaches toward withstanding related attacks with small overhead have thus recently been studied by many researchers. Numerous studies have focused on the authentication scheme for WSNs, but most of these works cannot achieve the security performance and overhead perfectly. Nam et al. proposed a two-factor authentication scheme with lightweight sensor computation for WSNs. In this paper, we review this scheme, emphasize its drawbacks, and propose a temporal credential-based mutual authentication with a multiple-password scheme for WSNs. Our scheme uses multiple passwords to achieve three-factor security performance and generate a session key between user and sensor nodes. The security analysis phase shows that our scheme can withstand related attacks, including a lost password threat, and the comparison phase shows that our scheme involves a relatively small overhead. In the comparison of the overhead phase, the result indicates that more than 95% of the overhead is composed of communication and not computation overhead. Therefore, the result motivates us to pay further attention to communication overhead than computation overhead in future research. PMID:28135288

A Temporal Credential-Based Mutual Authentication with Multiple-Password Scheme for Wireless Sensor Networks.

PubMed

Liu, Xin; Zhang, Ruisheng; Liu, Qidong

2017-01-01

Wireless sensor networks (WSNs), which consist of a large number of sensor nodes, have become among the most important technologies in numerous fields, such as environmental monitoring, military surveillance, control systems in nuclear reactors, vehicle safety systems, and medical monitoring. The most serious drawback for the widespread application of WSNs is the lack of security. Given the resource limitation of WSNs, traditional security schemes are unsuitable. Approaches toward withstanding related attacks with small overhead have thus recently been studied by many researchers. Numerous studies have focused on the authentication scheme for WSNs, but most of these works cannot achieve the security performance and overhead perfectly. Nam et al. proposed a two-factor authentication scheme with lightweight sensor computation for WSNs. In this paper, we review this scheme, emphasize its drawbacks, and propose a temporal credential-based mutual authentication with a multiple-password scheme for WSNs. Our scheme uses multiple passwords to achieve three-factor security performance and generate a session key between user and sensor nodes. The security analysis phase shows that our scheme can withstand related attacks, including a lost password threat, and the comparison phase shows that our scheme involves a relatively small overhead. In the comparison of the overhead phase, the result indicates that more than 95% of the overhead is composed of communication and not computation overhead. Therefore, the result motivates us to pay further attention to communication overhead than computation overhead in future research.

Construction on Practical Talents Training Mode in Environmental Monitoring Curriculum

ERIC Educational Resources Information Center

Wang, Jing-Ping; Wang, Xin-Hong

2017-01-01

Environmental Monitoring is a basic and comprehensive course for students majoring in environmental sciences and engineering. Based on the characteristics of this course, a new teaching mode in application of practical talents training in Environmental Monitoring Curriculum teaching mode is proposed including the new scheme of training applied…

Smartphone-Based Patients' Activity Recognition by Using a Self-Learning Scheme for Medical Monitoring.

PubMed

Guo, Junqi; Zhou, Xi; Sun, Yunchuan; Ping, Gong; Zhao, Guoxing; Li, Zhuorong

2016-06-01

Smartphone based activity recognition has recently received remarkable attention in various applications of mobile health such as safety monitoring, fitness tracking, and disease prediction. To achieve more accurate and simplified medical monitoring, this paper proposes a self-learning scheme for patients' activity recognition, in which a patient only needs to carry an ordinary smartphone that contains common motion sensors. After the real-time data collection though this smartphone, we preprocess the data using coordinate system transformation to eliminate phone orientation influence. A set of robust and effective features are then extracted from the preprocessed data. Because a patient may inevitably perform various unpredictable activities that have no apriori knowledge in the training dataset, we propose a self-learning activity recognition scheme. The scheme determines whether there are apriori training samples and labeled categories in training pools that well match with unpredictable activity data. If not, it automatically assembles these unpredictable samples into different clusters and gives them new category labels. These clustered samples combined with the acquired new category labels are then merged into the training dataset to reinforce recognition ability of the self-learning model. In experiments, we evaluate our scheme using the data collected from two postoperative patient volunteers, including six labeled daily activities as the initial apriori categories in the training pool. Experimental results demonstrate that the proposed self-learning scheme for activity recognition works very well for most cases. When there exist several types of unseen activities without any apriori information, the accuracy reaches above 80 % after the self-learning process converges.

Mobile devices for community-based REDD+ monitoring: a case study for Central Vietnam.

PubMed

Pratihast, Arun Kumar; Herold, Martin; Avitabile, Valerio; de Bruin, Sytze; Bartholomeus, Harm; Souza, Carlos M; Ribbe, Lars

2012-12-20

Monitoring tropical deforestation and forest degradation is one of the central elements for the Reduced Emissions from Deforestation and Forest Degradation in developing countries (REDD+) scheme. Current arrangements for monitoring are based on remote sensing and field measurements. Since monitoring is the periodic process of assessing forest stands properties with respect to reference data, adopting the current REDD+ requirements for implementing monitoring at national levels is a challenging task. Recently, the advancement in Information and Communications Technologies (ICT) and mobile devices has enabled local communities to monitor their forest in a basic resource setting such as no or slow internet connection link, limited power supply, etc. Despite the potential, the use of mobile device system for community based monitoring (CBM) is still exceptional and faces implementation challenges. This paper presents an integrated data collection system based on mobile devices that streamlines the community-based forest monitoring data collection, transmission and visualization process. This paper also assesses the accuracy and reliability of CBM data and proposes a way to fit them into national REDD+ Monitoring, Reporting and Verification (MRV) scheme. The system performance is evaluated at Tra Bui commune, Quang Nam province, Central Vietnam, where forest carbon and change activities were tracked. The results show that the local community is able to provide data with accuracy comparable to expert measurements (index of agreement greater than 0.88), but against lower costs. Furthermore, the results confirm that communities are more effective to monitor small scale forest degradation due to subsistence fuel wood collection and selective logging, than high resolution remote sensing SPOT imagery.

Mobile Devices for Community-Based REDD+ Monitoring: A Case Study for Central Vietnam

PubMed Central

Pratihast, Arun Kumar; Herold, Martin; Avitabile, Valerio; de Bruin, Sytze; Bartholomeus, Harm; Souza, Carlos M.; Ribbe, Lars

2013-01-01

Monitoring tropical deforestation and forest degradation is one of the central elements for the Reduced Emissions from Deforestation and Forest Degradation in developing countries (REDD+) scheme. Current arrangements for monitoring are based on remote sensing and field measurements. Since monitoring is the periodic process of assessing forest stands properties with respect to reference data, adopting the current REDD+ requirements for implementing monitoring at national levels is a challenging task. Recently, the advancement in Information and Communications Technologies (ICT) and mobile devices has enabled local communities to monitor their forest in a basic resource setting such as no or slow internet connection link, limited power supply, etc. Despite the potential, the use of mobile device system for community based monitoring (CBM) is still exceptional and faces implementation challenges. This paper presents an integrated data collection system based on mobile devices that streamlines the community-based forest monitoring data collection, transmission and visualization process. This paper also assesses the accuracy and reliability of CBM data and proposes a way to fit them into national REDD+ Monitoring, Reporting and Verification (MRV) scheme. The system performance is evaluated at Tra Bui commune, Quang Nam province, Central Vietnam, where forest carbon and change activities were tracked. The results show that the local community is able to provide data with accuracy comparable to expert measurements (index of agreement greater than 0.88), but against lower costs. Furthermore, the results confirm that communities are more effective to monitor small scale forest degradation due to subsistence fuel wood collection and selective logging, than high resolution remote sensing SPOT imagery. PMID:23344371

On-Line Modal State Monitoring of Slowly Time-Varying Structures

NASA Technical Reports Server (NTRS)

Johnson, Erik A.; Bergman, Lawrence A.; Voulgaris, Petros G.

1997-01-01

Monitoring the dynamic response of structures is often performed for a variety of reasons. These reasons include condition-based maintenance, health monitoring, performance improvements, and control. In many cases the data analysis that is performed is part of a repetitive decision-making process, and in these cases the development of effective on-line monitoring schemes help to speed the decision-making process and reduce the risk of erroneous decisions. This report investigates the use of spatial modal filters for tracking the dynamics of slowly time-varying linear structures. The report includes an overview of modal filter theory followed by an overview of several structural system identification methods. Included in this discussion and comparison are H-infinity, eigensystem realization, and several time-domain least squares approaches. Finally, a two-stage adaptive on-line monitoring scheme is developed and evaluated.

An efficient and secure dynamic ID-based authentication scheme for telecare medical information systems.

PubMed

Chen, Hung-Ming; Lo, Jung-Wen; Yeh, Chang-Kuo

2012-12-01

The rapidly increased availability of always-on broadband telecommunication environments and lower-cost vital signs monitoring devices bring the advantages of telemedicine directly into the patient's home. Hence, the control of access to remote medical servers' resources has become a crucial challenge. A secure authentication scheme between the medical server and remote users is therefore needed to safeguard data integrity, confidentiality and to ensure availability. Recently, many authentication schemes that use low-cost mobile devices have been proposed to meet these requirements. In contrast to previous schemes, Khan et al. proposed a dynamic ID-based remote user authentication scheme that reduces computational complexity and includes features such as a provision for the revocation of lost or stolen smart cards and a time expiry check for the authentication process. However, Khan et al.'s scheme has some security drawbacks. To remedy theses, this study proposes an enhanced authentication scheme that overcomes the weaknesses inherent in Khan et al.'s scheme and demonstrated this scheme is more secure and robust for use in a telecare medical information system.

A Wavelet Bicoherence-Based Quadratic Nonlinearity Feature for Translational Axis Condition Monitoring

PubMed Central

Li, Yong; Wang, Xiufeng; Lin, Jing; Shi, Shengyu

2014-01-01

The translational axis is one of the most important subsystems in modern machine tools, as its degradation may result in the loss of the product qualification and lower the control precision. Condition-based maintenance (CBM) has been considered as one of the advanced maintenance schemes to achieve effective, reliable and cost-effective operation of machine systems, however, current vibration-based maintenance schemes cannot be employed directly in the translational axis system, due to its complex structure and the inefficiency of commonly used condition monitoring features. In this paper, a wavelet bicoherence-based quadratic nonlinearity feature is proposed for translational axis condition monitoring by using the torque signature of the drive servomotor. Firstly, the quadratic nonlinearity of the servomotor torque signature is discussed, and then, a biphase randomization wavelet bicoherence is introduced for its quadratic nonlinear detection. On this basis, a quadratic nonlinearity feature is proposed for condition monitoring of the translational axis. The properties of the proposed quadratic nonlinearity feature are investigated by simulations. Subsequently, this feature is applied to the real-world servomotor torque data collected from the X-axis on a high precision vertical machining centre. All the results show that the performance of the proposed feature is much better than that of original condition monitoring features. PMID:24473281

Emerging Security Mechanisms for Medical Cyber Physical Systems.

PubMed

Kocabas, Ovunc; Soyata, Tolga; Aktas, Mehmet K

2016-01-01

The following decade will witness a surge in remote health-monitoring systems that are based on body-worn monitoring devices. These Medical Cyber Physical Systems (MCPS) will be capable of transmitting the acquired data to a private or public cloud for storage and processing. Machine learning algorithms running in the cloud and processing this data can provide decision support to healthcare professionals. There is no doubt that the security and privacy of the medical data is one of the most important concerns in designing an MCPS. In this paper, we depict the general architecture of an MCPS consisting of four layers: data acquisition, data aggregation, cloud processing, and action. Due to the differences in hardware and communication capabilities of each layer, different encryption schemes must be used to guarantee data privacy within that layer. We survey conventional and emerging encryption schemes based on their ability to provide secure storage, data sharing, and secure computation. Our detailed experimental evaluation of each scheme shows that while the emerging encryption schemes enable exciting new features such as secure sharing and secure computation, they introduce several orders-of-magnitude computational and storage overhead. We conclude our paper by outlining future research directions to improve the usability of the emerging encryption schemes in an MCPS.

On the security of a dynamic ID-based authentication scheme for telecare medical information systems.

PubMed

Lin, Han-Yu

2013-04-01

Telecare medical information systems (TMISs) are increasingly popular technologies for healthcare applications. Using TMISs, physicians and caregivers can monitor the vital signs of patients remotely. Since the database of TMISs stores patients' electronic medical records (EMRs), only authorized users should be granted the access to this information for the privacy concern. To keep the user anonymity, recently, Chen et al. proposed a dynamic ID-based authentication scheme for telecare medical information system. They claimed that their scheme is more secure and robust for use in a TMIS. However, we will demonstrate that their scheme fails to satisfy the user anonymity due to the dictionary attacks. It is also possible to derive a user password in case of smart card loss attacks. Additionally, an improved scheme eliminating these weaknesses is also presented.

a Thtee-Dimensional Variational Assimilation Scheme for Satellite Aod

NASA Astrophysics Data System (ADS)

Liang, Y.; Zang, Z.; You, W.

2018-04-01

A three-dimensional variational data assimilation scheme is designed for satellite AOD based on the IMPROVE (Interagency Monitoring of Protected Visual Environments) equation. The observation operator that simulates AOD from the control variables is established by the IMPROVE equation. All of the 16 control variables in the assimilation scheme are the mass concentrations of aerosol species from the Model for Simulation Aerosol Interactions and Chemistry scheme, so as to take advantage of this scheme in providing comprehensive analyses of species concentrations and size distributions as well as be calculating efficiently. The assimilation scheme can save computational resources as the IMPROVE equation is a quadratic equation. A single-point observation experiment shows that the information from the single-point AOD is effectively spread horizontally and vertically.

High-Performance Sensors Based on Resistance Fluctuations of Single-Layer-Graphene Transistors.

PubMed

Amin, Kazi Rafsanjani; Bid, Aveek

2015-09-09

One of the most interesting predicted applications of graphene-monolayer-based devices is as high-quality sensors. In this article, we show, through systematic experiments, a chemical vapor sensor based on the measurement of low-frequency resistance fluctuations of single-layer-graphene field-effect-transistor devices. The sensor has extremely high sensitivity, very high specificity, high fidelity, and fast response times. The performance of the device using this scheme of measurement (which uses resistance fluctuations as the detection parameter) is more than 2 orders of magnitude better than a detection scheme in which changes in the average value of the resistance is monitored. We propose a number-density-fluctuation-based model to explain the superior characteristics of a noise-measurement-based detection scheme presented in this article.

A novel multi-scale adaptive sampling-based approach for energy saving in leak detection for WSN-based water pipelines

NASA Astrophysics Data System (ADS)

Saqib, Najam us; Faizan Mysorewala, Muhammad; Cheded, Lahouari

2017-12-01

In this paper, we propose a novel monitoring strategy for a wireless sensor networks (WSNs)-based water pipeline network. Our strategy uses a multi-pronged approach to reduce energy consumption based on the use of two types of vibration sensors and pressure sensors, all having different energy levels, and a hierarchical adaptive sampling mechanism to determine the sampling frequency. The sampling rate of the sensors is adjusted according to the bandwidth of the vibration signal being monitored by using a wavelet-based adaptive thresholding scheme that calculates the new sampling frequency for the following cycle. In this multimodal sensing scheme, the duty-cycling approach is used for all sensors to reduce the sampling instances, such that the high-energy, high-precision (HE-HP) vibration sensors have low duty cycles, and the low-energy, low-precision (LE-LP) vibration sensors have high duty cycles. The low duty-cycling (HE-HP) vibration sensor adjusts the sampling frequency of the high duty-cycling (LE-LP) vibration sensor. The simulated test bed considered here consists of a water pipeline network which uses pressure and vibration sensors, with the latter having different energy consumptions and precision levels, at various locations in the network. This is all the more useful for energy conservation for extended monitoring. It is shown that by using the novel features of our proposed scheme, a significant reduction in energy consumption is achieved and the leak is effectively detected by the sensor node that is closest to it. Finally, both the total energy consumed by monitoring as well as the time to detect the leak by a WSN node are computed, and show the superiority of our proposed hierarchical adaptive sampling algorithm over a non-adaptive sampling approach.

A Novel Deployment Scheme Based on Three-Dimensional Coverage Model for Wireless Sensor Networks

PubMed Central

Xiao, Fu; Yang, Yang; Wang, Ruchuan; Sun, Lijuan

2014-01-01

Coverage pattern and deployment strategy are directly related to the optimum allocation of limited resources for wireless sensor networks, such as energy of nodes, communication bandwidth, and computing power, and quality improvement is largely determined by these for wireless sensor networks. A three-dimensional coverage pattern and deployment scheme are proposed in this paper. Firstly, by analyzing the regular polyhedron models in three-dimensional scene, a coverage pattern based on cuboids is proposed, and then relationship between coverage and sensor nodes' radius is deduced; also the minimum number of sensor nodes to maintain network area's full coverage is calculated. At last, sensor nodes are deployed according to the coverage pattern after the monitor area is subdivided into finite 3D grid. Experimental results show that, compared with traditional random method, sensor nodes number is reduced effectively while coverage rate of monitor area is ensured using our coverage pattern and deterministic deployment scheme. PMID:25045747

Real-Time Two-Dimensional Magnetic Particle Imaging for Electromagnetic Navigation in Targeted Drug Delivery.

PubMed

Le, Tuan-Anh; Zhang, Xingming; Hoshiar, Ali Kafash; Yoon, Jungwon

2017-09-07

Magnetic nanoparticles (MNPs) are effective drug carriers. By using electromagnetic actuated systems, MNPs can be controlled noninvasively in a vascular network for targeted drug delivery (TDD). Although drugs can reach their target location through capturing schemes of MNPs by permanent magnets, drugs delivered to non-target regions can affect healthy tissues and cause undesirable side effects. Real-time monitoring of MNPs can improve the targeting efficiency of TDD systems. In this paper, a two-dimensional (2D) real-time monitoring scheme has been developed for an MNP guidance system. Resovist particles 45 to 65 nm in diameter (5 nm core) can be monitored in real-time (update rate = 2 Hz) in 2D. The proposed 2D monitoring system allows dynamic tracking of MNPs during TDD and renders magnetic particle imaging-based navigation more feasible.

Real-Time Two-Dimensional Magnetic Particle Imaging for Electromagnetic Navigation in Targeted Drug Delivery

PubMed Central

Le, Tuan-Anh; Zhang, Xingming; Hoshiar, Ali Kafash; Yoon, Jungwon

2017-01-01

Magnetic nanoparticles (MNPs) are effective drug carriers. By using electromagnetic actuated systems, MNPs can be controlled noninvasively in a vascular network for targeted drug delivery (TDD). Although drugs can reach their target location through capturing schemes of MNPs by permanent magnets, drugs delivered to non-target regions can affect healthy tissues and cause undesirable side effects. Real-time monitoring of MNPs can improve the targeting efficiency of TDD systems. In this paper, a two-dimensional (2D) real-time monitoring scheme has been developed for an MNP guidance system. Resovist particles 45 to 65 nm in diameter (5 nm core) can be monitored in real-time (update rate = 2 Hz) in 2D. The proposed 2D monitoring system allows dynamic tracking of MNPs during TDD and renders magnetic particle imaging-based navigation more feasible. PMID:28880220

Design and experiment of FBG-based icing monitoring on overhead transmission lines with an improvement trial for windy weather.

PubMed

Zhang, Min; Xing, Yimeng; Zhang, Zhiguo; Chen, Qiguan

2014-12-12

A scheme for monitoring icing on overhead transmission lines with fiber Bragg grating (FBG) strain sensors is designed and evaluated both theoretically and experimentally. The influences of temperature and wind are considered. The results of field experiments using simulated ice loading on windless days indicate that the scheme is capable of monitoring the icing thickness within 0-30 mm with an accuracy of ±1 mm, a load cell error of 0.0308v, a repeatability error of 0.3328v and a hysteresis error is 0.026%. To improve the measurement during windy weather, a correction factor is added to the effective gravity acceleration, and the absolute FBG strain is replaced by its statistical average.

Secure and Efficient Key Coordination Algorithm for Line Topology Network Maintenance for Use in Maritime Wireless Sensor Networks.

PubMed

Elgenaidi, Walid; Newe, Thomas; O'Connell, Eoin; Toal, Daniel; Dooly, Gerard

2016-12-21

There has been a significant increase in the proliferation and implementation of Wireless Sensor Networks (WSNs) in different disciplines, including the monitoring of maritime environments, healthcare systems, and industrial sectors. It has now become critical to address the security issues of data communication while considering sensor node constraints. There are many proposed schemes, including the scheme being proposed in this paper, to ensure that there is a high level of security in WSNs. This paper presents a symmetric security scheme for a maritime coastal environment monitoring WSN. The scheme provides security for travelling packets via individually encrypted links between authenticated neighbors, thus avoiding a reiteration of a global rekeying process. Furthermore, this scheme proposes a dynamic update key based on a trusted node configuration, called a leader node, which works as a trusted third party. The technique has been implemented in real time on a Waspmote test bed sensor platform and the results from both field testing and indoor bench testing environments are discussed in this paper.

Secure and Efficient Key Coordination Algorithm for Line Topology Network Maintenance for Use in Maritime Wireless Sensor Networks

PubMed Central

Elgenaidi, Walid; Newe, Thomas; O’Connell, Eoin; Toal, Daniel; Dooly, Gerard

2016-01-01

There has been a significant increase in the proliferation and implementation of Wireless Sensor Networks (WSNs) in different disciplines, including the monitoring of maritime environments, healthcare systems, and industrial sectors. It has now become critical to address the security issues of data communication while considering sensor node constraints. There are many proposed schemes, including the scheme being proposed in this paper, to ensure that there is a high level of security in WSNs. This paper presents a symmetric security scheme for a maritime coastal environment monitoring WSN. The scheme provides security for travelling packets via individually encrypted links between authenticated neighbors, thus avoiding a reiteration of a global rekeying process. Furthermore, this scheme proposes a dynamic update key based on a trusted node configuration, called a leader node, which works as a trusted third party. The technique has been implemented in real time on a Waspmote test bed sensor platform and the results from both field testing and indoor bench testing environments are discussed in this paper. PMID:28009834

Power Terminal Communication Access Network Monitoring System Scheme Based on Design Patterns

NASA Astrophysics Data System (ADS)

Yan, Shengchao; Wu, Desheng; Zhu, Jiang

2018-01-01

In order to realize patterns design for terminal communication monitoring system, this paper introduces manager-workers, tasks-workers design patterns, based on common design patterns such as factory method, chain of responsibility, facade. Using these patterns, the communication monitoring system which combines module-groups like networking communication, business data processing and the peripheral support has been designed successfully. Using these patterns makes this system have great flexibility and scalability and improves the degree of systematic pattern design structure.

Adaptive video-based vehicle classification technique for monitoring traffic.

DOT National Transportation Integrated Search

2015-08-01

This report presents a methodology for extracting two vehicle features, vehicle length and number of axles in order : to classify the vehicles from video, based on Federal Highway Administration (FHWA)s recommended vehicle : classification scheme....

A bilinear pairing based anonymous authentication scheme in wireless body area networks for mHealth.

PubMed

Jiang, Qi; Lian, Xinxin; Yang, Chao; Ma, Jianfeng; Tian, Youliang; Yang, Yuanyuan

2016-11-01

Wireless body area networks (WBANs) have become one of the key components of mobile health (mHealth) which provides 24/7 health monitoring service and greatly improves the quality and efficiency of healthcare. However, users' concern about the security and privacy of their health information has become one of the major obstacles that impede the wide adoption of WBANs. Anonymous and unlinkable authentication is critical to protect the security and privacy of sensitive physiological information in transit from the client to the application provider. We first show that the anonymous authentication scheme of Wang and Zhang based on bilinear pairing is prone to client impersonation attack. Then, we propose an enhanced anonymous authentication scheme to remedy the flaw in Wang and Zhang's scheme. We give the security analysis to demonstrate that the enhanced scheme achieves the desired security features and withstands various known attacks.

[History and present status of butterfly monitoring in Europe and related development strategies for China].

PubMed

Fang, Li-Jun; Xu, Hai-Gen; Guan, Jian-Ling

2013-09-01

Butterfly is an important bio-indicator for biodiversity monitoring and ecological environment assessment. In Europe, the species composition, population dynamics, and distribution pattern of butterfly have been monitored for decades, and many long-term monitoring schemes with international effects have been implemented. These schemes are aimed to assess the regional and national variation trends of butterfly species abundance, and to analyze the relationships of this species abundance with habitat, climate change, and other environmental factors, providing basic data for researching, protecting, and utilizing butterfly resources and predicting environmental changes, and playing important roles in the division of butterfly' s threatened level, the formulation of related protection measures, and the protection and management of ecological environment. This paper reviewed the history and present status of butterfly monitoring in Europe, with the focus on the well-known long-term monitoring programs, e. g. , the UK Butterfly Monitoring Scheme and the Germany and European Union Butterfly Monitoring Scheme. Some specific proposals for conducting butterflies monitoring in China were suggested.

A systematic approach for the accurate non-invasive estimation of blood glucose utilizing a novel light-tissue interaction adaptive modelling scheme

NASA Astrophysics Data System (ADS)

Rybynok, V. O.; Kyriacou, P. A.

2007-10-01

Diabetes is one of the biggest health challenges of the 21st century. The obesity epidemic, sedentary lifestyles and an ageing population mean prevalence of the condition is currently doubling every generation. Diabetes is associated with serious chronic ill health, disability and premature mortality. Long-term complications including heart disease, stroke, blindness, kidney disease and amputations, make the greatest contribution to the costs of diabetes care. Many of these long-term effects could be avoided with earlier, more effective monitoring and treatment. Currently, blood glucose can only be monitored through the use of invasive techniques. To date there is no widely accepted and readily available non-invasive monitoring technique to measure blood glucose despite the many attempts. This paper challenges one of the most difficult non-invasive monitoring techniques, that of blood glucose, and proposes a new novel approach that will enable the accurate, and calibration free estimation of glucose concentration in blood. This approach is based on spectroscopic techniques and a new adaptive modelling scheme. The theoretical implementation and the effectiveness of the adaptive modelling scheme for this application has been described and a detailed mathematical evaluation has been employed to prove that such a scheme has the capability of extracting accurately the concentration of glucose from a complex biological media.

Comparison of wavelet based denoising schemes for gear condition monitoring: An Artificial Neural Network based Approach

NASA Astrophysics Data System (ADS)

Ahmed, Rounaq; Srinivasa Pai, P.; Sriram, N. S.; Bhat, Vasudeva

2018-02-01

Vibration Analysis has been extensively used in recent past for gear fault diagnosis. The vibration signals extracted is usually contaminated with noise and may lead to wrong interpretation of results. The denoising of extracted vibration signals helps the fault diagnosis by giving meaningful results. Wavelet Transform (WT) increases signal to noise ratio (SNR), reduces root mean square error (RMSE) and is effective to denoise the gear vibration signals. The extracted signals have to be denoised by selecting a proper denoising scheme in order to prevent the loss of signal information along with noise. An approach has been made in this work to show the effectiveness of Principal Component Analysis (PCA) to denoise gear vibration signal. In this regard three selected wavelet based denoising schemes namely PCA, Empirical Mode Decomposition (EMD), Neighcoeff Coefficient (NC), has been compared with Adaptive Threshold (AT) an extensively used wavelet based denoising scheme for gear vibration signal. The vibration signals acquired from a customized gear test rig were denoised by above mentioned four denoising schemes. The fault identification capability as well as SNR, Kurtosis and RMSE for the four denoising schemes have been compared. Features extracted from the denoised signals have been used to train and test artificial neural network (ANN) models. The performances of the four denoising schemes have been evaluated based on the performance of the ANN models. The best denoising scheme has been identified, based on the classification accuracy results. PCA is effective in all the regards as a best denoising scheme.

FORUM: A Suggestion for an Improved Vegetation Scheme for Local and Global Mapping and Monitoring.

PubMed

ADAMS

1999-01-01

/ Understanding of global ecological problems is at least partly dependent on clear assessments of vegetation change, and such assessment is always dependent on the use of a vegetation classification scheme. Use of satellite remotely sensed data is the only practical means of carrying out any global-scale vegetation mapping exercise, but if the resulting maps are to be useful to most ecologists and conservationists, they must be closely tied to clearly defined features of vegetation on the ground. Furthermore, much of the mapping that does take place involves more local-scale description of field sites; for purposes of cost and practicality, such studies usually do not involve remote sensing using satellites. There is a need for a single scheme that integrates the smallest to the largest scale in a way that is meaningful to most environmental scientists. Existing schemes are unsatisfactory for this task; they are ambiguous, unnecessarily complex, and their categories do not correspond to common-sense definitions. In response to these problems, a simple structural-physiognomically based scheme with 23 fundamental categories is proposed here for mapping and monitoring on any scale, from local to global. The fundamental categories each subdivide into more specific structural categories for more detailed mapping, but all the categories can be used throughout the world and at any scale, allowing intercomparison between regions. The next stage in the process will be to obtain the views of as many people working in as many different fields as possible, to see whether the proposed scheme suits their needs and how it should be modified. With a few modifications, such a scheme could easily be appended to an existing land cover classification scheme, such as the FAO system, greatly increasing the usefulness and accessability of the results of the landcover classification. KEY WORDS: Vegetation scheme; Mapping; Monitoring; Land cover

A user anonymity preserving three-factor authentication scheme for telecare medicine information systems.

PubMed

Tan, Zuowen

2014-03-01

The telecare medicine information system enables the patients gain health monitoring at home and access medical services over internet or mobile networks. In recent years, the schemes based on cryptography have been proposed to address the security and privacy issues in the telecare medicine information systems. However, many schemes are insecure or they have low efficiency. Recently, Awasthi and Srivastava proposed a three-factor authentication scheme for telecare medicine information systems. In this paper, we show that their scheme is vulnerable to the reflection attacks. Furthermore, it fails to provide three-factor security and the user anonymity. We propose a new three-factor authentication scheme for the telecare medicine information systems. Detailed analysis demonstrates that the proposed scheme provides mutual authentication, server not knowing password and freedom of password, biometric update and three-factor security. Moreover, the new scheme provides the user anonymity. As compared with the previous three-factor authentication schemes, the proposed scheme is more secure and practical.

On design of sensor nodes in the rice planthopper monitoring system based on the internet of things

NASA Astrophysics Data System (ADS)

Wang, Ke Qiang; Cai, Ken

2011-02-01

Accurate records and prediction of the number of the rice planthopper's outbreaks and the environmental information of farmland are effective measures to control pests' damages. On the other hand, a new round of technological revolution from the Internet to the Internet of things is taking place in the field of information. The application of the Internet of things in rice planthopper and environmental online monitoring is an effective measure to solve problems existing in the present wired sensor monitoring technology. Having described the general framework of wireless sensor nodes in the Internet of things in this paper, the software and hardware design schemes of wireless sensor nodes are proposed, combining the needs of rice planthopper and environmental monitoring. In these schemes, each module's design and key components' selection are both aiming to the characteristics of the Internet of things, so it has a strong practical value.

Remote Respiration Monitoring Using Ultra-wideband Microwave Sensor

NASA Astrophysics Data System (ADS)

Higashikatsuragi, Kenji; Nakahata, Youichiro; Matsunami, Isamu; Kajiwara, Akihiro

Impulse based ultra-wideband radio has lately attracted considerable attention as medical monitoring sensor since it is expected to measure bio-signals of a patient on a bed such as respiration rate and heartbeat with a remote non-contact approach. It is also friendly to the environment including the human body due to the very low electromagnetic energy emission. Using conventional ranging scheme, however, high speed A/D device should be required in order to detect the small respiratory displacement. This paper suggests a respiratory monitoring scheme where the respiration rate is measured by observing the variation of the path strength from the patient. Therefore, it does not require high speed A/D. It also makes possible to design the simultaneous monitoring of multiple patients in hospital beds, for example. In this paper the measurements were conducted for various scenarios and the feasibility is discussed.

An Efficient User Authentication and User Anonymity Scheme with Provably Security for IoT-Based Medical Care System.

PubMed

Li, Chun-Ta; Wu, Tsu-Yang; Chen, Chin-Ling; Lee, Cheng-Chi; Chen, Chien-Ming

2017-06-23

In recent years, with the increase in degenerative diseases and the aging population in advanced countries, demands for medical care of older or solitary people have increased continually in hospitals and healthcare institutions. Applying wireless sensor networks for the IoT-based telemedicine system enables doctors, caregivers or families to monitor patients' physiological conditions at anytime and anyplace according to the acquired information. However, transmitting physiological data through the Internet concerns the personal privacy of patients. Therefore, before users can access medical care services in IoT-based medical care system, they must be authenticated. Typically, user authentication and data encryption are most critical for securing network communications over a public channel between two or more participants. In 2016, Liu and Chung proposed a bilinear pairing-based password authentication scheme for wireless healthcare sensor networks. They claimed their authentication scheme cannot only secure sensor data transmission, but also resist various well-known security attacks. In this paper, we demonstrate that Liu-Chung's scheme has some security weaknesses, and we further present an improved secure authentication and data encryption scheme for the IoT-based medical care system, which can provide user anonymity and prevent the security threats of replay and password/sensed data disclosure attacks. Moreover, we modify the authentication process to reduce redundancy in protocol design, and the proposed scheme is more efficient in performance compared with previous related schemes. Finally, the proposed scheme is provably secure in the random oracle model under ECDHP.

MEMS-based power generation techniques for implantable biosensing applications.

PubMed

Lueke, Jonathan; Moussa, Walied A

2011-01-01

Implantable biosensing is attractive for both medical monitoring and diagnostic applications. It is possible to monitor phenomena such as physical loads on joints or implants, vital signs, or osseointegration in vivo and in real time. Microelectromechanical (MEMS)-based generation techniques can allow for the autonomous operation of implantable biosensors by generating electrical power to replace or supplement existing battery-based power systems. By supplementing existing battery-based power systems for implantable biosensors, the operational lifetime of the sensor is increased. In addition, the potential for a greater amount of available power allows additional components to be added to the biosensing module, such as computational and wireless and components, improving functionality and performance of the biosensor. Photovoltaic, thermovoltaic, micro fuel cell, electrostatic, electromagnetic, and piezoelectric based generation schemes are evaluated in this paper for applicability for implantable biosensing. MEMS-based generation techniques that harvest ambient energy, such as vibration, are much better suited for implantable biosensing applications than fuel-based approaches, producing up to milliwatts of electrical power. High power density MEMS-based approaches, such as piezoelectric and electromagnetic schemes, allow for supplemental and replacement power schemes for biosensing applications to improve device capabilities and performance. In addition, this may allow for the biosensor to be further miniaturized, reducing the need for relatively large batteries with respect to device size. This would cause the implanted biosensor to be less invasive, increasing the quality of care received by the patient.

Design and Experiment of FBG-Based Icing Monitoring on Overhead Transmission Lines with an Improvement Trial for Windy Weather

PubMed Central

Zhang, Min; Xing, Yimeng; Zhang, Zhiguo; Chen, Qiguan

2014-01-01

A scheme for monitoring icing on overhead transmission lines with fiber Bragg grating (FBG) strain sensors is designed and evaluated both theoretically and experimentally. The influences of temperature and wind are considered. The results of field experiments using simulated ice loading on windless days indicate that the scheme is capable of monitoring the icing thickness within 0–30 mm with an accuracy of ±1 mm, a load cell error of 0.0308v, a repeatability error of 0.3328v and a hysteresis error is 0.026%. To improve the measurement during windy weather, a correction factor is added to the effective gravity acceleration, and the absolute FBG strain is replaced by its statistical average. PMID:25615733

The Predatory Bird Monitoring Scheme: identifying chemical risks to top predators in Britain.

PubMed

Walker, Lee A; Shore, Richard F; Turk, Anthony; Pereira, M Glória; Best, Jennifer

2008-09-01

The Predatory Bird Monitoring Scheme (PBMS) is a long term (>40 y), UK-wide, exposure monitoring scheme that determines the concentration of selected pesticides and pollutants in the livers and eggs of predatory birds. This paper describes how the PBMS works, and in particular highlights some of the key scientific and policy drivers for monitoring contaminants in predatory birds and describes the specific aims, scope, and methods of the PBMS. We also present previously unpublished data that illustrates how the PBMS has been used to demonstrate the success of mitigation measures in reversing chemical-mediated impacts; identify and evaluate chemical threats to species of high conservation value; and finally to inform and refine monitoring methodologies. In addition, we discuss how such schemes can also address wider conservation needs.

An active monitoring method for flood events

NASA Astrophysics Data System (ADS)

Chen, Zeqiang; Chen, Nengcheng; Du, Wenying; Gong, Jianya

2018-07-01

Timely and active detecting and monitoring of a flood event are critical for a quick response, effective decision-making and disaster reduction. To achieve the purpose, this paper proposes an active service framework for flood monitoring based on Sensor Web services and an active model for the concrete implementation of the active service framework. The framework consists of two core components-active warning and active planning. The active warning component is based on a publish-subscribe mechanism implemented by the Sensor Event Service. The active planning component employs the Sensor Planning Service to control the execution of the schemes and models and plans the model input data. The active model, called SMDSA, defines the quantitative calculation method for five elements, scheme, model, data, sensor, and auxiliary information, as well as their associations. Experimental monitoring of the Liangzi Lake flood in the summer of 2010 is conducted to test the proposed framework and model. The results show that 1) the proposed active service framework is efficient for timely and automated flood monitoring. 2) The active model, SMDSA, is a quantitative calculation method used to monitor floods from manual intervention to automatic computation. 3) As much preliminary work as possible should be done to take full advantage of the active service framework and the active model.

New optical scheme for a polarimetric-based glucose sensor

NASA Technical Reports Server (NTRS)

Ansari, Rafat R.; Bockle, Stefan; Rovati, Luigi

2004-01-01

A new optical scheme to detect glucose concentration in the aqueous humor of the eye is presented. The ultimate aim is to apply this technique in designing a new instrument for, routinely and frequently, noninvasively monitoring blood glucose levels in diabetic patients without contact (no index matching) between the eye and the instrument. The optical scheme exploits the Brewster reflection of circularly polarized light off of the lens of the eye. Theoretically, this reflected linearly polarized light on its way to the detector is expected to rotate its state of polarization, owing to the presence of glucose molecules in the aqueous humor of a patient's eye. An experimental laboratory setup based on this scheme was designed and tested by measuring a range of known concentrations of glucose solutions dissolved in water. (c) 2004 Society of Photo-Optical Instrumentation Engineers.

Implementation of Open-Source Web Mapping Technologies to Support Monitoring of Governmental Schemes

NASA Astrophysics Data System (ADS)

Pulsani, B. R.

2015-10-01

Several schemes are undertaken by the government to uplift social and economic condition of people. The monitoring of these schemes is done through information technology where involvement of Geographic Information System (GIS) is lacking. To demonstrate the benefits of thematic mapping as a tool for assisting the officials in making decisions, a web mapping application for three government programs such as Mother and Child Tracking system (MCTS), Telangana State Housing Corporation Limited (TSHCL) and Ground Water Quality Mapping (GWQM) has been built. Indeed the three applications depicted the distribution of various parameters thematically and helped in identifying the areas with higher and weaker distributions. Based on the three applications, the study tends to find similarities of many government schemes reflecting the nature of thematic mapping and hence deduces to implement this kind of approach for other schemes as well. These applications have been developed using SharpMap Csharp library which is a free and open source mapping library for developing geospatial applications. The study highlights upon the cost benefits of SharpMap and brings out the advantage of this library over proprietary vendors and further discusses its advantages over other open source libraries as well.

Integrated Circuit Wear out Prediction and Recycling Detection using Radio Frequency Distinct Native Attribute Features

DTIC Science & Technology

2016-12-22

105 A.1 Main Loop ... loop monitoring for preventative maintenance rather than early replacement based on statistical projections or replacement-after- failure schemes. IC...estimates, RF-DNA may provide a means to track an IC’s physical degradation during actual use. Monitoring an IC’s degradation in a closed loop fashion

Statistical process control based chart for information systems security

NASA Astrophysics Data System (ADS)

Khan, Mansoor S.; Cui, Lirong

2015-07-01

Intrusion detection systems have a highly significant role in securing computer networks and information systems. To assure the reliability and quality of computer networks and information systems, it is highly desirable to develop techniques that detect intrusions into information systems. We put forward the concept of statistical process control (SPC) in computer networks and information systems intrusions. In this article we propose exponentially weighted moving average (EWMA) type quality monitoring scheme. Our proposed scheme has only one parameter which differentiates it from the past versions. We construct the control limits for the proposed scheme and investigate their effectiveness. We provide an industrial example for the sake of clarity for practitioner. We give comparison of the proposed scheme with EWMA schemes and p chart; finally we provide some recommendations for the future work.

An Efficient User Authentication and User Anonymity Scheme with Provably Security for IoT-Based Medical Care System

PubMed Central

Wu, Tsu-Yang; Chen, Chin-Ling; Lee, Cheng-Chi; Chen, Chien-Ming

2017-01-01

In recent years, with the increase in degenerative diseases and the aging population in advanced countries, demands for medical care of older or solitary people have increased continually in hospitals and healthcare institutions. Applying wireless sensor networks for the IoT-based telemedicine system enables doctors, caregivers or families to monitor patients’ physiological conditions at anytime and anyplace according to the acquired information. However, transmitting physiological data through the Internet concerns the personal privacy of patients. Therefore, before users can access medical care services in IoT-based medical care system, they must be authenticated. Typically, user authentication and data encryption are most critical for securing network communications over a public channel between two or more participants. In 2016, Liu and Chung proposed a bilinear pairing-based password authentication scheme for wireless healthcare sensor networks. They claimed their authentication scheme cannot only secure sensor data transmission, but also resist various well-known security attacks. In this paper, we demonstrate that Liu–Chung’s scheme has some security weaknesses, and we further present an improved secure authentication and data encryption scheme for the IoT-based medical care system, which can provide user anonymity and prevent the security threats of replay and password/sensed data disclosure attacks. Moreover, we modify the authentication process to reduce redundancy in protocol design, and the proposed scheme is more efficient in performance compared with previous related schemes. Finally, the proposed scheme is provably secure in the random oracle model under ECDHP. PMID:28644381

Comparison of Respiratory Disease Prevalence among Voluntary Monitoring Systems for Pig Health and Welfare in the UK.

PubMed

Eze, J I; Correia-Gomes, C; Borobia-Belsué, J; Tucker, A W; Sparrow, D; Strachan, D W; Gunn, G J

2015-01-01

Surveillance of animal diseases provides information essential for the protection of animal health and ultimately public health. The voluntary pig health schemes, implemented in the United Kingdom, are integrated systems which capture information on different macroscopic disease conditions detected in slaughtered pigs. Many of these conditions have been associated with a reduction in performance traits and consequent increases in production costs. The schemes are the Wholesome Pigs Scotland in Scotland, the BPEX Pig Health Scheme in England and Wales and the Pig Regen Ltd. health and welfare checks done in Northern Ireland. This report set out to compare the prevalence of four respiratory conditions (enzootic pneumonia-like lesions, pleurisy, pleuropneumonia lesions and abscesses in the lung) assessed by these three Pig Health Schemes. The seasonal variations and year trends associated with the conditions in each scheme are presented. The paper also highlights the differences in prevalence for each condition across these schemes and areas where further research is needed. A general increase in the prevalence of enzootic pneumonia like lesions was observed in Scotland, England and Wales since 2009, while a general decrease was observed in Northern Ireland over the years of the scheme. Pleurisy prevalence has increased since 2010 in all three schemes, whilst pleuropneumonia has been decreasing. Prevalence of abscesses in the lung has decreased in England, Wales and Northern Ireland but has increased in Scotland. This analysis highlights the value of surveillance schemes based on abattoir pathology monitoring of four respiratory lesions. The outputs at scheme level have significant value as indicators of endemic and emerging disease, and for producers and herd veterinarians in planning and evaluating herd health control programs when comparing individual farm results with national averages.

MEMS-Based Power Generation Techniques for Implantable Biosensing Applications

PubMed Central

Lueke, Jonathan; Moussa, Walied A.

2011-01-01

Implantable biosensing is attractive for both medical monitoring and diagnostic applications. It is possible to monitor phenomena such as physical loads on joints or implants, vital signs, or osseointegration in vivo and in real time. Microelectromechanical (MEMS)-based generation techniques can allow for the autonomous operation of implantable biosensors by generating electrical power to replace or supplement existing battery-based power systems. By supplementing existing battery-based power systems for implantable biosensors, the operational lifetime of the sensor is increased. In addition, the potential for a greater amount of available power allows additional components to be added to the biosensing module, such as computational and wireless and components, improving functionality and performance of the biosensor. Photovoltaic, thermovoltaic, micro fuel cell, electrostatic, electromagnetic, and piezoelectric based generation schemes are evaluated in this paper for applicability for implantable biosensing. MEMS-based generation techniques that harvest ambient energy, such as vibration, are much better suited for implantable biosensing applications than fuel-based approaches, producing up to milliwatts of electrical power. High power density MEMS-based approaches, such as piezoelectric and electromagnetic schemes, allow for supplemental and replacement power schemes for biosensing applications to improve device capabilities and performance. In addition, this may allow for the biosensor to be further miniaturized, reducing the need for relatively large batteries with respect to device size. This would cause the implanted biosensor to be less invasive, increasing the quality of care received by the patient. PMID:22319362

Total ozone column derived from GOME and SCIAMACHY using KNMI retrieval algorithms: Validation against Brewer measurements at the Iberian Peninsula

NASA Astrophysics Data System (ADS)

Antón, M.; Kroon, M.; López, M.; Vilaplana, J. M.; Bañón, M.; van der A, R.; Veefkind, J. P.; Stammes, P.; Alados-Arboledas, L.

2011-11-01

This article focuses on the validation of the total ozone column (TOC) data set acquired by the Global Ozone Monitoring Experiment (GOME) and the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) satellite remote sensing instruments using the Total Ozone Retrieval Scheme for the GOME Instrument Based on the Ozone Monitoring Instrument (TOGOMI) and Total Ozone Retrieval Scheme for the SCIAMACHY Instrument Based on the Ozone Monitoring Instrument (TOSOMI) retrieval algorithms developed by the Royal Netherlands Meteorological Institute. In this analysis, spatially colocated, daily averaged ground-based observations performed by five well-calibrated Brewer spectrophotometers at the Iberian Peninsula are used. The period of study runs from January 2004 to December 2009. The agreement between satellite and ground-based TOC data is excellent (R2 higher than 0.94). Nevertheless, the TOC data derived from both satellite instruments underestimate the ground-based data. On average, this underestimation is 1.1% for GOME and 1.3% for SCIAMACHY. The SCIAMACHY-Brewer TOC differences show a significant solar zenith angle (SZA) dependence which causes a systematic seasonal dependence. By contrast, GOME-Brewer TOC differences show no significant SZA dependence and hence no seasonality although processed with exactly the same algorithm. The satellite-Brewer TOC differences for the two satellite instruments show a clear and similar dependence on the viewing zenith angle under cloudy conditions. In addition, both the GOME-Brewer and SCIAMACHY-Brewer TOC differences reveal a very similar behavior with respect to the satellite cloud properties, being cloud fraction and cloud top pressure, which originate from the same cloud algorithm (Fast Retrieval Scheme for Clouds from the Oxygen A-Band (FRESCO+)) in both the TOSOMI and TOGOMI retrieval algorithms.

Monitoring Poisson observations using combined applications of Shewhart and EWMA charts

NASA Astrophysics Data System (ADS)

Abujiya, Mu'azu Ramat

2017-11-01

The Shewhart and exponentially weighted moving average (EWMA) charts for nonconformities are the most widely used procedures of choice for monitoring Poisson observations in modern industries. Individually, the Shewhart EWMA charts are only sensitive to large and small shifts, respectively. To enhance the detection abilities of the two schemes in monitoring all kinds of shifts in Poisson count data, this study examines the performance of combined applications of the Shewhart, and EWMA Poisson control charts. Furthermore, the study proposes modifications based on well-structured statistical data collection technique, ranked set sampling (RSS), to detect shifts in the mean of a Poisson process more quickly. The relative performance of the proposed Shewhart-EWMA Poisson location charts is evaluated in terms of the average run length (ARL), standard deviation of the run length (SDRL), median run length (MRL), average ratio ARL (ARARL), average extra quadratic loss (AEQL) and performance comparison index (PCI). Consequently, all the new Poisson control charts based on RSS method are generally more superior than most of the existing schemes for monitoring Poisson processes. The use of these combined Shewhart-EWMA Poisson charts is illustrated with an example to demonstrate the practical implementation of the design procedure.

Setting monitoring objectives for landscape-size areas

Treesearch

Craig M. Olson; Dean Angelides

2000-01-01

The setting of objectives for monitoring schemes for landscape-size areas should be a complex task in today's regulatory and sociopolitical atmosphere. The technology available today, the regulatory environment, and the sociopolitical considerations require multiresource inventory and monitoring schemes, whether tile ownership is industrial or for preservation....

Secure anonymity-preserving password-based user authentication and session key agreement scheme for telecare medicine information systems.

PubMed

Sutrala, Anil Kumar; Das, Ashok Kumar; Odelu, Vanga; Wazid, Mohammad; Kumari, Saru

2016-10-01

Information and communication and technology (ICT) has changed the entire paradigm of society. ICT facilitates people to use medical services over the Internet, thereby reducing the travel cost, hospitalization cost and time to a greater extent. Recent advancements in Telecare Medicine Information System (TMIS) facilitate users/patients to access medical services over the Internet by gaining health monitoring facilities at home. Amin and Biswas recently proposed a RSA-based user authentication and session key agreement protocol usable for TMIS, which is an improvement over Giri et al.'s RSA-based user authentication scheme for TMIS. In this paper, we show that though Amin-Biswas's scheme considerably improves the security drawbacks of Giri et al.'s scheme, their scheme has security weaknesses as it suffers from attacks such as privileged insider attack, user impersonation attack, replay attack and also offline password guessing attack. A new RSA-based user authentication scheme for TMIS is proposed, which overcomes the security pitfalls of Amin-Biswas's scheme and also preserves user anonymity property. The careful formal security analysis using the two widely accepted Burrows-Abadi-Needham (BAN) logic and the random oracle models is done. Moreover, the informal security analysis of the scheme is also done. These security analyses show the robustness of our new scheme against the various known attacks as well as attacks found in Amin-Biswas's scheme. The simulation of the proposed scheme using the widely accepted Automated Validation of Internet Security Protocols and Applications (AVISPA) tool is also done. We present a new user authentication and session key agreement scheme for TMIS, which fixes the mentioned security pitfalls found in Amin-Biswas's scheme, and we also show that the proposed scheme provides better security than other existing schemes through the rigorous security analysis and verification tool. Furthermore, we present the formal security verification of our scheme using the widely accepted AVISPA tool. High security and extra functionality features allow our proposed scheme to be applicable for telecare medicine information systems which is used for e-health care medical applications. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The Effect of a Monitoring Scheme on Tutorial Attendance and Assignment Submission

ERIC Educational Resources Information Center

Burke, Grainne; Mac an Bhaird, Ciaran; O'Shea, Ann

2013-01-01

We report on the implementation of a monitoring scheme by the Department of Mathematics and Statistics at the National University of Ireland Maynooth. The scheme was introduced in an attempt to increase the level and quality of students' engagement with certain aspects of their undergraduate course. It is well documented that students with higher…

Recombination monitor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, S. Y.; Blaskiewicz, M.

This is a brief report on LEReC recombination monitor design considerations. The recombination produced Au 78+ ion rate is reviewed. Based on this two designs are discussed. One is to use the large dispersion lattice. It is shown that even with the large separation of the Au 78+ beam from the Au 79+ beam, the continued monitoring of the recombination is not possible. Accumulation of Au 78+ ions is needed, plus collimation of the Au79+ beam. In another design, it is shown that the recombination monitor can be built based on the proposed scheme with the nominal lattice. From machinemore » operation point of view, this design is preferable. Finally, possible studies and the alternative strategies with the basic goal of the monitor are discussed.« less

Athermal laser design.

PubMed

Bovington, Jock; Srinivasan, Sudharsanan; Bowers, John E

2014-08-11

This paper discusses circuit based and waveguide based athermalization schemes and provides some design examples of athermalized lasers utilizing fully integrated athermal components as an alternative to power hungry thermo-electric controllers (TECs), off-chip wavelength lockers or monitors with lookup tables for tunable lasers. This class of solutions is important for uncooled transmitters on silicon.

A broadcast-based key agreement scheme using set reconciliation for wireless body area networks.

PubMed

Ali, Aftab; Khan, Farrukh Aslam

2014-05-01

Information and communication technologies have thrived over the last few years. Healthcare systems have also benefited from this progression. A wireless body area network (WBAN) consists of small, low-power sensors used to monitor human physiological values remotely, which enables physicians to remotely monitor the health of patients. Communication security in WBANs is essential because it involves human physiological data. Key agreement and authentication are the primary issues in the security of WBANs. To agree upon a common key, the nodes exchange information with each other using wireless communication. This information exchange process must be secure enough or the information exchange should be minimized to a certain level so that if information leak occurs, it does not affect the overall system. Most of the existing solutions for this problem exchange too much information for the sake of key agreement; getting this information is sufficient for an attacker to reproduce the key. Set reconciliation is a technique used to reconcile two similar sets held by two different hosts with minimal communication complexity. This paper presents a broadcast-based key agreement scheme using set reconciliation for secure communication in WBANs. The proposed scheme allows the neighboring nodes to agree upon a common key with the personal server (PS), generated from the electrocardiogram (EKG) feature set of the host body. Minimal information is exchanged in a broadcast manner, and even if every node is missing a different subset, by reconciling these feature sets, the whole network will still agree upon a single common key. Because of the limited information exchange, if an attacker gets the information in any way, he/she will not be able to reproduce the key. The proposed scheme mitigates replay, selective forwarding, and denial of service attacks using a challenge-response authentication mechanism. The simulation results show that the proposed scheme has a great deal of adoptability in terms of security, communication overhead, and running time complexity, as compared to the existing EKG-based key agreement scheme.

Superframe Duration Allocation Schemes to Improve the Throughput of Cluster-Tree Wireless Sensor Networks

PubMed Central

Leão, Erico; Montez, Carlos; Moraes, Ricardo; Portugal, Paulo; Vasques, Francisco

2017-01-01

The use of Wireless Sensor Network (WSN) technologies is an attractive option to support wide-scale monitoring applications, such as the ones that can be found in precision agriculture, environmental monitoring and industrial automation. The IEEE 802.15.4/ZigBee cluster-tree topology is a suitable topology to build wide-scale WSNs. Despite some of its known advantages, including timing synchronisation and duty-cycle operation, cluster-tree networks may suffer from severe network congestion problems due to the convergecast pattern of its communication traffic. Therefore, the careful adjustment of transmission opportunities (superframe durations) allocated to the cluster-heads is an important research issue. This paper proposes a set of proportional Superframe Duration Allocation (SDA) schemes, based on well-defined protocol and timing models, and on the message load imposed by child nodes (Load-SDA scheme), or by number of descendant nodes (Nodes-SDA scheme) of each cluster-head. The underlying reasoning is to adequately allocate transmission opportunities (superframe durations) and parametrize buffer sizes, in order to improve the network throughput and avoid typical problems, such as: network congestion, high end-to-end communication delays and discarded messages due to buffer overflows. Simulation assessments show how proposed allocation schemes may clearly improve the operation of wide-scale cluster-tree networks. PMID:28134822

Developing a risk-based trading scheme for cattle in England: farmer perspectives on managing trading risk for bovine tuberculosis.

PubMed

Little, R; Wheeler, K; Edge, S

2017-02-11

This paper examines farmer attitudes towards the development of a voluntary risk-based trading scheme for cattle in England as a risk mitigation measure for bovine tuberculosis (bTB). The research reported here was commissioned to gather evidence on the type of scheme that would have a good chance of success in improving the information farmers receive about the bTB risk of cattle they buy. Telephone interviews were conducted with a stratified random sample of 203 cattle farmers in England, splitting the interviews equally between respondents in the high-risk area and low-risk area for bTB. Supplementary interviews and focus groups with farmers were also carried out across the risk areas. Results suggest a greater enthusiasm for a risk-based trading scheme in low-risk areas compared with high-risk areas and among members of breed societies and cattle health schemes. Third-party certification of herds by private vets or the Animal and Plant Health Agency were regarded as the most credible source, with farmer self-certification being favoured by sellers, but being regarded as least credible by buyers. Understanding farmers' attitudes towards voluntary risk-based trading is important to gauge likely uptake, understand preferences for information provision and to assist in monitoring, evaluating and refining the scheme once established. British Veterinary Association.

Distributed fiber-optic laser-ultrasound generation based on ghost-mode of tilted fiber Bragg gratings.

PubMed

Tian, Jiajun; Zhang, Qi; Han, Ming

2013-03-11

Active ultrasonic testing is widely used for medical diagnosis, material characterization and structural health monitoring. Ultrasonic transducer is a key component in active ultrasonic testing. Due to their many advantages such as small size, light weight, and immunity to electromagnetic interference, fiber-optic ultrasonic transducers are particularly attractive for permanent, embedded applications in active ultrasonic testing for structural health monitoring. However, current fiber-optic transducers only allow effective ultrasound generation at a single location of the fiber end. Here we demonstrate a fiber-optic device that can effectively generate ultrasound at multiple, selected locations along a fiber in a controllable manner based on a smart light tapping scheme that only taps out the light of a particular wavelength for laser-ultrasound generation and allow light of longer wavelengths pass by without loss. Such a scheme may also find applications in remote fiber-optic device tuning and quasi-distributed biochemical fiber-optic sensing.

Volcanic risk metrics at Mt Ruapehu, New Zealand: some background to a probabilistic eruption forecasting scheme and a cost/benefit analysis at an open conduit volcano

NASA Astrophysics Data System (ADS)

Jolly, Gill; Sandri, Laura; Lindsay, Jan; Scott, Brad; Sherburn, Steve; Jolly, Art; Fournier, Nico; Keys, Harry; Marzocchi, Warner

2010-05-01

The Bayesian Event Tree for Eruption Forecasting software (BET_EF) is a probabilistic model based on an event tree scheme that was created specifically to compute long- and short-term probabilities of different outcomes (volcanic unrest, magmatic unrest, eruption, vent location and eruption size) at long-time dormant and routinely monitored volcanoes. It is based on the assumption that upward movements of magma in a closed conduit volcano will produce detectable changes in the monitored parameters at the surface. In this perspective, the goal of BET_EF is to compute probabilities by merging information from geology, models, past data and present monitoring measurements, through a Bayesian inferential method. In the present study, we attempt to apply BET_EF to Mt Ruapehu, a very active and well-monitored volcano exhibiting the typical features of open conduit volcanoes. In such conditions, current monitoring at the surface is not necessarily able to detect short term changes at depth that may occur only seconds to minutes before an eruption. This results in so-called "blue sky eruptions" of Mt Ruapehu (for example in September 2007), that are volcanic eruptions apparently not preceded by any presently detectable signal in the current monitoring. A further complication at Mt Ruapehu arises from the well-developed hydrothermal system and the permanent crater lake sitting on top of the magmatic conduit. Both the hydrothermal system and crater lake may act to mask or change monitoring signals (if present) that magma produces deeper in the edifice. Notwithstanding these potential drawbacks, we think that an attempt to apply BET_EF at Ruapehu is worthwhile, for several reasons. First, with the exception of a few "blue sky" events, monitoring data at Mt Ruapehu can be helpful in forecasting major events, especially if a large amount of magma is intruded into the edifice and becomes available for phreatomagmatic or magmatic eruptions, as for example in 1995-96. Secondly, in setting up BET_EF for Mt Ruapehu we are forced to define quantitatively what the background activity is. This will result in a quantitative evaluation of what changes in long time monitored parameters may influence the probability of future eruptions. The slopes of Mt Ruapehu host the largest ski area in North Island, New Zealand. Lahars have been generated as a result of several eruptions in the last 50 years, and some of these have reached the ski runs in a very short time frame (around 90 seconds from the beginning of the eruption). In the light of these potentially hazardous lahars, we use the output probabilities provided by BET_EF in a practical and rational decision scheme recently proposed by Marzocchi and Woo (2009) based on a cost/benefit analysis (CBA). In such scheme, a C/L ratio is computed, based on the costs (C) of practical mitigation actions to reduce risk (e.g., a public warning scheme and other means of raising awareness, and a call for a temporary and/or partial closure of the ski area) and on the potential loss (L) if no mitigation action is taken and an eruption occurs causing lahars down the ski fields. By comparing the probability of eruption-driven lahars and the C/L ratio, it is possible to define the most rational mitigation actions that can be taken to reduce the risk to skiers, snowboarders and staff on skifield. As BET_EF probability of eruption changes dynamically as updated monitoring data are received, the authorities can decide, at any specific point in time, what is the best action according to the current monitoring of the volcano. In this respect, CBA represents a bridge linking scientific output (probabilities) and Decision Makers (practical mitigation actions).

A new cooperative MIMO scheme based on SM for energy-efficiency improvement in wireless sensor network.

PubMed

Peng, Yuyang; Choi, Jaeho

2014-01-01

Improving the energy efficiency in wireless sensor networks (WSN) has attracted considerable attention nowadays. The multiple-input multiple-output (MIMO) technique has been proved as a good candidate for improving the energy efficiency, but it may not be feasible in WSN which is due to the size limitation of the sensor node. As a solution, the cooperative multiple-input multiple-output (CMIMO) technique overcomes this constraint and shows a dramatically good performance. In this paper, a new CMIMO scheme based on the spatial modulation (SM) technique named CMIMO-SM is proposed for energy-efficiency improvement. We first establish the system model of CMIMO-SM. Based on this model, the transmission approach is introduced graphically. In order to evaluate the performance of the proposed scheme, a detailed analysis in terms of energy consumption per bit of the proposed scheme compared with the conventional CMIMO is presented. Later, under the guide of this new scheme we extend our proposed CMIMO-SM to a multihop clustered WSN for further achieving energy efficiency by finding an optimal hop-length. Equidistant hop as the traditional scheme will be compared in this paper. Results from the simulations and numerical experiments indicate that by the use of the proposed scheme, significant savings in terms of total energy consumption can be achieved. Combining the proposed scheme with monitoring sensor node will provide a good performance in arbitrary deployed WSN such as forest fire detection system.

A New Wavelength Optimization and Energy-Saving Scheme Based on Network Coding in Software-Defined WDM-PON Networks

NASA Astrophysics Data System (ADS)

Ren, Danping; Wu, Shanshan; Zhang, Lijing

2016-09-01

In view of the characteristics of the global control and flexible monitor of software-defined networks (SDN), we proposes a new optical access network architecture dedicated to Wavelength Division Multiplexing-Passive Optical Network (WDM-PON) systems based on SDN. The network coding (NC) technology is also applied into this architecture to enhance the utilization of wavelength resource and reduce the costs of light source. Simulation results show that this scheme can optimize the throughput of the WDM-PON network, greatly reduce the system time delay and energy consumption.

A multi-view face recognition system based on cascade face detector and improved Dlib

NASA Astrophysics Data System (ADS)

Zhou, Hongjun; Chen, Pei; Shen, Wei

2018-03-01

In this research, we present a framework for multi-view face detect and recognition system based on cascade face detector and improved Dlib. This method is aimed to solve the problems of low efficiency and low accuracy in multi-view face recognition, to build a multi-view face recognition system, and to discover a suitable monitoring scheme. For face detection, the cascade face detector is used to extracted the Haar-like feature from the training samples, and Haar-like feature is used to train a cascade classifier by combining Adaboost algorithm. Next, for face recognition, we proposed an improved distance model based on Dlib to improve the accuracy of multiview face recognition. Furthermore, we applied this proposed method into recognizing face images taken from different viewing directions, including horizontal view, overlooks view, and looking-up view, and researched a suitable monitoring scheme. This method works well for multi-view face recognition, and it is also simulated and tested, showing satisfactory experimental results.

Sensor Proxy Mobile IPv6 (SPMIPv6)—A Novel Scheme for Mobility Supported IP-WSNs

PubMed Central

Islam, Md. Motaharul; Huh, Eui-Nam

2011-01-01

IP based Wireless Sensor Networks (IP-WSNs) are gaining importance for their broad range of applications in health-care, home automation, environmental monitoring, industrial control, vehicle telematics and agricultural monitoring. In all these applications, mobility in the sensor network with special attention to energy efficiency is a major issue to be addressed. Host-based mobility management protocols are not suitable for IP-WSNs because of their energy inefficiency, so network based mobility management protocols can be an alternative for the mobility supported IP-WSNs. In this paper we propose a network based mobility supported IP-WSN protocol called Sensor Proxy Mobile IPv6 (SPMIPv6). We present its architecture, message formats and also evaluate its performance considering signaling cost, mobility cost and energy consumption. Our analysis shows that with respect to the number of IP-WSN nodes, the proposed scheme reduces the signaling cost by 60% and 56%, as well as the mobility cost by 62% and 57%, compared to MIPv6 and PMIPv6, respectively. The simulation results also show that in terms of the number of hops, SPMIPv6 decreases the signaling cost by 56% and 53% as well as mobility cost by 60% and 67% as compared to MIPv6 and PMIPv6 respectively. It also indicates that proposed scheme reduces the level of energy consumption significantly. PMID:22319386

Sensor proxy mobile IPv6 (SPMIPv6)--a novel scheme for mobility supported IP-WSNs.

PubMed

Islam, Md Motaharul; Huh, Eui-Nam

2011-01-01

IP based Wireless Sensor Networks (IP-WSNs) are gaining importance for their broad range of applications in health-care, home automation, environmental monitoring, industrial control, vehicle telematics and agricultural monitoring. In all these applications, mobility in the sensor network with special attention to energy efficiency is a major issue to be addressed. Host-based mobility management protocols are not suitable for IP-WSNs because of their energy inefficiency, so network based mobility management protocols can be an alternative for the mobility supported IP-WSNs. In this paper we propose a network based mobility supported IP-WSN protocol called Sensor Proxy Mobile IPv6 (SPMIPv6). We present its architecture, message formats and also evaluate its performance considering signaling cost, mobility cost and energy consumption. Our analysis shows that with respect to the number of IP-WSN nodes, the proposed scheme reduces the signaling cost by 60% and 56%, as well as the mobility cost by 62% and 57%, compared to MIPv6 and PMIPv6, respectively. The simulation results also show that in terms of the number of hops, SPMIPv6 decreases the signaling cost by 56% and 53% as well as mobility cost by 60% and 67% as compared to MIPv6 and PMIPv6 respectively. It also indicates that proposed scheme reduces the level of energy consumption significantly.

High-Fidelity Modeling for Health Monitoring in Honeycomb Sandwich Structures

NASA Technical Reports Server (NTRS)

Luchinsky, Dimitry G.; Hafiychuk, Vasyl; Smelyanskiy, Vadim; Tyson, Richard W.; Walker, James L.; Miller, Jimmy L.

2011-01-01

High-Fidelity Model of the sandwich composite structure with real geometry is reported. The model includes two composite facesheets, honeycomb core, piezoelectric actuator/sensors, adhesive layers, and the impactor. The novel feature of the model is that it includes modeling of the impact and wave propagation in the structure before and after the impact. Results of modeling of the wave propagation, impact, and damage detection in sandwich honeycomb plates using piezoelectric actuator/sensor scheme are reported. The results of the simulations are compared with the experimental results. It is shown that the model is suitable for analysis of the physics of failure due to the impact and for testing structural health monitoring schemes based on guided wave propagation.

Temporal abstraction for the analysis of intensive care information

NASA Astrophysics Data System (ADS)

Hadad, Alejandro J.; Evin, Diego A.; Drozdowicz, Bartolomé; Chiotti, Omar

2007-11-01

This paper proposes a scheme for the analysis of time-stamped series data from multiple monitoring devices of intensive care units, using Temporal Abstraction concepts. This scheme is oriented to obtain a description of the patient state evolution in an unsupervised way. The case of study is based on a dataset clinically classified with Pulmonary Edema. For this dataset a trends based Temporal Abstraction mechanism is proposed, by means of a Behaviours Base of time-stamped series and then used in a classification step. Combining this approach with the introduction of expert knowledge, using Fuzzy Logic, and multivariate analysis by means of Self-Organizing Maps, a states characterization model is obtained. This model is feasible of being extended to different patients groups and states. The proposed scheme allows to obtain intermediate states descriptions through which it is passing the patient and that could be used to anticipate alert situations.

An Adaptive Monitoring Scheme for Automatic Control of Anaesthesia in dynamic surgical environments based on Bispectral Index and Blood Pressure.

PubMed

Yu, Yu-Ning; Doctor, Faiyaz; Fan, Shou-Zen; Shieh, Jiann-Shing

2018-04-13

During surgical procedures, bispectral index (BIS) is a well-known measure used to determine the patient's depth of anesthesia (DOA). However, BIS readings can be subject to interference from many factors during surgery, and other parameters such as blood pressure (BP) and heart rate (HR) can provide more stable indicators. However, anesthesiologist still consider BIS as a primary measure to determine if the patient is correctly anaesthetized while relaying on the other physiological parameters to monitor and ensure the patient's status is maintained. The automatic control of administering anesthesia using intelligent control systems has been the subject of recent research in order to alleviate the burden on the anesthetist to manually adjust drug dosage in response physiological changes for sustaining DOA. A system proposed for the automatic control of anesthesia based on type-2 Self Organizing Fuzzy Logic Controllers (T2-SOFLCs) has been shown to be effective in the control of DOA under simulated scenarios while contending with uncertainties due to signal noise and dynamic changes in pharmacodynamics (PD) and pharmacokinetic (PK) effects of the drug on the body. This study considers both BIS and BP as part of an adaptive automatic control scheme, which can adjust to the monitoring of either parameter in response to changes in the availability and reliability of BIS signals during surgery. The simulation of different control schemes using BIS data obtained during real surgical procedures to emulate noise and interference factors have been conducted. The use of either or both combined parameters for controlling the delivery Propofol to maintain safe target set points for DOA are evaluated. The results show that combing BIS and BP based on the proposed adaptive control scheme can ensure the target set points and the correct amount of drug in the body is maintained even with the intermittent loss of BIS signal that could otherwise disrupt an automated control system.

Farmer Attitudes and Livestock Disease: Exploring Citizenship Behaviour and Peer Monitoring across Two BVD Control Schemes in the UK.

PubMed

Heffernan, Claire; Azbel-Jackson, Lena; Brownlie, Joe; Gunn, George

2016-01-01

The eradication of BVD in the UK is technically possible but appears to be socially untenable. The following study explored farmer attitudes to BVD control schemes in relation to advice networks and information sharing, shared aims and goals, motivation and benefits of membership, notions of BVD as a priority disease and attitudes toward regulation. Two concepts from the organisational management literature framed the study: citizenship behaviour where actions of individuals support the collective good (but are not explicitly recognised as such) and peer to peer monitoring (where individuals evaluate other's behaviour). Farmers from two BVD control schemes in the UK participated in the study: Orkney Livestock Association BVD Eradication Scheme and Norfolk and Suffolk Cattle Breeders Association BVD Eradication Scheme. In total 162 farmers participated in the research (109 in-scheme and 53 out of scheme). The findings revealed that group helping and information sharing among scheme members was low with a positive BVD status subject to social censure. Peer monitoring in the form of gossip with regard to the animal health status of other farms was high. Interestingly, farmers across both schemes supported greater regulation with regard to animal health, largely due to the mistrust of fellow farmers following voluntary disease control measures. While group cohesiveness varied across the two schemes, without continued financial inducements, longer-term sustainability is questionable.

Magnetic resonance image compression using scalar-vector quantization

NASA Astrophysics Data System (ADS)

Mohsenian, Nader; Shahri, Homayoun

1995-12-01

A new coding scheme based on the scalar-vector quantizer (SVQ) is developed for compression of medical images. SVQ is a fixed-rate encoder and its rate-distortion performance is close to that of optimal entropy-constrained scalar quantizers (ECSQs) for memoryless sources. The use of a fixed-rate quantizer is expected to eliminate some of the complexity issues of using variable-length scalar quantizers. When transmission of images over noisy channels is considered, our coding scheme does not suffer from error propagation which is typical of coding schemes which use variable-length codes. For a set of magnetic resonance (MR) images, coding results obtained from SVQ and ECSQ at low bit-rates are indistinguishable. Furthermore, our encoded images are perceptually indistinguishable from the original, when displayed on a monitor. This makes our SVQ based coder an attractive compression scheme for picture archiving and communication systems (PACS), currently under consideration for an all digital radiology environment in hospitals, where reliable transmission, storage, and high fidelity reconstruction of images are desired.

A smart checkpointing scheme for improving the reliability of clustering routing protocols.

PubMed

Min, Hong; Jung, Jinman; Kim, Bongjae; Cho, Yookun; Heo, Junyoung; Yi, Sangho; Hong, Jiman

2010-01-01

In wireless sensor networks, system architectures and applications are designed to consider both resource constraints and scalability, because such networks are composed of numerous sensor nodes with various sensors and actuators, small memories, low-power microprocessors, radio modules, and batteries. Clustering routing protocols based on data aggregation schemes aimed at minimizing packet numbers have been proposed to meet these requirements. In clustering routing protocols, the cluster head plays an important role. The cluster head collects data from its member nodes and aggregates the collected data. To improve reliability and reduce recovery latency, we propose a checkpointing scheme for the cluster head. In the proposed scheme, backup nodes monitor and checkpoint the current state of the cluster head periodically. We also derive the checkpointing interval that maximizes reliability while using the same amount of energy consumed by clustering routing protocols that operate without checkpointing. Experimental comparisons with existing non-checkpointing schemes show that our scheme reduces both energy consumption and recovery latency.

A Smart Checkpointing Scheme for Improving the Reliability of Clustering Routing Protocols

PubMed Central

Min, Hong; Jung, Jinman; Kim, Bongjae; Cho, Yookun; Heo, Junyoung; Yi, Sangho; Hong, Jiman

2010-01-01

In wireless sensor networks, system architectures and applications are designed to consider both resource constraints and scalability, because such networks are composed of numerous sensor nodes with various sensors and actuators, small memories, low-power microprocessors, radio modules, and batteries. Clustering routing protocols based on data aggregation schemes aimed at minimizing packet numbers have been proposed to meet these requirements. In clustering routing protocols, the cluster head plays an important role. The cluster head collects data from its member nodes and aggregates the collected data. To improve reliability and reduce recovery latency, we propose a checkpointing scheme for the cluster head. In the proposed scheme, backup nodes monitor and checkpoint the current state of the cluster head periodically. We also derive the checkpointing interval that maximizes reliability while using the same amount of energy consumed by clustering routing protocols that operate without checkpointing. Experimental comparisons with existing non-checkpointing schemes show that our scheme reduces both energy consumption and recovery latency. PMID:22163389

Ultrasensitive and Highly Stable Resistive Pressure Sensors with Biomaterial-Incorporated Interfacial Layers for Wearable Health-Monitoring and Human-Machine Interfaces.

PubMed

Chang, Hochan; Kim, Sungwoong; Jin, Sumin; Lee, Seung-Woo; Yang, Gil-Tae; Lee, Ki-Young; Yi, Hyunjung

2018-01-10

Flexible piezoresistive sensors have huge potential for health monitoring, human-machine interfaces, prosthetic limbs, and intelligent robotics. A variety of nanomaterials and structural schemes have been proposed for realizing ultrasensitive flexible piezoresistive sensors. However, despite the success of recent efforts, high sensitivity within narrower pressure ranges and/or the challenging adhesion and stability issues still potentially limit their broad applications. Herein, we introduce a biomaterial-based scheme for the development of flexible pressure sensors that are ultrasensitive (resistance change by 5 orders) over a broad pressure range of 0.1-100 kPa, promptly responsive (20 ms), and yet highly stable. We show that employing biomaterial-incorporated conductive networks of single-walled carbon nanotubes as interfacial layers of contact-based resistive pressure sensors significantly enhances piezoresistive response via effective modulation of the interlayer resistance and provides stable interfaces for the pressure sensors. The developed flexible sensor is capable of real-time monitoring of wrist pulse waves under external medium pressure levels and providing pressure profiles applied by a thumb and a forefinger during object manipulation at a low voltage (1 V) and power consumption (<12 μW). This work provides a new insight into the material candidates and approaches for the development of wearable health-monitoring and human-machine interfaces.

AWG-based WDM-PON monitoring system using an optical switch and a WDM filter

NASA Astrophysics Data System (ADS)

Liaw, S.-K.; Lai, Y.-T.; Chang, C.-L.; Shung, O.

2008-09-01

A new WDM-PON scheme with real-time monitoring based on a time-sharing method is proposed. It uses an optical time domain reflectometer (OTDR) to monitor multiple ports by integrating an optical switch (OSW) with a dense wavelength division multiplexer (DWDM) at the optical line terminal (OLT) site. Each downstream signal and its corresponding monitoring signal are separated by m times the free-space range (FSR) of an array waveguide grating (AWG). A bit error rate (BER) test in 2.5 Gb/s × 27 km is performed with and without turning on the OTDR. A small power penalty of 0.7 dB is observed compared to the back-to-back measurement.

Applicability of Kerker preconditioning scheme to the self-consistent density functional theory calculations of inhomogeneous systems

NASA Astrophysics Data System (ADS)

Zhou, Yuzhi; Wang, Han; Liu, Yu; Gao, Xingyu; Song, Haifeng

2018-03-01

The Kerker preconditioner, based on the dielectric function of homogeneous electron gas, is designed to accelerate the self-consistent field (SCF) iteration in the density functional theory calculations. However, a question still remains regarding its applicability to the inhomogeneous systems. We develop a modified Kerker preconditioning scheme which captures the long-range screening behavior of inhomogeneous systems and thus improves the SCF convergence. The effectiveness and efficiency is shown by the tests on long-z slabs of metals, insulators, and metal-insulator contacts. For situations without a priori knowledge of the system, we design the a posteriori indicator to monitor if the preconditioner has suppressed charge sloshing during the iterations. Based on the a posteriori indicator, we demonstrate two schemes of the self-adaptive configuration for the SCF iteration.

Experimental demonstration of an active phase randomization and monitor module for quantum key distribution

NASA Astrophysics Data System (ADS)

Sun, Shi-Hai; Liang, Lin-Mei

2012-08-01

Phase randomization is a very important assumption in the BB84 quantum key distribution (QKD) system with weak coherent source; otherwise, eavesdropper may spy the final key. In this Letter, a stable and monitored active phase randomization scheme for the one-way and two-way QKD system is proposed and demonstrated in experiments. Furthermore, our scheme gives an easy way for Alice to monitor the degree of randomization in experiments. Therefore, we expect our scheme to become a standard part in future QKD systems due to its secure significance and feasibility.

Automated identification of sleep states from EEG signals by means of ensemble empirical mode decomposition and random under sampling boosting.

PubMed

Hassan, Ahnaf Rashik; Bhuiyan, Mohammed Imamul Hassan

2017-03-01

Automatic sleep staging is essential for alleviating the burden of the physicians of analyzing a large volume of data by visual inspection. It is also a precondition for making an automated sleep monitoring system feasible. Further, computerized sleep scoring will expedite large-scale data analysis in sleep research. Nevertheless, most of the existing works on sleep staging are either multichannel or multiple physiological signal based which are uncomfortable for the user and hinder the feasibility of an in-home sleep monitoring device. So, a successful and reliable computer-assisted sleep staging scheme is yet to emerge. In this work, we propose a single channel EEG based algorithm for computerized sleep scoring. In the proposed algorithm, we decompose EEG signal segments using Ensemble Empirical Mode Decomposition (EEMD) and extract various statistical moment based features. The effectiveness of EEMD and statistical features are investigated. Statistical analysis is performed for feature selection. A newly proposed classification technique, namely - Random under sampling boosting (RUSBoost) is introduced for sleep stage classification. This is the first implementation of EEMD in conjunction with RUSBoost to the best of the authors' knowledge. The proposed feature extraction scheme's performance is investigated for various choices of classification models. The algorithmic performance of our scheme is evaluated against contemporary works in the literature. The performance of the proposed method is comparable or better than that of the state-of-the-art ones. The proposed algorithm gives 88.07%, 83.49%, 92.66%, 94.23%, and 98.15% for 6-state to 2-state classification of sleep stages on Sleep-EDF database. Our experimental outcomes reveal that RUSBoost outperforms other classification models for the feature extraction framework presented in this work. Besides, the algorithm proposed in this work demonstrates high detection accuracy for the sleep states S1 and REM. Statistical moment based features in the EEMD domain distinguish the sleep states successfully and efficaciously. The automated sleep scoring scheme propounded herein can eradicate the onus of the clinicians, contribute to the device implementation of a sleep monitoring system, and benefit sleep research. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Assessing the feasibility of using uniaxial accelerometers with an online support platform in the delivery of a community-based exercise referral scheme.

PubMed

Hawkins, Jemma L; Oliver, Emily J; Wyatt-Williams, Jeannie; Scale, Elaine; van Woerden, Hugo C

2014-10-01

Exercise referral schemes are established within community-based health care; however, they have been criticized for failing to evidence long-term behavior change relative to usual care. As such, recent reviews have called for refinement of their delivery with a focus on embedded strategies targeting client motivation. This research letter presents findings from an initial pilot trial conducted within Wales' National Exercise Referral Scheme (NERS), examining the feasibility of using validated physical activity monitoring devices and an accompanying online platform within standard scheme delivery. 30 individuals referred to generic or cardiovascular pathways were offered the system; of these 17 agreed to participate. Common reasons for declining were clustered into lack of technology literacy or access, condition severity, or fear of costs associated with losing the device. Analysis of follow-up interviews after 4 weeks of use indicated that while participants found the monitoring devices practical and informative, only a minority (n = 4) were using the system in full. Crucially, the system element most aligned with contemporary theories of motivation (the online portal) was not used as expected. In addition, feedback from exercise referral professionals indicated that there were demands for support from clients, which might be mitigated by more effective independent system use. Recommendations for larger scale trials using similar systems include consideration of targeted patient groups, equity of access, and providing adequate technological support that is currently beyond the capacity of the NERS system. © The Author(s) 2014.

Performance Analysis of Inter-Domain Handoff Scheme Based on Virtual Layer in PMIPv6 Networks for IP-Based Internet of Things.

PubMed

Cho, Chulhee; Choi, Jae-Young; Jeong, Jongpil; Chung, Tai-Myoung

2017-01-01

Lately, we see that Internet of things (IoT) is introduced in medical services for global connection among patients, sensors, and all nearby things. The principal purpose of this global connection is to provide context awareness for the purpose of bringing convenience to a patient's life and more effectively implementing clinical processes. In health care, monitoring of biosignals of a patient has to be continuously performed while the patient moves inside and outside the hospital. Also, to monitor the accurate location and biosignals of the patient, appropriate mobility management is necessary to maintain connection between the patient and the hospital network. In this paper, a binding update scheme on PMIPv6, which reduces signal traffic during location updates by Virtual LMA (VLMA) on the top original Local Mobility Anchor (LMA) Domain, is proposed to reduce the total cost. If a Mobile Node (MN) moves to a Mobile Access Gateway (MAG)-located boundary of an adjacent LMA domain, the MN changes itself into a virtual mode, and this movement will be assumed to be a part of the VLMA domain. In the proposed scheme, MAGs eliminate global binding updates for MNs between LMA domains and significantly reduce the packet loss and latency by eliminating the handoff between LMAs. In conclusion, the performance analysis results show that the proposed scheme improves performance significantly versus PMIPv6 and HMIPv6 in terms of the binding update rate per user and average handoff latency.

Biomass burning influences on atmospheric composition: A case study to assess the impact of aerosol data assimilation

NASA Astrophysics Data System (ADS)

Keslake, Tim; Chipperfield, Martyn; Mann, Graham; Flemming, Johannes; Remy, Sam; Dhomse, Sandip; Morgan, Will

2016-04-01

The C-IFS (Composition Integrated Forecast System) developed under the MACC series of projects and to be continued under the Copernicus Atmospheric Monitoring System, provides global operational forecasts and re-analyses of atmospheric composition at high spatial resolution (T255, ~80km). Currently there are 2 aerosol schemes implemented within C-IFS, a mass-based scheme with externally mixed particle types and an aerosol microphysics scheme (GLOMAP-mode). The simpler mass-based scheme is the current operational system, also used in the existing system to assimilate satellite measurements of aerosol optical depth (AOD) for improved forecast capability. The microphysical GLOMAP scheme has now been implemented and evaluated in the latest C-IFS cycle alongside the mass-based scheme. The upgrade to the microphysical scheme provides for higher fidelity aerosol-radiation and aerosol-cloud interactions, accounting for global variations in size distribution and mixing state, and additional aerosol properties such as cloud condensation nuclei concentrations. The new scheme will also provide increased aerosol information when used as lateral boundary conditions for regional air quality models. Here we present a series of experiments highlighting the influence and accuracy of the two different aerosol schemes and the impact of MODIS AOD assimilation. In particular, we focus on the influence of biomass burning emissions on aerosol properties in the Amazon, comparing to ground-based and aircraft observations from the 2012 SAMBBA campaign. Biomass burning can affect regional air quality, human health, regional weather and the local energy budget. Tropical biomass burning generates particles primarily composed of particulate organic matter (POM) and black carbon (BC), the local ratio of these two different constituents often determining the properties and subsequent impacts of the aerosol particles. Therefore, the model's ability to capture the concentrations of these two carbonaceous aerosol types, during the tropical dry season, is essential for quantifying these wide ranging impacts. Comparisons to SAMBBA aircraft observations show that while both schemes underestimate POM and BC mass concentrations, the GLOMAP scheme provides a more accurate simulation. When satellite AOD is assimilated into the GEMS-AER scheme, the model is successfully adjusted, capturing observed mass concentrations to a good degree of accuracy.

An overview of existing raptor contaminant monitoring activities in Europe.

PubMed

Gómez-Ramírez, P; Shore, R F; van den Brink, N W; van Hattum, B; Bustnes, J O; Duke, G; Fritsch, C; García-Fernández, A J; Helander, B O; Jaspers, V; Krone, O; Martínez-López, E; Mateo, R; Movalli, P; Sonne, C

2014-06-01

Biomonitoring using raptors as sentinels can provide early warning of the potential impacts of contaminants on humans and the environment and also a means of tracking the success of associated mitigation measures. Examples include detection of heavy metal-induced immune system impairment, PCB-induced altered reproductive impacts, and toxicity associated with lead in shot game. Authorisation of such releases and implementation of mitigation is now increasingly delivered through EU-wide directives but there is little established pan-European monitoring to quantify outcomes. We investigated the potential for EU-wide coordinated contaminant monitoring using raptors as sentinels. We did this using a questionnaire to ascertain the current scale of national activity across 44 European countries. According to this survey, there have been 52 different contaminant monitoring schemes with raptors over the last 50years. There were active schemes in 15 (predominantly western European) countries and 23 schemes have been running for >20years; most monitoring was conducted for >5years. Legacy persistent organic compounds (specifically organochlorine insecticides and PCBs), and metals/metalloids were monitored in most of the 15 countries. Fungicides, flame retardants and anticoagulant rodenticides were also relatively frequently monitored (each in at least 6 countries). Common buzzard (Buteo buteo), common kestrel (Falco tinnunculus), golden eagle (Aquila chrysaetos), white-tailed sea eagle (Haliaeetus albicilla), peregrine falcon (Falco peregrinus), tawny owl (Strix aluco) and barn owl (Tyto alba) were most commonly monitored (each in 6-10 countries). Feathers and eggs were most widely analysed although many schemes also analysed body tissues. Our study reveals an existing capability across multiple European countries for contaminant monitoring using raptors. However, coordination between existing schemes and expansion of monitoring into Eastern Europe is needed. This would enable assessment of the appropriateness of the EU-regulation of substances that are hazardous to humans and the environment, the effectiveness of EU level mitigation policies, and identify pan-European spatial and temporal trends in current and emerging contaminants of concern. Copyright © 2014. Published by Elsevier Ltd.

Monitoring of Batch Industrial Crystallization with Growth, Nucleation, and Agglomeration. Part 1: Modeling with Method of Characteristics.

PubMed

Porru, Marcella; Özkan, Leyla

2017-05-24

This paper develops a new simulation model for crystal size distribution dynamics in industrial batch crystallization. The work is motivated by the necessity of accurate prediction models for online monitoring purposes. The proposed numerical scheme is able to handle growth, nucleation, and agglomeration kinetics by means of the population balance equation and the method of characteristics. The former offers a detailed description of the solid phase evolution, while the latter provides an accurate and efficient numerical solution. In particular, the accuracy of the prediction of the agglomeration kinetics, which cannot be ignored in industrial crystallization, has been assessed by comparing it with solutions in the literature. The efficiency of the solution has been tested on a simulation of a seeded flash cooling batch process. Since the proposed numerical scheme can accurately simulate the system behavior more than hundred times faster than the batch duration, it is suitable for online applications such as process monitoring tools based on state estimators.

Monitoring of Batch Industrial Crystallization with Growth, Nucleation, and Agglomeration. Part 1: Modeling with Method of Characteristics

PubMed Central

2017-01-01

This paper develops a new simulation model for crystal size distribution dynamics in industrial batch crystallization. The work is motivated by the necessity of accurate prediction models for online monitoring purposes. The proposed numerical scheme is able to handle growth, nucleation, and agglomeration kinetics by means of the population balance equation and the method of characteristics. The former offers a detailed description of the solid phase evolution, while the latter provides an accurate and efficient numerical solution. In particular, the accuracy of the prediction of the agglomeration kinetics, which cannot be ignored in industrial crystallization, has been assessed by comparing it with solutions in the literature. The efficiency of the solution has been tested on a simulation of a seeded flash cooling batch process. Since the proposed numerical scheme can accurately simulate the system behavior more than hundred times faster than the batch duration, it is suitable for online applications such as process monitoring tools based on state estimators. PMID:28603342

Multiobjective design of aquifer monitoring networks for optimal spatial prediction and geostatistical parameter estimation

NASA Astrophysics Data System (ADS)

Alzraiee, Ayman H.; Bau, Domenico A.; Garcia, Luis A.

2013-06-01

Effective sampling of hydrogeological systems is essential in guiding groundwater management practices. Optimal sampling of groundwater systems has previously been formulated based on the assumption that heterogeneous subsurface properties can be modeled using a geostatistical approach. Therefore, the monitoring schemes have been developed to concurrently minimize the uncertainty in the spatial distribution of systems' states and parameters, such as the hydraulic conductivity K and the hydraulic head H, and the uncertainty in the geostatistical model of system parameters using a single objective function that aggregates all objectives. However, it has been shown that the aggregation of possibly conflicting objective functions is sensitive to the adopted aggregation scheme and may lead to distorted results. In addition, the uncertainties in geostatistical parameters affect the uncertainty in the spatial prediction of K and H according to a complex nonlinear relationship, which has often been ineffectively evaluated using a first-order approximation. In this study, we propose a multiobjective optimization framework to assist the design of monitoring networks of K and H with the goal of optimizing their spatial predictions and estimating the geostatistical parameters of the K field. The framework stems from the combination of a data assimilation (DA) algorithm and a multiobjective evolutionary algorithm (MOEA). The DA algorithm is based on the ensemble Kalman filter, a Monte-Carlo-based Bayesian update scheme for nonlinear systems, which is employed to approximate the posterior uncertainty in K, H, and the geostatistical parameters of K obtained by collecting new measurements. Multiple MOEA experiments are used to investigate the trade-off among design objectives and identify the corresponding monitoring schemes. The methodology is applied to design a sampling network for a shallow unconfined groundwater system located in Rocky Ford, Colorado. Results indicate that the effect of uncertainties associated with the geostatistical parameters on the spatial prediction might be significantly alleviated (by up to 80% of the prior uncertainty in K and by 90% of the prior uncertainty in H) by sampling evenly distributed measurements with a spatial measurement density of more than 1 observation per 60 m × 60 m grid block. In addition, exploration of the interaction of objective functions indicates that the ability of head measurements to reduce the uncertainty associated with the correlation scale is comparable to the effect of hydraulic conductivity measurements.

A hybrid feature selection and health indicator construction scheme for delay-time-based degradation modelling of rolling element bearings

NASA Astrophysics Data System (ADS)

Zhang, Bin; Deng, Congying; Zhang, Yi

2018-03-01

Rolling element bearings are mechanical components used frequently in most rotating machinery and they are also vulnerable links representing the main source of failures in such systems. Thus, health condition monitoring and fault diagnosis of rolling element bearings have long been studied to improve operational reliability and maintenance efficiency of rotatory machines. Over the past decade, prognosis that enables forewarning of failure and estimation of residual life attracted increasing attention. To accurately and efficiently predict failure of the rolling element bearing, the degradation requires to be well represented and modelled. For this purpose, degradation of the rolling element bearing is analysed with the delay-time-based model in this paper. Also, a hybrid feature selection and health indicator construction scheme is proposed for extraction of the bearing health relevant information from condition monitoring sensor data. Effectiveness of the presented approach is validated through case studies on rolling element bearing run-to-failure experiments.

Demagnetization monitoring and life extending control for permanent magnet-driven traction systems

NASA Astrophysics Data System (ADS)

Niu, Gang; Liu, Senyi

2018-03-01

This paper presents a novel scheme of demagnetization monitoring and life extending control for traction systems driven by permanent magnet synchronous motors (PMSMs). Firstly, the offline training is carried to evaluate fatigue damage of insulated gate bipolar transistors (IGBTs) under different flux loss based on first-principle modeling. Then an optimal control law can be extracted by turning down the power distribution factor of the demagnetizing PMSM until all damages of IGBTs turn to balance. Next, the similarity-based empirical modeling is employed to online estimate remaining flux of PMSMs, which is used to update the power distribution factor by referring the optimal control law for the health-oriented autonomous control. The proposed strategy can be demonstrated by a case study of traction drive system coupled with dual-PMSMs. Compared with traditional control strategy, the results show that the novel scheme can not only guarantee traction performance but also extend remaining useful life (RUL) of the system after suffering demagnetization fault.

Simultaneous trilateral communication based on three mutually coupled chaotic semiconductor lasers with optical feedback.

PubMed

Li, Qiliang; Lu, Shanshan; Bao, Qi; Chen, Dewang; Hu, Miao; Zeng, Ran; Yang, Guowei; Li, Shuqin

2018-01-10

In this paper, we propose a chaos-based scheme allowing for trilateral communication among three mutually coupled chaotic semiconductor lasers. The coupling through a partially transparent optical mirror between two lasers induces the chaotic dynamics. We numerically solve the delay rate equations of three lasers and demonstrate that the dynamics is completely synchronous. Herein, each laser is not only a transmitter but a receiver; three different messages are encoded by simultaneously modulating bias current of the three lasers. By monitoring the synchronization error between transmitter and receiver, and comparing the error with the message of the local laser, we can decipher the message of the sender. The investigation indicates that these messages introduced on the two ends of each link among three lasers can be simultaneously transmitted and restored, so the system can realize simultaneous trilateral communication. In this scheme, an eavesdropper can monitor the synchronization error, but one has no way to obtain the bits that are being sent, so the trilateral communication is secure.

Research on crude oil storage and transportation based on optimization algorithm

NASA Astrophysics Data System (ADS)

Yuan, Xuhua

2018-04-01

At present, the optimization theory and method have been widely used in the optimization scheduling and optimal operation scheme of complex production systems. Based on C++Builder 6 program development platform, the theoretical research results are implemented by computer. The simulation and intelligent decision system of crude oil storage and transportation inventory scheduling are designed. The system includes modules of project management, data management, graphics processing, simulation of oil depot operation scheme. It can realize the optimization of the scheduling scheme of crude oil storage and transportation system. A multi-point temperature measuring system for monitoring the temperature field of floating roof oil storage tank is developed. The results show that by optimizing operating parameters such as tank operating mode and temperature, the total transportation scheduling costs of the storage and transportation system can be reduced by 9.1%. Therefore, this method can realize safe and stable operation of crude oil storage and transportation system.

Characterization of malaria infected blood cells by scanning confocal laser and acoustic vector contrast microscopy

NASA Astrophysics Data System (ADS)

Ahmed Mohamed, E. T.; Schubert, S.; Gilberger, T. W.; Kamanyi, A., Jr.; Wannemacher, R.; Grill, W.

2006-03-01

Acoustic and optical multiple contrast microscopy has been employed in order to explore characterizable parameters of red blood cells, including cells infected by the parasite Plasmodium falciparum, in order to investigate cellular modifications caused by the infection and to identify possible detection schemes for disease monitoring. Imaging schemes were based on fluorescence, optical transmission, optical reflection, and amplitude and phase of ultrasound reflected from the cells. Contrast variations observed in acoustic microscopy, but not in optical microscopy, were tentatively ascribed to changes caused by the infection.

Dynamic electrical impedance imaging with the interacting multiple model scheme.

PubMed

Kim, Kyung Youn; Kim, Bong Seok; Kim, Min Chan; Kim, Sin; Isaacson, David; Newell, Jonathan C

2005-04-01

In this paper, an effective dynamical EIT imaging scheme is presented for on-line monitoring of the abruptly changing resistivity distribution inside the object, based on the interacting multiple model (IMM) algorithm. The inverse problem is treated as a stochastic nonlinear state estimation problem with the time-varying resistivity (state) being estimated on-line with the aid of the IMM algorithm. In the design of the IMM algorithm multiple models with different process noise covariance are incorporated to reduce the modeling uncertainty. Simulations and phantom experiments are provided to illustrate the proposed algorithm.

Evaluation of a new microphysical aerosol module in the ECMWF Integrated Forecasting System

NASA Astrophysics Data System (ADS)

Woodhouse, Matthew; Mann, Graham; Carslaw, Ken; Morcrette, Jean-Jacques; Schulz, Michael; Kinne, Stefan; Boucher, Olivier

2013-04-01

The Monitoring Atmospheric Composition and Climate II (MACC-II) project will provide a system for monitoring and predicting atmospheric composition. As part of the first phase of MACC, the GLOMAP-mode microphysical aerosol scheme (Mann et al., 2010, GMD) was incorporated within the ECMWF Integrated Forecasting System (IFS). The two-moment modal GLOMAP-mode scheme includes new particle formation, condensation, coagulation, cloud-processing, and wet and dry deposition. GLOMAP-mode is already incorporated as a module within the TOMCAT chemistry transport model and within the UK Met Office HadGEM3 general circulation model. The microphysical, process-based GLOMAP-mode scheme allows an improved representation of aerosol size and composition and can simulate aerosol evolution in the troposphere and stratosphere. The new aerosol forecasting and re-analysis system (known as IFS-GLOMAP) will also provide improved boundary conditions for regional air quality forecasts, and will benefit from assimilation of observed aerosol optical depths in near real time. Presented here is an evaluation of the performance of the IFS-GLOMAP system in comparison to in situ aerosol mass and number measurements, and remotely-sensed aerosol optical depth measurements. Future development will provide a fully-coupled chemistry-aerosol scheme, and the capability to resolve nitrate aerosol.

Enhance the Quality of Crowdsensing for Fine-Grained Urban Environment Monitoring via Data Correlation

PubMed Central

Kang, Xu; Liu, Liang; Ma, Huadong

2017-01-01

Monitoring the status of urban environments, which provides fundamental information for a city, yields crucial insights into various fields of urban research. Recently, with the popularity of smartphones and vehicles equipped with onboard sensors, a people-centric scheme, namely “crowdsensing”, for city-scale environment monitoring is emerging. This paper proposes a data correlation based crowdsensing approach for fine-grained urban environment monitoring. To demonstrate urban status, we generate sensing images via crowdsensing network, and then enhance the quality of sensing images via data correlation. Specifically, to achieve a higher quality of sensing images, we not only utilize temporal correlation of mobile sensing nodes but also fuse the sensory data with correlated environment data by introducing a collective tensor decomposition approach. Finally, we conduct a series of numerical simulations and a real dataset based case study. The results validate that our approach outperforms the traditional spatial interpolation-based method. PMID:28054968

Laser based structural health monitoring for civil, mechanical, and aerospace systems

NASA Astrophysics Data System (ADS)

Sohn, Hoon

2012-04-01

This paper provides an overview of ongoing laser ultrasonics based structural health monitoring (SHM) activities being performed by the author. Particular focus is given to (1) the development of a fully noncontact laser ultrasonic system that can easily visualize defects with high spatial resolution, (2) laser based wireless power and data transmission schemes for remote guided waves and impedance measurements, (3) minimization of false alarms due to varying operational and environmental conditions, and (4) extension to embedded laser ultrasonic excitation and sensing. SHM examples ranging from bridges to airplanes, as well as nuclear power plants, high-speed rails and wind turbines are also presented.

Energy Efficient Cluster Based Scheduling Scheme for Wireless Sensor Networks

PubMed Central

Srie Vidhya Janani, E.; Ganesh Kumar, P.

2015-01-01

The energy utilization of sensor nodes in large scale wireless sensor network points out the crucial need for scalable and energy efficient clustering protocols. Since sensor nodes usually operate on batteries, the maximum utility of network is greatly dependent on ideal usage of energy leftover in these sensor nodes. In this paper, we propose an Energy Efficient Cluster Based Scheduling Scheme for wireless sensor networks that balances the sensor network lifetime and energy efficiency. In the first phase of our proposed scheme, cluster topology is discovered and cluster head is chosen based on remaining energy level. The cluster head monitors the network energy threshold value to identify the energy drain rate of all its cluster members. In the second phase, scheduling algorithm is presented to allocate time slots to cluster member data packets. Here congestion occurrence is totally avoided. In the third phase, energy consumption model is proposed to maintain maximum residual energy level across the network. Moreover, we also propose a new packet format which is given to all cluster member nodes. The simulation results prove that the proposed scheme greatly contributes to maximum network lifetime, high energy, reduced overhead, and maximum delivery ratio. PMID:26495417

Provably Secure Heterogeneous Access Control Scheme for Wireless Body Area Network.

PubMed

Omala, Anyembe Andrew; Mbandu, Angolo Shem; Mutiria, Kamenyi Domenic; Jin, Chunhua; Li, Fagen

2018-04-28

Wireless body area network (WBAN) provides a medium through which physiological information could be harvested and transmitted to application provider (AP) in real time. Integrating WBAN in a heterogeneous Internet of Things (IoT) ecosystem would enable an AP to monitor patients from anywhere and at anytime. However, the IoT roadmap of interconnected 'Things' is still faced with many challenges. One of the challenges in healthcare is security and privacy of streamed medical data from heterogeneously networked devices. In this paper, we first propose a heterogeneous signcryption scheme where a sender is in a certificateless cryptographic (CLC) environment while a receiver is in identity-based cryptographic (IBC) environment. We then use this scheme to design a heterogeneous access control protocol. Formal security proof for indistinguishability against adaptive chosen ciphertext attack and unforgeability against adaptive chosen message attack in random oracle model is presented. In comparison with some of the existing access control schemes, our scheme has lower computation and communication cost.

Assessment strategies for municipal selective waste collection schemes.

PubMed

Ferreira, Fátima; Avelino, Catarina; Bentes, Isabel; Matos, Cristina; Teixeira, Carlos Afonso

2017-01-01

An important strategy to promote a strong sustainable growth relies on an efficient municipal waste management, and phasing out waste landfilling through waste prevention and recycling emerges as a major target. For this purpose, effective collection schemes are required, in particular those regarding selective waste collection, pursuing a more efficient and high quality recycling of reusable materials. This paper addresses the assessment and benchmarking of selective collection schemes, relevant to guide future operational improvements. In particular, the assessment is based on the monitoring and statistical analysis of a core-set of performance indicators that highlights collection trends, complemented with a performance index that gathers a weighted linear combination of these indicators. This combined analysis underlines a potential tool to support decision makers involved in the process of selecting the collection scheme with best overall performance. The presented approach was applied to a case study conducted in Oporto Municipality, with data gathered from two distinct selective collection schemes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Determination of power distribution in the VVER-440 core on the basis of data from in-core monitors by means of a metric analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kryanev, A. V.; Udumyan, D. K.; Kurchenkov, A. Yu., E-mail: s327@vver.kiae.ru

2014-12-15

Problems associated with determining the power distribution in the VVER-440 core on the basis of a neutron-physics calculation and data from in-core monitors are considered. A new mathematical scheme is proposed for this on the basis of a metric analysis. In relation to the existing mathematical schemes, the scheme in question improves the accuracy and reliability of the resulting power distribution.

Organic electronics based pressure sensor towards intracranial pressure monitoring

NASA Astrophysics Data System (ADS)

Rai, Pratyush; Varadan, Vijay K.

2010-04-01

The intra-cranial space, which houses the brain, contains cerebrospinal fluid (CSF) that acts as a fluid suspension medium for the brain. The CSF is always in circulation, is secreted in the cranium and is drained out through ducts called epidural veins. The venous drainage system has inherent resistance to the flow. Pressure is developed inside the cranium, which is similar to a rigid compartment. Normally a pressure of 5-15 mm Hg, in excess of atmospheric pressure, is observed at different locations inside the cranium. Increase in Intra-Cranial Pressure (ICP) can be caused by change in CSF volume caused by cerebral tumors, meningitis, by edema of a head injury or diseases related to cerebral atrophy. Hence, efficient ways of monitoring ICP need to be developed. A sensor system and monitoring scheme has been discussed here. The system architecture consists of a membrane less piezoelectric pressure sensitive element, organic thin film transistor (OTFT) based signal transduction, and signal telemetry. The components were fabricated on flexible substrate and have been assembled using flip-chip packaging technology. Material science and fabrication processes, subjective to the device performance, have been discussed. Capability of the device in detecting pressure variation, within the ICP pressure range, is investigated and applicability of measurement scheme to medical conditions has been argued for. Also, applications of such a sensor-OTFT assembly for logic sensor switching and patient specific-secure monitoring system have been discussed.

Utilizing a Homecare Platform for Remote Monitoring of Patients with Idiopathic Pulmonary Fibrosis.

PubMed

Panagopoulos, Christos; Malli, Foteini; Menychtas, Andreas; Smyrli, Efstathia-Petrina; Georgountzou, Aikaterini; Daniil, Zoe; Gourgoulianis, Konstantinos I; Tsanakas, Panayiotis; Maglogiannis, Ilias

2017-01-01

Homecare and home telemonitoring are a focal point of emerging healthcare schemes, with proven benefits for both patients, caregivers and providers, including reduction of healthcare costs and improved patients' quality of life, especially in the case of chronic disease management. Studies have evaluated solutions for remote monitoring of chronic patients based on technologies that allow daily symptom and vital signs monitoring, tailored to the needs of specific diseases. In this work, we present an affordable home telemonitoring system for patients with idiopathic pulmonary fibrosis (IPF), based on an application for mobile devices and Bluetooth-enabled sensors for pulse oximetry and blood pressure measurements. Besides monitoring of vital signs, the system incorporates communication via videoconferencing and emergency response, with support from a helpdesk service. A pilot study was conducted, in order to verify the proposed solution's feasibility. The results support the utilization of the system for effective monitoring of patients with IPF.

Protection of Renewable-dominated Microgrids: Challenges and Potential Solutions.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elkhatib, Mohamed; Ellis, Abraham; Milan Biswal

keywords : Microgrid Protection, Impedance Relay, Signal Processing-based Fault Detec- tion, Networked Microgrids, Communication-Assisted Protection In this report we address the challenge of designing efficient protection system for inverter- dominated microgrids. These microgrids are characterised with limited fault current capacity as a result of current-limiting protection functions of inverters. Typically, inverters limit their fault contribution in sub-cycle time frame to as low as 1.1 per unit. As a result, overcurrent protection could fail completely to detect faults in inverter-dominated microgrids. As part of this project a detailed literature survey of existing and proposed microgrid protection schemes were conducted. The surveymore » concluded that there is a gap in the available microgrid protection methods. The only credible protection solution available in literature for low- fault inverter-dominated microgrids is the differential protection scheme which represents a robust transmission-grade protection solution but at a very high cost. Two non-overcurrent protection schemes were investigated as part of this project; impedance-based protection and transient-based protection. Impedance-based protection depends on monitoring impedance trajectories at feeder relays to detect faults. Two communication-based impedance-based protection schemes were developed. the first scheme utilizes directional elements and pilot signals to locate the fault. The second scheme depends on a Central Protection Unit that communicates with all feeder relays to locate the fault based on directional flags received from feeder relays. The later approach could potentially be adapted to protect networked microgrids and dynamic topology microgrids. Transient-based protection relies on analyzing high frequency transients to detect and locate faults. This approach is very promising but its implementation in the filed faces several challenges. For example, high frequency transients due to faults can be confused with transients due to other events such as capacitor switching. Additionally, while detecting faults by analyzing transients could be doable, locating faults based on analyzing transients is still an open question.« less

A privacy-strengthened scheme for E-Healthcare monitoring system.

PubMed

Huang, Chanying; Lee, Hwaseong; Lee, Dong Hoon

2012-10-01

Recent Advances in Wireless Body Area Networks (WBANs) offer unprecedented opportunities and challenges to the development of pervasive electronic healthcare (E-Healthcare) monitoring system. In E-Healthcare system, the processed data are patients' sensitive health data that are directly related to individuals' privacy. For this reason, privacy concern is of great importance for E-Healthcare system. Current existing systems for E-Healthcare services, however, have not yet provided sufficient privacy protection for patients. In order to offer adequate security and privacy, in this paper, we propose a privacy-enhanced scheme for patients' physical condition monitoring, which achieves dual effects: (1) providing unlinkability of health records and individual identity, and (2) supporting anonymous authentication and authorized data access. We also conduct a simulation experiment to evaluate the performance of the proposed scheme. The experimental results demonstrate that the proposed scheme achieves better performance in terms of computational complexity, communication overheads and querying efficiency compared with previous results.

Performance Analysis of Inter-Domain Handoff Scheme Based on Virtual Layer in PMIPv6 Networks for IP-Based Internet of Things

PubMed Central

Choi, Jae-Young; Jeong, Jongpil; Chung, Tai-Myoung

2017-01-01

Lately, we see that Internet of things (IoT) is introduced in medical services for global connection among patients, sensors, and all nearby things. The principal purpose of this global connection is to provide context awareness for the purpose of bringing convenience to a patient’s life and more effectively implementing clinical processes. In health care, monitoring of biosignals of a patient has to be continuously performed while the patient moves inside and outside the hospital. Also, to monitor the accurate location and biosignals of the patient, appropriate mobility management is necessary to maintain connection between the patient and the hospital network. In this paper, a binding update scheme on PMIPv6, which reduces signal traffic during location updates by Virtual LMA (VLMA) on the top original Local Mobility Anchor (LMA) Domain, is proposed to reduce the total cost. If a Mobile Node (MN) moves to a Mobile Access Gateway (MAG)-located boundary of an adjacent LMA domain, the MN changes itself into a virtual mode, and this movement will be assumed to be a part of the VLMA domain. In the proposed scheme, MAGs eliminate global binding updates for MNs between LMA domains and significantly reduce the packet loss and latency by eliminating the handoff between LMAs. In conclusion, the performance analysis results show that the proposed scheme improves performance significantly versus PMIPv6 and HMIPv6 in terms of the binding update rate per user and average handoff latency. PMID:28129355

Hybrid wireless sensor network for rescue site monitoring after earthquake

NASA Astrophysics Data System (ADS)

Wang, Rui; Wang, Shuo; Tang, Chong; Zhao, Xiaoguang; Hu, Weijian; Tan, Min; Gao, Bowei

2016-07-01

This paper addresses the design of a low-cost, low-complexity, and rapidly deployable wireless sensor network (WSN) for rescue site monitoring after earthquakes. The system structure of the hybrid WSN is described. Specifically, the proposed hybrid WSN consists of two kinds of wireless nodes, i.e., the monitor node and the sensor node. Then the mechanism and the system configuration of the wireless nodes are detailed. A transmission control protocol (TCP)-based request-response scheme is proposed to allow several monitor nodes to communicate with the monitoring center. UDP-based image transmission algorithms with fast recovery have been developed to meet the requirements of in-time delivery of on-site monitor images. In addition, the monitor node contains a ZigBee module that used to communicate with the sensor nodes, which are designed with small dimensions to monitor the environment by sensing different physical properties in narrow spaces. By building a WSN using these wireless nodes, the monitoring center can display real-time monitor images of the monitoring area and visualize all collected sensor data on geographic information systems. In the end, field experiments were performed at the Training Base of Emergency Seismic Rescue Troops of China and the experimental results demonstrate the feasibility and effectiveness of the monitor system.

IEEE 802.15.4 Frame Aggregation Enhancement to Provide High Performance in Life-Critical Patient Monitoring Systems

PubMed Central

Akbar, Muhammad Sajjad; Yu, Hongnian; Cang, Shuang

2017-01-01

In wireless body area sensor networks (WBASNs), Quality of Service (QoS) provision for patient monitoring systems in terms of time-critical deadlines, high throughput and energy efficiency is a challenging task. The periodic data from these systems generates a large number of small packets in a short time period which needs an efficient channel access mechanism. The IEEE 802.15.4 standard is recommended for low power devices and widely used for many wireless sensor networks applications. It provides a hybrid channel access mechanism at the Media Access Control (MAC) layer which plays a key role in overall successful transmission in WBASNs. There are many WBASN’s MAC protocols that use this hybrid channel access mechanism in variety of sensor applications. However, these protocols are less efficient for patient monitoring systems where life critical data requires limited delay, high throughput and energy efficient communication simultaneously. To address these issues, this paper proposes a frame aggregation scheme by using the aggregated-MAC protocol data unit (A-MPDU) which works with the IEEE 802.15.4 MAC layer. To implement the scheme accurately, we develop a traffic patterns analysis mechanism to understand the requirements of the sensor nodes in patient monitoring systems, then model the channel access to find the performance gap on the basis of obtained requirements, finally propose the design based on the needs of patient monitoring systems. The mechanism is initially verified using numerical modelling and then simulation is conducted using NS2.29, Castalia 3.2 and OMNeT++. The proposed scheme provides the optimal performance considering the required QoS. PMID:28134853

IEEE 802.15.4 Frame Aggregation Enhancement to Provide High Performance in Life-Critical Patient Monitoring Systems.

PubMed

Akbar, Muhammad Sajjad; Yu, Hongnian; Cang, Shuang

2017-01-28

In wireless body area sensor networks (WBASNs), Quality of Service (QoS) provision for patient monitoring systems in terms of time-critical deadlines, high throughput and energy efficiency is a challenging task. The periodic data from these systems generates a large number of small packets in a short time period which needs an efficient channel access mechanism. The IEEE 802.15.4 standard is recommended for low power devices and widely used for many wireless sensor networks applications. It provides a hybrid channel access mechanism at the Media Access Control (MAC) layer which plays a key role in overall successful transmission in WBASNs. There are many WBASN's MAC protocols that use this hybrid channel access mechanism in variety of sensor applications. However, these protocols are less efficient for patient monitoring systems where life critical data requires limited delay, high throughput and energy efficient communication simultaneously. To address these issues, this paper proposes a frame aggregation scheme by using the aggregated-MAC protocol data unit (A-MPDU) which works with the IEEE 802.15.4 MAC layer. To implement the scheme accurately, we develop a traffic patterns analysis mechanism to understand the requirements of the sensor nodes in patient monitoring systems, then model the channel access to find the performance gap on the basis of obtained requirements, finally propose the design based on the needs of patient monitoring systems. The mechanism is initially verified using numerical modelling and then simulation is conducted using NS2.29, Castalia 3.2 and OMNeT++. The proposed scheme provides the optimal performance considering the required QoS.

Macroinvertebrates as Indicators of Stream Health.

ERIC Educational Resources Information Center

McDonald, Brook S.; And Others

1991-01-01

Describes Ohio's Scenic Rivers Monitoring Program that uses benthic macroinvertebrates, such as the stonefly, mayfly, and water penny beetle larva, as key indicators of water quality and stream health. Presents a three-category scheme for invertebrates based upon their tolerance to pollution. Students can collect samples of these organisms,…

A Lossless Multichannel Bio-Signal Compression Based on Low-Complexity Joint Coding Scheme for Portable Medical Devices

PubMed Central

Kim, Dong-Sun; Kwon, Jin-San

2014-01-01

Research on real-time health systems have received great attention during recent years and the needs of high-quality personal multichannel medical signal compression for personal medical product applications are increasing. The international MPEG-4 audio lossless coding (ALS) standard supports a joint channel-coding scheme for improving compression performance of multichannel signals and it is very efficient compression method for multi-channel biosignals. However, the computational complexity of such a multichannel coding scheme is significantly greater than that of other lossless audio encoders. In this paper, we present a multichannel hardware encoder based on a low-complexity joint-coding technique and shared multiplier scheme for portable devices. A joint-coding decision method and a reference channel selection scheme are modified for a low-complexity joint coder. The proposed joint coding decision method determines the optimized joint-coding operation based on the relationship between the cross correlation of residual signals and the compression ratio. The reference channel selection is designed to select a channel for the entropy coding of the joint coding. The hardware encoder operates at a 40 MHz clock frequency and supports two-channel parallel encoding for the multichannel monitoring system. Experimental results show that the compression ratio increases by 0.06%, whereas the computational complexity decreases by 20.72% compared to the MPEG-4 ALS reference software encoder. In addition, the compression ratio increases by about 11.92%, compared to the single channel based bio-signal lossless data compressor. PMID:25237900

Protection of Renewable-dominated Microgrids: Challenges and Potential Solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elkhatib, Mohamed; Ellis, Abraham; Biswal, Milan

In this report we address the challenge of designing efficient protection system for inverter- dominated microgrids. These microgrids are characterised with limited fault current capacity as a result of current-limiting protection functions of inverters. Typically, inverters limit their fault contribution in sub-cycle time frame to as low as 1.1 per unit. As a result, overcurrent protection could fail completely to detect faults in inverter-dominated microgrids. As part of this project a detailed literature survey of existing and proposed microgrid protection schemes were conducted. The survey concluded that there is a gap in the available microgrid protection methods. The only crediblemore » protection solution available in literature for low- fault inverter-dominated microgrids is the differential protection scheme which represents a robust transmission-grade protection solution but at a very high cost. Two non-overcurrent protection schemes were investigated as part of this project; impedance-based protection and transient-based protection. Impedance-based protection depends on monitoring impedance trajectories at feeder relays to detect faults. Two communication-based impedance-based protection schemes were developed. the first scheme utilizes directional elements and pilot signals to locate the fault. The second scheme depends on a Central Protection Unit that communicates with all feeder relays to locate the fault based on directional flags received from feeder relays. The later approach could potentially be adapted to protect networked microgrids and dynamic topology microgrids. Transient-based protection relies on analyzing high frequency transients to detect and locate faults. This approach is very promising but its implementation in the filed faces several challenges. For example, high frequency transients due to faults can be confused with transients due to other events such as capacitor switching. Additionally, while detecting faults by analyzing transients could be doable, locating faults based on analyzing transients is still an open question.« less

Multiple Sensing Application on Wireless Sensor Network Simulation using NS3

NASA Astrophysics Data System (ADS)

Kurniawan, I. F.; Bisma, R.

2018-01-01

Hardware enhancement provides opportunity to install various sensor device on single monitoring node which then enables users to acquire multiple data simultaneously. Constructing multiple sensing application in NS3 is a challenging task since numbers of aspects such as wireless communication, packet transmission pattern, and energy model must be taken into account. Despite of numerous types of monitoring data available, this study only considers two types such as periodic, and event-based data. Periodical data will generate monitoring data follows configured interval, while event-based transmit data when certain determined condition is met. Therefore, this study attempts to cover mentioned aspects in NS3. Several simulations are performed with different number of nodes on arbitrary communication scheme.

Distributed optical fiber-based monitoring approach of spatial seepage behavior in dike engineering

NASA Astrophysics Data System (ADS)

Su, Huaizhi; Ou, Bin; Yang, Lifu; Wen, Zhiping

2018-07-01

The failure caused by seepage is the most common one in dike engineering. As to the characteristics of seepage in dike, such as longitudinal extension engineering, the randomness, strong concealment and small initial quantity order, by means of distributed fiber temperature sensor system (DTS), adopting an improved optical fiber layer layout scheme, the location of initial interpolation point of the saturation line is obtained. With the barycentric Lagrange interpolation collocation method (BLICM), the infiltrated surface of dike full-section is generated. Combined with linear optical fiber monitoring seepage method, BLICM is applied in an engineering case, which shows that a real-time seepage monitoring technique is presented in full-section of dike based on the combination method.

Optical signal monitoring in phase modulated optical fiber transmission systems

NASA Astrophysics Data System (ADS)

Zhao, Jian

Optical performance monitoring (OPM) is one of the essential functions for future high speed optical networks. Among the parameters to be monitored, chromatic dispersion (CD) is especially important since it has a significant impact on overall system performance. In this thesis effective CD monitoring approaches for phase-shift keying (PSK) based optical transmission systems are investigated. A number of monitoring schemes based on radio frequency (RF) spectrum analysis and delay-tap sampling are proposed and their performance evaluated. A method for dispersion monitoring of differential phase-shift keying (DPSK) signals based on RF power detection is studied. The RF power spectrum is found to increase with the increase of CD and decrease with polarization mode dispersion (PMD). The spectral power density dependence on CD is studied theoretically and then verified through simulations and experiments. The monitoring sensitivity for nonreturn-to-zero differential phase-shift keying (NRZ-DPSK) and return-to-zero differential phase-shift keying (RZ-DPSK) based systems can reach 80ps/nm/dB and 34ps/nm/dB respectively. The scheme enables the monitoring of differential group delay (DGD) and CD simultaneously. The monitoring sensitivity of CD and DGD can reach 56.7ps/nm/dB and 3.1ps/dB using a bandpass filter. The effects of optical signal-to-noise ratio (OSNR), DGD, fiber nonlinearity and chirp on the monitoring results are investigated. Two RF pilot tones are employed for CD monitoring of DPSK signals. Specially selected pilot tone frequencies enable good monitoring sensitivity with minimum influence on the received signals. The dynamic range exceeding 35dB and monitoring sensitivity up to 9.5ps/nm/dB are achieved. Asynchronous sampling technique is employed for CD monitoring. A signed CD monitoring method for 10Gb/s NRZ-DPSK and RZ-DPSK systems using asynchronous delay-tap sampling technique is studied. The demodulated signals suffer asymmetric waveform distortion if there is a phase error (Deltaphi) in the delay interferometer (DI) and in the presence of residual CD. Using delay-tap sampling the scatter plots can reflect this signal distortion through their asymmetric characteristics. A distance ratio (DR) is defined to represent the change of the scatter plots which is directly related to the accumulated CD. The monitoring range can be up to +/-400ps/nm and to +/-720ps/nm for 10Gb/s NRZ-DPSK and RZ-DPSK signals with 450 phase error in DI. The monitoring sensitivity reaches +/-8ps/nm and CD polarity discrimination is realized. It is found that the signal degradation is related to the increment of the absolute value of CD or phase mismatch. The effect of different polarities of phase error on CD monitoring is also analyzed. The shoulders location depends on the sign of the product DLDeltaphi. If DLDeltaphi > 0, the shoulder will appear on trailing edge else the shoulder will appear on leading edge when DLDeltaphi < 0. The analysis shows that the phase error is identical to the frequency offset of optical source so a signed frequency offset monitoring is also demonstrated. The monitoring results show that the monitoring range can reach +/-2.2GHz and the monitoring sensitivity is around 27MHz. The effect of nonlinearity, OSNR and bandwidth of the lowpass filter on the proposed monitoring method has also been studied. The signed CD monitoring for 100Gb/s carrier suppressed return-to-zero differential quadrature phase-shift keying (CSRZ-DQPSK) system based on the delay-tap sampling technology is demonstrated. The monitoring range and monitoring resolution can goes up to +/-32ps/nm and +/-8ps/nm, respectively. A signed CD and optical carrier wavelength monitoring scheme using cross-correlation method for on-off keying (00K) wavelength division multiplexing (WDM) system is proposed and demonstrated. CD monitoring sensitivity is high and can be less than 10% of the bit period. Wavelength monitoring is implemented using the proposed approach. The monitoring results show that the sensitivity can reach up to 1.37ps/GHz.

PCA Based Stress Monitoring of Cylindrical Specimens Using PZTs and Guided Waves

PubMed Central

Mujica, Luis; Ruiz, Magda; Camacho, Johanatan

2017-01-01

Since mechanical stress in structures affects issues such as strength, expected operational life and dimensional stability, a continuous stress monitoring scheme is necessary for a complete integrity assessment. Consequently, this paper proposes a stress monitoring scheme for cylindrical specimens, which are widely used in structures such as pipelines, wind turbines or bridges. The approach consists of tracking guided wave variations due to load changes, by comparing wave statistical patterns via Principal Component Analysis (PCA). Each load scenario is projected to the PCA space by means of a baseline model and represented using the Q-statistical indices. Experimental validation of the proposed methodology is conducted on two specimens: (i) a 12.7 mm (1/2″) diameter, 0.4 m length, AISI 1020 steel rod, and (ii) a 25.4 mm (1″) diameter, 6m length, schedule 40, A-106, hollow cylinder. Specimen 1 was subjected to axial loads, meanwhile specimen 2 to flexion. In both cases, simultaneous longitudinal and flexural guided waves were generated via piezoelectric devices (PZTs) in a pitch-catch configuration. Experimental results show the feasibility of the approach and its potential use as in-situ continuous stress monitoring application. PMID:29194384

Dynamic Computation Offloading for Low-Power Wearable Health Monitoring Systems.

PubMed

Kalantarian, Haik; Sideris, Costas; Mortazavi, Bobak; Alshurafa, Nabil; Sarrafzadeh, Majid

2017-03-01

The objective of this paper is to describe and evaluate an algorithm to reduce power usage and increase battery lifetime for wearable health-monitoring devices. We describe a novel dynamic computation offloading scheme for real-time wearable health monitoring devices that adjusts the partitioning of data processing between the wearable device and mobile application as a function of desired classification accuracy. By making the correct offloading decision based on current system parameters, we show that we are able to reduce system power by as much as 20%. We demonstrate that computation offloading can be applied to real-time monitoring systems, and yields significant power savings. Making correct offloading decisions for health monitoring devices can extend battery life and improve adherence.

A civil structural monitoring system based on fiber grating sensors

NASA Astrophysics Data System (ADS)

Zhang, Yan; Cai, Haiwen; Pastore, Robert; Ju, Jing; Zeng, Debing; Yin, Zhifan; Cui, Hong-Liang

2003-08-01

Optical fiber sensors based on Fiber Bragg Grating (FBG) technology have found many applications in the area of civil structural monitoring systems, such as in bridge monitoring and maintenance. FBG sensors can measure the deformation, overload and cracks on bridge with a high sensitivity. In this paper we report on our recent work a structural monitoring system using FBG sensors. Basic theoretical background and design of the system is described here, including the light source, FBG sensors, demodulator sensors, signal detection and processing schemes. The system will be installed on a major arch bridge currently under construction in Shanghai, China for long-term in situ health monitoring. The system schematic arrangement on the bridge is introduced in brief. Simulation experiments in the laboratory were carried out to test the performance of FBG strain sensors. The sensor response shows excellent linearity against the strain imposed on it. Traffic and overload monitoring on bridge using FBG sensors is also discussed and planned for the near future.

The fault monitoring and diagnosis knowledge-based system for space power systems: AMPERES, phase 1

NASA Technical Reports Server (NTRS)

Lee, S. C.

1989-01-01

The objective is to develop a real time fault monitoring and diagnosis knowledge-based system (KBS) for space power systems which can save costly operational manpower and can achieve more reliable space power system operation. The proposed KBS was developed using the Autonomously Managed Power System (AMPS) test facility currently installed at NASA Marshall Space Flight Center (MSFC), but the basic approach taken for this project could be applicable for other space power systems. The proposed KBS is entitled Autonomously Managed Power-System Extendible Real-time Expert System (AMPERES). In Phase 1 the emphasis was put on the design of the overall KBS, the identification of the basic research required, the initial performance of the research, and the development of a prototype KBS. In Phase 2, emphasis is put on the completion of the research initiated in Phase 1, and the enhancement of the prototype KBS developed in Phase 1. This enhancement is intended to achieve a working real time KBS incorporated with the NASA space power system test facilities. Three major research areas were identified and progress was made in each area. These areas are real time data acquisition and its supporting data structure; sensor value validations; development of inference scheme for effective fault monitoring and diagnosis, and its supporting knowledge representation scheme.

Visual privacy by context: proposal and evaluation of a level-based visualisation scheme.

PubMed

Padilla-López, José Ramón; Chaaraoui, Alexandros Andre; Gu, Feng; Flórez-Revuelta, Francisco

2015-06-04

Privacy in image and video data has become an important subject since cameras are being installed in an increasing number of public and private spaces. Specifically, in assisted living, intelligent monitoring based on computer vision can allow one to provide risk detection and support services that increase people's autonomy at home. In the present work, a level-based visualisation scheme is proposed to provide visual privacy when human intervention is necessary, such as at telerehabilitation and safety assessment applications. Visualisation levels are dynamically selected based on the previously modelled context. In this way, different levels of protection can be provided, maintaining the necessary intelligibility required for the applications. Furthermore, a case study of a living room, where a top-view camera is installed, is presented. Finally, the performed survey-based evaluation indicates the degree of protection provided by the different visualisation models, as well as the personal privacy preferences and valuations of the users.

A digital data acquisition scheme for SPECT and PET small animal imaging detectors for Theranostic applications

NASA Astrophysics Data System (ADS)

Georgiou, M.; Fysikopoulos, E.; Loudos, G.

2017-11-01

Nanoparticle based drug delivery is considered as a new, promising technology for the efficient treatment of various diseases. When nanoparticles are radiolabelled it is possible to image them, using molecular imaging techniques. The use of magnetic nanoparticles in hyperthermia is one of the most promising nanomedicine directions and requires the accurate, non-invasive, monitoring of temperature increase and drug release. The combination of imaging and therapy has opened the very promising Theranostics domain. In this work, we present a digital data acquisition scheme for nuclear medicine dedicated detectors for Theranostic applications.

[GIS and scenario analysis aid to water pollution control planning of river basin].

PubMed

Wang, Shao-ping; Cheng, Sheng-tong; Jia, Hai-feng; Ou, Zhi-dan; Tan, Bin

2004-07-01

The forward and backward algorithms for watershed water pollution control planning were summarized in this paper as well as their advantages and shortages. The spatial databases of water environmental function region, pollution sources, monitoring sections and sewer outlets were built with ARCGIS8.1 as the platform in the case study of Ganjiang valley, Jiangxi province. Based on the principles of the forward algorithm, four scenarios were designed for the watershed pollution control. Under these scenarios, ten sets of planning schemes were generated to implement cascade pollution source control. The investment costs of sewage treatment for these schemes were estimated by means of a series of cost-effective functions; with pollution source prediction, the water quality was modeled with CSTR model for each planning scheme. The modeled results of different planning schemes were visualized through GIS to aid decision-making. With the results of investment cost and water quality attainment as decision-making accords and based on the analysis of the economic endurable capacity for water pollution control in Ganjiang river basin, two optimized schemes were proposed. The research shows that GIS technology and scenario analysis can provide a good guidance to the synthesis, integrity and sustainability aspects for river basin water quality planning.

Applications of 1.55 μm optically injection-locked VCSELs in wavelength division multiplexed passive optical networks

NASA Astrophysics Data System (ADS)

Wong, Elaine; Zhao, Xiaoxue; Chang-Hasnain, Connie J.; Hofmann, Werner; Amann, Marcus C.

2007-11-01

In this paper, we will discuss the utilization of optically injection-locked (OIL) 1.55 μm vertical-cavity surface-emitting lasers (VCSELs) for operation as low-cost, stable, directly modulated, and potentially uncooled transmitters, whereby the injection-locking master source is furnished by modulated downstream signals. Such a transmitter will find useful application in wavelength division multiplexed passive optical networks (WDM-PONs) which is actively being developed to meet the ever-increasing bandwidth demands of end users. Our scheme eliminates the need for external injection locking optical sources, external modulators, and wavelength stabilization circuitry. We show through experiments that the injection-locked VCSEL favors low injection powers and responds only strongly to the carrier but not the modulated data of the downstream signal. Further, we will discuss results from experimental studies performed on the dependence of OIL-VCSELs in bidirectional networks on the degree of Rayleigh backscattered signal and extinction ratio. We show that error-free upstream performance can be achieved when the upstream signal to Rayleigh backscattering ratio is greater than 13.4 dB, and with minimal dependence on the downstream extinction ratio. We will also review a fault monitoring and localization scheme based on a highly-sensitive yet low-cost monitor comprising a low output power broadband source and low bandwidth detectors. The proposed scheme benefits from the high reflectivity top distributed Bragg reflector mirror of the OIL-VCSEL, incurring only a minimal penalty on the upstream transmissions of the existing infrastructure. Such a scheme provides fault monitoring without having to further invest in the upgrade of customer premises.

Can paying for results help to achieve the Millennium Development Goals? A critical review of selected evaluations of results-based financing.

PubMed

Oxman, Andrew D; Fretheim, Atle

2009-08-01

Results-based financing (RBF) refers to the transfer of money or material goods conditional on taking a measurable action or achieving a predetermined performance target. RBF is being promoted for helping to achieve the Millennium Development Goals (MDGs). We undertook a critical appraisal of selected evaluations of RBF schemes in the health sector in low and middle-income countries (LMIC). In addition, key informants were interviewed to identify literature relevant to the use of RBF in the health sector in LMIC, key examples, evaluations, and other key informants. The use of RBF in LMIC has commonly been a part of a package that may include increased funding, technical support, training, changes in management, and new information systems. It is not possible to disentangle the effects of financial incentives as one element of RBF schemes, and there is very limited evidence of RBF per se having an effect. RBF schemes can have unintended effects. When RBF schemes are used, they should be designed carefully, including the level at which they are targeted, the choice of targets and indicators, the type and magnitude of incentives, the proportion of financing that is paid based on results, and the ancillary components of the scheme. For RBF to be effective, it must be part of an appropriate package of interventions, and technical capacity or support must be available. RBF schemes should be monitored for possible unintended effects and evaluated using rigorous study designs. © 2009 Blackwell Publishing Asia Pty Ltd and Chinese Cochrane Center, West China Hospital of Sichuan University.

Magentic Cell labeling of primary and stem cell-derived pig hepatocytes for MRI-based cell tracking of heptocytes transplantation

USDA-ARS?s Scientific Manuscript database

Pig hepatocytes are an important investigational tool for optimizing hepatocyte transplantation schemes in both allogeneic and xenogeneic transplant scenarios. MRI can be used to serially monitor the transplanted cells, but only if the hepatocytes can be labeled with a magnetic particle. In this wo...

Distributed strain measurement based on long-gauge FBG and delayed transmission/reflection ratiometric reflectometry for dynamic structural deformation monitoring.

PubMed

Nishiyama, Michiko; Igawa, Hirotaka; Kasai, Tokio; Watanabe, Naoyuki

2015-02-10

In this paper, we propose a delayed transmission/reflection ratiometric reflectometry (DTR(3)) scheme using a long-gauge fiber Bragg grating (FBG), which can be used for dynamic structural deformation monitoring of structures of between a few to tens of meters in length, such as airplane wings and helicopter blades. FBG sensors used for multipoint sensing generally employ wavelength division multiplexing techniques utilizing several Bragg central wavelengths; by contrast, the DTR(3) interrogator uses a continuous pulse array based on a pseudorandom number code and a long-gauge FBG utilizing a single Bragg wavelength and composed of simple hardware devices. The DTR(3) scheme can detect distributed strain at a 50 cm spatial resolution using a long-gauge FBG with a 100 Hz sampling rate. We evaluated the strain sensing characteristics of the long-gauge FBG when attached to a 2.5 m aluminum bar and a 5.5 m helicopter blade model, determining these structure natural frequencies in free vibration tests and their distributed strain characteristics in static tests.

New Multilocus Variable-Number Tandem-Repeat Analysis (MLVA) Scheme for Fine-Scale Monitoring and Microevolution-Related Study of Ralstonia pseudosolanacearum Phylotype I Populations

PubMed Central

Guinard, Jérémy; Latreille, Anne; Guérin, Fabien; Poussier, Stéphane

2016-01-01

ABSTRACT Bacterial wilt caused by the Ralstonia solanacearum species complex (RSSC) is considered one of the most harmful plant diseases in the world. Special attention should be paid to R. pseudosolanacearum phylotype I due to its large host range, its worldwide distribution, and its high evolutionary potential. So far, the molecular epidemiology and population genetics of this bacterium are poorly understood. Until now, the genetic structure of the RSSC has been analyzed on the worldwide and regional scales. Emerging questions regarding evolutionary forces in RSSC adaptation to hosts now require genetic markers that are able to monitor RSSC field populations. In this study, we aimed to evaluate the multilocus variable-number tandem-repeat analysis (MLVA) approach for its ability to discriminate genetically close phylotype I strains and for population genetics studies. We developed a new MLVA scheme (MLVA-7) allowing us to genotype 580 R. pseudosolanacearum phylotype I strains extracted from susceptible and resistant hosts and from different habitats (stem, soil, and rhizosphere). Based on specificity, polymorphism, and the amplification success rate, we selected seven fast-evolving variable-number tandem-repeat (VNTR) markers. The newly developed MLVA-7 scheme showed higher discriminatory power than the previously published MLVA-13 scheme when applied to collections sampled from the same location on different dates and to collections from different locations on very small scales. Our study provides a valuable tool for fine-scale monitoring and microevolution-related study of R. pseudosolanacearum phylotype I populations. IMPORTANCE Understanding the evolutionary dynamics of adaptation of plant pathogens to new hosts or ecological niches has become a key point for the development of innovative disease management strategies, including durable resistance. Whereas the molecular mechanisms underlying virulence or pathogenicity changes have been studied thoroughly, the population genetics of plant pathogen adaptation remains an open, unexplored field, especially for plant-pathogenic bacteria. MLVA has become increasingly popular for epidemiosurveillance and molecular epidemiology studies of plant pathogens. However, this method has been used mostly for genotyping and identification on a regional or global scale. In this study, we developed a new MLVA scheme, targeting phylotype I of the soilborne Ralstonia solanacearum species complex (RSSC), specifically to address the bacterial population genetics on the field scale. Such a MLVA scheme, based on fast-evolving loci, may be a tool of choice for field experimental evolution and spatial genetics studies. PMID:28003195

A Tree Based Broadcast Scheme for (m, k)-firm Real-Time Stream in Wireless Sensor Networks.

PubMed

Park, HoSung; Kim, Beom-Su; Kim, Kyong Hoon; Shah, Babar; Kim, Ki-Il

2017-11-09

Recently, various unicast routing protocols have been proposed to deliver measured data from the sensor node to the sink node within the predetermined deadline in wireless sensor networks. In parallel with their approaches, some applications demand the specific service, which is based on broadcast to all nodes within the deadline, the feasible real-time traffic model and improvements in energy efficiency. However, current protocols based on either flooding or one-to-one unicast cannot meet the above requirements entirely. Moreover, as far as the authors know, there is no study for the real-time broadcast protocol to support the application-specific traffic model in WSN yet. Based on the above analysis, in this paper, we propose a new ( m , k )-firm-based Real-time Broadcast Protocol (FRBP) by constructing a broadcast tree to satisfy the ( m , k )-firm, which is applicable to the real-time model in resource-constrained WSNs. The broadcast tree in FRBP is constructed by the distance-based priority scheme, whereas energy efficiency is improved by selecting as few as nodes on a tree possible. To overcome the unstable network environment, the recovery scheme invokes rapid partial tree reconstruction in order to designate another node as the parent on a tree according to the measured ( m , k )-firm real-time condition and local states monitoring. Finally, simulation results are given to demonstrate the superiority of FRBP compared to the existing schemes in terms of average deadline missing ratio, average throughput and energy consumption.

Development of a Blood Pressure Measurement Instrument with Active Cuff Pressure Control Schemes.

PubMed

Kuo, Chung-Hsien; Wu, Chun-Ju; Chou, Hung-Chyun; Chen, Guan-Ting; Kuo, Yu-Cheng

2017-01-01

This paper presents an oscillometric blood pressure (BP) measurement approach based on the active control schemes of cuff pressure. Compared with conventional electronic BP instruments, the novelty of the proposed BP measurement approach is to utilize a variable volume chamber which actively and stably alters the cuff pressure during inflating or deflating cycles. The variable volume chamber is operated with a closed-loop pressure control scheme, and it is activated by controlling the piston position of a single-acting cylinder driven by a screw motor. Therefore, the variable volume chamber could significantly eliminate the air turbulence disturbance during the air injection stage when compared to an air pump mechanism. Furthermore, the proposed active BP measurement approach is capable of measuring BP characteristics, including systolic blood pressure (SBP) and diastolic blood pressure (DBP), during the inflating cycle. Two modes of air injection measurement (AIM) and accurate dual-way measurement (ADM) were proposed. According to the healthy subject experiment results, AIM reduced 34.21% and ADM reduced 15.78% of the measurement time when compared to a commercial BP monitor. Furthermore, the ADM performed much consistently (i.e., less standard deviation) in the measurements when compared to a commercial BP monitor.

Towards a sampling strategy for the assessment of forest condition at European level: combining country estimates.

PubMed

Travaglini, Davide; Fattorini, Lorenzo; Barbati, Anna; Bottalico, Francesca; Corona, Piermaria; Ferretti, Marco; Chirici, Gherardo

2013-04-01

A correct characterization of the status and trend of forest condition is essential to support reporting processes at national and international level. An international forest condition monitoring has been implemented in Europe since 1987 under the auspices of the International Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests). The monitoring is based on harmonized methodologies, with individual countries being responsible for its implementation. Due to inconsistencies and problems in sampling design, however, the ICP Forests network is not able to produce reliable quantitative estimates of forest condition at European and sometimes at country level. This paper proposes (1) a set of requirements for status and change assessment and (2) a harmonized sampling strategy able to provide unbiased and consistent estimators of forest condition parameters and of their changes at both country and European level. Under the assumption that a common definition of forest holds among European countries, monitoring objectives, parameters of concern and accuracy indexes are stated. On the basis of fixed-area plot sampling performed independently in each country, an unbiased and consistent estimator of forest defoliation indexes is obtained at both country and European level, together with conservative estimators of their sampling variance and power in the detection of changes. The strategy adopts a probabilistic sampling scheme based on fixed-area plots selected by means of systematic or stratified schemes. Operative guidelines for its application are provided.

A cost-effective, community-based, mosquito-trapping scheme that captures spatial and temporal heterogeneities of malaria transmission in rural Zambia

PubMed Central

2014-01-01

Background Monitoring mosquito population dynamics is essential to guide selection and evaluation of malaria vector control interventions but is typically implemented by mobile, centrally-managed teams who can only visit a limited number of locations frequently enough to capture longitudinal trends. Community-based (CB) mosquito trapping schemes for parallel, continuous monitoring of multiple locations are therefore required that are practical, affordable, effective, and reliable. Methods A CB surveillance scheme, with a monthly sampling and reporting cycle for capturing malaria vectors, using Centers for Disease Control and Prevention light traps (LT) and Ifakara Tent Traps (ITT), were conducted by trained community health workers (CHW) in 14 clusters of households immediately surrounding health facilities in rural south-east Zambia. At the end of the study, a controlled quality assurance (QA) survey was conducted by a centrally supervised expert team using human landing catch (HLC), LT and ITT to evaluate accuracy of the CB trapping data. Active surveillance of malaria parasite infection rates amongst humans was conducted by CHWs in the same clusters to determine the epidemiological relevance of these CB entomological surveys. Results CB-LT and CB-ITT exhibited relative sampling efficiencies of 50 and 7%, respectively, compared with QA surveys using the same traps. However, cost per sampling night was lowest for CB-LT ($13.6), followed closely by CB-ITT ($18.0), both of which were far less expensive than any QA survey (HLC: $138, LT: $289, ITT: $269). Cost per specimen of Anopheles funestus captured was lowest for CB-LT ($5.3), followed by potentially hazardous QA-HLC ($10.5) and then CB-ITT ($28.0), all of which were far more cost-effective than QA-LT ($141) and QA-ITT ($168). Time-trends of malaria diagnostic positivity (DP) followed those of An. funestus density with a one-month lag and the wide range of mean DP across clusters was closely associated with mean densities of An. funestus caught by CB-LT (P < 0.001). Conclusions CB trapping schemes appear to be far more affordable, epidemiologically relevant and cost-effective than centrally supervised trapping schemes and may well be applicable to enhance intervention trials and even enable routine programmatic monitoring of vector population dynamics on unprecedented national scales. PMID:24906704

An Orbit And Dispersion Correction Scheme for the PEP II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cai, Y.; Donald, M.; Shoaee, H.

2011-09-01

To achieve optimum luminosity in a storage ring it is vital to control the residual vertical dispersion. In the original PEP storage ring, a scheme to control the residual dispersion function was implemented using the ring orbit as the controlling element. The 'best' orbit not necessarily giving the lowest vertical dispersion. A similar scheme has been implemented in both the on-line control code and in the simulation code LEGO. The method involves finding the response matrices (sensitivity of orbit/dispersion at each Beam-Position-Monitor (BPM) to each orbit corrector) and solving in a least squares sense for minimum orbit, dispersion function ormore » both. The optimum solution is usually a subset of the full least squares solution. A scheme of simultaneously correcting the orbits and dispersion has been implemented in the simulation code and on-line control system for PEP-II. The scheme is based on the eigenvector decomposition method. An important ingredient of the scheme is to choose the optimum eigenvectors that minimize the orbit, dispersion and corrector strength. Simulations indicate this to be a very effective way to control the vertical residual dispersion.« less

Smart sensor technology for advanced launch vehicles

NASA Astrophysics Data System (ADS)

Schoess, Jeff

1989-07-01

Next-generation advanced launch vehicles will require improved use of sensor data and the management of multisensor resources to achieve automated preflight checkout, prelaunch readiness assessment and vehicle inflight condition monitoring. Smart sensor technology is a key component in meeting these needs. This paper describes the development of a smart sensor-based condition monitoring system concept referred to as the Distributed Sensor Architecture. A significant event and anomaly detection scheme that provides real-time condition assessment and fault diagnosis of advanced launch system rocket engines is described. The design and flight test of a smart autonomous sensor for Space Shuttle structural integrity health monitoring is presented.

Global biodiversity monitoring: from data sources to essential biodiversity variables

USGS Publications Warehouse

Proenca, Vania; Martin, Laura J.; Pereira, Henrique M.; Fernandez, Miguel; McRae, Louise; Belnap, Jayne; Böhm, Monika; Brummitt, Neil; Garcia-Moreno, Jaime; Gregory, Richard D.; Honrado, Joao P; Jürgens, Norbert; Opige, Michael; Schmeller, Dirk S.; Tiago, Patricia; van Sway, Chris A

2016-01-01

Essential Biodiversity Variables (EBVs) consolidate information from varied biodiversity observation sources. Here we demonstrate the links between data sources, EBVs and indicators and discuss how different sources of biodiversity observations can be harnessed to inform EBVs. We classify sources of primary observations into four types: extensive and intensive monitoring schemes, ecological field studies and satellite remote sensing. We characterize their geographic, taxonomic and temporal coverage. Ecological field studies and intensive monitoring schemes inform a wide range of EBVs, but the former tend to deliver short-term data, while the geographic coverage of the latter is limited. In contrast, extensive monitoring schemes mostly inform the population abundance EBV, but deliver long-term data across an extensive network of sites. Satellite remote sensing is particularly suited to providing information on ecosystem function and structure EBVs. Biases behind data sources may affect the representativeness of global biodiversity datasets. To improve them, researchers must assess data sources and then develop strategies to compensate for identified gaps. We draw on the population abundance dataset informing the Living Planet Index (LPI) to illustrate the effects of data sources on EBV representativeness. We find that long-term monitoring schemes informing the LPI are still scarce outside of Europe and North America and that ecological field studies play a key role in covering that gap. Achieving representative EBV datasets will depend both on the ability to integrate available data, through data harmonization and modeling efforts, and on the establishment of new monitoring programs to address critical data gaps.

Power of sign surveys to monitor population trend

USGS Publications Warehouse

Kendall, Katherine C.; Metzgar, Lee H.; Patterson, David A.; Steele, Brian M.

1992-01-01

The urgent need for an effective monitoring scheme for grizzly bear (Ursus arctos) populations led us to investigate the effort required to detect changes in populations of low—density dispersed animals, using sign (mainly scats and tracks) they leave on trails. We surveyed trails in Glacier National Park for bear tracks and scats during five consecutive years. Using these data, we modeled the occurrence of bear sign on trails, then estimated the power of various sampling schemes. Specifically, we explored the power of bear sign surveys to detect a 20% decline in sign occurrence. Realistic sampling schemes appear feasible if the density of sign is high enough, and we provide guidelines for designs with adequate replication to monitor long—term trends of dispersed populations using sign occurrences on trails.

Adaptive backstepping sliding mode control with fuzzy monitoring strategy for a kind of mechanical system.

PubMed

Song, Zhankui; Sun, Kaibiao

2014-01-01

A novel adaptive backstepping sliding mode control (ABSMC) law with fuzzy monitoring strategy is proposed for the tracking-control of a kind of nonlinear mechanical system. The proposed ABSMC scheme combining the sliding mode control and backstepping technique ensure that the occurrence of the sliding motion in finite-time and the trajectory of tracking-error converge to equilibrium point. To obtain a better perturbation rejection property, an adaptive control law is employed to compensate the lumped perturbation. Furthermore, we introduce fuzzy monitoring strategy to improve adaptive capacity and soften the control signal. The convergence and stability of the proposed control scheme are proved by using Lyaponov's method. Finally, numerical simulations demonstrate the effectiveness of the proposed control scheme. © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

Missing texture reconstruction method based on error reduction algorithm using Fourier transform magnitude estimation scheme.

PubMed

Ogawa, Takahiro; Haseyama, Miki

2013-03-01

A missing texture reconstruction method based on an error reduction (ER) algorithm, including a novel estimation scheme of Fourier transform magnitudes is presented in this brief. In our method, Fourier transform magnitude is estimated for a target patch including missing areas, and the missing intensities are estimated by retrieving its phase based on the ER algorithm. Specifically, by monitoring errors converged in the ER algorithm, known patches whose Fourier transform magnitudes are similar to that of the target patch are selected from the target image. In the second approach, the Fourier transform magnitude of the target patch is estimated from those of the selected known patches and their corresponding errors. Consequently, by using the ER algorithm, we can estimate both the Fourier transform magnitudes and phases to reconstruct the missing areas.

Low-cost and high-resolution interrogation scheme for LPG-based temperature sensor

NASA Astrophysics Data System (ADS)

Venkata Reddy, M.; Srimannarayana, K.; Venkatappa Rao, T.; Vengal Rao, P.

2015-09-01

A low-cost and high-resolution interrogation scheme for a long-period fiber grating (LPG) temperature sensor with adjustable temperature range has been designed, developed and tested. In general LPGs are widely used as optical sensors and can be used as optical edge filters to interrogate the wavelength encoded signal from sensors such as fiber Bragg grating (FBG) by converting it into intensity modulated signal. But the interrogation of LPG sensors using FBG is a bit novel and it is to be studied experimentally. The sensor works based on measurement of shift in attenuation band of LPG corresponding to the applied temperature. The wavelength shift of LPG attenuation band is monitored using an optical spectrum analyser (OSA). Further the bulk and expensive OSA is replaced with a low-cost interrogation system that employ an FBG, photodiode and a transimpedance amplifier (TIA). The designed interrogation scheme makes the system low-cost, fast in response, and also enhances its resolution up to 0.1°C. The measurable temperature range using the proposed scheme is limited to 120 °C. However this range can be shifted within 15-450 °C by means of adjusting the Bragg wavelength of FBG.

An Efficient Wireless Sensor Network for Industrial Monitoring and Control.

PubMed

Aponte-Luis, Juan; Gómez-Galán, Juan Antonio; Gómez-Bravo, Fernando; Sánchez-Raya, Manuel; Alcina-Espigado, Javier; Teixido-Rovira, Pedro Miguel

2018-01-10

This paper presents the design of a wireless sensor network particularly designed for remote monitoring and control of industrial parameters. The article describes the network components, protocol and sensor deployment, aimed to accomplish industrial constraint and to assure reliability and low power consumption. A particular case of study is presented. The system consists of a base station, gas sensing nodes, a tree-based routing scheme for the wireless sensor nodes and a real-time monitoring application that operates from a remote computer and a mobile phone. The system assures that the industrial safety quality and the measurement and monitoring system achieves an efficient industrial monitoring operations. The robustness of the developed system and the security in the communications have been guaranteed both in hardware and software level. The system is flexible and can be adapted to different environments. The testing of the system confirms the feasibility of the proposed implementation and validates the functional requirements of the developed devices, the networking solution and the power consumption management.

An Efficient Wireless Sensor Network for Industrial Monitoring and Control

PubMed Central

Aponte-Luis, Juan; Gómez-Bravo, Fernando; Sánchez-Raya, Manuel; Alcina-Espigado, Javier; Teixido-Rovira, Pedro Miguel

2018-01-01

This paper presents the design of a wireless sensor network particularly designed for remote monitoring and control of industrial parameters. The article describes the network components, protocol and sensor deployment, aimed to accomplish industrial constraint and to assure reliability and low power consumption. A particular case of study is presented. The system consists of a base station, gas sensing nodes, a tree-based routing scheme for the wireless sensor nodes and a real-time monitoring application that operates from a remote computer and a mobile phone. The system assures that the industrial safety quality and the measurement and monitoring system achieves an efficient industrial monitoring operations. The robustness of the developed system and the security in the communications have been guaranteed both in hardware and software level. The system is flexible and can be adapted to different environments. The testing of the system confirms the feasibility of the proposed implementation and validates the functional requirements of the developed devices, the networking solution and the power consumption management. PMID:29320466

An adaptive morphological gradient lifting wavelet for detecting bearing defects

NASA Astrophysics Data System (ADS)

Li, Bing; Zhang, Pei-lin; Mi, Shuang-shan; Hu, Ren-xi; Liu, Dong-sheng

2012-05-01

This paper presents a novel wavelet decomposition scheme, named adaptive morphological gradient lifting wavelet (AMGLW), for detecting bearing defects. The adaptability of the AMGLW consists in that the scheme can select between two filters, mean the average filter and morphological gradient filter, to update the approximation signal based on the local gradient of the analyzed signal. Both a simulated signal and vibration signals acquired from bearing are employed to evaluate and compare the proposed AMGLW scheme with the traditional linear wavelet transform (LWT) and another adaptive lifting wavelet (ALW) developed in literature. Experimental results reveal that the AMGLW outperforms the LW and ALW obviously for detecting bearing defects. The impulsive components can be enhanced and the noise can be depressed simultaneously by the presented AMGLW scheme. Thus the fault characteristic frequencies of bearing can be clearly identified. Furthermore, the AMGLW gets an advantage over LW in computation efficiency. It is quite suitable for online condition monitoring of bearings and other rotating machineries.

[The use of telemedicine in dialysis and new professional practices].

PubMed

Grangier, Jean-Pierre

2016-11-01

Since 2006, a remote patient monitoring scheme using digital pens has enabled patients with chronic kidney disease to be monitored remotely in their own home. The implementation of this project was accompanied by a technical and economic study. Today, this scheme has evolved to integrate therapeutic patient education programmes and their evaluation. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Monitoring of Ritz modal generation

NASA Technical Reports Server (NTRS)

Chargin, Mladen; Butler, Thomas G.

1990-01-01

A scheme is proposed to monitor the adequacy of a set of Ritz modes to represent a solution by comparing the quantity generated with certain properties involving the forcing function. In so doing an attempt was made to keep this algorithm lean and efficient, so that it will be economical to apply. Using this monitoring scheme during Ritz Mode generation will automatically ensure that the k Ritz modes theta k that are generated are adequate to represent both the spatial and temporal behavior of the structure when forced under the given transient condition defined by F(s,t).

A phase angle based diagnostic scheme to planetary gear faults diagnostics under non-stationary operational conditions

NASA Astrophysics Data System (ADS)

Feng, Ke; Wang, Kesheng; Ni, Qing; Zuo, Ming J.; Wei, Dongdong

2017-11-01

Planetary gearbox is a critical component for rotating machinery. It is widely used in wind turbines, aerospace and transmission systems in heavy industry. Thus, it is important to monitor planetary gearboxes, especially for fault diagnostics, during its operational conditions. However, in practice, operational conditions of planetary gearbox are often characterized by variations of rotational speeds and loads, which may bring difficulties for fault diagnosis through the measured vibrations. In this paper, phase angle data extracted from measured planetary gearbox vibrations is used for fault detection under non-stationary operational conditions. Together with sample entropy, fault diagnosis on planetary gearbox is implemented. The proposed scheme is explained and demonstrated in both simulation and experimental studies. The scheme proves to be effective and features advantages on fault diagnosis of planetary gearboxes under non-stationary operational conditions.

Fiber-Optic Distribution Of Pulsed Power To Multiple Sensors

NASA Technical Reports Server (NTRS)

Kirkham, Harold

1996-01-01

Optoelectronic systems designed according to time-sharing scheme distribute optical power to multiple integrated-circuit-based sensors in fiber-optic networks. Networks combine flexibility of electronic sensing circuits with advantage of electrical isolation afforded by use of optical fibers instead of electrical conductors to transmit both signals and power. Fiber optics resist corrosion and immune to electromagnetic interference. Sensor networks of this type useful in variety of applications; for example, in monitoring strains in aircraft, buildings, and bridges, and in monitoring and controlling shapes of flexible structures.

Modified Beer-Lambert law for blood flow.

PubMed

Baker, Wesley B; Parthasarathy, Ashwin B; Busch, David R; Mesquita, Rickson C; Greenberg, Joel H; Yodh, A G

2014-11-01

We develop and validate a Modified Beer-Lambert law for blood flow based on diffuse correlation spectroscopy (DCS) measurements. The new formulation enables blood flow monitoring from temporal intensity autocorrelation function data taken at single or multiple delay-times. Consequentially, the speed of the optical blood flow measurement can be substantially increased. The scheme facilitates blood flow monitoring of highly scattering tissues in geometries wherein light propagation is diffusive or non-diffusive, and it is particularly well-suited for utilization with pressure measurement paradigms that employ differential flow signals to reduce contributions of superficial tissues.

Mapping Mangrove Density from Rapideye Data in Central America

NASA Astrophysics Data System (ADS)

Son, Nguyen-Thanh; Chen, Chi-Farn; Chen, Cheng-Ru

2017-06-01

Mangrove forests provide a wide range of socioeconomic and ecological services for coastal communities. Extensive aquaculture development of mangrove waters in many developing countries has constantly ignored services of mangrove ecosystems, leading to unintended environmental consequences. Monitoring the current status and distribution of mangrove forests is deemed important for evaluating forest management strategies. This study aims to delineate the density distribution of mangrove forests in the Gulf of Fonseca, Central America with Rapideye data using the support vector machines (SVM). The data collected in 2012 for density classification of mangrove forests were processed based on four different band combination schemes: scheme-1 (bands 1-3, 5 excluding the red-edge band 4), scheme-2 (bands 1-5), scheme-3 (bands 1-3, 5 incorporating with the normalized difference vegetation index, NDVI), and scheme-4 (bands 1-3, 5 incorporating with the normalized difference red-edge index, NDRI). We also hypothesized if the obvious contribution of Rapideye red-edge band could improve the classification results. Three main steps of data processing were employed: (1), data pre-processing, (2) image classification, and (3) accuracy assessment to evaluate the contribution of red-edge band in terms of the accuracy of classification results across these four schemes. The classification maps compared with the ground reference data indicated the slightly higher accuracy level observed for schemes 2 and 4. The overall accuracies and Kappa coefficients were 97% and 0.95 for scheme-2 and 96.9% and 0.95 for scheme-4, respectively.

System-wide hybrid MPC-PID control of a continuous pharmaceutical tablet manufacturing process via direct compaction.

PubMed

Singh, Ravendra; Ierapetritou, Marianthi; Ramachandran, Rohit

2013-11-01

The next generation of QbD based pharmaceutical products will be manufactured through continuous processing. This will allow the integration of online/inline monitoring tools, coupled with an efficient advanced model-based feedback control systems, to achieve precise control of process variables, so that the predefined product quality can be achieved consistently. The direct compaction process considered in this study is highly interactive and involves time delays for a number of process variables due to sensor placements, process equipment dimensions, and the flow characteristics of the solid material. A simple feedback regulatory control system (e.g., PI(D)) by itself may not be sufficient to achieve the tight process control that is mandated by regulatory authorities. The process presented herein comprises of coupled dynamics involving slow and fast responses, indicating the requirement of a hybrid control scheme such as a combined MPC-PID control scheme. In this manuscript, an efficient system-wide hybrid control strategy for an integrated continuous pharmaceutical tablet manufacturing process via direct compaction has been designed. The designed control system is a hybrid scheme of MPC-PID control. An effective controller parameter tuning strategy involving an ITAE method coupled with an optimization strategy has been used for tuning of both MPC and PID parameters. The designed hybrid control system has been implemented in a first-principles model-based flowsheet that was simulated in gPROMS (Process System Enterprise). Results demonstrate enhanced performance of critical quality attributes (CQAs) under the hybrid control scheme compared to only PID or MPC control schemes, illustrating the potential of a hybrid control scheme in improving pharmaceutical manufacturing operations. Copyright © 2013 Elsevier B.V. All rights reserved.

Blood pulse wave velocity and pressure sensing via fiber based and free space based optical sensors

NASA Astrophysics Data System (ADS)

Sirkis, Talia; Beiderman, Yevgeny; Agdarov, Sergey; Beiderman, Yafim; Zalevsky, Zeev

2017-02-01

Continuous noninvasive measurement of vital bio-signs, such as cardiopulmonary parameters, is an important tool in evaluation of the patient's physiological condition and health monitoring. On the demand of new enabling technologies, some works have been done in continuous monitoring of blood pressure and pulse wave velocity. In this paper, we introduce two techniques for non-contact sensing of vital bio signs. In the first approach the optical sensor is based on single mode in-fibers Mach-Zehnder interferometer (MZI) to detect heartbeat, respiration and pulse wave velocity (PWV). The introduced interferometer is based on a new implanted scheme. It replaces the conventional MZI realized by inserting of discontinuities in the fiber to break the total internal reflection and scatter/collect light. The proposed fiber sensor was successfully incorporated into shirt to produce smart clothing. The measurements obtained from the smart clothing could be obtained in comfortable manner and there is no need to have an initial calibration or a direct contact between the sensor and the skin of the tested individual. In the second concept we show a remote noncontact blood pulse wave velocity and pressure measurement based on tracking the temporal changes of reflected secondary speckle patterns produced in human skin when illuminated by a laser beams. In both concept experimental validation of the proposed schemes is shown and analyzed.

The Blood Stocks Management Scheme, a partnership venture between the National Blood Service of England and North Wales and participating hospitals for maximizing blood supply chain management.

PubMed

Chapman, J F; Cook, R

2002-10-01

The Blood Stocks Management Scheme (BSMS) has been established as a joint venture between the National Blood Service (NBS) in England and North Wales and participating hospitals to monitor the blood supply chain. Stock and wastage data are submitted to a web-based data-management system, facilitating continuous and complete red cell data collection and 'real time' data extraction. The data-management system enables peer review of performance in respect of stock holding levels and red cell wastage. The BSMS has developed an innovative web-based data-management system that enables data collection and benchmarking of practice, which should drive changes in stock management practice, therefore optimizing the use of donated blood.

Noncontacting acoustics-based temperature measurement techniques in rapid thermal processing

NASA Astrophysics Data System (ADS)

Lee, Yong J.; Chou, Ching-Hua; Khuri-Yakub, Butrus T.; Saraswat, Krishna C.

1991-04-01

Temperature measurement of silicon wafers based on the temperature dependence of acoustic waves is studied. The change in the temperature-dependent dispersion relations of the plate modes through the wafer can be exploited to provide a viable temperature monitoring scheme with advantages over both thermocouples and pyrometers. Velocity measurements of acoustic waves through a thin layer of ambient directly above the wafer provides the temperature of the wafer-ambient interface. 1.

Sampling procedures for throughfall monitoring: A simulation study

NASA Astrophysics Data System (ADS)

Zimmermann, Beate; Zimmermann, Alexander; Lark, Richard Murray; Elsenbeer, Helmut

2010-01-01

What is the most appropriate sampling scheme to estimate event-based average throughfall? A satisfactory answer to this seemingly simple question has yet to be found, a failure which we attribute to previous efforts' dependence on empirical studies. Here we try to answer this question by simulating stochastic throughfall fields based on parameters for statistical models of large monitoring data sets. We subsequently sampled these fields with different sampling designs and variable sample supports. We evaluated the performance of a particular sampling scheme with respect to the uncertainty of possible estimated means of throughfall volumes. Even for a relative error limit of 20%, an impractically large number of small, funnel-type collectors would be required to estimate mean throughfall, particularly for small events. While stratification of the target area is not superior to simple random sampling, cluster random sampling involves the risk of being less efficient. A larger sample support, e.g., the use of trough-type collectors, considerably reduces the necessary sample sizes and eliminates the sensitivity of the mean to outliers. Since the gain in time associated with the manual handling of troughs versus funnels depends on the local precipitation regime, the employment of automatically recording clusters of long troughs emerges as the most promising sampling scheme. Even so, a relative error of less than 5% appears out of reach for throughfall under heterogeneous canopies. We therefore suspect a considerable uncertainty of input parameters for interception models derived from measured throughfall, in particular, for those requiring data of small throughfall events.

Self-Monitoring Symptoms in Glaucoma: A Feasibility Study of a Web-Based Diary Tool

PubMed Central

McDonald, Leanne; Glen, Fiona C.; Taylor, Deanna J.

2017-01-01

Purpose. Glaucoma patients annually spend only a few hours in an eye clinic but spend more than 5000 waking hours engaged in everything else. We propose that patients could self-monitor changes in visual symptoms providing valuable between clinic information; we test the hypothesis that this is feasible using a web-based diary tool. Methods. Ten glaucoma patients with a range of visual field loss took part in an eight-week pilot study. After completing a series of baseline tests, volunteers were prompted to monitor symptoms every three days and complete a diary about their vision during daily life using a bespoke web-based diary tool. Response to an end of a study questionnaire about the usefulness of the exercise was a main outcome measure. Results. Eight of the 10 patients rated the monitoring scheme to be “valuable” or “very valuable.” Completion rate to items was excellent (96%). Themes from a qualitative synthesis of the diary entries related to behavioural aspects of glaucoma. One patient concluded that a constant focus on monitoring symptoms led to negative feelings. Conclusions. A web-based diary tool for monitoring self-reported glaucoma symptoms is practically feasible. The tool must be carefully designed to ensure participants are benefitting, and it is not increasing anxiety. PMID:28546876

Feasibility of vibration monitoring of small rotating machines for the environmental control and life support systems (ECLSS) of the NASA advanced space craft

NASA Technical Reports Server (NTRS)

Milner, G. Martin; Black, Mike; Hovenga, Mike; Mcclure, Paul; Miller, Patrice

1988-01-01

The application of vibration monitoring to the rotating machinery typical of ECLSS components in advanced NASA spacecraft was studied. It is found that the weighted summation of the accelerometer power spectrum is the most successful detection scheme for a majority of problem types. Other detection schemes studied included high-frequency demodulation, cepstrum, clustering, and amplitude processing.

An Internet of Things based physiological signal monitoring and receiving system for virtual enhanced health care network.

PubMed

Rajan, J Pandia; Rajan, S Edward

2018-01-01

Wireless physiological signal monitoring system designing with secured data communication in the health care system is an important and dynamic process. We propose a signal monitoring system using NI myRIO connected with the wireless body sensor network through multi-channel signal acquisition method. Based on the server side validation of the signal, the data connected to the local server is updated in the cloud. The Internet of Things (IoT) architecture is used to get the mobility and fast access of patient data to healthcare service providers. This research work proposes a novel architecture for wireless physiological signal monitoring system using ubiquitous healthcare services by virtual Internet of Things. We showed an improvement in method of access and real time dynamic monitoring of physiological signal of this remote monitoring system using virtual Internet of thing approach. This remote monitoring and access system is evaluated in conventional value. This proposed system is envisioned to modern smart health care system by high utility and user friendly in clinical applications. We claim that the proposed scheme significantly improves the accuracy of the remote monitoring system compared to the other wireless communication methods in clinical system.

A Tree Based Broadcast Scheme for (m, k)-firm Real-Time Stream in Wireless Sensor Networks

PubMed Central

Park, HoSung; Kim, Beom-Su; Kim, Kyong Hoon; Shah, Babar; Kim, Ki-Il

2017-01-01

Recently, various unicast routing protocols have been proposed to deliver measured data from the sensor node to the sink node within the predetermined deadline in wireless sensor networks. In parallel with their approaches, some applications demand the specific service, which is based on broadcast to all nodes within the deadline, the feasible real-time traffic model and improvements in energy efficiency. However, current protocols based on either flooding or one-to-one unicast cannot meet the above requirements entirely. Moreover, as far as the authors know, there is no study for the real-time broadcast protocol to support the application-specific traffic model in WSN yet. Based on the above analysis, in this paper, we propose a new (m, k)-firm-based Real-time Broadcast Protocol (FRBP) by constructing a broadcast tree to satisfy the (m, k)-firm, which is applicable to the real-time model in resource-constrained WSNs. The broadcast tree in FRBP is constructed by the distance-based priority scheme, whereas energy efficiency is improved by selecting as few as nodes on a tree possible. To overcome the unstable network environment, the recovery scheme invokes rapid partial tree reconstruction in order to designate another node as the parent on a tree according to the measured (m, k)-firm real-time condition and local states monitoring. Finally, simulation results are given to demonstrate the superiority of FRBP compared to the existing schemes in terms of average deadline missing ratio, average throughput and energy consumption. PMID:29120404

Fisheye camera around view monitoring system

NASA Astrophysics Data System (ADS)

Feng, Cong; Ma, Xinjun; Li, Yuanyuan; Wu, Chenchen

2018-04-01

360 degree around view monitoring system is the key technology of the advanced driver assistance system, which is used to assist the driver to clear the blind area, and has high application value. In this paper, we study the transformation relationship between multi coordinate system to generate panoramic image in the unified car coordinate system. Firstly, the panoramic image is divided into four regions. By using the parameters obtained by calibration, four fisheye images pixel corresponding to the four sub regions are mapped to the constructed panoramic image. On the basis of 2D around view monitoring system, 3D version is realized by reconstructing the projection surface. Then, we compare 2D around view scheme and 3D around view scheme in unified coordinate system, 3D around view scheme solves the shortcomings of the traditional 2D scheme, such as small visual field, prominent ground object deformation and so on. Finally, the image collected by a fisheye camera installed around the car body can be spliced into a 360 degree panoramic image. So it has very high application value.

Energy harvesting schemes for building interior environment monitoring

NASA Astrophysics Data System (ADS)

Zylka, Pawel; Pociecha, Dominik

2016-11-01

A vision to supply microelectronic devices without batteries making them perpetual or extending time of service in battery-oriented mobile supply schemes is the driving force of the research related to ambient energy harvesting. Energy harnessing aims thus at extracting energy from various ambient energy "pools", which generally are cost- or powerineffective to be scaled up for full-size, power-plant energy generation schemes supplying energy in electric form. These include - but are not limited to - waste heat, electromagnetic hum, vibrations, or human-generated power in addition to traditional renewable energy resources like water flow, tidal and wind energy or sun radiation which can also be exploited at the miniature scale by energy scavengers. However, in case of taking advantage of energy harvesting strategies to power up sensors monitoring environment inside buildings adaptable energy sources are restrained to only some which additionally are limited in spatial and temporal accessibility as well as available power. The paper explores experimentally an energy harvesting scheme exploiting human kinesis applicable in indoor environment for supplying a wireless indoor micro-system, monitoring ambient air properties (pressure, humidity and temperature).

A Mutual Authentication Framework for Wireless Medical Sensor Networks.

PubMed

Srinivas, Jangirala; Mishra, Dheerendra; Mukhopadhyay, Sourav

2017-05-01

Wireless medical sensor networks (WMSN) comprise of distributed sensors, which can sense human physiological signs and monitor the health condition of the patient. It is observed that providing privacy to the patient's data is an important issue and can be challenging. The information passing is done via the public channel in WMSN. Thus, the patient, sensitive information can be obtained by eavesdropping or by unauthorized use of handheld devices which the health professionals use in monitoring the patient. Therefore, there is an essential need of restricting the unauthorized access to the patient's medical information. Hence, the efficient authentication scheme for the healthcare applications is needed to preserve the privacy of the patients' vital signs. To ensure secure and authorized communication in WMSN, we design a symmetric key based authentication protocol for WMSN environment. The proposed protocol uses only computationally efficient operations to achieve lightweight attribute. We analyze the security of the proposed protocol. We use a formal security proof algorithm to show the scheme security against known attacks. We also use the Automated Validation of Internet Security Protocols and Applications (AVISPA) simulator to show protocol secure against man-in-the-middle attack and replay attack. Additionally, we adopt an informal analysis to discuss the key attributes of the proposed scheme. From the formal proof of security, we can see that an attacker has a negligible probability of breaking the protocol security. AVISPA simulator also demonstrates the proposed scheme security against active attacks, namely, man-in-the-middle attack and replay attack. Additionally, through the comparison of computational efficiency and security attributes with several recent results, proposed scheme seems to be battered.

Comparison of medicines management strategies in insurance schemes in middle-income countries: four case studies.

PubMed

Kaplan, Warren A; Ashigbie, Paul G; Brooks, Mohamad I; Wirtz, Veronika J

2017-01-01

Many middle-income countries are scaling up health insurance schemes to provide financial protection and access to affordable medicines to poor and uninsured populations. Although there is a wealth of evidence on how high income countries with mature insurance schemes manage cost-effective use of medicines, there is limited evidence on the strategies used in middle-income countries. This paper compares the medicines management strategies that four insurance schemes in middle-income countries use to improve access and cost-effective use of medicines among beneficiaries. We compare key strategies promoting cost-effective medicines use in the New Rural Cooperative Medical Scheme (NCMS) in China, National Health Insurance Scheme in Ghana, Jamkesmas in Indonesia and Seguro Popular in Mexico. Through the peer-reviewed and grey literature as of late 2013, we identified strategies that met our inclusion criteria as well as any evidence showing if, and/or how, these strategies affected medicines management. Stakeholders involved and affected by medicines coverage policies in these insurance schemes were asked to provide relevant documents describing the medicines related aspects of these insurance programs. We also asked them specifically to identify publications discussing the unintended consequences of the strategies implemented. Use of formularies, bulk procurement, standard treatment guidelines and separation of prescribing and dispensing were present in all four schemes. Also, increased transparency through publication of tender agreements and procurement prices was introduced in all four. Common strategies shared by three out of four schemes were medicine price negotiation or rebates, generic reference pricing, fixed salaries for prescribers, accredited preferred provider network, disease management programs, and monitoring of medicines purchases. Cost-sharing and payment for performance was rarely used. There was a lack of performance monitoring strategies in all schemes. Most of the strategies used in the insurance schemes focus on containing expenditure growth, including budget caps on pharmaceutical expenditures (Mexico) and ceiling prices on medicines (all four countries). There were few strategies targeting quality improvement as healthcare providers are mostly paid through fixed salaries, irrespective of the quality of their prescribing or the health outcomes actually achieved. Monitoring healthcare system performance has received little attention.

Visual Privacy by Context: Proposal and Evaluation of a Level-Based Visualisation Scheme

PubMed Central

Padilla-López, José Ramón; Chaaraoui, Alexandros Andre; Gu, Feng; Flórez-Revuelta, Francisco

2015-01-01

Privacy in image and video data has become an important subject since cameras are being installed in an increasing number of public and private spaces. Specifically, in assisted living, intelligent monitoring based on computer vision can allow one to provide risk detection and support services that increase people's autonomy at home. In the present work, a level-based visualisation scheme is proposed to provide visual privacy when human intervention is necessary, such as at telerehabilitation and safety assessment applications. Visualisation levels are dynamically selected based on the previously modelled context. In this way, different levels of protection can be provided, maintaining the necessary intelligibility required for the applications. Furthermore, a case study of a living room, where a top-view camera is installed, is presented. Finally, the performed survey-based evaluation indicates the degree of protection provided by the different visualisation models, as well as the personal privacy preferences and valuations of the users. PMID:26053746

Using Ada to implement the operations management system in a community of experts

NASA Technical Reports Server (NTRS)

Frank, M. S.

1986-01-01

An architecture is described for the Space Station Operations Management System (OMS), consisting of a distributed expert system framework implemented in Ada. The motivation for such a scheme is based on the desire to integrate the very diverse elements of the OMS while taking maximum advantage of knowledge based systems technology. Part of the foundation of an Ada based distributed expert system was accomplished in the form of a proof of concept prototype for the KNOMES project (Knowledge-based Maintenance Expert System). This prototype successfully used concurrently active experts to accomplish monitoring and diagnosis for the Remote Manipulator System. The basic concept of this software architecture is named ACTORS for Ada Cognitive Task ORganization Scheme. It is when one considers the overall problem of integrating all of the OMS elements into a cooperative system that the AI solution stands out. By utilizing a distributed knowledge based system as the framework for OMS, it is possible to integrate those components which need to share information in an intelligent manner.

Establishing sustainable performance-based incentive schemes: views of rural health workers from qualitative research in three sub-Saharan African countries.

PubMed

Yé, M; Aninanya, G A; Sié, A; Kakoko, D C V; Chatio, S; Kagoné, M; Prytherch, H; Loukanova, S; Williams, J E; Sauerborn, R

2014-01-01

Performance-based incentives (PBIs) are currently receiving attention as a strategy for improving the quality of care that health providers deliver. Experiences from several African countries have shown that PBIs can trigger improvements, particularly in the area of maternal and neonatal health. The involvement of health workers in deciding how their performance should be measured is recommended. Only limited information is available about how such schemes can be made sustainable. This study explored the types of PBIs that rural health workers suggested, their ideas regarding the management and sustainability of such schemes, and their views on which indicators best lend themselves to the monitoring of performance. In this article the authors reported the findings from a cross-country survey conducted in Burkina Faso, Ghana and Tanzania. The study was exploratory with qualitative methodology. In-depth interviews were conducted with 29 maternal and neonatal healthcare providers, four district health managers and two policy makers (total 35 respondents) from one district in each of the three countries. The respondents were purposively selected from six peripheral health facilities. Care was taken to include providers who had a management role. By also including respondents from district and policy level a comparison of perspectives from different levels of the health system was facilitated. The data that was collected was coded and analysed with support of NVivo v8 software. The most frequently suggested PBIs amongst the respondents in Burkina Faso were training with per-diems, bonuses and recognition of work done. The respondents in Tanzania favoured training with per-diems, as well as payment of overtime, and timely promotion. The respondents in Ghana also called for training, including paid study leave, payment of overtime and recognition schemes for health workers or facilities. Respondents in the three countries supported the mobilisation of local resources to make incentive schemes more sustainable. There was a general view that it was easier to integrate the cost of non-financial incentives in local budgets. There were concerns about the fairness of such schemes from the provider level in all three countries. District managers were worried about the workload that would be required to manage the schemes. The providers themselves were less clear about which indicators best lent themselves to the purpose of performance monitoring. District managers and policy makers most commonly suggested indicators that were in line with national maternal and neonatal healthcare indicators. The study showed that health workers have considerable interest in performance-based incentive schemes and are concerned about their sustainability. There is a need to further explore the use of non-financial incentives in PBI schemes, as such incentives were considered to stand a greater chance of being integrated into local budgets. Ensuring participation of healthcare providers in the design of such schemes is likely to achieve buy-in and endorsement from the health workers involved. However, input from managers and policy makers is essential to keep expectations realistic and to ensure the indicators selected fit the purpose and are part of routine reporting systems.

EEMD-Based Steady-State Indexes and Their Applications to Condition Monitoring and Fault Diagnosis of Railway Axle Bearings

PubMed Central

Fan, Wei; Tsui, Kwok-Leung; Lin, Jianhui

2018-01-01

Railway axle bearings are one of the most important components used in vehicles and their failures probably result in unexpected accidents and economic losses. To realize a condition monitoring and fault diagnosis scheme of railway axle bearings, three dimensionless steadiness indexes in a time domain, a frequency domain, and a shape domain are respectively proposed to measure the steady states of bearing vibration signals. Firstly, vibration data collected from some designed experiments are pre-processed by using ensemble empirical mode decomposition (EEMD). Then, the coefficient of variation is introduced to construct two steady-state indexes from pre-processed vibration data in a time domain and a frequency domain, respectively. A shape function is used to construct a steady-state index in a shape domain. At last, to distinguish normal and abnormal bearing health states, some guideline thresholds are proposed. Further, to identify axle bearings with outer race defects, a pin roller defect, a cage defect, and coupling defects, the boundaries of all steadiness indexes are experimentally established. Experimental results showed that the proposed condition monitoring and fault diagnosis scheme is effective in identifying different bearing health conditions. PMID:29495446

Development of optical micro resonance based sensor for detection and identification of microparticles and biological agents

NASA Astrophysics Data System (ADS)

Saetchnikov, Vladimir A.; Tcherniavskaia, Elina A.; Schweiger, Gustav

2009-05-01

A novel emerging technique for the label-free analysis of nanoparticles including biomolecules using optical micro cavity resonance of whispering-gallery-type modes is being developed. Schemes of such a method based on microsphere melted by laser on the tip of a standard single mode fiber optical cable with a laser and free microsphere matrix have been developed. Using a calibration principal of ultra high resolution spectroscopy based on such a scheme the method is being transformed to make further development for microbial application. The sensitivity of developed schemes has been tested to refractive index changes by monitoring the magnitude of the whispering gallery modes spectral shift. Water solutions of ethanol, glucose, vitamin C and biotin have been used. Some other schemes using similar principals: stand-alone, array and matrix microsphere resonators, liquid core optical ring resonators are also being under development. The influences of the gap in whispering-gallery modes on energy coupling, resonance quality and frequency have been investigated. An optimum gap for sensing applications has been defined at the half maximum energy coupling where both the Q factor and coupling efficiency are high and the resonance frequency is little affected by the gap variation. Developed schemes have been demonstrated to be a promising technology platform for sensitive, lab-on-chip type sensor which can be used for development of diagnostic tools for different biological molecules, e.g. proteins, oligonucleotides, oligosaccharides, lipids, small molecules, viral particles, cells as well as in different experimental contexts e.g. proteomics, genomics, drug discovery, and membrane studies.

Characterization of Signal Quality Monitoring Techniques for Multipath Detection in GNSS Applications.

PubMed

Pirsiavash, Ali; Broumandan, Ali; Lachapelle, Gérard

2017-07-05

The performance of Signal Quality Monitoring (SQM) techniques under different multipath scenarios is analyzed. First, SQM variation profiles are investigated as critical requirements in evaluating the theoretical performance of SQM metrics. The sensitivity and effectiveness of SQM approaches for multipath detection and mitigation are then defined and analyzed by comparing SQM profiles and multipath error envelopes for different discriminators. Analytical discussions includes two discriminator strategies, namely narrow and high resolution correlator techniques for BPSK(1), and BOC(1,1) signaling schemes. Data analysis is also carried out for static and kinematic scenarios to validate the SQM profiles and examine SQM performance in actual multipath environments. Results show that although SQM is sensitive to medium and long-delay multipath, its effectiveness in mitigating these ranges of multipath errors varies based on tracking strategy and signaling scheme. For short-delay multipath scenarios, the multipath effect on pseudorange measurements remains mostly undetected due to the low sensitivity of SQM metrics.

An Efficient Audio Coding Scheme for Quantitative and Qualitative Large Scale Acoustic Monitoring Using the Sensor Grid Approach

PubMed Central

Gontier, Félix; Lagrange, Mathieu; Can, Arnaud; Lavandier, Catherine

2017-01-01

The spreading of urban areas and the growth of human population worldwide raise societal and environmental concerns. To better address these concerns, the monitoring of the acoustic environment in urban as well as rural or wilderness areas is an important matter. Building on the recent development of low cost hardware acoustic sensors, we propose in this paper to consider a sensor grid approach to tackle this issue. In this kind of approach, the crucial question is the nature of the data that are transmitted from the sensors to the processing and archival servers. To this end, we propose an efficient audio coding scheme based on third octave band spectral representation that allows: (1) the estimation of standard acoustic indicators; and (2) the recognition of acoustic events at state-of-the-art performance rate. The former is useful to provide quantitative information about the acoustic environment, while the latter is useful to gather qualitative information and build perceptually motivated indicators using for example the emergence of a given sound source. The coding scheme is also demonstrated to transmit spectrally encoded data that, reverted to the time domain using state-of-the-art techniques, are not intelligible, thus protecting the privacy of citizens. PMID:29186021

An Improved EKG-Based Key Agreement Scheme for Body Area Networks

NASA Astrophysics Data System (ADS)

Ali, Aftab; Khan, Farrukh Aslam

Body area networks (BANs) play an important role in mobile health monitoring such as, monitoring the health of patients in a hospital or physical status of soldiers in a battlefield. By securing the BAN, we actually secure the lives of soldiers or patients. This work presents an electrocardiogram (EKG) based key agreement scheme using discrete wavelet transform (DWT) for the sake of generating a common key in a body area network. The use of EKG brings plug-and-play capability in BANs; i.e., the sensors are just placed on the human body and a secure communication is started among these sensors. The process is made secure by using the iris or fingerprints to lock and then unlock the blocks during exchange between the communicating sensors. The locking and unlocking is done through watermarking. When a watermark is added at the sender side, the block is locked and when it is removed at the receiver side, the block is unlocked. By using iris or fingerprints, the security of the technique improves and its plug-and-play capability is not affected. The analysis is done by using real 2-lead EKG data sampled at a rate of 125 Hz taken from MIT PhysioBank database.

A Novel Energy Efficient Topology Control Scheme Based on a Coverage-Preserving and Sleep Scheduling Model for Sensor Networks

PubMed Central

Shi, Binbin; Wei, Wei; Wang, Yihuai; Shu, Wanneng

2016-01-01

In high-density sensor networks, scheduling some sensor nodes to be in the sleep mode while other sensor nodes remain active for monitoring or forwarding packets is an effective control scheme to conserve energy. In this paper, a Coverage-Preserving Control Scheduling Scheme (CPCSS) based on a cloud model and redundancy degree in sensor networks is proposed. Firstly, the normal cloud model is adopted for calculating the similarity degree between the sensor nodes in terms of their historical data, and then all nodes in each grid of the target area can be classified into several categories. Secondly, the redundancy degree of a node is calculated according to its sensing area being covered by the neighboring sensors. Finally, a centralized approximation algorithm based on the partition of the target area is designed to obtain the approximate minimum set of nodes, which can retain the sufficient coverage of the target region and ensure the connectivity of the network at the same time. The simulation results show that the proposed CPCSS can balance the energy consumption and optimize the coverage performance of the sensor network. PMID:27754405

A Novel Energy Efficient Topology Control Scheme Based on a Coverage-Preserving and Sleep Scheduling Model for Sensor Networks.

PubMed

Shi, Binbin; Wei, Wei; Wang, Yihuai; Shu, Wanneng

2016-10-14

In high-density sensor networks, scheduling some sensor nodes to be in the sleep mode while other sensor nodes remain active for monitoring or forwarding packets is an effective control scheme to conserve energy. In this paper, a Coverage-Preserving Control Scheduling Scheme (CPCSS) based on a cloud model and redundancy degree in sensor networks is proposed. Firstly, the normal cloud model is adopted for calculating the similarity degree between the sensor nodes in terms of their historical data, and then all nodes in each grid of the target area can be classified into several categories. Secondly, the redundancy degree of a node is calculated according to its sensing area being covered by the neighboring sensors. Finally, a centralized approximation algorithm based on the partition of the target area is designed to obtain the approximate minimum set of nodes, which can retain the sufficient coverage of the target region and ensure the connectivity of the network at the same time. The simulation results show that the proposed CPCSS can balance the energy consumption and optimize the coverage performance of the sensor network.

Subranging scheme for SQUID sensors

NASA Technical Reports Server (NTRS)

Penanen, Konstantin I. (Inventor)

2008-01-01

A readout scheme for measuring the output from a SQUID-based sensor-array using an improved subranging architecture that includes multiple resolution channels (such as a coarse resolution channel and a fine resolution channel). The scheme employs a flux sensing circuit with a sensing coil connected in series to multiple input coils, each input coil being coupled to a corresponding SQUID detection circuit having a high-resolution SQUID device with independent linearizing feedback. A two-resolution configuration (course and fine) is illustrated with a primary SQUID detection circuit for generating a fine readout, and a secondary SQUID detection circuit for generating a course readout, both having feedback current coupled to the respective SQUID devices via feedback/modulation coils. The primary and secondary SQUID detection circuits function and derive independent feedback. Thus, the SQUID devices may be monitored independently of each other (and read simultaneously) to dramatically increase slew rates and dynamic range.

A novel Kalman filter based video image processing scheme for two-photon fluorescence microscopy

NASA Astrophysics Data System (ADS)

Sun, Wenqing; Huang, Xia; Li, Chunqiang; Xiao, Chuan; Qian, Wei

2016-03-01

Two-photon fluorescence microscopy (TPFM) is a perfect optical imaging equipment to monitor the interaction between fast moving viruses and hosts. However, due to strong unavoidable background noises from the culture, videos obtained by this technique are too noisy to elaborate this fast infection process without video image processing. In this study, we developed a novel scheme to eliminate background noises, recover background bacteria images and improve video qualities. In our scheme, we modified and implemented the following methods for both host and virus videos: correlation method, round identification method, tree-structured nonlinear filters, Kalman filters, and cell tracking method. After these procedures, most of noises were eliminated and host images were recovered with their moving directions and speed highlighted in the videos. From the analysis of the processed videos, 93% bacteria and 98% viruses were correctly detected in each frame on average.

A uniqueness-and-anonymity-preserving remote user authentication scheme for connected health care.

PubMed

Chang, Ya-Fen; Yu, Shih-Hui; Shiao, Ding-Rui

2013-04-01

Connected health care provides new opportunities for improving financial and clinical performance. Many connected health care applications such as telecare medicine information system, personally controlled health records system, and patient monitoring have been proposed. Correct and quality care is the goal of connected heath care, and user authentication can ensure the legality of patients. After reviewing authentication schemes for connected health care applications, we find that many of them cannot protect patient privacy such that others can trace users/patients by the transmitted data. And the verification tokens used by these authentication schemes to authenticate users or servers are only password, smart card and RFID tag. Actually, these verification tokens are not unique and easy to copy. On the other hand, biometric characteristics, such as iris, face, voiceprint, fingerprint and so on, are unique, easy to be verified, and hard to be copied. In this paper, a biometrics-based user authentication scheme will be proposed to ensure uniqueness and anonymity at the same time. With the proposed scheme, only the legal user/patient himself/herself can access the remote server, and no one can trace him/her according to transmitted data.

The potential of financial incentives to enhance householders' kerbside recycling behaviour.

PubMed

Shaw, P J; Maynard, S J

2008-01-01

Although the successful enhancement of householders' participation in kerbside recycling schemes is essential for household waste recycling schemes to reach their desired levels of achievement, our understanding of householders' responses to the various incentives available to waste managers is incomplete. In particular, whether and how the recycling behaviour of householders may be favourably altered through imposition of financial penalties or rewards is not fully understood. Surveys of householders' attitudes in the London Borough of Havering, served by a kerbside co-mingled survival bag recycling scheme, showed they might be better encouraged to recycle more through improvements to structural and promotional aspects of the recycling scheme than through imposition of financial incentives. If financial incentives were to be imposed to enhance kerbside recycling, householders preferred: (1) rewards to penalties, and (2) community-based rewards and local taxation rebates to other or individual rewards. Given the attitudes of householders and the resources that would be needed to monitor their recycling behaviour as a basis for delivering financial incentives, it is suggested that the priority for enhancing recycling should be to make appropriate improvements in the infrastructure and support of the kerbside scheme and service.

Defect classification in sparsity-based structural health monitoring

NASA Astrophysics Data System (ADS)

Golato, Andrew; Ahmad, Fauzia; Santhanam, Sridhar; Amin, Moeness G.

2017-05-01

Guided waves have gained popularity in structural health monitoring (SHM) due to their ability to inspect large areas with little attenuation, while providing rich interactions with defects. For thin-walled structures, the propagating waves are Lamb waves, which are a complex but well understood type of guided waves. Recent works have cast the defect localization problem of Lamb wave based SHM within the sparse reconstruction framework. These methods make use of a linear model relating the measurements with the scene reflectivity under the assumption of point-like defects. However, most structural defects are not perfect points but tend to assume specific forms, such as surface cracks or internal cracks. Knowledge of the "type" of defects is useful in the assessment phase of SHM. In this paper, we present a dual purpose sparsity-based imaging scheme which, in addition to accurately localizing defects, properly classifies the defects present simultaneously. The proposed approach takes advantage of the bias exhibited by certain types of defects toward a specific Lamb wave mode. For example, some defects strongly interact with the anti-symmetric modes, while others strongly interact with the symmetric modes. We build model based dictionaries for the fundamental symmetric and anti-symmetric wave modes, which are then utilized in unison to properly localize and classify the defects present. Simulated data of surface and internal defects in a thin Aluminum plate are used to validate the proposed scheme.

Classification of Dust Days by Satellite Remotely Sensed Aerosol Products

NASA Technical Reports Server (NTRS)

Sorek-Hammer, M.; Cohen, A.; Levy, Robert C.; Ziv, B.; Broday, D. M.

2013-01-01

Considerable progress in satellite remote sensing (SRS) of dust particles has been seen in the last decade. From an environmental health perspective, such an event detection, after linking it to ground particulate matter (PM) concentrations, can proxy acute exposure to respirable particles of certain properties (i.e. size, composition, and toxicity). Being affected considerably by atmospheric dust, previous studies in the Eastern Mediterranean, and in Israel in particular, have focused on mechanistic and synoptic prediction, classification, and characterization of dust events. In particular, a scheme for identifying dust days (DD) in Israel based on ground PM10 (particulate matter of size smaller than 10 nm) measurements has been suggested, which has been validated by compositional analysis. This scheme requires information regarding ground PM10 levels, which is naturally limited in places with sparse ground-monitoring coverage. In such cases, SRS may be an efficient and cost-effective alternative to ground measurements. This work demonstrates a new model for identifying DD and non-DD (NDD) over Israel based on an integration of aerosol products from different satellite platforms (Moderate Resolution Imaging Spectroradiometer (MODIS) and Ozone Monitoring Instrument (OMI)). Analysis of ground-monitoring data from 2007 to 2008 in southern Israel revealed 67 DD, with more than 88 percent occurring during winter and spring. A Classification and Regression Tree (CART) model that was applied to a database containing ground monitoring (the dependent variable) and SRS aerosol product (the independent variables) records revealed an optimal set of binary variables for the identification of DD. These variables are combinations of the following primary variables: the calendar month, ground-level relative humidity (RH), the aerosol optical depth (AOD) from MODIS, and the aerosol absorbing index (AAI) from OMI. A logistic regression that uses these variables, coded as binary variables, demonstrated 93.2 percent correct classifications of DD and NDD. Evaluation of the combined CART-logistic regression scheme in an adjacent geographical region (Gush Dan) demonstrated good results. Using SRS aerosol products for DD and NDD, identification may enable us to distinguish between health, ecological, and environmental effects that result from exposure to these distinct particle populations.

Real-Time Agent-Based Modeling Simulation with in-situ Visualization of Complex Biological Systems: A Case Study on Vocal Fold Inflammation and Healing.

PubMed

Seekhao, Nuttiiya; Shung, Caroline; JaJa, Joseph; Mongeau, Luc; Li-Jessen, Nicole Y K

2016-05-01

We present an efficient and scalable scheme for implementing agent-based modeling (ABM) simulation with In Situ visualization of large complex systems on heterogeneous computing platforms. The scheme is designed to make optimal use of the resources available on a heterogeneous platform consisting of a multicore CPU and a GPU, resulting in minimal to no resource idle time. Furthermore, the scheme was implemented under a client-server paradigm that enables remote users to visualize and analyze simulation data as it is being generated at each time step of the model. Performance of a simulation case study of vocal fold inflammation and wound healing with 3.8 million agents shows 35× and 7× speedup in execution time over single-core and multi-core CPU respectively. Each iteration of the model took less than 200 ms to simulate, visualize and send the results to the client. This enables users to monitor the simulation in real-time and modify its course as needed.

Autonomous Performance Monitoring System: Monitoring and Self-Tuning (MAST)

NASA Technical Reports Server (NTRS)

Peterson, Chariya; Ziyad, Nigel A.

2000-01-01

Maintaining the long-term performance of software onboard a spacecraft can be a major factor in the cost of operations. In particular, the task of controlling and maintaining a future mission of distributed spacecraft will undoubtedly pose a great challenge, since the complexity of multiple spacecraft flying in formation grows rapidly as the number of spacecraft in the formation increases. Eventually, new approaches will be required in developing viable control systems that can handle the complexity of the data and that are flexible, reliable and efficient. In this paper we propose a methodology that aims to maintain the accuracy of flight software, while reducing the computational complexity of software tuning tasks. The proposed Monitoring and Self-Tuning (MAST) method consists of two parts: a flight software monitoring algorithm and a tuning algorithm. The dependency on the software being monitored is mostly contained in the monitoring process, while the tuning process is a generic algorithm independent of the detailed knowledge on the software. This architecture will enable MAST to be applicable to different onboard software controlling various dynamics of the spacecraft, such as attitude self-calibration, and formation control. An advantage of MAST over conventional techniques such as filter or batch least square is that the tuning algorithm uses machine learning approach to handle uncertainty in the problem domain, resulting in reducing over all computational complexity. The underlying concept of this technique is a reinforcement learning scheme based on cumulative probability generated by the historical performance of the system. The success of MAST will depend heavily on the reinforcement scheme used in the tuning algorithm, which guarantees the tuning solutions exist.

Real-time video quality monitoring

NASA Astrophysics Data System (ADS)

Liu, Tao; Narvekar, Niranjan; Wang, Beibei; Ding, Ran; Zou, Dekun; Cash, Glenn; Bhagavathy, Sitaram; Bloom, Jeffrey

2011-12-01

The ITU-T Recommendation G.1070 is a standardized opinion model for video telephony applications that uses video bitrate, frame rate, and packet-loss rate to measure the video quality. However, this model was original designed as an offline quality planning tool. It cannot be directly used for quality monitoring since the above three input parameters are not readily available within a network or at the decoder. And there is a great room for the performance improvement of this quality metric. In this article, we present a real-time video quality monitoring solution based on this Recommendation. We first propose a scheme to efficiently estimate the three parameters from video bitstreams, so that it can be used as a real-time video quality monitoring tool. Furthermore, an enhanced algorithm based on the G.1070 model that provides more accurate quality prediction is proposed. Finally, to use this metric in real-world applications, we present an example emerging application of real-time quality measurement to the management of transmitted videos, especially those delivered to mobile devices.

Modified Beer-Lambert law for blood flow

PubMed Central

Baker, Wesley B.; Parthasarathy, Ashwin B.; Busch, David R.; Mesquita, Rickson C.; Greenberg, Joel H.; Yodh, A. G.

2014-01-01

We develop and validate a Modified Beer-Lambert law for blood flow based on diffuse correlation spectroscopy (DCS) measurements. The new formulation enables blood flow monitoring from temporal intensity autocorrelation function data taken at single or multiple delay-times. Consequentially, the speed of the optical blood flow measurement can be substantially increased. The scheme facilitates blood flow monitoring of highly scattering tissues in geometries wherein light propagation is diffusive or non-diffusive, and it is particularly well-suited for utilization with pressure measurement paradigms that employ differential flow signals to reduce contributions of superficial tissues. PMID:25426330

MO-FG-202-08: Real-Time Monte Carlo-Based Treatment Dose Reconstruction and Monitoring for Radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tian, Z; Shi, F; Gu, X

2016-06-15

Purpose: This proof-of-concept study is to develop a real-time Monte Carlo (MC) based treatment-dose reconstruction and monitoring system for radiotherapy, especially for the treatments with complicated delivery, to catch treatment delivery errors at the earliest possible opportunity and interrupt the treatment only when an unacceptable dosimetric deviation from our expectation occurs. Methods: First an offline scheme is launched to pre-calculate the expected dose from the treatment plan, used as ground truth for real-time monitoring later. Then an online scheme with three concurrent threads is launched while treatment delivering, to reconstruct and monitor the patient dose in a temporally resolved fashionmore » in real-time. Thread T1 acquires machine status every 20 ms to calculate and accumulate fluence map (FM). Once our accumulation threshold is reached, T1 transfers the FM to T2 for dose reconstruction ad starts to accumulate a new FM. A GPU-based MC dose calculation is performed on T2 when MC dose engine is ready and a new FM is available. The reconstructed instantaneous dose is directed to T3 for dose accumulation and real-time visualization. Multiple dose metrics (e.g. maximum and mean dose for targets and organs) are calculated from the current accumulated dose and compared with the pre-calculated expected values. Once the discrepancies go beyond our tolerance, an error message will be send to interrupt the treatment delivery. Results: A VMAT Head-and-neck patient case was used to test the performance of our system. Real-time machine status acquisition was simulated here. The differences between the actual dose metrics and the expected ones were 0.06%–0.36%, indicating an accurate delivery. ∼10Hz frequency of dose reconstruction and monitoring was achieved, with 287.94s online computation time compared to 287.84s treatment delivery time. Conclusion: Our study has demonstrated the feasibility of computing a dose distribution in a temporally resolved fashion in real-time and quantitatively and dosimetrically monitoring the treatment delivery.« less

Sequence and batch language programs and alarm related C Programs for the 242-A MCS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berger, J.F.

1996-04-15

A Distributive Process Control system was purchased by Project B-534, 242-A Evaporator/Crystallizer Upgrades. This control system, called the Monitor and Control system (MCS), was installed in the 242-A evaporator located in the 200 East Area. The purpose of the MCS is to monitor and control the Evaporator and monitor a number of alarms and other signals from various Tank Farm facilities. Applications software for the MCS was developed by the Waste Treatment Systems Engineering (WTSE) group of Westinghouse. The standard displays and alarm scheme provide for control and monitoring, but do not directly indicate the signal location or depict themore » overall process. To do this, WTSE developed a second alarm scheme.« less

Refinement of current monitoring methodology for electroosmotic flow assessment under low ionic strength conditions

PubMed Central

Saucedo-Espinosa, Mario A.; Lapizco-Encinas, Blanca H.

2016-01-01

Current monitoring is a well-established technique for the characterization of electroosmotic (EO) flow in microfluidic devices. This method relies on monitoring the time response of the electric current when a test buffer solution is displaced by an auxiliary solution using EO flow. In this scheme, each solution has a different ionic concentration (and electric conductivity). The difference in the ionic concentration of the two solutions defines the dynamic time response of the electric current and, hence, the current signal to be measured: larger concentration differences result in larger measurable signals. A small concentration difference is needed, however, to avoid dispersion at the interface between the two solutions, which can result in undesired pressure-driven flow that conflicts with the EO flow. Additional challenges arise as the conductivity of the test solution decreases, leading to a reduced electric current signal that may be masked by noise during the measuring process, making for a difficult estimation of an accurate EO mobility. This contribution presents a new scheme for current monitoring that employs multiple channels arranged in parallel, producing an increase in the signal-to-noise ratio of the electric current to be measured and increasing the estimation accuracy. The use of this parallel approach is particularly useful in the estimation of the EO mobility in systems where low conductivity mediums are required, such as insulator based dielectrophoresis devices. PMID:27375813

State-of-the-art practices in farmland biodiversity monitoring for North America and Europe.

PubMed

Herzog, Felix; Franklin, Janet

2016-12-01

Policy makers and farmers need to know the status of farmland biodiversity in order to meet conservation goals and evaluate management options. Based on a review of 11 monitoring programs in Europe and North America and on related literature, we identify the design choices or attributes of a program that balance monitoring costs and usefulness for stakeholders. A useful program monitors habitats, vascular plants, and possibly faunal groups (ecosystem service providers, charismatic species) using a stratified random sample of the agricultural landscape, including marginal and intensive regions. The size of landscape samples varies with the grain of the agricultural landscape; for example, samples are smaller in Europe and larger in North America. Raw data are collected in a rolling survey, which distributes sampling over several years. Sufficient practical experience is now available to implement broad monitoring schemes on both continents. Technological developments in remote sensing, metagenomics, and social media may offer new opportunities for affordable farmland biodiversity monitoring and help to lower the overall costs of monitoring programs.

Autonomous health management for PMSM rail vehicles through demagnetization monitoring and prognosis control.

PubMed

Niu, Gang; Jiang, Junjie; Youn, Byeng D; Pecht, Michael

2018-01-01

Autonomous vehicles are playing an increasingly importance in support of a wide variety of critical events. This paper presents a novel autonomous health management scheme on rail vehicles driven by permanent magnet synchronous motors (PMSMs). Firstly, the PMSMs are modeled based on first principle to deduce the initial profile of pneumatic braking (p-braking) force, then which is utilized for real-time demagnetization monitoring and degradation prognosis through similarity-based theory and generate prognosis-enhanced p-braking force strategy for final optimal control. A case study is conducted to demonstrate the feasibility and benefit of using the real-time prognostics and health management (PHM) information in vehicle 'drive-brake' control automatically. The results show that accurate demagnetization monitoring, degradation prognosis, and real-time capability for control optimization can be obtained, which can effectively relieve brake shoe wear. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

The monitoring and managing application of cloud computing based on Internet of Things.

PubMed

Luo, Shiliang; Ren, Bin

2016-07-01

Cloud computing and the Internet of Things are the two hot points in the Internet application field. The application of the two new technologies is in hot discussion and research, but quite less on the field of medical monitoring and managing application. Thus, in this paper, we study and analyze the application of cloud computing and the Internet of Things on the medical field. And we manage to make a combination of the two techniques in the medical monitoring and managing field. The model architecture for remote monitoring cloud platform of healthcare information (RMCPHI) was established firstly. Then the RMCPHI architecture was analyzed. Finally an efficient PSOSAA algorithm was proposed for the medical monitoring and managing application of cloud computing. Simulation results showed that our proposed scheme can improve the efficiency about 50%. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Health Monitoring and Management for Manufacturing Workers in Adverse Working Conditions.

PubMed

Xu, Xiaoya; Zhong, Miao; Wan, Jiafu; Yi, Minglun; Gao, Tiancheng

2016-10-01

In adverse working conditions, environmental parameters such as metallic dust, noise, and environmental temperature, directly affect the health condition of manufacturing workers. It is therefore important to implement health monitoring and management based on important physiological parameters (e.g., heart rate, blood pressure, and body temperature). In recent years, new technologies, such as body area networks, cloud computing, and smart clothing, have allowed the improvement of the quality of services. In this article, we first give five-layer architecture for health monitoring and management of manufacturing workers. Then, we analyze the system implementation process, including environmental data processing, physical condition monitoring and system services and management, and present the corresponding algorithms. Finally, we carry out an evaluation and analysis from the perspective of insurance and compensation for manufacturing workers in adverse working conditions. The proposed scheme will contribute to the improvement of workplace conditions, realize health monitoring and management, and protect the interests of manufacturing workers.

Adaptive angular-velocity Vold-Kalman filter order tracking - Theoretical basis, numerical implementation and parameter investigation

NASA Astrophysics Data System (ADS)

Pan, M.-Ch.; Chu, W.-Ch.; Le, Duc-Do

2016-12-01

The paper presents an alternative Vold-Kalman filter order tracking (VKF_OT) method, i.e. adaptive angular-velocity VKF_OT technique, to extract and characterize order components in an adaptive manner for the condition monitoring and fault diagnosis of rotary machinery. The order/spectral waveforms to be tracked can be recursively solved by using Kalman filter based on the one-step state prediction. The paper comprises theoretical derivation of computation scheme, numerical implementation, and parameter investigation. Comparisons of the adaptive VKF_OT scheme with two other ones are performed through processing synthetic signals of designated order components. Processing parameters such as the weighting factor and the correlation matrix of process noise, and data conditions like the sampling frequency, which influence tracking behavior, are explored. The merits such as adaptive processing nature and computation efficiency brought by the proposed scheme are addressed although the computation was performed in off-line conditions. The proposed scheme can simultaneously extract multiple spectral components, and effectively decouple close and crossing orders associated with multi-axial reference rotating speeds.

Defining functional biomes and monitoring their change globally.

PubMed

Higgins, Steven I; Buitenwerf, Robert; Moncrieff, Glenn R

2016-11-01

Biomes are important constructs for organizing understanding of how the worlds' major terrestrial ecosystems differ from one another and for monitoring change in these ecosystems. Yet existing biome classification schemes have been criticized for being overly subjective and for explicitly or implicitly invoking climate. We propose a new biome map and classification scheme that uses information on (i) an index of vegetation productivity, (ii) whether the minimum of vegetation activity is in the driest or coldest part of the year, and (iii) vegetation height. Although biomes produced on the basis of this classification show a strong spatial coherence, they show little congruence with existing biome classification schemes. Our biome map provides an alternative classification scheme for comparing the biogeochemical rates of terrestrial ecosystems. We use this new biome classification scheme to analyse the patterns of biome change observed over recent decades. Overall, 13% to 14% of analysed pixels shifted in biome state over the 30-year study period. A wide range of biome transitions were observed. For example, biomes with tall vegetation and minimum vegetation activity in the cold season shifted to higher productivity biome states. Biomes with short vegetation and low seasonality shifted to seasonally moisture-limited biome states. Our findings and method provide a new source of data for rigorously monitoring global vegetation change, analysing drivers of vegetation change and for benchmarking models of terrestrial ecosystem function. © 2016 John Wiley & Sons Ltd.

Resolution-improved in situ DNA hybridization detection based on microwave photonic interrogation.

PubMed

Cao, Yuan; Guo, Tuan; Wang, Xudong; Sun, Dandan; Ran, Yang; Feng, Xinhuan; Guan, Bai-ou

2015-10-19

In situ bio-sensing system based on microwave photonics filter (MPF) interrogation method with improved resolution is proposed and experimentally demonstrated. A microfiber Bragg grating (mFBG) is used as sensing probe for DNA hybridization detection. Different from the traditional wavelength monitoring technique, we use the frequency interrogation scheme for resolution-improved bio-sensing detection. Experimental results show that the frequency shift of MPF notch presents a linear response to the surrounding refractive index (SRI) change over the range of 1.33 to 1.38, with a SRI resolution up to 2.6 × 10(-5) RIU, which has been increased for almost two orders of magnitude compared with the traditional fundamental mode monitoring technique (~3.6 × 10(-3) RIU). Due to the high Q value (about 27), the whole process of DNA hybridization can be in situ monitored. The proposed MPF-based bio-sensing system provides a new interrogation method over the frequency domain with improved sensing resolution and rapid interrogation rate for biochemical and environmental measurement.

Automated monitor and control for deep space network subsystems

NASA Technical Reports Server (NTRS)

Smyth, P.

1989-01-01

The problem of automating monitor and control loops for Deep Space Network (DSN) subsystems is considered and an overview of currently available automation techniques is given. The use of standard numerical models, knowledge-based systems, and neural networks is considered. It is argued that none of these techniques alone possess sufficient generality to deal with the demands imposed by the DSN environment. However, it is shown that schemes that integrate the better aspects of each approach and are referenced to a formal system model show considerable promise, although such an integrated technology is not yet available for implementation. Frequent reference is made to the receiver subsystem since this work was largely motivated by experience in developing an automated monitor and control loop for the advanced receiver.

CENet: A Cabinet Environmental Sensing Network

PubMed Central

Zhang, Zusheng; Yu, Fengqi; Chen, Liang; Cao, Guangmin

2010-01-01

For data center cooling and intelligent substation systems, real time cabinet environmental monitoring is a strong requirement. Monitoring data, such as temperature, humidity, and noise, is important for operators to manage the facilities in cabinets. We here propose a sensing network, called CENet, which is energy efficient and reliable for cabinet environmental monitoring. CENet achieves above 93% reliable data yield and sends fewer beacons compared to periodic beaconing. It does so through a data-aided routing protocol. In addition, based on B-MAC, we propose a scheduling scheme to increase the lifetime of the network by reducing unnecessary message snooping and channel listening, thus it is more energy efficient than B-MAC. The performance of CENet is evaluated by simulations and experiments. PMID:22205856

Advancing Data assimilation for Baltic Monitoring and Forecasting Center: implementation and evaluation of HBP-PDAF system

NASA Astrophysics Data System (ADS)

Korabel, Vasily; She, Jun; Huess, Vibeke; Woge Nielsen, Jacob; Murawsky, Jens; Nerger, Lars

2017-04-01

The potential of an efficient data assimilation (DA) scheme to improve model forecast skill was successfully demonstrated by many operational centres around the world. The Baltic-North Sea region is one of the most heavily monitored seas. Ferryboxes, buoys, ADCP moorings, shallow water Argo floats, and research vessels are providing more and more near-real time observations. Coastal altimetry has now providing increasing amount of high resolution sea level observations, which will be significantly expanded by the launch of SWOT satellite in next years. This will turn operational DA into a valuable tool for improving forecast quality in the region. This motivated us to focus on advancing DA for the Baltic Monitoring and Forecasting Centre (BAL MFC) in order to create a common framework for operational data assimilation in the Baltic Sea. We have implemented HBM-PDAF system based on the Parallel Data Assimilation Framework (PDAF), a highly versatile and optimised parallel suit with a choice of sequential schemes originally developed at AWI, and a hydrodynamic HIROMB-BOOS Model (HBM). At initial phase, only the satellite Sea Surface Temperature (SST) Level 3 data has been assimilated. Several related aspects are discussed, including improvements of the forecast quality for both surface and subsurface fields, the estimation of ensemble-based forecast error covariance, as well as possibilities of assimilating new types of observations, such as in-situ salinity and temperature profiles, coastal altimetry, and ice concentration.

Investigating the limits of PET/CT imaging at very low true count rates and high random fractions in ion-beam therapy monitoring.

PubMed

Kurz, Christopher; Bauer, Julia; Conti, Maurizio; Guérin, Laura; Eriksson, Lars; Parodi, Katia

2015-07-01

External beam radiotherapy with protons and heavier ions enables a tighter conformation of the applied dose to arbitrarily shaped tumor volumes with respect to photons, but is more sensitive to uncertainties in the radiotherapeutic treatment chain. Consequently, an independent verification of the applied treatment is highly desirable. For this purpose, the irradiation-induced β(+)-emitter distribution within the patient is detected shortly after irradiation by a commercial full-ring positron emission tomography/x-ray computed tomography (PET/CT) scanner installed next to the treatment rooms at the Heidelberg Ion-Beam Therapy Center (HIT). A major challenge to this approach is posed by the small number of detected coincidences. This contribution aims at characterizing the performance of the used PET/CT device and identifying the best-performing reconstruction algorithm under the particular statistical conditions of PET-based treatment monitoring. Moreover, this study addresses the impact of radiation background from the intrinsically radioactive lutetium-oxyorthosilicate (LSO)-based detectors at low counts. The authors have acquired 30 subsequent PET scans of a cylindrical phantom emulating a patientlike activity pattern and spanning the entire patient counting regime in terms of true coincidences and random fractions (RFs). Accuracy and precision of activity quantification, image noise, and geometrical fidelity of the scanner have been investigated for various reconstruction algorithms and settings in order to identify a practical, well-suited reconstruction scheme for PET-based treatment verification. Truncated listmode data have been utilized for separating the effects of small true count numbers and high RFs on the reconstructed images. A corresponding simulation study enabled extending the results to an even wider range of counting statistics and to additionally investigate the impact of scatter coincidences. Eventually, the recommended reconstruction scheme has been applied to exemplary postirradiation patient data-sets. Among the investigated reconstruction options, the overall best results in terms of image noise, activity quantification, and accurate geometrical recovery were achieved using the ordered subset expectation maximization reconstruction algorithm with time-of-flight (TOF) and point-spread function (PSF) information. For this algorithm, reasonably accurate (better than 5%) and precise (uncertainty of the mean activity below 10%) imaging can be provided down to 80,000 true coincidences at 96% RF. Image noise and geometrical fidelity are generally improved for fewer iterations. The main limitation for PET-based treatment monitoring has been identified in the small number of true coincidences, rather than the high intrinsic random background. Application of the optimized reconstruction scheme to patient data-sets results in a 25% - 50% reduced image noise at a comparable activity quantification accuracy and an improved geometrical performance with respect to the formerly used reconstruction scheme at HIT, adopted from nuclear medicine applications. Under the poor statistical conditions in PET-based treatment monitoring, improved results can be achieved by considering PSF and TOF information during image reconstruction and by applying less iterations than in conventional nuclear medicine imaging. Geometrical fidelity and image noise are mainly limited by the low number of true coincidences, not the high LSO-related random background. The retrieved results might also impact other emerging PET applications at low counting statistics.

Lessons from community-based payment for ecosystem service schemes: from forests to rangelands.

PubMed

Dougill, Andrew J; Stringer, Lindsay C; Leventon, Julia; Riddell, Mike; Rueff, Henri; Spracklen, Dominick V; Butt, Edward

2012-11-19

Climate finance investments and international policy are driving new community-based projects incorporating payments for ecosystem services (PES) to simultaneously store carbon and generate livelihood benefits. Most community-based PES (CB-PES) research focuses on forest areas. Rangelands, which store globally significant quantities of carbon and support many of the world's poor, have seen little CB-PES research attention, despite benefitting from several decades of community-based natural resource management (CBNRM) projects. Lessons from CBNRM suggest institutional considerations are vital in underpinning the design and implementation of successful community projects. This study uses documentary analysis to explore the institutional characteristics of three African community-based forest projects that seek to deliver carbon-storage and poverty-reduction benefits. Strong existing local institutions, clear land tenure, community control over land management decision-making and up-front, flexible payment schemes are found to be vital. Additionally, we undertake a global review of rangeland CBNRM literature and identify that alongside the lessons learned from forest projects, rangeland CB-PES project design requires specific consideration of project boundaries, benefit distribution, capacity building for community monitoring of carbon storage together with awareness-raising using decision-support tools to display the benefits of carbon-friendly land management. We highlight that institutional analyses must be undertaken alongside improved scientific studies of the carbon cycle to enable links to payment schemes, and for them to contribute to poverty alleviation in rangelands.

Lessons from community-based payment for ecosystem service schemes: from forests to rangelands

PubMed Central

Dougill, Andrew J.; Stringer, Lindsay C.; Leventon, Julia; Riddell, Mike; Rueff, Henri; Spracklen, Dominick V.; Butt, Edward

2012-01-01

Climate finance investments and international policy are driving new community-based projects incorporating payments for ecosystem services (PES) to simultaneously store carbon and generate livelihood benefits. Most community-based PES (CB-PES) research focuses on forest areas. Rangelands, which store globally significant quantities of carbon and support many of the world's poor, have seen little CB-PES research attention, despite benefitting from several decades of community-based natural resource management (CBNRM) projects. Lessons from CBNRM suggest institutional considerations are vital in underpinning the design and implementation of successful community projects. This study uses documentary analysis to explore the institutional characteristics of three African community-based forest projects that seek to deliver carbon-storage and poverty-reduction benefits. Strong existing local institutions, clear land tenure, community control over land management decision-making and up-front, flexible payment schemes are found to be vital. Additionally, we undertake a global review of rangeland CBNRM literature and identify that alongside the lessons learned from forest projects, rangeland CB-PES project design requires specific consideration of project boundaries, benefit distribution, capacity building for community monitoring of carbon storage together with awareness-raising using decision-support tools to display the benefits of carbon-friendly land management. We highlight that institutional analyses must be undertaken alongside improved scientific studies of the carbon cycle to enable links to payment schemes, and for them to contribute to poverty alleviation in rangelands. PMID:23045714

Development of online, continuous heavy metals detection and monitoring sensors based on microfluidic plasma reactors

NASA Astrophysics Data System (ADS)

Abdul-Majeed, Wameath Sh

This research is dedicated to develop a fully integrated system for heavy metals determination in water samples based on micro fluidic plasma atomizers. Several configurations of dielectric barrier discharge (DBD) atomizer are designed, fabricated and tested toward this target. Finally, a combination of annular and rectangular DBD atomizers has been utilized to develop a scheme for heavy metals determination. The present thesis has combined both theoretical and experimental investigations to fulfil the requirements. Several mathematical studies are implemented to explore the optimal design parameters for best system performance. On the other hand, expanded experimental explorations are conducted to assess the proposed operational approaches. The experiments were designed according to a central composite rotatable design; hence, an empirical model has been produced for each studied case. Moreover, several statistical approaches are adopted to analyse the system performance and to deduce the optimal operational parameters.. The introduction of the examined analyte to the plasma atomizer has been achieved by applying chemical schemes, where the element in the sample has been derivitized by using different kinds of reducing agents to produce vapour species (e.g. hydrides) for a group of nine elements examined in this research individually and simultaneously. Moreover, other derivatization schemes based on photochemical vapour generation assisted by ultrasound irradiation are also investigated. Generally speaking, the detection limits achieved in this research for the examined set of elements (by applying hydroborate scheme) are found to be acceptable in accordance with the standard limits in drinking water. The results of copper compared with the data from other technologies in the literature, showed a competitive detection limit obtained from applying the developed scheme, with an advantage of conducting simultaneous, fully automated, insitu, online- real time analysis as well as a possibility of connecting the proposed device to control loops..

Natural Resource Management Schemes as Entry Points for Integrated Landscape Approaches: Evidence from Ghana and Burkina Faso.

PubMed

Foli, Samson; Ros-Tonen, Mirjam A F; Reed, James; Sunderland, Terry

2018-07-01

In recognition of the failures of sectoral approaches to overcome global challenges of biodiversity loss, climate change, food insecurity and poverty, scientific discourse on biodiversity conservation and sustainable development is shifting towards integrated landscape governance arrangements. Current landscape initiatives however very much depend on external actors and funding, raising the question of whether, and how, and under what conditions, locally embedded resource management schemes can serve as entry points for the implementation of integrated landscape approaches. This paper assesses the entry point potential for three established natural resource management schemes in West Africa that target landscape degradation with involvement of local communities: the Chantier d'Aménagement Forestier scheme encompassing forest management sites across Burkina Faso and the Modified Taungya System and community wildlife resource management initiatives in Ghana. Based on a review of the current literature, we analyze the extent to which design principles that define a landscape approach apply to these schemes. We found that the CREMA meets most of the desired criteria, but that its scale may be too limited to guarantee effective landscape governance, hence requiring upscaling. Conversely, the other two initiatives are strongly lacking in their design principles on fundamental components regarding integrated approaches, continual learning, and capacity building. Monitoring and evaluation bodies and participatory learning and negotiation platforms could enhance the schemes' alignment with integrated landscape approaches.

Reduction of catastrophic health care expenditures by a community-based health insurance scheme in Gujarat, India: current experiences and challenges.

PubMed Central

Ranson, Michael Kent

2002-01-01

OBJECTIVE: To assess the Self Employed Women's Association's Medical Insurance Fund in Gujarat in terms of insurance coverage according to income groups, protection of claimants from costs of hospitalization, time between discharge and reimbursement, and frequency of use. METHODS: One thousand nine hundred and thirty claims submitted over six years were analysed. FINDINGS: Two hundred and fifteen (11%) of 1927 claims were rejected. The mean household income of claimants was significantly lower than that of the general population. The percentage of households below the poverty line was similar for claimants and the general population. One thousand seven hundred and twelve (1712) claims were reimbursed: 805 (47%) fully and 907 (53%) at a mean reimbursement rate of 55.6%. Reimbursement more than halved the percentage of catastrophic hospitalizations (>10% of annual household income) and hospitalizations resulting in impoverishment. The average time between discharge and reimbursement was four months. The frequency of submission of claims was low (18.0/1000 members per year: 22-37% of the estimated frequency of hospitalization). CONCLUSIONS: The findings have implications for community-based health insurance schemes in India and elsewhere. Such schemes can protect poor households against the uncertain risk of medical expenses. They can be implemented in areas where institutional capacity is too weak to organize nationwide risk-pooling. Such schemes can cover poor people, including people and households below the poverty line. A trade off exists between maintaining the scheme's financial viability and protecting members against catastrophic expenditures. To facilitate reimbursement, administration, particularly processing of claims, should happen near claimants. Fine-tuning the design of a scheme is an ongoing process - a system of monitoring and evaluation is vital. PMID:12219151

Reduction of catastrophic health care expenditures by a community-based health insurance scheme in Gujarat, India: current experiences and challenges.

PubMed

Ranson, Michael Kent

2002-01-01

To assess the Self Employed Women's Association's Medical Insurance Fund in Gujarat in terms of insurance coverage according to income groups, protection of claimants from costs of hospitalization, time between discharge and reimbursement, and frequency of use. One thousand nine hundred and thirty claims submitted over six years were analysed. Two hundred and fifteen (11%) of 1927 claims were rejected. The mean household income of claimants was significantly lower than that of the general population. The percentage of households below the poverty line was similar for claimants and the general population. One thousand seven hundred and twelve (1712) claims were reimbursed: 805 (47%) fully and 907 (53%) at a mean reimbursement rate of 55.6%. Reimbursement more than halved the percentage of catastrophic hospitalizations (>10% of annual household income) and hospitalizations resulting in impoverishment. The average time between discharge and reimbursement was four months. The frequency of submission of claims was low (18.0/1000 members per year: 22-37% of the estimated frequency of hospitalization). The findings have implications for community-based health insurance schemes in India and elsewhere. Such schemes can protect poor households against the uncertain risk of medical expenses. They can be implemented in areas where institutional capacity is too weak to organize nationwide risk-pooling. Such schemes can cover poor people, including people and households below the poverty line. A trade off exists between maintaining the scheme's financial viability and protecting members against catastrophic expenditures. To facilitate reimbursement, administration, particularly processing of claims, should happen near claimants. Fine-tuning the design of a scheme is an ongoing process - a system of monitoring and evaluation is vital.

Structural Health Monitoring for a Z-Type Special Vehicle

PubMed Central

Yuan, Chaolin; Ren, Liang; Li, Hongnan

2017-01-01

Nowadays there exist various kinds of special vehicles designed for some purposes, which are different from regular vehicles in overall dimension and design. In that case, accidents such as overturning will lead to large economical loss and casualties. There are still no technical specifications to follow to ensure the safe operation and driving of these special vehicles. Owing to the poor efficiency of regular maintenance, it is more feasible and effective to apply real-time monitoring during the operation and driving process. In this paper, the fiber Bragg grating (FBG) sensors are used to monitor the safety of a z-type special vehicle. Based on the structural features and force distribution, a reasonable structural health monitoring (SHM) scheme is presented. Comparing the monitoring results with the finite element simulation results guarantees the accuracy and reliability of the monitoring results. Large amounts of data are collected during the operation and driving progress to evaluate the structural safety condition and provide reference for SHM systems developed for other special vehicles. PMID:28587161

Exploiting Auto-Collimation for Real-Time Onboard Monitoring of Space Optical Camera Geometric Parameters

NASA Astrophysics Data System (ADS)

Liu, W.; Wang, H.; Liu, D.; Miu, Y.

2018-05-01

Precise geometric parameters are essential to ensure the positioning accuracy for space optical cameras. However, state-of-the-art onorbit calibration method inevitably suffers from long update cycle and poor timeliness performance. To this end, in this paper we exploit the optical auto-collimation principle and propose a real-time onboard calibration scheme for monitoring key geometric parameters. Specifically, in the proposed scheme, auto-collimation devices are first designed by installing collimated light sources, area-array CCDs, and prisms inside the satellite payload system. Through utilizing those devices, the changes in the geometric parameters are elegantly converted into changes in the spot image positions. The variation of geometric parameters can be derived via extracting and processing the spot images. An experimental platform is then set up to verify the feasibility and analyze the precision index of the proposed scheme. The experiment results demonstrate that it is feasible to apply the optical auto-collimation principle for real-time onboard monitoring.

What evidence do we have to replace in-hospital implantable cardioverter defibrillator follow-up?

PubMed

Brugada, P

2006-01-01

Due to the increasing number of patients with an implantable cardioverter defibrillator (ICD), new options for ICD patient follow-up management are required. Patients with ICD indication according to the guidelines received an ICD with Home Monitoring technology. The devices enabled the transmission of the relevant episode, therapy, and system integrity data. Patients were followed for 12 months with routine controls every 3 months. The physician analyzed the Home Monitoring data before the routine follow-up visit (FU) and gave a forecast on the necessity of the pending FU, which was compared with the evaluation after the FU. Based on the derived forecast reliability, a patient management scheme was developed and its impact on patient safety was assessed retrospectively. A total of 271 patients were enrolled (40 f, mean age 62+/-12 years, mean LVEF 39+/-15%, 65% ischemic heart disease, 20% cardiomyopathy) and followed for 339+/-109 days. Of 908 pairs of Home Monitoring data and FU data evaluation, 129 there were false negative results for 92 patients. Safety concerns from false negative forecasts can be minimized with a patient management scheme containing the following elements: 1) never skip the first routine FU; 2) never skip a routine FU for a patient having already shown pacing threshold problems; 3) perform FU following hospitalizations; 4) perform FU following episode detection by the ICD; and 5) perform a routine FU if the patient reports symptoms. The retrospective analysis showed, that if the patients had been managed using this scheme, 503 of 1079 routine FU could have been skipped with only one safety concern, a three month delay in the detection of silent paroxysmal atrial fibrillation in one patient. Home Monitoring in ICD therapy over 12 months is feasible. The data transmitted relevantly contribute to a remarkable reduction of follow-up burden and enable the individualization of routine follow-up.

A Novel Loss Recovery and Tracking Scheme for Maneuvering Target in Hybrid WSNs.

PubMed

Qian, Hanwang; Fu, Pengcheng; Li, Baoqing; Liu, Jianpo; Yuan, Xiaobing

2018-01-25

Tracking a mobile target, which aims to timely monitor the invasion of specific target, is one of the most prominent applications in wireless sensor networks (WSNs). Traditional tracking methods in WSNs only based on static sensor nodes (SNs) have several critical problems. For example, to void the loss of mobile target, many SNs must be active to track the target in all possible directions, resulting in excessive energy consumption. Additionally, when entering coverage holes in the monitoring area, the mobile target may be missing and then its state is unknown during this period. To tackle these problems, in this paper, a few mobile sensor nodes (MNs) are introduced to cooperate with SNs to form a hybrid WSN due to their stronger abilities and less constrained energy. Then, we propose a valid target tracking scheme for hybrid WSNs to dynamically schedule the MNs and SNs. Moreover, a novel loss recovery mechanism is proposed to find the lost target and recover the tracking with fewer SNs awakened. Furthermore, to improve the robustness and accuracy of the recovery mechanism, an adaptive unscented Kalman filter (AUKF) algorithm is raised to dynamically adjust the process noise covariance. Simulation results demonstrate that our tracking scheme for maneuvering target in hybrid WSNs can not only track the target effectively even if the target is lost but also maintain an excellent accuracy and robustness with fewer activated nodes.

A Novel Loss Recovery and Tracking Scheme for Maneuvering Target in Hybrid WSNs

PubMed Central

Liu, Jianpo; Yuan, Xiaobing

2018-01-01

Tracking a mobile target, which aims to timely monitor the invasion of specific target, is one of the most prominent applications in wireless sensor networks (WSNs). Traditional tracking methods in WSNs only based on static sensor nodes (SNs) have several critical problems. For example, to void the loss of mobile target, many SNs must be active to track the target in all possible directions, resulting in excessive energy consumption. Additionally, when entering coverage holes in the monitoring area, the mobile target may be missing and then its state is unknown during this period. To tackle these problems, in this paper, a few mobile sensor nodes (MNs) are introduced to cooperate with SNs to form a hybrid WSN due to their stronger abilities and less constrained energy. Then, we propose a valid target tracking scheme for hybrid WSNs to dynamically schedule the MNs and SNs. Moreover, a novel loss recovery mechanism is proposed to find the lost target and recover the tracking with fewer SNs awakened. Furthermore, to improve the robustness and accuracy of the recovery mechanism, an adaptive unscented Kalman filter (AUKF) algorithm is raised to dynamically adjust the process noise covariance. Simulation results demonstrate that our tracking scheme for maneuvering target in hybrid WSNs can not only track the target effectively even if the target is lost but also maintain an excellent accuracy and robustness with fewer activated nodes. PMID:29370103

Electric terminal performance and characterization of solid oxide fuel cells and systems

NASA Astrophysics Data System (ADS)

Lindahl, Peter Allan

Solid Oxide Fuel Cells (SOFCs) are electrochemical devices which can effect efficient, clean, and quiet conversion of chemical to electrical energy. In contrast to conventional electricity generation systems which feature multiple discrete energy conversion processes, SOFCs are direct energy conversion devices. That is, they feature a fully integrated chemical to electrical energy conversion process where the electric load demanded of the cell intrinsically drives the electrochemical reactions and associated processes internal to the cell. As a result, the cell's electric terminals provide a path for interaction between load side electric demand and the conversion side processes. The implication of this is twofold. First, the magnitude and dynamic characteristics of the electric load demanded of the cell can directly impact the long-term efficacy of the cell's chemical to electrical energy conversion. Second, the electric terminal response to dynamic loads can be exploited for monitoring the cell's conversion side processes and used in diagnostic analysis and degradation-mitigating control schemes. This dissertation presents a multi-tier investigation into this electric terminal based performance characterization of SOFCs through the development of novel test systems, analysis techniques and control schemes. First, a reference-based simulation system is introduced. This system scales up the electric terminal performance of a prototype SOFC system, e.g. a single fuel cell, to that of a full power-level stack. This allows realistic stack/load interaction studies while maintaining explicit ability for post-test analysis of the prototype system. Next, a time-domain least squares fitting method for electrochemical impedance spectroscopy (EIS) is developed for reduced-time monitoring of the electrochemical and physicochemical mechanics of the fuel cell through its electric terminals. The utility of the reference-based simulator and the EIS technique are demonstrated through their combined use in the performance testing of a hybrid-source power management (HSPM) system designed to allow in-situ EIS monitoring of a stack under dynamic loading conditions. The results from the latter study suggest that an HSPM controller allows an opportunity for in-situ electric terminal monitoring and control-based mitigation of SOFC degradation. As such, an exploration of control-based SOFC degradation mitigation is presented and ideas for further work are suggested.

A CLS-based survivable and energy-saving WDM-PON architecture

NASA Astrophysics Data System (ADS)

Zhu, Min; Zhong, Wen-De; Zhang, Zhenrong; Luan, Feng

2013-11-01

We propose and demonstrate an improved survivable and energy-saving WDM-PON with colorless ONUs. It incorporates both energy-saving and self-healing operations. A simple effective energy-saving scheme is proposed by including an energy-saving control unit in the OLT and a control unit at each ONU. The energy-saving scheme realizes both dozing and sleep (offline) modes, which greatly improves the energy-saving efficiency for WDM-PONs. An intelligent protection switching scheme is designed in the OLT, which can distinguish if an ONU is in dozing/sleep (offline) state or a fiber is faulty. Moreover, by monitoring the optical power of each channel on both working and protection paths, the OLT can know the connection status of every fiber path, thus facilitating an effective protection switching and a faster failure recovery. The improved WDM-PON architecture not only significantly reduces energy consumption, but also performs self-healing operation in practical operation scenarios. The scheme feasibility is experimentally verified with 10 Gbit/s downstream and 1.25 Gbit/s upstream transmissions. We also examine the energy-saving efficiency of our proposed energy-saving scheme by simulation, which reveals that energy saving mainly arises from the dozing mode, not from the sleep mode when the ONU is in the online state.

Sensor Fault Detection and Diagnosis Simulation of a Helicopter Engine in an Intelligent Control Framework

NASA Technical Reports Server (NTRS)

Litt, Jonathan; Kurtkaya, Mehmet; Duyar, Ahmet

1994-01-01

This paper presents an application of a fault detection and diagnosis scheme for the sensor faults of a helicopter engine. The scheme utilizes a model-based approach with real time identification and hypothesis testing which can provide early detection, isolation, and diagnosis of failures. It is an integral part of a proposed intelligent control system with health monitoring capabilities. The intelligent control system will allow for accommodation of faults, reduce maintenance cost, and increase system availability. The scheme compares the measured outputs of the engine with the expected outputs of an engine whose sensor suite is functioning normally. If the differences between the real and expected outputs exceed threshold values, a fault is detected. The isolation of sensor failures is accomplished through a fault parameter isolation technique where parameters which model the faulty process are calculated on-line with a real-time multivariable parameter estimation algorithm. The fault parameters and their patterns can then be analyzed for diagnostic and accommodation purposes. The scheme is applied to the detection and diagnosis of sensor faults of a T700 turboshaft engine. Sensor failures are induced in a T700 nonlinear performance simulation and data obtained are used with the scheme to detect, isolate, and estimate the magnitude of the faults.

Environmental monitoring techniques and wave energy potential assessment: an integrated approach for planning marine energy conversion schemes in the northern Tyrrhenian sea, Italy

NASA Astrophysics Data System (ADS)

Scanu, Sergio; Peviani, Maximo; Carli, Filippo Maria; Paladini de Mendoza, Francesco; Piermattei, Viviana; Bonamano, Simone; Marcelli, Marco

2015-04-01

This work proposes a multidisciplinary approach in which wave power potential maps are used as baseline for the application of environmental monitoring techniques identified through the use of a Database for Environmental Monitoring Techniques and Equipment (DEMTE), derived in the frame of the project "Marine Renewables Infrastructure Network for Emerging Energy Technologies" (Marinet - FP7). This approach aims to standardize the monitoring of the marine environment in the event of installation, operation and decommissioning of Marine Energy Conversion Systems. The database has been obtained through the collection of techniques and instrumentation available among the partners of the consortium, in relation with all environmental marine compounds potentially affected by any impacts. Furthermore in order to plan marine energy conversion schemes, the wave potential was assessed at regional and local scales using the numerical modelling downscaling methodology. The regional scale lead to the elaboration of the Italian Wave Power Atlas, while the local scale lead to the definition of nearshore hot spots useful for the planning of devices installation along the Latium coast. The present work focus in the application of environmental monitoring techniques identified in the DEMTE, in correspondence of the hotspot derived from the wave potential maps with particular reference to the biological interaction of the devices and the management of the marine space. The obtained results are the bases for the development of standardized procedures which aims to an effective application of marine environmental monitoring techniques during the installation, operation and decommissioning of Marine Energy Conversion Systems. The present work gives a consistent contribution to overcome non-technological barriers in the concession procedures, as far as the protection of the marine environment is of concern.

Peer teaching and information retrieval: the role of the NICE Evidence search student champion scheme in enhancing students' confidence.

PubMed

Sbaffi, Laura; Hallsworth, Elaine; Weist, Anne

2018-03-01

This research reports on the NICE Evidence search (ES) student champion scheme (SCS) first five years of activity (2011-2016) in terms of its impact on health care undergraduate students' information search skills and search confidence. A review of students' evaluation of the scheme was carried out to chart the changes in attitude towards NICE Evidence search as an online health care information source and to monitor students' approach to information seeking. This study is based on the results of questionnaires distributed to students before and after attending a training session on NICE Evidence search delivered by their own peers. The exercise was implemented in health related universities in England over a period of five consecutive academic years. (i) Students' search confidence improved considerably after the training; (ii) ES was perceived as being an increasingly useful resource of evidence based information for their studies; (iii) the training helped students develop discerning search skills and use evidence based information sources more consistently and critically. The NICE SCS improves confidence in approaching information tasks amongst health care undergraduate students. Future developments could involve offering the training at the onset of a course of study and adopting online delivery formats to expand its geographical reach. © 2018 Health Libraries Group.

Examination of a Capabilities-based Prioritization Scheme for Service-Oriented Architecture Afloat

DTIC Science & Technology

2012-09-01

Oriented Architecture Afloat 5. FUNDING NUMBERS 6. AUTHOR(S) Matthew C. Horton 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS (ES) Naval...Postgraduate School Monterey, CA 93943–5000 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING /MONITORING AGENCY NAME(S) AND ADDRESS (ES) N/A...within the Internet Protocol Version 4 ( IPv4 ) header (Xiao & Ni, 1999). By manipulating three bits within this byte, applications may specify

Proactive Fault Tolerance for HPC with Xen Virtualization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nagarajan, Arun Babu; Mueller, Frank; Engelmann, Christian

2007-01-01

with thousands of processors. At such large counts of compute nodes, faults are becoming common place. Current techniques to tolerate faults focus on reactive schemes to recover from faults and generally rely on a checkpoint/restart mechanism. Yet, in today's systems, node failures can often be anticipated by detecting a deteriorating health status. Instead of a reactive scheme for fault tolerance (FT), we are promoting a proactive one where processes automatically migrate from “unhealthy” nodes to healthy ones. Our approach relies on operating system virtualization techniques exemplied by but not limited to Xen. This paper contributes an automatic and transparent mechanismmore » for proactive FT for arbitrary MPI applications. It leverages virtualization techniques combined with health monitoring and load-based migration. We exploit Xen's live migration mechanism for a guest operating system (OS) to migrate an MPI task from a health-deteriorating node to a healthy one without stopping the MPI task during most of the migration. Our proactive FT daemon orchestrates the tasks of health monitoring, load determination and initiation of guest OS migration. Experimental results demonstrate that live migration hides migration costs and limits the overhead to only a few seconds making it an attractive approach to realize FT in HPC systems. Overall, our enhancements make proactive FT a valuable asset for long-running MPI application that is complementary to reactive FT using full checkpoint/ restart schemes since checkpoint frequencies can be reduced as fewer unanticipated failures are encountered. In the context of OS virtualization, we believe that this is the rst comprehensive study of proactive fault tolerance where live migration is actually triggered by health monitoring.« less

Remote observing with NASA's Deep Space Network

NASA Astrophysics Data System (ADS)

Kuiper, T. B. H.; Majid, W. A.; Martinez, S.; Garcia-Miro, C.; Rizzo, J. R.

2012-09-01

The Deep Space Network (DSN) communicates with spacecraft as far away as the boundary between the Solar System and the interstellar medium. To make this possible, large sensitive antennas at Canberra, Australia, Goldstone, California, and Madrid, Spain, provide for constant communication with interplanetary missions. We describe the procedures for radioastronomical observations using this network. Remote access to science monitor and control computers by authorized observers is provided by two-factor authentication through a gateway at the Jet Propulsion Laboratory (JPL) in Pasadena. To make such observations practical, we have devised schemes based on SSH tunnels and distributed computing. At the very minimum, one can use SSH tunnels and VNC (Virtual Network Computing, a remote desktop software suite) to control the science hosts within the DSN Flight Operations network. In this way we have controlled up to three telescopes simultaneously. However, X-window updates can be slow and there are issues involving incompatible screen sizes and multi-screen displays. Consequently, we are now developing SSH tunnel-based schemes in which instrument control and monitoring, and intense data processing, are done on-site by the remote DSN hosts while data manipulation and graphical display are done at the observer's host. We describe our approaches to various challenges, our experience with what worked well and lessons learned, and directions for future development.

Flexible risk metrics for identifying and monitoring conservation-priority species

USGS Publications Warehouse

Stanton, Jessica C.; Semmens, Brice X.; McKann, Patrick C.; Will, Tom; Thogmartin, Wayne E.

2016-01-01

Region-specific conservation programs should have objective, reliable metrics for species prioritization and progress evaluation that are customizable to the goals of a program, easy to comprehend and communicate, and standardized across time. Regional programs may have vastly different goals, spatial coverage, or management agendas, and one-size-fits-all schemes may not always be the best approach. We propose a quantitative and objective framework for generating metrics for prioritizing species that is straightforward to implement and update, customizable to different spatial resolutions, and based on readily available time-series data. This framework is also well-suited to handling missing-data and observer error. We demonstrate this approach using North American Breeding Bird Survey (NABBS) data to identify conservation priority species from a list of over 300 landbirds across 33 bird conservation regions (BCRs). To highlight the flexibility of the framework for different management goals and timeframes we calculate two different metrics. The first identifies species that may be inadequately monitored by NABBS protocols in the near future (TMT, time to monitoring threshold), and the other identifies species likely to decline significantly in the near future based on recent trends (TPD, time to percent decline). Within the individual BCRs we found up to 45% (mean 28%) of the species analyzed had overall declining population trajectories, which could result in up to 37 species declining below a minimum NABBS monitoring threshold in at least one currently occupied BCR within the next 50 years. Additionally, up to 26% (mean 8%) of the species analyzed within the individual BCRs may decline by 30% within the next decade. Conservation workers interested in conserving avian diversity and abundance within these BCRs can use these metrics to plan alternative monitoring schemes or highlight the urgency of those populations experiencing the fastest declines. However, this framework is adaptable to many taxa besides birds where abundance time-series data are available.

A Double Chaotic Layer Encryption Algorithm for Clinical Signals in Telemedicine.

PubMed

Murillo-Escobar, M A; Cardoza-Avendaño, L; López-Gutiérrez, R M; Cruz-Hernández, C

2017-04-01

Recently, telemedicine offers medical services remotely via telecommunications systems and physiological monitoring devices. This scheme provides healthcare delivery services between physicians and patients conveniently, since some patients can not attend the hospital due to any reason. However, transmission of information over an insecure channel such as internet or private data storing generates a security problem. Therefore, authentication, confidentiality, and privacy are important challenges in telemedicine, where only authorized users should have access to medical or clinical records. On the other hand, chaotic systems have been implemented efficiently in cryptographic systems to provide confidential and privacy. In this work, we propose a novel symmetric encryption algorithm based on logistic map with double chaotic layer encryption (DCLE) in diffusion process and just one round of confusion-diffusion for the confidentiality and privacy of clinical information such as electrocardiograms (ECG), electroencephalograms (EEG), and blood pressure (BP) for applications in telemedicine. The clinical signals are acquired from PhysioBank data base for encryption proposes and analysis. In contrast with recent schemes in literature, we present a secure cryptographic algorithm based on chaos validated with the most complete security analysis until this time. In addition, the cryptograms are validated with the most complete pseudorandomness tests based on National Institute of Standards and Technology (NIST) 800-22 suite. All results are at MATLAB simulations and all them show the effectiveness, security, robustness, and the potential use of the proposed scheme in telemedicine.

Monitoring change in the abundance and distribution of insects using butterflies and other indicator groups

PubMed Central

Thomas, J.A

2005-01-01

Conservative estimates suggest that 50–90% of the existing insect species on Earth have still to be discovered, yet the named insects alone comprise more than half of all known species of organism. With such poor baseline knowledge, monitoring change in insect diversity poses a formidable challenge to scientists and most attempts to generalize involve large extrapolations from a few well-studied taxa. Butterflies are often the only group for which accurate measures of change can be obtained. Four schemes, used successfully to assess change in British butterflies, that are increasingly being applied across the world are described: Red Data Books (RDB) list the best judgements of experts of the conservation status of species in their field of expertise; mapping schemes plot the changing distributions of species at scales of 1–100 km2; transect monitoring schemes generate time series of changes in abundance in sample populations of species on fixed sites across the UK; and occasional surveys measure the number, boundaries and size of all populations of a (usually RDB) species at intervals of 10–30 years. All schemes describe consistent patterns of change, but if they are to be more generally useful, it is important to understand how well butterflies are representative of other taxa. Comparisons with similarly measured changes in native bird and plant species suggest that butterflies have declined more rapidly that these other groups in Britain; it should soon be possible to test whether this pattern exists elsewhere. It is also demonstrated that extinction rates in British butterflies are similar to those in a range of other insect groups over 100 years once recording bias is accounted for, although probably lower than in aquatic or parasitic taxa. It is concluded that butterflies represent adequate indicators of change for many terrestrial insect groups, but recommended that similar schemes be extended to other popular groups, especially dragonflies, bumblebees, hoverflies and ants. Given institutional backing, similar projects could be employed internationally and standardized. Finally, a range of schemes designed to monitor change in communities of aquatic macro-invertebrates is described. Although designed to use invertebrates as a bio-indicator of water quality for human use, these programmes could be extended to monitor the 2010 biodiversity targets of the World Summit on Sustainable Development. PMID:15814349

Monitoring change in the abundance and distribution of insects using butterflies and other indicator groups.

PubMed

Thomas, J A

2005-02-28

Conservative estimates suggest that 50-90% of the existing insect species on Earth have still to be discovered, yet the named insects alone comprise more than half of all known species of organism. With such poor baseline knowledge, monitoring change in insect diversity poses a formidable challenge to scientists and most attempts to generalize involve large extrapolations from a few well-studied taxa. Butterflies are often the only group for which accurate measures of change can be obtained. Four schemes, used successfully to assess change in British butterflies, that are increasingly being applied across the world are described: Red Data Books (RDB) list the best judgements of experts of the conservation status of species in their field of expertise; mapping schemes plot the changing distributions of species at scales of 1-100 km2; transect monitoring schemes generate time series of changes in abundance in sample populations of species on fixed sites across the UK; and occasional surveys measure the number, boundaries and size of all populations of a (usually RDB) species at intervals of 10-30 years. All schemes describe consistent patterns of change, but if they are to be more generally useful, it is important to understand how well butterflies are representative of other taxa. Comparisons with similarly measured changes in native bird and plant species suggest that butterflies have declined more rapidly that these other groups in Britain; it should soon be possible to test whether this pattern exists elsewhere. It is also demonstrated that extinction rates in British butterflies are similar to those in a range of other insect groups over 100 years once recording bias is accounted for, although probably lower than in aquatic or parasitic taxa. It is concluded that butterflies represent adequate indicators of change for many terrestrial insect groups, but recommended that similar schemes be extended to other popular groups, especially dragonflies, bumblebees, hoverflies and ants. Given institutional backing, similar projects could be employed internationally and standardized. Finally, a range of schemes designed to monitor change in communities of aquatic macro-invertebrates is described. Although designed to use invertebrates as a bio-indicator of water quality for human use, these programmes could be extended to monitor the 2010 biodiversity targets of the World Summit on Sustainable Development.

An efficient recursive least square-based condition monitoring approach for a rail vehicle suspension system

NASA Astrophysics Data System (ADS)

Liu, X. Y.; Alfi, S.; Bruni, S.

2016-06-01

A model-based condition monitoring strategy for the railway vehicle suspension is proposed in this paper. This approach is based on recursive least square (RLS) algorithm focusing on the deterministic 'input-output' model. RLS has Kalman filtering feature and is able to identify the unknown parameters from a noisy dynamic system by memorising the correlation properties of variables. The identification of suspension parameter is achieved by machine learning of the relationship between excitation and response in a vehicle dynamic system. A fault detection method for the vertical primary suspension is illustrated as an instance of this condition monitoring scheme. Simulation results from the rail vehicle dynamics software 'ADTreS' are utilised as 'virtual measurements' considering a trailer car of Italian ETR500 high-speed train. The field test data from an E464 locomotive are also employed to validate the feasibility of this strategy for the real application. Results of the parameter identification performed indicate that estimated suspension parameters are consistent or approximate with the reference values. These results provide the supporting evidence that this fault diagnosis technique is capable of paving the way for the future vehicle condition monitoring system.

A VCSEL based system for on-site monitoring of low level methane emission

NASA Astrophysics Data System (ADS)

Kannath, A.; Hodgkinson, J.; Gillard, R. G.; Riley, R. J.; Tatam, R. P.

2011-03-01

Continuous monitoring of methane emissions has assumed greater significance in the recent past due to increasing focus on global warming issues. Many industries have also identified the need for ppm level methane measurement as a means of gaining carbon credits. Conventional instruments based on NDIR spectroscopy are unable to offer the high selectivity and sensitivity required for such measurements. Here we discuss the development of a robust VCSEL based system for accurate low level measurements of methane. A possible area of application is the measurement of residual methane whilst monitoring the output of flare stacks and exhaust gases from methane combustion engines. The system employs a Wavelength Modulation Spectroscopy (WMS) scheme with second harmonic detection at 1651 nm. Optimum modulation frequency and ramp rates were chosen to maintain high resolution and fast response times which are vital for the intended application. Advanced data processing techniques were used to achieve long term sensitivity of the order of 10-5 in absorbance. The system is immune to cross interference from other gases and its inherent design features makes it ideal for large scale commercial production. The instrument maintains its calibration and offers a completely automated continuous monitoring solution for remote on site deployment.

Channel Deviation-Based Power Control in Body Area Networks.

PubMed

Van, Son Dinh; Cotton, Simon L; Smith, David B

2018-05-01

Internet enabled body area networks (BANs) will form a core part of future remote health monitoring and ambient assisted living technology. In BAN applications, due to the dynamic nature of human activity, the off-body BAN channel can be prone to deep fading caused by body shadowing and multipath fading. Using this knowledge, we present some novel practical adaptive power control protocols based on the channel deviation to simultaneously prolong the lifetime of wearable devices and reduce outage probability. The proposed schemes are both flexible and relatively simple to implement on hardware platforms with constrained resources making them inherently suitable for BAN applications. We present the key algorithm parameters used to dynamically respond to the channel variation. This allows the algorithms to achieve a better energy efficiency and signal reliability in everyday usage scenarios such as those in which a person undertakes many different activities (e.g., sitting, walking, standing, etc.). We also profile their performance against traditional, optimal, and other existing schemes for which it is demonstrated that not only does the outage probability reduce significantly, but the proposed algorithms also save up to average transmit power compared to the competing schemes.

Ship Detection in Gaofen-3 SAR Images Based on Sea Clutter Distribution Analysis and Deep Convolutional Neural Network

PubMed Central

You, Hongjian

2018-01-01

Target detection is one of the important applications in the field of remote sensing. The Gaofen-3 (GF-3) Synthetic Aperture Radar (SAR) satellite launched by China is a powerful tool for maritime monitoring. This work aims at detecting ships in GF-3 SAR images using a new land masking strategy, the appropriate model for sea clutter and a neural network as the discrimination scheme. Firstly, the fully convolutional network (FCN) is applied to separate the sea from the land. Then, by analyzing the sea clutter distribution in GF-3 SAR images, we choose the probability distribution model of Constant False Alarm Rate (CFAR) detector from K-distribution, Gamma distribution and Rayleigh distribution based on a tradeoff between the sea clutter modeling accuracy and the computational complexity. Furthermore, in order to better implement CFAR detection, we also use truncated statistic (TS) as a preprocessing scheme and iterative censoring scheme (ICS) for boosting the performance of detector. Finally, we employ a neural network to re-examine the results as the discrimination stage. Experiment results on three GF-3 SAR images verify the effectiveness and efficiency of this approach. PMID:29364194

Ship Detection in Gaofen-3 SAR Images Based on Sea Clutter Distribution Analysis and Deep Convolutional Neural Network.

PubMed

An, Quanzhi; Pan, Zongxu; You, Hongjian

2018-01-24

Target detection is one of the important applications in the field of remote sensing. The Gaofen-3 (GF-3) Synthetic Aperture Radar (SAR) satellite launched by China is a powerful tool for maritime monitoring. This work aims at detecting ships in GF-3 SAR images using a new land masking strategy, the appropriate model for sea clutter and a neural network as the discrimination scheme. Firstly, the fully convolutional network (FCN) is applied to separate the sea from the land. Then, by analyzing the sea clutter distribution in GF-3 SAR images, we choose the probability distribution model of Constant False Alarm Rate (CFAR) detector from K-distribution, Gamma distribution and Rayleigh distribution based on a tradeoff between the sea clutter modeling accuracy and the computational complexity. Furthermore, in order to better implement CFAR detection, we also use truncated statistic (TS) as a preprocessing scheme and iterative censoring scheme (ICS) for boosting the performance of detector. Finally, we employ a neural network to re-examine the results as the discrimination stage. Experiment results on three GF-3 SAR images verify the effectiveness and efficiency of this approach.

A Low-Cost Tracking System for Running Race Applications Based on Bluetooth Low Energy Technology.

PubMed

Perez-Diaz-de-Cerio, David; Hernández-Solana, Ángela; Valdovinos, Antonio; Valenzuela, Jose Luis

2018-03-20

Timing points used in running races and other competition events are generally based on radio-frequency identification (RFID) technology. Athletes' times are calculated via passive RFID tags and reader kits. Specifically, the reader infrastructure needed is complex and requires the deployment of a mat or ramps which hide the receiver antennae under them. Moreover, with the employed tags, it is not possible to transmit additional and dynamic information such as pulse or oximetry monitoring, alarms, etc. In this paper we present a system based on two low complex schemes allowed in Bluetooth Low Energy (BLE): the non-connectable undirected advertisement process and a modified version of scannable undirected advertisement process using the new capabilities present in Bluetooth 5. After fully describing the system architecture, which allows full real-time position monitoring of the runners using mobile phones on the organizer side and BLE sensors on the participants' side, we derive the mobility patterns of runners and capacity requirements, which are determinant for evaluating the performance of the proposed system. They have been obtained from the analysis of the real data measured in the last Barcelona Marathon. By means of simulations, we demonstrate that, even under disadvantageous conditions (50% error ratio), both schemes perform reliably and are able to detect the 100% of the participants in all the cases. The cell coverage of the system needs to be adjusted when non-connectable process is considered. Nevertheless, through simulation and experimental, we show that the proposed scheme based on the new events available in Bluetooth 5 is clearly the best implementation alternative for all the cases, no matter the coverage area and the runner speed. The proposal widely exceeds the detection requirements of the real scenario, surpassing the measured peaks of 20 sensors per second incoming in the coverage area, moving at speeds that range from 1.5 m/s to 6.25 m/s. The designed real test-bed shows that the scheme is able to detect 72 sensors below 600 ms, fulfilling comfortably the requirements determined for the intended application. The main disadvantage of this system would be that the sensors are active, but we have proved that its consumption can be so low (9.5 µA) that, with a typical button cell, the sensor battery life would be over 10,000 h of use.

A Low-Cost Tracking System for Running Race Applications Based on Bluetooth Low Energy Technology

PubMed Central

2018-01-01

Timing points used in running races and other competition events are generally based on radio-frequency identification (RFID) technology. Athletes’ times are calculated via passive RFID tags and reader kits. Specifically, the reader infrastructure needed is complex and requires the deployment of a mat or ramps which hide the receiver antennae under them. Moreover, with the employed tags, it is not possible to transmit additional and dynamic information such as pulse or oximetry monitoring, alarms, etc. In this paper we present a system based on two low complex schemes allowed in Bluetooth Low Energy (BLE): the non-connectable undirected advertisement process and a modified version of scannable undirected advertisement process using the new capabilities present in Bluetooth 5. After fully describing the system architecture, which allows full real-time position monitoring of the runners using mobile phones on the organizer side and BLE sensors on the participants’ side, we derive the mobility patterns of runners and capacity requirements, which are determinant for evaluating the performance of the proposed system. They have been obtained from the analysis of the real data measured in the last Barcelona Marathon. By means of simulations, we demonstrate that, even under disadvantageous conditions (50% error ratio), both schemes perform reliably and are able to detect the 100% of the participants in all the cases. The cell coverage of the system needs to be adjusted when non-connectable process is considered. Nevertheless, through simulation and experimental, we show that the proposed scheme based on the new events available in Bluetooth 5 is clearly the best implementation alternative for all the cases, no matter the coverage area and the runner speed. The proposal widely exceeds the detection requirements of the real scenario, surpassing the measured peaks of 20 sensors per second incoming in the coverage area, moving at speeds that range from 1.5 m/s to 6.25 m/s. The designed real test-bed shows that the scheme is able to detect 72 sensors below 600 ms, fulfilling comfortably the requirements determined for the intended application. The main disadvantage of this system would be that the sensors are active, but we have proved that its consumption can be so low (9.5 µA) that, with a typical button cell, the sensor battery life would be over 10,000 h of use. PMID:29558432

Output Consensus of Heterogeneous Linear Multi-Agent Systems by Distributed Event-Triggered/Self-Triggered Strategy.

PubMed

Hu, Wenfeng; Liu, Lu; Feng, Gang

2016-09-02

This paper addresses the output consensus problem of heterogeneous linear multi-agent systems. We first propose a novel distributed event-triggered control scheme. It is shown that, with the proposed control scheme, the output consensus problem can be solved if two matrix equations are satisfied. Then, we further propose a novel self-triggered control scheme, with which continuous monitoring is avoided. By introducing a fixed timer into both event- and self-triggered control schemes, Zeno behavior can be ruled out for each agent. The effectiveness of the event- and self-triggered control schemes is illustrated by an example.

French citizens monitoring ordinary birds provide tools for conservation and ecological sciences

NASA Astrophysics Data System (ADS)

Jiguet, Frédéric; Devictor, Vincent; Julliard, Romain; Couvet, Denis

2012-10-01

Volunteer-based standardized monitoring of birds has been widely implemented in Europe and North America. In France, a breeding bird survey is running since 1989 and offers keen birdwatchers to count spring birds annually during 5 min exactly on 10 fix points within a randomly selected square. The first goal of such breeding bird surveys is to measure temporal trends in order to detect possible species declines. Combining annual indices of species sharing ecological affinities or a protected/red list status further provides biodiversity indicators for policy makers. Because the sampling effort is similar among sites, and because the initial selection of monitored sites is random, the temporal trends can be considered representative of national trends, and spatial comparisons of the obtained metrics are possible. Species abundance, community richness but also community specialization and average trophic level can be estimated for each site and each year and further related to the wide range of habitat and landscape characteristics and to agricultural or forestry practices. The large number of sites allows overcoming the opposition between adaptive and passive monitoring, making such schemes fitted to adaptive monitoring. This provides opportunities to determine which type of management or practices favour biodiversity. The comparison of population fate or community dynamics across a wide range of climates and temperatures, e.g. from southern to northern Europe, revealed how European birds are already affected by climate change. Bird communities are shifting northwards, but at a slower rate than temperatures, while bird populations have larger growth rates away from their hot thermal limit. Finally, such large-scale long-term monitoring data on a complete taxonomic group (Aves) is original and offers the opportunity to compare different measures of biological diversity, such as taxonomic, phylogenetic and functional diversity. Such a citizen science scheme is an efficient scientific tool (numerous papers published in international peer-reviewed journals) which is furthermore highly cost-effective, with a reduced permanent staff in a state insitution coordonating the network and analysing the data, while a similar survey conducted by state staff only would cost more than one million euros annually. The future development of bio-economic dynamic models for providing scenarios of sustainable farming and logging to maintain biodiversity will further highlight the necessity of such volunteer monitoring for policy makers and decision planning. Scientific and logistic partnerships could be proposed to help developing such a monitoring scheme in China.

Cost-effective accurate coarse-grid method for highly convective multidimensional unsteady flows

NASA Technical Reports Server (NTRS)

Leonard, B. P.; Niknafs, H. S.

1991-01-01

A fundamentally multidimensional convection scheme is described based on vector transient interpolation modeling rewritten in conservative control-volume form. Vector third-order upwinding is used as the basis of the algorithm; this automatically introduces important cross-difference terms that are absent from schemes using component-wise one-dimensional formulas. Third-order phase accuracy is good; this is important for coarse-grid large-eddy or full simulation. Potential overshoots or undershoots are avoided by using a recently developed universal limiter. Higher order accuracy is obtained locally, where needed, by the cost-effective strategy of adaptive stencil expansion in a direction normal to each control-volume face; this is controlled by monitoring the absolute normal gradient and curvature across the face. Higher (than third) order cross-terms do not appear to be needed. Since the wider stencil is used only in isolated narrow regions (near discontinuities), extremely high (in this case, seventh) order accuracy can be achieved for little more than the cost of a globally third-order scheme.

Distributed dynamic strain measurement using long-gauge FBG and DTR3 interrogator based on delayed transmission/reflection ratiometric reflectometry

NASA Astrophysics Data System (ADS)

Nishiyama, M.; Igawa, H.; Kasai, T.; Watanabe, N.

2013-09-01

In this paper, we reveal characteristics of static and dynamic distributed strain measurement using a long-gauge fiber Bragg grating (FBG) and a Delayed Transmission/Reflection Ratiometric Reflectometry (DTR3) scheme. The DTR3 scheme has capability of detecting distributed strain using the long-gauge FBG with 50-cm spatial resolution. Additionally, dynamic strain measurement can be achieved using this technique in 100-Hz sampling rate. We evaluated strain sensing characteristics of the long-gauge FBG attached on 2.5-m aluminum bar by a four-point bending equipment. Experimental results showed that the DTR3 using the long-gauge FBG could detect distributed strain in static tests and resonance frequency of structure in free vibration tests. As a result, it is suggested that the DTR3 scheme using the longgauge FBG is attractive to structural health monitoring (SHM) as dynamic deformation detection of a few and tensmeters structure such as the airplane wing and the helicopter blade.

Anti-islanding Protection of Distributed Generation Using Rate of Change of Impedance

NASA Astrophysics Data System (ADS)

Shah, Pragnesh; Bhalja, Bhavesh

2013-08-01

Distributed Generation (DG), which is interlinked with distribution system, has inevitable effect on distribution system. Integrating DG with the utility network demands an anti-islanding scheme to protect the system. Failure to trip islanded generators can lead to problems such as threats to personnel safety, out-of-phase reclosing, and degradation of power quality. In this article, a new method for anti-islanding protection based on impedance monitoring of distribution network is carried out in presence of DG. The impedance measured between two phases is used to derive the rate of change of impedance (dz/dt), and its peak values are used for final trip decision. Test data are generated using PSCAD/EMTDC software package and the performance of the proposed method is evaluated in MatLab software. The simulation results show the effectiveness of the proposed scheme as it is capable to detect islanding condition accurately. Subsequently, it is also observed that the proposed scheme does not mal-operate during other disturbances such as short circuit and switching event.

76 FR 2011 - High Seas Driftnet Fishing Moratorium Protection Act; Identification and Certification Procedures...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-12

... unauthorized or other IUU catch; Catch and effort monitoring, including licensing and permitting schemes, reporting, and vessel monitoring systems (VMS); Bycatch reduction and mitigation strategies and techniques... effective sanctions and monitoring, control and surveillance (MCS) capacity; and Participation in voluntary...

A Secure and Robust User Authenticated Key Agreement Scheme for Hierarchical Multi-medical Server Environment in TMIS.

PubMed

Das, Ashok Kumar; Odelu, Vanga; Goswami, Adrijit

2015-09-01

The telecare medicine information system (TMIS) helps the patients to gain the health monitoring facility at home and access medical services over the Internet of mobile networks. Recently, Amin and Biswas presented a smart card based user authentication and key agreement security protocol usable for TMIS system using the cryptographic one-way hash function and biohashing function, and claimed that their scheme is secure against all possible attacks. Though their scheme is efficient due to usage of one-way hash function, we show that their scheme has several security pitfalls and design flaws, such as (1) it fails to protect privileged-insider attack, (2) it fails to protect strong replay attack, (3) it fails to protect strong man-in-the-middle attack, (4) it has design flaw in user registration phase, (5) it has design flaw in login phase, (6) it has design flaw in password change phase, (7) it lacks of supporting biometric update phase, and (8) it has flaws in formal security analysis. In order to withstand these security pitfalls and design flaws, we aim to propose a secure and robust user authenticated key agreement scheme for the hierarchical multi-server environment suitable in TMIS using the cryptographic one-way hash function and fuzzy extractor. Through the rigorous security analysis including the formal security analysis using the widely-accepted Burrows-Abadi-Needham (BAN) logic, the formal security analysis under the random oracle model and the informal security analysis, we show that our scheme is secure against possible known attacks. Furthermore, we simulate our scheme using the most-widely accepted and used Automated Validation of Internet Security Protocols and Applications (AVISPA) tool. The simulation results show that our scheme is also secure. Our scheme is more efficient in computation and communication as compared to Amin-Biswas's scheme and other related schemes. In addition, our scheme supports extra functionality features as compared to other related schemes. As a result, our scheme is very appropriate for practical applications in TMIS.

Towards uncertainty estimates in global operational forecasts of trace gases in the Copernicus Atmosphere Monitoring System

NASA Astrophysics Data System (ADS)

Huijnen, V.; Bouarar, I.; Chabrillat, S. H.; Christophe, Y.; Thierno, D.; Karydis, V.; Marecal, V.; Pozzer, A.; Flemming, J.

2017-12-01

Operational atmospheric composition analyses and forecasts such as developed in the Copernicus Atmosphere Monitoring Service (CAMS) rely on modules describing emissions, chemical conversion, transport and removal processing, as well as data assimilation methods. The CAMS forecasts can be used to drive regional air quality models across the world. Critical analyses of uncertainties in any of these processes are continuously needed to advance the quality of such systems on a global scale, ranging from the surface up to the stratosphere. With regard to the atmospheric chemistry to describe the fate of trace gases, the operational system currently relies on a modified version of the CB05 chemistry scheme for the troposphere combined with the Cariolle scheme to describe stratospheric ozone, as integrated in ECMWF's Integrated Forecasting System (IFS). It is further constrained by assimilation of satellite observations of CO, O3 and NO2. As part of CAMS we have recently developed three fully independent schemes to describe the chemical conversion throughout the atmosphere. These parameterizations originate from parent model codes in MOZART, MOCAGE and a combination of TM5/BASCOE. In this contribution we evaluate the correspondence and elemental differences in the performance of the three schemes in an otherwise identical model configuration (excluding data-assimilation) against a large range of in-situ and satellite-based observations of ozone, CO, VOC's and chlorine-containing trace gases for both troposphere and stratosphere. This analysis aims to provide a measure of model uncertainty in the operational system for tracers that are not, or poorly, constrained by data assimilation. It aims also to provide guidance on the directions for further model improvement with regard to the chemical conversion module.

Characterization of protein--DNA interactions using surface plasmon resonance spectroscopy with various assay schemes.

PubMed

Teh, Huey Fang; Peh, Wendy Y X; Su, Xiaodi; Thomsen, Jane S

2007-02-27

Specific protein-DNA interactions play a central role in transcription and other biological processes. A comprehensive characterization of protein-DNA interactions should include information about binding affinity, kinetics, sequence specificity, and binding stoichiometry. In this study, we have used surface plasmon resonance spectroscopy (SPR) to study the interactions between human estrogen receptors (ER, alpha and beta subtypes) and estrogen response elements (ERE), with four assay schemes. First, we determined the sequence-dependent receptors' binding capacity by monitoring the binding of ER to various ERE sequences immobilized on a sensor surface (assay format denoted as the direct assay). Second, we screened the relative affinity of ER for various ERE sequences using a competition assay, in which the receptors bind to an ERE-immobilized surface in the presence of competitor ERE sequences. Third, we monitored the assembly of ER-ERE complexes on a SPR surface and thereafter the removal and/or dissociation of the ER (assay scheme denoted as the dissociation assay) to determine the binding stoichiometry. Last, a sandwich assay (ER binding to ERE followed by anti-ER recognition of a specific ER subtype) was performed in an effort to understand how ERalpha and ERbeta may associate and compete when binding to the DNA. With these assay schemes, we reaffirmed that (1) ERalpha is more sensitive than ERbeta to base pair change(s) in the consensus ERE, (2) ERalpha and ERbeta form a heterodimer when they bind to the consensus ERE, and (3) the binding stoichiometry of both ERalpha- and ERbeta-ERE complexes is dependent on salt concentration. With this study, we demonstrate the versatility of the SPR analysis. With the involvement of various assay arrangements, the SPR analysis can be further extended to more than kinetics and affinity study.

[Intelligent watch system for health monitoring based on Bluetooth low energy technology].

PubMed

Wang, Ji; Guo, Hailiang; Ren, Xiaoli

2017-08-01

According to the development status of wearable technology and the demand of intelligent health monitoring, we studied the multi-function integrated smart watches solution and its key technology. First of all, the sensor technology with high integration density, Bluetooth low energy (BLE) and mobile communication technology were integrated and used in develop practice. Secondly, for the hardware design of the system in this paper, we chose the scheme with high integration density and cost-effective computer modules and chips. Thirdly, we used real-time operating system FreeRTOS to develop the friendly graphical interface interacting with touch screen. At last, the high-performance application software which connected with BLE hardware wirelessly and synchronized data was developed based on android system. The function of this system included real-time calendar clock, telephone message, address book management, step-counting, heart rate and sleep quality monitoring and so on. Experiments showed that the collecting data accuracy of various sensors, system data transmission capacity, the overall power consumption satisfy the production standard. Moreover, the system run stably with low power consumption, which could realize intelligent health monitoring effectively.

Image-Based Environmental Monitoring Sensor Application Using an Embedded Wireless Sensor Network

PubMed Central

Paek, Jeongyeup; Hicks, John; Coe, Sharon; Govindan, Ramesh

2014-01-01

This article discusses the experiences from the development and deployment of two image-based environmental monitoring sensor applications using an embedded wireless sensor network. Our system uses low-power image sensors and the Tenet general purpose sensing system for tiered embedded wireless sensor networks. It leverages Tenet's built-in support for reliable delivery of high rate sensing data, scalability and its flexible scripting language, which enables mote-side image compression and the ease of deployment. Our first deployment of a pitfall trap monitoring application at the James San Jacinto Mountain Reserve provided us with insights and lessons learned into the deployment of and compression schemes for these embedded wireless imaging systems. Our three month-long deployment of a bird nest monitoring application resulted in over 100,000 images collected from a 19-camera node network deployed over an area of 0.05 square miles, despite highly variable environmental conditions. Our biologists found the on-line, near-real-time access to images to be useful for obtaining data on answering their biological questions. PMID:25171121

Image-based environmental monitoring sensor application using an embedded wireless sensor network.

PubMed

Paek, Jeongyeup; Hicks, John; Coe, Sharon; Govindan, Ramesh

2014-08-28

This article discusses the experiences from the development and deployment of two image-based environmental monitoring sensor applications using an embedded wireless sensor network. Our system uses low-power image sensors and the Tenet general purpose sensing system for tiered embedded wireless sensor networks. It leverages Tenet's built-in support for reliable delivery of high rate sensing data, scalability and its flexible scripting language, which enables mote-side image compression and the ease of deployment. Our first deployment of a pitfall trap monitoring application at the James San Cannot Mountain Reserve provided us with insights and lessons learned into the deployment of and compression schemes for these embedded wireless imaging systems. Our three month-long deployment of a bird nest monitoring application resulted in over 100,000 images collected from a 19-camera node network deployed over an area of 0.05 square miles, despite highly variable environmental conditions. Our biologists found the on-line, near-real-time access to images to be useful for obtaining data on answering their biological questions.

A diagnostic signal selection scheme for planetary gearbox vibration monitoring under non-stationary operational conditions

NASA Astrophysics Data System (ADS)

Feng, Ke; Wang, KeSheng; Zhang, Mian; Ni, Qing; Zuo, Ming J.

2017-03-01

The planetary gearbox, due to its unique mechanical structures, is an important rotating machine for transmission systems. Its engineering applications are often in non-stationary operational conditions, such as helicopters, wind energy systems, etc. The unique physical structures and working conditions make the vibrations measured from planetary gearboxes exhibit a complex time-varying modulation and therefore yield complicated spectral structures. As a result, traditional signal processing methods, such as Fourier analysis, and the selection of characteristic fault frequencies for diagnosis face serious challenges. To overcome this drawback, this paper proposes a signal selection scheme for fault-emphasized diagnostics based upon two order tracking techniques. The basic procedures for the proposed scheme are as follows. (1) Computed order tracking is applied to reveal the order contents and identify the order(s) of interest. (2) Vold-Kalman filter order tracking is used to extract the order(s) of interest—these filtered order(s) constitute the so-called selected vibrations. (3) Time domain statistic indicators are applied to the selected vibrations for faulty information-emphasized diagnostics. The proposed scheme is explained and demonstrated in a signal simulation model and experimental studies and the method proves to be effective for planetary gearbox fault diagnosis.

Protocol for a feasibility randomised controlled trial of the use of Physical ACtivity monitors in an Exercise Referral Setting: the PACERS study.

PubMed

Hawkins, Jemma; Edwards, Michelle; Charles, Joanna; Jago, Russell; Kelson, Mark; Morgan, Kelly; Murphy, Simon; Oliver, Emily; Simpson, Sharon; Edwards, Rhiannon Tudor; Moore, Graham

2017-01-01

Exercise referral schemes are recommended by the National Institute for Clinical Excellence (NICE) for physical activity promotion among inactive patients with health conditions or risk factors. Whilst there is evidence for the initial effectiveness and cost-effectiveness of such schemes for increasing physical activity, evidence of long-term effects is limited. Techniques such as goal setting, self-monitoring and personalised feedback may support motivation for physical activity. Technologies such as activity monitoring devices provide an opportunity to enhance delivery of motivational techniques. This paper describes the PACERS study protocol, which aims to assess the feasibility and acceptability of implementing an activity monitor within the existing Welsh National Exercise Referral Scheme (NERS) and proposed evaluation methodology for a full-scale randomised controlled trial. The PACERS study consists of a pilot randomised controlled trial, process evaluation and exploratory economic analyses. Participants will be recruited from the generic pathway of the Welsh NERS and will be randomly assigned to receive the intervention or usual practice. Usual practice is a 16-week structured exercise programme; the intervention consists of an accelerometry-based activity monitor (MyWellnessKey) and an associated web platform (MyWellnessCloud). The primary outcomes are predefined progression criteria assessing the acceptability and feasibility of the intervention and feasibility of the proposed evaluation methodology. Postal questionnaires will be completed at baseline (time 0: T0), 16 weeks after T0 (T1) and 12 months after T0 (T2). Routinely collected data will also be accessed at the same time points. A sub-sample of intervention participants and exercise referral staff will be interviewed following initiation of intervention delivery and at the end of the study. The PACERS study seeks to assess the feasibility of adding a novel motivational component to an existing effective intervention in order to enhance effects on physical activity and support longer-term maintenance. The study will provide insight into the acceptability of activity-monitoring technologies to an exercise referral population and delivery staff. Data from this study will be used to determine whether and how to proceed to a full-scale trial of effectiveness of the intervention, including any necessary refinements to intervention implementation or the proposed evaluation methodology. ISRCTN85785652.

Research on time synchronization scheme of MES systems in manufacturing enterprise

NASA Astrophysics Data System (ADS)

Yuan, Yuan; Wu, Kun; Sui, Changhao; Gu, Jin

2018-04-01

With the popularity of information and automatic production in the manufacturing enterprise, data interaction between business systems is more and more frequent. Therefore, the accuracy of time is getting higher and higher. However, the NTP network time synchronization methods lack the corresponding redundancy and monitoring mechanisms. When failure occurs, it can only make up operations after the event, which has a great effect on production data and systems interaction. Based on this, the paper proposes a RHCS-based NTP server architecture, automatically detect NTP status and failover by script.

Optimal rotated staggered-grid finite-difference schemes for elastic wave modeling in TTI media

NASA Astrophysics Data System (ADS)

Yang, Lei; Yan, Hongyong; Liu, Hong

2015-11-01

The rotated staggered-grid finite-difference (RSFD) is an effective approach for numerical modeling to study the wavefield characteristics in tilted transversely isotropic (TTI) media. But it surfaces from serious numerical dispersion, which directly affects the modeling accuracy. In this paper, we propose two different optimal RSFD schemes based on the sampling approximation (SA) method and the least-squares (LS) method respectively to overcome this problem. We first briefly introduce the RSFD theory, based on which we respectively derive the SA-based RSFD scheme and the LS-based RSFD scheme. Then different forms of analysis are used to compare the SA-based RSFD scheme and the LS-based RSFD scheme with the conventional RSFD scheme, which is based on the Taylor-series expansion (TE) method. The contrast in numerical accuracy analysis verifies the greater accuracy of the two proposed optimal schemes, and indicates that these schemes can effectively widen the wavenumber range with great accuracy compared with the TE-based RSFD scheme. Further comparisons between these two optimal schemes show that at small wavenumbers, the SA-based RSFD scheme performs better, while at large wavenumbers, the LS-based RSFD scheme leads to a smaller error. Finally, the modeling results demonstrate that for the same operator length, the SA-based RSFD scheme and the LS-based RSFD scheme can achieve greater accuracy than the TE-based RSFD scheme, while for the same accuracy, the optimal schemes can adopt shorter difference operators to save computing time.

Remote Health Monitoring Outcome Success Prediction Using Baseline and First Month Intervention Data.

PubMed

Alshurafa, Nabil; Sideris, Costas; Pourhomayoun, Mohammad; Kalantarian, Haik; Sarrafzadeh, Majid; Eastwood, Jo-Ann

2017-03-01

Remote health monitoring (RHM) systems are becoming more widely adopted by clinicians and hospitals to remotely monitor and communicate with patients while optimizing clinician time, decreasing hospital costs, and improving quality of care. In the Women's heart health study (WHHS), we developed Wanda-cardiovascular disease (CVD), where participants received healthy lifestyle education followed by six months of technology support and reinforcement. Wanda-CVD is a smartphone-based RHM system designed to assist participants in reducing identified CVD risk factors through wireless coaching using feedback and prompts as social support. Many participants benefitted from this RHM system. In response to the variance in participants' success, we developed a framework to identify classification schemes that predicted successful and unsuccessful participants. We analyzed both contextual baseline features and data from the first month of intervention such as activity, blood pressure, and questionnaire responses transmitted through the smartphone. A prediction tool can aid clinicians and scientists in identifying participants who may optimally benefit from the RHM system. Targeting therapies could potentially save healthcare costs, clinician, and participant time and resources. Our classification scheme yields RHM outcome success predictions with an F-measure of 91.9%, and identifies behaviors during the first month of intervention that help determine outcome success. We also show an improvement in prediction by using intervention-based smartphone data. Results from the WHHS study demonstrates that factors such as the variation in first month intervention response to the consumption of nuts, beans, and seeds in the diet help predict patient RHM protocol outcome success in a group of young Black women ages 25-45.

Using two classification schemes to develop vegetation indices of biological integrity for wetlands in West Virginia, USA.

PubMed

Veselka, Walter; Rentch, James S; Grafton, William N; Kordek, Walter S; Anderson, James T

2010-11-01

Bioassessment methods for wetlands, and other bodies of water, have been developed worldwide to measure and quantify changes in "biological integrity." These assessments are based on a classification system, meant to ensure appropriate comparisons between wetland types. Using a local site-specific disturbance gradient, we built vegetation indices of biological integrity (Veg-IBIs) based on two commonly used wetland classification systems in the USA: One based on vegetative structure and the other based on a wetland's position in a landscape and sources of water. The resulting class-specific Veg-IBIs were comprised of 1-5 metrics that varied in their sensitivity to the disturbance gradient (R2=0.14-0.65). Moreover, the sensitivity to the disturbance gradient increased as metrics from each of the two classification schemes were combined (added). Using this information to monitor natural and created wetlands will help natural resource managers track changes in biological integrity of wetlands in response to anthropogenic disturbance and allows the use of vegetative communities to set ecological performance standards for mitigation banks.

Wastewater quality monitoring system using sensor fusion and machine learning techniques.

PubMed

Qin, Xusong; Gao, Furong; Chen, Guohua

2012-03-15

A multi-sensor water quality monitoring system incorporating an UV/Vis spectrometer and a turbidimeter was used to monitor the Chemical Oxygen Demand (COD), Total Suspended Solids (TSS) and Oil & Grease (O&G) concentrations of the effluents from the Chinese restaurant on campus and an electrocoagulation-electroflotation (EC-EF) pilot plant. In order to handle the noise and information unbalance in the fused UV/Vis spectra and turbidity measurements during the calibration model building, an improved boosting method, Boosting-Iterative Predictor Weighting-Partial Least Squares (Boosting-IPW-PLS), was developed in the present study. The Boosting-IPW-PLS method incorporates IPW into boosting scheme to suppress the quality-irrelevant variables by assigning small weights, and builds up the models for the wastewater quality predictions based on the weighted variables. The monitoring system was tested in the field with satisfactory results, underlying the potential of this technique for the online monitoring of water quality. Copyright © 2011 Elsevier Ltd. All rights reserved.

[Extension of cardiac monitoring function by used of ordinary ECG machine].

PubMed

Chen, Zhencheng; Jiang, Yong; Ni, Lili; Wang, Hongyan

2002-06-01

This paper deals with a portable monitor system on liquid crystal display (LCD) based on this available ordinary ECG machine, which is low power and suitable for China's specific condition. Apart from developing the overall scheme of the system, this paper also has completed the design of the hardware and the software. The 80c196 single chip microcomputer is taken as the central microprocessor and real time electrocardiac single is data treated and analyzed in the system. With the performance of ordinary monitor, this machine also possesses the following functions: five types of arrhythmia analysis, alarm, freeze, and record of automatic pappering, convenient in carrying, with alternate-current (AC) or direct-current (DC) powered. The hardware circuit is simplified and the software structure is optimized in this paper. Multiple low power designs and LCD unit design are adopted and completed in it. Popular in usage, low in cost price, the portable monitor system will have a valuable influence on China's monitor system field.

The effects of sample scheduling and sample numbers on estimates of the annual fluxes of suspended sediment in fluvial systems

USGS Publications Warehouse

Horowitz, Arthur J.; Clarke, Robin T.; Merten, Gustavo Henrique

2015-01-01

Since the 1970s, there has been both continuing and growing interest in developing accurate estimates of the annual fluvial transport (fluxes and loads) of suspended sediment and sediment-associated chemical constituents. This study provides an evaluation of the effects of manual sample numbers (from 4 to 12 year−1) and sample scheduling (random-based, calendar-based and hydrology-based) on the precision, bias and accuracy of annual suspended sediment flux estimates. The evaluation is based on data from selected US Geological Survey daily suspended sediment stations in the USA and covers basins ranging in area from just over 900 km2 to nearly 2 million km2 and annual suspended sediment fluxes ranging from about 4 Kt year−1 to about 200 Mt year−1. The results appear to indicate that there is a scale effect for random-based and calendar-based sampling schemes, with larger sample numbers required as basin size decreases. All the sampling schemes evaluated display some level of positive (overestimates) or negative (underestimates) bias. The study further indicates that hydrology-based sampling schemes are likely to generate the most accurate annual suspended sediment flux estimates with the fewest number of samples, regardless of basin size. This type of scheme seems most appropriate when the determination of suspended sediment concentrations, sediment-associated chemical concentrations, annual suspended sediment and annual suspended sediment-associated chemical fluxes only represent a few of the parameters of interest in multidisciplinary, multiparameter monitoring programmes. The results are just as applicable to the calibration of autosamplers/suspended sediment surrogates currently used to measure/estimate suspended sediment concentrations and ultimately, annual suspended sediment fluxes, because manual samples are required to adjust the sample data/measurements generated by these techniques so that they provide depth-integrated and cross-sectionally representative data. 

MeMoVolc report on classification and dynamics of volcanic explosive eruptions

NASA Astrophysics Data System (ADS)

Bonadonna, C.; Cioni, R.; Costa, A.; Druitt, T.; Phillips, J.; Pioli, L.; Andronico, D.; Harris, A.; Scollo, S.; Bachmann, O.; Bagheri, G.; Biass, S.; Brogi, F.; Cashman, K.; Dominguez, L.; Dürig, T.; Galland, O.; Giordano, G.; Gudmundsson, M.; Hort, M.; Höskuldsson, A.; Houghton, B.; Komorowski, J. C.; Küppers, U.; Lacanna, G.; Le Pennec, J. L.; Macedonio, G.; Manga, M.; Manzella, I.; Vitturi, M. de'Michieli; Neri, A.; Pistolesi, M.; Polacci, M.; Ripepe, M.; Rossi, E.; Scheu, B.; Sulpizio, R.; Tripoli, B.; Valade, S.; Valentine, G.; Vidal, C.; Wallenstein, N.

2016-11-01

Classifications of volcanic eruptions were first introduced in the early twentieth century mostly based on qualitative observations of eruptive activity, and over time, they have gradually been developed to incorporate more quantitative descriptions of the eruptive products from both deposits and observations of active volcanoes. Progress in physical volcanology, and increased capability in monitoring, measuring and modelling of explosive eruptions, has highlighted shortcomings in the way we classify eruptions and triggered a debate around the need for eruption classification and the advantages and disadvantages of existing classification schemes. Here, we (i) review and assess existing classification schemes, focussing on subaerial eruptions; (ii) summarize the fundamental processes that drive and parameters that characterize explosive volcanism; (iii) identify and prioritize the main research that will improve the understanding, characterization and classification of volcanic eruptions and (iv) provide a roadmap for producing a rational and comprehensive classification scheme. In particular, classification schemes need to be objective-driven and simple enough to permit scientific exchange and promote transfer of knowledge beyond the scientific community. Schemes should be comprehensive and encompass a variety of products, eruptive styles and processes, including for example, lava flows, pyroclastic density currents, gas emissions and cinder cone or caldera formation. Open questions, processes and parameters that need to be addressed and better characterized in order to develop more comprehensive classification schemes and to advance our understanding of volcanic eruptions include conduit processes and dynamics, abrupt transitions in eruption regime, unsteadiness, eruption energy and energy balance.

Monitoring tumor motion by real time 2D/3D registration during radiotherapy.

PubMed

Gendrin, Christelle; Furtado, Hugo; Weber, Christoph; Bloch, Christoph; Figl, Michael; Pawiro, Supriyanto Ardjo; Bergmann, Helmar; Stock, Markus; Fichtinger, Gabor; Georg, Dietmar; Birkfellner, Wolfgang

2012-02-01

In this paper, we investigate the possibility to use X-ray based real time 2D/3D registration for non-invasive tumor motion monitoring during radiotherapy. The 2D/3D registration scheme is implemented using general purpose computation on graphics hardware (GPGPU) programming techniques and several algorithmic refinements in the registration process. Validation is conducted off-line using a phantom and five clinical patient data sets. The registration is performed on a region of interest (ROI) centered around the planned target volume (PTV). The phantom motion is measured with an rms error of 2.56 mm. For the patient data sets, a sinusoidal movement that clearly correlates to the breathing cycle is shown. Videos show a good match between X-ray and digitally reconstructed radiographs (DRR) displacement. Mean registration time is 0.5 s. We have demonstrated that real-time organ motion monitoring using image based markerless registration is feasible. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Investigating the limits of PET/CT imaging at very low true count rates and high random fractions in ion-beam therapy monitoring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kurz, Christopher, E-mail: Christopher.Kurz@physik.uni-muenchen.de; Bauer, Julia; Conti, Maurizio

Purpose: External beam radiotherapy with protons and heavier ions enables a tighter conformation of the applied dose to arbitrarily shaped tumor volumes with respect to photons, but is more sensitive to uncertainties in the radiotherapeutic treatment chain. Consequently, an independent verification of the applied treatment is highly desirable. For this purpose, the irradiation-induced β{sup +}-emitter distribution within the patient is detected shortly after irradiation by a commercial full-ring positron emission tomography/x-ray computed tomography (PET/CT) scanner installed next to the treatment rooms at the Heidelberg Ion-Beam Therapy Center (HIT). A major challenge to this approach is posed by the small numbermore » of detected coincidences. This contribution aims at characterizing the performance of the used PET/CT device and identifying the best-performing reconstruction algorithm under the particular statistical conditions of PET-based treatment monitoring. Moreover, this study addresses the impact of radiation background from the intrinsically radioactive lutetium-oxyorthosilicate (LSO)-based detectors at low counts. Methods: The authors have acquired 30 subsequent PET scans of a cylindrical phantom emulating a patientlike activity pattern and spanning the entire patient counting regime in terms of true coincidences and random fractions (RFs). Accuracy and precision of activity quantification, image noise, and geometrical fidelity of the scanner have been investigated for various reconstruction algorithms and settings in order to identify a practical, well-suited reconstruction scheme for PET-based treatment verification. Truncated listmode data have been utilized for separating the effects of small true count numbers and high RFs on the reconstructed images. A corresponding simulation study enabled extending the results to an even wider range of counting statistics and to additionally investigate the impact of scatter coincidences. Eventually, the recommended reconstruction scheme has been applied to exemplary postirradiation patient data-sets. Results: Among the investigated reconstruction options, the overall best results in terms of image noise, activity quantification, and accurate geometrical recovery were achieved using the ordered subset expectation maximization reconstruction algorithm with time-of-flight (TOF) and point-spread function (PSF) information. For this algorithm, reasonably accurate (better than 5%) and precise (uncertainty of the mean activity below 10%) imaging can be provided down to 80 000 true coincidences at 96% RF. Image noise and geometrical fidelity are generally improved for fewer iterations. The main limitation for PET-based treatment monitoring has been identified in the small number of true coincidences, rather than the high intrinsic random background. Application of the optimized reconstruction scheme to patient data-sets results in a 25% − 50% reduced image noise at a comparable activity quantification accuracy and an improved geometrical performance with respect to the formerly used reconstruction scheme at HIT, adopted from nuclear medicine applications. Conclusions: Under the poor statistical conditions in PET-based treatment monitoring, improved results can be achieved by considering PSF and TOF information during image reconstruction and by applying less iterations than in conventional nuclear medicine imaging. Geometrical fidelity and image noise are mainly limited by the low number of true coincidences, not the high LSO-related random background. The retrieved results might also impact other emerging PET applications at low counting statistics.« less

A new sampling scheme for tropical forest monitoring using satellite imagery

Treesearch

Frederic Achard; Tim Richards; Javier Gallego

2000-01-01

At the global level, a sampling scheme for tropical forest change assessment, using high resolution satellite images, has been defined using sampling units independent of any particular satellite sensor. For this purpose, a sampling frame has been chosen a hexagonal tessellation of 3,600 km².

An evaluation of supervised classifiers for indirectly detecting salt-affected areas at irrigation scheme level

NASA Astrophysics Data System (ADS)

Muller, Sybrand Jacobus; van Niekerk, Adriaan

2016-07-01

Soil salinity often leads to reduced crop yield and quality and can render soils barren. Irrigated areas are particularly at risk due to intensive cultivation and secondary salinization caused by waterlogging. Regular monitoring of salt accumulation in irrigation schemes is needed to keep its negative effects under control. The dynamic spatial and temporal characteristics of remote sensing can provide a cost-effective solution for monitoring salt accumulation at irrigation scheme level. This study evaluated a range of pan-fused SPOT-5 derived features (spectral bands, vegetation indices, image textures and image transformations) for classifying salt-affected areas in two distinctly different irrigation schemes in South Africa, namely Vaalharts and Breede River. The relationship between the input features and electro conductivity measurements were investigated using regression modelling (stepwise linear regression, partial least squares regression, curve fit regression modelling) and supervised classification (maximum likelihood, nearest neighbour, decision tree analysis, support vector machine and random forests). Classification and regression trees and random forest were used to select the most important features for differentiating salt-affected and unaffected areas. The results showed that the regression analyses produced weak models (<0.4 R squared). Better results were achieved using the supervised classifiers, but the algorithms tend to over-estimate salt-affected areas. A key finding was that none of the feature sets or classification algorithms stood out as being superior for monitoring salt accumulation at irrigation scheme level. This was attributed to the large variations in the spectral responses of different crops types at different growing stages, coupled with their individual tolerances to saline conditions.

[The Jena Anxiety Monitoring List (JAMoL) - a tool for the evidence-based treatment of panic disorder with or without agoraphobia in primary care].

PubMed

Hiller, Thomas Stephan; Freytag, Antje; Breitbart, Jörg; Teismann, Tobias; Schöne, Elisabeth; Blank, Wolfgang; Schelle, Mercedes; Vollmar, Horst Christian; Margraf, Jürgen; Gensichen, Jochen

2018-04-01

Behavior therapy-oriented methods are recommended for treating anxiety disorders in primary care. The treatment of patients with long-term conditions can be improved by case management and structured clinical monitoring. The present paper describes the rationale, design and application of the 'Jena Anxiety Monitoring List' (JAMoL), a monitoring tool for the treatment of patients with panic disorder, with or without agoraphobia, in primary care. JAMoL's design was based on established clinical measures, the rationale of exposure-based anxiety treatment, and research on family practice-based case management. After piloting, the JAMoL was used in the clinical study 'Jena-PARADISE' (ISRCTN64669297), where non-physician practice staff monitored patients with panic disorder by telephone. Using semi-structured interviews in concomitant studies, study participants were asked about the instrument's functionality. The JAMoL assesses the severity of anxiety symptoms (6 items) as well as the patient's adherence to therapy (4 items) and fosters the case management-related information exchange (3 items). An integrated traffic light scheme facilitates the evaluation of monitoring results. Within the clinical study, non-physician practice staff carried out a total of 1,525 JAMoL-supported monitoring calls on 177 patients from 30 primary care practices (median calls per patient: 10 [interquartile range, 9-10]). Qualitative analyses revealed that most practice teams and patients rated the JAMoL as a practicable and treatment-relevant tool. The JAMoL enables primary care practice teams to continuously monitor anxiety symptoms and treatment adherence in patients with panic disorder with or without agoraphobia. Within the behavior therapy-oriented treatment program 'Jena-PARADISE', the JAMoL constitutes an important case management tool. Copyright © 2018. Published by Elsevier GmbH.

Definition of a near real time microbiological monitor for space vehicles

NASA Technical Reports Server (NTRS)

Kilgore, Melvin V., Jr.; Zahorchak, Robert J.; Arendale, William F.

1989-01-01

Efforts to identify the ideal candidate to serve as the biological monitor on the space station Freedom are discussed. The literature review, the evaluation scheme, descriptions of candidate monitors, experimental studies, test beds, and culture techniques are discussed. Particular attention is given to descriptions of five candidate monitors or monitoring techniques: laser light scattering, primary fluorescence, secondary fluorescence, the volatile product detector, and the surface acoustic wave detector.

Wavelet subspace decomposition of thermal infrared images for defect detection in artworks

NASA Astrophysics Data System (ADS)

Ahmad, M. Z.; Khan, A. A.; Mezghani, S.; Perrin, E.; Mouhoubi, K.; Bodnar, J. L.; Vrabie, V.

2016-07-01

Health of ancient artworks must be routinely monitored for their adequate preservation. Faults in these artworks may develop over time and must be identified as precisely as possible. The classical acoustic testing techniques, being invasive, risk causing permanent damage during periodic inspections. Infrared thermometry offers a promising solution to map faults in artworks. It involves heating the artwork and recording its thermal response using infrared camera. A novel strategy based on pseudo-random binary excitation principle is used in this work to suppress the risks associated with prolonged heating. The objective of this work is to develop an automatic scheme for detecting faults in the captured images. An efficient scheme based on wavelet based subspace decomposition is developed which favors identification of, the otherwise invisible, weaker faults. Two major problems addressed in this work are the selection of the optimal wavelet basis and the subspace level selection. A novel criterion based on regional mutual information is proposed for the latter. The approach is successfully tested on a laboratory based sample as well as real artworks. A new contrast enhancement metric is developed to demonstrate the quantitative efficiency of the algorithm. The algorithm is successfully deployed for both laboratory based and real artworks.

Plasmonic rainbow rings induced by white radial polarization.

PubMed

Lan, Tzu-Hsiang; Chung, Yi-Kuan; Li, Jie-En; Tien, Chung-Hao

2012-04-01

This Letter presents a scheme to embed both angular/spectral surface plasmon resonance (SPR) in a unique far-field rainbow feature by tightly focusing (effective NA=1.45) a polychromatic radially polarized beam on an Au (20 nm)/SiO2 (500 nm)/Au (20 nm) sandwich structure. Without the need for angular or spectral scanning, the virtual spectral probe snapshots a wide operation range (n=1-1.42; λ=400-700 nm) of SPR excitation in a locally nanosized region. Combined with the high-speed spectral analysis, a proof-of-concept scenario was given by monitoring the NaCl liquid concentration change in real time. The proposed scheme will certainly has a promising impact on the development of objective-based SPR sensor and biometric studies due to its rapidity and versatility.

Controlling front-end electronics boards using commercial solutions

NASA Astrophysics Data System (ADS)

Beneyton, R.; Gaspar, C.; Jost, B.; Schmeling, S.

2002-04-01

LHCb is a dedicated B-physics experiment under construction at CERN's large hadron collider (LHC) accelerator. This paper will describe the novel approach LHCb is taking toward controlling and monitoring of electronics boards. Instead of using the bus in a crate to exercise control over the boards, we use credit-card sized personal computers (CCPCs) connected via Ethernet to cheap control PCs. The CCPCs will provide a simple parallel, I2C, and JTAG buses toward the electronics board. Each board will be equipped with a CCPC and, hence, will be completely independently controlled. The advantages of this scheme versus the traditional bus-based scheme will be described. Also, the integration of the controls of the electronics boards into a commercial supervisory control and data acquisition (SCADA) system will be shown.

Quality-based purchasing in health care.

PubMed

Waters, Hugh R; Morlock, Laura L; Hatt, Laurel

2004-01-01

Quality-based purchasing is a growing trend that seeks to improve healthcare quality through the purchaser-provider relationship. This article provides a unifying conceptual framework, presents examples of the purchaser-provider relationship in countries at different income levels, and identifies important supporting mechanisms for quality-based purchasing. As countries become wealthier, a higher proportion of healthcare spending is channeled through pooled arrangements, allowing for greater involvement of purchasers in promoting the quality of service provision. Global and line item budgets are the most common type of provider payment system in low and middle-income countries. In these countries, improving public hospital performance through contracting and incentives is a key issue. In middle and high-income countries, there are several documented examples of governments contracting to private or non-governmental health care providers, resulting in higher perceived quality of care and lower delivery costs. Encouraging quality through employer purchasing arrangements has been promoted in several countries, particularly the United States. Community-based financing schemes are an increasingly common form of health financing in parts of sub-Saharan Africa and Asia, but these schemes still cover less than 10% of national populations in countries in which they are active. To date, there is little evidence of their impact on healthcare quality. The availability of information--concerning healthcare service provision and outcomes--determines the options for establishing and monitoring contract provisions and promoting quality. Regardless of the context, quality-based purchasing depends critically on informa-tion--reporting, monitoring, and providing useful information to healthcare consumers. In many low and middle-income countries, the lack of availability of information is the principal constraint on measuring performance, a critical component of quality-based purchasing.

New Authentication Scheme for Wireless Body Area Networks Using the Bilinear Pairing.

PubMed

Wang, Chunzhi; Zhang, Yanmei

2015-11-01

Due to the development of information technologies and network technologies, healthcare systems have been employed in many countries. As an important part of healthcare systems, the wireless body area network (WBAN) could bring convenience to both patients and physicians because it could help physicians to monitor patients' physiological values remotely. It is essential to ensure secure communication in WBANs because patients' physiological values are very sensitive. Recently, Liu et al. proposed an efficient authentication scheme for WBANs. Unfortunately, Zhao pointed out that their scheme suffered from the stolen verifier-table attack. To improve security and efficiency, Zhao proposed an anonymous authentication scheme for WBANs. However, Zhao's scheme cannot provide real anonymity because the users' pseudo identities are constant value and the attack could tract the users. In this paper, we propose a new anonymous authentication scheme for WBANs. Security analysis shows that the proposed scheme could overcome weaknesses in previous scheme. We also use the BAN logic to demonstrate the security of the proposed scheme.

Time vs. Money: A Quantitative Evaluation of Monitoring Frequency vs. Monitoring Duration.

PubMed

McHugh, Thomas E; Kulkarni, Poonam R; Newell, Charles J

2016-09-01

The National Research Council has estimated that over 126,000 contaminated groundwater sites are unlikely to achieve low ug/L clean-up goals in the foreseeable future. At these sites, cost-effective, long-term monitoring schemes are needed in order to understand the long-term changes in contaminant concentrations. Current monitoring optimization schemes rely on site-specific evaluations to optimize groundwater monitoring frequency. However, when using linear regression to estimate the long-term zero-order or first-order contaminant attenuation rate, the effect of monitoring frequency and monitoring duration on the accuracy and confidence for the estimated attenuation rate is not site-specific. For a fixed number of monitoring events, doubling the time between monitoring events (e.g., changing from quarterly monitoring to semi-annual monitoring) will double the accuracy of estimated attenuation rate. For a fixed monitoring frequency (e.g., semi-annual monitoring), increasing the number of monitoring events by 60% will double the accuracy of the estimated attenuation rate. Combining these two factors, doubling the time between monitoring events (e.g., quarterly monitoring to semi-annual monitoring) while decreasing the total number of monitoring events by 38% will result in no change in the accuracy of the estimated attenuation rate. However, the time required to collect this dataset will increase by 25%. Understanding that the trade-off between monitoring frequency and monitoring duration is not site-specific should simplify the process of optimizing groundwater monitoring frequency at contaminated groundwater sites. © 2016 The Authors. Groundwater published by Wiley Periodicals, Inc. on behalf of National Ground Water Association.

Assessing the impact of a cattle risk-based trading scheme on the movement of bovine tuberculosis infected animals in England and Wales.

PubMed

Adkin, A; Brouwer, A; Downs, S H; Kelly, L

2016-01-01

The adoption of bovine tuberculosis (bTB) risk-based trading (RBT) schemes has the potential to reduce the risk of bTB spread. However, any scheme will have cost implications that need to be balanced against its likely success in reducing bTB. This paper describes the first stochastic quantitative model assessing the impact of the implementation of a cattle risk-based trading scheme to inform policy makers and contribute to cost-benefit analyses. A risk assessment for England and Wales was developed to estimate the number of infected cattle traded using historic movement data recorded between July 2010 and June 2011. Three scenarios were implemented: cattle traded with no RBT scheme in place, voluntary provision of the score and a compulsory, statutory scheme applying a bTB risk score to each farm. For each scenario, changes in trade were estimated due to provision of the risk score to potential purchasers. An estimated mean of 3981 bTB infected animals were sold to purchasers with no RBT scheme in place in one year, with 90% confidence the true value was between 2775 and 5288. This result is dependent on the estimated between herd prevalence used in the risk assessment which is uncertain. With the voluntary provision of the risk score by farmers, on average, 17% of movements was affected (purchaser did not wish to buy once the risk score was available), with a reduction of 23% in infected animals being purchased initially. The compulsory provision of the risk score in a statutory scheme resulted in an estimated mean change to 26% of movements, with a reduction of 37% in infected animals being purchased initially, increasing to a 53% reduction in infected movements from higher risk sellers (score 4 and 5). The estimated mean reduction in infected animals being purchased could be improved to 45% given a 10% reduction in risky purchase behaviour by farmers which may be achieved through education programmes, or to an estimated mean of 49% if a rule was implemented preventing farmers from the purchase of animals of higher risk than their own herd. Given voluntary trials currently taking place of a trading scheme, recommendations for future work include the monitoring of initial uptake and changes in the purchase patterns of farmers. Such data could be used to update the risk assessment to reduce uncertainty associated with model estimates. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

Master-slave control scheme in electric vehicle smart charging infrastructure.

PubMed

Chung, Ching-Yen; Chynoweth, Joshua; Chu, Chi-Cheng; Gadh, Rajit

2014-01-01

WINSmartEV is a software based plug-in electric vehicle (PEV) monitoring, control, and management system. It not only incorporates intelligence at every level so that charge scheduling can avoid grid bottlenecks, but it also multiplies the number of PEVs that can be plugged into a single circuit. This paper proposes, designs, and executes many upgrades to WINSmartEV. These upgrades include new hardware that makes the level 1 and level 2 chargers faster, more robust, and more scalable. It includes algorithms that provide a more optimal charge scheduling for the level 2 (EVSE) and an enhanced vehicle monitoring/identification module (VMM) system that can automatically identify PEVs and authorize charging.

Master-Slave Control Scheme in Electric Vehicle Smart Charging Infrastructure

PubMed Central

Chung, Ching-Yen; Chynoweth, Joshua; Chu, Chi-Cheng; Gadh, Rajit

2014-01-01

WINSmartEV is a software based plug-in electric vehicle (PEV) monitoring, control, and management system. It not only incorporates intelligence at every level so that charge scheduling can avoid grid bottlenecks, but it also multiplies the number of PEVs that can be plugged into a single circuit. This paper proposes, designs, and executes many upgrades to WINSmartEV. These upgrades include new hardware that makes the level 1 and level 2 chargers faster, more robust, and more scalable. It includes algorithms that provide a more optimal charge scheduling for the level 2 (EVSE) and an enhanced vehicle monitoring/identification module (VMM) system that can automatically identify PEVs and authorize charging. PMID:24982956

Long open-path TDL based system for monitoring the background concentration for deployment at Jungfraujoch High Altitude Research Station- Switzerland

NASA Astrophysics Data System (ADS)

Simeonov, V.; van den Bergh, H.; Parlange, M. B.

2009-12-01

A new long-open-path instrument developed at EPFL for methane and water vapor observation will be presented. The instrument is developed and will be used within the GAW+ CH program and aims at long-term monitoring of background methane concentration at the High Altitude Research Station Jungfraujoch (3580 mASL). The instrument is built on the monostatic scheme (transceiver -distant retroreflector) using a 1.65 nm tunable diode laser (TDL) and a retroreflector at 1200 m from the transceiver. The data will be compared with in-situ measurements to evaluate the effect of the station on the in-situ data.

Diagnostic grade wireless ECG monitoring.

PubMed

Garudadri, Harinath; Chi, Yuejie; Baker, Steve; Majumdar, Somdeb; Baheti, Pawan K; Ballard, Dan

2011-01-01

In remote monitoring of Electrocardiogram (ECG), it is very important to ensure that the diagnostic integrity of signals is not compromised by sensing artifacts and channel errors. It is also important for the sensors to be extremely power efficient to enable wearable form factors and long battery life. We present an application of Compressive Sensing (CS) as an error mitigation scheme at the application layer for wearable, wireless sensors in diagnostic grade remote monitoring of ECG. In our previous work, we described an approach to mitigate errors due to packet losses by projecting ECG data to a random space and recovering a faithful representation using sparse reconstruction methods. Our contributions in this work are twofold. First, we present an efficient hardware implementation of random projection at the sensor. Second, we validate the diagnostic integrity of the reconstructed ECG after packet loss mitigation. We validate our approach on MIT and AHA databases comprising more than 250,000 normal and abnormal beats using EC57 protocols adopted by the Food and Drug Administration (FDA). We show that sensitivity and positive predictivity of a state-of-the-art ECG arrhythmia classifier is essentially invariant under CS based packet loss mitigation for both normal and abnormal beats even at high packet loss rates. In contrast, the performance degrades significantly in the absence of any error mitigation scheme, particularly for abnormal beats such as Ventricular Ectopic Beats (VEB).

A Fiber-Optic Interferometric Tri-Component Geophone for Ocean Floor Seismic Monitoring

PubMed Central

Chen, Jiandong; Chang, Tianying; Fu, Qunjian; Lang, Jinpeng; Gao, Wenzhi; Wang, Zhongmin; Yu, Miao; Zhang, Yanbo; Cui, Hong-Liang

2016-01-01

For the implementation of an all fiber observation network for submarine seismic monitoring, a tri-component geophone based on Michelson interferometry is proposed and tested. A compliant cylinder-based sensor head is analyzed with finite element method and tested. The operation frequency ranges from 2 Hz to 150 Hz for acceleration detection, employing a phase generated carrier demodulation scheme, with a responsivity above 50 dB re rad/g for the whole frequency range. The transverse suppression ratio is about 30 dB. The system noise at low frequency originated mainly from the 1/f fluctuation, with an average system noise level −123.55 dB re rad/Hz ranging from 0 Hz to 500 Hz. The minimum detectable acceleration is about 2 ng/Hz, and the dynamic range is above 116 dB. PMID:28036011

Reliability-based optimization of an active vibration controller using evolutionary algorithms

NASA Astrophysics Data System (ADS)

Saraygord Afshari, Sajad; Pourtakdoust, Seid H.

2017-04-01

Many modern industrialized systems such as aircrafts, rotating turbines, satellite booms, etc. cannot perform their desired tasks accurately if their uninhibited structural vibrations are not controlled properly. Structural health monitoring and online reliability calculations are emerging new means to handle system imposed uncertainties. As stochastic forcing are unavoidable, in most engineering systems, it is often needed to take them into the account for the control design process. In this research, smart material technology is utilized for structural health monitoring and control in order to keep the system in a reliable performance range. In this regard, a reliability-based cost function is assigned for both controller gain optimization as well as sensor placement. The proposed scheme is implemented and verified for a wing section. Comparison of results for the frequency responses is considered to show potential applicability of the presented technique.

A Scheme for the Evaluation of Electron Delocalization and Conjugation Efficiency in Linearly π-Conjugated Systems.

PubMed

Bruschi, Maurizio; Limacher, Peter A; Hutter, Jürg; Lüthi, Hans Peter

2009-03-10

In this study, we present a scheme for the evaluation of electron delocalization and conjugation efficiency in lineraly π-conjugated systems. The scheme, based on the natural bond orbital theory, allows monitoring the evolution of electron delocalization along an extended conjugation path as well as its response to chemical modification. The scheme presented is evaluated and illustrated by means of a computational investigation of π-conjugation in all-trans polyacetylene [PA; H(-CH═CH)n-H], polydiacetylene [PDA, H(-C≡C-CH═CH)n-H], and polytriacetylene [PTA, H(-C≡C-CH═CH-C≡C)n-H] with up to 180 carbon atoms, all related by the number of ethynyl units incorporated in the chain. We are able to show that for short oligomers the incorporation of ethynyl spacers into the PA chain increases the π-delocalization energy, but, on the other hand, reduces the efficiency with which π-electron delocalization is promoted along the backbone. This explains the generally shorter effective conjugation lengths observed for the properties of the polyeneynes (PDA and PTA) relative to the polyenes (PA). It will also be shown that the reduced conjugation efficiency, within the NBO-based model presented in this work, can be related to the orbital interaction pattern along the π-conjugated chain. We will show that the orbital interaction energy pattern is characteristic for the type and the length of the backbone and may therefore serve as a descriptor for linearly π-conjugated chains.

Real-time monitoring of single-photon detectors against eavesdropping in quantum key distribution systems.

PubMed

da Silva, Thiago Ferreira; Xavier, Guilherme B; Temporão, Guilherme P; von der Weid, Jean Pierre

2012-08-13

By employing real-time monitoring of single-photon avalanche photodiodes we demonstrate how two types of practical eavesdropping strategies, the after-gate and time-shift attacks, may be detected. Both attacks are identified with the detectors operating without any special modifications, making this proposal well suited for real-world applications. The monitoring system is based on accumulating statistics of the times between consecutive detection events, and extracting the afterpulse and overall efficiency of the detectors in real-time using mathematical models fit to the measured data. We are able to directly observe changes in the afterpulse probabilities generated from the after-gate and faint after-gate attacks, as well as different timing signatures in the time-shift attack. We also discuss the applicability of our scheme to other general blinding attacks.

Secure Data Access Control for Fog Computing Based on Multi-Authority Attribute-Based Signcryption with Computation Outsourcing and Attribute Revocation.

PubMed

Xu, Qian; Tan, Chengxiang; Fan, Zhijie; Zhu, Wenye; Xiao, Ya; Cheng, Fujia

2018-05-17

Nowadays, fog computing provides computation, storage, and application services to end users in the Internet of Things. One of the major concerns in fog computing systems is how fine-grained access control can be imposed. As a logical combination of attribute-based encryption and attribute-based signature, Attribute-based Signcryption (ABSC) can provide confidentiality and anonymous authentication for sensitive data and is more efficient than traditional "encrypt-then-sign" or "sign-then-encrypt" strategy. Thus, ABSC is suitable for fine-grained access control in a semi-trusted cloud environment and is gaining more and more attention recently. However, in many existing ABSC systems, the computation cost required for the end users in signcryption and designcryption is linear with the complexity of signing and encryption access policy. Moreover, only a single authority that is responsible for attribute management and key generation exists in the previous proposed ABSC schemes, whereas in reality, mostly, different authorities monitor different attributes of the user. In this paper, we propose OMDAC-ABSC, a novel data access control scheme based on Ciphertext-Policy ABSC, to provide data confidentiality, fine-grained control, and anonymous authentication in a multi-authority fog computing system. The signcryption and designcryption overhead for the user is significantly reduced by outsourcing the undesirable computation operations to fog nodes. The proposed scheme is proven to be secure in the standard model and can provide attribute revocation and public verifiability. The security analysis, asymptotic complexity comparison, and implementation results indicate that our construction can balance the security goals with practical efficiency in computation.

Design of an FPGA-based electronic flow regulator (EFR) for spacecraft propulsion system

NASA Astrophysics Data System (ADS)

Manikandan, J.; Jayaraman, M.; Jayachandran, M.

2011-02-01

This paper describes a scheme for electronically regulating the flow of propellant to the thruster from a high-pressure storage tank used in spacecraft application. Precise flow delivery of propellant to thrusters ensures propulsion system operation at best efficiency by maximizing the propellant and power utilization for the mission. The proposed field programmable gate array (FPGA) based electronic flow regulator (EFR) is used to ensure precise flow of propellant to the thrusters from a high-pressure storage tank used in spacecraft application. This paper presents hardware and software design of electronic flow regulator and implementation of the regulation logic onto an FPGA.Motivation for proposed FPGA-based electronic flow regulation is on the disadvantages of conventional approach of using analog circuits. Digital flow regulation overcomes the analog equivalent as digital circuits are highly flexible, are not much affected due to noise, accurate performance is repeatable, interface is easier to computers, storing facilities are possible and finally failure rate of digital circuits is less. FPGA has certain advantages over ASIC and microprocessor/micro-controller that motivated us to opt for FPGA-based electronic flow regulator. Also the control algorithm being software, it is well modifiable without changing the hardware. This scheme is simple enough to adopt for a wide range of applications, where the flow is to be regulated for efficient operation.The proposed scheme is based on a space-qualified re-configurable field programmable gate arrays (FPGA) and hybrid micro circuit (HMC). A graphical user interface (GUI) based application software is also developed for debugging, monitoring and controlling the electronic flow regulator from PC COM port.

Monitoring of the Permeable Pavement Demonstration Site at the Edison Environmental Center (Poster)

EPA Science Inventory

This is a poster on the permeable pavement parking lot at the Edison Environmental Center. The monitoring scheme for the project is discussed in-depth with graphics explaining the instrumentation installed at the site.

System level modeling and component level control of fuel cells

NASA Astrophysics Data System (ADS)

Xue, Xingjian

This dissertation investigates the fuel cell systems and the related technologies in three aspects: (1) system-level dynamic modeling of both PEM fuel cell (PEMFC) and solid oxide fuel cell (SOFC); (2) condition monitoring scheme development of PEM fuel cell system using model-based statistical method; and (3) strategy and algorithm development of precision control with potential application in energy systems. The dissertation first presents a system level dynamic modeling strategy for PEM fuel cells. It is well known that water plays a critical role in PEM fuel cell operations. It makes the membrane function appropriately and improves the durability. The low temperature operating conditions, however, impose modeling difficulties in characterizing the liquid-vapor two phase change phenomenon, which becomes even more complex under dynamic operating conditions. This dissertation proposes an innovative method to characterize this phenomenon, and builds a comprehensive model for PEM fuel cell at the system level. The model features the complete characterization of multi-physics dynamic coupling effects with the inclusion of dynamic phase change. The model is validated using Ballard stack experimental result from open literature. The system behavior and the internal coupling effects are also investigated using this model under various operating conditions. Anode-supported tubular SOFC is also investigated in the dissertation. While the Nernst potential plays a central role in characterizing the electrochemical performance, the traditional Nernst equation may lead to incorrect analysis results under dynamic operating conditions due to the current reverse flow phenomenon. This dissertation presents a systematic study in this regard to incorporate a modified Nernst potential expression and the heat/mass transfer into the analysis. The model is used to investigate the limitations and optimal results of various operating conditions; it can also be utilized to perform the optimal design of tubular SOFC. With the system-level dynamic model as a basis, a framework for the robust, online monitoring of PEM fuel cell is developed in the dissertation. The monitoring scheme employs the Hotelling T2 based statistical scheme to handle the measurement noise and system uncertainties and identifies the fault conditions through a series of self-checking and conformal testing. A statistical sampling strategy is also utilized to improve the computation efficiency. Fuel/gas flow control is the fundamental operation for fuel cell energy systems. In the final part of the dissertation, a high-precision and robust tracking control scheme using piezoelectric actuator circuit with direct hysteresis compensation is developed. The key characteristic of the developed control algorithm includes the nonlinear continuous control action with the adaptive boundary layer strategy.

Deployment-based lifetime optimization model for homogeneous Wireless Sensor Network under retransmission.

PubMed

Li, Ruiying; Liu, Xiaoxi; Xie, Wei; Huang, Ning

2014-12-10

Sensor-deployment-based lifetime optimization is one of the most effective methods used to prolong the lifetime of Wireless Sensor Network (WSN) by reducing the distance-sensitive energy consumption. In this paper, data retransmission, a major consumption factor that is usually neglected in the previous work, is considered. For a homogeneous WSN, monitoring a circular target area with a centered base station, a sensor deployment model based on regular hexagonal grids is analyzed. To maximize the WSN lifetime, optimization models for both uniform and non-uniform deployment schemes are proposed by constraining on coverage, connectivity and success transmission rate. Based on the data transmission analysis in a data gathering cycle, the WSN lifetime in the model can be obtained through quantifying the energy consumption at each sensor location. The results of case studies show that it is meaningful to consider data retransmission in the lifetime optimization. In particular, our investigations indicate that, with the same lifetime requirement, the number of sensors needed in a non-uniform topology is much less than that in a uniform one. Finally, compared with a random scheme, simulation results further verify the advantage of our deployment model.

Advanced overlay: sampling and modeling for optimized run-to-run control

NASA Astrophysics Data System (ADS)

Subramany, Lokesh; Chung, WoongJae; Samudrala, Pavan; Gao, Haiyong; Aung, Nyan; Gomez, Juan Manuel; Gutjahr, Karsten; Park, DongSuk; Snow, Patrick; Garcia-Medina, Miguel; Yap, Lipkong; Demirer, Onur Nihat; Pierson, Bill; Robinson, John C.

2016-03-01

In recent years overlay (OVL) control schemes have become more complicated in order to meet the ever shrinking margins of advanced technology nodes. As a result, this brings up new challenges to be addressed for effective run-to- run OVL control. This work addresses two of these challenges by new advanced analysis techniques: (1) sampling optimization for run-to-run control and (2) bias-variance tradeoff in modeling. The first challenge in a high order OVL control strategy is to optimize the number of measurements and the locations on the wafer, so that the "sample plan" of measurements provides high quality information about the OVL signature on the wafer with acceptable metrology throughput. We solve this tradeoff between accuracy and throughput by using a smart sampling scheme which utilizes various design-based and data-based metrics to increase model accuracy and reduce model uncertainty while avoiding wafer to wafer and within wafer measurement noise caused by metrology, scanner or process. This sort of sampling scheme, combined with an advanced field by field extrapolated modeling algorithm helps to maximize model stability and minimize on product overlay (OPO). Second, the use of higher order overlay models means more degrees of freedom, which enables increased capability to correct for complicated overlay signatures, but also increases sensitivity to process or metrology induced noise. This is also known as the bias-variance trade-off. A high order model that minimizes the bias between the modeled and raw overlay signature on a single wafer will also have a higher variation from wafer to wafer or lot to lot, that is unless an advanced modeling approach is used. In this paper, we characterize the bias-variance trade off to find the optimal scheme. The sampling and modeling solutions proposed in this study are validated by advanced process control (APC) simulations to estimate run-to-run performance, lot-to-lot and wafer-to- wafer model term monitoring to estimate stability and ultimately high volume manufacturing tests to monitor OPO by densely measured OVL data.

Privacy-preserving self-helped medical diagnosis scheme based on secure two-party computation in wireless sensor networks.

PubMed

Sun, Yi; Wen, Qiaoyan; Zhang, Yudong; Li, Wenmin

2014-01-01

With the continuing growth of wireless sensor networks in pervasive medical care, people pay more and more attention to privacy in medical monitoring, diagnosis, treatment, and patient care. On one hand, we expect the public health institutions to provide us with better service. On the other hand, we would not like to leak our personal health information to them. In order to balance this contradiction, in this paper we design a privacy-preserving self-helped medical diagnosis scheme based on secure two-party computation in wireless sensor networks so that patients can privately diagnose themselves by inputting a health card into a self-helped medical diagnosis ATM to obtain a diagnostic report just like drawing money from a bank ATM without revealing patients' health information and doctors' diagnostic skill. It makes secure self-helped disease diagnosis feasible and greatly benefits patients as well as relieving the heavy pressure of public health institutions.

Privacy-Preserving Self-Helped Medical Diagnosis Scheme Based on Secure Two-Party Computation in Wireless Sensor Networks

PubMed Central

Wen, Qiaoyan; Zhang, Yudong; Li, Wenmin

2014-01-01

With the continuing growth of wireless sensor networks in pervasive medical care, people pay more and more attention to privacy in medical monitoring, diagnosis, treatment, and patient care. On one hand, we expect the public health institutions to provide us with better service. On the other hand, we would not like to leak our personal health information to them. In order to balance this contradiction, in this paper we design a privacy-preserving self-helped medical diagnosis scheme based on secure two-party computation in wireless sensor networks so that patients can privately diagnose themselves by inputting a health card into a self-helped medical diagnosis ATM to obtain a diagnostic report just like drawing money from a bank ATM without revealing patients' health information and doctors' diagnostic skill. It makes secure self-helped disease diagnosis feasible and greatly benefits patients as well as relieving the heavy pressure of public health institutions. PMID:25126107

Kinespell: Kinesthetic Learning Activity and Assessment in a Digital Game-Based Learning Environment

NASA Astrophysics Data System (ADS)

Cariaga, Ada Angeli; Salvador, Jay Andrae; Solamo, Ma. Rowena; Feria, Rommel

Various approaches in learning are commonly classified into visual, auditory and kinesthetic (VAK) learning styles. One way of addressing the VAK learning styles is through game-based learning which motivates learners pursue knowledge holistically. The paper presents Kinespell, an unconventional method of learning through digital game-based learning. Kinespell is geared towards enhancing not only the learner’s spelling abilities but also the motor skills through utilizing wireless controllers. It monitors player’s performance through integrated assessment scheme. Results show that Kinespell may accommodate the VAK learning styles and is a promising alternative to established methods in learning and assessing students’ performance in Spelling.

Impact of Vegetation Cover Fraction Parameterization schemes on Land Surface Temperature Simulation in the Tibetan Plateau

NASA Astrophysics Data System (ADS)

Lv, M.; Li, C.; Lu, H.; Yang, K.; Chen, Y.

2017-12-01

The parameterization of vegetation cover fraction (VCF) is an important component of land surface models. This paper investigates the impacts of three VCF parameterization schemes on land surface temperature (LST) simulation by the Common Land Model (CoLM) in the Tibetan Plateau (TP). The first scheme is a simple land cover (LC) based method; the second one is based on remote sensing observation (hereafter named as RNVCF) , in which multi-year climatology VCFs is derived from Moderate-resolution Imaging Spectroradiometer (MODIS) NDVI (Normalized Difference Vegetation Index); the third VCF parameterization scheme derives VCF from the LAI simulated by LSM and clump index at every model time step (hereafter named as SMVCF). Simulated land surface temperature(LST) and soil temperature by CoLM with three VCF parameterization schemes were evaluated by using satellite LST observation and in situ soil temperature observation, respectively, during the period of 2010 to 2013. The comparison against MODIS Aqua LST indicates that (1) CTL produces large biases for both four seasons in early afternoon (about 13:30, local solar time), while the mean bias in spring reach to 12.14K; (2) RNVCF and SMVCF reduce the mean bias significantly, especially in spring as such reduce is about 6.5K. Surface soil temperature observed at 5 cm depth from three soil moisture and temperature monitoring networks is also employed to assess the skill of three VCF schemes. The three networks, crossing TP from West to East, have different climate and vegetation conditions. In the Ngari network, located in the Western TP with an arid climate, there are not obvious differences among three schemes. In Naqu network, located in central TP with a semi-arid climate condition, CTL shows a severe overestimates (12.1 K), but such overestimations can be reduced by 79% by RNVCF and 87% by SMVCF. In the third humid network (Maqu in eastern TP), CoLM performs similar to Naqu. However, at both Naqu and Maqu networks, RNVCF shows significant overestimation in summer, perhaps due to RNVCF ignores the growing characteristics of vegetation (mainly grass) in these two regions. Our results demonstrate that VCF schemes have significant influence on LSM performance, and indicate that it is important to consider vegetation growing characteristics in VCF schemes for different LCs.

A High Fuel Consumption Efficiency Management Scheme for PHEVs Using an Adaptive Genetic Algorithm

PubMed Central

Lee, Wah Ching; Tsang, Kim Fung; Chi, Hao Ran; Hung, Faan Hei; Wu, Chung Kit; Chui, Kwok Tai; Lau, Wing Hong; Leung, Yat Wah

2015-01-01

A high fuel efficiency management scheme for plug-in hybrid electric vehicles (PHEVs) has been developed. In order to achieve fuel consumption reduction, an adaptive genetic algorithm scheme has been designed to adaptively manage the energy resource usage. The objective function of the genetic algorithm is implemented by designing a fuzzy logic controller which closely monitors and resembles the driving conditions and environment of PHEVs, thus trading off between petrol versus electricity for optimal driving efficiency. Comparison between calculated results and publicized data shows that the achieved efficiency of the fuzzified genetic algorithm is better by 10% than existing schemes. The developed scheme, if fully adopted, would help reduce over 600 tons of CO2 emissions worldwide every day. PMID:25587974

Performance evaluation of a health insurance in Nigeria using optimal resource use: health care providers perspectives

PubMed Central

2014-01-01

Background Performance measures are often neglected during the transition period of national health insurance scheme implementation in many low and middle income countries. These measurements evaluate the extent to which various aspects of the schemes meet their key objectives. This study assesses the implementation of a health insurance scheme using optimal resource use domains and examines possible factors that influence each domain, according to providers’ perspectives. Methods A retrospective, cross-sectional survey was done between August and December 2010 in Kaduna state, and 466 health care provider personnel were interviewed. Optimal-resource-use was defined in four domains: provider payment mechanism (capitation and fee-for-service payment methods), benefit package, administrative efficiency, and active monitoring mechanism. Logistic regression analysis was used to identify provider factors that may influence each domain. Results In the provider payment mechanism domain, capitation payment method (95%) performed better than fee-for-service payment method (62%). Benefit package domain performed strongly (97%), while active monitoring mechanism performed weakly (37%). In the administrative efficiency domain, both promptness of referral system (80%) and prompt arrival of funds (93%) performed well. At the individual level, providers with fewer enrolees encountered difficulties with reimbursement. Other factors significantly influenced each of the optimal-resource-use domains. Conclusions Fee-for-service payment method and claims review, in the provider payment and active monitoring mechanisms, respectively, performed weakly according to the providers’ (at individual-level) perspectives. A short-fall on the supply-side of health insurance could lead to a direct or indirect adverse effect on the demand-side of the scheme. Capitation payment per enrolees should be revised to conform to economic circumstances. Performance indicators and providers’ characteristics and experiences associated with resource use can assist policy makers to monitor and evaluate health insurance implementation. PMID:24628889

Respiratory function monitoring using a real-time three-dimensional fiber-optic shaping sensing scheme based upon fiber Bragg gratings

NASA Astrophysics Data System (ADS)

Allsop, Thomas; Bhamber, Ranjeet; Lloyd, Glynn; Miller, Martin R.; Dixon, Andrew; Webb, David; Ania Castañón, Juan Diego; Bennion, Ian

2012-11-01

An array of in-line curvature sensors on a garment is used to monitor the thoracic and abdominal movements of a human during respiration. The results are used to obtain volumetric changes of the human torso in agreement with a spirometer used simultaneously at the mouth. The array of 40 in-line fiber Bragg gratings is used to produce 20 curvature sensors at different locations, each sensor consisting of two fiber Bragg gratings. The 20 curvature sensors and adjoining fiber are encapsulated into a low-temperature-cured synthetic silicone. The sensors are wavelength interrogated by a commercially available system from Moog Insensys, and the wavelength changes are calibrated to recover curvature. A three-dimensional algorithm is used to generate shape changes during respiration that allow the measurement of absolute volume changes at various sections of the torso. It is shown that the sensing scheme yields a volumetric error of 6%. Comparing the volume data obtained from the spirometer with the volume estimated with the synchronous data from the shape-sensing array yielded a correlation value 0.86 with a Pearson's correlation coefficient p<0.01.

ReTrust: attack-resistant and lightweight trust management for medical sensor networks.

PubMed

He, Daojing; Chen, Chun; Chan, Sammy; Bu, Jiajun; Vasilakos, Athanasios V

2012-07-01

Wireless medical sensor networks (MSNs) enable ubiquitous health monitoring of users during their everyday lives, at health sites, without restricting their freedom. Establishing trust among distributed network entities has been recognized as a powerful tool to improve the security and performance of distributed networks such as mobile ad hoc networks and sensor networks. However, most existing trust systems are not well suited for MSNs due to the unique operational and security requirements of MSNs. Moreover, similar to most security schemes, trust management methods themselves can be vulnerable to attacks. Unfortunately, this issue is often ignored in existing trust systems. In this paper, we identify the security and performance challenges facing a sensor network for wireless medical monitoring and suggest it should follow a two-tier architecture. Based on such an architecture, we develop an attack-resistant and lightweight trust management scheme named ReTrust. This paper also reports the experimental results of the Collection Tree Protocol using our proposed system in a network of TelosB motes, which show that ReTrust not only can efficiently detect malicious/faulty behaviors, but can also significantly improve the network performance in practice.

A hybrid prognostic model for multistep ahead prediction of machine condition

NASA Astrophysics Data System (ADS)

Roulias, D.; Loutas, T. H.; Kostopoulos, V.

2012-05-01

Prognostics are the future trend in condition based maintenance. In the current framework a data driven prognostic model is developed. The typical procedure of developing such a model comprises a) the selection of features which correlate well with the gradual degradation of the machine and b) the training of a mathematical tool. In this work the data are taken from a laboratory scale single stage gearbox under multi-sensor monitoring. Tests monitoring the condition of the gear pair from healthy state until total brake down following several days of continuous operation were conducted. After basic pre-processing of the derived data, an indicator that correlated well with the gearbox condition was obtained. Consecutively the time series is split in few distinguishable time regions via an intelligent data clustering scheme. Each operating region is modelled with a feed-forward artificial neural network (FFANN) scheme. The performance of the proposed model is tested by applying the system to predict the machine degradation level on unseen data. The results show the plausibility and effectiveness of the model in following the trend of the timeseries even in the case that a sudden change occurs. Moreover the model shows ability to generalise for application in similar mechanical assets.

Network-aware scalable video monitoring system for emergency situations with operator-managed fidelity control

NASA Astrophysics Data System (ADS)

Al Hadhrami, Tawfik; Nightingale, James M.; Wang, Qi; Grecos, Christos

2014-05-01

In emergency situations, the ability to remotely monitor unfolding events using high-quality video feeds will significantly improve the incident commander's understanding of the situation and thereby aids effective decision making. This paper presents a novel, adaptive video monitoring system for emergency situations where the normal communications network infrastructure has been severely impaired or is no longer operational. The proposed scheme, operating over a rapidly deployable wireless mesh network, supports real-time video feeds between first responders, forward operating bases and primary command and control centers. Video feeds captured on portable devices carried by first responders and by static visual sensors are encoded in H.264/SVC, the scalable extension to H.264/AVC, allowing efficient, standard-based temporal, spatial, and quality scalability of the video. A three-tier video delivery system is proposed, which balances the need to avoid overuse of mesh nodes with the operational requirements of the emergency management team. In the first tier, the video feeds are delivered at a low spatial and temporal resolution employing only the base layer of the H.264/SVC video stream. Routing in this mode is designed to employ all nodes across the entire mesh network. In the second tier, whenever operational considerations require that commanders or operators focus on a particular video feed, a `fidelity control' mechanism at the monitoring station sends control messages to the routing and scheduling agents in the mesh network, which increase the quality of the received picture using SNR scalability while conserving bandwidth by maintaining a low frame rate. In this mode, routing decisions are based on reliable packet delivery with the most reliable routes being used to deliver the base and lower enhancement layers; as fidelity is increased and more scalable layers are transmitted they will be assigned to routes in descending order of reliability. The third tier of video delivery transmits a high-quality video stream including all available scalable layers using the most reliable routes through the mesh network ensuring the highest possible video quality. The proposed scheme is implemented in a proven simulator, and the performance of the proposed system is numerically evaluated through extensive simulations. We further present an in-depth analysis of the proposed solutions and potential approaches towards supporting high-quality visual communications in such a demanding context.

Multi-Level Modeling of Complex Socio-Technical Systems - Phase 1

DTIC Science & Technology

2013-06-06

is to detect anomalous organizational outcomes, diagnose the causes of these anomalies , and decide upon appropriate compensation schemes. All of...monitor process outcomes. The purpose of this monitoring is to detect anomalous process outcomes, diagnose the causes of these anomalies , and decide upon...monitor work outcomes in terms of performance. The purpose of this monitoring is to detect anomalous work outcomes, diagnose the causes of these anomalies

Comparison of bird community indices for riparian restoration planning and monitoring

USGS Publications Warehouse

Young, Jock S.; Ammon, Elisabeth M.; Weisburg, Peter J.; Dilts, Thomas E.; Newton, Wesley E.; Wong-Kone, Diane C.; Heki, Lisa G.

2013-01-01

The use of a bird community index that characterizes ecosystem integrity is very attractive to conservation planners and habitat managers, particularly in the absence of any single focal species. In riparian areas of the western USA, several attempts at arriving at a community index signifying a functioning riparian bird community have been made previously, mostly resorting to expert opinions or national conservation rankings for species weights. Because extensive local and regional bird monitoring data were available for Nevada, we were able to develop three different indices that were derived empirically, rather than from expert opinion. We formally examined the use of three species weighting schemes in comparison with simple species richness, using different definitions of riparian species assemblage size, for the purpose of predicting community response to changes in vegetation structure from riparian restoration. For the three indices, species were weighted according to the following criteria: (1) the degree of riparian habitat specialization based on regional data, (2) the relative conservation ranking of landbird species, and (3) the degree to which a species is under-represented compared to the regional species pool for riparian areas. To evaluate the usefulness of these indices for habitat restoration planning and monitoring, we modeled them using habitat variables that are expected to respond to riparian restoration efforts, using data from 64 sampling sites in the Walker River Basin in Nevada and California. We found that none of the species-weighting schemes performed any better as an index for evaluating overall habitat condition than using species richness alone as a community index. Based on our findings, the use of a fairly complete list of 30–35 riparian specialists appears to be the best indicator group for predicting the response of bird communities to the restoration of riparian vegetation.

A microcomputer-based whole-body counter for personnel routine monitoring.

PubMed

Chou, H P; Tsai, T M; Lan, C Y

1993-05-01

The paper describes a cost-effective NaI(Tl) whole-body counter developed for routine examinations of worker intakes at an isotope production facility. Signal processing, data analysis and system operation are microcomputer-controlled for minimum human interactions. The pulse height analyzer is developed as an microcomputer add-on card for easy manipulation. The scheme for radionuclide analysis is aimed for fast running according to a knowledge base established from background samples and phantom experiments in conjunction with a multivariate regression analysis. Long-term stability and calibration with standards and in vivo measurements are reported.

Introduction of structural health and safety monitoring warning systems for Shenzhen-Hong Kong Western Corridor Shenzhen Bay Bridge

NASA Astrophysics Data System (ADS)

Li, N.; Zhang, X. Y.; Zhou, X. T.; Leng, J.; Liang, Z.; Zheng, C.; Sun, X. F.

2008-03-01

Though the brief introduction of the completed structural health and safety monitoring warning systems for Shenzhen-Hongkong western corridor Shenzhen bay highway bridge (SZBHMS), the self-developed system frame, hardware and software scheme of this practical research project are systematically discussed in this paper. The data acquisition and transmission hardware and the basic software based on the NI (National Instruments) Company virtual instruments technology were selected in this system, which adopted GPS time service receiver technology and so on. The objectives are to establish the structural safety monitoring and status evaluation system to monitor the structural responses and working conditions in real time and to analyze the structural working statue using information obtained from the measured data. It will be also provided the scientific decision-making bases for the bridge management and maintenance. Potential technical approaches to the structural safety warning systems, status identification and evaluation method are presented. The result indicated that the performance of the system has achieved the desired objectives, ensure the longterm high reliability, real time concurrence and advanced technology of SZBHMS. The innovate achievement which is the first time to implement in domestic, provide the reference for long-span bridge structural health and safety monitoring warning systems design.

Pathways to increase consumer trust in meat as a safe and wholesome food.

PubMed

Gellynck, Xavier; Verbeke, Wim; Vermeire, Bert

2006-09-01

This paper focuses on the effect of information about meat safety and wholesomeness on consumer trust based on several studies with data collected in Belgium. The research is grounded in the observation that despite the abundant rise of information through labelling, traceability systems and quality assurance schemes, the effect on consumer trust in meat as a safe and wholesome product is only limited. The overload and complexity of information on food products results in misunderstanding and misinterpretation. Functional traceability attributes such as organisational efficiency and chain monitoring are considered to be highly important but not as a basis for market segmentation. However, process traceability attributes such as origin and production method are of interest for particular market segments as a response to meat quality concerns. Quality assurance schemes and associated labels have a poor impact on consumers' perception. It is argued that the high interest of retailers in such schemes is driven by procurement management efficiency rather than safety or overall quality. Future research could concentrate on the distribution of costs and benefits associated with meat quality initiatives among the chain participants.

RUASN: a robust user authentication framework for wireless sensor networks.

PubMed

Kumar, Pardeep; Choudhury, Amlan Jyoti; Sain, Mangal; Lee, Sang-Gon; Lee, Hoon-Jae

2011-01-01

In recent years, wireless sensor networks (WSNs) have been considered as a potential solution for real-time monitoring applications and these WSNs have potential practical impact on next generation technology too. However, WSNs could become a threat if suitable security is not considered before the deployment and if there are any loopholes in their security, which might open the door for an attacker and hence, endanger the application. User authentication is one of the most important security services to protect WSN data access from unauthorized users; it should provide both mutual authentication and session key establishment services. This paper proposes a robust user authentication framework for wireless sensor networks, based on a two-factor (password and smart card) concept. This scheme facilitates many services to the users such as user anonymity, mutual authentication, secure session key establishment and it allows users to choose/update their password regularly, whenever needed. Furthermore, we have provided the formal verification using Rubin logic and compare RUASN with many existing schemes. As a result, we found that the proposed scheme possesses many advantages against popular attacks, and achieves better efficiency at low computation cost.

Truthful Channel Sharing for Self Coexistence of Overlapping Medical Body Area Networks

PubMed Central

Dutkiewicz, Eryk; Zheng, Guanglou

2016-01-01

As defined by IEEE 802.15.6 standard, channel sharing is a potential method to coordinate inter-network interference among Medical Body Area Networks (MBANs) that are close to one another. However, channel sharing opens up new vulnerabilities as selfish MBANs may manipulate their online channel requests to gain unfair advantage over others. In this paper, we address this issue by proposing a truthful online channel sharing algorithm and a companion protocol that allocates channel efficiently and truthfully by punishing MBANs for misreporting their channel request parameters such as time, duration and bid for the channel. We first present an online channel sharing scheme for unit-length channel requests and prove that it is truthful. We then generalize our model to settings with variable-length channel requests, where we propose a critical value based channel pricing and preemption scheme. A bid adjustment procedure prevents unbeneficial preemption by artificially raising the ongoing winner’s bid controlled by a penalty factor λ. Our scheme can efficiently detect selfish behaviors by monitoring a trust parameter α of each MBAN and punish MBANs from cheating by suspending their requests. Our extensive simulation results show our scheme can achieve a total profit that is more than 85% of the offline optimum method in the typical MBAN settings. PMID:26844888

Computer-aided detection and diagnosis of masses and clustered microcalcifications from digital mammograms

NASA Astrophysics Data System (ADS)

Nishikawa, Robert M.; Giger, Maryellen L.; Doi, Kunio; Vyborny, Carl J.; Schmidt, Robert A.; Metz, Charles E.; Wu, Chris Y.; Yin, Fang-Fang; Jiang, Yulei; Huo, Zhimin; Lu, Ping; Zhang, Wei; Ema, Takahiro; Bick, Ulrich; Papaioannou, John; Nagel, Rufus H.

1993-07-01

We are developing an 'intelligent' workstation to assist radiologists in diagnosing breast cancer from mammograms. The hardware for the workstation will consist of a film digitizer, a high speed computer, a large volume storage device, a film printer, and 4 high resolution CRT monitors. The software for the workstation is a comprehensive package of automated detection and classification schemes. Two rule-based detection schemes have been developed, one for breast masses and the other for clustered microcalcifications. The sensitivity of both schemes is 85% with a false-positive rate of approximately 3.0 and 1.5 false detections per image, for the mass and cluster detection schemes, respectively. Computerized classification is performed by an artificial neural network (ANN). The ANN has a sensitivity of 100% with a specificity of 60%. Currently, the ANN, which is a three-layer, feed-forward network, requires as input ratings of 14 different radiographic features of the mammogram that were determined subjectively by a radiologist. We are in the process of developing automated techniques to objectively determine these 14 features. The workstation will be placed in the clinical reading area of the radiology department in the near future, where controlled clinical tests will be performed to measure its efficacy.

Image Corruption Detection in Diffusion Tensor Imaging for Post-Processing and Real-Time Monitoring

PubMed Central

Li, Yue; Shea, Steven M.; Lorenz, Christine H.; Jiang, Hangyi; Chou, Ming-Chung; Mori, Susumu

2013-01-01

Due to the high sensitivity of diffusion tensor imaging (DTI) to physiological motion, clinical DTI scans often suffer a significant amount of artifacts. Tensor-fitting-based, post-processing outlier rejection is often used to reduce the influence of motion artifacts. Although it is an effective approach, when there are multiple corrupted data, this method may no longer correctly identify and reject the corrupted data. In this paper, we introduce a new criterion called “corrected Inter-Slice Intensity Discontinuity” (cISID) to detect motion-induced artifacts. We compared the performance of algorithms using cISID and other existing methods with regard to artifact detection. The experimental results show that the integration of cISID into fitting-based methods significantly improves the retrospective detection performance at post-processing analysis. The performance of the cISID criterion, if used alone, was inferior to the fitting-based methods, but cISID could effectively identify severely corrupted images with a rapid calculation time. In the second part of this paper, an outlier rejection scheme was implemented on a scanner for real-time monitoring of image quality and reacquisition of the corrupted data. The real-time monitoring, based on cISID and followed by post-processing, fitting-based outlier rejection, could provide a robust environment for routine DTI studies. PMID:24204551

Real-time combustion monitoring of PCDD/F indicators by REMPI-TOFMS

EPA Science Inventory

Analyses for polychlorinated dibenzodioxin and dibenzofuran (PCDD/F) emissions typically require a 4 h extractive sample taken on an annual or less frequent basis. This results in a potentially minimally representative monitoring scheme. More recently, methods for continual sampl...

Adaptive Packet Combining Scheme in Three State Channel Model

NASA Astrophysics Data System (ADS)

Saring, Yang; Bulo, Yaka; Bhunia, Chandan Tilak

2018-01-01

The two popular techniques of packet combining based error correction schemes are: Packet Combining (PC) scheme and Aggressive Packet Combining (APC) scheme. PC scheme and APC scheme have their own merits and demerits; PC scheme has better throughput than APC scheme, but suffers from higher packet error rate than APC scheme. The wireless channel state changes all the time. Because of this random and time varying nature of wireless channel, individual application of SR ARQ scheme, PC scheme and APC scheme can't give desired levels of throughput. Better throughput can be achieved if appropriate transmission scheme is used based on the condition of channel. Based on this approach, adaptive packet combining scheme has been proposed to achieve better throughput. The proposed scheme adapts to the channel condition to carry out transmission using PC scheme, APC scheme and SR ARQ scheme to achieve better throughput. Experimentally, it was observed that the error correction capability and throughput of the proposed scheme was significantly better than that of SR ARQ scheme, PC scheme and APC scheme.

Sequence and batch language programs and alarm-related ``C`` programs for the 242-A MCS. Revision 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berger, J.F.

1995-03-01

A Distributive Process Control system was purchased by Project B-534, ``242-A Evaporator/Crystallizer Upgrades``. This control system, called the Monitor and Control System (MCS), was installed in the 242-A Evaporator located in the 200 East Area. The purpose of the MCS is to monitor and control the Evaporator and monitor a number of alarms and other signals from various Tank Farm facilities. Applications software for the MCS was developed by the Waste Treatment Systems Engineering (WTSE) group of Westinghouse. The standard displays and alarm scheme provide for control and monitoring, but do not directly indicate the signal location or depict themore » overall process. To do this, WTSE developed a second alarm scheme which uses special programs, annunciator keys, and process graphics. The special programs are written in two languages; Sequence and Batch Language (SABL), and ``C`` language. The WTSE-developed alarm scheme works as described below: SABL relates signals and alarms to the annunciator keys, called SKID keys. When an alarm occurs, a SABL program causes a SKID key to flash, and if the alarm is of yellow or white priority then a ``C`` program turns on an audible horn (the D/3 system uses a different audible horn for the red priority alarms). The horn and flashing key draws the attention of the operator.« less

Efficient security mechanisms for mHealth applications using wireless body sensor networks.

PubMed

Sahoo, Prasan Kumar

2012-01-01

Recent technological advances in wireless communications and physiological sensing allow miniature, lightweight, ultra-low power, intelligent monitoring devices, which can be integrated into a Wireless Body Sensor Network (WBSN) for health monitoring. Physiological signals of humans such as heartbeats, temperature and pulse can be monitored from a distant location using tiny biomedical wireless sensors. Hence, it is highly essential to combine the ubiquitous computing with mobile health technology using wireless sensors and smart phones to monitor the well-being of chronic patients such as cardiac, Parkinson and epilepsy patients. Since physiological data of a patient are highly sensitive, maintaining its confidentiality is highly essential. Hence, security is a vital research issue in mobile health (mHealth) applications, especially if a patient has an embarrassing disease. In this paper a three tier security architecture for the mHealth application is proposed, in which light weight data confidentiality and authentication protocols are proposed to maintain the privacy of a patient. Moreover, considering the energy and hardware constraints of the wireless body sensors, low complexity data confidential and authentication schemes are designed. Performance evaluation of the proposed architecture shows that they can satisfy the energy and hardware limitations of the sensors and still can maintain the secure fabrics of the wireless body sensor networks. Besides, the proposed schemes can outperform in terms of energy consumption, memory usage and computation time over standard key establishment security scheme.

Efficient Security Mechanisms for mHealth Applications Using Wireless Body Sensor Networks

PubMed Central

Sahoo, Prasan Kumar

2012-01-01

Recent technological advances in wireless communications and physiological sensing allow miniature, lightweight, ultra-low power, intelligent monitoring devices, which can be integrated into a Wireless Body Sensor Network (WBSN) for health monitoring. Physiological signals of humans such as heartbeats, temperature and pulse can be monitored from a distant location using tiny biomedical wireless sensors. Hence, it is highly essential to combine the ubiquitous computing with mobile health technology using wireless sensors and smart phones to monitor the well-being of chronic patients such as cardiac, Parkinson and epilepsy patients. Since physiological data of a patient are highly sensitive, maintaining its confidentiality is highly essential. Hence, security is a vital research issue in mobile health (mHealth) applications, especially if a patient has an embarrassing disease. In this paper a three tier security architecture for the mHealth application is proposed, in which light weight data confidentiality and authentication protocols are proposed to maintain the privacy of a patient. Moreover, considering the energy and hardware constraints of the wireless body sensors, low complexity data confidential and authentication schemes are designed. Performance evaluation of the proposed architecture shows that they can satisfy the energy and hardware limitations of the sensors and still can maintain the secure fabrics of the wireless body sensor networks. Besides, the proposed schemes can outperform in terms of energy consumption, memory usage and computation time over standard key establishment security scheme. PMID:23112734

An Efficient Method for Detecting Misbehaving Zone Manager in MANET

NASA Astrophysics Data System (ADS)

Rafsanjani, Marjan Kuchaki; Pakzad, Farzaneh; Asadinia, Sanaz

In recent years, one of the wireless technologies increased tremendously is mobile ad hoc networks (MANETs) in which mobile nodes organize themselves without the help of any predefined infrastructure. MANETs are highly vulnerable to attack due to the open medium, dynamically changing network topology, cooperative algorithms, lack of centralized monitoring, management point and lack of a clear defense line. In this paper, we report our progress in developing intrusion detection (ID) capabilities for MANET. In our proposed scheme, the network with distributed hierarchical architecture is partitioned into zones, so that in each of them there is one zone manager. The zone manager is responsible for monitoring the cluster heads in its zone and cluster heads are in charge of monitoring their members. However, the most important problem is how the trustworthiness of the zone manager can be recognized. So, we propose a scheme in which "honest neighbors" of zone manager specify the validation of their zone manager. These honest neighbors prevent false accusations and also allow manager if it is wrongly misbehaving. However, if the manger repeats its misbehavior, then it will lose its management degree. Therefore, our scheme will be improved intrusion detection and also provide a more reliable network.

Influence of data collection schemes on the Life Cycle Assessment of a municipal wastewater treatment plant.

PubMed

Yoshida, Hiroko; Clavreul, Julie; Scheutz, Charlotte; Christensen, Thomas H

2014-06-01

A Life Cycle Assessment (LCA) of a municipal wastewater treatment plant (WWTP) was conducted to illustrate the effect of an emission inventory data collection scheme on the outcomes of an environmental impact assessment. Due to their burden in respect to data collection, LCAs often rely heavily on existing emission and operational data, which are gathered under either compulsory monitoring or reporting requirements under law. In this study, an LCA was conducted using three input data sources: Information compiled under compulsory disclosure requirements (the European Pollutant Release and Transfer Registry), compliance with national discharge limits, and a state-of-the-art emission data collection scheme conducted at the same WWTP. Parameter uncertainty for each collection scheme was assessed through Monte Carlo simulation. The comparison of the results confirmed that LCA results depend heavily on input data coverage. Due to the threshold on reporting value, the E-PRTR did not capture the impact for particulate matter emission, terrestrial acidification, or terrestrial eutrophication. While the current practice can capture more than 90% of non-carcinogenic human toxicity and marine eutrophication, an LCA based on the data collection scheme underestimates impact potential due to limitations of substance coverage. Besides differences between data collection schemes, the results showed that 3-13,500% of the impacts came from background systems, such as from the provisioning of fuel, electricity, and chemicals, which do not need to be disclosed currently under E-PRTR. The incidental release of pollutants was also assessed by employing a scenario-based approach, the results of which demonstrated that these non-routine emissions could increase overall WWTP greenhouse gas emissions by between 113 and 210%. Overall, current data collection schemes have the potential to provide standardized data collection and form the basis for a sound environmental impact assessment, but several improvements are recommended, including the additional collection of energy and chemical usage data, the elimination of a reporting threshold, the expansion of substance coverage, and the inclusion of non-point fugitive gas emissions. Copyright © 2014 Elsevier Ltd. All rights reserved.

A Novel Addressing Scheme for PMIPv6 Based Global IP-WSNs

PubMed Central

Islam, Md. Motaharul; Huh, Eui-Nam

2011-01-01

IP based Wireless Sensor Networks (IP-WSNs) are being used in healthcare, home automation, industrial control and agricultural monitoring. In most of these applications global addressing of individual IP-WSN nodes and layer-three routing for mobility enabled IP-WSN with special attention to reliability, energy efficiency and end to end delay minimization are a few of the major issues to be addressed. Most of the routing protocols in WSN are based on layer-two approaches. For reliability and end to end communication enhancement the necessity of layer-three routing for IP-WSNs is generating significant attention among the research community, but due to the hurdle of maintaining routing state and other communication overhead, it was not possible to introduce a layer-three routing protocol for IP-WSNs. To address this issue we propose in this paper a global addressing scheme and layer-three based hierarchical routing protocol. The proposed addressing and routing approach focuses on all the above mentioned issues. Simulation results show that the proposed addressing and routing approach significantly enhances the reliability, energy efficiency and end to end delay minimization. We also present architecture, message formats and different routing scenarios in this paper. PMID:22164084

A novel addressing scheme for PMIPv6 based global IP-WSNs.

PubMed

Islam, Md Motaharul; Huh, Eui-Nam

2011-01-01

IP based Wireless Sensor Networks (IP-WSNs) are being used in healthcare, home automation, industrial control and agricultural monitoring. In most of these applications global addressing of individual IP-WSN nodes and layer-three routing for mobility enabled IP-WSN with special attention to reliability, energy efficiency and end to end delay minimization are a few of the major issues to be addressed. Most of the routing protocols in WSN are based on layer-two approaches. For reliability and end to end communication enhancement the necessity of layer-three routing for IP-WSNs is generating significant attention among the research community, but due to the hurdle of maintaining routing state and other communication overhead, it was not possible to introduce a layer-three routing protocol for IP-WSNs. To address this issue we propose in this paper a global addressing scheme and layer-three based hierarchical routing protocol. The proposed addressing and routing approach focuses on all the above mentioned issues. Simulation results show that the proposed addressing and routing approach significantly enhances the reliability, energy efficiency and end to end delay minimization. We also present architecture, message formats and different routing scenarios in this paper.

Vector magnetometer based on synchronous manipulation of nitrogen-vacancy centers in all crystal directions

NASA Astrophysics Data System (ADS)

Zhang, Chen; Yuan, Heng; Zhang, Ning; Xu, Lixia; Zhang, Jixing; Li, Bo; Fang, Jiancheng

2018-04-01

Negatively charged nitrogen vacancy (NV‑) centers in diamond have been extensively studied as high-sensitivity magnetometers, showcasing a wide range of applications. This study experimentally demonstrates a vector magnetometry scheme based on synchronous manipulation of NV‑ center ensembles in all crystal directions using double frequency microwaves (MWs) and multi-coupled-strip-lines (mCSL) waveguide. The application of the mCSL waveguide ensures a high degree of synchrony (99%) for manipulating NV‑ centers in multiple orientations in a large volume. Manipulation with double frequency MWs makes NV‑ centers of all four crystal directions involved, and additionally leads to an enhancement of the manipulation field. In this work, by monitoring the changes in the slope of the resonance line consisting of multi-axes NV‑ centers, measurement of the direction of the external field vector was demonstrated with a sensitivity of {{10}\\prime}/\\sqrt{Hz} . Based on the scheme, the fluorescence signal contrast was improved by four times higher and the sensitivity to the magnetic field strength was improved by two times. The method provides a more practical way of achieving vector sensors based on NV‑ center ensembles in diamond.

Comb-referenced ultra-high sensitivity spectroscopic molecular detection by compact non-linear sources

NASA Astrophysics Data System (ADS)

Cancio, P.; Gagliardi, G.; Galli, I.; Giusfredi, G.; Maddaloni, P.; Malara, P.; Mazzotti, D.; De Natale, P.

2017-11-01

We present a new generation of compact and rugged mid-infrared (MIR) difference-frequency coherent radiation sources referenced to fiber-based optical frequency comb synthesizers (OFCSs). By coupling the MIR radiation to high-finesse optical cavities, high-resolution and high-sensitivity spectroscopy is demonstrated for CH4 and CO2 around 3.3 and 4.5 μm respectively. Finally, the most effective detection schemes for space-craft trace-gas monitoring applications are singled out.

Fault tolerant features and experiments of ANTS distributed real-time system

NASA Astrophysics Data System (ADS)

Dominic-Savio, Patrick; Lo, Jien-Chung; Tufts, Donald W.

1995-01-01

The ANTS project at the University of Rhode Island introduces the concept of Active Nodal Task Seeking (ANTS) as a way to efficiently design and implement dependable, high-performance, distributed computing. This paper presents the fault tolerant design features that have been incorporated in the ANTS experimental system implementation. The results of performance evaluations and fault injection experiments are reported. The fault-tolerant version of ANTS categorizes all computing nodes into three groups. They are: the up-and-running green group, the self-diagnosing yellow group and the failed red group. Each available computing node will be placed in the yellow group periodically for a routine diagnosis. In addition, for long-life missions, ANTS uses a monitoring scheme to identify faulty computing nodes. In this monitoring scheme, the communication pattern of each computing node is monitored by two other nodes.

Fiber sensor for non-contact estimation of vital bio-signs

NASA Astrophysics Data System (ADS)

Sirkis, Talia; Beiderman, Yevgeny; Agdarov, Sergey; Beiderman, Yafim; Zalevsky, Zeev

2017-05-01

Continuous noninvasive measurement of vital bio-signs, such as cardiopulmonary parameters, is an important tool in evaluation of the patient's physiological condition and health monitoring. On the demand of new enabling technologies, some works have been done in arterial pulse monitoring using optical fiber sensors. In this paper, we introduce a novel device based on single mode in-fibers Mach-Zehnder interferometer (MZI) to detect heartbeat, respiration and pulse wave velocity (PWV). The introduced interferometer is based on a new implanted scheme. It replaces the conventional MZI realized by inserting of discontinuities in the fiber to break the total internal reflection and scatter/collect light. The proposed fiber sensor was successfully incorporated into shirt to produce smart clothing. The measurements obtained from the smart clothing could be obtained in comfortable manner and there is no need to have an initial calibration or a direct contact between the sensor and the skin of the tested individual.

Remote sensing estimation of the total phosphorus concentration in a large lake using band combinations and regional multivariate statistical modeling techniques.

PubMed

Gao, Yongnian; Gao, Junfeng; Yin, Hongbin; Liu, Chuansheng; Xia, Ting; Wang, Jing; Huang, Qi

2015-03-15

Remote sensing has been widely used for ater quality monitoring, but most of these monitoring studies have only focused on a few water quality variables, such as chlorophyll-a, turbidity, and total suspended solids, which have typically been considered optically active variables. Remote sensing presents a challenge in estimating the phosphorus concentration in water. The total phosphorus (TP) in lakes has been estimated from remotely sensed observations, primarily using the simple individual band ratio or their natural logarithm and the statistical regression method based on the field TP data and the spectral reflectance. In this study, we investigated the possibility of establishing a spatial modeling scheme to estimate the TP concentration of a large lake from multi-spectral satellite imagery using band combinations and regional multivariate statistical modeling techniques, and we tested the applicability of the spatial modeling scheme. The results showed that HJ-1A CCD multi-spectral satellite imagery can be used to estimate the TP concentration in a lake. The correlation and regression analysis showed a highly significant positive relationship between the TP concentration and certain remotely sensed combination variables. The proposed modeling scheme had a higher accuracy for the TP concentration estimation in the large lake compared with the traditional individual band ratio method and the whole-lake scale regression-modeling scheme. The TP concentration values showed a clear spatial variability and were high in western Lake Chaohu and relatively low in eastern Lake Chaohu. The northernmost portion, the northeastern coastal zone and the southeastern portion of western Lake Chaohu had the highest TP concentrations, and the other regions had the lowest TP concentration values, except for the coastal zone of eastern Lake Chaohu. These results strongly suggested that the proposed modeling scheme, i.e., the band combinations and the regional multivariate statistical modeling techniques, demonstrated advantages for estimating the TP concentration in a large lake and had a strong potential for universal application for the TP concentration estimation in large lake waters worldwide. Copyright © 2014 Elsevier Ltd. All rights reserved.

Control of parallel manipulators using force feedback

NASA Technical Reports Server (NTRS)

Nanua, Prabjot

1994-01-01

Two control schemes are compared for parallel robotic mechanisms actuated by hydraulic cylinders. One scheme, the 'rate based scheme', uses the position and rate information only for feedback. The second scheme, the 'force based scheme' feeds back the force information also. The force control scheme is shown to improve the response over the rate control one. It is a simple constant gain control scheme better suited to parallel mechanisms. The force control scheme can be easily modified for the dynamic forces on the end effector. This paper presents the results of a computer simulation of both the rate and force control schemes. The gains in the force based scheme can be individually adjusted in all three directions, whereas the adjustment in just one direction of the rate based scheme directly affects the other two directions.

Enabling end-user network monitoring via the multicast consolidated proxy monitor

NASA Astrophysics Data System (ADS)

Kanwar, Anshuman; Almeroth, Kevin C.; Bhattacharyya, Supratik; Davy, Matthew

2001-07-01

The debugging of problems in IP multicast networks relies heavily on an eclectic set of stand-alone tools. These tools traditionally neither provide a consistent interface nor do they generate readily interpretable results. We propose the ``Multicast Consolidated Proxy Monitor''(MCPM), an integrated system for collecting, analyzing and presenting multicast monitoring results to both the end user and the network operator at the user's Internet Service Provider (ISP). The MCPM accesses network state information not normally visible to end users and acts as a proxy for disseminating this information. Functionally, through this architecture, we aim to a) provide a view of the multicast network at varying levels of granularity, b) provide end users with a limited ability to query the multicast infrastructure in real time, and c) protect the infrastructure from overwhelming amount of monitoring load through load control. Operationally, our scheme allows scaling to the ISPs dimensions, adaptability to new protocols (introduced as multicast evolves), threshold detection for crucial parameters and an access controlled, customizable interface design. Although the multicast scenario is used to illustrate the benefits of consolidated monitoring, the ultimate aim is to scale the scheme to unicast IP networks.

Monitoring Technological Change.

ERIC Educational Resources Information Center

Brinkworth, B. J.; Eckersall, K. E.

A project was conducted to design and pilot a scheme for monitoring trade/industry/commerce technological changes and reporting them to Technical and Further Education (TAFE) teachers and authorities. A matrix of information categories was used to facilitate the collection and storage of information relative to technological advancements in the…

Arc-Welding Spectroscopic Monitoring based on Feature Selection and Neural Networks.

PubMed

Garcia-Allende, P Beatriz; Mirapeix, Jesus; Conde, Olga M; Cobo, Adolfo; Lopez-Higuera, Jose M

2008-10-21

A new spectral processing technique designed for application in the on-line detection and classification of arc-welding defects is presented in this paper. A noninvasive fiber sensor embedded within a TIG torch collects the plasma radiation originated during the welding process. The spectral information is then processed in two consecutive stages. A compression algorithm is first applied to the data, allowing real-time analysis. The selected spectral bands are then used to feed a classification algorithm, which will be demonstrated to provide an efficient weld defect detection and classification. The results obtained with the proposed technique are compared to a similar processing scheme presented in previous works, giving rise to an improvement in the performance of the monitoring system.

Structural Health Monitoring Using Textile Reinforcement Structures with Integrated Optical Fiber Sensors

PubMed Central

Bremer, Kort; Weigand, Frank; Zheng, Yulong; Alwis, Lourdes Shanika; Helbig, Reinhard; Roth, Bernhard

2017-01-01

Optical fiber-based sensors “embedded” in functionalized carbon structures (FCSs) and textile net structures (TNSs) based on alkaline-resistant glass are introduced for the purpose of structural health monitoring (SHM) of concrete-based structures. The design aims to monitor common SHM parameters such as strain and cracks while at the same time acting as a structural strengthening mechanism. The sensor performances of the two systems are characterized in situ using Mach-Zehnder interferometric (MZI) and optical attenuation measurement techniques, respectively. For this purpose, different FCS samples were subjected to varying elongation using a tensile testing machine by carefully incrementing the applied force, and good correlation between the applied force and measured length change was observed. For crack detection, the functionalized TNSs were embedded into a concrete block which was then exposed to varying load using the three-point flexural test until destruction. Promising results were observed, identifying that the location of the crack can be determined using the conventional optical time domain reflectometry (OTDR) technique. The embedded sensors thus evaluated show the value of the dual achievement of the schemes proposed in obtaining strain/crack measurement while being utilized as strengthening agents as well. PMID:28208636

Transient stability enhancement of modern power grid using predictive Wide-Area Monitoring and Control

NASA Astrophysics Data System (ADS)

Yousefian, Reza

This dissertation presents a real-time Wide-Area Control (WAC) designed based on artificial intelligence for large scale modern power systems transient stability enhancement. The WAC using the measurements available from Phasor Measurement Units (PMUs) at generator buses, monitors the global oscillations in the system and optimally augments the local excitation system of the synchronous generators. The complexity of the power system stability problem along with uncertainties and nonlinearities makes the conventional modeling non-practical or inaccurate. In this work Reinforcement Learning (RL) algorithm on the benchmark of Neural Networks (NNs) is used to map the nonlinearities of the system in real-time. This method different from both the centralized and the decentralized control schemes, employs a number of semi-autonomous agents to collaborate with each other to perform optimal control theory well-suited for WAC applications. Also, to handle the delays in Wide-Area Monitoring (WAM) and adapt the RL toward the robust control design, Temporal Difference (TD) is proposed as a solver for RL problem or optimal cost function. However, the main drawback of such WAC design is that it is challenging to determine if an offline trained network is valid to assess the stability of the power system once the system is evolved to a different operating state or network topology. In order to address the generality issue of NNs, a value priority scheme is proposed in this work to design a hybrid linear and nonlinear controllers. The algorithm so-called supervised RL is based on mixture of experts, where it is initialized by linear controller and as the performance and identification of the RL controller improves in real-time switches to the other controller. This work also focuses on transient stability and develops Lyapunov energy functions for synchronous generators to monitor the stability stress of the system. Using such energies as a cost function guarantees the convergence toward optimal post-fault solutions. These energy functions are developed on inter-area oscillations of the system identified online with Prony analysis. Finally, this work investigates the impacts of renewable energy resources, in specific Doubly Fed Induction Generator (DFIG)-based wind turbines, on power system transient stability and control. As the penetration of such resources is increased in transmission power system, neglecting the impacts of them will make the WAC design non-realistic. An energy function is proposed for DFIGs based on their dynamic performance in transient disturbances. Further, this energy is augmented to synchronous generators' energy as a global cost function, which is minimized by the WAC signals. We discuss the relative advantages and bottlenecks of each architecture and methodology using dynamic simulations of several test systems including a 2-area 8 bus system, IEEE 39 bus system, and IEEE 68 bus system in EMTP and real-time simulators. Being nonlinear-based, fast, accurate, and non-model based design, the proposed WAC system shows better transient and damping response when compared to conventional control schemes and local PSSs.

MPDATA: Third-order accuracy for variable flows

NASA Astrophysics Data System (ADS)

Waruszewski, Maciej; Kühnlein, Christian; Pawlowska, Hanna; Smolarkiewicz, Piotr K.

2018-04-01

This paper extends the multidimensional positive definite advection transport algorithm (MPDATA) to third-order accuracy for temporally and spatially varying flows. This is accomplished by identifying the leading truncation error of the standard second-order MPDATA, performing the Cauchy-Kowalevski procedure to express it in a spatial form and compensating its discrete representation-much in the same way as the standard MPDATA corrects the first-order accurate upwind scheme. The procedure of deriving the spatial form of the truncation error was automated using a computer algebra system. This enables various options in MPDATA to be included straightforwardly in the third-order scheme, thereby minimising the implementation effort in existing code bases. Following the spirit of MPDATA, the error is compensated using the upwind scheme resulting in a sign-preserving algorithm, and the entire scheme can be formulated using only two upwind passes. Established MPDATA enhancements, such as formulation in generalised curvilinear coordinates, the nonoscillatory option or the infinite-gauge variant, carry over to the fully third-order accurate scheme. A manufactured 3D analytic solution is used to verify the theoretical development and its numerical implementation, whereas global tracer-transport benchmarks demonstrate benefits for chemistry-transport models fundamental to air quality monitoring, forecasting and control. A series of explicitly-inviscid implicit large-eddy simulations of a convective boundary layer and explicitly-viscid simulations of a double shear layer illustrate advantages of the fully third-order-accurate MPDATA for fluid dynamics applications.

Autonomous Component Health Management with Failed Component Detection, Identification, and Avoidance

NASA Technical Reports Server (NTRS)

Davis, Robert N.; Polites, Michael E.; Trevino, Luis C.

2004-01-01

This paper details a novel scheme for autonomous component health management (ACHM) with failed actuator detection and failed sensor detection, identification, and avoidance. This new scheme has features that far exceed the performance of systems with triple-redundant sensing and voting, yet requires fewer sensors and could be applied to any system with redundant sensing. Relevant background to the ACHM scheme is provided, and the simulation results for the application of that scheme to a single-axis spacecraft attitude control system with a 3rd order plant and dual-redundant measurement of system states are presented. ACHM fulfills key functions needed by an integrated vehicle health monitoring (IVHM) system. It is: autonomous; adaptive; works in realtime; provides optimal state estimation; identifies failed components; avoids failed components; reconfigures for multiple failures; reconfigures for intermittent failures; works for hard-over, soft, and zero-output failures; and works for both open- and closed-loop systems. The ACHM scheme combines a prefilter that generates preliminary state estimates, detects and identifies failed sensors and actuators, and avoids the use of failed sensors in state estimation with a fixed-gain Kalman filter that generates optimal state estimates and provides model-based state estimates that comprise an integral part of the failure detection logic. The results show that ACHM successfully isolates multiple persistent and intermittent hard-over, soft, and zero-output failures. It is now ready to be tested on a computer model of an actual system.

Channel Efficiency with Security Enhancement for Remote Condition Monitoring of Multi Machine System Using Hybrid Huffman Coding

NASA Astrophysics Data System (ADS)

Datta, Jinia; Chowdhuri, Sumana; Bera, Jitendranath

2016-12-01

This paper presents a novel scheme of remote condition monitoring of multi machine system where a secured and coded data of induction machine with different parameters is communicated between a state-of-the-art dedicated hardware Units (DHU) installed at the machine terminal and a centralized PC based machine data management (MDM) software. The DHUs are built for acquisition of different parameters from the respective machines, and hence are placed at their nearby panels in order to acquire different parameters cost effectively during their running condition. The MDM software collects these data through a communication channel where all the DHUs are networked using RS485 protocol. Before transmitting, the parameter's related data is modified with the adoption of differential pulse coded modulation (DPCM) and Huffman coding technique. It is further encrypted with a private key where different keys are used for different DHUs. In this way a data security scheme is adopted during its passage through the communication channel in order to avoid any third party attack into the channel. The hybrid mode of DPCM and Huffman coding is chosen to reduce the data packet length. A MATLAB based simulation and its practical implementation using DHUs at three machine terminals (one healthy three phase, one healthy single phase and one faulty three phase machine) proves its efficacy and usefulness for condition based maintenance of multi machine system. The data at the central control room are decrypted and decoded using MDM software. In this work it is observed that Chanel efficiency with respect to different parameter measurements has been increased very much.

Secure Data Access Control for Fog Computing Based on Multi-Authority Attribute-Based Signcryption with Computation Outsourcing and Attribute Revocation

PubMed Central

Xu, Qian; Tan, Chengxiang; Fan, Zhijie; Zhu, Wenye; Xiao, Ya; Cheng, Fujia

2018-01-01

Nowadays, fog computing provides computation, storage, and application services to end users in the Internet of Things. One of the major concerns in fog computing systems is how fine-grained access control can be imposed. As a logical combination of attribute-based encryption and attribute-based signature, Attribute-based Signcryption (ABSC) can provide confidentiality and anonymous authentication for sensitive data and is more efficient than traditional “encrypt-then-sign” or “sign-then-encrypt” strategy. Thus, ABSC is suitable for fine-grained access control in a semi-trusted cloud environment and is gaining more and more attention recently. However, in many existing ABSC systems, the computation cost required for the end users in signcryption and designcryption is linear with the complexity of signing and encryption access policy. Moreover, only a single authority that is responsible for attribute management and key generation exists in the previous proposed ABSC schemes, whereas in reality, mostly, different authorities monitor different attributes of the user. In this paper, we propose OMDAC-ABSC, a novel data access control scheme based on Ciphertext-Policy ABSC, to provide data confidentiality, fine-grained control, and anonymous authentication in a multi-authority fog computing system. The signcryption and designcryption overhead for the user is significantly reduced by outsourcing the undesirable computation operations to fog nodes. The proposed scheme is proven to be secure in the standard model and can provide attribute revocation and public verifiability. The security analysis, asymptotic complexity comparison, and implementation results indicate that our construction can balance the security goals with practical efficiency in computation. PMID:29772840

Modified Beer-Lambert law for blood flow

NASA Astrophysics Data System (ADS)

Baker, Wesley B.; Parthasarathy, Ashwin B.; Busch, David R.; Mesquita, Rickson C.; Greenberg, Joel H.; Yodh, A. G.

2015-03-01

The modified Beer-Lambert law is among the most widely used approaches for analysis of near-infrared spectroscopy (NIRS) reflectance signals for measurements of tissue blood volume and oxygenation. Briefly, the modified Beer-Lambert paradigm is a scheme to derive changes in tissue optical properties based on continuous-wave (CW) diffuse optical intensity measurements. In its simplest form, the scheme relates differential changes in light transmission (in any geometry) to differential changes in tissue absorption. Here we extend this paradigm to the measurement of tissue blood flow by diffuse correlation spectroscopy (DCS). In the new approach, differential changes of the intensity temporal auto-correlation function at a single delay-time are related to differential changes in blood flow. The key theoretical results for measurement of blood flow changes in any tissue geometry are derived, and we demonstrate the new method to monitor cerebral blood flow in a pig under conditions wherein the semi-infinite geometry approximation is fairly good. Specifically, the drug dinitrophenol was injected in the pig to induce a gradual 200% increase in cerebral blood flow, as measured with MRI velocity flow mapping and by DCS. The modified Beer-Lambert law for flow accurately recovered these flow changes using only a single delay-time in the intensity auto-correlation function curve. The scheme offers increased DCS measurement speed of blood flow. Further, the same techniques using the modified Beer-Lambert law to filter out superficial tissue effects in NIRS measurements of deep tissues can be applied to the DCS modified Beer-Lambert law for blood flow monitoring of deep tissues.

Prioritizing hazardous pollutants in two Nigerian water supply schemes: a risk-based approach.

PubMed

Etchie, Ayotunde T; Etchie, Tunde O; Adewuyi, Gregory O; Krishnamurthi, Kannan; Saravanadevi, S; Wate, Satish R

2013-08-01

To rank pollutants in two Nigerian water supply schemes according to their effect on human health using a risk-based approach. Hazardous pollutants in drinking-water in the study area were identified from a literature search and selected pollutants were monitored from April 2010 to December 2011 in catchments, treatment works and consumer taps. The disease burden due to each pollutant was estimated in disability-adjusted life years (DALYs) using data on the pollutant's concentration, exposure to the pollutant, the severity of its health effects and the consumer population. The pollutants identified were microbial organisms, cadmium, cobalt, chromium, copper, iron, manganese, nickel, lead and zinc. All were detected in the catchments but only cadmium, cobalt, chromium, manganese and lead exceeded World Health Organization (WHO) guideline values after water treatment. Post-treatment contamination was observed. The estimated disease burden was greatest for chromium in both schemes, followed in decreasing order by cadmium, lead, manganese and cobalt. The total disease burden of all pollutants in the two schemes was 46 000 and 9500 DALYs per year or 0.14 and 0.088 DALYs per person per year, respectively, much higher than the WHO reference level of 1 × 10(-6) DALYs per person per year. For each metal, the disease burden exceeded the reference level and was comparable with that due to microbial contamination reported elsewhere in Africa. The estimated disease burden of metal contamination of two Nigerian water supply systems was high. It could best be reduced by protection of water catchment and pretreatment by electrocoagulation.

Predictable and reliable ECG monitoring over IEEE 802.11 WLANs within a hospital.

PubMed

Park, Juyoung; Kang, Kyungtae

2014-09-01

Telecardiology provides mobility for patients who require constant electrocardiogram (ECG) monitoring. However, its safety is dependent on the predictability and robustness of data delivery, which must overcome errors in the wireless channel through which the ECG data are transmitted. We report here a framework that can be used to gauge the applicability of IEEE 802.11 wireless local area network (WLAN) technology to ECG monitoring systems in terms of delay constraints and transmission reliability. For this purpose, a medical-grade WLAN architecture achieved predictable delay through the combination of a medium access control mechanism based on the point coordination function provided by IEEE 802.11 and an error control scheme based on Reed-Solomon coding and block interleaving. The size of the jitter buffer needed was determined by this architecture to avoid service dropout caused by buffer underrun, through analysis of variations in transmission delay. Finally, we assessed this architecture in terms of service latency and reliability by modeling the transmission of uncompressed two-lead electrocardiogram data from the MIT-BIH Arrhythmia Database and highlight the applicability of this wireless technology to telecardiology.

Participatory Carbon Monitoring System in Community Forests of Nepal

NASA Astrophysics Data System (ADS)

Karki, S.

2016-12-01

With the adoption of climate change agreement, Reducing emissions from deforestation and forest degradation (REDD) has advanced as a performance based policy instruments to curtailing the deforestation and forest degradation. Developing countries are working to get REDD ready. However, the readiness assessment process entails criteria such as REDD+ Safeguards are met, monitoring and reporting of emission reductions are verified (MRV). For counties to have MRV in place, technical know-how on measuring forest carbon and capacity of the human resources are limited. International Centre for Integrated Mountain Development (ICIMOD) together with its national partners implemented REDD+ pilot project from 2009-2013 in 105 community forests (CF) of three watersheds namely Charnawati, Kayarkhola and Ludikhola in Nepal. This paper discuss prototype of the participatory carbon monitoring and measurement approach tested in these105 CFs that is systematic, transparent, and cost effective. Additionally it will demonstrate the enhanced carbon stock data from 2010-2013 assembled at ICIMOD Regional Database Initiative are made freely available. Such application can be scaled up or considered in decision making for performance based payment schemes.

Post-marketing studies: the work of the Drug Safety Research Unit.

PubMed

Mackay, F J

1998-11-01

The Drug Safety Research Unit (DSRU) is the centre for prescription-event monitoring (PEM) in England. PEM studies are noninterventional observational cohort studies which monitor the safety of newly marketed drugs. The need for post-marketing surveillance is well recognised in the UK and general practice is an ideal source of data. PEM studies are general practitioner (community)-based and exposure is based on dispensed prescription data in England. To date, 65 PEM studies have been completed with a mean cohort size of 10 979 patients and the DSRU database has clinical information on over 700000 patients prescribed new drugs. Unlike spontaneous reporting schemes, PEM produces incidence rates for events reported during treatment. Comparative studies can be conducted for drugs in the same class. The DSRU aggregates outcome data for pregnancies exposed to new drugs. Data for children and the elderly can also be specifically examined. PEM data have a number of advantages over data from computerised general practice databases in the UK. PEM is the only technique within the UK capable of monitoring newly marketed drugs in such a comprehensive and systematic way.

A robust trust establishment scheme for wireless sensor networks.

PubMed

Ishmanov, Farruh; Kim, Sung Won; Nam, Seung Yeob

2015-03-23

Security techniques like cryptography and authentication can fail to protect a network once a node is compromised. Hence, trust establishment continuously monitors and evaluates node behavior to detect malicious and compromised nodes. However, just like other security schemes, trust establishment is also vulnerable to attack. Moreover, malicious nodes might misbehave intelligently to trick trust establishment schemes. Unfortunately, attack-resistance and robustness issues with trust establishment schemes have not received much attention from the research community. Considering the vulnerability of trust establishment to different attacks and the unique features of sensor nodes in wireless sensor networks, we propose a lightweight and robust trust establishment scheme. The proposed trust scheme is lightweight thanks to a simple trust estimation method. The comprehensiveness and flexibility of the proposed trust estimation scheme make it robust against different types of attack and misbehavior. Performance evaluation under different types of misbehavior and on-off attacks shows that the detection rate of the proposed trust mechanism is higher and more stable compared to other trust mechanisms.

Lot quality assurance sampling techniques in health surveys in developing countries: advantages and current constraints.

PubMed

Lanata, C F; Black, R E

1991-01-01

Traditional survey methods, which are generally costly and time-consuming, usually provide information at the regional or national level only. The utilization of lot quality assurance sampling (LQAS) methodology, developed in industry for quality control, makes it possible to use small sample sizes when conducting surveys in small geographical or population-based areas (lots). This article describes the practical use of LQAS for conducting health surveys to monitor health programmes in developing countries. Following a brief description of the method, the article explains how to build a sample frame and conduct the sampling to apply LQAS under field conditions. A detailed description of the procedure for selecting a sampling unit to monitor the health programme and a sample size is given. The sampling schemes utilizing LQAS applicable to health surveys, such as simple- and double-sampling schemes, are discussed. The interpretation of the survey results and the planning of subsequent rounds of LQAS surveys are also discussed. When describing the applicability of LQAS in health surveys in developing countries, the article considers current limitations for its use by health planners in charge of health programmes, and suggests ways to overcome these limitations through future research. It is hoped that with increasing attention being given to industrial sampling plans in general, and LQAS in particular, their utilization to monitor health programmes will provide health planners in developing countries with powerful techniques to help them achieve their health programme targets.

Strain Wave Acquisition by a Fiber Optic Coherent Sensor for Impact Monitoring

PubMed Central

Sbarufatti, Claudio; Beligni, Alessio; Gilioli, Andrea; Ferrario, Maddalena; Mattarei, Marco; Martinelli, Mario; Giglio, Marco

2017-01-01

A novel fiber optic sensing technology for high frequency dynamics detection is proposed in this paper, specifically tailored for structural health monitoring applications based on strain wave analysis, for both passive impact identification and active Lamb wave monitoring. The sensing solution relies on a fiber optic-based interferometric architecture associated to an innovative coherent detection scheme, which retrieves in a completely passive way the high-frequency phase information of the received optical signal. The sensing fiber can be arranged into different layouts, depending on the requirement of the specific application, in order to enhance the sensor sensitivity while still ensuring a limited gauge length if punctual measures are required. For active Lamb wave monitoring, this results in a sensing fiber arranged in multiple loops glued on an aluminum thin panel in order to increase the phase signal only in correspondence to the sensing points of interest. Instead, for passive impact identification, the required sensitivity is guaranteed by simply exploiting a longer gauge length glued to the structure. The fiber optic coherent (FOC) sensor is exploited to detect the strain waves emitted by a piezoelectric transducer placed on the aluminum panel or generated by an impulse hammer, respectively. The FOC sensor measurements have been compared with both a numerical model based on Finite Elements and traditional piezoelectric sensors, confirming a good agreement between experimental and simulated results for both active and passive impact monitoring scenarios. PMID:28773154

[Open-path online monitoring of ambient atmospheric CO2 based on laser absorption spectrum].

PubMed

He, Ying; Zhang, Yu-Jun; Kan, Rui-Feng; Xia, Hui; Geng, Hui; Ruan, Jun; Wang, Min; Cui, Xiao-Juan; Liu, Wen-Qing

2009-01-01

With the conjunction of tunable diode laser absorption spectroscopy technology (TDLAS) and the open long optical path technology, the system designing scheme of CO2 on-line monitoring based on near infrared tunable diode laser absorption spectroscopy technology was discussed in detail, and the instrument for large-range measurement was set up. By choosing the infrared absorption line of CO2 at 1.57 microm whose line strength is strong and suitable for measurement, the ambient atmospheric CO2 was measured continuously with a 30 s temporal resolution at an suburb site in the autumn of 2007. The diurnal atmospheric variations of CO2 and continuous monitoring results were presented. The results show that the variation in CO2 concentration has an obvious diurnal periodicity in suburb where the air is free of interference and contamination. The general characteristic of diurnal variation is that the concentration is low in the daytime and high at night, so it matches the photosynthesis trend. The instrument can detect gas concentration online with high resolution, high sensitivity, high precision, short response time and many other advantages, the monitoring requires no gas sampling, the calibration is easy, and the detection limit is about 4.2 x 10(-7). It has been proved that the system and measurement project are feasible, so it is an effective method for gas flux continuous online monitoring of large range in ecosystem based on TDLAS technology.

Mapping edge-based traffic measurements onto the internal links in MPLS network

NASA Astrophysics Data System (ADS)

Zhao, Guofeng; Tang, Hong; Zhang, Yi

2004-09-01

Applying multi-protocol label switching techniques to IP-based backbone for traffic engineering goals has shown advantageous. Obtaining a volume of load on each internal link of the network is crucial for traffic engineering applying. Though collecting can be available for each link, such as applying traditional SNMP scheme, the approach may cause heavy processing load and sharply degrade the throughput of the core routers. Then monitoring merely at the edge of the network and mapping the measurements onto the core provides a good alternative way. In this paper, we explore a scheme for traffic mapping with edge-based measurements in MPLS network. It is supposed that the volume of traffic on each internal link over the domain would be mapped onto by measurements available only at ingress nodes. We apply path-based measurements at ingress nodes without enabling measurements in the core of the network. We propose a method that can infer a path from the ingress to the egress node using label distribution protocol without collecting routing data from core routers. Based on flow theory and queuing theory, we prove that our approach is effective and present the algorithm for traffic mapping. We also show performance simulation results that indicate potential of our approach.

Designing and implementing a trust-wide quality assurance programme.

PubMed

Coope, Sally-Ann

2018-04-02

Derbyshire Community Health Services (DCHS) NHS Foundation Trust provides a wide range of community-based health services. After the Care Quality Commission (CQC) found gaps in the trust's assurance process, its board decided to develop a method of continuous quality improvements that could be used as a basis for the trust's quality assurance system. The trust adapted and built on an acute model so it was suitable for community services. The final assurance system, Quality Always, has four elements: the clinical assessment and accreditation scheme; leadership development; 'champions' within clinical teams to support and promote the scheme; and dashboards to record and monitor progress. A system to recognise and reward achievement was essential for success. Quality Always has resulted in better care quality, an improved CQC rating, a sense of achievement among staff, the development of support networks, learning (especially among support staff) and good practice being shared.

Regulation control and energy management scheme for wireless power transfer

DOEpatents

Miller, John M.

2015-12-29

Power transfer rate at a charging facility can be maximized by employing a feedback scheme. The state of charge (SOC) and temperature of the regenerative energy storage system (RESS) pack of a vehicle is monitored to determine the load due to the RESS pack. An optimal frequency that cancels the imaginary component of the input impedance for the output signal from a grid converter is calculated from the load of the RESS pack, and a frequency offset f* is made to the nominal frequency f.sub.0 of the grid converter output based on the resonance frequency of a magnetically coupled circuit. The optimal frequency can maximize the efficiency of the power transfer. Further, an optimal grid converter duty ratio d* can be derived from the charge rate of the RESS pack. The grid converter duty ratio d* regulates wireless power transfer (WPT) power level.

A Scheme for Targeting Optical SETI Observations

NASA Astrophysics Data System (ADS)

Shostak, Seth

2004-06-01

In optical SETI (OSETI) experiments, it is generally assumed that signals will be deliberate, narrowly targeted beacons sent by extraterrestrial societies to large numbers of candidate star systems. If this is so, then it may be unrealistic to expect a high duty cycle for the received signal. Ergo, an advantage accrues to any OSETI scheme that realistically suggests where and when to search. In this paper, we elaborate a proposal (Castellano, Doyle, &McIntosh 2000) for selecting regions of sky for intensive optical SETI monitoring based on characteristics of our solar system that would be visible at great distance. This can enormously lessen the amount of sky that needs to be searched. In addition, this is an attractive approach for the transmitting society because it both increases the chances of reception and provides a large reduction in energy required. With good astrometric information, the transmitter need be no more powerful than an automobile tail light.

Train integrity detection risk analysis based on PRISM

NASA Astrophysics Data System (ADS)

Wen, Yuan

2018-04-01

GNSS based Train Integrity Monitoring System (TIMS) is an effective and low-cost detection scheme for train integrity detection. However, as an external auxiliary system of CTCS, GNSS may be influenced by external environments, such as uncertainty of wireless communication channels, which may lead to the failure of communication and positioning. In order to guarantee the reliability and safety of train operation, a risk analysis method of train integrity detection based on PRISM is proposed in this article. First, we analyze the risk factors (in GNSS communication process and the on-board communication process) and model them. Then, we evaluate the performance of the model in PRISM based on the field data. Finally, we discuss how these risk factors influence the train integrity detection process.

Genetic algorithms with memory- and elitism-based immigrants in dynamic environments.

PubMed

Yang, Shengxiang

2008-01-01

In recent years the genetic algorithm community has shown a growing interest in studying dynamic optimization problems. Several approaches have been devised. The random immigrants and memory schemes are two major ones. The random immigrants scheme addresses dynamic environments by maintaining the population diversity while the memory scheme aims to adapt genetic algorithms quickly to new environments by reusing historical information. This paper investigates a hybrid memory and random immigrants scheme, called memory-based immigrants, and a hybrid elitism and random immigrants scheme, called elitism-based immigrants, for genetic algorithms in dynamic environments. In these schemes, the best individual from memory or the elite from the previous generation is retrieved as the base to create immigrants into the population by mutation. This way, not only can diversity be maintained but it is done more efficiently to adapt genetic algorithms to the current environment. Based on a series of systematically constructed dynamic problems, experiments are carried out to compare genetic algorithms with the memory-based and elitism-based immigrants schemes against genetic algorithms with traditional memory and random immigrants schemes and a hybrid memory and multi-population scheme. The sensitivity analysis regarding some key parameters is also carried out. Experimental results show that the memory-based and elitism-based immigrants schemes efficiently improve the performance of genetic algorithms in dynamic environments.

Development of Algorithms for Control of Humidity in Plant Growth Chambers

NASA Technical Reports Server (NTRS)

Costello, Thomas A.

2003-01-01

Algorithms were developed to control humidity in plant growth chambers used for research on bioregenerative life support at Kennedy Space Center. The algorithms used the computed water vapor pressure (based on measured air temperature and relative humidity) as the process variable, with time-proportioned outputs to operate the humidifier and de-humidifier. Algorithms were based upon proportional-integral-differential (PID) and Fuzzy Logic schemes and were implemented using I/O Control software (OPTO-22) to define and download the control logic to an autonomous programmable logic controller (PLC, ultimate ethernet brain and assorted input-output modules, OPTO-22), which performed the monitoring and control logic processing, as well the physical control of the devices that effected the targeted environment in the chamber. During limited testing, the PLC's successfully implemented the intended control schemes and attained a control resolution for humidity of less than 1%. The algorithms have potential to be used not only with autonomous PLC's but could also be implemented within network-based supervisory control programs. This report documents unique control features that were implemented within the OPTO-22 framework and makes recommendations regarding future uses of the hardware and software for biological research by NASA.

A Digital Compressed Sensing-Based Energy-Efficient Single-Spot Bluetooth ECG Node

PubMed Central

Cai, Zhipeng; Zou, Fumin; Zhang, Xiangyu

2018-01-01

Energy efficiency is still the obstacle for long-term real-time wireless ECG monitoring. In this paper, a digital compressed sensing- (CS-) based single-spot Bluetooth ECG node is proposed to deal with the challenge in wireless ECG application. A periodic sleep/wake-up scheme and a CS-based compression algorithm are implemented in a node, which consists of ultra-low-power analog front-end, microcontroller, Bluetooth 4.0 communication module, and so forth. The efficiency improvement and the node's specifics are evidenced by the experiments using the ECG signals sampled by the proposed node under daily activities of lay, sit, stand, walk, and run. Under using sparse binary matrix (SBM), block sparse Bayesian learning (BSBL) method, and discrete cosine transform (DCT) basis, all ECG signals were essentially undistorted recovered with root-mean-square differences (PRDs) which are less than 6%. The proposed sleep/wake-up scheme and data compression can reduce the airtime over energy-hungry wireless links, the energy consumption of proposed node is 6.53 mJ, and the energy consumption of radio decreases 77.37%. Moreover, the energy consumption increase caused by CS code execution is negligible, which is 1.3% of the total energy consumption. PMID:29599945

A Digital Compressed Sensing-Based Energy-Efficient Single-Spot Bluetooth ECG Node.

PubMed

Luo, Kan; Cai, Zhipeng; Du, Keqin; Zou, Fumin; Zhang, Xiangyu; Li, Jianqing

2018-01-01

Energy efficiency is still the obstacle for long-term real-time wireless ECG monitoring. In this paper, a digital compressed sensing- (CS-) based single-spot Bluetooth ECG node is proposed to deal with the challenge in wireless ECG application. A periodic sleep/wake-up scheme and a CS-based compression algorithm are implemented in a node, which consists of ultra-low-power analog front-end, microcontroller, Bluetooth 4.0 communication module, and so forth. The efficiency improvement and the node's specifics are evidenced by the experiments using the ECG signals sampled by the proposed node under daily activities of lay, sit, stand, walk, and run. Under using sparse binary matrix (SBM), block sparse Bayesian learning (BSBL) method, and discrete cosine transform (DCT) basis, all ECG signals were essentially undistorted recovered with root-mean-square differences (PRDs) which are less than 6%. The proposed sleep/wake-up scheme and data compression can reduce the airtime over energy-hungry wireless links, the energy consumption of proposed node is 6.53 mJ, and the energy consumption of radio decreases 77.37%. Moreover, the energy consumption increase caused by CS code execution is negligible, which is 1.3% of the total energy consumption.

Integrated wireless sensor network and real time smart controlling and monitoring system for efficient energy management in standalone photovoltaic systems

NASA Astrophysics Data System (ADS)

Abou-Elnour, Ali; Thabt, A.; Helmy, S.; Kashf, Y.; Hadad, Y.; Tarique, M.; Abo-Elnor, Ossama

2014-04-01

In the present work, wireless sensor network and smart real-time controlling and monitoring system are integrated for efficient energy management of standalone photovoltaic system. The proposed system has two main components namely the monitoring and controlling system and the wireless communication system. LabView software has been used in the implementation of the monitoring and controlling system. On the other hand, ZigBee wireless modules have been used to implement the wireless system. The main functions of monitoring and controlling unit is to efficiently control the energy consumption form the photovoltaic system based on accurate determination of the periods of times at which the loads are required to be operated. The wireless communication system send the data from the monitoring and controlling unit to the loads at which desired switching operations are performed. The wireless communication system also continuously feeds the monitoring and controlling unit with updated input data from the sensors and from the photovoltaic module send to calculate and record the generated, the consumed, and the stored energy to apply load switching saving schemes if necessary. It has to be mentioned that our proposed system is a low cost and low power system because and it is flexible to be upgraded to fulfill additional users' requirements.

An On-Demand Emergency Packet Transmission Scheme for Wireless Body Area Networks.

PubMed

Al Ameen, Moshaddique; Hong, Choong Seon

2015-12-04

The rapid developments of sensor devices that can actively monitor human activities have given rise to a new field called wireless body area network (BAN). A BAN can manage devices in, on and around the human body. Major requirements of such a network are energy efficiency, long lifetime, low delay, security, etc. Traffic in a BAN can be scheduled (normal) or event-driven (emergency). Traditional media access control (MAC) protocols use duty cycling to improve performance. A sleep-wake up cycle is employed to save energy. However, this mechanism lacks features to handle emergency traffic in a prompt and immediate manner. To deliver an emergency packet, a node has to wait until the receiver is awake. It also suffers from overheads, such as idle listening, overhearing and control packet handshakes. An external radio-triggered wake up mechanism is proposed to handle prompt communication. It can reduce the overheads and improve the performance through an on-demand scheme. In this work, we present a simple-to-implement on-demand packet transmission scheme by taking into considerations the requirements of a BAN. The major concern is handling the event-based emergency traffic. The performance analysis of the proposed scheme is presented. The results showed significant improvements in the overall performance of a BAN compared to state-of-the-art protocols in terms of energy consumption, delay and lifetime.

An On-Demand Emergency Packet Transmission Scheme for Wireless Body Area Networks

PubMed Central

Al Ameen, Moshaddique; Hong, Choong Seon

2015-01-01

The rapid developments of sensor devices that can actively monitor human activities have given rise to a new field called wireless body area network (BAN). A BAN can manage devices in, on and around the human body. Major requirements of such a network are energy efficiency, long lifetime, low delay, security, etc. Traffic in a BAN can be scheduled (normal) or event-driven (emergency). Traditional media access control (MAC) protocols use duty cycling to improve performance. A sleep-wake up cycle is employed to save energy. However, this mechanism lacks features to handle emergency traffic in a prompt and immediate manner. To deliver an emergency packet, a node has to wait until the receiver is awake. It also suffers from overheads, such as idle listening, overhearing and control packet handshakes. An external radio-triggered wake up mechanism is proposed to handle prompt communication. It can reduce the overheads and improve the performance through an on-demand scheme. In this work, we present a simple-to-implement on-demand packet transmission scheme by taking into considerations the requirements of a BAN. The major concern is handling the event-based emergency traffic. The performance analysis of the proposed scheme is presented. The results showed significant improvements in the overall performance of a BAN compared to state-of-the-art protocols in terms of energy consumption, delay and lifetime. PMID:26690161

Comparison of the co-gasification of sewage sludge and food wastes and cost-benefit analysis of gasification- and incineration-based waste treatment schemes.

PubMed

You, Siming; Wang, Wei; Dai, Yanjun; Tong, Yen Wah; Wang, Chi-Hwa

2016-10-01

The compositions of food wastes and their co-gasification producer gas were compared with the existing data of sewage sludge. Results showed that food wastes are more favorable than sewage sludge for co-gasification based on residue generation and energy output. Two decentralized gasification-based schemes were proposed to dispose of the sewage sludge and food wastes in Singapore. Monte Carlo simulation-based cost-benefit analysis was conducted to compare the proposed schemes with the existing incineration-based scheme. It was found that the gasification-based schemes are financially superior to the incineration-based scheme based on the data of net present value (NPV), benefit-cost ratio (BCR), and internal rate of return (IRR). Sensitivity analysis was conducted to suggest effective measures to improve the economics of the schemes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Cognitive Achievement and Motivation in Hands-on and Teacher-Centred Science Classes: Does an additional hands-on consolidation phase (concept mapping) optimise cognitive learning at work stations?

NASA Astrophysics Data System (ADS)

Gerstner, Sabine; Bogner, Franz X.

2010-05-01

Our study monitored the cognitive and motivational effects within different educational instruction schemes: On the one hand, teacher-centred versus hands-on instruction; on the other hand, hands-on instruction with and without a knowledge consolidation phase (concept mapping). All the instructions dealt with the same content. For all participants, the hands-on approach as well as the concept mapping adaptation were totally new. Our hands-on approach followed instruction based on "learning at work stations". A total of 397 high-achieving fifth graders participated in our study. We used a pre-test, post-test, retention test design both to detect students' short-term learning success and long-term learning success, and to document their decrease rates of newly acquired knowledge. Additionally, we monitored intrinsic motivation. Although the teacher-centred approach provided higher short-term learning success, hands-on instruction resulted in relatively lower decrease rates. However, after six weeks, all students reached similar levels of newly acquired knowledge. Nevertheless, concept mapping as a knowledge consolidation phase positively affected short-term increase in knowledge. Regularly placed in instruction, it might increase long-term retention rates. Scores of interest, perceived competence and perceived choice were very high in all the instructional schemes.

ALICE HLT Run 2 performance overview.

NASA Astrophysics Data System (ADS)

Krzewicki, Mikolaj; Lindenstruth, Volker; ALICE Collaboration

2017-10-01

For the LHC Run 2 the ALICE HLT architecture was consolidated to comply with the upgraded ALICE detector readout technology. The software framework was optimized and extended to cope with the increased data load. Online calibration of the TPC using online tracking capabilities of the ALICE HLT was deployed. Offline calibration code was adapted to run both online and offline and the HLT framework was extended to support that. The performance of this schema is important for Run 3 related developments. An additional data transport approach was developed using the ZeroMQ library, forming at the same time a test bed for the new data flow model of the O2 system, where further development of this concept is ongoing. This messaging technology was used to implement the calibration feedback loop augmenting the existing, graph oriented HLT transport framework. Utilising the online reconstruction of many detectors, a new asynchronous monitoring scheme was developed to allow real-time monitoring of the physics performance of the ALICE detector, on top of the new messaging scheme for both internal and external communication. Spare computing resources comprising the production and development clusters are run as a tier-2 GRID site using an OpenStack-based setup. The development cluster is running continuously, the production cluster contributes resources opportunistically during periods of LHC inactivity.

Primates decline rapidly in unprotected forests: evidence from a monitoring program with data constraints.

PubMed

Rovero, Francesco; Mtui, Arafat; Kitegile, Amani; Jacob, Philipo; Araldi, Alessandro; Tenan, Simone

2015-01-01

Growing threats to primates in tropical forests make robust and long-term population abundance assessments increasingly important for conservation. Concomitantly, monitoring becomes particularly relevant in countries with primate habitat. Yet monitoring schemes in these countries often suffer from logistic constraints and/or poor rigor in data collection, and a lack of consideration of sources of bias in analysis. To address the need for feasible monitoring schemes and flexible analytical tools for robust trend estimates, we analyzed data collected by local technicians on abundance of three species of arboreal monkey in the Udzungwa Mountains of Tanzania (two Colobus species and one Cercopithecus), an area of international importance for primate endemism and conservation. We counted primate social groups along eight line transects in two forest blocks in the area, one protected and one unprotected, over a span of 11 years. We applied a recently proposed open metapopulation model to estimate abundance trends while controlling for confounding effects of observer, site, and season. Primate populations were stable in the protected forest, while the colobines, including the endemic Udzungwa red colobus, declined severely in the unprotected forest. Targeted hunting pressure at this second site is the most plausible explanation for the trend observed. The unexplained variability in detection probability among transects was greater than the variability due to observers, indicating consistency in data collection among observers. There were no significant differences in both primate abundance and detectability between wet and dry seasons, supporting the choice of sampling during the dry season only based on minimizing practical constraints. Results show that simple monitoring routines implemented by trained local technicians can effectively detect changes in primate populations in tropical countries. The hierarchical Bayesian model formulation adopted provides a flexible tool to determine temporal trends with full account for any imbalance in the data set and for imperfect detection.

Adaptive hidden Markov model-based online learning framework for bearing faulty detection and performance degradation monitoring

NASA Astrophysics Data System (ADS)

Yu, Jianbo

2017-01-01

This study proposes an adaptive-learning-based method for machine faulty detection and health degradation monitoring. The kernel of the proposed method is an "evolving" model that uses an unsupervised online learning scheme, in which an adaptive hidden Markov model (AHMM) is used for online learning the dynamic health changes of machines in their full life. A statistical index is developed for recognizing the new health states in the machines. Those new health states are then described online by adding of new hidden states in AHMM. Furthermore, the health degradations in machines are quantified online by an AHMM-based health index (HI) that measures the similarity between two density distributions that describe the historic and current health states, respectively. When necessary, the proposed method characterizes the distinct operating modes of the machine and can learn online both abrupt as well as gradual health changes. Our method overcomes some drawbacks of the HIs (e.g., relatively low comprehensibility and applicability) based on fixed monitoring models constructed in the offline phase. Results from its application in a bearing life test reveal that the proposed method is effective in online detection and adaptive assessment of machine health degradation. This study provides a useful guide for developing a condition-based maintenance (CBM) system that uses an online learning method without considerable human intervention.

Three-dimensional dynamic deformation monitoring using a laser-scanning system

NASA Astrophysics Data System (ADS)

Al-Hanbali, Nedal N.; Teskey, William F.

1994-10-01

Non-contact dynamic deformation monitoring (e.g. with a laser scanning system) is very useful in monitoring changes in alignment and changes in size and shape of coupled operating machines. If relative movements between coupled operating machines are large, excessive wear in the machines or unplanned shutdowns due to machinery failure will occur. The purpose of non-contact dynamic deformation monitoring is to identify the causes of large movements and point to remedial action that can be taken to prevent them. The laser scanning system is a laser-based 3D vision system. The system-technique is based on an auto- synchronized triangulation scanning scheme. The system provides accurate, fast, and reliable 3D measurements and can measure objects between 0.5 m to 100 m with a field of view of 40 degree(s) X 50 degree(s). The system is flexible in terms of providing control over the scanned area and depth. The system also provides the user with the intensity image in addition to the depth coded image. This paper reports on the preliminary testing of this system to monitor surface movements and target (point) movements. The monitoring resolution achieved for an operating motorized alignment test rig in the lab was 1 mm for surface movements and 0.50 m for target movements. Raw data manipulation, local calibration, and the method of relating measurements to control points will be discussed. Possibilities for improving the resolution and recommendations for future development will also be presented.

Classifying Human Activity Patterns from Smartphone Collected GPS data: a Fuzzy Classification and Aggregation Approach.

PubMed

Wan, Neng; Lin, Ge

2016-12-01

Smartphones have emerged as a promising type of equipment for monitoring human activities in environmental health studies. However, degraded location accuracy and inconsistency of smartphone-measured GPS data have limited its effectiveness for classifying human activity patterns. This study proposes a fuzzy classification scheme for differentiating human activity patterns from smartphone-collected GPS data. Specifically, a fuzzy logic reasoning was adopted to overcome the influence of location uncertainty by estimating the probability of different activity types for single GPS points. Based on that approach, a segment aggregation method was developed to infer activity patterns, while adjusting for uncertainties of point attributes. Validations of the proposed methods were carried out based on a convenient sample of three subjects with different types of smartphones. The results indicate desirable accuracy (e.g., up to 96% in activity identification) with use of this method. Two examples were provided in the appendix to illustrate how the proposed methods could be applied in environmental health studies. Researchers could tailor this scheme to fit a variety of research topics.

Near-infrared surface-enhanced-Raman-scattering (SERS) mediated identification of single optically trapped, bacterial spores

NASA Astrophysics Data System (ADS)

Alexander, Troy A.; Gillespie, James B.; Pellegrino, Paul M.; Fell, Nicholas F., Jr.; Wood, Gary L.; Salamo, Gregory J.

2003-03-01

A novel methodology has been developed for the investigation of bacterial spores. Specifically, this method has been used to probe the spore coat composition of several Bacillus species. This technique may be useful in many applications; most notably, development of novel detection schemes toward potentially harmful biological agents. This method would also be useful as an ancillary environmental monitoring system where sterility is of importance (i.e., food preparation areas as well as invasive and minimally invasive medical applications). This unique detection scheme is based on the near-infrared (NIR) Surface-Enhanced-Raman-Scattering (SERS) from single, optically trapped, bacterial spores. The SERS spectra of several bacterial spores in aqueous media have been measured using SERS substrates based on 60-nm diameter gold colloids bound to 3-Aminopropyltriethoxysilane derivatized glass. The light from a 785-nm laser diode was used to capture/manipulate as well as simultaneously excite the SERS of an individual bacterial spore. The collected SERS spectra were examined for uniqueness and the applicability of this technique for the species identification of bacterial spores.

An Efficient and Adaptive Mutual Authentication Framework for Heterogeneous Wireless Sensor Network-Based Applications

PubMed Central

Kumar, Pardeep; Ylianttila, Mika; Gurtov, Andrei; Lee, Sang-Gon; Lee, Hoon-Jae

2014-01-01

Robust security is highly coveted in real wireless sensor network (WSN) applications since wireless sensors' sense critical data from the application environment. This article presents an efficient and adaptive mutual authentication framework that suits real heterogeneous WSN-based applications (such as smart homes, industrial environments, smart grids, and healthcare monitoring). The proposed framework offers: (i) key initialization; (ii) secure network (cluster) formation (i.e., mutual authentication and dynamic key establishment); (iii) key revocation; and (iv) new node addition into the network. The correctness of the proposed scheme is formally verified. An extensive analysis shows the proposed scheme coupled with message confidentiality, mutual authentication and dynamic session key establishment, node privacy, and message freshness. Moreover, the preliminary study also reveals the proposed framework is secure against popular types of attacks, such as impersonation attacks, man-in-the-middle attacks, replay attacks, and information-leakage attacks. As a result, we believe the proposed framework achieves efficiency at reasonable computation and communication costs and it can be a safeguard to real heterogeneous WSN applications. PMID:24521942

An efficient and adaptive mutual authentication framework for heterogeneous wireless sensor network-based applications.

PubMed

Kumar, Pardeep; Ylianttila, Mika; Gurtov, Andrei; Lee, Sang-Gon; Lee, Hoon-Jae

2014-02-11

Robust security is highly coveted in real wireless sensor network (WSN) applications since wireless sensors' sense critical data from the application environment. This article presents an efficient and adaptive mutual authentication framework that suits real heterogeneous WSN-based applications (such as smart homes, industrial environments, smart grids, and healthcare monitoring). The proposed framework offers: (i) key initialization; (ii) secure network (cluster) formation (i.e., mutual authentication and dynamic key establishment); (iii) key revocation; and (iv) new node addition into the network. The correctness of the proposed scheme is formally verified. An extensive analysis shows the proposed scheme coupled with message confidentiality, mutual authentication and dynamic session key establishment, node privacy, and message freshness. Moreover, the preliminary study also reveals the proposed framework is secure against popular types of attacks, such as impersonation attacks, man-in-the-middle attacks, replay attacks, and information-leakage attacks. As a result, we believe the proposed framework achieves efficiency at reasonable computation and communication costs and it can be a safeguard to real heterogeneous WSN applications.

A data fusion-based methodology for optimal redesign of groundwater monitoring networks

NASA Astrophysics Data System (ADS)

Hosseini, Marjan; Kerachian, Reza

2017-09-01

In this paper, a new data fusion-based methodology is presented for spatio-temporal (S-T) redesigning of Groundwater Level Monitoring Networks (GLMNs). The kriged maps of three different criteria (i.e. marginal entropy of water table levels, estimation error variances of mean values of water table levels, and estimation values of long-term changes in water level) are combined for determining monitoring sub-areas of high and low priorities in order to consider different spatial patterns for each sub-area. The best spatial sampling scheme is selected by applying a new method, in which a regular hexagonal gridding pattern and the Thiessen polygon approach are respectively utilized in sub-areas of high and low monitoring priorities. An Artificial Neural Network (ANN) and a S-T kriging models are used to simulate water level fluctuations. To improve the accuracy of the predictions, results of the ANN and S-T kriging models are combined using a data fusion technique. The concept of Value of Information (VOI) is utilized to determine two stations with maximum information values in both sub-areas with high and low monitoring priorities. The observed groundwater level data of these two stations are considered for the power of trend detection, estimating periodic fluctuations and mean values of the stationary components, which are used for determining non-uniform sampling frequencies for sub-areas. The proposed methodology is applied to the Dehgolan plain in northwestern Iran. The results show that a new sampling configuration with 35 and 7 monitoring stations and sampling intervals of 20 and 32 days, respectively in sub-areas with high and low monitoring priorities, leads to a more efficient monitoring network than the existing one containing 52 monitoring stations and monthly temporal sampling.

Compressed-Sensing Reconstruction Based on Block Sparse Bayesian Learning in Bearing-Condition Monitoring

PubMed Central

Sun, Jiedi; Yu, Yang; Wen, Jiangtao

2017-01-01

Remote monitoring of bearing conditions, using wireless sensor network (WSN), is a developing trend in the industrial field. In complicated industrial environments, WSN face three main constraints: low energy, less memory, and low operational capability. Conventional data-compression methods, which concentrate on data compression only, cannot overcome these limitations. Aiming at these problems, this paper proposed a compressed data acquisition and reconstruction scheme based on Compressed Sensing (CS) which is a novel signal-processing technique and applied it for bearing conditions monitoring via WSN. The compressed data acquisition is realized by projection transformation and can greatly reduce the data volume, which needs the nodes to process and transmit. The reconstruction of original signals is achieved in the host computer by complicated algorithms. The bearing vibration signals not only exhibit the sparsity property, but also have specific structures. This paper introduced the block sparse Bayesian learning (BSBL) algorithm which works by utilizing the block property and inherent structures of signals to reconstruct CS sparsity coefficients of transform domains and further recover the original signals. By using the BSBL, CS reconstruction can be improved remarkably. Experiments and analyses showed that BSBL method has good performance and is suitable for practical bearing-condition monitoring. PMID:28635623

GPS data processing of networks with mixed single- and dual-frequency receivers for deformation monitoring

NASA Astrophysics Data System (ADS)

Zou, X.; Deng, Z.; Ge, M.; Dick, G.; Jiang, W.; Liu, J.

2010-07-01

In order to obtain crustal deformations of higher spatial resolution, existing GPS networks must be densified. This densification can be carried out using single-frequency receivers at moderate costs. However, ionospheric delay handling is required in the data processing. We adapt the Satellite-specific Epoch-differenced Ionospheric Delay model (SEID) for GPS networks with mixed single- and dual-frequency receivers. The SEID model is modified to utilize the observations from the three nearest dual-frequency reference stations in order to avoid contaminations from more remote stations. As data of only three stations are used, an efficient missing data constructing approach with polynomial fitting is implemented to minimize data losses. Data from large scale reference networks extended with single-frequency receivers can now be processed, based on the adapted SEID model. A new data processing scheme is developed in order to make use of existing GPS data processing software packages without any modifications. This processing scheme is evaluated using a sub-network of the German SAPOS network. The results verify that the new scheme provides an efficient way to densify existing GPS networks with single-frequency receivers.

Interpretation for scales of measurement linking with abstract algebra

PubMed Central

2014-01-01

The Stevens classification of levels of measurement involves four types of scale: “Nominal”, “Ordinal”, “Interval” and “Ratio”. This classification has been used widely in medical fields and has accomplished an important role in composition and interpretation of scale. With this classification, levels of measurements appear organized and validated. However, a group theory-like systematization beckons as an alternative because of its logical consistency and unexceptional applicability in the natural sciences but which may offer great advantages in clinical medicine. According to this viewpoint, the Stevens classification is reformulated within an abstract algebra-like scheme; ‘Abelian modulo additive group’ for “Ordinal scale” accompanied with ‘zero’, ‘Abelian additive group’ for “Interval scale”, and ‘field’ for “Ratio scale”. Furthermore, a vector-like display arranges a mixture of schemes describing the assessment of patient states. With this vector-like notation, data-mining and data-set combination is possible on a higher abstract structure level based upon a hierarchical-cluster form. Using simple examples, we show that operations acting on the corresponding mixed schemes of this display allow for a sophisticated means of classifying, updating, monitoring, and prognosis, where better data mining/data usage and efficacy is expected. PMID:24987515

RUASN: A Robust User Authentication Framework for Wireless Sensor Networks

PubMed Central

Kumar, Pardeep; Choudhury, Amlan Jyoti; Sain, Mangal; Lee, Sang-Gon; Lee, Hoon-Jae

2011-01-01

In recent years, wireless sensor networks (WSNs) have been considered as a potential solution for real-time monitoring applications and these WSNs have potential practical impact on next generation technology too. However, WSNs could become a threat if suitable security is not considered before the deployment and if there are any loopholes in their security, which might open the door for an attacker and hence, endanger the application. User authentication is one of the most important security services to protect WSN data access from unauthorized users; it should provide both mutual authentication and session key establishment services. This paper proposes a robust user authentication framework for wireless sensor networks, based on a two-factor (password and smart card) concept. This scheme facilitates many services to the users such as user anonymity, mutual authentication, secure session key establishment and it allows users to choose/update their password regularly, whenever needed. Furthermore, we have provided the formal verification using Rubin logic and compare RUASN with many existing schemes. As a result, we found that the proposed scheme possesses many advantages against popular attacks, and achieves better efficiency at low computation cost. PMID:22163888

Interpretation for scales of measurement linking with abstract algebra.

PubMed

Sawamura, Jitsuki; Morishita, Shigeru; Ishigooka, Jun

2014-01-01

THE STEVENS CLASSIFICATION OF LEVELS OF MEASUREMENT INVOLVES FOUR TYPES OF SCALE: "Nominal", "Ordinal", "Interval" and "Ratio". This classification has been used widely in medical fields and has accomplished an important role in composition and interpretation of scale. With this classification, levels of measurements appear organized and validated. However, a group theory-like systematization beckons as an alternative because of its logical consistency and unexceptional applicability in the natural sciences but which may offer great advantages in clinical medicine. According to this viewpoint, the Stevens classification is reformulated within an abstract algebra-like scheme; 'Abelian modulo additive group' for "Ordinal scale" accompanied with 'zero', 'Abelian additive group' for "Interval scale", and 'field' for "Ratio scale". Furthermore, a vector-like display arranges a mixture of schemes describing the assessment of patient states. With this vector-like notation, data-mining and data-set combination is possible on a higher abstract structure level based upon a hierarchical-cluster form. Using simple examples, we show that operations acting on the corresponding mixed schemes of this display allow for a sophisticated means of classifying, updating, monitoring, and prognosis, where better data mining/data usage and efficacy is expected.

PMD compensation in multilevel coded-modulation schemes with coherent detection using BLAST algorithm and iterative polarization cancellation.

PubMed

Djordjevic, Ivan B; Xu, Lei; Wang, Ting

2008-09-15

We present two PMD compensation schemes suitable for use in multilevel (M>or=2) block-coded modulation schemes with coherent detection. The first scheme is based on a BLAST-type polarization-interference cancellation scheme, and the second scheme is based on iterative polarization cancellation. Both schemes use the LDPC codes as channel codes. The proposed PMD compensations schemes are evaluated by employing coded-OFDM and coherent detection. When used in combination with girth-10 LDPC codes those schemes outperform polarization-time coding based OFDM by 1 dB at BER of 10(-9), and provide two times higher spectral efficiency. The proposed schemes perform comparable and are able to compensate even 1200 ps of differential group delay with negligible penalty.

Monitoring substrate enables real-time regulation of a protein localization pathway.

PubMed

Ito, Koreaki; Mori, Hiroyuki; Chiba, Shinobu

2018-06-01

Protein localization machinery supports cell survival and physiology, suggesting the potential importance of its expression regulation. Here, we summarize a remarkable scheme of regulation, which allows real-time feedback regulation of the machinery expression. A class of regulatory nascent polypeptides, called monitoring substrates, undergoes force-sensitive translation arrest. The resulting ribosome stalling on the mRNA then affects mRNA folding to expose the ribosome-binding site of the downstream target gene and upregulate its translation. The target gene encodes a component of the localization machinery, whose physical action against the monitoring substrate leads to arrest cancellation. Thus, this scheme of feedback loop allows the cell to adjust the amount of the machinery to correlate inversely with the effectiveness of the process at a given moment. The system appears to have emerged late in evolution, in which a narrow range of organisms selected a distinct monitoring substrate-machinery combination. Currently, regulatory systems of SecM-SecA, VemP-SecDF2 and MifM-YidC2 are known to occur in different bacterial species.

Simulation of heart rate variability model in a network

NASA Astrophysics Data System (ADS)

Cascaval, Radu C.; D'Apice, Ciro; D'Arienzo, Maria Pia

2017-07-01

We consider a 1-D model for the simulation of the blood flow in the cardiovascular system. As inflow condition we consider a model for the aortic valve. The opening and closing of the valve is dynamically determined by the pressure difference between the left ventricular and aortic pressures. At the outflow we impose a peripheral resistance model. To approximate the solution we use a numerical scheme based on the discontinuous Galerkin method. We also considering a variation in heart rate and terminal reflection coefficient due to monitoring of the pressure in the network.

New Applications of Portable Raman Spectroscopy in Agri-Bio-Photonics

NASA Astrophysics Data System (ADS)

Voronine, Dmitri; Scully, Rob; Sanders, Virgil

2014-03-01

Modern optical techniques based on Raman spectroscopy are being used to monitor and analyze the health of cattle, crops and their natural environment. These optical tools are now available to perform fast, noninvasive analysis of live animals and plants in situ. We will report new applications of a portable handheld Raman spectroscopy to identification and taxonomy of plants. In addition, detection of organic food residues will be demonstrated. Advantages and limitations of current portable instruments will be discussed with suggestions for improved performance by applying enhanced Raman spectroscopic schemes.

Nuclear techniques for the on-line bulk analysis of carbon in coal-fired power stations.

PubMed

Sowerby, B D

2009-09-01

Carbon trading schemes usually require large emitters of CO(2), such as coal-fired power stations, to monitor, report and be audited on their CO(2) emissions. The emission price provides a significant additional incentive for power stations to improve efficiency. In the present paper, previous work on the bulk determination of carbon in coal is reviewed and assessed. The most favourable method is that based on neutron inelastic scattering. The potential role of on-line carbon analysers in improving boiler efficiency and in carbon accounting is discussed.

Dual-stage periodic event-triggered output-feedback control for linear systems.

PubMed

Ruan, Zhen; Chen, Wu-Hua; Lu, Xiaomei

2018-05-01

This paper proposes an event-triggered control framework, called dual-stage periodic event-triggered control (DSPETC), which unifies periodic event-triggered control (PETC) and switching event-triggered control (SETC). Specifically, two period parameters h 1 and h 2 are introduced to characterize the new event-triggering rule, where h 1 denotes the sampling period, while h 2 denotes the monitoring period. By choosing some specified values of h 2 , the proposed control scheme can reduce to PETC or SETC scheme. In the DSPETC framework, the controlled system is represented as a switched system model and its stability is analyzed via a switching-time-dependent Lyapunov functional. Both the cases with/without network-induced delays are investigated. Simulation and experimental results show that the DSPETC scheme is superior to the PETC scheme and the SETC scheme. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

Report on Pairing-based Cryptography.

PubMed

Moody, Dustin; Peralta, Rene; Perlner, Ray; Regenscheid, Andrew; Roginsky, Allen; Chen, Lily

2015-01-01

This report summarizes study results on pairing-based cryptography. The main purpose of the study is to form NIST's position on standardizing and recommending pairing-based cryptography schemes currently published in research literature and standardized in other standard bodies. The report reviews the mathematical background of pairings. This includes topics such as pairing-friendly elliptic curves and how to compute various pairings. It includes a brief introduction to existing identity-based encryption (IBE) schemes and other cryptographic schemes using pairing technology. The report provides a complete study of the current status of standard activities on pairing-based cryptographic schemes. It explores different application scenarios for pairing-based cryptography schemes. As an important aspect of adopting pairing-based schemes, the report also considers the challenges inherent in validation testing of cryptographic algorithms and modules. Based on the study, the report suggests an approach for including pairing-based cryptography schemes in the NIST cryptographic toolkit. The report also outlines several questions that will require further study if this approach is followed.

Report on Pairing-based Cryptography

PubMed Central

Moody, Dustin; Peralta, Rene; Perlner, Ray; Regenscheid, Andrew; Roginsky, Allen; Chen, Lily

2015-01-01

This report summarizes study results on pairing-based cryptography. The main purpose of the study is to form NIST’s position on standardizing and recommending pairing-based cryptography schemes currently published in research literature and standardized in other standard bodies. The report reviews the mathematical background of pairings. This includes topics such as pairing-friendly elliptic curves and how to compute various pairings. It includes a brief introduction to existing identity-based encryption (IBE) schemes and other cryptographic schemes using pairing technology. The report provides a complete study of the current status of standard activities on pairing-based cryptographic schemes. It explores different application scenarios for pairing-based cryptography schemes. As an important aspect of adopting pairing-based schemes, the report also considers the challenges inherent in validation testing of cryptographic algorithms and modules. Based on the study, the report suggests an approach for including pairing-based cryptography schemes in the NIST cryptographic toolkit. The report also outlines several questions that will require further study if this approach is followed. PMID:26958435

Prioritizing hazardous pollutants in two Nigerian water supply schemes: a risk-based approach

PubMed Central

Etchie, Ayotunde T; Etchie, Tunde O; Krishnamurthi, Kannan; SaravanaDevi, S; Wate, Satish R

2013-01-01

Abstract Objective To rank pollutants in two Nigerian water supply schemes according to their effect on human health using a risk-based approach. Methods Hazardous pollutants in drinking-water in the study area were identified from a literature search and selected pollutants were monitored from April 2010 to December 2011 in catchments, treatment works and consumer taps. The disease burden due to each pollutant was estimated in disability-adjusted life years (DALYs) using data on the pollutant’s concentration, exposure to the pollutant, the severity of its health effects and the consumer population. Findings The pollutants identified were microbial organisms, cadmium, cobalt, chromium, copper, iron, manganese, nickel, lead and zinc. All were detected in the catchments but only cadmium, cobalt, chromium, manganese and lead exceeded World Health Organization (WHO) guideline values after water treatment. Post-treatment contamination was observed. The estimated disease burden was greatest for chromium in both schemes, followed in decreasing order by cadmium, lead, manganese and cobalt. The total disease burden of all pollutants in the two schemes was 46 000 and 9500 DALYs per year or 0.14 and 0.088 DALYs per person per year, respectively, much higher than the WHO reference level of 1 × 10−6 DALYs per person per year. For each metal, the disease burden exceeded the reference level and was comparable with that due to microbial contamination reported elsewhere in Africa. Conclusion The estimated disease burden of metal contamination of two Nigerian water supply systems was high. It could best be reduced by protection of water catchment and pretreatment by electrocoagulation. PMID:23940402

Fault detection and diagnosis in a spacecraft attitude determination system

NASA Astrophysics Data System (ADS)

Pirmoradi, F. N.; Sassani, F.; de Silva, C. W.

2009-09-01

This paper presents a new scheme for fault detection and diagnosis (FDD) in spacecraft attitude determination (AD) sensors. An integrated attitude determination system, which includes measurements of rate and angular position using rate gyros and vector sensors, is developed. Measurement data from all sensors are fused by a linearized Kalman filter, which is designed based on the system kinematics, to provide attitude estimation and the values of the gyro bias. Using this information the erroneous sensor measurements are corrected, and unbounded sensor measurement errors are avoided. The resulting bias-free data are used in the FDD scheme. The FDD algorithm uses model-based state estimation, combining the information from the rotational dynamics and kinematics of a spacecraft with the sensor measurements to predict the future sensor outputs. Fault isolation is performed through extended Kalman filters (EKFs). The innovation sequences of EKFs are monitored by several statistical tests to detect the presence of a failure and to localize the failures in all AD sensors. The isolation procedure is developed in two phases. In the first phase, two EKFs are designed, which use subsets of measurements to provide state estimates and form residuals, which are used to verify the source of the fault. In the second phase of isolation, testing of multiple hypotheses is performed. The generalized likelihood ratio test is utilized to identify the faulty components. In the scheme developed in this paper a relatively small number of hypotheses is used, which results in faster isolation and highly distinguishable fault signatures. An important feature of the developed FDD scheme is that it can provide attitude estimations even if only one type of sensors is functioning properly.

Moraine-dammed lake failures in Patagonia and assessment of outburst susceptibility in the Baker Basin

NASA Astrophysics Data System (ADS)

Iribarren Anacona, P.; Norton, K. P.; Mackintosh, A.

2014-07-01

Glacier retreat since the Little Ice Age has resulted in the development or expansion of hundreds of glacial lakes in Patagonia. Some of these lakes have produced large (≥106 m3) Glacial Lake Outburst Floods (GLOFs) damaging inhabited areas. GLOF hazard studies in Patagonia have been mainly based on the analysis of short-term series (≤50 years) of flood data and until now no attempt has been made to identify the relative susceptibility of lakes to failure. Power schemes and associated infrastructure are planned for Patagonian basins that have historically been affected by GLOFs, and we now require a thorough understanding of the characteristics of dangerous lakes in order to assist with hazard assessment and planning. In this paper, the conditioning factors of 16 outbursts from moraine dammed lakes in Patagonia were analysed. These data were used to develop a classification scheme designed to assess outburst susceptibility, based on image classification techniques, flow routine algorithms and the Analytical Hierarchy Process. This scheme was applied to the Baker Basin, Chile, where at least 7 moraine-dammed lakes have failed in historic time. We identified 386 moraine-dammed lakes in the Baker Basin of which 28 were classified with high or very high outburst susceptibility. Commonly, lakes with high outburst susceptibility are in contact with glaciers and have moderate (>8°) to steep (>15°) dam outlet slopes, akin to failed lakes in Patagonia. The proposed classification scheme is suitable for first-order GLOF hazard assessments in this region. However, rapidly changing glaciers in Patagonia make detailed analysis and monitoring of hazardous lakes and glaciated areas upstream from inhabited areas or critical infrastructure necessary, in order to better prepare for hazards emerging from an evolving cryosphere.

Moraine-dammed lake failures in Patagonia and assessment of outburst susceptibility in the Baker Basin

NASA Astrophysics Data System (ADS)

Iribarren Anacona, P.; Norton, K. P.; Mackintosh, A.

2014-12-01

Glacier retreat since the Little Ice Age has resulted in the development or expansion of hundreds of glacial lakes in Patagonia. Some of these lakes have produced large (≥ 106 m3) Glacial Lake Outburst Floods (GLOFs) damaging inhabited areas. GLOF hazard studies in Patagonia have been mainly based on the analysis of short-term series (≤ 50 years) of flood data and until now no attempt has been made to identify the relative susceptibility of lakes to failure. Power schemes and associated infrastructure are planned for Patagonian basins that have historically been affected by GLOFs, and we now require a thorough understanding of the characteristics of dangerous lakes in order to assist with hazard assessment and planning. In this paper, the conditioning factors of 16 outbursts from moraine-dammed lakes in Patagonia were analysed. These data were used to develop a classification scheme designed to assess outburst susceptibility, based on image classification techniques, flow routine algorithms and the Analytical Hierarchy Process. This scheme was applied to the Baker Basin, Chile, where at least seven moraine-dammed lakes have failed in historic time. We identified 386 moraine-dammed lakes in the Baker Basin of which 28 were classified with high or very high outburst susceptibility. Commonly, lakes with high outburst susceptibility are in contact with glaciers and have moderate (> 8°) to steep (> 15°) dam outlet slopes, akin to failed lakes in Patagonia. The proposed classification scheme is suitable for first-order GLOF hazard assessments in this region. However, rapidly changing glaciers in Patagonia make detailed analysis and monitoring of hazardous lakes and glaciated areas upstream from inhabited areas or critical infrastructure necessary, in order to better prepare for hazards emerging from an evolving cryosphere.

Quantifying and Reducing Uncertainties in Estimating OMI Tropospheric Column NO2 Trend over The United States

NASA Astrophysics Data System (ADS)

Smeltzer, C. D.; Wang, Y.; Boersma, F.; Celarier, E. A.; Bucsela, E. J.

2013-12-01

We investigate the effects of retrieval radiation schemes and parameters on trend analysis using tropospheric nitrogen dioxide (NO2) vertical column density (VCD) measurements over the United States. Ozone Monitoring Instrument (OMI) observations from 2005 through 2012 are used in this analysis. We investigated two radiation schemes, provided by National Aeronautics and Space Administration (NASA TOMRAD) and Koninklijk Nederlands Meteorologisch Instituut (KNMI DAK). In addition, we analyzed trend dependence on radiation parameters, including surface albedo and viewing geometry. The cross-track mean VCD average difference is 10-15% between the two radiation schemes in 2005. As the OMI anomaly developed and progressively worsens, the difference between the two schemes becomes larger. Furthermore, applying surface albedo measurements from the Moderate Resolution Imaging Spectroradiometer (MODIS) leads to increases of estimated NO2 VCD trends over high-emission regions. We find that the uncertainties of OMI-derived NO2 VCD trends can be reduced by up to a factor of 3 by selecting OMI cross-track rows on the basis of their performance over the ocean [see abstract figure]. Comparison of OMI tropospheric VCD trends to those estimated based on the EPA surface NO2 observations indicate using MODIS surface albedo data and a more narrow selection of OMI cross-track rows greatly improves the agreement of estimated trends between satellite and surface data. This figure shows the reduction of uncertainty in OMI NO2 trend by selecting OMI cross-track rows based on the performance over the ocean. With this technique, uncertainties within the seasonal trend may be reduced by a factor of 3 or more (blue) compared with only removing the anomalous rows: considering OMI cross-track rows 4-24 (red).

Development Of A Data Assimilation Capability For RAPID

NASA Astrophysics Data System (ADS)

Emery, C. M.; David, C. H.; Turmon, M.; Hobbs, J.; Allen, G. H.; Famiglietti, J. S.

2017-12-01

The global decline of in situ observations associated with the increasing ability to monitor surface water from space motivates the creation of data assimilation algorithms that merge computer models and space-based observations to produce consistent estimates of terrestrial hydrology that fill the spatiotemporal gaps in observations. RAPID is a routing model based on the Muskingum method that is capable of estimating river streamflow over large scales with a relatively short computing time. This model only requires limited inputs: a reach-based river network, and lateral surface and subsurface flow into the rivers. The relatively simple model physics imply that RAPID simulations could be significantly improved by including a data assimilation capability. Here we present the early developments of such data assimilation approach into RAPID. Given the linear and matrix-based structure of the model, we chose to apply a direct Kalman filter, hence allowing for the preservation of high computational speed. We correct the simulated streamflows by assimilating streamflow observations and our early results demonstrate the feasibility of the approach. Additionally, the use of in situ gauges at continental scales motivates the application of our new data assimilation scheme to altimetry measurements from existing (e.g. EnviSat, Jason 2) and upcoming satellite missions (e.g. SWOT), and ultimately apply the scheme globally.

All sky imaging observations in visible and infrared waveband for validation of satellite cloud and aerosol products

NASA Astrophysics Data System (ADS)

Lu, Daren; Huo, Juan; Zhang, W.; Liu, J.

A series of satellite sensors in visible and infrared wavelengths have been successfully operated on board a number of research satellites, e.g. NOAA/AVHRR, the MODIS onboard Terra and Aqua, etc. A number of cloud and aerosol products are produced and released in recent years. However, the validation of the product quality and accuracy are still a challenge to the atmospheric remote sensing community. In this paper, we suggest a ground based validation scheme for satellite-derived cloud and aerosol products by using combined visible and thermal infrared all sky imaging observations as well as surface meteorological observations. In the scheme, a visible digital camera with a fish-eye lens is used to continuously monitor the all sky with the view angle greater than 180 deg. The digital camera system is calibrated for both its geometry and radiance (broad blue, green, and red band) so as to a retrieval method can be used to detect the clear and cloudy sky spatial distribution and their temporal variations. A calibrated scanning thermal infrared thermometer is used to monitor the all sky brightness temperature distribution. An algorithm is developed to detect the clear and cloudy sky as well as cloud base height by using sky brightness distribution and surface temperature and humidity as input. Based on these composite retrieval of clear and cloudy sky distribution, it can be used to validate the satellite retrievals in the sense of real-simultaneous comparison and statistics, respectively. What will be presented in this talk include the results of the field observations and comparisons completed in Beijing (40 deg N, 116.5 deg E) in year 2003 and 2004. This work is supported by NSFC grant No. 4002700, and MOST grant No 2001CCA02200

Enhancing the Extreme Climate Index (ECI) to monitor climate extremes for an index-based insurance scheme across Africa

NASA Astrophysics Data System (ADS)

Helmschrot, J.; Malherbe, J.; Chamunorwa, M.; Muthige, M.; Petitta, M.; Calmanti, S.; Cucchi, M.; Syroka, J.; Iyahen, E.; Engelbrecht, F.

2017-12-01

Climate services are a key component of National Adaptation Plan (NAP) processes, which require the analysis of current climate conditions, future climate change scenarios and the identification of adaptation strategies, including the capacity to finance and implement effective adaptation options. The Extreme Climate Facility (XCF) proposed by the African Risk Capacity (ARC) developed a climate index insurance scheme, which is based on the Extreme Climate Index (ECI): an objective, multi-hazard index capable of tracking changes in the frequency or magnitude of extreme weather events, thus indicating possible shifts to a new climate regime in various regions. The main hazards covered by ECI are extreme dry, wet and heat events, with the possibility of adding other region-specific risk events. The ECI is standardized across broad geographical regions, so that extreme events occurring under different climatic regimes in Africa can be compared. Initially developed by an Italian company specialized in Climate Services, research is now conducted at the CSIR and SASSCAL, to verify and further develop the ECI for application in southern African countries, through a project initiated by the World Food Programme (WFP) and ARC. The paper will present findings on the most appropriate definitions of extremely wet and dry conditions in Africa, in terms of their impact across a multitude of sub-regional climates of the African continent. Findings of a verification analysis of the ECI, as determined through vegetation monitoring data and the SASSCAL weather station network will be discussed. Changes in the ECI under climate change will subsequently be projected, using detailed regional projections generated by the CSIR and through the Coordinated Regional Downscaling Experiment (CORDEX). This work will be concluded by the development of a web-based climate service informing African Stakeholders on climate extremes.

Sampling design for long-term regional trends in marine rocky intertidal communities

USGS Publications Warehouse

Irvine, Gail V.; Shelley, Alice

2013-01-01

Probability-based designs reduce bias and allow inference of results to the pool of sites from which they were chosen. We developed and tested probability-based designs for monitoring marine rocky intertidal assemblages at Glacier Bay National Park and Preserve (GLBA), Alaska. A multilevel design was used that varied in scale and inference. The levels included aerial surveys, extensive sampling of 25 sites, and more intensive sampling of 6 sites. Aerial surveys of a subset of intertidal habitat indicated that the original target habitat of bedrock-dominated sites with slope ≤30° was rare. This unexpected finding illustrated one value of probability-based surveys and led to a shift in the target habitat type to include steeper, more mixed rocky habitat. Subsequently, we evaluated the statistical power of different sampling methods and sampling strategies to detect changes in the abundances of the predominant sessile intertidal taxa: barnacles Balanomorpha, the mussel Mytilus trossulus, and the rockweed Fucus distichus subsp. evanescens. There was greatest power to detect trends in Mytilus and lesser power for barnacles and Fucus. Because of its greater power, the extensive, coarse-grained sampling scheme was adopted in subsequent years over the intensive, fine-grained scheme. The sampling attributes that had the largest effects on power included sampling of “vertical” line transects (vs. horizontal line transects or quadrats) and increasing the number of sites. We also evaluated the power of several management-set parameters. Given equal sampling effort, sampling more sites fewer times had greater power. The information gained through intertidal monitoring is likely to be useful in assessing changes due to climate, including ocean acidification; invasive species; trampling effects; and oil spills.

Verification and accreditation schemes for climate change activities: A review of requirements for verification of greenhouse gas reductions and accreditation of verifiers—Implications for long-term carbon sequestration

NASA Astrophysics Data System (ADS)

Roed-Larsen, Trygve; Flach, Todd

The purpose of this chapter is to provide a review of existing national and international requirements for verification of greenhouse gas reductions and associated accreditation of independent verifiers. The credibility of results claimed to reduce or remove anthropogenic emissions of greenhouse gases (GHG) is of utmost importance for the success of emerging schemes to reduce such emissions. Requirements include transparency, accuracy, consistency, and completeness of the GHG data. The many independent verification processes that have developed recently now make up a quite elaborate tool kit for best practices. The UN Framework Convention for Climate Change and the Kyoto Protocol specifications for project mechanisms initiated this work, but other national and international actors also work intensely with these issues. One initiative gaining wide application is that taken by the World Business Council for Sustainable Development with the World Resources Institute to develop a "GHG Protocol" to assist companies in arranging for auditable monitoring and reporting processes of their GHG activities. A set of new international standards developed by the International Organization for Standardization (ISO) provides specifications for the quantification, monitoring, and reporting of company entity and project-based activities. The ISO is also developing specifications for recognizing independent GHG verifiers. This chapter covers this background with intent of providing a common understanding of all efforts undertaken in different parts of the world to secure the reliability of GHG emission reduction and removal activities. These verification schemes may provide valuable input to current efforts of securing a comprehensive, trustworthy, and robust framework for verification activities of CO2 capture, transport, and storage.

Occurrence of pharmaceutically active and non-steroidal estrogenic compounds in three different wastewater recycling schemes in Australia.

PubMed

Al-Rifai, Jawad H; Gabelish, Candace L; Schäfer, Andrea I

2007-10-01

The discovery that natural and synthetic chemicals, in the form of excreted hormones and pharmaceuticals, as well as a vast array of compounds with domestic and industrial applications, can enter the environment via wastewater treatment plants and cause a wide variety of environmental and health problems even at very low concentrations, suggests the need for improvement of water recycling. Three Australian wastewater recycling schemes, two of which employ reverse osmosis (RO) technology, the other applying ozonation and biological activated carbon filtration, have been studied for their ability to remove trace organic contaminants including 11 pharmaceutically active compounds and two non-steroidal estrogenic compounds. Contaminant concentrations were determined using a sensitive analytical method comprising solid phase extraction, derivatization and GC with MS using selected ion monitoring. In raw wastewater, concentrations of analgesics and non-steroidal anti-inflammatory medications were comparable to those found in wastewaters around the world. Remarkably, removal efficiencies for the three schemes were superior to literature values and RO was responsible for the greatest proportion of contaminant removal. The ability of RO membranes to concentrate many of the compounds was demonstrated and highlights the need for continued research into monitoring wastewater treatment, concentrate disposal, improved water recycling schemes and ultimately, safer water and a cleaner environment.

The social security scheme in Thailand: what lessons can be drawn?

PubMed

Tangcharoensathien, V; Supachutikul, A; Lertiendumrong, J

1999-04-01

The Social Security Scheme was launched in 1990, covering formal sector private employees for non-work related sickness, maternity and invalidity including cash benefits and funeral grants. The scheme is financed by tripartite contributions from government, employers and employees, each of 1.5% of payroll (total of 4.5%). The scheme decided to pay health care providers, whether public or private, on a flat rate capitation basis to cover both ambulatory and inpatient care. Registration of the insured with a contractor hospital was a necessary consequence of the chosen capitation payment system. The aim of this paper is to review the operation of the scheme, and to explore the implications of capitation payment and registration for utilisation levels and provider behaviour. A key weakness of the scheme's design is suggested to be the initial decision to give employers not employees the responsibility for choosing the registered hospitals. This was done for administrative reasons, but it contributed to low levels of use of the contractor hospitals. In addition, low levels of use were also probably the result of the potential for cream skimming, cost shifting from inpatient to ambulatory care and under-provision of patient care, though since monitoring mechanisms by the Social Security Office were weak, these effects are difficult to detect conclusively. Mechanisms to improve utilisation levels were gradually introduced, such as employee choice of registered hospitals and the formation of sub-contractor networks to improve access to care. A beneficial effect of the capitation payment system was that the Social Security Fund generated substantial reserves and expenditures on sickness benefits were well stabilised. The paper ends by recommending that future policy amendments should be guided by research and empirical findings and that tougher monitoring and enforcement of quality of care standards are required.

Standardisation of radiation portal monitor controls and readouts.

PubMed

Tinker, M

2010-10-01

There is an urgent need to standardise the numbering configuration of radiation portal monitor sensing panels. Currently, manufacturers use conflicting numbering schemes that may confuse operators of these varied systems. There is a similar problem encountered with the varied choices of coloured indicator lights and coloured print lines designated for gamma and neutron alarms. In addition, second-party software that changes the alarm colour scheme may also have been installed. Furthermore, no provision exists for the colour blind or to provide work stations with only black ink on alarm printouts. These inconsistencies and confusing set-ups could inadvertently cause a misinterpretation of the alarm, resulting in the potential release of a radiological hazard into a sovereign country. These issues are discussed, and a proposed solution is offered.

Enhanced Cumulative Sum Charts for Monitoring Process Dispersion

PubMed Central

Abujiya, Mu’azu Ramat; Riaz, Muhammad; Lee, Muhammad Hisyam

2015-01-01

The cumulative sum (CUSUM) control chart is widely used in industry for the detection of small and moderate shifts in process location and dispersion. For efficient monitoring of process variability, we present several CUSUM control charts for monitoring changes in standard deviation of a normal process. The newly developed control charts based on well-structured sampling techniques - extreme ranked set sampling, extreme double ranked set sampling and double extreme ranked set sampling, have significantly enhanced CUSUM chart ability to detect a wide range of shifts in process variability. The relative performances of the proposed CUSUM scale charts are evaluated in terms of the average run length (ARL) and standard deviation of run length, for point shift in variability. Moreover, for overall performance, we implore the use of the average ratio ARL and average extra quadratic loss. A comparison of the proposed CUSUM control charts with the classical CUSUM R chart, the classical CUSUM S chart, the fast initial response (FIR) CUSUM R chart, the FIR CUSUM S chart, the ranked set sampling (RSS) based CUSUM R chart and the RSS based CUSUM S chart, among others, are presented. An illustrative example using real dataset is given to demonstrate the practicability of the application of the proposed schemes. PMID:25901356

A TCP/IP framework for ethernet-based measurement, control and experiment data distribution

NASA Astrophysics Data System (ADS)

Ocaya, R. O.; Minny, J.

2010-11-01

A complete modular but scalable TCP/IP based scientific instrument control and data distribution system has been designed and realized. The system features an IEEE 802.3 compliant 10 Mbps Medium Access Controller (MAC) and Physical Layer Device that is suitable for the full-duplex monitoring and control of various physically widespread measurement transducers in the presence of a local network infrastructure. The cumbersomeness of exchanging and synchronizing data between the various transducer units using physical storage media led to the choice of TCP/IP as a logical alternative. The system and methods developed are scalable for broader usage over the Internet. The system comprises a PIC18f2620 and ENC28j60 based hardware and a software component written in C, Java/Javascript and Visual Basic.NET programming languages for event-level monitoring and browser user-interfaces respectively. The system exchanges data with the host network through IPv4 packets requested and received on a HTTP page. It also responds to ICMP echo, UDP and ARP requests through a user selectable integrated DHCP and static IPv4 address allocation scheme. The round-trip time, throughput and polling frequency are estimated and reported. A typical application to temperature monitoring and logging is also presented.

A secure smart-card based authentication and key agreement scheme for telecare medicine information systems.

PubMed

Lee, Tian-Fu; Liu, Chuan-Ming

2013-06-01

A smart-card based authentication scheme for telecare medicine information systems enables patients, doctors, nurses, health visitors and the medicine information systems to establish a secure communication platform through public networks. Zhu recently presented an improved authentication scheme in order to solve the weakness of the authentication scheme of Wei et al., where the off-line password guessing attacks cannot be resisted. This investigation indicates that the improved scheme of Zhu has some faults such that the authentication scheme cannot execute correctly and is vulnerable to the attack of parallel sessions. Additionally, an enhanced authentication scheme based on the scheme of Zhu is proposed. The enhanced scheme not only avoids the weakness in the original scheme, but also provides users' anonymity and authenticated key agreements for secure data communications.

Cryptanalysis and Improvement of a Biometric-Based Multi-Server Authentication and Key Agreement Scheme.

PubMed

Wang, Chengqi; Zhang, Xiao; Zheng, Zhiming

2016-01-01

With the security requirements of networks, biometrics authenticated schemes which are applied in the multi-server environment come to be more crucial and widely deployed. In this paper, we propose a novel biometric-based multi-server authentication and key agreement scheme which is based on the cryptanalysis of Mishra et al.'s scheme. The informal and formal security analysis of our scheme are given, which demonstrate that our scheme satisfies the desirable security requirements. The presented scheme provides a variety of significant functionalities, in which some features are not considered in the most of existing authentication schemes, such as, user revocation or re-registration and biometric information protection. Compared with several related schemes, our scheme has more secure properties and lower computation cost. It is obviously more appropriate for practical applications in the remote distributed networks.

A Niche-Based Framework to Assess Current Monitoring of European Forest Birds and Guide Indicator Species' Selection

PubMed Central

Wade, Amy S. I.; Barov, Boris; Burfield, Ian J.; Gregory, Richard D.; Norris, Ken; Vorisek, Petr; Wu, Taoyang; Butler, Simon J.

2014-01-01

Concern that European forest biodiversity is depleted and declining has provoked widespread efforts to improve management practices. To gauge the success of these actions, appropriate monitoring of forest ecosystems is paramount. Multi-species indicators are frequently used to assess the state of biodiversity and its response to implemented management, but generally applicable and objective methodologies for species' selection are lacking. Here we use a niche-based approach, underpinned by coarse quantification of species' resource use, to objectively select species for inclusion in a pan-European forest bird indicator. We identify both the minimum number of species required to deliver full resource coverage and the most sensitive species' combination, and explore the trade-off between two key characteristics, sensitivity and redundancy, associated with indicators comprising different numbers of species. We compare our indicator to an existing forest bird indicator selected on the basis of expert opinion and show it is more representative of the wider community. We also present alternative indicators for regional and forest type specific monitoring and show that species' choice can have a significant impact on the indicator and consequent projections about the state of the biodiversity it represents. Furthermore, by comparing indicator sets drawn from currently monitored species and the full forest bird community, we identify gaps in the coverage of the current monitoring scheme. We believe that adopting this niche-based framework for species' selection supports the objective development of multi-species indicators and that it has good potential to be extended to a range of habitats and taxa. PMID:24819734

ID-based encryption scheme with revocation

NASA Astrophysics Data System (ADS)

Othman, Hafizul Azrie; Ismail, Eddie Shahril

2017-04-01

In 2015, Meshram proposed an efficient ID-based cryptographic encryption based on the difficulty of solving discrete logarithm and integer-factoring problems. The scheme was pairing free and claimed to be secure against adaptive chosen plaintext attacks (CPA). Later, Tan et al. proved that the scheme was insecure by presenting a method to recover the secret master key and to obtain prime factorization of modulo n. In this paper, we propose a new pairing-free ID-based encryption scheme with revocation based on Meshram's ID-based encryption scheme, which is also secure against Tan et al.'s attacks.

Fault Diagnosis in HVAC Chillers

NASA Technical Reports Server (NTRS)

Choi, Kihoon; Namuru, Setu M.; Azam, Mohammad S.; Luo, Jianhui; Pattipati, Krishna R.; Patterson-Hine, Ann

2005-01-01

Modern buildings are being equipped with increasingly sophisticated power and control systems with substantial capabilities for monitoring and controlling the amenities. Operational problems associated with heating, ventilation, and air-conditioning (HVAC) systems plague many commercial buildings, often the result of degraded equipment, failed sensors, improper installation, poor maintenance, and improperly implemented controls. Most existing HVAC fault-diagnostic schemes are based on analytical models and knowledge bases. These schemes are adequate for generic systems. However, real-world systems significantly differ from the generic ones and necessitate modifications of the models and/or customization of the standard knowledge bases, which can be labor intensive. Data-driven techniques for fault detection and isolation (FDI) have a close relationship with pattern recognition, wherein one seeks to categorize the input-output data into normal or faulty classes. Owing to the simplicity and adaptability, customization of a data-driven FDI approach does not require in-depth knowledge of the HVAC system. It enables the building system operators to improve energy efficiency and maintain the desired comfort level at a reduced cost. In this article, we consider a data-driven approach for FDI of chillers in HVAC systems. To diagnose the faults of interest in the chiller, we employ multiway dynamic principal component analysis (MPCA), multiway partial least squares (MPLS), and support vector machines (SVMs). The simulation of a chiller under various fault conditions is conducted using a standard chiller simulator from the American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE). We validated our FDI scheme using experimental data obtained from different types of chiller faults.

A secure biometrics-based authentication scheme for telecare medicine information systems.

PubMed

Yan, Xiaopeng; Li, Weiheng; Li, Ping; Wang, Jiantao; Hao, Xinhong; Gong, Peng

2013-10-01

The telecare medicine information system (TMIS) allows patients and doctors to access medical services or medical information at remote sites. Therefore, it could bring us very big convenient. To safeguard patients' privacy, authentication schemes for the TMIS attracted wide attention. Recently, Tan proposed an efficient biometrics-based authentication scheme for the TMIS and claimed their scheme could withstand various attacks. However, in this paper, we point out that Tan's scheme is vulnerable to the Denial-of-Service attack. To enhance security, we also propose an improved scheme based on Tan's work. Security and performance analysis shows our scheme not only could overcome weakness in Tan's scheme but also has better performance.

A Regional, Integrated Monitoring System for the Hydrology of the Pan-Arctic Land Mass

NASA Technical Reports Server (NTRS)

Serreze, Mark; Barry, Roger; Nolin, Anne; Armstrong, Richard; Zhang, Ting-Jung; Vorosmarty, Charles; Lammers, Richard; Frolking, Steven; Bromwich, David; McDonald, Kyle

2005-01-01

Work under this NASA contract developed a system for monitoring and historical analysis of the major components of the pan-Arctic terrestrial water cycle. It is known as Arctic-RIMS (Regional Integrated Hydrological Monitoring System for the Pan-Arctic Landmass). The system uses products from EOS-era satellites, numerical weather prediction models, station records and other data sets in conjunction with an atmosphere-land surface water budgeting scheme. The intent was to compile operational (at 1-2 month time lags) gridded fields of precipitation (P), evapotranspiration (ET), P-ET, soil moisture, soil freeze/thaw state, active layer thickness, snow extent and its water equivalent, soil water storage, runoff and simulated discharge along with estimates of non-closure in the water budget. Using "baseline" water budgeting schemes in conjunction with atmospheric reanalyses and pre-EOS satellite data, water budget fields were conjunction with atmospheric reanalyses and pre-EOS satellite data, water budget fields were compiled to provide historical time series. The goals as outlined in the original proposal can be summarized as follows: 1) Use EOS data to compile hydrologic products for the pan-Arctic terrestrial regions including snowcover/snow water equivalent (SSM/A MODIS, AMSR) and near-surface freeze/thaw dynamics (Sea Winds on QuikSCAT and ADEOS I4 SSMI and AMSR). 2) Implement Arctic-RIMS to use EOS data streams, allied fields and hydrologic models to produce allied outputs that fully characterize pan-Arctic terrestrial and aerological water budgets. 3) Compile hydrologically-based historical products providing a long-term baseline of spatial and temporal variability in the water cycle.

Sequential enzymatic derivatization coupled with online microdialysis sampling for simultaneous profiling of mouse tumor extracellular hydrogen peroxide, lactate, and glucose.

PubMed

Su, Cheng-Kuan; Tseng, Po-Jen; Chiu, Hsien-Ting; Del Vall, Andrea; Huang, Yu-Fen; Sun, Yuh-Chang

2017-03-01

Probing tumor extracellular metabolites is a vitally important issue in current cancer biology. In this study an analytical system was constructed for the in vivo monitoring of mouse tumor extracellular hydrogen peroxide (H 2 O 2 ), lactate, and glucose by means of microdialysis (MD) sampling and fluorescence determination in conjunction with a smart sequential enzymatic derivatization scheme-involving a loading sequence of fluorogenic reagent/horseradish peroxidase, microdialysate, lactate oxidase, pyruvate, and glucose oxidase-for step-by-step determination of sampled H 2 O 2 , lactate, and glucose in mouse tumor microdialysate. After optimization of the overall experimental parameters, the system's detection limit reached as low as 0.002 mM for H 2 O 2 , 0.058 mM for lactate, and 0.055 mM for glucose, based on 3 μL of microdialysate, suggesting great potential for determining tumor extracellular concentrations of lactate and glucose. Spike analyses of offline-collected mouse tumor microdialysate and monitoring of the basal concentrations of mouse tumor extracellular H 2 O 2 , lactate, and glucose, as well as those after imparting metabolic disturbance through intra-tumor administration of a glucose solution through a prior-implanted cannula, were conducted to demonstrate the system's applicability. Our results evidently indicate that hyphenation of an MD sampling device with an optimized sequential enzymatic derivatization scheme and a fluorescence spectrometer can be used successfully for multi-analyte monitoring of tumor extracellular metabolites in living animals. Copyright © 2016 Elsevier B.V. All rights reserved.

Modelling street level PM10 concentrations across Europe: source apportionment and possible futures

NASA Astrophysics Data System (ADS)

Kiesewetter, G.; Borken-Kleefeld, J.; Schöpp, W.; Heyes, C.; Thunis, P.; Bessagnet, B.; Terrenoire, E.; Fagerli, H.; Nyiri, A.; Amann, M.

2015-02-01

Despite increasing emission controls, particulate matter (PM) has remained a critical issue for European air quality in recent years. The various sources of PM, both from primary particulate emissions as well as secondary formation from precursor gases, make this a complex problem to tackle. In order to allow for credible predictions of future concentrations under policy assumptions, a modelling approach is needed that considers all chemical processes and spatial dimensions involved, from long-range transport of pollution to local emissions in street canyons. Here we describe a modelling scheme which has been implemented in the GAINS integrated assessment model to assess compliance with PM10 (PM with aerodynamic diameter <10 μm) limit values at individual air quality monitoring stations reporting to the AirBase database. The modelling approach relies on a combination of bottom up modelling of emissions, simplified atmospheric chemistry and dispersion calculations, and a traffic increment calculation wherever applicable. At each monitoring station fulfilling a few data coverage criteria, measured concentrations in the base year 2009 are explained to the extent possible and then modelled for the past and future. More than 1850 monitoring stations are covered, including more than 300 traffic stations and 80% of the stations which exceeded the EU air quality limit values in 2009. As a validation, we compare modelled trends in the period 2000-2008 to observations, which are well reproduced. The modelling scheme is applied here to quantify explicitly source contributions to ambient concentrations at several critical monitoring stations, displaying the differences in spatial origin and chemical composition of urban roadside PM10 across Europe. Furthermore, we analyse the predicted evolution of PM10 concentrations in the European Union until 2030 under different policy scenarios. Significant improvements in ambient PM10 concentrations are expected assuming successful implementation of already agreed legislation; however, these will not be large enough to ensure attainment of PM10 limit values in hot spot locations such as Southern Poland and major European cities. Remaining issues are largely eliminated in a scenario applying the best available emission control technologies to the maximal technically feasible extent.

Modelling street level PM10 concentrations across Europe: source apportionment and possible futures

NASA Astrophysics Data System (ADS)

Kiesewetter, G.; Borken-Kleefeld, J.; Schöpp, W.; Heyes, C.; Thunis, P.; Bessagnet, B.; Terrenoire, E.; Amann, M.

2014-07-01

Despite increasing emission controls, particulate matter (PM) has remained a critical issue for European air quality in recent years. The various sources of PM, both from primary particulate emissions as well as secondary formation from precursor gases, make this a complex problem to tackle. In order to allow for credible predictions of future concentrations under policy assumptions, a modelling approach is needed that considers all chemical processes and spatial dimensions involved, from long-range transport of pollution to local emissions in street canyons. Here we describe a modelling scheme which has been implemented in the GAINS integrated assessment model to assess compliance with PM10 (PM with aerodynamic diameter < 10 μm) limit values at individual air quality monitoring stations reporting to the AirBase database. The modelling approach relies on a combination of bottom up modelling of emissions, simplified atmospheric chemistry and dispersion calculations, and a traffic increment calculation wherever applicable. At each monitoring station fulfilling a few data coverage criteria, measured concentrations in the base year 2009 are explained to the extent possible and then modelled for the past and future. More than 1850 monitoring stations are covered, including more than 300 traffic stations and 80% of the stations which exceeded the EU air quality limit values in 2009. As a validation, we compare modelled trends in the period 2000-2008 to observations, which are well reproduced. The modelling scheme is applied here to quantify explicitly source contributions to ambient concentrations at several critical monitoring stations, displaying the differences in spatial origin and chemical composition of urban roadside PM10 across Europe. Furthermore, we analyse the predicted evolution of PM10 concentrations in the European Union until 2030 under different policy scenarios. Significant improvements in ambient PM10 concentrations are expected assuming successful implementation of already agreed legislation; however, these will not be large enough to ensure attainment of PM10 limit values in hot spot locations such as Southern Poland and major European cities. Remaining issues are largely eliminated in a scenario applying the best available emission control technologies to the maximal technically feasible extent.

Linking payment to health outcomes: a taxonomy and examination of performance-based reimbursement schemes between healthcare payers and manufacturers.

PubMed

Carlson, Josh J; Sullivan, Sean D; Garrison, Louis P; Neumann, Peter J; Veenstra, David L

2010-08-01

To identify, categorize and examine performance-based health outcomes reimbursement schemes for medical technology. We performed a review of performance-based health outcomes reimbursement schemes over the past 10 years (7/98-010/09) using publicly available databases, web and grey literature searches, and input from healthcare reimbursement experts. We developed a taxonomy of scheme types by inductively organizing the schemes identified according to the timing, execution, and health outcomes measured in the schemes. Our search yielded 34 coverage with evidence development schemes, 10 conditional treatment continuation schemes, and 14 performance-linked reimbursement schemes. The majority of schemes are in Europe and Australia, with an increasing number in Canada and the U.S. These schemes have the potential to alter the reimbursement and pricing landscape for medical technology, but significant challenges, including high transaction costs and insufficient information systems, may limit their long-term impact. Future studies regarding experiences and outcomes of implemented schemes are necessary. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

Process evaluation of community care centers providing care, support, and treatment to people living with human immunodeficiency virus in India.

PubMed

Sogarwal, Ruchi; Bachani, Damodar

2011-01-01

Since 2007, the concept of community care centers (CCC) has evolved to provide care, support, and treatment services to the people living with human immunodeficiency virus in a community-based environment so as to bridge the gap between secondary/tertiary level institutional and home-based care. Monitoring and evaluation, including process evaluation (PE), are integral parts of this scheme. This article presents the design of the "PE" for CCC and the results pertaining to the gaps and constraints in the implementation of the scheme. The CCC PE was conducted in 197 of the 273 CCCs that have been functioning for at least 1 year as on November 30, 2009. Data were collected by structured observations and individual interviews through checklists and semistructured tools. The targeted population for PE was inpatient/outpatient beneficiaries, caregivers, and service providers of CCCs. The findings revealed that of 197 CCCs evaluated, 55, 57, 52, and 33 were graded as A, B, C, and D, respectively. Of the 33 grade-D CCCs, 22 were from 4 high-prevalence states (Andhra Pradesh, Karnataka, Maharashtra, and Tamil Nadu). There was dearth of good nongovernment organizations in the Northeastern region of the country with more nongovernment organizations in C and D category. The PE indicated some critical constraints in the services, such as shortage of medicines for treatment of opportunistic infections, poor coordination with anti-retroviral treatment centers, and transportation for referral cases. In spite of various constraints in the scheme, the majority of the patients were satisfied with the services available at CCC. The PE had provided an invaluable base to improve the CCC scheme, which will enhance the quality of service delivery system. The results of our experience may help other researchers and managers plan similar and more improved assessment.

Paying for performance and the social relations of health care provision: an anthropological perspective.

PubMed

Magrath, Priscilla; Nichter, Mark

2012-11-01

Over the past decade, the use of financial incentive schemes has become a popular form of intervention to boost performance in the health sector. Often termed "paying for performance" or P4P, they involve "…the transfer of money or material goods conditional upon taking a measurable action or achieving a predetermined performance target" (Eldridge & Palmer, 2009, p.160). P4P appear to bring about rapid improvements in some measured indicators of provider performance, at least over the short term. However, evidence for the impact of these schemes on the wider health system remains limited, and even where evaluations have been positive, unintended effects have been identified. These have included: "gaming" the system; crowding out of "intrinsic motivation"; a drop in morale where schemes are viewed as unfair; and the undermining of social relations and teamwork through competition, envy or ill feeling. Less information is available concerning how these processes occur, and how they vary across social and cultural contexts. While recognizing the potential of P4P, the authors argue for greater care in adapting schemes to particular local contexts. We suggest that insights from social science theory coupled with the focused ethnographic methods of anthropology can contribute to the critical assessment of P4P schemes and to their adaptation to particular social environments and reward systems. We highlight the need for monitoring P4P schemes in relation to worker motivation and the quality of social relations, since these have implications both for health sector performance over the long term and for the success and sustainability of a P4P scheme. Suggestions are made for ethnographies, undertaken in collaboration with local stakeholders, to assess readiness for P4P; package rewards in ways that minimize perverse responses; identify process variables for monitoring and evaluation; and build sustainability into program design through linkage with complementary reforms. Copyright © 2012 Elsevier Ltd. All rights reserved.

Understanding security failures of two authentication and key agreement schemes for telecare medicine information systems.

PubMed

Mishra, Dheerendra

2015-03-01

Smart card based authentication and key agreement schemes for telecare medicine information systems (TMIS) enable doctors, nurses, patients and health visitors to use smart cards for secure login to medical information systems. In recent years, several authentication and key agreement schemes have been proposed to present secure and efficient solution for TMIS. Most of the existing authentication schemes for TMIS have either higher computation overhead or are vulnerable to attacks. To reduce the computational overhead and enhance the security, Lee recently proposed an authentication and key agreement scheme using chaotic maps for TMIS. Xu et al. also proposed a password based authentication and key agreement scheme for TMIS using elliptic curve cryptography. Both the schemes provide better efficiency from the conventional public key cryptography based schemes. These schemes are important as they present an efficient solution for TMIS. We analyze the security of both Lee's scheme and Xu et al.'s schemes. Unfortunately, we identify that both the schemes are vulnerable to denial of service attack. To understand the security failures of these cryptographic schemes which are the key of patching existing schemes and designing future schemes, we demonstrate the security loopholes of Lee's scheme and Xu et al.'s scheme in this paper.

Robust and efficient biometrics based password authentication scheme for telecare medicine information systems using extended chaotic maps.

PubMed

Lu, Yanrong; Li, Lixiang; Peng, Haipeng; Xie, Dong; Yang, Yixian

2015-06-01

The Telecare Medicine Information Systems (TMISs) provide an efficient communicating platform supporting the patients access health-care delivery services via internet or mobile networks. Authentication becomes an essential need when a remote patient logins into the telecare server. Recently, many extended chaotic maps based authentication schemes using smart cards for TMISs have been proposed. Li et al. proposed a secure smart cards based authentication scheme for TMISs using extended chaotic maps based on Lee's and Jiang et al.'s scheme. In this study, we show that Li et al.'s scheme has still some weaknesses such as violation the session key security, vulnerability to user impersonation attack and lack of local verification. To conquer these flaws, we propose a chaotic maps and smart cards based password authentication scheme by applying biometrics technique and hash function operations. Through the informal and formal security analyses, we demonstrate that our scheme is resilient possible known attacks including the attacks found in Li et al.'s scheme. As compared with the previous authentication schemes, the proposed scheme is more secure and efficient and hence more practical for telemedical environments.

Technological innovations in the development of cardiovascular clinical information systems.

PubMed

Hsieh, Nan-Chen; Chang, Chung-Yi; Lee, Kuo-Chen; Chen, Jeen-Chen; Chan, Chien-Hui

2012-04-01

Recent studies have shown that computerized clinical case management and decision support systems can be used to assist surgeons in the diagnosis of disease, optimize surgical operation, aid in drug therapy and decrease the cost of medical treatment. Therefore, medical informatics has become an extensive field of research and many of these approaches have demonstrated potential value for improving medical quality. The aim of this study was to develop a web-based cardiovascular clinical information system (CIS) based on innovative techniques, such as electronic medical records, electronic registries and automatic feature surveillance schemes, to provide effective tools and support for clinical care, decision-making, biomedical research and training activities. The CIS developed for this study contained monitoring, surveillance and model construction functions. The monitoring layer function provided a visual user interface. At the surveillance and model construction layers, we explored the application of model construction and intelligent prognosis to aid in making preoperative and postoperative predictions. With the use of the CIS, surgeons can provide reasonable conclusions and explanations in uncertain environments.

Application of fiber Bragg grating sensor for rebar corrosion

NASA Astrophysics Data System (ADS)

Geng, Jiang; Wu, Jin; Zhao, Xinming

2009-07-01

Corrosion of rebar is one of the most important factors which can affect the durability of concrete structure, so in the service of these structures, measuring the degree of corrosion, and then evaluating the reliability of these structures are very important. The most significant characteristic of the rebar corrosion is its volume expansion. By the principle and characteristics of fiber bragg grating (FBG), a sensor for rebar corrosion is designed. In this paper, based upon laboratory studies, the fiber bragg grating sensor is applied in No.58 Berth of Lianyungang Port. According to the filed condition, a proper embedding scheme is proposed. Considering the optimal sensor placement, the monitoring points are determined and five sensor groups were applied in the structure. Based on the results of the calibration experiment, the relationship between corrosion ratio and the change of wavelength is established. So the corrosion status of the structure can be obtained by measuring wavelength. The study shows that the FBG sensor was feasible to monitor the status of rebar in concrete structures.

Fast blood flow monitoring in deep tissues with real-time software correlators

PubMed Central

Wang, Detian; Parthasarathy, Ashwin B.; Baker, Wesley B.; Gannon, Kimberly; Kavuri, Venki; Ko, Tiffany; Schenkel, Steven; Li, Zhe; Li, Zeren; Mullen, Michael T.; Detre, John A.; Yodh, Arjun G.

2016-01-01

We introduce, validate and demonstrate a new software correlator for high-speed measurement of blood flow in deep tissues based on diffuse correlation spectroscopy (DCS). The software correlator scheme employs standard PC-based data acquisition boards to measure temporal intensity autocorrelation functions continuously at 50 – 100 Hz, the fastest blood flow measurements reported with DCS to date. The data streams, obtained in vivo for typical source-detector separations of 2.5 cm, easily resolve pulsatile heart-beat fluctuations in blood flow which were previously considered to be noise. We employ the device to separate tissue blood flow from tissue absorption/scattering dynamics and thereby show that the origin of the pulsatile DCS signal is primarily flow, and we monitor cerebral autoregulation dynamics in healthy volunteers more accurately than with traditional instrumentation as a result of increased data acquisition rates. Finally, we characterize measurement signal-to-noise ratio and identify count rate and averaging parameters needed for optimal performance. PMID:27231588

Enhanced smartcard-based password-authenticated key agreement using extended chaotic maps.

PubMed

Lee, Tian-Fu; Hsiao, Chia-Hung; Hwang, Shi-Han; Lin, Tsung-Hung

2017-01-01

A smartcard based password-authenticated key agreement scheme enables a legal user to log in to a remote authentication server and access remote services through public networks using a weak password and a smart card. Lin recently presented an improved chaotic maps-based password-authenticated key agreement scheme that used smartcards to eliminate the weaknesses of the scheme of Guo and Chang, which does not provide strong user anonymity and violates session key security. However, the improved scheme of Lin does not exhibit the freshness property and the validity of messages so it still fails to withstand denial-of-service and privileged-insider attacks. Additionally, a single malicious participant can predetermine the session key such that the improved scheme does not exhibit the contributory property of key agreements. This investigation discusses these weaknesses and proposes an enhanced smartcard-based password-authenticated key agreement scheme that utilizes extended chaotic maps. The session security of this enhanced scheme is based on the extended chaotic map-based Diffie-Hellman problem, and is proven in the real-or-random and the sequence of games models. Moreover, the enhanced scheme ensures the freshness of communicating messages by appending timestamps, and thereby avoids the weaknesses in previous schemes.

Enhanced smartcard-based password-authenticated key agreement using extended chaotic maps

PubMed Central

Lee, Tian-Fu; Hsiao, Chia-Hung; Hwang, Shi-Han

2017-01-01

A smartcard based password-authenticated key agreement scheme enables a legal user to log in to a remote authentication server and access remote services through public networks using a weak password and a smart card. Lin recently presented an improved chaotic maps-based password-authenticated key agreement scheme that used smartcards to eliminate the weaknesses of the scheme of Guo and Chang, which does not provide strong user anonymity and violates session key security. However, the improved scheme of Lin does not exhibit the freshness property and the validity of messages so it still fails to withstand denial-of-service and privileged-insider attacks. Additionally, a single malicious participant can predetermine the session key such that the improved scheme does not exhibit the contributory property of key agreements. This investigation discusses these weaknesses and proposes an enhanced smartcard-based password-authenticated key agreement scheme that utilizes extended chaotic maps. The session security of this enhanced scheme is based on the extended chaotic map-based Diffie-Hellman problem, and is proven in the real-or-random and the sequence of games models. Moreover, the enhanced scheme ensures the freshness of communicating messages by appending timestamps, and thereby avoids the weaknesses in previous schemes. PMID:28759615

Cryptanalysis and Improvement of a Biometric-Based Multi-Server Authentication and Key Agreement Scheme

PubMed Central

Wang, Chengqi; Zhang, Xiao; Zheng, Zhiming

2016-01-01

With the security requirements of networks, biometrics authenticated schemes which are applied in the multi-server environment come to be more crucial and widely deployed. In this paper, we propose a novel biometric-based multi-server authentication and key agreement scheme which is based on the cryptanalysis of Mishra et al.’s scheme. The informal and formal security analysis of our scheme are given, which demonstrate that our scheme satisfies the desirable security requirements. The presented scheme provides a variety of significant functionalities, in which some features are not considered in the most of existing authentication schemes, such as, user revocation or re-registration and biometric information protection. Compared with several related schemes, our scheme has more secure properties and lower computation cost. It is obviously more appropriate for practical applications in the remote distributed networks. PMID:26866606

Location of Sinabung volcano magma chamber on 2013 using lavenberg-marquardt inversion scheme

NASA Astrophysics Data System (ADS)

Kumalasari, R.; Srigutomo, W.; Djamal, M.; Meilano, I.; Gunawan, H.

2018-05-01

Sinabung Volcano has been monitoring using GPS after his eruption on August 2010. We Applied Levenberg-Marquardt Inversion Scheme to GPS data on 2013 because deformation of Sinabung Volcano in this year show an inflation and deflation, first we applied Levenberg-Marquardt to velocity data on 23 January 2013 then we applied Levenberg-Marquardt Inversion Scheme to data on 31 December 2013. From our analysis we got the depth of the pressure source modeling results that indicate some possibilities that Sinabung has a deep magma chamber about 15km and also shallow magma chamber about 1km from the surface.

Development of a nonlocal convective mixing scheme with varying upward mixing rates for use in air quality and chemical transport models.

PubMed

Mihailović, Dragutin T; Alapaty, Kiran; Sakradzija, Mirjana

2008-06-01

Asymmetrical convective non-local scheme (CON) with varying upward mixing rates is developed for simulation of vertical turbulent mixing in the convective boundary layer in air quality and chemical transport models. The upward mixing rate form the surface layer is parameterized using the sensible heat flux and the friction and convective velocities. Upward mixing rates varying with height are scaled with an amount of turbulent kinetic energy in layer, while the downward mixing rates are derived from mass conservation. This scheme provides a less rapid mass transport out of surface layer into other layers than other asymmetrical convective mixing schemes. In this paper, we studied the performance of a nonlocal convective mixing scheme with varying upward mixing in the atmospheric boundary layer and its impact on the concentration of pollutants calculated with chemical and air-quality models. This scheme was additionally compared versus a local eddy-diffusivity scheme (KSC). Simulated concentrations of NO(2) and the nitrate wet deposition by the CON scheme are closer to the observations when compared to those obtained from using the KSC scheme. Concentrations calculated with the CON scheme are in general higher and closer to the observations than those obtained by the KSC scheme (of the order of 15-20%). Nitrate wet deposition calculated with the CON scheme are in general higher and closer to the observations than those obtained by the KSC scheme. To examine the performance of the scheme, simulated and measured concentrations of a pollutant (NO(2)) and nitrate wet deposition was compared for the year 2002. The comparison was made for the whole domain used in simulations performed by the chemical European Monitoring and Evaluation Programme Unified model (version UNI-ACID, rv2.0) where schemes were incorporated.

Comparative Analysis of Upper Ocean Heat Content Variability from Ensemble Operational Ocean Analyses

NASA Technical Reports Server (NTRS)

Xue, Yan; Balmaseda, Magdalena A.; Boyer, Tim; Ferry, Nicolas; Good, Simon; Ishikawa, Ichiro; Rienecker, Michele; Rosati, Tony; Yin, Yonghong; Kumar, Arun

2012-01-01

Upper ocean heat content (HC) is one of the key indicators of climate variability on many time-scales extending from seasonal to interannual to long-term climate trends. For example, HC in the tropical Pacific provides information on thermocline anomalies that is critical for the longlead forecast skill of ENSO. Since HC variability is also associated with SST variability, a better understanding and monitoring of HC variability can help us understand and forecast SST variability associated with ENSO and other modes such as Indian Ocean Dipole (IOD), Pacific Decadal Oscillation (PDO), Tropical Atlantic Variability (TAV) and Atlantic Multidecadal Oscillation (AMO). An accurate ocean initialization of HC anomalies in coupled climate models could also contribute to skill in decadal climate prediction. Errors, and/or uncertainties, in the estimation of HC variability can be affected by many factors including uncertainties in surface forcings, ocean model biases, and deficiencies in data assimilation schemes. Changes in observing systems can also leave an imprint on the estimated variability. The availability of multiple operational ocean analyses (ORA) that are routinely produced by operational and research centers around the world provides an opportunity to assess uncertainties in HC analyses, to help identify gaps in observing systems as they impact the quality of ORAs and therefore climate model forecasts. A comparison of ORAs also gives an opportunity to identify deficiencies in data assimilation schemes, and can be used as a basis for development of real-time multi-model ensemble HC monitoring products. The OceanObs09 Conference called for an intercomparison of ORAs and use of ORAs for global ocean monitoring. As a follow up, we intercompared HC variations from ten ORAs -- two objective analyses based on in-situ data only and eight model analyses based on ocean data assimilation systems. The mean, annual cycle, interannual variability and longterm trend of HC have been analyzed

Prediction of Root Zone Soil Moisture using Remote Sensing Products and In-Situ Observation under Climate Change Scenario

NASA Astrophysics Data System (ADS)

Singh, G.; Panda, R. K.; Mohanty, B.

2015-12-01

Prediction of root zone soil moisture status at field level is vital for developing efficient agricultural water management schemes. In this study, root zone soil moisture was estimated across the Rana watershed in Eastern India, by assimilation of near-surface soil moisture estimate from SMOS satellite into a physically-based Soil-Water-Atmosphere-Plant (SWAP) model. An ensemble Kalman filter (EnKF) technique coupled with SWAP model was used for assimilating the satellite soil moisture observation at different spatial scales. The universal triangle concept and artificial intelligence techniques were applied to disaggregate the SMOS satellite monitored near-surface soil moisture at a 40 km resolution to finer scale (1 km resolution), using higher spatial resolution of MODIS derived vegetation indices (NDVI) and land surface temperature (Ts). The disaggregated surface soil moisture were compared to ground-based measurements in diverse landscape using portable impedance probe and gravimetric samples. Simulated root zone soil moisture were compared with continuous soil moisture profile measurements at three monitoring stations. In addition, the impact of projected climate change on root zone soil moisture were also evaluated. The climate change projections of rainfall were analyzed for the Rana watershed from statistically downscaled Global Circulation Models (GCMs). The long-term root zone soil moisture dynamics were estimated by including a rainfall generator of likely scenarios. The predicted long term root zone soil moisture status at finer scale can help in developing efficient agricultural water management schemes to increase crop production, which lead to enhance the water use efficiency.

An efficient and provable secure revocable identity-based encryption scheme.

PubMed

Wang, Changji; Li, Yuan; Xia, Xiaonan; Zheng, Kangjia

2014-01-01

Revocation functionality is necessary and crucial to identity-based cryptosystems. Revocable identity-based encryption (RIBE) has attracted a lot of attention in recent years, many RIBE schemes have been proposed in the literature but shown to be either insecure or inefficient. In this paper, we propose a new scalable RIBE scheme with decryption key exposure resilience by combining Lewko and Waters' identity-based encryption scheme and complete subtree method, and prove our RIBE scheme to be semantically secure using dual system encryption methodology. Compared to existing scalable and semantically secure RIBE schemes, our proposed RIBE scheme is more efficient in term of ciphertext size, public parameters size and decryption cost at price of a little looser security reduction. To the best of our knowledge, this is the first construction of scalable and semantically secure RIBE scheme with constant size public system parameters.

Efficiently Multi-User Searchable Encryption Scheme with Attribute Revocation and Grant for Cloud Storage

PubMed Central

Wang, Shangping; Zhang, Xiaoxue; Zhang, Yaling

2016-01-01

Cipher-policy attribute-based encryption (CP-ABE) focus on the problem of access control, and keyword-based searchable encryption scheme focus on the problem of finding the files that the user interested in the cloud storage quickly. To design a searchable and attribute-based encryption scheme is a new challenge. In this paper, we propose an efficiently multi-user searchable attribute-based encryption scheme with attribute revocation and grant for cloud storage. In the new scheme the attribute revocation and grant processes of users are delegated to proxy server. Our scheme supports multi attribute are revoked and granted simultaneously. Moreover, the keyword searchable function is achieved in our proposed scheme. The security of our proposed scheme is reduced to the bilinear Diffie-Hellman (BDH) assumption. Furthermore, the scheme is proven to be secure under the security model of indistinguishability against selective ciphertext-policy and chosen plaintext attack (IND-sCP-CPA). And our scheme is also of semantic security under indistinguishability against chosen keyword attack (IND-CKA) in the random oracle model. PMID:27898703

Efficiently Multi-User Searchable Encryption Scheme with Attribute Revocation and Grant for Cloud Storage.

PubMed

Wang, Shangping; Zhang, Xiaoxue; Zhang, Yaling

2016-01-01

Cipher-policy attribute-based encryption (CP-ABE) focus on the problem of access control, and keyword-based searchable encryption scheme focus on the problem of finding the files that the user interested in the cloud storage quickly. To design a searchable and attribute-based encryption scheme is a new challenge. In this paper, we propose an efficiently multi-user searchable attribute-based encryption scheme with attribute revocation and grant for cloud storage. In the new scheme the attribute revocation and grant processes of users are delegated to proxy server. Our scheme supports multi attribute are revoked and granted simultaneously. Moreover, the keyword searchable function is achieved in our proposed scheme. The security of our proposed scheme is reduced to the bilinear Diffie-Hellman (BDH) assumption. Furthermore, the scheme is proven to be secure under the security model of indistinguishability against selective ciphertext-policy and chosen plaintext attack (IND-sCP-CPA). And our scheme is also of semantic security under indistinguishability against chosen keyword attack (IND-CKA) in the random oracle model.

A provably-secure ECC-based authentication scheme for wireless sensor networks.

PubMed

Nam, Junghyun; Kim, Moonseong; Paik, Juryon; Lee, Youngsook; Won, Dongho

2014-11-06

A smart-card-based user authentication scheme for wireless sensor networks (in short, a SUA-WSN scheme) is designed to restrict access to the sensor data only to users who are in possession of both a smart card and the corresponding password. While a significant number of SUA-WSN schemes have been suggested in recent years, their intended security properties lack formal definitions and proofs in a widely-accepted model. One consequence is that SUA-WSN schemes insecure against various attacks have proliferated. In this paper, we devise a security model for the analysis of SUA-WSN schemes by extending the widely-accepted model of Bellare, Pointcheval and Rogaway (2000). Our model provides formal definitions of authenticated key exchange and user anonymity while capturing side-channel attacks, as well as other common attacks. We also propose a new SUA-WSN scheme based on elliptic curve cryptography (ECC), and prove its security properties in our extended model. To the best of our knowledge, our proposed scheme is the first SUA-WSN scheme that provably achieves both authenticated key exchange and user anonymity. Our scheme is also computationally competitive with other ECC-based (non-provably secure) schemes.

A Provably-Secure ECC-Based Authentication Scheme for Wireless Sensor Networks

PubMed Central

Nam, Junghyun; Kim, Moonseong; Paik, Juryon; Lee, Youngsook; Won, Dongho

2014-01-01

A smart-card-based user authentication scheme for wireless sensor networks (in short, a SUA-WSN scheme) is designed to restrict access to the sensor data only to users who are in possession of both a smart card and the corresponding password. While a significant number of SUA-WSN schemes have been suggested in recent years, their intended security properties lack formal definitions and proofs in a widely-accepted model. One consequence is that SUA-WSN schemes insecure against various attacks have proliferated. In this paper, we devise a security model for the analysis of SUA-WSN schemes by extending the widely-accepted model of Bellare, Pointcheval and Rogaway (2000). Our model provides formal definitions of authenticated key exchange and user anonymity while capturing side-channel attacks, as well as other common attacks. We also propose a new SUA-WSN scheme based on elliptic curve cryptography (ECC), and prove its security properties in our extended model. To the best of our knowledge, our proposed scheme is the first SUA-WSN scheme that provably achieves both authenticated key exchange and user anonymity. Our scheme is also computationally competitive with other ECC-based (non-provably secure) schemes. PMID:25384009

A soft-hard combination-based cooperative spectrum sensing scheme for cognitive radio networks.

PubMed

Do, Nhu Tri; An, Beongku

2015-02-13

In this paper we propose a soft-hard combination scheme, called SHC scheme, for cooperative spectrum sensing in cognitive radio networks. The SHC scheme deploys a cluster based network in which Likelihood Ratio Test (LRT)-based soft combination is applied at each cluster, and weighted decision fusion rule-based hard combination is utilized at the fusion center. The novelties of the SHC scheme are as follows: the structure of the SHC scheme reduces the complexity of cooperative detection which is an inherent limitation of soft combination schemes. By using the LRT, we can detect primary signals in a low signal-to-noise ratio regime (around an average of -15 dB). In addition, the computational complexity of the LRT is reduced since we derive the closed-form expression of the probability density function of LRT value. The SHC scheme also takes into account the different effects of large scale fading on different users in the wide area network. The simulation results show that the SHC scheme not only provides the better sensing performance compared to the conventional hard combination schemes, but also reduces sensing overhead in terms of reporting time compared to the conventional soft combination scheme using the LRT.

FVID: Fishing Vessel Type Identification Based on VMS Trajectories

NASA Astrophysics Data System (ADS)

Huang, Haiguang; Hong, Feng; Liu, Jing; Liu, Chao; Feng, Yuan; Guo, Zhongwen

2018-05-01

Vessel Monitoring System (VMS) provides a new opportunity for quantified fishing research. Many approaches have been proposed to recognize fishing activities with VMS trajectories based on the types of fishing vessels. However, one research problem is still calling for solutions, how to identify the fishing vessel type based on only VMS trajectories. This problem is important because it requires the fishing vessel type as a preliminary to recognize fishing activities from VMS trajectories. This paper proposes fishing vessel type identification scheme (FVID) based only on VMS trajectories. FVID exploits feature engineering and machine learning schemes of XGBoost as its two key blocks and classifies fishing vessels into nine types. The dataset contains all the fishing vessel trajectories in the East China Sea in March 2017, including 10031 pre-registered fishing vessels and 1350 unregistered vessels of unknown types. In order to verify type identification accuracy, we first conduct a 4-fold cross-validation on the trajectories of registered fishing vessels. The classification accuracy is 95.42%. We then apply FVID to the unregistered fishing vessels to identify their types. After classifying the unregistered fishing vessel types, their fishing activities are further recognized based upon their types. At last, we calculate and compare the fishing density distribution in the East China Sea before and after applying the unregistered fishing vessels, confirming the importance of type identification of unregistered fishing vessels.

Public-private delivery of insecticide-treated nets: a voucher scheme in Volta Region, Ghana

PubMed Central

Kweku, Margaret; Webster, Jayne; Taylor, Ian; Burns, Susan; Dedzo, McDamien

2007-01-01

Background Coverage of vulnerable groups with insecticide-treated nets (ITNs) in Ghana, as in the majority of countries of sub-Saharan Africa is currently low. A voucher scheme was introduced in Volta Region as a possible sustainable delivery system for increasing this coverage through scale-up to other regions. Successful scale-up of public health interventions depends upon optimal delivery processes but operational research for delivery processes in large-scale implementation has been inadequate. Methods A simple tool was developed to monitor numbers of vouchers given to each health facility, numbers issued to pregnant women by the health staff, and numbers redeemed by the distributors back to the management agent. Three rounds of interviews were undertaken with health facility staff, retailers and pregnant women who had attended antenatal clinic (ANC). Results During the one year pilot 25,926 vouchers were issued to eligible women from clinics, which equates to 50.7% of the 51,658 ANC registrants during this time period. Of the vouchers issued 66.7% were redeemed by distributors back to the management agent. Initially, non-issuing of vouchers to pregnant women was mainly due to eligibility criteria imposed by the midwives; later in the year it was due to decisions of the pregnant women, and supply constraints. These in turn were heavily influenced by factors external to the programme: current household ownership of nets, competing ITN delivery strategies, and competition for the limited number of ITNs available in the country from major urban areas of other regions. Conclusion Both issuing and redemption of vouchers should be monitored as factors assumed to influence voucher redemption had an influence on issuing, and vice versa. More evidence is needed on how specific contextual factors influence the success of voucher schemes and other models of delivery of ITNs. Such an evidence base will facilitate optimal strategic decision making so that the delivery model with the best probability of success within a given context is implemented. Rigorous monitoring has an important role to play in the successful scaling-up of delivery of effective public health interventions. PMID:17274810

Setting temporal baselines for biodiversity: the limits of available monitoring data for capturing the full impact of anthropogenic pressures

PubMed Central

Mihoub, Jean-Baptiste; Henle, Klaus; Titeux, Nicolas; Brotons, Lluís; Brummitt, Neil A.; Schmeller, Dirk S.

2017-01-01

Temporal baselines are needed for biodiversity, in order for the change in biodiversity to be measured over time, the targets for biodiversity conservation to be defined and conservation progress to be evaluated. Limited biodiversity information is widely recognized as a major barrier for identifying temporal baselines, although a comprehensive quantitative assessment of this is lacking. Here, we report on the temporal baselines that could be drawn from biodiversity monitoring schemes in Europe and compare those with the rise of important anthropogenic pressures. Most biodiversity monitoring schemes were initiated late in the 20th century, well after anthropogenic pressures had already reached half of their current magnitude. Setting temporal baselines from biodiversity monitoring data would therefore underestimate the full range of impacts of major anthropogenic pressures. In addition, biases among taxa and organization levels provide a truncated picture of biodiversity over time. These limitations need to be explicitly acknowledged when designing management strategies and policies as they seriously constrain our ability to identify relevant conservation targets aimed at restoring or reversing biodiversity losses. We discuss the need for additional research efforts beyond standard biodiversity monitoring to reconstruct the impacts of major anthropogenic pressures and to identify meaningful temporal baselines for biodiversity. PMID:28134310

A Novel Passive Tracking Scheme Exploiting Geometric and Intercept Theorems

PubMed Central

Zhou, Biao; Sun, Chao; Ahn, Deockhyeon; Kim, Youngok

2018-01-01

Passive tracking aims to track targets without assistant devices, that is, device-free targets. Passive tracking based on Radio Frequency (RF) Tomography in wireless sensor networks has recently been addressed as an emerging field. The passive tracking scheme using geometric theorems (GTs) is one of the most popular RF Tomography schemes, because the GT-based method can effectively mitigate the demand for a high density of wireless nodes. In the GT-based tracking scheme, the tracking scenario is considered as a two-dimensional geometric topology and then geometric theorems are applied to estimate crossing points (CPs) of the device-free target on line-of-sight links (LOSLs), which reveal the target’s trajectory information in a discrete form. In this paper, we review existing GT-based tracking schemes, and then propose a novel passive tracking scheme by exploiting the Intercept Theorem (IT). To create an IT-based CP estimation scheme available in the noisy non-parallel LOSL situation, we develop the equal-ratio traverse (ERT) method. Finally, we analyze properties of three GT-based tracking algorithms and the performance of these schemes is evaluated experimentally under various trajectories, node densities, and noisy topologies. Analysis of experimental results shows that tracking schemes exploiting geometric theorems can achieve remarkable positioning accuracy even under rather a low density of wireless nodes. Moreover, the proposed IT scheme can provide generally finer tracking accuracy under even lower node density and noisier topologies, in comparison to other schemes. PMID:29562621

Sulfur dioxide retrievals from OMI and GOME-2 in preparation of TROPOMI

NASA Astrophysics Data System (ADS)

Theys, Nicolas; De Smedt, Isabelle; Danckaert, Thomas; Yu, Huan; van Gent, Jeroen; Van Roozendael, Michel

2016-04-01

The TROPOspheric Monitoring Instrument (TROPOMI) will be launched in 2016 onboard the ESA Sentinel-5 Precursor (S5P) platform and will provide global observations of atmospheric trace gases, with unprecedented spatial resolution. Sulfur dioxide (SO2) measurements from S5P will significantly improve the current capabilities for anthropogenic and volcanic emissions monitoring, and will extend the long-term datasets from past and existing UV sensors (TOMS, GOME, SCIAMACHY, OMI, GOME-2, OMPS). This work presents the SO2 retrieval schemes performed at BIRA-IASB as part of level-2 algorithm prototyping activities for S5P and tested on OMI and GOME-2. With a focus on anthropogenic sources, we show comparisons between OMI and GOME-2 as well as ground-based measurements, and discuss the possible reasons for the differences.

National Mosquito (Diptera: Culicidae) Survey in The Netherlands 2010-2013.

PubMed

Ibañez-Justicia, A; Stroo, A; Dik, M; Beeuwkes, J; Scholte, E J

2015-03-01

From 2010 onwards, a nationwide mosquito monitoring scheme has been conducted in The Netherlands with the aim of gaining crucial information about mosquito (Diptera: Culicidae) species composition, geographical distributions, biodiversity, and habitat preferences. The results of this study are based on 778 randomly sampled mosquito locations. These are divided into three main habitat types: urban, rural-agricultural, and natural areas. Twenty-seven mosquito species were found: 26 indigenous and 1 exotic, Aedes japonicus japonicus (Theobald, 1901). The preliminary results are presented here, with details of their species distribution and seasonality. Monitoring the temporal and spatial distribution of mosquitoes is an essential step in the risk analysis of emerging mosquito-borne diseases. © The Author 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Temperature grid sensor for the measurement of spatial temperature distributions at object surfaces.

PubMed

Schäfer, Thomas; Schubert, Markus; Hampel, Uwe

2013-01-25

This paper presents results of the development and application of a new temperature grid sensor based on the wire-mesh sensor principle. The grid sensor consists of a matrix of 256 Pt1000 platinum chip resistors and an associated electronics that measures the grid resistances with a multiplexing scheme at high speed. The individual sensor elements can be spatially distributed on an object surface and measure transient temperature distributions in real time. The advantage compared with other temperature field measurement approaches such as infrared cameras is that the object under investigation can be thermally insulated and the radiation properties of the surface do not affect the measurement accuracy. The sensor principle is therefore suited for various industrial monitoring applications. Its applicability for surface temperature monitoring has been demonstrated through heating and mixing experiments in a vessel.

Processing Approaches for DAS-Enabled Continuous Seismic Monitoring

NASA Astrophysics Data System (ADS)

Dou, S.; Wood, T.; Freifeld, B. M.; Robertson, M.; McDonald, S.; Pevzner, R.; Lindsey, N.; Gelvin, A.; Saari, S.; Morales, A.; Ekblaw, I.; Wagner, A. M.; Ulrich, C.; Daley, T. M.; Ajo Franklin, J. B.

2017-12-01

Distributed Acoustic Sensing (DAS) is creating a "field as laboratory" capability for seismic monitoring of subsurface changes. By providing unprecedented spatial and temporal sampling at a relatively low cost, DAS enables field-scale seismic monitoring to have durations and temporal resolutions that are comparable to those of laboratory experiments. Here we report on seismic processing approaches developed during data analyses of three case studies all using DAS-enabled seismic monitoring with applications ranging from shallow permafrost to deep reservoirs: (1) 10-hour downhole monitoring of cement curing at Otway, Australia; (2) 2-month surface monitoring of controlled permafrost thaw at Fairbanks, Alaska; (3) multi-month downhole and surface monitoring of carbon sequestration at Decatur, Illinois. We emphasize the data management and processing components relevant to DAS-based seismic monitoring, which include scalable approaches to data management, pre-processing, denoising, filtering, and wavefield decomposition. DAS has dramatically increased the data volume to the extent that terabyte-per-day data loads are now typical, straining conventional approaches to data storage and processing. To achieve more efficient use of disk space and network bandwidth, we explore improved file structures and data compression schemes. Because noise floor of DAS measurements is higher than that of conventional sensors, optimal processing workflow involving advanced denoising, deconvolution (of the source signatures), and stacking approaches are being established to maximize signal content of DAS data. The resulting workflow of data management and processing could accelerate the broader adaption of DAS for continuous monitoring of critical processes.

An Improved Biometrics-Based Remote User Authentication Scheme with User Anonymity

PubMed Central

Kumari, Saru

2013-01-01

The authors review the biometrics-based user authentication scheme proposed by An in 2012. The authors show that there exist loopholes in the scheme which are detrimental for its security. Therefore the authors propose an improved scheme eradicating the flaws of An's scheme. Then a detailed security analysis of the proposed scheme is presented followed by its efficiency comparison. The proposed scheme not only withstands security problems found in An's scheme but also provides some extra features with mere addition of only two hash operations. The proposed scheme allows user to freely change his password and also provides user anonymity with untraceability. PMID:24350272

An improved biometrics-based remote user authentication scheme with user anonymity.

PubMed

Khan, Muhammad Khurram; Kumari, Saru

2013-01-01

The authors review the biometrics-based user authentication scheme proposed by An in 2012. The authors show that there exist loopholes in the scheme which are detrimental for its security. Therefore the authors propose an improved scheme eradicating the flaws of An's scheme. Then a detailed security analysis of the proposed scheme is presented followed by its efficiency comparison. The proposed scheme not only withstands security problems found in An's scheme but also provides some extra features with mere addition of only two hash operations. The proposed scheme allows user to freely change his password and also provides user anonymity with untraceability.

Provably secure identity-based identification and signature schemes from code assumptions

PubMed Central

Zhao, Yiming

2017-01-01

Code-based cryptography is one of few alternatives supposed to be secure in a post-quantum world. Meanwhile, identity-based identification and signature (IBI/IBS) schemes are two of the most fundamental cryptographic primitives, so several code-based IBI/IBS schemes have been proposed. However, with increasingly profound researches on coding theory, the security reduction and efficiency of such schemes have been invalidated and challenged. In this paper, we construct provably secure IBI/IBS schemes from code assumptions against impersonation under active and concurrent attacks through a provably secure code-based signature technique proposed by Preetha, Vasant and Rangan (PVR signature), and a security enhancement Or-proof technique. We also present the parallel-PVR technique to decrease parameter values while maintaining the standard security level. Compared to other code-based IBI/IBS schemes, our schemes achieve not only preferable public parameter size, private key size, communication cost and signature length due to better parameter choices, but also provably secure. PMID:28809940

Provably secure identity-based identification and signature schemes from code assumptions.

PubMed

Song, Bo; Zhao, Yiming

2017-01-01

Code-based cryptography is one of few alternatives supposed to be secure in a post-quantum world. Meanwhile, identity-based identification and signature (IBI/IBS) schemes are two of the most fundamental cryptographic primitives, so several code-based IBI/IBS schemes have been proposed. However, with increasingly profound researches on coding theory, the security reduction and efficiency of such schemes have been invalidated and challenged. In this paper, we construct provably secure IBI/IBS schemes from code assumptions against impersonation under active and concurrent attacks through a provably secure code-based signature technique proposed by Preetha, Vasant and Rangan (PVR signature), and a security enhancement Or-proof technique. We also present the parallel-PVR technique to decrease parameter values while maintaining the standard security level. Compared to other code-based IBI/IBS schemes, our schemes achieve not only preferable public parameter size, private key size, communication cost and signature length due to better parameter choices, but also provably secure.

A secure and efficient chaotic map-based authenticated key agreement scheme for telecare medicine information systems.

PubMed

Mishra, Dheerendra; Srinivas, Jangirala; Mukhopadhyay, Sourav

2014-10-01

Advancement in network technology provides new ways to utilize telecare medicine information systems (TMIS) for patient care. Although TMIS usually faces various attacks as the services are provided over the public network. Recently, Jiang et al. proposed a chaotic map-based remote user authentication scheme for TMIS. Their scheme has the merits of low cost and session key agreement using Chaos theory. It enhances the security of the system by resisting various attacks. In this paper, we analyze the security of Jiang et al.'s scheme and demonstrate that their scheme is vulnerable to denial of service attack. Moreover, we demonstrate flaws in password change phase of their scheme. Further, our aim is to propose a new chaos map-based anonymous user authentication scheme for TMIS to overcome the weaknesses of Jiang et al.'s scheme, while also retaining the original merits of their scheme. We also show that our scheme is secure against various known attacks including the attacks found in Jiang et al.'s scheme. The proposed scheme is comparable in terms of the communication and computational overheads with Jiang et al.'s scheme and other related existing schemes. Moreover, we demonstrate the validity of the proposed scheme through the BAN (Burrows, Abadi, and Needham) logic.

Security analysis and improvement of a privacy authentication scheme for telecare medical information systems.

PubMed

Wu, Fan; Xu, Lili

2013-08-01

Nowadays, patients can gain many kinds of medical service on line via Telecare Medical Information Systems(TMIS) due to the fast development of computer technology. So security of communication through network between the users and the server is very significant. Authentication plays an important part to protect information from being attacked by malicious attackers. Recently, Jiang et al. proposed a privacy enhanced scheme for TMIS using smart cards and claimed their scheme was better than Chen et al.'s. However, we have showed that Jiang et al.'s scheme has the weakness of ID uselessness and is vulnerable to off-line password guessing attack and user impersonation attack if an attacker compromises the legal user's smart card. Also, it can't resist DoS attack in two cases: after a successful impersonation attack and wrong password input in Password change phase. Then we propose an improved mutual authentication scheme used for a telecare medical information system. Remote monitoring, checking patients' past medical history record and medical consultant can be applied in the system where information transmits via Internet. Finally, our analysis indicates that the suggested scheme overcomes the disadvantages of Jiang et al.'s scheme and is practical for TMIS.

Research to Assembly Scheme for Satellite Deck Based on Robot Flexibility Control Principle

NASA Astrophysics Data System (ADS)

Guo, Tao; Hu, Ruiqin; Xiao, Zhengyi; Zhao, Jingjing; Fang, Zhikai

2018-03-01

Deck assembly is critical quality control point in final satellite assembly process, and cable extrusion and structure collision problems in assembly process will affect development quality and progress of satellite directly. Aimed at problems existing in deck assembly process, assembly project scheme for satellite deck based on robot flexibility control principle is proposed in this paper. Scheme is introduced firstly; secondly, key technologies on end force perception and flexible docking control in the scheme are studied; then, implementation process of assembly scheme for satellite deck is described in detail; finally, actual application case of assembly scheme is given. Result shows that compared with traditional assembly scheme, assembly scheme for satellite deck based on robot flexibility control principle has obvious advantages in work efficiency, reliability and universality aspects etc.

A keyword searchable attribute-based encryption scheme with attribute update for cloud storage.

PubMed

Wang, Shangping; Ye, Jian; Zhang, Yaling

2018-01-01

Ciphertext-policy attribute-based encryption (CP-ABE) scheme is a new type of data encryption primitive, which is very suitable for data cloud storage for its fine-grained access control. Keyword-based searchable encryption scheme enables users to quickly find interesting data stored in the cloud server without revealing any information of the searched keywords. In this work, we provide a keyword searchable attribute-based encryption scheme with attribute update for cloud storage, which is a combination of attribute-based encryption scheme and keyword searchable encryption scheme. The new scheme supports the user's attribute update, especially in our new scheme when a user's attribute need to be updated, only the user's secret key related with the attribute need to be updated, while other user's secret key and the ciphertexts related with this attribute need not to be updated with the help of the cloud server. In addition, we outsource the operation with high computation cost to cloud server to reduce the user's computational burden. Moreover, our scheme is proven to be semantic security against chosen ciphertext-policy and chosen plaintext attack in the general bilinear group model. And our scheme is also proven to be semantic security against chosen keyword attack under bilinear Diffie-Hellman (BDH) assumption.

A keyword searchable attribute-based encryption scheme with attribute update for cloud storage

PubMed Central

Wang, Shangping; Zhang, Yaling

2018-01-01

Ciphertext-policy attribute-based encryption (CP-ABE) scheme is a new type of data encryption primitive, which is very suitable for data cloud storage for its fine-grained access control. Keyword-based searchable encryption scheme enables users to quickly find interesting data stored in the cloud server without revealing any information of the searched keywords. In this work, we provide a keyword searchable attribute-based encryption scheme with attribute update for cloud storage, which is a combination of attribute-based encryption scheme and keyword searchable encryption scheme. The new scheme supports the user's attribute update, especially in our new scheme when a user's attribute need to be updated, only the user's secret key related with the attribute need to be updated, while other user's secret key and the ciphertexts related with this attribute need not to be updated with the help of the cloud server. In addition, we outsource the operation with high computation cost to cloud server to reduce the user's computational burden. Moreover, our scheme is proven to be semantic security against chosen ciphertext-policy and chosen plaintext attack in the general bilinear group model. And our scheme is also proven to be semantic security against chosen keyword attack under bilinear Diffie-Hellman (BDH) assumption. PMID:29795577

Exponential Arithmetic Based Self-Healing Group Key Distribution Scheme with Backward Secrecy under the Resource-Constrained Wireless Networks

PubMed Central

Guo, Hua; Zheng, Yandong; Zhang, Xiyong; Li, Zhoujun

2016-01-01

In resource-constrained wireless networks, resources such as storage space and communication bandwidth are limited. To guarantee secure communication in resource-constrained wireless networks, group keys should be distributed to users. The self-healing group key distribution (SGKD) scheme is a promising cryptographic tool, which can be used to distribute and update the group key for the secure group communication over unreliable wireless networks. Among all known SGKD schemes, exponential arithmetic based SGKD (E-SGKD) schemes reduce the storage overhead to constant, thus is suitable for the the resource-constrained wireless networks. In this paper, we provide a new mechanism to achieve E-SGKD schemes with backward secrecy. We first propose a basic E-SGKD scheme based on a known polynomial-based SGKD, where it has optimal storage overhead while having no backward secrecy. To obtain the backward secrecy and reduce the communication overhead, we introduce a novel approach for message broadcasting and self-healing. Compared with other E-SGKD schemes, our new E-SGKD scheme has the optimal storage overhead, high communication efficiency and satisfactory security. The simulation results in Zigbee-based networks show that the proposed scheme is suitable for the resource-restrained wireless networks. Finally, we show the application of our proposed scheme. PMID:27136550

An Effective Delay Reduction Approach through a Portion of Nodes with a Larger Duty Cycle for Industrial WSNs

PubMed Central

Wu, Minrui; Wu, Yanhui; Liu, Chuyao; Cai, Zhiping; Ma, Ming

2018-01-01

For Industrial Wireless Sensor Networks (IWSNs), sending data with timely style to the stink (or control center, CC) that is monitored by sensor nodes is a challenging issue. However, in order to save energy, wireless sensor networks based on a duty cycle are widely used in the industrial field, which can bring great delay to data transmission. We observe that if the duty cycle of a small number of nodes in the network is set to 1, the sleep delay caused by the duty cycle can be effectively reduced. Thus, in this paper, a novel Portion of Nodes with Larger Duty Cycle (PNLDC) scheme is proposed to reduce delay and optimize energy efficiency for IWSNs. In the PNLDC scheme, a portion of nodes are selected to set their duty cycle to 1, and the proportion of nodes with the duty cycle of 1 is determined according to the energy abundance of the area in which the node is located. The more the residual energy in the region, the greater the proportion of the selected nodes. Because there are a certain proportion of nodes with the duty cycle of 1 in the network, the PNLDC scheme can effectively reduce delay in IWSNs. The performance analysis and experimental results show that the proposed scheme significantly reduces the delay for forwarding data by 8.9~26.4% and delay for detection by 2.1~24.6% without reducing the network lifetime when compared with the fixed duty cycle method. Meanwhile, compared with the dynamic duty cycle strategy, the proposed scheme has certain advantages in terms of energy utilization and delay reduction. PMID:29757236

Automatic identification of epileptic seizures from EEG signals using linear programming boosting.

PubMed

Hassan, Ahnaf Rashik; Subasi, Abdulhamit

2016-11-01

Computerized epileptic seizure detection is essential for expediting epilepsy diagnosis and research and for assisting medical professionals. Moreover, the implementation of an epilepsy monitoring device that has low power and is portable requires a reliable and successful seizure detection scheme. In this work, the problem of automated epilepsy seizure detection using singe-channel EEG signals has been addressed. At first, segments of EEG signals are decomposed using a newly proposed signal processing scheme, namely complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN). Six spectral moments are extracted from the CEEMDAN mode functions and train and test matrices are formed afterward. These matrices are fed into the classifier to identify epileptic seizures from EEG signal segments. In this work, we implement an ensemble learning based machine learning algorithm, namely linear programming boosting (LPBoost) to perform classification. The efficacy of spectral features in the CEEMDAN domain is validated by graphical and statistical analyses. The performance of CEEMDAN is compared to those of its predecessors to further inspect its suitability. The effectiveness and the appropriateness of LPBoost are demonstrated as opposed to the commonly used classification models. Resubstitution and 10 fold cross-validation error analyses confirm the superior algorithm performance of the proposed scheme. The algorithmic performance of our epilepsy seizure identification scheme is also evaluated against state-of-the-art works in the literature. Experimental outcomes manifest that the proposed seizure detection scheme performs better than the existing works in terms of accuracy, sensitivity, specificity, and Cohen's Kappa coefficient. It can be anticipated that owing to its use of only one channel of EEG signal, the proposed method will be suitable for device implementation, eliminate the onus of clinicians for analyzing a large bulk of data manually, and expedite epilepsy diagnosis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

An Effective Delay Reduction Approach through a Portion of Nodes with a Larger Duty Cycle for Industrial WSNs.

PubMed

Wu, Minrui; Wu, Yanhui; Liu, Chuyao; Cai, Zhiping; Xiong, Neal N; Liu, Anfeng; Ma, Ming

2018-05-12

For Industrial Wireless Sensor Networks (IWSNs), sending data with timely style to the stink (or control center, CC) that is monitored by sensor nodes is a challenging issue. However, in order to save energy, wireless sensor networks based on a duty cycle are widely used in the industrial field, which can bring great delay to data transmission. We observe that if the duty cycle of a small number of nodes in the network is set to 1, the sleep delay caused by the duty cycle can be effectively reduced. Thus, in this paper, a novel Portion of Nodes with Larger Duty Cycle (PNLDC) scheme is proposed to reduce delay and optimize energy efficiency for IWSNs. In the PNLDC scheme, a portion of nodes are selected to set their duty cycle to 1, and the proportion of nodes with the duty cycle of 1 is determined according to the energy abundance of the area in which the node is located. The more the residual energy in the region, the greater the proportion of the selected nodes. Because there are a certain proportion of nodes with the duty cycle of 1 in the network, the PNLDC scheme can effectively reduce delay in IWSNs. The performance analysis and experimental results show that the proposed scheme significantly reduces the delay for forwarding data by 8.9~26.4% and delay for detection by 2.1~24.6% without reducing the network lifetime when compared with the fixed duty cycle method. Meanwhile, compared with the dynamic duty cycle strategy, the proposed scheme has certain advantages in terms of energy utilization and delay reduction.

A Review of the National Health Insurance Scheme in Ghana: What Are the Sustainability Threats and Prospects?

PubMed

Alhassan, Robert Kaba; Nketiah-Amponsah, Edward; Arhinful, Daniel Kojo

2016-01-01

The introduction of the national health insurance scheme (NHIS) in Ghana in 2003 significantly contributed to improved health services utilization and health outcomes. However, stagnating active membership, reports of poor quality health care rendered to NHIS-insured clients and cost escalations have raised concerns on the operational and financial sustainability of the scheme. This paper reviewed peer reviewed articles and grey literature on the sustainability challenges and prospects of the NHIS in Ghana. Electronic search was done for literature published between 2003-2016 on the NHIS and its sustainability in Ghana. A total of 66 publications relevant to health insurance in Ghana and other developing countries were retrieved from Cochrane, PubMed, ScienceDirect and Googlescholar for initial screening. Out of this number, 31 eligible peer reviewed articles were selected for final review based on specific relevance to the Ghanaian context. Ability of the NHIS to continue its operations in Ghana is threatened financially and operationally by factors such as: cost escalation, possible political interference, inadequate technical capacity, spatial distribution of health facilities and health workers, inadequate monitoring mechanisms, broad benefits package, large exemption groups, inadequate client education, and limited community engagement. Moreover, poor quality care in NHIS-accredited health facilities potentially reduces clients' trust in the scheme and consequently decreases (re)enrolment rates. These sustainability challenges were reviewed and discussed in this paper. The NHIS continues to play a critical role towards attaining universal health coverage in Ghana albeit confronted by challenges that could potentially collapse the scheme. Averting this possible predicament will largely depend on concerted efforts of key stakeholders such as health insurance managers, service providers, insurance subscribers, policy makers and political actors.

A Review of the National Health Insurance Scheme in Ghana: What Are the Sustainability Threats and Prospects?

PubMed Central

Alhassan, Robert Kaba; Nketiah-Amponsah, Edward; Arhinful, Daniel Kojo

2016-01-01

Background The introduction of the national health insurance scheme (NHIS) in Ghana in 2003 significantly contributed to improved health services utilization and health outcomes. However, stagnating active membership, reports of poor quality health care rendered to NHIS-insured clients and cost escalations have raised concerns on the operational and financial sustainability of the scheme. This paper reviewed peer reviewed articles and grey literature on the sustainability challenges and prospects of the NHIS in Ghana. Methods Electronic search was done for literature published between 2003–2016 on the NHIS and its sustainability in Ghana. A total of 66 publications relevant to health insurance in Ghana and other developing countries were retrieved from Cochrane, PubMed, ScienceDirect and Googlescholar for initial screening. Out of this number, 31 eligible peer reviewed articles were selected for final review based on specific relevance to the Ghanaian context. Results Ability of the NHIS to continue its operations in Ghana is threatened financially and operationally by factors such as: cost escalation, possible political interference, inadequate technical capacity, spatial distribution of health facilities and health workers, inadequate monitoring mechanisms, broad benefits package, large exemption groups, inadequate client education, and limited community engagement. Moreover, poor quality care in NHIS-accredited health facilities potentially reduces clients’ trust in the scheme and consequently decreases (re)enrolment rates. These sustainability challenges were reviewed and discussed in this paper. Conclusions The NHIS continues to play a critical role towards attaining universal health coverage in Ghana albeit confronted by challenges that could potentially collapse the scheme. Averting this possible predicament will largely depend on concerted efforts of key stakeholders such as health insurance managers, service providers, insurance subscribers, policy makers and political actors. PMID:27832082

A data seamless interaction scheme between electric power secondary business systems

NASA Astrophysics Data System (ADS)

Ai, Wenkai; Qian, Feng

2018-03-01

At present, the data interaction of electric power secondary business systems is very high, and it is not universal to develop programs when data interaction is carried out by different manufacturers' electric power secondary business systems. There are different interaction schemes for electric power secondary business systems with different manufacturers, which lead to high development cost, low reusability and high maintenance difficulty. This paper introduces a new data seamless interaction scheme between electric power secondary business systems. The scheme adopts the international common Java message service protocol as the transmission protocol, adopts the common JavaScript object symbol format as the data interactive format, unified electric power secondary business systems data interactive way, improve reusability, reduce complexity, monitor the operation of the electric power secondary business systems construction has laid a solid foundation.

A data acquisition protocol for a reactive wireless sensor network monitoring application.

PubMed

Aderohunmu, Femi A; Brunelli, Davide; Deng, Jeremiah D; Purvis, Martin K

2015-04-30

Limiting energy consumption is one of the primary aims for most real-world deployments of wireless sensor networks. Unfortunately, attempts to optimize energy efficiency are often in conflict with the demand for network reactiveness to transmit urgent messages. In this article, we propose SWIFTNET: a reactive data acquisition scheme. It is built on the synergies arising from a combination of the data reduction methods and energy-efficient data compression schemes. Particularly, it combines compressed sensing, data prediction and adaptive sampling strategies. We show how this approach dramatically reduces the amount of unnecessary data transmission in the deployment for environmental monitoring and surveillance networks. SWIFTNET targets any monitoring applications that require high reactiveness with aggressive data collection and transmission. To test the performance of this method, we present a real-world testbed for a wildfire monitoring as a use-case. The results from our in-house deployment testbed of 15 nodes have proven to be favorable. On average, over 50% communication reduction when compared with a default adaptive prediction method is achieved without any loss in accuracy. In addition, SWIFTNET is able to guarantee reactiveness by adjusting the sampling interval from 5 min up to 15 s in our application domain.

A Data Acquisition Protocol for a Reactive Wireless Sensor Network Monitoring Application

PubMed Central

Aderohunmu, Femi A.; Brunelli, Davide; Deng, Jeremiah D.; Purvis, Martin K.

2015-01-01

Limiting energy consumption is one of the primary aims for most real-world deployments of wireless sensor networks. Unfortunately, attempts to optimize energy efficiency are often in conflict with the demand for network reactiveness to transmit urgent messages. In this article, we propose SWIFTNET: a reactive data acquisition scheme. It is built on the synergies arising from a combination of the data reduction methods and energy-efficient data compression schemes. Particularly, it combines compressed sensing, data prediction and adaptive sampling strategies. We show how this approach dramatically reduces the amount of unnecessary data transmission in the deployment for environmental monitoring and surveillance networks. SWIFTNET targets any monitoring applications that require high reactiveness with aggressive data collection and transmission. To test the performance of this method, we present a real-world testbed for a wildfire monitoring as a use-case. The results from our in-house deployment testbed of 15 nodes have proven to be favorable. On average, over 50% communication reduction when compared with a default adaptive prediction method is achieved without any loss in accuracy. In addition, SWIFTNET is able to guarantee reactiveness by adjusting the sampling interval from 5 min up to 15 s in our application domain. PMID:25942642

Integrating multisensor satellite data merging and image reconstruction in support of machine learning for better water quality management.

PubMed

Chang, Ni-Bin; Bai, Kaixu; Chen, Chi-Farn

2017-10-01

Monitoring water quality changes in lakes, reservoirs, estuaries, and coastal waters is critical in response to the needs for sustainable development. This study develops a remote sensing-based multiscale modeling system by integrating multi-sensor satellite data merging and image reconstruction algorithms in support of feature extraction with machine learning leading to automate continuous water quality monitoring in environmentally sensitive regions. This new Earth observation platform, termed "cross-mission data merging and image reconstruction with machine learning" (CDMIM), is capable of merging multiple satellite imageries to provide daily water quality monitoring through a series of image processing, enhancement, reconstruction, and data mining/machine learning techniques. Two existing key algorithms, including Spectral Information Adaptation and Synthesis Scheme (SIASS) and SMart Information Reconstruction (SMIR), are highlighted to support feature extraction and content-based mapping. Whereas SIASS can support various data merging efforts to merge images collected from cross-mission satellite sensors, SMIR can overcome data gaps by reconstructing the information of value-missing pixels due to impacts such as cloud obstruction. Practical implementation of CDMIM was assessed by predicting the water quality over seasons in terms of the concentrations of nutrients and chlorophyll-a, as well as water clarity in Lake Nicaragua, providing synergistic efforts to better monitor the aquatic environment and offer insightful lake watershed management strategies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Geo-referenced multimedia environmental fate model (G-CIEMS): model formulation and comparison to the generic model and monitoring approaches.

PubMed

Suzuki, Noriyuki; Murasawa, Kaori; Sakurai, Takeo; Nansai, Keisuke; Matsuhashi, Keisuke; Moriguchi, Yuichi; Tanabe, Kiyoshi; Nakasugi, Osami; Morita, Masatoshi

2004-11-01

A spatially resolved and geo-referenced dynamic multimedia environmental fate model, G-CIEMS (Grid-Catchment Integrated Environmental Modeling System) was developed on a geographical information system (GIS). The case study for Japan based on the air grid cells of 5 x 5 km resolution and catchments with an average area of 9.3 km2, which corresponds to about 40,000 air grid cells and 38,000 river segments/catchment polygons, were performed for dioxins, benzene, 1,3-butadiene, and di-(2-ethyhexyl)phthalate. The averaged concentration of the model and monitoring output were within a factor of 2-3 for all the media. Outputs from G-CIEMS and the generic model were essentially comparable when identical parameters were employed, whereas the G-CIEMS model gave explicit information of distribution of chemicals in the environment. Exposure-weighted averaged concentrations (EWAC) in air were calculated to estimate the exposure ofthe population, based on the results of generic, G-CIEMS, and monitoring approaches. The G-CIEMS approach showed significantly better agreement with the monitoring-derived EWAC than the generic model approach. Implication for the use of a geo-referenced modeling approach in the risk assessment scheme is discussed as a generic-spatial approach, which can be used to provide more accurate exposure estimation with distribution information, using generally available data sources for a wide range of chemicals.

Absorbable energy monitoring scheme: new design protocol to test vehicle structural crashworthiness.

PubMed

Ofochebe, Sunday M; Enibe, Samuel O; Ozoegwu, Chigbogu G

2016-05-01

In vehicle crashworthiness design optimization detailed system evaluation capable of producing reliable results are basically achieved through high-order numerical computational (HNC) models such as the dynamic finite element model, mesh-free model etc. However the application of these models especially during optimization studies is basically challenged by their inherent high demand on computational resources, conditional stability of the solution process, and lack of knowledge of viable parameter range for detailed optimization studies. The absorbable energy monitoring scheme (AEMS) presented in this paper suggests a new design protocol that attempts to overcome such problems in evaluation of vehicle structure for crashworthiness. The implementation of the AEMS involves studying crash performance of vehicle components at various absorbable energy ratios based on a 2DOF lumped-mass-spring (LMS) vehicle impact model. This allows for prompt prediction of useful parameter values in a given design problem. The application of the classical one-dimensional LMS model in vehicle crash analysis is further improved in the present work by developing a critical load matching criterion which allows for quantitative interpretation of the results of the abstract model in a typical vehicle crash design. The adequacy of the proposed AEMS for preliminary vehicle crashworthiness design is demonstrated in this paper, however its extension to full-scale design-optimization problem involving full vehicle model that shows greater structural detail requires more theoretical development.

Resolving Turbine Degradation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walker, Matthew; Kruizenga, Alan Michael; Withey, Elizabeth Ann

2017-08-01

The supercritical carbon dioxide (S-CO2) Brayton Cycle has gained significant attention in the last decade as an advanced power cycle capable of achieving high efficiency power conversion. Sandia National Laboratories, with support from the U.S. Department of Energy Office of Nuclear Energy (US DOE-NE), has been conducting research and development in order to deliver a technology that is ready for commercialization. Root cause analysis has been performed on the Recompression Loop at Sandia National Laboratories. It was found that particles throughout the loop are stainless steel, likely alloy 316 based upon the elemental composition. Deployment of a filter scheme ismore » underway to both protect the turbomachinery and also for purposes of determining the specific cause for the particulate. Shake down tests of electric resistance (ER) as a potential in-situ monitoring scheme shows promise in high temperature systems. A modified instrument was purchased and held at 650°C for more than 1.5 months to date without issue. Quantitative measurements of this instrument will be benchmarked against witness samples in the future, but all qualitative trends to date are as to be expected. ER is a robust method for corrosion monitoring, but very slow at responding and can take several weeks under conditions to see obvious changes in behavior. Electrochemical noise was identified as an advanced technique that should be pursued for the ability to identify transients that would lead to poor material performance.« less

Enhancement tuning and control for high dynamic range images in multi-scale locally adaptive contrast enhancement algorithms

NASA Astrophysics Data System (ADS)

Cvetkovic, Sascha D.; Schirris, Johan; de With, Peter H. N.

2009-01-01

For real-time imaging in surveillance applications, visibility of details is of primary importance to ensure customer confidence. If we display High Dynamic-Range (HDR) scenes whose contrast spans four or more orders of magnitude on a conventional monitor without additional processing, results are unacceptable. Compression of the dynamic range is therefore a compulsory part of any high-end video processing chain because standard monitors are inherently Low- Dynamic Range (LDR) devices with maximally two orders of display dynamic range. In real-time camera processing, many complex scenes are improved with local contrast enhancements, bringing details to the best possible visibility. In this paper, we show how a multi-scale high-frequency enhancement scheme, in which gain is a non-linear function of the detail energy, can be used for the dynamic range compression of HDR real-time video camera signals. We also show the connection of our enhancement scheme to the processing way of the Human Visual System (HVS). Our algorithm simultaneously controls perceived sharpness, ringing ("halo") artifacts (contrast) and noise, resulting in a good balance between visibility of details and non-disturbance of artifacts. The overall quality enhancement, suitable for both HDR and LDR scenes, is based on a careful selection of the filter types for the multi-band decomposition and a detailed analysis of the signal per frequency band.

From multi-disciplinary monitoring observation to probabilistic eruption forecasting: a Bayesian view

NASA Astrophysics Data System (ADS)

Marzocchi, W.

2011-12-01

Eruption forecasting is the probability of eruption in a specific time-space-magnitude window. The use of probabilities to track the evolution of a phase of unrest is unavoidable for two main reasons: first, eruptions are intrinsically unpredictable in a deterministic sense, and, second, probabilities represent a quantitative tool that can be rationally used by decision-makers (this is usually done in many other fields). The primary information for the probability assessment during a phase of unrest come from monitoring data of different quantities, such as the seismic activity, ground deformation, geochemical signatures, and so on. Nevertheless, the probabilistic forecast based on monitoring data presents two main difficulties. First, many high-risk volcanoes do not have monitoring pre-eruptive and unrest databases, making impossible a probabilistic assessment based on the frequency of past observations. The ongoing project WOVOdat (led by Christopher Newhall) is trying to tackle this limitation creating a sort of worldwide epidemiological database that may cope with the lack of monitoring pre-eruptive and unrest databases for a specific volcano using observations of 'analogs' volcanoes. Second, the quantity and quality of monitoring data are rapidly increasing in many volcanoes, creating strongly inhomogeneous dataset. In these cases, classical statistical analysis can be performed on high quality monitoring observations only for (usually too) short periods of time, or alternatively using only few specific monitoring data that are available for longer times (such as the number of earthquakes), therefore neglecting a lot of information carried out by the most recent kind of monitoring. Here, we explore a possible strategy to cope with these limitations. In particular, we present a Bayesian strategy that merges different kinds of information. In this approach, all relevant monitoring observations are embedded into a probabilistic scheme through expert opinion, conceptual models, and, possibly, real past data. After discussing all scientific and philosophical aspects of such approach, we present some applications for Campi Flegrei and Vesuvius.

Combining Particle Filters and Consistency-Based Approaches for Monitoring and Diagnosis of Stochastic Hybrid Systems

NASA Technical Reports Server (NTRS)

Narasimhan, Sriram; Dearden, Richard; Benazera, Emmanuel

2004-01-01

Fault detection and isolation are critical tasks to ensure correct operation of systems. When we consider stochastic hybrid systems, diagnosis algorithms need to track both the discrete mode and the continuous state of the system in the presence of noise. Deterministic techniques like Livingstone cannot deal with the stochasticity in the system and models. Conversely Bayesian belief update techniques such as particle filters may require many computational resources to get a good approximation of the true belief state. In this paper we propose a fault detection and isolation architecture for stochastic hybrid systems that combines look-ahead Rao-Blackwellized Particle Filters (RBPF) with the Livingstone 3 (L3) diagnosis engine. In this approach RBPF is used to track the nominal behavior, a novel n-step prediction scheme is used for fault detection and L3 is used to generate a set of candidates that are consistent with the discrepant observations which then continue to be tracked by the RBPF scheme.

Real-Time Robust Tracking for Motion Blur and Fast Motion via Correlation Filters.

PubMed

Xu, Lingyun; Luo, Haibo; Hui, Bin; Chang, Zheng

2016-09-07

Visual tracking has extensive applications in intelligent monitoring and guidance systems. Among state-of-the-art tracking algorithms, Correlation Filter methods perform favorably in robustness, accuracy and speed. However, it also has shortcomings when dealing with pervasive target scale variation, motion blur and fast motion. In this paper we proposed a new real-time robust scheme based on Kernelized Correlation Filter (KCF) to significantly improve performance on motion blur and fast motion. By fusing KCF and STC trackers, our algorithm also solve the estimation of scale variation in many scenarios. We theoretically analyze the problem for CFs towards motions and utilize the point sharpness function of the target patch to evaluate the motion state of target. Then we set up an efficient scheme to handle the motion and scale variation without much time consuming. Our algorithm preserves the properties of KCF besides the ability to handle special scenarios. In the end extensive experimental results on benchmark of VOT datasets show our algorithm performs advantageously competed with the top-rank trackers.

Rural health prepayment schemes in China: towards a more active role for government.

PubMed

Bloom, G; Shenglan, T

1999-04-01

A large majority of China's rural population were members of health prepayment schemes in the 1970's. Most of these schemes collapsed during the transition to a market economy. Some localities subsequently reestablished schemes. In early 1997 a new government policy identified health prepayment as a major potential source of rural health finance. This paper draws on the experience of existing schemes to explore how government can support implementation of this policy. The decision to support the establishment of health prepayment schemes is part of the government's effort to establish new sources of finance for social services. It believes that individuals are more likely to accept voluntary contributions to a prepayment scheme than tax increases. The voluntary nature of the contributions limits the possibilities for risk-sharing and redistribution between rich and poor. This underlines the need for the government to fund a substantial share of health expenditure out of general revenues, particularly in poor localities. The paper notes that many successful prepayment schemes depend on close supervision by local political leaders. It argues that the national programme will have to translate these measures into a regulatory system which defines the responsibilities of scheme management bodies and local governments. A number of prepayment schemes have collapsed because members did not feel they got value for money. Local health bureaux will have to cooperate with prepayment schemes to ensure that health facilities provide good quality services at a reasonable cost. Users' representatives can also monitor performance. The paper concludes that government needs to clarify the relationship between health prepayment schemes and other actors in rural localities in order to increase the chance that schemes will become a major source rural health finance.

An improved biometrics-based authentication scheme for telecare medical information systems.

PubMed

Guo, Dianli; Wen, Qiaoyan; Li, Wenmin; Zhang, Hua; Jin, Zhengping

2015-03-01

Telecare medical information system (TMIS) offers healthcare delivery services and patients can acquire their desired medical services conveniently through public networks. The protection of patients' privacy and data confidentiality are significant. Very recently, Mishra et al. proposed a biometrics-based authentication scheme for telecare medical information system. Their scheme can protect user privacy and is believed to resist a range of network attacks. In this paper, we analyze Mishra et al.'s scheme and identify that their scheme is insecure to against known session key attack and impersonation attack. Thereby, we present a modified biometrics-based authentication scheme for TMIS to eliminate the aforementioned faults. Besides, we demonstrate the completeness of the proposed scheme through BAN-logic. Compared to the related schemes, our protocol can provide stronger security and it is more practical.

Implications of non-sustainable agricultural water policies for the water-food nexus in large-scale irrigation systems: A remote sensing approach

NASA Astrophysics Data System (ADS)

Al Zayed, Islam Sabry; Elagib, Nadir Ahmed

2017-12-01

This study proposes a novel monitoring tool based on Satellite Remote Sensing (SRS) data to examine the status of water distribution and Water Use Efficiency (WUE) under changing water policies in large-scale and complex irrigation schemes. The aim is to improve our understanding of the water-food nexus in such schemes. With a special reference to the Gezira Irrigation Scheme (GeIS) in Sudan during the period 2000-2014, the tool devised herein is well suited for cases where validation data are absent. First, it introduces an index, referred to as the Crop Water Consumption Index (CWCI), to assess the efficiency of water policies. The index is defined as the ratio of actual evapotranspiration (ETa) over agricultural areas to total ETa for the whole scheme where ETa is estimated using the Simplified Surface Energy Balance model (SSEB). Second, the tool uses integrated Normalized Difference Vegetation Index (iNDVI), as a proxy for crop productivity, and ETa to assess the WUE. Third, the tool uses SSEB ETa and NDVI in an attempt to detect wastage of water. Four key results emerged from this research as follows: 1) the WUE has not improved despite the changing agricultural and water policies, 2) the seasonal ETa can be used to detect the drier areas of GeIS, i.e. areas with poor irrigation water supply, 3) the decreasing trends of CWCI, slope of iNDVI-ETa linear regression and iNDVI are indicative of inefficient utilization of irrigation water in the scheme, and 4) it is possible to use SSEB ETa and NDVI to identify channels with spillover problems and detect wastage of rainwater that is not used as a source for irrigation. In conclusion, the innovative tool developed herein has provided important information on the efficiency of a large-scale irrigation scheme to help rationalize laborious water management processes and increase productivity.

Cognitive fiber Bragg grating sensors system based on fiber Fabry-Perot tunable filter technology

NASA Astrophysics Data System (ADS)

Zhang, Hongtao; Wang, Pengfei; Zou, Jilin; Xie, Jing; Cui, Hong-Liang

2011-05-01

The wavelength demodulation based on a Fiber Fabry-Pérot Tunable Filter (FFP-TF) is a common method for multiplexing Fiber Bragg Grating (FBG) sensors. But this method cannot be used to detect high frequency signals due to the limitation by the highest scanning rate that the FFP-TF can achieve. To overcome this disadvantage, in this paper we present a scheme of cognitive sensors network based on FFP-TF technology. By perceiving the sensing environment, system can automatically switch into monitoring signals in two modes to obtain better measurement results: multi measurement points, low frequency (<1 KHz) signal, and few measurement points but high frequency (~50 KHz) signals. This cognitive sensors network can be realized in current technology and satisfy current most industrial requirements.

Parallelised photoacoustic signal acquisition using a Fabry-Perot sensor and a camera-based interrogation scheme

NASA Astrophysics Data System (ADS)

Saeb Gilani, T.; Villringer, C.; Zhang, E.; Gundlach, H.; Buchmann, J.; Schrader, S.; Laufer, J.

2018-02-01

Tomographic photoacoustic (PA) images acquired using a Fabry-Perot (FP) based scanner offer high resolution and image fidelity but can result in long acquisition times due to the need for raster scanning. To reduce the acquisition times, a parallelised camera-based PA signal detection scheme is developed. The scheme is based on using a sCMOScamera and FPI sensors with high homogeneity of optical thickness. PA signals were acquired using the camera-based setup and the signal to noise ratio (SNR) was measured. A comparison of the SNR of PA signal detected using 1) a photodiode in a conventional raster scanning detection scheme and 2) a sCMOS camera in parallelised detection scheme is made. The results show that the parallelised interrogation scheme has the potential to provide high speed PA imaging.

Phytoremediation of landfill leachate.

PubMed

Jones, D L; Williamson, K L; Owen, A G

2006-01-01

Leachate emissions from landfill sites are of concern, primarily due to their toxic impact when released unchecked into the environment, and the potential for landfill sites to generate leachate for many hundreds of years following closure. Consequently, economically and environmentally sustainable disposal options are a priority in waste management. One potential option is the use of soil-plant based remediation schemes. In many cases, using either trees (including short rotation coppice) or grassland, phytoremediation of leachate has been successful. However, there are a significant number of examples where phytoremediation has failed. Typically, this failure can be ascribed to excessive leachate application and poor management due to a fundamental lack of understanding of the plant-soil system. On balance, with careful management, phytoremediation can be viewed as a sustainable, cost effective and environmentally sound option which is capable of treating 250m(3)ha(-1)yr(-1). However, these schemes have a requirement for large land areas and must be capable of responding to changes in leachate quality and quantity, problems of scheme establishment and maintenance, continual environmental monitoring and seasonal patterns of plant growth. Although the fundamental underpinning science is well understood, further work is required to create long-term predictive remediation models, full environmental impact assessments, a complete life-cycle analysis and economic analyses for a wide range of landfill scenarios.

Tile prediction schemes for wide area motion imagery maps in GIS

NASA Astrophysics Data System (ADS)

Michael, Chris J.; Lin, Bruce Y.

2017-11-01

Wide-area surveillance, traffic monitoring, and emergency management are just several of many applications benefiting from the incorporation of Wide-Area Motion Imagery (WAMI) maps into geographic information systems. Though the use of motion imagery as a GIS base map via the Web Map Service (WMS) standard is not a new concept, effectively streaming imagery is particularly challenging due to its large scale and the multidimensionally interactive nature of clients that use WMS. Ineffective streaming from a server to one or more clients can unnecessarily overwhelm network bandwidth and cause frustratingly large amounts of latency in visualization to the user. Seamlessly streaming WAMI through GIS requires good prediction to accurately guess the tiles of the video that will be traversed in the near future. In this study, we present an experimental framework for such prediction schemes by presenting a stochastic interaction model that represents a human user's interaction with a GIS video map. We then propose several algorithms by which the tiles of the stream may be predicted. Results collected both within the experimental framework and using human analyst trajectories show that, though each algorithm thrives under certain constraints, the novel Markovian algorithm yields the best results overall. Furthermore, we make the argument that the proposed experimental framework is sufficient for the study of these prediction schemes.

D-MSR: a distributed network management scheme for real-time monitoring and process control applications in wireless industrial automation.

PubMed

Zand, Pouria; Dilo, Arta; Havinga, Paul

2013-06-27

Current wireless technologies for industrial applications, such as WirelessHART and ISA100.11a, use a centralized management approach where a central network manager handles the requirements of the static network. However, such a centralized approach has several drawbacks. For example, it cannot cope with dynamicity/disturbance in large-scale networks in a real-time manner and it incurs a high communication overhead and latency for exchanging management traffic. In this paper, we therefore propose a distributed network management scheme, D-MSR. It enables the network devices to join the network, schedule their communications, establish end-to-end connections by reserving the communication resources for addressing real-time requirements, and cope with network dynamicity (e.g., node/edge failures) in a distributed manner. According to our knowledge, this is the first distributed management scheme based on IEEE 802.15.4e standard, which guides the nodes in different phases from joining until publishing their sensor data in the network. We demonstrate via simulation that D-MSR can address real-time and reliable communication as well as the high throughput requirements of industrial automation wireless networks, while also achieving higher efficiency in network management than WirelessHART, in terms of delay and overhead.

Laser line illumination scheme allowing the reduction of background signal and the correction of absorption heterogeneities effects for fluorescence reflectance imaging.

PubMed

Fantoni, Frédéric; Hervé, Lionel; Poher, Vincent; Gioux, Sylvain; Mars, Jérôme I; Dinten, Jean-Marc

2015-10-01

Intraoperative fluorescence imaging in reflectance geometry is an attractive imaging modality as it allows to noninvasively monitor the fluorescence targeted tumors located below the tissue surface. Some drawbacks of this technique are the background fluorescence decreasing the contrast and absorption heterogeneities leading to misinterpretations concerning fluorescence concentrations. We propose a correction technique based on a laser line scanning illumination scheme. We scan the medium with the laser line and acquire, at each position of the line, both fluorescence and excitation images. We then use the finding that there is a relationship between the excitation intensity profile and the background fluorescence one to predict the amount of signal to subtract from the fluorescence images to get a better contrast. As the light absorption information is contained both in fluorescence and excitation images, this method also permits us to correct the effects of absorption heterogeneities. This technique has been validated on simulations and experimentally. Fluorescent inclusions are observed in several configurations at depths ranging from 1 mm to 1 cm. Results obtained with this technique are compared with those obtained with a classical wide-field detection scheme for contrast enhancement and with the fluorescence by an excitation ratio approach for absorption correction.

D-MSR: A Distributed Network Management Scheme for Real-Time Monitoring and Process Control Applications in Wireless Industrial Automation

PubMed Central

Zand, Pouria; Dilo, Arta; Havinga, Paul

2013-01-01

Current wireless technologies for industrial applications, such as WirelessHART and ISA100.11a, use a centralized management approach where a central network manager handles the requirements of the static network. However, such a centralized approach has several drawbacks. For example, it cannot cope with dynamicity/disturbance in large-scale networks in a real-time manner and it incurs a high communication overhead and latency for exchanging management traffic. In this paper, we therefore propose a distributed network management scheme, D-MSR. It enables the network devices to join the network, schedule their communications, establish end-to-end connections by reserving the communication resources for addressing real-time requirements, and cope with network dynamicity (e.g., node/edge failures) in a distributed manner. According to our knowledge, this is the first distributed management scheme based on IEEE 802.15.4e standard, which guides the nodes in different phases from joining until publishing their sensor data in the network. We demonstrate via simulation that D-MSR can address real-time and reliable communication as well as the high throughput requirements of industrial automation wireless networks, while also achieving higher efficiency in network management than WirelessHART, in terms of delay and overhead. PMID:23807687

Development of a stationary carbon emission inventory for Shanghai using pollution source census data

NASA Astrophysics Data System (ADS)

Li, Xianzhe; Jiang, Ping; Zhang, Yan; Ma, Weichun

2016-12-01

This study utilizes 521,631 activity data points from the 2007 Shanghai Pollution Source Census to compile a stationary carbon emission inventory for Shanghai. The inventory generated from our dataset shows that a large portion of Shanghai's total energy use consists of coal-oriented energy consumption. The electricity and heat production industries, iron and steel mills, and the petroleum refining industry are the main carbon emitters. In addition, most of these industries are located in Baoshan District, which is Shanghai's largest contributor of carbon emissions. Policy makers can use the enterpriselevel carbon emission inventory and the method designed in this study to construct sound carbon emission reduction policies. The carbon trading scheme to be established in Shanghai based on the developed carbon inventory is also introduced in this paper with the aim of promoting the monitoring, reporting and verification of carbon trading. Moreover, we believe that it might be useful to consider the participation of industries, such as those for food processing, beverage, and tobacco, in Shanghai's carbon trading scheme. Based on the results contained herein, we recommend establishing a comprehensive carbon emission inventory by inputting data from the pollution source census used in this study.

A smartphone-based chip-scale microscope using ambient illumination.

PubMed

Lee, Seung Ah; Yang, Changhuei

2014-08-21

Portable chip-scale microscopy devices can potentially address various imaging needs in mobile healthcare and environmental monitoring. Here, we demonstrate the adaptation of a smartphone's camera to function as a compact lensless microscope. Unlike other chip-scale microscopy schemes, this method uses ambient illumination as its light source and does not require the incorporation of a dedicated light source. The method is based on the shadow imaging technique where the sample is placed on the surface of the image sensor, which captures direct shadow images under illumination. To improve the image resolution beyond the pixel size, we perform pixel super-resolution reconstruction with multiple images at different angles of illumination, which are captured while the user is manually tilting the device around any ambient light source, such as the sun or a lamp. The lensless imaging scheme allows for sub-micron resolution imaging over an ultra-wide field-of-view (FOV). Image acquisition and reconstruction are performed on the device using a custom-built Android application, constructing a stand-alone imaging device for field applications. We discuss the construction of the device using a commercial smartphone and demonstrate the imaging capabilities of our system.

A smartphone-based chip-scale microscope using ambient illumination

PubMed Central

Lee, Seung Ah; Yang, Changhuei

2014-01-01

Portable chip-scale microscopy devices can potentially address various imaging needs in mobile healthcare and environmental monitoring. Here, we demonstrate the adaptation of a smartphone’s camera to function as a compact lensless microscope. Unlike other chip-scale microscopy schemes, this method uses ambient illumination as its light source and does not require the incorporation of a dedicated light source. The method is based on the shadow imaging technique where the sample is placed on the surface of the image sensor, which captures direct shadow images under illumination. To improve the imaging resolution beyond the pixel size, we perform pixel super-resolution reconstruction with multiple images at different angles of illumination, which are captured while the user is manually tilting the device around any ambient light source, such as the sun or a lamp. The lensless imaging scheme allows for sub-micron resolution imaging over an ultra-wide field-of-view (FOV). Image acquisition and reconstruction is performed on the device using a custom-built android application, constructing a stand-alone imaging device for field applications. We discuss the construction of the device using a commercial smartphone and demonstrate the imaging capabilities of our system. PMID:24964209

Microfluidics on compliant substrates: recent developments in foldable and bendable devices and system packaging

NASA Astrophysics Data System (ADS)

Gray, Bonnie L.

2012-04-01

Microfluidics is revolutionizing laboratory methods and biomedical devices, offering new capabilities and instrumentation in multiple areas such as DNA analysis, proteomics, enzymatic analysis, single cell analysis, immunology, point-of-care medicine, personalized medicine, drug delivery, and environmental toxin and pathogen detection. For many applications (e.g., wearable and implantable health monitors, drug delivery devices, and prosthetics) mechanically flexible polymer devices and systems that can conform to the body offer benefits that cannot be achieved using systems based on conventional rigid substrate materials. However, difficulties in implementing active devices and reliable packaging technologies have limited the success of flexible microfluidics. Employing highly compliant materials such as PDMS that are typically employed for prototyping, we review mechanically flexible polymer microfluidic technologies based on free-standing polymer substrates and novel electronic and microfluidic interconnection schemes. Central to these new technologies are hybrid microfabrication methods employing novel nanocomposite polymer materials and devices. We review microfabrication methods using these materials, along with demonstrations of example devices and packaging schemes that employ them. We review these recent developments and place them in the context of the fields of flexible microfluidics and conformable systems, and discuss cross-over applications to conventional rigid-substrate microfluidics.

An Effective Collaborative Mobile Weighted Clustering Schemes for Energy Balancing in Wireless Sensor Networks.

PubMed

Tang, Chengpei; Shokla, Sanesy Kumcr; Modhawar, George; Wang, Qiang

2016-02-19

Collaborative strategies for mobile sensor nodes ensure the efficiency and the robustness of data processing, while limiting the required communication bandwidth. In order to solve the problem of pipeline inspection and oil leakage monitoring, a collaborative weighted mobile sensing scheme is proposed. By adopting a weighted mobile sensing scheme, the adaptive collaborative clustering protocol can realize an even distribution of energy load among the mobile sensor nodes in each round, and make the best use of battery energy. A detailed theoretical analysis and experimental results revealed that the proposed protocol is an energy efficient collaborative strategy such that the sensor nodes can communicate with a fusion center and produce high power gain.

Hydraulic fracture monitoring in hard rock at 410 m depth with an advanced fluid-injection protocol and extensive sensor array

NASA Astrophysics Data System (ADS)

Zang, Arno; Stephansson, Ove; Stenberg, Leif; Plenkers, Katrin; Specht, Sebastian; Milkereit, Claus; Schill, Eva; Kwiatek, Grzegorz; Dresen, Georg; Zimmermann, Günter; Dahm, Torsten; Weber, Michael

2017-02-01

In this paper, an underground experiment at the Äspö Hard Rock Laboratory (HRL) is described. Main goal is optimizing geothermal heat exchange in crystalline rock mass at depth by multistage hydraulic fracturing with minimal impact on the environment, that is, seismic events. For this, three arrays with acoustic emission, microseismicity and electromagnetic sensors are installed mapping hydraulic fracture initiation and growth. Fractures are driven by three different water injection schemes (continuous, progressive and pulse pressurization). After a brief review of hydraulic fracture operations in crystalline rock mass at mine scale, the site geology and the stress conditions at Äspö HRL are described. Then, the continuous, single-flow rate and alternative, multiple-flow rate fracture breakdown tests in a horizontal borehole at depth level 410 m are described together with the monitoring networks and sensitivity. Monitoring results include the primary catalogue of acoustic emission hypocentres obtained from four hydraulic fractures with the in situ trigger and localizing network. The continuous versus alternative water injection schemes are discussed in terms of the fracture breakdown pressure, the fracture pattern from impression packer result and the monitoring at the arrays. An example of multistage hydraulic fracturing with several phases of opening and closing of fracture walls is evaluated using data from acoustic emissions, seismic broad-band recordings and electromagnetic signal response. Based on our limited amount of in situ tests (six) and evaluation of three tests in Ävrö granodiorite, in the multiple-flow rate test with progressively increasing target pressure, the acoustic emission activity starts at a later stage in the fracturing process compared to the conventional fracturing case with continuous water injection. In tendency, also the total number and magnitude of acoustic events are found to be smaller in the progressive treatment with frequent phases of depressurization.

Improving both imaging speed and spatial resolution in MR-guided neurosurgery

NASA Astrophysics Data System (ADS)

Liu, Haiying; Hall, Walter A.; Truwit, Charles L.

2002-05-01

A robust near real-time MRI based surgical guidance scheme has been developed and used in neurosurgical procedure performed in our combined 1.5 Tesla MR operating room. Because of the increased susceptibility difference in the area of surgical site during surgery, the preferred real- time imaging technique is a single shot imaging sequence based on the concept of the half acquisition with turbo spin echoes (HASTE). In order to maintain sufficient spatial resolution for visualizing the surgical devices, such as a biopsy needle and catheter, we used focused field of view (FOV) in the phase-encoding (PE) direction coupled with an out-volume signal suppression (OVS) technique. The key concept of the method is to minimize the total number of the required phase encoding steps and the effective echo time (TE) as well as the longest TE for the high spatial encoding step. The concept has been first demonstrated with a phantom experiment, which showed when the water was doped with Gd- DTPA to match the relaxation rates of the brain tissue there was a significant spatial blurring primarily along the phase encoding direction if the conventional HASTE technique, and the new scheme indeed minimized the spatial blur in the resulting image and improved the needle visualization as anticipated. Using the new scheme in a typical MR-guided neurobiopsy procedure, the brain biopsy needle was easily seen against the tissue background with minimal blurring due the inevitable T2 signal decay even when the PE direction was set parallel to the needle axis. This MR based guidance technique has practically allowed neurosurgeons to visualize the biopsy needle and to monitor its insertion with a better certainty at near real-time pace.

Optical sensors for application in intelligent food-packaging technology

NASA Astrophysics Data System (ADS)

McEvoy, Aisling K.; Von Bueltzingsloewen, Christoph; McDonagh, Colette M.; MacCraith, Brian D.; Klimant, Ingo; Wolfbeis, Otto S.

2003-03-01

Modified Atmosphere Packaged (MAP) food employs a protective gas mixture, which normally contains selected amounts of carbon dioxide (CO2) and oxygen (O2), in order to extend the shelf life of food. Conventional MAP analysis of package integrity involves destructive sampling of packages followed by carbon dioxide and oxygen detection. For quality control reasons, as well as to enhance food safety, the concept of optical on-pack sensors for monitoring the gas composition of the MAP package at different stages of the distribution process is very attractive. The objective of this work was to develop printable formulations of oxygen and carbon dioxide sensors for use in food packaging. Oxygen sensing is achieved by detecting the degree of quenching of a fluorescent ruthenium complex entrapped in a sol-gel matrix. In particular, a measurement technique based on the quenching of the fluorescence decay time, phase fluorometric detection, is employed. A scheme for detecting CO2 has been developed which is compatible with the oxygen detection scheme. It is fluorescence-based and uses the pH-sensitive 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS) indicator dye encapsulated in an organically modified silica (ORMOSIL) glass matrix. Dual Luminophore Referencing (DLR) has been employed as an internal referencing scheme, which provides many of the advantages of lifetime-based fluorometric methods. Oxygen cross-sensitivity was minimised by encapsulating the reference luminophore in dense sol-gel microspheres. The sensor performance compared well with standard methods for both oxygen and carbon dioxide detection. The results of preliminary on-pack print trials are presented and a preliminary design of an integrated dual gas optical read-out device is discussed.

An Identity-Based Anti-Quantum Privacy-Preserving Blind Authentication in Wireless Sensor Networks.

PubMed

Zhu, Hongfei; Tan, Yu-An; Zhu, Liehuang; Wang, Xianmin; Zhang, Quanxin; Li, Yuanzhang

2018-05-22

With the development of wireless sensor networks, IoT devices are crucial for the Smart City; these devices change people's lives such as e-payment and e-voting systems. However, in these two systems, the state-of-art authentication protocols based on traditional number theory cannot defeat a quantum computer attack. In order to protect user privacy and guarantee trustworthy of big data, we propose a new identity-based blind signature scheme based on number theorem research unit lattice, this scheme mainly uses a rejection sampling theorem instead of constructing a trapdoor. Meanwhile, this scheme does not depend on complex public key infrastructure and can resist quantum computer attack. Then we design an e-payment protocol using the proposed scheme. Furthermore, we prove our scheme is secure in the random oracle, and satisfies confidentiality, integrity, and non-repudiation. Finally, we demonstrate that the proposed scheme outperforms the other traditional existing identity-based blind signature schemes in signing speed and verification speed, outperforms the other lattice-based blind signature in signing speed, verification speed, and signing secret key size.

An Identity-Based Anti-Quantum Privacy-Preserving Blind Authentication in Wireless Sensor Networks

PubMed Central

Zhu, Hongfei; Tan, Yu-an; Zhu, Liehuang; Wang, Xianmin; Zhang, Quanxin; Li, Yuanzhang

2018-01-01

With the development of wireless sensor networks, IoT devices are crucial for the Smart City; these devices change people’s lives such as e-payment and e-voting systems. However, in these two systems, the state-of-art authentication protocols based on traditional number theory cannot defeat a quantum computer attack. In order to protect user privacy and guarantee trustworthy of big data, we propose a new identity-based blind signature scheme based on number theorem research unit lattice, this scheme mainly uses a rejection sampling theorem instead of constructing a trapdoor. Meanwhile, this scheme does not depend on complex public key infrastructure and can resist quantum computer attack. Then we design an e-payment protocol using the proposed scheme. Furthermore, we prove our scheme is secure in the random oracle, and satisfies confidentiality, integrity, and non-repudiation. Finally, we demonstrate that the proposed scheme outperforms the other traditional existing identity-based blind signature schemes in signing speed and verification speed, outperforms the other lattice-based blind signature in signing speed, verification speed, and signing secret key size. PMID:29789475

Adaptive Numerical Dissipative Control in High Order Schemes for Multi-D Non-Ideal MHD

NASA Technical Reports Server (NTRS)

Yee, H. C.; Sjoegreen, B.

2004-01-01

The goal is to extend our adaptive numerical dissipation control in high order filter schemes and our new divergence-free methods for ideal MHD to non-ideal MHD that include viscosity and resistivity. The key idea consists of automatic detection of different flow features as distinct sensors to signal the appropriate type and amount of numerical dissipation/filter where needed and leave the rest of the region free of numerical dissipation contamination. These scheme-independent detectors are capable of distinguishing shocks/shears, flame sheets, turbulent fluctuations and spurious high-frequency oscillations. The detection algorithm is based on an artificial compression method (ACM) (for shocks/shears), and redundant multi-resolution wavelets (WAV) (for the above types of flow feature). These filter approaches also provide a natural and efficient way for the minimization of Div(B) numerical error. The filter scheme consists of spatially sixth order or higher non-dissipative spatial difference operators as the base scheme for the inviscid flux derivatives. If necessary, a small amount of high order linear dissipation is used to remove spurious high frequency oscillations. For example, an eighth-order centered linear dissipation (AD8) might be included in conjunction with a spatially sixth-order base scheme. The inviscid difference operator is applied twice for the viscous flux derivatives. After the completion of a full time step of the base scheme step, the solution is adaptively filtered by the product of a 'flow detector' and the 'nonlinear dissipative portion' of a high-resolution shock-capturing scheme. In addition, the scheme independent wavelet flow detector can be used in conjunction with spatially compact, spectral or spectral element type of base schemes. The ACM and wavelet filter schemes using the dissipative portion of a second-order shock-capturing scheme with sixth-order spatial central base scheme for both the inviscid and viscous MHD flux derivatives and a fourth-order Runge-Kutta method are denoted.

A Bayesian least squares support vector machines based framework for fault diagnosis and failure prognosis

NASA Astrophysics Data System (ADS)

Khawaja, Taimoor Saleem

A high-belief low-overhead Prognostics and Health Management (PHM) system is desired for online real-time monitoring of complex non-linear systems operating in a complex (possibly non-Gaussian) noise environment. This thesis presents a Bayesian Least Squares Support Vector Machine (LS-SVM) based framework for fault diagnosis and failure prognosis in nonlinear non-Gaussian systems. The methodology assumes the availability of real-time process measurements, definition of a set of fault indicators and the existence of empirical knowledge (or historical data) to characterize both nominal and abnormal operating conditions. An efficient yet powerful Least Squares Support Vector Machine (LS-SVM) algorithm, set within a Bayesian Inference framework, not only allows for the development of real-time algorithms for diagnosis and prognosis but also provides a solid theoretical framework to address key concepts related to classification for diagnosis and regression modeling for prognosis. SVM machines are founded on the principle of Structural Risk Minimization (SRM) which tends to find a good trade-off between low empirical risk and small capacity. The key features in SVM are the use of non-linear kernels, the absence of local minima, the sparseness of the solution and the capacity control obtained by optimizing the margin. The Bayesian Inference framework linked with LS-SVMs allows a probabilistic interpretation of the results for diagnosis and prognosis. Additional levels of inference provide the much coveted features of adaptability and tunability of the modeling parameters. The two main modules considered in this research are fault diagnosis and failure prognosis. With the goal of designing an efficient and reliable fault diagnosis scheme, a novel Anomaly Detector is suggested based on the LS-SVM machines. The proposed scheme uses only baseline data to construct a 1-class LS-SVM machine which, when presented with online data is able to distinguish between normal behavior and any abnormal or novel data during real-time operation. The results of the scheme are interpreted as a posterior probability of health (1 - probability of fault). As shown through two case studies in Chapter 3, the scheme is well suited for diagnosing imminent faults in dynamical non-linear systems. Finally, the failure prognosis scheme is based on an incremental weighted Bayesian LS-SVR machine. It is particularly suited for online deployment given the incremental nature of the algorithm and the quick optimization problem solved in the LS-SVR algorithm. By way of kernelization and a Gaussian Mixture Modeling (GMM) scheme, the algorithm can estimate "possibly" non-Gaussian posterior distributions for complex non-linear systems. An efficient regression scheme associated with the more rigorous core algorithm allows for long-term predictions, fault growth estimation with confidence bounds and remaining useful life (RUL) estimation after a fault is detected. The leading contributions of this thesis are (a) the development of a novel Bayesian Anomaly Detector for efficient and reliable Fault Detection and Identification (FDI) based on Least Squares Support Vector Machines, (b) the development of a data-driven real-time architecture for long-term Failure Prognosis using Least Squares Support Vector Machines, (c) Uncertainty representation and management using Bayesian Inference for posterior distribution estimation and hyper-parameter tuning, and finally (d) the statistical characterization of the performance of diagnosis and prognosis algorithms in order to relate the efficiency and reliability of the proposed schemes.

Evaluation of management measures of software development. Volume 1: Analysis summary

NASA Technical Reports Server (NTRS)

Page, J.; Card, D.; Mcgarry, F.

1982-01-01

The conceptual model, the data classification scheme, and the analytic procedures are explained. The analytic results are summarized and specific software measures for collection and monitoring are recommended.

Gaussian mixture modeling of acoustic emissions for structural health monitoring of reinforced concrete structures

NASA Astrophysics Data System (ADS)

Farhidzadeh, Alireza; Dehghan-Niri, Ehsan; Salamone, Salvatore

2013-04-01

Reinforced Concrete (RC) has been widely used in construction of infrastructures for many decades. The cracking behavior in concrete is crucial due to the harmful effects on structural performance such as serviceability and durability requirements. In general, in loading such structures until failure, tensile cracks develop at the initial stages of loading, while shear cracks dominate later. Therefore, monitoring the cracking modes is of paramount importance as it can lead to the prediction of the structural performance. In the past two decades, significant efforts have been made toward the development of automated structural health monitoring (SHM) systems. Among them, a technique that shows promises for monitoring RC structures is the acoustic emission (AE). This paper introduces a novel probabilistic approach based on Gaussian Mixture Modeling (GMM) to classify AE signals related to each crack mode. The system provides an early warning by recognizing nucleation of numerous critical shear cracks. The algorithm is validated through an experimental study on a full-scale reinforced concrete shear wall subjected to a reversed cyclic loading. A modified conventional classification scheme and a new criterion for crack classification are also proposed.

Error function attack of chaos synchronization based encryption schemes.

PubMed

Wang, Xingang; Zhan, Meng; Lai, C-H; Gang, Hu

2004-03-01

Different chaos synchronization based encryption schemes are reviewed and compared from the practical point of view. As an efficient cryptanalysis tool for chaos encryption, a proposal based on the error function attack is presented systematically and used to evaluate system security. We define a quantitative measure (quality factor) of the effective applicability of a chaos encryption scheme, which takes into account the security, the encryption speed, and the robustness against channel noise. A comparison is made of several encryption schemes and it is found that a scheme based on one-way coupled chaotic map lattices performs outstandingly well, as judged from quality factor. Copyright 2004 American Institute of Physics.

Security analysis and enhancements of an effective biometric-based remote user authentication scheme using smart cards.

PubMed

An, Younghwa

2012-01-01

Recently, many biometrics-based user authentication schemes using smart cards have been proposed to improve the security weaknesses in user authentication system. In 2011, Das proposed an efficient biometric-based remote user authentication scheme using smart cards that can provide strong authentication and mutual authentication. In this paper, we analyze the security of Das's authentication scheme, and we have shown that Das's authentication scheme is still insecure against the various attacks. Also, we proposed the enhanced scheme to remove these security problems of Das's authentication scheme, even if the secret information stored in the smart card is revealed to an attacker. As a result of security analysis, we can see that the enhanced scheme is secure against the user impersonation attack, the server masquerading attack, the password guessing attack, and the insider attack and provides mutual authentication between the user and the server.

Security Analysis and Enhancements of an Effective Biometric-Based Remote User Authentication Scheme Using Smart Cards

PubMed Central

An, Younghwa

2012-01-01

Recently, many biometrics-based user authentication schemes using smart cards have been proposed to improve the security weaknesses in user authentication system. In 2011, Das proposed an efficient biometric-based remote user authentication scheme using smart cards that can provide strong authentication and mutual authentication. In this paper, we analyze the security of Das's authentication scheme, and we have shown that Das's authentication scheme is still insecure against the various attacks. Also, we proposed the enhanced scheme to remove these security problems of Das's authentication scheme, even if the secret information stored in the smart card is revealed to an attacker. As a result of security analysis, we can see that the enhanced scheme is secure against the user impersonation attack, the server masquerading attack, the password guessing attack, and the insider attack and provides mutual authentication between the user and the server. PMID:22899887

An efficient chaotic maps-based authentication and key agreement scheme using smartcards for telecare medicine information systems.

PubMed

Lee, Tian-Fu

2013-12-01

A smartcard-based authentication and key agreement scheme for telecare medicine information systems enables patients, doctors, nurses and health visitors to use smartcards for secure login to medical information systems. Authorized users can then efficiently access remote services provided by the medicine information systems through public networks. Guo and Chang recently improved the efficiency of a smartcard authentication and key agreement scheme by using chaotic maps. Later, Hao et al. reported that the scheme developed by Guo and Chang had two weaknesses: inability to provide anonymity and inefficient double secrets. Therefore, Hao et al. proposed an authentication scheme for telecare medicine information systems that solved these weaknesses and improved performance. However, a limitation in both schemes is their violation of the contributory property of key agreements. This investigation discusses these weaknesses and proposes a new smartcard-based authentication and key agreement scheme that uses chaotic maps for telecare medicine information systems. Compared to conventional schemes, the proposed scheme provides fewer weaknesses, better security, and more efficiency.

Improved scheme for parametrization of convection in the Met Office's Numerical Atmospheric-dispersion Modelling Environment (NAME)

NASA Astrophysics Data System (ADS)

Meneguz, Elena; Thomson, David; Witham, Claire; Kusmierczyk-Michulec, Jolanta

2015-04-01

NAME is a Lagrangian atmospheric dispersion model used by the Met Office to predict the dispersion of both natural and man-made contaminants in the atmosphere, e.g. volcanic ash, radioactive particles and chemical species. Atmospheric convection is responsible for transport and mixing of air resulting in a large exchange of heat and energy above the boundary layer. Although convection can transport material through the whole troposphere, convective clouds have a small horizontal length scale (of the order of few kilometres). Therefore, for large-scale transport the horizontal scale on which the convection exists is below the global NWP resolution used as input to NAME and convection must be parametrized. Prior to the work presented here, the enhanced vertical mixing generated by non-resolved convection was reproduced by randomly redistributing Lagrangian particles between the cloud base and cloud top with probability equal to 1/25th of the NWP predicted convective cloud fraction. Such a scheme is essentially diffusive and it does not make optimal use of all the information provided by the driving meteorological model. To make up for these shortcomings and make the parametrization more physically based, the convection scheme has been recently revised. The resulting version, presented in this paper, is now based on the balance equation between upward, entrainment and detrainment fluxes. In particular, upward mass fluxes are calculated with empirical formulas derived from Cloud Resolving Models and using the NWP convective precipitation diagnostic as closure. The fluxes are used to estimate how many particles entrain, move upward and detrain. Lastly, the scheme is completed by applying a compensating subsidence flux. The performance of the updated convection scheme is benchmarked against available observational data of passive tracers. In particular, radioxenon is a noble gas that can undergo significant long range transport: this study makes use of observations of the isotope 133Xe available at International Monitoring System stations around the South Pacific Ocean. In addition, timeseries of modelled output concentrations obtained using NAME on a grid of 25 km size are compared with those obtained with FLEXPART, another well-known atmospheric dispersion model used by the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) and other scientific communities. Findings are discussed and discrepancies investigated.

Lightweight ECC based RFID authentication integrated with an ID verifier transfer protocol.

PubMed

He, Debiao; Kumar, Neeraj; Chilamkurti, Naveen; Lee, Jong-Hyouk

2014-10-01

The radio frequency identification (RFID) technology has been widely adopted and being deployed as a dominant identification technology in a health care domain such as medical information authentication, patient tracking, blood transfusion medicine, etc. With more and more stringent security and privacy requirements to RFID based authentication schemes, elliptic curve cryptography (ECC) based RFID authentication schemes have been proposed to meet the requirements. However, many recently published ECC based RFID authentication schemes have serious security weaknesses. In this paper, we propose a new ECC based RFID authentication integrated with an ID verifier transfer protocol that overcomes the weaknesses of the existing schemes. A comprehensive security analysis has been conducted to show strong security properties that are provided from the proposed authentication scheme. Moreover, the performance of the proposed authentication scheme is analyzed in terms of computational cost, communicational cost, and storage requirement.

Searchable attribute-based encryption scheme with attribute revocation in cloud storage.

PubMed

Wang, Shangping; Zhao, Duqiao; Zhang, Yaling

2017-01-01

Attribute based encryption (ABE) is a good way to achieve flexible and secure access control to data, and attribute revocation is the extension of the attribute-based encryption, and the keyword search is an indispensable part for cloud storage. The combination of both has an important application in the cloud storage. In this paper, we construct a searchable attribute-based encryption scheme with attribute revocation in cloud storage, the keyword search in our scheme is attribute based with access control, when the search succeeds, the cloud server returns the corresponding cipher text to user and the user can decrypt the cipher text definitely. Besides, our scheme supports multiple keywords search, which makes the scheme more practical. Under the assumption of decisional bilinear Diffie-Hellman exponent (q-BDHE) and decisional Diffie-Hellman (DDH) in the selective security model, we prove that our scheme is secure.

Software Defined Network Monitoring Scheme Using Spectral Graph Theory and Phantom Nodes

DTIC Science & Technology

2014-09-01

networks is the emergence of software - defined networking ( SDN ) [1]. SDN has existed for the...Chapter III for network monitoring. A. SOFTWARE DEFINED NETWORKS SDNs provide a new and innovative method to simplify network hardware by logically...and R. Giladi, “Performance analysis of software - defined networking ( SDN ),” in Proc. of IEEE 21st International Symposium on Modeling, Analysis

Mountain birdwatch: developing a coordinated monitoring program for high-elevation birds in the Atlantic northern forest

Treesearch

John D. Lloyd; Julie Hart; J. Dan Lambert

2010-01-01

Birds occupying high-elevation forests in the northeast are perceived to be at risk from a variety of external forces, most notably the potential loss and alteration of habitat associated with global climate change and the increased deployment of wind-energy facilities. However, the Breeding Bird Survey (BBS), a standardized national monitoring scheme widely used to...

Simple scheme to implement decoy-state reference-frame-independent quantum key distribution

NASA Astrophysics Data System (ADS)

Zhang, Chunmei; Zhu, Jianrong; Wang, Qin

2018-06-01

We propose a simple scheme to implement decoy-state reference-frame-independent quantum key distribution (RFI-QKD), where signal states are prepared in Z, X, and Y bases, decoy states are prepared in X and Y bases, and vacuum states are set to no bases. Different from the original decoy-state RFI-QKD scheme whose decoy states are prepared in Z, X and Y bases, in our scheme decoy states are only prepared in X and Y bases, which avoids the redundancy of decoy states in Z basis, saves the random number consumption, simplifies the encoding device of practical RFI-QKD systems, and makes the most of the finite pulses in a short time. Numerical simulations show that, considering the finite size effect with reasonable number of pulses in practical scenarios, our simple decoy-state RFI-QKD scheme exhibits at least comparable or even better performance than that of the original decoy-state RFI-QKD scheme. Especially, in terms of the resistance to the relative rotation of reference frames, our proposed scheme behaves much better than the original scheme, which has great potential to be adopted in current QKD systems.

Work, Train, Win: Work-Based Learning Design and Management for Productivity Gains. OECD Education Working Papers, No. 135

ERIC Educational Resources Information Center

Kis, Viktoria

2016-01-01

Realising the potential of work-based learning schemes as a driver of productivity requires careful design and support. The length of work-based learning schemes should be adapted to the profile of productivity gains. A scheme that is too long for a given skill set might be unattractive for learners and waste public resources, but a scheme that is…

Cryptanalysis and improvement of Yan et al.'s biometric-based authentication scheme for telecare medicine information systems.

PubMed

Mishra, Dheerendra; Mukhopadhyay, Sourav; Chaturvedi, Ankita; Kumari, Saru; Khan, Muhammad Khurram

2014-06-01

Remote user authentication is desirable for a Telecare Medicine Information System (TMIS) for the safety, security and integrity of transmitted data over the public channel. In 2013, Tan presented a biometric based remote user authentication scheme and claimed that his scheme is secure. Recently, Yan et al. demonstrated some drawbacks in Tan's scheme and proposed an improved scheme to erase the drawbacks of Tan's scheme. We analyze Yan et al.'s scheme and identify that their scheme is vulnerable to off-line password guessing attack, and does not protect anonymity. Moreover, in their scheme, login and password change phases are inefficient to identify the correctness of input where inefficiency in password change phase can cause denial of service attack. Further, we design an improved scheme for TMIS with the aim to eliminate the drawbacks of Yan et al.'s scheme.

An Improvement of Robust and Efficient Biometrics Based Password Authentication Scheme for Telecare Medicine Information Systems Using Extended Chaotic Maps.

PubMed

Moon, Jongho; Choi, Younsung; Kim, Jiye; Won, Dongho

2016-03-01

Recently, numerous extended chaotic map-based password authentication schemes that employ smart card technology were proposed for Telecare Medical Information Systems (TMISs). In 2015, Lu et al. used Li et al.'s scheme as a basis to propose a password authentication scheme for TMISs that is based on biometrics and smart card technology and employs extended chaotic maps. Lu et al. demonstrated that Li et al.'s scheme comprises some weaknesses such as those regarding a violation of the session-key security, a vulnerability to the user impersonation attack, and a lack of local verification. In this paper, however, we show that Lu et al.'s scheme is still insecure with respect to issues such as a violation of the session-key security, and that it is vulnerable to both the outsider attack and the impersonation attack. To overcome these drawbacks, we retain the useful properties of Lu et al.'s scheme to propose a new password authentication scheme that is based on smart card technology and requires the use of chaotic maps. Then, we show that our proposed scheme is more secure and efficient and supports security properties.

Ground-based remote sensing scheme for monitoring aerosol–cloud interactions

DOE PAGES

Sarna, Karolina; Russchenberg, Herman W. J.

2016-03-14

A new method for continuous observation of aerosol–cloud interactions with ground-based remote sensing instruments is presented. The main goal of this method is to enable the monitoring of the change of the cloud droplet size due to the change in the aerosol concentration. We use high-resolution measurements from a lidar, a radar and a radiometer, which allow us to collect and compare data continuously. This method is based on a standardised data format from Cloudnet and can be implemented at any observatory where the Cloudnet data set is available. Two example case studies were chosen from the Atmospheric Radiation Measurementmore » (ARM) Program deployment on Graciosa Island, Azores, Portugal, in 2009 to present the method. We use the cloud droplet effective radius ( r e) to represent cloud microphysical properties and an integrated value of the attenuated backscatter coefficient (ATB) below the cloud to represent the aerosol concentration. All data from each case study are divided into bins of the liquid water path (LWP), each 10 g m -2 wide. For every LWP bin we present the correlation coefficient between ln r e and ln ATB, as well as ACI r (defined as ACI r = -d ln r e d ln ATB, change in cloud droplet effective radius with aerosol concentration). Obtained values of ACI r are in the range 0.01–0.1. In conclusion, we show that ground-based remote sensing instruments used in synergy can efficiently and continuously monitor aerosol–cloud interactions.« less

A privacy preserving secure and efficient authentication scheme for telecare medical information systems.

PubMed

Mishra, Raghavendra; Barnwal, Amit Kumar

2015-05-01

The Telecare medical information system (TMIS) presents effective healthcare delivery services by employing information and communication technologies. The emerging privacy and security are always a matter of great concern in TMIS. Recently, Chen at al. presented a password based authentication schemes to address the privacy and security. Later on, it is proved insecure against various active and passive attacks. To erase the drawbacks of Chen et al.'s anonymous authentication scheme, several password based authentication schemes have been proposed using public key cryptosystem. However, most of them do not present pre-smart card authentication which leads to inefficient login and password change phases. To present an authentication scheme with pre-smart card authentication, we present an improved anonymous smart card based authentication scheme for TMIS. The proposed scheme protects user anonymity and satisfies all the desirable security attributes. Moreover, the proposed scheme presents efficient login and password change phases where incorrect input can be quickly detected and a user can freely change his password without server assistance. Moreover, we demonstrate the validity of the proposed scheme by utilizing the widely-accepted BAN (Burrows, Abadi, and Needham) logic. The proposed scheme is also comparable in terms of computational overheads with relevant schemes.

Drive Control System for Pipeline Crawl Robot Based on CAN Bus

NASA Astrophysics Data System (ADS)

Chen, H. J.; Gao, B. T.; Zhang, X. H.; Deng2, Z. Q.

2006-10-01

Drive control system plays important roles in pipeline robot. In order to inspect the flaw and corrosion of seabed crude oil pipeline, an original mobile pipeline robot with crawler drive unit, power and monitor unit, central control unit, and ultrasonic wave inspection device is developed. The CAN bus connects these different function units and presents a reliable information channel. Considering the limited space, a compact hardware system is designed based on an ARM processor with two CAN controllers. With made-to-order CAN protocol for the crawl robot, an intelligent drive control system is developed. The implementation of the crawl robot demonstrates that the presented drive control scheme can meet the motion control requirements of the underwater pipeline crawl robot.

A secure user anonymity-preserving three-factor remote user authentication scheme for the telecare medicine information systems.

PubMed

Das, Ashok Kumar

2015-03-01

Recent advanced technology enables the telecare medicine information system (TMIS) for the patients to gain the health monitoring facility at home and also to access medical services over the Internet of mobile networks. Several remote user authentication schemes have been proposed in the literature for TMIS. However, most of them are either insecure against various known attacks or they are inefficient. Recently, Tan proposed an efficient user anonymity preserving three-factor authentication scheme for TMIS. In this paper, we show that though Tan's scheme is efficient, it has several security drawbacks such as (1) it fails to provide proper authentication during the login phase, (2) it fails to provide correct updation of password and biometric of a user during the password and biometric update phase, and (3) it fails to protect against replay attack. In addition, Tan's scheme lacks the formal security analysis and verification. Later, Arshad and Nikooghadam also pointed out some security flaws in Tan's scheme and then presented an improvement on Tan's s scheme. However, we show that Arshad and Nikooghadam's scheme is still insecure against the privileged-insider attack through the stolen smart-card attack, and it also lacks the formal security analysis and verification. In order to withstand those security loopholes found in both Tan's scheme, and Arshad and Nikooghadam's scheme, we aim to propose an effective and more secure three-factor remote user authentication scheme for TMIS. Our scheme provides the user anonymity property. Through the rigorous informal and formal security analysis using random oracle models and the widely-accepted AVISPA (Automated Validation of Internet Security Protocols and Applications) tool, we show that our scheme is secure against various known attacks, including the replay and man-in-the-middle attacks. Furthermore, our scheme is also efficient as compared to other related schemes.

Ultimate limits for quantum magnetometry via time-continuous measurements

NASA Astrophysics Data System (ADS)

Albarelli, Francesco; Rossi, Matteo A. C.; Paris, Matteo G. A.; Genoni, Marco G.

2017-12-01

We address the estimation of the magnetic field B acting on an ensemble of atoms with total spin J subjected to collective transverse noise. By preparing an initial spin coherent state, for any measurement performed after the evolution, the mean-square error of the estimate is known to scale as 1/J, i.e. no quantum enhancement is obtained. Here, we consider the possibility of continuously monitoring the atomic environment, and conclusively show that strategies based on time-continuous non-demolition measurements followed by a final strong measurement may achieve Heisenberg-limited scaling 1/{J}2 and also a monitoring-enhanced scaling in terms of the interrogation time. We also find that time-continuous schemes are robust against detection losses, as we prove that the quantum enhancement can be recovered also for finite measurement efficiency. Finally, we analytically prove the optimality of our strategy.

Virtual instrument: remote control and monitoring of an artificial heart driver

NASA Astrophysics Data System (ADS)

Nguyen, An H.; Farrar, David

1993-07-01

A development of a virtual instrument based on the top-down model approach for an artificial heart driver is presented. Driver parameters and status were being dynamically updated on the virtual system at the remote station. The virtual system allowed the remote operator to interact with the physical heart driver as if he/she were at the local station. Besides use as an effective training tool, the system permits an expert operator to monitor and also control the Thoratec heart driver from a distant location. We believe that the virtual instrument for biomedical devices in general and for the Thoratec heart driver in particular, not only improves system reliability but also opens up a real possibility in reducing medical cost. Utilizing the top-down scheme developed recently for telerobotics, realtime operation in both instrument display and remote communication were possible via a low bandwidth telephone medium.

Multiple bio-monitoring system using visible light for electromagnetic-wave free indoor healthcare

NASA Astrophysics Data System (ADS)

An, Jinyoung; Pham, Ngoc Quan; Chung, Wan-Young

2017-12-01

In this paper, a multiple biomedical data transmission system with visible light communication (VLC) is proposed for an electromagnetic-wave-free indoor healthcare. VLC technology has emerged as an alternative solution to radio-frequency (RF) wireless systems, due to its various merits, e.g., ubiquity, power efficiency, no RF radiation, and security. With VLC, critical bio-medical signals, including electrocardiography (ECG), can be transmitted in places where RF radiation is restricted. This potential advantage of VLC could save more lives in emergency situations. A time hopping (TH) scheme is employed to transfer multiple medical-data streams in real time with a simple system design. Multiple data streams are transmitted using identical color LEDs and go into an optical detector. The received multiple data streams are demodulated and rearranged using a TH-based demodulator. The medical data is then monitored and managed to provide the necessary medical care for each patient.

Optical imaging of localized chemical events using programmable diamond quantum nanosensors

NASA Astrophysics Data System (ADS)

Rendler, Torsten; Neburkova, Jitka; Zemek, Ondrej; Kotek, Jan; Zappe, Andrea; Chu, Zhiqin; Cigler, Petr; Wrachtrup, Jörg

2017-03-01

Development of multifunctional nanoscale sensors working under physiological conditions enables monitoring of intracellular processes that are important for various biological and medical applications. By attaching paramagnetic gadolinium complexes to nanodiamonds (NDs) with nitrogen-vacancy (NV) centres through surface engineering, we developed a hybrid nanoscale sensor that can be adjusted to directly monitor physiological species through a proposed sensing scheme based on NV spin relaxometry. We adopt a single-step method to measure spin relaxation rates enabling time-dependent measurements on changes in pH or redox potential at a submicrometre-length scale in a microfluidic channel that mimics cellular environments. Our experimental data are reproduced by numerical simulations of the NV spin interaction with gadolinium complexes covering the NDs. Considering the versatile engineering options provided by polymer chemistry, the underlying mechanism can be expanded to detect a variety of physiologically relevant species and variables.

Microchannel conductivity measurements in microchip for on line monitoring of dephosphorylation rates of organic phosphates using paramagnetic-beads linked alkaline phosphatase.

PubMed

Kechadi, Mohammed; Sotta, Bruno; Gamby, Jean

2015-01-01

This paper presents the use of polymer coated microelectrodes for the realtime conductivity monitoring in a microchannel photoablated through the polymer without contact. Based on this strategy, a small conductometry sensor has been developed to record in time conductivity variation when an enzymatic reaction occurs through the channel. The rate constant determination, k2, for the dephosphorylation of organic phosphate-alkaline phosphatase-superparamagnetic beads complex using chemically different substrates such as adenosine monoesterphosphate, adenosine diphosphate and adenosine triphosphate was taken as an example to demonstrate selectivity and sensivity of the detection scheme. The k2 value measured for each adenosine phosphate decreases from 39 to 30 s(-1) in proportion with the number (3, 2 and 1) of attached phosphate moiety, thus emphasizing the steric hindrance effect on kinetics. Copyright © 2014 Elsevier B.V. All rights reserved.