IEEE International Symposium Information Theory, held at Santa Monica California, February 9-12, 1981.

DTIC Science & Technology

1981-01-01

Channel and study permutation codes as a special case. ,uch a code is generated by an initial vector x, a group G of orthogonal n by n matrices, and a...random-access components, is introduced and studied . Under this scheme, the network stations are divided into groups , each of which is assigned a...IEEE INFORMATION THEORY GROUP CO-SPONSORED BY: UNION RADIO SCIENTIFIQUE INTERNATIONALE IEEE Catalog Number 81 CH 1609-7 IT 𔃻. 81 ~20 04Q SECURITY

Introduction to the IEEE International Symposium on Applications of Ferroelectrics and International Symposium on Piezoresponse Force Microscopy and Nanoscale Phenomena in Polar Materials.

PubMed

Ye, Zuo-Guang; Tan, Xiaoli; Bokov, Alexei A

2012-09-01

The 20th IEEE International Symposium on Applications of Ferroelectrics (ISAF) was held on July 24-27, 2011, in Vancouver, British Columbia, Canada, jointly with the International Symposium on Piezoresponse Force Microscopy and Nanoscale Phenomena in Polar Materials (PFM). Over a period of four days, approximately 400 scientists, engineers, and students from around the world presented their work and discussed the latest developments in the field of ferroelectrics, related materials, and their applications. It is particularly encouraging to see that a large number of students (115) were attracted to the joint conference and presented high-quality research works. This trend is not only important to this conference series, but more importantly, it is vital to the future of the ferroelectrics field.

Introduction to the special issue on the 2011 Joint IEEE International Frequency Control Symposium and European Frequency and Time Forum.

PubMed

Burt, Eric; Gill, Patrick

2012-03-01

The 8 invited and 17 contributed papers in this special issue focus on the following topical areas covered at the 2011 Joint IEEE International Frequency Control Symposium and European Frequency and Time Forum, held in San Francisco, California: 1) Materials and Resonators; 2) Oscillators, Synthesizers, and Noise; 3) Microwave Frequency Standards; 4) Sensors and Transducers; 5) Timekeeping and Time and Frequency Transfer; and 6) Optical Frequency Standards.

IEEE Standards activities: A year in review. Annual activities report 1996

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

NONE

1997-09-01

For IEEE Standards and the constituency it serves, 1996 was a milestone year. It was a period that signaled the beginning of the Standards Program of the future. This program responds to worldwide standards issues and to the technical, market and competitive strategies of industrial sectors. It represents technological innovation, global participation in electrotechnology standards development and dedication to the on-going advancement and promotion of new concepts and technology. Instrumental in ensuring IEEE`s growth opportunities and leadership position in electrotechnology standards development and dissemination is IEEE membership. The value of members and their involvement in IEEE Standards is vital tomore » IEEE`s ability to continuously be the best professional association in the world. To fulfill this vision, IEEE set forth five goals -- increased globalization, career enhancement, electronic dissemination of existing products and services, organizational improvements and public responsibility. Key in the process for the achievement of these goals is to make certain that IEEE members are well informed about opportunities and benefits the present system of standardization offers, and what the future system will offer. With the member in mind, the Standards Board reviewed its strategic direction and operational structures, and its ability to deliver products and services that are needed now and, more importantly, that will be needed in the future. This Annual Activities Report provides a comprehensive picture of 1996 accomplishments and performance. It gives readers a broad picture of the Standards Board`s activities, the evolving role of IEEE Standards and the technological opportunities that the Board encourages.« less

Implicit Block ACK Scheme for IEEE 802.11 WLANs

PubMed Central

Sthapit, Pranesh; Pyun, Jae-Young

2016-01-01

The throughput of IEEE 802.11 standard is significantly bounded by the associated Medium Access Control (MAC) overhead. Because of the overhead, an upper limit exists for throughput, which is bounded, including situations where data rates are extremely high. Therefore, an overhead reduction is necessary to achieve higher throughput. The IEEE 802.11e amendment introduced the block ACK mechanism, to reduce the number of control messages in MAC. Although the block ACK scheme greatly reduces overhead, further improvements are possible. In this letter, we propose an implicit block ACK method that further reduces the overhead associated with IEEE 802.11e’s block ACK scheme. The mathematical analysis results are presented for both the original protocol and the proposed scheme. A performance improvement of greater than 10% was achieved with the proposed implementation.

Performance trade-off in an adaptive IEEE 802.11ad waveform design for a joint automotive radar and communication system.

DOT National Transportation Integrated Search

2017-05-01

The IEEE 802.11ad waveform can be used for automotive radar by exploiting the Golay complementary sequences in the preamble of a frame. The performance of radar, however, is limited by the preamble structure. In this paper, we propose an adaptive pre...

Segmentized Clear Channel Assessment for IEEE 802.15.4 Networks.

PubMed

Son, Kyou Jung; Hong, Sung Hyeuck; Moon, Seong-Pil; Chang, Tae Gyu; Cho, Hanjin

2016-06-03

This paper proposed segmentized clear channel assessment (CCA) which increases the performance of IEEE 802.15.4 networks by improving carrier sense multiple access with collision avoidance (CSMA/CA). Improving CSMA/CA is important because the low-power consumption feature and throughput performance of IEEE 802.15.4 are greatly affected by CSMA/CA behavior. To improve the performance of CSMA/CA, this paper focused on increasing the chance to transmit a packet by assessing precise channel status. The previous method used in CCA, which is employed by CSMA/CA, assesses the channel by measuring the energy level of the channel. However, this method shows limited channel assessing behavior, which comes from simple threshold dependent channel busy evaluation. The proposed method solves this limited channel decision problem by dividing CCA into two groups. Two groups of CCA compare their energy levels to get precise channel status. To evaluate the performance of the segmentized CCA method, a Markov chain model has been developed. The validation of analytic results is confirmed by comparing them with simulation results. Additionally, simulation results show the proposed method is improving a maximum 8.76% of throughput and decreasing a maximum 3.9% of the average number of CCAs per packet transmission than the IEEE 802.15.4 CCA method.

Segmentized Clear Channel Assessment for IEEE 802.15.4 Networks

PubMed Central

Son, Kyou Jung; Hong, Sung Hyeuck; Moon, Seong-Pil; Chang, Tae Gyu; Cho, Hanjin

2016-01-01

This paper proposed segmentized clear channel assessment (CCA) which increases the performance of IEEE 802.15.4 networks by improving carrier sense multiple access with collision avoidance (CSMA/CA). Improving CSMA/CA is important because the low-power consumption feature and throughput performance of IEEE 802.15.4 are greatly affected by CSMA/CA behavior. To improve the performance of CSMA/CA, this paper focused on increasing the chance to transmit a packet by assessing precise channel status. The previous method used in CCA, which is employed by CSMA/CA, assesses the channel by measuring the energy level of the channel. However, this method shows limited channel assessing behavior, which comes from simple threshold dependent channel busy evaluation. The proposed method solves this limited channel decision problem by dividing CCA into two groups. Two groups of CCA compare their energy levels to get precise channel status. To evaluate the performance of the segmentized CCA method, a Markov chain model has been developed. The validation of analytic results is confirmed by comparing them with simulation results. Additionally, simulation results show the proposed method is improving a maximum 8.76% of throughput and decreasing a maximum 3.9% of the average number of CCAs per packet transmission than the IEEE 802.15.4 CCA method. PMID:27271626

Defining the IEEE-854 floating-point standard in PVS

NASA Technical Reports Server (NTRS)

Miner, Paul S.

1995-01-01

A significant portion of the ANSI/IEEE-854 Standard for Radix-Independent Floating-Point Arithmetic is defined in PVS (Prototype Verification System). Since IEEE-854 is a generalization of the ANSI/IEEE-754 Standard for Binary Floating-Point Arithmetic, the definition of IEEE-854 in PVS also formally defines much of IEEE-754. This collection of PVS theories provides a basis for machine checked verification of floating-point systems. This formal definition illustrates that formal specification techniques are sufficiently advanced that is is reasonable to consider their use in the development of future standards.

An IEEE 1451.1 Architecture for ISHM Applications

NASA Technical Reports Server (NTRS)

Morris, Jon A.; Turowski, Mark; Schmalzel, John L.; Figueroa, Jorge F.

2007-01-01

converted engineering units) and health statistics produced by each intelligent element. The handling of configuration, calibration and health information is automated by using the TEDS in combination with other electronic data sheets extensions to convey health parameters. By integrating the IEEE 1451.1 Standard for a Smart Transducer Interface with ISHM technologies, each element within a complex system becomes a highly flexible computation engine capable of self-validation and performing other measures of the quality of information it is producing.

Evaluation of H.264/AVC over IEEE 802.11p vehicular networks

NASA Astrophysics Data System (ADS)

Rozas-Ramallal, Ismael; Fernández-Caramés, Tiago M.; Dapena, Adriana; García-Naya, José Antonio

2013-12-01

The capacity of vehicular networks to offer non-safety services, like infotainment applications or the exchange of multimedia information between vehicles, have attracted a great deal of attention to the field of Intelligent Transport Systems (ITS). In particular, in this article we focus our attention on IEEE 802.11p which defines enhancements to IEEE 802.11 required to support ITS applications. We present an FPGA-based testbed developed to evaluate H.264/AVC (Advanced Video Coding) video transmission over vehicular networks. The testbed covers some of the most common situations in vehicle-to-vehicle and roadside-to-vehicle communications and it is highly flexible, allowing the performance evaluation of different vehicular standard configurations. We also show several experimental results to illustrate the quality obtained when H.264/AVC encoded video is transmitted over IEEE 802.11p networks. The quality is measured considering two important parameters: the percentage of recovered group of pictures and the frame quality. In order to improve performance, we propose to substitute the convolutional channel encoder used in IEEE 802.11p for a low-density parity-check code encoder. In addition, we suggest a simple strategy to decide the optimum number of iterations needed to decode each packet received.

Study of Allocation Guaranteed Time Slot Wireless Body Area Networks Based on IEEE 802.15.4

NASA Astrophysics Data System (ADS)

Yundra, E.; Harsono, G. D.

2018-04-01

This paper aims to determine the size of the Guaranteed Time Slot (GTS) on the super frame structure required for each sensor as well as to know the performance of the GTS resized system compared to the GTS standard on IEEE 802.15.4. This article proposes a scheme to improve IEEE 802.15.4 medium access control, called allocation Guaranteed Time Slot (ALGATIS). ALGATIS is expected to effectively allocate guaranteed time slot to the requested sensors, it adjusts the length of the slot in super frame duration based on the length of the packet data. This article presents a simulation experiment of IEEE 802.15.4, especially for star network, to predict the throughput of networks and average energy consumption. The simulation experiments show that the performance of ALGATIS is better than that of IEEE 802.15.4 standard in term of the throughput of networks and average energy consumption

Throughput and delay analysis of IEEE 802.15.6-based CSMA/CA protocol.

PubMed

Ullah, Sana; Chen, Min; Kwak, Kyung Sup

2012-12-01

The IEEE 802.15.6 is a new communication standard on Wireless Body Area Network (WBAN) that focuses on a variety of medical, Consumer Electronics (CE) and entertainment applications. In this paper, the throughput and delay performance of the IEEE 802.15.6 is presented. Numerical formulas are derived to determine the maximum throughput and minimum delay limits of the IEEE 802.15.6 for an ideal channel with no transmission errors. These limits are derived for different frequency bands and data rates. Our analysis is validated by extensive simulations using a custom C+ + simulator. Based on analytical and simulation results, useful conclusions are derived for network provisioning and packet size optimization for different applications.

Study on additional carrier sensing for IEEE 802.15.4 wireless sensor networks.

PubMed

Lee, Bih-Hwang; Lai, Ruei-Lung; Wu, Huai-Kuei; Wong, Chi-Ming

2010-01-01

Wireless sensor networks based on the IEEE 802.15.4 standard are able to achieve low-power transmissions in the guise of low-rate and short-distance wireless personal area networks (WPANs). The slotted carrier sense multiple access with collision avoidance (CSMA/CA) is used for contention mechanism. Sensor nodes perform a backoff process as soon as the clear channel assessment (CCA) detects a busy channel. In doing so they may neglect the implicit information of the failed CCA detection and further cause the redundant sensing. The blind backoff process in the slotted CSMA/CA will cause lower channel utilization. This paper proposes an additional carrier sensing (ACS) algorithm based on IEEE 802.15.4 to enhance the carrier sensing mechanism for the original slotted CSMA/CA. An analytical Markov chain model is developed to evaluate the performance of the ACS algorithm. Both analytical and simulation results show that the proposed algorithm performs better than IEEE 802.15.4, which in turn significantly improves throughput, average medium access control (MAC) delay and power consumption of CCA detection.

IEEE802.15.6 NB portable BAN clinic and M2M international standardization.

PubMed

Kuroda, Masahiro; Nohara, Yasunobu

2013-01-01

The increase of non communicable diseases (NCDs) will change the direction of health services to emphasize the role of preventive medicine in healthcare services. The first short-range medical body are network (BAN) standard IEEE802.15.6 is expected to be used for secure and user-friendly sensor devices for portable medical equipment. A BAN is an enabler for uploading medical data to a backend system for remote diagnoses and treatment. Machine-to-Machine (M2M) infrastructure is also a key technology for providing flexible and affordable services extending electronic health record (EHR) systems. This paper proposes a BAN-based portable clinic that collects health-check data from user-friendly medical devices and sensors and sends the data to a local backend server, and it evaluates the clinic in fields of actual usage. We discuss issues experienced from actual deployment of the system and focus on integrating it into upcoming healthcare M2M infrastructure to achieve affordable and dependable clinic services. We explain the components and workflow of the clinic and the system model. The system is set up at a temporary health center and has a network link to a remote medical help center. The paper concludes with our plan to introduce our system to contribute to internationally standardized preventive medicine.

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.

An Authentication and Key Management Mechanism for Resource Constrained Devices in IEEE 802.11-based IoT Access Networks.

PubMed

Kim, Ki-Wook; Han, Youn-Hee; Min, Sung-Gi

2017-09-21

Many Internet of Things (IoT) services utilize an IoT access network to connect small devices with remote servers. They can share an access network with standard communication technology, such as IEEE 802.11ah. However, an authentication and key management (AKM) mechanism for resource constrained IoT devices using IEEE 802.11ah has not been proposed as yet. We therefore propose a new AKM mechanism for an IoT access network, which is based on IEEE 802.11 key management with the IEEE 802.1X authentication mechanism. The proposed AKM mechanism does not require any pre-configured security information between the access network domain and the IoT service domain. It considers the resource constraints of IoT devices, allowing IoT devices to delegate the burden of AKM processes to a powerful agent. The agent has sufficient power to support various authentication methods for the access point, and it performs cryptographic functions for the IoT devices. Performance analysis shows that the proposed mechanism greatly reduces computation costs, network costs, and memory usage of the resource-constrained IoT device as compared to the existing IEEE 802.11 Key Management with the IEEE 802.1X authentication mechanism.

An Authentication and Key Management Mechanism for Resource Constrained Devices in IEEE 802.11-based IoT Access Networks

PubMed Central

Han, Youn-Hee; Min, Sung-Gi

2017-01-01

Many Internet of Things (IoT) services utilize an IoT access network to connect small devices with remote servers. They can share an access network with standard communication technology, such as IEEE 802.11ah. However, an authentication and key management (AKM) mechanism for resource constrained IoT devices using IEEE 802.11ah has not been proposed as yet. We therefore propose a new AKM mechanism for an IoT access network, which is based on IEEE 802.11 key management with the IEEE 802.1X authentication mechanism. The proposed AKM mechanism does not require any pre-configured security information between the access network domain and the IoT service domain. It considers the resource constraints of IoT devices, allowing IoT devices to delegate the burden of AKM processes to a powerful agent. The agent has sufficient power to support various authentication methods for the access point, and it performs cryptographic functions for the IoT devices. Performance analysis shows that the proposed mechanism greatly reduces computation costs, network costs, and memory usage of the resource-constrained IoT device as compared to the existing IEEE 802.11 Key Management with the IEEE 802.1X authentication mechanism. PMID:28934152

Performance Evaluation of IEEE 802.11ah Networks With High-Throughput Bidirectional Traffic.

PubMed

Šljivo, Amina; Kerkhove, Dwight; Tian, Le; Famaey, Jeroen; Munteanu, Adrian; Moerman, Ingrid; Hoebeke, Jeroen; De Poorter, Eli

2018-01-23

So far, existing sub-GHz wireless communication technologies focused on low-bandwidth, long-range communication with large numbers of constrained devices. Although these characteristics are fine for many Internet of Things (IoT) applications, more demanding application requirements could not be met and legacy Internet technologies such as Transmission Control Protocol/Internet Protocol (TCP/IP) could not be used. This has changed with the advent of the new IEEE 802.11ah Wi-Fi standard, which is much more suitable for reliable bidirectional communication and high-throughput applications over a wide area (up to 1 km). The standard offers great possibilities for network performance optimization through a number of physical- and link-layer configurable features. However, given that the optimal configuration parameters depend on traffic patterns, the standard does not dictate how to determine them. Such a large number of configuration options can lead to sub-optimal or even incorrect configurations. Therefore, we investigated how two key mechanisms, Restricted Access Window (RAW) grouping and Traffic Indication Map (TIM) segmentation, influence scalability, throughput, latency and energy efficiency in the presence of bidirectional TCP/IP traffic. We considered both high-throughput video streaming traffic and large-scale reliable sensing traffic and investigated TCP behavior in both scenarios when the link layer introduces long delays. This article presents the relations between attainable throughput per station and attainable number of stations, as well as the influence of RAW, TIM and TCP parameters on both. We found that up to 20 continuously streaming IP-cameras can be reliably connected via IEEE 802.11ah with a maximum average data rate of 160 kbps, whereas 10 IP-cameras can achieve average data rates of up to 255 kbps over 200 m. Up to 6960 stations transmitting every 60 s can be connected over 1 km with no lost packets. The presented results enable the fine tuning

Performance Analyses and Improvements for the IEEE 802.15.4 CSMA/CA Scheme with Heterogeneous Buffered Conditions

PubMed Central

Zhu, Jianping; Tao, Zhengsu; Lv, Chunfeng

2012-01-01

Studies of the IEEE 802.15.4 Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) scheme have been received considerable attention recently, with most of these studies focusing on homogeneous or saturated traffic. Two novel transmission schemes—OSTS/BSTS (One Service a Time Scheme/Bulk Service a Time Scheme)—are proposed in this paper to improve the behaviors of time-critical buffered networks with heterogeneous unsaturated traffic. First, we propose a model which contains two modified semi-Markov chains and a macro-Markov chain combined with the theory of M/G/1/K queues to evaluate the characteristics of these two improved CSMA/CA schemes, in which traffic arrivals and accessing packets are bestowed with non-preemptive priority over each other, instead of prioritization. Then, throughput, packet delay and energy consumption of unsaturated, unacknowledged IEEE 802.15.4 beacon-enabled networks are predicted based on the overall point of view which takes the dependent interactions of different types of nodes into account. Moreover, performance comparisons of these two schemes with other non-priority schemes are also proposed. Analysis and simulation results show that delay and fairness of our schemes are superior to those of other schemes, while throughput and energy efficiency are superior to others in more heterogeneous situations. Comprehensive simulations demonstrate that the analysis results of these models match well with the simulation results. PMID:22666076

Performance analyses and improvements for the IEEE 802.15.4 CSMA/CA scheme with heterogeneous buffered conditions.

PubMed

Zhu, Jianping; Tao, Zhengsu; Lv, Chunfeng

2012-01-01

Studies of the IEEE 802.15.4 Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) scheme have been received considerable attention recently, with most of these studies focusing on homogeneous or saturated traffic. Two novel transmission schemes-OSTS/BSTS (One Service a Time Scheme/Bulk Service a Time Scheme)-are proposed in this paper to improve the behaviors of time-critical buffered networks with heterogeneous unsaturated traffic. First, we propose a model which contains two modified semi-Markov chains and a macro-Markov chain combined with the theory of M/G/1/K queues to evaluate the characteristics of these two improved CSMA/CA schemes, in which traffic arrivals and accessing packets are bestowed with non-preemptive priority over each other, instead of prioritization. Then, throughput, packet delay and energy consumption of unsaturated, unacknowledged IEEE 802.15.4 beacon-enabled networks are predicted based on the overall point of view which takes the dependent interactions of different types of nodes into account. Moreover, performance comparisons of these two schemes with other non-priority schemes are also proposed. Analysis and simulation results show that delay and fairness of our schemes are superior to those of other schemes, while throughput and energy efficiency are superior to others in more heterogeneous situations. Comprehensive simulations demonstrate that the analysis results of these models match well with the simulation results.

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 802.11ah: A Technology to Face the IoT Challenge.

PubMed

Baños-Gonzalez, Victor; Afaqui, M Shahwaiz; Lopez-Aguilera, Elena; Garcia-Villegas, Eduard

2016-11-22

Since the conception of the Internet of things (IoT), a large number of promising applications and technologies have been developed, which will change different aspects in our daily life. This paper explores the key characteristics of the forthcoming IEEE 802.11ah specification. This future IEEE 802.11 standard aims to amend the IEEE 802.11 legacy specification to support IoT requirements. We present a thorough evaluation of the foregoing amendment in comparison to the most notable IEEE 802.11 standards. In addition, we expose the capabilities of future IEEE 802.11ah in supporting different IoT applications. Also, we provide a brief overview of the technology contenders that are competing to cover the IoT communications framework. Numerical results are presented showing how the future IEEE 802.11ah specification offers the features required by IoT communications, thus putting forward IEEE 802.11ah as a technology to cater the needs of the Internet of Things paradigm.

IEEE 802.11ah: A Technology to Face the IoT Challenge

PubMed Central

Baños-Gonzalez, Victor; Afaqui, M. Shahwaiz; Lopez-Aguilera, Elena; Garcia-Villegas, Eduard

2016-01-01

Since the conception of the Internet of things (IoT), a large number of promising applications and technologies have been developed, which will change different aspects in our daily life. This paper explores the key characteristics of the forthcoming IEEE 802.11ah specification. This future IEEE 802.11 standard aims to amend the IEEE 802.11 legacy specification to support IoT requirements. We present a thorough evaluation of the foregoing amendment in comparison to the most notable IEEE 802.11 standards. In addition, we expose the capabilities of future IEEE 802.11ah in supporting different IoT applications. Also, we provide a brief overview of the technology contenders that are competing to cover the IoT communications framework. Numerical results are presented showing how the future IEEE 802.11ah specification offers the features required by IoT communications, thus putting forward IEEE 802.11ah as a technology to cater the needs of the Internet of Things paradigm. PMID:27879688

Specialty Engineering Supplement to IEEE-15288.1

DTIC Science & Technology

2015-05-15

receiver required to work in a dense EMI environment. (15) Any RF receiver with a burnout level of less than 30 dBm (1 mW). b. A summary of all...Context 2.1 ISO-IEC-IEEE-15288: 2015, Systems and Software Engineering — System life cycle processes ISO-IEC-IEEE 15288 is the DOD-adopted standard for...to ISO-15288 for application of systems engineering on defense programs that was developed by a joint services working group under the auspices of the

Performance Evaluation of IEEE 802.11ah Networks With High-Throughput Bidirectional Traffic

PubMed Central

Kerkhove, Dwight; Tian, Le; Munteanu, Adrian; De Poorter, Eli

2018-01-01

So far, existing sub-GHz wireless communication technologies focused on low-bandwidth, long-range communication with large numbers of constrained devices. Although these characteristics are fine for many Internet of Things (IoT) applications, more demanding application requirements could not be met and legacy Internet technologies such as Transmission Control Protocol/Internet Protocol (TCP/IP) could not be used. This has changed with the advent of the new IEEE 802.11ah Wi-Fi standard, which is much more suitable for reliable bidirectional communication and high-throughput applications over a wide area (up to 1 km). The standard offers great possibilities for network performance optimization through a number of physical- and link-layer configurable features. However, given that the optimal configuration parameters depend on traffic patterns, the standard does not dictate how to determine them. Such a large number of configuration options can lead to sub-optimal or even incorrect configurations. Therefore, we investigated how two key mechanisms, Restricted Access Window (RAW) grouping and Traffic Indication Map (TIM) segmentation, influence scalability, throughput, latency and energy efficiency in the presence of bidirectional TCP/IP traffic. We considered both high-throughput video streaming traffic and large-scale reliable sensing traffic and investigated TCP behavior in both scenarios when the link layer introduces long delays. This article presents the relations between attainable throughput per station and attainable number of stations, as well as the influence of RAW, TIM and TCP parameters on both. We found that up to 20 continuously streaming IP-cameras can be reliably connected via IEEE 802.11ah with a maximum average data rate of 160 kbps, whereas 10 IP-cameras can achieve average data rates of up to 255 kbps over 200 m. Up to 6960 stations transmitting every 60 s can be connected over 1 km with no lost packets. The presented results enable the fine tuning

A Fast MAC-Layer Handover for an IEEE 802.16e-Based WMAN

NASA Astrophysics Data System (ADS)

Ray, Sayan K.; Pawlikowski, Krzysztof; Sirisena, Harsha

We propose a modification of the IEEE 802.16e hard handover (HHO) procedure, which significantly reduces the handover latency constraint of the original HHO procedure in IEEE 802.16e networks. It allows a better handling of the delay-sensitive traffic by avoiding unnecessary time-consuming scanning and synchronization activity as well as simplifies the network re-entry procedure. With the help of the backhaul network, it reduces the number of control messages in the original handover policy, making the handover latency acceptable also for real-time streaming traffic. Preliminary performance evaluation studies show that the modified handover procedure is able to reduce the total handover latency by about 50%.

IEEE 342 Node Low Voltage Networked Test System

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

Schneider, Kevin P.; Phanivong, Phillippe K.; Lacroix, Jean-Sebastian

The IEEE Distribution Test Feeders provide a benchmark for new algorithms to the distribution analyses community. The low voltage network test feeder represents a moderate size urban system that is unbalanced and highly networked. This is the first distribution test feeder developed by the IEEE that contains unbalanced networked components. The 342 node Low Voltage Networked Test System includes many elements that may be found in a networked system: multiple 13.2kV primary feeders, network protectors, a 120/208V grid network, and multiple 277/480V spot networks. This paper presents a brief review of the history of low voltage networks and how theymore » evolved into the modern systems. This paper will then present a description of the 342 Node IEEE Low Voltage Network Test System and power flow results.« less

On IEEE 802.15.6 IR-UWB receivers - simulations for DBPSK modulation.

PubMed

Niemelä, Ville; Hämäläinen, Matti; Iinatti, Jari

2013-01-01

In 2002, Federal Communications Commission (FCC) was the first in defining regulations for ultra wideband (UWB) communications followed by Europe and Japan some years later. Focusing on impulse radio (IR) UWB, in 2007 was the time for the first published standard targeting in personal area networks, released by the IEEE. The second IEEE released standard including UWB definitions is targeted for wireless body area networks (WBAN) and was published in 2012. As the wireless communications has been and will be passing through almost any levels in society, the natural step with WBAN is using it in different medical, healthcare and wellbeing applications. The arguments for these are related to the modern lifestyle, in which people have increasingly more free time and are more interested in taking care of their health and wellbeing. Another challenge is the population composition, i.e., aging in developed countries which call for new solutions and procedures, particularly from cost wise. In this paper, we are evaluating UWB receivers based on the IEEE 802.15.6 physical layer definitions and capable of detecting differentially encoded modulation. The evaluation is performed using two different WBAN channel models.

Standard-compliant real-time transmission of ECGs: harmonization of ISO/IEEE 11073-PHD and SCP-ECG.

PubMed

Trigo, Jesús D; Chiarugi, Franco; Alesanco, Alvaro; Martínez-Espronceda, Miguel; Chronaki, Catherine E; Escayola, Javier; Martínez, Ignacio; García, José

2009-01-01

Ambient assisted living and integrated care in an aging society is based on the vision of the lifelong Electronic Health Record calling for HealthCare Information Systems and medical device interoperability. For medical devices this aim can be achieved by the consistent implementation of harmonized international interoperability standards. The ISO/IEEE 11073 (x73) family of standards is a reference standard for medical device interoperability. In its Personal Health Device (PHD) version several devices have been included, but an ECG device specialization is not yet available. On the other hand, the SCP-ECG standard for short-term diagnostic ECGs (EN1064) has been recently approved as an international standard ISO/IEEE 11073-91064:2009. In this paper, the relationships between a proposed x73-PHD model for an ECG device and the fields of the SCP-ECG standard are investigated. A proof-of-concept implementation of the proposed x73-PHD ECG model is also presented, identifying open issues to be addressed by standards development for the wider interoperability adoption of x73-PHD standards.

Performance analysis for IEEE 802.11 distributed coordination function in radio-over-fiber-based distributed antenna systems.

PubMed

Fan, Yuting; Li, Jianqiang; Xu, Kun; Chen, Hao; Lu, Xun; Dai, Yitang; Yin, Feifei; Ji, Yuefeng; Lin, Jintong

2013-09-09

In this paper, we analyze the performance of IEEE 802.11 distributed coordination function in simulcast radio-over-fiber-based distributed antenna systems (RoF-DASs) where multiple remote antenna units (RAUs) are connected to one wireless local-area network (WLAN) access point (AP) with different-length fiber links. We also present an analytical model to evaluate the throughput of the systems in the presence of both the inter-RAU hidden-node problem and fiber-length difference effect. In the model, the unequal delay induced by different fiber length is involved both in the backoff stage and in the calculation of Ts and Tc, which are the period of time when the channel is sensed busy due to a successful transmission or a collision. The throughput performances of WLAN-RoF-DAS in both basic access and request to send/clear to send (RTS/CTS) exchange modes are evaluated with the help of the derived model.

A network architecture for precision formation flying using the IEEE 802.11 MAC Protocol

NASA Technical Reports Server (NTRS)

Clare, Loren P.; Gao, Jay L.; Jennings, Esther H.; Okino, Clayton

2005-01-01

Precision Formation Flying missions involve the tracking and maintenance of spacecraft in a desired geometric formation. The strong coupling of spacecraft in formation flying control requires inter-spacecraft communication to exchange information. In this paper, we present a network architecture that supports PFF control, from the initial random deployment phase to the final formation. We show that a suitable MAC layer for the application protocol is IEEE's 802.11 MAC protocol. IEEE 802.11 MAC has two modes of operations: DCF and PCF. We show that DCF is suitable for the initial deployment phase while switching to PCF when the spacecraft are in formation improves jitter and throughput. We also consider the effect of routing on protocol performance and suggest when it is profitable to turn off route discovery to achieve better network performance.

IEEE Conference Publications in Libraries.

ERIC Educational Resources Information Center

Johnson, Karl E.

1984-01-01

Conclusions of surveys (63 libraries, OCLC database, University of Rhode Island users) assessing handling of Institute of Electrical and Electronics Engineers (IEEE) conference publications indicate that most libraries fully catalog these publications using LC cataloging, and library patrons frequently require series access to publications. Eight…

Strategies for Optimal MAC Parameters Tuning in IEEE 802.15.6 Wearable Wireless Sensor Networks.

PubMed

Alam, Muhammad Mahtab; Ben Hamida, Elyes

2015-09-01

Wireless body area networks (WBAN) has penetrated immensely in revolutionizing the classical heath-care system. Recently, number of WBAN applications has emerged which introduce potential limits to existing solutions. In particular, IEEE 802.15.6 standard has provided great flexibility, provisions and capabilities to deal emerging applications. In this paper, we investigate the application-specific throughput analysis by fine-tuning the physical (PHY) and medium access control (MAC) parameters of the IEEE 802.15.6 standard. Based on PHY characterizations in narrow band, at the MAC layer, carrier sense multiple access collision avoidance (CSMA/CA) and scheduled access protocols are extensively analyzed. It is concluded that, IEEE 802.15.6 standard can satisfy most of the WBANs applications throughput requirements by maximum achieving 680 Kbps. However, those emerging applications which require high quality audio or video transmissions, standard is not able to meet their constraints. Moreover, delay, energy efficiency and successful packet reception are considered as key performance metrics for comparing the MAC protocols. CSMA/CA protocol provides the best results to meet the delay constraints of medical and non-medical WBAN applications. Whereas, the scheduled access approach, performs very well both in energy efficiency and packet reception ratio.

Dynamic subframe allocation for mobile broadband m-health using IEEE 802.16j mobile multihop relay networks.

PubMed

Alinejad, Ali; Istepanian, R S H; Philip, N

2012-01-01

The concept of 4G health will be one of the key focus areas of future m-health research and enterprise activities in the coming years. WiMAX technology is one of the constituent 4G wireless technologies that provides broadband wireless access (BWA). Despite the fact that WiMAX is able to provide a high data rate in a relatively large coverage; this technology has specific limitations such as: coverage, signal attenuation problems due to shadowing or path loss, and limited available spectrum. The IEEE 802.16j mobile multihop relay (MMR) technology is a pragmatic solution designed to overcome these limitations. The aim of IEEE 802.16j MMR is to expand the IEEE 802.16e's capabilities with multihop features. In particular, the uplink (UL) and downlink (DL) subframe allocation in WiMAX network is usually fixed. However, dynamic frame allocation is a useful mechanism to optimize uplink and downlink subframe size dynamically based on the traffic conditions through real-time traffic monitoring. This particular mechanism is important for future WiMAX based m-health applications as it allows the tradeoff in both UL and DL channels. In this paper, we address the dynamic frame allocation issue in IEEE 802.16j MMR network for m-health applications. A comparative performance analysis of the proposed approach is validated using the OPNET Modeler(®). The simulation results have shown an improved performance of resource allocation and end-to-end delay performance for typical medical video streaming application.

Real-Time-Simulation of IEEE-5-Bus Network on OPAL-RT-OP4510 Simulator

NASA Astrophysics Data System (ADS)

Atul Bhandakkar, Anjali; Mathew, Lini, Dr.

2018-03-01

The Real-Time Simulator tools have high computing technologies, improved performance. They are widely used for design and improvement of electrical systems. The advancement of the software tools like MATLAB/SIMULINK with its Real-Time Workshop (RTW) and Real-Time Windows Target (RTWT), real-time simulators are used extensively in many engineering fields, such as industry, education, and research institutions. OPAL-RT-OP4510 is a Real-Time Simulator which is used in both industry and academia. In this paper, the real-time simulation of IEEE-5-Bus network is carried out by means of OPAL-RT-OP4510 with CRO and other hardware. The performance of the network is observed with the introduction of fault at various locations. The waveforms of voltage, current, active and reactive power are observed in the MATLAB simulation environment and on the CRO. Also, Load Flow Analysis (LFA) of IEEE-5-Bus network is computed using MATLAB/Simulink power-gui load flow tool.

Validating the Test Procedures Described in UL 1741 SA and IEEE P1547.1: Preprint

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

Mahmud, Rasel; Hoke, Anderson F; Narang, David J

This paper investigates the test procedures specified in UL 1741 SA and the upcoming revision to IEEE P1547.1. A 550 kVA photovoltaic inverter was chosen for the tests. This research reveals some of key the components to consider while doing certification tests for UL 1741 SA and IEEE P1547.1. This paper also identifies some issues requiring consideration for future releases of the standard, i.e. IEEE P1547.1. This paper investigates the test procedures specified in UL 1741 SA and the upcoming revision to IEEE P1547.1. A 550 kVA photovoltaic inverter was chosen for the tests. This research reveals some of keymore » the components to consider while doing certification tests for UL 1741 SA and IEEE P1547.1. This paper also identifies some issues requiring consideration for future releases of the standard, i.e. IEEE P1547.1.« less

IEEE 1451.2 based Smart sensor system using ADuc847

NASA Astrophysics Data System (ADS)

Sreejithlal, A.; Ajith, Jose

IEEE 1451 standard defines a standard interface for connecting transducers to microprocessor based data acquisition systems, instrumentation systems, control and field networks. Smart transducer interface module (STIM) acts as a unit which provides signal conditioning, digitization and data packet generation functions to the transducers connected to it. This paper describes the implementation of a microcontroller based smart transducer interface module based on IEEE 1451.2 standard. The module, implemented using ADuc847 microcontroller has 2 transducer channels and is programmed using Embedded C language. The Sensor system consists of a Network Controlled Application Processor (NCAP) module which controls the Smart transducer interface module (STIM) over an IEEE1451.2-RS232 bus. The NCAP module is implemented as a software module in C# language. The hardware details, control principles involved and the software implementation for the STIM are described in detail.

The IEEE Software Engineering Standards Process

PubMed Central

Buckley, Fletcher J.

1984-01-01

Software Engineering has emerged as a field in recent years, and those involved increasingly recognize the need for standards. As a result, members of the Institute of Electrical and Electronics Engineers (IEEE) formed a subcommittee to develop these standards. This paper discusses the ongoing standards development, and associated efforts.

Performance evaluation of complete data transfer of physical layer according to IEEE 802.15.4 standard

NASA Astrophysics Data System (ADS)

Raju, Kota Solomon; Merugu, Naresh Babu; Neetu, Babu, E. Ram

2016-03-01

ZigBee is well-accepted industrial standard for wireless sensor networks based on IEEE 802.15.4 standard. Wireless Sensor Networks is the major concern of communication these days. These Wireless Sensor Networks investigate the properties of networks of small battery-powered sensors with wireless communication. The communication between any two wireless nodes of wireless sensor networks is carried out through a protocol stack. This protocol stack has been designed by different vendors in various ways. Every custom vendor possesses his own protocol stack and algorithms especially at the MAC layer. But, many applications require modifications in their algorithms at various layers as per their requirements, especially energy efficient protocols at MAC layer that are simulated in Wireless sensor Network Simulators which are not being tested in real time systems because vendors do not allow the programmability of each layer in their protocol stack. This problem can be quoted as Vendor-Interoperability. The solution is to develop the programmable protocol stack where we can design our own application as required. As a part of the task first we tried implementing physical layer and transmission of data using physical layer. This paper describes about the transmission of the total number of bytes of Frame according to the IEEE 802.15.4 standard using Physical Layer.

IEEE Conference on Software Engineering Education and Training (CSEE&T 2012) Proceedings (25th, Nanjing, Jiangsu, China, April 17-19, 2012)

ERIC Educational Resources Information Center

IEEE Conference on Software Engineering Education and Training, Proceedings (MS), 2012

2012-01-01

The Conference on Software Engineering Education and Training (CSEE&T) is the premier international peer-reviewed conference, sponsored by the Institute of Electrical and Electronics Engineers, Inc. (IEEE) Computer Society, which addresses all major areas related to software engineering education, training, and professionalism. This year, as…

A distributed scheme to manage the dynamic coexistence of IEEE 802.15.4-based health-monitoring WBANs.

PubMed

Deylami, Mohammad N; Jovanov, Emil

2014-01-01

The overlap of transmission ranges between wireless networks as a result of mobility is referred to as dynamic coexistence. The interference caused by coexistence may significantly affect the performance of wireless body area networks (WBANs) where reliability is particularly critical for health monitoring applications. In this paper, we analytically study the effects of dynamic coexistence on the operation of IEEE 802.15.4-based health monitoring WBANs. The current IEEE 802.15.4 standard lacks mechanisms for effectively managing the coexistence of mobile WBANs. Considering the specific characteristics and requirements of health monitoring WBANs, we propose the dynamic coexistence management (DCM) mechanism to make IEEE 802.15.4-based WBANs able to detect and mitigate the harmful effects of coexistence. We assess the effectiveness of this scheme using extensive OPNET simulations. Our results indicate that DCM improves the successful transmission rates of dynamically coexisting WBANs by 20%-25% for typical medical monitoring applications.

An NTP Stratum-One Server Farm Fed By IEEE-1588

DTIC Science & Technology

2010-01-01

Serial Time Code Formats,” U.S. Army White Sands Missile Range, N.M. [11] J. Eidson , 2005, “IEEE-1588 Standard for a Precision Clock Synchronization ... synchronized to its Master Clocks via IRIG-B time code on a low- frequency RF distribution system. The availability of Precise Time Protocol (PTP, IEEE...forwarding back to the requestor. The farm NTP servers are synchronized to the USNO Master Clocks using IRIG-B time code. The current standard NTP

IEEE 802.16J-Relay Fortified Aeromacs Networks; Benefits and Challenges

NASA Technical Reports Server (NTRS)

Kamali, Behnam; Apaza, Rafael D.

2014-01-01

Aeronautical Mobile Airport Communications System (AeroMACS) is an IEEE 802.16 standard-based (WiMAX) broadband aviation transmission technology, developed to provide safety critical communications coverage for airport surface in support of fixed and mobile ground to ground applications and services. We have previously demonstrated that IEEE 802.16j-amendment-based WiMAX is most feasible for AeroMACS applications. The principal argument in favor of application of IEEE 802.16j technology is the flexible and cost effective extension of radio coverage that is afforded by relay fortified WiMAX networks, with virtually no increase in the power requirements. In this article, following introductory remarks on airport surface communications, WiMAX and AeroMACS; the IEEE 802.16j-based WiMAX technology and multihop relay systems are briefly described. The two modes of relay operation supported by IEEE 802.16j amendment; i.e., transparent (TRS) and non-transparent (NTRS) modes, are discussed in some detail. Advantages and disadvantages of using TRS and NTRS in AeroMACS networks are summarized in a table. Practical issues vis--vis the inclusion of relays in AeroMACS networks are addressed. It is argued that the selection of relay type may affect a number of network parameters. A discussion on specific benefits and challenges of inclusion of relays in AeroMACS networks is provided. The article concludes that in case it is desired or necessary to exclusively employ one type of relay mode for all applications throughout an AeroMACS network, the proper selection would be the non-transparent mode.

[Mobile Health: IEEE Standard for Wearable Cuffless Blood Pressure Measuring Devices].

PubMed

Zhou, Xia; Wu, Wenli; Bao, Shudi

2015-07-01

IEEE Std 1708-2014 breaks through the traditional standards of cuff based blood pressure measuring devices and establishes a normative definition of wearable cuffless blood pressure measuring devices and the objective performance evaluation of this kind of devices. This study firstly introduces the background of the new standard. Then, the standard details will be described, and the impact of cuffless blood pressure measuring devices with the new standard on manufacturers and end users will be addressed.

A Novel IEEE 802.15.4e DSME MAC for Wireless Sensor Networks.

PubMed

Sahoo, Prasan Kumar; Pattanaik, Sudhir Ranjan; Wu, Shih-Lin

2017-01-16

IEEE 802.15.4e standard proposes Deterministic and Synchronous Multichannel Extension (DSME) mode for wireless sensor networks (WSNs) to support industrial, commercial and health care applications. In this paper, a new channel access scheme and beacon scheduling schemes are designed for the IEEE 802.15.4e enabled WSNs in star topology to reduce the network discovery time and energy consumption. In addition, a new dynamic guaranteed retransmission slot allocation scheme is designed for devices with the failure Guaranteed Time Slot (GTS) transmission to reduce the retransmission delay. To evaluate our schemes, analytical models are designed to analyze the performance of WSNs in terms of reliability, delay, throughput and energy consumption. Our schemes are validated with simulation and analytical results and are observed that simulation results well match with the analytical one. The evaluated results of our designed schemes can improve the reliability, throughput, delay, and energy consumptions significantly.

An Efficient Power Saving Mechanism for Delay-Guaranteed Services in IEEE 802.16e

NASA Astrophysics Data System (ADS)

Park, Yunju; Hwang, Gang Uk

As the IEEE 802.16e Wireless Metropolitan Access Network (WMAN) supports the mobility of a mobile station (MS), increasing MS power efficiency has become an important issue. In this paper, we analyze the sleep-mode operation for an efficient power saving mechanism for delay-guaranteed services in the IEEE 802.16e WMAN and observe the effects of the operating parameters related to this operation. For the analysis we use the M/GI/1/K queueing system with multiple vacations, exhaustive services and setup times. In the analysis, we consider the power consumption during the wake-mode period as well as the sleep-mode period. As a performance measure for the power consumption, we propose the power consumption per unit time per effective arrival which considers the power consumption and the packet blocking probability simultaneously. In addition, since we consider delay-guaranteed services, the average packet response delay is also considered as a performance measure. Based on the performance measures, we obtain the optimal sleep-mode operation which minimizes the power consumption per unit time per effective arrival with a given delay requirement. Numerical studies are also provided to investigate the system performance and to show how to achieve our objective.

Real-Time Support on IEEE 802.11 Wireless Ad-Hoc Networks: Reality vs. Theory

NASA Astrophysics Data System (ADS)

Kang, Mikyung; Kang, Dong-In; Suh, Jinwoo

The usable throughput of an IEEE 802.11 system for an application is much less than the raw bandwidth. Although 802.11b has a theoretical maximum of 11Mbps, more than half of the bandwidth is consumed by overhead leaving at most 5Mbps of usable bandwidth. Considering this characteristic, this paper proposes and analyzes a real-time distributed scheduling scheme based on the existing IEEE 802.11 wireless ad-hoc networks, using USC/ISI's Power Aware Sensing Tracking and Analysis (PASTA) hardware platform. We compared the distributed real-time scheduling scheme with the real-time polling scheme to meet deadline, and compared a measured real bandwidth with a theoretical result. The theoretical and experimental results show that the distributed scheduling scheme can guarantee real-time traffic and enhances the performance up to 74% compared with polling scheme.

A Novel IEEE 802.15.4e DSME MAC for Wireless Sensor Networks

PubMed Central

Sahoo, Prasan Kumar; Pattanaik, Sudhir Ranjan; Wu, Shih-Lin

2017-01-01

IEEE 802.15.4e standard proposes Deterministic and Synchronous Multichannel Extension (DSME) mode for wireless sensor networks (WSNs) to support industrial, commercial and health care applications. In this paper, a new channel access scheme and beacon scheduling schemes are designed for the IEEE 802.15.4e enabled WSNs in star topology to reduce the network discovery time and energy consumption. In addition, a new dynamic guaranteed retransmission slot allocation scheme is designed for devices with the failure Guaranteed Time Slot (GTS) transmission to reduce the retransmission delay. To evaluate our schemes, analytical models are designed to analyze the performance of WSNs in terms of reliability, delay, throughput and energy consumption. Our schemes are validated with simulation and analytical results and are observed that simulation results well match with the analytical one. The evaluated results of our designed schemes can improve the reliability, throughput, delay, and energy consumptions significantly. PMID:28275216

IEEE Std 730 Software Quality Assurance: Supporting CMMI-DEV v1.3, Product and Process Quality Assurance

DTIC Science & Technology

2011-05-27

frameworks 4 CMMI-DEV IEEE / ISO / IEC 15288 / 12207 Quality Assurance ©2011 Walz IEEE Life Cycle Processes & Artifacts • Systems Life Cycle Processes...TAG to ISO TC 176 Quality Management • Quality: ASQ, work experience • Software: three books, consulting, work experience • Systems: Telecom & DoD...and IEEE 730 SQA need to align. The P730 IEEE standards working group has expanded the scope of the SQA process standard to align with IS 12207

Introduction to the special issue on the joint meeting of the 19th IEEE International Symposium on the Applications of Ferroelectrics and the 10th European Conference on the Applications of Polar Dielectrics.

PubMed

Tsurumi, Takaaki

2011-09-01

The joint meeting of the 19th IEEE International Symposium on the Applications of Ferroelectrics and the 10th European Conference on the Applications of Polar Dielectrics took place in Edinburgh from August 9-12, 2010. The conference was attended by 390 delegates from more than 40 different countries. There were 4 plenary speakers, 56 invited speakers, and a further 222 contributed oral presentations in 7 parallel session. In addition there were 215 poster presentations. Key topics addressed at the conference included piezoelectric materials, leadfree piezoelectrics, and multiferroics.

Performance Of The IEEE 802.15.4 Protocol As The Marker Of Augmented Reality In Museum

NASA Astrophysics Data System (ADS)

Kurniawan Saputro, Adi; Sumpeno, Surya; Hariadi, Mochamad

2018-04-01

Museum is a place to keep the historic objects and historical education center to introduce the nation’s culture. Utilizing technology in a museum to become a smart city is a challenge. Internet of thing (IOT) is a technological advance in Information and communication (ICT) that can be applied in the museum The current ICT development is not only a transmission medium, but Augmented Reality technology is also being developed. Currently, Augmented Reality technology creates virtual objects into the real world using markers or images. In this study, researcher used signals to make virtual objects appear in the real world using the IEEE 802.14.5 protocol replacing the Augmented Reality marker. RSSI and triangulation are used as a substitute microlocation for AR objects. The result is the performance of Wireless Sensor Network could be used for data transmission in the museum. LOS research at a distance of 15 meters with 1000 ms delay found 1.4% error rate and NLOS with 2.3% error rate. So it can be concluded that utilization technology (IOT) using signal wireless sensor network as a replace for marker augmented reality can be used in museum

Performance Analysis of Power Saving Class of Type I for Voice Service in Two-Way Communication in IEEE 802.16e

NASA Astrophysics Data System (ADS)

Hwang, Eunju; Kim, Kyung Jae; Choi, Bong Dae

In IEEE 802.16e, power saving is one of the important issues for battery-powered mobile stations (MSs). We present a performance analysis of power saving class (PSC) of type I in IEEE 802.16e standard for voice over Internet protocol (VoIP) service with silence suppression in two-way communication. On-off pattern of a voice user in two-way communication is characterized by the modified Brady model, which includes short silence gaps less than 200ms and talkspurt periods shorter than 15ms, and so differs from the Brady model. Our analysis of PSC I follows the standard-based procedure for the deactivation of the sleep mode, where a uplink packet arrival during a mutual silence period wakes up the MS immediately while a downlink packet arrival waits to be served until the next listening window. We derive the delay distribution of the first downlink packet arriving during a mutual silence period, and find the dropping probability of downlink packets since a voice packet drops if it is not transmitted within maximum delay constraint. In addition, we calculate the average power consumption under the modified Brady model. Analysis and simulation results show that the sleep mode operation for the MS with VoIP service yields 32 ∼ 39% reduction in the power consumption of the MS. Finally we obtain the optimal initial/final-sleep windows that yield the minimum average power consumption while satisfying QoS constraints on the packet dropping probability and the maximum delay.

Verification of IEEE Compliant Subtractive Division Algorithms

NASA Technical Reports Server (NTRS)

Miner, Paul S.; Leathrum, James F., Jr.

1996-01-01

A parameterized definition of subtractive floating point division algorithms is presented and verified using PVS. The general algorithm is proven to satisfy a formal definition of an IEEE standard for floating point arithmetic. The utility of the general specification is illustrated using a number of different instances of the general algorithm.

An Extended IEEE 118-Bus Test System With High Renewable Penetration

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

Pena, Ivonne; Martinez-Anido, Carlo Brancucci; Hodge, Bri-Mathias

This article describes a new publicly available version of the IEEE 118-bus test system, named NREL-118. The database is based on the transmission representation (buses and lines) of the IEEE 118-bus test system, with a reconfigured generation representation using three regions of the US Western Interconnection from the latest Western Electricity Coordination Council (WECC) 2024 Common Case [1]. Time-synchronous hourly load, wind, and solar time series are provided for over one year (8784 hours). The public database presented and described in this manuscript will allow researchers to model a test power system using detailed transmission, generation, load, wind, and solarmore » data. This database includes key additional features that add to the current IEEE 118-bus test model, such as: the inclusion of 10 generation technologies with different heat rate functions, minimum stable levels and ramping rates, GHG emissions rates, regulation and contingency reserves, and hourly time series data for one full year for load, wind and solar generation.« less

Performance Evaluation of Phasor Measurement Systems

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

Huang, Zhenyu; Kasztenny, Bogdan; Madani, Vahid

2008-07-20

After two decades of phasor network deployment, phasor measurements are now available at many major substations and power plants. The North American SynchroPhasor Initiative (NASPI), supported by both the US Department of Energy and the North American Electricity Reliability Council (NERC), provides a forum to facilitate the efforts in phasor technology in North America. Phasor applications have been explored and some are in today’s utility practice. IEEE C37.118 Standard is a milestone in standardizing phasor measurements and defining performance requirements. To comply with IEEE C37.118 and to better understand the impact of phasor quality on applications, the NASPI Performance andmore » Standards Task Team (PSTT) initiated and accomplished the development of two important documents to address characterization of PMUs and instrumentation channels, which leverage prior work (esp. in WECC) and international experience. This paper summarizes the accomplished PSTT work and presents the methods for phasor measurement evaluation.« less

A Green Media Access Method for IEEE 802.15.6 Wireless Body Area Network.

PubMed

Jacob, Anil K; Jacob, Lillykutty

2017-09-30

It is of utmost importance to conserve battery energy to the maximum possible extent in WBAN nodes while collecting and transferring medical data. The IEEE 802.15.6 WBAN standard does not specify any method to conserve energy. This paper focuses on a method to conserve energy in IEEE 802.15.6 WBAN nodes when using CSMA/CA, while simultaneously restricting data delivery delay to the required value as specified in medical applications. The technique is to allow the nodes to sleep all the times except for receiving beacons and for transmitting data frames whenever a data frame enters an empty buffer. The energy consumed by the nodes and the average latency of data frame for periodical arrival of data are found out analytically. The analytical results are validated and also the proposed method is compared with other energy conserving schemes, using Castalia simulation studies. The proposed method shows superior performance in both device lifetime and latency of emergency medical data.

2012 Special NSREC Issue of the IEEE Transactions on Nuclear Science Comments by the Editors

NASA Astrophysics Data System (ADS)

Schwank, Jim; Brown, Dennis; Girard, Sylvain; Gouker, Pascale; Gerardin, Simone; Quinn, Heather; Barnaby, Hugh

2012-12-01

The December 2012 special issue of the IEEE Transactions on Nuclear Science contains selected papers from the 49th annual IEEE International Nuclear and Space Radiation Effects Conference (NSREC) held July 16-20, 2012, in Miami, Florida USA. 95 papers presented at the 2012 NSREC were submitted for consideration for this year’s special issue. Those papers that appear in this special issue were able to successfully complete the review process before the deadline for the December issue. A few additional papers may appear in subsequent issues of the TRANSACTIONS. This publication is the premier archival journal for research on space and nuclear radiation effects in materials, devices, circuits, and systems. This distinction is the direct result of the conscientious efforts of both the authors, who present and document their work, and the reviewers, who selflessly volunteer their time and talent to help review the manuscripts. Each paper in this journal has been reviewed by experts selected by the editors for their expertise and knowledge of the particular subject areas. The peer review process for a typical technical journal generally takes six months to one year to complete. To publish this special issue of the IEEE Transactions on Nuclear Science (in December), the review process, from initial submission to final form, must be completed in about 10 weeks. Because of the short schedule, both the authors and reviewers are required to respond very quickly. The reviewers listed on the following pages contributed vitally to this quick-turn review process.We would like to express our sincere appreciation to each of them for accepting this difficult, but critical role in the process. To provide consistent reviews of papers throughout the year, the IEEE Transactions on Nuclear Science relies on a year-round editorial board that manages reviews for submissions throughout the year to the TRANSACTIONS in the area of radiation effects. The review process is managed by a Senior

Consideration of IP Telephony Quality on the IEEE802.11a Wireless LAN

NASA Astrophysics Data System (ADS)

Miyashita, Michifumi; Takamatsu, Hideyuki; Kurono, Masahiro

Recently, IP telephony services in wired network are started, and paid attention for its charge-free nature due to IP technology. On the other hand, the Hot-Spot service, which provides one to access the Internet at the public space such as cafe, using the IEEE wireless LAN has been evolved, and it is expected that the IP telephony service on the Hot-Spot network will be developed. However, the IP telephony quality on the IEEE802.11a wireless LAN has not been fully studied yet. In this paper, we discuss about the quality of IP telephony service on the IEEE802.11a wireless LAN from the aspect of R-value, and show ability to improve the IP telephony quality on the Hot-Spot network employing PLC function defined in the ITU-T Recommendation G.711 Appendix I.

Algorithm XXX : functions to support the IEEE standard for binary floating-point arithmetic.

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

Cody, W. J.; Mathematics and Computer Science

1993-12-01

This paper describes C programs for the support functions copysign(x,y), logb(x), scalb(x,n), nextafter(x,y), finite(x), and isnan(x) recommended in the Appendix to the IEEE Standard for Binary Floating-Point Arithmetic. In the case of logb, the modified definition given in the later IEEE Standard for Radix-Independent Floating-Point Arithmetic is followed. These programs should run without modification on most systems conforming to the binary standard.

Performance evaluation of reactive and proactive routing protocol in IEEE 802.11 ad hoc network

NASA Astrophysics Data System (ADS)

Hamma, Salima; Cizeron, Eddy; Issaka, Hafiz; Guédon, Jean-Pierre

2006-10-01

Wireless technology based on the IEEE 802.11 standard is widely deployed. This technology is used to support multiple types of communication services (data, voice, image) with different QoS requirements. MANET (Mobile Adhoc NETwork) does not require a fixed infrastructure. Mobile nodes communicate through multihop paths. The wireless communication medium has variable and unpredictable characteristics. Furthermore, node mobility creates a continuously changing communication topology in which paths break and new one form dynamically. The routing table of each router in an adhoc network must be kept up-to-date. MANET uses Distance Vector or Link State algorithms which insure that the route to every host is always known. However, this approach must take into account the adhoc networks specific characteristics: dynamic topologies, limited bandwidth, energy constraints, limited physical security, ... Two main routing protocols categories are studied in this paper: proactive protocols (e.g. Optimised Link State Routing - OLSR) and reactive protocols (e.g. Ad hoc On Demand Distance Vector - AODV, Dynamic Source Routing - DSR). The proactive protocols are based on periodic exchanges that update the routing tables to all possible destinations, even if no traffic goes through. The reactive protocols are based on on-demand route discoveries that update routing tables only for the destination that has traffic going through. The present paper focuses on study and performance evaluation of these categories using NS2 simulations. We have considered qualitative and quantitative criteria. The first one concerns distributed operation, loop-freedom, security, sleep period operation. The second are used to assess performance of different routing protocols presented in this paper. We can list end-to-end data delay, jitter, packet delivery ratio, routing load, activity distribution. Comparative study will be presented with number of networking context consideration and the results show

Performance Characterization and Optimization of Microgrid-Based Energy Generation and Storage Technologies

DTIC Science & Technology

2012-01-01

A. Rufer, “Multiphysics and energetic modeling of a vanadium redox flow battery ,” in Proc. 2008 IEEE International Conference on Sustainable...p. 81. [11] K.W. Knehr and E.C. Kumbur, "Open circuit voltage of vanadium redox flow batteries : Discrepancy between models and experiments...Blanc and A. Rufer, “Multiphysics and energetic modeling of a vanadium redox flow battery ,” in Proc. 2008 IEEE International Conference on Sustainable

IEEE 1547 and 2030 Standards for Distributed Energy Resources Interconnection and Interoperability with the Electricity Grid

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

Basso, T.

Public-private partnerships have been a mainstay of the U.S. Department of Energy and the National Renewable Energy Laboratory (DOE/NREL) approach to research and development. These partnerships also include technology development that enables grid modernization and distributed energy resources (DER) advancement, especially renewable energy systems integration with the grid. Through DOE/NREL and industry support of Institute of Electrical and Electronics Engineers (IEEE) standards development, the IEEE 1547 series of standards has helped shape the way utilities and other businesses have worked together to realize increasing amounts of DER interconnected with the distribution grid. And more recently, the IEEE 2030 series ofmore » standards is helping to further realize greater implementation of communications and information technologies that provide interoperability solutions for enhanced integration of DER and loads with the grid. For these standards development partnerships, for approximately $1 of federal funding, industry partnering has contributed $5. In this report, the status update is presented for the American National Standards IEEE 1547 and IEEE 2030 series of standards. A short synopsis of the history of the 1547 standards is first presented, then the current status and future direction of the ongoing standards development activities are discussed.« less

IEEE/NASA Workshop on Leveraging Applications of Formal Methods, Verification, and Validation

NASA Technical Reports Server (NTRS)

Margaria, Tiziana (Editor); Steffen, Bernhard (Editor); Hichey, Michael G.

2005-01-01

This volume contains the Preliminary Proceedings of the 2005 IEEE ISoLA Workshop on Leveraging Applications of Formal Methods, Verification, and Validation, with a special track on the theme of Formal Methods in Human and Robotic Space Exploration. The workshop was held on 23-24 September 2005 at the Loyola College Graduate Center, Columbia, MD, USA. The idea behind the Workshop arose from the experience and feedback of ISoLA 2004, the 1st International Symposium on Leveraging Applications of Formal Methods held in Paphos (Cyprus) last October-November. ISoLA 2004 served the need of providing a forum for developers, users, and researchers to discuss issues related to the adoption and use of rigorous tools and methods for the specification, analysis, verification, certification, construction, test, and maintenance of systems from the point of view of their different application domains.

A High Performance Frequency Standard and Distribution System for Cassini Ka-Band Experiment

DTIC Science & Technology

2005-08-01

Orthogonal Polarization In Anisotropic Dielectric Resonators”, Proceedings of the 2002 IEEE International Frequency Control Symposium , pp. 553-558...2002. [9] G. J. Dick, Rabi T. Wang, Robert Tjoelker, “Design and Progress Report for Compact Cryocooled Sapphire Oscillator "VCSO"”, Proc. 2005 Joint...IEEE FCS/ PTTI. [10] R. Basu, G. J. Dick, Rabi T. Wang,” Novel Design of an All- Cryogenic RF Pound Circuit “,Proc. 2005 Joint IEEE FCS/ PTTI

Eleanor McElwee and the Formation of IEEE PCS

ERIC Educational Resources Information Center

Malone, Edward A.

2015-01-01

This article examines the historical professional project that created the Institute of Radio Engineers' Professional Group on Engineering Writing an Speech (IRE PGEWS)--now called the Institute of Electrical and Electronics Engineers' Professional Communication Society (IEEE PCS)--and recounts the group's early history in detail. It also traces…

Endlessly Circulating Messages in IEEE 1588-2008 Systems

DTIC Science & Technology

2014-05-13

section 13.5 of the standard. Once the timing topology is established by the BMC algo- rithm, each clock synchronizes to its master by exchanging timing ...Endlessly Circulating Messages in IEEE 1588-2008 Systems David Broman Patricia Derler Ankush Desai John Eidson Sanjit A. Seshia Electrical...estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the

Simple Adaptive Single Differential Coherence Detection of BPSK Signals in IEEE 802.15.4 Wireless Sensor Networks

PubMed Central

Wen, Hong; Wang, Longye; Xie, Ping; Song, Liang; Tang, Jie; Liao, Runfa

2017-01-01

In this paper, we propose an adaptive single differential coherent detection (SDCD) scheme for the binary phase shift keying (BPSK) signals in IEEE 802.15.4 Wireless Sensor Networks (WSNs). In particular, the residual carrier frequency offset effect (CFOE) for differential detection is adaptively estimated, with only linear operation, according to the changing channel conditions. It was found that the carrier frequency offset (CFO) and chip signal-to-noise ratio (SNR) conditions do not need a priori knowledge. This partly benefits from that the combination of the trigonometric approximation sin−1(x)≈x and a useful assumption, namely, the asymptotic or high chip SNR, is considered for simplification of the full estimation scheme. Simulation results demonstrate that the proposed algorithm can achieve an accurate estimation and the detection performance can completely meet the requirement of the IEEE 802.15.4 standard, although with a little loss of reliability and robustness as compared with the conventional optimal single-symbol detector. PMID:29278404

Simple Adaptive Single Differential Coherence Detection of BPSK Signals in IEEE 802.15.4 Wireless Sensor Networks.

PubMed

Zhang, Gaoyuan; Wen, Hong; Wang, Longye; Xie, Ping; Song, Liang; Tang, Jie; Liao, Runfa

2017-12-26

In this paper, we propose an adaptive single differential coherent detection (SDCD) scheme for the binary phase shift keying (BPSK) signals in IEEE 802.15.4 Wireless Sensor Networks (WSNs). In particular, the residual carrier frequency offset effect (CFOE) for differential detection is adaptively estimated, with only linear operation, according to the changing channel conditions. It was found that the carrier frequency offset (CFO) and chip signal-to-noise ratio (SNR) conditions do not need a priori knowledge. This partly benefits from that the combination of the trigonometric approximation sin - 1 ( x ) ≈ x and a useful assumption, namely, the asymptotic or high chip SNR, is considered for simplification of the full estimation scheme. Simulation results demonstrate that the proposed algorithm can achieve an accurate estimation and the detection performance can completely meet the requirement of the IEEE 802.15.4 standard, although with a little loss of reliability and robustness as compared with the conventional optimal single-symbol detector.

The ac power line protection for an IEEE 587 Class B environment

NASA Technical Reports Server (NTRS)

Roehr, W. D.; Clark, O. M.

1984-01-01

The 587B series of protectors are unique, low clamping voltage transient suppressors to protect ac-powered equipment from the 6000V peak open-circuit voltage and 3000A short circuit current as defined in IEEE standard 587 for Category B transients. The devices, which incorporate multiple-stage solid-state protector components, were specifically designed to operate under multiple exposures to maximum threat levels in this severe environment. The output voltage peaks are limited to 350V under maximum threat conditions for a 120V ac power line, thus providing adequate protection to vulnerable electronic equipment. The principle of operation and test performance data is discussed.

IEEE Nuclear and Space Radiation Effects Conference: Notes on the Early Conferences

NASA Technical Reports Server (NTRS)

Pellish, Jonathan A.; Galloway, Kenneth F.

2013-01-01

This paper gathers the remembrances of several key contributors who participated in the earliest Institute of Electrical and Electronics Engineers (IEEE) Nuclear and Space Radiation Effects Conferences (NSREC).

An Energy-Efficient Sleep Mode in IEEE 802.15.4 by Considering Sensor Device Mobility

NASA Astrophysics Data System (ADS)

Kim, Jinho; Lee, Jun; Hong, Choong Seon; Lee, Sungwon

The current version of IEEE 802.15.4 MAC protocol does not support energy-efficient mobility for the low-power device. In this paper, we propose an energy-efficient sleep mode as part of the IEEE 802.15.4 that can conserve energy by considering mobility of mobile sensor devices. The proposed energy-efficient sleep mode dynamically extends the sleep interval if there is no data to transmit from the device or receive from corresponding nodes.

FPGA Implementation of Reed-Solomon Decoder for IEEE 802.16 WiMAX Systems using Simulink-Sysgen Design Environment

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

Bobrek, Miljko; Albright, Austin P

This paper presents FPGA implementation of the Reed-Solomon decoder for use in IEEE 802.16 WiMAX systems. The decoder is based on RS(255,239) code, and is additionally shortened and punctured according to the WiMAX specifications. Simulink model based on Sysgen library of Xilinx blocks was used for simulation and hardware implementation. At the end, simulation results and hardware implementation performances are presented.

IEEE 1547 Standards Advancing Grid Modernization

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

Basso, Thomas; Chakraborty, Sudipta; Hoke, Andy

Technology advances including development of advanced distributed energy resources (DER) and grid-integrated operations and controls functionalities have surpassed the requirements in current standards and codes for DER interconnection with the distribution grid. The full revision of IEEE Standards 1547 (requirements for DER-grid interconnection and interoperability) and 1547.1 (test procedures for conformance to 1547) are establishing requirements and best practices for state-of-the-art DER including variable renewable energy sources. The revised standards will also address challenges associated with interoperability and transmission-level effects, in addition to strictly addressing the distribution grid needs. This paper provides the status and future direction of the ongoingmore » development focus for the 1547 standards.« less

Beamforming Transmission in IEEE 802.11ac under Time-Varying Channels

PubMed Central

2014-01-01

The IEEE 802.11ac wireless local area network (WLAN) standard has adopted beamforming (BF) schemes to improve spectral efficiency and throughput with multiple antennas. To design the transmit beam, a channel sounding process to feedback channel state information (CSI) is required. Due to sounding overhead, throughput increases with the amount of transmit data under static channels. Under practical channel conditions with mobility, however, the mismatch between the transmit beam and the channel at transmission time causes performance loss when transmission duration after channel sounding is too long. When the fading rate, payload size, and operating signal-to-noise ratio are given, the optimal transmission duration (i.e., packet length) can be determined to maximize throughput. The relationship between packet length and throughput is also investigated for single-user and multiuser BF modes. PMID:25152927

Beamforming transmission in IEEE 802.11ac under time-varying channels.

PubMed

Yu, Heejung; Kim, Taejoon

2014-01-01

The IEEE 802.11ac wireless local area network (WLAN) standard has adopted beamforming (BF) schemes to improve spectral efficiency and throughput with multiple antennas. To design the transmit beam, a channel sounding process to feedback channel state information (CSI) is required. Due to sounding overhead, throughput increases with the amount of transmit data under static channels. Under practical channel conditions with mobility, however, the mismatch between the transmit beam and the channel at transmission time causes performance loss when transmission duration after channel sounding is too long. When the fading rate, payload size, and operating signal-to-noise ratio are given, the optimal transmission duration (i.e., packet length) can be determined to maximize throughput. The relationship between packet length and throughput is also investigated for single-user and multiuser BF modes.

An Improved Cross-Layering Design for IPv6 Fast Handover with IEEE 802.16m Entry Before Break Handover

NASA Astrophysics Data System (ADS)

Kim, Ronny Yongho; Jung, Inuk; Kim, Young Yong

IEEE 802.16m is an advanced air interface standard which is under development for IMT-Advanced systems, known as 4G systems. IEEE 802.16m is designed to provide a high data rate and a Quality of Service (QoS) level in order to meet user service requirements, and is especially suitable for mobilized environments. There are several factors that have great impact on such requirements. As one of the major factors, we mainly focus on latency issues. In IEEE 802.16m, an enhanced layer 2 handover scheme, described as Entry Before Break (EBB) was proposed and adopted to reduce handover latency. EBB provides significant handover interruption time reduction with respect to the legacy IEEE 802.16 handover scheme. Fast handovers for mobile IPv6 (FMIPv6) was standardized by Internet Engineering Task Force (IETF) in order to provide reduced handover interruption time from IP layer perspective. Since FMIPv6 utilizes link layer triggers to reduce handover latency, it is very critical to jointly design FMIPv6 with its underlying link layer protocol. However, FMIPv6 based on new handover scheme, EBB has not been proposed. In this paper, we propose an improved cross-layering design for FMIPv6 based on the IEEE 802.16m EBB handover. In comparison with the conventional FMIPv6 based on the legacy IEEE 802.16 network, the overall handover interruption time can be significantly reduced by employing the proposed design. Benefits of this improvement on latency reduction for mobile user applications are thoroughly investigated with both numerical analysis and simulation on various IP applications.

An IEEE802.15.4-Based System for Locating Children on Their School Commutes

NASA Astrophysics Data System (ADS)

Sugiura, Akihiko; Baba, Ryoichi; Kobayashi, Hideyuki

With the increasing number of crimes and accidents in which children are becoming involved, there is a growing demand for devices to safeguard children's security by detecting their locations on their way to and from school. This paper proposes a system that uses an IEEE802.15.4-standard network to detect children's locations. To overcome the susceptibility of radio interference from nearby wireless LANs, frequency division multiplexing is applied to this IEEE802.15.4-based network, toward improving data acquisition from terminal units. The effectiveness of the system was field-tested with elementary school students who used about 400 IEEE 802.15.4-compliant terminal units. An experiment verified that the use of frequency division multiplexing in an environment where radio interference by wireless LANs is strong allowed the network to double the success rate of information communication from terminal units relative to that without frequency division multiplexing. In the experiment for detecting elementary schoolers' arrival at and departure from school, the terminal detection rate was 99% and the terminal detection rate on the designated school routes was 90%. These results prove the effectiveness of the system in detecting locations.

Self-Coexistence among IEEE 802.22 Networks: Distributed Allocation of Power and Channel

PubMed Central

Sakin, Sayef Azad; Alamri, Atif; Tran, Nguyen H.

2017-01-01

Ensuring self-coexistence among IEEE 802.22 networks is a challenging problem owing to opportunistic access of incumbent-free radio resources by users in co-located networks. In this study, we propose a fully-distributed non-cooperative approach to ensure self-coexistence in downlink channels of IEEE 802.22 networks. We formulate the self-coexistence problem as a mixed-integer non-linear optimization problem for maximizing the network data rate, which is an NP-hard one. This work explores a sub-optimal solution by dividing the optimization problem into downlink channel allocation and power assignment sub-problems. Considering fairness, quality of service and minimum interference for customer-premises-equipment, we also develop a greedy algorithm for channel allocation and a non-cooperative game-theoretic framework for near-optimal power allocation. The base stations of networks are treated as players in a game, where they try to increase spectrum utilization by controlling power and reaching a Nash equilibrium point. We further develop a utility function for the game to increase the data rate by minimizing the transmission power and, subsequently, the interference from neighboring networks. A theoretical proof of the uniqueness and existence of the Nash equilibrium has been presented. Performance improvements in terms of data-rate with a degree of fairness compared to a cooperative branch-and-bound-based algorithm and a non-cooperative greedy approach have been shown through simulation studies. PMID:29215591

Self-Coexistence among IEEE 802.22 Networks: Distributed Allocation of Power and Channel.

PubMed

Sakin, Sayef Azad; Razzaque, Md Abdur; Hassan, Mohammad Mehedi; Alamri, Atif; Tran, Nguyen H; Fortino, Giancarlo

2017-12-07

Ensuring self-coexistence among IEEE 802.22 networks is a challenging problem owing to opportunistic access of incumbent-free radio resources by users in co-located networks. In this study, we propose a fully-distributed non-cooperative approach to ensure self-coexistence in downlink channels of IEEE 802.22 networks. We formulate the self-coexistence problem as a mixed-integer non-linear optimization problem for maximizing the network data rate, which is an NP-hard one. This work explores a sub-optimal solution by dividing the optimization problem into downlink channel allocation and power assignment sub-problems. Considering fairness, quality of service and minimum interference for customer-premises-equipment, we also develop a greedy algorithm for channel allocation and a non-cooperative game-theoretic framework for near-optimal power allocation. The base stations of networks are treated as players in a game, where they try to increase spectrum utilization by controlling power and reaching a Nash equilibrium point. We further develop a utility function for the game to increase the data rate by minimizing the transmission power and, subsequently, the interference from neighboring networks. A theoretical proof of the uniqueness and existence of the Nash equilibrium has been presented. Performance improvements in terms of data-rate with a degree of fairness compared to a cooperative branch-and-bound-based algorithm and a non-cooperative greedy approach have been shown through simulation studies.

Service differentiated and adaptive CSMA/CA over IEEE 802.15.4 for Cyber-Physical Systems.

PubMed

Xia, Feng; Li, Jie; Hao, Ruonan; Kong, Xiangjie; Gao, Ruixia

2013-01-01

Cyber-Physical Systems (CPS) that collect, exchange, manage information, and coordinate actions are an integral part of the Smart Grid. In addition, Quality of Service (QoS) provisioning in CPS, especially in the wireless sensor/actuator networks, plays an essential role in Smart Grid applications. IEEE 802.15.4, which is one of the most widely used communication protocols in this area, still needs to be improved to meet multiple QoS requirements. This is because IEEE 802.15.4 slotted Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) employs static parameter configuration without supporting differentiated services and network self-adaptivity. To address this issue, this paper proposes a priority-based Service Differentiated and Adaptive CSMA/CA (SDA-CSMA/CA) algorithm to provide differentiated QoS for various Smart Grid applications as well as dynamically initialize backoff exponent according to traffic conditions. Simulation results demonstrate that the proposed SDA-CSMA/CA scheme significantly outperforms the IEEE 802.15.4 slotted CSMA/CA in terms of effective data rate, packet loss rate, and average delay.

Service Differentiated and Adaptive CSMA/CA over IEEE 802.15.4 for Cyber-Physical Systems

PubMed Central

Gao, Ruixia

2013-01-01

Cyber-Physical Systems (CPS) that collect, exchange, manage information, and coordinate actions are an integral part of the Smart Grid. In addition, Quality of Service (QoS) provisioning in CPS, especially in the wireless sensor/actuator networks, plays an essential role in Smart Grid applications. IEEE 802.15.4, which is one of the most widely used communication protocols in this area, still needs to be improved to meet multiple QoS requirements. This is because IEEE 802.15.4 slotted Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) employs static parameter configuration without supporting differentiated services and network self-adaptivity. To address this issue, this paper proposes a priority-based Service Differentiated and Adaptive CSMA/CA (SDA-CSMA/CA) algorithm to provide differentiated QoS for various Smart Grid applications as well as dynamically initialize backoff exponent according to traffic conditions. Simulation results demonstrate that the proposed SDA-CSMA/CA scheme significantly outperforms the IEEE 802.15.4 slotted CSMA/CA in terms of effective data rate, packet loss rate, and average delay. PMID:24260021

Performance Evaluation of Glottal Inverse Filtering Algorithms Using a Physiologically Based Articulatory Speech Synthesizer

DTIC Science & Technology

2017-01-05

1 Performance Evaluation of Glottal Inverse Filtering Algorithms Using a Physiologically Based Articulatory Speech Synthesizer Yu-Ren Chien, Daryush...D. Mehta, Member, IEEE, Jón Guðnason, Matías Zañartu, Member, IEEE, and Thomas F. Quatieri, Fellow, IEEE Abstract—Glottal inverse filtering aims to...of inverse filtering performance has been challenging due to the practical difficulty in measuring the true glottal signals while speech signals are

An Enhanced Reservation-Based MAC Protocol for IEEE 802.15.4 Networks

PubMed Central

Afonso, José A.; Silva, Helder D.; Macedo, Pedro; Rocha, Luis A.

2011-01-01

The IEEE 802.15.4 Medium Access Control (MAC) protocol is an enabling standard for wireless sensor networks. In order to support applications requiring dedicated bandwidth or bounded delay, it provides a reservation-based scheme named Guaranteed Time Slot (GTS). However, the GTS scheme presents some drawbacks, such as inefficient bandwidth utilization and support to a maximum of only seven devices. This paper presents eLPRT (enhanced Low Power Real Time), a new reservation-based MAC protocol that introduces several performance enhancing features in comparison to the GTS scheme. This MAC protocol builds on top of LPRT (Low Power Real Time) and includes various mechanisms designed to increase data transmission reliability against channel errors, improve bandwidth utilization and increase the number of supported devices. A motion capture system based on inertial and magnetic sensors has been used to validate the protocol. The effectiveness of the performance enhancements introduced by each of the new features is demonstrated through the provision of both simulation and experimental results. PMID:22163826

Real-Time Station Grouping under Dynamic Traffic for IEEE 802.11ah

PubMed Central

Tian, Le; Latré, Steven

2017-01-01

IEEE 802.11ah, marketed as Wi-Fi HaLow, extends Wi-Fi to the sub-1 GHz spectrum. Through a number of physical layer (PHY) and media access control (MAC) optimizations, it aims to bring greatly increased range, energy-efficiency, and scalability. This makes 802.11ah the perfect candidate for providing connectivity to Internet of Things (IoT) devices. One of these new features, referred to as the Restricted Access Window (RAW), focuses on improving scalability in highly dense deployments. RAW divides stations into groups and reduces contention and collisions by only allowing channel access to one group at a time. However, the standard does not dictate how to determine the optimal RAW grouping parameters. The optimal parameters depend on the current network conditions, and it has been shown that incorrect configuration severely impacts throughput, latency and energy efficiency. In this paper, we propose a traffic-adaptive RAW optimization algorithm (TAROA) to adapt the RAW parameters in real time based on the current traffic conditions, optimized for sensor networks in which each sensor transmits packets with a certain (predictable) frequency and may change the transmission frequency over time. The TAROA algorithm is executed at each target beacon transmission time (TBTT), and it first estimates the packet transmission interval of each station only based on packet transmission information obtained by access point (AP) during the last beacon interval. Then, TAROA determines the RAW parameters and assigns stations to RAW slots based on this estimated transmission frequency. The simulation results show that, compared to enhanced distributed channel access/distributed coordination function (EDCA/DCF), the TAROA algorithm can highly improve the performance of IEEE 802.11ah dense networks in terms of throughput, especially when hidden nodes exist, although it does not always achieve better latency performance. This paper contributes with a practical approach to optimizing

Real-Time Station Grouping under Dynamic Traffic for IEEE 802.11ah.

PubMed

Tian, Le; Khorov, Evgeny; Latré, Steven; Famaey, Jeroen

2017-07-04

IEEE 802.11ah, marketed as Wi-Fi HaLow, extends Wi-Fi to the sub-1 GHz spectrum. Through a number of physical layer (PHY) and media access control (MAC) optimizations, it aims to bring greatly increased range, energy-efficiency, and scalability. This makes 802.11ah the perfect candidate for providing connectivity to Internet of Things (IoT) devices. One of these new features, referred to as the Restricted Access Window (RAW), focuses on improving scalability in highly dense deployments. RAW divides stations into groups and reduces contention and collisions by only allowing channel access to one group at a time. However, the standard does not dictate how to determine the optimal RAW grouping parameters. The optimal parameters depend on the current network conditions, and it has been shown that incorrect configuration severely impacts throughput, latency and energy efficiency. In this paper, we propose a traffic-adaptive RAW optimization algorithm (TAROA) to adapt the RAW parameters in real time based on the current traffic conditions, optimized for sensor networks in which each sensor transmits packets with a certain (predictable) frequency and may change the transmission frequency over time. The TAROA algorithm is executed at each target beacon transmission time (TBTT), and it first estimates the packet transmission interval of each station only based on packet transmission information obtained by access point (AP) during the last beacon interval. Then, TAROA determines the RAW parameters and assigns stations to RAW slots based on this estimated transmission frequency. The simulation results show that, compared to enhanced distributed channel access/distributed coordination function (EDCA/DCF), the TAROA algorithm can highly improve the performance of IEEE 802.11ah dense networks in terms of throughput, especially when hidden nodes exist, although it does not always achieve better latency performance. This paper contributes with a practical approach to optimizing

Implementing ISO/IEEE 11073: proposal of two different strategic approaches.

PubMed

Martínez-Espronceda, M; Serrano, L; Martínez, I; Escayola, J; Led, S; Trigo, J; García, J

2008-01-01

This paper explains the challenges encountered during the ISO/IEEE 11073 standard implementation process. The complexity of the standard and the consequent heavy requirements, which have not encouraged software engineers to adopt the standard. The developing complexity evaluation drives us to propose two possible implementation strategies that cover almost all possible use cases and eases handling the standard by non-expert users. The first one is focused on medical devices (MD) and proposes a low-memory and low-processor usage technique. It is based on message patterns that allow simple functions to generate ISO/IEEE 11073 messages and to process them easily. In this way a framework for MDs can be obtained. Second one is focused on more powerful machines such as data loggers or gateways (aka. computer engines (CE)), which do not have the MDs' memory and processor usage constraints. For CEs a more intelligent and adaptative Plug&Play (P&P) solution is provided. It consists on a general platform that can access to any device supported by the standard. Combining both strategies will cut developing time for applications based on ISO/EEE 11073.

Integration of IEEE 1451 and HL7 exchanging information for patients' sensor data.

PubMed

Kim, Wooshik; Lim, Suyoung; Ahn, Jinsoo; Nah, Jiyoung; Kim, Namhyun

2010-12-01

HL7 (Health Level 7) is a standard developed for exchanging incompatible healthcare information generated from programs or devices among heterogenous medical information systems. At present, HL7 is growing as a global standard. However, the HL7 standard does not support effective methods for treating data from various medical sensors, especially from mobile sensors. As ubiquitous systems are growing, HL7 must communicate with various medical transducers. In the area of sensor fields, IEEE 1451 is a group of standards for controlling transducers and for communicating data from/to various transducers. In this paper, we present the possibility of interoperability between the two standards, i.e., HL7 and IEEE 1451. After we present a method to integrate them and show the preliminary results of this approach.

International standards for optical wireless communications: state-of-the-art and future directions

NASA Astrophysics Data System (ADS)

Marciniak, Marian

2017-10-01

As the number of active OWC installations is growing fast, the standards for compatibility of co-existing neighbouring systems are being developed. The paper addresses the Laser Safety (IEC standards), ITU-T Study Group 15 standards (G.640 Co-location longitudinally compatible interfaces for free space optical systems), ITU-Radiocommunication Sector standards (P.1817-1 Propagation data required for the design of terrestrial free-space optical links), and the IEEE Work in Progress - standardization activity on Visible Light Communications. International standards of FSO communications have been reviewed and discussed. ITU, IEC, and IEEE International standards for Free-Space Optical links have been reviewed. The system reliability and availability as well as security issues will be addressed as well in the talk.

NREL's Jerry Olson Wins Prestigious Cherry Award from IEEE | News | NREL

Science.gov Websites

at the IEEE's annual Photovoltaic Specialists Conference in Seattle. See the feature article on Olson based on his invention to power most space satellites, as well as the Mars rovers, Spirit and of the photovoltaic community. In the 1950s, he was instrumental in establishing solar cells as the

IEEE 802.15.4 MAC with GTS transmission for heterogeneous devices with application to wheelchair body-area sensor networks.

PubMed

Shrestha, Bharat; Hossain, Ekram; Camorlinga, Sergio

2011-09-01

In wireless personal area networks, such as wireless body-area sensor networks, stations or devices have different bandwidth requirements and, thus, create heterogeneous traffics. For such networks, the IEEE 802.15.4 medium access control (MAC) can be used in the beacon-enabled mode, which supports guaranteed time slot (GTS) allocation for time-critical data transmissions. This paper presents a general discrete-time Markov chain model for the IEEE 802.15.4-based networks taking into account the slotted carrier sense multiple access with collision avoidance and GTS transmission phenomena together in the heterogeneous traffic scenario and under nonsaturated condition. For this purpose, the standard GTS allocation scheme is modified. For each non-identical device, the Markov model is solved and the average service time and the service utilization factor are analyzed in the non-saturated mode. The analysis is validated by simulations using network simulator version 2.33. Also, the model is enhanced with a wireless propagation model and the performance of the MAC is evaluated in a wheelchair body-area sensor network scenario.

Adaptive threshold control for auto-rate fallback algorithm in IEEE 802.11 multi-rate WLANs

NASA Astrophysics Data System (ADS)

Wu, Qilin; Lu, Yang; Zhu, Xiaolin; Ge, Fangzhen

2012-03-01

The IEEE 802.11 standard supports multiple rates for data transmission in the physical layer. Nowadays, to improve network performance, a rate adaptation scheme called auto-rate fallback (ARF) is widely adopted in practice. However, ARF scheme suffers performance degradation in multiple contending nodes environments. In this article, we propose a novel rate adaptation scheme called ARF with adaptive threshold control. In multiple contending nodes environment, the proposed scheme can effectively mitigate the frame collision effect on rate adaptation decision by adaptively adjusting rate-up and rate-down threshold according to the current collision level. Simulation results show that the proposed scheme can achieve significantly higher throughput than the other existing rate adaptation schemes. Furthermore, the simulation results also demonstrate that the proposed scheme can effectively respond to the varying channel condition.

A programmable positioning stepper-motor controller with a multibus/IEEE 796 compatible interface.

PubMed

Papoff, P; Ricci, D

1984-02-01

A programmable positioning stepper-motor controller, based on the Multibus/IEEE 796 standard interface, has been assembled by use of some intelligent and programmable integrated circuits. This controller, organized as a bus-slave unit, has been planned for local management of up to four stepper motors working simultaneously. The number of steps, the direction of rotation and the step-rate for the positioning of each motor are issued by the bus master microcomputer to the controller which handles all the required operations. Once each positioning has been performed, the controller informs the master by generating a proper bus-vectored interrupt. Displacements in up to 64,000 steps may be programmed with step-rates ranging from 0.1 to 6550 steps/sec. This device, for which only low-cost, high-performance components are required, can be successfully used in a wide range of applications and can be easily extended to control more than four stepper motors.

Modeling and Performance Evaluation of Backoff Misbehaving Nodes in CSMA/CA Networks

DTIC Science & Technology

2012-08-01

Modeling and Performance Evaluation of Backoff Misbehaving Nodes in CSMA/CA Networks Zhuo Lu, Student Member, IEEE, Wenye Wang, Senior Member, IEEE... misbehaving nodes can obtain, we define and study two general classes of backoff misbehavior: continuous misbehavior, which keeps manipulating the backoff...misbehavior sporadically. Our approach is to introduce a new performance metric, namely order gain, to characterize the performance benefits of misbehaving

Accurate Energy Consumption Modeling of IEEE 802.15.4e TSCH Using Dual-BandOpenMote Hardware.

PubMed

Daneels, Glenn; Municio, Esteban; Van de Velde, Bruno; Ergeerts, Glenn; Weyn, Maarten; Latré, Steven; Famaey, Jeroen

2018-02-02

The Time-Slotted Channel Hopping (TSCH) mode of the IEEE 802.15.4e amendment aims to improve reliability and energy efficiency in industrial and other challenging Internet-of-Things (IoT) environments. This paper presents an accurate and up-to-date energy consumption model for devices using this IEEE 802.15.4e TSCH mode. The model identifies all network-related CPU and radio state changes, thus providing a precise representation of the device behavior and an accurate prediction of its energy consumption. Moreover, energy measurements were performed with a dual-band OpenMote device, running the OpenWSN firmware. This allows the model to be used for devices using 2.4 GHz, as well as 868 MHz. Using these measurements, several network simulations were conducted to observe the TSCH energy consumption effects in end-to-end communication for both frequency bands. Experimental verification of the model shows that it accurately models the consumption for all possible packet sizes and that the calculated consumption on average differs less than 3% from the measured consumption. This deviation includes measurement inaccuracies and the variations of the guard time. As such, the proposed model is very suitable for accurate energy consumption modeling of TSCH networks.

Accurate Energy Consumption Modeling of IEEE 802.15.4e TSCH Using Dual-BandOpenMote Hardware

PubMed Central

Municio, Esteban; Van de Velde, Bruno; Latré, Steven

2018-01-01

The Time-Slotted Channel Hopping (TSCH) mode of the IEEE 802.15.4e amendment aims to improve reliability and energy efficiency in industrial and other challenging Internet-of-Things (IoT) environments. This paper presents an accurate and up-to-date energy consumption model for devices using this IEEE 802.15.4e TSCH mode. The model identifies all network-related CPU and radio state changes, thus providing a precise representation of the device behavior and an accurate prediction of its energy consumption. Moreover, energy measurements were performed with a dual-band OpenMote device, running the OpenWSN firmware. This allows the model to be used for devices using 2.4 GHz, as well as 868 MHz. Using these measurements, several network simulations were conducted to observe the TSCH energy consumption effects in end-to-end communication for both frequency bands. Experimental verification of the model shows that it accurately models the consumption for all possible packet sizes and that the calculated consumption on average differs less than 3% from the measured consumption. This deviation includes measurement inaccuracies and the variations of the guard time. As such, the proposed model is very suitable for accurate energy consumption modeling of TSCH networks. PMID:29393900

DoS detection in IEEE 802.11 with the presence of hidden nodes

PubMed Central

Soryal, Joseph; Liu, Xijie; Saadawi, Tarek

2013-01-01

The paper presents a novel technique to detect Denial of Service (DoS) attacks applied by misbehaving nodes in wireless networks with the presence of hidden nodes employing the widely used IEEE 802.11 Distributed Coordination Function (DCF) protocols described in the IEEE standard [1]. Attacker nodes alter the IEEE 802.11 DCF firmware to illicitly capture the channel via elevating the probability of the average number of packets transmitted successfully using up the bandwidth share of the innocent nodes that follow the protocol standards. We obtained the theoretical network throughput by solving two-dimensional Markov Chain model as described by Bianchi [2], and Liu and Saadawi [3] to determine the channel capacity. We validated the results obtained via the theoretical computations with the results obtained by OPNET simulator [4] to define the baseline for the average attainable throughput in the channel under standard conditions where all nodes follow the standards. The main goal of the DoS attacker is to prevent the innocent nodes from accessing the channel and by capturing the channel’s bandwidth. In addition, the attacker strives to appear as an innocent node that follows the standards. The protocol resides in every node to enable each node to police other nodes in its immediate wireless coverage area. All innocent nodes are able to detect and identify the DoS attacker in its wireless coverage area. We applied the protocol to two Physical Layer technologies: Direct Sequence Spread Spectrum (DSSS) and Frequency Hopping Spread Spectrum (FHSS) and the results are presented to validate the algorithm. PMID:25685510

DoS detection in IEEE 802.11 with the presence of hidden nodes.

PubMed

Soryal, Joseph; Liu, Xijie; Saadawi, Tarek

2014-07-01

The paper presents a novel technique to detect Denial of Service (DoS) attacks applied by misbehaving nodes in wireless networks with the presence of hidden nodes employing the widely used IEEE 802.11 Distributed Coordination Function (DCF) protocols described in the IEEE standard [1]. Attacker nodes alter the IEEE 802.11 DCF firmware to illicitly capture the channel via elevating the probability of the average number of packets transmitted successfully using up the bandwidth share of the innocent nodes that follow the protocol standards. We obtained the theoretical network throughput by solving two-dimensional Markov Chain model as described by Bianchi [2], and Liu and Saadawi [3] to determine the channel capacity. We validated the results obtained via the theoretical computations with the results obtained by OPNET simulator [4] to define the baseline for the average attainable throughput in the channel under standard conditions where all nodes follow the standards. The main goal of the DoS attacker is to prevent the innocent nodes from accessing the channel and by capturing the channel's bandwidth. In addition, the attacker strives to appear as an innocent node that follows the standards. The protocol resides in every node to enable each node to police other nodes in its immediate wireless coverage area. All innocent nodes are able to detect and identify the DoS attacker in its wireless coverage area. We applied the protocol to two Physical Layer technologies: Direct Sequence Spread Spectrum (DSSS) and Frequency Hopping Spread Spectrum (FHSS) and the results are presented to validate the algorithm.

Improving the communication reliability of body sensor networks based on the IEEE 802.15.4 protocol.

PubMed

Gomes, Diogo; Afonso, José A

2014-03-01

Body sensor networks (BSNs) enable continuous monitoring of patients anywhere, with minimum constraints to daily life activities. Although the IEEE 802.15.4 and ZigBee(®) (ZigBee Alliance, San Ramon, CA) standards were mainly developed for use in wireless sensors network (WSN) applications, they are also widely used in BSN applications because of device characteristics such as low power, low cost, and small form factor. However, compared with WSNs, BSNs present some very distinctive characteristics in terms of traffic and mobility patterns, heterogeneity of the nodes, and quality of service requirements. This article evaluates the suitability of the carrier sense multiple access-collision avoidance protocol, used by the IEEE 802.15.4 and ZigBee standards, for data-intensive BSN applications, through the execution of experimental tests in different evaluation scenarios, in order to take into account the effects of contention, clock drift, and hidden nodes on the communication reliability. Results show that the delivery ratio may decrease substantially during transitory periods, which can last for several minutes, to a minimum of 90% with retransmissions and 13% without retransmissions. This article also proposes and evaluates the performance of the BSN contention avoidance mechanism, which was designed to solve the identified reliability problems. This mechanism was able to restore the delivery ratio to 100% even in the scenario without retransmissions.

The Impact of IEEE-1076 on VHDL (Hardware Description Language)

DTIC Science & Technology

1988-12-01

Portability simply refers to how machine-independent the language is defined. The Efficiency criterion looks at how fast a program compiles and how ...if a programming language is good. The evaluation was done to determine if IEEE Standard 1076-1987 was indeed a better version of VHDL than its...must be UNIX-based and be able to * use the tools that are common to that operating system such as lex [Lesk78I, yacc [John78] and the programming

Investigating the efficiency of IEEE 802.15.4 for medical monitoring applications.

PubMed

Pelegris, P; Banitsas, K

2011-01-01

Recent advancements in wireless communications technologies bring us one step closer to provide reliable Telecare services as an alternative to patients staying in a hospital mainly for monitoring purposes. In this research we investigate the efficiency of IEEE 802.15.4 in a simple scenario where a patient is being monitored using an ECG and a blood analysis module. This approach binds well with assisted living solutions, by sharing the network infrastructure for both monitoring and control while taking advantage of the low power features of the protocol. Such applications are becoming more and more realistic to implement as IEEE 802.15.4 compatible hardware becomes increasingly available. Our aim is to examine the impact of Beacon and Superframe Order in the medium access delay, dropped packets, end to end delay, average retransmission attempts and consumed power focusing on this bandwidth demanding situation where the network load does not allow low duty cycles, in order to draw some conclusions on the effect that this will have to telemonitoring applications.

Intern Performance in Three Supervisory Models

ERIC Educational Resources Information Center

Womack, Sid T.; Hanna, Shellie L.; Callaway, Rebecca; Woodall, Peggy

2011-01-01

Differences in intern performance, as measured by a Praxis III-similar instrument were found between interns supervised in three supervisory models: Traditional triad model, cohort model, and distance supervision. Candidates in this study's particular form of distance supervision were not as effective as teachers as candidates in traditional-triad…

Interoperability in digital electrocardiography: harmonization of ISO/IEEE x73-PHD and SCP-ECG.

PubMed

Trigo, Jesús D; Chiarugi, Franco; Alesanco, Alvaro; Martínez-Espronceda, Miguel; Serrano, Luis; Chronaki, Catherine E; Escayola, Javier; Martínez, Ignacio; García, José

2010-11-01

The ISO/IEEE 11073 (x73) family of standards is a reference frame for medical device interoperability. A draft for an ECG device specialization (ISO/IEEE 11073-10406-d02) has already been presented to the Personal Health Device (PHD) Working Group, and the Standard Communications Protocol for Computer-Assisted ElectroCardioGraphy (SCP-ECG) Standard for short-term diagnostic ECGs (EN1064:2005+A1:2007) has recently been approved as part of the x73 family (ISO 11073-91064:2009). These factors suggest the coordinated use of these two standards in foreseeable telecardiology environments, and hence the need to harmonize them. Such harmonization is the subject of this paper. Thus, a mapping of the mandatory attributes defined in the second draft of the ISO/IEEE 11073-10406-d02 and the minimum SCP-ECG fields is presented, and various other capabilities of the SCP-ECG Standard (such as the messaging part) are also analyzed from an x73-PHD point of view. As a result, this paper addresses and analyzes the implications of some inconsistencies in the coordinated use of these two standards. Finally, a proof-of-concept implementation of the draft x73-PHD ECG device specialization is presented, along with the conversion from x73-PHD to SCP-ECG. This paper, therefore, provides recommendations for future implementations of telecardiology systems that are compliant with both x73-PHD and SCP-ECG.

NIH-IEEE 2015 Strategic Conference on Healthcare Innovations and Point-of-Care Technologies for Prec

Cancer.gov

NIH and the Institute for Electrical and Electronics Engineering, Engineering in Medicine and Biology Society (IEEE/EMBS) hosted the third iteration of the Healthcare Innovations and Point-of-Care Technologies Conference last week.

Link Investigation of IEEE 802.15.4 Wireless Sensor Networks in Forests

PubMed Central

Ding, Xingjian; Sun, Guodong; Yang, Gaoxiang; Shang, Xinna

2016-01-01

Wireless sensor networks are expected to automatically monitor the ecological evolution and wildlife habits in forests. Low-power links (transceivers) are often adopted in wireless sensor network applications, in order to save the precious sensor energy and then achieve long-term, unattended monitoring. Recent research has presented some performance characteristics of such low-power wireless links under laboratory or outdoor scenarios with less obstacles, and they have found that low-power wireless links are unreliable and prone to be affected by the target environment. However, there is still less understanding about how well the low-power wireless link performs in real-world forests and to what extent the complex in-forest surrounding environments affect the link performances. In this paper, we empirically evaluate the low-power links of wireless sensors in three typical different forest environments. Our experiment investigates the performance of the link layer compatible with the IEEE 802.15.4 standard and analyzes the variation patterns of the packet reception ratio (PRR), the received signal strength indicator (RSSI) and the link quality indicator (LQI) under diverse experimental settings. Some observations of this study are inconsistent with or even contradict prior results that are achieved in open fields or relatively clean environments and thus, provide new insights both into effectively evaluating the low-power wireless links and into efficiently deploying wireless sensor network systems in forest environments. PMID:27355957

Link Investigation of IEEE 802.15.4 Wireless Sensor Networks in Forests.

PubMed

Ding, Xingjian; Sun, Guodong; Yang, Gaoxiang; Shang, Xinna

2016-06-27

Wireless sensor networks are expected to automatically monitor the ecological evolution and wildlife habits in forests. Low-power links (transceivers) are often adopted in wireless sensor network applications, in order to save the precious sensor energy and then achieve long-term, unattended monitoring. Recent research has presented some performance characteristics of such low-power wireless links under laboratory or outdoor scenarios with less obstacles, and they have found that low-power wireless links are unreliable and prone to be affected by the target environment. However, there is still less understanding about how well the low-power wireless link performs in real-world forests and to what extent the complex in-forest surrounding environments affect the link performances. In this paper, we empirically evaluate the low-power links of wireless sensors in three typical different forest environments. Our experiment investigates the performance of the link layer compatible with the IEEE 802.15.4 standard and analyzes the variation patterns of the packet reception ratio (PRR), the received signal strength indicator (RSSI) and the link quality indicator (LQI) under diverse experimental settings. Some observations of this study are inconsistent with or even contradict prior results that are achieved in open fields or relatively clean environments and thus, provide new insights both into effectively evaluating the low-power wireless links and into efficiently deploying wireless sensor network systems in forest environments.

A note on bound constraints handling for the IEEE CEC'05 benchmark function suite.

PubMed

Liao, Tianjun; Molina, Daniel; de Oca, Marco A Montes; Stützle, Thomas

2014-01-01

The benchmark functions and some of the algorithms proposed for the special session on real parameter optimization of the 2005 IEEE Congress on Evolutionary Computation (CEC'05) have played and still play an important role in the assessment of the state of the art in continuous optimization. In this article, we show that if bound constraints are not enforced for the final reported solutions, state-of-the-art algorithms produce infeasible best candidate solutions for the majority of functions of the IEEE CEC'05 benchmark function suite. This occurs even though the optima of the CEC'05 functions are within the specified bounds. This phenomenon has important implications on algorithm comparisons, and therefore on algorithm designs. This article's goal is to draw the attention of the community to the fact that some authors might have drawn wrong conclusions from experiments using the CEC'05 problems.

Human exposure standards in the frequency range 1 Hz To 100 kHz: the case for adoption of the IEEE standard.

PubMed

Patrick Reilly, J

2014-10-01

Differences between IEEE C95 Standards (C95.6-2002 and C95.1-2005) in the low-frequency (1 Hz-100 kHz) and the ICNIRP-2010 guidelines appear across the frequency spectrum. Factors accounting for lack of convergence include: differences between the IEEE standards and the ICNIRP guidelines with respect to biological induction models, stated objectives, data trail from experimentally derived thresholds through physical and biological principles, selection and justification of safety/reduction factors, use of probability models, compliance standards for the limbs as distinct from the whole body, defined population categories, strategies for central nervous system protection below 20 Hz, and correspondence of environmental electric field limits with contact currents. This paper discusses these factors and makes the case for adoption of the limits in the IEEE standards.

Performance Analysis of Power Saving Class of Type 1 with Both Downlink and Uplink Traffics in IEEE 802.16e

NASA Astrophysics Data System (ADS)

Baek, Sangkyu; Choi, Bong Dae

We investigate power consumption of a mobile station with the power saving class of type 1 in the IEEE 802.16e. We deal with stochastic behavior of mobile station during not only sleep mode period but also awake mode period with both downlink and uplink traffics. Our methods for investigating the power saving class of type 1 are to construct the embedded Markov chain and the semi-Markov chain generated by the embedded Markov chain. To see the effect of the sleep mode, we obtain the average power consumption of a mobile station and the mean queueing delay of a message. Numerical results show that the larger size of the sleep window makes the power consumption of a mobile station smaller and the queueing delay of a downlink message longer.

An SNMP-based solution to enable remote ISO/IEEE 11073 technical management.

PubMed

Lasierra, Nelia; Alesanco, Alvaro; García, José

2012-07-01

This paper presents the design and implementation of an architecture based on the integration of simple network management protocol version 3 (SNMPv3) and the standard ISO/IEEE 11073 (X73) to manage technical information in home-based telemonitoring scenarios. This architecture includes the development of an SNMPv3-proxyX73 agent which comprises a management information base (MIB) module adapted to X73. In the proposed scenario, medical devices (MDs) send information to a concentrator device [designated as compute engine (CE)] using the X73 standard. This information together with extra information collected in the CE is stored in the developed MIB. Finally, the information collected is available for remote access via SNMP connection. Moreover, alarms and events can be configured by an external manager in order to provide warnings of irregularities in the MDs' technical performance evaluation. This proposed SNMPv3 agent provides a solution to integrate and unify technical device management in home-based telemonitoring scenarios fully adapted to X73.

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.

WIH-based IEEE 802.11 ECG monitoring implementation.

PubMed

Moein, A; Pouladian, M

2007-01-01

New wireless technologies make possible the implementation of high level integration wireless devices which allow the replacement of traditional large wired monitoring devices. It offers new functionalities to physicians and will reduce the costs. Among these functionalities, biomedical signals can be sent to other devices (PDA, PC . . . ) or processing centers, without restricting the patients' mobility. This article discusses the WIH (Ward-In-Hand) structure and the software required for its implementation before an operational example is presented with its results. The aim of this project is the development and implementation of a reduced size electrocardiograph based on IEEE 802.11 with high speed and more accuracy, which allows wireless monitoring of patients, and the insertion of the information into the Wi-Fi hospital networks.

Application of Multihop Relay for Performance Enhancement of AeroMACS Networks

NASA Technical Reports Server (NTRS)

Kamali, Behnam; Wilson, Jeffrey D.; Kerczewski, Robert J.

2012-01-01

A new transmission technology, based on IEEE 802.16-2009 (WiMAX), is currently being developed for airport surface communications. A C-band spectrum allocation at 5091 to 5150 MHz has been created by International Telecommunications Union (ITU) to carry this application. The proposed technology, known as AeroMACS, will be used to support fixed and mobile ground to ground applications and services. This article proposes and demonstrates that IEEE 802.16j-amendment-based WiMAX is most feasible for AeroMACS applications. This amendment introduces multihop relay as an optional deployment that may be used to provide additional coverage and/or enhance the capacity of the network. Particular airport surface radio coverage situations for which IEEE 802.16-2009-WiMAX provides resolutions that are inefficient, costly, or excessively power consuming are discussed. In all these cases, it is argued that 16j technology offers a much better alternative. A major concern about deployment of AeroMACS is interference to co-allocated applications such as the Mobile Satellite Service (MSS) feeder link. Our initial simulation results suggest that no additional interference to MSS feeder link is caused by deployment of IEEE 802.16j-based AeroMACS.

Conductivity Of Explosively Shocked Potassium Chloride

DTIC Science & Technology

2009-06-01

explosives and in a light gas gun were performed in [6, 7, 10]. In these works, it was demonstrated that KCl samples pass through the dielectric-to... plasma on the recorded signals. (a) (b) Figure 1. Schematic diagram of the device developed for investigation...Papers 1976-2013, and Abstracts of the 2013 IEEE International Conference on Plasma Science. IEEE International Pulsed Power Conference (19th). Held in San

On the seamless, harmonized use of ISO/IEEE11073 and openEHR.

PubMed

Trigo, Jesús D; Kohl, Christian D; Eguzkiza, Aitor; Martínez-Espronceda, Miguel; Alesanco, Álvaro; Serrano, Luis; García, José; Knaup, Petra

2014-05-01

Standardized exchange of clinical information is a key factor in the provision of high quality health care systems. In this context, the openEHR specification facilitates the management of health data in electronic health records (EHRs), while the ISO/IEEE11073 (also referred to as X73PHD) family of standards provides a reference framework for medical device interoperability. Hospitals and health care providers using openEHR require flawless integration of data coming from external sources, such as X73PHD. Hence, a harmonization process is crucial for achieving a seamless, coherent use of those specifications in real scenarios. Such harmonization is the aim of this paper. Thus, the classes and attributes of a representative number of X73PHD specializations for medical devices--weight, temperature, blood pressure, pulse and heart rate, oximetry, and electrocardiograph--along with the X73PHD core document--ISO/IEEE11073-20601--have been analyzed and mapped to openEHR archetypes. The proposed methodology reuses the existing archetypes when possible and suggests new ones--or appropriate modifications--otherwise. As a result, this paper analyzes the inconsistencies found and the implications thereof in the coordinated use of these two standards. The procedure has also shown how existing standards are able to influence the archetype development process, enhancing the existing archetype corpus.

A Data Specification for Software Project Performance Measures: Results of a Collaboration on Performance Measurement

DTIC Science & Technology

2008-07-01

cycle Evolution of a system, product, service, project or other human-made entity from conception through retirement [ ISO 12207 ]. Logical line of...012 [ ISO 1995] International Organization for Standardization. ISO /IEC 12207 :1995—Information technology— Software life cycle processes. http...definitions, authors were asked to use or align with already existing standards such as those available through ISO and IEEE when possible. Literature

Knock-limited performance of several internal coolants

NASA Technical Reports Server (NTRS)

Bellman, Donald R; Evvard, John C

1945-01-01

The effect of internal cooling on the knock-limited performance of an-f-28 fuel was investigated in a CFR engine, and the following internal coolants were used: (1) water, (2), methyl alcohol-water mixture, (3) ammonia-methyl alcohol-water mixture, (4) monomethylamine-water mixture, (5) dimethylamine-water mixture, and (6) trimethylamine-water mixture. Tests were run at inlet-air temperatures of 150 degrees and 250 degrees F. to indicate the temperature sensitivity of the internal-coolant solutions.

Multiple Power-Saving MSSs Scheduling Methods for IEEE802.16e Broadband Wireless Networks

PubMed Central

2014-01-01

This work proposes two enhanced multiple mobile subscriber stations (MSSs) power-saving scheduling methods for IEEE802.16e broadband wireless networks. The proposed methods are designed for the Unsolicited Grant Service (UGS) of IEEE802.16e. To reduce the active periods of all power-saving MSSs, the base station (BS) allocates each MSS fewest possible transmission frames to retrieve its data from the BS. The BS interlaces the active periods of each MSS to increase the amount of scheduled MSSs and splits the overflowing transmission frames to maximize the bandwidth utilization. Simulation results reveal that interlacing the active periods of MSSs can increase the number of scheduled MSSs to more than four times of that in the Direct scheduling method. The bandwidth utilization can thus be improved by 60%–70%. Splitting the overflowing transmission frames can improve bandwidth utilization by more than 10% over that achieved using the method of interlacing active periods, with a sacrifice of only 1% of the sleep periods in the interlacing active period method. PMID:24523656

Trustworthy data collection from implantable medical devices via high-speed security implementation based on IEEE 1363.

PubMed

Hu, Fei; Hao, Qi; Lukowiak, Marcin; Sun, Qingquan; Wilhelm, Kyle; Radziszowski, Stanisław; Wu, Yao

2010-11-01

Implantable medical devices (IMDs) have played an important role in many medical fields. Any failure in IMDs operations could cause serious consequences and it is important to protect the IMDs access from unauthenticated access. This study investigates secure IMD data collection within a telehealthcare [mobile health (m-health)] network. We use medical sensors carried by patients to securely access IMD data and perform secure sensor-to-sensor communications between patients to relay the IMD data to a remote doctor's server. To meet the requirements on low computational complexity, we choose N-th degree truncated polynomial ring (NTRU)-based encryption/decryption to secure IMD-sensor and sensor-sensor communications. An extended matryoshkas model is developed to estimate direct/indirect trust relationship among sensors. An NTRU hardware implementation in very large integrated circuit hardware description language is studied based on industry Standard IEEE 1363 to increase the speed of key generation. The performance analysis results demonstrate the security robustness of the proposed IMD data access trust model.

Interpretation of IEEE-854 floating-point standard and definition in the HOL system

NASA Technical Reports Server (NTRS)

Carreno, Victor A.

1995-01-01

The ANSI/IEEE Standard 854-1987 for floating-point arithmetic is interpreted by converting the lexical descriptions in the standard into mathematical conditional descriptions organized in tables. The standard is represented in higher-order logic within the framework of the HOL (Higher Order Logic) system. The paper is divided in two parts with the first part the interpretation and the second part the description in HOL.

IEEE (Institute of Electrical and Electronics Engineers) International Pulsed Power Conference on (2nd) Held in Lubbock, Texas on 12-14 June 1979 (Digest of Technical Papers)

DTIC Science & Technology

1980-02-01

PHOTOGRAPH THIS SHEET 0 FILE P.IwLEVEL IVETRY U- AFP65,f-7YA ga- - II IDS DTIBUTION T ATEMNT A App.-ove~d for public release; Di.-tribuilon Unlinitod... PHOTOGRAPH THIS SHEET AND RETURN TO DTIC-FDAC DTIC FORM 70A DOCUMENT PROCESSING SHEET PREVIOUS EDITION MAY BE USED UNTIL MAR 86 STOCK IS EXHAUSTED. IEEE 2rd...Kolm devel- transfers momencum from a massive ch..ically diven oped the "mass driver" as part of two NASA -AMES sum- armacure to a much lighter, hi h r

Performance management of multiple access communication networks

NASA Astrophysics Data System (ADS)

Lee, Suk; Ray, Asok

1993-12-01

This paper focuses on conceptual design, development, and implementation of a performance management tool for computer communication networks to serve large-scale integrated systems. The objective is to improve the network performance in handling various types of messages by on-line adjustment of protocol parameters. The techniques of perturbation analysis of Discrete Event Dynamic Systems (DEDS), stochastic approximation (SA), and learning automata have been used in formulating the algorithm of performance management. The efficacy of the performance management tool has been demonstrated on a network testbed. The conceptual design presented in this paper offers a step forward to bridging the gap between management standards and users' demands for efficient network operations since most standards such as ISO (International Standards Organization) and IEEE address only the architecture, services, and interfaces for network management. The proposed concept of performance management can also be used as a general framework to assist design, operation, and management of various DEDS such as computer integrated manufacturing and battlefield C(sup 3) (Command, Control, and Communications).

Startle reduces recall of a recently learned internal model.

PubMed

Wright, Zachary; Patton, James L; Ravichandran, Venn

2011-01-01

Recent work has shown that preplanned motor programs are released early from subcortical areas by the using a startling acoustic stimulus (SAS). Our question is whether this response might also contain a recently learned internal model, which draws on experience to predict and compensate for expected perturbations in a feedforward manner. Studies of adaptation to robotic forces have shown some evidence of this, but were potentially confounded by cocontraction caused by startle. We performed a new adaptation experiment using a visually distorted field that could not be confounded by cocontraction. We found that in all subjects that exhibited startle, the startle stimulus (1) reduced performance of the recently learned task (2) reduced after-effect magnitudes. Because startle reduced but did not eliminate the recall of learned control, we suggest that multiple neural centers (cortical and subcortical) are involved in such learning and adaptation, which can impact training areas such as piloting, teleoperation, sports, and rehabilitation. © 2011 IEEE

Internal performance predictions for Langley scramjet engine module

NASA Technical Reports Server (NTRS)

Pinckney, S. Z.

1978-01-01

A one dimensional theoretical method for the prediction of the internal performance of a scramjet engine is presented. The effects of changes in vehicle forebody flow parameters and characteristics on predicted thrust for the scramjet engine were evaluated using this method, and results are presented. A theoretical evaluation of the effects of changes in the scramjet engine's internal parameters is also presented. Theoretical internal performance predictions, in terms thrust coefficient and specific impulse, are provided for the scramjet engine for free stream Mach numbers of 5, 6, and 7 free stream dynamic pressure of 23,940 N/sq m forebody surface angles of 4.6 deg to 14.6 deg, and fuel equivalence ratio of 1.0.

Field-programmable gate array implementation of an all-digital IEEE 802.15.4-compliant transceiver

NASA Astrophysics Data System (ADS)

Cornetta, Gianluca; Touhafi, Abdellah; Santos, David J.; Vázquez, José M.

2010-12-01

An architecture for a low-cost, low-complexity digital transceiver is presented in this article. The proposed architecture targets the IEEE 802.15.4 standard for short-range wireless personal area networks and has been implemented as a synthesisable VHDL register transfer level description. The system has been evaluated and tested using a Xilinx 90 nm Virtex-4 field-programmable gate array as the target technology. Bit error rate (BER) and error vector magnitude (EVM) have been used as the figures of merit for modem performance. Simulations show that the recommended minimum BER is achieved at E b/N 0 = 8.7 dB, whereas the EVM is 19.5%. The implemented device occupies 10% of the target FPGA and has a normalised maximum power consumption of 44 mW in transmit mode and 53 mW in receiver mode.

A pseudo differential Gm—C complex filter with frequency tuning for IEEE802.15.4 applications

NASA Astrophysics Data System (ADS)

Xin, Cheng; Lungui, Zhong; Haigang, Yang; Fei, Liu; Tongqiang, Gao

2011-07-01

This paper presents a CMOS Gm—C complex filter for a low-IF receiver of the IEEE 802.15.4 standard. A pseudo differential OTA with reconfigurable common mode feedback and common mode feed-forward is proposed as well as the frequency tuning method based on a relaxation oscillator. A detailed analysis of non-ideality of the OTA and the frequency tuning method is elaborated. The analysis and measurement results have shown that the center frequency of the complex filter could be tuned accurately. The chip was fabricated in a standard 0.35 μm CMOS process, with a single 3.3 V power supply. The filter consumes 2.1mA current, has a measured in-band group delay ripple of less than 0.16 μs and an IRR larger than 28 dB at 2 MHz apart, which could meet the requirements oftheIEEE802.15.4 standard.

Provision of QoS for Multimedia Services in IEEE 802.11 Wireless Network

DTIC Science & Technology

2006-10-01

Provision of QoS for Multimedia Services in IEEE 802.11 Wireless Network. In Dynamic Communications Management (pp. 10-1 – 10-16). Meeting Proceedings...mechanisms have been used for managing a limited bandwidth link within the IPv6 military narrowband network. The detailed description of these...confirms that implemented video rate adaptation mechanism enables improvement of qaulity of video transfer. Provision of QoS for Multimedia Services in

Throughput analysis of the IEEE 802.4 token bus standard under heavy load

NASA Technical Reports Server (NTRS)

Pang, Joseph; Tobagi, Fouad

1987-01-01

It has become clear in the last few years that there is a trend towards integrated digital services. Parallel to the development of public Integrated Services Digital Network (ISDN) is service integration in the local area (e.g., a campus, a building, an aircraft). The types of services to be integrated depend very much on the specific local environment. However, applications tend to generate data traffic belonging to one of two classes. According to IEEE 802.4 terminology, the first major class of traffic is termed synchronous, such as packetized voice and data generated from other applications with real-time constraints, and the second class is called asynchronous which includes most computer data traffic such as file transfer or facsimile. The IEEE 802.4 token bus protocol which was designed to support both synchronous and asynchronous traffic is examined. The protocol is basically a timer-controlled token bus access scheme. By a suitable choice of the design parameters, it can be shown that access delay is bounded for synchronous traffic. As well, the bandwidth allocated to asynchronous traffic can be controlled. A throughput analysis of the protocol under heavy load with constant channel occupation of synchronous traffic and constant token-passing times is presented.

48 CFR 52.223-16 - IEEE 1680 Standard for the Environmental Assessment of Personal Computer Products.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Environmental Assessment of Personal Computer Products. 52.223-16 Section 52.223-16 Federal Acquisition... Assessment of Personal Computer Products. As prescribed in 23.705(b)(1), insert the following clause: IEEE 1680 Standard for the Environmental Assessment of Personal Computer Products (DEC 2007) (a) Definitions...

48 CFR 52.223-16 - IEEE 1680 Standard for the Environmental Assessment of Personal Computer Products.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Environmental Assessment of Personal Computer Products. 52.223-16 Section 52.223-16 Federal Acquisition... Assessment of Personal Computer Products. As prescribed in 23.705(b)(1), insert the following clause: IEEE 1680 Standard for the Environmental Assessment of Personal Computer Products (DEC 2007) (a) Definitions...

48 CFR 52.223-16 - IEEE 1680 Standard for the Environmental Assessment of Personal Computer Products.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Environmental Assessment of Personal Computer Products. 52.223-16 Section 52.223-16 Federal Acquisition... Assessment of Personal Computer Products. As prescribed in 23.705(b)(1), insert the following clause: IEEE 1680 Standard for the Environmental Assessment of Personal Computer Products (DEC 2007) (a) Definitions...

48 CFR 52.223-16 - IEEE 1680 Standard for the Environmental Assessment of Personal Computer Products.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Environmental Assessment of Personal Computer Products. 52.223-16 Section 52.223-16 Federal Acquisition... Assessment of Personal Computer Products. As prescribed in 23.706(b)(1), insert the following clause: IEEE 1680 Standard for the Environmental Assessment of Personal Computer Products (DEC 2007) (a) Definitions...

NASA/IEEE MSST 2004 Twelfth NASA Goddard Conference on Mass Storage Systems and Technologies in cooperation with the Twenty-First IEEE Conference on Mass Storage Systems and Technologies

NASA Technical Reports Server (NTRS)

Kobler, Ben (Editor); Hariharan, P. C. (Editor)

2004-01-01

MSST2004, the Twelfth NASA Goddard / Twenty-first IEEE Conference on Mass Storage Systems and Technologies has as its focus long-term stewardship of globally-distributed storage. The increasing prevalence of e-anything brought about by widespread use of applications based, among others, on the World Wide Web, has contributed to rapid growth of online data holdings. A study released by the School of Information Management and Systems at the University of California, Berkeley, estimates that over 5 exabytes of data was created in 2002. Almost 99 percent of this information originally appeared on magnetic media. The theme for MSST2004 is therefore both timely and appropriate. There have been many discussions about rapid technological obsolescence, incompatible formats and inadequate attention to the permanent preservation of knowledge committed to digital storage. Tutorial sessions at MSST2004 detail some of these concerns, and steps being taken to alleviate them. Over 30 papers deal with topics as diverse as performance, file systems, and stewardship and preservation. A number of short papers, extemporaneous presentations, and works in progress will detail current and relevant research on the MSST2004 theme.

Book of Abstracts, 1983 IEEE International Symposium on Applications of Ferroelectrics (ISAF).

DTIC Science & Technology

1984-05-31

adverse internal stresses develop which can contribute to the a31 coefficient. To lower the a31 coefficient the polyurethane is foamed , in addition to...light beams. Since the grating shift depends on the recording mechanism, measurements of the energy transfer can also give additional information on the... addition of Mn ( 1-2 ,ol %) to complete the sintering and decrease the dielectric loss at microwave frequnecy. The sintering w=s madc at 1500W-1600 C

Proceedings of the 1986 IEEE international conference on systems, man and cybernetics

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

Not Available

1986-01-01

This book presents the papers given at a conference on man-machine systems. Topics considered at the conference included neural model-based cognitive theory and engineering, user interfaces, adaptive and learning systems, human interaction with robotics, decision making, the testing and evaluation of expert systems, software development, international conflict resolution, intelligent interfaces, automation in man-machine system design aiding, knowledge acquisition in expert systems, advanced architectures for artificial intelligence, pattern recognition, knowledge bases, and machine vision.

University Employment Transitions in International Performing Arts: The Intern's Story

ERIC Educational Resources Information Center

Carneiro, Maria

2013-01-01

This article reflects my journey as a performing arts student and intern both in Portugal and abroad. It is not intended as a personal journal, but rather a reflection and an aftermath comment on my experiences and learning processes. First it provides a context regarding my university education in a Southern European country, against a previous…

Invisible watermarking optical camera communication and compatibility issues of IEEE 802.15.7r1 specification

NASA Astrophysics Data System (ADS)

Le, Nam-Tuan

2017-05-01

Copyright protection and information security are two most considered issues of digital data following the development of internet and computer network. As an important solution for protection, watermarking technology has become one of the challenged roles in industry and academic research. The watermarking technology can be classified by two categories: visible watermarking and invisible watermarking. With invisible technique, there is an advantage on user interaction because of the visibility. By applying watermarking for communication, it will be a challenge and a new direction for communication technology. In this paper we will propose one new research on communication technology using optical camera communications (OCC) based invisible watermarking. Beside the analysis on performance of proposed system, we also suggest the frame structure of PHY and MAC layer for IEEE 802.15.7r1 specification which is a revision of visible light communication (VLC) standardization.

Performance of International Medical Students In psychosocial medicine.

PubMed

Huhn, D; Lauter, J; Roesch Ely, D; Koch, E; Möltner, A; Herzog, W; Resch, F; Herpertz, S C; Nikendei, C

2017-07-10

Particularly at the beginning of their studies, international medical students face a number of language-related, social and intercultural challenges. Thus, they perform poorer than their local counterparts in written and oral examinations as well as in Objective Structured Clinical Examinations (OSCEs) in the fields of internal medicine and surgery. It is still unknown how international students perform in an OSCE in the field of psychosocial medicine compared to their local fellow students. All students (N = 1033) taking the OSCE in the field of psychosocial medicine and an accompanying written examination in their eighth or ninth semester between 2012 and 2015 were included in the analysis. The OSCE consisted of four different stations, in which students had to perform and manage a patient encounter with simulated patients suffering from 1) post-traumatic stress disorder, 2) schizophrenia, 3) borderline personality disorder and 4) either suicidal tendency or dementia. Students were evaluated by trained lecturers using global checklists assessing specific professional domains, namely building a relationship with the patient, conversational skills, anamnesis, as well as psychopathological findings and decision-making. International medical students scored significantly poorer than their local peers (p < .001; η 2  = .042). Within the specific professional domains assessed, they showed poorer scores, with differences in conversational skills showing the highest effect (p < .001; η 2  = .053). No differences emerged within the multiple-choice examination (p = .127). International students showed poorer results in clinical-practical exams in the field of psychosocial medicine, with conversational skills yielding the poorest scores. However, regarding factual and practical knowledge examined via a multiple-choice test, no differences emerged between international and local students. These findings have decisive implications for relationship building in

Mathematical modeling of a radio-frequency path for IEEE 802.11ah based wireless sensor networks

NASA Astrophysics Data System (ADS)

Tyshchenko, Igor; Cherepanov, Alexander; Dmitrii, Vakhnin; Popova, Mariia

2017-09-01

This article discusses the process of creating the mathematical model of a radio-frequency path for an IEEE 802.11ah based wireless sensor networks using M atLab Simulink CAD tools. In addition, it describes occurring perturbing effects and determining the presence of a useful signal in the received mixture.

Robust Multi-Agent Sensor Network Systems

DTIC Science & Technology

2012-05-08

Localization on the Sphere, International Journal of Intelligent Defence Support System, Vol. 4, no. 4, 2011, pp. 328-350. Quality of Network... Quality of Service (QoS). The following standards are included in the IEEE 1609 standard family: IEEE P1609.0, IEEE P1609.1, IEEE P1609.2, IEEE P1609.3...protocols to support safety services in ITS,” in IEEE International Conference on Emerging Technologies and Factory Au- tomation (ETFA), 2008, pp. 1189

Performance Analysis of Wireless Networks for Industrial Automation-Process Automation (WIA-PA)

DTIC Science & Technology

2017-09-01

electrical, water and wastewater, oil and natural gas, chemical, transportation, pharmaceutical, pulp and paper, food and beverage, and discrete...scheduling method for isa100.11a,” in 2013 11th IEEE International Conference on Industrial Informatics (INDIN), 2013, pp. 649–654. [24] Y. Wei and D.-S

Notice of Violation of IEEE Publication PrinciplesJoint Redundant Residue Number Systems and Module Isolation for Mitigating Single Event Multiple Bit Upsets in Datapath

NASA Astrophysics Data System (ADS)

Li, Lei; Hu, Jianhao

2010-12-01

Notice of Violation of IEEE Publication Principles"Joint Redundant Residue Number Systems and Module Isolation for Mitigating Single Event Multiple Bit Upsets in Datapath"by Lei Li and Jianhao Hu,in the IEEE Transactions on Nuclear Science, vol.57, no.6, Dec. 2010, pp. 3779-3786After careful and considered review of the content and authorship of this paper by a duly constituted expert committee, this paper has been found to be in violation of IEEE's Publication Principles.This paper contains substantial duplication of original text from the paper cited below. The original text was copied without attribution (including appropriate references to the original author(s) and/or paper title) and without permission.Due to the nature of this violation, reasonable effort should be made to remove all past references to this paper, and future references should be made to the following articles:"Multiple Error Detection and Correction Based on Redundant Residue Number Systems"by Vik Tor Goh and M.U. Siddiqi,in the IEEE Transactions on Communications, vol.56, no.3, March 2008, pp.325-330"A Coding Theory Approach to Error Control in Redundant Residue Number Systems. I: Theory and Single Error Correction"by H. Krishna, K-Y. Lin, and J-D. Sun, in the IEEE Transactions on Circuits and Systems II: Analog and Digital Signal Processing, vol.39, no.1, Jan 1992, pp.8-17In this paper, we propose a joint scheme which combines redundant residue number systems (RRNS) with module isolation (MI) for mitigating single event multiple bit upsets (SEMBUs) in datapath. The proposed hardening scheme employs redundant residues to improve the fault tolerance for datapath and module spacings to guarantee that SEMBUs caused by charge sharing do not propagate among the operation channels of different moduli. The features of RRNS, such as independence, parallel and error correction, are exploited to establish the radiation hardening architecture for the datapath in radiation environments. In the proposed

Introduction to IEEE 841-1994, IEEE standard for petroleum and chemical industry: Severe duty totally enclosed fan-cooled (TEFC) squirrel cage induction motors -- up to and including 500 hp

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

Doughty, R.L.

1995-12-31

IEEE 841, Recommended Practice for Chemical Industry Severe Duty Squirrel-Cage Induction Motors--600 V and Below, first issued in 1986, has been significantly revised and reissued as a Standard. The scope has been increased to include severe duty TEFC squirrel-cage induction motors with antifriction bearings in sizes up to and including 500 horsepower. Motor rated voltages of 2,300 V and 4,000 V have been added. Changes to the standard are reviewed in detail. Requirements are identified that improve motor reliability and increase motor life.

On the Network Convergence Process in RPL over IEEE 802.15.4 Multihop Networks: Improvement and Trade-Offs

PubMed Central

Kermajani, Hamidreza; Gomez, Carles

2014-01-01

The IPv6 Routing Protocol for Low-power and Lossy Networks (RPL) has been recently developed by the Internet Engineering Task Force (IETF). Given its crucial role in enabling the Internet of Things, a significant amount of research effort has already been devoted to RPL. However, the RPL network convergence process has not yet been investigated in detail. In this paper we study the influence of the main RPL parameters and mechanisms on the network convergence process of this protocol in IEEE 802.15.4 multihop networks. We also propose and evaluate a mechanism that leverages an option available in RPL for accelerating the network convergence process. We carry out extensive simulations for a wide range of conditions, considering different network scenarios in terms of size and density. Results show that network convergence performance depends dramatically on the use and adequate configuration of key RPL parameters and mechanisms. The findings and contributions of this work provide a RPL configuration guideline for network convergence performance tuning, as well as a characterization of the related performance trade-offs. PMID:25004154

On the network convergence process in RPL over IEEE 802.15.4 multihop networks: improvement and trade-offs.

PubMed

Kermajani, Hamidreza; Gomez, Carles

2014-07-07

The IPv6 Routing Protocol for Low-power and Lossy Networks (RPL) has been recently developed by the Internet Engineering Task Force (IETF). Given its crucial role in enabling the Internet of Things, a significant amount of research effort has already been devoted to RPL. However, the RPL network convergence process has not yet been investigated in detail. In this paper we study the influence of the main RPL parameters and mechanisms on the network convergence process of this protocol in IEEE 802.15.4 multihop networks. We also propose and evaluate a mechanism that leverages an option available in RPL for accelerating the network convergence process. We carry out extensive simulations for a wide range of conditions, considering different network scenarios in terms of size and density. Results show that network convergence performance depends dramatically on the use and adequate configuration of key RPL parameters and mechanisms. The findings and contributions of this work provide a RPL configuration guideline for network convergence performance tuning, as well as a characterization of the related performance trade-offs.

Extending the IEEE 802.15.4 Security Suite with a Compact Implementation of the NIST P-192/B-163 Elliptic Curves

PubMed Central

de la Piedra, Antonio; Braeken, An; Touhafi, Abdellah

2013-01-01

Typically, commercial sensor nodes are equipped with MCUsclocked at a low-frequency (i.e., within the 4–12 MHz range). Consequently, executing cryptographic algorithms in those MCUs generally requires a huge amount of time. In this respect, the required energy consumption can be higher than using a separate accelerator based on a Field-programmable Gate Array (FPGA) that is switched on when needed. In this manuscript, we present the design of a cryptographic accelerator suitable for an FPGA-based sensor node and compliant with the IEEE802.15.4 standard. All the embedded resources of the target platform (Xilinx Artix-7) have been maximized in order to provide a cost-effective solution. Moreover, we have added key negotiation capabilities to the IEEE 802.15.4 security suite based on Elliptic Curve Cryptography (ECC;. Our results suggest that tailored accelerators based on FPGA can behave better in terms of energy than contemporary software solutions for motes, such as the TinyECC and NanoECC libraries. In this regard, a point multiplication (PM) can be performed between 8.58- and 15.4-times faster, 3.40- to 23.59-times faster (Elliptic Curve Diffie-Hellman, ECDH) and between 5.45- and 34.26-times faster (Elliptic Curve Integrated Encryption Scheme, ECIES). Moreover, the energy consumption was also improved with a factor of 8.96 (PM). PMID:23899936

Extending the IEEE 802.15.4 security suite with a compact implementation of the NIST P-192/B-163 elliptic curves.

PubMed

de la Piedra, Antonio; Braeken, An; Touhafi, Abdellah

2013-07-29

Typically, commercial sensor nodes are equipped with MCUsclocked at a low-frequency (i.e., within the 4-12 MHz range). Consequently, executing cryptographic algorithms in those MCUs generally requires a huge amount of time. In this respect, the required energy consumption can be higher than using a separate accelerator based on a Field-programmable Gate Array (FPGA) that is switched on when needed. In this manuscript, we present the design of a cryptographic accelerator suitable for an FPGA-based sensor node and compliant with the IEEE802.15.4 standard. All the embedded resources of the target platform (Xilinx Artix-7) have been maximized in order to provide a cost-effective solution. Moreover, we have added key negotiation capabilities to the IEEE 802.15.4 security suite based on Elliptic Curve Cryptography (ECC). Our results suggest that tailored accelerators based on FPGA can behave better in terms of energy than contemporary software solutions for motes, such as the TinyECC and NanoECC libraries. In this regard, a point multiplication (PM) can be performed between 8.58- and 15.4-times faster, 3.40- to 23.59-times faster (Elliptic Curve Diffie-Hellman, ECDH) and between 5.45- and 34.26-times faster (Elliptic Curve Integrated Encryption Scheme, ECIES). Moreover, the energy consumption was also improved with a factor of 8.96 (PM).

Impact of electric vehicles on the IEEE 34 node distribution infrastructure

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

Jiang, Zeming; Shalalfel, Laith; Beshir, Mohammed J.

With the growing penetration of the electric vehicles to our daily life owing to their economic and environmental benefits, there will be both opportunities and challenges to the utilities when adopting plug-in electric vehicles (PEV) to the distribution network. In this study, a thorough analysis based on real-world project is conducted to evaluate the impacts of electric vehicles infrastructure on the grid relating to system load flow, load factor, and voltage stability. IEEE 34 node test feeder was selected and tested along with different case scenarios utilizing the electrical distribution design (EDD) software to find out the potential impacts tomore » the grid.« less

Impact of electric vehicles on the IEEE 34 node distribution infrastructure

DOE PAGES

Jiang, Zeming; Shalalfel, Laith; Beshir, Mohammed J.

2014-10-01

With the growing penetration of the electric vehicles to our daily life owing to their economic and environmental benefits, there will be both opportunities and challenges to the utilities when adopting plug-in electric vehicles (PEV) to the distribution network. In this study, a thorough analysis based on real-world project is conducted to evaluate the impacts of electric vehicles infrastructure on the grid relating to system load flow, load factor, and voltage stability. IEEE 34 node test feeder was selected and tested along with different case scenarios utilizing the electrical distribution design (EDD) software to find out the potential impacts tomore » the grid.« less

Deployment of Directory Service for IEEE N Bus Test System Information

NASA Astrophysics Data System (ADS)

Barman, Amal; Sil, Jaya

2008-10-01

Exchanging information over Internet and Intranet becomes a defacto standard in computer applications, among various users and organizations. Distributed system study, e-governance etc require transparent information exchange between applications, constituencies, manufacturers, and vendors. To serve these purposes database system is needed for storing system data and other relevant information. Directory service, which is a specialized database along with access protocol, could be the single solution since it runs over TCP/IP, supported by all POSIX compliance platforms and is based on open standard. This paper describes a way to deploy directory service, to store IEEE n bus test system data and integrating load flow program with it.

Implementing Remote Image Capture/Control in a Wireless Sensor Network Utilizing the IEEE 802.15.4 Standard

DTIC Science & Technology

2009-09-01

with the flexibility provided by a wireless sensor network , could provide such enhancements. The objective of this research was to explore the...feasibility of remote management and control of a low-power/low-cost wireless sensor network by implementing a point-to-point wireless network utilizing IEEE

Vispubdata.org: A Metadata Collection About IEEE Visualization (VIS) Publications.

PubMed

Isenberg, Petra; Heimerl, Florian; Koch, Steffen; Isenberg, Tobias; Xu, Panpan; Stolper, Charles D; Sedlmair, Michael; Chen, Jian; Moller, Torsten; Stasko, John

2017-09-01

We have created and made available to all a dataset with information about every paper that has appeared at the IEEE Visualization (VIS) set of conferences: InfoVis, SciVis, VAST, and Vis. The information about each paper includes its title, abstract, authors, and citations to other papers in the conference series, among many other attributes. This article describes the motivation for creating the dataset, as well as our process of coalescing and cleaning the data, and a set of three visualizations we created to facilitate exploration of the data. This data is meant to be useful to the broad data visualization community to help understand the evolution of the field and as an example document collection for text data visualization research.

Adaptive management of energy consumption, reliability and delay of wireless sensor node: Application to IEEE 802.15.4 wireless sensor node.

PubMed

Kone, Cheick Tidjane; Mathias, Jean-Denis; De Sousa, Gil

2017-01-01

Designing a Wireless Sensor Network (WSN) to achieve a high Quality of Service (QoS) (network performance and durability) is a challenging problem. We address it by focusing on the performance of the 802.15.4 communication protocol because the IEEE 802.15.4 Standard is actually considered as one of the reference technologies in WSNs. In this paper, we propose to control the sustainable use of resources (i.e., energy consumption, reliability and timely packet transmission) of a wireless sensor node equipped with photovoltaic cells by an adaptive tuning not only of the MAC (Medium Access Control) parameters but also of the sampling frequency of the node. To do this, we use one of the existing control approaches, namely the viability theory, which aims to preserve the functions and the controls of a dynamic system in a set of desirable states. So, an analytical model, describing the evolution over time of nodal resources, is derived and used by a viability algorithm for the adaptive tuning of the IEEE 802.15.4 MAC protocol. The simulation analysis shows that our solution allows ensuring indefinitely, in the absence of hardware failure, the operations (lifetime duration, reliability and timely packet transmission) of an 802.15.4 WSN and one can temporarily increase the sampling frequency of the node beyond the regular sampling one. This latter brings advantages for agricultural and environmental applications such as precision agriculture, flood or fire prevention. Main results show that our current approach enable to send more information when critical events occur without the node runs out of energy. Finally, we argue that our approach is generic and can be applied to other types of WSN.

BabelFish-Tools for IEEE C37.118.2-compliant real-time synchrophasor data mediation

NASA Astrophysics Data System (ADS)

Almas, M. S.; Vanfretti, L.; Baudette, M.

BabelFish (BF) is a real-time data mediator for development and fast prototyping of synchrophasor applications. BF is compliant with the synchrophasor data transmission IEEE Std C37.118.2-2011. BF establishes a TCP/IP connection with any Phasor Measurement Unit (PMU) or Phasor Data Concentrator (PDC) stream and parses the IEEE Std C37.118.2-2011 frames in real-time to provide access to raw numerical data in the LabVIEW environment. Furthermore, BF allows the user to select "data-of-interest" and transmit it to either a local or remote application using the User Datagram Protocol (UDP) in order to support both unicast and multicast communication. In the power systems Wide Area Monitoring Protection and Control (WAMPAC) domain, BF provides the first Free/Libre and Open Source Software (FLOSS) for the purpose of giving the users tools for fast prototyping of new applications processing PMU measurements in their chosen environment, thus liberating them of time consuming synchrophasor data handling and allowing them to develop applications in a modular fashion, without a need of a large and monolithic synchrophasor software environment.

Proceedings of the 1987 IEEE international conference on systems, man, and cybernetics. Volume 1

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

Not Available

1987-01-01

This book contains the proceedings of the IEE international conference on systems Man, and cybernetics. Topics include the following: robotics; knowledge base simulation; software systems, image and pattern recognition; neural networks; and image processing.

Analyzing the Engineering Educational Research in Spain: A Global Vision through the Awards of CESEI-IEEE

ERIC Educational Resources Information Center

Plaza, I.; Arcega, F.; Castro, M.; Llamas, M.

2011-01-01

CESEI is the acronym of the Spanish Chapter of the Education Society of IEEE (the Institute of Electric and Electronics Engineers). Every year, the CESEI awards a prize for the best doctoral thesis and FDP (final (master) degree projects) about education. The thesis or the project must be developed in the areas of electrical engineering,…

42 CFR 460.136 - Internal quality assessment and performance improvement activities.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 4 2010-10-01 2010-10-01 false Internal quality assessment and performance improvement activities. 460.136 Section 460.136 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES....136 Internal quality assessment and performance improvement activities. (a) Quality assessment and...

Researching the Performance of International Students in the UK

ERIC Educational Resources Information Center

Morrison, Jo; Merrick, Beatrice; Higgs, Samantha; Le Matais, Joanna

2005-01-01

This article considers how well international students in the UK perform academically, seeking to identify factors which affect their ability to fulfil their potential. It provides a short survey of the literature and summarises the findings of a research project commissioned by UKCOSA: The Council for International Education. The research…

Performance analysis of a SOFC under direct internal reforming conditions

NASA Astrophysics Data System (ADS)

Janardhanan, Vinod M.; Heuveline, Vincent; Deutschmann, Olaf

This paper presents the performance analysis of a planar solid-oxide fuel cell (SOFC) under direct internal reforming conditions. A detailed solid-oxide fuel cell model is used to study the influences of various operating parameters on cell performance. Significant differences in efficiency and power density are observed for isothermal and adiabatic operational regimes. The influence of air number, specific catalyst area, anode thickness, steam to carbon (s/c) ratio of the inlet fuel, and extend of pre-reforming on cell performance is analyzed. In all cases except for the case of pre-reformed fuel, adiabatic operation results in lower performance compared to isothermal operation. It is further discussed that, though direct internal reforming may lead to cost reduction and increased efficiency by effective utilization of waste heat, the efficiency of the fuel cell itself is higher for pre-reformed fuel compared to non-reformed fuel. Furthermore, criteria for the choice of optimal operating conditions for cell stacks operating under direct internal reforming conditions are discussed.

Architectural and Functional Design and Evaluation of E-Learning VUIS Based on the Proposed IEEE LTSA Reference Model.

ERIC Educational Resources Information Center

O'Droma, Mairtin S.; Ganchev, Ivan; McDonnell, Fergal

2003-01-01

Presents a comparative analysis from the Institute of Electrical and Electronics Engineers (IEEE) Learning Technology Standards Committee's (LTSC) of the architectural and functional design of e-learning delivery platforms and applications, e-learning course authoring tools, and learning management systems (LMSs), with a view of assessing how…

Relationship between Small Animal Intern Rank and Performance at a University Teaching Hospital.

PubMed

Hofmeister, Erik H; Saba, Corey; Kent, Marc; Creevy, Kate E

2015-01-01

The purpose of this study was to determine if there is a relationship between selection committee rankings of internship applicants and the performance of small animal interns. The hypothesis was that there would be a relationship between selection committee rank order and intern performance; the more highly an application was ranked, the better the intern's performance scores would be. In 2007, the Department of Small Animal Medicine and Surgery instituted a standardized approach to its intern selection process both to streamline the process and to track its effectiveness. At the end of intern years 2010-2014, every faculty member in the department was provided an intern assessment form for that year's class. There was no relationship between an individual intern's final rank by the selection committee and his/her performance either as a percentile score or a Likert-type score (p=.25, R2=0.04; p=0.31, R2=0.03, respectively). Likewise, when interns were divided into the top and bottom quartile based on their final rank by the selection committee, there was no relationship between their rank and their performance as a percentile score (median rank 15 vs. 20; p=.14) or Likert-type score (median rank 14 vs. 19; p=.27). Institutions that use a similar intern selection method may need to reconsider the time and effort being expended for an outcome that does not predict performance. Alternatively, specific criteria more predictive of performance outcomes should be identified and employed in the internship selection process.

Static internal performance of single-expansion-ramp nozzles with various combinations of internal geometric parameters

NASA Technical Reports Server (NTRS)

Re, R. J.; Leavitt, L. D.

1984-01-01

The effects of five geometric design parameters on the internal performance of single-expansion-ramp nozzles were investigated at nozzle pressure ratios up to 10 in the static-test facility of the Langley 16-Foot Transonic Tunnel. The geometric variables on the expansion-ramp surface of the upper flap consisted of ramp chordal angle, ramp length, and initial ramp angle. On the lower flap, the geometric variables consisted of flap angle and flap length. Both internal performance and static-pressure distributions on the centerlines of the upper and lower flaps were obtained for all 43 nozzle configurations tested.

Formal analysis and evaluation of the back-off procedure in IEEE802.11P VANET

NASA Astrophysics Data System (ADS)

Jin, Li; Zhang, Guoan; Zhu, Xiaojun

2017-07-01

The back-off procedure is one of the media access control technologies in 802.11P communication protocol. It plays an important role in avoiding message collisions and allocating channel resources. Formal methods are effective approaches for studying the performances of communication systems. In this paper, we establish a discrete time model for the back-off procedure. We use Markov Decision Processes (MDPs) to model the non-deterministic and probabilistic behaviors of the procedure, and use the probabilistic computation tree logic (PCTL) language to express different properties, which ensure that the discrete time model performs their basic functionality. Based on the model and PCTL specifications, we study the effect of contention window length on the number of senders in the neighborhood of given receivers, and that on the station’s expected cost required by the back-off procedure to successfully send packets. The variation of the window length may increase or decrease the maximum probability of correct transmissions within a time contention unit. We propose to use PRISM model checker to describe our proposed back-off procedure for IEEE802.11P protocol in vehicle network, and define different probability properties formulas to automatically verify the model and derive numerical results. The obtained results are helpful for justifying the values of the time contention unit.

Performance Analysis of the Mobile IP Protocol (RFC 3344 and Related RFCS)

DTIC Science & Technology

2006-12-01

Encapsulation HMAC Keyed-Hash Message Authentication Code ICMP Internet Control Message Protocol IEEE Institute of Electrical and Electronics Engineers IETF...Internet Engineering Task Force IOS Internetwork Operating System IP Internet Protocol ITU International Telecommunication Union LAN Local Area...network computing. Most organizations today have sophisticated networks that are connected to the Internet. The major benefit reaped from such a

IEEE-1588(Trademark) Standard for a Precision Clock Synchronization Protocol for Networked Measurement and Control Systems

DTIC Science & Technology

2002-12-01

34th Annual Precise Time and Time Interval (PTTI) Meeting 243 IEEE-1588™ STANDARD FOR A PRECISION CLOCK SYNCHRONIZATION PROTOCOL FOR... synchronization . 2. Cyclic-systems. In cyclic-systems, timing is periodic and is usually defined by the characteristics of a cyclic network or bus...incommensurate, timing schedules for each device are easily implemented. In addition, synchronization accuracy depends on the accuracy of the common

Eighth Goddard Conference on Mass Storage Systems and Technologies in Cooperation with the Seventeenth IEEE Symposium on Mass Storage Systems

NASA Technical Reports Server (NTRS)

Kobler, Benjamin (Editor); Hariharan, P. C. (Editor)

2000-01-01

This document contains copies of those technical papers received in time for publication prior to the Eighth Goddard Conference on Mass Storage Systems and Technologies which is being held in cooperation with the Seventeenth IEEE Symposium on Mass Storage Systems at the University of Maryland University College Inn and Conference Center March 27-30, 2000. As one of an ongoing series, this Conference continues to provide a forum for discussion of issues relevant to the management of large volumes of data. The Conference encourages all interested organizations to discuss long term mass storage requirements and experiences in fielding solutions. Emphasis is on current and future practical solutions addressing issues in data management, storage systems and media, data acquisition, long term retention of data, and data distribution. This year's discussion topics include architecture, future of current technology, new technology with a special emphasis on holographic storage, performance, standards, site reports, vendor solutions. Tutorials will be available on stability of optical media, disk subsystem performance evaluation, I/O and storage tuning, functionality and performance evaluation of file systems for storage area networks.

39 CFR 3050.52 - Information on service performance for international products. [Reserved

Code of Federal Regulations, 2010 CFR

2010-07-01

... 39 Postal Service 1 2010-07-01 2010-07-01 false Information on service performance for international products. [Reserved] 3050.52 Section 3050.52 Postal Service POSTAL REGULATORY COMMISSION PERSONNEL PERIODIC REPORTING § 3050.52 Information on service performance for international products. [Reserved] ...

Proceeding of the ACM/IEEE-CS Joint Conference on Digital Libraries (1st, Roanoke, Virginia, June 24-28, 2001).

ERIC Educational Resources Information Center

Association for Computing Machinery, New York, NY.

Papers in this Proceedings of the ACM/IEEE-CS Joint Conference on Digital Libraries (Roanoke, Virginia, June 24-28, 2001) discuss: automatic genre analysis; text categorization; automated name authority control; automatic event generation; linked active content; designing e-books for legal research; metadata harvesting; mapping the…

Software Aspects of IEEE Floating-Point Computations for Numerical Applications in High Energy Physics

ScienceCinema

Arnold, Jeffrey

2018-05-14

Floating-point computations are at the heart of much of the computing done in high energy physics. The correctness, speed and accuracy of these computations are of paramount importance. The lack of any of these characteristics can mean the difference between new, exciting physics and an embarrassing correction. This talk will examine practical aspects of IEEE 754-2008 floating-point arithmetic as encountered in HEP applications. After describing the basic features of IEEE floating-point arithmetic, the presentation will cover: common hardware implementations (SSE, x87) techniques for improving the accuracy of summation, multiplication and data interchange compiler options for gcc and icc affecting floating-point operations hazards to be avoided. About the speaker: Jeffrey M Arnold is a Senior Software Engineer in the Intel Compiler and Languages group at Intel Corporation. He has been part of the Digital->Compaq->Intel compiler organization for nearly 20 years; part of that time, he worked on both low- and high-level math libraries. Prior to that, he was in the VMS Engineering organization at Digital Equipment Corporation. In the late 1980s, Jeff spent 2½ years at CERN as part of the CERN/Digital Joint Project. In 2008, he returned to CERN to spent 10 weeks working with CERN/openlab. Since that time, he has returned to CERN multiple times to teach at openlab workshops and consult with various LHC experiments. Jeff received his Ph.D. in physics from Case Western Reserve University.

Smart City Pilot Projects Using LoRa and IEEE802.15.4 Technologies

PubMed Central

Buratti, Chiara; Zabini, Flavio; De Castro, Cristina; Verdone, Roberto; Andrisano, Oreste

2018-01-01

Information and Communication Technologies (ICTs), through wireless communications and the Internet of Things (IoT) paradigm, are the enabling keys for transforming traditional cities into smart cities, since they provide the core infrastructure behind public utilities and services. However, to be effective, IoT-based services could require different technologies and network topologies, even when addressing the same urban scenario. In this paper, we highlight this aspect and present two smart city testbeds developed in Italy. The first one concerns a smart infrastructure for public lighting and relies on a heterogeneous network using the IEEE 802.15.4 short-range communication technology, whereas the second one addresses smart-building applications and is based on the LoRa low-rate, long-range communication technology. The smart lighting scenario is discussed providing the technical details and the economic benefits of a large-scale (around 3000 light poles) flexible and modular implementation of a public lighting infrastructure, while the smart-building testbed is investigated, through measurement campaigns and simulations, assessing the coverage and the performance of the LoRa technology in a real urban scenario. Results show that a proper parameter setting is needed to cover large urban areas while maintaining the airtime sufficiently low to keep packet losses at satisfactory levels. PMID:29642391

Smart City Pilot Projects Using LoRa and IEEE802.15.4 Technologies.

PubMed

Pasolini, Gianni; Buratti, Chiara; Feltrin, Luca; Zabini, Flavio; De Castro, Cristina; Verdone, Roberto; Andrisano, Oreste

2018-04-06

Information and Communication Technologies (ICTs), through wireless communications and the Internet of Things (IoT) paradigm, are the enabling keys for transforming traditional cities into smart cities, since they provide the core infrastructure behind public utilities and services. However, to be effective, IoT-based services could require different technologies and network topologies, even when addressing the same urban scenario. In this paper, we highlight this aspect and present two smart city testbeds developed in Italy. The first one concerns a smart infrastructure for public lighting and relies on a heterogeneous network using the IEEE 802.15.4 short-range communication technology, whereas the second one addresses smart-building applications and is based on the LoRa low-rate, long-range communication technology. The smart lighting scenario is discussed providing the technical details and the economic benefits of a large-scale (around 3000 light poles) flexible and modular implementation of a public lighting infrastructure, while the smart-building testbed is investigated, through measurement campaigns and simulations, assessing the coverage and the performance of the LoRa technology in a real urban scenario. Results show that a proper parameter setting is needed to cover large urban areas while maintaining the airtime sufficiently low to keep packet losses at satisfactory levels.

Internal Control, CPA Recognition and Performance Consequence: Evidence from Chinese Real Estate Enterprises

NASA Astrophysics Data System (ADS)

Zhang, Chuan; Zhang, Lili; Geng, Yi

In recent years, internal control has caught more and more attention over the whole globe. However, whether internal control could improve business efficiency also lacks the empirical supports. Based on a sample size of 146 Chinese real estate enterprises, this study analyses the CPA’s recognition degree on firm’s implementing internal control, and its performance consequence. The evidence suggests that CPAs are able to give exact evaluation on firm’s internal control implement, and the higher the internal control implemented, the better performance the enterprise will have.

Introduction of the UNIX International Performance Management Work Group

NASA Technical Reports Server (NTRS)

Newman, Henry

1993-01-01

In this paper we presented the planned direction of the UNIX International Performance Management Work Group. This group consists of concerned system developers and users who have organized to synthesize recommendations for standard UNIX performance management subsystem interfaces and architectures. The purpose of these recommendations is to provide a core set of performance management functions and these functions can be used to build tools by hardware system developers, vertical application software developers, and performance application software developers.

Comparison and Analysis of ISO/IEEE 11073, IHE PCD-01, and HL7 FHIR Messages for Personal Health Devices

PubMed Central

Do, Hyoungho

2018-01-01

Objectives Increasing use of medical devices outside of healthcare facilities inevitably requires connectivity and interoperability between medical devices and healthcare information systems. To this end, standards have been developed and used to provide interoperability between personal health devices (PHDs) and external systems. ISO/IEEE 11073 standards and IHE PCD-01 standard messages have been used the most in the exchange of observation data of health devices. Recently, transmitting observation data using the HL7 FHIR standard has been devised in the name of DoF (Devices on FHIR) and adopted very fast. We compare and analyze these standards and suggest that which standard will work best at the different environments of device usage. Methods We generated each message/resource of the three standards for observed vital signs from blood pressure monitor and thermometer. Then, the size, the contents, and the exchange processes of these messages are compared and analyzed. Results ISO/IEEE 11073 standard message has the smallest data size, but it has no ability to contain the key information, patient information. On the other hand, PCD-01 messages and FHIR standards have the fields for patient information. HL7 DoF standards provide reusing of information unit known as resource, and it is relatively easy to parse DoF messages since it uses widely known XML and JSON. Conclusions ISO/IEEE 11073 standards are suitable for devices having very small computing power. IHE PCD-01 and HL7 DoF messages can be used for the devices that need to be connected to hospital information systems that require patient information. When information reuse is frequent, DoF is advantageous over PCD-01. PMID:29503752

Comparison and Analysis of ISO/IEEE 11073, IHE PCD-01, and HL7 FHIR Messages for Personal Health Devices.

PubMed

Lee, Sungkee; Do, Hyoungho

2018-01-01

Increasing use of medical devices outside of healthcare facilities inevitably requires connectivity and interoperability between medical devices and healthcare information systems. To this end, standards have been developed and used to provide interoperability between personal health devices (PHDs) and external systems. ISO/IEEE 11073 standards and IHE PCD-01 standard messages have been used the most in the exchange of observation data of health devices. Recently, transmitting observation data using the HL7 FHIR standard has been devised in the name of DoF (Devices on FHIR) and adopted very fast. We compare and analyze these standards and suggest that which standard will work best at the different environments of device usage. We generated each message/resource of the three standards for observed vital signs from blood pressure monitor and thermometer. Then, the size, the contents, and the exchange processes of these messages are compared and analyzed. ISO/IEEE 11073 standard message has the smallest data size, but it has no ability to contain the key information, patient information. On the other hand, PCD-01 messages and FHIR standards have the fields for patient information. HL7 DoF standards provide reusing of information unit known as resource, and it is relatively easy to parse DoF messages since it uses widely known XML and JSON. ISO/IEEE 11073 standards are suitable for devices having very small computing power. IHE PCD-01 and HL7 DoF messages can be used for the devices that need to be connected to hospital information systems that require patient information. When information reuse is frequent, DoF is advantageous over PCD-01.

Proceedings of the 1995 Particle Accelerator Conference and international Conference on High-Energy Accelerators

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

None

1996-01-01

Papers from the sixteenth biennial Particle Accelerator Conference, an international forum on accelerator science and technology held May 1–5, 1995, in Dallas, Texas, organized by Los Alamos National Laboratory (LANL) and Stanford Linear Accelerator Center (SLAC), jointly sponsored by the Institute of Electrical and Electronics Engineers (IEEE) Nuclear and Plasma Sciences Society (NPSS), the American Physical Society (APS) Division of Particles and Beams (DPB), and the International Union of Pure and Applied Physics (IUPAP), and conducted with support from the US Department of Energy, the National Science Foundation, and the Office of Naval Research.

Mindfulness, burnout, and effects on performance evaluations in internal medicine residents.

PubMed

Braun, Sarah E; Auerbach, Stephen M; Rybarczyk, Bruce; Lee, Bennett; Call, Stephanie

2017-01-01

Burnout has been documented at high levels in medical residents with negative effects on performance. Some dispositional qualities, like mindfulness, may protect against burnout. The purpose of the present study was to assess burnout prevalence among internal medicine residents at a single institution, examine the relationship between mindfulness and burnout, and provide preliminary findings on the relation between burnout and performance evaluations in internal medicine residents. Residents (n = 38) completed validated measures of burnout at three time points separated by 2 months and a validated measure of dispositional mindfulness at baseline. Program director end-of-year performance evaluations were also obtained on 22 milestones used to evaluate internal medicine resident performance; notably, these milestones have not yet been validated for research purposes; therefore, the investigation here is exploratory. Overall, 71.1% (n = 27) of the residents met criteria for burnout during the study. Lower scores on the "acting with awareness" facet of dispositional mindfulness significantly predicted meeting burnout criteria χ 2 (5) = 11.88, p = 0.04. Lastly, meeting burnout criteria significantly predicted performance on three of the performance milestones, with positive effects on milestones from the "system-based practices" and "professionalism" domains and negative effects on a milestone from the "patient care" domain. Burnout rates were high in this sample of internal medicine residents and rates were consistent with other reports of burnout during medical residency. Dispositional mindfulness was supported as a protective factor against burnout. Importantly, results from the exploratory investigation of the relationship between burnout and resident evaluations suggested that burnout may improve performance on some domains of resident evaluations while compromising performance on other domains. Implications and directions for future research are discussed.

Evaluating Internal Model Strength and Performance of Myoelectric Prosthesis Control Strategies.

PubMed

Shehata, Ahmed W; Scheme, Erik J; Sensinger, Jonathon W

2018-05-01

On-going developments in myoelectric prosthesis control have provided prosthesis users with an assortment of control strategies that vary in reliability and performance. Many studies have focused on improving performance by providing feedback to the user but have overlooked the effect of this feedback on internal model development, which is key to improve long-term performance. In this paper, the strength of internal models developed for two commonly used myoelectric control strategies: raw control with raw feedback (using a regression-based approach) and filtered control with filtered feedback (using a classifier-based approach), were evaluated using two psychometric measures: trial-by-trial adaptation and just-noticeable difference. The performance of both strategies was also evaluated using Schmidt's style target acquisition task. Results obtained from 24 able-bodied subjects showed that although filtered control with filtered feedback had better short-term performance in path efficiency ( ), raw control with raw feedback resulted in stronger internal model development ( ), which may lead to better long-term performance. Despite inherent noise in the control signals of the regression controller, these findings suggest that rich feedback associated with regression control may be used to improve human understanding of the myoelectric control system.

A Novel Energy Saving Algorithm with Frame Response Delay Constraint in IEEE 802.16e

NASA Astrophysics Data System (ADS)

Nga, Dinh Thi Thuy; Kim, Mingon; Kang, Minho

Sleep-mode operation of a Mobile Subscriber Station (MSS) in IEEE 802.16e effectively saves energy consumption; however, it induces frame response delay. In this letter, we propose an algorithm to quickly find the optimal value of the final sleep interval in sleep-mode in order to minimize energy consumption with respect to a given frame response delay constraint. The validations of our proposed algorithm through analytical results and simulation results suggest that our algorithm provide a potential guidance to energy saving.

Achievable Rate Estimation of IEEE 802.11ad Visual Big-Data Uplink Access in Cloud-Enabled Surveillance Applications.

PubMed

Kim, Joongheon; Kim, Jong-Kook

2016-01-01

This paper addresses the computation procedures for estimating the impact of interference in 60 GHz IEEE 802.11ad uplink access in order to construct visual big-data database from randomly deployed surveillance camera sensing devices. The acquired large-scale massive visual information from surveillance camera devices will be used for organizing big-data database, i.e., this estimation is essential for constructing centralized cloud-enabled surveillance database. This performance estimation study captures interference impacts on the target cloud access points from multiple interference components generated by the 60 GHz wireless transmissions from nearby surveillance camera devices to their associated cloud access points. With this uplink interference scenario, the interference impacts on the main wireless transmission from a target surveillance camera device to its associated target cloud access point with a number of settings are measured and estimated under the consideration of 60 GHz radiation characteristics and antenna radiation pattern models.

IEEE 1393 Spaceborne Fiber Optic Data Bus: A Standard Approach to On-Board Payload Data Handling Networks for the AIAA Space Technology Conference and Exposition "Partnering in the 21th Century"

NASA Technical Reports Server (NTRS)

Andrucyk, Dennis J.; Orlando, Fred J.; Chalfant, Charles H.

1999-01-01

The Spaceborne Fiber Optic Data Bus (SFODB) is the next generation in on-board data handling networks. It will do for high speed payloads what SAE 1773 has done for on-board command and telemetry systems. That is, it will significantly reduce the cost of payload development, integration and test through interface standardization. As defined in IEEE 1393, SFODB is a 1 Gb/s, fiber optic network specifically designed to support the real-time, on-board data handling requirements of remote sensing spacecraft. The network is highly reliable, fault tolerant, and capable of withstanding the rigors of launch and the harsh space environment. SFODB achieves this operational and environmental performance while maintaining the small size, light weight, and low power necessary for spaceborne applications. SFODB was developed jointly by DoD and NASA GSFC to meet the on-board data handling needs of Remote Sensing satellites. This jointly funded project produced a complete set of flight transmitters, receivers and protocol ASICS; a complete Development & Evaluation System; and, the IEEE 1393 standard.

A Comparison of Ionospheric Model Performance for International Space Station Orbits

DTIC Science & Technology

2013-03-01

Huang, C. Y., F. A . Marcos, P. A . Roddy, M . R. Hairston, W. R. Coley, C. Roth, S . Bruinsma, and D. E. Hunton (2009), Broad plasma decreases in the... A COMPARISON OF IONOSPHERIC MODEL PERFORMANCE FOR INTERNATIONAL SPACE STATION ORBITS THESIS David J. Broadwater, Captain, USAF AFIT-ENP-13- M -04...not subject to copyright protection in the United States. AFIT-ENP-13- M -04 A COMPARISON OF IONOSPHERIC MODEL PERFORMANCE FOR INTERNATIONAL SPACE

Performance analysis and improvement of WPAN MAC for home networks.

PubMed

Mehta, Saurabh; Kwak, Kyung Sup

2010-01-01

The wireless personal area network (WPAN) is an emerging wireless technology for future short range indoor and outdoor communication applications. The IEEE 802.15.3 medium access control (MAC) is proposed to coordinate the access to the wireless medium among the competing devices, especially for short range and high data rate applications in home networks. In this paper we use analytical modeling to study the performance analysis of WPAN (IEEE 802.15.3) MAC in terms of throughput, efficient bandwidth utilization, and delay with various ACK policies under error channel condition. This allows us to introduce a K-Dly-ACK-AGG policy, payload size adjustment mechanism, and Improved Backoff algorithm to improve the performance of the WPAN MAC. Performance evaluation results demonstrate the impact of our improvements on network capacity. Moreover, these results can be very useful to WPAN application designers and protocol architects to easily and correctly implement WPAN for home networking.

Performance Analysis and Improvement of WPAN MAC for Home Networks

PubMed Central

Mehta, Saurabh; Kwak, Kyung Sup

2010-01-01

The wireless personal area network (WPAN) is an emerging wireless technology for future short range indoor and outdoor communication applications. The IEEE 802.15.3 medium access control (MAC) is proposed to coordinate the access to the wireless medium among the competing devices, especially for short range and high data rate applications in home networks. In this paper we use analytical modeling to study the performance analysis of WPAN (IEEE 802.15.3) MAC in terms of throughput, efficient bandwidth utilization, and delay with various ACK policies under error channel condition. This allows us to introduce a K-Dly-ACK-AGG policy, payload size adjustment mechanism, and Improved Backoff algorithm to improve the performance of the WPAN MAC. Performance evaluation results demonstrate the impact of our improvements on network capacity. Moreover, these results can be very useful to WPAN application designers and protocol architects to easily and correctly implement WPAN for home networking. PMID:22319274

Mindfulness, burnout, and effects on performance evaluations in internal medicine residents

PubMed Central

Braun, Sarah E; Auerbach, Stephen M; Rybarczyk, Bruce; Lee, Bennett; Call, Stephanie

2017-01-01

Purpose Burnout has been documented at high levels in medical residents with negative effects on performance. Some dispositional qualities, like mindfulness, may protect against burnout. The purpose of the present study was to assess burnout prevalence among internal medicine residents at a single institution, examine the relationship between mindfulness and burnout, and provide preliminary findings on the relation between burnout and performance evaluations in internal medicine residents. Methods Residents (n = 38) completed validated measures of burnout at three time points separated by 2 months and a validated measure of dispositional mindfulness at baseline. Program director end-of-year performance evaluations were also obtained on 22 milestones used to evaluate internal medicine resident performance; notably, these milestones have not yet been validated for research purposes; therefore, the investigation here is exploratory. Results Overall, 71.1% (n = 27) of the residents met criteria for burnout during the study. Lower scores on the “acting with awareness” facet of dispositional mindfulness significantly predicted meeting burnout criteria χ2(5) = 11.88, p = 0.04. Lastly, meeting burnout criteria significantly predicted performance on three of the performance milestones, with positive effects on milestones from the “system-based practices” and “professionalism” domains and negative effects on a milestone from the “patient care” domain. Conclusion Burnout rates were high in this sample of internal medicine residents and rates were consistent with other reports of burnout during medical residency. Dispositional mindfulness was supported as a protective factor against burnout. Importantly, results from the exploratory investigation of the relationship between burnout and resident evaluations suggested that burnout may improve performance on some domains of resident evaluations while compromising performance on other domains. Implications and

Improving cylinder-type LiFePO4 battery performance via control of internal resistance

NASA Astrophysics Data System (ADS)

Purwanto, Agus; Jumari, Arif; Nizam, Muhammad; Widiyandari, Hendri; Sudaryanto; Deswita; Azmin Mohamad, Ahmad

2018-04-01

Strategies for controlling the internal resistance to improve battery performance were systematically investigated. Electrode densification of LiFePO4 cathodes significantly reduced the internal resistance of the prepared batteries. Densification by reduction to 31.25% of initial thickness resulted in optimal electrochemical performance of the prepared LiFePO4 batteries. The addition of KS 6 graphite material improved the conductivity of the cathodes, which was indicated by a lowering of the internal resistance. The internal resistance was decreased from 73 to 54 when the KS6/AB ratio was varied from 3 to 1. Another factor in controlling the internal resistance was the location of a welded aluminum tab in the cathode. The welding of an aluminum tab in a small gap in the cathode significantly reduced the internal resistance. Thus, three main factors can be performed during fabrication to reduce the internal resistance of a LiFePO4 battery: cathode densification, KS-6 graphite addition, and the arrangement of an aluminum tab welded to the cathode. By optimizing these factors, high-performance LFP batteries were produced.

International Continence Society guidelines on urodynamic equipment performance.

PubMed

Gammie, Andrew; Clarkson, Becky; Constantinou, Chris; Damaser, Margot; Drinnan, Michael; Geleijnse, Geert; Griffiths, Derek; Rosier, Peter; Schäfer, Werner; Van Mastrigt, Ron

2014-04-01

These guidelines provide benchmarks for the performance of urodynamic equipment, and have been developed by the International Continence Society to assist purchasing decisions, design requirements, and performance checks. The guidelines suggest ranges of specification for uroflowmetry, volume, pressure, and EMG measurement, along with recommendations for user interfaces and performance tests. Factors affecting measurement relating to the different technologies used are also described. Summary tables of essential and desirable features are included for ease of reference. It is emphasized that these guidelines can only contribute to good urodynamics if equipment is used properly, in accordance with good practice. © 2014 Wiley Periodicals, Inc.

A Study of IEEE 802.15.4 Security Framework for Wireless Body Area Networks

PubMed Central

Saleem, Shahnaz; Ullah, Sana; Kwak, Kyung Sup

2011-01-01

A Wireless Body Area Network (WBAN) is a collection of low-power and lightweight wireless sensor nodes that are used to monitor the human body functions and the surrounding environment. It supports a number of innovative and interesting applications, including ubiquitous healthcare and Consumer Electronics (CE) applications. Since WBAN nodes are used to collect sensitive (life-critical) information and may operate in hostile environments, they require strict security mechanisms to prevent malicious interaction with the system. In this paper, we first highlight major security requirements and Denial of Service (DoS) attacks in WBAN at Physical, Medium Access Control (MAC), Network, and Transport layers. Then we discuss the IEEE 802.15.4 security framework and identify the security vulnerabilities and major attacks in the context of WBAN. Different types of attacks on the Contention Access Period (CAP) and Contention Free Period (CFP) parts of the superframe are analyzed and discussed. It is observed that a smart attacker can successfully corrupt an increasing number of GTS slots in the CFP period and can considerably affect the Quality of Service (QoS) in WBAN (since most of the data is carried in CFP period). As we increase the number of smart attackers the corrupted GTS slots are eventually increased, which prevents the legitimate nodes to utilize the bandwidth efficiently. This means that the direct adaptation of IEEE 802.15.4 security framework for WBAN is not totally secure for certain WBAN applications. New solutions are required to integrate high level security in WBAN. PMID:22319358

A study of IEEE 802.15.4 security framework for wireless body area networks.

PubMed

Saleem, Shahnaz; Ullah, Sana; Kwak, Kyung Sup

2011-01-01

A Wireless Body Area Network (WBAN) is a collection of low-power and lightweight wireless sensor nodes that are used to monitor the human body functions and the surrounding environment. It supports a number of innovative and interesting applications, including ubiquitous healthcare and Consumer Electronics (CE) applications. Since WBAN nodes are used to collect sensitive (life-critical) information and may operate in hostile environments, they require strict security mechanisms to prevent malicious interaction with the system. In this paper, we first highlight major security requirements and Denial of Service (DoS) attacks in WBAN at Physical, Medium Access Control (MAC), Network, and Transport layers. Then we discuss the IEEE 802.15.4 security framework and identify the security vulnerabilities and major attacks in the context of WBAN. Different types of attacks on the Contention Access Period (CAP) and Contention Free Period (CFP) parts of the superframe are analyzed and discussed. It is observed that a smart attacker can successfully corrupt an increasing number of GTS slots in the CFP period and can considerably affect the Quality of Service (QoS) in WBAN (since most of the data is carried in CFP period). As we increase the number of smart attackers the corrupted GTS slots are eventually increased, which prevents the legitimate nodes to utilize the bandwidth efficiently. This means that the direct adaptation of IEEE 802.15.4 security framework for WBAN is not totally secure for certain WBAN applications. New solutions are required to integrate high level security in WBAN.

Internal performance characteristics of vectored axisymmetric ejector nozzles

NASA Technical Reports Server (NTRS)

Lamb, Milton

1993-01-01

A series of vectoring axisymmetric ejector nozzles were designed and experimentally tested for internal performance and pumping characteristics at NASA-Langley Research Center. These ejector nozzles used convergent-divergent nozzles as the primary nozzles. The model geometric variables investigated were primary nozzle throat area, primary nozzle expansion ratio, effective ejector expansion ratio (ratio of shroud exit area to primary nozzle throat area), ratio of minimum ejector area to primary nozzle throat area, ratio of ejector upper slot height to lower slot height (measured on the vertical centerline), and thrust vector angle. The primary nozzle pressure ratio was varied from 2.0 to 10.0 depending upon primary nozzle throat area. The corrected ejector-to-primary nozzle weight-flow ratio was varied from 0 (no secondary flow) to approximately 0.21 (21 percent of primary weight-flow rate) depending on ejector nozzle configuration. In addition to the internal performance and pumping characteristics, static pressures were obtained on the shroud walls.

International Space Station Human Behavior and Performance Competency Model: Volume II

NASA Technical Reports Server (NTRS)

Schmidt, Lacey

2008-01-01

This document further defines the behavioral markers identified in the document "Human Behavior and Performance Competency Model" Vol. I. The Human Behavior and Performance (HBP) competencies were recommended as requirements to participate in international long duration missions, and form the basis for determining the HBP training curriculum for long duration crewmembers. This document provides details, examples, knowledge areas, and affective skills to support the use of the HBP competencies in training and evaluation. This document lists examples and details specific to HBP competencies required of astronauts/cosmonauts who participate in ISS expedition and other international long-duration missions. Please note that this model does not encompass all competencies required. While technical competencies are critical for crewmembers, they are beyond the scope of this document. Additionally, the competencies in this model (and subsequent objectives) are not intended to limit the internal activities or training programs of any international partner.

Distributed Continuous Event-Based Data Acquisition Using the IEEE 1588 Synchronization and FlexRIO FPGA

NASA Astrophysics Data System (ADS)

Taliercio, C.; Luchetta, A.; Manduchi, G.; Rigoni, A.

2017-07-01

High-speed event driven acquisition is normally performed by analog-to-digital converter (ADC) boards with a given number of pretrigger sample and posttrigger sample that are recorded upon the occurrence of a hardware trigger. A direct physical connection is, therefore, required between the source of event (trigger) and the ADC, because any other software-based communication method would introduce a delay in triggering that would turn out to be not acceptable in many cases. This paper proposes a solution for the relaxation of the event communication time that can be, in this case, carried out by software messaging (e.g., via an LAN), provided that the system components are synchronized in time using the IEEE 1588 synchronization mechanism. The information about the exact event occurrence time is contained in the software packet that is sent to communicate the event and is used by the ADC FPGA to identify the exact sample in the ADC sample queue. The length of the ADC sample queue will depend on the maximum delay in software event message communication time. A prototype implementation using a National FlexRIO FPGA board connected with an ADC device is presented as the proof of concept.

42 CFR 460.136 - Internal quality assessment and performance improvement activities.

Code of Federal Regulations, 2014 CFR

2014-10-01

... in quality assessment and performance improvement activities, including providing information about... 42 Public Health 4 2014-10-01 2014-10-01 false Internal quality assessment and performance...) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Quality Assessment and Performance Improvement § 460...

42 CFR 460.136 - Internal quality assessment and performance improvement activities.

Code of Federal Regulations, 2012 CFR

2012-10-01

... in quality assessment and performance improvement activities, including providing information about... 42 Public Health 4 2012-10-01 2012-10-01 false Internal quality assessment and performance...) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Quality Assessment and Performance Improvement § 460...

42 CFR 460.136 - Internal quality assessment and performance improvement activities.

Code of Federal Regulations, 2013 CFR

2013-10-01

... in quality assessment and performance improvement activities, including providing information about... 42 Public Health 4 2013-10-01 2013-10-01 false Internal quality assessment and performance...) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Quality Assessment and Performance Improvement § 460...

Path loss variation of on-body UWB channel in the frequency bands of IEEE 802.15.6 standard.

PubMed

Goswami, Dayananda; Sarma, Kanak C; Mahanta, Anil

2016-06-01

The wireless body area network (WBAN) has gaining tremendous attention among researchers and academicians for its envisioned applications in healthcare service. Ultra wideband (UWB) radio technology is considered as excellent air interface for communication among body area network devices. Characterisation and modelling of channel parameters are utmost prerequisite for the development of reliable communication system. The path loss of on-body UWB channel for each frequency band defined in IEEE 802.15.6 standard is experimentally determined. The parameters of path loss model are statistically determined by analysing measurement data. Both the line-of-sight and non-line-of-sight channel conditions are considered in the measurement. Variations of parameter values with the size of human body are analysed along with the variation of parameter values with the surrounding environments. It is observed that the parameters of the path loss model vary with the frequency band as well as with the body size and surrounding environment. The derived parameter values are specific to the particular frequency bands of IEEE 802.15.6 standard, which will be useful for the development of efficient UWB WBAN system.

Wireless Local Area Network Performance Inside Aircraft Passenger Cabins

NASA Technical Reports Server (NTRS)

Whetten, Frank L.; Soroker, Andrew; Whetten, Dennis A.; Whetten, Frank L.; Beggs, John H.

2005-01-01

An examination of IEEE 802.11 wireless network performance within an aircraft fuselage is performed. This examination measured the propagated RF power along the length of the fuselage, and the associated network performance: the link speed, total throughput, and packet losses and errors. A total of four airplanes: one single-aisle and three twin-aisle airplanes were tested with 802.11a, 802.11b, and 802.11g networks.

Internal and external environmental factors affecting the performance of hospital-based home nursing care.

PubMed

Noh, J-W; Kwon, Y-D; Yoon, S-J; Hwang, J-I

2011-06-01

Numerous studies on HNC services have been carried out by signifying their needs, efficiency and effectiveness. However, no study has ever been performed to determine the critical factors associated with HNC's positive results despite the deluge of positive studies on the service. This study included all of the 89 training hospitals that were practising HNC service in Korea as of November 2006. The input factors affecting the performance were classified as either internal or external environmental factors. This analysis was conducted to understand the impact that the corresponding factors had on performance. Data were analysed by using multiple linear regressions. The internal and external environment variables affected the performance of HNC based on univariate analysis. The meaningful variables were internal environmental factors. Specifically, managerial resource (the number of operating beds and the outpatient/inpatient ratio) were meaningful when the multiple linear regression analysis was performed. Indeed, the importance of organizational culture (the passion of HNC nurses) was significant. This study, considering the limited market size of Korea, illustrates that the critical factor for the development of hospital-led HNC lies with internal environmental factors rather than external ones. Among the internal environmental factors, the hospitals' managerial resource-related factors (specifically, the passion of nurses) were the most important contributing element. © 2011 The Authors. International Nursing Review © 2011 International Council of Nurses.

Important Publications in the Area of Photovoltaic Performance |

Science.gov Websites

, 2011, DOI: 978-0-12-385934-1. Photoelectrochemical Water Splitting: Standards, Experimental Methods Energy Systems Testing, Solar Energy 73, 443-467 (2002). D.R. Myers, K. Emery, and C. Gueymard, Revising Performance Evaluation Methodologies for Energy Ratings," Proc. 24th IEEE Photovoltaic Specialists Conf

Performance Analysis of Different Backoff Algorithms for WBAN-Based Emerging Sensor Networks

PubMed Central

Khan, Pervez; Ullah, Niamat; Ali, Farman; Ullah, Sana; Hong, Youn-Sik; Lee, Ki-Young; Kim, Hoon

2017-01-01

The Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) procedure of IEEE 802.15.6 Medium Access Control (MAC) protocols for the Wireless Body Area Network (WBAN) use an Alternative Binary Exponential Backoff (ABEB) procedure. The backoff algorithm plays an important role to avoid collision in wireless networks. The Binary Exponential Backoff (BEB) algorithm used in different standards does not obtain the optimum performance due to enormous Contention Window (CW) gaps induced from packet collisions. Therefore, The IEEE 802.15.6 CSMA/CA has developed the ABEB procedure to avoid the large CW gaps upon each collision. However, the ABEB algorithm may lead to a high collision rate (as the CW size is incremented on every alternative collision) and poor utilization of the channel due to the gap between the subsequent CW. To minimize the gap between subsequent CW sizes, we adopted the Prioritized Fibonacci Backoff (PFB) procedure. This procedure leads to a smooth and gradual increase in the CW size, after each collision, which eventually decreases the waiting time, and the contending node can access the channel promptly with little delay; while ABEB leads to irregular and fluctuated CW values, which eventually increase collision and waiting time before a re-transmission attempt. We analytically approach this problem by employing a Markov chain to design the PFB scheme for the CSMA/CA procedure of the IEEE 80.15.6 standard. The performance of the PFB algorithm is compared against the ABEB function of WBAN CSMA/CA. The results show that the PFB procedure adopted for IEEE 802.15.6 CSMA/CA outperforms the ABEB procedure. PMID:28257112

ARO PECASE: Information Assurance for Energy-Constrained Wireless Sensor Networks

DTIC Science & Technology

2011-12-21

Distribution, 18th Annual IEEE International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC), September 2007. 2. 2010 IEEE...received the following awards: Student Best Paper Award at the IEEE International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC...Localization in Wireless Ad Hoc Networks – Many current and future appli- cations of mobile ad hoc networks, including disaster response and event

Effect of Interface States on the Performance of Antimonide nMOSFETs

DTIC Science & Technology

2013-01-14

Member, IEEE, Himanshu Madan , Student Member, IEEE, Michael J. Barth, J. Brad Boos, Member, IEEE, Brian R. Bennett, and Suman Datta, Fellow, IEEE...now with Intel Corporation, Hillsboro, OR 97124 USA (e-mail: AshkarAli@psualum.com). H. Madan , M. J. Barth, and S. Datta are with the Pennsylvania...S. Chau, “Sb-based CMOS devices,” U.S. Patent 7 429 747, Sep. 30, 2008. [2] A. Ali, H. Madan , A. Agrawal, I. Ramirez, R. Misra, J. B. Boos, B. R

Internal curing of high performance concrete using lightweight aggregates and other techniques.

DOT National Transportation Integrated Search

2014-02-01

Internally cured concrete has been rapidly emerging over the last decade as an effective way to improve the : performance of concrete. Internal curing (IC) holds promise for producing concrete with an increased : resistance to early-age cracking and ...

Internal Structure and Morphology Profile in Optimizing Filter Membrane Performance

NASA Astrophysics Data System (ADS)

Sanaei, Pejman; Cummings, Linda J.

Membrane filters are in widespread use, and manufacturers have considerable interest in improving their performance, in terms of particle retention properties, and total throughput over the filter lifetime. A good question to ask is therefore: what is the optimal configuration of filter membranes, in terms of internal morphology (pore size and shape), to achieve the most efficient filtration? To answer this question, we must first propose a robust measure of filtration performance. As filtration occurs the membrane becomes blocked, or fouled, by the impurities in the feed solution, and any performance measure must take account of this. For example, one performance measure might be the total throughput (the volume of filtered feed solution) at the end of the filtration process, when the membrane is so badly blocked that it is deemed no longer functional. Here we present a simplified mathematical model, which (i) characterizes membrane internal pore structure via pore or permeability profiles in the depth of the membrane; (ii) accounts for various membrane fouling mechanisms (adsorption, blocking and cake formation); and (iv) predicts the optimum pore profile for our chosen performance measure. NSF DMS-1261596 and NSF DMS-1615719.

M-DCPS Student Performance in International Baccalaureate and Cambridge Advanced International Certificate of Education Programs. Research Brief. Volume 1102

ERIC Educational Resources Information Center

Blazer, Christie

2011-01-01

This Research Brief summarizes the performance of M-DCPS students participating in the International Baccalaureate (IB) and Cambridge Advanced International Certificate of Education (AICE) programs. Outcome data are provided for the eight M-DCPS schools offering the two programs and corresponding examinations. Participation in international…

A Reliable Data Transmission Model for IEEE 802.15.4e Enabled Wireless Sensor Network under WiFi Interference.

PubMed

Sahoo, Prasan Kumar; Pattanaik, Sudhir Ranjan; Wu, Shih-Lin

2017-06-07

The IEEE 802.15.4e standard proposes Medium Access Control (MAC) to support collision-free wireless channel access mechanisms for industrial, commercial and healthcare applications. However, unnecessary wastage of energy and bandwidth consumption occur due to inefficient backoff management and collisions. In this paper, a new channel access mechanism is designed for the buffer constraint sensor devices to reduce the packet drop rate, energy consumption and collisions. In order to avoid collision due to the hidden terminal problem, a new frame structure is designed for the data transmission. A new superframe structure is proposed to mitigate the problems due to WiFi and ZigBee interference. A modified superframe structure with a new retransmission opportunity for failure devices is proposed to reduce the collisions and retransmission delay with high reliability. Performance evaluation and validation of our scheme indicate that the packet drop rate, throughput, reliability, energy consumption and average delay of the nodes can be improved significantly.

A Reliable Data Transmission Model for IEEE 802.15.4e Enabled Wireless Sensor Network under WiFi Interference

PubMed Central

Sahoo, Prasan Kumar; Pattanaik, Sudhir Ranjan; Wu, Shih-Lin

2017-01-01

The IEEE 802.15.4e standard proposes Medium Access Control (MAC) to support collision-free wireless channel access mechanisms for industrial, commercial and healthcare applications. However, unnecessary wastage of energy and bandwidth consumption occur due to inefficient backoff management and collisions. In this paper, a new channel access mechanism is designed for the buffer constraint sensor devices to reduce the packet drop rate, energy consumption and collisions. In order to avoid collision due to the hidden terminal problem, a new frame structure is designed for the data transmission. A new superframe structure is proposed to mitigate the problems due to WiFi and ZigBee interference. A modified superframe structure with a new retransmission opportunity for failure devices is proposed to reduce the collisions and retransmission delay with high reliability. Performance evaluation and validation of our scheme indicate that the packet drop rate, throughput, reliability, energy consumption and average delay of the nodes can be improved significantly. PMID:28590434

Interoperable End-to-End Remote Patient Monitoring Platform Based on IEEE 11073 PHD and ZigBee Health Care Profile.

PubMed

Clarke, Malcolm; de Folter, Joost; Verma, Vivek; Gokalp, Hulya

2018-05-01

This paper describes the implementation of an end-to-end remote monitoring platform based on the IEEE 11073 standards for personal health devices (PHD). It provides an overview of the concepts and approaches and describes how the standard has been optimized for small devices with limited resources of processor, memory, and power that use short-range wireless technology. It explains aspects of IEEE 11073, including the domain information model, state model, and nomenclature, and how these support its plug-and-play architecture. It shows how these aspects underpin a much larger ecosystem of interoperable devices and systems that include IHE PCD-01, HL7, and BlueTooth LE medical devices, and the relationship to the Continua Guidelines, advocating the adoption of data standards and nomenclature to support semantic interoperability between health and ambient assisted living in future platforms. The paper further describes the adaptions that have been made in order to implement the standard on the ZigBee Health Care Profile and the experiences of implementing an end-to-end platform that has been deployed to frail elderly patients with chronic disease(s) and patients with diabetes.

Performance indicators related to points scoring and winning in international rugby sevens.

PubMed

Higham, Dean G; Hopkins, Will G; Pyne, David B; Anson, Judith M

2014-05-01

Identification of performance indicators related to scoring points and winning is needed to inform tactical approaches to international rugby sevens competition. The aim of this study was to characterize team performance indicators in international rugby sevens and quantify their relationship with a team's points scored and probability of winning. Performance indicators of each team during 196 matches of the 2011/2012 International Rugby Board Sevens World Series were modeled for their linear relationships with points scored and likelihood of winning within (changes in team values from match to match) and between (differences between team values averaged over all matches) teams. Relationships were evaluated as the change and difference in points and probability of winning associated with a two within- and between-team standard deviations increase in performance indicator values. Inferences about relationships were assessed using a smallest meaningful difference of one point and a 10% probability of a team changing the outcome of a close match. All indicators exhibited high within-team match-to-match variability (intraclass correlation coefficients ranged from 0.00 to 0.23). Excluding indicators representing points-scoring actions or events occurring on average less than once per match, 13 of 17 indicators had substantial clear within-team relationships with points scored and/or likelihood of victory. Relationships between teams were generally similar in magnitude but unclear. Tactics that increase points scoring and likelihood of winning should be based on greater ball possession, fewer rucks, mauls, turnovers, penalties and free kicks, and limited passing. Key pointsSuccessful international rugby sevens teams tend to maintain ball possession; more frequently avoid taking the ball into contact; concede fewer turnovers, penalties and free kicks; retain possession in scrums, rucks and mauls; and limit passing the ball.Selected performance indicators may be used to

Performance Indicators Related to Points Scoring and Winning in International Rugby Sevens

PubMed Central

Higham, Dean G.; Hopkins, Will G.; Pyne, David B.; Anson, Judith M.

2014-01-01

Identification of performance indicators related to scoring points and winning is needed to inform tactical approaches to international rugby sevens competition. The aim of this study was to characterize team performance indicators in international rugby sevens and quantify their relationship with a team’s points scored and probability of winning. Performance indicators of each team during 196 matches of the 2011/2012 International Rugby Board Sevens World Series were modeled for their linear relationships with points scored and likelihood of winning within (changes in team values from match to match) and between (differences between team values averaged over all matches) teams. Relationships were evaluated as the change and difference in points and probability of winning associated with a two within- and between-team standard deviations increase in performance indicator values. Inferences about relationships were assessed using a smallest meaningful difference of one point and a 10% probability of a team changing the outcome of a close match. All indicators exhibited high within-team match-to-match variability (intraclass correlation coefficients ranged from 0.00 to 0.23). Excluding indicators representing points-scoring actions or events occurring on average less than once per match, 13 of 17 indicators had substantial clear within-team relationships with points scored and/or likelihood of victory. Relationships between teams were generally similar in magnitude but unclear. Tactics that increase points scoring and likelihood of winning should be based on greater ball possession, fewer rucks, mauls, turnovers, penalties and free kicks, and limited passing. Key points Successful international rugby sevens teams tend to maintain ball possession; more frequently avoid taking the ball into contact; concede fewer turnovers, penalties and free kicks; retain possession in scrums, rucks and mauls; and limit passing the ball. Selected performance indicators may be used

Compliance and Functional Testing of IEEE 1451.1 for NCAP-to-NCAP Communications in a Sensor Network

NASA Technical Reports Server (NTRS)

Figueroa, Jorge; Gurkan, Deniz; Yuan, X.; Benhaddou, D.; Liu, H.; Singla, A.; Franzl, R.; Ma, H.; Bhatt, S.; Morris, J.;

Reproducibility of the Internal Load and Performance-Based Responses to Simulated Amateur Boxing.

PubMed

Thomson, Edward D; Lamb, Kevin L

2017-12-01

Thomson, ED and Lamb, KL. Reproducibility of the internal load and performance-based responses to simulated amateur boxing. J Strength Cond Res 31(12): 3396-3402, 2017-The aim of this study was to examine the reproducibility of the internal load and performance-based responses to repeated bouts of a three-round amateur boxing simulation protocol (boxing conditioning and fitness test [BOXFIT]). Twenty-eight amateur boxers completed 2 familiarization trials before performing 2 complete trials of the BOXFIT, separated by 4-7 days. To characterize the internal load, mean (HRmean) and peak (HRpeak) heart rate, breath-by-breath oxygen uptake (V[Combining Dot Above]O2), aerobic energy expenditure, excess carbon dioxide production (CO2excess), and ratings of perceived exertion were recorded throughout each round, and blood lactate determined post-BOXFIT. Additionally, an indication of the performance-based demands of the BOXFIT was provided by a measure of acceleration of the punches thrown in each round. Analyses revealed there were no significant differences (p > 0.05) between repeated trials in any round for all dependent measures. The typical error (coefficient variation %) for all but 1 marker of internal load (CO2excess) was 1.2-16.5% and reflected a consistency that was sufficient for the detection of moderate changes in variables owing to an intervention. The reproducibility of the punch accelerations was high (coefficient of variance % range = 2.1-2.7%). In general, these findings suggest that the internal load and performance-based efforts recorded during the BOXFIT are reproducible and, thereby, offer practitioners a method by which meaningful changes impacting on performance could be identified.

The bidirectional pathways between internalizing and externalizing problems and academic performance from 6 to 18 years.

PubMed

Van der Ende, Jan; Verhulst, Frank C; Tiemeier, Henning

2016-08-01

Internalizing and externalizing problems are associated with poor academic performance, both concurrently and longitudinally. Important questions are whether problems precede academic performance or vice versa, whether both internalizing and externalizing are associated with academic problems when simultaneously tested, and whether associations and their direction depend on the informant providing information. These questions were addressed in a sample of 816 children who were assessed four times. The children were 6-10 years at baseline and 14-18 years at the last assessment. Parent-reported internalizing and externalizing problems and teacher-reported academic performance were tested in cross-lagged models to examine bidirectional paths between these constructs. These models were compared with cross-lagged models testing paths between teacher-reported internalizing and externalizing problems and parent-reported academic performance. Both final models revealed similar pathways from mostly externalizing problems to academic performance. No paths emerged from internalizing problems to academic performance. Moreover, paths from academic performance to internalizing and externalizing problems were only found when teachers reported on children's problems and not for parent-reported problems. Additional model tests revealed that paths were observed in both childhood and adolescence. Externalizing problems place children at increased risk of poor academic performance and should therefore be the target for interventions.

[Definition and specification requirements for PAC-systems (picture archiving and communication system). A performance index with reference to the standard "IEEE Recommended Practice for Software Requirement Specifications"].

PubMed

König, H; Klose, K J

1999-04-01

The formulation of requirements is necessary to control the goals of a PACS project. Furthermore, in this way, the scope of functionality necessary to support radiological working processes becomes clear. Definitions of requirements and specification are formulated independently of systems according to the IEEE standard "Recommended Practice for Software Requirements Specifications". Definitions are given in the Request for Information, specifications in the Request for Proposal. Functional and non-functional requirements are distinguished. The solutions are rated with respect to scope, appropriateness and quality of implementation. A PACS checklist was created according to the methods described above. It is published on the homepage of the "Arbeitsgemeinschaft Informationstechnologie" (AGIT) within the "Deutsche Röntgengesellschaft" (DRG) (http://www.uni-marburg.de/mzr/agit). The checklist provides a discussion forum which should contribute to an agreement on accepted basic PACS functionalities.

International Space Station Human Behavior and Performance Competency Model: Volume I

NASA Technical Reports Server (NTRS)

Schmidt, Lacey

2008-01-01

This document defines Human Behavior and Performance (HBP) competencies that are recommended to be included as requirements to participate in international long duration missions. They were developed in response to the Multilateral Crew Operations Panel (MMOP) request to develop HBP training requirements for the International Space Station (ISS). The competency model presented here was developed by the ITCB HBPT WG and forms the basis for determining the HBP training curriculum for long duration crewmembers. This document lists specific HBP competencies and behaviors required of astronauts/cosmonauts who participate in ISS expedition and other international longduration missions. Please note that this model does not encompass all competencies required. For example, outside the scope of this document are cognitive skills and abilities, including but not limited to concentration, memorization, perception, imagination, and thinking. It is assumed that these skills, which are crucial in terms of human behavior and performance, are considered during selection phase since such professionally significant qualities of the operator should be taken into consideration in order to ensure sufficient baseline levels that can be further improved during general astronaut training. Also, technical competencies, even though critical for crewmembers, are beyond the scope of this document. It should also be noted that the competencies in this model (and subsequent objectives) are not intended to limit the internal activities or training programs of any international partner.

Effect of several geometric parameters on the static internal performance of three nonaxisymmetric nozzle concepts

NASA Technical Reports Server (NTRS)

Berrier, B. L.; Re, R. J.

1979-01-01

Effects of several geometric parameters on the internal performance of nonaxisymmetric convergent-divergent, single-ramp expansion, and wedge nozzles were investigated at nozzle pressure ratios up to approximately 10. In addition, two different thrust-vectoring schemes were investigated with the wedge nozzle. The results indicated that as with conventional round nozzles, peak nonaxisymmetric nozzle, internal performance occurred near the nozzle pressure ratio required for fully expanded exhaust flow. Nozzle sidewall length or area generally had little effect on the internal performance of the nozzles investigated.

IEEE 802.21 Assisted Seamless and Energy Efficient Handovers in Mixed Networks

NASA Astrophysics Data System (ADS)

Liu, Huaiyu; Maciocco, Christian; Kesavan, Vijay; Low, Andy L. Y.

Network selection is the decision process for a mobile terminal to handoff between homogeneous or heterogeneous networks. With multiple available networks, the selection process must evaluate factors like network services/conditions, monetary cost, system conditions, user preferences etc. In this paper, we investigate network selection using a cost function and information provided by IEEE 802.21. The cost function provides flexibility to balance different factors in decision making and our research is focused on improving both seamlessness and energy efficiency of handovers. Our solution is evaluated using real WiFi, WiMax, and 3G signal strength traces. The results show that appropriate networks were selected based on selection policies, handovers were triggered at optimal times to increase overall network connectivity as compared to traditional triggering schemes, while at the same time the energy consumption of multi-radio devices for both on-going operations as well as during handovers is optimized.

The association of students requiring remediation in the internal medicine clerkship with poor performance during internship.

PubMed

Hemann, Brian A; Durning, Steven J; Kelly, William F; Dong, Ting; Pangaro, Louis N; Hemmer, Paul A

2015-04-01

To determine whether the Uniformed Services University (USU) system of workplace performance assessment for students in the internal medicine clerkship at the USU continues to be a sensitive predictor of subsequent poor performance during internship, when compared with assessments in other USU third year clerkships. Utilizing Program Director survey results from 2007 through 2011 and U.S. Medical Licensing Examination (USMLE) Step 3 examination results as the outcomes of interest, we compared performance during internship for students who had less than passing performance in the internal medicine clerkship and required remediation, against students whose performance in the internal medicine clerkship was successful. We further analyzed internship ratings for students who received less than passing grades during the same time period on other third year clerkships such as general surgery, pediatrics, obstetrics and gynecology, family medicine, and psychiatry to evaluate whether poor performance on other individual clerkships were associated with future poor performance at the internship level. Results for this recent cohort of graduates were compared with previously published findings. The overall survey response rate for this 5 year cohort was 81% (689/853). Students who received a less than passing grade in the internal medicine clerkship and required further remediation were 4.5 times more likely to be given poor ratings in the domain of medical expertise and 18.7 times more likely to demonstrate poor professionalism during internship. Further, students requiring internal medicine remediation were 8.5 times more likely to fail USMLE Step 3. No other individual clerkship showed any statistically significant associations with performance at the intern level. On the other hand, 40% of students who successfully remediated and did graduate were not identified during internship as having poor performance. Unsuccessful clinical performance which requires remediation in

Student performance of the general physical examination in internal medicine: an observational study.

PubMed

Haring, Catharina M; Cools, Bernadette M; van der Meer, Jos Wm; Postma, Cornelis T

2014-04-08

Many practicing physicians lack skills in physical examination. It is not known whether physical examination skills already show deficiencies after an early phase of clinical training. At the end of the internal medicine clerkship students are expected to be able to perform a general physical examination in every new patient encounter. In a previous study, the basic physical examination items that should standardly be performed were set by consensus. The aim of the current observational study was to assess whether medical students were able to correctly perform a general physical examination regarding completeness as well as technique at the end of the clerkship internal medicine. One hundred students who had just finished their clerkship internal medicine were asked to perform a general physical examination on a standardized patient as they had learned during the clerkship. They were recorded on camera. Frequency of performance of each component of the physical examination was counted. Adequacy of performance was determined as either correct or incorrect or not assessable using a checklist of short descriptions of each physical examination component. A reliability analysis was performed by calculation of the intra class correlation coefficient for total scores of five physical examinations rated by three trained physicians and for their agreement on performance of all items. Approximately 40% of the agreed standard physical examination items were not performed by the students. Students put the most emphasis on examination of general parameters, heart, lungs and abdomen. Many components of the physical examination were not performed as was taught during precourses. Intra-class correlation was high for total scores of the physical examinations 0.91 (p <0.001) and for agreement on performance of the five physical examinations (0.79-0.92 p <0.001). In conclusion, performance of the general physical examination was already below expectation at the end of the internal

Student performance of the general physical examination in internal medicine: an observational study

PubMed Central

2014-01-01

Background Many practicing physicians lack skills in physical examination. It is not known whether physical examination skills already show deficiencies after an early phase of clinical training. At the end of the internal medicine clerkship students are expected to be able to perform a general physical examination in every new patient encounter. In a previous study, the basic physical examination items that should standardly be performed were set by consensus. The aim of the current observational study was to assess whether medical students were able to correctly perform a general physical examination regarding completeness as well as technique at the end of the clerkship internal medicine. Methods One hundred students who had just finished their clerkship internal medicine were asked to perform a general physical examination on a standardized patient as they had learned during the clerkship. They were recorded on camera. Frequency of performance of each component of the physical examination was counted. Adequacy of performance was determined as either correct or incorrect or not assessable using a checklist of short descriptions of each physical examination component. A reliability analysis was performed by calculation of the intra class correlation coefficient for total scores of five physical examinations rated by three trained physicians and for their agreement on performance of all items. Results Approximately 40% of the agreed standard physical examination items were not performed by the students. Students put the most emphasis on examination of general parameters, heart, lungs and abdomen. Many components of the physical examination were not performed as was taught during precourses. Intra-class correlation was high for total scores of the physical examinations 0.91 (p <0.001) and for agreement on performance of the five physical examinations (0.79-0.92 p <0.001). Conclusions In conclusion, performance of the general physical examination was already below

IEEE Validation of the Continuing Education Achievement of Engineers Registry System. Procedures for Use with a CPT 8000 Word Processor and Communications Package.

ERIC Educational Resources Information Center

Institute of Electrical and Electronics Engineers, Inc., New York, NY.

The Institute of Electrical and Electronics Engineers (IEEE) validation program is designed to motivate persons practicing in electrical and electronics engineering to pursue quality technical continuing education courses offered by any responsible sponsor. The rapid acceptance of the validation program necessitated the additional development of a…

Individual Differences Influencing Immediate Effects of Internal and External Focus Instructions on Children's Motor Performance.

PubMed

van Abswoude, Femke; Nuijen, Nienke B; van der Kamp, John; Steenbergen, Bert

2018-06-01

A large pool of evidence supports the beneficial effect of an external focus of attention on motor skill performance in adults. In children, this effect has been studied less and results are inconclusive. Importantly, individual differences are often not taken into account. We investigated the role of working memory, conscious motor control, and task-specific focus preferences on performance with an internal and external focus of attention in children. Twenty-five children practiced a golf putting task in both an internal focus condition and external focus condition. Performance was defined as the average distance toward the hole in 3 blocks of 10 trials. Task-specific focus preference was determined by asking how much effort it took to apply the instruction in each condition. In addition, working memory capacity and conscious motor control were assessed. Children improved performance in both the internal focus condition and external focus condition (ŋ p 2  = .47), with no difference between conditions (ŋ p 2  = .01). Task-specific focus preference was the only factor moderately related to the difference between performance with an internal focus and performance with an external focus (r = .56), indicating better performance for the preferred instruction in Block 3. Children can benefit from instruction with both an internal and external focus of attention to improve short-term motor performance. Individual, task-specific focus preference influenced the effect of the instructions, with children performing better with their preferred focus. The results highlight that individual differences are a key factor in the effectiveness in children's motor performance. The precise mechanisms underpinning this effect warrant further research.

Antenna Efficiency and the Genius of the IEEE Standard for Antenna Terms [Education Column

NASA Astrophysics Data System (ADS)

Warnick, Karl F.

2012-08-01

At a 2007 Square Kilometre Array Design Studies (SKADS) workshop in Dwingeloo, Wim van Cappellen of the Nether lands Institute for Radio Astronomy (ASTRON) gave a presentation on figures of merit, in which he memorably compared antenna terms to apples. What seems like a simple, homogeneous fruit comes in all colors and varieties. Similarly, a survey of antenna literature and textbooks shows that authors use a wide variety of antenna figures of merit, often not in compliance with the relevant IEEE Standard Definitions of Terms for Antennas [1]. Since this standard is now in the process of revision by the Antennas and Propagation Society Antenna Standards Committee, it seems worth while to consider the standard, and clarify some common misunderstandings and inconsistent usages.

International Space Station Major Constituent Analyzer On-Orbit Performance

NASA Technical Reports Server (NTRS)

Gardner, Ben D.; Erwin, Phillip M.; Thoresen, Souzan; Granahan, John; Matty, Chris

2012-01-01

The Major Constituent Analyzer is a mass spectrometer based system that measures the major atmospheric constituents on the International Space Station. A number of limited-life components require periodic changeout, including the ORU 02 analyzer and the ORU 08 Verification Gas Assembly. Over the past two years, two ORU 02 analyzer assemblies have operated nominally while two others have experienced premature on-orbit failures. These failures as well as nominal performances demonstrate that ORU 02 performance remains a key determinant of MCA performance and logistical support. It can be shown that monitoring several key parameters can maximize the capacity to monitor ORU health and properly anticipate end of life. Improvements to ion pump operation and ion source tuning are expected to improve lifetime performance of the current ORU 02 design.

Numerical assessment of the performance of a scalp-implantable antenna: effects of head anatomy and dielectric parameters.

PubMed

Kiourti, Asimina; Nikita, Konstantina S

2013-04-01

We numerically assess the effects of head properties (anatomy and dielectric parameters) on the performance of a scalp-implantable antenna for telemetry in the Medical Implant Communications Service band (402.0-405.0 MHz). Safety issues and performance (resonance, radiation) are analyzed for an experimentally validated implantable antenna (volume of 203.6 mm(3) ), considering five head models (3- and 5-layer spherical, 6-, 10-, and 13-tissue anatomical) and seven scenarios (variations ± 20% in the reference permittivity and conductivity values). Simulations are carried out at 403.5 MHz using the finite-difference time-domain method. Anatomy of the head model around the implantation site is found to mainly affect antenna performance, whereas overall tissue anatomy and dielectric parameters are less significant. Compared to the reference dielectric parameter scenario within the 3-layer spherical head, maximum variations of -19.9%, +3.7%, -55.1%, and -39.2% are computed in the maximum allowable net input power imposed by the IEEE Std C95.1-1999 and Std C95.1-2005 safety guidelines, return loss, and maximum far-field gain, respectively. Compliance with the recent IEEE Std C95.1-2005 is found to be almost insensitive to head properties, in contrast with IEEE Std C95.1-1999. Taking tissue property uncertainties into account is highlighted as crucial for implantable antenna design and performance assessment. Bioelectromagnetics 34:167-179, 2013. © 2012 Wiley Periodicals, Inc. Copyright © 2012 Wiley Periodicals, Inc.

An Improved Approach for RSSI-Based only Calibration-Free Real-Time Indoor Localization on IEEE 802.11 and 802.15.4 Wireless Networks.

PubMed

Passafiume, Marco; Maddio, Stefano; Cidronali, Alessandro

2017-03-29

Assuming a reliable and responsive spatial contextualization service is a must-have in IEEE 802.11 and 802.15.4 wireless networks, a suitable approach consists of the implementation of localization capabilities, as an additional application layer to the communication protocol stack. Considering the applicative scenario where satellite-based positioning applications are denied, such as indoor environments, and excluding data packet arrivals time measurements due to lack of time resolution, received signal strength indicator (RSSI) measurements, obtained according to IEEE 802.11 and 802.15.4 data access technologies, are the unique data sources suitable for indoor geo-referencing using COTS devices. In the existing literature, many RSSI based localization systems are introduced and experimentally validated, nevertheless they require periodic calibrations and significant information fusion from different sensors that dramatically decrease overall systems reliability and their effective availability. This motivates the work presented in this paper, which introduces an approach for an RSSI-based calibration-free and real-time indoor localization. While switched-beam array-based hardware (compliant with IEEE 802.15.4 router functionality) has already been presented by the author, the focus of this paper is the creation of an algorithmic layer for use with the pre-existing hardware capable to enable full localization and data contextualization over a standard 802.15.4 wireless sensor network using only RSSI information without the need of lengthy offline calibration phase. System validation reports the localization results in a typical indoor site, where the system has shown high accuracy, leading to a sub-metrical overall mean error and an almost 100% site coverage within 1 m localization error.

An Improved Approach for RSSI-Based only Calibration-Free Real-Time Indoor Localization on IEEE 802.11 and 802.15.4 Wireless Networks

PubMed Central

Passafiume, Marco; Maddio, Stefano; Cidronali, Alessandro

2017-01-01

Assuming a reliable and responsive spatial contextualization service is a must-have in IEEE 802.11 and 802.15.4 wireless networks, a suitable approach consists of the implementation of localization capabilities, as an additional application layer to the communication protocol stack. Considering the applicative scenario where satellite-based positioning applications are denied, such as indoor environments, and excluding data packet arrivals time measurements due to lack of time resolution, received signal strength indicator (RSSI) measurements, obtained according to IEEE 802.11 and 802.15.4 data access technologies, are the unique data sources suitable for indoor geo-referencing using COTS devices. In the existing literature, many RSSI based localization systems are introduced and experimentally validated, nevertheless they require periodic calibrations and significant information fusion from different sensors that dramatically decrease overall systems reliability and their effective availability. This motivates the work presented in this paper, which introduces an approach for an RSSI-based calibration-free and real-time indoor localization. While switched-beam array-based hardware (compliant with IEEE 802.15.4 router functionality) has already been presented by the author, the focus of this paper is the creation of an algorithmic layer for use with the pre-existing hardware capable to enable full localization and data contextualization over a standard 802.15.4 wireless sensor network using only RSSI information without the need of lengthy offline calibration phase. System validation reports the localization results in a typical indoor site, where the system has shown high accuracy, leading to a sub-metrical overall mean error and an almost 100% site coverage within 1 m localization error. PMID:28353676

Correlation of United States Medical Licensing Examination and Internal Medicine In-Training Examination Performance

ERIC Educational Resources Information Center

Perez, Jose A., Jr.; Greer, Sharon

2009-01-01

The Internal Medicine In-Training Examination (ITE) is administered during residency training in the United States as a self-assessment and program assessment tool. Performance on this exam correlates with outcome on the American Board of Internal Medicine Certifying examination. Internal Medicine Program Directors use the United States Medical…

2011 IEEE Visualization Contest winner: Visualizing unsteady vortical behavior of a centrifugal pump.

PubMed

Otto, Mathias; Kuhn, Alexander; Engelke, Wito; Theisel, Holger

2012-01-01

In the 2011 IEEE Visualization Contest, the dataset represented a high-resolution simulation of a centrifugal pump operating below optimal speed. The goal was to find suitable visualization techniques to identify regions of rotating stall that impede the pump's effectiveness. The winning entry split analysis of the pump into three parts based on the pump's functional behavior. It then applied local and integration-based methods to communicate the unsteady flow behavior in different regions of the dataset. This research formed the basis for a comparison of common vortex extractors and more recent methods. In particular, integration-based methods (separation measures, accumulated scalar fields, particle path lines, and advection textures) are well suited to capture the complex time-dependent flow behavior. This video (http://youtu.be/oD7QuabY0oU) shows simulations of unsteady flow in a centrifugal pump.

New IEEE 11073 Standards for interoperable, networked Point-of-Care Medical Devices.

PubMed

Kasparick, Martin; Schlichting, Stefan; Golatowski, Frank; Timmermann, Dirk

2015-08-01

Surgical procedures become more and more complex and the number of medical devices in an operating room (OR) increases continuously. Today's vendor-dependent solutions for integrated ORs are not able to handle this complexity. They can only form isolated solutions. Furthermore, high costs are a result of vendor-dependent approaches. Thus we present a service-oriented device communication for distributed medical systems that enables the integration and interconnection between medical devices among each other and to (medical) information systems, including plug-and-play functionality. This system will improve patient's safety by making technical complexity of a comprehensive integration manageable. It will be available as open standards that are part of the IEEE 11073 family of standards. The solution consists of a service-oriented communication technology, the so called Medical Devices Profile for Web Services (MDPWS), a Domain Information & Service Model, and a binding between the first two mechanisms. A proof of this concept has been done with demonstrators of real world OR devices.

Effect of Advanced Trauma Life Support program on medical interns' performance in simulated trauma patient management.

PubMed

Ahmadi, Koorosh; Sedaghat, Mohammad; Safdarian, Mahdi; Hashemian, Amir-Masoud; Nezamdoust, Zahra; Vaseie, Mohammad; Rahimi-Movaghar, Vafa

2013-01-01

Since appropriate and time-table methods in trauma care have an important impact on patients'outcome, we evaluated the effect of Advanced Trauma Life Support (ATLS) program on medical interns' performance in simulated trauma patient management. A descriptive and analytical study before and after the training was conducted on 24 randomly selected undergraduate medical interns from Imam Reza Hospital in Mashhad, Iran. On the first day, we assessed interns' clinical knowledge and their practical skill performance in confronting simulated trauma patients. After 2 days of ATLS training, we performed the same study and evaluated their score again on the fourth day. The two findings, pre- and post- ATLS periods, were compared through SPSS version 15.0 software. P values less than 0.05 were considered statistically significant. Our findings showed that interns'ability in all the three tasks improved after the training course. On the fourth day after training, there was a statistically significant increase in interns' clinical knowledge of ATLS procedures, the sequence of procedures and skill performance in trauma situations (P less than 0.001, P equal to 0.016 and P equal to 0.01 respectively). ATLS course has an important role in increasing clinical knowledge and practical skill performance of trauma care in medical interns.

Telemonitoring systems interoperability challenge: an updated review of the applicability of ISO/IEEE 11073 standards for interoperability in telemonitoring.

PubMed

Galarraga, M; Serrano, L; Martinez, I; de Toledo, P; Reynolds, Melvin

2007-01-01

Advances in Information and Communication Technologies, ICT, are bringing new opportunities and use cases in the field of systems and Personal Health Devices used for the telemonitoring of citizens in Home or Mobile scenarios. At a time of such challenges, this review arises from the need to identify robust technical telemonitoring solutions that are both open and interoperable. These systems demand standardized solutions to be cost effective and to take advantage of standardized operation and interoperability. Thus, the fundamental challenge is to design plug-&-play devices that, either as individual elements or as components, can be incorporated in a simple way into different Telecare systems, perhaps configuring a personal user network. Moreover, there is an increasing market pressure from companies not traditionally involved in medical markets, asking for a standard for Personal Health Devices, which foresee a vast demand for telemonitoring, wellness, Ambient Assisted Living (AAL) and e-health applications. However, the newly emerging situations imply very strict requirements for the protocols involved in the communication. The ISO/IEEE 11073 family of standards is adapting and moving in order to face the challenge and might appear the best positioned international standards to reach this goal. This work presents an updated survey of these standards, trying to track the changes that are being fulfilled, and tries to serve as a starting-point for those who want to familiarize themselves with them.

UTC Time Transfer for High Frequency Trading Using IS-95 CDMA Base Station Transmissions and IEEE-1588 Precision Time Protocol

DTIC Science & Technology

2010-11-01

CDMA base stations are each synchronized by GPS receivers, they provide an indirect link to GPS system time and UTC time . The major stock...antenna synchronizes the Local Area Network (LAN) to within 10 microseconds of UTC using the IEEE-1588 Precision Time Protocol (PTP). This is an...activities. Understanding and measuring latency on the LAN is key to the success of HFTs. Without precise time synchronization below 1 millisecond

Solid-propellant rocket motor internal ballistics performance variation analysis, phase 5

NASA Technical Reports Server (NTRS)

Sforzini, R. H.; Murph, J. E.

1980-01-01

The results of research aimed at improving the predictability of internal ballistics performance of solid-propellant rocket motors (SRM's) including thrust imbalance between two SRM's firing in parallel are presented. Static test data from the first six Space Shuttle SRM's is analyzed using a computer program previously developed for this purpose. The program permits intentional minor design biases affecting the imbalance between any two SMR's to be removed. Results for the last four of the six SRM's, with only the propellant bulk temperature as a non-random variable, are generally within limits predicted by theory. Extended studies of internal ballistic performance of single SRM's are presented based on an earlier developed mathematical model which includes an assessment of grain deformation. The erosive burning rate law used in the model is upgraded and made more general. Excellent results are obtained in predictions of the performances of five different SRM's of quite different sizes and configurations. These SRM's all employ PBAN type propellants with ammonium perchlorate oxidizer and 16 to 20% aluminum except one which uses carboxyl terminated butadiene binder. The only non-calculated parameters in the burning rate equations that are changed for the different SRM's are the zero crossflow velocity burning rate coefficients and exponents. The results, in general, confirm the importance of grain deformation. The improved internal ballistic model makes practical development of an effective computer program for application of an optimization technique to SRM design which is also demonstrated. The program uses a pattern search technique to minimize the difference between a desired thrust-time trace and one calculated based on the internal ballistic model.

International Ultraviolet Explorer (IUE) Battery History and Performance

NASA Technical Reports Server (NTRS)

Rao, Gopalskrishna M.; Tiller, Smith E.

1999-01-01

The "International Ultraviolet Explorer (IUE) Battery History and Performance" report provides the information on the cell/battery design, battery performance during the thirty eight (38) solar eclipse seasons and the end-of-life test data. It is noteworthy that IUE spacecraft was an in-house project and that the batteries were designed, fabricated and tested (Qualification and Acceptance) at the Goddard Space Flight Center. A detailed information is given on the cell and battery design criteria and the designs, on the Qualification and the Acceptance tests, and on the cell life cycling tests. The environmental, thermal, and vibration tests were performed on the batteries at the battery level as well as with the interface on the spacecraft. The telemetry data were acquired, analyzed, and trended for various parameters over the mission life. Rigorous and diligent battery management programs were developed and implemented from time to time to extend the mission life over eighteen plus years. Prior to the termination of spacecraft operation, special tests were conducted to check the battery switching operation, battery residual capacity, third electrode performance and battery impedance.

Overhead-Performance Tradeoffs in Distributed Wireless Networks

DTIC Science & Technology

2015-06-26

grew this fraction. See the tutorial for details and acronym definitions. Key Publication & Abstract • Gwanmo Ku and John MacLaren Walsh, Resource...tradeoffs. Key Publication & Abstract • Gwanmo Ku , Jie Ren, and John MacLaren Walsh, Computing the Rate Distortion Region for the CEO Problem with...IID. • Jie Ren, Bradford Boyle, Gwanmo Ku , Steven Weber, John MacLaren Walsh, Overhead Performance Tradeoffs A Resource Allocation Perspective, IEEE

Sixth Goddard Conference on Mass Storage Systems and Technologies Held in Cooperation with the Fifteenth IEEE Symposium on Mass Storage Systems

NASA Technical Reports Server (NTRS)

Kobler, Benjamin (Editor); Hariharan, P. C. (Editor)

1998-01-01

This document contains copies of those technical papers received in time for publication prior to the Sixth Goddard Conference on Mass Storage Systems and Technologies which is being held in cooperation with the Fifteenth IEEE Symposium on Mass Storage Systems at the University of Maryland-University College Inn and Conference Center March 23-26, 1998. As one of an ongoing series, this Conference continues to provide a forum for discussion of issues relevant to the management of large volumes of data. The Conference encourages all interested organizations to discuss long term mass storage requirements and experiences in fielding solutions. Emphasis is on current and future practical solutions addressing issues in data management, storage systems and media, data acquisition, long term retention of data, and data distribution. This year's discussion topics include architecture, tape optimization, new technology, performance, standards, site reports, vendor solutions. Tutorials will be available on shared file systems, file system backups, data mining, and the dynamics of obsolescence.

Selection Factors among International Medical Graduates and Psychiatric Residency Performance

ERIC Educational Resources Information Center

Shiroma, Paulo R.; Alarcon, Renato D.

2010-01-01

Objective: The authors examine the association between the selection factors used in a psychiatric residency program and subsequent clinical and academic performance among international medical graduate (IMG) candidates. Methods: The authors completed a retrospective review of application files and residency evaluations of 50 IMG residents who…

Cross-National Variations in Student Employment and Academic Performance: The Roles of National Context and International Law*

PubMed Central

Byun, Soo-yong; Henck, Adrienne; Post, David

2014-01-01

Most existing research indicates that working students perform more poorly than do full-time students on standardized achievement tests. However, we know there are wide international variations in this gap. This article shows that national and international contexts help to explain the gap in the academic performance between working and non-working middle-school students. We combined data from the 2003 Trends in International Mathematics and Science Study (TIMSS) eighth-grade assessment with the country specific information on socioeconomic and educational conditions, as well as the timing of each country's ratification of an international treaty regulating child labor. Our multilevel analyses show that, while student employment was generally negatively associated with academic performance, this negative association is smaller in countries that by 1995 had ratified the International Labour Organization's Convention No. 138 on child labor. These findings highlight the role of national and international policy in structuring the consequences of student employment for academic performance. PMID:25632163

Orthopedic surgery postgraduate year 1 intern curriculum improves initial orthopedic in-training examination performance.

PubMed

Roberts, Craig S; Nyland, John; Broome, Brandon

2012-04-01

To determine the efficacy of an educational curriculum designed for orthopedic surgery postgraduate year 1 (PGY-1) interns to improve initial Orthopedic In-Training Examination (OITE) performance. A retrospective cohort study was performed that evaluated the PGY-1 intern OITE performance of one residency training program (n = 55) during 7-year periods before (1996-2002) and after structured curriculum implementation (2003-2009). Linear regression analysis revealed insignificant changes in median PGY-1 intern OITE percentile rank during the precurriculum period (R = 0.08, P = 0.53). Postcurriculum period comparisons revealed significantly improving PGY-1 intern OITE percentile rank (R = 0.46, P = 0.048). Pre- and postcurriculum median US Medical Licensing Examination (USMLE) Step I scores did not display statistically significant differences (218.2 ± 6.6 vs 229.1 ± 13.8, Mann-Whitney U test, z = -1.5, P = 0.10). Spearman rho correlations revealed a moderate relation (r = 0.61) between postcurriculum PGY-1 intern OITE percentile rank and USMLE Step I score, but not during the precurriculum period. A moderate relation (r = 0.50) also was observed between postcurriculum USMLE Step I score and average OITE percentile rank during the 5-year residency program, but not during the precurriculum period. PGY-1 intern OITE percentile rank improved significantly with the addition of a specially designed educational curriculum. The stronger USMLE Step I score and PGY-1 intern OITE percentile rank relation observed during the postcurriculum period suggests that interns who participated in the educational curriculum were better prepared to translate general medical and patient care knowledge into orthopedic surgery knowledge.

Performance-driven Multimodality Sensor Fusion

DTIC Science & Technology

2012-01-23

in IEEE Intl Conf. on Acoust., Speech , Signal Processing, (Dallas), Mar. 2010. [10] K. Sricharan, R. Raich, and A. Hero III, “Boundary compensated knn ...nearest neighbor ( kNN ) plug-in estima- tors, we have developed a generally applicable theory that gives analytical closed-form expressions for asymptotic...Co-PI’s Raich and Hero and was published in the IEEE Proc. of 2011 Intl Conf. on Acoustics, Speech , and Signal Processing. 2.4 Dimension estimation in

Performance Evaluation of Parallel Algorithms and Architectures in Concurrent Multiprocessor Systems

DTIC Science & Technology

1988-09-01

HEP and Other Parallel processors, Report no. ANL-83-97, Argonne National Laboratory, Argonne, Ill. 1983. [19] Davidson, G . S. A Practical Paradigm for...IEEE Comp. Soc., 1986. [241 Peir, Jih-kwon, and D. Gajski , "CAMP: A Programming Aide For Multiprocessors," Proc. 1986 ICPP, IEEE Comp. Soc., pp475...482. [251 Pfister, G . F., and V. A. Norton, "Hot Spot Contention and Combining in Multistage Interconnection Networks,"IEEE Trans. Comp., C-34, Oct

Effect of varying internal geometry on the static performance of rectangular thrust-reverser ports

NASA Technical Reports Server (NTRS)

Re, Richard J.; Mason, Mary L.

1987-01-01

An investigation has been conducted to evaluate the effects of several geometric parameters on the internal performance of rectangular thrust-reverser ports for nonaxisymmetric nozzles. Internal geometry was varied with a test apparatus which simulated a forward-flight nozzle with a single, fully deployed reverser port. The test apparatus was designed to simulate thrust reversal (conceptually) either in the convergent section of the nozzle or in the constant-area duct just upstream of the nozzle. The main geometric parameters investigated were port angle, port corner radius, port location, and internal flow blocker angle. For all reverser port geometries, the port opening had an aspect ratio (throat width to throat height) of 6.1 and had a constant passage area from the geometric port throat to the exit. Reverser-port internal performance and thrust-vector angles computed from force-balance measurements are presented.

Impact of English Proficiency on Academic Performance of International Students

ERIC Educational Resources Information Center

Martirosyan, Nara M.; Hwang, Eunjin; Wanjohi, Reubenson

2015-01-01

Using an ex-post facto, non-experimental approach, this research examined the impact of English language proficiency and multilingualism on the academic performance of international students enrolled in a four-year university located in north central Louisiana in the United States. Data were collected through a self-reported questionnaire from 59…

Genomics, molecular imaging, bioinformatics, and bio-nano-info integration are synergistic components of translational medicine and personalized healthcare research.

PubMed

Yang, Jack Y; Yang, Mary Qu; Arabnia, Hamid R; Deng, Youping

2008-09-16

Supported by National Science Foundation (NSF), International Society of Intelligent Biological Medicine (ISIBM), International Journal of Computational Biology and Drug Design and International Journal of Functional Informatics and Personalized Medicine, IEEE 7th Bioinformatics and Bioengineering attracted more than 600 papers and 500 researchers and medical doctors. It was the only synergistic inter/multidisciplinary IEEE conference with 24 Keynote Lectures, 7 Tutorials, 5 Cutting-Edge Research Workshops and 32 Scientific Sessions including 11 Special Research Interest Sessions that were designed dynamically at Harvard in response to the current research trends and advances. The committee was very grateful for the IEEE Plenary Keynote Lectures given by: Dr. A. Keith Dunker (Indiana), Dr. Jun Liu (Harvard), Dr. Brian Athey (Michigan), Dr. Mark Borodovsky (Georgia Tech and President of ISIBM), Dr. Hamid Arabnia (Georgia and Vice-President of ISIBM), Dr. Ruzena Bajcsy (Berkeley and Member of United States National Academy of Engineering and Member of United States Institute of Medicine of the National Academies), Dr. Mary Yang (United States National Institutes of Health and Oak Ridge, DOE), Dr. Chih-Ming Ho (UCLA and Member of United States National Academy of Engineering and Academician of Academia Sinica), Dr. Andy Baxevanis (United States National Institutes of Health), Dr. Arif Ghafoor (Purdue), Dr. John Quackenbush (Harvard), Dr. Eric Jakobsson (UIUC), Dr. Vladimir Uversky (Indiana), Dr. Laura Elnitski (United States National Institutes of Health) and other world-class scientific leaders. The Harvard meeting was a large academic event 100% full-sponsored by IEEE financially and academically. After a rigorous peer-review process, the committee selected 27 high-quality research papers from 600 submissions. The committee is grateful for contributions from keynote speakers Dr. Russ Altman (IEEE BIBM conference keynote lecturer on combining simulation and machine

Genomics, molecular imaging, bioinformatics, and bio-nano-info integration are synergistic components of translational medicine and personalized healthcare research

PubMed Central

2008-01-01

Supported by National Science Foundation (NSF), International Society of Intelligent Biological Medicine (ISIBM), International Journal of Computational Biology and Drug Design and International Journal of Functional Informatics and Personalized Medicine, IEEE 7th Bioinformatics and Bioengineering attracted more than 600 papers and 500 researchers and medical doctors. It was the only synergistic inter/multidisciplinary IEEE conference with 24 Keynote Lectures, 7 Tutorials, 5 Cutting-Edge Research Workshops and 32 Scientific Sessions including 11 Special Research Interest Sessions that were designed dynamically at Harvard in response to the current research trends and advances. The committee was very grateful for the IEEE Plenary Keynote Lectures given by: Dr. A. Keith Dunker (Indiana), Dr. Jun Liu (Harvard), Dr. Brian Athey (Michigan), Dr. Mark Borodovsky (Georgia Tech and President of ISIBM), Dr. Hamid Arabnia (Georgia and Vice-President of ISIBM), Dr. Ruzena Bajcsy (Berkeley and Member of United States National Academy of Engineering and Member of United States Institute of Medicine of the National Academies), Dr. Mary Yang (United States National Institutes of Health and Oak Ridge, DOE), Dr. Chih-Ming Ho (UCLA and Member of United States National Academy of Engineering and Academician of Academia Sinica), Dr. Andy Baxevanis (United States National Institutes of Health), Dr. Arif Ghafoor (Purdue), Dr. John Quackenbush (Harvard), Dr. Eric Jakobsson (UIUC), Dr. Vladimir Uversky (Indiana), Dr. Laura Elnitski (United States National Institutes of Health) and other world-class scientific leaders. The Harvard meeting was a large academic event 100% full-sponsored by IEEE financially and academically. After a rigorous peer-review process, the committee selected 27 high-quality research papers from 600 submissions. The committee is grateful for contributions from keynote speakers Dr. Russ Altman (IEEE BIBM conference keynote lecturer on combining simulation and machine

Match Physical Performance of Elite Female Soccer Players During International Competition.

PubMed

Datson, Naomi; Drust, Barry; Weston, Matthew; Jarman, Ian H; Lisboa, Paulo J; Gregson, Warren

2017-09-01

Datson, N, Drust, B, Weston, M, Jarman, IH, Lisboa, P, and Gregson, W. Match physical performance of elite female soccer players during international competition. J Strength Cond Res 31(9): 2379-2387, 2017-The purpose of this study was to provide a detailed analysis of the physical demands of competitive international female soccer match play. A total of 148 individual match observations were undertaken on 107 outfield players competing in competitive international matches during the 2011-2012 and 2012-2013 seasons, using a computerized tracking system (Prozone Sports Ltd., Leeds, England). Total distance and total high-speed running distances were influenced by playing position, with central midfielders completing the highest (10,985 ± 706 m and 2,882 ± 500 m) and central defenders the lowest (9,489 ± 562 m and 1,901 ± 268 m) distances, respectively. Greater total very high-speed running distances were completed when a team was without (399 ± 143 m) compared to with (313 ± 210 m) possession of the ball. Most sprints were over short distances with 76% and 95% being less than 5 and 10 m, respectively. Between half reductions in physical performance were present for all variables, independent of playing position. This study provides novel findings regarding the physical demands of different playing positions in competitive international female match play and provides important insights for physical coaches preparing elite female players for competition.

False Belief Performance of Children Adopted Internationally.

PubMed

Hwa-Froelich, Deborah A; Matsuo, Hisako; Jacobs, Kristal

2017-02-01

The purpose of this study was to explore relationships among adoption, individual, and family variables on false belief performance of children adopted internationally (CAI). Using a quasiexperimental design, thirty-five 4-year-old children adopted from Asian and Eastern European countries before age 2 years were compared with a U.S. group of 33 nonadopted 4-year-old children on a standardized English-language measure, 3 false belief tasks, and a go/no-go inhibition measure. The adopted group differed significantly from the U.S. nonadopted group in expressive language and false belief performance. For the adopted group, inhibition measures were significantly correlated with core language scores. Core language scores and number of older siblings predicted false belief performance. Similar to children who are not adopted, language competence and living with older siblings positively influenced social understanding in CAI. Because CAI experience interrupted language acquisition and live with fewer older siblings, they are at risk of having weaker language competence and social understanding in their adopted language. When working with CAI, practitioners should assess social communication, language competence, and inhibition skills. They should assist adoptive families in providing socially mentored opportunities for their children to observe and interact with older children.

Tenth Goddard Conference on Mass Storage Systems and Technologies in Cooperation with the Nineteenth IEEE Symposium on Mass Storage Systems

NASA Technical Reports Server (NTRS)

Kobler, Benjamin (Editor); Hariharan, P. C. (Editor)

2002-01-01

This document contains copies of those technical papers received in time for publication prior to the Tenth Goddard Conference on Mass Storage Systems and Technologies which is being held in cooperation with the Nineteenth IEEE Symposium on Mass Storage Systems at the University of Maryland University College Inn and Conference Center April 15-18, 2002. As one of an ongoing series, this Conference continues to provide a forum for discussion of issues relevant to the ingest, storage, and management of large volumes of data. The Conference encourages all interested organizations to discuss long-term mass storage requirements and experiences in fielding solutions. Emphasis is on current and future practical solutions addressing issues in data management, storage systems and media, data acquisition, long-term retention of data, and data distribution. This year's discussion topics include architecture, future of current technology, storage networking with emphasis on IP storage, performance, standards, site reports, and vendor solutions. Tutorials will be available on perpendicular magnetic recording, object based storage, storage virtualization and IP storage.

Assessment of predictive performance in incomplete data by combining internal validation and multiple imputation.

PubMed

Wahl, Simone; Boulesteix, Anne-Laure; Zierer, Astrid; Thorand, Barbara; van de Wiel, Mark A

2016-10-26

Missing values are a frequent issue in human studies. In many situations, multiple imputation (MI) is an appropriate missing data handling strategy, whereby missing values are imputed multiple times, the analysis is performed in every imputed data set, and the obtained estimates are pooled. If the aim is to estimate (added) predictive performance measures, such as (change in) the area under the receiver-operating characteristic curve (AUC), internal validation strategies become desirable in order to correct for optimism. It is not fully understood how internal validation should be combined with multiple imputation. In a comprehensive simulation study and in a real data set based on blood markers as predictors for mortality, we compare three combination strategies: Val-MI, internal validation followed by MI on the training and test parts separately, MI-Val, MI on the full data set followed by internal validation, and MI(-y)-Val, MI on the full data set omitting the outcome followed by internal validation. Different validation strategies, including bootstrap und cross-validation, different (added) performance measures, and various data characteristics are considered, and the strategies are evaluated with regard to bias and mean squared error of the obtained performance estimates. In addition, we elaborate on the number of resamples and imputations to be used, and adopt a strategy for confidence interval construction to incomplete data. Internal validation is essential in order to avoid optimism, with the bootstrap 0.632+ estimate representing a reliable method to correct for optimism. While estimates obtained by MI-Val are optimistically biased, those obtained by MI(-y)-Val tend to be pessimistic in the presence of a true underlying effect. Val-MI provides largely unbiased estimates, with a slight pessimistic bias with increasing true effect size, number of covariates and decreasing sample size. In Val-MI, accuracy of the estimate is more strongly improved by

A mathematical problem and a Spacecraft Control Laboratory Experiment (SCOLE) used to evaluate control laws for flexible spacecraft. NASA/IEEE design challenge

NASA Technical Reports Server (NTRS)

Taylor, Lawrence W., Jr.; Balakrishnan, A. V.

1988-01-01

The problen of controlling large, flexible space systems has been evaluated using computer simulation. In several cases, ground experiments have also been used to validate system performance under more realistic conditions. There remains a need, however, to test additional control laws for flexible spacecraft and to directly compare competing design techniques. A program is discussed which has been initiated to make direct comparisons of control laws for, first, a mathematical problem, then and experimental test article being assembled under the cognizance of the Spacecraft Control Branch at the NASA Langley Research Center with the advice and counsel of the IEEE Subcommittee on Large Space Structures. The physical apparatus will consist of a softly supported dynamic model of an antenna attached to the Shuttle by a flexible beam. The control objective will include the task of directing the line-of-sight of the Shuttle antenna configuration toward a fixed target, under conditions of noisy data, control authority and random disturbances.

Paediatric International Nursing Study: using person-centred key performance indicators to benchmark children's services.

PubMed

McCance, Tanya; Wilson, Val; Kornman, Kelly

2016-07-01

The aim of the Paediatric International Nursing Study was to explore the utility of key performance indicators in developing person-centred practice across a range of services provided to sick children. The objective addressed in this paper was evaluating the use of these indicators to benchmark services internationally. This study builds on primary research, which produced indicators that were considered novel both in terms of their positive orientation and use in generating data that privileges the patient voice. This study extends this research through wider testing on an international platform within paediatrics. The overall methodological approach was a realistic evaluation used to evaluate the implementation of the key performance indicators, which combined an integrated development and evaluation methodology. The study involved children's wards/hospitals in Australia (six sites across three states) and Europe (seven sites across four countries). Qualitative and quantitative methods were used during the implementation process, however, this paper reports the quantitative data only, which used survey, observations and documentary review. The findings demonstrate the quality of care being delivered to children and their families across different international sites. The benchmarking does, however, highlight some differences between paediatric and general hospitals, and between the different key performance indicators across all the sites. The findings support the use of the key performance indicators as a novel method to benchmark services internationally. Whilst the data collected across 20 paediatric sites suggest services are more similar than different, benchmarking illuminates variations that encourage a critical dialogue about what works and why. The transferability of the key performance indicators and measurement framework across different settings has significant implications for practice. The findings offer an approach to benchmarking and celebrating

Performance nutrition guidelines for international rugby sevens tournaments.

PubMed

Dziedzic, Christine E; Higham, Dean G

2014-06-01

Rugby sevens is an abbreviated version of rugby union, played by teams of seven players over 7-min halves. International competitions are usually played in a tournament format. While shorter in duration, the movement demands of rugby sevens per min of match time are greater than rugby union, resulting in an accentuated load on players. This load can be repeated up to six times over a typical 2- or 3-day competition period. The potential cumulative effect of inadequate carbohydrate, protein and/or fluid intake over the course of a tournament is the greatest nutrition-related concern for players. Nutritional strategies before and during competition are suggested to replenish substrate stores, maintain fluid balance and promote recovery between matches. The use of ergogenic aids known to enhance intermittent, high-intensity activity and/or the execution of motor skills may be advantageous to rugby sevens performance and is discussed. This review provides a best-practice model of nutritional support for international rugby sevens competition based on our current understanding of the sport combined with pragmatic guidelines and considerations for the practitioner.

International Space Station Major Constituent Analyzer On-Orbit Performance

NASA Technical Reports Server (NTRS)

Gardner, Ben D.; Erwin, Phillip M.; Thoresen, Souzan; Wiedemann, Rachel; Matty, Chris

2015-01-01

The Major Constituent Analyzer is a mass spectrometer based system that measures the major atmospheric constituents on the International Space Station. A number of limited-life components require periodic change-out, including the ORU 02 analyzer and the ORU 08 Verification Gas Assembly. Improvements to ion pump operation and ion source tuning have improved lifetime performance of the current ORU 02 design. The most recent ORU 02 analyzer assemblies, as well as ORU 08, have operated nominally. For ORU 02, the ion source filaments and ion pump lifetime continue to be key determinants of MCA performance and logistical support. Monitoring several key parameters provides the capacity to monitor ORU health and properly anticipate end of life.

Numerical Simulation of Mixing Performances of a Passive Micromixer with Internal Ribs

NASA Astrophysics Data System (ADS)

Guo, L.; Zhang, S. S.; Han, K. J.

2010-03-01

Effective mixing of microfluids is the basic requirement for biochemical analysis. Unfortunately, the macroscale mixing methods such as stirring and creation of turbulent flow are not applicable to the mixing of microfluids. To tackle such problems, we proposed a new, passive micromixer with internal ribs, which improves the mixing performances by changing the internal structure and shape of microchannels, and increasing the interfacial surface areas as far as possible. In this paper, the impact of geometric parameters on the mixing performance, and the pressure loss of the proposed micromixer were simulated using the software package FLUENT. The simulation shows that the mixing index M of each crosssection increases initially and then decreases with the increase of inlet velocity V. It also shows that at Point V = 0.01 m/s, the fluid mixing changes from convective mass transfer to molecular diffusion mass transfer. With the increase of W1, the mixing index M of each crosssection decreases gradually, whereas it increases accordingly with the growth of P/W. The larger the number of internal ribs is, the better the mixing performance of the micromixer will be. On the other hand, the mixing index M of the proposed micromixer decreases with the increase of H/W. At H/W> = 0.6, the variation of H/W imposes little influence on the micromixer's mixing performance. At Q = 28.8 mLh-1, an improved mixing efficiency and lowered pressure loss will be achieved, thus meeting the requirement of microfluidic chip.

A comparison between the ANSI/IEEE and the CENELEC/IEC approach to overload protection of insulated power cables

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

Parise, G.; Rubino, G.

1995-12-31

The same basic principles, on which the methods of power cables protection against overloads are based, are summed up by different criteria and formulations within ANSI/IEEE and CENELEC/IEC publications. The studies carried out by the technical committees of these organizations have been examined and compared in order to point out not only their differences but also their complementary aspects. By arranging the two approaches, it has been possible to outline a third way to determine the admissible duration of overload currents and define intermediate criteria for the emergency ratings of cables and for the coordination of protective devices.

Development of Sub-Ischial Prosthetic Sockets with Vacuum-Assisted Suspension for Highly Active Persons with Transfemoral Amputations

DTIC Science & Technology

2011-10-01

International Conference on Robotics and Automation, Pasadena CA, USA, May 19-23, 2008, p 3672-3677. APPENDICES A Socket Breakdown for Scanning...the LimbLogic is the more efficient of the two pumps. These tests also showed that the performance for both pumps was self -consistent over the...Donelan, J. M. Biomechanical Energy Harvesting: Apparatus and Method. IEEE International Conference on Robotics and Automation, May 19-23, 2008. Lyon

Rapid Prototyping of High Performance Signal Processing Applications

DTIC Science & Technology

2011-01-01

understand- ing broadband wireless networking . Prentice Hall, 2007. [4] J.W.M. Baars, L.R. D’Addario, and A.R. Thompson. Radio astronomy in the... wireless sensor net- works. In Proceedings of the IEEE Real-Time Systems Symposium, pages 214–223, Tucson, Arizona, December 2007. 147 [74] C. Shen, H. Wu...computing platforms. In this region of high performance DSP, rapid prototyping is critical for faster time-to-market (e.g., in the wireless

Internal performance characteristics of thrust-vectored axisymmetric ejector nozzles

NASA Technical Reports Server (NTRS)

Lamb, Milton

1995-01-01

A series of thrust-vectored axisymmetric ejector nozzles were designed and experimentally tested for internal performance and pumping characteristics at the Langley research center. This study indicated that discontinuities in the performance occurred at low primary nozzle pressure ratios and that these discontinuities were mitigated by decreasing expansion area ratio. The addition of secondary flow increased the performance of the nozzles. The mid-to-high range of secondary flow provided the most overall improvements, and the greatest improvements were seen for the largest ejector area ratio. Thrust vectoring the ejector nozzles caused a reduction in performance and discharge coefficient. With or without secondary flow, the vectored ejector nozzles produced thrust vector angles that were equivalent to or greater than the geometric turning angle. With or without secondary flow, spacing ratio (ejector passage symmetry) had little effect on performance (gross thrust ratio), discharge coefficient, or thrust vector angle. For the unvectored ejectors, a small amount of secondary flow was sufficient to reduce the pressure levels on the shroud to provide cooling, but for the vectored ejector nozzles, a larger amount of secondary air was required to reduce the pressure levels to provide cooling.

Determination of safety distance limits for a human near a cellular base station antenna, adopting the IEEE standard or ICNIRP guidelines.

PubMed

Cooper, Justin; Marx, Bernd; Buhl, Johannes; Hombach, Volker

2002-09-01

This paper investigates the minimum distance for a human body in the near field of a cellular telephone base station antenna for which there is compliance with the IEEE or ICNIRP threshold values for radio frequency electromagnetic energy absorption in the human body. First, local maximum specific absorption rates (SARs), measured and averaged over volumes equivalent to 1 and to 10 g tissue within the trunk region of a physical, liquid filled shell phantom facing and irradiated by a typical GSM 900 base station antenna, were compared to corresponding calculated SAR values. The calculation used a homogeneous Visible Human body model in front of a simulated base station antenna of the same type. Both real and simulated base station antennas operated at 935 MHz. Antenna-body distances were between 1 and 65 cm. The agreement between measurements and calculations was excellent. This gave confidence in the subsequent calculated SAR values for the heterogeneous Visible Human model, for which each tissue was assigned the currently accepted values for permittivity and conductivity at 935 MHz. Calculated SAR values within the trunk of the body were found to be about double those for the homogeneous case. When the IEEE standard and the ICNIRP guidelines are both to be complied with, the local SAR averaged over 1 g tissue was found to be the determining parameter. Emitted power values from the antenna that produced the maximum SAR value over 1 g specified in the IEEE standard at the base station are less than those needed to reach the ICNIRP threshold specified for the local SAR averaged over 10 g. For the GSM base station antenna investigated here operating at 935 MHz with 40 W emitted power, the model indicates that the human body should not be closer to the antenna than 18 cm for controlled environment exposure, or about 95 cm for uncontrolled environment exposure. These safe distance limits are for SARs averaged over 1 g tissue. The corresponding safety distance limits

PREFACE: I International Scientific School Methods of Digital Image Processing in Optics and Photonics

NASA Astrophysics Data System (ADS)

Gurov, I. P.; Kozlov, S. A.

2014-09-01

The first international scientific school "Methods of Digital Image Processing in Optics and Photonics" was held with a view to develop cooperation between world-class experts, young scientists, students and post-graduate students, and to exchange information on the current status and directions of research in the field of digital image processing in optics and photonics. The International Scientific School was managed by: Saint Petersburg National Research University of Information Technologies, Mechanics and Optics (ITMO University) - Saint Petersburg (Russia) Chernyshevsky Saratov State University - Saratov (Russia) National research nuclear University "MEPHI" (NRNU MEPhI) - Moscow (Russia) The school was held with the participation of the local chapters of Optical Society of America (OSA), the Society of Photo-Optical Instrumentation Engineers (SPIE) and IEEE Photonics Society. Further details, including topics, committees and conference photos are available in the PDF

Location versus task relevance: The impact of differing internal focus of attention instructions on motor performance.

PubMed

Pelleck, Valerie; Passmore, Steven R

2017-05-01

Impaired performance while executing a motor task is attributed to a disruption of normal automatic processes when an internal focus of attention is used. What remains unclear is whether the specificity of internally focused task instructions may impact task performance. The present study assessed the implications of changing the attentional focus of novice and skilled golfers by measuring behavioural, neurophysiological and kinematic changes during a golf putting task. Over six blocks of ten putting trials each, attention was directed either externally (towards the target) or internally in one of two ways: 1) proximal (keeping the elbows extended and the hands gripping the putter); or 2) distal (keeping the weight evenly distributed between both legs) to the critical elements of the task. Results provided evidence that when novice participants use an internal focus of attention more closely associated with task performance that their: 1) execution; 2) accuracy; 3) variability of surface electromyography (sEMG) activity; and 4) kinematics of the putter movement are all adversely affected. Skilled golfers are much more resilient to changes in attentional focus, while all participants interpret a distal internal focus of attention similar to an external focus. All participants produced decreased activity in the muscle (tibialis anterior) associated with the distal (less task relevant) focus of attention even when the "internal" focus was on the lower extremity. Our results provide evidence that the skill level of the participant and the distance of the internal focus of attention from the key elements of a motor skill directly impact the execution, muscle activity, and movement kinematics associated with skilled motor task performance. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluation of goal kicking performance in international rugby union matches.

PubMed

Quarrie, Kenneth L; Hopkins, Will G

2015-03-01

Goal kicking is an important element in rugby but has been the subject of minimal research. To develop and apply a method to describe the on-field pattern of goal-kicking and rank the goal kicking performance of players in international rugby union matches. Longitudinal observational study. A generalized linear mixed model was used to analyze goal-kicking performance in a sample of 582 international rugby matches played from 2002 to 2011. The model adjusted for kick distance, kick angle, a rating of the importance of each kick, and venue-related conditions. Overall, 72% of the 6769 kick attempts were successful. Forty-five percent of points scored during the matches resulted from goal kicks, and in 5.7% of the matches the result of the match hinged on the outcome of a kick attempt. There was an extremely large decrease in success with increasing distance (odds ratio for two SD distance 0.06, 90% confidence interval 0.05-0.07) and a small decrease with increasingly acute angle away from the mid-line of the goal posts (odds ratio for 2 SD angle, 0.44, 0.39-0.49). Differences between players were typically small (odds ratio for 2 between-player SD 0.53, 0.45-0.65). The generalized linear mixed model with its random-effect solutions provides a tool for ranking the performance of goal kickers in rugby. This modelling approach could be applied to other performance indicators in rugby and in other sports in which discrete outcomes are measured repeatedly on players or teams. Copyright © 2015. Published by Elsevier Ltd.

Coexistence: Threat to the Performance of Heterogeneous Network

NASA Astrophysics Data System (ADS)

Sharma, Neetu; Kaur, Amanpreet

2010-11-01

Wireless technology is gaining broad acceptance as users opt for the freedom that only wireless network can provide. Well-accepted wireless communication technologies generally operate in frequency bands that are shared among several users, often using different RF schemes. This is true in particular for WiFi, Bluetooth, and more recently ZigBee. These all three operate in the unlicensed 2.4 GHz band, also known as ISM band, which has been key to the development of a competitive and innovative market for wireless embedded devices. But, as with any resource held in common, it is crucial that those technologies coexist peacefully to allow each user of the band to fulfill its communication goals. This has led to an increase in wireless devices intended for use in IEEE 802.11 wireless local area networks (WLANs) and wireless personal area networks (WPANs), both of which support operation in the crowded 2.4-GHz industrial, scientific and medical (ISM) band. Despite efforts made by standardization bodies to ensure smooth coexistence it may occur that communication technologies transmitting for instance at very different power levels interfere with each other. In particular, it has been pointed out that ZigBee could potentially experience interference from WiFi traffic given that while both protocols can transmit on the same channel, WiFi transmissions usually occur at much higher power level. In this work, we considered a heterogeneous network and analyzed the impact of coexistence between IEEE 802.15.4 and IEEE 802.11b. To evaluate the performance of this network, measurement and simulation study are conducted and developed in the QualNet Network simulator, version 5.0.Model is analyzed for different placement models or topologies such as Random. Grid & Uniform. Performance is analyzed on the basis of characteristics such as throughput, average jitter and average end to end delay. Here, the impact of varying different antenna gain & shadowing model for this

Cross-National Variations in Student Employment and Academic Performance: The Roles of National Context and International Law

ERIC Educational Resources Information Center

Byun, Soo-yong; Henck, Adrienne; Post, David

2014-01-01

Most existing research indicates that working students perform more poorly than do full-time students on standardized achievement tests. However, we know there are wide international variations in this gap. This article shows that national and international contexts help to explain the gap in the academic performance between working and nonworking…

Delay Analysis and Optimization of Bandwidth Request under Unicast Polling in IEEE 802.16e over Gilbert-Elliot Error Channel

NASA Astrophysics Data System (ADS)

Hwang, Eunju; Kim, Kyung Jae; Roijers, Frank; Choi, Bong Dae

In the centralized polling mode in IEEE 802.16e, a base station (BS) polls mobile stations (MSs) for bandwidth reservation in one of three polling modes; unicast, multicast, or broadcast pollings. In unicast polling, the BS polls each individual MS to allow to transmit a bandwidth request packet. This paper presents an analytical model for the unicast polling of bandwidth request in IEEE 802.16e networks over Gilbert-Elliot error channel. We derive the probability distribution for the delay of bandwidth requests due to wireless transmission errors and find the loss probability of request packets due to finite retransmission attempts. By using the delay distribution and the loss probability, we optimize the number of polling slots within a frame and the maximum retransmission number while satisfying QoS on the total loss probability which combines two losses: packet loss due to the excess of maximum retransmission and delay outage loss due to the maximum tolerable delay bound. In addition, we obtain the utilization of polling slots, which is defined as the ratio of the number of polling slots used for the MS's successful transmission to the total number of polling slots used by the MS over a long run time. Analysis results are shown to well match with simulation results. Numerical results give examples of the optimal number of polling slots within a frame and the optimal maximum retransmission number depending on delay bounds, the number of MSs, and the channel conditions.

Development of a low mobility IEEE 802.15.4 compliant VANET system for urban environments.

PubMed

Nazabal, Juan Antonio; Falcone, Francisco; Fernández-Valdivielso, Carlos; Matías, Ignacio Raúl

2013-05-29

The use of Vehicular Ad-Hoc Networks (VANETs) is growing nowadays and it includes both roadside-to-vehicle communication (RVC) and inter-vehicle communication (IVC). The purpose of VANETs is to exchange useful information between vehicles and the roadside infrastructures for making an intelligent use of them. There are several possible applications for this technology like: emergency warning system for vehicles, cooperative adaptive cruise control or collision avoidance, among others. The objective of this work is to develop a VANET prototype system for urban environments using IEEE 802.15.4 compliant devices. Simulation-based values of the estimated signal strength and radio link quality values are obtained and compared with measurements in outdoor conditions to validate an implemented VANET system. The results confirm the possibility of implementing low cost vehicular communication networks operating at moderate vehicular speeds.

Toward a Set of Internationally Applicable Indicators for Measuring University Internationalization Performance

ERIC Educational Resources Information Center

Gao, Yuan

2015-01-01

This article emphasizes the urgent demand for measurements of university internationalization and proposes a new approach to develop a set of internationally applicable indicators for measuring university internationalization performance. The article looks into existing instruments developed for assessing university internationalization,…

Health system frameworks and performance indicators in eight countries: A comparative international analysis

PubMed Central

Braithwaite, Jeffrey; Hibbert, Peter; Blakely, Brette; Plumb, Jennifer; Hannaford, Natalie; Long, Janet Cameron; Marks, Danielle

2017-01-01

Objectives: Performance indicators are a popular mechanism for measuring the quality of healthcare to facilitate both quality improvement and systems management. Few studies make comparative assessments of different countries’ performance indicator frameworks. This study identifies and compares frameworks and performance indicators used in selected Organisation for Economic Co-operation and Development health systems to measure and report on the performance of healthcare organisations and local health systems. Countries involved are Australia, Canada, Denmark, England, the Netherlands, New Zealand, Scotland and the United States. Methods: Identification of comparable international indicators and analyses of their characteristics and of their broader national frameworks and contexts were undertaken. Two dimensions of indicators – that they are nationally consistent (used across the country rather than just regionally) and locally relevant (measured and reported publicly at a local level, for example, a health service) – were deemed important. Results: The most commonly used domains in performance frameworks were safety, effectiveness and access. The search found 401 indicators that fulfilled the ‘nationally consistent and locally relevant’ criteria. Of these, 45 indicators are reported in more than one country. Cardiovascular, surgery and mental health were the most frequently reported disease groups. Conclusion: These comparative data inform researchers and policymakers internationally when designing health performance frameworks and indicator sets. PMID:28228948

Solid rocket booster performance evaluation model. Volume 3: Sample case. [propellant combustion simulation/internal ballistics

NASA Technical Reports Server (NTRS)

1974-01-01

The solid rocket booster performance evaluation model (SRB-11) is used to predict internal ballistics in a sample motor. This motor contains a five segmented grain. The first segment has a 14 pointed star configuration with a web which wraps partially around the forward dome. The other segments are circular in cross-section and are tapered along the interior burning surface. Two of the segments are inhibited on the forward face. The nozzle is not assumed to be submerged. The performance prediction is broken into two simulation parts: the delivered end item specific impulse and the propellant properties which are required as inputs for the internal ballistics module are determined; and the internal ballistics for the entire burn duration of the motor are simulated.

Advanced Numerical Techniques of Performance Evaluation. Volume 1

DTIC Science & Technology

1990-06-01

system scheduling3thread. The scheduling thread then runs any other ready thread that can be found. A thread can only sleep or switch out on itself...Polychronopoulos and D.J. Kuck. Guided Self- Scheduling : A Practical Scheduling Scheme for Parallel Supercomputers. IEEE Transactions on Computers C...Kuck 1987] C.D. Polychronopoulos and D.J. Kuck. Guided Self- Scheduling : A Practical Scheduling Scheme for Parallel Supercomputers. IEEE Trans. on Comp

International Space Station Major Constituent Analyzer On-Orbit Performance

NASA Technical Reports Server (NTRS)

Gardner, Ben D.; Erwin, Phillip M.; Cougar, Tamara; Ulrich, BettyLynn

2017-01-01

The Major Constituent Analyzer (MCA) is a mass spectrometer based system that measures the major atmospheric constituents on the International Space Station. A number of limited-life components require periodic change-out, including the ORU 02 analyzer and the ORU 08 Verification Gas Assembly. The most recent ORU 02 and ORU 08 assemblies in the LAB MCA are operating nominally. For ORU 02, the ion source filaments and ion pump lifetime continue to be key determinants of MCA performance. Finally, the Node 3 MCA is being brought to an operational configuration.

Internal Medicine House Officers' Performance as Assessed by Experts and Standardized Patients.

ERIC Educational Resources Information Center

Calhoun, Judith G.; And Others

1987-01-01

Three chronically ill patients were trained to evaluate the performance of 31 second-year internal medicine house officers based upon: a checklist for the medical data elicited during the medical interview; the process of the interview; and the physical examination technique. (Author/MLW)

Performance during internal medicine residency training and subsequent disciplinary action by state licensing boards.

PubMed

Papadakis, Maxine A; Arnold, Gerald K; Blank, Linda L; Holmboe, Eric S; Lipner, Rebecca S

2008-06-03

Physicians who are disciplined by state licensing boards are more likely to have demonstrated unprofessional behavior in medical school. Information is limited on whether similar performance measures taken during residency can predict performance as practicing physicians. To determine whether performance measures during residency predict the likelihood of future disciplinary actions against practicing internists. Retrospective cohort study. State licensing board disciplinary actions against physicians from 1990 to 2006. 66,171 physicians who entered internal medicine residency training in the United States from 1990 to 2000 and became diplomates. Predictor variables included components of the Residents' Annual Evaluation Summary ratings and American Board of Internal Medicine (ABIM) certification examination scores. 2 performance measures independently predicted disciplinary action. A low professionalism rating on the Residents' Annual Evaluation Summary predicted increased risk for disciplinary action (hazard ratio, 1.7 [95% CI, 1.3 to 2.2]), and high performance on the ABIM certification examination predicted decreased risk for disciplinary action (hazard ratio, 0.7 [CI, 0.60 to 0.70] for American or Canadian medical school graduates and 0.9 [CI, 0.80 to 1.0] for international medical school graduates). Progressively better professionalism ratings and ABIM certification examination scores were associated with less risk for subsequent disciplinary actions; the risk ranged from 4.0% for the lowest professionalism rating to 0.5% for the highest and from 2.5% for the lowest examination scores to 0.0% for the highest. The study was retrospective. Some diplomates may have practiced outside of the United States. Nondiplomates were excluded. Poor performance on behavioral and cognitive measures during residency are associated with greater risk for state licensing board actions against practicing physicians at every point on a performance continuum. These findings support

Communication Delays Impact Behavior and Performance Aboard the International Space Station.

PubMed

Kintz, Natalie M; Palinkas, Lawrence A

Long-duration space explorations will involve significant communication delays that will likely impact individual and team outcomes. However, the extent of these impacts and the appropriate countermeasures for their mitigation remain largely unknown. This study examined the feasibility and acceptability of utilizing the International Space Station (ISS) as a research platform to assess the impacts of communication delays on individual and team behavior and performance. For this study, 3 ISS crewmembers and 18 mission support personnel performed 10 tasks identified by subject matter experts as meeting study criteria, 6 tasks without a delay in communication and 4 tasks with a 50-s one-way delay. Assessments of individual and team performance and behavior were obtained after each task. The completion rate of posttask assessments and postmission interviews with astronauts were used to assess feasibility and acceptability. Posttask assessments were completed in 100% of the instances where a crewmember was assigned to a task and in 83% where mission support personnel were involved. Qualitative analysis of postmission interviews found the study to be important and acceptable to the three astronauts. However, they also reported the study was limited in the number and type of tasks included, limitations in survey questions, and preference for open-ended to scaled items. Although the ISS is considered a high fidelity analog for long-duration space missions, future studies of communication delays on the ISS must take into considerations the constraints imposed by mission operations and subject preferences and priorities. Kintz KM, Palinkas LA. Communication delays impact behavior and performance aboard the International Space Station. Aerosp Med Hum Perform. 2017; 87(11):940-946.

Memorias Conferencia Internacional IEEE Mexico 1971, Sobre Sistemas, Redes Y Computadoras. Volumen I and Volumen II. (Proceedings of International Conference of IEEE Concerning Systems, Networks, and Computers. Volume I and Volume II.

ERIC Educational Resources Information Center

Concheiro, A. Alonso, Ed.; And Others

The following papers in English from this international conference may be of particular interest to those in the field of education. T. Nakahara, A. Tsukamota, and M. Matsumoto describe a computer-aided design technique for an economical urban cable television system. W. D. Wasson and R. K. Chitkara outline a recognition scheme based on analysis…

International Space Station Major Constituent Analyzer On-Orbit Performance

NASA Technical Reports Server (NTRS)

Gardner, Ben D.; Erwin, Philip M.; Thoresen, Souzan; Granahan, John; Matty, Chris

2010-01-01

The Major Constituent Analyzer is a mass spectrometer based system that measures the major atmospheric constituents on the International Space Station. A number of limited-life components require periodic changeout, including the analyzer (ORU 02) and the verification gas assembly (ORU 08). The longest lasting ORU 02 was recently replaced after a record service length of 1033 days. The comparatively high performance duration may be attributable to a reduced inlet flow rate into the analyzer, resulting in increased ion pump lifetime; however, there may be other factors as well. A recent schedule slip for delivery of replacement verification gas led to a demonstration that the calibration interval could be extended on a short-term basis. An analysis of ORU 08 performance characteristics indicates that it is possible to temporarily extend the calibration interval from 6 weeks to 12 weeks if necessary.

Superconductor Armature Winding for High Performance Electrical Machines

DTIC Science & Technology

2016-12-05

Vol. 3, pp.489-507 [Kalsi1] S. S. Kalsi, ‘Superconducting Wind Turbine Generator Employing MgB2 Windings Both on Rotor and Stator’, IEEE Trans. on...Contract  Number:  N00014-­‐14-­‐1-­‐0272   Contract  Title:  Superconductor  armature   winding  for  high  performance  electrical...an all-superconducting machine. Superconductor armature windings in electrical machines bring many design challenges that need to be addressed en

The Starlite Project

DTIC Science & Technology

1990-09-01

conflicts. The current prototyping tool also provides a multiversion data object control mechanism. From a series of experiments, we found that the...performance of a multiversion distributed database system is quite sensitive to the size of read-sets and write-sets of transactions. A multiversion database...510-512. (18) Son, S. H. and N. Haghighi, "Performance Evaluation of Multiversion Database Systems," Sixth IEEE International Conference on Data

International Space Station (ISS) Crew Quarters On-Orbit Performance and Sustaining

NASA Technical Reports Server (NTRS)

Schlesinger, Thilini P.; Rodriquez, Branelle R.

2013-01-01

The International Space Station (ISS) Crew Quarters (CQ) is a permanent personal space for crew members to sleep, perform personal recreation and communication, as well as provide on-orbit stowage of personal belongings. The CQs provide visual, light, and acoustic isolation for the crew member. Over a 2-year period, four CQs were launched to the ISS and currently reside in Node 2. Since their deployment, all CQs have been occupied and continue to be utilized. This paper will review failures that have occurred after 4 years on-orbit, and the investigations that have resulted in successful on-orbit operations. This paper documents the on-orbit performance and sustaining activities that have been performed to maintain the integrity and utilization of the CQs.

Internalizing versus Externalizing Control: Different Ways to Perform a Time-Based Prospective Memory Task

ERIC Educational Resources Information Center

Huang, Tracy; Loft, Shayne; Humphreys, Michael S.

2014-01-01

"Time-based prospective memory" (PM) refers to performing intended actions at a future time. Participants with time-based PM tasks can be slower to perform ongoing tasks (costs) than participants without PM tasks because internal control is required to maintain the PM intention or to make prospective-timing estimates. However, external…

Self-Regulated Learning Strategies and Pre-University Math Performance of International Students in Malaysia

ERIC Educational Resources Information Center

Loong, Tang Eng

2012-01-01

This study is an attempt to compare the use of self-regulated learning strategies and their math performance between home and international students in the Monash University Foundation Year (MUFY) and determine the self-regulated learning strategies that are significantly associated with their math performance. The participants of the study were…

DESPIC: Detecting Early Signatures of Persuasion in Information Cascades

DTIC Science & Technology

2015-08-27

over NoSQL Databases, Proceedings of the 14th IEEE/ACM International Symposium on Cluster, Cloud and Grid Computing (CCGrid 2014). 26-MAY-14, . : , P...over NoSQL Databases. Proceedings of the 14th IEEE/ACM International Symposium on Cluster, Cloud and Grid Computing (CCGrid 2014). Chicago, IL, USA...distributed NoSQL databases including HBase and Riak, we finalized the requirements of the optimal computational architecture to support our framework

Advanced Relay Design and Technology for Energy-Efficient Electronics

DTIC Science & Technology

2011-07-07

Estimates and Unique Failure Mechanisms of the Digital Micromirror Device (DMD),” in Proceedings of the IEEE Annual International Reliability Physics...Symposium (IRPS 󈨦), pp. 9-16, March 1998. [18] A. B. Sontheimer, “Digital Micromirror Device (DMD) Hinge Memory Lifetime Reliability Modeling,” in...Mechanisms of the Digital Micromirror Device (DMD),” in Proceedings of the IEEE Annual International Reliability Physics Symposium (IRPS 󈨦), pp. 9-16

Internal Challenges Affecting Academic Performance of Student-Athletes in Ghanaian Public Universities

ERIC Educational Resources Information Center

Apaak, Daniel; Sarpong, Emmanuel Osei

2015-01-01

This paper examined internal challenges affecting academic performance of student-athletes in Ghanaian public universities, using a descriptive survey research design. Proportionate random sampling technique was employed to select Three Hundred and Thirty-Two (332) respondents for the study. The instrument used in gathering data for the study was…

Assessment and Remediation for Physicians with Suspected Performance Problems: An International Survey

ERIC Educational Resources Information Center

Humphrey, Charlotte

2010-01-01

Introduction: Little is known about the overall appropriateness and value of the various programs available internationally for assessment and remediation for individual physicians whose performance in their clinical practice has been identified as giving cause for concern. Method: A questionnaire was e-mailed to members of the International…

Organization of the 17th Advanced Accelerator Concepts (AAC16) Workshop by the IEEE. Final Scientific/Technical Report On AWARD NO. DE-SC0015635

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

Sutter, David F.

The 2016 Workshop on Advanced Accelerator Concepts (AAC) was held at the Gaylord Hotel and Conference Center, National Harbor, Maryland, from July 31 through August 5, 2016. This workshop was the seventeenth in a biennial series that began at Los Alamos National Laboratory in 1982 with a workshop on laser acceleration of particles (see AIP Conf. Proc. 91). AAC16 was organized under the sponsorship of the IEEE Council on Superconductivity with financial support from the U. S. Department of Energy Office of High Energy Physics and the National Science Foundation. The scope of the AAC Workshop has grown since 1982more » to encompass a broad range of topics related to advancing accelerator science and technology beyond its current scientific and technical limits and is now an internationally acknowledged forum for interdisciplinary discussions on advanced accelerator and beam physics/technology concepts covering the widest possible range of applications. The Workshop continued the trend of growing worldwide participation, attracting world wide participation. The Workshop had a total of 256 attendees comprising (including the U.S.) representatives from 11 countries representing 65 different institutions. Each day’s schedule began with plenary sessions covering broad, cross disciplinary interests or general tutorial topics as selected by the Program Committee, followed by a break out into more narrowly focused working groups. The Workshop was organized into eight Working Groups each with a published statement of topical focus, scope of discussion and goals. A summary of the Working Group activities and conclusions is included in the American Institute of Physics’ (AIP) Conference Proceedings now available as an on line open source document. It has been a long tradition of the AAC workshops to encourage strong student participation. This is accomplished in part by subsidizing student attendance, done for this work shop by using funds from the DOE and National

Measuring Mental Workload: A Performance Battery.

DTIC Science & Technology

1987-09-01

1982). Subjective mental workload. Human Factors, 24, 25-40. Neisser , U ., Novick, R., & Lazar, R. (1963). Searching for ten targets 0...818 MES~A [G MENTAL WORKLOAD: A PERFORMANCE BATTERY( U ) 1/ • i NUN ENGINEERING LAS ABERDEEN PROVING GROUND MO L A MHITAKER ET AL .EP 87 HEL-TH-21-87...UNCLASSIFIED FG 5/9IIEEEEEEIE EhhIEllE~lllEE I.E.E.E I1.2 P e- - ,uIII j .. - - I ,,, 65 -S S p *q 0 0 0 0 0 0 0 0 0 u -; 5 . . ~qqr AD-A187 118

Static internal performance of single expansion-ramp nozzles with thrust vectoring and reversing

NASA Technical Reports Server (NTRS)

Re, R. J.; Berrier, B. L.

1982-01-01

The effects of geometric design parameters on the internal performance of nonaxisymmetric single expansion-ramp nozzles were investigated at nozzle pressure ratios up to approximately 10. Forward-flight (cruise), vectored-thrust, and reversed-thrust nozzle operating modes were investigated.

Static internal performance of convergent single-expansion-ramp nozzles with various combinations of internal geometric parameters

NASA Technical Reports Server (NTRS)

Bare, E. Ann; Capone, Francis J.

1989-01-01

An investigation was conducted in the Static Test Facility of the Langley 16-Foot Transonic Tunnel to determine the effects of five geometric design parameters on the internal performance of convergent single expansion ramp nozzles. The effects of ramp chordal angle, initial ramp angle, flap angle, flap length, and ramp length were determined. All nozzles tested has a nominally constant throat area and aspect ratio. Static pressure distributions along the centerlines of the ramp and flap were also obtained for each configuration. Nozzle pressure ratio was varied up to 10.0 for all configurations.

Performance Optimization of Priority Assisted CSMA/CA Mechanism of 802.15.6 under Saturation Regime

PubMed Central

Shakir, Mustafa; Rehman, Obaid Ur; Rahim, Mudassir; Alrajeh, Nabil; Khan, Zahoor Ali; Khan, Mahmood Ashraf; Niaz, Iftikhar Azim; Javaid, Nadeem

2016-01-01

Due to the recent development in the field of Wireless Sensor Networks (WSNs), the Wireless Body Area Networks (WBANs) have become a major area of interest for the developers and researchers. Human body exhibits postural mobility due to which distance variation occurs and the status of connections amongst sensors change time to time. One of the major requirements of WBAN is to prolong the network lifetime without compromising on other performance measures, i.e., delay, throughput and bandwidth efficiency. Node prioritization is one of the possible solutions to obtain optimum performance in WBAN. IEEE 802.15.6 CSMA/CA standard splits the nodes with different user priorities based on Contention Window (CW) size. Smaller CW size is assigned to higher priority nodes. This standard helps to reduce delay, however, it is not energy efficient. In this paper, we propose a hybrid node prioritization scheme based on IEEE 802.15.6 CSMA/CA to reduce energy consumption and maximize network lifetime. In this scheme, optimum performance is achieved by node prioritization based on CW size as well as power in respective user priority. Our proposed scheme reduces the average back off time for channel access due to CW based prioritization. Additionally, power based prioritization for a respective user priority helps to minimize required number of retransmissions. Furthermore, we also compare our scheme with IEEE 802.15.6 CSMA/CA standard (CW assisted node prioritization) and power assisted node prioritization under postural mobility in WBAN. Mathematical expressions are derived to determine the accurate analytical model for throughput, delay, bandwidth efficiency, energy consumption and life time for each node prioritization scheme. With the intention of analytical model validation, we have performed the simulations in OMNET++/MIXIM framework. Analytical and simulation results show that our proposed hybrid node prioritization scheme outperforms other node prioritization schemes in

Handbook for the Supervision of the Intern in School Administration...A Performance Based Guide for the Intern and His Advisors

ERIC Educational Resources Information Center

Hensarling, Paul R.; Erlandson, David A.

This handbook is a comprehensive guide to the supervision of the intern for all positions with school administrative responsibilities: principal, superintendent, and middle administrator. It consists of eight sections, the first five of which are introductory, explaining the concept of the internship as a performance-based evaluative technique and…

Internal performance of a nonaxisymmetric nozzle with a rotating upper flap and a center-pivoted lower flap

NASA Technical Reports Server (NTRS)

Wing, David J.; Leavitt, Laurence D.; Re, Richard J.

1993-01-01

An investigation was conducted at wind-off conditions in the static-test facility of the Langley 16-Foot Transonic Tunnel to determine the internal performance characteristics of a single expansion-ramp nozzle with thrust-vectoring capability to 105 degrees. Thrust vectoring was accomplished by the downward rotation of an upper flap with adaptive capability for internal contouring and a corresponding rotation of a center-pivoted lower flap. The static internal performance of configurations with pitch thrust-vector angles of 0 degrees, 60 degrees, and 105 degrees each with two throat areas, was investigated. The nozzle pressure ratio was varied from 1.5 to approximately 8.0 (5.0 for the maximum throat area configurations). Results of this study indicated that the nozzle configuration of the present investigation, when vectored, provided excellent flow-turning capability with relatively high levels of internal performance. In all cases, the thrust vector angle was a function of the nozzle pressure ratio. This result is expected because the flow is bounded by a single expansion surface on both vectored- and unvectored-nozzle geometries.

Performance of Wireless Unattended Sensor Network in Maritime Applications

DTIC Science & Technology

2007-06-01

longevity. Crossbow Technologies produces a number of gateways for use with their motes which include the MIB510, the MIB600 and the Stargate . The...MIB510 and MIB600 gateways require interface directly with a PC while he Stargate gateway interfaces remotely using the IEEE 802.11 standard for access...dedicated PC is unfeasible, the Stargate gateway allows remote access using the IEEE 802.11 standard. This can be accomplished via a Personal Computer

Internally Heated Screw Pyrolysis Reactor (IHSPR) heat transfer performance study

NASA Astrophysics Data System (ADS)

Teo, S. H.; Gan, H. L.; Alias, A.; Gan, L. M.

2018-04-01

1.5 billion end-of-life tyres (ELT) were discarded globally each year and pyrolysis is considered the best solution to convert the ELT into valuable high energy-density products. Among all pyrolysis technologies, screw reactor is favourable. However, conventional screw reactor risks plugging issue due to its lacklustre heat transfer performance. An internally heated screw pyrolysis reactor (IHSPR) was developed by local renewable energy industry, which serves as the research subject for heat transfer performance study of this particular paper. Zero-load heating test (ZLHT) was first carried out to obtain the operational parameters of the reactor, followed by the one dimensional steady-state heat transfer analysis carried out using SolidWorks Flow Simulation 2016. Experiments with feed rate manipulations and pyrolysis products analyses were conducted last to conclude the study.

International Space Station Major Constituent Analyzer On-orbit Performance

NASA Technical Reports Server (NTRS)

Gardner, Ben D.; Erwin, Phillip M.; Wiedemann, Rachel; Matty, Chris

2016-01-01

The Major Constituent Analyzer (MCA) is a mass spectrometer based system that measures the major atmospheric constituents on the International Space Station. A number of limited-life components require periodic change-out, including the ORU 02 analyzer and the ORU 08 Verification Gas Assembly. The most recent ORU 02 and ORU 08 assemblies are operating nominally. For ORU 02, the ion source filaments and ion pump lifetime continue to be key determinants of MCA performance. Additionally, testing is underway to evaluate the capacity of the MCA to analyze ammonia. Finally, plans are being made to bring the second MCA on ISS to an operational configuration.

The Impact of Placements on the Academic Performance of UK and International Students in Higher Education

ERIC Educational Resources Information Center

Crawford, Ian; Wang, Zhiqi

2016-01-01

Motivated by an increasing number of international students in UK higher education, this study investigates the effect of year-long placements on the academic performance of 268 accounting and finance students enrolled between 2006 and 2009. The results show differences between UK and international students although both statistically and…

Utilization of Additive Manufacturing in Evaluating the Performance of Internally Defected Materials

NASA Astrophysics Data System (ADS)

Mourad, A.-H. I.; Ghazal, A. M.; Syam, M. M.; Qadi, O. D. Al; Jassmi, H. Al

2018-05-01

The elimination of internal defects in a material present in the raw material or generated during the manufacturing or service is difficult. The inclusions of the defects have an adverse effect on the load bearing capacity. The presence of the cracks subjected to a specific orientation in materials or machinery can cause devastating unexpected failure during operation. Analysis of the failure in the components with cracks is more confined to analytical and numerical evaluation. The experimental evaluation has been tedious due to the complexity of replicating the actual defected component. The potential of additive manufacturing in developing user-defined components with cracks for the experimental evaluation is explored in this research. The present research investigated the effect of the internal elliptical cracks aligned at different orientations on the mechanical performance of polylactic acid (Green filament). The Fusion Deposition Method was utilized for the development of the standard tensile specimens with internal elliptical crack oriented at 0°, 45° and 90° using UltiMaker 2. The results proved that there is a considerable reduction in the load bearing capacity due to the presence of the cracks. The maximum load bearing capacity decreased by 15.01% for the specimen with crack inclined at 0° to the lateral axis compared to crack- free specimen. The nature of the fracture and the stress-strain graph evidently showcase the brittle nature of the material. The SEM image of the fractured region proved the phenomenal characteristics such as strong adhesion between the layers and the proper material flow. In the light of the results of this work, it can be concluded that the 3-D printing methodology is effective for evaluating the mechanical performance of the internally defected material.

Solid propellant rocket motor internal ballistics performance variation analysis, phase 3

NASA Technical Reports Server (NTRS)

Sforzini, R. H.; Foster, W. A., Jr.; Murph, J. E.; Adams, G. W., Jr.

1977-01-01

Results of research aimed at improving the predictability of off nominal internal ballistics performance of solid propellant rocket motors (SRMs) including thrust imbalance between two SRMs firing in parallel are reported. The potential effects of nozzle throat erosion on internal ballistic performance were studied and a propellant burning rate low postulated. The propellant burning rate model when coupled with the grain deformation model permits an excellent match between theoretical results and test data for the Titan IIIC, TU455.02, and the first Space Shuttle SRM (DM-1). Analysis of star grain deformation using an experimental model and a finite element model shows the star grain deformation effects for the Space Shuttle to be small in comparison to those of the circular perforated grain. An alternative technique was developed for predicting thrust imbalance without recourse to the Monte Carlo computer program. A scaling relationship used to relate theoretical results to test results may be applied to the alternative technique of predicting thrust imbalance or to the Monte Carlo evaluation. Extended investigation into the effect of strain rate on propellant burning rate leads to the conclusion that the thermoelastic effect is generally negligible for both steadily increasing pressure loads and oscillatory loads.

A Location-Based Duplex Scheme for Cost Effective Rural Broadband Connectivity Using IEEE 802.22 Cognitive Radio Based Wireless Regional Area Networks

NASA Astrophysics Data System (ADS)

Kalidoss, R.; Bhagyaveni, M. A.; Vishvaksenan, K. S.

2014-08-01

The search for a method of utilizing the scarce spectrum in an efficient manner is an active area of research in both academic and industrial communities. IEEE 802.22 is a standard for wireless regional area network (WRAN) based on cognitive radio (CR) that operates over underutilized portions of TV bands (54-862 MHz). Time division duplex (TDD)-based WRAN cells have such advantages as dynamic traffic allocation, traffic asymmetry to users and ease of spectrum allocation. However, these cells suffer from severe cross time slot (CTS) interference when the frames of the cells are not synchronized with adjacent WRAN cells. In this paper, we evaluate the location-based duplex (LBD) scheme for eliminating the CTS interference. The proposed LBD system is much more flexible and efficient in providing asymmetric data service and eliminating CTS interference by exploiting the advantages of both TDD and frequency division duplex (FDD) schemes. We also compare the performance of LBD systems with virtual cell concepts. Furthermore, our simulation results reveal that LBD-based systems outperform the virtual cell approach in terms of the low signal-to-interference (SIR) ratio requirement by mitigating the effects of CTS.

Interoperability of medical device information and the clinical applications: an HL7 RMIM based on the ISO/IEEE 11073 DIM.

PubMed

Yuksel, Mustafa; Dogac, Asuman

2011-07-01

Medical devices are essential to the practice of modern healthcare services. Their benefits will increase if clinical software applications can seamlessly acquire the medical device data. The need to represent medical device observations in a format that can be consumable by clinical applications has already been recognized by the industry. Yet, the solutions proposed involve bilateral mappings from the ISO/IEEE 11073 Domain Information Model (DIM) to specific message or document standards. Considering that there are many different types of clinical applications such as the electronic health record and the personal health record systems, the clinical workflows, and the clinical decision support systems each conforming to different standard interfaces, detailing a mapping mechanism for every one of them introduces significant work and, thus, limits the potential health benefits of medical devices. In this paper, to facilitate the interoperability of clinical applications and the medical device data, we use the ISO/IEEE 11073 DIM to derive an HL7 v3 Refined Message Information Model (RMIM) of the medical device domain from the HL7 v3 Reference Information Mode (RIM). This makes it possible to trace the medical device data back to a standard common denominator, that is, HL7 v3 RIM from which all the other medical domains under HL7 v3 are derived. Hence, once the medical device data are obtained in the RMIM format, it can easily be transformed into HL7-based standard interfaces through XML transformations because these interfaces all have their building blocks from the same RIM. To demonstrate this, we provide the mappings from the developed RMIM to some of the widely used HL7 v3-based standard interfaces.

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

Using Artificial Physics to Control Agents

DTIC Science & Technology

1999-11-01

unlimited 13. SUPPLEMENTARY NOTES IEEE International Conference on Information, Intelligence, and Systems, Oct 31 -Nov 3,1999. Bethesda, MD 14. ABSTRACT...distributed control can also perform distributed computation. 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT Same...1995. [9] H. Pattee. Artificial life needs a real epistemology. In Moran, Moreno, Merelo, and Chacon , editors, Advances in Artificial Life, pages

Application of Multihop Relay for Performance Enhancement of AeroMACS Networks

NASA Technical Reports Server (NTRS)

Kamali, Behnam; Wilson, Jeffrey D.; Kerczewski, Robert J.

2012-01-01

A new transmission technology, based on IEEE 802.16-2009 (WiMAX), is currently being developed for airport surface communications. A C-band spectrum allocation at 5091-5150 MHz has been created by ITU to carry this application. The proposed technology, known as AeroMACS, will be used to support fixed and mobile ground to ground applications and services. This article proposes and demonstrates that IEEE 802.16j-amendment-based WiMAX is most feasible for AeroMACS applications. This amendment introduces multihop relay as an optional deployment that may be used to provide additional coverage and/or enhance the capacity of the network. Particular airport surface radio coverage situations for which IEEE 802.16-2009-WiMAX provides resolutions that are inefficient, costly, or excessively power consuming are discussed. In all these cases, it is argued that 16j technology offers a much better alternative. A major concern about deployment of AeroMACS is interference to co-allocated applications such as the Mobile Satellite Service (MSS) feeder link. Our initial simulation results suggest that no additional interference to MSS feeder link is caused by deployment of IEEE 802.16j-based AeroMACS.

Internal Flow Simulation of Enhanced Performance Solid Rocket Booster for the Space Transportation System

NASA Technical Reports Server (NTRS)

Ahmad, Rashid A.; McCool, Alex (Technical Monitor)

2001-01-01

An enhanced performance solid rocket booster concept for the space shuttle system has been proposed. The concept booster will have strong commonality with the existing, proven, reliable four-segment Space Shuttle Reusable Solid Rocket Motors (RSRM) with individual component design (nozzle, insulator, etc.) optimized for a five-segment configuration. Increased performance is desirable to further enhance safety/reliability and/or increase payload capability. Performance increase will be achieved by adding a fifth propellant segment to the current four-segment booster and opening the throat to accommodate the increased mass flow while maintaining current pressure levels. One development concept under consideration is the static test of a "standard" RSRM with a fifth propellant segment inserted and appropriate minimum motor modifications. Feasibility studies are being conducted to assess the potential for any significant departure in component performance/loading from the well-characterized RSRM. An area of concern is the aft motor (submerged nozzle inlet, aft dome, etc.) where the altered internal flow resulting from the performance enhancing features (25% increase in mass flow rate, higher Mach numbers, modified subsonic nozzle contour) may result in increased component erosion and char. To assess this issue and to define the minimum design changes required to successfully static test a fifth segment RSRM engineering test motor, internal flow studies have been initiated. Internal aero-thermal environments were quantified in terms of conventional convective heating and discrete phase alumina particle impact/concentration and accretion calculations via Computational Fluid Dynamics (CFD) simulation. Two sets of comparative CFD simulations of the RSRM and the five-segment (IBM) concept motor were conducted with CFD commercial code FLUENT. The first simulation involved a two-dimensional axi-symmetric model of the full motor, initial grain RSRM. The second set of analyses

IEEE 1588 Time Synchronization Board in MTCA.4 Form Factor

NASA Astrophysics Data System (ADS)

Jabłoński, G.; Makowski, D.; Mielczarek, A.; Orlikowski, M.; Perek, P.; Napieralski, A.; Makijarvi, P.; Simrock, S.

2015-06-01

Distributed data acquisition and control systems in large-scale scientific experiments, like e.g. ITER, require time synchronization with nanosecond precision. A protocol commonly used for that purpose is the Precise Timing Protocol (PTP), also known as IEEE 1588 standard. It uses the standard Ethernet signalling and protocols and allows obtaining timing accuracy of the order of tens of nanoseconds. The MTCA.4 is gradually becoming the platform of choice for building such systems. Currently there is no commercially available implementation of the PTP receiver on that platform. In this paper, we present a module in the MTCA.4 form factor supporting this standard. The module may be used as a timing receiver providing reference clocks in an MTCA.4 chassis, generating a Pulse Per Second (PPS) signal and allowing generation of triggers and timestamping of events on 8 configurable backplane lines and two front panel connectors. The module is based on the Xilinx Spartan 6 FPGA and thermally stabilized Voltage Controlled Oscillator controlled by the digital-to-analog converter. The board supports standalone operation, without the support from the host operating system, as the entire control algorithm is run on a Microblaze CPU implemented in the FPGA. The software support for the card includes the low-level API in the form of Linux driver, user-mode library, high-level API: ITER Nominal Device Support and EPICS IOC. The device has been tested in the ITER timing distribution network (TCN) with three cascaded PTP-enabled Hirschmann switches and a GPS reference clock source. An RMS synchronization accuracy, measured by direct comparison of the PPS signals, better than 20 ns has been obtained.

Performance of the internal audit department under ERP systems: empirical evidence from Taiwanese firms

NASA Astrophysics Data System (ADS)

Tsai, Wen-Hsien; Chen, Hui-Chiao; Chang, Jui-Chu; Leu, Jun-Der; Chao Chen, Der; Purbokusumo, Yuyun

2015-10-01

In this study, the performance of the internal audit department (IAD) and its contribution to a company under enterprise resource planning (ERP) systems was examined. It is anticipated that this will provide insight into the factors perceived to be crucial to a company's effectiveness. A theoretical framework was developed and tested using the sample of Taiwanese companies. Using mail survey procedures, we elicited perceptions from key internal auditors about the ERP system and auditing software, as well as their opinions concerning the IAD's effectiveness and its contribution within a company. Data were analysed using the partial least square (PLS) regression to test the hypotheses. Drawing upon a sample of Taiwanese firms, the study suggests that a firm can improve the performance of the IAD through an enterprise-wide integrated, effective ERP system and appropriate auditing software. At the same time, the performance of the IAD can also contribute significantly to the company. The results also show that investments in computer-assisted auditing techniques (CAATs) are crucial due to their tremendous effectiveness in regard to the performance of the IAD and for the contributions CAATs can make to a company.

Internal Branding: Using Performance Technology To Create an Organization Focused on Customer Value.

ERIC Educational Resources Information Center

Tosti, Donald T.; Stotz, Rodger

2000-01-01

Presents a performance technology approach to revenue enhancement, with the goal of improving customer retention through building customer value. Topics include internal branding, a way to make sure that what the company delivers matches what's promised in the advertising; product versus service brands; and customer satisfaction, including…

Device interoperability and authentication for telemedical appliance based on the ISO/IEEE 11073 Personal Health Device (PHD) Standards.

PubMed

Caranguian, Luther Paul R; Pancho-Festin, Susan; Sison, Luis G

2012-01-01

In this study, we focused on the interoperability and authentication of medical devices in the context of telemedical systems. A recent standard called the ISO/IEEE 11073 Personal Health Device (X73-PHD) Standards addresses the device interoperability problem by defining common protocols for agent (medical device) and manager (appliance) interface. The X73-PHD standard however has not addressed security and authentication of medical devices which is important in establishing integrity of a telemedical system. We have designed and implemented a security policy within the X73-PHD standards. The policy will enable device authentication using Asymmetric-Key Cryptography and the RSA algorithm as the digital signature scheme. We used two approaches for performing the digital signatures: direct software implementation and use of embedded security modules (ESM). The two approaches were evaluated and compared in terms of execution time and memory requirement. For the standard 2048-bit RSA, ESM calculates digital signatures only 12% of the total time for the direct implementation. Moreover, analysis shows that ESM offers more security advantage such as secure storage of keys compared to using direct implementation. Interoperability with other systems was verified by testing the system with LNI Healthlink, a manager software that implements the X73-PHD standard. Lastly, security analysis was done and the system's response to common attacks on authentication systems was analyzed and several measures were implemented to protect the system against them.

Performance improvements from imagery: evidence that internal visual imagery is superior to external visual imagery for slalom performance

PubMed Central

Callow, Nichola; Roberts, Ross; Hardy, Lew; Jiang, Dan; Edwards, Martin Gareth

2013-01-01

We report three experiments investigating the hypothesis that use of internal visual imagery (IVI) would be superior to external visual imagery (EVI) for the performance of different slalom-based motor tasks. In Experiment 1, three groups of participants (IVI, EVI, and a control group) performed a driving-simulation slalom task. The IVI group achieved significantly quicker lap times than EVI and the control group. In Experiment 2, participants performed a downhill running slalom task under both IVI and EVI conditions. Performance was again quickest in the IVI compared to EVI condition, with no differences in accuracy. Experiment 3 used the same group design as Experiment 1, but with participants performing a downhill ski-slalom task. Results revealed the IVI group to be significantly more accurate than the control group, with no significant differences in time taken to complete the task. These results support the beneficial effects of IVI for slalom-based tasks, and significantly advances our knowledge related to the differential effects of visual imagery perspectives on motor performance. PMID:24155710

Mother-Daughter Agreement on Adolescent Adopted Chinese Girls' Academic Performance and Internalizing Symptoms

ERIC Educational Resources Information Center

Tan, Tony Xing; Marn, Travis

2014-01-01

This study reported mother-daughter agreement on adolescent adopted Chinese girls' adjustment. Data on the girls' academic performance and internalizing syndromes were collected from the adopted Chinese girls and their adoptive mothers separately. The adoptive mothers also provided data on mother-daughter relationship quality. There were 219 girls…

Referral for competency committee review for poor performance on the internal medicine clerkship is associated with poor performance in internship.

PubMed

Hemann, Brian A; Durning, Steven J; Kelly, William F; Dong, Ting; Pangaro, Louis N; Hemmer, Paul A

2015-04-01

To determine how students who are referred to a competency committee for concern over performance, and ultimately judged not to require remediation, perform during internship. Uniformed Services University of the Health Sciences' students who graduated between 2007 and 2011 were included in this study. We compared the performance during internship of three groups: students who were referred to the internal medicine competency committee for review who met passing criterion, students who were reviewed by the internal medicine competency committee who were determined not to have passed the clerkship and were prescribed remediation, and students who were never reviewed by this competency committee. Program Director survey results and United States Medical Licensing Examination (USMLE) Step 3 examination results were used as the outcomes of interest. The overall survey response rate for this 5-year cohort was 81% (689/853). 102 students were referred to this competency committee for review. 63/102 students were reviewed by this competency committee, given passing grades in the internal medicine clerkship, and were not required to do additional remediation. 39/102 students were given less than passing grades by this competency committee and required to perform additional clinical work in the department of medicine to remediate their performance. 751 students were never presented to this competency committee. Compared to students who were never presented for review, the group of reviewed students who did not require remediation was 5.6 times more likely to receive low internship survey ratings in the realm of professionalism, 8.6 times more likely to receive low ratings in the domain of medical expertise, and had a higher rate of USMLE Step 3 failure (9.4% vs. 2.8%). When comparing the reviewed group to students who were reviewed and also required remediation, the only significant difference between groups regarding professionalism ratings with 50% of the group requiring

IEEE 1988 International Symposium on Electromagnetic Compatibility, Seattle, WA, Aug. 2-4, 1988, Record

NASA Astrophysics Data System (ADS)

Various papers on electromagnetic compatibility are presented. Some of the optics considered include: field-to-wire coupling 1 to 18 GHz, SHF/EHF field-to-wire coupling model, numerical method for the analysis of coupling to thin wire structures, spread-spectrum system with an adaptive array for combating interference, technique to select the optimum modulation indices for suppression of undesired signals for simultaneous range and data operations, development of a MHz RF leak detector technique for aircraft harness surveillance, and performance of standard aperture shielding techniques at microwave frequncies. Also discussed are: spectrum efficiency of spread-spectrum systems, control of power supply ripple produced sidebands in microwave transistor amplifiers, an intership SATCOM versus radar electromagnetic interference prediction model, considerations in the design of a broadband E-field sensing system, unique bonding methods for spacecraft, and review of EMC practice for launch vehicle systems.

Improving International-Level Chess Players' Performance with an Acceptance-Based Protocol: Preliminary Findings

ERIC Educational Resources Information Center

Ruiz, Francisco J.; Luciano, Carmen

2012-01-01

This study compared an individual, 4-hr intervention based on acceptance and commitment therapy (ACT) versus a no-contact control condition in improving the performance of international-level chess players. Five participants received the brief ACT protocol, with each matched to another chess player with similar characteristics in the control…

Class of 2015 Advanced Placement and International Baccalaureate Exam Participation and Performance. Memorandum

ERIC Educational Resources Information Center

Navarro, Maria V.

2016-01-01

This memorandum describes the Advanced Placement (AP) and International Baccalaureate (IB) exams participation and performance of 2013 to 2015 public school graduates in Montgomery County Public Schools (MCPS) and the state of Maryland. The results are disaggregated by demographics and high schools. Students in the MCPS Class of 2015 continued to…

Implementation of a wireless ECG acquisition SoC for IEEE 802.15.4 (ZigBee) applications.

PubMed

Wang, Liang-Hung; Chen, Tsung-Yen; Lin, Kuang-Hao; Fang, Qiang; Lee, Shuenn-Yuh

2015-01-01

This paper presents a wireless biosignal acquisition system-on-a-chip (WBSA-SoC) specialized for electrocardiogram (ECG) monitoring. The proposed system consists of three subsystems, namely, 1) the ECG acquisition node, 2) the protocol for standard IEEE 802.15.4 ZigBee system, and 3) the RF transmitter circuits. The ZigBee protocol is adopted for wireless communication to achieve high integration, applicability, and portability. A fully integrated CMOS RF front end containing a quadrature voltage-controlled oscillator and a 2.4-GHz low-IF (i.e., zero-IF) transmitter is employed to transmit ECG signals through wireless communication. The low-power WBSA-SoC is implemented by the TSMC 0.18-μm standard CMOS process. An ARM-based displayer with FPGA demodulation and an RF receiver with analog-to-digital mixed-mode circuits are constructed as verification platform to demonstrate the wireless ECG acquisition system. Measurement results on the human body show that the proposed SoC can effectively acquire ECG signals.

Implementation experiences of ISO/IEEE11073 standard applied to new use cases for e-health environments.

PubMed

Martinez, I; Escayola, J; Martinez-Espronceda, M; Serrano, L; Trigo, J D; Led, S; Garcia, J

2009-01-01

Recent advances in biomedical engineering and continuous technological innovations in last decade are promoting new challenges, especially in e-Health environments. In this context, the medical devices interoperability is one of the interest fields wherein these improvements require a standard-based design in order to achieve homogeneous solutions. Furthermore, the spreading of wearable devices, oriented to the paradigm of patient environment and supported by wireless technologies as Bluetooth or ZigBee, is bringing new medical use cases based on Ambient Assisted Living, home monitoring of elderly, heart failure, chronic, under palliative care or patients who have undergone surgery, urgencies and emergencies, or even fitness auto-control and health follow-up. In this paper, several implementation experiences based on ISO/IEEE11073 standard are detailed. These evolved e-Health services can improve the quality of the patient's care, increase the user's interaction, and assure these e-Health applications to be fully compatible with global telemedicine systems.

Cold Cathode Electron Beam Controlled CO2 Laser Performance.

DTIC Science & Technology

1974-10-01

Siegman (ref. 7), the cavity parameters are g, - 3/2, g2 3/4 so that 0he cavity will be confocal when the mirror separation is 2.5 m. The laser output was...E. Siegman , Laser Focus 7, 42, 1971. 8. W. F. Krupke and W. R. Sooy, IEEE Journal Quant. Elec. QE-5, 575, 1969. 9. 0. R. Wood, et al., Appl. Phys...U t AD/A-000 413 COLD CATHODE ELECTRON BEAM CONTROLLED C02 LASER PERFORMANCE Leslie L. McKee, 1II, et al Air Force Weapons Laboratory Kirtland Air

Fundamental Studies of Electronic Properties of Materials and Devices for High Power, Compact Terahertz Vacuum Electron Devices

DTIC Science & Technology

2011-12-23

International Conference on Plasma Science, Karlsruhe, Germany, 2008. [9] K.J. Willis, S.C. Hagness, and I. Knezevic, “A global EMC/FDTD simulation...Materials,” 2010 IEEE AP-S International Symposium on Antennas and Propagation and 2010 USNC/ CNC /URSI Meeting in Toronto, ON, Canada, July 11-17...with a High-Q Quasioptical Resonator,” IEEE Int’l Conf. Plasma Sci., Chicago, IL, June 26-30, (2011), paper IO2B-4. [21] M.J. Weber, B.B. Yang, S.L

Audit feedback on reading performance of screening mammograms: An international comparison.

PubMed

Hofvind, S; Bennett, R L; Brisson, J; Lee, W; Pelletier, E; Flugelman, A; Geller, B

2016-09-01

Providing feedback to mammography radiologists and facilities may improve interpretive performance. We conducted a web-based survey to investigate how and why such feedback is undertaken and used in mammographic screening programmes. The survey was sent to representatives in 30 International Cancer Screening Network member countries where mammographic screening is offered. Seventeen programmes in 14 countries responded to the survey. Audit feedback was aimed at readers in 14 programmes, and facilities in 12 programmes. Monitoring quality assurance was the most common purpose of audit feedback. Screening volume, recall rate, and rate of screen-detected cancers were typically reported performance measures. Audit reports were commonly provided annually, but more frequently when target guidelines were not reached. The purpose, target audience, performance measures included, form and frequency of the audit feedback varied amongst mammographic screening programmes. These variations may provide a basis for those developing and improving such programmes. © The Author(s) 2016.

NREL Expert Honored for Energy Systems Innovations | News | NREL

Science.gov Websites

Research and Social Science, a new academic journal dedicated to examining the relationship between energy and distributed energy systems. Kroposki conducted original research that led to several IEEE standards and chaired IEEE 1547.4, which was the first international standard on microgrids. In 2007

Evaluating the Limits of Network Topology Inference Via Virtualized Network Emulation

DTIC Science & Technology

2015-06-01

76 xi Figure 5.33 Hop-plot of five best reduction methods. KDD most closely matches the Internet plot...respectively, located around the world. These monitors provide locations from which to perform network measurement experiments, primarily using the ping ...International Symposium on Modeling, Analysis and Simulation of Computer Telecommunication Systems. IEEE, 2001, pp. 346–353. 90 [21] C. Jin , Q. Chen, and S

Women in biomedical engineering and health informatics and its impact on gender representation for accepted publications at IEEE EMBC 2007.

PubMed

McGregor, Carolyn; Smith, Kathleen P; Percival, Jennifer

2008-01-01

The study of women within the professions of Engineering and Computer Science has consistently been found to demonstrate women as a minority within these professions. However none of that previous work has assessed publication behaviours based on gender. This paper presents research findings on gender distribution of authors of accepted papers for the IEEE Engineering and Medicine Society annual conference for 2007 (EMBC '07) held in Lyon, France. This information is used to present a position statement of the current state of gender representation for conference publication within the domain of biomedical engineering and health informatics. Issues in data preparation resulting from the lack of inclusion of gender in information gathered from accepted authors are presented and discussed.

Investigating Differences in the Writing Performance of International and Generation 1.5 Students

ERIC Educational Resources Information Center

di Gennaro, Kristen

2009-01-01

Practitioners working closely with second language (L2) writers in the US recognize at least two types of L2 students: international (IL2) and Generation 1.5 (G1.5) students. Some argue that specific differences in each group's writing performance are evident (cf. Harklau, 2003; Reid, 2006); however, investigations into observable and measurable…

Effects of Computer Architecture on FFT (Fast Fourier Transform) Algorithm Performance.

DTIC Science & Technology

1983-12-01

Criteria for Efficient Implementation of FFT Algorithms," IEEE Transactions on Acoustics, Speech, and Signal Processing, Vol. ASSP-30, pp. 107-109, Feb...1982. Burrus, C. S. and P. W. Eschenbacher. "An In-Place, In-Order Prime Factor FFT Algorithm," IEEE Transactions on Acoustics, Speech, and Signal... Transactions on Acoustics, Speech, and Signal Processing, Vol. ASSP-30, pp. 217-226, Apr. 1982. Control Data Corporation. CDC Cyber 170 Computer Systems

Modeling and Performance Optimization of Large-Scale Data-Communication Networks.

DTIC Science & Technology

1981-06-01

IT-17, no. 1, pp. 71-76, 1971. 12. Y. Ho, M. Kastner, and E. Wong, "Teams, market signalling, and information theory," IEEE Trans. Automat. Contr...modifies the flow assignment to satisfy end-to-end delay constraints. 3.2.1 Rationale for Min-Hop Strategr The Min-Hop algorithm proposed in this...Prentice-Hall, 1980. Ho, Y., M. Kostner and E. Wong, "Teams, market signalling, and information theory," IEEE Trans. Automat. Contr., vol. AC-23, pp

Editorial Conference Comments by the General Chair

NASA Astrophysics Data System (ADS)

Reed, Robert A.

2017-01-01

The 53rd IEEE Nuclear and Space Radiation Effects Conference (NSREC) was held July 11-15, 2016, at the Oregon Convention Center in Portland; the conference hotel was the Portland Doubletree. The NSREC is recognized as one of the premier international conferences on radiation effects in electronic materials, devices, and systems. The 2016 conference continued this tradition with a strong technical program, a one-day tutorial short course, radiation effects data workshop, industrial exhibit, and meetings for the IEEE Women in Engineering and Young Professionals organizations. The conference was sponsored by the Radiation Effects Committee of the IEEE Nuclear and Plasma Sciences Society (NPSS), and supported by Atmel, BAE Systems, Boeing, Cobham Semiconductor Solutions, Freebird Semiconductor, Honeywell, International Rectifier, Intersil Corporation, Jet Propulsion Laboratory, Northrop Grumman, Southwest Research Institute, and VPT Rad.

Command and Telemetry Latency Effects on Operator Performance during International Space Station Robotics Operations

NASA Technical Reports Server (NTRS)

Currie, Nancy J.; Rochlis, Jennifer

2004-01-01

International Space Station (ISS) operations will require the on-board crew to perform numerous robotic-assisted assembly, maintenance, and inspection activities. Current estimates for some robotically performed maintenance timelines are disproportionate and potentially exceed crew availability and duty times. Ground-based control of the ISS robotic manipulators, specifically the Special Purpose Dexterous Manipulator (SPDM), is being examined as one potential solution to alleviate the excessive amounts of crew time required for extravehicular robotic maintenance and inspection tasks.

Differential Relations Between Youth Internalizing/Externalizing Problems and Cortisol Responses to Performance vs. Interpersonal Stress

PubMed Central

Laurent, Heidemarie; Vergara-Lopez, Chrystal; Stroud, Laura R.

2016-01-01

Efforts to define hypothalamic-pituitary-adrenal (HPA) axis profiles conferring risk for psychopathology have yielded inconclusive results, perhaps in part due to limited assessment of the stress response. In particular, research has typically focused on HPA responses to performance tasks, while neglecting the interpersonal stressors that become salient during adolescence. In this study we investigated links between psychosocial adjustment—youth internalizing and externalizing problems, as well as competence—and HPA responses to both performance and interpersonal stressors in a normative sample of children and adolescents. Participants (n = 59) completed a set of performance (public speaking, mental arithmetic, mirror tracing) and/or interpersonal (peer rejection) tasks and gave 9 saliva samples, which were assayed for cortisol. Hierarchical linear models of cortisol response trajectories in relation to CBCL scores revealed stressor- and sex-specific associations. Whereas internalizing problems related to earlier peaking, less dynamic cortisol responses to interpersonal stress (across males and females), externalizing problems related to lower, earlier peaking, and less dynamic cortisol responses to performance stress for males only, and competence related to later peaking cortisol responses to interpersonal stress for females only. Implications for understanding contextual stress profiles underlying different forms of psychopathology are discussed. PMID:27470923

Internal Performance of a Fixed-Shroud Nonaxisymmetric Nozzle Equipped with an Aft-Hood Exhaust Deflector

NASA Technical Reports Server (NTRS)

Asbury, Scott C.

1997-01-01

An investigation was conducted in the model preparation area of the Langley 16-Foot Transonic Tunnel to determine the internal performance of a fixed-shroud nonaxisymmetric nozzle equipped with an aft-hood exhaust deflector. Model geometric parameters investigated included nozzle power setting, aft-hood deflector angle, throat area control with the aft-hood deflector deployed, and yaw vector angle. Results indicate that cruise configurations produced peak performance in the range consistent with previous investigations of nonaxisymmetric convergent-divergent nozzles. The aft-hood deflector produced resultant pitch vector angles that were always less than the geometric aft-hood deflector angle when the nozzle throat was positioned upstream of the deflector exit. Significant losses in resultant thrust ratio occurred when the aft-hood deflector was deployed with an upstream throat location. At each aft-hood deflector angle, repositioning the throat to the deflector exit improved pitch vectoring performance and, in some cases, substantially improved resultant thrust ratio performance. Transferring the throat to the deflector exit allowed the flow to be turned upstream of the throat at subsonic Mach numbers, thereby eliminating losses associated with turning supersonic flow. Internal throat panel deflections were largely unsuccessful in generating yaw vectoring.

Static internal performance of a two-dimensional convergent nozzle with thrust-vectoring capability up to 60 deg

NASA Technical Reports Server (NTRS)

Leavitt, L. D.

1985-01-01

An investigation was conducted at wind-off conditions in the static-test facility of the Langley 16-Foot Transonic Tunnel to determine the internal performance characteristics of a two-dimensional convergent nozzle with a thrust-vectoring capability up to 60 deg. Vectoring was accomplished by a downward rotation of a hinged upper convergent flap and a corresponding rotation of a center-pivoted lower convergent flap. The effects of geometric thrust-vector angle and upper-rotating-flap geometry on internal nozzle performance characteristics were investigated. Nozzle pressure ratio was varied from 1.0 (jet off) to approximately 5.0.

The International Learning Object Metadata Survey

ERIC Educational Resources Information Center

Friesen, Norm

2004-01-01

A wide range of projects and organizations is currently making digital learning resources (learning objects) available to instructors, students, and designers via systematic, standards-based infrastructures. One standard that is central to many of these efforts and infrastructures is known as Learning Object Metadata (IEEE 1484.12.1-2002, or LOM).…

Scheduling Mission-Critical Flows in Congested and Contested Airborne Network Environments

DTIC Science & Technology

2018-03-01

precision agriculture [64–71]. However, designing, implementing, and testing UAV networks poses numerous interdisciplinary challenges because the...applications including search and rescue, disaster relief, precision agriculture , environmental monitoring, and surveillance. Many of these applications...monitoring enabling precision agriculture ,” in Automation Science and Engineering (CASE), 2015 IEEE International Conference on. IEEE, 2015, pp. 462–469. [65

Silicon Compilation Using a Lisp-Based Layout Language.

DTIC Science & Technology

1986-06-01

12, 15 October 19184. Gajski , D.D., "The Structure of A Silicon Compiler", IEEE International Conference on Circuits and Comouters 1982(ICCC 82...IEEE Press, 1982. Gajski , D.D. and Kuhn, R.H.," Guest Editors’ Introduction: New VLSI Tools", Comguter Volume 16, Number 12, 1983. Gajs i, D.D., "Silicon

78 FR 66422 - Appointment of Members of the Legal Division to the Performance Review Board, Internal Revenue...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-05

... DEPARTMENT OF THE TREASURY Appointment of Members of the Legal Division to the Performance Review... Performance Review Board, Internal Revenue Service Panel: 1. Chairperson, Christopher Sterner, Deputy Chief... & Accounting) This publication is required by 5 U.S.C. 4314(c)(4). [[Page 66423

Risk assessment of student performance in the International Foundations of Medicine Clinical Science Examination by the use of statistical modeling.

PubMed

David, Michael C; Eley, Diann S; Schafer, Jennifer; Davies, Leo

2016-01-01

The primary aim of this study was to assess the predictive validity of cumulative grade point average (GPA) for performance in the International Foundations of Medicine (IFOM) Clinical Science Examination (CSE). A secondary aim was to develop a strategy for identifying students at risk of performing poorly in the IFOM CSE as determined by the National Board of Medical Examiners' International Standard of Competence. Final year medical students from an Australian university medical school took the IFOM CSE as a formative assessment. Measures included overall IFOM CSE score as the dependent variable, cumulative GPA as the predictor, and the factors age, gender, year of enrollment, international or domestic status of student, and language spoken at home as covariates. Multivariable linear regression was used to measure predictor and covariate effects. Optimal thresholds of risk assessment were based on receiver-operating characteristic (ROC) curves. Cumulative GPA (nonstandardized regression coefficient [B]: 81.83; 95% confidence interval [CI]: 68.13 to 95.53) and international status (B: -37.40; 95% CI: -57.85 to -16.96) from 427 students were found to be statistically associated with increased IFOM CSE performance. Cumulative GPAs of 5.30 (area under ROC [AROC]: 0.77; 95% CI: 0.72 to 0.82) and 4.90 (AROC: 0.72; 95% CI: 0.66 to 0.78) were identified as being thresholds of significant risk for domestic and international students, respectively. Using cumulative GPA as a predictor of IFOM CSE performance and accommodating for differences in international status, it is possible to identify students who are at risk of failing to satisfy the National Board of Medical Examiners' International Standard of Competence.

The use of performance standards by AAALAC International to evaluate ethical review in European institutions.

PubMed

Guillen, Javier

2010-02-01

During the past several decades, society has become increasingly concerned about the welfare of animals used in research. Today, the public asks scientists to justify the use of research animals and to be accountable for their welfare. Research institutions, government bodies and other regulatory authorities have developed mechanisms to ensure that researchers follow the principles of the 3Rs and use and care for research animals in an ethical manner. Additionally, organizations such as the Association for Assessment and Accreditation of Laboratory Animal Care International (AAALAC International) have developed voluntary programs that can help researchers to ensure that they are caring for research animals appropriately. The author discusses how AAALAC International uses performance standards to evaluate the ethical review processes of European institutions.

Pre-game perceived wellness highly associates with match running performances during an international field hockey tournament.

PubMed

Ihsan, Mohammed; Tan, Frankie; Sahrom, Sofyan; Choo, Hui Cheng; Chia, Michael; Aziz, Abdul Rashid

2017-06-01

This study examined the associations between pre-game wellness and changes in match running performance normalised to either (i) playing time, (ii) post-match RPE or (iii) both playing time and post-match RPE, over the course of a field hockey tournament. Twelve male hockey players were equipped with global positioning system (GPS) units while competing in an international tournament (six matches over 9 days). The following GPS-derived variables, total distance (TD), low-intensity activity (LIA; <15 km/h), high-intensity running (HIR; >15 km/h), high-intensity accelerations (HIACC; >2 m/s 2 ) and decelerations (HIDEC; >-2 m/s 2 ) were acquired and normalised to either (i) playing time, (ii) post-match RPE or (iii) both playing time and post-match RPE. Each morning, players completed ratings on a 0-10 scale for four variables: fatigue, muscle soreness, mood state and sleep quality, with cumulative scores determined as wellness. Associations between match performances and wellness were analysed using Pearson's correlation coefficient. Combined time and RPE normalisation demonstrated the largest associations with Δwellness compared with time or RPE alone for most variables; TD (r = -0.95; -1.00 to -0.82, p = .004), HIR (r = -0.95; -1.00 to -0.83, p = .003), LIA (r = -0.94; -1.00 to -0.81, p = .026), HIACC (r = -0.87; -1.00 to -0.66, p = .004) and HIDEC (r = -0.90; -0.99 to -0.74, p = .008). These findings support the use of wellness measures as a pre-match tool to assist with managing internal load over the course of a field hockey tournament. Highlights Fixtures during international field hockey tournaments are typically congested and impose high physiological demands on an athlete. To minimise decrements in running performance over the course of a tournament, measures to identify players who have sustained high internal loads are logically warranted. The present study examined the association between changes in

Competitor presence reduces internal attentional focus and improves 16.1km cycling time trial performance.

PubMed

Williams, Emily L; Jones, Hollie S; Andy Sparks, S; Marchant, David C; Midgley, Adrian W; Mc Naughton, Lars R

2015-07-01

Whilst the presence of a competitor has been found to improve performance, the mechanisms influencing the change in selected work rates during direct competition have been suggested but not specifically assessed. The aim was to investigate the physiological and psychological influences of a visual avatar competitor during a 16.1-km cycling time trial performance, using trained, competitive cyclists. Randomised cross-over design. Fifteen male cyclists completed four 16.1km cycling time trials on a cycle ergometer, performing two with a visual display of themselves as a simulated avatar (FAM and SELF), one with no visual display (DO), and one with themselves and an opponent as simulated avatars (COMP). Participants were informed the competitive avatar was a similar ability cyclist but it was actually a representation of their fastest previous performance. Increased performance times were evident during COMP (27.8±2.0min) compared to SELF (28.7±1.9min) and DO (28.4±2.3min). Greater power output, speed and heart rate were apparent during COMP trial than SELF (p<0.05) and DO (p≤0.06). There were no differences between SELF and DO. Ratings of perceived exertion were unchanged across all conditions. Internal attentional focus was significantly reduced during COMP trial (p<0.05), suggesting reduced focused on internal sensations during an increase in performance. Competitive cyclists performed significantly faster during a 16.1-km competitive trial than when performing maximally, without a competitor. The improvement in performance was elicited due to a greater external distraction, deterring perceived exertion. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

TESTING AND PERFORMANCE EVALUATION OF AN INNOVATIVE INTERNAL PIPE SEALING SYSTEM FOR WASTEWATER MAIN REHABILITATION

EPA Science Inventory

Many utilities are seeking emerging and innovative rehabilitation technologies to extend the service life of their infrastructure systems. This report describes the testing and performance evaluation of an internal pipe sealing system, which provides a permanent physical seal fo...

Static internal performance of an axisymmetric nozzle with multiaxis thrust-vectoring capability

NASA Technical Reports Server (NTRS)

Carson, George T., Jr.; Capone, Francis J.

1991-01-01

An investigation was conducted in the static test facility of the Langley 16 Foot Transonic Tunnel in order to determine the internal performance characteristics of a multiaxis thrust vectoring axisymmetric nozzle. Thrust vectoring for this nozzle was achieved by deflection of only the divergent section of this nozzle. The effects of nozzle power setting and divergent flap length were studied at nozzle deflection angles of 0 to 30 at nozzle pressure ratios up to 8.0.

Internal Consistency of Performance Evaluations as a Function of Music Expertise and Excerpt Familiarity

ERIC Educational Resources Information Center

Kinney, Daryl W.

2009-01-01

The purpose of this study was to examine the effects of music experience and excerpt familiarity on the internal consistency of performance evaluations. Participants included nonmusic majors who had not participated in high school music ensembles, nonmusic majors who had participated in high school music ensembles, music majors, and experts…

Implementing the Victory Access Control Framework in a Military Ground Vehicle

DTIC Science & Technology

2015-08-01

Protocol ( SOAP ) message body, but lacked the ability to encrypt individual XML elements within the SOAP body. Several attempts were made to augment the C...Service and both use SOAP and provide freely available WSDLs with similarly defined operations. TS3 even leverages the same XACML engine that is...Characterizing the Performance of SOAP Toolkits”, Fifth IEEE/ACM International Workshop on Grid Computing, pages 365- 372, November 2004. [8] J.A

Low-power secure body area network for vital sensors toward IEEE802.15.6.

PubMed

Kuroda, Masahiro; Qiu, Shuye; Tochikubo, Osamu

2009-01-01

Many healthcare/medical services have started using personal area networks, such as Bluetooth and ZigBee; these networks consist of various types of vital sensors. These works focus on generalized functions for sensor networks that expect enough battery capacity and low-power CPU/RF (Radio Frequency) modules, but less attention to easy-to-use privacy protection. In this paper, we propose a commercially-deployable secure body area network (S-BAN) with reduced computational burden on a real sensor that has limited RAM/ROM sizes and CPU/RF power consumption under a light-weight battery. Our proposed S-BAN provides vital data ordering among sensors that are involved in an S-BAN and also provides low-power networking with zero-administration security by automatic private key generation. We design and implement the power-efficient media access control (MAC) with resource-constraint security in sensors. Then, we evaluate the power efficiency of the S-BAN consisting of small sensors, such as an accessory type ECG and ring-type SpO2. The evaluation of power efficiency of the S-BAN using real sensors convinces us in deploying S-BAN and will also help us in providing feedbacks to the IEEE802.15.6 MAC, which will be the standard for BANs.

IEEE-802.15.4-based low-power body sensor node with RF energy harvester.

PubMed

Tran, Thang Viet; Chung, Wan-Young

2014-01-01

This paper proposes the design and implementation of a low-voltage and low-power body sensor node based on the IEEE 802.15.4 standard to collect electrocardiography (ECG) and photoplethysmography (PPG) signals. To achieve compact size, low supply voltage, and low power consumption, the proposed platform is integrated into a ZigBee mote, which contains a DC-DC booster, a PPG sensor interface module, and an ECG front-end circuit that has ultra-low current consumption. The input voltage of the proposed node is very low and has a wide range, from 0.65 V to 3.3 V. An RF energy harvester is also designed to charge the battery during the working mode or standby mode of the node. The power consumption of the proposed node reaches 14 mW in working mode to prolong the battery lifetime. The software is supported by the nesC language under the TinyOS environment, which enables the proposed node to be easily configured to function as an individual health monitoring node or a node in a wireless body sensor network (BSN). The proposed node is used to set up a wireless BSN that can simultaneously collect ECG and PPG signals and monitor the results on the personal computer.

Static internal performance evaluation of several thrust reversing concepts for 2D-CD nozzles

NASA Technical Reports Server (NTRS)

Rowe, R. K.; Duss, D. J.; Leavitt, L. D.

1984-01-01

Recent performance testing of the two-dimensional convergent-divergent (2D-CD) nozzle has established the concept as a viable alternative to the axisymmetric nozzle for advanced technology aircraft. This type of exhaust system also offers potential integration and performance advantages in the areas of thrust reversing and vectoring over axi-symmetric nozzles. These advantages include the practical integration of thrust reversers which operate not only to reduce landing roll but also operate in-flight for enhanced maneuvering and thrust spoiling. To date there is a very limited data base available from which criteria can be developed for the design and evaluation of this type of thrust reverser system. For this reason, a static scale model test was conducted in which five different thrust reverser designs were evaluated. Each of the five models had varying performance/integration requirements which dictated the five different designs. Some of the parameters investigated in this test included; variable angle external cascade vanes, fixed angle internal cascade vanes, variable position inner doors, external slider doors and internal slider valves. In addition, normal force and yawing moment generation was investigated using the thrust reverser system. Selected results from this test will be presented and discussed in this paper.

Differential relations between youth internalizing/externalizing problems and cortisol responses to performance vs. interpersonal stress.

PubMed

Laurent, Heidemarie; Vergara-Lopez, Chrystal; Stroud, Laura R

2016-09-01

Efforts to define hypothalamic-pituitary-adrenal (HPA) axis profiles conferring risk for psychopathology have yielded inconclusive results, perhaps in part due to limited assessment of the stress response. In particular, research has typically focused on HPA responses to performance tasks, while neglecting the interpersonal stressors that become salient during adolescence. In this study we investigated links between psychosocial adjustment - youth internalizing and externalizing problems, as well as competence - and HPA responses to both performance and interpersonal stressors in a normative sample of children and adolescents. Participants (n = 59) completed a set of performance (public speaking, mental arithmetic, mirror tracing) and/or interpersonal (peer rejection) tasks and gave nine saliva samples, which were assayed for cortisol. Hierarchical linear models of cortisol response trajectories in relation to child behavior checklist (CBCL) scores revealed stressor- and sex-specific associations. Whereas internalizing problems related to earlier peaking, less dynamic cortisol responses to interpersonal stress (across males and females), externalizing problems related to lower, earlier peaking and less dynamic cortisol responses to performance stress for males only, and competence-related to later peaking cortisol responses to interpersonal stress for females only. Implications for understanding contextual stress profiles underlying different forms of psychopathology are discussed.

Bill Lang's contributions to acoustics at International Business Machines Corporation (IBM), signal processing, international standards, and professionalism in noise control engineering

NASA Astrophysics Data System (ADS)

Maling, George C.

2005-09-01

Bill Lang joined IBM in the late 1950s with a mandate from Thomas Watson Jr. himself to establish an acoustics program at IBM. Bill created the facilities in Poughkeepsie, developed the local program, and was the leader in having other IBM locations with development and manufacturing responsibilities construct facilities and hire staff under the Interdivisional Liaison Program. He also directed IBMs acoustics technology program. In the mid-1960s, he led an IEEE standards group in Audio and Electroacoustics, and, with the help of James Cooley, Peter Welch, and others, introduced the fast Fourier transform to the acoustics community. He was the convenor of ISO TC 43 SC1 WG6 that began writing the 3740 series of standards in the 1970s. It was his suggestion to promote professionalism in noise control engineering, and, through meetings with Leo Beranek and others, led the founding of INCE/USA in 1971. He was also a leader of the team that founded International INCE in 1974, and he served as president from 1988 until 1999.

On the Feasibility of Wireless Multimedia Sensor Networks over IEEE 802.15.5 Mesh Topologies

PubMed Central

Garcia-Sanchez, Antonio-Javier; Losilla, Fernando; Rodenas-Herraiz, David; Cruz-Martinez, Felipe; Garcia-Sanchez, Felipe

2016-01-01

Wireless Multimedia Sensor Networks (WMSNs) are a special type of Wireless Sensor Network (WSN) where large amounts of multimedia data are transmitted over networks composed of low power devices. Hierarchical routing protocols typically used in WSNs for multi-path communication tend to overload nodes located within radio communication range of the data collection unit or data sink. The battery life of these nodes is therefore reduced considerably, requiring frequent battery replacement work to extend the operational life of the WSN system. In a wireless sensor network with mesh topology, any node may act as a forwarder node, thereby enabling multiple routing paths toward any other node or collection unit. In addition, mesh topologies have proven advantages, such as data transmission reliability, network robustness against node failures, and potential reduction in energy consumption. This work studies the feasibility of implementing WMSNs in mesh topologies and their limitations by means of exhaustive computer simulation experiments. To this end, a module developed for the Synchronous Energy Saving (SES) mode of the IEEE 802.15.5 mesh standard has been integrated with multimedia tools to thoroughly test video sequences encoded using H.264 in mesh networks. PMID:27164106

On the Feasibility of Wireless Multimedia Sensor Networks over IEEE 802.15.5 Mesh Topologies.

PubMed

Garcia-Sanchez, Antonio-Javier; Losilla, Fernando; Rodenas-Herraiz, David; Cruz-Martinez, Felipe; Garcia-Sanchez, Felipe

2016-05-05

Wireless Multimedia Sensor Networks (WMSNs) are a special type of Wireless Sensor Network (WSN) where large amounts of multimedia data are transmitted over networks composed of low power devices. Hierarchical routing protocols typically used in WSNs for multi-path communication tend to overload nodes located within radio communication range of the data collection unit or data sink. The battery life of these nodes is therefore reduced considerably, requiring frequent battery replacement work to extend the operational life of the WSN system. In a wireless sensor network with mesh topology, any node may act as a forwarder node, thereby enabling multiple routing paths toward any other node or collection unit. In addition, mesh topologies have proven advantages, such as data transmission reliability, network robustness against node failures, and potential reduction in energy consumption. This work studies the feasibility of implementing WMSNs in mesh topologies and their limitations by means of exhaustive computer simulation experiments. To this end, a module developed for the Synchronous Energy Saving (SES) mode of the IEEE 802.15.5 mesh standard has been integrated with multimedia tools to thoroughly test video sequences encoded using H.264 in mesh networks.

The Ionizing Radiation Environment on the International Space Station: Performance vs. Expectations for Avionics and Materials

NASA Technical Reports Server (NTRS)

Koontz, Steven L.; Boeder, Paul A.; Pankop, Courtney; Reddell, Brandon

2005-01-01

The role of structural shielding mass in the design, verification, and in-flight performance of International Space Station (ISS), in both the natural and induced orbital ionizing radiation (IR) environments, is reported.

Ready or not, here they come: acting interns' experience and perceived competency performing basic medical procedures.

PubMed

Coberly, LeAnn; Goldenhar, Linda M

2007-04-01

To assess acting interns' (AI's) experience with and perceived level of competency performing 6 basic medical procedures. Fourth-year medical students at the University of Cincinnati (UCCOM) are required to complete 2 AI rotations in Internal Medicine. All AIs in 2003-2004 (n = 150) and 2004-2005 (n = 151) were asked to complete a survey about whether during each of their rotations they had performed and felt competent performing the following procedures: phlebotomy, intravenous (IV) catheter insertion, arterial blood gas (ABG), nasogastric (NG) tube insertion, lumbar puncture (LP), and Foley catheter insertion. Four hundred sixty-seven of 601 possible surveys (across both years and both rotations) were completed (78% response rate). During both rotations, relatively few students performed the procedures, ranging from 9% for Foley catheter insertion (24/208) to 50% for both ABG and NG tube insertion (130/259). The two procedures most often performed were ABG (range 46-50%) and NG tube insertion (range 42-50%). Feelings of competency varied from 12% (LP) to 82% (Foley catheter). Except for LP, if students performed a procedure at least once, they reported feeling more competent (range 85% for ABG to 96% for Foley catheter insertion). Among the students who performed LP during a rotation, many still did not feel competent performing LPs: 23 (74%) in rotation 1 and 20 (40%) in rotation 2. Many fourth-year students at UCCOM do not perform basic procedures during their acting internship rotations. Procedural performance correlates with feelings of competency. Lumbar puncture competency may be too ambitious a goal for medical students.

Sparsity Aware Adaptive Radar Sensor Imaging in Complex Scattering Environments

DTIC Science & Technology

2015-06-15

while meeting the requirement on the peak to average power ratio. Third, we study impact of waveform encoding on nonlinear electromagnetic tomographic...Enyue Lu. Time Domain Electromagnetic Tomography Using Propagation and Backpropagation Method, IEEE International Conference on Image Processing...Received Paper 3.00 4.00 Yuanwei Jin, Chengdon Dong, Enyue Lu. Waveform Encoding for Nonlinear Electromagnetic Tomographic Imaging, IEEE Global

A Strategy for Improved System Assurance

DTIC Science & Technology

2007-06-20

Quality (Measurements Life Cycle Safety, Security & Others) ISO /IEC 12207 * Software Life Cycle Processes ISO 9001 Quality Management System...14598 Software Product Evaluation Related ISO /IEC 90003 Guidelines for the Application of ISO 9001:2000 to Computer Software IEEE 12207 Industry...Implementation of International Standard ISO /IEC 12207 IEEE 1220 Standard for Application and Management of the System Engineering Process Use in

From Social Class to Self-Efficacy: Internalization of Low Social Status Pupils' School Performance

ERIC Educational Resources Information Center

Wiederkehr, Virginie; Darnon, Céline; Chazal, Sébastien; Guimond, Serge; Martinot, Delphine

2015-01-01

Previous research has largely documented that socioeconomic status (SES) is a strong and consistent predictor of pupils' school performance in several countries. In this research, we argue that children internalize the SES achievement gap in the form of a lower/higher sense of school self-efficacy. In two studies, teenaged students' (Study 1) and…

Flight model performances of HISUI hyperspectral sensor onboard ISS (International Space Station)

NASA Astrophysics Data System (ADS)

Tanii, Jun; Kashimura, Osamu; Ito, Yoshiyuki; Iwasaki, Akira

2016-10-01

Hyperspectral Imager Suite (HISUI) is a next-generation Japanese sensor that will be mounted on Japanese Experiment Module (JEM) of ISS (International Space Station) in 2019 as timeframe. HISUI hyperspectral sensor obtains spectral images of 185 bands with the ground sampling distance of 20x31 meter from the visible to shortwave-infrared region. The sensor system is the follow-on mission of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) in the visible to shortwave infrared region. The critical design review of the instrument was accomplished in 2014. Integration and tests of an flight model of HISUI hyperspectral sensor is being carried out. Simultaneously, the development of JEM-External Facility (EF) Payload system for the instrument started. The system includes the structure, the thermal control system, the electrical system and the pointing mechanism. The development status and the performances including some of the tests results of Instrument flight model, such as optical performance, optical distortion and radiometric performance are reported.

9977 TYPE B PACKAGING INTERNAL DATA COLLECTION FEASIBILITY TESTING - MAGNETIC FIELD COMMUNICATIONS

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

Shull, D.

2012-06-18

The objective of this report is to document the findings from proof-of-concept testing performed by the Savannah River National Laboratory (SRNL) R&D Engineering and Visible Assets, Inc. for the DOE Packaging Certification Program (PCP) to determine if RuBee (IEEE 1902.1) tags and readers could be used to provide a communication link from within a drum-style DOE certified Type B radioactive materials packaging. A Model 9977 Type B Packaging was used to test the read/write capability and range performance of a RuBee tag and reader. Testing was performed with the RuBee tags placed in various locations inside the packaging including insidemore » the drum on the outside of the lid of the containment vessel and also inside of the containment vessel. This report documents the test methods and results. A path forward will also be recommended.« less

International Freshman Performance: GPA, Retention, Graduation

ERIC Educational Resources Information Center

Ward, Terri; Jacobs, Jonathan; Thompson, Roger T.

2016-01-01

The number of international students enrolling at U.S. higher education institutions has increased dramatically in the last 20 years. U.S. institutions welcome these students as they affirm their academic reputation and their claims to provide a global experience for domestic students. Is this student group being served effectively? The increase…

SELF-POWERED WIRELESS SENSOR NODE POWER MODELING BASED ON IEEE 802.11 COMMUNICATION PROTOCOL

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

Vivek Agarwal; Raymond A. DeCarlo; Lefteri H. Tsoukalas

Design and technical advancements in sensing, processing, and wireless communication capabilities of small, portable devices known as wireless sensor nodes (WSNs) have drawn extensive research attention and are vastly applied in science and engineering applications. The WSNs are typically powered by a chemical battery source that has a load dependent finite lifetime. Most applications, including the nuclear industry applications, require WSNs to operate for an extended period of time beginning with their deployment. To ensure longevity, it is important to develop self-powered WSNs. The benefit of self-powered WSNs goes far beyond the cost savings of removing the need for cablemore » installation and maintenance. Self-powered WSNs will potentially offer significant expansion in remote monitoring of nuclear facilities, and provide important data on plant equipment and component status during normal operation, as well as in case of abnormal operation, station blackouts or post-accident evaluation. Advancements in power harvesting technologies enable electric energy generation from many sources, including kinetic, thermal, and radiated energy. For the ongoing research at Idaho National Laboratory, a solid-state thermoelectric-based technology, the thermoelectric generator (TEG), is used to convert thermal energy to power a WSN. The design and development of TEGs to power WSNs that would remain active for a long period of time requires comprehensive understanding of WSN operational. This motivates the research in modeling the lifetime, i.e., power consumption, of a WSN by taking into consideration various node and network level activities. A WSN must perform three essential tasks: sense events, perform quick local information processing of sensed events, and wirelessly exchange locally processed data with the base station or with other WSNs in the network. Each task has a power cost per unit tine and an additional cost when switching between tasks. There are number of

The International Space Station's Multi-Purpose Logistics Module, Thermal Performance of the First Five Flights

NASA Technical Reports Server (NTRS)

Holladay, Jon; Cho, Frank

2003-01-01

The Multi-Purpose Logistics Module is the primary carrier for transport of pressurized payload to the International Space Station. Performing five missions within a thirteen month span provided a unique opportunity to gather a great deal of information toward understanding and verifying the orbital performance of the vehicle. This paper will provide a brief overview of the hardware history and design capabilities followed by a summary of the missions flown, resource requirements and possibilities for the future.

High-performance mass storage system for workstations

NASA Technical Reports Server (NTRS)

Chiang, T.; Tang, Y.; Gupta, L.; Cooperman, S.

1993-01-01

Reduced Instruction Set Computer (RISC) workstations and Personnel Computers (PC) are very popular tools for office automation, command and control, scientific analysis, database management, and many other applications. However, when using Input/Output (I/O) intensive applications, the RISC workstations and PC's are often overburdened with the tasks of collecting, staging, storing, and distributing data. Also, by using standard high-performance peripherals and storage devices, the I/O function can still be a common bottleneck process. Therefore, the high-performance mass storage system, developed by Loral AeroSys' Independent Research and Development (IR&D) engineers, can offload a RISC workstation of I/O related functions and provide high-performance I/O functions and external interfaces. The high-performance mass storage system has the capabilities to ingest high-speed real-time data, perform signal or image processing, and stage, archive, and distribute the data. This mass storage system uses a hierarchical storage structure, thus reducing the total data storage cost, while maintaining high-I/O performance. The high-performance mass storage system is a network of low-cost parallel processors and storage devices. The nodes in the network have special I/O functions such as: SCSI controller, Ethernet controller, gateway controller, RS232 controller, IEEE488 controller, and digital/analog converter. The nodes are interconnected through high-speed direct memory access links to form a network. The topology of the network is easily reconfigurable to maximize system throughput for various applications. This high-performance mass storage system takes advantage of a 'busless' architecture for maximum expandability. The mass storage system consists of magnetic disks, a WORM optical disk jukebox, and an 8mm helical scan tape to form a hierarchical storage structure. Commonly used files are kept in the magnetic disk for fast retrieval. The optical disks are used as archive

Internal Performance of Several Divergent-Shroud Ejector Nozzles with High Divergence Angles

NASA Technical Reports Server (NTRS)

Trout, Arthur M.; Papell, S. Stephen; Povolny, John H.

1957-01-01

Nine divergent-shroud ejector configurations were investigated to determine the effect of shroud divergence angle on ejector internal performance. Unheated dry air was used for both the primary and secondary flows. The decrease in the design-point thrust coefficient with increasing flow divergence angle (angle measured from primary exit to shroud exit) followed very closely a simple relation involving the cosine of the angle. This indicates that design-point thrust performance for divergent-shroud ejectors can be predicted with reasonable accuracy within the range investigated. The decrease in design-point thrust coefficient due to increasing the flow divergence engle from 120deg to 30deg (half-singles) was approximately 6 percent. Ejector air-handling characteristics and the primary-nozzle flow coefficient were not significantly affected by change in shroud divergence angle.

Kinesthetic Imagery Provides Additive Benefits to Internal Visual Imagery on Slalom Task Performance.

PubMed

Callow, Nichola; Jiang, Dan; Roberts, Ross; Edwards, Martin G

2017-02-01

Recent brain imaging research demonstrates that the use of internal visual imagery (IVI) or kinesthetic imagery (KIN) activates common and distinct brain areas. In this paper, we argue that combining the imagery modalities (IVI and KIN) will lead to a greater cognitive representation (with more brain areas activated), and this will cause a greater slalom-based motor performance compared with using IVI alone. To examine this assertion, we randomly allocated 56 participants to one of the three groups: IVI, IVI and KIN, or a math control group. Participants performed a slalom-based driving task in a driving simulator, with average lap time used as a measure of performance. Results revealed that the IVI and KIN group achieved significantly quicker lap times than the IVI and the control groups. The discussion includes a theoretical advancement on why the combination of imagery modalities might facilitate performance, with links made to the cognitive neuroscience literature and applied practice.

PREFACE: 8th International Conference on Advanced Infocomm Technology (ICAIT 2015)

NASA Astrophysics Data System (ADS)

Qiu, M.; Zhao, W.; Shum, P. Ping

2016-02-01

The 2015 IEEE 8th International Conference on Advanced Infocomm Technology (ICAIT 2015) was held in Hangzhou, China, during 25-27, October 2015, following the successes of previous events held in Shenzhan, Xi'an, Haikou, Wuhan, Paris, Hsinchu, and Fuzhou. This year the ICAIT 2015 aimed to bring together researchers, developers, and users in both industry and academia in the world for sharing state-of-art results, for exploring new areas of research and development, and to discuss emerging issues on advanced infocomm technology. The conference was hosted by Zhejiang University and China Satellite Maritime Tracking and Control Department. It was organized by the State Ley Laboratory of Modern Optical Instrumentation of Zhejiang University, in collaboration with the Joint International Research Laboratory of Photonics of Zhejiang University. More than 150 international participants from 9 foreign countries attended the conference. The ICAIT 2015 was featured with 4 plenary lectures (by Xiaoyi Bao, Benjamin J. Eggleton, Min Gu, and Chinlon Lin, respectively), and 40 invited talks, in which a wide range of topics were covered and the most recent significant results were presented. Including oral and poster presentations, 138 abstracts were presented in the conference, some of which were selected to publish in full papers in this edition of Journal of Physics: Conference Series. With the excellent quality of the presentations, the ICAIT 2015 was a success. We also wish to thank the sponsors of the conference, and particularly the technical program committee and the local organizing committee.

On-Orbit Performance Degradation of the International Space Station P6 Photovoltaic Arrays

NASA Technical Reports Server (NTRS)

Kerslake, Thomas W.; Gustafson, Eric D.

2003-01-01

This paper discusses the on-orbit performance and performance degradation of the International Space Station P6 solar array wings (SAWs) from the period of December 2000 through February 2003. Data selection considerations and data reduction methods are reviewed along with the approach for calculating array performance degradation based on measured string shunt current levels. Measured degradation rates are compared with those predicted by the computational tool SPACE and prior degradation rates measured with the same SAW technology on the Mir space station. Initial results show that the measured SAW short-circuit current is degrading 0.2 to 0.5 percent per year. This degradation rate is below the predicted rate of 0.8 percent per year and is well within the 3 percent estimated uncertainty in measured SAW current levels. General contributors to SAW degradation are briefly discussed.

Effect of altitude on physiological performance: a statistical analysis using results of international football games

PubMed Central

2007-01-01

Objective To assess the effect of altitude on match results and physiological performance of a large and diverse population of professional athletes. Design Statistical analysis of international football (soccer) scores and results. Data resources FIFA extensive database of 1460 football matches in 10 countries spanning over 100 years. Results Altitude had a significant (P<0.001) negative impact on physiological performance as revealed through the overall underperformance of low altitude teams when playing against high altitude teams in South America. High altitude teams score more and concede fewer goals with increasing altitude difference. Each additional 1000 m of altitude difference increases the goal difference by about half of a goal. The probability of the home team winning for two teams from the same altitude is 0.537, whereas this rises to 0.825 for a home team with an altitude difference of 3695 m (such as Bolivia v Brazil) and falls to 0.213 when the altitude difference is −3695 m (such as Brazil v Bolivia). Conclusions Altitude provides a significant advantage for high altitude teams when playing international football games at both low and high altitudes. Lowland teams are unable to acclimatise to high altitude, reducing physiological performance. As physiological performance does not protect against the effect of altitude, better predictors of individual susceptibility to altitude illness would facilitate team selection. PMID:18156225

Academic performance and personal experience of local, international, and collaborative exchange students enrolled in an Australian pharmacy program.

PubMed

Davey, Andrew K; Grant, Gary D; Anoopkumar-Dukie, Shailendra

2013-09-12

To assess the academic performance and experiences of local, international, and collaborative exchange students enrolled in a 4-year Australian bachelor of pharmacy degree program. Survey instruments exploring the demographics, background, and academic and cultural experiences of students during the program were administered in 2005 to students in all 4 years. Additionally, grades from each semester of the program for students (406 local, 70 international, 155 exchange) who graduated between 2002 and 2006 were analyzed retrospectively. The main differences found in the survey responses among the 3 groups were in students' motivations for choosing the degree program and school, with international and collaborative exchange students having put more thought into these decisions than local students. The average grades over the duration of the program were similar in all 3 demographic groups. However, local students slightly outperformed international students, particularly at the start of the year, whereas collaborative exchange students' grades mirrored those of local students during the 2 years prior to leaving their home country of Malaysia but more closely mirrored those of international students in the final 2 years after arriving on campus in Australia. Despite differences in academic backgrounds and culture, international and exchange students can perform well compared to local students in a bachelor of pharmacy program and were actually more satisfied than local students with the overall experience. Studying in a foreign country can negatively influence academic grades to a small extent and this is probably related to adjusting to the new environment.

US Medical Student Performance on the NBME Subject Examination in Internal Medicine: Do Clerkship Sequence and Clerkship Length Matter?

PubMed

Ouyang, Wenli; Cuddy, Monica M; Swanson, David B

2015-09-01

Prior to graduation, US medical students are required to complete clinical clerkship rotations, most commonly in the specialty areas of family medicine, internal medicine, obstetrics and gynecology (ob/gyn), pediatrics, psychiatry, and surgery. Within a school, the sequence in which students complete these clerkships varies. In addition, the length of these rotations varies, both within a school for different clerkships and between schools for the same clerkship. The present study investigated the effects of clerkship sequence and length on performance on the National Board of Medical Examiner's subject examination in internal medicine. The study sample included 16,091 students from 67 US Liaison Committee on Medical Education (LCME)-accredited medical schools who graduated in 2012 or 2013. Student-level measures included first-attempt internal medicine subject examination scores, first-attempt USMLE Step 1 scores, and five dichotomous variables capturing whether or not students completed rotations in family medicine, ob/gyn, pediatrics, psychiatry, and surgery prior to taking the internal medicine rotation. School-level measures included clerkship length and average Step 1 score. Multilevel models with students nested in schools were estimated with internal medicine subject examination scores as the dependent measure. Step 1 scores and the five dichotomous variables were treated as student-level predictors. Internal medicine clerkship length and average Step 1 score were used to predict school-to-school variation in average internal medicine subject examination scores. Completion of rotations in surgery, pediatrics and family medicine prior to taking the internal medicine examination significantly improved scores, with the largest benefit observed for surgery (coefficient = 1.58 points; p value < 0.01); completion of rotations in ob/gyn and psychiatry were unrelated to internal medicine subject examination performance. At the school level, longer internal medicine

Dexterous Robotic Hands: Kinematics and Control

DTIC Science & Technology

1988-11-01

Halstead. Our first implementation was based largely on their Concert system. Secondly, I would like to thank David Kriegman, and George Gerpheide for...environment and the grasped object (see Brost et al. [1983]). It practice, using this type of control, we have been able to perform a number of...May, 1986. 19. Brost , R. C., "Automatic Grasp Planning in the Presence of Uncertainty", Proc. IEEE International Conference on Robotics and

Software Acquisition Risk Management Key Process Area (KPA) - A Guidebook Version 1.0.

DTIC Science & Technology

1997-08-01

Budget - Software Project Management Practices and Techniques. McGraw-Hill International (UK) Limited, 1992. [Boehm 81 ] Boehm, Barry . Software...Engineering Economics. Englewood Cliffs, N.J.: Prentice-Hall, Inc., 1981. [Boehm 89] Boehm, Barry . IEEE Tutorial on Software Risk Management. New York: IEEE...95] [Mayrhauser 90] [Moran 90] [Myers 96] [NRC 89] [Osborn 53] [Paulk 95] [ Pressman 92] [Pulford 96] [Scholtes 88] [Sisti 94] [STSC 96

Analysis of Global Properties of Shapes

DTIC Science & Technology

2010-06-01

Conference on Computer Vision (ICCV) ( Bejing , China , 2005), IEEE. [113] Thrun, S., and Wegbreit, B. Shape from symmetry. In Proceedings of the...International Conference on Computer Vision (ICCV) ( Bejing , China , 2005), IEEE. [114] Toshev, A., Shi, J., and Daniilidis, K. Image matching via saliency...applications ranging from sampling points to finding correspondences to shape simplification. Discrete variants of the Laplace-Beltrami opera - tor [108] and

An Infrastructure for Multi-Level Secure Service-Oriented Architecture (MLS-SOA) Using the Multiple Single-Level Approach

DTIC Science & Technology

2009-12-17

IEEE TDKE, 1996. 8( 1). 14. Garvey, T.D., The inference Problem for Computer Security. 1992, SRI International. 15. Chaum , D ., Blind Signatures for...Pervasive Computing Environments. IEEE Transactions on Vehicular Technology, 2006. 55(4). 17. Chaum , D ., Security without Identification: Transaction...Systems to make Big Brother Obsolete. Communications of the ACM 1985. 28(10). 18. Chaum , D ., Untraceable Electronic Mail, Return Addresses, and Digital

USAF Distributed Mission Operations, an ADF Synthetic Range Interoperability Model and an AOD Mission Training Centre Capability Concept Demonstrator - What are They and Why Does the RAAF Need Them

DTIC Science & Technology

2010-10-01

the 2004 Fall Simulation Interoperability Workshop, Orlando, Florida, USA, September 2004, 04F- SIW -090. [Blacklock (2007)] - Blacklock, J. and Zalcman...Valley, CA, USA, March 2009, 09S- SIW -084. [DIS (1995)] - IEEE Standard – Protocols for Distributed Interactive Simulation Application (1995), IEEE...Workshop, Orlando, FL, USA, September 2007, 07F- SIW -111. [Gresche] - Gresche, D. et al, (2006), “International Mission Training Research

International Space Station Nickel-Hydrogen Battery On-Orbit Performance

NASA Technical Reports Server (NTRS)

Dalton, Penni; Cohen, Fred

2002-01-01

International Space Station (ISS) Electric Power System (EPS) utilizes Nickel-Hydrogen (Ni-H2) batteries as part of its power system to store electrical energy. The batteries are charged during insolation and discharged during eclipse. The batteries are designed to operate at a 35 percent depth of discharge (DOD) maximum during normal operation. Thirty-eight individual pressure vessel (IPV) Ni-H2 battery cells are series-connected and packaged in an Orbital Replacement Unit (ORU). Two ORUs are series-connected utilizing a total of 76 cells to form one battery. The ISS is the first application for low earth orbit (LEO) cycling of this quantity of series-connected cells. The P6 (Port) Integrated Equipment Assembly (IEA) containing the initial ISS high-power components was successfully launched on November 30, 2000. The IEA contains 12 Battery Subassembly ORUs (6 batteries) that provide station power during eclipse periods. This paper will discuss the battery performance data after eighteen months of cycling.

Using PELA to Predict International Business Students' English Writing Performance with Contextualised English Writing Workshops as Intervention Program

ERIC Educational Resources Information Center

Wong, Caroline; Delante, Nimrod Lawsin; Wang, Pengji

2017-01-01

This study examines the effectiveness of Post-Entry English Language Assessment (PELA) as a predictor of international business students' English writing performance and academic performance. An intervention involving the implementation of contextualised English writing workshops was embedded in a specific business subject targeted at students who…

Predicting academic performance and clinical competency for international dental students: seeking the most efficient and effective measures.

PubMed

Stacey, D Graham; Whittaker, John M

2005-02-01

Measures used in the selection of international dental students to a U.S. D.D.S. program were examined to identify the grouping that most effectively and efficiently predicted academic performance and clinical competency. Archival records from the International Dental Program (IDP) at Loma Linda University provided data on 171 students who had trained in countries outside the United States. The students sought admission to the D.D.S. degree program, successful completion of which qualified them to sit for U.S. licensure. As with most dental schools, competition is high for admission to the D.D.S. program. The study's goal was to identify what measures contributed to a fair and accurate selection process for dental school applicants from other nations. Multiple regression analyses identified National Board Part II and dexterity measures as significant predictors of academic performance and clinical competency. National Board Part I, TOEFL, and faculty interviews added no significant additional help in predicting eventual academic performance and clinical competency.

New methods to quantify the cracking performance of cementitious systems made with internal curing

NASA Astrophysics Data System (ADS)

Schlitter, John L.

The use of high performance concretes that utilize low water-cement ratios have been promoted for use in infrastructure based on their potential to increase durability and service life because they are stronger and less porous. Unfortunately, these benefits are not always realized due to the susceptibility of high performance concrete to undergo early age cracking caused by shrinkage. This problem is widespread and effects federal, state, and local budgets that must maintain or replace deterioration caused by cracking. As a result, methods to reduce or eliminate early age shrinkage cracking have been investigated. Internal curing is one such method in which a prewetted lightweight sand is incorporated into the concrete mixture to provide internal water as the concrete cures. This action can significantly reduce or eliminate shrinkage and in some cases causes a beneficial early age expansion. Standard laboratory tests have been developed to quantify the shrinkage cracking potential of concrete. Unfortunately, many of these tests may not be appropriate for use with internally cured mixtures and only provide limited amounts of information. Most standard tests are not designed to capture the expansive behavior of internally cured mixtures. This thesis describes the design and implementation of two new testing devices that overcome the limitations of current standards. The first device discussed in this thesis is called the dual ring. The dual ring is a testing device that quantifies the early age restrained shrinkage performance of cementitious mixtures. The design of the dual ring is based on the current ASTM C 1581-04 standard test which utilizes one steel ring to restrain a cementitious specimen. The dual ring overcomes two important limitations of the standard test. First, the standard single ring test cannot restrain the expansion that takes place at early ages which is not representative of field conditions. The dual ring incorporates a second restraining ring

Unravelling the differences in attrition and academic performance of international and domestic nursing students with English as an additional language.

PubMed

Zheng, Roy Xun; Everett, Bronwyn; Glew, Paul; Salamonson, Yenna

2014-12-01

High attrition and academic underperformance have been highlighted among students who speak English as an additional language (EAL) in higher education, and a lack of language skills is often cited as a key explanatory factor. Although the relationship between English-language skills and academic performance among EAL students has been established, group differences between international and domestic EAL nursing students is not known. The aim of this study was to compare attrition rates and academic performance of international and domestic EAL nursing students, taking into consideration levels of English-language usage and socio-demographic characteristics of these groups. A prospective correlational study. From 2010 to 2012, nursing students at a large Australian university, who attended an orientation session before course commencement, were invited to complete a survey to assess their English-language usage. Data collected included students' enrolment status and GPA at 12months. Compared with their domestic counterparts, the attrition rate of international EAL students was significantly lower (7.9% versus 13.3%, p=0.018). Similarly, international students also had higher GPAs (4.1 versus 4.0, p=0.011). Although the levels of English-language usage were not related to academic performance, recent arrivals in both international (p=0.047) and domestic (p=0.001) student groups had higher GPAs. This study suggests that language acculturation, indicated by English-language usage and the length of stay in the host country, was not sufficient to ensure successful transition into the academic environment for either international or domestic EAL nursing students. Copyright © 2014 Elsevier Ltd. All rights reserved.

International Space Station Sustaining Engineering: A Ground-Based Test Bed for Evaluating Integrated Environmental Control and Life Support System and Internal Thermal Control System Flight Performance

NASA Technical Reports Server (NTRS)

Ray, Charles D.; Perry, Jay L.; Callahan, David M.

2000-01-01

As the International Space Station's (ISS) various habitable modules are placed in service on orbit, the need to provide for sustaining engineering becomes increasingly important to ensure the proper function of critical onboard systems. Chief among these are the Environmental Control and Life Support System (ECLSS) and the Internal Thermal Control System (ITCS). Without either, life onboard the ISS would prove difficult or nearly impossible. For this reason, a ground-based ECLSS/ITCS hardware performance simulation capability has been developed at NASA's Marshall Space Flight Center. The ECLSS/ITCS Sustaining Engineering Test Bed will be used to assist the ISS Program in resolving hardware anomalies and performing periodic performance assessments. The ISS flight configuration being simulated by the test bed is described as well as ongoing activities related to its preparation for supporting ISS Mission 5A. Growth options for the test facility are presented whereby the current facility may be upgraded to enhance its capability for supporting future station operation well beyond Mission 5A. Test bed capabilities for demonstrating technology improvements of ECLSS hardware are also described.

International comparisons of health system performance among OECD countries: opportunities and data privacy protection challenges.

PubMed

Oderkirk, Jillian; Ronchi, Elettra; Klazinga, Niek

2013-09-01

Health data constitute a significant resource in most OECD countries that could be used to improve health system performance. Well-intended policies to allay concerns about breaches of confidentiality and to reduce potential misuse of personal health information may be limiting data use. A survey of 20 OECD countries explored the extent to which countries have developed and use personal health data and the reasons why data use may be problematic in some. Countries are divided, with one-half engaged regularly in national data linkage studies to monitor health care quality. Country variation is linked to risk management in granting an exemption to patient consent requirements; in sharing identifiable data among government authorities; and in project approvals and granting access to data. The resources required to comply with data protection requirements is a secondary problem. The sharing of person-level data across borders for international comparisons is rarely reported and there were few examples of studies of health system performance. Laws and policies enabling data sharing and data linkage are needed to strengthen national information infrastructure. To develop international studies comparing health care quality and health system performance, actions are needed to address heterogeneity in data protection practices. Copyright © 2013 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

IEEE 802.15.4 ZigBee-Based Time-of-Arrival Estimation for Wireless Sensor Networks.

PubMed

Cheon, Jeonghyeon; Hwang, Hyunsu; Kim, Dongsun; Jung, Yunho

2016-02-05

Precise time-of-arrival (TOA) estimation is one of the most important techniques in RF-based positioning systems that use wireless sensor networks (WSNs). Because the accuracy of TOA estimation is proportional to the RF signal bandwidth, using broad bandwidth is the most fundamental approach for achieving higher accuracy. Hence, ultra-wide-band (UWB) systems with a bandwidth of 500 MHz are commonly used. However, wireless systems with broad bandwidth suffer from the disadvantages of high complexity and high power consumption. Therefore, it is difficult to employ such systems in various WSN applications. In this paper, we present a precise time-of-arrival (TOA) estimation algorithm using an IEEE 802.15.4 ZigBee system with a narrow bandwidth of 2 MHz. In order to overcome the lack of bandwidth, the proposed algorithm estimates the fractional TOA within the sampling interval. Simulation results show that the proposed TOA estimation algorithm provides an accuracy of 0.5 m at a signal-to-noise ratio (SNR) of 8 dB and achieves an SNR gain of 5 dB as compared with the existing algorithm. In addition, experimental results indicate that the proposed algorithm provides accurate TOA estimation in a real indoor environment.

Towards actionable international comparisons of health system performance: expert revision of the OECD framework and quality indicators.

PubMed

Carinci, F; Van Gool, K; Mainz, J; Veillard, J; Pichora, E C; Januel, J M; Arispe, I; Kim, S M; Klazinga, N S

2015-04-01

To review and update the conceptual framework, indicator content and research priorities of the Organisation for Economic Cooperation and Development's (OECD) Health Care Quality Indicators (HCQI) project, after a decade of collaborative work. A structured assessment was carried out using a modified Delphi approach, followed by a consensus meeting, to assess the suite of HCQI for international comparisons, agree on revisions to the original framework and set priorities for research and development. International group of countries participating to OECD projects. Members of the OECD HCQI expert group. A reference matrix, based on a revised performance framework, was used to map and assess all seventy HCQI routinely calculated by the OECD expert group. A total of 21 indicators were agreed to be excluded, due to the following concerns: (i) relevance, (ii) international comparability, particularly where heterogeneous coding practices might induce bias, (iii) feasibility, when the number of countries able to report was limited and the added value did not justify sustained effort and (iv) actionability, for indicators that were unlikely to improve on the basis of targeted policy interventions. The revised OECD framework for HCQI represents a new milestone of a long-standing international collaboration among a group of countries committed to building common ground for performance measurement. The expert group believes that the continuation of this work is paramount to provide decision makers with a validated toolbox to directly act on quality improvement strategies. © The Author 2015. Published by Oxford University Press in association with the International Society for Quality in Health Care; all rights reserved.

Academic Performance and Personal Experience of Local, International, and Collaborative Exchange Students Enrolled in an Australian Pharmacy Program

PubMed Central

Grant, Gary D.; Anoopkumar-Dukie, Shailendra

2013-01-01

Objective. To assess the academic performance and experiences of local, international, and collaborative exchange students enrolled in a 4-year Australian bachelor of pharmacy degree program. Methods. Survey instruments exploring the demographics, background, and academic and cultural experiences of students during the program were administered in 2005 to students in all 4 years. Additionally, grades from each semester of the program for students (406 local, 70 international, 155 exchange) who graduated between 2002 and 2006 were analyzed retrospectively. Results. The main differences found in the survey responses among the 3 groups were in students’ motivations for choosing the degree program and school, with international and collaborative exchange students having put more thought into these decisions than local students. The average grades over the duration of the program were similar in all 3 demographic groups. However, local students slightly outperformed international students, particularly at the start of the year, whereas collaborative exchange students’ grades mirrored those of local students during the 2 years prior to leaving their home country of Malaysia but more closely mirrored those of international students in the final 2 years after arriving on campus in Australia. Conclusion. Despite differences in academic backgrounds and culture, international and exchange students can perform well compared to local students in a bachelor of pharmacy program and were actually more satisfied than local students with the overall experience. Studying in a foreign country can negatively influence academic grades to a small extent and this is probably related to adjusting to the new environment. PMID:24052651

Performance Testing of a Trace Contaminant Control Subassembly for the International Space Station

NASA Technical Reports Server (NTRS)

Perry, J. L.; Curtis, R. E.; Alexandre, K. L.; Ruggiero, L. L.; Shtessel, N.

1998-01-01

As part of the International Space Station (ISS) Trace Contaminant Control Subassembly (TCCS) development, a performance test has been conducted to provide reference data for flight verification analyses. This test, which used the U.S. Habitation Module (U.S. Hab) TCCS as the test article, was designed to add to the existing database on TCCS performance. Included in this database are results obtained during ISS development testing; testing of functionally similar TCCS prototype units; and bench scale testing of activated charcoal, oxidation catalyst, and granular lithium hydroxide (LiOH). The present database has served as the basis for the development and validation of a computerized TCCS process simulation model. This model serves as the primary means for verifying the ISS TCCS performance. In order to mitigate risk associated with this verification approach, the U.S. Hab TCCS performance test provides an additional set of data which serve to anchor both the process model and previously-obtained development test data to flight hardware performance. The following discussion provides relevant background followed by a summary of the test hardware, objectives, requirements, and facilities. Facility and test article performance during the test is summarized, test results are presented, and the TCCS's performance relative to past test experience is discussed. Performance predictions made with the TCCS process model are compared with the U.S. Hab TCCS test results to demonstrate its validation.

Correlation of United States Medical Licensing Examination and Internal Medicine In-Training Examination performance.

PubMed

Perez, Jose A; Greer, Sharon

2009-12-01

The Internal Medicine In-Training Examination (ITE) is administered during residency training in the United States as a self-assessment and program assessment tool. Performance on this exam correlates with outcome on the American Board of Internal Medicine Certifying examination. Internal Medicine Program Directors use the United States Medical Licensing Examination (USMLE) to make decisions in recruitment of potential applicants. This study was done to determine a correlation of USMLE Steps 1, 2 and 3 results with ITE scores in each level of Internal Medicine training. A retrospective review of all residents graduating from an Internal Medicine program from 1999 to 2006 was done. Subjects included had data for all USMLE Steps and ITE during all years of training. Thirty-one subjects were included in the study. Correlations of USMLE Steps 1, 2 and 3 were done with ITE scores (percent correct) in each year of training. Pearson's correlation coefficient (r) was determined for each pairing and a t test to determine statistical significance of the correlation was done. Statistical significance was defined as P value <0.05. The r values for USMLE Step 1 and ITE percent correct in PGY I, II and III were 0.46, 0.55 and 0.51 respectively. Corresponding r values for USMLE Step 2 and ITE percent correct were 0.79, 0.70 and 0.72; for USMLE Step 3 these values were 0.51, 0.37 and 0.51 respectively for each training year. USMLE scores are correlated with ITE scores. This correlation was strongest for USMLE Step 2.

Effects of Job Burnout and Emotional Labor on Objective Structured Clinical Examination Performance Among Interns and Residents in Taiwan.

PubMed

Wang, Chen-Yu; Chen, Jen-De; Wang, Chih-Hung; Wang, Jong-Yi; Tai, Chih-Jaan; Hsieh, Tsu-Yi; Chen, Der-Yuan

2017-01-01

Medical education faces challenges concerning job burnout and emotional labor among junior physicians, which poses a potential threat to the quality of medical care. Although studies have investigated job burnout and emotional labor among physicians, empirical research on the association between job burnout, emotional labor, and clinical performance is lacking. This study investigated the effects of job burnout and emotional labor on clinical performance by using the objective structured clinical examination (OSCE) scores of interns and residents. Specifically, this cross-sectional study utilized the Maslach Burnout Inventory and the Emotional Labor Questionnaire as measurement instruments. A total of 225 interns and residents in central Taiwan answered structured questionnaires before beginning their OSCE. The major statistical analysis method employed was logistic regression. After adjustment for covariates, first-year residents were less likely than other residents to obtain high OSCE scores. The odds of high OSCE performance among interns and residents with high interaction component scores in emotional labor were significantly higher than those with low interaction scores. A high score in the interaction dimension of emotional labor was associated with strong clinical performance. The findings suggest that interventions which motivate positive attitudes and increase interpersonal interaction skills among physicians should receive higher priority.

International Students' Enhanced Academic Performance: Effects of Campus Resources

ERIC Educational Resources Information Center

Banjong, Delphine N.

2015-01-01

This article investigates international students' challenges, such as financial, English proficiency, loneliness/homesickness in the United States. In addition, it assesses how these students coped with such difficulties by making use of resources on campus, such as an international center, writing center, counseling center, and the student…

International Space Station Electric Power System Performance Code-SPACE

NASA Technical Reports Server (NTRS)

Hojnicki, Jeffrey; McKissock, David; Fincannon, James; Green, Robert; Kerslake, Thomas; Delleur, Ann; Follo, Jeffrey; Trudell, Jeffrey; Hoffman, David J.; Jannette, Anthony;

Investigation of International Space Station Major Constituent Analyzer Anomalous ORU 02 Performance

NASA Technical Reports Server (NTRS)

Gardner, Ben D.; Burchfield, David E.; Pargellis, Andrew; Erwin, Phillip M.; Thoresen, Souzan; Gentry, Grey; Granahan, John; Matty, Chris

2013-01-01

The Major Constituent Analyzer (MCA) is a mass spectrometer based system that measures the major atmospheric constituents on the International Space Station. In 2011, two MCA ORU 02 analyzer assemblies experienced premature on-orbit failures. These failures were determined to be the result of off-nominal ion source filament performance. Recent product improvements to ORU 02 designed to improve the lifetime of the ion pump also constrained the allowable tuning criteria for the ion source filaments. This presentation describes the filament failures as well as the corrective actions implemented to preclude such failures in the future.

International Space Station USOS Crew Quarters On-orbit vs Design Performance Comparison

NASA Technical Reports Server (NTRS)

Broyan, James Lee, Jr.; Borrego, Melissa Ann; Bahr, Juergen F.

2008-01-01

The International Space Station (ISS) United States Operational Segment (USOS) received the first two permanent ISS Crew Quarters (CQ) on Utility Logistics Flight Two (ULF2) in November 2008. Up to four CQs can be installed into the Node 2 element to increase the ISS crewmember size to six. The CQs provide private crewmember space with enhanced acoustic noise mitigation, integrated radiation reduction material, communication equipment, redundant electrical systems, and redundant caution and warning systems. The racksized CQ is a system with multiple crewmember restraints, adjustable lighting, controllable ventilation, and interfaces that allow each crewmember to personalize their CQ workspace. The deployment and initial operational checkout during integration of the ISS CQ to the Node is described. Additionally, the comparison of on-orbit to original design performance is outlined for the following key operational parameters: interior acoustic performance, air flow rate, temperature rise, and crewmember feedback on provisioning and restraint layout.

Study on turbulent flow and heat transfer performance of tubes with internal fins in EGR cooler

NASA Astrophysics Data System (ADS)

Liu, Lin; Ling, Xiang; Peng, Hao

2015-07-01

In this paper, flow and heat transfer performances of the tubes with internal longitudinal fins in Exhaust Gas Recirculation (EGR ) cooler were investigated by three-dimension computation and experiment . Each test tube was a single-pipe structure, without inner tube. Three-dimension computation was performed to determine the thermal characteristics difference between the two kinds of tubes, that is, the tube with an inner solid staff as a blocked structure and the tube without the blocked structure. The effects of fin width and fin height on heat transfer and flow are examined. For proving the validity of numerical method, the calculated results were compared with corresponding experimental data. The tube-side friction factor and heat transfer coefficient were examined. As a result, the maximum deviations between the numerical results and the experimental data are approximately 5.4 % for friction factor and 8.6 % for heat transfer coefficient, respectively. It is found that two types of internally finned tubes enhance significantly heat transfer. The heat transfer of the tube with blocked structure is better, while the pressure drop of the tube without blocked structure is lower. The comprehensive performance of the unblocked tube is better to applied in EGR cooler.

Effects of simulated domestic and international air travel on sleep, performance, and recovery for team sports.

PubMed

Fowler, P; Duffield, R; Vaile, J

2015-06-01

The present study examined effects of simulated air travel on physical performance. In a randomized crossover design, 10 physically active males completed a simulated 5-h domestic flight (DOM), 24-h simulated international travel (INT), and a control trial (CON). The mild hypoxia, seating arrangements, and activity levels typically encountered during air travel were simulated in a normobaric, hypoxic altitude room. Physical performance was assessed in the afternoon of the day before (D - 1 PM) and in the morning (D + 1 AM) and afternoon (D + 1 PM) of the day following each trial. Mood states and physiological and perceptual responses to exercise were also examined at these time points, while sleep quantity and quality were monitored throughout each condition. Sleep quantity and quality were significantly reduced during INT compared with CON and DOM (P < 0.01). Yo-Yo Intermittent Recovery level 1 test performance was significantly reduced at D + 1 PM following INT compared with CON and DOM (P < 0.01), where performance remained unchanged (P > 0.05). Compared with baseline, physiological and perceptual responses to exercise, and mood states were exacerbated following the INT trial (P < 0.05). Attenuated intermittent-sprint performance following simulated international air travel may be due to sleep disruption during travel and the subsequent exacerbated physiological and perceptual markers of fatigue. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Photovoltaic performance and reliability workshop

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

Kroposki, B

1996-10-01

This proceedings is the compilation of papers presented at the ninth PV Performance and Reliability Workshop held at the Sheraton Denver West Hotel on September 4--6, 1996. This years workshop included presentations from 25 speakers and had over 100 attendees. All of the presentations that were given are included in this proceedings. Topics of the papers included: defining service lifetime and developing models for PV module lifetime; examining and determining failure and degradation mechanisms in PV modules; combining IEEE/IEC/UL testing procedures; AC module performance and reliability testing; inverter reliability/qualification testing; standardization of utility interconnect requirements for PV systems; need activitiesmore » to separate variables by testing individual components of PV systems (e.g. cells, modules, batteries, inverters,charge controllers) for individual reliability and then test them in actual system configurations; more results reported from field experience on modules, inverters, batteries, and charge controllers from field deployed PV systems; and system certification and standardized testing for stand-alone and grid-tied systems.« less

High-performance floating-point image computing workstation for medical applications

NASA Astrophysics Data System (ADS)

Mills, Karl S.; Wong, Gilman K.; Kim, Yongmin

1990-07-01

.g., three 1280 x 1024 monitors, each with a 16-Mbyte frame buffer). Each add-in board provides an expansion connector to which an optional image computing coprocessor board may be added. Each coprocessor board supports up to four processors for a peak performance of 160 MFLOPS. The coprocessors can execute programs from external high-speed microcode memory as well as built-in internal microcode routines. The internal microcode routines provide support for 2-D and 3-D graphics operations, matrix and vector arithmetic, and image processing in integer, IEEE single-precision floating point, or IEEE double-precision floating point. In addition to providing a library of C functions which links the NeXT computer to the add-in board and supports its various operational modes, algorithms and medical imaging application programs are being developed and implemented for image display and enhancement. As an extension to the built-in algorithms of the coprocessors, 2-D Fast Fourier Transform (FF1), 2-D Inverse FFF, convolution, warping and other algorithms (e.g., Discrete Cosine Transform) which exploit the parallel architecture of the coprocessor board are being implemented.

Letters: Comment on "Effects of multi-scattering on the performance of a single-beam acoustic manipulation device".

PubMed

Mitri, F G

2013-11-01

The concern addressed in the present commentary is to point out the omission of the azimuthal component Fφ of the axial acoustic radiation force provided in M. Azarpeyvand, M. A. Alibakhshi, R. Self, "Effects of multi-scattering on the performance of a single-beam acoustic manipulation device," IEEE Trans. Ultrason. Ferroelectr. Freq. Control, vol. 59, no. 8, pp. 1741-1749, 2012, which may suggest a miscalculation of the radiation force function Ym and its related numerical computations.

Flexibility of internal and external glenohumeral rotation of junior female tennis players and its correlation with performance ranking.

PubMed

Chiang, Ching-Cheng; Hsu, Chih-Chia; Chiang, Jinn-Yen; Chang, Weng-Cheng; Tsai, Jong-Chang

2016-12-01

[Purpose] The purpose of this study was to compare the internal and external rotation of the dominant and nondominant shoulders of adolescent female tennis players. The correlation between the shoulder rotation range of motion and the player's ranking was also analyzed. [Subjects and Methods] Twenty-one female junior tennis players who were 13 to 18 years old participated in this study. A standard goniometer was used to measure the internal and external rotation of both glenohumeral joints. The difference in internal and external rotation was calculated as the glenohumeral rotation deficit. The year-end ranking of each player was obtained from the Chinese Taipei Tennis Association. [Results] The internal rotation of the dominant shoulder was significantly smaller than that of the nondominant shoulder. Moreover, player ranking was significantly and negatively correlated with the internal rotation range of motion of both shoulders. On the other hand, the correlations of the internal and external rotation ranges of motion with the age, height, and weight were not significant. [Conclusion] The flexibility of the glenohumeral internal rotation is smaller in the dominant shoulder than of the nondominant shoulder in these junior female tennis players. Flexibility of the glenohumeral internal rotation may be a factor affecting performance in junior female tennis players.

Internal performance of two nozzles utilizing gimbal concepts for thrust vectoring

NASA Technical Reports Server (NTRS)

Berrier, Bobby L.; Taylor, John G.

1990-01-01

The internal performance of an axisymmetric convergent-divergent nozzle and a nonaxisymmetric convergent-divergent nozzle, both of which utilized a gimbal type mechanism for thrust vectoring was evaluated in the Static Test Facility of the Langley 16-Foot Transonic Tunnel. The nonaxisymmetric nozzle used the gimbal concept for yaw thrust vectoring only; pitch thrust vectoring was accomplished by simultaneous deflection of the upper and lower divergent flaps. The model geometric parameters investigated were pitch vector angle for the axisymmetric nozzle and pitch vector angle, yaw vector angle, nozzle throat aspect ratio, and nozzle expansion ratio for the nonaxisymmetric nozzle. All tests were conducted with no external flow, and nozzle pressure ratio was varied from 2.0 to approximately 12.0.

Factors Associated with International Graduate Students' Academic Performance: A Comparative Analysis between the First Semester and the Subsequent Semester in the U.S.

ERIC Educational Resources Information Center

Cavusoglu, Muhittin; White, Williemae; James, Waynne B.; Cobanoglu, Cihan

2016-01-01

The purpose of this study was to identify differences that impact international graduate student performance in the first semester compared to the subsequent semesters. This study was a qualitative study focused on the factors associated with international graduate student academic performance between the first semester and their subsequent…

Myopia and international educational performance.

PubMed

Morgan, Ian G; Rose, Kathryn A

2013-05-01

To analyse the relationship between myopia, educational performance and engagement in after-school tutorial classes. Educational performance data and data on engagement in after-school tutorial classes were taken from the results of the Organisation for Economic Cooperation and Development (OECD) Program in Secondary Assessment (PISA) reports for 2009, which tested educational outcomes in representative samples of 15 year-old school children from 65 jurisdictions. High prevalence of myopia (>70%) and low prevalence of myopia (<40%) locations were identified by systematic literature search. Six locations with a high prevalence of myopia were identified from among the participants in PISA 2009 - Shanghai-China, Hong Kong-China, Taiwan, Singapore, Japan and South Korea. All were ranked in the top quartile on educational performance. Other participants in the top educational performance quartile were identified as locations with a low prevalence of myopia, including Australia and Finland. The locations with a high prevalence of myopia combined high educational performance and high engagement in after-school tutorials, whereas the locations with a low prevalence of myopia combined high educational performance with little engagement in tutorials. These results show that it is possible to achieve high educational outcomes without extensive engagement in after-school tutorials, and that the combination of high educational outcomes with extensive use of tutorials is associated with high prevalence rates of myopia. We suggest that extensive use of after-school tutorials may be a marker of educational environments which impose high educational loads. Further quantification of educational loads to include after- school educational activities, such as homework, tutorials and other after-school classes, as well as formal school classes, is desirable. Policy initiatives to decrease these loads may contribute to the prevention of myopia, perhaps, at least in part, by enabling

On Demand Internal Short Circuit Device Enables Verification of Safer, Higher Performing Battery Designs

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

Darcy, Eric; Keyser, Matthew

The Internal Short Circuit (ISC) device enables critical battery safety verification. With the aluminum interstitial heat sink between the cells, normal trigger cells cannot be driven into thermal runaway without excessive temperature bias of adjacent cells. With an implantable, on-demand ISC device, thermal runaway tests show that the conductive heat sinks protected adjacent cells from propagation. High heat dissipation and structural support of Al heat sinks show high promise for safer, higher performing batteries.

Internal performance of a hybrid axisymmetric/nonaxisymmetric convergent-divergent nozzle

NASA Technical Reports Server (NTRS)

Taylor, John G.

1991-01-01

An investigation was conducted in the static test facility of the Langley 16-foot transonic tunnel to determine the internal performance of a hybrid axisymmetric/nonaxisymmetric nozzle in forward-thrust mode. Nozzle cross-sections in the spherical convergent section were axisymmetric whereas cross-sections in the divergent flap area nonaxisymmetric (two-dimensional). Nozzle concepts simulating dry and afterburning power settings were investigated. Both subsonic cruise and supersonic cruise expansion ratios were tested for the dry power nozzle concepts. Afterburning power configurations were tested at an expansion ratio typical for subsonic acceleration. The spherical convergent flaps were designed in such a way that the transition from axisymmetric to nonaxisymmetric cross-section occurred in the region of the nozzle throat. Three different nozzle throat geometries were tested for each nozzle power setting. High-pressure air was used to simulate jet exhaust at nozzle pressure ratios up to 12.0.

Overview of International Space Station Carbon Dioxide Removal Assembly On-Orbit Operations and Performance

NASA Technical Reports Server (NTRS)

Matty, Christopher M.

2013-01-01

Controlling Carbon Dioxide (CO2) partial pressure in the habitable vehicle environment is a critical part of operations on the International Space Station (ISS). On the United States segment of ISS, CO2 levels are primarily controlled by the Carbon Dioxide Removal Assembly (CDRA). There are two CDRAs on ISS; one in the United States Laboratory module, and one in the Node3 module. CDRA has been through several significant operational issues, performance issues and subsequent re-design of various components, primarily involving the Desiccant Adsorbent Bed (DAB) assembly and Air Selector Valves (ASV). This paper will focus on significant operational and performance issues experienced by the CDRA team from 2008-2012.

Humans on the International Space Station-How Research, Operations, and International Collaboration are Leading to New Understanding of Human Physiology and Performance in Microgravity

NASA Technical Reports Server (NTRS)

Ronbinson, Julie A.; Harm, Deborah L.

2009-01-01

As the International Space Station (ISS) nears completion, and full international utilization is achieved, we are at a scientific crossroads. ISS is the premier location for research aimed at understanding the effects of microgravity on the human body. For applications to future human exploration, it is key for validation, quantification, and mitigation of a wide variety of spaceflight risks to health and human performance. Understanding and mitigating these risks is the focus of NASA s Human Research Program. However, NASA s approach to defining human research objectives is only one of many approaches within the ISS international partnership (including Roscosmos, the European Space Agency, the Canadian Space Agency, and the Japan Aerospace Exploration Agency). Each of these agencies selects and implements their own ISS research, with independent but related objectives for human and life sciences research. Because the science itself is also international and collaborative, investigations that are led by one ISS partner also often include cooperative scientists from around the world. The operation of the ISS generates significant additional data that is not directly linked to specific investigations. Such data comes from medical monitoring of crew members, life support and radiation monitoring, and from the systems that have been implemented to protect the health of the crew (such as exercise hardware). We provide examples of these international synergies in human research on ISS and highlight key early accomplishments that derive from these broad interfaces. Taken as a whole, the combination of diverse research objectives, operational data, international sharing of research resources on ISS, and scientific collaboration provide a robust research approach and capability that no one partner could achieve alone.

The Ships Below-Decks Electromagnetic Compatibility (EMC) Program. A compilation of Papers Presented at the 1987 IEEE International Symposium on EMC

DTIC Science & Technology

1987-09-30

were producing below-deck environ - such that after 24 hours the performance loss ranged mental levels exceeding the "normal" environmental from 13 to...SGA performance environmental EMI testing in the electromagnetically measurements b- made in the laboratory. However, it quiet laboratory environments ... Environmentally Sealed SGAs.................................... 1-1 Need for Long Term SGA Performance Evaluation .................... 1-2 Performance

Highlights from PISA 2006: Performance of U.S. 15-Year-Old Students in Science and Mathematics Literacy in an International Context. NCES 2008-016

ERIC Educational Resources Information Center

Baldi, Stephane; Jin, Ying; Green, Patricia J.; Herget, Deborah

2007-01-01

The Program for International Student Assessment (PISA) is a system of international assessments administered by the Organization for Economic Cooperation and Development (OECD) that measures 15-year-olds' performance in reading literacy, mathematics literacy, and science literacy every 3 years. This report focuses on the performance of U.S.…

User-Driven Geolocation of Untagged Desert Imagery Using Digital Elevation Models (Open Access)

DTIC Science & Technology

2013-09-12

IEEE International Conference on, pages 3677–3680. IEEE, 2011. [13] W. Zhang and J. Kosecka. Image based localization in urban environments. In 3D ...non- urban environments such as deserts. Our system generates synthetic skyline views from a DEM and extracts stable concavity-based features from these...fine as 100m2. 1. Introduction Automatic geolocation of imagery has many exciting use cases. For example, such a tool could semantically orga- nize

Static internal performance of a two-dimensional convergent-divergent nozzle with thrust vectoring

NASA Technical Reports Server (NTRS)

Bare, E. Ann; Reubush, David E.

1987-01-01

A parametric investigation of the static internal performance of multifunction two-dimensional convergent-divergent nozzles has been made in the static test facility of the Langley 16-Foot Transonic Tunnel. All nozzles had a constant throat area and aspect ratio. The effects of upper and lower flap angles, divergent flap length, throat approach angle, sidewall containment, and throat geometry were determined. All nozzles were tested at a thrust vector angle that varied from 5.60 tp 23.00 deg. The nozzle pressure ratio was varied up to 10 for all configurations.

Developing a high-performance team training framework for internal medicine residents: the ABC'S of teamwork.

PubMed

Carbo, Alexander R; Tess, Anjala V; Roy, Christopher; Weingart, Saul N

2011-06-01

Effective teamwork and communication can prevent error and mitigate harm. High-performance team training was developed in the aviation industry for flight crews and is being incorporated in health care settings, such as emergency departments, operating rooms, and labor and delivery suites. We translated and adapted high-performance teamwork and communication principles from other industries and other disciplines to an inpatient internal medicine environment. We selected key principles from aviation and anesthesia crew training programs in 2004 and organized them into the ABC'S of teamwork. These included appropriate Assertiveness, effective Briefings, Callback and verification, Situational awareness, and Shared mental models. Based on this content, we developed a training session for internal medicine residents and faculty, and evaluated learners' patient safety attitudes and knowledge before and after training with a written survey. More than 50 residents participated in the module. The percentage of correct answers on a question related to key teamwork principles increased from 35% before training to 67% after training (P = 0.03). Before training, 65% of the residents reported that they "would feel comfortable telling a senior clinician his/her plan was unsafe"; this increased to 94% after training (P = 0.005). After the training session, residents were able to provide examples from their clinical practice that emphasized all of the ABC'S of teamwork. Teamwork principles can be adapted from other disciplines and applied to internal medicine. After a single session, residents displayed greater knowledge of teamwork principles and reported changed attitudes toward key teamwork behaviors.

Study on internal to surface fingerprint correlation using optical coherence tomography and internal fingerprint extraction

NASA Astrophysics Data System (ADS)

Darlow, Luke Nicholas; Connan, James

2015-11-01

Surface fingerprint scanners are limited to a two-dimensional representation of the fingerprint topography, and thus, are vulnerable to fingerprint damage, distortion, and counterfeiting. Optical coherence tomography (OCT) scanners are able to image (in three dimensions) the internal structure of the fingertip skin. Techniques for obtaining the internal fingerprint from OCT scans have since been developed. This research presents an internal fingerprint extraction algorithm designed to extract high-quality internal fingerprints from touchless OCT fingertip scans. Furthermore, it serves as a correlation study between surface and internal fingerprints. Provided the scanned region contains sufficient fingerprint information, correlation to the surface topography is shown to be good (74% have true matches). The cross-correlation of internal fingerprints (96% have true matches) is substantial that internal fingerprints can constitute a fingerprint database. The internal fingerprints' performance was also compared to the performance of cropped surface counterparts, to eliminate bias owing to information level present, showing that the internal fingerprints' performance is superior 63.6% of the time.

International Research and Development in Systems Biology

DTIC Science & Technology

2005-10-01

Poolla K., P. Khargonekar, A. Tikku, J. Krause , and K. Nagpal. 1994. A Time-Domain Approach to Model Validation. IEEE Trans Automat Contr 39: 951...Another European researcher modeling chemotaxis and cell motility is Wolfgang Alt (Bonn, Germany), although the panel did not visit his laboratory...Center/Hepatocyte Project Heidelberg, Germany Otmar Wiestler, Siegfried Neumann, Ursula Klingmüller, Willi Jager, Wolfgang Driever, Matthias Reuss

Impact of Distribution Feeders that do not have Voltage Regulators on the number of Charged Electric Vehicles using IEEE 34 Bus Test Feeder

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

Allehyani, Ahmed; Beshir, Mohammed

Voltage regulators help maintain an acceptable voltage profile for the system. This paper discusses the effect of installing voltage regulators to the system to fix the voltage drop resulting from the electrical vehicles loading increase when they are being charged. The effect will be studied in the afternoon, when the peak load occurs, using the IEEE 34 bus test feeder. First, only one spot node is used to charge the electric vehicles while a voltage regulator is present. Second, five spot nodes are loaded at the same time to charge the electric vehicles while voltage regulators are installed at eachmore » node. After that, the impact of electric vehicles on distribution feeders that do not have voltage regulators will appear.« less

The Effect of Computer Assisted Language Learning (CALL) on Performance in the Test of English for International Communication (TOEIC) Listening Module

ERIC Educational Resources Information Center

van Han, Nguyen; van Rensburg, Henriette

2014-01-01

Many companies and organizations have been using the Test of English for International Communication (TOEIC) for business and commercial communication purpose in Vietnam and around the world. The present study investigated the effect of Computer Assisted Language Learning (CALL) on performance in the Test of English for International Communication…

Enhancement-Mode Antimonide Quantum-Well MOSFETs With High Electron Mobility and Gigahertz Small-Signal Switching Performance

DTIC Science & Technology

2011-12-01

grown on GaAs by molecular beam epitaxy and the defect-free active device layers. Fig. 1(c) shows the quantitative mobility spec- trum analysis (QMSA...dielectric deposition. A Pd/Au gate metal was defined using e- beam lithography and 0741-3106/$26.00 © 2011 IEEE Report Documentation Page Form...2010, pp. 6.3.1–6.3.4. [2] N. Kharche, G. Klimeck, D. Kim, J. A. del Alamo, and M. Luisier, “Performance analysis of ultra-scaled InAs HEMTs ,” in IEDM

High performance internal reforming unit for high temperature fuel cells

DOEpatents

Ma, Zhiwen [Sandy Hook, CT; Venkataraman, Ramakrishnan [New Milford, CT; Novacco, Lawrence J [Brookfield, CT

2008-10-07

A fuel reformer having an enclosure with first and second opposing surfaces, a sidewall connecting the first and second opposing surfaces and an inlet port and an outlet port in the sidewall. A plate assembly supporting a catalyst and baffles are also disposed in the enclosure. A main baffle extends into the enclosure from a point of the sidewall between the inlet and outlet ports. The main baffle cooperates with the enclosure and the plate assembly to establish a path for the flow of fuel gas through the reformer from the inlet port to the outlet port. At least a first directing baffle extends in the enclosure from one of the sidewall and the main baffle and cooperates with the plate assembly and the enclosure to alter the gas flow path. Desired graded catalyst loading pattern has been defined for optimized thermal management for the internal reforming high temperature fuel cells so as to achieve high cell performance.

IEEE 1982. Proceedings of the international conference on cybernetics and society

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

Not Available

1982-01-01

The following topics were dealt with: knowledge-based systems; risk analysis; man-machine interactions; human information processing; metaphor, analogy and problem-solving; manual control modelling; transportation systems; simulation; adaptive and learning systems; biocybernetics; cybernetics; mathematical programming; robotics; decision support systems; analysis, design and validation of models; computer vision; systems science; energy systems; environmental modelling and policy; pattern recognition; nuclear warfare; technological forecasting; artificial intelligence; the Turin shroud; optimisation; workloads. Abstracts of individual papers can be found under the relevant classification codes in this or future issues.

Performance of internal covariance estimators for cosmic shear correlation functions

DOE PAGES

Friedrich, O.; Seitz, S.; Eifler, T. F.; ...

2015-12-31

Data re-sampling methods such as the delete-one jackknife are a common tool for estimating the covariance of large scale structure probes. In this paper we investigate the concepts of internal covariance estimation in the context of cosmic shear two-point statistics. We demonstrate how to use log-normal simulations of the convergence field and the corresponding shear field to carry out realistic tests of internal covariance estimators and find that most estimators such as jackknife or sub-sample covariance can reach a satisfactory compromise between bias and variance of the estimated covariance. In a forecast for the complete, 5-year DES survey we show that internally estimated covariance matrices can provide a large fraction of the true uncertainties on cosmological parameters in a 2D cosmic shear analysis. The volume inside contours of constant likelihood in themore » $$\\Omega_m$$-$$\\sigma_8$$ plane as measured with internally estimated covariance matrices is on average $$\\gtrsim 85\\%$$ of the volume derived from the true covariance matrix. The uncertainty on the parameter combination $$\\Sigma_8 \\sim \\sigma_8 \\Omega_m^{0.5}$$ derived from internally estimated covariances is $$\\sim 90\\%$$ of the true uncertainty.« less

Performance indicators for public mental healthcare: a systematic international inventory

PubMed Central

2012-01-01

Background The development and use of performance indicators (PI) in the field of public mental health care (PMHC) has increased rapidly in the last decade. To gain insight in the current state of PI for PMHC in nations and regions around the world, we conducted a structured review of publications in scientific peer-reviewed journals supplemented by a systematic inventory of PI published in policy documents by (non-) governmental organizations. Methods Publications on PI for PMHC were identified through database- and internet searches. Final selection was based on review of the full content of the publications. Publications were ordered by nation or region and chronologically. Individual PI were classified by development method, assessment level, care domain, performance dimension, diagnostic focus, and data source. Finally, the evidence on feasibility, data reliability, and content-, criterion-, and construct validity of the PI was evaluated. Results A total of 106 publications were included in the sample. The majority of the publications (n = 65) were peer-reviewed journal articles and 66 publications specifically dealt with performance of PMHC in the United States. The objectives of performance measurement vary widely from internal quality improvement to increasing transparency and accountability. The characteristics of 1480 unique PI were assessed. The majority of PI is based on stakeholder opinion, assesses care processes, is not specific to any diagnostic group, and utilizes administrative data sources. The targeted quality dimensions varied widely across and within nations depending on local professional or political definitions and interests. For all PI some evidence for the content validity and feasibility has been established. Data reliability, criterion- and construct validity have rarely been assessed. Only 18 publications on criterion validity were included. These show significant associations in the expected direction on the majority of PI, but mixed

Training the intern: The value of a pre-intern year in preparing students for practice.

PubMed

Dare, Anna; Fancourt, Nicholas; Robinson, Elizabeth; Wilkinson, Tim; Bagg, Warwick

2009-08-01

To evaluate the clinical and professional development that occurs during a New Zealand trainee intern year in preparation for the first house officer role. A quantitative questionnaire was distributed to all trainee interns (year 6) and year 5 medical students in New Zealand at the end of the 2007 academic year. This survey assessed self-reported competency and performance across clinical, professional and role development domains. Response rate was 65% (457/702). Compared to year 5 students, trainee interns reported significantly greater competence and performance levels across all three domains. The greatest improvement occurred in the independent performance of procedural skills (trainee interns: 77%, year 5: 35%, p < 0.001) and clinical tasks (trainee interns: 94%, year 5: 56%, p < 0.001) and in the level of clinical responsibility taken (p < 0.001). At the end of the trainee intern year, 92% of students felt prepared to be a junior doctor, versus only 53% at the end of their 5th year (p < 0.0001). The trainee intern year is important in preparing graduates for the intern role. The year affords increased responsibility and practical experience, whilst retaining an educational focus, facilitating the move from competence towards performance. Preparedness for practice was substantially higher following the New Zealand trainee intern year than has been reported with other pre-intern placements.

The internal processes and behavioral dynamics of hospital boards: an exploration of differences between high- and low-performing hospitals.

PubMed

Kane, Nancy M; Clark, Jonathan R; Rivenson, Howard L

2009-01-01

Nonprofit hospital boards are under increasing pressure to improve financial, clinical, and charitable and community benefit performance. Most research on board effectiveness focuses on variables measuring board structure and attributes associated with competing ideal models of board roles. However, the results do not provide clear evidence that one role is superior to another and suggest that in practice boards pursue hybrid roles. Board dynamics and processes have received less attention from researchers, but emerging theoretical frameworks highlight them as key to effective corporate governance. We explored differences in board processes and behavioral dynamics between financially high- and low-performing hospitals, with the goal of developing a better understanding of the best board practices in nonprofit hospitals. A comparative case study approach allowed for in-depth, qualitative assessments of how the internal workings of boards differ between low- and high-performing facilities. Boards of hospitals with strong financial performance exhibited behavioral dynamics and internal processes that differed in important ways from those of hospitals with poor financial performance. Boards need to actively attend to key processes and foster positive group dynamics in decision making to be more effective in governing hospitals.

International Space Station Major Constituent Analyzer On-Orbit Performance

NASA Technical Reports Server (NTRS)

Gardner, Ben D.; Erwin, Philip M.; Thoresen, Souzan; Granahan, John; Matty, Chris

2011-01-01

The Major Constituent Analyzer (MCA) is an integral part of the International Space Station (ISS) Environmental Control and Life Support System (ECLSS). The MCA is a mass spectrometer-based instrument designed to provide critical monitoring of six major atmospheric constituents; nitrogen, oxygen, hydrogen, carbon dioxide, methane, and water vapor. These gases are sampled continuously and automatically in all United States On-Orbit Segment (USOS) modules via the Sample Distribution System (SDS). The MCA is the primary tool for management of atmosphere constituents and is therefore critical for ensuring a habitable ISS environment during both nominal ISS operations and campout EVA preparation in the Airlock. The MCA has been in operation in the US Destiny Laboratory Module for over 10 years, and a second MCA has been delivered to the ISS for Node 3 operation. This paper discusses the performance of the MCA over the two past year, with particular attention to lessons learned regarding the operational life of critical components. Recent data have helped drive design upgrades for a new set of orbit-replaceable units (ORUs) currently in production. Several ORU upgrades are expected to increase expected lifetimes and reliability.

Performance measures and reporting for international border crossings.

DOT National Transportation Integrated Search

2016-04-01

There are several international borders shared among the ENTERPRISE Pooled Fund Study members (Washington State Department of Transportation, Minnesota Department of Transportation, Michigan Department of Transportation, Ministry of Transportation On...

Electrical Performance of the International Space Station U.S. Photovoltaic Array During Bifacial Illumination

NASA Technical Reports Server (NTRS)

Delleur, Ann M.; Kerslake, Thomas W.

2002-01-01

With the first United States (U.S.) photovoltaic array (PVA) activated on International Space Station (ISS) in December 2000, on-orbit data can now be compared to analytical predictions. Due to ISS operational constraints, it is not always possible to point the front side of the arrays at the Sun. Thus, in many cases, sunlight directly illuminates the backside of the PVA as well as albedo illumination on either the front or the back. During this time, appreciable power is produced since the solar cells are mounted on a thin, solar transparent substrate. It is important to present accurate predictions for both front and backside power generation for mission planning, certification of flight readiness for a given mission, and on-orbit mission support. To provide a more detailed assessment of the ISS power production capability, the authors developed a PVA electrical performance model applicable to generalized bifacial illumination conditions. On-orbit PVA performance data were also collected and analyzed. This paper describes the ISS PVA performance model, and the methods used to reduce orbital performance data. Analyses were performed using SPACE. a NASA-GRC developed computer code for the ISS program office. Results showed a excellent comparison of on-orbit performance data and analytical results.

A World of Learning: Canada's Performance and Potential in International Education

ERIC Educational Resources Information Center

Canadian Bureau for International Education (CBIE) - Bureau canadien de l’éducation internationale (BCEI), 2015

2015-01-01

This annual report explores the state of international education in Canada, taking an in-depth look at international students, study abroad by Canadian students, Canadian education overseas, as well as the overall internationalization agenda in Canada. The report features results of an international student survey and case studies from member…

Reliability Analysis/Assessment of Advanced Technologies

DTIC Science & Technology

1990-05-01

34, Reliability Physics 1980 , IEEE, p. 165. 25. RADC-TR-83-244. 26. Towner, Janet M., et. al., "Aluminum Electromigration Under Pulsed D.C. Conditions...Duvvury, Redwine, Kitagawa, Haas, Chuang, Beydler, Hyslop , "Impact of Hot Carriers On DRAM circuits", 1987 IEEE/IRPS. 58. Cahoon, Thornewell, Tsai...et. a]., "Substrate for Large Silicon Chip and Full Wafer Packaging", Semiconductor International, pp. 149-156, April 1980 . 5. T.E. Lewis and D.L

Harmonizing Measures of Cognitive Performance Across International Surveys of Aging Using Item Response Theory.

PubMed

Chan, Kitty S; Gross, Alden L; Pezzin, Liliana E; Brandt, Jason; Kasper, Judith D

2015-12-01

To harmonize measures of cognitive performance using item response theory (IRT) across two international aging studies. Data for persons ≥65 years from the Health and Retirement Study (HRS, N = 9,471) and the English Longitudinal Study of Aging (ELSA, N = 5,444). Cognitive performance measures varied (HRS fielded 25, ELSA 13); 9 were in common. Measurement precision was examined for IRT scores based on (a) common items, (b) common items adjusted for differential item functioning (DIF), and (c) DIF-adjusted all items. Three common items (day of date, immediate word recall, and delayed word recall) demonstrated DIF by survey. Adding survey-specific items improved precision but mainly for HRS respondents at lower cognitive levels. IRT offers a feasible strategy for harmonizing cognitive performance measures across other surveys and for other multi-item constructs of interest in studies of aging. Practical implications depend on sample distribution and the difficulty mix of in-common and survey-specific items. © The Author(s) 2015.

Technical Division | Fermilab

Science.gov Websites

Martinello wins 2018 IEEE PAST Doctoral Student Award November 28, 2017 PAST has awarded Fermilab scientist Martina Martinello the 2018 IEEE PAST Doctoral Student Award. Performance recognition awards go to

Validation of the internalization of the Model Minority Myth Measure (IM-4) and its link to academic performance and psychological adjustment among Asian American adolescents.

PubMed

Yoo, Hyung Chol; Miller, Matthew J; Yip, Pansy

2015-04-01

There is limited research examining psychological correlates of a uniquely racialized experience of the model minority stereotype faced by Asian Americans. The present study examined the factor structure and fit of the only published measure of the internalization of the model minority myth, the Internalization of the Model Minority Myth Measure (IM-4; Yoo et al., 2010), with a sample of 155 Asian American high school adolescents. We also examined the link between internalization of the model minority myth types (i.e., myth associated with achievement and myth associated with unrestricted mobility) and psychological adjustment (i.e., affective distress, somatic distress, performance difficulty, academic expectations stress), and the potential moderating effect of academic performance (cumulative grade point average). Results suggested the 2-factor model of the IM-4 had an acceptable fit to the data and supported the factor structure using confirmatory factor analyses. Internalizing the model minority myth of achievement related positively to academic expectations stress; however, internalizing the model minority myth of unrestricted mobility related negatively to academic expectations stress, both controlling for gender and academic performance. Finally, academic performance moderated the model minority myth associated with unrestricted mobility and affective distress link and the model minority myth associated with achievement and performance difficulty link. These findings highlight the complex ways in which the model minority myth relates to psychological outcomes. (c) 2015 APA, all rights reserved).

Performance Evaluation of the International Space Station Flow Boiling and Condensation Experiment (FBCE) Test Facility

NASA Technical Reports Server (NTRS)

Hasan, Mohammad; Balasubramaniam, R.; Nahra, Henry; Mackey, Jeff; Hall, Nancy; Frankenfield, Bruce; Harpster, George; May, Rochelle; Mudawar, Issam; Kharangate, Chirag R.;

Biomedical learning experiences for middle school girls sponsored by the Kansas State University Student Chapter of the IEEE EMBS.

PubMed

Gruber, Lucinda; Griffith, Connor; Young, Ethan; Sullivan, Adriann; Schuler, Jeff; Arnold-Christian, Susan; Warren, Steve

2009-01-01

Learning experiences for middle school girls are an effective means to steer young women toward secondary engineering curricula that they might not have otherwise considered. Sponsorship of such experiences by a collegiate student group is worthwhile, as it gives the group common purpose and places college students in a position to mentor these young women. This paper addresses learning experiences in different areas of bio-medical engineering offered to middle school girls in November 2008 via a day-long workshop entitled "Engineering The Body." The Kansas State University (KSU) Student Chapter of the IEEE Engineering in Medicine and Biology Society (EMBS) worked with the KSU Women in Engineering and Science Program (WESP) to design and sponsor these experiences, which addressed the areas of joint mechanics, electrocardiograms, membrane transport, computer mouse design, and audio filters for cochlear implants. Fifty five middle-school girls participated in this event, affirming the notion that biomedical engineering appeals to young women and that early education and recruitment efforts have the potential to expand the biomedical engineering talent pool.

Methodological challenges in international performance measurement using patient-level administrative data.

PubMed

Kiivet, Raul; Sund, Reijo; Linna, Miika; Silverman, Barbara; Pisarev, Heti; Friedman, Nurit

2013-09-01

We conducted this case study in order to test how health system performance could be compared using the existing national administrative health databases containing individual data. In this comparative analysis we used national data set from three countries, Estonia, Israel and Finland to follow the medical history, treatment outcome and resource use of patients with a chronic disease (diabetes) for 8 years after medical treatment was initiated. This study showed that several clinically important aspects of quality of care as well as health policy issues of cost-effectiveness and efficiency of health systems can be assessed by using the national administrative health data systems, in case those collecting person-level health service data. We developed a structured study protocol and detailed data specifications to generate standardized data sets, in each country, for long-term follow up of incident cohort of diabetic persons as well as shared analyzing programs to produce performance measures from the standardized data sets. This stepwise decentralized approach and use of anonymous person-level data allowed us to mitigate any legal, ownership, confidentiality and privacy concerns and to create internationally comparative data with the extent of detail that is seldom seen before. For example, our preliminary performance comparisons indicate that higher mortality among relatively young diabetes patients in Estonia may be related to considerably higher rates of cardiovascular complications and lower use of statins. Modern administrative person-level health service databases contain sufficiently rich data in details to assess the performance of health systems in the management of chronic diseases. This paper presents and discusses the methodological challenges and the way the problems were solved or avoided to enhance the representativeness and comparability of results. Copyright © 2013 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Investigations of a simulated geomagnetic field experienced by the International Space Station on attentional performance

NASA Astrophysics Data System (ADS)

Del Seppia, C.; Mezzasalma, L.; Messerotti, M.; Cordelli, A.; Ghione, S.

2009-01-01

We have previously reported that the exposure to an abnormal magnetic field simulating the one encountered by the International Space Station (ISS) orbiting around the Earth may enhance autonomic response to emotional stimuli. Here we report the results of the second part of that study which tested whether this field also affects cognitive functions. Twenty-four volunteers participated in the study, 12 exposed to the natural geomagnetic field and 12 to the magnetic field encountered by ISS. The test protocol consisted of a set of eight tests chosen from a computerized test battery for the assessment of attentional performance. The duration of exposure was 90 min. No effect of exposure to ISS magnetic field was observed on attentional performance.

Performing international outreach: PhUn Week in an Australian primary school.

PubMed

Halpin, Patricia A

2017-03-01

Physiology Understanding (PhUn) Week is an annual science outreach program sponsored by the American Physiological Society in which K-12 students learn about physiology through meeting a physiologist and performing an experiment. Performing PhUn Week at an Australian private primary school during a family vacation in 2014 enabled me to receive a fellowship to return the following year for further implementation. To set up the outreach, I contacted the assistant principal of a public primary school, and she connected me with the physical education (PE) teacher. Together, the PE teacher and I planned the event. Over the course of 2 days, I taught eight classes, a total of 176 K-12 students. I started each lesson by explaining the role of a physiologist. The scientific method was described and explained. A hypothesis, "Exercise increases heart rate," was designed and tested. The students measured their heart rates, exercised, and measured their heart rates again. After data collection, results were reported, and the students all agreed that their hypothesis was supported. We then discussed heart function and why heart rate increases with exercise. The students then performed a pedometer challenge, where they estimated the number of steps during walking, running, and kangaroo hopping. They enjoyed testing their predictions and repeated these experiments several times. The students then made suggestions of ways they could continue this lesson outside of school. This first report of an international PhUn week confirmed that these events form partnerships among educators and inspire K-12 students to think about becoming scientists. Copyright © 2017 the American Physiological Society.

Pre-Primary Education and Long-Term Education Performance: Evidence from Programme for International Student Assessment (PISA) Thailand

ERIC Educational Resources Information Center

Pholphirul, Piriya

2017-01-01

Several research papers have assessed the long-term benefits of pre-primary education in terms of academic performance and labor market outcomes. This study analyzes data obtained from the Programme for International Student Assessment (PISA) to estimate the effects of preschool enrollment of Thai students on producing long-term benefits in their…

Validation of International Space Station Electrical Performance Model via On-orbit Telemetry

NASA Technical Reports Server (NTRS)

Jannette, Anthony G.; Hojnicki, Jeffrey S.; McKissock, David B.; Fincannon, James; Kerslake, Thomas W.; Rodriguez, Carlos D.

2002-01-01

The first U.S. power module on International Space Station (ISS) was activated in December 2000. Comprised of solar arrays, nickel-hydrogen (NiH2) batteries, and a direct current power management and distribution (PMAD) system, the electric power system (EPS) supplies power to housekeeping and user electrical loads. Modeling EPS performance is needed for several reasons, but primarily to assess near-term planned and off-nominal operations and because the EPS configuration changes over the life of the ISS. The System Power Analysis for Capability Evaluation (SPACE) computer code is used to assess the ISS EPS performance. This paper describes the process of validating the SPACE EPS model via ISS on-orbit telemetry. To accomplish this goal, telemetry was first used to correct assumptions and component models in SPACE. Then on-orbit data was directly input to SPACE to facilitate comparing model predictions to telemetry. It will be shown that SPACE accurately predicts on-orbit component and system performance. For example, battery state-of-charge was predicted to within 0.6 percentage points over a 0 to 100 percent scale and solar array current was predicted to within a root mean square (RMS) error of 5.1 Amps out of a typical maximum of 220 Amps. First, SPACE model predictions are compared to telemetry for the ISS EPS components: solar arrays, NiH2 batteries, and the PMAD system. Second, SPACE predictions for the overall performance of the ISS EPS are compared to telemetry and again demonstrate model accuracy.

Hardware Timestamping for an Image Acquisition System Based on FlexRIO and IEEE 1588 v2 Standard

NASA Astrophysics Data System (ADS)

Esquembri, S.; Sanz, D.; Barrera, E.; Ruiz, M.; Bustos, A.; Vega, J.; Castro, R.

2016-02-01

Current fusion devices usually implement distributed acquisition systems for the multiple diagnostics of their experiments. However, each diagnostic is composed by hundreds or even thousands of signals, including images from the vessel interior. These signals and images must be correctly timestamped, because all the information will be analyzed to identify plasma behavior using temporal correlations. For acquisition devices without synchronization mechanisms the timestamp is given by another device with timing capabilities when signaled by the first device. Later, each data should be related with its timestamp, usually via software. This critical action is unfeasible for software applications when sampling rates are high. In order to solve this problem this paper presents the implementation of an image acquisition system with real-time hardware timestamping mechanism. This is synchronized with a master clock using the IEEE 1588 v2 Precision Time Protocol (PTP). Synchronization, image acquisition and processing, and timestamping mechanisms are implemented using Field Programmable Gate Array (FPGA) and a timing card -PTP v2 synchronized. The system has been validated using a camera simulator streaming videos from fusion databases. The developed architecture is fully compatible with ITER Fast Controllers and has been integrated with EPICS to control and monitor the whole system.

Comparing International Curriculum Systems: The International Instructional Systems Study

ERIC Educational Resources Information Center

Creese, Brian; Gonzalez, Alvaro; Isaacs, Tina

2016-01-01

This paper sets out the main findings of the International Instructional Systems Study (IISS), conducted by the UCL Institute of Education and funded by the Center on International Education Benchmarking (CIEB). The study examined the instructional systems and intended curricula of six "high performing" countries and two US states. The…

Online Performance-Improvement Algorithms

DTIC Science & Technology

1994-08-01

fault rate as the request sequence length approaches infinity. Their algorithms are based on an innovative use of the classical Ziv - Lempel [85] data ...Report CS-TR-348-91. [85] J. Ziv and A. Lempel . Compression of individual sequences via variable-rate coding. IEEE Trans. Inf. Theory, 24:530-53`, 1978. 94...Deferred Data Structuring Recall that our incremental multi-trip algorithm spreads the building of the fence-tree over several trips in order to

Comparison of Analytical and Numerical Performance Predictions for an International Space Station Node 3 Internal Active Thermal Control System Regenerative Heat Exchanger

NASA Technical Reports Server (NTRS)

Wise, Stephen A.; Holt, James M.

2002-01-01

The complexity of International Space Station (ISS) systems modeling often necessitates the concurrence of various dissimilar, parallel analysis techniques to validate modeling. This was the case with a feasibility and performance study of the ISS Node 3 Regenerative Heat Exchanger (RHX). A thermo-hydraulic network model was created and analyzed in SINDA/FLUINT. A less complex, closed form solution of the systems dynamics was created using an Excel Spreadsheet. The purpose of this paper is to provide a brief description of the modeling processes utilized, the results and benefits of each to the ISS Node 3 RHX study.

Validity of three clinical performance assessments of internal medicine clerks.

PubMed

Hull, A L; Hodder, S; Berger, B; Ginsberg, D; Lindheim, N; Quan, J; Kleinhenz, M E

1995-06-01

To analyze the construct validity of three methods to assess the clinical performances of internal medicine clerks. A multitrait-multimethod (MTMM) study was conducted at the Case Western Reserve University School of Medicine to determine the convergent and divergent validity of a clinical evaluation form (CEF) completed by faculty and residents, an objective structured clinical examination (OSCE), and the medicine subject test of the National Board of Medical Examiners. Three traits were involved in the analysis: clinical skills, knowledge, and personal characteristics. A correlation matrix was computed for 410 third-year students who completed the clerkship between August 1988 and July 1991. There was a significant (p < .01) convergence of the four correlations that assessed the same traits by using different methods. However, the four convergent correlations were of moderate magnitude (ranging from .29 to .47). Divergent validity was assessed by comparing the magnitudes of the convergence correlations with the magnitudes of correlations among unrelated assessments (i.e., different traits by different methods). Seven of nine possible coefficients were smaller than the convergent coefficients, suggesting evidence of divergent validity. A significant CEF method effect was identified. There was convergent validity and some evidence of divergent validity with a significant method effect. The findings were similar for correlations corrected for attenuation. Four conclusions were reached: (1) the reliability of the OSCE must be improved, (2) the CEF ratings must be redesigned to further discriminate among the specific traits assessed, (3) additional methods to assess personal characteristics must be instituted, and (4) several assessment methods should be used to evaluate individual student performances.

Examination performances of German and international medical students in the preclinical studying-term – A descriptive study

PubMed Central

Huhn, D.; Resch, F.; Duelli, R.; Möltner, A.; Huber, J.; Karimian Jazi, K.; Amr, A.; Eckart, W.; Herzog, W.; Nikendei, C.

2014-01-01

Introduction: Medical students with a migration background face several specific problems during their studies. International surveys show first indications that this group of students performs worse in written, oral or practical exams. However, so far, nothing is known about the performance of international students in written pre-clinical tests as well as in pre-clinical State Examinations for German-speaking countries. Method: A descriptive, retrospective analysis of the exam performances of medical students in the pre-clinical part of their studies was conducted at the Faculty of Medicine of Heidelberg in for the year 2012. Performance in written tests of the final exams in the second (N=276), third (N=292) and fourth semester (N=285) were compared between German students, students from EU countries and students from non-EU countries. Same comparison was drawn for the performance in the oral exam of the First State Examination in the period from 2009 - 2012 (N=1137). Results: German students performed significantly better than students with a non-EU migration background both in all written exams and in the oral State Examination (all p<.05). The performance of students with an EU migration background was significantly better than that of students with a non-EU background in the written exam at the end of the third and fourth semester (p<.05). Furthermore, German students completed the oral exam of the First State Examination significantly earlier than students with a non-EU migration background (<.01). Discussion: Due to its poorer performance in written and oral examinations and its simultaneously longer duration of study, the group of non-German medical students with a country of origin outside of the European Union has to be seen as a high-risk group among students with a migration background. For this group, there is an urgent need for early support to prepare for written and oral examinations. PMID:25228931

Double Intracavernous Breakage of Sachse's Knife Blade: Management of a Rare Complication Performing Direct Vision Internal Urethrotomy.

PubMed

Benincasa, Alfonso; Saita, Alberto; Pinto, Angelo; Pilerci, Carmine; Francesco, Lamberti; Russo, Aniello; Benincasa, Giuseppe

2017-01-01

Background: Although the breakage of a Sachse's knife blade is already a rare event while performing optical internal urethrotomy, a double failure appears to be at the same time a unique and a challenging complication to manage since no reference has emerged from literature review. Case Presentation: A male patient, 80 years of age, underwent retreatment of recurrent urethral stricture that occurred after transurethral resection of the prostate. The latter was complicated by severe intraoperative urethrorrhagia; this is the reason he was transferred from another institution where at first a suprapubic cystostomy was carried out, followed by urethral recanalization through internal urethrotomy and finally he underwent intracavernous Sachse's knife blade discharge. Preoperative evaluation included combined retrograde and voiding urethrography and CT to evaluate the complete resolution of the urethral stenosis and to establish the correct location of the blades inside the corpus cavernosum. A transperineal approach to the left corpus cavernosum was carried out with manageable removal of the foreign body and postoperative assessment showed no early considerable complications for the patient. Conclusion: To our knowledge, this is the first case of double breakage of Sachse's knife blade performing optical internal urethrotomy reported in literature. Although it may appear to be an easy procedure, close attention to its execution must always be paid to prevent major complications. A transperineal approach has proven to be effective and safe without creating any further outcomes to the patient.

Investigations of a simulated geomagnetic field experienced by the International Space Station on attentional performance.

PubMed

Del Seppia, Cristina; Mezzasalma, Lorena; Messerotti, Mauro; Cordelli, Alessandro; Ghione, Sergio

2009-01-01

We have previously reported that the exposure to an abnormal magnetic field simulating the one encountered by the International Space Station (ISS) orbiting around the Earth may enhance autonomic response to emotional stimuli. Here we report the results of the second part of that study which tested whether this field also affects cognitive functions. Twenty-four volunteers participated in the study, 12 exposed to the natural geomagnetic field and 12 to the magnetic field encountered by ISS. The test protocol consisted of a set of eight tests chosen from a computerized test battery for the assessment of attentional performance. The duration of exposure was 90 min. No effect of exposure to ISS magnetic field was observed on attentional performance. (c) 2008 Wiley-Liss, Inc.

Analysis of ISO/IEEE 11073 built-in security and its potential IHE-based extensibility.

PubMed

Rubio, Óscar J; Trigo, Jesús D; Alesanco, Álvaro; Serrano, Luis; García, José

2016-04-01

The ISO/IEEE 11073 standard for Personal Health Devices (X73PHD) aims to ensure interoperability between Personal Health Devices and aggregators-e.g. health appliances, routers-in ambulatory setups. The Integrating the Healthcare Enterprise (IHE) initiative promotes the coordinated use of different standards in healthcare systems (e.g. Personal/Electronic Health Records, alert managers, Clinical Decision Support Systems) by defining profiles intended for medical use cases. X73PHD provides a robust syntactic model and a comprehensive terminology, but it places limited emphasis on security and on interoperability with IHE-compliant systems and frameworks. However, the implementation of eHealth/mHealth applications in environments such as health and fitness monitoring, independent living and disease management (i.e. the X73PHD domains) increasingly requires features such as secure connections to mobile aggregators-e.g. smartphones, tablets-, the sharing of devices among different users with privacy, and interoperability with certain IHE-compliant healthcare systems. This work proposes a comprehensive IHE-based X73PHD extension consisting of additive layers adapted to different eHealth/mHealth applications, after having analyzed the features of X73PHD (especially its built-in security), IHE profiles related with these applications and other research works. Both the new features proposed for each layer and the procedures to support them have been carefully chosen to minimize the impact on X73PHD, on its architecture (in terms of delays and overhead) and on its framework. Such implications are thoroughly analyzed in this paper. As a result, an extended model of X73PHD is proposed, preserving its essential features while extending them with added value. Copyright © 2016 Elsevier Inc. All rights reserved.

Optimizing the MAC Protocol in Localization Systems Based on IEEE 802.15.4 Networks.

PubMed

Pérez-Solano, Juan J; Claver, Jose M; Ezpeleta, Santiago

2017-07-06

Radio frequency signals are commonly used in the development of indoor localization systems. The infrastructure of these systems includes some beacons placed at known positions that exchange radio packets with users to be located. When the system is implemented using wireless sensor networks, the wireless transceivers integrated in the network motes are usually based on the IEEE 802.15.4 standard. But, the CSMA-CA, which is the basis for the medium access protocols in this category of communication systems, is not suitable when several users want to exchange bursts of radio packets with the same beacon to acquire the radio signal strength indicator (RSSI) values needed in the location process. Therefore, new protocols are necessary to avoid the packet collisions that appear when multiple users try to communicate with the same beacons. On the other hand, the RSSI sampling process should be carried out very quickly because some systems cannot tolerate a large delay in the location process. This is even more important when the RSSI sampling process includes measures with different signal power levels or frequency channels. The principal objective of this work is to speed up the RSSI sampling process in indoor localization systems. To achieve this objective, the main contribution is the proposal of a new MAC protocol that eliminates the medium access contention periods and decreases the number of packet collisions to accelerate the RSSI collection process. Moreover, the protocol increases the overall network throughput taking advantage of the frequency channel diversity. The presented results show the suitability of this protocol for reducing the RSSI gathering delay and increasing the network throughput in simulated and real environments.

Optimizing the MAC Protocol in Localization Systems Based on IEEE 802.15.4 Networks

PubMed Central

Claver, Jose M.; Ezpeleta, Santiago

2017-01-01

Radio frequency signals are commonly used in the development of indoor localization systems. The infrastructure of these systems includes some beacons placed at known positions that exchange radio packets with users to be located. When the system is implemented using wireless sensor networks, the wireless transceivers integrated in the network motes are usually based on the IEEE 802.15.4 standard. But, the CSMA-CA, which is the basis for the medium access protocols in this category of communication systems, is not suitable when several users want to exchange bursts of radio packets with the same beacon to acquire the radio signal strength indicator (RSSI) values needed in the location process. Therefore, new protocols are necessary to avoid the packet collisions that appear when multiple users try to communicate with the same beacons. On the other hand, the RSSI sampling process should be carried out very quickly because some systems cannot tolerate a large delay in the location process. This is even more important when the RSSI sampling process includes measures with different signal power levels or frequency channels. The principal objective of this work is to speed up the RSSI sampling process in indoor localization systems. To achieve this objective, the main contribution is the proposal of a new MAC protocol that eliminates the medium access contention periods and decreases the number of packet collisions to accelerate the RSSI collection process. Moreover, the protocol increases the overall network throughput taking advantage of the frequency channel diversity. The presented results show the suitability of this protocol for reducing the RSSI gathering delay and increasing the network throughput in simulated and real environments. PMID:28684666

Relationships between triathlon performance and pacing strategy during the run in an international competition.

PubMed

Le Meur, Yann; Bernard, Thierry; Dorel, Sylvain; Abbiss, Chris R; Honnorat, Gérard; Brisswalter, Jeanick; Hausswirth, Christophe

2011-06-01

The purpose of the present study was to examine relationships between athlete's pacing strategies and running performance during an international triathlon competition. Running split times for each of the 107 finishers of the 2009 European Triathlon Championships (42 females and 65 males) were determined with the use of a digital synchronized video analysis system. Five cameras were placed at various positions of the running circuit (4 laps of 2.42 km). Running speed and an index of running speed variability (IRSVrace) were subsequently calculated over each section or running split. Mean running speed over the first 1272 m of lap 1 was 0.76 km·h-1 (+4.4%) and 1.00 km·h-1 (+5.6%) faster than the mean running speed over the same section during the three last laps, for females and males, respectively (P < .001). A significant inverse correlation was observed between RSrace and IRSVrace for all triathletes (females r = -0.41, P = .009; males r = -0.65, P = .002; and whole population -0.76, P = .001). Females demonstrated higher IRSVrace compared with men (6.1 ± 0.5 km·h-1 and 4.0 ± 1.4 km·h-1, for females and males, respectively, P = .001) due to greater decrease in running speed over uphill sections. Pacing during the run appears to play a key role in high-level triathlon performance. Elite triathletes should reduce their initial running speed during international competitions, even if high levels of motivation and direct opponents lead them to adopt an aggressive strategy.

High-performing simulations of the space radiation environment for the International Space Station and Apollo Missions

NASA Astrophysics Data System (ADS)

Lund, Matthew Lawrence

The space radiation environment is a significant challenge to future manned and unmanned space travels. Future missions will rely more on accurate simulations of radiation transport in space through spacecraft to predict astronaut dose and energy deposition within spacecraft electronics. The International Space Station provides long-term measurements of the radiation environment in Low Earth Orbit (LEO); however, only the Apollo missions provided dosimetry data beyond LEO. Thus dosimetry analysis for deep space missions is poorly supported with currently available data, and there is a need to develop dosimetry-predicting models for extended deep space missions. GEANT4, a Monte Carlo Method, provides a powerful toolkit in C++ for simulation of radiation transport in arbitrary media, thus including the spacecraft and space travels. The newest version of GEANT4 supports multithreading and MPI, resulting in faster distributive processing of simulations in high-performance computing clusters. This thesis introduces a new application based on GEANT4 that greatly reduces computational time using Kingspeak and Ember computational clusters at the Center for High Performance Computing (CHPC) to simulate radiation transport through full spacecraft geometry, reducing simulation time to hours instead of weeks without post simulation processing. Additionally, this thesis introduces a new set of detectors besides the historically used International Commission of Radiation Units (ICRU) spheres for calculating dose distribution, including a Thermoluminescent Detector (TLD), Tissue Equivalent Proportional Counter (TEPC), and human phantom combined with a series of new primitive scorers in GEANT4 to calculate dose equivalence based on the International Commission of Radiation Protection (ICRP) standards. The developed models in this thesis predict dose depositions in the International Space Station and during the Apollo missions showing good agreement with experimental measurements

Update on International Space Station Nickel-Hydrogen Battery On-Orbit Performance

NASA Technical Reports Server (NTRS)

Dalton, Penni; Cohen, Fred

2003-01-01

International Space Station (ISS) Electric Power System (EPS) utilizes Nickel-Hydrogen (Ni-H2) batteries as part of its power system to store electrical energy. The batteries are charged during insolation and discharged during eclipse. The batteries are designed to operate at a 35% depth of discharge (DOD) maximum during normal operation. Thirty-eight individual pressure vessel (IPV) Ni-H2 battery cells are series-connected and packaged in an Orbital Replacement Unit (ORU). Two ORUs are series-connected utilizing a total of 76 cells, to form one battery. The ISS is the first application for low earth orbit (LEO) cycling of this quantity of series-connected cells. The P6 (Port) Integrated Equipment Assembly (IEA) containing the initial ISS high-power components was successfully launched on November 30, 2000. The IEA contains 12 Battery Subassembly ORUs (6 batteries) that provide station power during eclipse periods. This paper will discuss the battery performance data after two and a half years of cycling.

A World of Learning: Canada's Performance and Potential in International Education 2012

ERIC Educational Resources Information Center

Humphries, Jennifer; Knight-Grofe, Janine; McDine, David

2012-01-01

This annual report explores the state of international education in Canada, taking an in-depth look at international students, study abroad by Canadian students, Canadian education overseas, as well as the overall internationalization agenda in Canada. The report features results of an international student survey and case studies from member…

A World of Learning: Canada's Performance and Potential in International Education 2013

ERIC Educational Resources Information Center

Humphries, Jennifer; Rauh, Karen; McDine, David

2013-01-01

This annual report explores the state of international education in Canada, taking an in-depth look at international students, study abroad by Canadian students, Canadian education overseas, as well as the overall internationalization agenda in Canada. The report features results of an international student survey and case studies from member…

Delphi Method Validation of a Procedural Performance Checklist for Insertion of an Ultrasound-Guided Internal Jugular Central Line.

PubMed

Hartman, Nicholas; Wittler, Mary; Askew, Kim; Manthey, David

2016-01-01

Placement of ultrasound-guided central lines is a critical skill for physicians in several specialties. Improving the quality of care delivered surrounding this procedure demands rigorous measurement of competency, and validated tools to assess performance are essential. Using the iterative, modified Delphi technique and experts in multiple disciplines across the United States, the study team created a 30-item checklist designed to assess competency in the placement of ultrasound-guided internal jugular central lines. Cronbach α was .94, indicating an excellent degree of internal consistency. Further validation of this checklist will require its implementation in simulated and clinical environments. © The Author(s) 2014.

Internal performance characteristics of short convergent-divergent exhaust nozzles designed by the method of characteristics

NASA Technical Reports Server (NTRS)

Krull, H George; Beale, William T

1956-01-01

Internal performance data on a short exhaust nozzle designed by the method of characteristics were obtained over a range of pressure ratios from 1.5 to 22. The peak thrust coefficient was not affected by a shortened divergent section, but it occurred at lower pressure ratios due to reduction in expansion ratio. This nozzle contour based on characteristics solution gave higher thrust coefficients than a conical convergent-divergent nozzle of equivalent length. Abrupt-inlet sections permitted a reduction in nozzle length without a thrust-coefficient reduction.

Physiological and performance changes in national and international judo athletes during block periodization training

PubMed Central

Marques, Lucas; Franchini, Emerson; Drago, Gustavo; Aoki, Marcelo S.

2017-01-01

Block periodization (BP) has been proposed as an alternative approach for application in the context of high-level sports. Despite its growing acceptance, there is no empirical evidence of BP adoption in high-level judo athletes. Therefore, this study aimed to compare the maximal strength, muscle power, judo-specific performances, and hormonal concentration changes of state/national level (NG) and international level (IG) judo athletes subjected to BP. Twenty-one elite judo athletes (international level = 10; 21.7±1.9 years, 167.2±7.6 cm, 67.6±9.4 kg, 15.7±1.9 years of practice; national level = 11; 21.9±3.0 years, 167.5±9.1 cm, 71.8±16.5, 15.9±3.0 years of practice) were subjected to 13-week BP training (5-week accumulation phase [ACP], 5-week transmutation phase [TP], and 3-week realization phase [RP]). The judo-specific performance (SJFT) increased as there was observed a decrease in the SJFT index (final heart rate [HR] (bpm) + HR1 min after the test divided by the number of throws) for both NG (effect size [ES] = 0.83) and IG (ES = 0.53) from ACP to TP (p < 0.05). The row exercise maximal strength decreased (p < 0.05; ES = 1.35) after the ACP but returned to the baseline level after the TP, for the whole group (ES = 1.39). The athletes did seem to cope appropriately with the demands of BP, as besides increases in SJFT performance no significant changes were observed for cortisol and testosterone concentrations. This is the first study to demonstrate that judo athletes from different competitive levels subjected to BP improved SJFT, likely due to an appropriate balance between training loads and recovery. Thus, the BP approach may be a useful alternative periodization strategy for high-level judo athletes. PMID:29472740

Effects of Caffeine Ingestion on Skill Performance During an International Female Rugby Sevens Competition.

PubMed

Portillo, Javier; Del Coso, Juan; Abián-Vicén, Javier

2017-12-01

Portillo, J, Del Coso, J, and Abián-Vicén, J. Effects of caffeine ingestion on skill performance during an international female rugby sevens competition. J Strength Cond Res 31(12): 3351-3357, 2017-The aim of this study was to establish the effects of a caffeine-containing energy drink on skills and technical performance during a match in female elite rugby sevens players. On 2 nonconsecutive days of a friendly tournament, 16 women from the Spanish national rugby sevens team (mean age = 23 ± 2 years) ingested 3 mg of caffeine per kilogram of body mass in the form of an energy drink or the same drink without caffeine (placebo drink). After 60 minutes for caffeine absorption, participants played 3 rugby sevens matches against another national team. Body impacts during the matches were assessed by triaxial accelerometers. The matches were videotaped, and each individual technical action was notated afterward by 2 experienced observers. In comparison with the placebo drink, the ingestion of the caffeinated energy drink increased the rate of body impacts in zone 1 (16.1 ± 4.9 vs. 20.8 ± 9.9 impacts/min, p < 0.05), zone 2 (12.2 ± 10.6 vs. 16.2 ± 15.2 impacts/min, p < 0.05), zone 3 (3.8 ± 1.5 vs. 4.7 ± 2.6 impacts/min, p < 0.05), and zone 5 (0.8 ± 0.4 vs. 1.1 ± 0.6 impacts/min, p < 0.05). The pre-exercise ingestion of the caffeinated energy drink did not affect the frequency or the quality of any rugby-specific technical actions during the games. In conclusion, the ingestion of 3 mg·kg of caffeine in the form of an energy drink increased the number of body impacts during a rugby sevens international competition which suggests a higher engagement of the players during the game. However, the caffeine ingestion did not influence the quality of the technical actions performed during the competition.

Effects of objectifying gaze on female cognitive performance: The role of flow experience and internalization of beauty ideals.

PubMed

Guizzo, Francesca; Cadinu, Mara

2017-06-01

Although previous research has demonstrated that objectification impairs female cognitive performance, no research to date has investigated the mechanisms underlying such decrement. Therefore, we tested the role of flow experience as one mechanism leading to performance decrement under sexual objectification. Gaze gender was manipulated by having male versus female experimenters take body pictures of female participants (N = 107) who then performed a Sustained Attention to Response Task. As predicted, a moderated mediation model showed that under male versus female gaze, higher internalization of beauty ideals was associated with lower flow, which in turn decreased performance. The implications of these results are discussed in relation to objectification theory and strategies to prevent sexually objectifying experiences. © 2016 The British Psychological Society.

Performance Analysis of IEEE 802.11g Waveform Transmitted Over a Fading Channel with Pulse-Noise Interference

DTIC Science & Technology

2006-06-01

called packet binary convolutional code (PBCC), was included as an option for performance at rate of either 5.5 or 11 Mpbs. The second offshoot...and the code rate is r k n= . A general convolutional encoder can be implemented with k shift-registers and n modulo-2 adders. Higher rates can be...derived from lower rate codes by employing “ puncturing .” Puncturing is a procedure for omitting some of the encoded bits in the transmitter (thus

International consensus on military research priorities and gaps - Survey results from the 4th International Congress on Soldiers' Physical Performance.

PubMed

Lovalekar, Mita; Sharp, Marilyn A; Billing, Daniel C; Drain, Jace R; Nindl, Bradley C; Zambraski, Edward J

2018-06-06

The objectives of this study were to identify perceived priorities related to military personnel's health and physical performance, among attendees at the 4th International Congress on Soldiers' Physical Performance (ICSPP), and to determine if perceived priorities had changed between the 3rd ICSPP survey held in 2014 and the 4th ICSPP survey held in 2017. Electronic survey. Respondents were asked to grade priority areas on a Likert scale, and average ratings were used to rank priority areas. Responses to free text questions were analyzed qualitatively. Responses to the 4th ICSPP survey were described and compared to responses to the 3rd ICSPP survey. The 4th ICSPP survey respondents were a diverse group (40.6% military, 58.9% civilian). The two most important priority areas identified were physical demands in operational environments (mean score=4.41/5) and measuring physical performance/fitness (4.38/5), which were also the top two areas in the 3rd ICSPP survey. There was remarkable overlap in the rankings of priority areas between the two surveys. Sleep and nutrition were emerging priority areas and were perceived as relatively more important in the 4th ICSPP survey compared to the 3rd ICSPP survey. The greatest perceived emerging threat was resilience/psychological fitness of recruits (4.16/5). Physiological status monitoring (2.79/4) was identified as the most important technology. Despite the diverse backgrounds of the respondents, there was a clear continuing consensus about perceived important priority areas influencing military personnel's health and physical performance. Soldier resiliency and assessment of physiological status were research topics identified as top priorities. Copyright © 2018 Sports Medicine Australia. All rights reserved.

Performance evaluation of radiation sensors with internal signal amplification based on the BJT effect

NASA Astrophysics Data System (ADS)

Bosisio, Luciano; Batignani, Giovanni; Bettarini, Stefano; Boscardin, Maurizio; Dalla Betta, Gian-Franco; Giacomini, Gabriele; Piemonte, Claudio; Verzellesi, Giovanni; Zorzi, Nicola

2006-11-01

Prototypes of ionizing radiation detectors with internal signal amplification based on the bipolar transistor effect have been fabricated at ITC-irst (Trento, Italy). Results from the electrical characterization and preliminary functional tests of the devices have been previously reported. Here, we present a more detailed investigation of the performance of this type of detector, with particular attention to their noise and rate limits. Measurements of the signal waveform and of the gain versus frequency dependence are performed by illuminating the devices with, respectively, pulsed or sinusoidally modulated IR light. Pulse height spectra of X-rays from an Am241 source have been taken with very simple front-end electronics (an LF351 operational amplifier) or by directly reading with an oscilloscope the voltage drop across a load resistor connected to the emitter. An equivalent noise charge (referred to input) of 380 electrons r.m.s. has been obtained with the first setup for a small device, with an active area of 0.5×0.5 mm2 and a depleted thickness of 0.6 mm. The corresponding power dissipation in the BJT was 17 μW. The performance limitations of the devices are discussed.

Evaluation of the Air Quality Monitor's Performance on the International Space Station

NASA Technical Reports Server (NTRS)

Limero, Thomas; Reese, Eric; Ballard, Ken; Durham, Tamara

2010-01-01

The Air Quality Monitor (AQM) was flown to the International Space Station (ISS) as an experiment to evaluate its potential to replace the aging Volatile Organic Analyzer (VOA), which ceased operations in August 2009. The AQM (Figure 1) is a small gas chromatography/differential mobility spectrometer (GC/DMS) manufactured by Sionex. Data was presented at last year s ISIMS conference that detailed the preparation of the AQM for flight, including instrument calibration. Furthermore, initial AQM data was compared to VOA results from simultaneous runs of the two instruments. Although comparison with VOA data provided a measure of confidence in the AQM performance, it is the comparison with results from simultaneously acquired air samples (grab sample containers-GSCs) that will define the success (or failure) of the AQM performance. This paper will update the progress in the AQM investigation by comparing AQM data to results from the analyses of GSC samples, returned from ISS. Additionally, a couple of example will illustrate the AQM s ability to detect disruptions in the spacecraft s air quality. Discussion will also focus upon a few unexpected issues that have arisen and how these will be a addressed in the final operational unit now being built.

Transmission Loss Calculation using A and B Loss Coefficients in Dynamic Economic Dispatch Problem

NASA Astrophysics Data System (ADS)

Jethmalani, C. H. Ram; Dumpa, Poornima; Simon, Sishaj P.; Sundareswaran, K.

2016-04-01

This paper analyzes the performance of A-loss coefficients while evaluating transmission losses in a Dynamic Economic Dispatch (DED) Problem. The performance analysis is carried out by comparing the losses computed using nominal A loss coefficients and nominal B loss coefficients in reference with load flow solution obtained by standard Newton-Raphson (NR) method. Density based clustering method based on connected regions with sufficiently high density (DBSCAN) is employed in identifying the best regions of A and B loss coefficients. Based on the results obtained through cluster analysis, a novel approach in improving the accuracy of network loss calculation is proposed. Here, based on the change in per unit load values between the load intervals, loss coefficients are updated for calculating the transmission losses. The proposed algorithm is tested and validated on IEEE 6 bus system, IEEE 14 bus, system IEEE 30 bus system and IEEE 118 bus system. All simulations are carried out using SCILAB 5.4 (www.scilab.org) which is an open source software.

Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) and performance of everyday life tasks: Actual Reality.

PubMed

Goverover, Yael; Chiaravalloti, Nancy; DeLuca, John

2016-04-01

Recently, a brief cognitive assessment (Brief International Cognitive Assessment for Multiple Sclerosis: BICAMS) has been recommended for use with patients diagnosed with multiple sclerosis (MS) to screen for cognitive impairments. However, the relationship between the BICAMS and everyday life activity has not been examined. The aim of this study was to examine whether the BICAMS can predict performance of activities of daily living using Actual Reality(TM) (AR) in persons with MS. A between-subjects design was utilized to compare 41 individuals with MS and 32 healthy controls (HC) performing BICAMS and an AR task. Participants were asked to access the internet to purchase a flight ticket or cookies, and were administered the BICAMS and questionnaires to assess quality of life (QOL), affect symptomatology, and prior internet experience. Participants with MS performed significantly worse than HC on the BICAMS and the AR. Additionally, better BICAMS performance was associated with more independent AR performance. Self-reports of QOL were not correlated with AR or BICAMS performance. Individuals with MS have greater problems with actual everyday life tasks as compared to HC. The BICAMS is a promising cognitive screening tool to predict actual functional performance in participants with MS. © The Author(s), 2015.

Fenestration system energy performance research, implementation, and international harmonization

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

McGowan, Raymond F

The research conducted by the NFRC and its contractors adds significantly to the understanding of several areas of investigation. NFRC enables manufacturers to rate fenestration energy performance to comply with building energy codes, participate in ENERGY STAR, and compete fairly. NFRC continuously seeks to improve its ratings and also seeks to simplify the rating process. Several research projects investigated rating improvement potential such as • Complex Product VT Rating Research • Window 6 and Therm 6 Validation Research Project • Complex Product VT Rating Research Conclusions from these research projects led to important changes and increased confidence in the existingmore » NFRC rating process. Conclusions from the Window 6/Therm 6 project will enable window manufacturers to rate an expanded array of products and improve existing ratings. Some research lead to an improved new rating method called the Component Modeling Approach. A primary goal of the CMA was a simplification of the commercial energy rating process to increase participation and make the commercial industry more competitive and code compliant. The project below contributed towards CMA development: • Component Modeling Approach Condensation Resistance Research NFRC continues to implement the Component Modeling Approach program. The program includes the CMA software tool, CMAST, and several procedural documents to govern the certification process. This significant accomplishment was a response the commercial fenestration industry’s need for a simplification of the present NFRC energy rating method (named site built). To date, most commercial fenestration is self-rated by a variety of techniques. The CMA enables commercial fenestration manufacturers to rate according to the NFRC 100/200 as most commercial energy codes require. International Harmonization NFRC achieved significant international harmonization success by continuing its licensing agreements with the Australian

Analysis and performance assessment of a fragment retransmission scheme for energy efficient IEEE 802.11 WLANs.

PubMed

Mafole, Prosper; Aritsugi, Masayoshi

2016-01-01

Backoff-free fragment retransmission (BFFR) scheme enhances the performance of legacy MAC layer fragmentation by eliminating contention overhead. The eliminated overhead is the result of backoff executed before a retransmission attempt is made when fragment transmission failure occurs within a fragment burst. This paper provides a mathematical analysis of BFFR energy efficiency and further assesses, by means of simulations, the energy efficiency, throughput and delay obtained when BFFR is used. The validity of the new scheme is evaluated in different scenarios namely, constant bit rate traffic, realistic bursty internet traffic, node mobility, rigid and elastic flows and their combinations at different traffic loads. We also evaluate and discuss the impact of BFFR on MAC fairness when the number of nodes is varied from 4 to 10. It is shown that BFFR has advantages over legacy MAC fragmentation scheme in all the scenarios.

Industrial Wireless Sensors: A User's Perspective on the Impact of Standards on Wide-spread Deployment

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

Taft, Cyrus W.; Manges, Wayne W; Sorge, John N

2012-01-01

The role of wireless sensing technologies in industrial instrumentation will undoubtedly become more important in the years ahead. . Deployment of such instrumentation in an industrial setting with its heightened security and robustness criteria hinges on user acceptance of verified performance as well as meeting cost requirements. Today, industrial users face many choices when specifying a wireless sensor network, including radio performance, battery life, interoperability, security, and standards compliance. The potential market for industrial wireless sensors is literally millions of wireless instruments and it is imperative that accurate information for applying the technology to real-world applications be available to themore » end-user so that they can make informed deployment decisions. The majority of industrial wireless automation designs now being deployed or being considered for deployment are based on three different standards . The HART Communications Foundation s WirelessHART (IEC 62591), the International Society of Automation s ISA100.11a, and the offering from the Industrial Wireless Alliance of China known as WIA-PA (IEC 62601). Aside from these industrial automation standards, users must also be cognizant of the underlying wireless network standards IEEE 802.11, IEEE 802.15.4, and IEEE 802.15.3a and their interactions with the three principal industrial automation protocols mentioned previously. The crucial questions being asked by end users revolve around sensor network performance, interoperability, reliability, and security. This paper will discuss potential wireless sensor applications in power plants, barriers to the acceptance of wireless technology, concerns related to standards, and provide an end user prospective on the issues affecting wide-spread deployment of wireless sensors. Finally, the authors conclude with a discussion of a recommended path forward including how standards organizations can better facilitate end user decision

Assisting Design Given Multiple Performance Criteria

DTIC Science & Technology

1988-08-01

with uninstantiated operators is created then each operator’s implementation is selected. g - Keywords: computer-aided design, artificial...IEEE Trans- actions on Software Engineering, SE-7(1), 1981. [BG86] Forrest D. Brewer and Daniel D. Gajski . An expert-system paradigm for de- sign. In...Teukolsky, api William T. Vet- terling. Numerical Recipes. Cambridge University Press, Cambridge, England, 1987. [RFS83] G . G . Rassweiler, M. D

Partial Bibliography of Work on Expert Systems,

DTIC Science & Technology

1982-12-01

Bibliography: AAAI American Association for Artificial Intelligence ACM Association for Computing Machinery AFIPS American Federation of Information...Processing Societies ECAI European Conference on Artificial Intelligence IEEE Institute for Electrical and Electronic Engineers IFIPS International...Federation of Information Processing Societies IJCAI International Joint Conferences on Artificial Intelligence SIGPLAN ACM Special Interest Group on

Internal Wave Impact on the Performance of a Hypothetical Mine Hunting Sonar

DTIC Science & Technology

2014-10-01

time steps) to simulate the propagation of the internal wave field through the mine field. Again the transmission loss and acoustic signal strength...dependent internal wave perturbed sound speed profile was evaluated by calculating the temporal variability of the signal excess (SE) of acoustic...internal wave perturbation of the sound speed profile, was calculated for a limited sound speed field time section. Acoustic signals were projected

The Association between Medical Education Accreditation and Examination Performance of Internationally Educated Physicians Seeking Certification in the United States