42 CFR 485.719 - Condition of participation: Arrangements for physical therapy and speech pathology services to be...

Code of Federal Regulations, 2011 CFR

2011-10-01

... physical therapy and speech pathology services to be performed by other than salaried organization... Agencies as Providers of Outpatient Physical Therapy and Speech-Language Pathology Services § 485.719 Condition of participation: Arrangements for physical therapy and speech pathology services to be performed...

42 CFR 485.719 - Condition of participation: Arrangements for physical therapy and speech pathology services to be...

Code of Federal Regulations, 2010 CFR

2010-10-01

... physical therapy and speech pathology services to be performed by other than salaried organization... Agencies as Providers of Outpatient Physical Therapy and Speech-Language Pathology Services § 485.719 Condition of participation: Arrangements for physical therapy and speech pathology services to be performed...

42 CFR 485.719 - Condition of participation: Arrangements for physical therapy and speech pathology services to be...

Code of Federal Regulations, 2013 CFR

2013-10-01

... physical therapy and speech pathology services to be performed by other than salaried organization... Agencies as Providers of Outpatient Physical Therapy and Speech-Language Pathology Services § 485.719 Condition of participation: Arrangements for physical therapy and speech pathology services to be performed...

42 CFR 485.719 - Condition of participation: Arrangements for physical therapy and speech pathology services to be...

Code of Federal Regulations, 2014 CFR

2014-10-01

... physical therapy and speech pathology services to be performed by other than salaried organization... Agencies as Providers of Outpatient Physical Therapy and Speech-Language Pathology Services § 485.719 Condition of participation: Arrangements for physical therapy and speech pathology services to be performed...

42 CFR 485.719 - Condition of participation: Arrangements for physical therapy and speech pathology services to be...

Code of Federal Regulations, 2012 CFR

2012-10-01

... physical therapy and speech pathology services to be performed by other than salaried organization... Agencies as Providers of Outpatient Physical Therapy and Speech-Language Pathology Services § 485.719 Condition of participation: Arrangements for physical therapy and speech pathology services to be performed...

SERVER DEVELOPMENT FOR NSLS-II PHYSICS APPLICATIONS AND PERFORMANCE ANALYSIS

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

Shen, G.; Kraimer, M.

2011-03-28

The beam commissioning software framework of NSLS-II project adopts a client/server based architecture to replace the more traditional monolithic high level application approach. The server software under development is available via an open source sourceforge project named epics-pvdata, which consists of modules pvData, pvAccess, pvIOC, and pvService. Examples of two services that already exist in the pvService module are itemFinder, and gather. Each service uses pvData to store in-memory transient data, pvService to transfer data over the network, and pvIOC as the service engine. The performance benchmarking for pvAccess and both gather service and item finder service are presented inmore » this paper. The performance comparison between pvAccess and Channel Access are presented also. For an ultra low emittance synchrotron radiation light source like NSLS II, the control system requirements, especially for beam control are tight. To control and manipulate the beam effectively, a use case study has been performed to satisfy the requirement and theoretical evaluation has been performed. The analysis shows that model based control is indispensable for beam commissioning and routine operation. However, there are many challenges such as how to re-use a design model for on-line model based control, and how to combine the numerical methods for modeling of a realistic lattice with the analytical techniques for analysis of its properties. To satisfy the requirements and challenges, adequate system architecture for the software framework for beam commissioning and operation is critical. The existing traditional approaches are self-consistent, and monolithic. Some of them have adopted a concept of middle layer to separate low level hardware processing from numerical algorithm computing, physics modelling, data manipulating and plotting, and error handling. However, none of the existing approaches can satisfy the requirement. A new design has been proposed by introducing service oriented architecture technology, and client interface is undergoing. The design and implementation adopted a new EPICS implementation, namely epics-pvdata [9], which is under active development. The implementation of this project under Java is close to stable, and binding to other language such as C++ and/or Python is undergoing. In this paper, we focus on the performance benchmarking and comparison for pvAccess and Channel Access, the performance evaluation for 2 services, gather and item finder respectively.« less

Resilient control of cyber-physical systems against intelligent attacker: a hierarchal stackelberg game approach

NASA Astrophysics Data System (ADS)

Yuan, Yuan; Sun, Fuchun; Liu, Huaping

2016-07-01

This paper is concerned with the resilient control under denial-of-service attack launched by the intelligent attacker. The resilient control system is modelled as a multi-stage hierarchical game with a corresponding hierarchy of decisions made at cyber and physical layer, respectively. Specifically, the interaction in the cyber layer between different security agents is modelled as a static infinite Stackelberg game, while in the underlying physical layer the full-information H∞ minimax control with package drops is modelled as a different Stackelberg game. Both games are solved sequentially, which is consistent with the actual situations. Finally, the proposed method is applied to the load frequency control of the power system, which demonstrates its effectiveness.

Application of Athletic Movement Tests that Predict Injury Risk in a Military Population: Development of Normative Data.

PubMed

Teyhen, Deydre S; Shaffer, Scott W; Butler, Robert J; Goffar, Stephen L; Kiesel, Kyle B; Rhon, Daniel I; Boyles, Robert E; McMillian, Daniel J; Williamson, Jared N; Plisky, Phillip J

2016-10-01

Performance on movement tests helps to predict injury risk in a variety of physically active populations. Understanding baseline measures for normal is an important first step. Determine differences in physical performance assessments and describe normative values for these tests based on military unit type. Assessment of power, balance, mobility, motor control, and performance on the Army Physical Fitness Test were assessed in a cohort of 1,466 soldiers. Analysis of variance was performed to compare the results based on military unit type (Rangers, Combat, Combat Service, and Combat Service Support) and analysis of covariance was performed to determine the influence of age and gender. Rangers performed the best on all performance and fitness measures (p < 0.05). Combat soldiers performed better than Combat Service and Service Support soldiers on several physical performance tests and the Army Physical Fitness Test (p < 0.05). Performance in Combat Service and Service Support soldiers was equivalent on most measures (p < 0.05). Functional performance and level of fitness varied significantly by military unit type. Understanding these differences will provide a foundation for future injury prediction and prevention strategies. Reprint & Copyright © 2016 Association of Military Surgeons of the U.S.

Variable weight spectral amplitude coding for multiservice OCDMA networks

NASA Astrophysics Data System (ADS)

Seyedzadeh, Saleh; Rahimian, Farzad Pour; Glesk, Ivan; Kakaee, Majid H.

2017-09-01

The emergence of heterogeneous data traffic such as voice over IP, video streaming and online gaming have demanded networks with capability of supporting quality of service (QoS) at the physical layer with traffic prioritisation. This paper proposes a new variable-weight code based on spectral amplitude coding for optical code-division multiple-access (OCDMA) networks to support QoS differentiation. The proposed variable-weight multi-service (VW-MS) code relies on basic matrix construction. A mathematical model is developed for performance evaluation of VW-MS OCDMA networks. It is shown that the proposed code provides an optimal code length with minimum cross-correlation value when compared to other codes. Numerical results for a VW-MS OCDMA network designed for triple-play services operating at 0.622 Gb/s, 1.25 Gb/s and 2.5 Gb/s are considered.

Cross-layer protocol design for QoS optimization in real-time wireless sensor networks

NASA Astrophysics Data System (ADS)

Hortos, William S.

2010-04-01

The metrics of quality of service (QoS) for each sensor type in a wireless sensor network can be associated with metrics for multimedia that describe the quality of fused information, e.g., throughput, delay, jitter, packet error rate, information correlation, etc. These QoS metrics are typically set at the highest, or application, layer of the protocol stack to ensure that performance requirements for each type of sensor data are satisfied. Application-layer metrics, in turn, depend on the support of the lower protocol layers: session, transport, network, data link (MAC), and physical. The dependencies of the QoS metrics on the performance of the higher layers of the Open System Interconnection (OSI) reference model of the WSN protocol, together with that of the lower three layers, are the basis for a comprehensive approach to QoS optimization for multiple sensor types in a general WSN model. The cross-layer design accounts for the distributed power consumption along energy-constrained routes and their constituent nodes. Following the author's previous work, the cross-layer interactions in the WSN protocol are represented by a set of concatenated protocol parameters and enabling resource levels. The "best" cross-layer designs to achieve optimal QoS are established by applying the general theory of martingale representations to the parameterized multivariate point processes (MVPPs) for discrete random events occurring in the WSN. Adaptive control of network behavior through the cross-layer design is realized through the parametric factorization of the stochastic conditional rates of the MVPPs. The cross-layer protocol parameters for optimal QoS are determined in terms of solutions to stochastic dynamic programming conditions derived from models of transient flows for heterogeneous sensor data and aggregate information over a finite time horizon. Markov state processes, embedded within the complex combinatorial history of WSN events, are more computationally tractable and lead to simplifications for any simulated or analytical performance evaluations of the cross-layer designs.

Cross-Service Investigation of Geographical Information Systems

DTIC Science & Technology

2004-03-01

Figure 8 illustrates the combined layers. Information for the layers is stored in a database format. The two types of storage are vector and...raster models. In a vector model, the image and information are stored as geometric objects such as points, lines, or polygons. In a raster model...DNCs are a vector -based digital database with selected maritime significant physical features from hydrographic charts. Layers within the DNC are data

Oxygen-reducing catalyst layer

DOEpatents

O'Brien, Dennis P [Maplewood, MN; Schmoeckel, Alison K [Stillwater, MN; Vernstrom, George D [Cottage Grove, MN; Atanasoski, Radoslav [Edina, MN; Wood, Thomas E [Stillwater, MN; Yang, Ruizhi [Halifax, CA; Easton, E Bradley [Halifax, CA; Dahn, Jeffrey R [Hubley, CA; O'Neill, David G [Lake Elmo, MN

2011-03-22

An oxygen-reducing catalyst layer, and a method of making the oxygen-reducing catalyst layer, where the oxygen-reducing catalyst layer includes a catalytic material film disposed on a substrate with the use of physical vapor deposition and thermal treatment. The catalytic material film includes a transition metal that is substantially free of platinum. At least one of the physical vapor deposition and the thermal treatment is performed in a processing environment comprising a nitrogen-containing gas.

Intercomparison of 7 Planetary Boundary-Layer/Surface-Layer Physics Schemes over Complex Terrain for Battlefield Situational Awareness

DTIC Science & Technology

This study considers the performance of 7 of the Weather Research and Forecast model boundary-layer (BL) parameterization schemes in a complex...schemes performed best. The surface parameters, planetary BL structure, and vertical profiles are important for US Army Research Laboratory

High-Performance CCSDS Encapsulation Service Implementation in FPGA

NASA Technical Reports Server (NTRS)

Clare, Loren P.; Torgerson, Jordan L.; Pang, Jackson

2010-01-01

The Consultative Committee for Space Data Systems (CCSDS) Encapsulation Service is a convergence layer between lower-layer space data link framing protocols, such as CCSDS Advanced Orbiting System (AOS), and higher-layer networking protocols, such as CFDP (CCSDS File Delivery Protocol) and Internet Protocol Extension (IPE). CCSDS Encapsulation Service is considered part of the data link layer. The CCSDS AOS implementation is described in the preceding article. Recent advancement in RF modem technology has allowed multi-megabit transmission over space links. With this increase in data rate, the CCSDS Encapsulation Service needs to be optimized to both reduce energy consumption and operate at a high rate. CCSDS Encapsulation Service has been implemented as an intellectual property core so that the aforementioned problems are solved by way of operating the CCSDS Encapsulation Service inside an FPGA. The CCSDS En capsula tion Service in FPGA implementation consists of both packetizing and de-packetizing features

Assessment of physical server reliability in multi cloud computing system

NASA Astrophysics Data System (ADS)

Kalyani, B. J. D.; Rao, Kolasani Ramchand H.

2018-04-01

Business organizations nowadays functioning with more than one cloud provider. By spreading cloud deployment across multiple service providers, it creates space for competitive prices that minimize the burden on enterprises spending budget. To assess the software reliability of multi cloud application layered software reliability assessment paradigm is considered with three levels of abstractions application layer, virtualization layer, and server layer. The reliability of each layer is assessed separately and is combined to get the reliability of multi-cloud computing application. In this paper, we focused on how to assess the reliability of server layer with required algorithms and explore the steps in the assessment of server reliability.

Positioning navigation and timing service applications in cyber physical systems

NASA Astrophysics Data System (ADS)

Qu, Yi; Wu, Xiaojing; Zeng, Lingchuan

2017-10-01

The positioning navigation and timing (PNT) architecture was discussed in detail, whose history, evolvement, current status and future plan were presented, main technologies were listed, advantages and limitations of most technologies were compared, novel approaches were introduced, and future capacities were sketched. The concept of cyber-physical system (CPS) was described and their primary features were interpreted. Then the three-layer architecture of CPS was illustrated. Next CPS requirements on PNT services were analyzed, including requirements on position reference and time reference, requirements on temporal-spatial error monitor, requirements on dynamic services, real-time services, autonomous services, security services and standard services. Finally challenges faced by PNT applications in CPS were concluded. The conclusion was expected to facilitate PNT applications in CPS, and furthermore to provide references to the design and implementation of both architectures.

Antisoiling technology: Theories of surface soiling and performance of antisoiling surface coatings

NASA Technical Reports Server (NTRS)

Cuddihy, E. F.; Willis, P. B.

1984-01-01

Physical examination of surfaces undergoing natural outdoor soiling suggests that soil matter accumulates in up to three distinct layers. The first layer involves strong chemical attachment or strong chemisorption of soil matter on the primary surface. The second layer is physical, consisting of a highly organized arrangement of soil creating a gradation in surface energy from a high associated with the energetic first layer to the lowest possible state on the outer surfce of the second layer. The lowest possible energy state is dictated by the physical nature of the regional atmospheric soiling materials. These first two layers are resistant to removal by rain. The third layer constitutes a settling of loose soil matter, accumulating in dry periods and being removed during rainy periods. Theories and evidence suggest that surfaces that should be naturally resistant to the formation of the first two-resistant layers should be hard, smooth, hydrophobic, free of first-period elements, and have the lowest possible surface energy. These characteristics, evolving as requirements for low-soiling surfaces, suggest that surfaces or surface coatings should be of fluorocarbon chemistry. Evidence for the three-soil-layer concept, and data on the positive performance of candidate fluorocarbon coatings on glass and transparent plastic films after 28 months of outdoor exposure, are presented.

Reliability Analysis and Modeling of ZigBee Networks

NASA Astrophysics Data System (ADS)

Lin, Cheng-Min

The architecture of ZigBee networks focuses on developing low-cost, low-speed ubiquitous communication between devices. The ZigBee technique is based on IEEE 802.15.4, which specifies the physical layer and medium access control (MAC) for a low rate wireless personal area network (LR-WPAN). Currently, numerous wireless sensor networks have adapted the ZigBee open standard to develop various services to promote improved communication quality in our daily lives. The problem of system and network reliability in providing stable services has become more important because these services will be stopped if the system and network reliability is unstable. The ZigBee standard has three kinds of networks; star, tree and mesh. The paper models the ZigBee protocol stack from the physical layer to the application layer and analyzes these layer reliability and mean time to failure (MTTF). Channel resource usage, device role, network topology and application objects are used to evaluate reliability in the physical, medium access control, network, and application layers, respectively. In the star or tree networks, a series system and the reliability block diagram (RBD) technique can be used to solve their reliability problem. However, a division technology is applied here to overcome the problem because the network complexity is higher than that of the others. A mesh network using division technology is classified into several non-reducible series systems and edge parallel systems. Hence, the reliability of mesh networks is easily solved using series-parallel systems through our proposed scheme. The numerical results demonstrate that the reliability will increase for mesh networks when the number of edges in parallel systems increases while the reliability quickly drops when the number of edges and the number of nodes increase for all three networks. More use of resources is another factor impact on reliability decreasing. However, lower network reliability will occur due to network complexity, more resource usage and complex object relationship.

Cross-layer restoration with software defined networking based on IP over optical transport networks

NASA Astrophysics Data System (ADS)

Yang, Hui; Cheng, Lei; Deng, Junni; Zhao, Yongli; Zhang, Jie; Lee, Young

2015-10-01

The IP over optical transport network is a very promising networking architecture applied to the interconnection of geographically distributed data centers due to the performance guarantee of low delay, huge bandwidth and high reliability at a low cost. It can enable efficient resource utilization and support heterogeneous bandwidth demands in highly-available, cost-effective and energy-effective manner. In case of cross-layer link failure, to ensure a high-level quality of service (QoS) for user request after the failure becomes a research focus. In this paper, we propose a novel cross-layer restoration scheme for data center services with software defined networking based on IP over optical network. The cross-layer restoration scheme can enable joint optimization of IP network and optical network resources, and enhance the data center service restoration responsiveness to the dynamic end-to-end service demands. We quantitatively evaluate the feasibility and performances through the simulation under heavy traffic load scenario in terms of path blocking probability and path restoration latency. Numeric results show that the cross-layer restoration scheme improves the recovery success rate and minimizes the overall recovery time.

Performance Assessment of New Land-Surface and Planetary Boundary Layer Physics in the WRF-ARW

EPA Science Inventory

The Pleim-Xiu land surface model, Pleim surface layer scheme, and Asymmetric Convective Model (version 2) are now options in version 3.0 of the Weather Research and Forecasting model (WRF) Advanced Research WRF (ARW) core. These physics parameterizations were developed for the f...

Catalog of Performance Objectives and Performance Guides for Physical Therapy Occupations.

ERIC Educational Resources Information Center

Reneau, Fred; Hahn, Dave

This catalog provides a worker-based description of duties, tasks, performance objectives and guides, and related data for physical therapy occupations. Duties covered include the following: (1) performing administrative/clerical functions; (2) communicating information; (3) providing patient care services; (4) performing support service; (5)…

A Chaos MIMO-OFDM Scheme for Mobile Communication with Physical-Layer Security

NASA Astrophysics Data System (ADS)

Okamoto, Eiji

Chaos communications enable a physical-layer security, which can enhance the transmission security in combining with upper-layer encryption techniques, or can omit the upper-layer secure protocol and enlarges the transmission efficiency. However, the chaos communication usually degrades the error rate performance compared to unencrypted digital modulations. To achieve both physical-layer security and channel coding gain, we have proposed a chaos multiple-input multiple-output (MIMO) scheme in which a rate-one chaos convolution is applied to MIMO multiplexing. However, in the conventional study only flat fading is considered. To apply this scheme to practical mobile environments, i.e., multipath fading channels, we propose a chaos MIMO-orthogonal frequency division multi-plexing (OFDM) scheme and show its effectiveness through computer simulations.

Digital Physical Activity Data Collection and Use by Endurance Runners and Distance Cyclists

ERIC Educational Resources Information Center

Lee, Victor R.; Drake, Joel

2013-01-01

The introduction of sensor technologies to sports has allowed athletes to quantify and track their performance, adding an information-based layer to athletic practices. This information layer is particularly prevalent in practices involving formal competition and high levels of physical endurance, such as biking and running. We interviewed 20…

42 CFR 484.32 - Condition of participation: Therapy services.

Code of Federal Regulations, 2011 CFR

2011-10-01

... and occupational therapy assistant. Services furnished by a qualified physical therapy assistant or qualified occupational therapy assistant may be furnished under the supervision of a qualified physical or occupational therapist. A physical therapy assistant or occupational therapy assistant performs services...

European Marine Observation Data Network - EMODnet Physics

NASA Astrophysics Data System (ADS)

Manzella, Giuseppe M. R.; Novellino, Antonio; D'Angelo, Paolo; Gorringe, Patrick; Schaap, Dick; Pouliquen, Sylvie; Loubrieu, Thomas; Rickards, Lesley

2015-04-01

The EMODnet-Physics portal (www.emodnet-physics.eu) makes layers of physical data and their metadata available for use and contributes towards the definition of an operational European Marine Observation and Data Network (EMODnet). It is based on a strong collaboration between EuroGOOS associates and its regional operational systems (ROOSs), and it is bringing together two very different marine communities: the "real time" ocean observing institute/centers and the National Oceanographic Data Centres (NODCs) that are in charge of ocean data validation, quality check and update for marine environmental monitoring. The EMODnet-Physics is a Marine Observation and Data Information System that provides a single point of access to near real time and historical achieved data (www.emodnet-physics.eu/map) it is built on existing infrastructure by adding value and avoiding any unless complexity, it provides data access to users, it is aimed at attracting new data holders, better and more data. With a long-term vision for a pan European Ocean Observation System sustainability, the EMODnet-Physics is supporting the coordination of the EuroGOOS Regional components and the empowerment and improvement of their data management infrastructure. In turn, EMODnet-Physics already implemented high-level interoperability features (WMS, Web catalogue, web services, etc…) to facilitate connection and data exchange with the ROOS and the Institutes within the ROOSs (www.emodnet-physics.eu/services). The on-going EMODnet-Physics structure delivers environmental marine physical data from the whole Europe (wave height and period, temperature of the water column, wind speed and direction, salinity of the water column, horizontal velocity of the water column, light attenuation, and sea level) as monitored by fixed stations, ARGO floats, drifting buoys, gliders, and ferry-boxes. It does provide discovering of data sets (both NRT - near real time - and Historical data sets), visualization and free download of data from more than 1500 platforms. The portal is composed mainly of three sections: the Map, the Selection List and the Station Info Panel. The Map is the core of the EMODnet-Physics system: here the user can access all available data, customize the map visualization and set different display layers. It is also possible to interact with all the information on the map using the filters provided by the service that can be used to select the stations of interest depending on the type, physical parameters measured, the time period of the observations in the database of the system, country of origin, the water basin of reference. It is also possible to browse the data in time by means of the slider in the lower part of the page that allows the user to view the stations that recorded data in a particular time period. Finally, it is possible to change the standard map view with different layers that provide additional visual information on the status of the waters. The Station Info panel available from the main map by clicking on a single platform provides information on the measurements carried out by the station. Moreover, the system provides full interoperability with third-party software through WMS service, Web Service and Web catalogue in order to exchange data and products according to the most recent interop standards. Further developments will ensure the compatibility to the OGS-SWE (Sensor Web Enablement) standard for the description of sensors and related observations using OpenGIS specifications (SensorML, O&M, SOS). The full list of services is available at www.emodnet-physics.eu/services. The result is an excellent example of innovative technologies for providing open and free access to geo-referenced data for the creation of new advanced (operational) oceanography services.

SSMNG Software Service Manager: A Scalable Building Blocks Architecture for PUS Services & FDIR Management

NASA Astrophysics Data System (ADS)

Lisio, Giovanni; Candia, Sante; Campolo, Giovanni; Pascucci, Dario

2011-08-01

Thales Alenia Space Italy has carried out the definition of a configurable (on mission basis) PUS ECSS-E_70- 41A see [3] Centralised Services Layer, characterised by:- a mission-independent set of 'classes' implementing the services logic.- a mission-dependent set of configuration data and selection flags.The software components belonging to this layer implement the PUS standard services ECSS-E_70-41A and a set of mission-specific services. The design of this layer has been performed by separating the services mechanisms (mission-independent execution logic) from the services configuration information (mission-dependent data). Once instantiated for a specific mission, the PUS Centralised Services Layer offers a large set of capabilities available to the CSCI's Applications Layer. This paper describes the building blocks PUS architectural solution developed by Thales Alenia Space Italy, emphasizing the mechanisms which allow easy configuration of the Scalable PUS library to fulfill the requirements of different missions. This paper also focus the Thales Alenia Space solution to automatically generate the mission-specific "PUS Services" flight software based on mission specific requirements. Building the PUS services mechanisms, which are configurable on mission basis is part of the PRIMA (Multipurpose Spacecraft Bus ) 'missionisation' process improvement. PRIMA Platform Avionics Software (ASW) is continuously evolving to improve modularity and standardization of interfaces and of SW components (see references in [1]).

A Client/Server Architecture for Supporting Science Data Using EPICS Version 4

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

Dalesio, Leo

2015-04-21

The Phase 1 grant that serves as a precursor to this proposal, prototyped complex storage techniques for high speed structured data that is being produced in accelerator diagnostics and beam line experiments. It demonstrates the technologies that can be used to archive and retrieve complex data structures and provide the performance required by our new accelerators, instrumentations, and detectors. Phase 2 is proposed to develop a high-performance platform for data acquisition and analysis to provide physicists and operators a better understanding of the beam dynamics. This proposal includes developing a platform for reading 109 MHz data at 10 KHz ratesmore » through a multicore front end processor, archiving the data to an archive repository that is then indexed for fast retrieval. The data is then retrieved from this data archive, integrated with the scalar data, to provide data sets to client applications for analysis, use in feedback, and to aid in identifying problem with the instrumentation, plant, beam steering, or model. This development is built on EPICS version 4 , which is being successfully deployed to implement physics applications. Through prior SBIR grants, EPICS version 4 has a solid communication protocol for middle layer services (PVAccess), structured data representation and methods for efficient transportation and access (PVData), an operational hierarchical record environment (JAVA IOC), and prototypes for standard structured data (Normative Types). This work was further developed through project funding to successfully deploy the first service based physics application environment with demonstrated services that provide arbitrary object views, save sets, model, lattice, and unit conversion. Thin client physics applications have been developed in Python that implement quad centering, orbit display, bump control, and slow orbit feedback. This service based architecture has provided a very modular and robust environment that enables commissioning teams to rapidly develop and deploy small scripts that build on powerful services. These services are all built on relational database data stores and scalar data. The work proposed herein, builds on these previous successes to provide data acquisition of high speed data for online analysis clients.« less

Comparison of WRF local and nonlocal boundary layer Physics in Greater Kuala Lumpur, Malaysia

NASA Astrophysics Data System (ADS)

Ooi, M. C. G.; Chan, A.; Kumarenthiran, S.; Morris, K. I.; Oozeer, M. Y.; Islam, M. A.; Salleh, S. A.

2018-02-01

The urban boundary layer (UBL) is the internal advection layer of atmosphere above urban region which determines the exchanges of momentum, water and other atmospheric constituents between the urban land surface and the free troposphere. This paper tested the performance of three planetary boundary layer (PBL) physics schemes of Weather Research and Forecast (WRF) software to ensure the appropriate representation of vertical structure of UBL in Greater Kuala Lumpur (GKL). Comparison was conducted on the performance of respective PBL schemes to generate vertical and near-surface weather profile and rainfall. Mellor-Yamada- Janjíc (MYJ) local PBL scheme coupled with Eta MM5 surface layer scheme was found to predict the near-surface temperature and wind profile and mixing height better than the nonlocal schemes during the intermonsoonal period with least influences of the synoptic background weather.

Cross-layer Joint Relay Selection and Power Allocation Scheme for Cooperative Relaying System

NASA Astrophysics Data System (ADS)

Zhi, Hui; He, Mengmeng; Wang, Feiyue; Huang, Ziju

2018-03-01

A novel cross-layer joint relay selection and power allocation (CL-JRSPA) scheme over physical layer and data-link layer is proposed for cooperative relaying system in this paper. Our goal is finding the optimal relay selection and power allocation scheme to maximize system achievable rate when satisfying total transmit power constraint in physical layer and statistical delay quality-of-service (QoS) demand in data-link layer. Using the concept of effective capacity (EC), our goal can be formulated into an optimal joint relay selection and power allocation (JRSPA) problem to maximize the EC when satisfying total transmit power limitation. We first solving optimal power allocation (PA) problem with Lagrange multiplier approach, and then solving optimal relay selection (RS) problem. Simulation results demonstrate that CL-JRSPA scheme gets larger EC than other schemes when satisfying delay QoS demand. In addition, the proposed CL-JRSPA scheme achieves the maximal EC when relay located approximately halfway between source and destination, and EC becomes smaller when the QoS exponent becomes larger.

An investigation of bleed configurations and their effect on shock wave/boundary layer interactions

NASA Technical Reports Server (NTRS)

Hamed, Awatef

1995-01-01

The design of high efficiency supersonic inlets is a complex task involving the optimization of a number of performance parameters such as pressure recovery, spillage, drag, and exit distortion profile, over the flight Mach number range. Computational techniques must be capable of accurately simulating the physics of shock/boundary layer interactions, secondary corner flows, flow separation, and bleed if they are to be useful in the design. In particular, bleed and flow separation, play an important role in inlet unstart, and the associated pressure oscillations. Numerical simulations were conducted to investigate some of the basic physical phenomena associated with bleed in oblique shock wave boundary layer interactions that affect the inlet performance.

Multi-layer service function chaining scheduling based on auxiliary graph in IP over optical network

NASA Astrophysics Data System (ADS)

Li, Yixuan; Li, Hui; Liu, Yuze; Ji, Yuefeng

2017-10-01

Software Defined Optical Network (SDON) can be considered as extension of Software Defined Network (SDN) in optical networks. SDON offers a unified control plane and makes optical network an intelligent transport network with dynamic flexibility and service adaptability. For this reason, a comprehensive optical transmission service, able to achieve service differentiation all the way down to the optical transport layer, can be provided to service function chaining (SFC). IP over optical network, as a promising networking architecture to interconnect data centers, is the most widely used scenarios of SFC. In this paper, we offer a flexible and dynamic resource allocation method for diverse SFC service requests in the IP over optical network. To do so, we firstly propose the concept of optical service function (OSF) and a multi-layer SFC model. OSF represents the comprehensive optical transmission service (e.g., multicast, low latency, quality of service, etc.), which can be achieved in multi-layer SFC model. OSF can also be considered as a special SF. Secondly, we design a resource allocation algorithm, which we call OSF-oriented optical service scheduling algorithm. It is able to address multi-layer SFC optical service scheduling and provide comprehensive optical transmission service, while meeting multiple optical transmission requirements (e.g., bandwidth, latency, availability). Moreover, the algorithm exploits the concept of Auxiliary Graph. Finally, we compare our algorithm with the Baseline algorithm in simulation. And simulation results show that our algorithm achieves superior performance than Baseline algorithm in low traffic load condition.

Who should swing the stethoscope? An audit of baseline physical examination and blood monitoring on new patients accepted by an early intervention in psychosis team.

PubMed

Crabb, Jim; McAllister, Mark; Blair, Alison

2009-11-01

It has been established that patients with severe mental illness are at increased risk of physical illness and that physical health screening should be performed when an individual experiences a first episode of psychosis. The aim of the audit was to examine how physical health screening was achieved in the real world of an early intervention in psychosis (EIP) service in Scotland. Of particular interest was considering if primary or secondary care were more effective in providing specific physical health assessment for those presenting to the service. A case note audit was performed. The audit shows that physical examination and blood tests were being completed in the majority of service users under the care of the Esteem service. However, an unacceptably high number were not undergoing sufficient initial screening for metabolic syndrome or having baseline monitoring prior to commencing antipsychotic medication. Our results suggest that relying on primary care to provide physical health screening was not an effective approach in a population experiencing first-episode psychosis. Having a psychiatrist motivated to perform physical health screening within the EIP team may help to improve the uptake of physical health screening. Strategies to improve physical health screening in EIP services are discussed. © 2009 The Authors. Journal compilation © 2009 Blackwell Publishing Asia Pty Ltd.

Markov Task Network: A Framework for Service Composition under Uncertainty in Cyber-Physical Systems.

PubMed

Mohammed, Abdul-Wahid; Xu, Yang; Hu, Haixiao; Agyemang, Brighter

2016-09-21

In novel collaborative systems, cooperative entities collaborate services to achieve local and global objectives. With the growing pervasiveness of cyber-physical systems, however, such collaboration is hampered by differences in the operations of the cyber and physical objects, and the need for the dynamic formation of collaborative functionality given high-level system goals has become practical. In this paper, we propose a cross-layer automation and management model for cyber-physical systems. This models the dynamic formation of collaborative services pursuing laid-down system goals as an ontology-oriented hierarchical task network. Ontological intelligence provides the semantic technology of this model, and through semantic reasoning, primitive tasks can be dynamically composed from high-level system goals. In dealing with uncertainty, we further propose a novel bridge between hierarchical task networks and Markov logic networks, called the Markov task network. This leverages the efficient inference algorithms of Markov logic networks to reduce both computational and inferential loads in task decomposition. From the results of our experiments, high-precision service composition under uncertainty can be achieved using this approach.

Performance Evaluation Model for Application Layer Firewalls.

PubMed

Xuan, Shichang; Yang, Wu; Dong, Hui; Zhang, Jiangchuan

2016-01-01

Application layer firewalls protect the trusted area network against information security risks. However, firewall performance may affect user experience. Therefore, performance analysis plays a significant role in the evaluation of application layer firewalls. This paper presents an analytic model of the application layer firewall, based on a system analysis to evaluate the capability of the firewall. In order to enable users to improve the performance of the application layer firewall with limited resources, resource allocation was evaluated to obtain the optimal resource allocation scheme in terms of throughput, delay, and packet loss rate. The proposed model employs the Erlangian queuing model to analyze the performance parameters of the system with regard to the three layers (network, transport, and application layers). Then, the analysis results of all the layers are combined to obtain the overall system performance indicators. A discrete event simulation method was used to evaluate the proposed model. Finally, limited service desk resources were allocated to obtain the values of the performance indicators under different resource allocation scenarios in order to determine the optimal allocation scheme. Under limited resource allocation, this scheme enables users to maximize the performance of the application layer firewall.

Modeling and sensitivity analysis of mass transfer in active multilayer polymeric film for food applications

NASA Astrophysics Data System (ADS)

Bedane, T.; Di Maio, L.; Scarfato, P.; Incarnato, L.; Marra, F.

2015-12-01

The barrier performance of multilayer polymeric films for food applications has been significantly improved by incorporating oxygen scavenging materials. The scavenging activity depends on parameters such as diffusion coefficient, solubility, concentration of scavenger loaded and the number of available reactive sites. These parameters influence the barrier performance of the film in different ways. Virtualization of the process is useful to characterize, design and optimize the barrier performance based on physical configuration of the films. Also, the knowledge of values of parameters is important to predict the performances. Inverse modeling and sensitivity analysis are sole way to find reasonable values of poorly defined, unmeasured parameters and to analyze the most influencing parameters. Thus, the objective of this work was to develop a model to predict barrier properties of multilayer film incorporated with reactive layers and to analyze and characterize their performances. Polymeric film based on three layers of Polyethylene terephthalate (PET), with a core reactive layer, at different thickness configurations was considered in the model. A one dimensional diffusion equation with reaction was solved numerically to predict the concentration of oxygen diffused into the polymer taking into account the reactive ability of the core layer. The model was solved using commercial software for different film layer configurations and sensitivity analysis based on inverse modeling was carried out to understand the effect of physical parameters. The results have shown that the use of sensitivity analysis can provide physical understanding of the parameters which highly affect the gas permeation into the film. Solubility and the number of available reactive sites were the factors mainly influencing the barrier performance of three layered polymeric film. Multilayer films slightly modified the steady transport properties in comparison to net PET, giving a small reduction in the permeability and oxygen transfer rate values. Scavenging capacity of the multilayer film increased linearly with the increase of the reactive layer thickness and the oxygen absorption reaction at short times decreased proportionally with the thickness of the external PET layer.

Modeling and sensitivity analysis of mass transfer in active multilayer polymeric film for food applications

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

Bedane, T.; Di Maio, L.; Scarfato, P.

The barrier performance of multilayer polymeric films for food applications has been significantly improved by incorporating oxygen scavenging materials. The scavenging activity depends on parameters such as diffusion coefficient, solubility, concentration of scavenger loaded and the number of available reactive sites. These parameters influence the barrier performance of the film in different ways. Virtualization of the process is useful to characterize, design and optimize the barrier performance based on physical configuration of the films. Also, the knowledge of values of parameters is important to predict the performances. Inverse modeling and sensitivity analysis are sole way to find reasonable values ofmore » poorly defined, unmeasured parameters and to analyze the most influencing parameters. Thus, the objective of this work was to develop a model to predict barrier properties of multilayer film incorporated with reactive layers and to analyze and characterize their performances. Polymeric film based on three layers of Polyethylene terephthalate (PET), with a core reactive layer, at different thickness configurations was considered in the model. A one dimensional diffusion equation with reaction was solved numerically to predict the concentration of oxygen diffused into the polymer taking into account the reactive ability of the core layer. The model was solved using commercial software for different film layer configurations and sensitivity analysis based on inverse modeling was carried out to understand the effect of physical parameters. The results have shown that the use of sensitivity analysis can provide physical understanding of the parameters which highly affect the gas permeation into the film. Solubility and the number of available reactive sites were the factors mainly influencing the barrier performance of three layered polymeric film. Multilayer films slightly modified the steady transport properties in comparison to net PET, giving a small reduction in the permeability and oxygen transfer rate values. Scavenging capacity of the multilayer film increased linearly with the increase of the reactive layer thickness and the oxygen absorption reaction at short times decreased proportionally with the thickness of the external PET layer.« less

CDF-II and B physics

NASA Astrophysics Data System (ADS)

Lockyer, Nigel S.

1998-02-01

This paper reports on the CDF-II B physics goals and new detector systems presently being built for Run-II of the Tevatron collider in the year 2000. The B physics goals are focused towards observing and studying CP violation and B s flavor oscillations. Estimates of expected performance are reported. The new detector systems described are: the 5-layer 3-D silicon vertex detector, the intermedia silicon tracking layers, the central tracking drift chamber, muon system upgrades, and a proposed time-of-flight system.

Research and development of service robot platform based on artificial psychology

NASA Astrophysics Data System (ADS)

Zhang, Xueyuan; Wang, Zhiliang; Wang, Fenhua; Nagai, Masatake

2007-12-01

Some related works about the control architecture of robot system are briefly summarized. According to the discussions above, this paper proposes control architecture of service robot based on artificial psychology. In this control architecture, the robot can obtain the cognition of environment through sensors, and then be handled with intelligent model, affective model and learning model, and finally express the reaction to the outside stimulation through its behavior. For better understanding the architecture, hierarchical structure is also discussed. The control system of robot can be divided into five layers, namely physical layer, drives layer, information-processing and behavior-programming layer, application layer and system inspection and control layer. This paper shows how to achieve system integration from hardware modules, software interface and fault diagnosis. Embedded system GENE-8310 is selected as the PC platform of robot APROS-I, and its primary memory media is CF card. The arms and body of the robot are constituted by 13 motors and some connecting fittings. Besides, the robot has a robot head with emotional facial expression, and the head has 13 DOFs. The emotional and intelligent model is one of the most important parts in human-machine interaction. In order to better simulate human emotion, an emotional interaction model for robot is proposed according to the theory of need levels of Maslom and mood information of Siminov. This architecture has already been used in our intelligent service robot.

A General Cross-Layer Cloud Scheduling Framework for Multiple IoT Computer Tasks.

PubMed

Wu, Guanlin; Bao, Weidong; Zhu, Xiaomin; Zhang, Xiongtao

2018-05-23

The diversity of IoT services and applications brings enormous challenges to improving the performance of multiple computer tasks' scheduling in cross-layer cloud computing systems. Unfortunately, the commonly-employed frameworks fail to adapt to the new patterns on the cross-layer cloud. To solve this issue, we design a new computer task scheduling framework for multiple IoT services in cross-layer cloud computing systems. Specifically, we first analyze the features of the cross-layer cloud and computer tasks. Then, we design the scheduling framework based on the analysis and present detailed models to illustrate the procedures of using the framework. With the proposed framework, the IoT services deployed in cross-layer cloud computing systems can dynamically select suitable algorithms and use resources more effectively to finish computer tasks with different objectives. Finally, the algorithms are given based on the framework, and extensive experiments are also given to validate its effectiveness, as well as its superiority.

Cross-layer design for intrusion detection and data security in wireless ad hoc sensor networks

NASA Astrophysics Data System (ADS)

Hortos, William S.

2007-09-01

A wireless ad hoc sensor network is a configuration for area surveillance that affords rapid, flexible deployment in arbitrary threat environments. There is no infrastructure support and sensor nodes communicate with each other only when they are in transmission range. The nodes are severely resource-constrained, with limited processing, memory and power capacities and must operate cooperatively to fulfill a common mission in typically unattended modes. In a wireless sensor network (WSN), each sensor at a node can observe locally some underlying physical phenomenon and sends a quantized version of the observation to sink (destination) nodes via wireless links. Since the wireless medium can be easily eavesdropped, links can be compromised by intrusion attacks from nodes that may mount denial-of-service attacks or insert spurious information into routing packets, leading to routing loops, long timeouts, impersonation, and node exhaustion. A cross-layer design based on protocol-layer interactions is proposed for detection and identification of various intrusion attacks on WSN operation. A feature set is formed from selected cross-layer parameters of the WSN protocol to detect and identify security threats due to intrusion attacks. A separate protocol is not constructed from the cross-layer design; instead, security attributes and quantified trust levels at and among nodes established during data exchanges complement customary WSN metrics of energy usage, reliability, route availability, and end-to-end quality-of-service (QoS) provisioning. Statistical pattern recognition algorithms are applied that use observed feature-set patterns observed during network operations, viewed as security audit logs. These algorithms provide the "best" network global performance in the presence of various intrusion attacks. A set of mobile (software) agents distributed at the nodes implement the algorithms, by moving among the layers involved in the network response at each active node and trust neighborhood, collecting parametric information and executing assigned decision tasks. The communications overhead due to security mechanisms and the latency in network response are thus minimized by reducing the need to move large amounts of audit data through resource-limited nodes and by locating detection/identification programs closer to audit data. If network partitioning occurs due to uncoordinated node exhaustion, data compromise or other effects of the attacks, the mobile agents can continue to operate, thereby increasing fault tolerance in the network response to intrusions. Since the mobile agents behave like an ant colony in securing the WSN, published ant colony optimization (ACO) routines and other evolutionary algorithms are adapted to protect network security, using data at and through nodes to create audit records to detect and respond to denial-of-service attacks. Performance evaluations of algorithms are performed by simulation of a few intrusion attacks, such as black hole, flooding, Sybil and others, to validate the ability of the cross-layer algorithms to enable WSNs to survive the attacks. Results are compared for the different algorithms.

Physical-enhanced secure strategy in an OFDM-PON.

PubMed

Zhang, Lijia; Xin, Xiangjun; Liu, Bo; Yu, Jianjun

2012-01-30

The physical layer of optical access network is vulnerable to various attacks. As the dramatic increase of users and network capacity, the issue of physical-layer security becomes more and more important. This paper proposes a physical-enhanced secure strategy for orthogonal frequency division multiplexing passive optical network (OFDM-PON) by employing frequency domain chaos scrambling. The Logistic map is adopted for the chaos mapping. The chaos scrambling strategy can dynamically allocate the scrambling matrices for different OFDM frames according to the initial condition, which enhance the confidentiality of the physical layer. A mathematical model of this secure system is derived firstly, which achieves a secure transmission at physical layer in OFDM-PON. The results from experimental implementation using Logistic mapped chaos scrambling are also given to further demonstrate the efficiency of this secure strategy. An 10.125 Gb/s 64QAM-OFDM data with Logistic mapped chaos scrambling are successfully transmitted over 25-km single mode fiber (SMF), and the experimental results show that proposed security scheme can protect the system from eavesdropper and attacker, while keep a good performance for the legal ONU.

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.

Physical-layer network coding for passive optical interconnect in datacenter networks.

PubMed

Lin, Rui; Cheng, Yuxin; Guan, Xun; Tang, Ming; Liu, Deming; Chan, Chun-Kit; Chen, Jiajia

2017-07-24

We introduce physical-layer network coding (PLNC) technique in a passive optical interconnect (POI) architecture for datacenter networks. The implementation of the PLNC in the POI at 2.5 Gb/s and 10Gb/s have been experimentally validated while the gains in terms of network layer performances have been investigated by simulation. The results reveal that in order to realize negligible packet drop, the wavelengths usage can be reduced by half while a significant improvement in packet delay especially under high traffic load can be achieved by employing PLNC over POI.

An experimental investigation of the flow physics of high-lift systems

NASA Technical Reports Server (NTRS)

Thomas, Flint O.; Nelson, R. C.

1995-01-01

This progress report, a series of viewgraphs, outlines experiments on the flow physics of confluent boundary layers for high lift systems. The design objective is to design high lift systems with improved C(sub Lmax) for landing approach and improved take-off L/D and simultaneously reduce acquisition and maintenance costs. In effect, achieve improved performance with simpler designs. The research objectives include: establish the role of confluent boundary layer flow physics in high-lift production; contrast confluent boundary layer structure for optimum and non-optimum C(sub L) cases; formation of a high quality, detailed archival data base for CFD/modeling; and examination of the role of relaminarization and streamline curvature.

SINET3: advanced optical and IP hybrid network

NASA Astrophysics Data System (ADS)

Urushidani, Shigeo

2007-11-01

This paper introduces the new Japanese academic backbone network called SINET3, which has been in full-scale operation since June 2007. SINET3 provides a wide variety of network services, such as multi-layer transfer, enriched VPN, enhanced QoS, and layer-1 bandwidth on demand (BoD) services to create an innovative and prolific science infrastructure for more than 700 universities and research institutions. The network applies an advanced hybrid network architecture composed of 75 layer-1 switches and 12 high-performance IP routers to accommodate such diversified services in a single network platform, and provides sufficient bandwidth using Japan's first STM256 (40 Gbps) lines. The network adopts lots of the latest networking technologies, such as next-generation SDH (VCAT/GFP/LCAS), GMPLS, advanced MPLS, and logical-router technologies, for high network convergence, flexible resource assignment, and high service availability. This paper covers the network services, network design, and networking technologies of SINET3.

Measuring the benefit of orthophosphate treatment on lead in drinking water.

PubMed

Cardew, P T

2009-03-01

Many water companies are adding low concentrations of orthophosphate to the water supply in order to reduce lead concentrations in drinking water produced from corrosion of lead service pipes. Despite the erratic nature of lead concentrations measured at customer properties it has been possible to quantify the impact of treatment on lead concentrations and thereby quantify the effectiveness of treatment at both a regional and zonal level. This showed that the treatment policy has delivered more than 90 per cent reduction in lead concentrations, and was largely in accordance with theory. Across the region, lead performance and the reduction in lead performance show significant variation. A large part of this variation can be accounted for by variations in the proportion of leaded properties supplied through lead service pipes. Analysis showed that the proportion of particulate lead has also reduced significantly over the last decade. This is attributed to improved mechanical robustness of the corrosion layer caused by changes in its physical structure. This appears to be a very slow process with a natural time-scale of years.

Cloud-based robot remote control system for smart factory

NASA Astrophysics Data System (ADS)

Wu, Zhiming; Li, Lianzhong; Xu, Yang; Zhai, Jingmei

2015-12-01

With the development of internet technologies and the wide application of robots, there is a prospect (trend/tendency) of integration between network and robots. A cloud-based robot remote control system over networks for smart factory is proposed, which enables remote users to control robots and then realize intelligent production. To achieve it, a three-layer system architecture is designed including user layer, service layer and physical layer. Remote control applications running on the cloud server is developed on Microsoft Azure. Moreover, DIV+ CSS technologies are used to design human-machine interface to lower maintenance cost and improve development efficiency. Finally, an experiment is implemented to verify the feasibility of the program.

Sensored Field Oriented Control of a Robust Induction Motor Drive Using a Novel Boundary Layer Fuzzy Controller

PubMed Central

Saghafinia, Ali; Ping, Hew Wooi; Uddin, Mohammad Nasir

2013-01-01

Physical sensors have a key role in implementation of real-time vector control for an induction motor (IM) drive. This paper presents a novel boundary layer fuzzy controller (NBLFC) based on the boundary layer approach for speed control of an indirect field-oriented control (IFOC) of an induction motor (IM) drive using physical sensors. The boundary layer approach leads to a trade-off between control performances and chattering elimination. For the NBLFC, a fuzzy system is used to adjust the boundary layer thickness to improve the tracking performance and eliminate the chattering problem under small uncertainties. Also, to eliminate the chattering under the possibility of large uncertainties, the integral filter is proposed inside the variable boundary layer. In addition, the stability of the system is analyzed through the Lyapunov stability theorem. The proposed NBLFC based IM drive is implemented in real-time using digital signal processor (DSP) board TI TMS320F28335. The experimental and simulation results show the effectiveness of the proposed NBLFC based IM drive at different operating conditions.

Method for making oxygen-reducing catalyst layers

DOEpatents

O'Brien, Dennis P.; Schmoeckel, Alison K.; Vernstrom, George D.; Atanasoski, Radoslav; Wood, Thomas E.; O'Neill, David G.

2010-06-22

Methods are provided for making oxygen-reducing catalyst layers, which include simultaneous or sequential stops of physical vapor depositing an oxygen-reducing catalytic material onto a substrate, the catalytic material comprising a transition metal that is substantially free of platinum; and thermally treating the catalytic material. At least one of the physical vapor deposition and the thermal treatment is performed in a processing environment comprising a nitrogen-containing gas.

The Physical Layer Security Experiments of Cooperative Communication System with Different Relay Behaviors.

PubMed

Su, Yishan; Han, Guangyao; Fu, Xiaomei; Xu, Naishen; Jin, Zhigang

2017-04-06

Physical layer security is an attractive security mechanism, which exploits the randomness characteristics of wireless transmission channel to achieve security. However, it is hampered by the limitation of the channel condition that the main channel must be better than the eavesdropper channel. To alleviate the limitation, cooperative communication is introduced. Few studies have investigated the physical layer security of the relay transmission model. In this paper, we performed some experiments to evaluate the physical layer security of a cooperative communication system, with a relay operating in decode-and-forward (DF) cooperative mode, selfish and malicious behavior in real non-ideal transmission environment. Security performance is evaluated in terms of the probability of non-zero secrecy capacity. Experiments showed some different results compared to theoretical simulation: (1) to achieve the maximum secrecy capacity, the optimal relay power according to the experiments result is larger than that of ideal theoretical results under both cooperative and selfish behavior relay; (2) the relay in malicious behavior who forwards noise to deteriorate the main channel may deteriorate the eavesdropper channel more seriously than the main channel; (3) the optimal relay positions under cooperative and selfish behavior relay cases are both located near the destination because of non-ideal transmission.

Nano-TiO2 decorated carbon coating on the separator to physically and chemically suppress the shuttle effect for lithium-sulfur battery

NASA Astrophysics Data System (ADS)

Shao, Hongyuan; Wang, Weikun; Zhang, Hao; Wang, Anbang; Chen, Xiaonong; Huang, Yaqin

2018-02-01

Despite recent progress in designing modified separators for lithium-sulfur (Li-S) batteries, detail in optimizing the synergistic effect between chemical and physical immobilization for lithium polysulfides (LiPS) in modified separator hasn't been investigated totally. Here, a nano-TiO2 decorated carbon layer (T-DCL) has been successfully applied to modify separator for the Li-S battery. The results indicate that appropriate weight percentage of nano-TiO2 uniformly distributed in conductive carbon layer is effective to chemically and physically immobilize for LiPS, and promote the electron transfer during discharge/charge process. The performance of the modified Li-S battery with T-DCL separator are significantly enhanced, with a specific capacity of 883 mAh g-1 retained after 180 cycles at 0.1 C and 762 mAh g-1 retained after 200 cycles at 0.5C, which are much higher than that of separators only coated with TiO2 layer or conductive carbon layer. Besides, the separator coated with T-DCL also shows low electrochemical impedance and good lithium anode protection. These results indicate that separator with T-DCL is promising to balance the physical and chemical LiPS trapping effect, and optimize the electrochemical performance for Li-S battery.

Modeling socio-cultural processes in network-centric environments

NASA Astrophysics Data System (ADS)

Santos, Eunice E.; Santos, Eugene, Jr.; Korah, John; George, Riya; Gu, Qi; Kim, Keumjoo; Li, Deqing; Russell, Jacob; Subramanian, Suresh

2012-05-01

The major focus in the field of modeling & simulation for network centric environments has been on the physical layer while making simplifications for the human-in-the-loop. However, the human element has a big impact on the capabilities of network centric systems. Taking into account the socio-behavioral aspects of processes such as team building, group decision-making, etc. are critical to realistically modeling and analyzing system performance. Modeling socio-cultural processes is a challenge because of the complexity of the networks, dynamism in the physical and social layers, feedback loops and uncertainty in the modeling data. We propose an overarching framework to represent, model and analyze various socio-cultural processes within network centric environments. The key innovation in our methodology is to simultaneously model the dynamism in both the physical and social layers while providing functional mappings between them. We represent socio-cultural information such as friendships, professional relationships and temperament by leveraging the Culturally Infused Social Network (CISN) framework. The notion of intent is used to relate the underlying socio-cultural factors to observed behavior. We will model intent using Bayesian Knowledge Bases (BKBs), a probabilistic reasoning network, which can represent incomplete and uncertain socio-cultural information. We will leverage previous work on a network performance modeling framework called Network-Centric Operations Performance and Prediction (N-COPP) to incorporate dynamism in various aspects of the physical layer such as node mobility, transmission parameters, etc. We validate our framework by simulating a suitable scenario, incorporating relevant factors and providing analyses of the results.

A Novel Physical Layer Assisted Authentication Scheme for Mobile Wireless Sensor Networks

PubMed Central

Wang, Qiuhua

2017-01-01

Physical-layer authentication can address physical layer vulnerabilities and security threats in wireless sensor networks, and has been considered as an effective complementary enhancement to existing upper-layer authentication mechanisms. In this paper, to advance the existing research and improve the authentication performance, we propose a novel physical layer assisted authentication scheme for mobile wireless sensor networks. In our proposed scheme, we explore the reciprocity and spatial uncorrelation of the wireless channel to verify the identities of involved transmitting users and decide whether all data frames are from the same sender. In our proposed scheme, a new method is developed for the legitimate users to compare their received signal strength (RSS) records, which avoids the information from being disclosed to the adversary. Our proposed scheme can detect the spoofing attack even in a high dynamic environment. We evaluate our scheme through experiments under indoor and outdoor environments. Experiment results show that our proposed scheme is more efficient and achieves a higher detection rate as well as keeping a lower false alarm rate. PMID:28165423

A Novel Physical Layer Assisted Authentication Scheme for Mobile Wireless Sensor Networks.

PubMed

Wang, Qiuhua

2017-02-04

Physical-layer authentication can address physical layer vulnerabilities and security threats in wireless sensor networks, and has been considered as an effective complementary enhancement to existing upper-layer authentication mechanisms. In this paper, to advance the existing research and improve the authentication performance, we propose a novel physical layer assisted authentication scheme for mobile wireless sensor networks. In our proposed scheme, we explore the reciprocity and spatial uncorrelation of the wireless channel to verify the identities of involved transmitting users and decide whether all data frames are from the same sender. In our proposed scheme, a new method is developed for the legitimate users to compare their received signal strength (RSS) records, which avoids the information from being disclosed to the adversary. Our proposed scheme can detect the spoofing attack even in a high dynamic environment. We evaluate our scheme through experiments under indoor and outdoor environments. Experiment results show that our proposed scheme is more efficient and achieves a higher detection rate as well as keeping a lower false alarm rate.

Perspectives of IT Professionals on Employing Server Virtualization Technologies

ERIC Educational Resources Information Center

Sligh, Darla

2010-01-01

Server virtualization enables a physical computer to support multiple applications logically by decoupling the application from the hardware layer, thereby reducing operational costs and competitive in delivering IT services to their enterprise organizations. IT organizations continually examine the efficiency of their internal IT systems and…

42 CFR 484.32 - Condition of participation: Therapy services.

Code of Federal Regulations, 2012 CFR

2012-10-01

... occupational therapist. A physical therapy assistant or occupational therapy assistant performs services... under arrangement are given by a qualified therapist or by a qualified therapy assistant under the... personnel, and participates in in-service programs. (a) Standard: Supervision of physical therapy assistant...

42 CFR 484.32 - Condition of participation: Therapy services.

Code of Federal Regulations, 2014 CFR

2014-10-01

... occupational therapist. A physical therapy assistant or occupational therapy assistant performs services... under arrangement are given by a qualified therapist or by a qualified therapy assistant under the... personnel, and participates in in-service programs. (a) Standard: Supervision of physical therapy assistant...

42 CFR 484.32 - Condition of participation: Therapy services.

Code of Federal Regulations, 2013 CFR

2013-10-01

... occupational therapist. A physical therapy assistant or occupational therapy assistant performs services... under arrangement are given by a qualified therapist or by a qualified therapy assistant under the... personnel, and participates in in-service programs. (a) Standard: Supervision of physical therapy assistant...

Improving the Performance of PbS Quantum Dot Solar Cells by Optimizing ZnO Window Layer

NASA Astrophysics Data System (ADS)

Yang, Xiaokun; Hu, Long; Deng, Hui; Qiao, Keke; Hu, Chao; Liu, Zhiyong; Yuan, Shengjie; Khan, Jahangeer; Li, Dengbing; Tang, Jiang; Song, Haisheng; Cheng, Chun

2017-04-01

Comparing with hot researches in absorber layer, window layer has attracted less attention in PbS quantum dot solar cells (QD SCs). Actually, the window layer plays a key role in exciton separation, charge drifting, and so on. Herein, ZnO window layer was systematically investigated for its roles in QD SCs performance. The physical mechanism of improved performance was also explored. It was found that the optimized ZnO films with appropriate thickness and doping concentration can balance the optical and electrical properties, and its energy band align well with the absorber layer for efficient charge extraction. Further characterizations demonstrated that the window layer optimization can help to reduce the surface defects, improve the heterojunction quality, as well as extend the depletion width. Compared with the control devices, the optimized devices have obtained an efficiency of 6.7% with an enhanced V oc of 18%, J sc of 21%, FF of 10%, and power conversion efficiency of 58%. The present work suggests a useful strategy to improve the device performance by optimizing the window layer besides the absorber layer.

A game-theoretic method for cross-layer stochastic resilient control design in CPS

NASA Astrophysics Data System (ADS)

Shen, Jiajun; Feng, Dongqin

2018-03-01

In this paper, the cross-layer security problem of cyber-physical system (CPS) is investigated from the game-theoretic perspective. Physical dynamics of plant is captured by stochastic differential game with cyber-physical influence being considered. The sufficient and necessary condition for the existence of state-feedback equilibrium strategies is given. The attack-defence cyber interactions are formulated by a Stackelberg game intertwined with stochastic differential game in physical layer. The condition such that the Stackelberg equilibrium being unique and the corresponding analytical solutions are both provided. An algorithm is proposed for obtaining hierarchical security strategy by solving coupled games, which ensures the operational normalcy and cyber security of CPS subject to uncertain disturbance and unexpected cyberattacks. Simulation results are given to show the effectiveness and performance of the proposed algorithm.

Metaworkflows and Workflow Interoperability for Heliophysics

NASA Astrophysics Data System (ADS)

Pierantoni, Gabriele; Carley, Eoin P.

2014-06-01

Heliophysics is a relatively new branch of physics that investigates the relationship between the Sun and the other bodies of the solar system. To investigate such relationships, heliophysicists can rely on various tools developed by the community. Some of these tools are on-line catalogues that list events (such as Coronal Mass Ejections, CMEs) and their characteristics as they were observed on the surface of the Sun or on the other bodies of the Solar System. Other tools offer on-line data analysis and access to images and data catalogues. During their research, heliophysicists often perform investigations that need to coordinate several of these services and to repeat these complex operations until the phenomena under investigation are fully analyzed. Heliophysicists combine the results of these services; this service orchestration is best suited for workflows. This approach has been investigated in the HELIO project. The HELIO project developed an infrastructure for a Virtual Observatory for Heliophysics and implemented service orchestration using TAVERNA workflows. HELIO developed a set of workflows that proved to be useful but lacked flexibility and re-usability. The TAVERNA workflows also needed to be executed directly in TAVERNA workbench, and this forced all users to learn how to use the workbench. Within the SCI-BUS and ER-FLOW projects, we have started an effort to re-think and re-design the heliophysics workflows with the aim of fostering re-usability and ease of use. We base our approach on two key concepts, that of meta-workflows and that of workflow interoperability. We have divided the produced workflows in three different layers. The first layer is Basic Workflows, developed both in the TAVERNA and WS-PGRADE languages. They are building blocks that users compose to address their scientific challenges. They implement well-defined Use Cases that usually involve only one service. The second layer is Science Workflows usually developed in TAVERNA. They- implement Science Cases (the definition of a scientific challenge) by composing different Basic Workflows. The third and last layer,Iterative Science Workflows, is developed in WSPGRADE. It executes sub-workflows (either Basic or Science Workflows) as parameter sweep jobs to investigate Science Cases on large multiple data sets. So far, this approach has proven fruitful for three Science Cases of which one has been completed and two are still being tested.

Physical criteria for the interface passivation layer in hydrogenated amorphous/crystalline silicon heterojunction solar cell

NASA Astrophysics Data System (ADS)

Zhao, Lei; Wang, Guanghong; Diao, Hongwei; Wang, Wenjing

2018-01-01

AFORS-HET (automat for simulation of heterostructures) simulation was utilized to explore the physical criteria for the passivation layer in hydrogenated amorphous/crystalline silicon heterojunction (SHJ) solar cells, by systematically investigating the solar cell current density-voltage (J-V) performance as a function of the interface defect density (D it) at the passivation layer/c-Si hetero-interface, the thickness (t) of the passivation layer, the bandgap (E g) of the passivation layer, and the density of dangling bond states (D db)/band tail states (D bt) in the band gap of the passivation layer. The corresponding impact regulations were presented clearly. Except for D it, the impacts of D db, D bt and E g are strongly dependent on the passivation layer thickness t. While t is smaller than 4-5 nm, the solar cell performance is less sensitive to the variation of D db, D bt and E g. Low D it at the a-Si:H/c-Si interface and small thickness t are the critical criteria for the passivation layer in such a case. However, if t has to be relatively larger, the microstructure, i.e. the material quality, including D db, D bt and E g, of the passivation layer should be controlled carefully. The mechanisms involved were analyzed and some applicable methods to prepare the passivation layer were proposed.

Enhanced AIS receiver design for satellite reception

NASA Astrophysics Data System (ADS)

Clazzer, Federico; Lázaro, Francisco; Plass, Simon

2016-12-01

The possibility to detect Automatic Identification System (AIS) messages from low earth orbit (LEO) satellites paves the road for a plurality of new and unexplored services. Besides worldwide tracking of vessels, maritime traffic monitoring, analysis of vessel routes employing big data, and oceans monitoring are just few of the fields, where satellite-aided AIS is beneficial. Designed for ship-to-ship communication and collision avoidance, AIS satellite reception performs poorly in regions with a high density of vessels. This calls for the development of advanced satellite AIS receivers able to improve the decoding capabilities. In this context, our contribution focuses on the introduction of a new enhanced AIS receiver design and its performance evaluation. The enhanced receiver makes use of a coherent receiver for the low signal-to-noise ratio (SNR) region, while for medium to high SNRs, a differential Viterbi receiver is used. Additional novelty of our work is in the exploitation of previously decoded packets from one vessel that is still under the LEO reception range, to improve the vessel detection probability. The assessment of the performance against a common receiver is done making the use of a simple and tight model of the medium access (MAC) layer and the multi-packet reception (MPR) matrix for physical layer (PHY) representation. Performance results show the benefits of such enhanced receiver, especially when it is bundled with successive interference cancellation (SIC).

Process Development for Reactive-Ion Etching of Molybdenum Disulfide (MoS2) Utilizing a Poly(methyl methacrylate) (PMMA) Etch Mask

DTIC Science & Technology

2017-10-01

Mazzoni Oak Ridge Associated Universities (ORAU) Maryland, Belcamp, MD Robert A Burke General Technical Services , LLC, Wall Township, NJ Barbara M...of this collection of information, including suggestions for reducing the burden, to Department of Defense, Washington Headquarters Services ...solvent, or sonication. However, by using these physical procedures, there is a larger risk that the quality and structural integrity of the 2-D layer may

Nanostructure multilayer dielectric materials for capacitors and insulators

DOEpatents

Barbee, Jr., Troy W.; Johnson, Gary W.

1998-04-21

A capacitor is formed of at least two metal conductors having a multilayer dielectric and opposite dielectric-conductor interface layers in between. The multilayer dielectric includes many alternating layers of amorphous zirconium oxide (ZrO.sub.2) and alumina (Al.sub.2 O.sub.3). The dielectric-conductor interface layers are engineered for increased voltage breakdown and extended service life. The local interfacial work function is increased to reduce charge injection and thus increase breakdown voltage. Proper material choices can prevent electrochemical reactions and diffusion between the conductor and dielectric. Physical vapor deposition is used to deposit the zirconium oxide (ZrO.sub.2) and alumina (Al.sub.2 O.sub.3) in alternating layers to form a nano-laminate.

Nanostructure multilayer dielectric materials for capacitors and insulators

DOEpatents

Barbee, T.W. Jr.; Johnson, G.W.

1998-04-21

A capacitor is formed of at least two metal conductors having a multilayer dielectric and opposite dielectric-conductor interface layers in between. The multilayer dielectric includes many alternating layers of amorphous zirconium oxide (ZrO{sub 2}) and alumina (Al{sub 2}O{sub 3}). The dielectric-conductor interface layers are engineered for increased voltage breakdown and extended service life. The local interfacial work function is increased to reduce charge injection and thus increase breakdown voltage. Proper material choices can prevent electrochemical reactions and diffusion between the conductor and dielectric. Physical vapor deposition is used to deposit the zirconium oxide (ZrO{sub 2}) and alumina (Al{sub 2}O{sub 3}) in alternating layers to form a nano-laminate. 1 fig.

Numerical and experimental study of the effects of the electrical resistance and diffusivity under clamping pressure on the performance of a metallic gas-diffusion layer in polymer electrolyte fuel cells

NASA Astrophysics Data System (ADS)

Tanaka, Shiro; Bradfield, Warwick W.; Legrand, Cloe; Malan, Arnaud G.

2016-10-01

The performance of a perforated metal-sheet gas-diffusion layer incorporated with a microporous layer in a fuel cell is evaluated with fine-pitch channel/land designs for the gas flow field on a bipolar plate. The combination of metal-sheet gas-diffusion layer and microporous layer exhibits significant performance without a large flooding effect. When comparing the performance with wider and narrower land cases, the land width affects the performance. To investigate the roles of the microporous layer, land width, etc. in the fuel cell with the metal-sheet gas-diffusion layer, a single-phase, isothermal, and multi-physics simulation is developed and coupled with electrical, mechanical, electrochemical and fluid dynamics factors. The simulated current-voltage performance is then compared to the experimentally measure performance. These are shown to be in good agreement apart for very high current-density cases i.e. greater than 1.5 A cm-2. This is due the flooding effect predominantly appearing. It is further demonstrated that the microporous layer serves as the key component in facilitating gas diffusion and for preventing flooding. Furthermore, the pressure is found to have a strong impact on the performance, affecting the gas diffusion and electric resistance around the microporous layer.

Assessment of mixed-layer height estimation from single-wavelength ceilometer profiles

EPA Science Inventory

Differing boundary/mixed-layer height measurement methods were assessed in moderately polluted and clean environments, with a focus on the Vaisala CL51 ceilometer. This intercomparison was performed as part of ongoing measurements at the Chemistry And Physics of the Atmospheric B...

Analytical approach to cross-layer protocol optimization in wireless sensor networks

NASA Astrophysics Data System (ADS)

Hortos, William S.

2008-04-01

In the distributed operations of route discovery and maintenance, strong interaction occurs across mobile ad hoc network (MANET) protocol layers. Quality of service (QoS) requirements of multimedia service classes must be satisfied by the cross-layer protocol, along with minimization of the distributed power consumption at nodes and along routes to battery-limited energy constraints. In previous work by the author, cross-layer interactions in the MANET protocol are modeled in terms of a set of concatenated design parameters and associated resource levels by multivariate point processes (MVPPs). Determination of the "best" cross-layer design is carried out using the optimal control of martingale representations of the MVPPs. In contrast to the competitive interaction among nodes in a MANET for multimedia services using limited resources, the interaction among the nodes of a wireless sensor network (WSN) is distributed and collaborative, based on the processing of data from a variety of sensors at nodes to satisfy common mission objectives. Sensor data originates at the nodes at the periphery of the WSN, is successively transported to other nodes for aggregation based on information-theoretic measures of correlation and ultimately sent as information to one or more destination (decision) nodes. The "multimedia services" in the MANET model are replaced by multiple types of sensors, e.g., audio, seismic, imaging, thermal, etc., at the nodes; the QoS metrics associated with MANETs become those associated with the quality of fused information flow, i.e., throughput, delay, packet error rate, data correlation, etc. Significantly, the essential analytical approach to MANET cross-layer optimization, now based on the MVPPs for discrete random events occurring in the WSN, can be applied to develop the stochastic characteristics and optimality conditions for cross-layer designs of sensor network protocols. Functional dependencies of WSN performance metrics are described in terms of the concatenated protocol parameters. New source-to-destination routes are sought that optimize cross-layer interdependencies to achieve the "best available" performance in the WSN. The protocol design, modified from a known reactive protocol, adapts the achievable performance to the transient network conditions and resource levels. Control of network behavior is realized through the conditional rates of the MVPPs. Optimal cross-layer protocol parameters are determined by stochastic dynamic programming conditions derived from models of transient packetized sensor data flows. Moreover, the defining conditions for WSN configurations, grouping sensor nodes into clusters and establishing data aggregation at processing nodes within those clusters, lead to computationally tractable solutions to the stochastic differential equations that describe network dynamics. Closed-form solution characteristics provide an alternative to the "directed diffusion" methods for resource-efficient WSN protocols published previously by other researchers. Performance verification of the resulting cross-layer designs is found by embedding the optimality conditions for the protocols in actual WSN scenarios replicated in a wireless network simulation environment. Performance tradeoffs among protocol parameters remain for a sequel to the paper.

Direct Simulations of Coupled Transport and Reaction on Nano-Scale X-Ray Computed Tomography Images of Platinum Group Metal-Free Catalyst Cathodes

DOE PAGES

Ogawa, S.; Komini Babu, S.; Chung, H. T.; ...

2016-08-22

The nano/micro-scale geometry of polymer electrolyte fuel cell (PEFC) catalyst layers critically affects cell performance. The small length scales and complex structure of these composite layers make it challenging to analyze cell performance and physics at the particle scale by experiment. We present a computational method to simulate transport and chemical reaction phenomena at the pore/particle-scale and apply it to a PEFC cathode with platinum group metal free (PGM-free) catalyst. Here, we numerically solve the governing equations for the physics with heterogeneous oxygen diffusion coefficient and proton conductivity evaluated using the actual electrode structure and ionomer distribution obtained using nano-scalemore » resolution X-ray computed tomography (nano-CT). Using this approach, the oxygen concentration and electrolyte potential distributions imposed by the oxygen reduction reaction are solved and the impact of the catalyst layer structure on performance is evaluated.« less

Direct Simulations of Coupled Transport and Reaction on Nano-Scale X-Ray Computed Tomography Images of Platinum Group Metal-Free Catalyst Cathodes

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

Ogawa, S.; Komini Babu, S.; Chung, H. T.

The nano/micro-scale geometry of polymer electrolyte fuel cell (PEFC) catalyst layers critically affects cell performance. The small length scales and complex structure of these composite layers make it challenging to analyze cell performance and physics at the particle scale by experiment. We present a computational method to simulate transport and chemical reaction phenomena at the pore/particle-scale and apply it to a PEFC cathode with platinum group metal free (PGM-free) catalyst. Here, we numerically solve the governing equations for the physics with heterogeneous oxygen diffusion coefficient and proton conductivity evaluated using the actual electrode structure and ionomer distribution obtained using nano-scalemore » resolution X-ray computed tomography (nano-CT). Using this approach, the oxygen concentration and electrolyte potential distributions imposed by the oxygen reduction reaction are solved and the impact of the catalyst layer structure on performance is evaluated.« less

High-resolution, low-delay, and error-resilient medical ultrasound video communication using H.264/AVC over mobile WiMAX networks.

PubMed

Panayides, Andreas; Antoniou, Zinonas C; Mylonas, Yiannos; Pattichis, Marios S; Pitsillides, Andreas; Pattichis, Constantinos S

2013-05-01

In this study, we describe an effective video communication framework for the wireless transmission of H.264/AVC medical ultrasound video over mobile WiMAX networks. Medical ultrasound video is encoded using diagnostically-driven, error resilient encoding, where quantization levels are varied as a function of the diagnostic significance of each image region. We demonstrate how our proposed system allows for the transmission of high-resolution clinical video that is encoded at the clinical acquisition resolution and can then be decoded with low-delay. To validate performance, we perform OPNET simulations of mobile WiMAX Medium Access Control (MAC) and Physical (PHY) layers characteristics that include service prioritization classes, different modulation and coding schemes, fading channels conditions, and mobility. We encode the medical ultrasound videos at the 4CIF (704 × 576) resolution that can accommodate clinical acquisition that is typically performed at lower resolutions. Video quality assessment is based on both clinical (subjective) and objective evaluations.

Dynamic VMs placement for energy efficiency by PSO in cloud computing

NASA Astrophysics Data System (ADS)

Dashti, Seyed Ebrahim; Rahmani, Amir Masoud

2016-03-01

Recently, cloud computing is growing fast and helps to realise other high technologies. In this paper, we propose a hieratical architecture to satisfy both providers' and consumers' requirements in these technologies. We design a new service in the PaaS layer for scheduling consumer tasks. In the providers' perspective, incompatibility between specification of physical machine and user requests in cloud leads to problems such as energy-performance trade-off and large power consumption so that profits are decreased. To guarantee Quality of service of users' tasks, and reduce energy efficiency, we proposed to modify Particle Swarm Optimisation to reallocate migrated virtual machines in the overloaded host. We also dynamically consolidate the under-loaded host which provides power saving. Simulation results in CloudSim demonstrated that whatever simulation condition is near to the real environment, our method is able to save as much as 14% more energy and the number of migrations and simulation time significantly reduces compared with the previous works.

156 Mbps Ultrahigh-Speed Wireless LAN Prototype in the 38 GHz Band

NASA Astrophysics Data System (ADS)

Wu, Gang; Inoue, Masugi; Murakami, Homare; Hase, Yoshihiro

2001-12-01

This paper describes a 156 Mbps ultrahigh-speed wireless LAN operating in the 38 GHz millimeter (mm)-wave band. The system is a third prototype developed at the Communications Research Laboratory since 1998. Compared with the previous prototypes, the system is faster (156 Mbps) and smaller (volume of radio transceiver less than 1000 cc), it has a larger service area (two overlapping basic service sets), and a longer transmission distance (the protocol can support a distance of more than two hundred meters). The development is focused on the physical layer and the data link control layer, and thus a GMSK-based mm-wave transceiver and an enhanced RS-ISMA (reservation-based slotted idle signal multiple access) protocol are key development components. This paper describes the prototype system's design, configuration, and implementation.

Organic field effect transistors - Study of performance parameters for different dielectric layer thickness

NASA Astrophysics Data System (ADS)

Assis, Anu; Shahul Hameed T., A.; Predeep, P.

2017-06-01

Mobility and current handling capabilities of Organic Field Effect Transistor (OFET) are vitally important parameters in the electrical performance where the material parameters and thickness of different layers play significant role. In this paper, we report the simulation of an OFET using multi physics tool, where the active layer is pentacene and Poly Methyl Methacrylate (PMMA) forms the dielectric. Electrical characterizations of the OFET on varying the thickness of the dielectric layer from 600nm to 400nm are simulated and drain current, transconductance and mobility are analyzed. In the study it is found that even though capacitance increases with reduction in dielectric layer thickness, the transconductance effect is reflected many more times in the mobility which in turn could be attributed to the variations in transverse electric field. The layer thickness below 300nm may result in gate leakage current points to the requirement of optimizing the thickness of different layers for better performance.

The Physical Activities Survey of Police Officers in New Jersey. Final Report.

ERIC Educational Resources Information Center

Goldstein, Leo S.

A survey of the physical activities of police officers in New Jersey was conducted to collect information about the kinds of physical activities they perform, their present health status, the measures they take to maintain good physical condition, and their appraisal of the present civil service physical performance test battery. Another purpose…

Local-Area-Network Simulator

NASA Technical Reports Server (NTRS)

Gibson, Jim; Jordan, Joe; Grant, Terry

1990-01-01

Local Area Network Extensible Simulator (LANES) computer program provides method for simulating performance of high-speed local-area-network (LAN) technology. Developed as design and analysis software tool for networking computers on board proposed Space Station. Load, network, link, and physical layers of layered network architecture all modeled. Mathematically models according to different lower-layer protocols: Fiber Distributed Data Interface (FDDI) and Star*Bus. Written in FORTRAN 77.

Correlation of phonatory behavior with vocal fold structure, observed in a physical model

NASA Astrophysics Data System (ADS)

Krane, Michael; Walters, Gage; McPhail, Michael

2017-11-01

The effect of vocal fold shape and internal structure on phonation was studied experimentally using a physical model of the human airway. Model folds used a ``M5'' or a swept ellipse coronal cross-section shape. Models were molded in either 2 or three layers. Two-layer models included a more stiff ``body'' layer and a much softer ``cover'' layer, while the 3-layer models also incorporated an additional, thin, ``ligament/conus'' layer stiffer than the body layer. The elliptical section models were all molded in 3 such layers. Measurements of transglottal pressure, volume flow, mouth sound pressure, and high-speed imaging of vocal fold vibration were performed. These show that models with the ``ligament'' layer experienced much attenuated vertical deformation, that glottal closure was more likely, and that phonation was much easier to initiate. These findings suggest that the combination of the vocal ligament and the conus elasticus stabilize the vocal fold for efficient phonation by limiting vertical deformation, while allowing transverse deformations to occur. Acknowledge support from NIH DC R01005642-11.

Analysis of pre-service physics teacher skills designing simple physics experiments based technology

NASA Astrophysics Data System (ADS)

Susilawati; Huda, C.; Kurniawan, W.; Masturi; Khoiri, N.

2018-03-01

Pre-service physics teacher skill in designing simple experiment set is very important in adding understanding of student concept and practicing scientific skill in laboratory. This study describes the skills of physics students in designing simple experiments based technologicall. The experimental design stages include simple tool design and sensor modification. The research method used is descriptive method with the number of research samples 25 students and 5 variations of simple physics experimental design. Based on the results of interviews and observations obtained the results of pre-service physics teacher skill analysis in designing simple experimental physics charged technology is good. Based on observation result, pre-service physics teacher skill in designing simple experiment is good while modification and sensor application are still not good. This suggests that pre-service physics teacher still need a lot of practice and do experiments in designing physics experiments using sensor modifications. Based on the interview result, it is found that students have high enough motivation to perform laboratory activities actively and students have high curiosity to be skilled at making simple practicum tool for physics experiment.

Performance of Chemically Treated Jute Geotextile in Unpaved Roads at Different in situ Conditions

NASA Astrophysics Data System (ADS)

Midha, Vinay Kumar; Joshi, Shubham; Suresh Kumar, S.

2017-06-01

Biodegradable jute geotextiles are an effective reinforcing material for unpaved roads, but its serviceability is limited because of faster microbial degradation. Different methods are in use to improve the serviceability of jute geotextiles. In this paper, influence of chemical treatment (transesterification and bitumen coating), road design and rainfall intensity on the time dependent serviceability of jute geotextiles has been studied. Chemically treated jute geotextiles, were laid in unpaved road designs with and without sand layer, for 30, 60 and 90 days' duration, and subjected to simulated rainfall intensities of 50 and 100 mm/h. With increase in time of usage, tensile strength and puncture resistance decrease due to microbial attack, and pore size decreases due to clogging of soil in jute geotextiles. Chemical treatment was observed to have greater influence on the serviceability, followed by the presence of sand layer in road design and the rainfall intensity. Further, overall performance of bitumen coated jute geotextiles was observed to be better than transesterified jute geotextile, due to its hydrophobic nature.

Vulnerability of water supply systems to cyber-physical attacks

NASA Astrophysics Data System (ADS)

Galelli, Stefano; Taormina, Riccardo; Tippenhauer, Nils; Salomons, Elad; Ostfeld, Avi

2016-04-01

The adoption of smart meters, distributed sensor networks and industrial control systems has largely improved the level of service provided by modern water supply systems. Yet, the progressive computerization exposes these critical infrastructures to cyber-physical attacks, which are generally aimed at stealing critical information (cyber-espionage) or causing service disruption (denial-of-service). Recent statistics show that water and power utilities are undergoing frequent attacks - such as the December power outage in Ukraine - , attracting the interest of operators and security agencies. Taking the security of Water Distribution Networks (WDNs) as domain of study, our work seeks to characterize the vulnerability of WDNs to cyber-physical attacks, so as to conceive adequate defense mechanisms. We extend the functionality of EPANET, which models hydraulic and water quality processes in pressurized pipe networks, to include a cyber layer vulnerable to repeated attacks. Simulation results on a medium-scale network show that several hydraulic actuators (valves and pumps, for example) can be easily attacked, causing both service disruption - i.e., water spillage and loss of pressure - and structural damages - e.g., pipes burst. Our work highlights the need for adequate countermeasures, such as attacks detection and reactive control systems.

Physical employment standards for U.K. fire and rescue service personnel.

PubMed

Blacker, S D; Rayson, M P; Wilkinson, D M; Carter, J M; Nevill, A M; Richmond, V L

2016-01-01

Evidence-based physical employment standards are vital for recruiting, training and maintaining the operational effectiveness of personnel in physically demanding occupations. (i) Develop criterion tests for in-service physical assessment, which simulate the role-related physical demands of UK fire and rescue service (UK FRS) personnel. (ii) Develop practical physical selection tests for FRS applicants. (iii) Evaluate the validity of the selection tests to predict criterion test performance. Stage 1: we conducted a physical demands analysis involving seven workshops and an expert panel to document the key physical tasks required of UK FRS personnel and to develop 'criterion' and 'selection' tests. Stage 2: we measured the performance of 137 trainee and 50 trained UK FRS personnel on selection, criterion and 'field' measures of aerobic power, strength and body size. Statistical models were developed to predict criterion test performance. Stage 3: matter experts derived minimum performance standards. We developed single person simulations of the key physical tasks required of UK FRS personnel as criterion and selection tests (rural fire, domestic fire, ladder lift, ladder extension, ladder climb, pump assembly, enclosed space search). Selection tests were marginally stronger predictors of criterion test performance (r = 0.88-0.94, 95% Limits of Agreement [LoA] 7.6-14.0%) than field test scores (r = 0.84-0.94, 95% LoA 8.0-19.8%) and offered greater face and content validity and more practical implementation. This study outlines the development of role-related, gender-free physical employment tests for the UK FRS, which conform to equal opportunities law. © The Author 2015. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Low back pain during military service predicts low back pain later in life.

PubMed

Mattila, Ville M; Kyröläinen, Heikki; Santtila, Matti; Pihlajamäki, Harri

2017-01-01

The aim of the present study was to assess associations between physician diagnosed unspecified low back pain (LBP) during compulsory military service and self-reported LBP and physical fitness measured on average four years after military service. From a total of 1155 persons who had been pass medical examination for military service and who had completed physically demanding military training between 1997 and 2007, 778 men participated in a refresher military training course and physical tests. In this study, the association between LBP during military service and LBP in later life in addition to the association between LBP and physical fitness were examined. A total of 219 out of 778 participants (28%) had visited a physician due to some musculoskeletal symptom (ICD-10 M-diagnosis) during their military service. Seventy-four participants (9.5%) had visited a physician due to unspecified LBP during their service, and 41 (5.3%) had temporarily been absent from duty due to LBP. At the follow-up examination, 122 (15.7%) had reported LBP during the past month. LBP during military service was associated with self-reported LBP in the follow-up (p = 0.004). Of those who had been absent from duty due to LBP during their military service, 13 (31.7%) reported LBP during the past month. In risk factor analysis, no initial health behaviour and physical performance variables were associated with baseline LBP in the follow-up. The main finding of the present study was that unspecified LBP during military service predicts LBP in later life. On the basis of previous literature, it is also known that LBP is a common symptom and thus, one cannot expect to be symptomless the entire life. Interestingly, none of the health behaviours nor the physical performance studied in the follow-up were associated with baseline LBP. It appears that individuals prone to LBP have symptoms during physically demanding military service and also later in their life.

Low back pain during military service predicts low back pain later in life

PubMed Central

Mattila, Ville M.; Kyröläinen, Heikki; Santtila, Matti; Pihlajamäki, Harri

2017-01-01

The aim of the present study was to assess associations between physician diagnosed unspecified low back pain (LBP) during compulsory military service and self-reported LBP and physical fitness measured on average four years after military service. From a total of 1155 persons who had been pass medical examination for military service and who had completed physically demanding military training between 1997 and 2007, 778 men participated in a refresher military training course and physical tests. In this study, the association between LBP during military service and LBP in later life in addition to the association between LBP and physical fitness were examined. A total of 219 out of 778 participants (28%) had visited a physician due to some musculoskeletal symptom (ICD-10 M-diagnosis) during their military service. Seventy-four participants (9.5%) had visited a physician due to unspecified LBP during their service, and 41 (5.3%) had temporarily been absent from duty due to LBP. At the follow-up examination, 122 (15.7%) had reported LBP during the past month. LBP during military service was associated with self-reported LBP in the follow-up (p = 0.004). Of those who had been absent from duty due to LBP during their military service, 13 (31.7%) reported LBP during the past month. In risk factor analysis, no initial health behaviour and physical performance variables were associated with baseline LBP in the follow-up. The main finding of the present study was that unspecified LBP during military service predicts LBP in later life. On the basis of previous literature, it is also known that LBP is a common symptom and thus, one cannot expect to be symptomless the entire life. Interestingly, none of the health behaviours nor the physical performance studied in the follow-up were associated with baseline LBP. It appears that individuals prone to LBP have symptoms during physically demanding military service and also later in their life. PMID:28282419

Caching strategies for improving performance of web-based Geographic applications

NASA Astrophysics Data System (ADS)

Liu, M.; Brodzik, M.; Collins, J. A.; Lewis, S.; Oldenburg, J.

2012-12-01

The NASA Operation IceBridge mission collects airborne remote sensing measurements to bridge the gap between NASA's Ice, Cloud and Land Elevation Satellite (ICESat) mission and the upcoming ICESat-2 mission. The IceBridge Data Portal from the National Snow and Ice Data Center provides an intuitive web interface for accessing IceBridge mission observations and measurements. Scientists and users usually do not have knowledge about the individual campaigns but are interested in data collected in a specific place. We have developed a high-performance map interface to allow users to quickly zoom to an area of interest and see any Operation IceBridge overflights. The map interface consists of two layers: the user can pan and zoom on the base map layer; the flight line layer that overlays the base layer provides all the campaign missions that intersect with the current map view. The user can click on the flight campaigns and download the data as needed. The OpenGIS® Web Map Service Interface Standard (WMS) provides a simple HTTP interface for requesting geo-registered map images from one or more distributed geospatial databases. Web Feature Service (WFS) provides an interface allowing requests for geographical features across the web using platform-independent calls. OpenLayers provides vector support (points, polylines and polygons) to build a WMS/WFS client for displaying both layers on the screen. Map Server, an open source development environment for building spatially enabled internet applications, is serving the WMS and WFS spatial data to OpenLayers. Early releases of the portal displayed unacceptably poor load time performance for flight lines and the base map tiles. This issue was caused by long response times from the map server in generating all map tiles and flight line vectors. We resolved the issue by implementing various caching strategies on top of the WMS and WFS services, including the use of Squid (www.squid-cache.org) to cache frequently-used content. Our presentation includes the architectural design of the application, and how we use OpenLayers, WMS and WFS with Squid to build a responsive web application capable of efficiently displaying geospatial data to allow the user to quickly interact with the displayed information. We describe the design, implementation and performance improvement of our caching strategies, and the tools and techniques developed to assist our data caching strategies.

An Experimental Investigation of the Confluent Boundary Layer on a High-Lift System

NASA Technical Reports Server (NTRS)

Thomas, F. O.; Nelson, R. C.

1997-01-01

This paper describes a fundamental experimental investigation of the confluent boundary layer generated by the interaction of a leading-edge slat wake with the boundary layer on the main element of a multi-element airfoil model. The slat and airfoil model geometry are both fully two-dimensional. The research reported in this paper is performed in an attempt to investigate the flow physics of confluent boundary layers and to build an archival data base on the interaction of the slat wake and the main element wall layer. In addition, an attempt is made to clearly identify the role that slat wake / airfoil boundary layer confluence has on lift production and how this occurs. Although complete LDV flow surveys were performed for a variety of slat gap and overhang settings, in this report the focus is on two cases representing both strong and weak wake boundary layer confluence.

Will electrical cyber-physical interdependent networks undergo first-order transition under random attacks?

NASA Astrophysics Data System (ADS)

Ji, Xingpei; Wang, Bo; Liu, Dichen; Dong, Zhaoyang; Chen, Guo; Zhu, Zhenshan; Zhu, Xuedong; Wang, Xunting

2016-10-01

Whether the realistic electrical cyber-physical interdependent networks will undergo first-order transition under random failures still remains a question. To reflect the reality of Chinese electrical cyber-physical system, the "partial one-to-one correspondence" interdependent networks model is proposed and the connectivity vulnerabilities of three realistic electrical cyber-physical interdependent networks are analyzed. The simulation results show that due to the service demands of power system the topologies of power grid and its cyber network are highly inter-similar which can effectively avoid the first-order transition. By comparing the vulnerability curves between electrical cyber-physical interdependent networks and its single-layer network, we find that complex network theory is still useful in the vulnerability analysis of electrical cyber-physical interdependent networks.

Strategies for optimizing military physical readiness and preventing musculoskeletal injuries in the 21st century.

PubMed

Nindl, Bradley C; Williams, Thomas J; Deuster, Patricia A; Butler, Nikki L; Jones, Bruce H

2013-01-01

With downsizing of the military services and significant budget cuts, it will be more important than ever to optimize the health and performance of individual service members. Musculoskeletal injuries (MSIs) represent a major threat to the health and fitness of Soldiers and other service members that degrade our nation's ability to project military power. This affects both financial (such as the economic burden from medical, healthcare, and disability costs) and human manpower resources (Soldiers medically unable to optimally perform their duties and to deploy). For example, in 2012, MSIs represented the leading cause of medical care visits across the military services resulting in almost 2,200,000 medical encounters. They also result in more disability discharges than any other health condition. Nonbattle injuries (NBIs) have caused more medical evacuations (34%) from recent theaters of operation than any other cause including combat injuries. Physical training and sports are the main cause of these NBIs. The majority (56%) of these injuries are the direct result of physical training. Higher levels of physical fitness protect against such injuries; however, more physical training to improve fitness also causes higher injury rates. Thus, military physical training programs must balance the need for fitness with the risks of injuries. The Army has launched several initiatives that may potentially improve military physical readiness and reduce injuries. These include the US Army Training and Doctrine Command's Baseline Soldier Physical Readiness Requirements and Gender Neutral Physical Performance Standards studies, as well as the reimplementation of the Master Fitness Trainer program and the Army Medical Command's Soldier Medical Readiness and Performance Triad Campaigns. It is imperative for military leaders to understand that military physical readiness can be enhanced at the same time that MSIs are prevented. A strategic paradigm shift in the military's approach to physical readiness policies is needed to avoid further degradation of warfighting capability in an era of austerity. We believe this can be best accomplished through leveraging scientific, evidence-based best practices by Army senior leadership which supports, prioritizes, and implements innovative, synchronized, and integrated human performance optimization/injury prevention policy changes.

Research on the Establishment and Evaluation of End - to - End Service Quality Index System

NASA Astrophysics Data System (ADS)

Wei, Chen; Jing, Tao; Ji, Yutong

2018-01-01

From the perspective of power data networks, put forward the index system model to measure the quality of service, covering user experience, business performance, network capacity support, etc., and gives the establishment and use of each layer index in the model.

Spatial resolution recovery utilizing multi-ray tracing and graphic processing unit in PET image reconstruction.

PubMed

Liang, Yicheng; Peng, Hao

2015-02-07

Depth-of-interaction (DOI) poses a major challenge for a PET system to achieve uniform spatial resolution across the field-of-view, particularly for small animal and organ-dedicated PET systems. In this work, we implemented an analytical method to model system matrix for resolution recovery, which was then incorporated in PET image reconstruction on a graphical processing unit platform, due to its parallel processing capacity. The method utilizes the concepts of virtual DOI layers and multi-ray tracing to calculate the coincidence detection response function for a given line-of-response. The accuracy of the proposed method was validated for a small-bore PET insert to be used for simultaneous PET/MR breast imaging. In addition, the performance comparisons were studied among the following three cases: 1) no physical DOI and no resolution modeling; 2) two physical DOI layers and no resolution modeling; and 3) no physical DOI design but with a different number of virtual DOI layers. The image quality was quantitatively evaluated in terms of spatial resolution (full-width-half-maximum and position offset), contrast recovery coefficient and noise. The results indicate that the proposed method has the potential to be used as an alternative to other physical DOI designs and achieve comparable imaging performances, while reducing detector/system design cost and complexity.

An Optimized, Data Distribution Service-Based Solution for Reliable Data Exchange Among Autonomous Underwater Vehicles

PubMed Central

Bilbao, Sonia; Martínez, Belén; Frasheri, Mirgita; Cürüklü, Baran

2017-01-01

Major challenges are presented when managing a large number of heterogeneous vehicles that have to communicate underwater in order to complete a global mission in a cooperative manner. In this kind of application domain, sending data through the environment presents issues that surpass the ones found in other overwater, distributed, cyber-physical systems (i.e., low bandwidth, unreliable transport medium, data representation and hardware high heterogeneity). This manuscript presents a Publish/Subscribe-based semantic middleware solution for unreliable scenarios and vehicle interoperability across cooperative and heterogeneous autonomous vehicles. The middleware relies on different iterations of the Data Distribution Service (DDS) software standard and their combined work between autonomous maritime vehicles and a control entity. It also uses several components with different functionalities deemed as mandatory for a semantic middleware architecture oriented to maritime operations (device and service registration, context awareness, access to the application layer) where other technologies are also interweaved with middleware (wireless communications, acoustic networks). Implementation details and test results, both in a laboratory and a deployment scenario, have been provided as a way to assess the quality of the system and its satisfactory performance. PMID:28783049

An Optimized, Data Distribution Service-Based Solution for Reliable Data Exchange Among Autonomous Underwater Vehicles.

PubMed

Rodríguez-Molina, Jesús; Bilbao, Sonia; Martínez, Belén; Frasheri, Mirgita; Cürüklü, Baran

2017-08-05

Major challenges are presented when managing a large number of heterogeneous vehicles that have to communicate underwater in order to complete a global mission in a cooperative manner. In this kind of application domain, sending data through the environment presents issues that surpass the ones found in other overwater, distributed, cyber-physical systems (i.e., low bandwidth, unreliable transport medium, data representation and hardware high heterogeneity). This manuscript presents a Publish/Subscribe-based semantic middleware solution for unreliable scenarios and vehicle interoperability across cooperative and heterogeneous autonomous vehicles. The middleware relies on different iterations of the Data Distribution Service (DDS) software standard and their combined work between autonomous maritime vehicles and a control entity. It also uses several components with different functionalities deemed as mandatory for a semantic middleware architecture oriented to maritime operations (device and service registration, context awareness, access to the application layer) where other technologies are also interweaved with middleware (wireless communications, acoustic networks). Implementation details and test results, both in a laboratory and a deployment scenario, have been provided as a way to assess the quality of the system and its satisfactory performance.

Evaluating the transport layer of the ALFA framework for the Intel® Xeon Phi™ Coprocessor

NASA Astrophysics Data System (ADS)

Santogidis, Aram; Hirstius, Andreas; Lalis, Spyros

2015-12-01

The ALFA framework supports the software development of major High Energy Physics experiments. As part of our research effort to optimize the transport layer of ALFA, we focus on profiling its data transfer performance for inter-node communication on the Intel Xeon Phi Coprocessor. In this article we present the collected performance measurements with the related analysis of the results. The optimization opportunities that are discovered, help us to formulate the future plans of enabling high performance data transfer for ALFA on the Intel Xeon Phi architecture.

Development of Predictive Models of Injury for the Lower Extremity, Lumbar, and Thoracic Spine after discharge from Physical Rehabilitation

DTIC Science & Technology

2017-10-01

discharge from Physical Rehabilitation PRINCIPAL INVESTIGATOR: MAJ Daniel Rhon CONTRACTING ORGANIZATION: The Geneva Foundation Tacoma, WA 98402...and Thoracic Spine after discharge from Physical Rehabilitation 5b. GRANT NUMBER W81XWH-14-2-0141 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S...The objective and overall hypothesis is that service member performance on a battery of physical performance tests performed upon discharge from

A New Approach to Integrate Internet-of-Things and Software-as-a-Service Model for Logistic Systems: A Case Study

PubMed Central

Chen, Shang-Liang; Chen, Yun-Yao; Hsu, Chiang

2014-01-01

Cloud computing is changing the ways software is developed and managed in enterprises, which is changing the way of doing business in that dynamically scalable and virtualized resources are regarded as services over the Internet. Traditional manufacturing systems such as supply chain management (SCM), customer relationship management (CRM), and enterprise resource planning (ERP) are often developed case by case. However, effective collaboration between different systems, platforms, programming languages, and interfaces has been suggested by researchers. In cloud-computing-based systems, distributed resources are encapsulated into cloud services and centrally managed, which allows high automation, flexibility, fast provision, and ease of integration at low cost. The integration between physical resources and cloud services can be improved by combining Internet of things (IoT) technology and Software-as-a-Service (SaaS) technology. This study proposes a new approach for developing cloud-based manufacturing systems based on a four-layer SaaS model. There are three main contributions of this paper: (1) enterprises can develop their own cloud-based logistic management information systems based on the approach proposed in this paper; (2) a case study based on literature reviews with experimental results is proposed to verify that the system performance is remarkable; (3) challenges encountered and feedback collected from T Company in the case study are discussed in this paper for the purpose of enterprise deployment. PMID:24686728

A new approach to integrate Internet-of-things and software-as-a-service model for logistic systems: a case study.

PubMed

Chen, Shang-Liang; Chen, Yun-Yao; Hsu, Chiang

2014-03-28

Cloud computing is changing the ways software is developed and managed in enterprises, which is changing the way of doing business in that dynamically scalable and virtualized resources are regarded as services over the Internet. Traditional manufacturing systems such as supply chain management (SCM), customer relationship management (CRM), and enterprise resource planning (ERP) are often developed case by case. However, effective collaboration between different systems, platforms, programming languages, and interfaces has been suggested by researchers. In cloud-computing-based systems, distributed resources are encapsulated into cloud services and centrally managed, which allows high automation, flexibility, fast provision, and ease of integration at low cost. The integration between physical resources and cloud services can be improved by combining Internet of things (IoT) technology and Software-as-a-Service (SaaS) technology. This study proposes a new approach for developing cloud-based manufacturing systems based on a four-layer SaaS model. There are three main contributions of this paper: (1) enterprises can develop their own cloud-based logistic management information systems based on the approach proposed in this paper; (2) a case study based on literature reviews with experimental results is proposed to verify that the system performance is remarkable; (3) challenges encountered and feedback collected from T Company in the case study are discussed in this paper for the purpose of enterprise deployment.

Joint Cross-Layer Design for Wireless QoS Content Delivery

NASA Astrophysics Data System (ADS)

Chen, Jie; Lv, Tiejun; Zheng, Haitao

2005-12-01

In this paper, we propose a joint cross-layer design for wireless quality-of-service (QoS) content delivery. Central to our proposed cross-layer design is the concept of adaptation. Adaptation represents the ability to adjust protocol stacks and applications to respond to channel variations. We focus our cross-layer design especially on the application, media access control (MAC), and physical layers. The network is designed based on our proposed fast frequency-hopping orthogonal frequency division multiplex (OFDM) technique. We also propose a QoS-awareness scheduler and a power adaptation transmission scheme operating at both the base station and mobile sides. The proposed MAC scheduler coordinates the transmissions of an IP base station and mobile nodes. The scheduler also selects appropriate transmission formats and packet priorities for individual users based on current channel conditions and the users' QoS requirements. The test results show that our cross-layer design provides an excellent framework for wireless QoS content delivery.

22 CFR 11.1 - Junior Foreign Service officer career candidate appointments.

Code of Federal Regulations, 2010 CFR

2010-04-01

... competence to perform the work of a Foreign Service officer at home and abroad, potential for growth in the.... The medical examination shall be conducted to determine the candidate's physical fitness to perform...

High-performance metal mesh/graphene hybrid films using prime-location and metal-doped graphene.

PubMed

Min, Jung-Hong; Jeong, Woo-Lim; Kwak, Hoe-Min; Lee, Dong-Seon

2017-08-31

We introduce high-performance metal mesh/graphene hybrid transparent conductive layers (TCLs) using prime-location and metal-doped graphene in near-ultraviolet light-emitting diodes (NUV LEDs). Despite the transparency and sheet resistance values being similar for hybrid TCLs, there were huge differences in the NUV LEDs' electrical and optical properties depending on the location of the graphene layer. We achieved better physical stability and current spreading when the graphene layer was located beneath the metal mesh, in direct contact with the p-GaN layer. We further improved the contact properties by adding a very thin Au mesh between the thick Ag mesh and the graphene layer to produce a dual-layered metal mesh. The Au mesh effectively doped the graphene layer to create a p-type electrode. Using Raman spectra, work function variations, and the transfer length method (TLM), we verified the effect of doping the graphene layer after depositing a very thin metal layer on the graphene layers. From our results, we suggest that the nature of the contact is an important criterion for improving the electrical and optical performance of hybrid TCLs, and the method of doping graphene layers provides new opportunities for solving contact issues in other semiconductor devices.

Evaluation of the construction and performance of multiple layer polymer concrete overlays : interim report no. 2, condition of the overlays after five years in service.

DOT National Transportation Integrated Search

1987-01-01

This interim report presents the results after 5 years of a study undertaken to evaluate multiple layer polymer concrete overlays over a 10-year period. The report indicates that an overlay of low permeability and high skid resistance can be successf...

Physical therapists familiarity and beliefs about health services utilization and health seeking behaviour.

PubMed

Clewley, Derek; Rhon, Dan; Flynn, Tim; Koppenhaver, Shane; Cook, Chad

2018-02-21

Physical therapists' familiarity, perceptions, and beliefs about health services utilization and health seeking behaviour have not been previously assessed. The purposes of this study were to identify physical therapists' characteristics related to familiarity of health services utilization and health seeking behaviour, and to assess what health seeking behaviour factors providers felt were related to health services utilization. We administered a survey based on the Andersen behavioural model of health services utilization to physical therapists using social media campaigns and email between March and June of 2017. In addition to descriptive statistics, we performed binomial logistic regression analysis. We asked respondents to rate familiarity with health services utilization and health seeking behaviour and collected additional characteristic variables. Physical therapists are more familiar with health services utilization than health seeking behaviour. Those who are familiar with either construct tend to be those who assess for health services utilization, use health services utilization for a prognosis, and believe that health seeking behaviour is measurable. Physical therapists rated need and enabling factors as having more influence on health services utilization than predisposing and health belief factors. Physical therapists are generally familiar with health services utilization and health seeking behaviour; however, there appears to be a disconnect between what is familiar, what is perceived to be important, and what can be assessed for both health services utilization and health seeking behaviour. Copyright © 2018 Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia. All rights reserved.

26 CFR 31.3121(b)(6)-1 - Services in employ of United States or instrumentality thereof.

Code of Federal Regulations, 2010 CFR

2010-04-01

... the comfort, pleasure, contentment, and mental and physical improvement of personnel of such... for the comfort, pleasure, contentment, and mental and physical improvement of personnel of the Coast...)(4)(ii) of this section, services performed by student nurses, medical or dental interns, residents...

Wetted Foam Liquid DT Layer ICF Experiments at the NIF

NASA Astrophysics Data System (ADS)

Olson, R. E.; Leeper, R. J.; Peterson, R. R.; Yi, S. A.; Zylstra, A. B.; Kline, J. L.; Bradley, P. A.; Yin, L.; Wilson, D. C.; Haines, B. M.; Batha, S. H.

2016-10-01

A key physics issue in indirect-drive ICF relates to the understanding of the limitations on hot spot convergence ratio (CR), principally set by the hohlraum drive symmetry, the capsule mounting hardware (the ``tent''), and the capsule fill tube. An additional key physics issue relates to the complex process by which a hot spot must be dynamically formed from the inner ice surface in a DT ice-layer implosion. These physics issues have helped to motivate the development of a new liquid DT layer wetted foam platform at the NIF that provides an ability to form the hot spot from DT vapor and experimentally study and understand hot spot formation at a variety of CR's in the range of 12

Convergence

NASA Astrophysics Data System (ADS)

Darcie, Thomas E.; Doverspike, Robert; Zirngibl, Martin; Korotky, Steven K.

2005-08-01

Call for Papers: Convergence The Journal of Optical Networking (JON) invites submissions to a special issue on Convergence. Convergence has become a popular theme in telecommunications, one that has broad implications across all segments of the industry. Continual evolution of technology and applications continues to erase lines between traditionally separate lines of business, with dramatic consequences for vendors, service providers, and consumers. Spectacular advances in all layers of optical networking-leading to abundant, dynamic, cost-effective, and reliable wide-area and local-area connections-have been essential drivers of this evolution. As services and networks continue to evolve towards some notion of convergence, the continued role of optical networks must be explored. One vision of convergence renders all information in a common packet (especially IP) format. This vision is driven by the proliferation of data services. For example, time-division multiplexed (TDM) voice becomes VoIP. Analog cable-television signals become MPEG bits streamed to digital set-top boxes. T1 or OC-N private lines migrate to Ethernet virtual private networks (VPNs). All these packets coexist peacefully within a single packet-routing methodology built on an optical transport layer that combines the flexibility and cost of data networks with telecom-grade reliability. While this vision is appealing in its simplicity and shared widely, specifics of implementation raise many challenges and differences of opinion. For example, many seek to expand the role of Ethernet in these transport networks, while massive efforts are underway to make traditional TDM networks more data friendly within an evolved but backward-compatible SDH/SONET (synchronous digital hierarchy and synchronous optical network) multiplexing hierarchy. From this common underlying theme follow many specific instantiations. Examples include the convergence at the physical, logical, and operational levels of voice and data, video and data, private-line and virtual private-line, fixed and mobile, and local and long-haul services. These trends have many consequences for consumers, vendors, and carriers. Faced with large volumes of low-margin data traffic mixed with traditional voice services, the need for capital conservation and operational efficiency drives carriers away from today's separate overlay networks for each service and towards "converged" platforms. For example, cable operators require transport of multiple services over both hybrid fiber coax (HFC) and DWDM transport technologies. Local carriers seek an economical architecture to deliver integrated services on optically enabled broadband-access networks. Services over wireless-access networks must coexist with those from wired networks. In each case, convergence of networks and services inspires an important set of questions and challenges, driven by the need for low cost, operational efficiency, service performance requirements, and optical transport technology options. This Feature Issue explores the various interpretations and implications of network convergence pertinent to optical networking. How does convergence affect the evolution of optical transport-layer and control approaches? Are the implied directions consistent with research vision for optical networks? Substantial challenges remain. Papers are solicited across the broad spectrum of interests. These include, but are not limited to: Architecture, design and performance of optical wide-area-network (WAN), metro, and access networks Integration strategies for multiservice transport platforms Access methods that bridge traditional and emerging services Network signaling and control methodologies All-optical packet routing and switching techniques

Convergence

NASA Astrophysics Data System (ADS)

Darcie, Thomas E.; Doverspike, Robert; Zirngibl, Martin; Korotky, Steven K.

2005-06-01

Call for Papers: Convergence The Journal of Optical Networking (JON) invites submissions to a special issue on Convergence. Convergence has become a popular theme in telecommunications, one that has broad implications across all segments of the industry. Continual evolution of technology and applications continues to erase lines between traditionally separate lines of business, with dramatic consequences for vendors, service providers, and consumers. Spectacular advances in all layers of optical networking-leading to abundant, dynamic, cost-effective, and reliable wide-area and local-area connections-have been essential drivers of this evolution. As services and networks continue to evolve towards some notion of convergence, the continued role of optical networks must be explored. One vision of convergence renders all information in a common packet (especially IP) format. This vision is driven by the proliferation of data services. For example, time-division multiplexed (TDM) voice becomes VoIP. Analog cable-television signals become MPEG bits streamed to digital set-top boxes. T1 or OC-N private lines migrate to Ethernet virtual private networks (VPNs). All these packets coexist peacefully within a single packet-routing methodology built on an optical transport layer that combines the flexibility and cost of data networks with telecom-grade reliability. While this vision is appealing in its simplicity and shared widely, specifics of implementation raise many challenges and differences of opinion. For example, many seek to expand the role of Ethernet in these transport networks, while massive efforts are underway to make traditional TDM networks more data friendly within an evolved but backward-compatible SDH/SONET (synchronous digital hierarchy and synchronous optical network) multiplexing hierarchy. From this common underlying theme follow many specific instantiations. Examples include the convergence at the physical, logical, and operational levels of voice and data, video and data, private-line and virtual private-line, fixed and mobile, and local and long-haul services. These trends have many consequences for consumers, vendors, and carriers. Faced with large volumes of low-margin data traffic mixed with traditional voice services, the need for capital conservation and operational efficiency drives carriers away from today's separate overlay networks for each service and towards "converged" platforms. For example, cable operators require transport of multiple services over both hybrid fiber coax (HFC) and DWDM transport technologies. Local carriers seek an economical architecture to deliver integrated services on optically enabled broadband-access networks. Services over wireless-access networks must coexist with those from wired networks. In each case, convergence of networks and services inspires an important set of questions and challenges, driven by the need for low cost, operational efficiency, service performance requirements, and optical transport technology options. This Feature Issue explores the various interpretations and implications of network convergence pertinent to optical networking. How does convergence affect the evolution of optical transport-layer and control approaches? Are the implied directions consistent with research vision for optical networks? Substantial challenges remain. Papers are solicited across the broad spectrum of interests. These include, but are not limited to: Architecture, design and performance of optical wide-area-network (WAN), metro, and access networks Integration strategies for multiservice transport platforms Access methods that bridge traditional and emerging services Network signaling and control methodologies All-optical packet routing and switching techniques

Convergence

NASA Astrophysics Data System (ADS)

Darcie, Thomas E.; Doverspike, Robert; Zirngibl, Martin; Korotky, Steven K.

2005-05-01

Call for Papers: Convergence The Journal of Optical Networking (JON) invites submissions to a special issue on Convergence. Convergence has become a popular theme in telecommunications, one that has broad implications across all segments of the industry. Continual evolution of technology and applications continues to erase lines between traditionally separate lines of business, with dramatic consequences for vendors, service providers, and consumers. Spectacular advances in all layers of optical networking-leading to abundant, dynamic, cost-effective, and reliable wide-area and local-area connections-have been essential drivers of this evolution. As services and networks continue to evolve towards some notion of convergence, the continued role of optical networks must be explored. One vision of convergence renders all information in a common packet (especially IP) format. This vision is driven by the proliferation of data services. For example, time-division multiplexed (TDM) voice becomes VoIP. Analog cable-television signals become MPEG bits streamed to digital set-top boxes. T1 or OC-N private lines migrate to Ethernet virtual private networks (VPNs). All these packets coexist peacefully within a single packet-routing methodology built on an optical transport layer that combines the flexibility and cost of data networks with telecom-grade reliability. While this vision is appealing in its simplicity and shared widely, specifics of implementation raise many challenges and differences of opinion. For example, many seek to expand the role of Ethernet in these transport networks, while massive efforts are underway to make traditional TDM networks more data friendly within an evolved but backward-compatible SDH/SONET (synchronous digital hierarchy and synchronous optical network) multiplexing hierarchy. From this common underlying theme follow many specific instantiations. Examples include the convergence at the physical, logical, and operational levels of voice and data, video and data, private-line and virtual private-line, fixed and mobile, and local and long-haul services. These trends have many consequences for consumers, vendors, and carriers. Faced with large volumes of low-margin data traffic mixed with traditional voice services, the need for capital conservation and operational efficiency drives carriers away from today's separate overlay networks for each service and towards "converged" platforms. For example, cable operators require transport of multiple services over both hybrid fiber coax (HFC) and DWDM transport technologies. Local carriers seek an economical architecture to deliver integrated services on optically enabled broadband-access networks. Services over wireless-access networks must coexist with those from wired networks. In each case, convergence of networks and services inspires an important set of questions and challenges, driven by the need for low cost, operational efficiency, service performance requirements, and optical transport technology options. This Feature Issue explores the various interpretations and implications of network convergence pertinent to optical networking. How does convergence affect the evolution of optical transport-layer and control approaches? Are the implied directions consistent with research vision for optical networks? Substantial challenges remain. Papers are solicited across the broad spectrum of interests. These include, but are not limited to: Architecture, design and performance of optical wide-area-network (WAN), metro, and access networks Integration strategies for multiservice transport platforms Access methods that bridge traditional and emerging services Network signaling and control methodologies All-optical packet routing and switching techniques

Convergence

NASA Astrophysics Data System (ADS)

Darcie, Thomas E.; Doverspike, Robert; Zirngibl, Martin; Korotky, Steven K.

2005-04-01

Call for Papers: Convergence The Journal of Optical Networking (JON) invites submissions to a special issue on Convergence. Convergence has become a popular theme in telecommunications, one that has broad implications across all segments of the industry. Continual evolution of technology and applications continues to erase lines between traditionally separate lines of business, with dramatic consequences for vendors, service providers, and consumers. Spectacular advances in all layers of optical networking-leading to abundant, dynamic, cost-effective, and reliable wide-area and local-area connections-have been essential drivers of this evolution. As services and networks continue to evolve towards some notion of convergence, the continued role of optical networks must be explored. One vision of convergence renders all information in a common packet (especially IP) format. This vision is driven by the proliferation of data services. For example, time-division multiplexed (TDM) voice becomes VoIP. Analog cable-television signals become MPEG bits streamed to digital set-top boxes. T1 or OC-N private lines migrate to Ethernet virtual private networks (VPNs). All these packets coexist peacefully within a single packet-routing methodology built on an optical transport layer that combines the flexibility and cost of data networks with telecom-grade reliability. While this vision is appealing in its simplicity and shared widely, specifics of implementation raise many challenges and differences of opinion. For example, many seek to expand the role of Ethernet in these transport networks, while massive efforts are underway to make traditional TDM networks more data friendly within an evolved but backward-compatible SDH/SONET (synchronous digital hierarchy and synchronous optical network) multiplexing hierarchy. From this common underlying theme follow many specific instantiations. Examples include the convergence at the physical, logical, and operational levels of voice and data, video and data, private-line and virtual private-line, fixed and mobile, and local and long-haul services. These trends have many consequences for consumers, vendors, and carriers. Faced with large volumes of low-margin data traffic mixed with traditional voice services, the need for capital conservation and operational efficiency drives carriers away from today's separate overlay networks for each service and towards "converged" platforms. For example, cable operators require transport of multiple services over both hybrid fiber coax (HFC) and DWDM transport technologies. Local carriers seek an economical architecture to deliver integrated services on optically enabled broadband-access networks. Services over wireless-access networks must coexist with those from wired networks. In each case, convergence of networks and services inspires an important set of questions and challenges, driven by the need for low cost, operational efficiency, service performance requirements, and optical transport technology options. This Feature Issue explores the various interpretations and implications of network convergence pertinent to optical networking. How does convergence affect the evolution of optical transport-layer and control approaches? Are the implied directions consistent with research vision for optical networks? Substantial challenges remain. Papers are solicited across the broad spectrum of interests. These include, but are not limited to: Architecture, design and performance of optical wide-area-network (WAN), metro, and access networks Integration strategies for multiservice transport platforms Access methods that bridge traditional and emerging services Network signaling and control methodologies All-optical packet routing and switching techniques

Physics and control of wall turbulence for drag reduction.

PubMed

Kim, John

2011-04-13

Turbulence physics responsible for high skin-friction drag in turbulent boundary layers is first reviewed. A self-sustaining process of near-wall turbulence structures is then discussed from the perspective of controlling this process for the purpose of skin-friction drag reduction. After recognizing that key parts of this self-sustaining process are linear, a linear systems approach to boundary-layer control is discussed. It is shown that singular-value decomposition analysis of the linear system allows us to examine different approaches to boundary-layer control without carrying out the expensive nonlinear simulations. Results from the linear analysis are consistent with those observed in full nonlinear simulations, thus demonstrating the validity of the linear analysis. Finally, fundamental performance limit expected of optimal control input is discussed.

Enhancing End-to-End Performance of Information Services Over Ka-Band Global Satellite Networks

NASA Technical Reports Server (NTRS)

Bhasin, Kul B.; Glover, Daniel R.; Ivancic, William D.; vonDeak, Thomas C.

1997-01-01

The Internet has been growing at a rapid rate as the key medium to provide information services such as e-mail, WWW and multimedia etc., however its global reach is limited. Ka-band communication satellite networks are being developed to increase the accessibility of information services via the Internet at global scale. There is need to assess satellite networks in their ability to provide these services and interconnect seamlessly with existing and proposed terrestrial telecommunication networks. In this paper the significant issues and requirements in providing end-to-end high performance for the delivery of information services over satellite networks based on various layers in the OSI reference model are identified. Key experiments have been performed to evaluate the performance of digital video and Internet over satellite-like testbeds. The results of the early developments in ATM and TCP protocols over satellite networks are summarized.

Interactions of double patterning technology with wafer processing, OPC and design flows

NASA Astrophysics Data System (ADS)

Lucas, Kevin; Cork, Chris; Miloslavsky, Alex; Luk-Pat, Gerry; Barnes, Levi; Hapli, John; Lewellen, John; Rollins, Greg; Wiaux, Vincent; Verhaegen, Staf

2008-03-01

Double patterning technology (DPT) is one of the main options for printing logic devices with half-pitch less than 45nm; and flash and DRAM memory devices with half-pitch less than 40nm. DPT methods decompose the original design intent into two individual masking layers which are each patterned using single exposures and existing 193nm lithography tools. The results of the individual patterning layers combine to re-create the design intent pattern on the wafer. In this paper we study interactions of DPT with lithography, masks synthesis and physical design flows. Double exposure and etch patterning steps create complexity for both process and design flows. DPT decomposition is a critical software step which will be performed in physical design and also in mask synthesis. Decomposition includes cutting (splitting) of original design intent polygons into multiple polygons where required; and coloring of the resulting polygons. We evaluate the ability to meet key physical design goals such as: reduce circuit area; minimize rework; ensure DPT compliance; guarantee patterning robustness on individual layer targets; ensure symmetric wafer results; and create uniform wafer density for the individual patterning layers.

A two layer chaotic encryption scheme of secure image transmission for DCT precoded OFDM-VLC transmission

NASA Astrophysics Data System (ADS)

Wang, Zhongpeng; Chen, Fangni; Qiu, Weiwei; Chen, Shoufa; Ren, Dongxiao

2018-03-01

In this paper, a two-layer image encryption scheme for a discrete cosine transform (DCT) precoded orthogonal frequency division multiplexing (OFDM) visible light communication (VLC) system is proposed. Firstly, in the proposed scheme the transmitted image is first encrypted by a chaos scrambling sequence,which is generated from the hybrid 4-D hyper- and Arnold map in the upper-layer. After that, the encrypted image is converted into digital QAM modulation signal, which is re-encrypted by chaos scrambling sequence based on Arnold map in physical layer to further enhance the security of the transmitted image. Moreover, DCT precoding is employed to improve BER performance of the proposed system and reduce the PAPR of OFDM signal. The BER and PAPR performances of the proposed system are evaluated by simulation experiments. The experiment results show that the proposed two-layer chaos scrambling schemes achieve image secure transmission for image-based OFDM VLC. Furthermore, DCT precoding can reduce the PAPR and improve the BER performance of OFDM-based VLC.

Probing Pre- and In-service Physics Teachers' Knowledge Using the Double-Slit Thought Experiment

NASA Astrophysics Data System (ADS)

Asikainen, Mervi A.; Hirvonen, Pekka E.

2014-09-01

This study describes the use of the double-slit thought experiment as a diagnostic tool for probing physics teachers' understanding. A total of 9 pre-service teachers and 18 in-service teachers with a variety of different experience in modern physics teaching at the upper secondary level responded in a paper-and-pencil test and three of these teachers were interviewed. The results showed that the physics teachers' thought experiments with classical particles, light, and electrons were often partial. Many teachers also suffered a lack of the basic ideas and principles of physics, which probably hindered thought experimenting. In particular, understanding the ontological nature of classical particles, light and electrons seemed to be essential in performing the double-slit experiment in an appropriate way. However, the in-service physics teachers who had teaching experience in modern physics were more prepared for the double-slit thought experiment than the pre-service teachers. The results suggest that both thought experiments and the double-slit experiment should be given more weight in physics teacher education, even if experience in modern physics teaching at upper secondary school seems to some extent to develop teachers' abilities.

42 CFR 410.74 - Physician assistants' services.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 2 2011-10-01 2011-10-01 false Physician assistants' services. 410.74 Section 410... Physician assistants' services. (a) Basic rule. Medicare Part B covers physician assistants' services only... physically present when the physician assistant is performing the services unless required by State law...

42 CFR 410.74 - Physician assistants' services.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 42 Public Health 2 2013-10-01 2013-10-01 false Physician assistants' services. 410.74 Section 410... Physician assistants' services. (a) Basic rule. Medicare Part B covers physician assistants' services only... physically present when the physician assistant is performing the services unless required by State law...

42 CFR 410.74 - Physician assistants' services.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 42 Public Health 2 2014-10-01 2014-10-01 false Physician assistants' services. 410.74 Section 410... Physician assistants' services. (a) Basic rule. Medicare Part B covers physician assistants' services only... physically present when the physician assistant is performing the services unless required by State law...

42 CFR 410.74 - Physician assistants' services.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 42 Public Health 2 2012-10-01 2012-10-01 false Physician assistants' services. 410.74 Section 410... Physician assistants' services. (a) Basic rule. Medicare Part B covers physician assistants' services only... physically present when the physician assistant is performing the services unless required by State law...

42 CFR 410.74 - Physician assistants' services.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 2 2010-10-01 2010-10-01 false Physician assistants' services. 410.74 Section 410... Physician assistants' services. (a) Basic rule. Medicare Part B covers physician assistants' services only... physically present when the physician assistant is performing the services unless required by State law...

Influence of the Mechanical Properties of Third-Generation Artificial Turf Systems on Soccer Players’ Physiological and Physical Performance and Their Perceptions

PubMed Central

Sánchez-Sánchez, Javier; García-Unanue, Jorge; Jiménez-Reyes, Pedro; Gallardo, Ana; Burillo, Pablo; Felipe, José Luis; Gallardo, Leonor

2014-01-01

The aim of this research was to evaluate the influence of the mechanical properties of artificial turf systems on soccer players’ performance. A battery of perceptive physiological and physical tests were developed on four different structural systems of artificial turf (System 1: Compacted gravel sub-base without elastic layer; System 2: Compacted gravel sub-base with elastic layer; System 3: Asphalt sub-base without elastic layer; System 4: Asphalt sub-base with elastic layer). The sample was composed of 18 soccer players (22.44±1.72 years) who typically train and compete on artificial turf. The artificial turf system with less rotational traction (S3) showed higher total time in the Repeated Sprint Ability test in comparison to the systems with intermediate values (49.46±1.75 s vs 47.55±1.82 s (S1) and 47.85±1.59 s (S2); p<0.001). The performance in jumping tests (countermovement jump and squat jump) and ball kicking to goal decreased after the RSA test in all surfaces assessed (p<0.05), since the artificial turf system did not affect performance deterioration (p>0.05). The physiological load was similar in all four artificial turf systems. However, players felt more comfortable on the harder and more rigid system (S4; visual analogue scale = 70.83±14.28) than on the softer artificial turf system (S2; visual analogue scale = 54.24±19.63). The lineal regression analysis revealed a significant influence of the mechanical properties of the surface of 16.5%, 15.8% and 7.1% on the mean time of the sprint, the best sprint time and the maximum mean speed in the RSA test respectively. Results suggest a mechanical heterogeneity between the systems of artificial turf which generate differences in the physical performance and in the soccer players’ perceptions. PMID:25354188

On the Effects of Surface Roughness on Boundary Layer Transition

NASA Technical Reports Server (NTRS)

Choudhari, Meelan M.; Li, Fei; Chang, Chau-Lyan; Edwards, Jack

2009-01-01

Surface roughness can influence laminar-turbulent transition in many different ways. This paper outlines selected analyses performed at the NASA Langley Research Center, ranging in speed from subsonic to hypersonic Mach numbers and highlighting the beneficial as well as adverse roles of the surface roughness in technological applications. The first theme pertains to boundary-layer tripping on the forebody of a hypersonic airbreathing configuration via a spanwise periodic array of trip elements, with the goal of understanding the physical mechanisms underlying roughness-induced transition in a high-speed boundary layer. The effect of an isolated, finite amplitude roughness element on a supersonic boundary layer is considered next. The other set of flow configurations examined herein corresponds to roughness based laminar flow control in subsonic and supersonic swept wing boundary layers. A common theme to all of the above configurations is the need to apply higher fidelity, physics based techniques to develop reliable predictions of roughness effects on laminar-turbulent transition.

Initial Results from an Energy-Aware Airborne Dynamic, Data-Driven Application System Performing Sampling in Coherent Boundary-Layer Structures

NASA Astrophysics Data System (ADS)

Frew, E.; Argrow, B. M.; Houston, A. L.; Weiss, C.

2014-12-01

The energy-aware airborne dynamic, data-driven application system (EA-DDDAS) performs persistent sampling in complex atmospheric conditions by exploiting wind energy using the dynamic data-driven application system paradigm. The main challenge for future airborne sampling missions is operation with tight integration of physical and computational resources over wireless communication networks, in complex atmospheric conditions. The physical resources considered here include sensor platforms, particularly mobile Doppler radar and unmanned aircraft, the complex conditions in which they operate, and the region of interest. Autonomous operation requires distributed computational effort connected by layered wireless communication. Onboard decision-making and coordination algorithms can be enhanced by atmospheric models that assimilate input from physics-based models and wind fields derived from multiple sources. These models are generally too complex to be run onboard the aircraft, so they need to be executed in ground vehicles in the field, and connected over broadband or other wireless links back to the field. Finally, the wind field environment drives strong interaction between the computational and physical systems, both as a challenge to autonomous path planning algorithms and as a novel energy source that can be exploited to improve system range and endurance. Implementation details of a complete EA-DDDAS will be provided, along with preliminary flight test results targeting coherent boundary-layer structures.

Four dimensional data assimilation (FDDA) impacts on WRF performance in simulating inversion layer structure and distributions of CMAQ-simulated winter ozone concentrations in Uintah Basin

NASA Astrophysics Data System (ADS)

Tran, Trang; Tran, Huy; Mansfield, Marc; Lyman, Seth; Crosman, Erik

2018-03-01

Four-dimensional data assimilation (FDDA) was applied in WRF-CMAQ model sensitivity tests to study the impact of observational and analysis nudging on model performance in simulating inversion layers and O3 concentration distributions within the Uintah Basin, Utah, U.S.A. in winter 2013. Observational nudging substantially improved WRF model performance in simulating surface wind fields, correcting a 10 °C warm surface temperature bias, correcting overestimation of the planetary boundary layer height (PBLH) and correcting underestimation of inversion strengths produced by regular WRF model physics without nudging. However, the combined effects of poor performance of WRF meteorological model physical parameterization schemes in simulating low clouds, and warm and moist biases in the temperature and moisture initialization and subsequent simulation fields, likely amplified the overestimation of warm clouds during inversion days when observational nudging was applied, impacting the resulting O3 photochemical formation in the chemistry model. To reduce the impact of a moist bias in the simulations on warm cloud formation, nudging with the analysis water mixing ratio above the planetary boundary layer (PBL) was applied. However, due to poor analysis vertical temperature profiles, applying analysis nudging also increased the errors in the modeled inversion layer vertical structure compared to observational nudging. Combining both observational and analysis nudging methods resulted in unrealistically extreme stratified stability that trapped pollutants at the lowest elevations at the center of the Uintah Basin and yielded the worst WRF performance in simulating inversion layer structure among the four sensitivity tests. The results of this study illustrate the importance of carefully considering the representativeness and quality of the observational and model analysis data sets when applying nudging techniques within stable PBLs, and the need to evaluate model results on a basin-wide scale.

Physics of magnetospheric boundary layers

NASA Technical Reports Server (NTRS)

Cairns, Iver H.

1995-01-01

This final report was concerned with the ideas that: (1) magnetospheric boundary layers link disparate regions of the magnetosphere-solar wind system together; and (2) global behavior of the magnetosphere can be understood only by understanding its internal linking mechanisms and those with the solar wind. The research project involved simultaneous research on the global-, meso-, and micro-scale physics of the magnetosphere and its boundary layers, which included the bow shock, the magnetosheath, the plasma sheet boundary layer, and the ionosphere. Analytic, numerical, and simulation projects were performed on these subjects, as well as comparisons of theoretical results with observational data. Other related activity included in the research included: (1) prediction of geomagnetic activity; (2) global MHD (magnetohydrodynamic) simulations; (3) Alfven resonance heating; and (4) Critical Ionization Velocity (CIV) effect. In the appendixes are list of personnel involved, list of papers published; and reprints or photocopies of papers produced for this report.

In-to-out body path loss for wireless radio frequency capsule endoscopy in a human body.

PubMed

Vermeeren, G; Tanghe, E; Thielens, A; Martens, L; Joseph, W

2016-08-01

Physical-layer characterization is important for design of in-to-out body communication for wireless body area networks (WBANs). This paper numerically investigates the path loss of an in-to-out body radio frequency (RF) wireless link between an endoscopy capsule and a receiver outside the body using a 3D electromagnetic solver. A spiral antenna in the endoscopy capsule is tuned to operate in the Medical Implant Communication Service (MICS) band at 402 MHz, accounting for the properties of the human body. The influence of misalignment, rotation of the capsule, and human body model are investigated. Semi-empirical path loss models for various homogeneous tissues and 3D realistic human body models are provided for manufacturers to evaluate the performance of in-to-out-body WBAN systems.

Tri-Service Dem/Val of the Pulsed Optical Energy Decoating (FLASHJET) Process for Military Applications - Rotary Wing Evaluation. Cost and Performance Report

DTIC Science & Technology

2003-01-01

substrate None Selective Coatings Removal 3.1.2 Topcoat layer removed, no damage to underlying primer layer None Strippable Area Assessment 3.1.3 At... selected . By implementing the FLASHJET® process and having a continuous workload, the FLASHJET® process has the potential for significant cost avoidances...to remove coating without damage to the underlying substrate, to selectively remove topcoat layers only, and to reach intricate areas of the test

CrossTalk: The Journal of Defense Software Engineering. Volume 21, Number 3

DTIC Science & Technology

2008-03-01

describes essentials for requirements development and management. In addi- tion to providing training, eLearning and consulting services, she speaks at and...information, support sense- making, enable collaborative decision making, and effect changes in the physical environment. For example, the Global ...across layers, which enables effective use of resources and helps enforce security and confiden- tiality policies. Global Data Space DDS provides a

Application-oriented integrated control center (AICC) for heterogeneous optical networks

NASA Astrophysics Data System (ADS)

Zhao, Yongli; Zhang, Jie; Cao, Xuping; Wang, Dajiang; Wu, Koubo; Cai, Yinxiang; Gu, Wanyi

2011-12-01

Various broad bandwidth services have being swallowing the bandwidth resource of optical networks, such as the data center application and cloud computation. There are still some challenges for future optical networks although the available bandwidth is increasing with the development of transmission technologies. The relationship between upper application layer and lower network resource layer is necessary to be researched further. In order to improve the efficiency of network resources and capability of service provisioning, heterogeneous optical networks resource can be abstracted as unified Application Programming Interfaces (APIs) which can be open to various upper applications through Application-oriented Integrated Control Center (AICC) proposed in the paper. A novel Openflow-based unified control architecture is proposed for the optimization of cross layer resources. Numeric results show good performance of AICC through simulation experiments.

Polymer/graphite oxide composites as high-performance materials for electric double layer capacitors

NASA Astrophysics Data System (ADS)

Tien, Chien-Pin; Teng, Hsisheng

A single graphene sheet represents a carbon material with the highest surface area available to accommodating molecules or ions for physical and chemical interactions. Here we demonstrate in an electric double layer capacitor the outstanding performance of graphite oxide for providing a platform for double layer formation. Graphite oxide is generally the intermediate compound for obtaining separated graphene sheets. Instead of reduction with hydrazine, we incorporate graphite oxide with a poly(ethylene oxide)-based polymer and anchor the graphene oxide sheets with poly(propylene oxide) diamines. This polymer/graphite oxide composite shows in a "dry" gel-electrolyte system a double layer capacitance as high as 130 F g -1. The polymer incorporation developed here can significantly diversify the application of graphene-based materials in energy storage devices.

Functional Basis for Efficient Physical Layer Classical Control in Quantum Processors

NASA Astrophysics Data System (ADS)

Ball, Harrison; Nguyen, Trung; Leong, Philip H. W.; Biercuk, Michael J.

2016-12-01

The rapid progress seen in the development of quantum-coherent devices for information processing has motivated serious consideration of quantum computer architecture and organization. One topic which remains open for investigation and optimization relates to the design of the classical-quantum interface, where control operations on individual qubits are applied according to higher-level algorithms; accommodating competing demands on performance and scalability remains a major outstanding challenge. In this work, we present a resource-efficient, scalable framework for the implementation of embedded physical layer classical controllers for quantum-information systems. Design drivers and key functionalities are introduced, leading to the selection of Walsh functions as an effective functional basis for both programing and controller hardware implementation. This approach leverages the simplicity of real-time Walsh-function generation in classical digital hardware, and the fact that a wide variety of physical layer controls, such as dynamic error suppression, are known to fall within the Walsh family. We experimentally implement a real-time field-programmable-gate-array-based Walsh controller producing Walsh timing signals and Walsh-synthesized analog waveforms appropriate for critical tasks in error-resistant quantum control and noise characterization. These demonstrations represent the first step towards a unified framework for the realization of physical layer controls compatible with large-scale quantum-information processing.

Developing Effective Physical Fitness Testing Standards for Pre Service Physical Educators

ERIC Educational Resources Information Center

Hill, Kory; Thornburg, Roland

2016-01-01

Physical educators are often held to a higher standard of physical fitness. The ability to effectively convey the importance of physical fitness may depend upon the ability to appear physically fit. The ability to perform at a minimal level of proficiency on fitness tests was deemed important by the faculty of one physical education teacher…

Physical fitness and physical training during Norwegian military service.

PubMed

Dyrstad, Sindre M; Soltvedt, Rune; Hallén, Jostein

2006-08-01

Evaluate the physical fitness and training of Norwegian infantry soldiers during 10 months of compulsory military service. Maximal oxygen uptake (VO2max) and maximal numbers of sit-ups, push-ups, and chin-ups and 3-km running time were tested in 107 male infantry soldiers at the beginning and end of basic training (BT), and again at demobilization. The amount of physical training was registered throughout the military service. During BT, major improvements in sit-ups and push-ups were found. VO2max increased in soldiers with the lowest initial VO2max, but decreased to pre-BT level at demobilization. The amount of obligatory physical training was 8.5 hours x week(-1) during BT and 35% lower after BT, and was usually performed in uniform at low to moderate intensity. The amount of high-intensity endurance and strength training during compulsory military service is to low to improve the soldiers' endurance and muscular strength.

Impact of a population based intervention to increase the adoption of multiple physical activity practices in centre based childcare services: a quasi experimental, effectiveness study

PubMed Central

2012-01-01

Background There is considerable scope to improve the delivery of practices that increase the physical activity of children in centre based childcare services. Few studies have reported the effectiveness of interventions to address this, particularly at a population level. The primary aim of this study was to describe the impact of an intervention to increase the adoption of multiple policies and practices to promote physical activity in centre based childcare services. Methods A quasi experimental study was conducted in centre based childcare services (n =228) in New South Wales (NSW), Australia and involved a three month intervention to increase the adoption of eight practices within childcare services that have been suggested to promote child physical activity. Intervention strategies to support the adoption of practices included staff training, resources, incentives, follow-up support and performance monitoring and feedback. Randomly selected childcare services in the remainder of NSW acted as a comparison group (n = 164) and did not receive the intervention but may have been exposed to a concurrent NSW government healthy eating and physical activity initiative. Self reported information on physical activity policies, fundamental movement skills sessions, structured physical activity opportunities, staff involvement in active play and provision of verbal prompts to encourage physical activity, small screen recreation opportunities, sedentary time, and staff trained in physical activity were collected by telephone survey with childcare service managers at baseline and 18 months later. Results Compared with the comparison area, the study found significantly greater increases in the prevalence of intervention services with a written physical activity policy, with policy referring to placing limits on small screen recreation, and with staff trained in physical activity. In addition, non-significant trends towards a greater increase in the proportion of intervention services conducting daily fundamental movement skill sessions, and such services having a physical activity policy supporting physical activity training for staff were also evident. Conclusion The intervention was effective in improving a number of centre based childcare service policies and practices associated with promoting child physical activity. Adoption of a broader range of practices may require more intensive and prolonged intervention support. PMID:22929434

Analysis of physical layer performance of hybrid optical-wireless access network

NASA Astrophysics Data System (ADS)

Shaddad, R. Q.; Mohammad, A. B.; Al-hetar, A. M.

2011-09-01

The hybrid optical-wireless access network (HOWAN) is a favorable architecture for next generation access network. It is an optimal combination of an optical backhaul and a wireless front-end for an efficient access network. In this paper, the HOWAN architecture is designed based on a wavelengths division multiplexing/time division multiplexing passive optical network (WDM/TDM PON) at the optical backhaul and a wireless fidelity (WiFi) technology at the wireless front-end. The HOWAN is proposed that can provide blanket coverage of broadband and flexible connection for end-users. Most of the existing works, based on performance evaluation are concerned on network layer aspects. This paper reports physical layer performance in terms of the bit error rate (BER), eye diagram, and signal-to-noise ratio (SNR) of the communication system. It accommodates 8 wavelength channels with 32 optical network unit/wireless access points (ONU/APs). It is demonstrated that downstream and upstream of 2 Gb/s can be achieved by optical backhaul for each wavelength channel along optical fiber length of 20 km and a data rate of 54 Mb/s per ONU/AP along a 50 m outdoor wireless link.

Convergence

NASA Astrophysics Data System (ADS)

Darcie, Thomas E.; Doverspike, Robert; Zirngibl, Martin; Korotky, Steven K.

2005-02-01

Call for Papers: Convergence Convergence has become a popular theme in telecommunications, one that has broad implications across all segments of the industry. Continual evolution of technology and applications continues to erase lines between traditionally separate lines of business, with dramatic consequences for vendors, service providers, and consumers. Spectacular advances in all layers of optical networking-leading to abundant, dynamic, cost-effective, and reliable wide-area and local-area connections-have been essential drivers of this evolution. As services and networks continue to evolve towards some notion of convergence, the continued role of optical networks must be explored. One vision of convergence renders all information in a common packet (especially IP) format. This vision is driven by the proliferation of data services. For example, time-division multiplexed (TDM) voice becomes VoIP. Analog cable-television signals become MPEG bits streamed to digital set-top boxes. T1 or OC-N private lines migrate to Ethernet virtual private networks (VPNs). All these packets coexist peacefully within a single packet-routing methodology built on an optical transport layer that combines the flexibility and cost of data networks with telecom-grade reliability. While this vision is appealing in its simplicity and shared widely, specifics of implementation raise many challenges and differences of opinion. For example, many seek to expand the role of Ethernet in these transport networks, while massive efforts are underway to make traditional TDM networks more data friendly within an evolved but backward-compatible SDH/SONET (synchronous digital hierarchy and synchronous optical network) multiplexing hierarchy. From this common underlying theme follow many specific instantiations. Examples include the convergence at the physical, logical, and operational levels of voice and data, video and data, private-line and virtual private-line, fixed and mobile, and local and long-haul services. These trends have many consequences for consumers, vendors, and carriers. Faced with large volumes of low-margin data traffic mixed with traditional voice services, the need for capital conservation and operational efficiency drives carriers away from today's separate overlay networks for each service and towards "converged" platforms. For example, cable operators require transport of multiple services over both hybrid fiber coax (HFC) and DWDM transport technologies. Local carriers seek an economical architecture to deliver integrated services on optically enabled broadband-access networks. Services over wireless-access networks must coexist with those from wired networks. In each case, convergence of networks and services inspires an important set of questions and challenges, driven by the need for low cost, operational efficiency, service performance requirements, and optical transport technology options. This Feature Issue explores the various interpretations and implications of network convergence pertinent to optical networking. How does convergence affect the evolution of optical transport-layer and control approaches? Are the implied directions consistent with research vision for optical networks? Substantial challenges remain. Papers are solicited across the broad spectrum of interests. These include, but are not limited to:

Convergence

NASA Astrophysics Data System (ADS)

Darcie, Thomas E.; Doverspike, Robert; Zirngibl, Martin; Korotky, Steven K.

2005-03-01

Call for Papers: Convergence Convergence has become a popular theme in telecommunications, one that has broad implications across all segments of the industry. Continual evolution of technology and applications continues to erase lines between traditionally separate lines of business, with dramatic consequences for vendors, service providers, and consumers. Spectacular advances in all layers of optical networking-leading to abundant, dynamic, cost-effective, and reliable wide-area and local-area connections-have been essential drivers of this evolution. As services and networks continue to evolve towards some notion of convergence, the continued role of optical networks must be explored. One vision of convergence renders all information in a common packet (especially IP) format. This vision is driven by the proliferation of data services. For example, time-division multiplexed (TDM) voice becomes VoIP. Analog cable-television signals become MPEG bits streamed to digital set-top boxes. T1 or OC-N private lines migrate to Ethernet virtual private networks (VPNs). All these packets coexist peacefully within a single packet-routing methodology built on an optical transport layer that combines the flexibility and cost of data networks with telecom-grade reliability. While this vision is appealing in its simplicity and shared widely, specifics of implementation raise many challenges and differences of opinion. For example, many seek to expand the role of Ethernet in these transport networks, while massive efforts are underway to make traditional TDM networks more data friendly within an evolved but backward-compatible SDH/SONET (synchronous digital hierarchy and synchronous optical network) multiplexing hierarchy. From this common underlying theme follow many specific instantiations. Examples include the convergence at the physical, logical, and operational levels of voice and data, video and data, private-line and virtual private-line, fixed and mobile, and local and long-haul services. These trends have many consequences for consumers, vendors, and carriers. Faced with large volumes of low-margin data traffic mixed with traditional voice services, the need for capital conservation and operational efficiency drives carriers away from today's separate overlay networks for each service and towards "converged" platforms. For example, cable operators require transport of multiple services over both hybrid fiber coax (HFC) and DWDM transport technologies. Local carriers seek an economical architecture to deliver integrated services on optically enabled broadband-access networks. Services over wireless-access networks must coexist with those from wired networks. In each case, convergence of networks and services inspires an important set of questions and challenges, driven by the need for low cost, operational efficiency, service performance requirements, and optical transport technology options. This Feature Issue explores the various interpretations and implications of network convergence pertinent to optical networking. How does convergence affect the evolution of optical transport-layer and control approaches? Are the implied directions consistent with research vision for optical networks? Substantial challenges remain. Papers are solicited across the broad spectrum of interests. These include, but are not limited to:

A three-dimensional non-isothermal model for a membraneless direct methanol redox fuel cell

NASA Astrophysics Data System (ADS)

Wei, Lin; Yuan, Xianxia; Jiang, Fangming

2018-05-01

In the membraneless direct methanol redox fuel cell (DMRFC), three-dimensional electrodes contribute to the reduction of methanol crossover and the open separator design lowers the system cost and extends its service life. In order to better understand the mechanisms of this configuration and further optimize its performance, the development of a three-dimensional numerical model is reported in this work. The governing equations of the multi-physics field are solved based on computational fluid dynamics methodology, and the influence of the CO2 gas is taken into consideration through the effective diffusivities. The numerical results are in good agreement with experimental data, and the deviation observed for cases of large current density may be related to the single-phase assumption made. The three-dimensional electrode is found to be effective in controlling methanol crossover in its multi-layer structure, while it also increases the flow resistance for the discharging products. It is found that the current density distribution is affected by both the electronic conductivity and the concentration of reactants, and the temperature rise can be primarily attributed to the current density distribution. The sensitivity and reliability of the model are analyzed through the investigation of the effects of cell parameters, including porosity values of gas diffusion layers and catalyst layers, methanol concentration and CO2 volume fraction, on the polarization characteristics.

Efficient evaluation of wireless real-time control networks.

PubMed

Horvath, Peter; Yampolskiy, Mark; Koutsoukos, Xenofon

2015-02-11

In this paper, we present a system simulation framework for the design and performance evaluation of complex wireless cyber-physical systems. We describe the simulator architecture and the specific developments that are required to simulate cyber-physical systems relying on multi-channel, multihop mesh networks. We introduce realistic and efficient physical layer models and a system simulation methodology, which provides statistically significant performance evaluation results with low computational complexity. The capabilities of the proposed framework are illustrated in the example of WirelessHART, a centralized, real-time, multi-hop mesh network designed for industrial control and monitor applications.

Experiments on the flow field physics of confluent boundary layers for high-lift systems

NASA Technical Reports Server (NTRS)

Nelson, Robert C.; Thomas, F. O.; Chu, H. C.

1994-01-01

The use of sub-scale wind tunnel test data to predict the behavior of commercial transport high lift systems at in-flight Reynolds number is limited by the so-called 'inverse Reynolds number effect'. This involves an actual deterioration in the performance of a high lift device with increasing Reynolds number. A lack of understanding of the relevant flow field physics associated with numerous complicated viscous flow interactions that characterize flow over high-lift devices prohibits computational fluid dynamics from addressing Reynolds number effects. Clearly there is a need for research that has as its objective the clarification of the fundamental flow field physics associated with viscous effects in high lift systems. In this investigation, a detailed experimental investigation is being performed to study the interaction between the slat wake and the boundary layer on the primary airfoil which is known as a confluent boundary layer. This little-studied aspect of the multi-element airfoil problem deserves special attention due to its importance in the lift augmentation process. The goal of this research is is to provide an improved understanding of the flow physics associated with high lift generation. This process report will discuss the status of the research being conducted at the Hessert Center for Aerospace Research at the University of Notre Dame. The research is sponsored by NASA Ames Research Center under NASA grant NAG2-905. The report will include a discussion of the models that have been built or that are under construction, a description of the planned experiments, a description of a flow visualization apparatus that has been developed for generating colored smoke for confluent boundary layer studies and some preliminary measurements made using our new 3-component fiber optic LDV system.

Parameterization Interactions in Global Aquaplanet Simulations

NASA Astrophysics Data System (ADS)

Bhattacharya, Ritthik; Bordoni, Simona; Suselj, Kay; Teixeira, João.

2018-02-01

Global climate simulations rely on parameterizations of physical processes that have scales smaller than the resolved ones. In the atmosphere, these parameterizations represent moist convection, boundary layer turbulence and convection, cloud microphysics, longwave and shortwave radiation, and the interaction with the land and ocean surface. These parameterizations can generate different climates involving a wide range of interactions among parameterizations and between the parameterizations and the resolved dynamics. To gain a simplified understanding of a subset of these interactions, we perform aquaplanet simulations with the global version of the Weather Research and Forecasting (WRF) model employing a range (in terms of properties) of moist convection and boundary layer (BL) parameterizations. Significant differences are noted in the simulated precipitation amounts, its partitioning between convective and large-scale precipitation, as well as in the radiative impacts. These differences arise from the way the subcloud physics interacts with convection, both directly and through various pathways involving the large-scale dynamics and the boundary layer, convection, and clouds. A detailed analysis of the profiles of the different tendencies (from the different physical processes) for both potential temperature and water vapor is performed. While different combinations of convection and boundary layer parameterizations can lead to different climates, a key conclusion of this study is that similar climates can be simulated with model versions that are different in terms of the partitioning of the tendencies: the vertically distributed energy and water balances in the tropics can be obtained with significantly different profiles of large-scale, convection, and cloud microphysics tendencies.

Optimization of bump and blowing to control the flow through a transonic compressor blade cascade

NASA Astrophysics Data System (ADS)

Mazaheri, K.; Khatibirad, S.

2018-03-01

Shock control bump (SCB) and blowing are two flow control methods, used here to improve the aerodynamic performance of transonic compressors. Both methods are applied to a NASA rotor 67 blade section and are optimized to minimize the total pressure loss. A continuous adjoint algorithm is used for multi-point optimization of a SCB to improve the aerodynamic performance of the rotor blade section, for a range of operational conditions around its design point. A multi-point and two single-point optimizations are performed in the design and off-design conditions. It is shown that the single-point optimized shapes have the best performance for their respective operating conditions, but the multi-point one has an overall better performance over the whole operating range. An analysis is given regarding how similarly both single- and multi-point optimized SCBs change the wave structure between blade sections resulting in a more favorable flow pattern. Interactions of the SCB with the boundary layer and the wave structure, and its effects on the separation regions are also studied. We have also introduced the concept of blowing for control of shock wave and boundary-layer interaction. A geometrical model is introduced, and the geometrical and physical parameters of blowing are optimized at the design point. The performance improvements of blowing are compared with the SCB. The physical interactions of SCB with the boundary layer and the shock wave are analyzed. The effects of SCB on the wave structure in the flow domain outside the boundary-layer region are investigated. It is shown that the effects of the blowing mechanism are very similar to the SCB.

Atomic layer deposition of ultrathin blocking layer for low-temperature solid oxide fuel cell on nanoporous substrate

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

Yu, Wonjong; Cho, Gu Young; Noh, Seungtak

2015-01-15

An ultrathin yttria-stabilized zirconia (YSZ) blocking layer deposited by atomic layer deposition (ALD) was utilized for improving the performance and reliability of low-temperature solid oxide fuel cells (SOFCs) supported by an anodic aluminum oxide substrate. Physical vapor-deposited YSZ and gadolinia-doped ceria (GDC) electrolyte layers were deposited by a sputtering method. The ultrathin ALD YSZ blocking layer was inserted between the YSZ and GDC sputtered layers. To investigate the effects of an inserted ultrathin ALD blocking layer, SOFCs with and without an ultrathin ALD blocking layer were electrochemically characterized. The open circuit voltage (1.14 V) of the ALD blocking-layered SOFC was visiblymore » higher than that (1.05 V) of the other cell. Furthermore, the ALD blocking layer augmented the power density and improved the reproducibility.« less

Physical meaning of the multiplicities of emitted nucleons in hadron-nucleus collisions

NASA Technical Reports Server (NTRS)

Strugalski, Z.

1985-01-01

The analysis of experimental data on hadron-nucleus collisions at energies from about 2 up to about 400 GeV was performed in order to discover a physical meaning of the multiplicity of emitted nucleons. Simple relations between the multiplicities and the thickness of the nuclear matter layer involved in collisions were obtained.

Fermilab | Science at Fermilab | Experiments & Projects | Intensity

Science.gov Websites

Theory Computing High-performance Computing Grid Computing Networking Mass Storage Plan for the Future List Historic Results Inquiring Minds Questions About Physics Other High-Energy Physics Sites More About Particle Physics Library Visual Media Services Timeline History High-Energy Physics Accelerator

Prediction of pavement remaining service life based on repetition of load and permanent deformation

NASA Astrophysics Data System (ADS)

Usman, R. S.; Setyawan, A.; Suprapto, M.

2018-03-01

One of the methods which was applied in the assessment of flexible pavement performance was mechanistic method assuming structures of road pavement to become multi-layer structure for flexible pavement, that the vehicle load working on the pavement layer under repetition with power failure worth 1 (one) unit which was assumed as evenly distributed static load, and therefore the pavement material would provide response in the form of stress, strain, and deflection. This is closely related in order to assess the structure of flexible pavement and to predict the remaining service life on the roads of Pulau Indah sta 0 + 000 to sta. 0 + 845 in Kota Kupang, Nusa Tenggara Timur. The performance appraisal indicator which was used was fatigue cracking happening bottom of the asphalt layer and permanent deformation (rutting) on the surface of subgrade. The strain estimate on the flexible pavement layer structure needs carefulness and high accuracy and therefore a software like KENPAVE which produces horizontal tensile strain of 8,802E-05 and vertical compressive strain of 2,642E-04 was used. By applying equation of The Asphalt Instituteit was obtained repetition of permit load when reaching fatigue cracking (Nf) was 16.071.516 ESAL and permanent deformation (rutting) was 14.703.867 ESAL and also it was predicted the remaining service life of pavement applied the equation of AASTHO 1993 by considering Traffic Multiplier factor (TM 1.8, TM 1.9 and TM 2.0) obtained the remaining life service due to fatigue of 5.51% in the year of 13th (TM 1.8), 7.95% in the year of12th (TM 1.9) and 3.11% (TM 2.0) in the year of 12th, also the remaining service life due to rutting of 4.69% in the year of 12th(TM 1.8), 7.79% in the year of 11th (TM 1.9), and 2.94 in the year of 11th (TM 2.0).

Adaptation technology between IP layer and optical layer in optical Internet

NASA Astrophysics Data System (ADS)

Ji, Yuefeng; Li, Hua; Sun, Yongmei

2001-10-01

Wavelength division multiplexing (WDM) optical network provides a platform with high bandwidth capacity and is supposed to be the backbone infrastructure supporting the next-generation high-speed multi-service networks (ATM, IP, etc.). In the foreseeable future, IP will be the predominant data traffic, to make fully use of the bandwidth of the WDM optical network, many attentions have been focused on IP over WDM, which has been proposed as the most promising technology for new kind of network, so-called Optical Internet. According to OSI model, IP is in the 3rd layer (network layer) and optical network is in the 1st layer (physical layer), so the key issue is what adaptation technology should be used in the 2nd layer (data link layer). In this paper, firstly, we analyze and compare the current adaptation technologies used in backbone network nowadays. Secondly, aiming at the drawbacks of above technologies, we present a novel adaptation protocol (DONA) between IP layer and optical layer in Optical Internet and describe it in details. Thirdly, the gigabit transmission adapter (GTA) we accomplished based on the novel protocol is described. Finally, we set up an experiment platform to apply and verify the DONA and GTA, the results and conclusions of the experiment are given.

Three-dimensional (3-D) model utilization for fracture reconstruction in oral and maxillofacial surgery: A case report

NASA Astrophysics Data System (ADS)

Damayanti, Ista; Lilies, Latief, Benny S.

2017-02-01

Three-dimensional (3-D) printing has been identified as an innovative manufacturing technology of functional parts. The 3-D model was produced based on CT-Scan using Osyrix software, where automatic segmentation was performed and convert into STL format. This STL format was then ready to be produced physically, layer-by-layer to create 3-D model.

DEADS: Depth and Energy Aware Dominating Set Based Algorithm for Cooperative Routing along with Sink Mobility in Underwater WSNs.

PubMed

Umar, Amara; Javaid, Nadeem; Ahmad, Ashfaq; Khan, Zahoor Ali; Qasim, Umar; Alrajeh, Nabil; Hayat, Amir

2015-06-18

Performance enhancement of Underwater Wireless Sensor Networks (UWSNs) in terms of throughput maximization, energy conservation and Bit Error Rate (BER) minimization is a potential research area. However, limited available bandwidth, high propagation delay, highly dynamic network topology, and high error probability leads to performance degradation in these networks. In this regard, many cooperative communication protocols have been developed that either investigate the physical layer or the Medium Access Control (MAC) layer, however, the network layer is still unexplored. More specifically, cooperative routing has not yet been jointly considered with sink mobility. Therefore, this paper aims to enhance the network reliability and efficiency via dominating set based cooperative routing and sink mobility. The proposed work is validated via simulations which show relatively improved performance of our proposed work in terms the selected performance metrics.

ATM technology and beyond

NASA Technical Reports Server (NTRS)

Cheung, Nim K.

1993-01-01

Networks based on Asynchronous Transfer Mode (ATM) are expected to provide cost-effective and ubiquitous infrastructure to support broadband and multimedia services. In this paper, we give an overview of the ATM standards and its associated physical layer transport technologies. We use the experimental HIPPI-ATM-SONET (HAS) interface in the Nectar Gigabit Testbed to illustrate how one can use the SONET/ATM public network to provide transport for bursty gigabit applications.

Service-oriented Software Defined Optical Networks for Cloud Computing

NASA Astrophysics Data System (ADS)

Liu, Yuze; Li, Hui; Ji, Yuefeng

2017-10-01

With the development of big data and cloud computing technology, the traditional software-defined network is facing new challenges (e.g., ubiquitous accessibility, higher bandwidth, more flexible management and greater security). This paper proposes a new service-oriented software defined optical network architecture, including a resource layer, a service abstract layer, a control layer and an application layer. We then dwell on the corresponding service providing method. Different service ID is used to identify the service a device can offer. Finally, we experimentally evaluate that proposed service providing method can be applied to transmit different services based on the service ID in the service-oriented software defined optical network.

Optimal Performance Monitoring of Hybrid Mid-Infrared Wavelength MIMO Free Space Optical and RF Wireless Networks in Fading Channels

NASA Astrophysics Data System (ADS)

Schmidt, Barnet Michael

An optimal performance monitoring metric for a hybrid free space optical and radio-frequency (RF) wireless network, the Outage Capacity Objective Function, is analytically developed and studied. Current and traditional methods of performance monitoring of both optical and RF wireless networks are centered on measurement of physical layer parameters, the most common being signal-to-noise ratio, error rate, Q factor, and eye diagrams, occasionally combined with link-layer measurements such as data throughput, retransmission rate, and/or lost packet rate. Network management systems frequently attempt to predict or forestall network failures by observing degradations of these parameters and to attempt mitigation (such as offloading traffic, increasing transmitter power, reducing the data rate, or combinations thereof) prior to the failure. These methods are limited by the frequent low sensitivity of the physical layer parameters to the atmospheric optical conditions (measured by optical signal-to-noise ratio) and the radio frequency fading channel conditions (measured by signal-to-interference ratio). As a result of low sensitivity, measurements of this type frequently are unable to predict impending failures sufficiently in advance for the network management system to take corrective action prior to the failure. We derive and apply an optimal measure of hybrid network performance based on the outage capacity of the hybrid optical and RF channel, the outage capacity objective function. The objective function provides high sensitivity and reliable failure prediction, and considers both the effects of atmospheric optical impairments on the performance of the free space optical segment as well as the effect of RF channel impairments on the radio frequency segment. The radio frequency segment analysis considers the three most common RF channel fading statistics: Rayleigh, Ricean, and Nakagami-m. The novel application of information theory to the underlying physics of the gamma-gamma optical channel and radio fading channels in determining the joint hybrid channel outage capacity provides the best performance estimate under any given set of operating conditions. It is shown that, unlike traditional physical layer performance monitoring techniques, the objective function based upon the outage capacity of the hybrid channel at any combination of OSNR and SIR, is able to predict channel degradation and failure well in advance of the actual outage. An outage in the information-theoretic definition occurs when the offered load exceeds the outage capacity under the current conditions of OSNR and SIR. The optical channel is operated at the "long" mid-infrared wavelength of 10000 nm. which provides improved resistance to scattering compared to shorter wavelengths such as 1550 nm.

Performance of composite boards from long strand oil palm trunk bonded by isocyanate and urea formaldehyde adhesives

NASA Astrophysics Data System (ADS)

Hermanto, Indra; Massijaya, M. Y.

2018-03-01

In this research, the obtained long strand were produced from the outer part of oil palm trunk and then hot-prepressed. The three-ply composite boards were made from hot-prepressed long strand and use bonded by isocyanate and urea formaldehyde adhesives with a glue spread variation of 150 g/m2, 225 g/m2, and 300 g/m2. The board target density was 0.65 g/cm3, face and back layers orientation is the same and the core layer was perpendicular to the face and back layers. The research results showed that : (1) composite boards bonded by isocyanate performed better physical and mechanical properties compared to those of bonded by urea formaldehyde, (2) utilization of higher glue spread level would improve the physical and mechanical properties of the composite board. (3) composite boards bonded by isocyanate and urea formaldehyde adhesives at glue spread of 225 g/m2, 300 g/m2, respectively were enough to fulfill the JIS A 5908 (2003) standard.

Metaporous layer to overcome the thickness constraint for broadband sound absorption

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

Yang, Jieun; Lee, Joong Seok; Kim, Yoon Young, E-mail: yykim@snu.ac.kr

The sound absorption of a porous layer is affected by its thickness, especially in a low-frequency range. If a hard-backed porous layer contains periodical arrangements of rigid partitions that are coordinated parallel and perpendicular to the direction of incoming sound waves, the lower bound of the effective sound absorption can be lowered much more and the overall absorption performance enhanced. The consequence of rigid partitioning in a porous layer is to make the first thickness resonance mode in the layer appear at much lower frequencies compared to that in the original homogeneous porous layer with the same thickness. Moreover, appropriatemore » partitioning yields multiple thickness resonances with higher absorption peaks through impedance matching. The physics of the partitioned porous layer, or the metaporous layer, is theoretically investigated in this study.« less

Influence of hole shape on sound absorption of underwater anechoic layers

NASA Astrophysics Data System (ADS)

Ye, Changzheng; Liu, Xuewei; Xin, Fengxian; Lu, Tian Jian

2018-07-01

A theoretical model is established to evaluate the sound absorption performance of underwater anechoic layers containing periodically distributed axial holes. Based on the concept for homogenized equivalent layer and on the theory of wave propagation in viscoelastic cylindrical tubes, the transfer function method is used to obtain the absorption coefficient of the anechoic layer adhered on the rigid plate. Three different types of axial holes are considered, the cylindrical, the conical and the horn shaped one. Results obtained with full finite element simulations are used to validate the model predictions. For each hole type, the vibration characteristics of the anechoic layer as well as the propagation of longitudinal and transverse waves in the layer are analyzed in detail to explore the physical mechanisms underlying its absorption performance. Furthermore, a three-dimensional finite element model for oblique incidence is developed to study the effect of hole shape at different incidence angles. The results show that two new absorption peaks appear since the oblique incidence excites two horizontal modes. Among the three hole types, the horn one achieves the best absorption performance at relatively low frequencies both in normal incidence and in oblique incidence.

Multilayer (TiN, TiAlN) ceramic coatings for nuclear fuel cladding

NASA Astrophysics Data System (ADS)

Alat, Ece; Motta, Arthur T.; Comstock, Robert J.; Partezana, Jonna M.; Wolfe, Douglas E.

2016-09-01

In an attempt to develop an accident-tolerant fuel (ATF) that can delay the deleterious consequences of loss-of-coolant-accidents (LOCA), multilayer coatings were deposited onto ZIRLO® coupon substrates by cathodic arc physical vapor deposition (CA-PVD). Coatings were composed of alternating TiN (top) and Ti1-xAlxN (2-layer, 4-layer, 8-layer and 16-layer) layers. The minimum TiN top coating thickness and coating architecture were optimized for good corrosion and oxidation resistance. Corrosion tests were performed in static pure water at 360 °C and 18.7 MPa for up to 90 days. The optimized coatings showed no spallation/delamination and had a maximum of 6 mg/dm2 weight gain, which is 6 times smaller than that of a control sample of uncoated ZIRLO® which showed a weight gain of 40.2 mg/dm2. The optimized architecture features a ∼1 μm TiN top layer to prevent boehmite phase formation during corrosion and a TiN/TiAlN 8-layer architecture which provides the best corrosion performance.

Physical modelling of LNG rollover in a depressurized container filled with water

NASA Astrophysics Data System (ADS)

Maksim, Dadonau; Denissenko, Petr; Hubert, Antoine; Dembele, Siaka; Wen, Jennifer

2015-11-01

Stable density stratification of multi-component Liquefied Natural Gas causes it to form distinct layers, with upper layer having a higher fraction of the lighter components. Heat flux through the walls and base of the container results in buoyancy-driven convection accompanied by heat and mass transfer between the layers. The equilibration of densities of the top and bottom layers, normally caused by the preferential evaporation of Nitrogen, may induce an imbalance in the system and trigger a rapid mixing process, so-called rollover. Numerical simulation of the rollover is complicated and codes require validation. Physical modelling of the phenomenon has been performed in a water-filled depressurized vessel. Reducing gas pressure in the container to levels comparable to the hydrostatic pressure in the water column allows modelling of tens of meters industrial reservoirs using a 20 cm laboratory setup. Additionally, it allows to model superheating of the base fluid layer at temperatures close the room temperature. Flow visualizations and parametric studies are presented. Results are related to outcomes of numerical modelling.

Physics of magnetospheric boundary layers

NASA Technical Reports Server (NTRS)

Cairns, I. H.

1993-01-01

The central ideas of this grant are that the magnetospheric boundary layers link disparate regions of the magnetosphere together, and the global behavior of the magnetosphere can be understood only by understanding the linking mechanisms. Accordingly the present grant includes simultaneous research on the global, meso-, and micro-scale physics of the magnetosphere and its boundary layers. These boundary layers include the bow shock, magnetosheath, the plasma sheet boundary layer, and the ionosphere. Analytic, numerical and simulation projects have been performed on these subjects, as well as comparison of theoretical results with observational data. Very good progress has been made, with four papers published or in press and two additional papers submitted for publication during the six month period 1 June - 30 November 1993. At least two projects are currently being written up. In addition, members of the group have given papers at scientific meetings. The further structure of this report is as follows: section two contains brief accounts of research completed during the last six months, while section three describes the research projects intended for the grant's final period.

The CCSDS return all frames Space Link Extension service

NASA Technical Reports Server (NTRS)

Uhrig, Hans; Pietras, John; Stoloff, Michael

1994-01-01

Existing Consultative Committee for Space Data Systems (CCSDS) Recommendations for Telemetry Channel Coding, Packet Telemetry, Advanced Orbiting Systems, and Telecommand have facilitated cross-support between Agencies by standardizing the link between spacecraft and ground terminal. CCSDS is currently defining a set of Space Link Extension (SLE) services that will enable remote science and mission operations facilities to access the ground termination of the Space Link services in a standard manner. The first SLE service to be defined is the Return All Frames (RAF) service. The RAF service delivers all CCSDS link-layer frames received on a single space link physical channel. The service provides both on-line and off-line data transfer modes to accommodate the variety of access methods typical of space mission operations. This paper describes the RAF service as of the Summer of 1994. It characterizes the behavior of the service as seen across the interface between the user and the service and gives an overview of the interactions involved in setting up and operating the service in a cross-support environment.

Physics considerations in MV-CBCT multi-layer imager design.

PubMed

Hu, Yue-Houng; Fueglistaller, Rony; Myronakis, Marios E; Rottmann, Joerg; Wang, Adam; Shedlock, Daniel; Morf, Daniel; Baturin, Paul; Huber, Pascal; Star-Lack, Josh M; Berbeco, Ross I

2018-05-30

Megavoltage (MV) cone-beam computed tomography (CBCT) using an electronic portal imaging (EPID) offers advantageous features, including 3D mapping, treatment beam registration, high-z artifact suppression, and direct radiation dose calculation. Adoption has been slowed by image quality limitations and concerns about imaging dose. Developments in imager design, including pixelated scintillators, structured phosphors, inexpensive scintillation materials, and multi-layer imager (MLI) architecture have been explored to improve EPID image quality and reduce imaging dose. The present study employs a hybrid Monte Carlo and linear systems model to determine the effect of detector design elements, such as multi-layer architecture and scintillation materials. We follow metrics of image quality including modulation transfer function (MTF) and noise power spectrum (NPS) from projection images to 3D reconstructions to in-plane slices and apply a task based figure-of-merit, the ideal observer signal-to-noise ratio (d') to determine the effect of detector design on object detectability. Generally, detectability was limited by detector noise performance. Deploying an MLI imager with a single scintillation material for all layers yields improvement in noise performance and d' linear with the number of layers. In general, improving x-ray absorption using thicker scintillators results in improved DQE(0). However, if light yield is low, performance will be affected by electronic noise at relatively high doses, resulting in rapid image quality degradation. Maximizing image quality in a heterogenous MLI detector (i.e. multiple different scintillation materials) is most affected by limiting imager noise. However, while a second-order effect, maximizing total spatial resolution of the MLI detector is a balance between the intensity contribution of each layer against its individual MTF. So, while a thinner scintillator may yield a maximal individual-layer MTF, its quantum efficiency will be relatively low in comparison to a thicker scintillator and thus, intensity contribution may be insufficient to noticeably improve the total detector MTF. © 2018 Institute of Physics and Engineering in Medicine.

Twelve Channel Optical Fiber Connector Assembly: From Commercial Off the Shelf to Space Flight Use

NASA Technical Reports Server (NTRS)

Ott, Melaine N.

1998-01-01

The commercial off the shelf (COTS) twelve channel optical fiber MTP array connector and ribbon cable assembly is being validated for space flight use and the results of this study to date are presented here. The interconnection system implemented for the Parallel Fiber Optic Data Bus (PFODB) physical layer will include a 100/140 micron diameter optical fiber in the cable configuration among other enhancements. As part of this investigation, the COTS 62.5/125 microns optical fiber cable assembly has been characterized for space environment performance as a baseline for improving the performance of the 100/140 micron diameter ribbon cable for the Parallel FODB application. Presented here are the testing and results of random vibration and thermal environmental characterization of this commercial off the shelf (COTS) MTP twelve channel ribbon cable assembly. This paper is the first in a series of papers which will characterize and document the performance of Parallel FODB's physical layer from COTS to space flight worthy.

Predictors of physical therapy clinic performance in the treatment of patients with low back pain syndromes.

PubMed

Resnik, Linda; Liu, Dawei; Mor, Vince; Hart, Dennis L

2008-09-01

Little is known about organizational and service delivery factors related to quality of care in physical therapy. This study sought to identify characteristics related to differences in practice outcomes and service utilization. The sample comprised 114 outpatient clinics and 1,058 therapists who treated 16,281 patients with low back pain syndromes during the period 2000-2001. Clinics participated with the Focus on Therapeutic Outcomes, Inc (FOTO) database. Hierarchical linear models were used to risk adjust treatment outcomes and number of visits per treatment episode. Aggregated residual scores from these models were used to classify each clinic into 1 of 3 categories in each of 3 types of performance groups: (1) effectiveness, (2) utilization, and (3) overall performance (ie, composite measure of effectiveness and utilization). Relationships between clinic classification and the following independent variables were examined by multinomial logistic regression: years of therapist experience, number of physical therapists, ratio of physical therapists to physical therapist assistants, proportion of patients with low back pain syndromes, number of new patients per physical therapist per month, utilization of physical therapist assistants, and setting. Clinics that were lower utilizers of physical therapist assistants were 6.6 times more likely to be classified into the high effectiveness group compared with the low effectiveness group, 6.7 times more likely to be classified in the low utilization group compared with the high utilization group, and 12.4 times more likely to be classified in the best performance group compared with the worst performance group. Serving a higher proportion of patients with low back pain syndromes was associated with an increased likelihood of being classified in the lowest or middle group. Years of physical therapist experience was inversely associated with being classified in the middle utilization group compared with the highest utilization group. These findings suggest that, in the treatment of patients with low back pain syndromes, clinics that are low utilizers of physical therapist assistants are more likely to provide superior care (ie, better patient outcomes and lower service use).

Quantum dot laser optimization: selectively doped layers

NASA Astrophysics Data System (ADS)

Korenev, Vladimir V.; Konoplev, Sergey S.; Savelyev, Artem V.; Shernyakov, Yurii M.; Maximov, Mikhail V.; Zhukov, Alexey E.

2016-08-01

Edge emitting quantum dot (QD) lasers are discussed. It has been recently proposed to use modulation p-doping of the layers that are adjacent to QD layers in order to control QD's charge state. Experimentally it has been proven useful to enhance ground state lasing and suppress the onset of excited state lasing at high injection. These results have been also confirmed with numerical calculations involving solution of drift-diffusion equations. However, deep understanding of physical reasons for such behavior and laser optimization requires analytical approaches to the problem. In this paper, under a set of assumptions we provide an analytical model that explains major effects of selective p-doping. Capture rates of elections and holes can be calculated by solving Poisson equations for electrons and holes around the charged QD layer. The charge itself is ruled by capture rates and selective doping concentration. We analyzed this self-consistent set of equations and showed that it can be used to optimize QD laser performance and to explain underlying physics.

Third order nonlinear optical response exhibited by mono- and few-layers of WS 2

DOE PAGES

Torres-Torres, Carlos; Perea-López, Néstor; Elías, Ana Laura; ...

2016-04-13

In this work, strong third order nonlinear optical properties exhibited by WS 2 layers are presented. Optical Kerr effect was identified as the dominant physical mechanism responsible for these third order optical nonlinearities. An extraordinary nonlinear refractive index together with an important contribution of a saturated absorptive response was observed to depend on the atomic layer stacking. Comparative experiments performed in mono- and few-layer samples of WS 2 revealed that this material is potentially capable of modulating nonlinear optical processes by selective near resonant induced birefringence. In conclusion, we envision applications for developing all-optical bidimensional nonlinear optical devices.

The Interactions of a Flame and Its Self-Induced Boundary Layer

NASA Technical Reports Server (NTRS)

Ott, James D.; Oran, Elaine S.; Anderson, John D.

1999-01-01

The interaction of a laminar flame with its self-generated boundary layer in a rectangular channel was numerically simulated using the two-dimensional, reacting, Navier-Stokes equations. A two species chemistry model was implemented which simulates the stoichiometric reaction of acetylene and air. Calculations were performed to investigate the effects of altering the boundary condition of the wall temperature, the Lewis number, the dynamic viscosity, and the ignition method. The purpose of this study was to examine the fundamental physics of the formation of the boundary layer and the interaction of the flame as it propagates into the boundary layer that its own motion has created.

Sensitivity of boundary layer variables to PBL schemes over the central Tibetan Plateau

NASA Astrophysics Data System (ADS)

Xu, L.; Liu, H.; Wang, L.; Du, Q.; Liu, Y.

2017-12-01

Planetary Boundary Layer (PBL) parameterization schemes play critical role in numerical weather prediction and research. They describe physical processes associated with the momentum, heat and humidity exchange between land surface and atmosphere. In this study, two non-local (YSU and ACM2) and two local (MYJ and BouLac) planetary boundary layer parameterization schemes in the Weather Research and Forecasting (WRF) model have been tested over the central Tibetan Plateau regarding of their capability to model boundary layer parameters relevant for surface energy exchange. The model performance has been evaluated against measurements from the Third Tibetan Plateau atmospheric scientific experiment (TIPEX-III). Simulated meteorological parameters and turbulence fluxes have been compared with observations through standard statistical measures. Model results show acceptable behavior, but no particular scheme produces best performance for all locations and parameters. All PBL schemes underestimate near surface air temperatures over the Tibetan Plateau. By investigating the surface energy budget components, the results suggest that downward longwave radiation and sensible heat flux are the main factors causing the lower near surface temperature. Because the downward longwave radiation and sensible heat flux are respectively affected by atmosphere moisture and land-atmosphere coupling, improvements in water vapor distribution and land-atmosphere energy exchange is meaningful for better presentation of PBL physical processes over the central Tibetan Plateau.

Physical Examination to Marshall Space Flight Center (MSFC) Employees

NASA Technical Reports Server (NTRS)

1998-01-01

Nurse performs tonometry examination, which measure the tension of the eyeball, during an employee's arnual physical examination given by MSFC Occupational Medicine Environmental Health Services under the Center Operations Directorate.

Physical Fitness and Body Anthropometrics Profiles of the Female Recruits Entering to Voluntary Military Service.

PubMed

Santtila, Matti; Pihlainen, Kai; Koski, Harri; Ojanen, Tommi; Kyröläinen, Heikki

2018-06-13

The physical fitness of male conscripts has decreased, and body mass increased during the last few decades, especially in Nordic countries. However, limited research-based reports are available concerning the physical fitness profiles of female recruits. Therefore, the purpose of this study was to investigate changes in physical fitness and body composition of female recruits entering voluntary Finnish military service between the years 2005 and 2015. Data were collected from the initial fitness tests performed in military units during the first 2 weeks of military service. A total of 3,875 healthy female recruits (19.9 ± 2.1 year) participated in the fitness tests. Fitness tests consisted 12-minute running test and muscle fitness tests, which were sit-ups, push-ups, and standing long jump. Increases in mean body mass (4.2%, p ≤ 0.01) and body mass index (3.8%, p < 0.01) were observed between 2005 and 2015. In addition, the proportion of overweight and obese female recruits increased by 12% (p ≤ 0.001). Mean endurance performance and overall muscle fitness remained unaltered during the study period, except for a decline in push-ups performance. However, the proportion of female recruits with poor endurance performance increased from 19.6% to 27.8% (p ≤ 0.001) between 2005 and 2015. Body mass was inversely associated with 12-minute running test distance (r = -0.35, p ≤ 0.001) and muscle fitness index (r = -0.25, p ≤ 0.001). In conclusion, the present study revealed that an increasing proportion of female recruits are overweight and/or have poor endurance performance, which are known risk factors for musculoskeletal injuries and premature discharge from military service. Therefore, specialized training programs should be designed specifically for female recruits with lower levels of fitness prior to military service.

A GIS application for assessing, mapping, and quantifying the social values of ecosystem services

USGS Publications Warehouse

Sherrouse, Benson C.; Clement, Jessica M.; Semmens, Darius J.

2011-01-01

As human pressures on ecosystems continue to increase, research involving the effective incorporation of social values information into the context of comprehensive ecosystem services assessments is becoming more important. Including quantified, spatially explicit social value metrics in such assessments will improve the analysis of relative tradeoffs among ecosystem services. This paper describes a GIS application, Social Values for Ecosystem Services (SolVES), developed to assess, map, and quantify the perceived social values of ecosystem services by deriving a non-monetary Value Index from responses to a public attitude and preference survey. SolVES calculates and maps the Value Index for social values held by various survey subgroups, as distinguished by their attitudes regarding ecosystem use. Index values can be compared within and among survey subgroups to explore the effect of social contexts on the valuation of ecosystem services. Index values can also be correlated and regressed against landscape metrics SolVES calculates from various environmental data layers. Coefficients derived through these analyses were applied to their corresponding data layers to generate a predicted social value map. This map compared favorably with other SolVES output and led to the addition of a predictive mapping function to SolVES for value transfer to areas where survey data are unavailable. A more robust application is being developed as a public domain tool for decision makers and researchers to map social values of ecosystem services and to facilitate discussions among diverse stakeholders involving relative tradeoffs among different ecosystem services in a variety of physical and social contexts.

A population-based study of physical function and risk for elder abuse reported to social service agency: findings from the Chicago health and aging project.

PubMed

Dong, XinQi; Simon, Melissa; Evans, Denis

2014-10-01

We examined the association between physical function and the risk for reported elder abuse. In the Chicago Health and Aging Project (N = 8,932), 238 participants had reported elder abuse. The independent variable was objectively assessed physical function using both directly observed physical performance testing and self-reported physical function (Katz activity of daily living scale, Nagi physical activity scale, and Rosow Breslau mobility scales). Outcomes were elder abuse and specific subtypes of elder abuse. After adjusting for confounders, lower levels of physical performance testing (OR, 2.71[1.58-4.64]), Katz impairment (OR, 1.84[1.29-2.59]), Nagi impairment (OR, 1.65[1.15-2.37]) and Rosow Breslau (OR, 1.76[1.26-2.47]) were associated with increased risk for elder abuse. Lowest levels of physical performance testing were associated with increased risk for psychological abuse (OR, 2.69[1.27-5.71]), caregiver neglect (OR, 2.66[1.22-5.79]), and financial exploitation (OR, 2.35 [1.21-4.55]). Our results may have important implications to healthcare professional, social services and other disciplines to prevent and treat elder abuse. © The Author(s) 2012.

Maritime vessel obsolescence, life cycle cost and design service life

NASA Astrophysics Data System (ADS)

Dinu, O.; Ilie, A. M.

2015-11-01

Maritime vessels have long service life and great costs of building, manning, operating, maintaining and repairing throughout their life. Major actions are needed to repair, renovate, sometime built or even replace those scrapped when technology or demand changes determine obsolescence. It is regarded as a concern throughout vessel's entire life cycle and reflects changes in expectation regarding performances in functioning, safety and environmental effects. While service live may differ from physical lives, expectations about physical lives is the main factors that determines design service life. Performance and failure are illustrated conceptually and represented in a simplified form considering the evolution of vessels parameters during its service life. In the proposed methodology an accumulated vessel lifecycle cost is analyzed and obsolescence is characterized from ship's design, performances, maintenance and management parameters point of view. Romanian ports feeding Black Sea are investigated in order to provide comprehensive information on: number and types of vessels, transport capacity and life cycle length. Recommendations are to be made in order to insure a best practice in lifecycle management in order to reduce costs.

78 FR 22025 - Eighteenth Meeting: RTCA Special Committee 214, Standards for Air Traffic Data Communication...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-12

... add to the SC deliverables Change 1 to DO-224C ``Singal-in-Space Minimum Aviation System Performance Standards (MASPS) for Advanced VHF Digital Data Communications Including Compatibility with Digital Voice... Performance Standards (MOPS) for Aircraft VDL Mode 2 Physical Link and Network Layer'' Other Business Adjourn...

The vibroacoustic response and sound absorption performance of multilayer, microperforated rib-stiffened plates

NASA Astrophysics Data System (ADS)

Zhou, Haian; Wang, Xiaoming; Wu, Huayong; Meng, Jianbing

2017-10-01

The vibroacoustic response and sound absorption performance of a structure composed of multilayer plates and one rigid back wall are theoretically analyzed. In this structure, all plates are two-dimensional, microperforated, and periodically rib-stiffened. To investigate such a structural system, semianalytical models of one-layer and multilayer plate structures considering the vibration effects are first developed. Then approaches of the space harmonic method and Fourier transforms are applied to a one-layer plate, and finally the cascade connection method is utilized for a multilayer plate structure. Based on fundamental acoustic formulas, the vibroacoustic responses of microperforated stiffened plates are expressed as functions of a series of harmonic amplitudes of plate displacement, which are then solved by employing the numerical truncation method. Applying the inverse Fourier transform, wave propagation, and linear addition properties, the equations of the sound pressures and absorption coefficients for the one-layer and multilayer stiffened plates in physical space are finally derived. Using numerical examples, the effects of the most important physical parameters—for example, the perforation ratio of the plate, sound incident angles, and periodical rib spacing—on sound absorption performance are examined. Numerical results indicate that the sound absorption performance of the studied structure is effectively enhanced by the flexural vibration of the plate in water. Finally, the proposed approaches are validated by comparing the results of stiffened plates of the present work with solutions from previous studies.

EPDM - Silicone blends - a high performance elastomeric composition for automotive applications

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

Mitchell, J.M.

1987-01-01

Styling and design changes have dramatically altered performance requirements for elastomers. High performance engines with electronic fuel injection have increased temperatures under the hood. Therefore, high performance elastomers are required to meet today's service conditions. New technology has been developed to compatibilize EPDM and silicone into high performance elastomeric compositions. These blends have physical, electrical and mechanical properties, for 175/sup 0/C service. Formulations are discussed for applications which require heat and weather resistance.

Defect physics vis-à-vis electrochemical performance in layered mixed-metal oxide cathode materials

NASA Astrophysics Data System (ADS)

Hoang, Khang; Johannes, Michelle

Layered mixed-metal oxides with different compositions of (Ni,Co,Mn) [NCM] or (Ni,Co,Al) [NCA] have been used in commercial lithium-ion batteries. Yet their defect physics and chemistry is still not well understood, despite having important implications for the electrochemical performance. In this presentation, we report a hybrid density functional study of intrinsic point defects in the compositions LiNi1/3Co1/3Mn1/3O2 (NCM1/3) and LiNi1/3Co1/3Al1/3O2 (NCA1/3) which can also be regarded as model compounds for NCM and NCA. We will discuss defect landscapes in NCM1/3 and NCA1/3 under relevant synthesis conditions with a focus on the formation of metal antisite defects and its implications on the electrochemical properties and ultimately the design of NCM and NCA cathode materials.

Software-Reconfigurable Processors for Spacecraft

NASA Technical Reports Server (NTRS)

Farrington, Allen; Gray, Andrew; Bell, Bryan; Stanton, Valerie; Chong, Yong; Peters, Kenneth; Lee, Clement; Srinivasan, Jeffrey

2005-01-01

A report presents an overview of an architecture for a software-reconfigurable network data processor for a spacecraft engaged in scientific exploration. When executed on suitable electronic hardware, the software performs the functions of a physical layer (in effect, acts as a software radio in that it performs modulation, demodulation, pulse-shaping, error correction, coding, and decoding), a data-link layer, a network layer, a transport layer, and application-layer processing of scientific data. The software-reconfigurable network processor is undergoing development to enable rapid prototyping and rapid implementation of communication, navigation, and scientific signal-processing functions; to provide a long-lived communication infrastructure; and to provide greatly improved scientific-instrumentation and scientific-data-processing functions by enabling science-driven in-flight reconfiguration of computing resources devoted to these functions. This development is an extension of terrestrial radio and network developments (e.g., in the cellular-telephone industry) implemented in software running on such hardware as field-programmable gate arrays, digital signal processors, traditional digital circuits, and mixed-signal application-specific integrated circuits (ASICs).

The next generation in optical transport semiconductors: IC solutions at the system level

NASA Astrophysics Data System (ADS)

Gomatam, Badri N.

2005-02-01

In this tutorial overview, we survey some of the challenging problems facing Optical Transport and their solutions using new semiconductor-based technologies. Advances in 0.13um CMOS, SiGe/HBT and InP/HBT IC process technologies and mixed-signal design strategies are the fundamental breakthroughs that have made these solutions possible. In combination with innovative packaging and transponder/transceiver architectures IC approaches have clearly demonstrated enhanced optical link budgets with simultaneously lower (perhaps the lowest to date) cost and manufacturability tradeoffs. This paper will describe: *Electronic Dispersion Compensation broadly viewed as the overcoming of dispersion based limits to OC-192 links and extending link budgets, *Error Control/Coding also known as Forward Error Correction (FEC), *Adaptive Receivers for signal quality monitoring for real-time estimation of Q/OSNR, eye-pattern, signal BER and related temporal statistics (such as jitter). We will discuss the theoretical underpinnings of these receiver and transmitter architectures, provide examples of system performance and conclude with general market trends. These Physical layer IC solutions represent a fundamental new toolbox of options for equipment designers in addressing systems level problems. With unmatched cost and yield/performance tradeoffs, it is expected that IC approaches will provide significant flexibility in turn, for carriers and service providers who must ultimately manage the network and assure acceptable quality of service under stringent cost constraints.

PCT MAO’s Enhanced Performance by Specially Designed Sealers for Superior Service & Environments

DTIC Science & Technology

2014-11-01

PCT’s Process is with low silicon content. • Aluminized Steel + PCT MAO can be a cost effective alternative to Stainless Steel, Super Duplex...is applied PCT – P seal • Typical Layer thickness: 40-80 micron* • Organic sealer • Hydrophobic surface, reduces sedimentation...PCT - S seal • Typical Layer thickness: 10-40 micron* • Organo-ceramic sealer • Hydrophobic surface, reduces sedimentation. PCT Classic 1000

Realizing IoT service's policy privacy over publish/subscribe-based middleware.

PubMed

Duan, Li; Zhang, Yang; Chen, Shiping; Wang, Shiyao; Cheng, Bo; Chen, Junliang

2016-01-01

The publish/subscribe paradigm makes IoT service collaborations more scalable and flexible, due to the space, time and control decoupling of event producers and consumers. Thus, the paradigm can be used to establish large-scale IoT service communication infrastructures such as Supervisory Control and Data Acquisition systems. However, preserving IoT service's policy privacy is difficult in this paradigm, because a classical publisher has little control of its own event after being published; and a subscriber has to accept all the events from the subscribed event type with no choice. Few existing publish/subscribe middleware have built-in mechanisms to address the above issues. In this paper, we present a novel access control framework, which is capable of preserving IoT service's policy privacy. In particular, we adopt the publish/subscribe paradigm as the IoT service communication infrastructure to facilitate the protection of IoT services policy privacy. The key idea in our policy-privacy solution is using a two-layer cooperating method to match bi-directional privacy control requirements: (a) data layer for protecting IoT events; and (b) application layer for preserving the privacy of service policy. Furthermore, the anonymous-set-based principle is adopted to realize the functionalities of the framework, including policy embedding and policy encoding as well as policy matching. Our security analysis shows that the policy privacy framework is Chosen-Plaintext Attack secure. We extend the open source Apache ActiveMQ broker by building into a policy-based authorization mechanism to enforce the privacy policy. The performance evaluation results indicate that our approach is scalable with reasonable overheads.

Combined peak-to-average power ratio reduction and physical layer security enhancement in optical orthogonal frequency division multiplexing visible-light communication systems

NASA Astrophysics Data System (ADS)

Wang, Zhongpeng; Chen, Shoufa

2016-07-01

A physical encryption scheme for discrete Hartley transform (DHT) precoded orthogonal frequency division multiplexing (OFDM) visible-light communication (VLC) systems using frequency domain chaos scrambling is proposed. In the scheme, the chaos scrambling, which is generated by a modified logistic mapping, is utilized to enhance the physical layer of security, and the DHT precoding is employed to reduce of OFDM signal for OFDM-based VLC. The influence of chaos scrambling on peak-to-average power ratio (PAPR) and bit error rate (BER) of systems is studied. The experimental simulation results prove the efficiency of the proposed encryption method for DHT-precoded, OFDM-based VLC systems. Furthermore, the influence of the proposed encryption to the PAPR and BER of systems is evaluated. The experimental results show that the proposed security scheme can protect the DHT-precoded, OFDM-based VLC from eavesdroppers, while keeping the good BER performance of DHT-precoded systems. The BER performance of the encrypted and DHT-precoded system is almost the same as that of the conventional DHT-precoded system without encryption.

MITRE sensor layer prototype

NASA Astrophysics Data System (ADS)

Duff, Francis; McGarry, Donald; Zasada, David; Foote, Scott

2009-05-01

The MITRE Sensor Layer Prototype is an initial design effort to enable every sensor to help create new capabilities through collaborative data sharing. By making both upstream (raw) and downstream (processed) sensor data visible, users can access the specific level, type, and quantities of data needed to create new data products that were never anticipated by the original designers of the individual sensors. The major characteristic that sets sensor data services apart from typical enterprise services is the volume (on the order of multiple terabytes) of raw data that can be generated by most sensors. Traditional tightly coupled processing approaches extract pre-determined information from the incoming raw sensor data, format it, and send it to predetermined users. The community is rapidly reaching the conclusion that tightly coupled sensor processing loses too much potentially critical information.1 Hence upstream (raw and partially processed) data must be extracted, rapidly archived, and advertised to the enterprise for unanticipated uses. The authors believe layered sensing net-centric integration can be achieved through a standardize-encapsulate-syndicateaggregate- manipulate-process paradigm. The Sensor Layer Prototype's technical approach focuses on implementing this proof of concept framework to make sensor data visible, accessible and useful to the enterprise. To achieve this, a "raw" data tap between physical transducers associated with sensor arrays and the embedded sensor signal processing hardware and software has been exploited. Second, we encapsulate and expose both raw and partially processed data to the enterprise within the context of a service-oriented architecture. Third, we advertise the presence of multiple types, and multiple layers of data through geographic-enabled Really Simple Syndication (GeoRSS) services. These GeoRSS feeds are aggregated, manipulated, and filtered by a feed aggregator. After filtering these feeds to bring just the type and location of data sought by multiple processes to the attention of each processing station, just that specifically sought data is downloaded to each process application. The Sensor Layer Prototype participated in a proof-of-concept demonstration in April 2008. This event allowed multiple MITRE innovation programs to interact among themselves to demonstrate the ability to couple value-adding but previously unanticipated users to the enterprise. For this event, the Sensor Layer Prototype was used to show data entering the environment in real time. Multiple data types were encapsulated and added to the database via the Sensor Layer Prototype, specifically National Imagery Transmission Format 2.1 (NITF), NATO Standardization Format 4607 (STANAG 4607), Cursor-on-Target (CoT), Joint Photographic Experts Group (JPEG), Hierarchical Data Format (HDF5) and several additional sensor file formats describing multiple sensors addressing a common scenario.

SDN-Enabled Dynamic Feedback Control and Sensing in Agile Optical Networks

NASA Astrophysics Data System (ADS)

Lin, Likun

Fiber optic networks are no longer just pipelines for transporting data in the long haul backbone. Exponential growth in traffic in metro-regional areas has pushed higher capacity fiber toward the edge of the network, and highly dynamic patterns of heterogeneous traffic have emerged that are often bursty, severely stressing the historical "fat and dumb pipe" static optical network, which would need to be massively over-provisioned to deal with these loads. What is required is a more intelligent network with a span of control over the optical as well as electrical transport mechanisms which enables handling of service requests in a fast and efficient way that guarantees quality of service (QoS) while optimizing capacity efficiency. An "agile" optical network is a reconfigurable optical network comprised of high speed intelligent control system fed by real-time in situ network sensing. It provides fast response in the control and switching of optical signals in response to changing traffic demands and network conditions. This agile control of optical signals is enabled by pushing switching decisions downward in the network stack to the physical layer. Implementing such agility is challenging due to the response dynamics and interactions of signals in the physical layer. Control schemes must deal with issues such as dynamic power equalization, EDFA transients and cascaded noise effects, impairments due to self-phase modulation and dispersion, and channel-to-channel cross talk. If these issues are not properly predicted and mitigated, attempts at dynamic control can drive the optical network into an unstable state. In order to enable high speed actuation of signal modulators and switches, the network controller must be able to make decisions based on predictive models. In this thesis, we consider how to take advantage of Software Defined Networking (SDN) capabilities for network reconfiguration, combined with embedded models that access updates from deployed network monitoring sensors. In order to maintain signal quality while optimizing network resources, we find that it is essential to model and update estimates of the physical link impairments in real-time. In this thesis, we consider the key elements required to enable an agile optical network, with contributions as follows: • Control Framework: extended the SDN concept to include the optical transport network through extensions to the OpenFlow (OF) protocol. A unified SDN control plane is built to facilitate control and management capability across the electrical/packet-switched and optical/circuit-switched portions of the network seamlessly. The SDN control plane serves as a platform to abstract the resources of multilayer/multivendor networks. Through this platform, applications can dynamically request the network resources to meet their service requirements. • Use of In-situ Monitors: enabled real-time physical impairment sensing in the control plane using in-situ Optical Performance Monitoring (OPM) and bit error rate (BER) analyzers. OPM and BER values are used as quantitative indicators of the link status and are fed to the control plane through a high-speed data collection interface to form a closed-loop feedback system to enable adaptive resource allocation. • Predictive Network Model: used a network model embedded in the control layer to study the link status. The estimated results of network status is fed into the control decisions to precompute the network resources. The performance of the network model can be enhanced by the sensing results. • Real-Time Control Algorithms: investigated various dynamic resource allocation mechanisms supporting an agile optical network. Intelligent routing and wavelength switching for recovering from traffic impairments is achieved experimentally in the agile optical network within one second. A distance-adaptive spectrum allocation scheme to address transmission impairments caused by cascaded Wavelength Selective Switches (WSS) is proposed and evaluated for improving network spectral efficiency.

Experimental Study of the Effects of Periodic Unsteady Wakes on Flow Separation in Low Pressure Turbines

NASA Technical Reports Server (NTRS)

Ozturk, Burak; Schobeiri, Meinhard T.

2009-01-01

The present study, which is the first of a series of investigations of low pressure turbine (LPT) boundary layer aerodynamics, is aimed at providing detailed unsteady boundary layer flow information to understand the underlying physics of the inception, onset, and extent of the separation zone. A detailed experimental study on the behavior of the separation zone on the suction surface of a highly loaded LPT-blade under periodic unsteady wake flow is presented. Experimental investigations were performed on a large-scale, high-subsonic unsteady turbine cascade research facility with an integrated wake generator and test section unit. Blade Pak B geometry was used in the cascade. The wakes were generated by continuously moving cylindrical bars device. Boundary layer investigations were performed using hot wire anemometry at Reynolds number of 110,000, based on the blade suction surface length and the exit velocity, for one steady and two unsteady inlet flow conditions, with the corresponding passing frequencies, wake velocities, and turbulence intensities. The reduced frequencies cover the entire operation range of LP-turbines. In addition to the unsteady boundary layer measurements, blade surface pressure measurements were performed at Re = 50,000, 75,000, 100,000, 110,000, and 125,000. For each Reynolds number, surface pressure measurements are carried out at one steady and two periodic unsteady inlet flow conditions. Detailed unsteady boundary layer measurement identifies the onset and extension of the separation zone as well as its behavior under unsteady wake flow. The results, presented in ensemble-averaged and contour plot forms, help to understand the physics of the separation phenomenon under periodic unsteady wake flow.

Use of quality indicators in physical therapist practice: an observational study.

PubMed

Jette, Diane U; Jewell, Dianne V

2012-04-01

The Patient Protection and Affordable Care Act and the Health Care and Education Reconciliation Act of 2010 contain provisions specific to health care quality that apply to physical therapists. Published evidence examining gaps in the quality of physical therapy services is limited. The primary purpose of this study was to determine the use of quality indicators in physical therapist practice. This was an observational study. All members of the Orthopaedic and Private Practice sections of the American Physical Therapy Association were invited to participate by completing an electronic survey. The survey included 22 brief patient descriptions, each followed by questions regarding the use of examinations and interventions based on the 2009 list of Medicare-approved quality measures. Separate multivariate logistic regression models were used to determine the odds ratios related to the performance of each examination and intervention on more than 90% of patients, given perceptions of its importance to care, the burden of performing it, and the level of evidence supporting its use. Participants (n=2,544) reported a relatively low frequency of performing examinations and interventions supporting primary and secondary prevention (3.6%-51.3%) and use of standardized measures (5.5%-35.8%). Perceptions of high importance and low burden were associated with greater odds of performing an examination or intervention. Importance and burden were more influential factors than the perceived availability of evidence to support use of identified techniques. The survey was not assessed for test-retest reliability. A low response rate was a source of potential bias. The study findings suggest that physical therapists may not see themselves as providers of primary or secondary prevention services. Patient management strategies associated with these types of services also may be perceived as relatively unimportant or burdensome.

Compulsory military service as a measure of later physical and cognitive performance in male survivors of childhood cancer.

PubMed

Ahomäki, Ritva; Harila-Saari, Arja; Parkkola, Kai; Matomäki, Jaakko; Lähteenmäki, Päivi M

2017-12-01

Compromised physical fitness and cognitive difficulties have been reported as late effects of cancer treatment during childhood. To assess this issue, the military rankings of cancer survivors in medical checkups at call-up, and conscripts' physical and cognitive performance during the first weeks of compulsory military education were compared to those of matched population controls without a history of cancer. A total of 1680 male patients born between 1960 and 1992 with a malignancy diagnosed before the age of 16 who were alive at the call-up age (18 years) were identified using the Finnish Cancer Registry, and five age, sex and place of residence matched controls for each patient using the Population Register Centre. Data on military service were gathered from Finnish Defense Forces. A conditional logistic regression analysis, the GEE-method with the cumulative logit link function, the chi-square test, the chi-square test for trend and a one-way analysis of variance were used in different analyses. Cancer survivors were exempted from military service more often than the controls (p < .001). The fit-for-service frequency was highest for survivors of kidney tumors (68%) and lowest after irradiated brain tumors (19%). In service, the results of the 12-min running test were poorer than those of controls for leukemia/non-Hodgkin lymphoma (p = .03) and brain tumor (p = .01) survivors. Interestingly, the standing long-jump test was the only muscle test for which survivor groups performed worse than controls. Performance on cognitive tests only differed from controls in brain tumor survivors. Exemption from service is still common under the current guidelines, but fit-for-service survivors do well in military education. These results can be used for reassuring survivors that completion of military service is possible for those fulfilling the national general guidelines for military fitness.

A TMS320-based modem for the aeronautical-satellite core data service

NASA Astrophysics Data System (ADS)

Moher, Michael L.; Lodge, John H.

The International Civil Aviation Organization (ICAO) Future Air Navigation Systems (FANS) committee, the Airlines Electronics Engineering Committee (AEEC), and Inmarsat have been developing standards for an aeronautical satellite communications service. These standards encompass a satellite communications system architecture to provide comprehensive aeronautical communications services. Incorporated into the architecture is a core service capability, providing only low rate data communications, which all service providers and all aircraft earth terminals are required to support. In this paper an implementation of the physical layer of this standard for the low data rate core service is described. This is a completely digital modem (up to a low intermediate frequency). The implementation uses a single TMS320C25 chip for the transmit baseband functions of scrambling, encoding, interleaving, block formatting and modulation. The receiver baseband unit uses a dual processor configuration to implement the functions of demodulation, synchronization, de-interleaving, decoding and de-scrambling. The hardware requirements, the software structure and the algorithms of this implementation are described.

Assessing Routing Strategies for Cognitive Radio Sensor Networks

PubMed Central

Zubair, Suleiman; Fisal, Norsheila; Baguda, Yakubu S.; Saleem, Kashif

2013-01-01

Interest in the cognitive radio sensor network (CRSN) paradigm has gradually grown among researchers. This concept seeks to fuse the benefits of dynamic spectrum access into the sensor network, making it a potential player in the next generation (NextGen) network, which is characterized by ubiquity. Notwithstanding its massive potential, little research activity has been dedicated to the network layer. By contrast, we find recent research trends focusing on the physical layer, the link layer and the transport layers. The fact that the cross-layer approach is imperative, due to the resource-constrained nature of CRSNs, can make the design of unique solutions non-trivial in this respect. This paper seeks to explore possible design opportunities with wireless sensor networks (WSNs), cognitive radio ad-hoc networks (CRAHNs) and cross-layer considerations for implementing viable CRSN routing solutions. Additionally, a detailed performance evaluation of WSN routing strategies in a cognitive radio environment is performed to expose research gaps. With this work, we intend to lay a foundation for developing CRSN routing solutions and to establish a basis for future work in this area. PMID:24077319

A metro-access integrated network with all-optical virtual private network function using DPSK/ASK modulation format

NASA Astrophysics Data System (ADS)

Tian, Yue; Leng, Lufeng; Su, Yikai

2008-11-01

All-optical virtual private network (VPN), which offers dedicated optical channels to connect users within a VPN group, is considered a promising approach to efficient internetworking with low latency and enhanced security implemented in the physical layer. On the other hand, time-division multiplexed (TDM) / wavelength-division multiplexed (WDM) network architecture based on a feeder-ring with access-tree topology, is considered a pragmatic migration scenario from current TDM-PONs to future WDM-PONs and a potential convergence scheme for access and metropolitan networks, due to its efficiently shared hardware and bandwidth resources. All-optical VPN internetworking in such a metro-access integrated structure is expected to cover a wider service area and therefore is highly desirable. In this paper, we present a TDM/WDM metro-access integrated network supporting all-optical VPN internetworking among ONUs in different sub- PONs based on orthogonal differential-phase-shift keying (DPSK) / amplitude-shift keying (ASK) modulation format. In each ONU, no laser but a single Mach-Zehnder modulator (MZM) is needed for the upstream and VPN signal generation, which is cost-effective. Experiments and simulations are performed to verify its feasibility as a potential solution to the future access service.

Detecting Water Bodies in LANDSAT8 Oli Image Using Deep Learning

NASA Astrophysics Data System (ADS)

Jiang, W.; He, G.; Long, T.; Ni, Y.

2018-04-01

Water body identifying is critical to climate change, water resources, ecosystem service and hydrological cycle. Multi-layer perceptron(MLP) is the popular and classic method under deep learning framework to detect target and classify image. Therefore, this study adopts this method to identify the water body of Landsat8. To compare the performance of classification, the maximum likelihood and water index are employed for each study area. The classification results are evaluated from accuracy indices and local comparison. Evaluation result shows that multi-layer perceptron(MLP) can achieve better performance than the other two methods. Moreover, the thin water also can be clearly identified by the multi-layer perceptron. The proposed method has the application potential in mapping global scale surface water with multi-source medium-high resolution satellite data.

Optical network democratization.

PubMed

Nejabati, Reza; Peng, Shuping; Simeonidou, Dimitra

2016-03-06

The current Internet infrastructure is not able to support independent evolution and innovation at physical and network layer functionalities, protocols and services, while at same time supporting the increasing bandwidth demands of evolving and heterogeneous applications. This paper addresses this problem by proposing a completely democratized optical network infrastructure. It introduces the novel concepts of the optical white box and bare metal optical switch as key technology enablers for democratizing optical networks. These are programmable optical switches whose hardware is loosely connected internally and is completely separated from their control software. To alleviate their complexity, a multi-dimensional abstraction mechanism using software-defined network technology is proposed. It creates a universal model of the proposed switches without exposing their technological details. It also enables a conventional network programmer to develop network applications for control of the optical network without specific technical knowledge of the physical layer. Furthermore, a novel optical network virtualization mechanism is proposed, enabling the composition and operation of multiple coexisting and application-specific virtual optical networks sharing the same physical infrastructure. Finally, the optical white box and the abstraction mechanism are experimentally evaluated, while the virtualization mechanism is evaluated with simulation. © 2016 The Author(s).

Framework of distributed coupled atmosphere-ocean-wave modeling system

NASA Astrophysics Data System (ADS)

Wen, Yuanqiao; Huang, Liwen; Deng, Jian; Zhang, Jinfeng; Wang, Sisi; Wang, Lijun

2006-05-01

In order to research the interactions between the atmosphere and ocean as well as their important role in the intensive weather systems of coastal areas, and to improve the forecasting ability of the hazardous weather processes of coastal areas, a coupled atmosphere-ocean-wave modeling system has been developed. The agent-based environment framework for linking models allows flexible and dynamic information exchange between models. For the purpose of flexibility, portability and scalability, the framework of the whole system takes a multi-layer architecture that includes a user interface layer, computational layer and service-enabling layer. The numerical experiment presented in this paper demonstrates the performance of the distributed coupled modeling system.

An autonomous recovery mechanism against optical distribution network failures in EPON

NASA Astrophysics Data System (ADS)

Liem, Andrew Tanny; Hwang, I.-Shyan; Nikoukar, AliAkbar

2014-10-01

Ethernet Passive Optical Network (EPON) is chosen for servicing diverse applications with higher bandwidth and Quality-of-Service (QoS), starting from Fiber-To-The-Home (FTTH), FTTB (business/building) and FTTO (office). Typically, a single OLT can provide services to both residential and business customers on the same Optical Line Terminal (OLT) port; thus, any failures in the system will cause a great loss for both network operators and customers. Network operators are looking for low-cost and high service availability mechanisms that focus on the failures that occur within the drop fiber section because the majority of faults are in this particular section. Therefore, in this paper, we propose an autonomous recovery mechanism that provides protection and recovery against Drop Distribution Fiber (DDF) link faults or transceiver failure at the ONU(s) in EPON systems. In the proposed mechanism, the ONU can automatically detect any signal anomalies in the physical layer or transceiver failure, switching the working line to the protection line and sending the critical event alarm to OLT via its neighbor. Each ONU has a protection line, which is connected to the nearest neighbor ONU, and therefore, when failure occurs, the ONU can still transmit and receive data via the neighbor ONU. Lastly, the Fault Dynamic Bandwidth Allocation for recovery mechanism is presented. Simulation results show that our proposed autonomous recovery mechanism is able to maintain the overall QoS performance in terms of mean packet delay, system throughput, packet loss and EF jitter.

Using the ACR/NEMA standard with TCP/IP and Ethernet

NASA Astrophysics Data System (ADS)

Chimiak, William J.; Williams, Rodney C.

1991-07-01

There is a need for a consolidated picture archival and communications system (PACS) in hospitals. At the Bowman Gray School of Medicine of Wake Forest University (BGSM), the authors are enhancing the ACR/NEMA Version 2 protocol using UNIX sockets and TCP/IP to greatly improve connectivity. Initially, nuclear medicine studies using gamma cameras are to be sent to PACS. The ACR/NEMA Version 2 protocol provides the functionality of the upper three layers of the open system interconnection (OSI) model in this implementation. The images, imaging equipment information, and patient information are then sent in ACR/NEMA format to a software socket. From there it is handed to the TCP/IP protocol, which provides the transport and network service. TCP/IP, in turn, uses the services of IEEE 802.3 (Ethernet) to complete the connectivity. The advantage of this implementation is threefold: (1) Only one I/O port is consumed by numerous nuclear medicine cameras, instead of a physical port for each camera. (2) Standard protocols are used which maximize interoperability with ACR/NEMA compliant PACSs. (3) The use of sockets allows a migration path to the transport and networking services of OSIs TP4 and connectionless network service as well as the high-performance protocol being considered by the American National Standards Institute (ANSI) and the International Standards Organization (ISO) -- the Xpress Transfer Protocol (XTP). The use of sockets also gives access to ANSI's Fiber Distributed Data Interface (FDDI) as well as other high-speed network standards.

Computer Self-Efficacy, Computer Anxiety, Performance and Personal Outcomes of Turkish Physical Education Teachers

ERIC Educational Resources Information Center

Aktag, Isil

2015-01-01

The purpose of this study is to determine the computer self-efficacy, performance outcome, personal outcome, and affect and anxiety level of physical education teachers. Influence of teaching experience, computer usage and participation of seminars or in-service programs on computer self-efficacy level were determined. The subjects of this study…

Centralized Routing and Scheduling Using Multi-Channel System Single Transceiver in 802.16d

NASA Astrophysics Data System (ADS)

Al-Hemyari, A.; Noordin, N. K.; Ng, Chee Kyun; Ismail, A.; Khatun, S.

This paper proposes a cross-layer optimized strategy that reduces the effect of interferences from neighboring nodes within a mesh networks. This cross-layer design relies on the routing information in network layer and the scheduling table in medium access control (MAC) layer. A proposed routing algorithm in network layer is exploited to find the best route for all subscriber stations (SS). Also, a proposed centralized scheduling algorithm in MAC layer is exploited to assign a time slot for each possible node transmission. The cross-layer optimized strategy is using multi-channel single transceiver and single channel single transceiver systems for WiMAX mesh networks (WMNs). Each node in WMN has a transceiver that can be tuned to any available channel for eliminating the secondary interference. Among the considered parameters in the performance analysis are interference from the neighboring nodes, hop count to the base station (BS), number of children per node, slot reuse, load balancing, quality of services (QoS), and node identifier (ID). Results show that the proposed algorithms significantly improve the system performance in terms of length of scheduling, channel utilization ratio (CUR), system throughput, and average end to end transmission delay.

Ceph-based storage services for Run2 and beyond

NASA Astrophysics Data System (ADS)

van der Ster, Daniel C.; Lamanna, Massimo; Mascetti, Luca; Peters, Andreas J.; Rousseau, Hervé

2015-12-01

In 2013, CERN IT evaluated then deployed a petabyte-scale Ceph cluster to support OpenStack use-cases in production. With now more than a year of smooth operations, we will present our experience and tuning best-practices. Beyond the cloud storage use-cases, we have been exploring Ceph-based services to satisfy the growing storage requirements during and after Run2. First, we have developed a Ceph back-end for CASTOR, allowing this service to deploy thin disk server nodes which act as gateways to Ceph; this feature marries the strong data archival and cataloging features of CASTOR with the resilient and high performance Ceph subsystem for disk. Second, we have developed RADOSFS, a lightweight storage API which builds a POSIX-like filesystem on top of the Ceph object layer. When combined with Xrootd, RADOSFS can offer a scalable object interface compatible with our HEP data processing applications. Lastly the same object layer is being used to build a scalable and inexpensive NFS service for several user communities.

Design and construction of a multi-layer CsI(Tl) telescope for high-energy reaction studies

NASA Astrophysics Data System (ADS)

Yan, D.; Sun, Z. Y.; Yue, K.; Wang, S. T.; Zhang, X. H.; Yu, Y. H.; Chen, J. L.; Tang, S. W.; Fang, F.; Zhou, Y.; Sun, Y.; Wang, Z. M.; Sun, Y. Z.

2017-01-01

A prototype of a new CsI(Tl) telescope, which will be used in the reaction studies of light isotopes with energy of several hundred AMeV, was constructed and tested at the Institute of Modern Physics, Chinese Academy of Sciences. The telescope has a multi-layer structure, and the range information was obtained to improve the particle identification performance. This prototype has seven layers of different thickness. An energy resolution of 5.0% (FWHM) was obtained for one of the layers in a beam test experiment. Positive improvement for the identification of 14O and 15O isotopes was achieved using the range information.

Analyses of Hubble Space Telescope Aluminized-Teflon Multilayer Insulation Blankets Retrieved After 19 Years of Space Exposure

NASA Technical Reports Server (NTRS)

de Groh, Kim K.; Perry, Bruce A.; Mohammed, Jelila S.; Banks, Bruce

2015-01-01

Since its launch in April 1990, the Hubble Space Telescope (HST) has made many important observations from its vantage point in low Earth orbit (LEO). However, as seen during five servicing missions, the outer layer of multilayer insulation (MLI) has become increasingly embrittled and has cracked in many areas. In May 2009, during the 5th servicing mission (called SM4), two MLI blankets were replaced with new insulation and the space-exposed MLI blankets were retrieved for degradation analyses by teams at NASA Glenn Research Center (GRC) and NASA Goddard Space Flight Center (GSFC). The retrieved MLI blankets were from Equipment Bay 8, which received direct sunlight, and Equipment Bay 5, which received grazing sunlight. Each blanket was divided into several regions based on environmental exposure and/or physical appearance. The aluminized-Teflon (DuPont, Wilmington, DE) fluorinated ethylene propylene (Al-FEP) outer layers of the retrieved MLI blankets have been analyzed for changes in optical, physical, and mechanical properties, along with chemical and morphological changes. Pristine and as-retrieved samples (materials) were heat treated to help understand degradation mechanisms. When compared to pristine material, the analyses have shown how the Al-FEP was severely affected by the space environment. Most notably, the Al-FEP was highly embrittled, fracturing like glass at strains of 1 to 8 percent. Across all measured properties, more significant degradation was observed for Bay 8 material as compared to Bay 5 material. This paper reviews the tensile and bend-test properties, density, thickness, solar absorptance, thermal emittance, x-ray photoelectron spectroscopy (XPS) and energy dispersive spectroscopy (EDS) elemental composition measurements, surface and crack morphologies, and atomic oxygen erosion yields of the Al-FEP outer layer of the retrieved HST blankets after 19 years of space exposure.

Analyses of Hubble Space Telescope Aluminized-Teflon Insulation Retrieved After 19 Years of Space Exposure

NASA Technical Reports Server (NTRS)

deGroh, Kim K.; Waters, Deborah L.; Mohammed, Jelila S.; Perry, Bruce A.; Banks, Bruce A.

2012-01-01

Since its launch in April 1990, the Hubble Space Telescope (HST) has made many important observations from its vantage point in low Earth orbit (LEO). However, as seen during five servicing missions, the outer layer of multilayer insulation (MLI) has become successively more embrittled and has cracked in many areas. In May 2009, during the 5th servicing mission (called SM4), two MLI blankets were replaced with new insulation pieces and the space-exposed MLI blankets were retrieved for degradation analyses by teams at NASA Glenn Research Center (GRC) and NASA Goddard Space Flight Center (GSFC). The MLI blankets were from Equipment Bay 8, which received direct sunlight, and Equipment Bay 5, which received grazing sunlight. Each blanket contained a range of unique regions based on environmental exposure and/or physical appearance. The retrieved MLI blanket s aluminized-Teflon (DuPont) fluorinated ethylene propylene (Al-FEP) outer layers have been analyzed for changes in optical, physical, and mechanical properties, along with space induced chemical and morphological changes. When compared to pristine material, the analyses have shown how the Al-FEP was severely affected by the space environment. This paper reviews tensile properties, solar absorptance, thermal emittance, x-ray photoelectron spectroscopy (XPS) data and atomic oxygen erosion values of the retrieved HST blankets after 19 years of space exposure.

Convergence

NASA Astrophysics Data System (ADS)

Darcie, Thomas E.; Doverspike, Robert; Zirngibl, Martin; Korotky, Steven K.

2005-09-01

Call for Papers: Convergence The Journal of Optical Networking (JON) invites submissions to a special issue on Convergence. Convergence has become a popular theme in telecommunications, one that has broad implications across all segments of the industry. Continual evolution of technology and applications continues to erase lines between traditionally separate lines of business, with dramatic consequences for vendors, service providers, and consumers. Spectacular advances in all layers of optical networking-leading to abundant, dynamic, cost-effective, and reliable wide-area and local-area connections-have been essential drivers of this evolution. As services and networks continue to evolve towards some notion of convergence, the continued role of optical networks must be explored. One vision of convergence renders all information in a common packet (especially IP) format. This vision is driven by the proliferation of data services. For example, time-division multiplexed (TDM) voice becomes VoIP. Analog cable-television signals become MPEG bits streamed to digital set-top boxes. T1 or OC-N private lines migrate to Ethernet virtual private networks (VPNs). All these packets coexist peacefully within a single packet-routing methodology built on an optical transport layer that combines the flexibility and cost of data networks with telecom-grade reliability. While this vision is appealing in its simplicity and shared widely, specifics of implementation raise many challenges and differences of opinion. For example, many seek to expand the role of Ethernet in these transport networks, while massive efforts are underway to make traditional TDM networks more data friendly within an evolved but backward-compatible SDH/SONET (synchronous digital hierarchy and synchronous optical network) multiplexing hierarchy. From this common underlying theme follow many specific instantiations. Examples include the convergence at the physical, logical, and operational levels of voice and data, video and data, private-line and virtual private-line, fixed and mobile, and local and long-haul services. These trends have many consequences for consumers, vendors, and carriers. Faced with large volumes of low-margin data traffic mixed with traditional voice services, the need for capital conservation and operational efficiency drives carriers away from today's separate overlay networks for each service and towards "converged" platforms. For example, cable operators require transport of multiple services over both hybrid fiber coax (HFC) and DWDM transport technologies. Local carriers seek an economical architecture to deliver integrated services on optically enabled broadband-access networks. Services over wireless-access networks must coexist with those from wired networks. In each case, convergence of networks and services inspires an important set of questions and challenges, driven by the need for low cost, operational efficiency, service performance requirements, and optical transport technology options. This Feature Issue explores the various interpretations and implications of network convergence pertinent to optical networking. How does convergence affect the evolution of optical transport-layer and control approaches? Are the implied directions consistent with research vision for optical networks? Substantial challenges remain. Papers are solicited across the broad spectrum of interests. These include, but are not limited to: Architecture, design and performance of optical wide-area-network (WAN), metro, and access networks Integration strategies for multiservice transport platforms Access methods that bridge traditional and emerging services Network signaling and control methodologies All-optical packet routing and switching techniques To submit to this special issue, follow the normal procedure for submission to JON, indicating "Convergence feature" in the "Comments" field of the online submission form. For all other questions relating to this feature issue, please send an e-mail to jon@osa.org, subject line "Convergence." Additional information can be found on the JON website: http://www.osa-jon.org/submission/ Submission Deadline: 1 October 2005

Convergence

NASA Astrophysics Data System (ADS)

Darcie, Thomas E.; Doverspike, Robert; Zirngibl, Martin; Korotky, Steven K.

2004-12-01

Convergence has become a popular theme in telecommunications, one that has broad implications across all segments of the industry. Continual evolution of technology and applications continues to erase lines between traditionally separate lines of business, with dramatic consequences for vendors, service providers, and consumers. Spectacular advances in all layers of optical networking-leading to abundant, dynamic, cost-effective, and reliable wide-area and local-area connections-have been essential drivers of this evolution. As services and networks continue to evolve towards some notion of convergence, the continued role of optical networks must be explored. One vision of convergence renders all information in a common packet (especially IP) format. This vision is driven by the proliferation of data services. For example, time-division multiplexed (TDM) voice becomes VoIP. Analog cable-television signals become MPEG bits streamed to digital set-top boxes. T1 or OC-N private lines migrate to Ethernet virtual private networks (VPNs). All these packets coexist peacefully within a single packet-routing methodology built on an optical transport layer that combines the flexibility and cost of data networks with telecom-grade reliability. While this vision is appealing in its simplicity and shared widely, specifics of implementation raise many challenges and differences of opinion. For example, many seek to expand the role of Ethernet in these transport networks, while massive efforts are underway to make traditional TDM networks more data friendly within an evolved but backward-compatible SDH/SONET (synchronous digital hierarchy and synchronous optical network) multiplexing hierarchy. From this common underlying theme follow many specific instantiations. Examples include the convergence at the physical, logical, and operational levels of voice and data, video and data, private-line and virtual private-line, fixed and mobile, and local and long-haul services. These trends have many consequences for consumers, vendors, and carriers. Faced with large volumes of low-margin data traffic mixed with traditional voice services, the need for capital conservation and operational efficiency drives carriers away from today's separate overlay networks for each service and towards "converged" platforms. For example, cable operators require transport of multiple services over both hybrid fiber coax (HFC) and DWDM transport technologies. Local carriers seek an economical architecture to deliver integrated services on optically enabled broadband-access networks. Services over wireless-access networks must coexist with those from wired networks. In each case, convergence of networks and services inspires an important set of questions and challenges, driven by the need for low cost, operational efficiency, service performance requirements, and optical transport technology options. This Feature Issue explores the various interpretations and implications of network convergence pertinent to optical networking. How does convergence affect the evolution of optical transport-layer and control approaches? Are the implied directions consistent with research vision for optical networks? Substantial challenges remain. Papers are solicited across the broad spectrum of interests. These include, but are not limited to:

• Architecture, design and performance of optical wide-area-network (WAN), metro, and access networks
• Integration strategies for multiservice transport platforms
• Access methods that bridge traditional and emerging services
• Network signaling and control methodologies
• All-optical packet routing and switching techniques

Manuscript Submission

On the Nonlinear Stability of a High-Speed, Axisymmetric Boundary Layer

DTIC Science & Technology

1991-03-01

NASA Contractor Report 187538 IN ICASE Report No. 91-30 ICASE ON THE NONLINEAR STABILITY OF A HIGH-SPEED, AXISYMMETRIC BOUNDARY LAYER C. David Pruett... David Pruett National Research Council Associate Lian L. Ng Analytical Services and Materials Gordon Erlebacher t Senior Scientist, ICASE NASA Langley...Oct. 5, 1989. 29) Fetterman , D. E., Jr., "Preliminary Sizing and Performance of Aircraft", NASA TM-86357, July 1985. 30) Gaster, M., "A Note on the

Development of an Internal Real-Time Wireless Diagnostic Tool for a Proton Exchange Membrane Fuel Cell

PubMed Central

Lee, Chi-Yuan; Chen, Chia-Hung; Tsai, Chao-Hsuan; Wang, Yu-Syuan

2018-01-01

To prolong the operating time of unmanned aerial vehicles which use proton exchange membrane fuel cells (PEMFC), the performance of PEMFC is the key. However, a long-term operation can make the Pt particles of the catalyst layer and the pollutants in the feedstock gas bond together (e.g., CO), so that the catalyst loses reaction activity. The performance decay and aging of PEMFC will be influenced by operating conditions, temperature, flow and CO concentration. Therefore, this study proposes the development of an internal real-time wireless diagnostic tool for PEMFC, and uses micro-electro-mechanical systems (MEMS) technology to develop a wireless and thin (<50 μm) flexible integrated (temperature, flow and CO) microsensor. The technical advantages are (1) compactness and three wireless measurement functions; (2) elastic measurement position and accurate embedding; (3) high accuracy and sensitivity and quick response; (4) real-time wireless monitoring of dynamic performance of PEMFC; (5) customized design and development. The flexible integrated microsensor is embedded in the PEMFC, three important physical quantities in the PEMFC, which are the temperature, flow and CO, can be measured simultaneously and instantly, so as to obtain the authentic and complete reaction in the PEMFC to enhance the performance of PEMFC and to prolong the service life. PMID:29342832

Development of an Internal Real-Time Wireless Diagnostic Tool for a Proton Exchange Membrane Fuel Cell.

PubMed

Lee, Chi-Yuan; Chen, Chia-Hung; Tsai, Chao-Hsuan; Wang, Yu-Syuan

2018-01-13

To prolong the operating time of unmanned aerial vehicles which use proton exchange membrane fuel cells (PEMFC), the performance of PEMFC is the key. However, a long-term operation can make the Pt particles of the catalyst layer and the pollutants in the feedstock gas bond together (e.g., CO), so that the catalyst loses reaction activity. The performance decay and aging of PEMFC will be influenced by operating conditions, temperature, flow and CO concentration. Therefore, this study proposes the development of an internal real-time wireless diagnostic tool for PEMFC, and uses micro-electro-mechanical systems (MEMS) technology to develop a wireless and thin (<50 μm) flexible integrated (temperature, flow and CO) microsensor. The technical advantages are (1) compactness and three wireless measurement functions; (2) elastic measurement position and accurate embedding; (3) high accuracy and sensitivity and quick response; (4) real-time wireless monitoring of dynamic performance of PEMFC; (5) customized design and development. The flexible integrated microsensor is embedded in the PEMFC, three important physical quantities in the PEMFC, which are the temperature, flow and CO, can be measured simultaneously and instantly, so as to obtain the authentic and complete reaction in the PEMFC to enhance the performance of PEMFC and to prolong the service life.

Range pattern matching with layer operations and continuous refinements

NASA Astrophysics Data System (ADS)

Tseng, I.-Lun; Lee, Zhao Chuan; Li, Yongfu; Perez, Valerio; Tripathi, Vikas; Ong, Jonathan Yoong Seang

2018-03-01

At advanced and mainstream process nodes (e.g., 7nm, 14nm, 22nm, and 55nm process nodes), lithography hotspots can exist in layouts of integrated circuits even if the layouts pass design rule checking (DRC). Existence of lithography hotspots in a layout can cause manufacturability issues, which can result in yield losses of manufactured integrated circuits. In order to detect lithography hotspots existing in physical layouts, pattern matching (PM) algorithms and commercial PM tools have been developed. However, there are still needs to use DRC tools to perform PM operations. In this paper, we propose a PM synthesis methodology, which uses a continuous refinement technique, for the automatic synthesis of a given lithography hotspot pattern into a DRC deck, which consists of layer operation commands, so that an equivalent PM operation can be performed by executing the synthesized deck with the use of a DRC tool. Note that the proposed methodology can deal with not only exact patterns, but also range patterns. Also, lithography hotspot patterns containing multiple layers can be processed. Experimental results show that the proposed methodology can accurately and efficiently detect lithography hotspots in physical layouts.

Underwater Wireless Sensor Networks: how do acoustic propagation models impact the performance of higher-level protocols?

PubMed

Llor, Jesús; Malumbres, Manuel P

2012-01-01

Several Medium Access Control (MAC) and routing protocols have been developed in the last years for Underwater Wireless Sensor Networks (UWSNs). One of the main difficulties to compare and validate the performance of different proposals is the lack of a common standard to model the acoustic propagation in the underwater environment. In this paper we analyze the evolution of underwater acoustic prediction models from a simple approach to more detailed and accurate models. Then, different high layer network protocols are tested with different acoustic propagation models in order to determine the influence of environmental parameters on the obtained results. After several experiments, we can conclude that higher-level protocols are sensitive to both: (a) physical layer parameters related to the network scenario and (b) the acoustic propagation model. Conditions like ocean surface activity, scenario location, bathymetry or floor sediment composition, may change the signal propagation behavior. So, when designing network architectures for UWSNs, the role of the physical layer should be seriously taken into account in order to assert that the obtained simulation results will be close to the ones obtained in real network scenarios.

Underwater Wireless Sensor Networks: How Do Acoustic Propagation Models Impact the Performance of Higher-Level Protocols?

PubMed Central

Llor, Jesús; Malumbres, Manuel P.

2012-01-01

Several Medium Access Control (MAC) and routing protocols have been developed in the last years for Underwater Wireless Sensor Networks (UWSNs). One of the main difficulties to compare and validate the performance of different proposals is the lack of a common standard to model the acoustic propagation in the underwater environment. In this paper we analyze the evolution of underwater acoustic prediction models from a simple approach to more detailed and accurate models. Then, different high layer network protocols are tested with different acoustic propagation models in order to determine the influence of environmental parameters on the obtained results. After several experiments, we can conclude that higher-level protocols are sensitive to both: (a) physical layer parameters related to the network scenario and (b) the acoustic propagation model. Conditions like ocean surface activity, scenario location, bathymetry or floor sediment composition, may change the signal propagation behavior. So, when designing network architectures for UWSNs, the role of the physical layer should be seriously taken into account in order to assert that the obtained simulation results will be close to the ones obtained in real network scenarios. PMID:22438712

An Assessment of Gigabit Ethernet Technology and Its Applications at the NASA Glenn Research Center

NASA Technical Reports Server (NTRS)

Bakes, Catherine Murphy; Kim, Chan M.; Ramos, Calvin T.

2000-01-01

This paper describes Gigabit Ethernet and its role in supporting R&D programs at NASA Glenn. These programs require an advanced high-speed network capable of transporting multimedia traffic, including real-time visualization, high- resolution graphics, and scientific data. GigE is a 1 Gbps extension to 10 and 100 Mbps Ethernet. The IEEE 802.3z and 802.3ab standards define the MAC layer and 1000BASE-X and 1000BASE-T physical layer specifications for GigE. GigE switches and buffered distributors support IEEE 802.3x flow control. The paper also compares GigE with ATM in terms of quality of service, data rate, throughput, scalability, interoperability, network management, and cost of ownership.

Chemical Intercalation of Topological Insulator Grid Nanostructures for High-Performance Transparent Electrodes.

PubMed

Guo, Yunfan; Zhou, Jinyuan; Liu, Yujing; Zhou, Xu; Yao, Fengrui; Tan, Congwei; Wu, Jinxiong; Lin, Li; Liu, Kaihui; Liu, Zhongfan; Peng, Hailin

2017-11-01

2D layered nanomaterials with strong covalent bonding within layers and weak van der Waals' interactions between layers have attracted tremendous interest in recent years. Layered Bi 2 Se 3 is a representative topological insulator material in this family, which holds promise for exploration of the fundamental physics and practical applications such as transparent electrode. Here, a simultaneous enhancement of optical transmittancy and electrical conductivity in Bi 2 Se 3 grid electrodes by copper-atom intercalation is presented. These Cu-intercalated 2D Bi 2 Se 3 electrodes exhibit high uniformity over large area and excellent stabilities to environmental perturbations, such as UV light, thermal fluctuation, and mechanical distortion. Remarkably, by intercalating a high density of copper atoms, the electrical and optical performance of Bi 2 Se 3 grid electrodes is greatly improved from 900 Ω sq -1 , 68% to 300 Ω sq -1 , 82% in the visible range; with better performance of 300 Ω sq -1 , 91% achieved in the near-infrared region. These unique properties of Cu-intercalated topological insulator grid nanostructures may boost their potential applications in high-performance optoelectronics, especially for infrared optoelectronic devices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Epistemological Perceptions of the Relationship between Physics and Mathematics and Its Effect on Problem-Solving among Pre-Service Teachers at Yarmouk University in Jordan

ERIC Educational Resources Information Center

Al-Omari, Wesal; Miqdadi, Ruba

2014-01-01

The purpose of this paper was to examine the perception pre-service teachers hold to the nature of the relationship between physics and mathematics. The study examined this relationship in reference to their performance in problem solving and strategies they used. The results of this empirical study suggested that most participants hold a naïve…

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

NASA Astrophysics Data System (ADS)

Park, Ju-Won; Kim, JongWon

2004-10-01

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

The tsunami service bus, an integration platform for heterogeneous sensor systems

NASA Astrophysics Data System (ADS)

Haener, R.; Waechter, J.; Kriegel, U.; Fleischer, J.; Mueller, S.

2009-04-01

1. INTRODUCTION Early warning systems are long living and evolving: New sensor-systems and -types may be developed and deployed, sensors will be replaced or redeployed on other locations and the functionality of analyzing software will be improved. To ensure a continuous operability of those systems their architecture must be evolution-enabled. From a computer science point of view an evolution-enabled architecture must fulfill following criteria: • Encapsulation of and functionality on data in standardized services. Access to proprietary sensor data is only possible via these services. • Loose coupling of system constituents which easily can be achieved by implementing standardized interfaces. • Location transparency of services what means that services can be provided everywhere. • Separation of concerns that means breaking a system into distinct features which overlap in functionality as little as possible. A Service Oriented Architecture (SOA) as e. g. realized in the German Indonesian Tsunami Early Warning System (GITEWS) and the advantages of functional integration on the basis of services described below adopt these criteria best. 2. SENSOR INTEGRATION Integration of data from (distributed) data sources is just a standard task in computer science. From few well known solution patterns, taking into account performance and security requirements of early warning systems only functional integration should be considered. Precondition for this is that systems are realized compliant to SOA patterns. Functionality is realized in form of dedicated components communicating via a service infrastructure. These components provide their functionality in form of services via standardized and published interfaces which could be used to access data maintained in - and functionality provided by dedicated components. Functional integration replaces the tight coupling at data level by a dependency on loosely coupled services. If the interfaces of the service providing components remain unchanged, components can be maintained and evolved independently on each other and service functionality as a whole can be reused. In GITEWS the functional integration pattern was adopted by applying the principles of an Enterprise Service Bus (ESB) as a backbone. Four services provided by the so called Tsunami Service Bus (TSB) which are essential for early warning systems are realized compliant to services specified within the Sensor Web Enablement (SWE) initiative of the Open Geospatial Consortium (OGC). 3. ARCHITECTURE The integration platform was developed to access proprietary, heterogeneous sensor data and to provide them in a uniform manner for further use. Its core, the TSB provides both a messaging-backbone and -interfaces on the basis of a Java Messaging Service (JMS). The logical architecture of GITEWS consists of four independent layers: • A resource layer where physical or virtual sensors as well as data or model storages provide relevant measurement-, event- and analysis-data: Utilizable for the TSB are any kind of data. In addition to sensors databases, model data and processing applications are adopted. SWE specifies encoding both to access and to describe these data in a comprehensive way: 1. Sensor Model Language (SensorML): Standardized description of sensors and sensor data 2. Observations and Measurements (O&M): Model and encoding of sensor measurements • A service layer to collect and conduct data from heterogeneous and proprietary resources and provide them via standardized interfaces: The TSB enables interaction with sensors via the following services: 1. Sensor Observation Service (SOS): Standardized access to sensor data 2. Sensor Planning Service (SPS): Controlling of sensors and sensor networks 3. Sensor Alert Service (SAS): Active sending of data if defined events occur 4. Web Notification Service (WNS): Conduction of asynchronous dialogues between services • An orchestration layer where atomic services are composed and arranged to high level processes like a decision support process: One of the outstanding features of service-oriented architectures is the possibility to compose new services from existing ones, which can be done programmatically or via declaration (workflow or process design). This allows e. g. the definition of new warning processes which could be adapted easily to new requirements. • An access layer which may contain graphical user interfaces for decision support, monitoring- or visualization-systems: To for example visualize time series graphical user interfaces request sensor data simply via the SOS. 4.BENEFIT The integration platform is realized on top of well known and widely used open source software implementing industrial standards. New sensors could be added easily to the infrastructure. Client components don't need to be adjusted if new sensor-types or -individuals are added to the system, because they access the sensors via standardized services. With implementing SWE fully compatible to the OGC specification it is possible to establish the "detection" and integration of sensors via the Web. Thus realizing a system of systems that combines early warning system functionality at different levels of detail (distant early warning systems, monitoring systems and any sensor system) is feasible.

Acoustical characterization and parameter optimization of polymeric noise control materials

NASA Astrophysics Data System (ADS)

Homsi, Emile N.

2003-10-01

The sound transmission loss (STL) characteristics of polymer-based materials are considered. Analytical models that predict, characterize and optimize the STL of polymeric materials, with respect to physical parameters that affect performance, are developed for single layer panel configuration and adapted for layered panel construction with homogenous core. An optimum set of material parameters is selected and translated into practical applications for validation. Sound attenuating thermoplastic materials designed to be used as barrier systems in the automotive and consumer industries have certain acoustical characteristics that vary in function of the stiffness and density of the selected material. The validity and applicability of existing theory is explored, and since STL is influenced by factors such as the surface mass density of the panel's material, a method is modified to improve STL performance and optimize load-bearing attributes. An experimentally derived function is applied to the model for better correlation. In-phase and out-of-phase motion of top and bottom layers are considered. It was found that the layered construction of the co-injection type would exhibit fused planes at the interface and move in-phase. The model for the single layer case is adapted to the layered case where it would behave as a single panel. Primary physical parameters that affect STL are identified and manipulated. Theoretical analysis is linked to the resin's matrix attribute. High STL material with representative characteristics is evaluated versus standard resins. It was found that high STL could be achieved by altering materials' matrix and by integrating design solution in the low frequency range. A suggested numerical approach is described for STL evaluation of simple and complex geometries. In practice, validation on actual vehicle systems proved the adequacy of the acoustical characterization process.

77 FR 37001 - Proposed Collection; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-20

... of the Interoperability Services Layer, Attn: Ron Chen, 400 Gigling Road, Seaside, CA 93955. Title; Associated Form; and OMB Number: Interoperability Services Layer; OMB Control Number 0704-TBD. Needs and Uses... INFORMATION: Summary of Information Collection IoLS (Interoperability Layer Services) is an application in a...

Synthesis of the Multilayer Cryogenic Insulation Modelling and Measurements

NASA Astrophysics Data System (ADS)

Polinski, J.; Chorowski, M.; Choudhury, A.; Datta, T. S.

2008-03-01

A thermodynamic approach towards insulation systems in cryogenic engineering is proposed. A mathematical model of the heat transfer through multilayer insulation (MLI) has been developed and experimentally verified. The model comprises both physical and engineering parameters determining the MLI performance and enables a complex optimization of the insulation system including the choice of the insulation location in a vacuum space. The model takes into account an interstitial (interlayer) gas pressure variation with the MLI number of layers and layers density. The paper presents the discussion of MLI performance in different conditions and provides comparison of computation results with experimental reference and measured data.

Optical burst switching for the next generation Optical Internet

NASA Astrophysics Data System (ADS)

Yoo, Myungsik

2000-11-01

In recent years, Internet Protocol (IP) over Wavelength Division Multiplexing (WDM) networks for the next generation Internet (or the so-called Optical Internet) have received enormous attention. There are two main drivers for an Optical Internet. One is the explosion of Internet traffic, which seems to keep growing exponentially. The other driver is the rapid advance in the WDM optical networking technology. In this study, key issues in the optical (WDM) layer will be investigated. As a novel switching paradigm for Optical Internet, Optical Burst Switching (OBS) is discussed. By leveraging the attractive properties of optical communications and at the same time, taking into account its limitations, OBS can combine the best of optical circuit-switching and packet/cell switching. The general concept of JET-based OBS protocol is described, including offset time and delayed reservation. In the next generation Optical Internet, one must address how to support Quality of Service (QoS) at the WDM layer since current IP provides only best effort services. The offset-time- based QoS scheme is proposed as a way of supporting QoS at the WDM layer. Unlike existing QoS schemes, offset- time-based QoS scheme does not mandate the use of buffer to differentiate services. For the bufferless WDM switch, the performance of offset- time-based QoS scheme is evaluated in term of blocking probability. In addition, the extra offset time required for class isolation is quantified and the theoretical bounds on blocking probability are analyzed. The offset-time-based scheme is applied to WDM switch with limited fiber delay line (FDL) buffer. We evaluate the effect of having a FDL buffer on the QoS performance of the offset-time-based scheme in terms of the loss probability and queuing delay of bursts. Finally, in order to dimension the network resources in Optical Internet backbone networks, the performance of the offset-time-based QoS scheme is evaluated for the multi-hop case. In particular, we consider very high performance Backbone Network Service (vBNS) backbone network. Various policies such as drop, retransmission, deflection routing and buffering are considered for performance evaluation. The performance results obtained under these policies are compared to decide the most efficient policy for the WDM backbone network.

Performance Analysis of Physical Layer Security of Opportunistic Scheduling in Multiuser Multirelay Cooperative Networks

PubMed Central

Shim, Kyusung; Do, Nhu Tri; An, Beongku

2017-01-01

In this paper, we study the physical layer security (PLS) of opportunistic scheduling for uplink scenarios of multiuser multirelay cooperative networks. To this end, we propose a low-complexity, yet comparable secrecy performance source relay selection scheme, called the proposed source relay selection (PSRS) scheme. Specifically, the PSRS scheme first selects the least vulnerable source and then selects the relay that maximizes the system secrecy capacity for the given selected source. Additionally, the maximal ratio combining (MRC) technique and the selection combining (SC) technique are considered at the eavesdropper, respectively. Investigating the system performance in terms of secrecy outage probability (SOP), closed-form expressions of the SOP are derived. The developed analysis is corroborated through Monte Carlo simulation. Numerical results show that the PSRS scheme significantly improves the secure ability of the system compared to that of the random source relay selection scheme, but does not outperform the optimal joint source relay selection (OJSRS) scheme. However, the PSRS scheme drastically reduces the required amount of channel state information (CSI) estimations compared to that required by the OJSRS scheme, specially in dense cooperative networks. PMID:28212286

Double-Layer Structured CO2 Adsorbent Functionalized with Modified Polyethyleneimine for High Physical and Chemical Stability.

PubMed

Jeon, Sunbin; Jung, Hyunchul; Kim, Sung Hyun; Lee, Ki Bong

2018-06-18

CO 2 capture using polyethyleneimine (PEI)-impregnated silica adsorbents has been receiving a lot of attention. However, the absence of physical stability (evaporation and leaching of amine) and chemical stability (urea formation) of the PEI-impregnated silica adsorbent has been generally established. Therefore, in this study, a double-layer impregnated structure, developed using modified PEI, is newly proposed to enhance the physical and chemical stabilities of the adsorbent. Epoxy-modified PEI and diepoxide-cross-linked PEI were impregnated via a dry impregnation method in the first and second layers, respectively. The physical stability of the double-layer structured adsorbent was noticeably enhanced when compared to the conventional adsorbents with a single layer. In addition to the enhanced physical stability, the result of simulated temperature swing adsorption cycles revealed that the double-layer structured adsorbent presented a high potential working capacity (3.5 mmol/g) and less urea formation under CO 2 -rich regeneration conditions. The enhanced physical and chemical stabilities as well as the high CO 2 working capacity of the double-layer structured adsorbent were mainly attributed to the second layer consisting of diepoxide-cross-linked PEI.

Architecture Design of Healthcare Software-as-a-Service Platform for Cloud-Based Clinical Decision Support Service.

PubMed

Oh, Sungyoung; Cha, Jieun; Ji, Myungkyu; Kang, Hyekyung; Kim, Seok; Heo, Eunyoung; Han, Jong Soo; Kang, Hyunggoo; Chae, Hoseok; Hwang, Hee; Yoo, Sooyoung

2015-04-01

To design a cloud computing-based Healthcare Software-as-a-Service (SaaS) Platform (HSP) for delivering healthcare information services with low cost, high clinical value, and high usability. We analyzed the architecture requirements of an HSP, including the interface, business services, cloud SaaS, quality attributes, privacy and security, and multi-lingual capacity. For cloud-based SaaS services, we focused on Clinical Decision Service (CDS) content services, basic functional services, and mobile services. Microsoft's Azure cloud computing for Infrastructure-as-a-Service (IaaS) and Platform-as-a-Service (PaaS) was used. The functional and software views of an HSP were designed in a layered architecture. External systems can be interfaced with the HSP using SOAP and REST/JSON. The multi-tenancy model of the HSP was designed as a shared database, with a separate schema for each tenant through a single application, although healthcare data can be physically located on a cloud or in a hospital, depending on regulations. The CDS services were categorized into rule-based services for medications, alert registration services, and knowledge services. We expect that cloud-based HSPs will allow small and mid-sized hospitals, in addition to large-sized hospitals, to adopt information infrastructures and health information technology with low system operation and maintenance costs.

NASA Polar Imagery: Have It Your Way or Have It Our Way

NASA Astrophysics Data System (ADS)

Schmaltz, J. E.; Alarcon, C.; Boller, R. A.; Cechini, M. F.; Davies, D.; Ilavajhala, S.; Hall, J. R.; Huang, T.; Joshi, T.; McGann, J. M.; Murphy, K. J.; Plesea, L.; Roberts, J. T.; Thompson, C. K.; Timmons, E.

2013-12-01

The MODIS Rapid Response project has been providing complete near real-time imagery coverage of Antarctica since December 2008 and the Arctic since March 2009. In late 2009, the Land Atmosphere Near real-time Capability for EOS (LANCE) was created to greatly expand the range of near real-time data products from a variety of Earth Observing System (EOS) instruments. NASA's Earth Observing System Data and Information System (EOSDIS) began exploring methods to distribute these data as imagery in an intuitive, geo-referenced format, which would be available within three hours of acquisition. Toward this end, EOSDIS has developed the Global Imagery Browse Services (GIBS, http://earthdata.nasa.gov/gibs) to provide highly responsive, scalable, and expandable imagery services. To meet these performance goals, the Open Geospatial Consortium (OGC) Web Map Tile Service (WMTS) was chosen as the standard interface for these services. GIBS has been one of the pioneers in providing tiled image services for the polar regions and also in the clarification of the time and elevation dimensions as used within the WMTS specification. Currently, there are more than a dozen MODIS imagery products available in polar stereographic projections for each pole, including four daily one kilometer 11 micron thermal infrared band images during all seasons. Imagery back to mid-2013 is currently available and reprocessing of imagery from the entire MODIS record is underway and community input is being solicited on recommendations for additional imagery layers from MODIS and other NASA instruments. A variety of geo-spatial client software is able to access these WMTS services. In addition, users can write their own interfaces using OpenLayers or the GDAL library. An OpenLayers demonstration client, Worldview (http://earthdata.nasa.gov/worldview), was developed at Goddard to showcase GIBS imagery. Worldview provides easy viewing of the entire imagery record. A search function allows discovery and selection of the different layers provided. Screen captures may be downloaded in a variety of formats. A catalog of current events helps users find interesting imagery. Data granules can be selected and downloaded from within the Worldview application. This provides an easy way to perform further analysis based on areas of interest discovered while browsing the imagery. Worldview also adapts for use on mobile devices, including both tablets and smart phones.

On the Physics of Flow Separation Along a Low Pressure Turbine Blade Under Unsteady Flow Conditions

NASA Technical Reports Server (NTRS)

Schobeiri, Meinhard T.; Ozturk, Burak; Ashpis, David E.

2005-01-01

The present study, which is the first of a series of investigations dealing with specific issues of low pressure turbine (LPT) boundary layer aerodynamics, is aimed at providing detailed unsteady boundary flow information to understand the underlying physics of the inception, onset, and extent of the separation zone. A detailed experimental study on the behavior of the separation zone on the suction surface of a highly loaded LPT-blade under periodic unsteady wake flow is presented. Experimental investigations were performed at Texas A&M Turbomachinery Performance and Flow Research Laboratory using a large-scale unsteady turbine cascade research facility with an integrated wake generator and test section unit. To account for a high flow deflection of LPT-cascades at design and off-design operating points, the entire wake generator and test section unit including the traversing system is designed to allow a precise angle adjustment of the cascade relative to the incoming flow. This is done by a hydraulic platform, which simultaneously lifts and rotates the wake generator and test section unit. The unit is then attached to the tunnel exit nozzle with an angular accuracy of better than 0.05 , which is measured electronically. Utilizing a Reynolds number of 110,000 based on the blade suction surface length and the exit velocity, one steady and two different unsteady inlet flow conditions with the corresponding passing frequencies, wake velocities and turbulence intensities are investigated using hot-wire anemometry. In addition to the unsteady boundary layer measurements, blade surface pressure measurements were performed at Re=50,000, 75,000, 100,000, and 125,000 at one steady and two periodic unsteady inlet flow conditions. Detailed unsteady boundary layer measurement identifies the onset and extent of the separation zone as well as its behavior under unsteady wake flow. The results presented in ensemble-averaged and contour plot forms contribute to understanding the physics of the separation phenomenon under periodic unsteady wake flow. Several physical mechanisms are discussed.

On the Physics of Flow Separation Along a Low Pressure Turbine Blade Under Unsteady Flow Conditions

NASA Technical Reports Server (NTRS)

Schobeiri, Meinhard T.; Ozturk, Burak; Ashpis, David E.

2003-01-01

The present study, which is the first of a series of investigations dealing with specific issues of low pressure turbine (LPT) boundary layer aerodynamics, is aimed at providing detailed unsteady boundary flow information to understand the underlying physics of the inception, onset, and extent of the separation zone. A detailed experimental study on the behavior of the separation zone on the suction surface of a highly loaded LPT-blade under periodic unsteady wake flow is presented. Experimental investigations were performed at Texas A&M Turbomachinery Performance and Flow Research Laboratory using a large-scale unsteady turbine cascade research facility with an integrated wake generator and test section unit. To account for a high flow deflection of LPT-cascades at design and off-design operating points, the entire wake generator and test section unit including the traversing system is designed to allow a precise angle adjustment of the cascade relative to the incoming flow. This is done by a hydraulic platform, which simultaneously lifts and rotates the wake generator and test section unit. The unit is then attached to the tunnel exit nozzle with an angular accuracy of better than 0.05 , which is measured electronically. Utilizing a Reynolds number of 110,000 based on the blade suction surface length and the exit velocity, one steady and two different unsteady inlet flowconditions with the corresponding passing frequencies, wake velocities and turbulence intensities are investigated using hot-wire anemometry. In addition to the unsteady boundary layer measurements, blade surface pressure measurements were performed at Re=50,000, 75,000, 100,000, and 125,000 at one steady and two periodic unsteady inlet flow conditions. Detailed unsteady boundary layer measurement identifies the onset and extent of the separation zone as well as its behavior under unsteady wake flow. The results presented in ensemble-averaged and contour plot forms contribute to understanding the physics of the separation phenomenon under periodic unsteady wake flow. Several physical mechanisms are discussed.

EVALUATING A COMPOSITE CARTRIDGE FOR SMALL SYSTEM DRINKING WATER TREATMENT

EPA Science Inventory

A multi-layer, cartridge-based system that combines physical filtration with carbon adsorption and ultraviolet (UV) light disinfection has been developed to perform as a water treatment security device to protect homes against accidental or intentional contaminant events. A seri...

Multi-Physics MRI-Based Two-Layer Fluid-Structure Interaction Anisotropic Models of Human Right and Left Ventricles with Different Patch Materials: Cardiac Function Assessment and Mechanical Stress Analysis

PubMed Central

Tang, Dalin; Yang, Chun; Geva, Tal; Gaudette, Glenn; del Nido, Pedro J.

2011-01-01

Multi-physics right and left ventricle (RV/LV) fluid-structure interaction (FSI) models were introduced to perform mechanical stress analysis and evaluate the effect of patch materials on RV function. The FSI models included three different patch materials (Dacron scaffold, treated pericardium, and contracting myocardium), two-layer construction, fiber orientation, and active anisotropic material properties. The models were constructed based on cardiac magnetic resonance (CMR) images acquired from a patient with severe RV dilatation and solved by ADINA. Our results indicate that the patch model with contracting myocardium leads to decreased stress level in the patch area, improved RV function and patch area contractility. PMID:21765559

Machine learning on-a-chip: a high-performance low-power reusable neuron architecture for artificial neural networks in ECG classifications.

PubMed

Sun, Yuwen; Cheng, Allen C

2012-07-01

Artificial neural networks (ANNs) are a promising machine learning technique in classifying non-linear electrocardiogram (ECG) signals and recognizing abnormal patterns suggesting risks of cardiovascular diseases (CVDs). In this paper, we propose a new reusable neuron architecture (RNA) enabling a performance-efficient and cost-effective silicon implementation for ANN. The RNA architecture consists of a single layer of physical RNA neurons, each of which is designed to use minimal hardware resource (e.g., a single 2-input multiplier-accumulator is used to compute the dot product of two vectors). By carefully applying the principal of time sharing, RNA can multiplexs this single layer of physical neurons to efficiently execute both feed-forward and back-propagation computations of an ANN while conserving the area and reducing the power dissipation of the silicon. A three-layer 51-30-12 ANN is implemented in RNA to perform the ECG classification for CVD detection. This RNA hardware also allows on-chip automatic training update. A quantitative design space exploration in area, power dissipation, and execution speed between RNA and three other implementations representative of different reusable hardware strategies is presented and discussed. Compared with an equivalent software implementation in C executed on an embedded microprocessor, the RNA ASIC achieves three orders of magnitude improvements in both the execution speed and the energy efficiency. Copyright © 2012 Elsevier Ltd. All rights reserved.

Relationship between cognition and gait performance in older adults receiving physical therapy interventions in the home.

PubMed

Whitney, Susan L; Marchetti, Gregory F; Ellis, Jennifer; Otis, Laurie; Asiri, Faisal; Alghadir, Ahmad

2013-01-01

Persons undergoing physical therapy home services often have difficulty with mobility and gait. The purpose of this study was to determine whether there was a relationship between gait and a rating of cognitive functioning in persons undergoing home-care physical therapy services. Patients over the age of 65 (n = 11,601) seen by a home-care agency between 2007 and 2008 were included in the retrospective analysis, and 10,953 (mean +/- standard deviation age 83.2 +/- 7.1; 31%) met the criteria of being able to ambulate independently or with an assistive device. All patients attempted to perform the modified Clinical Test of Sensory Integration and Balance plus either the Performance Oriented Measurement Assessment (POMA) or the Dynamic Gait Index (DGI). Mental function was scored as part of the Outcome and Assessment Information Set. A multivariate model with adjustment for age and sex identified gait performance as measured by the DGI to be independently associated with the likelihood that a patient required cognitive prompting (p = 0.03). Both the DGI and POMA scores were independently associated with requiring assistance/dependence with cognitive tasks. There was a strong relationship between cognition and gait performance in persons undergoing physical therapy interventions in the home. Changes in gait may be related to cognitive decline.

Co-extrusion of electrolyte/anode functional layer/anode triple-layer ceramic hollow fibres for micro-tubular solid oxide fuel cells-electrochemical performance study

NASA Astrophysics Data System (ADS)

Li, Tao; Wu, Zhentao; Li, K.

2015-01-01

In this study, the effects of an anode functional layer (AFL) with controlled thickness on physical and electrochemical properties of a micro-tubular SOFC have been systematically studied. A series of electrolyte/AFL/anode triple-layer hollow fibres with controllable AFL thicknesses (16.9-52.7 μm) have been fabricated via a single-step phase-inversion assisted co-extrusion technique. Both robustness of the cell and gas-tightness of the electrolyte layer are considerably improved by introducing the AFL of this type. The fracture force of the sample with the thickest AFL (9.67 N) almost doubles when compared to the electrolyte/anode dual-layer counterpart (5.24 N). Gas-tightness of the electrolyte layer is also considerably increased as AFL contributes to better-matched sintering behaviours between different components. Moreover, the formation of an AFL simultaneously with electrolyte and anode significantly improves the cell performances. The sample with the thinnest AFL (approximately 16.9 μm, 6% of the total anode thickness) leads to a 30% (from 0.89 to 1.21 W cm-2) increase in maximum power density, due to increased triple-phase boundaries (TPB). However, further increase in TPB from a thicker AFL is less effective for improving the cell performance, due to the substantially increased fuel diffusion resistance and subsequently higher concentration polarization. This indicates that the control over the AFL thickness is critically important in avoiding offsetting the benefits of extended TPB and consequently decreased cell performances.

A Big Data Platform for Storing, Accessing, Mining and Learning Geospatial Data

NASA Astrophysics Data System (ADS)

Yang, C. P.; Bambacus, M.; Duffy, D.; Little, M. M.

2017-12-01

Big Data is becoming a norm in geoscience domains. A platform that is capable to effiently manage, access, analyze, mine, and learn the big data for new information and knowledge is desired. This paper introduces our latest effort on developing such a platform based on our past years' experiences on cloud and high performance computing, analyzing big data, comparing big data containers, and mining big geospatial data for new information. The platform includes four layers: a) the bottom layer includes a computing infrastructure with proper network, computer, and storage systems; b) the 2nd layer is a cloud computing layer based on virtualization to provide on demand computing services for upper layers; c) the 3rd layer is big data containers that are customized for dealing with different types of data and functionalities; d) the 4th layer is a big data presentation layer that supports the effient management, access, analyses, mining and learning of big geospatial data.

A Logical Design of a Session Services Control Layer of a Distributed Network Architecture for SPLICE (Stock Point Logistics Integrated Communication Environment).

DTIC Science & Technology

1984-06-01

Eacn stock point is autonomous witn respect to how it implements data processing support, as long as it accommodates the Navy Supply Systems Command...has its own data elements, files, programs , transactions, users, reports, and some have additional hardware. To augment them all and not force redesign... programs are written to request session establishments among them using only logical addressing names (mailboxes) whicn are independent from physical

Effect of Payment Model on Patient Outcomes in Outpatient Physical Therapy.

PubMed

Charles, Derek; Boyd, Sylvester; Heckert, Logan; Lake, Austin; Petersen, Kevin

2018-01-01

Although the literature has well recognized the effectiveness of physical therapy for treating musculoskeletal injuries, reimbursement is evolving towards value-based or alternative payment models and away from procedure orientated, fee-for-service in the outpatient setting. Alternative models include cased-based clinics, pay-for-performance, out-of-network services, accountable care organizations, and concierge practices. There is the possibility that alternative payment models could produce different and even superior patient outcomes. Physical therapists should be alert to this possibility, and research is warranted in this area to conclude if outcomes in patient care are related to method of reimbursement.

Physician ownership of physical therapy services. Effects on charges, utilization, profits, and service characteristics.

PubMed

Mitchell, J M; Scott, E

1992-10-21

To evaluate the effects of physician ownership of freestanding physical therapy and rehabilitation facilities on utilization, charges, profits, and three measures of service characteristics for physical therapy treatments. Statistical comparison by physician joint venture ownership status of freestanding physical therapy and comprehensive rehabilitation facilities providing physical therapy treatments in Florida. A total of 118 outpatient physical therapy facilities and 63 outpatient comprehensive rehabilitation facilities providing services in Florida during 1989. The data from the facilities were collected under a legislative mandate. Visits per patient, average revenue per patient, percent operating income, percent markup, profits per patient, licensed therapist time per visit, and licensed and nonlicensed medical worker time per visit. Visits per patient were 39% to 45% higher in joint venture facilities. Both gross and net revenue per patient were 30% to 40% higher in facilities owned by referring physicians. Percent operating income and percent markup were significantly higher in joint venture physical therapy and rehabilitation facilities. Licensed physical therapists and licensed therapist assistants employed in non-joint venture facilities spend about 60% more time per visit treating physical therapy patients than licensed therapists and licensed therapist assistants working in joint venture facilities. Joint ventures also generate more of their revenues from patients with well-paying insurance. Our results indicate that utilization, charges per patient, and profits are higher when physical therapy and rehabilitation facilities are owned by referring physicians. With respect to service characteristics, joint venture firms employ proportionately fewer licensed therapists and licensed therapist assistants to perform physical therapy, so that licensed professionals employed in joint venture businesses spend significantly less time per visit treating patients. These results should be of interest to the medical profession, third-party payers, and policymakers, all of whom are concerned about the consequences of physician self-referral arrangements.

A Protocol Layer Trust-Based Intrusion Detection Scheme for Wireless Sensor Networks

PubMed Central

Wang, Jian; Jiang, Shuai; Fapojuwo, Abraham O.

2017-01-01

This article proposes a protocol layer trust-based intrusion detection scheme for wireless sensor networks. Unlike existing work, the trust value of a sensor node is evaluated according to the deviations of key parameters at each protocol layer considering the attacks initiated at different protocol layers will inevitably have impacts on the parameters of the corresponding protocol layers. For simplicity, the paper mainly considers three aspects of trustworthiness, namely physical layer trust, media access control layer trust and network layer trust. The per-layer trust metrics are then combined to determine the overall trust metric of a sensor node. The performance of the proposed intrusion detection mechanism is then analyzed using the t-distribution to derive analytical results of false positive and false negative probabilities. Numerical analytical results, validated by simulation results, are presented in different attack scenarios. It is shown that the proposed protocol layer trust-based intrusion detection scheme outperforms a state-of-the-art scheme in terms of detection probability and false probability, demonstrating its usefulness for detecting cross-layer attacks. PMID:28555023

A Protocol Layer Trust-Based Intrusion Detection Scheme for Wireless Sensor Networks.

PubMed

Wang, Jian; Jiang, Shuai; Fapojuwo, Abraham O

2017-05-27

This article proposes a protocol layer trust-based intrusion detection scheme for wireless sensor networks. Unlike existing work, the trust value of a sensor node is evaluated according to the deviations of key parameters at each protocol layer considering the attacks initiated at different protocol layers will inevitably have impacts on the parameters of the corresponding protocol layers. For simplicity, the paper mainly considers three aspects of trustworthiness, namely physical layer trust, media access control layer trust and network layer trust. The per-layer trust metrics are then combined to determine the overall trust metric of a sensor node. The performance of the proposed intrusion detection mechanism is then analyzed using the t-distribution to derive analytical results of false positive and false negative probabilities. Numerical analytical results, validated by simulation results, are presented in different attack scenarios. It is shown that the proposed protocol layer trust-based intrusion detection scheme outperforms a state-of-the-art scheme in terms of detection probability and false probability, demonstrating its usefulness for detecting cross-layer attacks.

Small-Scale Mechanical Characterization of Space-Exposed Fluorinated Ethylene Propylene Recovered from the Hubble Space Telescope

NASA Technical Reports Server (NTRS)

Jones, J. S.; Sharon, J. A.; Mohammed, J.; Hemker, K. J.

2012-01-01

Multi-layer insulation panels from the Hubble Space Telescope have been recovered after 19.1 years of on-orbit service and micro-tensile experiments have been performed to characterize the effect of space exposure on the mechanical response of the outermost layer. This outer layer, 127 m thick fluorinated ethylene propylene with a 100 nm thick vapor deposited aluminum reflective coating, maintained significant tensile ductility but exhibited a degradation of strength that scales with severity of space exposure. This change in properties is attributed to damage from incident solar flux, atomic oxygen damage, and thermal cycling.

Compressibility Considerations for kappa-omega Turbulence Models in Hypersonic Boundary Layer Applications

NASA Technical Reports Server (NTRS)

Rumsey, C. L.

2009-01-01

The ability of kappa-omega models to predict compressible turbulent skin friction in hypersonic boundary layers is investigated. Although uncorrected two-equation models can agree well with correlations for hot-wall cases, they tend to perform progressively worse - particularly for cold walls - as the Mach number is increased in the hypersonic regime. Simple algebraic models such as Baldwin-Lomax perform better compared to experiments and correlations in these circumstances. Many of the compressibility corrections described in the literature are summarized here. These include corrections that have only a small influence for kappa-omega models, or that apply only in specific circumstances. The most widely-used general corrections were designed for use with jet or mixing-layer free shear flows. A less well-known dilatation-dissipation correction intended for boundary layer flows is also tested, and is shown to agree reasonably well with the Baldwin-Lomax model at cold-wall conditions. It exhibits a less dramatic influence than the free shear type of correction. There is clearly a need for improved understanding and better overall physical modeling for turbulence models applied to hypersonic boundary layer flows.

A New, Two-layer Canopy Module For The Detailed Snow Model SNOWPACK

NASA Astrophysics Data System (ADS)

Gouttevin, I.; Lehning, M.; Jonas, T.; Gustafsson, D.; Mölder, M.

2014-12-01

A new, two-layer canopy module with thermal inertia for the detailed snow model SNOWPACK is presented. Compared to the old, one-layered canopy formulation with no heat mass, this module now offers a level of physical detail consistent with the detailed snow and soil representation in SNOWPACK. The new canopy model is designed to reproduce the difference in thermal regimes between leafy and woody canopy elements and their impact on the underlying snowpack energy balance. The new model is validated against data from an Alpine and a boreal site. Comparisons of modelled sub-canopy thermal radiations to stand-scale observations at Alptal, Switzerland, demonstrate the improvements induced by our new parameterizations. The main effect is a more realistic simulation of the canopy night-time drop in temperatures. The lower drop is induced by both thermal inertia and the two-layer representation. A specific result is that such a performance cannot be achieved by a single-layered canopy model. The impact of the new parameterizations on the modelled dynamics of the sub-canopy snowpack is analysed and yields consistent results, but the frequent occurrence of mixed-precipitation events at Alptal prevents a conclusive assessment of model performances against snow data.Without specific tuning, the model is also able to reproduce the measured summertime tree trunk temperatures and biomass heat storage at the boreal site of Norunda, Sweden, with an increased accuracy in amplitude and phase. Overall, the SNOWPACK model with its enhanced canopy module constitutes a unique (in its physical process representation) atmosphere-to-soil-through-canopy-and-snow modelling chain.

Triangular lattice atomic layer of Sn(1 × 1) at graphene/SiC(0001) interface

NASA Astrophysics Data System (ADS)

Hayashi, Shingo; Visikovskiy, Anton; Kajiwara, Takashi; Iimori, Takushi; Shirasawa, Tetsuroh; Nakastuji, Kan; Miyamachi, Toshio; Nakashima, Shuhei; Yaji, Koichiro; Mase, Kazuhiko; Komori, Fumio; Tanaka, Satoru

2018-01-01

Sn atomic layers attract considerable interest owing to their spin-related physical properties caused by their strong spin-orbit interactions. We performed Sn intercalation into the graphene/SiC(0001) interface and found a new type of Sn atomic layer. Sn atoms occupy on-top sites of Si-terminated SiC(0001) with in-plane Sn-Sn bondings, resulting in a triangular lattice. Angle-resolved photoemission spectroscopy revealed characteristic dispersions at \\bar{\\text{K}} and \\bar{\\text{M}} points, which agreed well with density functional theory calculations. The Sn triangular lattice atomic layer at the interface showed no oxidation upon exposure to air, which is useful for characterization and device fabrication ex situ.

Improved performance of GaN based light emitting diodes with ex-situ sputtered AlN nucleation layers

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

Chen, Shuo-Wei; Epistar Corporation, Hsinchu 300, Taiwan; Li, Heng

The crystal quality, electrical and optical properties of GaN based light emitting diodes (LEDs) with ex-situ sputtered physical vapor deposition (PVD) aluminum nitride (AlN) nucleation layers were investigated. It was found that the crystal quality in terms of defect density and x-ray diffraction linewidth was greatly improved in comparison to LEDs with in-situ low temperature GaN nucleation layer. The light output power was 3.7% increased and the reverse bias voltage of leakage current was twice on LEDs with ex-situ PVD AlN nucleation layers. However, larger compressive strain was discovered in LEDs with ex-situ PVD AlN nucleation layers. The study showsmore » the potential and constrain in applying ex-situ PVD AlN nucleation layers to fabricate high quality GaN crystals in various optoelectronics.« less

Effect of fabrication parameters on morphological and optical properties of highly doped p-porous silicon

NASA Astrophysics Data System (ADS)

Zare, Maryam; Shokrollahi, Abbas; Seraji, Faramarz E.

2011-09-01

Porous silicon (PS) layers were fabricated by anodization of low resistive (highly doped) p-type silicon in HF/ethanol solution, by varying current density, etching time and HF concentration. Atomic force microscopy (AFM) and field emission scanning electron microscope (FESEM) analyses were used to investigate the physical properties and reflection spectrum was used to investigate the optical behavior of PS layers in different fabrication conditions. Vertically aligned mesoporous morphology is observed in fabricated films and with HF concentration higher than 20%. The dependence of porosity, layer thickness and rms roughness of the PS layer on current density, etching time and composition of electrolyte is also observed in obtained results. Correlation between reflectivity and fabrication parameters was also explored. Thermal oxidation was performed on some mesoporous layers that resulted in changes of surface roughness, mean height and reflectivity of the layers.

Design, fabrication and characterization of a double layer solid oxide fuel cell (DLFC)

NASA Astrophysics Data System (ADS)

Wang, Guangjun; Wu, Xiangying; Cai, Yixiao; Ji, Yuan; Yaqub, Azra; Zhu, Bin

2016-11-01

A double layer solid oxide fuel cell (DLSOFC) without using the electrolyte (layer) has been designed by integrating advantages of positive electrode material of lithium ion battery(LiNi0.8Co0.15Al0.05O2) and oxygen-permeable membranes material (trace amount cobalt incorporated terbium doped ceria, TDC + Co) based on the semiconductor physics principle. Instead of using an electrolyte layer, the depletion layer between the anode and cathode served as an electronic insulator to block the electrons but to maintain the electrolyte function for ionic transport. Thus the device with two layers can realize the function of SOFC and at the same time avoids the electronic short circuiting problem. Such novel DLFC showed good performance at low temperatures, for instance, a maximum power density of 230 mWcm-2 was achieved at 500 °C. The working principle of the new device is presented.

A classification system for characterization of physical and non-physical work factors.

PubMed

Genaidy, A; Karwowski, W; Succop, P; Kwon, Y G; Alhemoud, A; Goyal, D

2000-01-01

A comprehensive evaluation of work-related performance factors is a prerequisite to developing integrated and long-term solutions to workplace performance improvement. This paper describes a work-factor classification system that categorizes the entire domain of workplace factors impacting performance. A questionnaire-based instrument was developed to implement this classification system in industry. Fifty jobs were evaluated in 4 different service and manufacturing companies using the proposed questionnaire-based instrument. The reliability coefficients obtained from the analyzed jobs were considered good (0.589 to 0.862). In general, the physical work factors resulted in higher reliability coefficients (0.847 to 0.862) than non-physical work factors (0.589 to 0.768).

Advances and Promises of Layered Halide Hybrid Perovskite Semiconductors.

PubMed

Pedesseau, Laurent; Sapori, Daniel; Traore, Boubacar; Robles, Roberto; Fang, Hong-Hua; Loi, Maria Antonietta; Tsai, Hsinhan; Nie, Wanyi; Blancon, Jean-Christophe; Neukirch, Amanda; Tretiak, Sergei; Mohite, Aditya D; Katan, Claudine; Even, Jacky; Kepenekian, Mikaël

2016-11-22

Layered halide hybrid organic-inorganic perovskites (HOP) have been the subject of intense investigation before the rise of three-dimensional (3D) HOP and their impressive performance in solar cells. Recently, layered HOP have also been proposed as attractive alternatives for photostable solar cells and revisited for light-emitting devices. In this review, we combine classical solid-state physics concepts with simulation tools based on density functional theory to overview the main features of the optoelectronic properties of layered HOP. A detailed comparison between layered and 3D HOP is performed to highlight differences and similarities. In the same way as the cubic phase was established for 3D HOP, here we introduce the tetragonal phase with D 4h symmetry as the reference phase for 2D monolayered HOP. It allows for detailed analysis of the spin-orbit coupling effects and structural transitions with corresponding electronic band folding. We further investigate the effects of octahedral tilting on the band gap, loss of inversion symmetry and possible Rashba effect, quantum confinement, and dielectric confinement related to the organic barrier, up to excitonic properties. Altogether, this paper aims to provide an interpretive and predictive framework for 3D and 2D layered HOP optoelectronic properties.

Amorphous TiO 2 Compact Layers via ALD for Planar Halide Perovskite Photovoltaics

DOE PAGES

Kim, In Soo; Haasch, Richard T.; Cao, Duyen H.; ...

2016-09-06

A low temperature (< 120 °C) route to pinhole-free amorphous TiO 2 compact layers may pave the way to more efficient, flexible, and stable inverted perovskite halide device designs. Toward this end, we utilize low-temperature thermal atomic layer deposition (ALD) to synthesize ultra-thin (12 nm) compact TiO 2 underlayers for planar halide perovskite PV. While device performance with as-deposited TiO 2 films is poor, we identify room temperature UV-O 3 treatment as a route to device efficiency comparable to crystalline TiO 2 thin films synthesized by higher temperature methods. Here, we further explore the chemical, physical, and interfacial properties 2more » that might explain the improved performance through x-ray diffraction, spectroscopic ellipsometry, Raman spectroscopy, and x-ray photoelectron spectroscopy. These findings challenge our intuition about effective electron selective layers as well as point the way to a greater selection of flexible substrates and more stable inverted device designs.« less

The effects of electron and hole transport layer with the electrode work function on perovskite solar cells

NASA Astrophysics Data System (ADS)

Deng, Quanrong; Li, Yiqi; Chen, Lian; Wang, Shenggao; Wang, Geming; Sheng, Yonglong; Shao, Guosheng

2016-09-01

The effects of electron and hole transport layer with the electrode work function on perovskite solar cells with the interface defects were simulated by using analysis of microelectronic and photonic structures-one-dimensional (AMPS-1D) software. The simulation results suggest that TiO2 electron transport layer provides best device performance with conversion efficiency of 25.9% compared with ZnO and CdS. The threshold value of back electrode work function for Spiro-OMeTAD, NiO, CuI and Cu2O hole transport layer are calculated to be 4.9, 4.8, 4.7 and 4.9 eV, respectively, to reach the highest conversion efficiency. The mechanisms of device physics with various electron and hole transport materials are discussed in details. The device performance deteriorates gradually as the increased density of interface defects located at ETM/absorber or absorber/HTM. This research results can provide helpful guidance for materials and metal electrode choice for perovskite solar cells.

Collision avoidance in TV white spaces: a cross-layer design approach for cognitive radio networks

NASA Astrophysics Data System (ADS)

Foukalas, Fotis; Karetsos, George T.

2015-07-01

One of the most promising applications of cognitive radio networks (CRNs) is the efficient exploitation of TV white spaces (TVWSs) for enhancing the performance of wireless networks. In this paper, we propose a cross-layer design (CLD) of carrier sense multiple access with collision avoidance (CSMA/CA) mechanism at the medium access control (MAC) layer with spectrum sensing (SpSe) at the physical layer, for identifying the occupancy status of TV bands. The proposed CLD relies on a Markov chain model with a state pair containing both the SpSe and the CSMA/CA from which we derive the collision probability and the achievable throughput. Analytical and simulation results are obtained for different collision avoidance and SpSe implementation scenarios by varying the contention window, back off stage and probability of detection. The obtained results depict the achievable throughput under different collision avoidance and SpSe implementation scenarios indicating thereby the performance of collision avoidance in TVWSs-based CRNs.

Cu(In,Ga)Se2 solar cells with In2S3 buffer layer deposited by thermal evaporation

NASA Astrophysics Data System (ADS)

Kim, SeongYeon; Rana, Tanka R.; Kim, JunHo; Yun, JaeHo

2017-12-01

We report on physical vapor deposition of indium sulfide (In2S3) buffer layers and its application to Cu(In,Ga)Se2 (CIGSe) thin film solar cell. The Indium sulfide buffer layers were evaporated onto CIGSe at various substrate temperatures from room temperature (RT) to 350 °C. The effect of deposition temperature of buffer layers on the solar cell device performance were investigated by analyzing temperature dependent current-voltage ( J- V- T), external quantum efficiency (EQE) and Raman spectroscopy. The fabricated device showed the highest power conversion efficiency of 6.56% at substrate temperature of 250 °C, which is due to the decreased interface recombination. However, the roll-over in J- V curves was observed for solar cell device having buffer deposited at substrate temperature larger than 250 °C. From the measurement results, the interface defect and roll-over related degradation were found to have limitation on the performance of solar cell device.

Learning relevant features of data with multi-scale tensor networks

NASA Astrophysics Data System (ADS)

Miles Stoudenmire, E.

2018-07-01

Inspired by coarse-graining approaches used in physics, we show how similar algorithms can be adapted for data. The resulting algorithms are based on layered tree tensor networks and scale linearly with both the dimension of the input and the training set size. Computing most of the layers with an unsupervised algorithm, then optimizing just the top layer for supervised classification of the MNIST and fashion MNIST data sets gives very good results. We also discuss mixing a prior guess for supervised weights together with an unsupervised representation of the data, yielding a smaller number of features nevertheless able to give good performance.

Structure of electroexplosive TiC-Ni composite coatings on steel after electron-beam treatment

NASA Astrophysics Data System (ADS)

Romanov, D. A.; Goncharova, E. N.; Budovskikh, E. A.; Gromov, V. E.; Ivanov, Yu. F.; Teresov, A. D.; Kazimirov, S. A.

2016-11-01

The phase and elemental compositions of the surface layer in Hardox 450 steel after electroexplosive spraying of a TiC-Ni composite coating and subsequent irradiation by a submillisecond high-energy electron beam are studied by the methods of modern physical metallurgy. The electron-beam treatment conditions that result in the formation of dense surface layers having high luster and a submicrocrystalline structure based on titanium carbide and nickel are found. It is shown that electron-beam treatment of an electroexplosive coating performed under melting conditions leads to the formation of a homogeneous (in structure and concentration) surface layer.

77 FR 33098 - Hours of Service of Drivers of Commercial Motor Vehicles; Regulatory Guidance for Oilfield Exception

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-05

... their ability to operate the vehicles safely; (3) the physical condition of operators of CMVs is adequate to enable them to operate the vehicles safely and the periodic physical examinations required of such operators are performed by medical examiners who have received training in physical and medical...

Physical layer simulation study for the coexistence of WLAN standards

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

Howlader, M. K.; Keiger, C.; Ewing, P. D.

This paper presents the results of a study on the performance of wireless local area network (WLAN) devices in the presence of interference from other wireless devices. To understand the coexistence of these wireless protocols, simplified physical-layer-system models were developed for the Bluetooth, Wireless Fidelity (WiFi), and Zigbee devices, all of which operate within the 2.4-GHz frequency band. The performances of these protocols were evaluated using Monte-Carlo simulations under various interference and channel conditions. The channel models considered were basic additive white Gaussian noise (AWGN), Rayleigh fading, and site-specific fading. The study also incorporated the basic modulation schemes, multiple accessmore » techniques, and channel allocations of the three protocols. This research is helping the U.S. Nuclear Regulatory Commission (NRC) understand the coexistence issues associated with deploying wireless devices and could prove useful in the development of a technical basis for guidance to address safety-related issues with the implementation of wireless systems in nuclear facilities. (authors)« less

Personalized Services Oriented towards Commercial Establishments

NASA Astrophysics Data System (ADS)

Marin Díaz, David; Rico Zuluaga, Alejandro; Carrillo-Ramos, Angela

This paper presents the platform PlaSerEs, whose main objective is to provide information about the products y/o services offered by commercial establishments to their clients in a personalized way. This platform is structured in four layers: i) the adaptation layer, composed of four modules: the one of the context, the one of the access device, the one of the user and the one of the wireless connection. The latter is one of the main contributions of this work. ii) The general services layer, iii) the personalized services layer and iv) the application layer. In order to validate and to evaluate how PlaSerEs works, we developed a functional prototype for a restaurant.

Actinide targets for fundamental research in nuclear physics

NASA Astrophysics Data System (ADS)

Eberhardt, K.; Düllmann, Ch. E.; Haas, R.; Mokry, Ch.; Runke, J.; Thörle-Pospiech, P.; Trautmann, N.

2018-05-01

Thin actinide layers deposited on various substrates are widely used as calibration sources in nuclear spectroscopy. Other applications include fundamental research in nuclear chemistry and -physics, e.g., the chemical and physical properties of super-heavy elements (SHE, Z > 103) or nuclear reaction studies with heavy ions. For the design of future nuclear reactors like fast-fission reactors and accelerator-driven systems for transmutation of nuclear waste, precise data for neutron absorption as well as neutron-induced fission cross section data for 242Pu with neutrons of different energies are of particular importance, requiring suitable Pu-targets. Another application includes studies of nuclear transitions in 229Th harvested as α-decay recoil product from a thin layer of its 233U precursor. For this, a thin and very smooth layer of 233U is used. We report here on the production of actinide layers mostly obtained by Molecular Plating (MP). MP is currently the only fabrication method in cases where the desired actinide material is available only in very limited amounts or possesses a high specific activity. Here, deposition is performed from organic solution applying a current density of 1-2 mA/cm2. Under these conditions target thicknesses of 500-1000 μg/cm2 are possible applying a single deposition step with deposition yields approaching 100 %. For yield determination α-particle spectroscopy, γ-spectroscopy and Neutron Activation Analysis is routinely used. Layer homogeneity is checked with Radiographic Imaging. As an alternative technique to MP the production of thin lanthanide and actinide layers by the so-called "Drop on Demand"-technique applied e.g., in ink-jet printing is currently under investigation.

A near one-dimensional indirectly driven implosion at convergence ratio 30

NASA Astrophysics Data System (ADS)

MacLaren, S. A.; Masse, L. P.; Czajka, C. E.; Khan, S. F.; Kyrala, G. A.; Ma, T.; Ralph, J. E.; Salmonson, J. D.; Bachmann, B.; Benedetti, L. R.; Bhandarkar, S. D.; Bradley, P. A.; Hatarik, R.; Herrmann, H. W.; Mariscal, D. A.; Millot, M.; Patel, P. K.; Pino, J. E.; Ratledge, M.; Rice, N. G.; Tipton, R. E.; Tommasini, R.; Yeamans, C. B.

2018-05-01

Inertial confinement fusion cryogenic-layered implosions at the National Ignition Facility, while successfully demonstrating self-heating due to alpha-particle deposition, have fallen short of the performance predicted by one-dimensional (1D) multi-physics implosion simulations. The current understanding, from experimental evidence as well as simulations, suggests that engineering features such as the capsule tent and fill tube, as well as time-dependent low-mode asymmetry, are to blame for the lack of agreement. A short series of experiments designed specifically to avoid these degradations to the implosion are described here in order to understand if, once they are removed, a high-convergence cryogenic-layered deuterium-tritium implosion can achieve the 1D simulated performance. The result is a cryogenic layered implosion, round at stagnation, that matches closely the performance predicted by 1D simulations. This agreement can then be exploited to examine the sensitivity of approximations in the model to the constraints imposed by the data.

Update of global TC simulations using a variable resolution non-hydrostatic model

NASA Astrophysics Data System (ADS)

Park, S. H.

2017-12-01

Using in a variable resolution meshes in MPAS during 2017 summer., Tropical cyclone (TC) forecasts are simulated. Two physics suite are tested to explore performance and bias of each physics suite for TC forecasting. A WRF physics suite is selected from experience on weather forecasting and CAM (Community Atmosphere Model) physics is taken from a AMIP type climate simulation. Based on the last year results from CAM5 physical parameterization package and comparing with WRF physics, we investigated a issue with intensity bias using updated version of CAM physics (CAM6). We also compared these results with coupled version of TC simulations. During this talk, TC structure will be compared specially around of boundary layer and investigate their relationship between TC intensity and different physics package.

Cross-Layer Scheme to Control Contention Window for Per-Flow in Asymmetric Multi-Hop Networks

NASA Astrophysics Data System (ADS)

Giang, Pham Thanh; Nakagawa, Kenji

The IEEE 802.11 MAC standard for wireless ad hoc networks adopts Binary Exponential Back-off (BEB) mechanism to resolve bandwidth contention between stations. BEB mechanism controls the bandwidth allocation for each station by choosing a back-off value from one to CW according to the uniform random distribution, where CW is the contention window size. However, in asymmetric multi-hop networks, some stations are disadvantaged in opportunity of access to the shared channel and may suffer severe throughput degradation when the traffic load is large. Then, the network performance is degraded in terms of throughput and fairness. In this paper, we propose a new cross-layer scheme aiming to solve the per-flow unfairness problem and achieve good throughput performance in IEEE 802.11 multi-hop ad hoc networks. Our cross-layer scheme collects useful information from the physical, MAC and link layers of own station. This information is used to determine the optimal Contention Window (CW) size for per-station fairness. We also use this information to adjust CW size for each flow in the station in order to achieve per-flow fairness. Performance of our cross-layer scheme is examined on various asymmetric multi-hop network topologies by using Network Simulator (NS-2).

[The influence of spray drying process conditions on physical, chemical properties and lung inhaling performance of Panax notoginseng saponins - tanshinone II A composite particles].

PubMed

Wang, Hua-Mei; Fu, Ting-Ming; Guo, Li-Wei

2013-06-01

This study is to report the influence of conditions in spray drying process on physical and chemical properties and lung inhaling performance of Panax notoginseng Saponins - Tanshinone II A composite particles. According to the physical and chemical properties of the two types of components within the composite particles, three solvent systems were selected including ethanol, ethanol : acetone (9 : 1, v/v) and ethanol : acetone (4 : 1, v/v), and three inlet temperature: 110 degrees C, 120 degrees C, 130 degrees C to prepare seven different composite particle samples; each sample was characterized using laser diffraction, scanning electron microscopy (SEM), dynamic vapour sorption (DVS) and atomic force microscope (AFM), and their aerodynamic behavior was evaluated by a Next Generation Impactor (NGI). The results indicate that under the conditions of using the mixed solvent system of ethanol--acetone volume ratio of 9 : 1, and the inlet temperature of 110 degrees C, the resulting composite particles showed rough surface, with more tanshinone II A distributing in the outer layer, such composite particles have the best lung inhaling performance and the fine particle fraction (FPF) close to 60%. Finally it is concluded that by adjusting the conditions in co-spray drying process, the distribution amount and existence form of tanshinone II A in the outer layer of the particles can be changed so that to enhance lung inhaling performance of the drug composite particles.

A data transmission method for particle physics experiments based on Ethernet physical layer

NASA Astrophysics Data System (ADS)

Huang, Xi-Ru; Cao, Ping; Zheng, Jia-Jun

2015-11-01

Due to its advantages of universality, flexibility and high performance, fast Ethernet is widely used in readout system design for modern particle physics experiments. However, Ethernet is usually used together with the TCP/IP protocol stack, which makes it difficult to implement readout systems because designers have to use the operating system to process this protocol. Furthermore, TCP/IP degrades the transmission efficiency and real-time performance. To maximize the performance of Ethernet in physics experiment applications, a data readout method based on the physical layer (PHY) is proposed. In this method, TCP/IP is replaced with a customized and simple protocol, which makes it easier to implement. On each readout module, data from the front-end electronics is first fed into an FPGA for protocol processing and then sent out to a PHY chip controlled by this FPGA for transmission. This kind of data path is fully implemented by hardware. From the side of the data acquisition system (DAQ), however, the absence of a standard protocol causes problems for the network related applications. To solve this problem, in the operating system kernel space, data received by the network interface card is redirected from the traditional flow to a specified memory space by a customized program. This memory space can easily be accessed by applications in user space. For the purpose of verification, a prototype system has been designed and implemented. Preliminary test results show that this method can meet the requirements of data transmission from the readout module to the DAQ with an efficient and simple manner. Supported by National Natural Science Foundation of China (11005107) and Independent Projects of State Key Laboratory of Particle Detection and Electronics (201301)

Leakage current and capacitance characteristics of Si/SiO2/Si single-barrier varactor

NASA Astrophysics Data System (ADS)

Mamor, M.; Fu, Y.; Nur, O.; Willander, M.; Bengtsson, S.

We investigate, both experimentally and theoretically, current and capacitance (I-V/C-V) characteristics and the device performance of Si/SiO2/Si single-barrier varactor diodes (SBVs). Two diodes were fabricated with different SiO2 layer thicknesses using the state-of-the-art wafer bonding technique. The devices have very low leakage currents (about 5×10-2 and 1.8×10-2 mA/mm2) and intrinsic capacitance levels of typically 1.5 and 50 nF/mm2 for diodes with 5-nm and 20-nm oxide layers, respectively. With the present device physical parameters (25-mm2 device area, 760-μm modulation layer thickness and 1015-cm-3 doping level), the estimated cut-off frequency is about 5×107 Hz. With the physical parameters of the present existing III-V triplers, the cut-off frequency of our Si-based SBV can be as high as 0.5 THz.

High-Performance Secure Database Access Technologies for HEP Grids

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

Matthew Vranicar; John Weicher

2006-04-17

The Large Hadron Collider (LHC) at the CERN Laboratory will become the largest scientific instrument in the world when it starts operations in 2007. Large Scale Analysis Computer Systems (computational grids) are required to extract rare signals of new physics from petabytes of LHC detector data. In addition to file-based event data, LHC data processing applications require access to large amounts of data in relational databases: detector conditions, calibrations, etc. U.S. high energy physicists demand efficient performance of grid computing applications in LHC physics research where world-wide remote participation is vital to their success. To empower physicists with data-intensive analysismore » capabilities a whole hyperinfrastructure of distributed databases cross-cuts a multi-tier hierarchy of computational grids. The crosscutting allows separation of concerns across both the global environment of a federation of computational grids and the local environment of a physicist’s computer used for analysis. Very few efforts are on-going in the area of database and grid integration research. Most of these are outside of the U.S. and rely on traditional approaches to secure database access via an extraneous security layer separate from the database system core, preventing efficient data transfers. Our findings are shared by the Database Access and Integration Services Working Group of the Global Grid Forum, who states that "Research and development activities relating to the Grid have generally focused on applications where data is stored in files. However, in many scientific and commercial domains, database management systems have a central role in data storage, access, organization, authorization, etc, for numerous applications.” There is a clear opportunity for a technological breakthrough, requiring innovative steps to provide high-performance secure database access technologies for grid computing. We believe that an innovative database architecture where the secure authorization is pushed into the database engine will eliminate inefficient data transfer bottlenecks. Furthermore, traditionally separated database and security layers provide an extra vulnerability, leaving a weak clear-text password authorization as the only protection on the database core systems. Due to the legacy limitations of the systems’ security models, the allowed passwords often can not even comply with the DOE password guideline requirements. We see an opportunity for the tight integration of the secure authorization layer with the database server engine resulting in both improved performance and improved security. Phase I has focused on the development of a proof-of-concept prototype using Argonne National Laboratory’s (ANL) Argonne Tandem-Linac Accelerator System (ATLAS) project as a test scenario. By developing a grid-security enabled version of the ATLAS project’s current relation database solution, MySQL, PIOCON Technologies aims to offer a more efficient solution to secure database access.« less

Physical and Cross-Layer Security Enhancement and Resource Allocation for Wireless Networks

ERIC Educational Resources Information Center

Bashar, Muhammad Shafi Al

2011-01-01

In this dissertation, we present novel physical (PHY) and cross-layer design guidelines and resource adaptation algorithms to improve the security and user experience in the future wireless networks. Physical and cross-layer wireless security measures can provide stronger overall security with high efficiency and can also provide better…

Flake Orientation Effects On Physical and Mechanical Properties of Sweetgum Flakeboard

Treesearch

T.F. Shupe; Chung-Yun Hse; E.W. Price

2001-01-01

Research was initiated to determine the effect of flake orientation on the physical and mechanical properties offlakeboard. The panel fabrication techniques investigated were single-layer panels with random and oriented flake distribution, three-layer, five-layer, and seven-layer panels. Single-layer oriented panels had panel directional property ratios of 11.8 and 12....

Cislan-2 extension final document by University of Twente (Netherlands)

NASA Astrophysics Data System (ADS)

Niemegeers, Ignas; Baumann, Frank; Beuwer, Wim; Jordense, Marcel; Pras, Aiko; Schutte, Leon; Tracey, Ian

1992-01-01

Results of worked performed under the so called Cislan extension contract are presented. The adaptation of the Cislan 2 prototype design to an environment of interconnected Local Area Networks (LAN's) instead of a single 802.5 token ring LAN is considered. In order to extend the network architecture, the Interconnection Function (IF) protocol layer was subdivided into two protocol layers: a new IF layer, and below the Medium Enhancement (ME) protocol layer. Some small enhancements to the distributed bandwidth allocation protocol were developed, which in fact are also applicable to the 'normal' Cislan 2 system. The new services and protocols are described together with some scenarios and requirements for the new internetting Cislan 2 system. How to overcome the degradation of the quality of speech due to packet loss on the LAN subsystem was studied. Experiments were planned in order to measure this speech quality degradation. Simulations were performed of two Cislan subsystems, the bandwidth allocation protocol and the clock synchronization mechanism. Results on both simulations, performed on SUN workstations using QNAP as a simulation tool, are given. Results of the simulations of the clock synchronization mechanism, and results of the simulation of the distributed bandwidth allocation protocol are given.

O-6 Optical Property Degradation of the Hubble Space Telescope's Wide Field Camera-2 Pick Off Mirror

NASA Technical Reports Server (NTRS)

McNamara, Karen M.; Hughes, D. W.; Lauer, H. V.; Burkett, P. J.; Reed, B. B.

2011-01-01

Degradation in the performance of optical components can be greatly affected by exposure to the space environment. Many factors can contribute to such degradation including surface contaminants; outgassing; vacuum, UV, and atomic oxygen exposure; temperature cycling; or combinations of parameters. In-situ observations give important clues to degradation processes, but there are relatively few opportunities to correlate those observations with post-flight ground analyses. The return of instruments from the Hubble Space Telescope (HST) after its final servicing mission in May 2009 provided such an opportunity. Among the instruments returned from HST was the Wide-Field Planetary Camera-2 (WFPC-2), which had been exposed to the space environment for 16 years. This work focuses on the identifying the sources of degradation in the performance of the Pick-off mirror (POM) from WFPC-2. Techniques including surface reflectivity measurements, spectroscopic ellipsometry, FTIR (and ATR-FTIR) analyses, SEM/EDS, X-ray photoelectron spectroscopy (XPS) with and without ion milling, and wet and dry physical surface sampling were performed. Destructive and contact analyses took place only after completion of the non-destructive measurements. Spectroscopic ellipsometry was then repeated to determine the extent of contaminant removal by the destructive techniques, providing insight into the nature and extent of polymerization of the contaminant layer.

Factors affecting behavior and welfare of service dogs for children with autism spectrum disorder.

PubMed

Burrows, Kristen E; Adams, Cindy L; Millman, Suzanne T

2008-01-01

The use of service dogs for children with autism spectrum disorder is a relatively new and growing assistance-dog application. The objectives of this article were to identify and describe the factors influencing an autism service dog's performance and the impact of this type of placement on the dog's welfare. A qualitative approach uses interview and observational data to characterize the dogs' behaviors and welfare with relevancy to the dogs' home environments. Identification of potential physical stressors included lack of rest or recovery time after working, unintentional maltreatment and prodding by children with autism, lack of predictability in daily routines, and insufficient opportunities for recreational activities. Results revealed that these dogs formed social relationships primarily with the parents and second with the children with autism. Failure to recognize and respond to the identified physical, emotional, and social needs can have serious impacts on the behavior, welfare, and performance of these autism service dogs, as well as parental satisfaction. As applications of service dogs expand to new domains, there is a need to assess and understand factors and variables affecting the relationship between family and service dog to ensure continued success of these programs.

Investigation on harsh environmental effects on polymer fiber optic link for aircraft systems

NASA Astrophysics Data System (ADS)

Cherian, Sandy; Spangenberg, Holger; Caspary, Reinhard

2014-09-01

To integrate polymer fiber based physical layer for avionic data network, it is necessary to understand the impact and cause of harsh environments on polymer fiber optic components and harnesses. Since temperature and vibration have a significant influence, we investigate the variation in optical transmittance and monitor the endurance of different types of connector and splices under extreme aircraft environments. Presently, there is no specific aerospace standard for the application of polymer fiber and components in the aircraft data network. Therefore, in the paper we examine and define the thermal cycling and vibration measurement set up and methods to evaluate the performance capability of the physical layer of the data network. Some of the interesting results observed during the measurements are also presented.

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

PubMed Central

Yang, Bin; Zhang, Jianfeng

2017-01-01

Wireless Sensor Networks (WSNs) are widely used in different disciplines, including transportation systems, agriculture field environment monitoring, healthcare systems, and industrial monitoring. The security challenge of the wireless communication link between sensor nodes is critical in WSNs. In this paper, we propose a new physical layer secret-key generation scheme for transportation security sensor network. The scheme is based on the cooperation of all the sensor nodes, thus avoiding the key distribution process, which increases the security of the system. Different passive and active attack models are analyzed in this paper. We also prove that when the cooperative node number is large enough, even when the eavesdropper is equipped with multiple antennas, the secret-key is still secure. Numerical results are performed to show the efficiency of the proposed scheme. PMID:28657588

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

PubMed

Yang, Bin; Zhang, Jianfeng

2017-06-28

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

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

Physical device safety is typically implemented locally using embedded controllers, while operations safety is primarily performed in control centers. Safe operations can be enhanced by correct design of device-level control algorithms, and protocols, procedures and operator training at the control-room level, but all can fail. Moreover, these elements exchange data and issue commands via vulnerable communication layers. In order to secure these gaps and enhance operational safety, we believe monitoring of command sequences must be combined with an awareness of physical device limitations and automata models that capture safety mechanisms. One way of doing this is by leveraging specification-based intrusionmore » detection to monitor for physical constraint violations. The method can also verify that physical infrastructure state is consistent with monitoring information and control commands exchanged between field devices and control centers. This additional security layer enhances protection from both outsider attacks and insider mistakes. We implemented specification-based SCADA command analyzers using physical constraint algorithms directly in the Bro framework and Broccoli APIs for three separate scenarios: a water heater, an automated distribution system, and an over-current protection scheme. To accomplish this, we added low-level analyzers capable of examining control system-specific protocol packets for both Modbus TCP and DNP3, and also higher-level analyzers able to interpret device command and data streams within the context of each device's physical capabilities and present operational state. Thus the software that we are making available includes the Bro/Broccoli scripts for these three scenarios, as well as simulators, written in C, of those scenarios that generate sample traffic that is monitored by the Bro/Broccoli scripts. In addition, we have also implemented systems to directly pull cyber-physical information from the OSIsoft PI historian system. We have included the Python scripts used to perform that monitoring.« less

Regional climate simulations over South America: sensitivity to model physics and to the treatment of lateral boundary conditions using the MM5 model

NASA Astrophysics Data System (ADS)

Solman, Silvina A.; Pessacg, Natalia L.

2012-01-01

In this study the capability of the MM5 model in simulating the main mode of intraseasonal variability during the warm season over South America is evaluated through a series of sensitivity experiments. Several 3-month simulations nested into ERA40 reanalysis were carried out using different cumulus schemes and planetary boundary layer schemes in an attempt to define the optimal combination of physical parameterizations for simulating alternating wet and dry conditions over La Plata Basin (LPB) and the South Atlantic Convergence Zone regions, respectively. The results were compared with different observational datasets and model evaluation was performed taking into account the spatial distribution of monthly precipitation and daily statistics of precipitation over the target regions. Though every experiment was able to capture the contrasting behavior of the precipitation during the simulated period, precipitation was largely underestimated particularly over the LPB region, mainly due to a misrepresentation in the moisture flux convergence. Experiments using grid nudging of the winds above the planetary boundary layer showed a better performance compared with those in which no constrains were imposed to the regional circulation within the model domain. Overall, no single experiment was found to perform the best over the entire domain and during the two contrasting months. The experiment that outperforms depends on the area of interest, being the simulation using the Grell (Kain-Fritsch) cumulus scheme in combination with the MRF planetary boundary layer scheme more adequate for subtropical (tropical) latitudes. The ensemble of the sensitivity experiments showed a better performance compared with any individual experiment.

The Requirements and Design of the Rapid Prototyping Capabilities System

NASA Astrophysics Data System (ADS)

Haupt, T. A.; Moorhead, R.; O'Hara, C.; Anantharaj, V.

2006-12-01

The Rapid Prototyping Capabilities (RPC) system will provide the capability to rapidly evaluate innovative methods of linking science observations. To this end, the RPC will provide the capability to integrate the software components and tools needed to evaluate the use of a wide variety of current and future NASA sensors, numerical models, and research results, model outputs, and knowledge, collectively referred to as "resources". It is assumed that the resources are geographically distributed, and thus RPC will provide the support for the location transparency of the resources. The RPC system requires providing support for: (1) discovery, semantic understanding, secure access and transport mechanisms for data products available from the known data provides; (2) data assimilation and geo- processing tools for all data transformations needed to match given data products to the model input requirements; (3) model management including catalogs of models and model metadata, and mechanisms for creation environments for model execution; and (4) tools for model output analysis and model benchmarking. The challenge involves developing a cyberinfrastructure for a coordinated aggregate of software, hardware and other technologies, necessary to facilitate RPC experiments, as well as human expertise to provide an integrated, "end-to-end" platform to support the RPC objectives. Such aggregation is to be achieved through a horizontal integration of loosely coupled services. The cyberinfrastructure comprises several software layers. At the bottom, the Grid fabric encompasses network protocols, optical networks, computational resources, storage devices, and sensors. At the top, applications use workload managers to coordinate their access to physical resources. Applications are not tightly bounded to a single physical resource. Instead, they bind dynamically to resources (i.e., they are provisioned) via a common grid infrastructure layer. For the RPC system, the cyberinfrastructure must support organizing computations (or "data transformations" in general) into complex workflows with resource discovery, automatic resource allocation, monitoring, preserving provenance as well as to aggregate heterogeneous, distributed data into knowledge databases. Such service orchestration is the responsibility of the "collective services" layer. For RPC, this layer will be based on Java Business Integration (JBI, [JSR-208]) specification which is a standards-based integration platform that combines messaging, web services, data transformation, and intelligent routing to reliably connect and coordinate the interaction of significant numbers of diverse applications (plug-in components) across organizational boundaries. JBI concept is a new approach to integration that can provide the underpinnings for loosely coupled, highly distributed integration network that can scale beyond the limits of currently used hub-and-spoke brokers. This presentation discusses the requirements, design and early prototype of the NASA-sponsored RPC system under development at Mississippi State University, demonstrating the integration of data provisioning mechanisms, data transformation tools and computational models into a single interoperable system enabling rapid execution of RPC experiments.

Using GIS for Developing Sustainable Urban Growth Case Kyrenia Region

NASA Astrophysics Data System (ADS)

Kara, C.; Akçit, N.

2018-03-01

It is critical to develop urban layers for analysis sustainable urban development possibilities within planning process. Kyrenia Region has many physical, environmental or economic issues that may danger the growth possibilities in sustainable manner. From this point, this study uses different spatial layers such as slope, distance to roads, distance to central zone, vegetation, soil productivity, environmental protection zones, distance to open/green space, distance to education for supporting sustainable urban growth policies and define suitable areas for urban development within this perspective. The study tries to convert sustainable urban growth policies such as; compact growth, environmental protection, equal accessibility to basic services; into spatial layers and establish proper framework for multi criteria evaluation in Kyrenia Region within using geographical information systems. It shows suitability values for Kyrenia region and constraints zones at final section. It clearly presents the suitable areas for the sustainable urbanization and also unsuitable or risky areas for reducing the possible disasters and may happen in the future.

Silicon homo-heterojunction solar cells: A promising candidate to realize high performance more stably

NASA Astrophysics Data System (ADS)

Tan, Miao; Zhong, Sihua; Wang, Wenjie; Shen, Wenzhong

2017-08-01

We have investigated the influences of diverse physical parameters on the performances of a silicon homo-heterojunction (H-H) solar cell, which encompasses both homojunction and heterojunction, together with their underlying mechanisms by the aid of AFORS-HET simulation. It is found that the performances of H-H solar cell are less sensitive to (i) the work function of the transparent conductive oxide layer, (ii) the interfacial density of states at the front hydrogenated amorphous silicon/crystalline silicon (a-Si:H/c-Si) interface, (iii) the peak dangling bond defect densities within the p-type a-Si:H (p-a-Si:H) layer, and (iv) the doping concentration of the p-a-Si:H layer, when compared to that of the conventional heterojunction with intrinsic thin layer (HIT) counterparts. These advantages are due to the fact that the interfacial recombination and the recombination within the a-Si:H region are less affected by all the above parameters, which fundamentally benefit from the field-effect passivation of the homojunction. Therefore, the design of H-H structure can provide an opportunity to produce high-efficiency solar cells more stably.

Physical layer security in fiber-optic MIMO-SDM systems: An overview

NASA Astrophysics Data System (ADS)

Guan, Kyle; Cho, Junho; Winzer, Peter J.

2018-02-01

Fiber-optic transmission systems provide large capacities over enormous distances but are vulnerable to simple eavesdropping attacks at the physical layer. We classify key-based and keyless encryption and physical layer security techniques and discuss them in the context of optical multiple-input-multiple-output space-division multiplexed (MIMO-SDM) fiber-optic communication systems. We show that MIMO-SDM not only increases system capacity, but also ensures the confidentiality of information transmission. Based on recent numerical and experimental results, we review how the unique channel characteristics of MIMO-SDM can be exploited to provide various levels of physical layer security.

The Black Sea Monitoring and Forecasting Center (BS-MFC) in the framework of the Copernicus Marine Service

NASA Astrophysics Data System (ADS)

Palazov, Atanas; Coppini, Giovanni; Ciliberti, Stefania Angela; Gregoire, Marilaure; Staneva, Joanna; Peneva, Elisaveta; Özsoy, Emin; Vandenbulcke, Luc; Storto, Andrea; Lemieux-Dudon, Benedicte; Lovato, Tomas; Masina, Simona; Pinardi, Nadia; Palermo, Francesco; Creti, Sergio; Macchia, Francesca; Lecci, Rita; Behrens, Arno; Marinova, Veselka; Slabakova, Violeta

2017-04-01

The BS-MFC entered the Copernicus Marine Environment Monitoring Service (CMEMS, http://marine.copernicus.eu/) in October 2016, providing regular and systematic information about the ocean state in the Black Sea in operational mode. An expert team constitutes the BS-MFC Consortium: the Institute of Oceanology, Bulgarian Academy of Sciences (IO-BAS, Bulgaria) coordinates the service and the management in collaboration with Fondazione Centro Euro-Mediterraneo sui Cambiamenti Climatici (CMCC, Italy), Helmholtz-Zentrum Geesthacht - Institute of Coastal Research (HZG, Germany), the University of Liege (ULG, Belgium), the Sofia University "St. Kliment Ohridski (USOF, Bulgaria) and the Eurasia Earth Sciences Institute - Istanbul Technical University (ITU, Turkey). The system provides a complete data catalogue for the Black Sea ocean variables such as temperature, salinity, sea level, currents, biogeochemistry and waves through a technologically advanced and resilient service, which is fully interconnected with the other Centers in the Copernicus network. The high level BS-MFC architecture is based on 3 Production Units, for Physics, Biogeochemistry and Waves products respectively, a Dissemination/Archiving Unit for the delivery of the products and their archiving/accessibility, a Local Service Desk connected to the CMEMS Service Desk devoted to support all the operational activities, and backup units for all the main service components. Products consist of analysis/hindcast, 10-days forecast and reanalysis, describing the physical (currents, temperature, salinity, sea level, mixed layer depth and bottom temperature), the biogeochemical state and waves. To implement and improve the service, the BS-MFC has detailed an evolution plan, actually under implementation, devoted to establish, assess and improve the systems and their operational functionalities, providing some improvements from the scientific point of view concerning the modeling components (e.g., the fully aligned Physics, Biogeochemistry and Waves systems, the open boundary conditions at the Bosporus, the state-of-the-art core models and increased spatial resolution among the major actions) and high quality products, towards an optimal interface between the Mediterranean and the Black Seas. The contribution will present the main operational and research & development activities at the basis of the systems, given an overview on the future plans for improving the service for the delivery of new products.

Expediting Scientific Data Analysis with Reorganization of Data

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

Byna, Surendra; Wu, Kesheng

2013-08-19

Data producers typically optimize the layout of data files to minimize the write time. In most cases, data analysis tasks read these files in access patterns different from the write patterns causing poor read performance. In this paper, we introduce Scientific Data Services (SDS), a framework for bridging the performance gap between writing and reading scientific data. SDS reorganizes data to match the read patterns of analysis tasks and enables transparent data reads from the reorganized data. We implemented a HDF5 Virtual Object Layer (VOL) plugin to redirect the HDF5 dataset read calls to the reorganized data. To demonstrate themore » effectiveness of SDS, we applied two parallel data organization techniques: a sort-based organization on a plasma physics data and a transpose-based organization on mass spectrometry imaging data. We also extended the HDF5 data access API to allow selection of data based on their values through a query interface, called SDS Query. We evaluated the execution time in accessing various subsets of data through existing HDF5 Read API and SDS Query. We showed that reading the reorganized data using SDS is up to 55X faster than reading the original data.« less

3D-FEM Analysis on Geogrid Reinforced Flexible Pavement Roads

NASA Astrophysics Data System (ADS)

Calvarano, Lidia Sarah; Palamara, Rocco; Leonardi, Giovanni; Moraci, Nicola

2017-12-01

Nowadays, the need to increase pavement service life, guarantee high performance, reduce service and maintenance costs has been turned a greater attention on the use of reinforcements. This paper presents findings of a numerical investigation on geogrid reinforced flexible pavement roads, under wheel traffic loads, using a three-dimensional Finite Element Method (FEM). The results obtained show the effectiveness of glass fibre grids as reinforcement which, with appropriate design and correct installation, by improving interface shear resistance, can be used to expand the performance of flexible pavements in different ways: by increasing the road service life providing a relevant contribution against superficial rutting or by decreasing the construction costs due to the reduction in the reinforced HMA layer thickness and thus of mineral aggregate required for its construction.

Design and Implementation of User-Created Information Systems with Mobile RFID

NASA Astrophysics Data System (ADS)

Lee, Jae Kwoen; Chin, Sungho; Kim, Hee Cheon; Chung, Kwang Sik

RFID (Radio Frequency Identification) has been usually applied at physical distribution field. The Mobile RFID can be the only technology that we can lead the market. In our country, ETRI standardizes MOBION (MOBile Identification ON), and the mobile-telecommunication companies provide the trial-mobile RFID service from 2006. In the trial-mobile RFID services, the Broker model is used to decode the mobile RFID code. However, the Broker model has some problems, such as communication overhead caused by the frequent ODS query, service performance, and various services for users. In this paper, we developed device application that is capable for filtering unrelated code from RFID service to improve the decoding performance. We also improve the performance through simplifying connection process between device application and the broker. Finally, we propose and develop the user-created information system to widely distribute the Mobile RFID service.

Architecture Design of Healthcare Software-as-a-Service Platform for Cloud-Based Clinical Decision Support Service

PubMed Central

Oh, Sungyoung; Cha, Jieun; Ji, Myungkyu; Kang, Hyekyung; Kim, Seok; Heo, Eunyoung; Han, Jong Soo; Kang, Hyunggoo; Chae, Hoseok; Hwang, Hee

2015-01-01

Objectives To design a cloud computing-based Healthcare Software-as-a-Service (SaaS) Platform (HSP) for delivering healthcare information services with low cost, high clinical value, and high usability. Methods We analyzed the architecture requirements of an HSP, including the interface, business services, cloud SaaS, quality attributes, privacy and security, and multi-lingual capacity. For cloud-based SaaS services, we focused on Clinical Decision Service (CDS) content services, basic functional services, and mobile services. Microsoft's Azure cloud computing for Infrastructure-as-a-Service (IaaS) and Platform-as-a-Service (PaaS) was used. Results The functional and software views of an HSP were designed in a layered architecture. External systems can be interfaced with the HSP using SOAP and REST/JSON. The multi-tenancy model of the HSP was designed as a shared database, with a separate schema for each tenant through a single application, although healthcare data can be physically located on a cloud or in a hospital, depending on regulations. The CDS services were categorized into rule-based services for medications, alert registration services, and knowledge services. Conclusions We expect that cloud-based HSPs will allow small and mid-sized hospitals, in addition to large-sized hospitals, to adopt information infrastructures and health information technology with low system operation and maintenance costs. PMID:25995962

Amorphous semiconductor solar cell

DOEpatents

Dalal, Vikram L.

1981-01-01

A solar cell comprising a back electrical contact, amorphous silicon semiconductor base and junction layers and a top electrical contact includes in its manufacture the step of heat treating the physical junction between the base layer and junction layer to diffuse the dopant species at the physical junction into the base layer.

Improved Wireless Security through Physical Layer Protocol Manipulation and Radio Frequency Fingerprinting

DTIC Science & Technology

2014-09-18

radios in a cognitive radio network using a radio frequency fingerprinting based method. In IEEE International Conference on Communications (ICC...IMPROVEDWIRELESS SECURITY THROUGH PHYSICAL LAYER PROTOCOL MANIPULATION AND RADIO FREQUENCY FINGERPRINTING DISSERTATION Benjamin W. Ramsey, Captain...PHYSICAL LAYER PROTOCOL MANIPULATION AND RADIO FREQUENCY FINGERPRINTING DISSERTATION Presented to the Faculty Graduate School of Engineering and

Physical properties and microstructure study of stainless steel 316L alloy fabricated by selective laser melting

NASA Astrophysics Data System (ADS)

Islam, Nurul Kamariah Md Saiful; Harun, Wan Sharuzi Wan; Ghani, Saiful Anwar Che; Omar, Mohd Asnawi; Ramli, Mohd Hazlen; Ismail, Muhammad Hussain

2017-12-01

Selective Laser Melting (SLM) demonstrates the 21st century's manufacturing infrastructure in which powdered raw material is melted by a high energy focused laser, and built up layer-by-layer until it forms three-dimensional metal parts. SLM process involves a variation of process parameters which affects the final material properties. 316L stainless steel compacts through the manipulation of building orientation and powder layer thickness parameters were manufactured by SLM. The effect of the manipulated parameters on the relative density and dimensional accuracy of the 316L stainless steel compacts, which were in the as-build condition, were experimented and analysed. The relationship between the microstructures and the physical properties of fabricated 316L stainless steel compacts was investigated in this study. The results revealed that 90° building orientation has higher relative density and dimensional accuracy than 0° building orientation. Building orientation was found to give more significant effect in terms of dimensional accuracy, and relative density of SLM compacts compare to build layer thickness. Nevertheless, the existence of large number and sizes of pores greatly influences the low performances of the density.

Temperature-driven evolution of critical points, interlayer coupling, and layer polarization in bilayer Mo S2

NASA Astrophysics Data System (ADS)

Du, Luojun; Zhang, Tingting; Liao, Mengzhou; Liu, Guibin; Wang, Shuopei; He, Rui; Ye, Zhipeng; Yu, Hua; Yang, Rong; Shi, Dongxia; Yao, Yugui; Zhang, Guangyu

2018-04-01

The recently emerging two-dimensional (2D) transition-metal dichalcogenides (TMDCs) have been a fertile ground for exploring abundant exotic physical properties. Critical points, the extrema or saddle points of electronic bands, are the cornerstone of condensed-matter physics and fundamentally determine the optical and transport phenomena of the TMDCs. However, for bilayer Mo S2 , a typical TMDC and the unprecedented electrically tunable venue for valleytronics, there has been a considerable controversy on its intrinsic electronic structure, especially for the conduction band-edge locations. Moreover, interlayer hopping and layer polarization in bilayer Mo S2 which play vital roles in valley-spintronic applications have remained experimentally elusive. Here, we report the experimental observation of intrinsic critical points locations, interlayer hopping, layer-spin polarization, and their evolution with temperature in bilayer Mo S2 by performing temperature-dependent photoluminescence. Our measurements confirm that the conduction-band minimum locates at the Kc instead of Qc, and the energy splitting between Qc and Kc redshifts with a descent of temperature. Furthermore, the interlayer hopping energy for holes and temperature-dependent layer polarization are quantitatively determined. Our observations are in good harmony with density-functional theory calculations.

Analysis of Student Satisfaction in The Process of Teaching and Learning Using Importance Performance Analysis

NASA Astrophysics Data System (ADS)

Sembiring, P.; Sembiring, S.; Tarigan, G.; Sembiring, OD

2017-12-01

This study aims to determine the level of student satisfaction in the learning process at the University of Sumatra Utara, Indonesia. The sample size of the study consisted 1204 students. Students’ response measured through questionnaires an adapted on a 5-point likert scale and interviews directly to the respondent. SERVQUAL method used to measure the quality of service with five dimensions of service characteristics, namely, physical evidence, reliability, responsiveness, assurance and concern. The result of Importance Performance Analysis reveals that six services attributes must be corrected by policy maker of University Sumatera Utara. The quality of service is still considered low by students.

High-Performance CCSDS AOS Protocol Implementation in FPGA

NASA Technical Reports Server (NTRS)

Clare, Loren P.; Torgerson, Jordan L.; Pang, Jackson

2010-01-01

The Consultative Committee for Space Data Systems (CCSDS) Advanced Orbiting Systems (AOS) space data link protocol provides a framing layer between channel coding such as LDPC (low-density parity-check) and higher-layer link multiplexing protocols such as CCSDS Encapsulation Service, which is described in the following article. Recent advancement in RF modem technology has allowed multi-megabit transmission over space links. With this increase in data rate, the CCSDS AOS protocol implementation needs to be optimized to both reduce energy consumption and operate at a high rate.

Physics Flash December 2016

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

Kippen, Karen Elizabeth

This is the December 2016 issue of Physics Flash, the newsletter of the Physics Division of Los Alamos National Laboratory (LANL). In this issue, the following topics are covered: Novel liquid helium technique to aid highly sensitive search for a neutron electrical dipole moment; Silverleaf: Prototype Red Sage experiments performed at Q-site; John L. Kline named 2016 APS Fellow; Physics students in the news; First Entropy Engine quantum random number generator hits the market; and celebrating service.

Formation of Multi-Layer Structures in Bi3Pb7 Intermetallic Compounds under an Ultra-High Gravitational Field

NASA Astrophysics Data System (ADS)

Mashimo, T.; Iguchi, Y.; Bagum, R.; Sano, T.; Sakata, O.; Ono, M.; Okayasu, S.

2008-02-01

Ultra-high gravitational field (Mega-gravity field) can promote sedimentation of atoms (diffusion) even in solids, and is expected to form a compositionally-graded structure and/or nonequilibrium phase in multi-component condensed matter. We had achieved sedimentation of substitutional solute atoms in miscible systems (Bi-Sb, In-Pb, etc.). In this study, a mega-gravity experiment at high temperature was performed on a thin-plate sample (0.7 mm in thickness) of the intermetallic compound Bi3Pb7. A visible four-layer structure was produced, which exhibited different microscopic structures. In the lowest-gravity region layer, Bi phase appeared. In the mid layers, a compositionally-graded structure was formed, with differences observed in the powder X-ray diffraction patterns. Such a multi-layer structure is expected to exhibit unique physical properties such as superconductivity.

Interference Drop Scheme: Enhancing QoS Provision in Multi-Hop Ad Hoc Networks

NASA Astrophysics Data System (ADS)

Luo, Chang-Yi; Komuro, Nobuyoshi; Takahashi, Kiyoshi; Kasai, Hiroyuki; Ueda, Hiromi; Tsuboi, Toshinori

Ad hoc networking uses wireless technologies to construct networks with no physical infrastructure and so are expected to provide instant networking in areas such as disaster recovery sites and inter-vehicle communication. Unlike conventional wired networks services, services in ad hoc networks are easily disrupted by the frequent changes in traffic and topology. Therefore, solutions to assure the Quality of Services (QoS) in ad hoc networks are different from the conventional ones used in wired networks. In this paper, we propose a new queue management scheme, Interference Drop Scheme (IDS) for ad hoc networks. In the conventional queue management approaches such as FIFO (First-in First-out) and RED (Random Early Detection), a queue is usually managed by a queue length limit. FIFO discards packets according to the queue limit, and RED discards packets in an early and random fashion. IDS, on the other hand, manages the queue according to wireless interference time, which increases as the number of contentions in the MAC layer increases. When there are many MAC contentions, IDS discards TCP data packets. By observing the interference time and discarding TCP data packets, our simulation results show that IDS improves TCP performance and reduces QoS violations in UDP in ad hoc networks with chain, grid, and random topologies. Our simulation results also demonstrate that wireless interference time is a better metric than queue length limit for queue management in multi-hop ad hoc networks.

Radio frequency identification enabled wireless sensing for intelligent food logistics.

PubMed

Zou, Zhuo; Chen, Qiang; Chen, Qing; Uysal, Ismail; Zheng, Lirong

2014-06-13

Future technologies and applications for the Internet of Things (IoT) will evolve the process of the food supply chain and create added value of business. Radio frequency identifications (RFIDs) and wireless sensor networks (WSNs) have been considered as the key technological enablers. Intelligent tags, powered by autonomous energy, are attached on objects, networked by short-range wireless links, allowing the physical parameters such as temperatures and humidities as well as the location information to seamlessly integrate with the enterprise information system over the Internet. In this paper, challenges, considerations and design examples are reviewed from system, implementation and application perspectives, particularly with focus on intelligent packaging and logistics for the fresh food tracking and monitoring service. An IoT platform with a two-layer network architecture is introduced consisting of an asymmetric tag-reader link (RFID layer) and an ad-hoc link between readers (WSN layer), which are further connected to the Internet via cellular or Wi-Fi. Then, we provide insights into the enabling technology of RFID with sensing capabilities. Passive, semi-passive and active RFID solutions are discussed. In particular, we describe ultra-wideband radio RFID which has been considered as one of the most promising techniques for ultra-low-power and low-cost wireless sensing. Finally, an example is provided in the form of an application in fresh food tracking services and corresponding field testing results.

Assembling nanoparticle coatings to improve the drug delivery performance of lipid based colloids

NASA Astrophysics Data System (ADS)

Simovic, Spomenka; Barnes, Timothy J.; Tan, Angel; Prestidge, Clive A.

2012-02-01

Lipid based colloids (e.g. emulsions and liposomes) are widely used as drug delivery systems, but often suffer from physical instabilities and non-ideal drug encapsulation and delivery performance. We review the application of engineered nanoparticle layers at the interface of lipid colloids to improve their performance as drug delivery systems. In addition we focus on the creation of novel hybrid nanomaterials from nanoparticle-lipid colloid assemblies and their drug delivery applications. Specifically, nanoparticle layers can be engineered to enhance the physical stability of submicron lipid emulsions and liposomes, satbilise encapsulated active ingredients against chemical degradation, control molecular transport and improve the dermal and oral delivery characteristics, i.e. increase absorption, bioavailability and facilitate targeted delivery. It is feasible that hybrid nanomaterials composed of nanoparticles and colloidal lipids are effective encapsulation and delivery systems for both poorly soluble drugs and biological drugs and may form the basis for the next generation of medicines. Additional pre-clinical research including specific animal model studies are required to advance the peptide/protein delivery systems, whereas the silica lipid hybrid systems have now entered human clinical trials for poorly soluble drugs.

Design and realization of intelligent tourism service system based on voice interaction

NASA Astrophysics Data System (ADS)

Hu, Lei-di; Long, Yi; Qian, Cheng-yang; Zhang, Ling; Lv, Guo-nian

2008-10-01

Voice technology is one of the important contents to improve the intelligence and humanization of tourism service system. Combining voice technology, the paper concentrates on application needs and the composition of system to present an overall intelligent tourism service system's framework consisting of presentation layer, Web services layer, and tourism application service layer. On the basis, the paper further elaborated the implementation of the system and its key technologies, including intelligent voice interactive technology, seamless integration technology of multiple data sources, location-perception-based guides' services technology, and tourism safety control technology. Finally, according to the situation of Nanjing tourism, a prototype of Tourism Services System is realized.

Physically Healthy and Ready to Learn. Technical Assistance Paper No. 1

ERIC Educational Resources Information Center

US Department of Health and Human Services, Head Start Bureau, 2006

2006-01-01

This Technical Assistance Paper offers guidance to programs regarding the implementation of the "Head Start Program Performance Standards" on child health and developmental services, child health and safety, and child nutrition. The paper examines how physical health influences children's development and how child health and development…

Unique Educational Needs of Learners with Physical and Other Health Impairments.

ERIC Educational Resources Information Center

Kendall, Robbie M.

This monograph addresses the educational needs of learners who have physical and health impairments that adversely interfere with their educational performance and who thus require special training, related services, adaptive equipment, modified materials, and/or barrier free facilities. The first section discusses the identification of learners…

Individual risk factors associated with premature discharge from military service.

PubMed

Larsson, Helena; Broman, Lisbet; Harms-Ringdahl, Karin

2009-01-01

Research on military populations indicates that failure to complete training is a significant problem for armed forces around the world. The present study estimated the prevalence of musculoskeletal complaints or injuries and potential individual risk factors leading to premature discharge from Swedish military service. Male conscripts, n=469 answered a questionnaire and performed physical tests at the start of their military service. A high prevalence of complaints or injuries in lower back and knee was shown. Logistic regression analyses showed an increased risk of discharge (odds ratio, OR) when reporting current complaints or injuries in any part of the body (OR 4.6), being physically inactive (OR 2.0), cigarette smoking (OR 2.7), or poor mental health (OR 3.6). The findings highlight the need for improved preenlistment examination and/or early preventive strategies addressing both physical and psychological interventions.

Dependence of the source performance on plasma parameters at the BATMAN test facility

NASA Astrophysics Data System (ADS)

Wimmer, C.; Fantz, U.

2015-04-01

The investigation of the dependence of the source performance (high jH-, low je) for optimum Cs conditions on the plasma parameters at the BATMAN (Bavarian Test MAchine for Negative hydrogen ions) test facility is desirable in order to find key parameters for the operation of the source as well as to deepen the physical understanding. The most relevant source physics takes place in the extended boundary layer, which is the plasma layer with a thickness of several cm in front of the plasma grid: the production of H-, its transport through the plasma and its extraction, inevitably accompanied by the co-extraction of electrons. Hence, a link of the source performance with the plasma parameters in the extended boundary layer is expected. In order to characterize electron and negative hydrogen ion fluxes in the extended boundary layer, Cavity Ring-Down Spectroscopy and Langmuir probes have been applied for the measurement of the H- density and the determination of the plasma density, the plasma potential and the electron temperature, respectively. The plasma potential is of particular importance as it determines the sheath potential profile at the plasma grid: depending on the plasma grid bias relative to the plasma potential, a transition in the plasma sheath from an electron repelling to an electron attracting sheath takes place, influencing strongly the electron fraction of the bias current and thus the amount of co-extracted electrons. Dependencies of the source performance on the determined plasma parameters are presented for the comparison of two source pressures (0.6 Pa, 0.45 Pa) in hydrogen operation. The higher source pressure of 0.6 Pa is a standard point of operation at BATMAN with external magnets, whereas the lower pressure of 0.45 Pa is closer to the ITER requirements (p ≤ 0.3 Pa).

The PESPERF Scale: An Instrument for Measuring Service Quality in the School of Physical Education and Sports Sciences (PESS)

ERIC Educational Resources Information Center

Yildiz, Suleyman M.; Kara, Ali

2009-01-01

Purpose: HEdPERF (Higher Education PERFormance) is one of the most recently developed scales in the literature to measure service quality in higher education. However, HEdPERF is designed to measure service quality at a macro level (university level) and may be considered as a more generic measurement instrument. In higher education, new scales…

Effect of intermediate layers on atomic layer deposition-aluminum oxide protected silver mirrors

NASA Astrophysics Data System (ADS)

Fryauf, David M.; Diaz Leon, Juan J.; Phillips, Andrew C.; Kobayashi, Nobuhiko P.

2017-07-01

This work investigates intermediate materials deposited between silver (Ag) thin-film mirrors and an aluminum oxide (AlOx) barrier overlayer and compares the effects on mirror durability to environmental stresses. Physical vapor deposition of various fluorides, oxides, and nitrides in combination with AlOx by atomic layer deposition (ALD) is used to develop several coating recipes. Ag-AlOx samples with different intermediate materials undergo aggressive high-temperature (80°C), high-humidity (80%) (HTHH) testing for 10 days. Reflectivity of mirror samples is measured before and after HTHH testing, and image processing techniques are used to analyze the specular surface of the samples after HTHH testing. Among the seven intermediate materials used in this work, TiN, MgAl2O4, NiO, and Al2O3 intermediate layers offer more robust protection against chemical corrosion and moisture when compared with samples with no intermediate layer. In addition, results show that the performance of the ALD-AlOx barrier overlayer depends significantly on the ALD-growth process temperature. Because higher durability is observed in samples with less transparent TiN and NiO layers, we propose a figure of merit based on post-HTHH testing reflectivity change and specular reflective mirror surface area remaining after HTHH testing to judge overall barrier performance.

Securing Wireless Communications of the Internet of Things from the Physical Layer, An Overview

NASA Astrophysics Data System (ADS)

Zhang, Junqing; Duong, Trung; Woods, Roger; Marshall, Alan

2017-08-01

The security of the Internet of Things (IoT) is receiving considerable interest as the low power constraints and complexity features of many IoT devices are limiting the use of conventional cryptographic techniques. This article provides an overview of recent research efforts on alternative approaches for securing IoT wireless communications at the physical layer, specifically the key topics of key generation and physical layer encryption. These schemes can be implemented and are lightweight, and thus offer practical solutions for providing effective IoT wireless security. Future research to make IoT-based physical layer security more robust and pervasive is also covered.

Probability theory for 3-layer remote sensing radiative transfer model: univariate case.

PubMed

Ben-David, Avishai; Davidson, Charles E

2012-04-23

A probability model for a 3-layer radiative transfer model (foreground layer, cloud layer, background layer, and an external source at the end of line of sight) has been developed. The 3-layer model is fundamentally important as the primary physical model in passive infrared remote sensing. The probability model is described by the Johnson family of distributions that are used as a fit for theoretically computed moments of the radiative transfer model. From the Johnson family we use the SU distribution that can address a wide range of skewness and kurtosis values (in addition to addressing the first two moments, mean and variance). In the limit, SU can also describe lognormal and normal distributions. With the probability model one can evaluate the potential for detecting a target (vapor cloud layer), the probability of observing thermal contrast, and evaluate performance (receiver operating characteristics curves) in clutter-noise limited scenarios. This is (to our knowledge) the first probability model for the 3-layer remote sensing geometry that treats all parameters as random variables and includes higher-order statistics. © 2012 Optical Society of America

Determination of layer-dependent exciton binding energies in few-layer black phosphorus

PubMed Central

Zhang, Guowei; Chaves, Andrey; Huang, Shenyang; Wang, Fanjie; Xing, Qiaoxia; Low, Tony; Yan, Hugen

2018-01-01

The attraction between electrons and holes in semiconductors forms excitons, which largely determine the optical properties of the hosting material, and hence the device performance, especially for low-dimensional systems. Mono- and few-layer black phosphorus (BP) are emerging two-dimensional (2D) semiconductors. Despite its fundamental importance and technological interest, experimental investigation of exciton physics has been rather limited. We report the first systematic measurement of exciton binding energies in ultrahigh-quality few-layer BP by infrared absorption spectroscopy, with layer (L) thickness ranging from 2 to 6 layers. Our experiments allow us to determine the exciton binding energy, decreasing from 213 meV (2L) to 106 meV (6L). The scaling behavior with layer numbers can be well described by an analytical model, which takes into account the nonlocal screening effect. Extrapolation to free-standing monolayer yields a large binding energy of ~800 meV. Our study provides insights into 2D excitons and their crossover from 2D to 3D, and demonstrates that few-layer BP is a promising high-quality optoelectronic material for potential infrared applications. PMID:29556530

Investigation of physical and chemical stability of ointment with herbals.

PubMed

Zdoryk, Oleksandr A; Khokhlova, Kateryna O; Georgiyants, Victoriya A; Vyshnevska, Liliia I

2014-01-01

The physical and chemical stability of a stock preparation ointment with active ingredients-herbal tinctures of calendula and arnica-for the treatment of hemorrhoids was studied. Evaluations for physical and chemical stability were performed initially and throughout the storage period. Physical stability of the ointment was assessed by means of visual observation in normal room light. Throughout the study period, the physical appearance of the ointment did not change. The chemical stability of the ointment was evaluated by means of a stability-indicating, thin-layer chromatography analytical technique. The shelf-life was found to be one month at 25 degrees C +/- 2 degrees C/60% RH and two months at 5 degrees C +/- 3 degrees C, when protected from light.

Protocol for Communication Networking for Formation Flying

NASA Technical Reports Server (NTRS)

Jennings, Esther; Okino, Clayton; Gao, Jay; Clare, Loren

2009-01-01

An application-layer protocol and a network architecture have been proposed for data communications among multiple autonomous spacecraft that are required to fly in a precise formation in order to perform scientific observations. The protocol could also be applied to other autonomous vehicles operating in formation, including robotic aircraft, robotic land vehicles, and robotic underwater vehicles. A group of spacecraft or other vehicles to which the protocol applies could be characterized as a precision-formation- flying (PFF) network, and each vehicle could be characterized as a node in the PFF network. In order to support precise formation flying, it would be necessary to establish a corresponding communication network, through which the vehicles could exchange position and orientation data and formation-control commands. The communication network must enable communication during early phases of a mission, when little positional knowledge is available. Particularly during early mission phases, the distances among vehicles may be so large that communication could be achieved only by relaying across multiple links. The large distances and need for omnidirectional coverage would limit communication links to operation at low bandwidth during these mission phases. Once the vehicles were in formation and distances were shorter, the communication network would be required to provide high-bandwidth, low-jitter service to support tight formation-control loops. The proposed protocol and architecture, intended to satisfy the aforementioned and other requirements, are based on a standard layered-reference-model concept. The proposed application protocol would be used in conjunction with conventional network, data-link, and physical-layer protocols. The proposed protocol includes the ubiquitous Institute of Electrical and Electronics Engineers (IEEE) 802.11 medium access control (MAC) protocol to be used in the datalink layer. In addition to its widespread and proven use in diverse local-area networks, this protocol offers both (1) a random- access mode needed for the early PFF deployment phase and (2) a time-bounded-services mode needed during PFF-maintenance operations. Switching between these two modes could be controlled by upper-layer entities using standard link-management mechanisms. Because the early deployment phase of a PFF mission can be expected to involve multihop relaying to achieve network connectivity (see figure), the proposed protocol includes the open shortest path first (OSPF) network protocol that is commonly used in the Internet. Each spacecraft in a PFF network would be in one of seven distinct states as the mission evolved from initial deployment, through coarse formation, and into precise formation. Reconfiguration of the formation to perform different scientific observations would also cause state changes among the network nodes. The application protocol provides for recognition and tracking of the seven states for each node and for protocol changes under specified conditions to adapt the network and satisfy communication requirements associated with the current PFF mission phase. Except during early deployment, when peer-to-peer random access discovery methods would be used, the application protocol provides for operation in a centralized manner.

Around Marshall

NASA Image and Video Library

1998-08-04

Nurse performs tonometry examination, which measure the tension of the eyeball, during an employee's arnual physical examination given by MSFC Occupational Medicine Environmental Health Services under the Center Operations Directorate.

Link prediction in multiplex online social networks

NASA Astrophysics Data System (ADS)

Jalili, Mahdi; Orouskhani, Yasin; Asgari, Milad; Alipourfard, Nazanin; Perc, Matjaž

2017-02-01

Online social networks play a major role in modern societies, and they have shaped the way social relationships evolve. Link prediction in social networks has many potential applications such as recommending new items to users, friendship suggestion and discovering spurious connections. Many real social networks evolve the connections in multiple layers (e.g. multiple social networking platforms). In this article, we study the link prediction problem in multiplex networks. As an example, we consider a multiplex network of Twitter (as a microblogging service) and Foursquare (as a location-based social network). We consider social networks of the same users in these two platforms and develop a meta-path-based algorithm for predicting the links. The connectivity information of the two layers is used to predict the links in Foursquare network. Three classical classifiers (naive Bayes, support vector machines (SVM) and K-nearest neighbour) are used for the classification task. Although the networks are not highly correlated in the layers, our experiments show that including the cross-layer information significantly improves the prediction performance. The SVM classifier results in the best performance with an average accuracy of 89%.

Link prediction in multiplex online social networks.

PubMed

Jalili, Mahdi; Orouskhani, Yasin; Asgari, Milad; Alipourfard, Nazanin; Perc, Matjaž

2017-02-01

Online social networks play a major role in modern societies, and they have shaped the way social relationships evolve. Link prediction in social networks has many potential applications such as recommending new items to users, friendship suggestion and discovering spurious connections. Many real social networks evolve the connections in multiple layers (e.g. multiple social networking platforms). In this article, we study the link prediction problem in multiplex networks. As an example, we consider a multiplex network of Twitter (as a microblogging service) and Foursquare (as a location-based social network). We consider social networks of the same users in these two platforms and develop a meta-path-based algorithm for predicting the links. The connectivity information of the two layers is used to predict the links in Foursquare network. Three classical classifiers (naive Bayes, support vector machines (SVM) and K-nearest neighbour) are used for the classification task. Although the networks are not highly correlated in the layers, our experiments show that including the cross-layer information significantly improves the prediction performance. The SVM classifier results in the best performance with an average accuracy of 89%.

Refinements to SSiB with an Emphasis on Snow-Physics: Evaluation and Validation Using GSWP and Valdai Data

NASA Technical Reports Server (NTRS)

Mocko, David M.; Sud, Y. C.

2000-01-01

Refinements to the snow-physics scheme of SSiB (Simplified Simple Biosphere Model) are described and evaluated. The upgrades include a partial redesign of the conceptual architecture to better simulate the diurnal temperature of the snow surface. For a deep snowpack, there are two separate prognostic temperature snow layers - the top layer responds to diurnal fluctuations in the surface forcing, while the deep layer exhibits a slowly varying response. In addition, the use of a very deep soil temperature and a treatment of snow aging with its influence on snow density is parameterized and evaluated. The upgraded snow scheme produces better timing of snow melt in GSWP-style simulations using ISLSCP Initiative I data for 1987-1988 in the Russian Wheat Belt region. To simulate more realistic runoff in regions with high orographic variability, additional improvements are made to SSiB's soil hydrology. These improvements include an orography-based surface runoff scheme as well as interaction with a water table below SSiB's three soil layers. The addition of these parameterizations further help to simulate more realistic runoff and accompanying prognostic soil moisture fields in the GSWP-style simulations. In intercomparisons of the performance of the new snow-physics SSiB with its earlier versions using an 18-year single-site dataset from Valdai Russia, the version of SSiB described in this paper again produces the earliest onset of snow melt. Soil moisture and deep soil temperatures also compare favorably with observations.

Service innovation: a comparison of two approaches for physical screening of psychiatric inpatients.

PubMed

Harrison, Mark Richard; McMillan, Catherine Frances; Dickinson, Timothy

2012-06-01

Psychiatric medications have clear links to obesity, diabetes, dyslipidaemia, hypertension, hyperprolactinaemia and movement disorders. These disorders are a common cause of morbidity and mortality in psychiatric patients but physical screening by health services is often haphazard. We report the findings of an audit of physical screening across two hospital wards. Each ward undertook a process of service improvement. One ward modified the admissions proforma and the other developed a discharge screening clinic. The effectiveness of each of these interventions was then compared through a reaudit of practice across both wards. At baseline, screening was performed inconsistently and infrequently. On average, the modified admissions proforma increased screening rates by 4.7% compared to 30.7% for discharge screening clinics. The discharge screening clinic demonstrated statistically significant improvements in screening rates and effectively delivered health promotion advice. Discharge screening clinics are significantly more likely than improved admissions procedures to detect clinically significant abnormalities. If these abnormalities are detected and treated then the long-term physical health of psychiatric patients may be improved.

Probability Density Functions for the CALIPSO Lidar Version 4 Cloud-Aerosol Discrimination (CAD) Algorithm

NASA Astrophysics Data System (ADS)

Liu, Z.; Kar, J.; Zeng, S.; Tackett, J. L.; Vaughan, M.; Trepte, C. R.; Omar, A. H.; Hu, Y.; Winker, D. M.

2017-12-01

In the CALIPSO retrieval algorithm, detection layers in the lidar measurements is followed by their classification as a "cloud" or "aerosol" using 5-dimensional probability density functions (PDFs). The five dimensions are the mean attenuated backscatter at 532 nm, the layer integrated total attenuated color ratio, the mid-layer altitude, integrated volume depolarization ratio and latitude. The new version 4 (V4) level 2 (L2) data products, released in November 2016, are the first major revision to the L2 product suite since May 2010. Significant calibration changes in the V4 level 1 data necessitated substantial revisions to the V4 L2 CAD algorithm. Accordingly, a new set of PDFs was generated to derive the V4 L2 data products. The V4 CAD algorithm is now applied to layers detected in the stratosphere, where volcanic layers and occasional cloud and smoke layers are observed. Previously, these layers were designated as `stratospheric', and not further classified. The V4 CAD algorithm is also applied to all layers detected at single shot (333 m) resolution. In prior data releases, single shot detections were uniformly classified as clouds. The CAD PDFs used in the earlier releases were generated using a full year (2008) of CALIPSO measurements. Because the CAD algorithm was not applied to stratospheric features, the properties of these layers were not incorporated into the PDFs. When building the V4 PDFs, the 2008 data were augmented with additional data from June 2011, and all stratospheric features were included. The Nabro and Puyehue-Cordon volcanos erupted in June 2011, and volcanic aerosol layers were observed in the upper troposphere and lower stratosphere in both the northern and southern hemispheres. The June 2011 data thus provides the stratospheric aerosol properties needed for comprehensive PDF generation. In contrast to earlier versions of the PDFs, which were generated based solely on observed distributions, construction of the V4 PDFs considered the typical optical and physical properties of feature subtypes, and thus provide a more comprehensive physical basis for discrimination. As a result of the changes made, the V4 CAD provides better performance and more reliable confidence levels. We describe the generation of V4 PDFs and present characterization and performance of the new CAD algorithm.

Gas sensing in 2D materials

NASA Astrophysics Data System (ADS)

Yang, Shengxue; Jiang, Chengbao; Wei, Su-huai

2017-06-01

Two-dimensional (2D) layered inorganic nanomaterials have attracted huge attention due to their unique electronic structures, as well as extraordinary physical and chemical properties for use in electronics, optoelectronics, spintronics, catalysts, energy generation and storage, and chemical sensors. Graphene and related layered inorganic analogues have shown great potential for gas-sensing applications because of their large specific surface areas and strong surface activities. This review aims to discuss the latest advancements in the 2D layered inorganic materials for gas sensors. We first elaborate the gas-sensing mechanisms and introduce various types of gas-sensing devices. Then, we describe the basic parameters and influence factors of the gas sensors to further enhance their performance. Moreover, we systematically present the current gas-sensing applications based on graphene, graphene oxide (GO), reduced graphene oxide (rGO), functionalized GO or rGO, transition metal dichalcogenides, layered III-VI semiconductors, layered metal oxides, phosphorene, hexagonal boron nitride, etc. Finally, we conclude the future prospects of these layered inorganic materials in gas-sensing applications.

Field Performance Of A Compacted Clay Landfill Final Cover At A Humid Site

EPA Science Inventory

A study was conducted in southern Georgia, USA, to evalaute how the hydraulic properties of the compacted clay barrier layer in a final landfill cover changed over a 4-year service life. The cover was part of a test section constructed in a large drainage lysimeter that allowed ...

State Policies on Service Dogs for Military Veterans.

PubMed

Reed, James B

2015-12-01

U.S. service members returning home from combat often face physical, mental and emotional challenges. Providing service dogs to these veterans is one method being used successfully to help address the difficulties they face. Under the federal Americans with Disabilities Act (ADA), a service animal is defined as "any dog that is individually trained to do work or perform tasks for the benefit of an individual with a disability, including a physical, sensory, psychiatric, intellectual or other mental disability." The work the dog undertakes must be directly related to the person's disability. Examples include guiding people who are blind, pulling a wheelchair, alerting a person with hearing loss, protecting a person having a seizure, and calming someone with post-traumatic stress disorder (PTSD) during an anxiety attack or psychiatric episode.

Materials Science and Device Physics of 2-Dimensional Semiconductors

NASA Astrophysics Data System (ADS)

Fang, Hui

Materials and device innovations are the keys to future technology revolution. For MOSFET scaling in particular, semiconductors with ultra-thin thickness on insulator platform is currently of great interest, due to the potential of integrating excellent channel materials with the industrially mature Si processing. Meanwhile, ultra-thin thickness also induces strong quantum confinement which in turn affect most of the material properties of these 2-dimensional (2-D) semiconductors, providing unprecedented opportunities for emerging technologies. In this thesis, multiple novel 2-D material systems are explored. Chapter one introduces the present challenges faced by MOSFET scaling. Chapter two covers the integration of ultrathin III V membranes with Si. Free standing ultrathin III-V is studied to enable high performance III-V on Si MOSFETs with strain engineering and alloying. Chapter three studies the light absorption in 2-D membranes. Experimental results and theoretical analysis reveal that light absorption in the 2-D quantum membranes is quantized into a fundamental physical constant, where we call it the quantum unit of light absorption, irrelevant of most of the material dependent parameters. Chapter four starts to focus on another 2-D system, atomic thin layered chalcogenides. Single and few layered chalcogenides are first explored as channel materials, with focuses in engineering the contacts for high performance MOSFETs. Contact treatment by molecular doping methods reveals that many layered chalcogenides other than MoS2 exhibit good transport properties at single layer limit. Finally, Chapter five investigated 2-D van der Waals heterostructures built from different single layer chalcogenides. The investigation in a WSe2/MoS2 hetero-bilayer shows a large Stokes like shift between photoluminescence peak and lowest absorption peak, as well as strong photoluminescence intensity, consistent with spatially indirect transition in a type II band alignment in this van der Waals heterostructure. This result enables new family of semiconductor heterostructures having tunable optoelectronic properties with customized composite layers and highlights the ability to build van der Waals semiconductor heterostructure lasers/LEDs.

7 CFR 91.2 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Agriculture. Analyses. Microbiological, chemical, or physical tests performed on a commodity. Applicant. Any person or organization requesting services provided by the Science and Technology (S&T) programs. Legal...

7 CFR 91.2 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Agriculture. Analyses. Microbiological, chemical, or physical tests performed on a commodity. Applicant. Any person or organization requesting services provided by the Science and Technology (S&T) programs. Legal...

7 CFR 91.2 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Agriculture. Analyses. Microbiological, chemical, or physical tests performed on a commodity. Applicant. Any person or organization requesting services provided by the Science and Technology (S&T) programs. Legal...

7 CFR 91.2 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Agriculture. Analyses. Microbiological, chemical, or physical tests performed on a commodity. Applicant. Any person or organization requesting services provided by the Science and Technology (S&T) programs. Legal...

Assessing performance of Botswana’s public hospital system: the use of the World Health Organization Health System Performance Assessment Framework

PubMed Central

Seitio-Kgokgwe, Onalenna; Gauld, Robin DC; Hill, Philip C; Barnett, Pauline

2014-01-01

Background: Very few studies have assessed performance of Botswana public hospitals. We draw from a large research study assessing performance of the Botswana Ministry of Health (MoH) to evaluate the performance of public hospital system using the World Health Organization Health Systems Performance Assessment Framework (WHO HSPAF). We aimed to evaluate performance of Botswana public hospital system; relate findings of the assessment to the potential for improvements in hospital performance; and determine the usefulness of the WHO HSPAF in assessing performance of hospital systems in a developing country. Methods: This article is based on data collected from document analysis, 54 key informants comprising senior managers and staff of the MoH (N= 40) and senior officers from stakeholder organizations (N= 14), and surveys of 42 hospital managers and 389 health workers. Data from documents and transcripts were analyzed using content and thematic analysis while data analysis for surveys was descriptive determining proportions and percentages. Results: The organizational structure of the Botswana’s public hospital system, authority and decision-making are highly centralized. Overall physical access to health services is high. However, challenges in the distribution of facilities and inpatient beds create inequities and inefficiencies. Capacity of the hospitals to deliver services is limited by inadequate resources. There are significant challenges with the quality of care. Conclusion: While Botswana invested considerably in building hospitals around the country resulting in high physical access to services, the organization and governance of the hospital system, and inadequate resources limit service delivery. The ongoing efforts to decentralize management of hospitals to district level entities should be expedited. The WHO HSPAF enabled us to conduct a comprehensive assessment of the public hospital system. Though relatively new, this approach proved useful in this study. PMID:25279380

Assessment of Existing Data and Reports for System Evaluation

NASA Technical Reports Server (NTRS)

Matolak, David W.; Skidmore, Trent A.

2000-01-01

This report describes work done as part of the Weather Datalink Research project grant. We describe the work done under Task 1 of this project: the assessment of the suitability of available reports and data for use in evaluation of candidate weather datalink systems, and the development of a performance parameter set for comparative system evaluation. It was found that existing data and reports are inadequate for a complete physical layer characterization, but that these reports provide a good foundation for system comparison. In addition, these reports also contain some information useful for evaluation at higher layers. The performance parameter list compiled can be viewed as near complete-additional investigations, both analytical/simulation and experimental, will likely result in additions and improvements to this list.

An in vivo study on the effect of coating stability on osteointegration performance of collagen/hyaluronic acid multilayer modified titanium implants.

PubMed

Ao, Haiyong; Zong, Jiajia; Nie, Yanjiao; Wan, Yizao; Zheng, Xiebin

2018-03-01

Aseptic loosening of implant is one of the main causes of Ti-based implant failure. In our previous work, a novel stable collagen/hyaluronic acid (Col/HA) multilayer modified titanium coatings (TCs) was developed by layer-by-layer (LBL) covalent immobilization technique, which showed enhanced biological properties compared with TCs that were physically absorbed with Col/HA multilayer in vitro . In this study, a rabbit model with femur condyle defect was employed to compare the osteointegration performance of them. Results indicated that Col/HA multilayer with favourable stability could better facilitate osteogenesis around implants and bone-implant contact. The Col/HA multilayer covalent-immobilized TC may reduce aseptic loosening of implant.

Going global in physical therapist education: International Service-Learning in US-based programmes.

PubMed

Pechak, Celia; Thompson, Mary

2011-12-01

 Internationalization is expanding its presence in higher education in the United States. Reflecting this trend that includes incorporating global perspectives in the curricula, physical therapist education programmes increasingly offer international opportunities such as International Service-Learning (ISL) to their students. Service-learning, a teaching strategy that integrates community service with structured learning activities, has gained broad acceptance in health professions education including physical therapy, and is therefore the focus of this paper. The specific purposes of this paper were to identify and analyse the commonalities that existed among established ISL programmes within physical therapist education programmes in terms of structures and processes, and to consider its broader implications for physical therapist education.   A descriptive, exploratory study was performed using grounded theory. Snowball and purposive, theoretical sampling yielded 14 faculty members with experience in international service, international learning or ISL in physical therapist education programmes. Faculty were interviewed by phone. Interview transcriptions and course documents were analysed applying grounded theory methodology. Data from eight programmes which met the operational definition of established ISL were used to address the purposes of this paper.   Five phases of establishing an ISL programme were identified: development, design, implementation, evaluation, and enhancement. Although no single model exists for ISL in physical therapist education; commonalities in structures and processes were identified in each phase. However, attention to service objectives and outcomes is lacking.   While analysis revealed that each programme shared commonalities and demonstrated differences in structures and processes compared with the other programmes, the study demonstrated a general lack of focus on formal community outcomes which raises ethical concerns. Future research and dialogue is warranted to explore ethics and good practice in ISL and other global health initiatives in physical therapy. This study may facilitate reflections and creative solutions by individual faculty and the profession. Copyright © 2010 John Wiley & Sons, Ltd.

Implementation of new integrated evaporation equipment for the preparation of 238U targets and improvement of the deposition process

NASA Astrophysics Data System (ADS)

Vanleeuw, D.; Lewis, D.; Moens, A.; Sibbens, G.; Wiss, T.

2018-05-01

Measurement of neutron cross section data is a core activity of the JRC-Directorate G for Nuclear Safety and Security in Geel. After a period of reduced activity and in line with a renewed interest for nuclear data required for GenIV reactors and waste minimization, the demand for high quality actinide targets increased. Physical vapour deposition by thermal evaporation is a key technique to prepare homogeneous thin actinide layers, but due to ageing effects the earlier in-house developed equipment can no longer provide the required quality. Because of a current lack of experience and human resources cooperation with private companies is required for the development of new deposition equipment directly integrated in a glove box. In this paper we describe the design, implementation and validation of the first commercial actinide evaporator in a glove box as well as the optimization of the deposition process. Highly enriched 238U3O8 was converted to 238UF4 powder and several deposition runs were performed on different substrates. The deposition parameters were varied and defined in order to guarantee physical and chemical stable homogeneous UF4 layers, even on polished substrates which was not longer feasible with the older equipment. The stability problem is discussed in view of the thin layer growth by physical vapour deposition and the influence of the deposition parameters on the layer quality. The deposits were characterized for the total mass by means of substitution weighing and for the areal density of 238U by means of alpha particle counting and thermal ionization mass spectrometry (TIMS). The quality of the layer was visually evaluated and by means of stereo microscopy and auto radiography.

7 CFR 91.5 - Where services are offered.

Code of Federal Regulations, 2011 CFR

2011-01-01

...) Science and Technology Programs National Science Laboratory. A variety of proximate for composition, chemical, physical, microbiological and biomolecular (DNA-based) tests and laboratory analyses performed on..., honey, meat and meat products, fiber products and processed foods are performed at the Science and...

7 CFR 91.5 - Where services are offered.

Code of Federal Regulations, 2013 CFR

2013-01-01

...) Science and Technology Programs National Science Laboratory. A variety of proximate for composition, chemical, physical, microbiological and biomolecular (DNA-based) tests and laboratory analyses performed on..., honey, meat and meat products, fiber products and processed foods are performed at the Science and...

7 CFR 91.5 - Where services are offered.

Code of Federal Regulations, 2014 CFR

2014-01-01

...) Science and Technology Programs National Science Laboratory. A variety of proximate for composition, chemical, physical, microbiological and biomolecular (DNA-based) tests and laboratory analyses performed on..., honey, meat and meat products, fiber products and processed foods are performed at the Science and...

7 CFR 91.5 - Where services are offered.

Code of Federal Regulations, 2012 CFR

2012-01-01

...) Science and Technology Programs National Science Laboratory. A variety of proximate for composition, chemical, physical, microbiological and biomolecular (DNA-based) tests and laboratory analyses performed on..., honey, meat and meat products, fiber products and processed foods are performed at the Science and...

Evaluation of AL-FEC performance for IP television services QoS

NASA Astrophysics Data System (ADS)

Mammi, E.; Russo, G.; Neri, A.

2010-01-01

The IP television services quality is a critical issue because of the nature of transport infrastructure. Packet loss is the main cause of service degradation in such kind of network platforms. The use of forward error correction (FEC) techniques in the application layer (AL-FEC), between the source of TV service (video server) and the user terminal, seams to be an efficient strategy to counteract packet losses alternatively or in addiction to suitable traffic management policies (only feasible in "managed networks"). A number of AL-FEC techniques have been discussed in literature and proposed for inclusion in TV over IP international standards. In this paper a performance evaluation of the AL-FEC defined in SMPTE 2022-1 standard is presented. Different typical events occurring in IP networks causing different types (in terms of statistic distribution) of IP packet losses have been studied and AL-FEC performance to counteract these kind of losses have been evaluated. The performed analysis has been carried out in view of fulfilling the TV services QoS requirements that are usually very demanding. For managed networks, this paper envisages a strategy to combine the use of AL-FEC with the set-up of a transport quality based on FEC packets prioritization. Promising results regard this kind of strategy have been obtained.

Cross-layer model design in wireless ad hoc networks for the Internet of Things.

PubMed

Yang, Xin; Wang, Ling; Xie, Jian; Zhang, Zhaolin

2018-01-01

Wireless ad hoc networks can experience extreme fluctuations in transmission traffic in the Internet of Things, which is widely used today. Currently, the most crucial issues requiring attention for wireless ad hoc networks are making the best use of low traffic periods, reducing congestion during high traffic periods, and improving transmission performance. To solve these problems, the present paper proposes a novel cross-layer transmission model based on decentralized coded caching in the physical layer and a content division multiplexing scheme in the media access control layer. Simulation results demonstrate that the proposed model effectively addresses these issues by substantially increasing the throughput and successful transmission rate compared to existing protocols without a negative influence on delay, particularly for large scale networks under conditions of highly contrasting high and low traffic periods.

Cross-layer model design in wireless ad hoc networks for the Internet of Things

PubMed Central

Wang, Ling; Xie, Jian; Zhang, Zhaolin

2018-01-01

Wireless ad hoc networks can experience extreme fluctuations in transmission traffic in the Internet of Things, which is widely used today. Currently, the most crucial issues requiring attention for wireless ad hoc networks are making the best use of low traffic periods, reducing congestion during high traffic periods, and improving transmission performance. To solve these problems, the present paper proposes a novel cross-layer transmission model based on decentralized coded caching in the physical layer and a content division multiplexing scheme in the media access control layer. Simulation results demonstrate that the proposed model effectively addresses these issues by substantially increasing the throughput and successful transmission rate compared to existing protocols without a negative influence on delay, particularly for large scale networks under conditions of highly contrasting high and low traffic periods. PMID:29734355

42 CFR 413.106 - Reasonable cost of physical and other therapy services furnished under arrangements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... provider or other organization had such services been performed by such person in an employment... of therapy, to therapists working full time in an employment relationship. (2) Fringe benefit and... that the study designs, questionnaires and instructions, as well as the resultant survey data for...

High conductivity and transparent aluminum-based multi-layer source/drain electrodes for thin film transistors

NASA Astrophysics Data System (ADS)

Yao, Rihui; Zhang, Hongke; Fang, Zhiqiang; Ning, Honglong; Zheng, Zeke; Li, Xiaoqing; Zhang, Xiaochen; Cai, Wei; Lu, Xubing; Peng, Junbiao

2018-02-01

In this study, high conductivity and transparent multi-layer (AZO/Al/AZO-/Al/AZO) source/drain (S/D) electrodes for thin film transistors were fabricated via conventional physical vapor deposition approaches, without toxic elements or further thermal annealing process. The 68 nm-thick multi-layer films with excellent optical properties (transparency: 82.64%), good electrical properties (resistivity: 6.64  ×  10-5 Ω m, work function: 3.95 eV), and superior surface roughness (R q   =  0.757 nm with scanning area of 5  ×  5 µm2) were fabricated as the S/D electrodes. Significantly, comprehensive performances of AZO films are enhanced by the insertion of ultra-thin Al layers. The optimal transparent TFT with this multi-layer S/D electrodes exhibited a decent electrical performance with a saturation mobility (µ sat) of 3.2 cm2 V-1 s-1, an I on/I off ratio of 1.59  ×  106, a subthreshold swing of 1.05 V/decade. The contact resistance of AZO/Al/AZO/Al/AZO multi-layer electrodes is as low as 0.29 MΩ. Moreover, the average visible light transmittance of the unpatterned multi-layers constituting a whole transparent TFT could reach 72.5%. The high conductivity and transparent multi-layer S/D electrodes for transparent TFTs possessed great potential for the applications of the green and transparent displays industry.

Marketing and commercialization of computational research services.

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

Toevs, J. W.

Physical and computational scientists and mathematicians in Russia's nuclear cities are turning their work toward generating profits from Western markets. Successful ventures require an understanding of the marketing of contract research as well as Western expectations regarding contract execution, quality, and performance. This paper will address fundamentals in business structure, marketing, and contract performance for organizations engaging in the marketing and commercialization of research services. Considerable emphasis will be placed on developing adequate communication within the organization.

Planar structured perovskite solar cells by hybrid physical chemical vapor deposition with optimized perovskite film thickness

NASA Astrophysics Data System (ADS)

Wei, Xiangyang; Peng, Yanke; Jing, Gaoshan; Cui, Tianhong

2018-05-01

The thickness of perovskite absorber layer is a critical parameter to determine a planar structured perovskite solar cell’s performance. By modifying the spin coating speed and PbI2/N,N-dimethylformamide (DMF) solution concentration, the thickness of perovskite absorber layer was optimized to obtain high-performance solar cells. Using a PbI2/DMF solution of 1.3 mol/L, maximum power conversion efficiency (PCE) of a perovskite solar cell is 15.5% with a perovskite film of 413 nm at 5000 rpm, and PCE of 14.3% was also obtained for a solar cell with a perovskite film of 182 nm thick. It is derived that higher concentration of PbI2/DMF will result in better perovskite solar cells. Additionally, these perovskite solar cells are highly uniform. In 14 sets of solar cells, standard deviations of 11 sets of solar cells were less than 0.50% and the smallest standard deviation was 0.25%, which demonstrates the reliability and effectiveness of hybrid physical chemical vapor deposition (HPCVD) method.

Steering disturbance rejection using a physics-based neuromusculoskeletal driver model

NASA Astrophysics Data System (ADS)

Mehrabi, Naser; Sharif Razavian, Reza; McPhee, John

2015-10-01

The aim of this work is to develop a comprehensive yet practical driver model to be used in studying driver-vehicle interactions. Drivers interact with their vehicle and the road through the steering wheel. This interaction forms a closed-loop coupled human-machine system, which influences the driver's steering feel and control performance. A hierarchical approach is proposed here to capture the complexity of the driver's neuromuscular dynamics and the central nervous system in the coordination of the driver's upper extremity activities, especially in the presence of external disturbance. The proposed motor control framework has three layers: the first (or the path planning) plans a desired vehicle trajectory and the required steering angles to perform the desired trajectory; the second (or the musculoskeletal controller) actuates the musculoskeletal arm to rotate the steering wheel accordingly; and the final layer ensures the precision control and disturbance rejection of the motor control units. The physics-based driver model presented here can also provide insights into vehicle control in relaxed and tensed driving conditions, which are simulated by adjusting the driver model parameters such as cognition delay and muscle co-contraction dynamics.

Clinical and cost-effectiveness of compression hosiery versus compression bandages in treatment of venous leg ulcers (Venous leg Ulcer Study IV, VenUS IV): a randomised controlled trial.

PubMed

Ashby, Rebecca L; Gabe, Rhian; Ali, Shehzad; Adderley, Una; Bland, J Martin; Cullum, Nicky A; Dumville, Jo C; Iglesias, Cynthia P; Kang'ombe, Arthur R; Soares, Marta O; Stubbs, Nikki C; Torgerson, David J

2014-03-08

Drawbacks exist with the standard treatment (four-layer compression bandages) for venous leg ulcers. We have therefore compared the clinical effectiveness and cost-effectiveness of two-layer compression hosiery with the four-layer bandage for the treatment of such ulcers. We undertook this pragmatic, open, randomised controlled trial with two parallel groups in 34 centres in England and Northern Ireland. The centres were community nurse teams or services, family doctor practices, leg ulcer clinics, tissue viability clinics or services, and wound clinics. Participants were aged 18 years or older with a venous leg ulcer and an ankle brachial pressure index of at least 0·8, and were tolerant of high compression. We randomly allocated participants (1:1) to receive two-layer compression hosiery or a four-layer bandage, using a remote randomisation service and prevalidated computer randomisation program. Participants were stratified by ulcer duration and ulcer area with permuted blocks (block sizes four and six). The primary endpoint was time to ulcer healing, with a maximum follow-up of 12 months. Although participants and health-care providers were not masked to treatment allocation, the primary endpoint was measured by masked assessment of photographs. Primary analysis was intention to treat with Cox regression, with adjustment for ulcer area, ulcer duration, physical mobility, and centre. This trial is registered with the ISRCTN register, number ISRCTN49373072. We randomly allocated 457 participants to the two treatment groups: 230 to two-layer hosiery and 227 to the four-layer bandage, of whom 453 (230 hosiery and 223 bandage) contributed data for analysis. Median time to ulcer healing was 99 days (95% CI 84-126) in the hosiery group and 98 days (85-112) in the bandage group, and the proportion of ulcers healing was much the same in the two groups (70·9% hosiery and 70·4% bandage). More hosiery participants changed their allocated treatment (38·3% hosiery vs 27·0% bandage; p=0·02). 300 participants had 895 adverse events, of which 85 (9·5%) were classed as serious but unrelated to trial treatment. Two-layer compression hosiery is a viable alternative to the four-layer bandage-it is equally as effective at healing venous leg ulcers. However, a higher rate of treatment changes in participants in the hosiery group than in the bandage group suggests that hosiery might not be suitable for all patients. NIHR Health Technology Assessment programme (07/60/26). Copyright © 2014 Elsevier Ltd. All rights reserved.

Observations and simulations of the bottom nepheloid layer in the Lafourche Trough, Louisiana Continental Shelf

NASA Astrophysics Data System (ADS)

Jolliff, J.; Jarosz, E.; Penko, A.; Smith, T.

2017-12-01

The "Lafourche Trough" is a mud/silt -dominated, elongate seafloor depression located between transgressive sandy shoals approximately 50 km south of Cocodrie, Louisiana. These irregular bathymetric features are relicts of the abandoned Lafourche delta complex that still have an impact upon coupled sediment-hydrodynamic processes occurring today. Repeated optical and physical oceanographic surveys conducted during the spring of 2015 and winter 2017 reveal persistent bottom nepheloid layers (BNLs) characterized by extreme optical turbidity (beam attenuation 10 m-1, 532 nm). The manifestation and persistence of cohesive sediment BNLs in this area appears to result from a complex interplay between tidal currents, bathymetry, and frontal dynamics along the edge of the Mississippi River plume. Numerical experiments were performed using the Coupled Ocean Atmosphere Mesoscale Prediction System (COAMPS), an integrated air-sea-wave operational forecasting tool, that includes a simplified numerical sediment resuspension and transport scheme in order to simulate the nepheloid layer observations through the trough. The model results suggest that the wave-current bottom boundary layer is a critical factor in BNL development, and thusly, without wave model integration into COAMPS the system struggles to replicate the observations. Future modeling work will need to explore the potential suppression of physical mixing due to density perturbations along the BNL to fluid mud continuum within the bottom boundary layer.

Guideposts and Roadblocks to the Career-Long Scholarly Engagement of Physical Education Teacher Education Faculty

ERIC Educational Resources Information Center

Berei, Catherine P.; Pratt, Erica; Parker, Melissa; Shephard, Kevin; Liang, Tanjian; Nampai, Udon; Neamphoka, Guntima

2017-01-01

Purpose: Scholarship is essential for the growth and development of the physical education field. Over time, scholarship expectations have changed, forcing faculty members to alter time spent for research, teaching, and service. Social-cognitive career theory (SCCT) presents a model for understanding performance and persistence in an occupational…

Performance of the cometary experiment MUPUS on the body Earth

NASA Astrophysics Data System (ADS)

Marczewski, W.; Usowicz, B.; Schröer, K.; Seiferlin, K.; Spohn, T.

2003-04-01

Thermal experiment MUPUS for the Rosetta mission was extensively experience in field and laboratory conditions to predict its performance under physical processes available on the Earth. The goal was not guessing a cometary material in the ground but available behavior of thermal sensor responses monitoring mass and energy transfer. The processes expected on a comet are different in composition and environmental from those met on the Earth but basically similar in physics. Nature of energy powering the processes is also essentially the same - solar radiation. Several simple laboratory experiments with freezing and thawing with water ice, with mixture of water and oil and water layers strongly diverged by salinity revealed capability of recognition layered structure of the medium under test. More over effects of slow convection and latent heat related to the layers are also observed well. Cometary environment without atmosphere makes process of sublimation dominant. Open air conditions on the Earth may also offer a change of state in matter but between different phases. Learning temperature gradient in snow layers under thawing show that effects stimulated by a cause of daily cycling may be detected thermally. Results from investigations in snow made on Spitzbergen are good proofs on capability of the method. Relevance of thermal effects to heat powered processes of mass transport in the matter of ground is meaningful for the cometary experiment of MUPUS and for Earth sciences much concerned on water, gas and solid matter transport in the terrestrial ground. Results leading to energy balance studied on the Earth surface may be interesting also for the experiment on the comet and are to be discussed.

Forensic examination of ink by high-performance thin layer chromatography--the United States Secret Service Digital Ink Library.

PubMed

Neumann, Cedric; Ramotowski, Robert; Genessay, Thibault

2011-05-13

Forensic examinations of ink have been performed since the beginning of the 20th century. Since the 1960s, the International Ink Library, maintained by the United States Secret Service, has supported those analyses. Until 2009, the search and identification of inks were essentially performed manually. This paper describes the results of a project designed to improve ink samples' analytical and search processes. The project focused on the development of improved standardization procedures to ensure the best possible reproducibility between analyses run on different HPTLC plates. The successful implementation of this new calibration method enabled the development of mathematical algorithms and of a software package to complement the existing ink library. Copyright © 2010 Elsevier B.V. All rights reserved.

Convergence

NASA Astrophysics Data System (ADS)

Darcie, Thomas E.; Doverspike, Robert; Zirngibl, Martin; Korotky, Steven K.

2005-01-01

Call for Papers: Convergence

Guest Editors: Thomas E. Darcie, University of Victoria Robert Doverspike, AT&T Martin Zirngibl, Lucent Technologies

Coordinating Associate Editor: Steven K. Korotky, Lucent Technologies

• Architecture, design and performance of optical wide-area-network (WAN), metro, and access networks
• Integration strategies for multiservice transport platforms
• Access methods that bridge traditional and emerging services
• Network signaling and control methodologies
• All-optical packet routing and switching techniques

Manuscript Submission

Dependable Networks as a Paradigm for Network Innovation

NASA Astrophysics Data System (ADS)

Miki, Tetsuya

In past, dependable networks meant minimizing network outages or the impact of the outages. However, over the decade, major network services have shifted from telephone and data transmission to Internet and to mobile communication, where higher layer services with a variety of contents are provided. Reviewing these backgrounds of network development, the importance of the dependability of higher layer network services are pointed out. Then, the main aspects to realize the dependability are given for lower, middle and higher layer network services. In addition, some particular issues for dependable networks are described.

Effects of discrete-electrode arrangement on traveling-wave electroosmotic pumping

NASA Astrophysics Data System (ADS)

Liu, Weiyu; Shao, Jinyou; Ren, Yukun; Wu, Yupan; Wang, Chunhui; Ding, Haitao; Jiang, Hongyuan; Ding, Yucheng

2016-09-01

Traveling-wave electroosmotic (TWEO) pumping arises from the action of an imposed traveling-wave (TW) electric field on its own induced charge in the diffuse double layer, which is formed on top of an electrode array immersed in electrolyte solutions. Such a traveling field can be merely realized in practice by a discrete electrode array upon which the corresponding voltages of correct phase are imposed. By employing the theory of linear and weakly nonlinear double-layer charging dynamics, a physical model incorporating both the nonlinear surface capacitance of diffuse layer and Faradaic current injection is developed herein in order to quantify the changes in TWEO pumping performance from a single-mode TW to discrete electrode configuration. Benefiting from the linear analysis, we investigate the influence of using discrete electrode array to create the TW signal on the resulting fluid motion, and several approaches are suggested to improve the pumping performance. In the nonlinear regime, our full numerical analysis considering the intervening isolation spacing indicates that a practical four-phase discrete electrode configuration of equal electrode and gap width exhibits stronger nonlinearity than expected from the idealized pump applied with a single-mode TW in terms of voltage-dependence of the ideal pumping frequency and peak flow rate, though it has a much lower pumping performance. For model validation, pumping of electrolytes by TWEO is achieved over a confocal spiral four-phase electrode array covered by an insulating microchannel; measurement of flow velocity indicates the modified nonlinear theory considering moderate Faradaic conductance is indeed a more accurate physical description of TWEO. These results offer useful guidelines for designing high-performance TWEO microfluidic pumps with discrete electrode array.

Software design for the VIS instrument onboard the Euclid mission: a multilayer approach

NASA Astrophysics Data System (ADS)

Galli, E.; Di Giorgio, A. M.; Pezzuto, S.; Liu, S. J.; Giusi, G.; Li Causi, G.; Farina, M.; Cropper, M.; Denniston, J.; Niemi, S.

2014-07-01

The Euclid mission scientific payload is composed of two instruments: a VISible Imaging Instrument (VIS) and a Near Infrared Spectrometer and Photometer instrument (NISP). Each instrument has its own control unit. The Instrument Command and Data Processing Unit (VI-CDPU) is the control unit of the VIS instrument. The VI-CDPU is connected directly to the spacecraft by means of a MIL-STD-1553B bus and to the satellite Mass Memory Unit via a SpaceWire link. All the internal interfaces are implemented via SpaceWire links and include 12 high speed lines for the data provided by the 36 focal plane CCDs readout electronics (ROEs) and one link to the Power and Mechanisms Control Unit (VI-PMCU). VI-CDPU is in charge of distributing commands to the instrument sub-systems, collecting their housekeeping parameters and monitoring their health status. Moreover, the unit has the task of acquiring, reordering, compressing and transferring the science data to the satellite Mass Memory. This last feature is probably the most challenging one for the VI-CDPU, since stringent constraints about the minimum lossless compression ratio, the maximum time for the compression execution and the maximum power consumption have to be satisfied. Therefore, an accurate performance analysis at hardware layer is necessary, which could delay too much the design and development of software. In order to mitigate this risk, in the multilayered design of software we decided to design a middleware layer that provides a set of APIs with the aim of hiding the implementation of the HW connected layer to the application one. The middleware is built on top of the Operating System layer (which includes the Real-Time OS that will be adopted) and the onboard Computer Hardware. The middleware itself has a multi-layer architecture composed of 4 layers: the Abstract RTOS Adapter Layer (AOSAL), the Speci_c RTOS Adapter Layer (SOSAL), the Common Patterns Layer (CPL), the Service Layer composed of two subgroups which are the Common Service (CSL) and the Specific Service layer (SSL). The middleware design is made using the UML 2.0 standard. The AOSAL includes the abstraction of services provided by a generic RTOS (e.g Thread/Task, Time Management, Mutex and Semaphores) as well as an abstraction of SpaceWire and 1553-B bus Interface. The SOSAL is the implementation of AOSAL for the adopted RTOS. The CPL provides a set of patterns that are a general solution for common problems related to embedded hard Real Time systems. This set includes patterns for memory management, homogenous redundancy channels, pipes and filters for data exchange, proxies for slow memories, watchdog and reactive objects. The CPL is designed using a soft-metamodeling approach, so as to be as general as possible. Finally, the SL provides a set of services that are common to space applications. The testing of this middleware can be done both during the design using appropriate tools of analysis and in the implementation phase by means of unit testing tools.

Enhancement of the Device Performance and the Stability with a Homojunction-structured Tungsten Indium Zinc Oxide Thin Film Transistor.

PubMed

Park, Hyun-Woo; Song, Aeran; Choi, Dukhyun; Kim, Hyung-Jun; Kwon, Jang-Yeon; Chung, Kwun-Bum

2017-09-14

Tungsten-indium-zinc-oxide thin-film transistors (WIZO-TFTs) were fabricated using a radio frequency (RF) co-sputtering system with two types of source/drain (S/D)-electrode material of conducting WIZO (homojunction structure) and the indium-tin oxide (ITO) (heterojunction structure) on the same WIZO active-channel layer. The electrical properties of the WIZO layers used in the S/D electrode and the active-channel layer were adjusted through oxygen partial pressure during the deposition process. To explain enhancements of the device performance and stability of the homojunction-structured WIZO-TFT, a systematic investigation of correlation between device performance and physical properties at the interface between the active layer and the S/D electrodes such as the contact resistance, surface/interfacial roughness, interfacial-trap density, and interfacial energy-level alignments was conducted. The homojunction-structured WIZO-TFT exhibited a lower contact resistance, smaller interfacial-trap density, and flatter interfacial roughness than the WIZO-TFT with the heterojunction structure. The 0.09 eV electron barrier of the homojunction-structured WIZO-TFT is lower than the 0.21 eV value that was obtained for the heterojunction-structured WIZO-TFT. This reduced electron barrier may be attributed to enhancements of device performance and stability, that are related to the carrier transport.

Tier One Performance Screen Initial Operational Test and Evaluation: Early Results

DTIC Science & Technology

2011-04-01

Requirement: In addition to educational, physical , and moral screens, the U.S. Army relies on a composite score from the Armed Services Vocational Aptitude...analyses suggest that the individual TAPAS scales significantly predict a number of criteria of interest. Most notably, the Physical Conditioning scale...predicted Soldiers’ self-reported Army Physical Fitness Test (APFT) scores, number of restarts in training, adjustment to Army life, and 3-month

[Exploration of the design of media access control layer of wireless body area network for medical healthcare].

PubMed

Liu, Xuemei; Ge, Baofeng

2012-04-01

This paper proposes a media access control (MAC) layer design for wireless body area network (WBAN) systems. WBAN is a technology that targets for wireless networking of wearable and implantable body sensors which monitor vital body signs, such as heart-rate, body temperature, blood pressure, etc. It has been receiving attentions from international organizations, e. g. the Institute of Electrical and Electronics Engineers (IEEE), due to its capability of providing efficient healthcare services and clinical management. This paper reviews the standardization procedure of WBAN and summarizes the challenge of the MAC layer design. It also discusses the methods of improving power consumption performance, which is one of the major issues of WBAN systems.

A novel (ex situ) method to quantify oxygen diffusion coefficient of polymer fuel cells backing and catalyst layers

NASA Astrophysics Data System (ADS)

Baricci, Andrea; Casalegno, Andrea

2016-09-01

Limiting current density of oxygen reduction reaction in polymer electrolyte fuel cells is determined by several mass transport resistances that lower the concentration of oxygen on the catalyst active site. Among them, diffusion across porous media plays a significant role. Despite the extensive experimental activity documented in PEMFC literature, only few efforts have been dedicated to the measurement of the effective transport properties in porous layers. In the present work, a methodology for ex situ measurement of the effective diffusion coefficient and Knudsen radius of porous layers for polymer electrolyte fuel cells (gas diffusion layer, micro porous layer and catalyst layer) is described and applied to high temperature polymer fuel cells State of Art materials. Regression of the measured quantities by means of a quasi 2D physical model is performed to quantify the Knudsen effect, which is reported to account, respectively, for 30% and 50% of the mass transport resistance in micro porous layer and catalyst layer. On the other side, the model reveals that pressure gradient consequent to permeation in porous layers of high temperature polymer fuel cells has a negligible effect on oxygen concentration in relevant operating conditions.

Studies of a new multi-layer compression bandage for the treatment of venous ulceration.

PubMed

Scriven, J M; Bello, M; Taylor, L E; Wood, A J; London, N J

2000-03-01

This study aimed to develop an alternative graduated compression bandage for the treatment of venous leg ulcers. Alternative bandage components were identified and assessed for optimal performance as a graduated multi-layer compression bandage. Subsequently the physical characteristics and clinical efficacy of the optimal bandage combination was prospectively examined. Ten healthy limbs were used to develop the optimal combination and 20 limbs with venous ulceration to compare the physical properties of the two bandage types. Subsequently 42 consecutive ulcerated limbs were prospectively treated to examine the efficacy of the new bandage combination. The new combination produced graduated median (range) sub-bandage pressures (mmHg) as follows: ankle 59 (42-100), calf 36 (27-67) and knee 35 (16-67). Over a seven-day period this combination maintained a comparable level of compression with the Charing Cross system, and achieved an overall healing rate at one year of 88%. The described combination should be brought to the attention of healthcare professionals treating venous ulcers as a possible alternative to other forms of multi-layer graduated compression bandages pending prospective, randomised clinical trials.

Influence of culture media on the physical and chemical properties of Ag-TiCN coatings

NASA Astrophysics Data System (ADS)

Carvalho, I.; Escobar Galindo, R.; Henriques, M.; Palacio, C.; Carvalho, S.

2014-08-01

The aim of this study was to verify the possible physical and chemical changes that may occur on the surface of Ag-TiCN coatings after exposure to the culture media used in microbiological and cytotoxic assays, respectively tryptic soy broth (TSB) and Dulbecco's modified eagle's medium (DMEM). After sample immersion for 24 h in the media, analyses were performed by glow discharge optical emission spectroscopy discharge radiation (GDOES), Rutherford backscattering spectroscopy (RBS) and x-ray photoelectron spectroscopy (XPS). The results of GDOES profile, RBS and XPS spectra, of samples immersed in TSB, demonstrated the formation of a thin layer of carbon, oxygen and nitrogen that could be due to the presence of proteins in TSB. After 24 h of immersion in DMEM, the results showed the formation of a thin layer of calcium phosphates on the surface, since the coatings displayed a highly oxidized surface in which calcium and phosphorus were detected. All these results suggested that the formation of a layer on the coating surface prevented the release of silver ions in concentrations that allow antibacterial activity.

Physical-chemical processes of diamond grinding

NASA Astrophysics Data System (ADS)

Lobanov, D. V.; Arhipov, P. V.; Yanyushkin, A. S.; Skeeba, V. Yu

2017-10-01

The article focuses on the relevance of the research into the problem of diamond abrasive metal-bonded tool performance loss with a view to enhancing the effectiveness of high-strength materials finishing processing. The article presents the results of theoretical and empirical studies of loading layer formation on the surface of diamond wheels during processing high-strength materials. The theoretical part deals with the physical and chemical processes at the contact area of the diamond wheel and work surface with the viewpoint of the electrochemical potentials equilibrium state. We defined dependencies for calculating the loading layer dimensions. The practical part of work centers on various electron-microscopic, spectral and X-ray diffraction studies of the metal-bonded wheel samples during diamond grinding. The analysis of the research results revealed the composition and structure of the loading layer. The validity of the theoretical data is confirmed by sufficient convergence of the calculated values with the results of empirical research. In order to reduce the intensity of loading and improve the cutting properties of metal-bonded diamond abrasive tools, it is recommended to use combined methods for more efficient processing of high-strength materials.

Noncoherent Physical-Layer Network Coding with FSK Modulation: Relay Receiver Design Issues

DTIC Science & Technology

2011-03-01

222 IEEE TRANSACTIONS ON COMMUNICATIONS, VOL. 59, NO. 9, SEPTEMBER 2011 2595 Noncoherent Physical-Layer Network Coding with FSK Modulation: Relay... noncoherent reception, channel estima- tion. I. INTRODUCTION IN the two-way relay channel (TWRC), a pair of sourceterminals exchange information...2011 4. TITLE AND SUBTITLE Noncoherent Physical-Layer Network Coding with FSK Modulation:Relay Receiver Design Issues 5a. CONTRACT NUMBER 5b

Dynamic layer rearrangement during growth of layered oxide films by molecular beam epitaxy

DOE PAGES

Lee, J. H.; Luo, G.; Tung, I. C.; ...

2014-08-03

The A n+1B nO 3n+1 Ruddlesden–Popper homologous series offers a wide variety of functionalities including dielectric, ferroelectric, magnetic and catalytic properties. Unfortunately, the synthesis of such layered oxides has been a major challenge owing to the occurrence of growth defects that result in poor materials behaviour in the higher-order members. To understand the fundamental physics of layered oxide growth, we have developed an oxide molecular beam epitaxy system with in situ synchrotron X-ray scattering capability. We present results demonstrating that layered oxide films can dynamically rearrange during growth, leading to structures that are highly unexpected on the basis of themore » intended layer sequencing. Theoretical calculations indicate that rearrangement can occur in many layered oxide systems and suggest a general approach that may be essential for the construction of metastable Ruddlesden–Popper phases. Lastly, we demonstrate the utility of the new-found growth strategy by performing the first atomically controlled synthesis of single-crystalline La 3Ni 2O 7.« less

Synthesis and characterization of high performing Fe-N-C catalyst for oxygen reduction reaction (ORR) in Alkaline Exchange Membrane Fuel Cells

NASA Astrophysics Data System (ADS)

Hossen, Md Mosaddek; Artyushkova, Kateryna; Atanassov, Plamen; Serov, Alexey

2018-01-01

In this article, three different Fe-N-C oxygen reduction reaction (ORR) catalysts derived from different organic molecules i.e. Fe-NMG, Fe-NMP, Fe-MBZ have been synthesized, characterized by physical-chemical methods and studied in the reaction of oxygen reduction (ORR). It is found that Fe-NMG shows higher ORR performance than Fe-NMP and Fe-MBZ, by both rotating ring disk electrode (RRDE) and fuel cell tests. From characterization and surface analysis, it can be explained that the presence of higher amount of surface oxides and pyridinic nitrogen is the main reason for better performance towards ORR in alkaline media. To achieve the highest performance in alkaline exchange membrane fuel cell (AEMFC), the optimization of catalyst layer composition using various concentrations of ionomer (Tokuyama, AS4) was performed. At the optimum cathode layer configuration utilizing Fe-NMG produces the peak power density of 218 mWcm-2, which is one of the highest values presented in the open literature.

Depth and Extent of Gas-Ablator Mix in Symcap Implosions at the National Ignition Facility

NASA Astrophysics Data System (ADS)

Pino, Jesse; Ma, T.; MacLaren, S. A.; Salmonson, J. D.; Ho, D.; Khan, S. F.; Masse, L.; Ralph, J. E.; Czajka, C.; Casey, D.; Sacks, R.; Smalyuk, V. A.; Tipton, R. E.; Kyrala, G. A.

2017-10-01

A longstanding question in ICF physics has been the extent to which capsule ablator material mixes into the burning fusion fuel and degrades performance. Several recent campaigns at the National Ignition Facility have examined this question through the use of separated reactants. A layer of CD plastic is placed on the inner surface of the CH shell and the shell is filled with a gas mixture of H and T. This allows for simultaneous neutron signals that inform different aspects of the physics; we get core TT neutron yield, atomic mix from the DT neutrons, and information about shell heating from the DD neutron signal. By systematically recessing the CD layer away from the gas boundary we gain an inference of the depth of the mixing layer. This presentation will cover three campaigns to look at mixing depth: An ignition-like design (``Low-foot'') at two convergence ratios, as well as a robust, nearly one-dimensional, low convergence, symmetric platform designed to minimize ablation front feed-through (HED 2-shock). We show that the 2-shock capsule has less ablator-gas mix, and compare the experimental results to mix-model simulations. This work was performed under the auspices of the U.S. Department of Energy by LLNL under Contract DE-AC52-07NA27344, LLNS, LLC.

Research on the architecture and key technologies of SIG

NASA Astrophysics Data System (ADS)

Fu, Zhongliang; Meng, Qingxiang; Huang, Yan; Liu, Shufan

2007-06-01

Along with the development of computer network, Grid has become one of the hottest issues of researches on sharing and cooperation of Internet resources throughout the world. This paper illustrates a new architecture of SIG-a five-hierarchy architecture (including Data Collecting Layer, Grid Layer, Service Layer, Application Layer and Client Layer) of SIG from the traditional three hierarchies (only including resource layer, service layer and client layer). In the paper, the author proposes a new mixed network mode of Spatial Information Grid which integrates CAG (Certificate Authority of Grid) and P2P (Peer to Peer) in the Grid Layer, besides, the author discusses some key technologies of SIG and analysis the functions of these key technologies.

Multicomponent, Rare-Earth-Doped Thermal-Barrier Coatings

NASA Technical Reports Server (NTRS)

Miller, Robert A.; Zhu, Dongming

2005-01-01

Multicomponent, rare-earth-doped, perovskite-type thermal-barrier coating materials have been developed in an effort to obtain lower thermal conductivity, greater phase stability, and greater high-temperature capability, relative to those of the prior thermal-barrier coating material of choice, which is yttria-partially stabilized zirconia. As used here, "thermal-barrier coatings" (TBCs) denotes thin ceramic layers used to insulate air-cooled metallic components of heat engines (e.g., gas turbines) from hot gases. These layers are generally fabricated by plasma spraying or physical vapor deposition of the TBC materials onto the metal components. A TBC as deposited has some porosity, which is desirable in that it reduces the thermal conductivity below the intrinsic thermal conductivity of the fully dense form of the material. Undesirably, the thermal conductivity gradually increases because the porosity gradually decreases as a consequence of sintering during high-temperature service. Because of these and other considerations such as phase transformations, the maximum allowable service temperature for yttria-partially stabilized zirconia TBCs lies in the range of about 1,200 to 1,300 C. In contrast, the present multicomponent, rare-earth-doped, perovskite-type TBCs can withstand higher temperatures.

Recent progress in photoactive organic field-effect transistors.

PubMed

Wakayama, Yutaka; Hayakawa, Ryoma; Seo, Hoon-Seok

2014-04-01

Recent progress in photoactive organic field-effect transistors (OFETs) is reviewed. Photoactive OFETs are divided into light-emitting (LE) and light-receiving (LR) OFETs. In the first part, LE-OFETs are reviewed from the viewpoint of the evolution of device structures. Device performances have improved in the last decade with the evolution of device structures from single-layer unipolar to multi-layer ambipolar transistors. In the second part, various kinds of LR-OFETs are featured. These are categorized according to their functionalities: phototransistors, non-volatile optical memories, and photochromism-based transistors. For both, various device configurations are introduced: thin-film based transistors for practical applications, single-crystalline transistors to investigate fundamental physics, nanowires, multi-layers, and vertical transistors based on new concepts.

Effects of preparation steps on the physical parameters and electromechanical properties of IPMC actuators

NASA Astrophysics Data System (ADS)

Wang, Yanjie; Zhu, Zicai; Chen, Hualing; Luo, Bin; Chang, Longfei; Wang, Yongquan; Li, Dichen

2014-12-01

The electromechanical properties of ionic polymer-metal composites (IPMC) are affected by many factors, including resistivity of surface electrodes, bending stiffness and dielectric modulus, etc, which are closely related to physical and chemical preparation steps. This paper focuses on the effects of preparation steps on these physical parameters and electromechanical properties of IPMC actuators. The mechanisms of electrode formation in the preparation steps are also clarified and investigated. To obtain samples with different features, one or more of the crucial process steps, including pretreatment, impregnation-reduction and chemical plating, were selected to fabricate IPMC. The experimental observations revealed that the physical parameters of IPMC strongly depend on their electrode morphologies caused by different steps, which were reasonable from the standpoint of physics. IPMC with the characteristics of low surface resistance and low bending stiffness, and a large area of interface electrode exhibits a perfect performance. The improvements were considered to be attributed to the double-layer electrostatic effect, induced by the broad dispersion of penetrated electrode nanoparticles. An electrical component, consisting of an equivalent circuit of a parallel combination of the serial circuit of the resistance and the electric double-layer capacitance, is introduced to qualitatively explain the deformation behaviors of IPMC. This research helps to improve the preparation steps and promote the understanding of IPMC.

A novel dynamic wavelength bandwidth allocation scheme over OFDMA PONs

NASA Astrophysics Data System (ADS)

Yan, Bo; Guo, Wei; Jin, Yaohui; Hu, Weisheng

2011-12-01

With rapid growth of Internet applications, supporting differentiated service and enlarging system capacity have been new tasks for next generation access system. In recent years, research in OFDMA Passive Optical Networks (PON) has experienced extraordinary development as for its large capacity and flexibility in scheduling. Although much work has been done to solve hardware layer obstacles for OFDMA PON, scheduling algorithm on OFDMA PON system is still under primary discussion. In order to support QoS service on OFDMA PON system, a novel dynamic wavelength bandwidth allocation (DWBA) algorithm is proposed in this paper. Per-stream QoS service is supported in this algorithm. Through simulation, we proved our bandwidth allocation algorithm performs better in bandwidth utilization and differentiate service support.

Long-term effects of conventional and reduced tillage systems on soil condition and yield of maize

NASA Astrophysics Data System (ADS)

Rátonyi, Tamás; Széles, Adrienn; Harsányi, Endre

2015-04-01

As a consequence of operations which neglect soil condition and consist of frequent soil disturbance, conventional tillage (primary tillage with autumn ploughing) results in the degradation and compaction of soil structure, as well as the reduction of organic matter. These unfavourable processes pose an increasing economic and environmental protection problem today. The unfavourable physical condition of soils on which conventional tillage was performed indicate the need for preserving methods and tools. The examinations were performed in the multifactorial long-term tillage experiment established at the Látókép experiment site of DE MÉK. The experiment site is located in the Hajdúság loess ridge (Hungary) and its soil is loess-based calcareous chernozem with deep humus layer. The physical soil type is mid-heavy adobe. The long-term experiment has a split-split plot design. The main plots are different tillage methods (autumn ploughing, spring shallow tillage) without replication. In this paper, the effect of conventional and reduced (shallow) tillage methods on soil conditions and maize yield was examined. A manual penetrometer was used to determine the physical condition and compactedness of the soil. The soil moisture content was determined with deep probe measurement (based on capacitive method). In addition to soil analyses, the yield per hectare of different plots was also observed. In reduced tillage, one compacted layer is shown in the soil resistance profile determined with a penetrometer, while there are two compacted layers in autumn ploughing. The highest resistance was measured in the case of primary tillage performed at the same depth for several years in the compacted (pan disk) layer developed under the developed layer in both treatments. The unfavourable impact of spring shallow primary tillage on physical soil conditions is shown by the fact that the compaction of the pan disk exceed the critical limit value of 3 MPa. Over the years, further deterioration of physical conditions were observed below the regularly cultivated layer. In shallow tillage, soil contained more moisture (at 40-50 cm deep and below) than in the ploughed treatment. There are multiple reasons for this phenomenon. This tillage method is moisture preserving as the depth of disturbance (15 cm) is lower than in ploughed treatments (25-30 cm). Soil surface is covered by stem residues after sowing, which may reduce the extent of evaporation. The soil surface CO2 emission was determined based on primary tillage depth, intensity and the period which passed since primary tillage. Spring shallow primary tillage resulted in higher CO2 emission than conventional tillage. The average maize yield was significantly higher in the autumn ploughing treatment (6,6-13,9 t/ha) in the first half (7 years) of the examined period (2000-2014). Higher average yields were observed in two years in the spring shallow tillage treatment and no significant yield difference was observed between tillage treatments in other examined years. Reduced (shallow) tillage increases the risk of near-surface soil compaction and the biological activity of the soil, while it reduces the moisture loss of the soil. Reducing tillage intensity does not necessarily reduce the average yield of the produced crop (maize).

A Delay-Aware and Reliable Data Aggregation for Cyber-Physical Sensing

PubMed Central

Zhang, Jinhuan; Long, Jun; Zhang, Chengyuan; Zhao, Guihu

2017-01-01

Physical information sensed by various sensors in a cyber-physical system should be collected for further operation. In many applications, data aggregation should take reliability and delay into consideration. To address these problems, a novel Tiered Structure Routing-based Delay-Aware and Reliable Data Aggregation scheme named TSR-DARDA for spherical physical objects is proposed. By dividing the spherical network constructed by dispersed sensor nodes into circular tiers with specifically designed widths and cells, TSTR-DARDA tries to enable as many nodes as possible to transmit data simultaneously. In order to ensure transmission reliability, lost packets are retransmitted. Moreover, to minimize the latency while maintaining reliability for data collection, in-network aggregation and broadcast techniques are adopted to deal with the transmission between data collecting nodes in the outer layer and their parent data collecting nodes in the inner layer. Thus, the optimization problem is transformed to minimize the delay under reliability constraints by controlling the system parameters. To demonstrate the effectiveness of the proposed scheme, we have conducted extensive theoretical analysis and comparisons to evaluate the performance of TSR-DARDA. The analysis and simulations show that TSR-DARDA leads to lower delay with reliability satisfaction. PMID:28218668

The CCSDS Next Generation Space Data Link Protocol (NGSLP)

NASA Technical Reports Server (NTRS)

Kazz, Greg J.; Greenberg, Edward

2014-01-01

The CCSDS space link protocols i.e., Telemetry (TM), Telecommand (TC), Advanced Orbiting Systems (AOS) were developed in the early growth period of the space program. They were designed to meet the needs of the early missions, be compatible with the available technology and focused on the specific link environments. Digital technology was in its infancy and spacecraft power and mass issues enforced severe constraints on flight implementations. Therefore the Telecommand protocol was designed around a simple Bose, Hocquenghem, Chaudhuri (BCH) code that provided little coding gain and limited error detection but was relatively simple to decode on board. The infusion of the concatenated Convolutional and Reed-Solomon codes5 for telemetry was a major milestone and transformed telemetry applications by providing them the ability to more efficiently utilize the telemetry link and its ability to deliver user data. The ability to significantly lower the error rates on the telemetry links enabled the use of packet telemetry and data compression. The infusion of the high performance codes for telemetry was enabled by the advent of digital processing, but it was limited to earth based systems supporting telemetry. The latest CCSDS space link protocol, Proximity-1 was developed in early 2000 to meet the needs of short-range, bi-directional, fixed or mobile radio links characterized by short time delays, moderate but not weak signals, and short independent sessions. Proximity-1 has been successfully deployed on both NASA and ESA missions at Mars and is planned to be utilized by all Mars missions in development. A new age has arisen, one that now provides the means to perform advanced digital processing in spacecraft systems enabling the use of improved transponders, digital correlators, and high performance forward error correcting codes for all communications links. Flight transponders utilizing digital technology have emerged and can efficiently provide the means to make the next leap in performance for space link communications. Field Programmable Gate Arrays (FPGAs) provide the capability to incorporate high performance forward error correcting codes implemented within software transponders providing improved performance in data transfer, ranging, link security, and time correlation. Given these synergistic technological breakthroughs, the time has come to take advantage of them in applying them to both on going (e.g., command, telemetry) and emerging (e.g., space link security, optical communication) space link applications. However one of the constraining factors within the Data Link Layer in realizing these performance gains is the lack of a generic transfer frame format and common supporting services amongst the existing CCSDS link layer protocols. Currently each of the four CCSDS link layer protocols (TM, TC, AOS, and Proximity-1) have unique formats and services which prohibits their reuse across the totality of all space link applications of CCSDS member space agencies. For example, Mars missions. These missions implement their proximity data link layer using the Proximity-1 frame format and the services it supports but is still required to support the direct from Earth (TC) protocols and the Direct To Earth (AOS/TM) protocols. The prime purpose of this paper, is to describe a new general purpose CCSDS Data Link layer protocol, the NGSLP that will provide the required services along with a common transfer frame format for all the CCSDS space links (ground to/from space and space to space links) targeted for emerging missions after a CCSDS agency-wide coordinated date. This paper will also describe related options that can be included for the Coding and Synchronization sub-layer of the Data Link layer to extend the capacities of the link and additionally provide an independence of the transfer frame sub-layer from the coding sublayer. This feature will provide missions the option of running either the currently performed synchronous coding and transfer frame data link or an asynchronous coding/frame data link, in which the transfer frame length is independent of the block size of the code. The benefits from the elimination of this constraint (frame synchronized to the code block) will simplify the interface between the transponder and the data handling equipment and reduce implementation costs and complexities. The benefits include: inclusion of encoders/decoders into transmitters and receivers without regard to data link protocols, providing the ability to insert latency sensitive messages into the link to support launch, landing/docking, telerobotics. and Variable Coded Modulation (VCM). In addition the ability to transfer different sized frames can provide a backup for delivering stored anomaly engineering data simultaneously with real time data, or relaying of frames from various sources onto a trunk line for delivery to Earth.

Gamified physical activation of young men – a Multidisciplinary Population-Based Randomized Controlled Trial (MOPO study)

PubMed Central

2013-01-01

Background Inactive and unhealthy lifestyles are common among adolescent men. The planned intervention examines the effectiveness of an interactive, gamified activation method, based on tailored health information, peer networks and participation, on physical activity, health and wellbeing in young men. We hypothesize that following the intervention the physical activation group will have an improved physical activity, as well as self-determined and measured health compared with the controls. Methods/design Conscription-aged men (18 years) attending compulsory annual call-ups for military service in the city of Oulu in Finland (n = 1500) will be randomized to a 6-months intervention (n = 640) or a control group (n = 640) during the fall 2013. A questionnaire on health, health behaviour, diet and wellbeing is administered in the beginning and end of the intervention. In addition, anthropometric measures (height, weight and waist circumference), body composition, grip strength, heart rate variability and aerobic fitness will be measured. The activation group utilizes an online gamified activation method in combination with communal youth services, objective physical activity measurement, social networking, tailored health information and exercise programs according to baseline activity level and the readiness of changes of each individual. Daily physical activity of the participants is monitored in both the activation and control groups. The activation service rewards improvements in physical activity or reductions in sedentary behaviour. The performance and completion of the military service of the participants will also be followed. Discussion The study will provide new information of physical activity, health and health behaviour of young men. Furthermore, a novel model including methods for increasing physical activity among young people is developed and its effects tested through an intervention. This unique gamified service for activating young men can provide a translational model for community use. It can also be utilized as such or tailored to other selected populations or age groups. Trial registration ClinicalTrials.gov Identifier: NCT01376986 PMID:23311678

Gamified physical activation of young men--a Multidisciplinary Population-Based Randomized Controlled Trial (MOPO study).

PubMed

Ahola, Riikka; Pyky, Riitta; Jämsä, Timo; Mäntysaari, Matti; Koskimäki, Heli; Ikäheimo, Tiina M; Huotari, Maija-Leena; Röning, Juha; Heikkinen, Hannu I; Korpelainen, Raija

2013-01-14

Inactive and unhealthy lifestyles are common among adolescent men. The planned intervention examines the effectiveness of an interactive, gamified activation method, based on tailored health information, peer networks and participation, on physical activity, health and wellbeing in young men. We hypothesize that following the intervention the physical activation group will have an improved physical activity, as well as self-determined and measured health compared with the controls. Conscription-aged men (18 years) attending compulsory annual call-ups for military service in the city of Oulu in Finland (n = 1500) will be randomized to a 6-months intervention (n = 640) or a control group (n = 640) during the fall 2013. A questionnaire on health, health behaviour, diet and wellbeing is administered in the beginning and end of the intervention. In addition, anthropometric measures (height, weight and waist circumference), body composition, grip strength, heart rate variability and aerobic fitness will be measured. The activation group utilizes an online gamified activation method in combination with communal youth services, objective physical activity measurement, social networking, tailored health information and exercise programs according to baseline activity level and the readiness of changes of each individual. Daily physical activity of the participants is monitored in both the activation and control groups. The activation service rewards improvements in physical activity or reductions in sedentary behaviour. The performance and completion of the military service of the participants will also be followed. The study will provide new information of physical activity, health and health behaviour of young men. Furthermore, a novel model including methods for increasing physical activity among young people is developed and its effects tested through an intervention. This unique gamified service for activating young men can provide a translational model for community use. It can also be utilized as such or tailored to other selected populations or age groups. ClinicalTrials.gov Identifier: NCT01376986.

Optical properties of Ag nanoclusters formed by irradiation and annealing of SiO2/SiO2:Ag thin films

NASA Astrophysics Data System (ADS)

Güner, S.; Budak, S.; Gibson, B.; Ila, D.

2014-08-01

We have deposited five periodic SiO2/SiO2 + Ag multi-nano-layered films on fused silica substrates using physical vapor deposition technique. The co-deposited SiO2:Ag layers were 2.7-5 nm and SiO2 buffer layers were 1-15 nm thick. Total thickness was between 30 and 105 nm. Different concentrations of Ag, ranging from 1.5 to 50 molecular% with respect to SiO2 were deposited to determine relevant rates of nanocluster formation and occurrence of interaction between nanoclusters. Using interferometry as well as in situ thickness monitoring, we measured the thickness of the layers. The concentration of Ag in SiO2 was measured with Rutherford Backscattering Spectrometry (RBS). To nucleate Ag nanoclusters, 5 MeV cross plane Si ion bombardments were performed with fluence varying between 5 × 1014 and 1 × 1016 ions/cm2 values. Optical absorption spectra were recorded in the range of 200-900 nm in order to monitor the Ag nanocluster formation in the thin films. Thermal annealing treatment at different temperatures was applied as second method to form varying size of nanoclusters. The physical properties of formed super lattice were criticized for thermoelectric applications.

Component Framework for Loosely Coupled High Performance Integrated Plasma Simulations

NASA Astrophysics Data System (ADS)

Elwasif, W. R.; Bernholdt, D. E.; Shet, A. G.; Batchelor, D. B.; Foley, S.

2010-11-01

We present the design and implementation of a component-based simulation framework for the execution of coupled time-dependent plasma modeling codes. The Integrated Plasma Simulator (IPS) provides a flexible lightweight component model that streamlines the integration of stand alone codes into coupled simulations. Standalone codes are adapted to the IPS component interface specification using a thin wrapping layer implemented in the Python programming language. The framework provides services for inter-component method invocation, configuration, task, and data management, asynchronous event management, simulation monitoring, and checkpoint/restart capabilities. Services are invoked, as needed, by the computational components to coordinate the execution of different aspects of coupled simulations on Massive parallel Processing (MPP) machines. A common plasma state layer serves as the foundation for inter-component, file-based data exchange. The IPS design principles, implementation details, and execution model will be presented, along with an overview of several use cases.

The Impact of Microphysics and Planetary Boundary Layer Physics on Model Simulation of U.S. Deep South Summer Convection

NASA Technical Reports Server (NTRS)

McCaul, Eugene W., Jr.; Case, Jonathan L.; Zavodsky, Bradley T.; Srikishen, Jayanthi; Medlin, Jeffrey M.; Wood, Lance

2014-01-01

Inspection of output from various configurations of high-resolution, explicit convection forecast models such as the Weather Research and Forecasting (WRF) model indicates significant sensitivity to the choices of model physics pararneterizations employed. Some of the largest apparent sensitivities are related to the specifications of the cloud microphysics and planetary boundary layer physics packages. In addition, these sensitivities appear to be especially pronounced for the weakly-sheared, multicell modes of deep convection characteristic of the Deep South of the United States during the boreal summer. Possible ocean-land sensitivities also argue for further examination of the impacts of using unique ocean-land surface initialization datasets provided by the NASA Short-term Prediction Research and Transition (SPoRn Center to select NOAAlNWS weather forecast offices. To obtain better quantitative understanding of these sensitivities and also to determine the utility of the ocean-land initialization data, we have executed matrices of regional WRF forecasts for selected convective events near Mobile, AL (MOB), and Houston, TX (HGX). The matrices consist of identically initialized WRF 24-h forecasts using any of eight microphysics choices and any of three planetary boWldary layer choices. The resulting 24 simulations performed for each event within either the MOB or HGX regions are then compared to identify the sensitivities of various convective storm metrics to the physics choices. Particular emphasis is placed on sensitivities of precipitation timing, intensity, and coverage, as well as amount and coverage oflightuing activity diagnosed from storm kinematics and graupel in the mixed phase layer. The results confirm impressions gleaned from study of the behavior of variously configured WRF runs contained in the ensembles produced each spring at the Center for the Analysis and Prediction of Storms, but with the benefit of more straightforward control of the physics package choices. The design of the experiments thus allows for more direct interpretation of the sensitivities to each possible physics combination. The results should assist forecasters in their efforts to anticipate and correct for possible biases in simulated WRF convection patterns, and help the modeling community refine their model parameterizations.

The Impacts of Microphysics and Planetary Boundary Layer Physics on Model Simulations of U. S. Deep South Summer Convection

NASA Technical Reports Server (NTRS)

McCaul, E. W., Jr.; Case, J. L.; Zavodsky, B. T.; Srikishen, J.; Medlin, J. M.; Wood, L.

2014-01-01

Inspection of output from various configurations of high-resolution, explicit convection forecast models such as the Weather Research and Forecasting (WRF) model indicates significant sensitivity to the choices of model physics parameterizations employed. Some of the largest apparent sensitivities are related to the specifications of the cloud microphysics and planetary boundary layer physics packages. In addition, these sensitivities appear to be especially pronounced for the weakly-sheared, multicell modes of deep convection characteristic of the Deep South of the United States during the boreal summer. Possible ocean-land sensitivities also argue for further examination of the impacts of using unique ocean-land surface initialization datasets provided by the NASA Short-term Prediction Research and Transition (SPoRT Center to select NOAA/NWS weather forecast offices. To obtain better quantitative understanding of these sensitivities and also to determine the utility of the ocean-land initialization data, we have executed matrices of regional WRF forecasts for selected convective events near Mobile, AL (MOB), and Houston, TX (HGX). The matrices consist of identically initialized WRF 24-h forecasts using any of eight microphysics choices and any of three planetary boundary layer choices. The resulting 24 simulations performed for each event within either the MOB or HGX regions are then compared to identify the sensitivities of various convective storm metrics to the physics choices. Particular emphasis is placed on sensitivities of precipitation timing, intensity, and coverage, as well as amount and coverage of lightning activity diagnosed from storm kinematics and graupel in the mixed phase layer. The results confirm impressions gleaned from study of the behavior of variously configured WRF runs contained in the ensembles produced each spring at the Center for the Analysis and Prediction of Storms, but with the benefit of more straightforward control of the physics package choices. The design of the experiments thus allows for more direct interpretation of the sensitivities to each possible physics combination. The results should assist forecasters in their efforts to anticipate and correct for possible biases in simulated WRF convection patterns, and help the modeling community refine their model parameterizations.

Out-Phased Array Linearized Signaling (OPALS): A Practical Approach to Physical Layer Encryption

DTIC Science & Technology

2015-10-26

Out-Phased Array Linearized Signaling ( OPALS ): A Practical Approach to Physical Layer Encryption Eric Tollefson, Bruce R. Jordan Jr., and Joseph D... OPALS ) which provides a practical approach to physical-layer encryption through spatial masking. Our approach modifies just the transmitter to employ...of the channel. With Out-Phased Array Linearized Signaling ( OPALS ), we propose a new masking technique that has some advantages of each of the

Global Lidar Measurements of Clouds and Aerosols from Space Using the Geoscience Laser Altimeter System (GLAS)

NASA Technical Reports Server (NTRS)

Hlavka, Dennis L.; Palm, S. P.; Welton, E. J.; Hart, W. D.; Spinhirne, J. D.; McGill, M.; Mahesh, A.; Starr, David OC. (Technical Monitor)

2001-01-01

The Geoscience Laser Altimeter System (GLAS) is scheduled for launch on the ICESat satellite as part of the NASA EOS mission in 2002. GLAS will be used to perform high resolution surface altimetry and will also provide a continuously operating atmospheric lidar to profile clouds, aerosols, and the planetary boundary layer with horizontal and vertical resolution of 175 and 76.8 m, respectively. GLAS is the first active satellite atmospheric profiler to provide global coverage. Data products include direct measurements of the heights of aerosol and cloud layers, and the optical depth of transmissive layers. In this poster we provide an overview of the GLAS atmospheric data products, present a simulated GLAS data set, and show results from the simulated data set using the GLAS data processing algorithm. Optical results from the ER-2 Cloud Physics Lidar (CPL), which uses many of the same processing algorithms as GLAS, show algorithm performance with real atmospheric conditions during the Southern African Regional Science Initiative (SAFARI 2000).

A Complex Systems Approach to More Resilient Multi-Layered Security Systems

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

Brown, Nathanael J. K.; Jones, Katherine A.; Bandlow, Alisa

In July 2012, protestors cut through security fences and gained access to the Y-12 National Security Complex. This was believed to be a highly reliable, multi-layered security system. This report documents the results of a Laboratory Directed Research and Development (LDRD) project that created a consistent, robust mathematical framework using complex systems analysis algorithms and techniques to better understand the emergent behavior, vulnerabilities and resiliency of multi-layered security systems subject to budget constraints and competing security priorities. Because there are several dimensions to security system performance and a range of attacks that might occur, the framework is multi-objective for amore » performance frontier to be estimated. This research explicitly uses probability of intruder interruption given detection (P I) as the primary resilience metric. We demonstrate the utility of this framework with both notional as well as real-world examples of Physical Protection Systems (PPSs) and validate using a well-established force-on-force simulation tool, Umbra.« less

Analytical Models of Cross-Layer Protocol Optimization in Real-Time Wireless Sensor Ad Hoc Networks

NASA Astrophysics Data System (ADS)

Hortos, William S.

The real-time interactions among the nodes of a wireless sensor network (WSN) to cooperatively process data from multiple sensors are modeled. Quality-of-service (QoS) metrics are associated with the quality of fused information: throughput, delay, packet error rate, etc. Multivariate point process (MVPP) models of discrete random events in WSNs establish stochastic characteristics of optimal cross-layer protocols. Discrete-event, cross-layer interactions in mobile ad hoc network (MANET) protocols have been modeled using a set of concatenated design parameters and associated resource levels by the MVPPs. Characterization of the "best" cross-layer designs for a MANET is formulated by applying the general theory of martingale representations to controlled MVPPs. Performance is described in terms of concatenated protocol parameters and controlled through conditional rates of the MVPPs. Modeling limitations to determination of closed-form solutions versus explicit iterative solutions for ad hoc WSN controls are examined.

26 CFR 31.3121(b)(6)-1 - Services in employ of United States or instrumentality thereof.

Code of Federal Regulations, 2013 CFR

2013-04-01

... volunteer or volunteer leader within the meaning of the Peace Corps Act, see § 31.3121(i)-2 and § 31.3121(i...)(4)(ii) of this section, services performed by student nurses, medical or dental interns, residents in training, student dietitians, student physical therapists, or student occupational therapists...

26 CFR 31.3121(b)(6)-1 - Services in employ of United States or instrumentality thereof.

Code of Federal Regulations, 2014 CFR

2014-04-01

... volunteer or volunteer leader within the meaning of the Peace Corps Act, see § 31.3121(i)-2 and § 31.3121(i...)(4)(ii) of this section, services performed by student nurses, medical or dental interns, residents in training, student dietitians, student physical therapists, or student occupational therapists...

26 CFR 31.3121(b)(6)-1 - Services in employ of United States or instrumentality thereof.

Code of Federal Regulations, 2012 CFR

2012-04-01

... volunteer or volunteer leader within the meaning of the Peace Corps Act, see § 31.3121(i)-2 and § 31.3121(i...)(4)(ii) of this section, services performed by student nurses, medical or dental interns, residents in training, student dietitians, student physical therapists, or student occupational therapists...

An Online Information System to Support Blended Training of Rural SMEs on E-Government

ERIC Educational Resources Information Center

Tzikopoulos, Argiris; Manouselis, Nikos; Kastrantas, Kostas; Costopoulou, Constantina

2012-01-01

Purpose: Away from central public authorities, regional (also called rural) enterprises do not have direct, physical access to all the services that governmental or public agencies offer. Very often, these services are essential for enterprises, mostly small and medium-sized enterprises (SMEs), in such areas, in order to perform their business…

[Supply services at health facilities: measuring performance].

PubMed

Dacosta Claro, I

2001-01-01

Performance measurement, in their different meanings--either balance scorecard or outputs measurement--have become an essential tool in today's organizations (World-Class organizations) to improve service quality and reduce costs. This paper presents a performance measurement system for the hospital supply chain. The system is organized in different levels and groups of indicators in order to show a hierarchical, coherent and integrated vision of the processes. Thus, supply services performance is measured according to (1) financial aspects, (2) customers satisfaction aspects and (3) internal aspects of the processes performed. Since the informational needs of the managers vary within the administrative structure, the performance measurement system is defined in three hierarchical levels. Firstly, the whole supply chain, with the different interrelation of activities. Secondly, the three main processes of the chain--physical management of products, purchasing and negotiation processes and the local storage units. And finally, the performance measurement of each activity involved. The system and the indicators have been evaluated with the participation of 17 health services of Quebec (Canada), however, and due to the similarities of the operation, could be equally implemented in Spanish hospitals.

Executive Summary From the National Strength and Conditioning Association's Second Blue Ribbon Panel on Military Physical Readiness: Military Physical Performance Testing.

PubMed

Nindl, Bradley C; Alvar, Brent A; R Dudley, Jason; Favre, Mike W; Martin, Gerard J; Sharp, Marilyn A; Warr, Brad J; Stephenson, Mark D; Kraemer, William J

2015-11-01

The National Strength and Conditioning Association's tactical strength and conditioning program sponsored the second Blue Ribbon Panel on military physical readiness: military physical performance testing, April 18-19, 2013, Norfolk, VA. This meeting brought together a total of 20 subject matter experts (SMEs) from the U.S. Air Force, Army, Marine Corps, Navy, and academia representing practitioners, operators, researchers, and policy advisors to discuss the current state of physical performance testing across the Armed Services. The SME panel initially rated 9 common military tasks (jumping over obstacles, moving with agility, carrying heavy loads, dragging heavy loads, running long distances, moving quickly over short distances, climbing over obstacles, lifting heavy objects, loading equipment) by the degree to which health-related fitness components (e.g., aerobic fitness, muscular strength, muscular endurance, flexibility, and body composition) and skill-related fitness components (e.g., muscular power, agility, balance, coordination, speed, and reaction time) were required to accomplish these tasks. A scale from 1 to 10 (10 being highest) was used. Muscular strength, power, and endurance received the highest rating scores. Panel consensus concluded that (a) selected fitness components (particularly for skill-related fitness components) are currently not being assessed by the military; (b) field-expedient options to measure both health-based and skill-based fitness components are currently available; and (c) 95% of the panel concurred that all services should consider a tier II test focused on both health-related and skill-related fitness components based on occupational, functional, and tactical military performance requirements.

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...

Forest service contributions to the national land cover database (NLCD): Tree Canopy Cover Production

Treesearch

Bonnie Ruefenacht; Robert Benton; Vicky Johnson; Tanushree Biswas; Craig Baker; Mark Finco; Kevin Megown; John Coulston; Ken Winterberger; Mark Riley

2015-01-01

A tree canopy cover (TCC) layer is one of three elements in the National Land Cover Database (NLCD) 2011 suite of nationwide geospatial data layers. In 2010, the USDA Forest Service (USFS) committed to creating the TCC layer as a member of the Multi-Resolution Land Cover (MRLC) consortium. A general methodology for creating the TCC layer was reported at the 2012 FIA...

The role of simulation in mixed-methods research: a framework & application to patient safety.

PubMed

Guise, Jeanne-Marie; Hansen, Matthew; Lambert, William; O'Brien, Kerth

2017-05-04

Research in patient safety is an important area of health services research and is a national priority. It is challenging to investigate rare occurrences, explore potential causes, and account for the complex, dynamic context of healthcare - yet all are required in patient safety research. Simulation technologies have become widely accepted as education and clinical tools, but have yet to become a standard tool for research. We developed a framework for research that integrates accepted patient safety models with mixed-methods research approaches and describe the performance of the framework in a working example of a large National Institutes of Health (NIH)-funded R01 investigation. This worked example of a framework in action, identifies the strengths and limitations of qualitative and quantitative research approaches commonly used in health services research. Each approach builds essential layers of knowledge. We describe how the use of simulation ties these layers of knowledge together and adds new and unique dimensions of knowledge. A mixed-methods research approach that includes simulation provides a broad multi-dimensional approach to health services and patient safety research.

Model test on partial expansion in stratified subsidence during foundation pit dewatering

NASA Astrophysics Data System (ADS)

Wang, Jianxiu; Deng, Yansheng; Ma, Ruiqiang; Liu, Xiaotian; Guo, Qingfeng; Liu, Shaoli; Shao, Yule; Wu, Linbo; Zhou, Jie; Yang, Tianliang; Wang, Hanmei; Huang, Xinlei

2018-02-01

Partial expansion was observed in stratified subsidence during foundation pit dewatering. However, the phenomenon was suspected to be an error because the compression of layers is known to occur when subsidence occurs. A slice of the subsidence cone induced by drawdown was selected as the prototype. Model tests were performed to investigate the phenomenon. The underlying confined aquifer was generated as a movable rigid plate with a hinge at one end. The overlying layers were simulated with remolded materials collected from a construction site. Model tests performed under the conceptual model indicated that partial expansion occurred in stratified settlements under coordination deformation and consolidation conditions. During foundation pit dewatering, rapid drawdown resulted in rapid subsidence in the dewatered confined aquifer. The rapidly subsiding confined aquifer top was the bottom deformation boundary of the overlying layers. Non-coordination deformation was observed at the top and bottom of the subsiding overlying layers. The subsidence of overlying layers was larger at the bottom than at the top. The layers expanded and became thicker. The phenomenon was verified using numerical simulation method based on finite difference method. Compared with numerical simulation results, the boundary effect of the physical tests was obvious in the observation point close to the movable endpoint. The tensile stress of the overlying soil layers induced by the underlying settlement of dewatered confined aquifer contributed to the expansion phenomenon. The partial expansion of overlying soil layers was defined as inversed rebound. The inversed rebound was induced by inversed coordination deformation. Compression was induced by the consolidation in the overlying soil layers because of drainage. Partial expansion occurred when the expansion exceeded the compression. Considering the inversed rebound, traditional layer-wise summation method for calculating subsidence should be revised and improved.

Spectral enstrophy budget in a shear-less flow with turbulent/non-turbulent interface

NASA Astrophysics Data System (ADS)

Cimarelli, Andrea; Cocconi, Giacomo; Frohnapfel, Bettina; De Angelis, Elisabetta

2015-12-01

A numerical analysis of the interaction between decaying shear free turbulence and quiescent fluid is performed by means of global statistical budgets of enstrophy, both, at the single-point and two point levels. The single-point enstrophy budget allows us to recognize three physically relevant layers: a bulk turbulent region, an inhomogeneous turbulent layer, and an interfacial layer. Within these layers, enstrophy is produced, transferred, and finally destroyed while leading to a propagation of the turbulent front. These processes do not only depend on the position in the flow field but are also strongly scale dependent. In order to tackle this multi-dimensional behaviour of enstrophy in the space of scales and in physical space, we analyse the spectral enstrophy budget equation. The picture consists of an inviscid spatial cascade of enstrophy from large to small scales parallel to the interface moving towards the interface. At the interface, this phenomenon breaks, leaving place to an anisotropic cascade where large scale structures exhibit only a cascade process normal to the interface thus reducing their thickness while retaining their lengths parallel to the interface. The observed behaviour could be relevant for both the theoretical and the modelling approaches to flow with interacting turbulent/nonturbulent regions. The scale properties of the turbulent propagation mechanisms highlight that the inviscid turbulent transport is a large-scale phenomenon. On the contrary, the viscous diffusion, commonly associated with small scale mechanisms, highlights a much richer physics involving small lengths, normal to the interface, but at the same time large scales, parallel to the interface.

Using the GlideinWMS System as a Common Resource Provisioning Layer in CMS

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

Balcas, J.; Belforte, S.; Bockelman, B.

2015-12-23

CMS will require access to more than 125k processor cores for the beginning of Run 2 in 2015 to carry out its ambitious physics program with more and higher complexity events. During Run1 these resources were predominantly provided by a mix of grid sites and local batch resources. During the long shut down cloud infrastructures, diverse opportunistic resources and HPC supercomputing centers were made available to CMS, which further complicated the operations of the submission infrastructure. In this presentation we will discuss the CMS effort to adopt and deploy the glideinWMS system as a common resource provisioning layer to grid,more » cloud, local batch, and opportunistic resources and sites. We will address the challenges associated with integrating the various types of resources, the efficiency gains and simplifications associated with using a common resource provisioning layer, and discuss the solutions found. We will finish with an outlook of future plans for how CMS is moving forward on resource provisioning for more heterogenous architectures and services.« less

Multilayer Black Phosphorus Near-Infrared Photodetectors.

PubMed

Hou, Chaojian; Yang, Lijun; Li, Bo; Zhang, Qihan; Li, Yuefeng; Yue, Qiuyang; Wang, Yang; Yang, Zhan; Dong, Lixin

2018-05-23

Black phosphorus (BP), owing to its distinguished properties, has become one of the most competitive candidates for photodetectors. However, there has been little attention paid on photo-response performance of multilayer BP nanoflakes with large layer thickness. In fact, multilayer BP nanoflakes with large layer thickness have greater potential from the fabrication viewpoint as well as due to the physical properties than single or few layer ones. In this report, the thickness-dependence of the intrinsic property of BP photodetectors in the dark was initially investigated. Then the photo-response performance (including responsivity, photo-gain, photo-switching time, noise equivalent power, and specific detectivity) of BP photodetectors with relative thicker thickness was explored under a near-infrared laser beam ( λ IR = 830 nm). Our experimental results reveal the impact of BP's thickness on the current intensity of the channel and show degenerated p-type BP is beneficial for larger current intensity. More importantly, the photo-response of our thicker BP photodetectors exhibited a larger responsivity up to 2.42 A/W than the few-layer ones and a fast response photo-switching speed (response time is ~2.5 ms) comparable to thinner BP nanoflakes was obtained, indicating BP nanoflakes with larger layer thickness are also promising for application for ultra-fast and ultra-high near-infrared photodetectors.

Characterization of spatial manipulation on ZnO nanocomposites consisting of Au nanoparticles, a graphene layer, and ZnO nanorods

NASA Astrophysics Data System (ADS)

Huang, Shen-Che; Lu, Chien-Cheng; Su, Wei-Ming; Weng, Chen-Yuan; Chen, Yi-Cian; Wang, Shing-Chung; Lu, Tien-Chang; Chen, Ching-Pang; Chen, Hsiang

2018-01-01

Three types of ZnO-based nanocomposites were fabricated consisting of 80-nm Au nanoparticles (NPs), a graphene layer, and ZnO nanorods (NRs). To investigate interactions between the ZnO NRs and Au nanoparticle, multiple material analysis techniques including field-emission scanning electron microscopy (FESEM), surface contact angle measurements, secondary ion mass spectrometry (SIMS), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopic characterizations were performed. Results indicate that incorporating a graphene layer could block the interaction between the ZnO NRs and the Au NPs. Furthermore, the Raman signal of the Au NPs could be enhanced by inserting a graphene layer on top of the ZnO NRs. Investigation of these graphene-incorporated nanocomposites would be helpful to future studies of the physical properties and Raman analysis of the ZnO-based nanostructure design.

Atomic Layer Deposited (ALD) coatings for future astronomical telescopes: recent developments

NASA Astrophysics Data System (ADS)

Moore, Christopher Samuel; Hennessy, John; Jewell, April D.; Nikzad, Shouleh; France, Kevin

2016-07-01

Atomic Layer Deposition (ALD) can create conformal, near stoichiometric and pinhole free transmissive metal fluoride coatings to protect reflective aluminum films. Spectral performance of astronomical mirror coatings strongly affect the science capabilities of astronomical satellite missions. We are utilizing ALD to create a transmissive overcoat to protect aluminum film mirrors from oxidation with the goal of achieving high reflectance (> 80%) from the UV ( 100 nm) to the IR ( 2,000 nm). This paper summarizes the recent developments of ALD aluminum fluoride (AlF3) coatings on Al. Reflectance measurements of aluminum mirrors protected by ALD AlF3 and future applications are discussed. These measurements demonstrate that Al + ALD AlF3, even with an interfacial oxide layer of a few nanometers, can provide higher reflectance than Al protected by traditional physical vapor deposited MgF2 without an oxide layer, below 115 nm.

Fine-tuning the Wall Thickness of Ordered Mesoporous Graphene by Exploiting Ligand Exchange of Colloidal Nanocrystals

NASA Astrophysics Data System (ADS)

Han, Dandan; Yan, Yancui; Wei, Jishi; Wang, Biwei; Li, Tongtao; Guo, Guannan; Yang, Dong; Xie, Songhai; Dong, Angang

2017-12-01

Because of their unique physical properties, three-dimensional (3D) graphene has attracted enormous attention over the past years. However, it is still a challenge to precisely control the layer thickness of 3D graphene. Here, we report a novel strategy to rationally adjust the wall thickness of ordered mesoporous graphene (OMG). By taking advantage of ligand exchange capability of colloidal Fe3O4 nanocrystals, we are able to fine-tune the wall thickness of OMG from 2 to 6 layers of graphene by tailoring the hydrocarbon ligands attached to the nanocrystal surface. When evaluated as electrocatalyst for oxygen reduction reaction upon S and N doping, the 4-layer OMG is found to show better catalytic performance compared with its 2- and 6-layer counterparts, which we attribute to the enhanced exposure of active sites resulting from its ultrathin wall thickness and high surface area.

Cross-Layer Adaptive Feedback Scheduling of Wireless Control Systems

PubMed Central

Xia, Feng; Ma, Longhua; Peng, Chen; Sun, Youxian; Dong, Jinxiang

2008-01-01

There is a trend towards using wireless technologies in networked control systems. However, the adverse properties of the radio channels make it difficult to design and implement control systems in wireless environments. To attack the uncertainty in available communication resources in wireless control systems closed over WLAN, a cross-layer adaptive feedback scheduling (CLAFS) scheme is developed, which takes advantage of the co-design of control and wireless communications. By exploiting cross-layer design, CLAFS adjusts the sampling periods of control systems at the application layer based on information about deadline miss ratio and transmission rate from the physical layer. Within the framework of feedback scheduling, the control performance is maximized through controlling the deadline miss ratio. Key design parameters of the feedback scheduler are adapted to dynamic changes in the channel condition. An event-driven invocation mechanism for the feedback scheduler is also developed. Simulation results show that the proposed approach is efficient in dealing with channel capacity variations and noise interference, thus providing an enabling technology for control over WLAN. PMID:27879934

New temperable solar coatings: Tempsol

NASA Astrophysics Data System (ADS)

Demiryont, Hulya

2001-11-01

This paper deals with the large area deposition and coating properties of the thermo-stable (temperable/bendable) solar coating material, CuO, and some new optical coating systems comprising CuO films for architectural and automotive/transportation applications. The CuO solar coating is combined with other coating layers, for example, an anti-reflection film, a reflection film, a coloration coating layer, etc., which are also thermo-stable. The film systems are developed at the research laboratory by D.C. Magnetron reactive sputtering process. The new developed technologies then transferred to the production line. Product performances are compared before and after heat treatment of the coating systems. Performance tables and other physical properties, including optical parameters, mechanical and environmental stability, storage properties, etc., are also presented for this new product series.

Silicon Cations Intermixed Indium Zinc Oxide Interface for High-Performance Thin-Film Transistors Using a Solution Process.

PubMed

Na, Jae Won; Rim, You Seung; Kim, Hee Jun; Lee, Jin Hyeok; Hong, Seonghwan; Kim, Hyun Jae

2017-09-06

Solution-processed amorphous metal-oxide thin-film transistors (TFTs) utilizing an intermixed interface between a metal-oxide semiconductor and a dielectric layer are proposed. In-depth physical characterizations are carried out to verify the existence of the intermixed interface that is inevitably formed by interdiffusion of cations originated from a thermal process. In particular, when indium zinc oxide (IZO) semiconductor and silicon dioxide (SiO 2 ) dielectric layer are in contact and thermally processed, a Si 4+ intermixed IZO (Si/IZO) interface is created. On the basis of this concept, a high-performance Si/IZO TFT having both a field-effect mobility exceeding 10 cm 2 V -1 s -1 and a on/off current ratio over 10 7 is successfully demonstrated.

Optimization of Layer Densities for Spacecraft Multilayered Insulation Systems

NASA Technical Reports Server (NTRS)

Johnson, W. L.

2009-01-01

Numerous tests of various multilayer insulation systems have indicated that there are optimal densities for these systems. However, the only method of calculating this optimal density was by a complex physics based algorithm developed by McIntosh. In the 1970's much data were collected on the performance of these insulation systems with many different variables analyzed. All formulas generated included number of layers and layer density as geometric variables in solving for the heat flux, none of them was in a differentiable form for a single geometric variable. It was recently discovered that by converting the equations from heat flux to thermal conductivity using Fourier's Law, the equations became functions of layer density, temperatures, and material properties only. The thickness and number of layers of the blanket were merged into a layer density. These equations were then differentiated with respect to layer density. By setting the first derivative equal to zero, and solving for the layer density, the critical layer density was determined. Taking a second derivative showed that the critical layer density is a minimum in the function and thus the optimum density for minimal heat leak, this is confirmed by plotting the original function. This method was checked and validated using test data from the Multipurpose Hydrogen Testbed which was designed using McIntosh's algorithm.

Use of Ground Penetrating Radar to Study Gradient Media

NASA Astrophysics Data System (ADS)

Titov, A.

2016-12-01

Nowadays Ground Penetrating Radar (GPR) is often used to solve different problems of applied geophysics including the hydrological ones. This work was motivated by detection of weak reflections in the body of water observed during the surveys on the freshwater lakes using GPR. The same reflections were first analyzed by John Bradford in 2007. These reflections can arise from the thermal gradient layer or thermocline due to different dielectric permittivity of cold and warm water. We employed physical and mathematical modeling to identify the properties of such thermoclines. We have constructed a special GPR stand to study the gradient media in our laboratory. The stand consists of a water-filled plastic tank and plastic tubes, which gather the cold water under the warm water. Our stand allows for changing parameters of the gradient layer, such as limits of dielectric permittivity and the thickness of the gradient layer. GPR antenna was placed slightly under the water surface to remove the parasitic reflections. To visualize the thermal distribution, an infrared camera and thermal sensors were used. Analysis of the GPR traces after physical modeling, performed in the MATLAB environment, allows us to locate the weak reflection from the gradient layer. We observed that (i) the change of the gradient boundary values alters the amplitude of the signal, (ii) the arrival time of the impulse reflected from the gradient layer corresponds to the arrival time of the impulse reflected from the top boundary of this layer, and (iii) the shape of the signal reflected from the gradient layer coincides with the shape of the signal reflected from the non-gradient boundary between two bodies. The quantitative properties of thermocline can be determined using amplitude analysis of GPR signals. Finally, the developed methods were successfully applied to real field data.

Implementation of 5-layer thermal diffusion scheme in weather research and forecasting model with Intel Many Integrated Cores

NASA Astrophysics Data System (ADS)

Huang, Melin; Huang, Bormin; Huang, Allen H.

2014-10-01

For weather forecasting and research, the Weather Research and Forecasting (WRF) model has been developed, consisting of several components such as dynamic solvers and physical simulation modules. WRF includes several Land- Surface Models (LSMs). The LSMs use atmospheric information, the radiative and precipitation forcing from the surface layer scheme, the radiation scheme, and the microphysics/convective scheme all together with the land's state variables and land-surface properties, to provide heat and moisture fluxes over land and sea-ice points. The WRF 5-layer thermal diffusion simulation is an LSM based on the MM5 5-layer soil temperature model with an energy budget that includes radiation, sensible, and latent heat flux. The WRF LSMs are very suitable for massively parallel computation as there are no interactions among horizontal grid points. The features, efficient parallelization and vectorization essentials, of Intel Many Integrated Core (MIC) architecture allow us to optimize this WRF 5-layer thermal diffusion scheme. In this work, we present the results of the computing performance on this scheme with Intel MIC architecture. Our results show that the MIC-based optimization improved the performance of the first version of multi-threaded code on Xeon Phi 5110P by a factor of 2.1x. Accordingly, the same CPU-based optimizations improved the performance on Intel Xeon E5- 2603 by a factor of 1.6x as compared to the first version of multi-threaded code.

An effective XML based name mapping mechanism within StoRM

NASA Astrophysics Data System (ADS)

Corso, E.; Forti, A.; Ghiselli, A.; Magnoni, L.; Zappi, R.

2008-07-01

In a Grid environment the naming capability allows users to refer to specific data resources in a physical storage system using a high level logical identifier. This logical identifier is typically organized in a file system like structure, a hierarchical tree of names. Storage Resource Manager (SRM) services map the logical identifier to the physical location of data evaluating a set of parameters as the desired quality of services and the VOMS attributes specified in the requests. StoRM is a SRM service developed by INFN and ICTP-EGRID to manage file and space on standard POSIX and high performing parallel and cluster file systems. An upcoming requirement in the Grid data scenario is the orthogonality of the logical name and the physical location of data, in order to refer, with the same identifier, to different copies of data archived in various storage areas with different quality of service. The mapping mechanism proposed in StoRM is based on a XML document that represents the different storage components managed by the service, the storage areas defined by the site administrator, the quality of service they provide and the Virtual Organization that want to use the storage area. An appropriate directory tree is realized in each storage component reflecting the XML schema. In this scenario StoRM is able to identify the physical location of a requested data evaluating the logical identifier and the specified attributes following the XML schema, without querying any database service. This paper presents the namespace schema defined, the different entities represented and the technical details of the StoRM implementation.

Assessing uncertainty and sensitivity of model parameterizations and parameters in WRF affecting simulated surface fluxes and land-atmosphere coupling over the Amazon region

NASA Astrophysics Data System (ADS)

Qian, Y.; Wang, C.; Huang, M.; Berg, L. K.; Duan, Q.; Feng, Z.; Shrivastava, M. B.; Shin, H. H.; Hong, S. Y.

2016-12-01

This study aims to quantify the relative importance and uncertainties of different physical processes and parameters in affecting simulated surface fluxes and land-atmosphere coupling strength over the Amazon region. We used two-legged coupling metrics, which include both terrestrial (soil moisture to surface fluxes) and atmospheric (surface fluxes to atmospheric state or precipitation) legs, to diagnose the land-atmosphere interaction and coupling strength. Observations made using the Department of Energy's Atmospheric Radiation Measurement (ARM) Mobile Facility during the GoAmazon field campaign together with satellite and reanalysis data are used to evaluate model performance. To quantify the uncertainty in physical parameterizations, we performed a 120 member ensemble of simulations with the WRF model using a stratified experimental design including 6 cloud microphysics, 3 convection, 6 PBL and surface layer, and 3 land surface schemes. A multiple-way analysis of variance approach is used to quantitatively analyze the inter- and intra-group (scheme) means and variances. To quantify parameter sensitivity, we conducted an additional 256 WRF simulations in which an efficient sampling algorithm is used to explore the multiple-dimensional parameter space. Three uncertainty quantification approaches are applied for sensitivity analysis (SA) of multiple variables of interest to 20 selected parameters in YSU PBL and MM5 surface layer schemes. Results show consistent parameter sensitivity across different SA methods. We found that 5 out of 20 parameters contribute more than 90% total variance, and first-order effects dominate comparing to the interaction effects. Results of this uncertainty quantification study serve as guidance for better understanding the roles of different physical processes in land-atmosphere interactions, quantifying model uncertainties from various sources such as physical processes, parameters and structural errors, and providing insights for improving the model physics parameterizations.

Boeing's STAR-FODB test results

NASA Astrophysics Data System (ADS)

Fritz, Martin E.; de la Chapelle, Michael; Van Ausdal, Arthur W.

1995-05-01

Boeing has successfully concluded a 2 1/2 year, two phase developmental contract for the STAR-Fiber Optic Data Bus (FODB) that is intended for future space-based applications. The first phase included system analysis, trade studies, behavior modeling, and architecture and protocal selection. During this phase we selected AS4074 Linear Token Passing Bus (LTPB) protocol operating at 200 Mbps, along with the passive, star-coupled fiber media. The second phase involved design, build, integration, and performance and environmental test of brassboard hardware. The resulting brassboard hardware successfully passed performance testing, providing 200 Mbps operation with a 32 X 32 star-coupled medium. This hardware is suitable for a spaceflight experiment to validate ground testing and analysis and to demonstrate performace in the intended environment. The fiber bus interface unit (FBIU) is a multichip module containing transceiver, protocol, and data formatting chips, buffer memory, and a station management controller. The FBIU has been designed for low power, high reliability, and radiation tolerance. Nine FBIUs were built and integrated with the fiber optic physical layer consisting of the fiber cable plant (FCP) and star coupler assembly (SCA). Performance and environmental testing, including radiation exposure, was performed on selected FBIUs and the physical layer. The integrated system was demonstrated with a full motion color video image transfer across the bus while simultaneously performing utility functions with a fiber bus control module (FBCM) over a telemetry and control (T&C) bus, in this case AS1773.

Adding Data Management Services to Parallel File Systems

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

Brandt, Scott

2015-03-04

The objective of this project, called DAMASC for “Data Management in Scientific Computing”, is to coalesce data management with parallel file system management to present a declarative interface to scientists for managing, querying, and analyzing extremely large data sets efficiently and predictably. Managing extremely large data sets is a key challenge of exascale computing. The overhead, energy, and cost of moving massive volumes of data demand designs where computation is close to storage. In current architectures, compute/analysis clusters access data in a physically separate parallel file system and largely leave it scientist to reduce data movement. Over the past decadesmore » the high-end computing community has adopted middleware with multiple layers of abstractions and specialized file formats such as NetCDF-4 and HDF5. These abstractions provide a limited set of high-level data processing functions, but have inherent functionality and performance limitations: middleware that provides access to the highly structured contents of scientific data files stored in the (unstructured) file systems can only optimize to the extent that file system interfaces permit; the highly structured formats of these files often impedes native file system performance optimizations. We are developing Damasc, an enhanced high-performance file system with native rich data management services. Damasc will enable efficient queries and updates over files stored in their native byte-stream format while retaining the inherent performance of file system data storage via declarative queries and updates over views of underlying files. Damasc has four key benefits for the development of data-intensive scientific code: (1) applications can use important data-management services, such as declarative queries, views, and provenance tracking, that are currently available only within database systems; (2) the use of these services becomes easier, as they are provided within a familiar file-based ecosystem; (3) common optimizations, e.g., indexing and caching, are readily supported across several file formats, avoiding effort duplication; and (4) performance improves significantly, as data processing is integrated more tightly with data storage. Our key contributions are: SciHadoop which explores changes to MapReduce assumption by taking advantage of semantics of structured data while preserving MapReduce’s failure and resource management; DataMods which extends common abstractions of parallel file systems so they become programmable such that they can be extended to natively support a variety of data models and can be hooked into emerging distributed runtimes such as Stanford’s Legion; and Miso which combines Hadoop and relational data warehousing to minimize time to insight, taking into account the overhead of ingesting data into data warehousing.« less

An Intelligent Agent for the K-12 Educational Community

NASA Technical Reports Server (NTRS)

Rorvig, Mark E.; Hutchison, Mark W.; Shelton, Robert O.; Smith, Stephanie L.; Yazbeck, Marwan E.

1995-01-01

Nearly every professional would like to have a personal assistant to perform the physical and mental work of searching libraries for needed information. This paper describes a tool which performs this function using commonly available Internet services. The promises and difficulties of developing such a tool are described.

A comparative study between titania and zirconia as material for scattering layer in dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Nursam, N. M.; Hidayat, J.; Shobih; Rosa, E. S.; Pranoto, L. M.

2018-04-01

The photoanode of dye-sensitized solar cells (DSSC) is typically composed of nanocrystalline titania (TiO2) layer that has been sensitized with light-absorbing dye molecules. Large portion of the light, however, could not be efficiently absorbed due to some physical reasons, such as TiO2 crystal size (typically 10-25 nm) that makes the photoanode remains partially transparent to the visible region in the solar spectrum. One of the ways to improve the light harvesting efficiency in DSSC could be achieved by employing an additional scattering layer over the TiO2 electron transport material. In this contribution, we evaluate the effect of light scattering properties on the performance of DSSC. Specifically, the light scattering properties provided from two different scattering materials, i.e. additional TiO2 scattering layer and zirconia (ZrO2) scattering layer, were compared. Both layers were deposited using screen printing technique under the same condition on top of 8 µm thick TiO2 photoanode layer. All samples subsequently received the same thermal annealing treatment at 500 °C and sensitized with ruthenium-based synthetic dyes. Our results revealed that the thickness of the scattering layer for both TiO2 and ZrO2 had a significant effect on the solar cell performance. The best photoconversion efficiency was achieved by samples that were coated with one screen-printing cycle, giving an overall efficiency of 3.50 % and 4.02% for TiO2 and ZrO2, respectively.

The multidriver: A reliable multicast service using the Xpress Transfer Protocol

NASA Technical Reports Server (NTRS)

Dempsey, Bert J.; Fenton, John C.; Weaver, Alfred C.

1990-01-01

A reliable multicast facility extends traditional point-to-point virtual circuit reliability to one-to-many communication. Such services can provide more efficient use of network resources, a powerful distributed name binding capability, and reduced latency in multidestination message delivery. These benefits will be especially valuable in real-time environments where reliable multicast can enable new applications and increase the availability and the reliability of data and services. We present a unique multicast service that exploits features in the next-generation, real-time transfer layer protocol, the Xpress Transfer Protocol (XTP). In its reliable mode, the service offers error, flow, and rate-controlled multidestination delivery of arbitrary-sized messages, with provision for the coordination of reliable reverse channels. Performance measurements on a single-segment Proteon ProNET-4 4 Mbps 802.5 token ring with heterogeneous nodes are discussed.

Decline in Physical Function and Risk for Elder Abuse Reported to Social Services in a Community-Dwelling Population of Older Adults

PubMed Central

Dong, XinQi; Simon, Melissa; Evans, Denis

2012-01-01

Objectives Elder abuse is an important public health and human rights issue and is associated with increased morbidity and mortality. This study aimed to examine the longitudinal association between decline in physical function and the risk for elder abuse. Design Prospective population-based study Setting Geographically defined community in Chicago. Participants Chicago Health and Aging Project (CHAP) is a population-based study (N=6,159), and we identified 143 CHAP participants who had elder abuse reported to social services agency from 1993–2010. Participants The primary independent variable was objectively assessed physical function using decline in physical performance testing (Tandem stand, measured walk and chair stand). Secondary independent variables were assessed using the decline in self-reported Katz, Nagi, and Rosow-Breslau scales. Outcomes were reported and confirmed elder abuse and specific subtypes of elder abuse (physical, psychological, caregiver neglect and financial exploitation). Logistic regression models were used to assess the association of decline in physical function measures and risk for elder abuse. Results After adjusting for potential confounders, every 1 point decline in physical performance testing (OR, 1.13(1.06–1.19)), Katz impairment (OR, 1.29(1.15–1.45)), Nagi impairment (OR, 1.30(1.13–1.49)) and Rosow Breslau impairment (OR, 1.42(1.15–1.74)) were associated with increased risk for elder abuse. Lowest tertiles of physical performance testing (OR, 4.92 (1.39–17.46), highest tertiles of Katz impairment (OR, 3.99 (2.18–7.31), Nagi impairment (OR, 2.37 (1.08–5.23), and Rosow Breslau impairment (2.85 (1.39–5.84) were associated with increased risk for elder abuse. Conclusion Decline in objectively assessed physical function and self-reported physical function are associated with increased risk for elder abuse. PMID:23002901

A randomised controlled trial of an intervention to facilitate the implementation of healthy eating and physical activity policies and practices in childcare services

PubMed Central

Jones, Jannah; Wolfenden, Luke; Wyse, Rebecca; Finch, Meghan; Yoong, Sze Lin; Dodds, Pennie; Pond, Nicole; Gillham, Karen; Freund, Megan; McElduff, Patrick; Wye, Paula; Wiggers, John

2014-01-01

Introduction Childhood overweight and obesity tracks into adulthood, increasing the risk of developing future chronic disease. Implementing initiatives promoting healthy eating and physical activity in childcare settings has been identified as a priority to prevent excessive child weight gain. Despite this, few trials have been conducted to assess the effectiveness of interventions to support population-wide implementation of such initiatives. The aim of this study is to assess the effectiveness of a multicomponent intervention in increasing the implementation of healthy eating and physical activity policies and practices by centre-based childcare services. Methods and analysis The study will employ a parallel group randomised controlled trial design. A sample of 128 childcare services in the Hunter region of New South Wales, Australia, will be recruited to participate in the trial. 64 services will be randomly allocated to a 12-month implementation intervention. The remaining 64 services will be allocated to a usual care control group. The intervention will consist of a number of strategies to facilitate childcare service implementation of healthy eating and physical activity policies and practices. Intervention strategies will include implementation support staff, securing executive support, consensus processes, staff training, academic detailing visits, performance monitoring and feedback, tools and resources, and a communications strategy. The primary outcome of the trial will be the prevalence of services implementing all healthy eating and physical activity policies and practices targeted by the intervention. To assess the effectiveness of the intervention, telephone surveys with nominated supervisors and room leaders of childcare services will be conducted at baseline and immediately postintervention. Ethics and dissemination The study was approved by the Hunter New England Human Research Ethics Committee and the University of Newcastle Human Research Ethics Committee. Study findings will be disseminated widely through peer-reviewed publications and conference presentations. Trial registration number Australian Clinical Trials Registry ACTRN12612000927820. PMID:24742978

Study of relationships of material properties and high efficiency solar cell performance on material composition

NASA Technical Reports Server (NTRS)

Sah, C. T.

1983-01-01

The performance improvements obtainable from extending the traditionally thin back-surface-field (BSF) layer deep into the base of silicon solar cells under terrestrial solar illumination (AM1) are analyzed. This extended BSF cell is also known as the back-drift-field cell. About 100 silicon cells were analyzed, each with a different emitter or base dopant impurity distribution whose selection was based on physically anticipated improvements. The four principal performance parameters (the open-circuit voltage, the short-circuit current, the fill factor, and the maximum efficiency) are computed using a FORTRAN program, called Circuit Technique for Semiconductor-device Analysis, CTSA, which numerically solves the six Shockley Equations under AM1 solar illumination at 88.92 mW/cm, at an optimum cell thickness of 50 um. The results show that very significant performance improvements can be realized by extending the BSF layer thickness from 2 um (18% efficiency) to 40 um (20% efficiency).

School-based physical therapy services and student functional performance at school.

PubMed

Mccoy, Sarah Westcott; Effgen, Susan K; Chiarello, Lisa A; Jeffries, Lynn M; Villasante Tezanos, Alejandro G

2018-03-30

We explored relationships of school-based physical therapy to standardized outcomes of students receiving physical therapy. Using a practice-based evidence research design, School Function Assessment (SFA) outcomes of 296 students with disabilities (mean age 7y 4mo [standard deviation 2y]; 166 males, 130 females), served by 109 physical therapists, were explored. After training, therapists completed 10 SFA scales on students at the beginning and end of the school year. Therapists collected detailed weekly data on services (activities, interventions, types, student participation) using the School-Physical Therapy Interventions for Pediatrics (S-PTIP) system. Stepwise linear regressions were used to investigate S-PTIP predictors of SFA outcomes. Predictors of SFA section outcomes varied in strength, with the coefficient of determination (R 2 ) for each outcome ranging from 0.107 to 0.326. Services that correlated positively with the SFA outcomes included mobility, sensory, motor learning, aerobic/conditioning, functional strengthening, playground access interventions, and higher student participation during therapy (standardized β=0.11-0.26). Services that correlated negatively with the SFA outcomes included providing services within student groups, within school activity, with students not in special education, during recreation activities, and with positioning, hands-on facilitation, sensory integration, orthoses, and equipment interventions (standardized β=-0.14 to -0.22). Consideration of outcomes is prudent to focus services. Overall results suggest we should emphasize active mobility practice by using motor learning interventions and engaging students within therapy sessions. No specific interventions predicted positively on all School Function Assessment (SFA) outcomes. Active movement practice seems related to overall better SFA outcomes. Active mobility practice improved SFA participation, mobility, recreation, and activities of daily living. Engaging students in therapy activities and interventions improved outcomes. © 2018 Mac Keith Press.

Self-service for software development projects and HPC activities

NASA Astrophysics Data System (ADS)

Husejko, M.; Høimyr, N.; Gonzalez, A.; Koloventzos, G.; Asbury, D.; Trzcinska, A.; Agtzidis, I.; Botrel, G.; Otto, J.

2014-05-01

This contribution describes how CERN has implemented several essential tools for agile software development processes, ranging from version control (Git) to issue tracking (Jira) and documentation (Wikis). Running such services in a large organisation like CERN requires many administrative actions both by users and service providers, such as creating software projects, managing access rights, users and groups, and performing tool-specific customisation. Dealing with these requests manually would be a time-consuming task. Another area of our CERN computing services that has required dedicated manual support has been clusters for specific user communities with special needs. Our aim is to move all our services to a layered approach, with server infrastructure running on the internal cloud computing infrastructure at CERN. This contribution illustrates how we plan to optimise the management of our of services by means of an end-user facing platform acting as a portal into all the related services for software projects, inspired by popular portals for open-source developments such as Sourceforge, GitHub and others. Furthermore, the contribution will discuss recent activities with tests and evaluations of High Performance Computing (HPC) applications on different hardware and software stacks, and plans to offer a dynamically scalable HPC service at CERN, based on affordable hardware.

Few Atomic Layered Lithium Cathode Materials to Achieve Ultrahigh Rate Capability in Lithium-Ion Batteries.

PubMed

Tai, Zhixin; Subramaniyam, Chandrasekar M; Chou, Shu-Lei; Chen, Lingna; Liu, Hua-Kun; Dou, Shi-Xue

2017-09-01

The most promising cathode materials, including LiCoO 2 (layered), LiMn 2 O 4 (spinel), and LiFePO 4 (olivine), have been the focus of intense research to develop rechargeable lithium-ion batteries (LIBs) for portable electronic devices. Sluggish lithium diffusion, however, and unsatisfactory long-term cycling performance still limit the development of present LIBs for several applications, such as plug-in/hybrid electric vehicles. Motivated by the success of graphene and novel 2D materials with unique physical and chemical properties, herein, a simple shear-assisted mechanical exfoliation method to synthesize few-layered nanosheets of LiCoO 2 , LiMn 2 O 4 , and LiFePO 4 is used. Importantly, these as-prepared nanosheets with preferred orientations and optimized stable structures exhibit excellent C-rate capability and long-term cycling performance with much reduced volume expansion during cycling. In particular, the zero-strain insertion phenomenon could be achieved in 2-3 such layers of LiCoO 2 electrode materials, which could open up a new way to the further development of next-generation long-life and high-rate batteries. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Analysis of buried interfaces in multilayer mirrors using grazing incidence extreme ultraviolet reflectometry near resonance edges.

PubMed

Sertsu, M G; Nardello, M; Giglia, A; Corso, A J; Maurizio, C; Juschkin, L; Nicolosi, P

2015-12-10

Accurate measurements of optical properties of multilayer (ML) mirrors and chemical compositions of interdiffusion layers are particularly challenging to date. In this work, an innovative and nondestructive experimental characterization method for multilayers is discussed. The method is based on extreme ultraviolet (EUV) reflectivity measurements performed on a wide grazing incidence angular range at an energy near the absorption resonance edge of low-Z elements in the ML components. This experimental method combined with the underlying physical phenomenon of abrupt changes of optical constants near EUV resonance edges enables us to characterize optical and structural properties of multilayers with high sensitivity. A major advantage of the method is to perform detailed quantitative analysis of buried interfaces of multilayer structures in a nondestructive and nonimaging setup. Coatings of Si/Mo multilayers on a Si substrate with period d=16.4  nm, number of bilayers N=25, and different capping structures are investigated. Stoichiometric compositions of Si-on-Mo and Mo-on-Si interface diffusion layers are derived. Effects of surface oxidation reactions and carbon contaminations on the optical constants of capping layers and the impact of neighboring atoms' interactions on optical responses of Si and Mo layers are discussed.

Assessing the physical service setting: a look at emergency departments.

PubMed

Steinke, Claudia

2015-01-01

To determine the attributes of the physical setting that are important for developing a positive service climate within emergency departments and to validate a measure for assessing physical service design. The design of the physical setting is an important and contributing factor for creating a service climate in organizations. Service climate is defined as employee perceptions of the practices, procedures, and behaviors that get rewarded, supported, and expected with regard to customer service and customer service quality. There has been research conducted which identifies antecedents within organization that promotes a positive service climate which in turn creates service-oriented behaviors by employees toward clients. The antecedent of the physical setting and its impact on perceptions of service climate has been less commonly explored. Using the concept of the physical service setting (which may be defined as aspects of the physical, built environment that facilitate the delivery of quality service), attributes of the physical setting and their relationship with service climate were explored by means of a quantitative paper survey distributed to emergency nurses (n = 180) throughout a province in Canada. The results highlight the validity and reliability of six scales measuring the physical setting and its relation to service. Respondents gave low ratings to the physical setting of their departments, in addition to low ratings of service climate. Respondents feel that the design of the physical setting in the emergency departments where they work is not conducive to providing quality service to clients. Certain attributes of the physical setting were found to be significant in influencing perceptions of service climate, hence service quality, within the emergency department setting. © The Author(s) 2015.

Care services ecosystem for ambient assisted living

NASA Astrophysics Data System (ADS)

Camarinha-Matos, Luis M.; Rosas, Joao; Ines Oliveira, Ana; Ferrada, Filipa

2015-08-01

Effective provision of care and assistance services in ambient assisted living requires the involvement and collaboration of multiple stakeholders. To support such collaboration, the development of an ecosystem of products and services for active ageing plays an important role. This article introduces a conceptual architecture that supports such care ecosystem. In order to facilitate understanding and better interrelate concepts, a 3-layered model is adopted: Infrastructure layer, Care and assistance services layer and Ambient Assisted Living ecosystem layer. A holistic perspective of ambient assisted living, namely considering four important life settings is adopted: (1) independent living; (2) health and care in life; (3) occupation in life and (4) recreation in life. The proposed architecture is designed in the context of a national Portuguese project and in accordance with the findings of a large European road mapping initiative on ICT and ageing.

13 CFR 123.201 - When am I not eligible to apply for a physical disaster business loan?

Code of Federal Regulations, 2011 CFR

2011-01-01

... limited to: (1) The elimination or substantial decrease in the market for your products or services, as a... eligible if your business presents live performances of a prurient sexual nature or derives directly or indirectly more than de minimis gross revenue through the sale of products or services, or the presentation...

School-Based Healthcare and Academic Performance: Implications of Physical Health Services for Educational Outcomes and Inequality. CEPA Working Paper No. 15-07

ERIC Educational Resources Information Center

Rochmes, Jane E.

2016-01-01

Health and education are reciprocally related, and research indicates that unhealthy students are poorly positioned to learn. Providing services that prevent health problems or help students cope with existing health concerns is one way that schools intervene in the relationship between student background and educational outcomes. Providing health…

Cloud Physics Lidar Optical Measurements During the SAFARI-2000 Field Campaign

NASA Technical Reports Server (NTRS)

Hlavka, Dennis L.; McGill, Matt; Hart, William D.; Spinhirne, James D.; Starr, David OC. (Technical Monitor)

2002-01-01

In this presentation, we will show new optical data processing results from the Cloud Physics War during SAFARI-2000. Retrieved products include aerosol and cloud layer location and identification, layer optical depths, vertical extinction profiles, and extinction-to-backscatter (S) ratios for 532 and 1064 nm. The retrievals will focus on the persistent and smoky planetary boundary layer and occasional elevated aerosol layers found in southern Africa during August and September 2000.

Social values for ecosystem services (SolVES): A GIS application for assessing, mapping, and quantifying the social values of ecosystem services-Documentation and user manual, version 1.0

USGS Publications Warehouse

Sherrouse, Benson C.; Riegle, Jodi L.; Semmens, Darius J.

2010-01-01

In response to the need for incorporating quantified and spatially explicit measures of social values into ecosystem services assessments, the Rocky Mountain Geographic Science Center, in collaboration with Colorado State University, has developed a geographic information system application, Social Values for Ecosystem Services (SolVES). SolVES can be used to assess, map, and quantify the perceived social values of ecosystem services. SolVES derives a quantitative social values metric, the Value Index, from a combination of spatial and nonspatial responses to public attitude and preference surveys. SolVES also generates landscape metrics, such as average elevation and distance to water, calculated from spatial data layers describing the underlying physical environment. Using kernel density calculations and zonal statistics, SolVES derives and maps the 10-point Value Index and reports landscape metrics associated with each index value for social value types such as aesthetics, biodiversity, and recreation. This can be repeated for various survey subgroups as distinguished by their attitudes and preferences regarding public uses of the forests such as motorized recreation and logging for fuels reduction. The Value Index provides a basis of comparison within and among survey subgroups to consider the effect of social contexts on the valuation of ecosystem services. SolVES includes regression coefficients linking the predicted value (the Value Index) to landscape metrics. These coefficients are used to generate predicted social value maps using value transfer techniques for areas where primary survey data are not available. SolVES was developed, and will continue to be enhanced through future versions, as a public domain tool to enable decision makers and researchers to map the social values of ecosystem services and to facilitate discussions among diverse stakeholders regarding tradeoffs between different ecosystem services in a variety of physical and social contexts.

Outage management and health physics issue, 2007

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

Agnihotri, Newal

2007-05-15

The focus of the May-June issue is on outage management and health physics. Major articles/reports in this issue include: India: a potential commercial opportunity, a U.S. Department of Commerce Report, by Joe Neuhoff and Justin Rathke; The changing climate for nuclear energy, by Skip Bowman, Nuclear Energy Insitute; Selecting protective clothing, by J. Mark Price, Southern California Edison; and Succssful refurbishment outage, by Sudesh K. Gambhir, Omaha Public Power District. Industry innovation articles in this issue are: Containment radiation monitoring spiking, by Michael W. Lantz and Robert Routolo, Arizona Public Service Company; Improved outage performance, by Michael Powell and Troymore » Wilfong, Arizona Public Service Company, Palo Verde Nuclear Generating Station; Stop repacking valves and achieve leak-free performance, by Kenneth Hart, PPL Susquehanna LLC; and Head assembly upgrade package, by Timothy Petit, Dominion Nuclear.« less

Co-occurring mental illness and health care utilization and expenditures in adults with obesity and chronic physical illness.

PubMed

Shen, Chan; Sambamoorthi, Usha; Rust, George

2008-06-01

The objectives of the study were to compare health care expenditures between adults with and without mental illness among individuals with obesity and chronic physical illness. We performed a cross-sectional analysis of 2440 adults (older than age 21) with obesity using a nationally representative survey of households, the Medical Expenditure Panel Survey. Chronic physical illness consisted of self-reported asthma, diabetes, heart disease, hypertension, or osteoarthritis. Mental illness included affective disorders; anxiety, somatoform, dissociative, personality disorders; and schizophrenia. Utilization and expenditures by type of service (total, inpatient, outpatient, emergency room, pharmacy, and other) were the dependent variables. Chi-square tests, logistic regression on likelihood of use, and ordinary least squares regression on logged expenditures among users were performed. All regressions controlled for gender, race/ethnicity, age, martial status, region, education, employment, poverty status, health insurance, smoking, and exercise. All analyses accounted for the complex design of the survey. We found that 25% of adults with obesity and physical illness had a mental illness. The average total expenditures for obese adults with physical illness and mental illness were $9897; average expenditures were $6584 for those with physical illness only. Mean pharmacy expenditures for obese adults with physical illness and mental illness and for those with physical illness only were $3343 and $1756, respectively. After controlling for all independent variables, among adults with obesity and physical illness, those with mental illness were more likely to use emergency services and had higher total, outpatient, and pharmaceutical expenditures than those without mental illness. Among individuals with obesity and chronic physical illness, expenditures increased when mental illness is added. Our study findings suggest cost-savings efforts should examine the reasons for high utilization and expenditures for those with obesity, chronic physical illness, and mental illness.

26 CFR 1.911-3 - Determination of amount of foreign earned income to be excluded.

Code of Federal Regulations, 2010 CFR

2010-04-01

... the physical presence requirement of § 1.911-2(a)(2)(ii) is met is any twelve consecutive month period... taxable year. Thus, if an individual's period of physical, presence is the twelve-month period beginning..., by the number of months in the period when services giving rise to such amount were performed, and...

26 CFR 1.911-3 - Determination of amount of foreign earned income to be excluded.

Code of Federal Regulations, 2012 CFR

2012-04-01

... the physical presence requirement of § 1.911-2(a)(2)(ii) is met is any twelve consecutive month period... taxable year. Thus, if an individual's period of physical, presence is the twelve-month period beginning..., by the number of months in the period when services giving rise to such amount were performed, and...

26 CFR 1.911-3 - Determination of amount of foreign earned income to be excluded.

Code of Federal Regulations, 2014 CFR

2014-04-01

... the physical presence requirement of § 1.911-2(a)(2)(ii) is met is any twelve consecutive month period... taxable year. Thus, if an individual's period of physical, presence is the twelve-month period beginning..., by the number of months in the period when services giving rise to such amount were performed, and...

26 CFR 1.911-3 - Determination of amount of foreign earned income to be excluded.

Code of Federal Regulations, 2013 CFR

2013-04-01

... the physical presence requirement of § 1.911-2(a)(2)(ii) is met is any twelve consecutive month period... taxable year. Thus, if an individual's period of physical, presence is the twelve-month period beginning..., by the number of months in the period when services giving rise to such amount were performed, and...

Association of Physical Inactivity, Weight, Smoking, and Prior Injury on Physical Performance in a Military Setting

PubMed Central

Teyhen, Deydre S.; Rhon, Daniel I.; Butler, Robert J.; Shaffer, Scott W.; Goffar, Stephen L.; McMillian, Danny J.; Boyles, Robert E.; Kiesel, Kyle B.; Plisky, Phillip J.

2016-01-01

Context: Although inactivity, being overweight, smoking, and a history of injury are identified as risk factors for poor health and injury, few authors have examined their association on physical performance. Young adults may be more likely to adopt healthier lifestyles if they understand the effect of health behaviors on performance. Objective: To determine the association of being overweight, smoking, inactivity, and a history of injury with physical performance. Design: Cross-sectional study. Setting: Military population. Patients or Other Participants: Active-duty service members (N = 1466; 1380 men, 86 women; age = 24.7 ± 5.0 years; body mass index = 26.7 ± 3.4 kg/m2). Main Outcome Measure(s): Participants performed 8 measures (the triple-crossover hop for distance, the 6-m timed-hop test, the Functional Movement Screen, the Lower Quarter Y-Balance Test, the Upper Quarter Y-Balance Test, and the 3-event Army Physical Fitness Test) for evaluation of endurance, strength, muscular endurance, power, agility, balance, and motor control. Participants were categorized based on the number of health risk factors present. Using an analysis of covariance, we assessed the relationship between risk factors and physical performance with age and sex as covariates. Results: Compared with those who had no risk factors (27.9% of men, 34.9% of women), physical performance was worse in those who had 1, 2, or 3 to 4 risk factors present by 4.3%, 6.7%, and 10.3%, respectively. Decrements in performance for those with 3 to 4 risk factors ranged from 3.3% to 14.4%. Conclusions: An unhealthy lifestyle habit or a history of injury was negatively associated with physical performance. Physical performance decrements were associated with the number of risk factors present. Understanding how risk factors contribute to decreased physical performance may enable clinicians to improve compliance with injury-prevention programs in occupational settings in which a young and relatively healthy workforce may be more concerned about performance than health. PMID:27690529

Association of Physical Inactivity, Weight, Smoking, and Prior Injury on Physical Performance in a Military Setting.

PubMed

Teyhen, Deydre S; Rhon, Daniel I; Butler, Robert J; Shaffer, Scott W; Goffar, Stephen L; McMillian, Danny J; Boyles, Robert E; Kiesel, Kyle B; Plisky, Phillip J

2016-11-01

 Although inactivity, being overweight, smoking, and a history of injury are identified as risk factors for poor health and injury, few authors have examined their association on physical performance. Young adults may be more likely to adopt healthier lifestyles if they understand the effect of health behaviors on performance.  To determine the association of being overweight, smoking, inactivity, and a history of injury with physical performance.  Cross-sectional study.  Military population.  Active-duty service members (N = 1466; 1380 men, 86 women; age = 24.7 ± 5.0 years; body mass index = 26.7 ± 3.4 kg/m 2 ).  Participants performed 8 measures (the triple-crossover hop for distance, the 6-m timed-hop test, the Functional Movement Screen, the Lower Quarter Y-Balance Test, the Upper Quarter Y-Balance Test, and the 3-event Army Physical Fitness Test) for evaluation of endurance, strength, muscular endurance, power, agility, balance, and motor control. Participants were categorized based on the number of health risk factors present. Using an analysis of covariance, we assessed the relationship between risk factors and physical performance with age and sex as covariates.  Compared with those who had no risk factors (27.9% of men, 34.9% of women), physical performance was worse in those who had 1, 2, or 3 to 4 risk factors present by 4.3%, 6.7%, and 10.3%, respectively. Decrements in performance for those with 3 to 4 risk factors ranged from 3.3% to 14.4%.  An unhealthy lifestyle habit or a history of injury was negatively associated with physical performance. Physical performance decrements were associated with the number of risk factors present. Understanding how risk factors contribute to decreased physical performance may enable clinicians to improve compliance with injury-prevention programs in occupational settings in which a young and relatively healthy workforce may be more concerned about performance than health.

High-speed and low-energy nitride memristors

DOE PAGES

Choi, Byung Joon; Torrezan, Antonio C.; Strachan, John Paul; ...

2016-05-24

High-performance memristors based on AlN films have been demonstrated, which exhibit ultrafast ON/OFF switching times (≈85 ps for microdevices with waveguide) and relatively low switching current (≈15 μA for 50 nm devices). Physical characterizations are carried out to understand the device switching mechanism, and rationalize speed and energy performance. The formation of an Al-rich conduction channel through the AlN layer is revealed. Here, the motion of positively charged nitrogen vacancies is likely responsible for the observed switching.

Interannual variability of primary production and air-sea CO2 flux in the Atlantic and Indian sectors of the Southern Ocean.

NASA Astrophysics Data System (ADS)

Dufour, Carolina; Merlivat, Liliane; Le Sommer, Julien; Boutin, Jacqueline; Antoine, David

2013-04-01

As one of the major oceanic sinks of anthropogenic CO2, the Southern Ocean plays a critical role in the climate system. However, due to the scarcity of observations, little is known about physical and biological processes that control air-sea CO2 fluxes and how these processes might respond to climate change. It is well established that primary production is one of the major drivers of air-sea CO2 fluxes, consuming surface Dissolved Inorganic Carbon (DIC) during Summer. Southern Ocean primary production is though constrained by several limiting factors such as iron and light availability, which are both sensitive to mixed layer depth. Mixed layer depth is known to be affected by current changes in wind stress or freshwater fluxes over the Southern Ocean. But we still don't know how primary production may respond to anomalous mixed layer depth neither how physical processes may balance this response to set the seasonal cycle of air-sea CO2 fluxes. In this study, we investigate the impact of anomalous mixed layer depth on surface DIC in the Atlantic and Indian sectors of the Subantarctic zone of the Southern Ocean (60W-60E, 38S-55S) with a combination of in situ data, satellite data and model experiment. We use both a regional eddy permitting ocean biogeochemical model simulation based on NEMO-PISCES and data-based reconstruction of biogeochemical fields based on CARIOCA buoys and SeaWiFS data. A decomposition of the physical and biological processes driving the seasonal variability of surface DIC is performed with both the model data and observations. A good agreement is found between the model and the data for the amplitude of biological and air-sea flux contributions. The model data are further used to investigate the impact of winter and summer anomalies in mixed layer depth on surface DIC over the period 1990-2004. The relative changes of each physical and biological process contribution are quantified and discussed.

Exploring barriers to remaining physically active: a case report of a person with multiple sclerosis.

PubMed

Zalewski, Kathryn

2007-03-01

Physical therapy intervention for those with chronic disabling conditions typically follows an episode of care approach: therapists provide services when a decrement in functional performance occurs such that individuals require intervention to return to baseline performance. Attention to the psychosocial supports required for successful transition can be unintentionally minimized when the focus of an episode of care follows a change in physical function. The purpose of this case report is to present and discuss the challenges to successful community reintegration following physical therapy intervention with an emphasis on developing independent exercise habits in management of a person with multiple sclerosis. RW, presented in this case study, is a 52-year-old man diagnosed with progressive multiple sclerosis five years before self-referral to a pro bono physical therapy clinic.

Two-color infrared detector

DOEpatents

Klem, John F; Kim, Jin K

2014-05-13

A two-color detector includes a first absorber layer. The first absorber layer exhibits a first valence band energy characterized by a first valence band energy function. A barrier layer adjoins the first absorber layer at a first interface. The barrier layer exhibits a second valence band energy characterized by a second valence band energy function. The barrier layer also adjoins a second absorber layer at a second interface. The second absorber layer exhibits a third valence band energy characterized by a third valence band energy function. The first and second valence band energy functions are substantially functionally or physically continuous at the first interface and the second and third valence band energy functions are substantially functionally or physically continuous at the second interface.

Korean Ministry of Environment's web-based visual consumer product exposure and risk assessment system (COPER).

PubMed

Lee, Hunjoo; Lee, Kiyoung; Park, Ji Young; Min, Sung-Gi

2017-05-01

With support from the Korean Ministry of the Environment (ME), our interdisciplinary research staff developed the COnsumer Product Exposure and Risk assessment system (COPER). This system includes various databases and features that enable the calculation of exposure and determination of risk caused by consumer products use. COPER is divided into three tiers: the integrated database layer (IDL), the domain specific service layer (DSSL), and the exposure and risk assessment layer (ERAL). IDL is organized by the form of the raw data (mostly non-aggregated data) and includes four sub-databases: a toxicity profile, an inventory of Korean consumer products, the weight fractions of chemical substances in the consumer products determined by chemical analysis and national representative exposure factors. DSSL provides web-based information services corresponding to each database within IDL. Finally, ERAL enables risk assessors to perform various exposure and risk assessments, including exposure scenario design via either inhalation or dermal contact by using or organizing each database in an intuitive manner. This paper outlines the overall architecture of the system and highlights some of the unique features of COPER based on visual and dynamic rendering engine for exposure assessment model on web.

Transferred wrinkled Al2O3 for highly stretchable and transparent graphene-carbon nanotube transistors

NASA Astrophysics Data System (ADS)

Chae, Sang Hoon; Yu, Woo Jong; Bae, Jung Jun; Duong, Dinh Loc; Perello, David; Jeong, Hye Yun; Ta, Quang Huy; Ly, Thuc Hue; Vu, Quoc An; Yun, Minhee; Duan, Xiangfeng; Lee, Young Hee

2013-05-01

Despite recent progress in producing transparent and bendable thin-film transistors using graphene and carbon nanotubes, the development of stretchable devices remains limited either by fragile inorganic oxides or polymer dielectrics with high leakage current. Here we report the fabrication of highly stretchable and transparent field-effect transistors combining graphene/single-walled carbon nanotube (SWCNT) electrodes and a SWCNT-network channel with a geometrically wrinkled inorganic dielectric layer. The wrinkled Al2O3 layer contained effective built-in air gaps with a small gate leakage current of 10-13 A. The resulting devices exhibited an excellent on/off ratio of ~105, a high mobility of ~40 cm2 V-1 s-1 and a low operating voltage of less than 1 V. Importantly, because of the wrinkled dielectric layer, the transistors retained performance under strains as high as 20% without appreciable leakage current increases or physical degradation. No significant performance loss was observed after stretching and releasing the devices for over 1,000 times. The sustainability and performance advances demonstrated here are promising for the adoption of stretchable electronics in a wide variety of future applications.

Scientific Data Services -- A High-Performance I/O System with Array Semantics

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

Wu, Kesheng; Byna, Surendra; Rotem, Doron

2011-09-21

As high-performance computing approaches exascale, the existing I/O system design is having trouble keeping pace in both performance and scalability. We propose to address this challenge by adopting database principles and techniques in parallel I/O systems. First, we propose to adopt an array data model because many scientific applications represent their data in arrays. This strategy follows a cardinal principle from database research, which separates the logical view from the physical layout of data. This high-level data model gives the underlying implementation more freedom to optimize the physical layout and to choose the most effective way of accessing the data.more » For example, knowing that a set of write operations is working on a single multi-dimensional array makes it possible to keep the subarrays in a log structure during the write operations and reassemble them later into another physical layout as resources permit. While maintaining the high-level view, the storage system could compress the user data to reduce the physical storage requirement, collocate data records that are frequently used together, or replicate data to increase availability and fault-tolerance. Additionally, the system could generate secondary data structures such as database indexes and summary statistics. We expect the proposed Scientific Data Services approach to create a “live” storage system that dynamically adjusts to user demands and evolves with the massively parallel storage hardware.« less

Evaluation of two working methods for screed floor layers on musculoskeletal complaints, work demands and workload.

PubMed

Visser, Steven; van der Molen, Henk F; Kuijer, P Paul F M; van Holland, Berry J; Frings-Dresen, Monique H W

2013-01-01

Screed floors are bound by sand-cement (SF) or by anhydrite (AF). Sand-cement floors are levelled manually and anhydrite floors are self-levelling and therefore differences in work demands and prevalences of musculoskeletal complaints might occur. The objective was to assess among SF layers and AF layers (1) the prevalence of musculoskeletal complaints and (2) the physical work demands, energetic workload, perceived workload and discomfort. A questionnaire survey and an observational field study were performed. Compared with AF layers (n = 35), SF layers (n = 203) had higher, however, not statistically significant different, prevalences of neck (20% vs. 7%), shoulder (27% vs. 13%), low back (39% vs. 26%) and ankles/feet (9% vs. 0%) complaints. Sand-cement-bound screed floor layers (n = 18) bent and kneeled significantly longer (Δ77 min and Δ94 min; respectively), whereas AF layers (n = 18) stood significantly longer (Δ60 min). The work demands of SF layers exceeded exposure criteria for low back and knee complaints and therefore new working measures should be developed and implemented. In comparison with anhydrite-bound screed floor layers, sand-cement-bound screed floor layers exceeded exposure criteria for work-related low back and knee complaints. New working methods and measures for sand-cement-bound screed floor layers should be developed and implemented to reduce the risk for work-related musculoskeletal complaints.

Distributed Electrical Energy Systems: Needs, Concepts, Approaches and Vision (in Chinese)

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

Zhang, Yingchen; Zhang, Jun; Gao, Wenzhong

Intelligent distributed electrical energy systems (IDEES) are featured by vast system components, diversifled component types, and difficulties in operation and management, which results in that the traditional centralized power system management approach no longer flts the operation. Thus, it is believed that the blockchain technology is one of the important feasible technical paths for building future large-scale distributed electrical energy systems. An IDEES is inherently with both social and technical characteristics, as a result, a distributed electrical energy system needs to be divided into multiple layers, and at each layer, a blockchain is utilized to model and manage its logicmore » and physical functionalities. The blockchains at difierent layers coordinate with each other and achieve successful operation of the IDEES. Speciflcally, the multi-layer blockchains, named 'blockchain group', consist of distributed data access and service blockchain, intelligent property management blockchain, power system analysis blockchain, intelligent contract operation blockchain, and intelligent electricity trading blockchain. It is expected that the blockchain group can be self-organized into a complex, autonomous and distributed IDEES. In this complex system, frequent and in-depth interactions and computing will derive intelligence, and it is expected that such intelligence can bring stable, reliable and efficient electrical energy production, transmission and consumption.« less

Modeling and Experiments with Carbon Nanotubes for Applications in High Performance Circuits

DTIC Science & Technology

2017-04-06

purchased and installed for experimental characterization of atomic layer deposited graphene on different substrates for radiation-hardened studies...72 3.6 Experimental Research in Graphene for Radiation Hardened Devices……………..73 4 Recommendations...physics for analysis and design of integrated circuits. The developed model is verified from published experimental data. Basic logic gates in

PVD coating for optical applications on temperature-resistant thermoplastics

NASA Astrophysics Data System (ADS)

Munzert, Peter; Schulz, Ulrike; Kaiser, Norbert

2004-02-01

The performance of the high temperature resistant polymers Pleximid, APEC and Ultrason as substrate materials in plasma-assisted physical vapor deposition processes was studied and compared with well-known thermoplastics for optical applications. Different effects of UV irradiation and plasma exposure on the polymers' optical features, surface energy and adhesion properties for oxide layers, typically used for interference multilayer coatings, are shown.

A Source-Term Based Boundary Layer Bleed/Effusion Model for Passive Shock Control

NASA Technical Reports Server (NTRS)

Baurle, Robert A.; Norris, Andrew T.

2011-01-01

A modeling framework for boundary layer effusion has been developed based on the use of source (or sink) terms instead of the usual practice of specifying bleed directly as a boundary condition. This framework allows the surface boundary condition (i.e. isothermal wall, adiabatic wall, slip wall, etc.) to remain unaltered in the presence of bleed. This approach also lends itself to easily permit the addition of empirical models for second order effects that are not easily accounted for by simply defining effective transpiration values. Two effusion models formulated for supersonic flows have been implemented into this framework; the Doerffer/Bohning law and the Slater formulation. These models were applied to unit problems that contain key aspects of the flow physics applicable to bleed systems designed for hypersonic air-breathing propulsion systems. The ability of each model to predict bulk bleed properties was assessed, as well as the response of the boundary layer as it passes through and downstream of a porous bleed system. The model assessment was performed with and without the presence of shock waves. Three-dimensional CFD simulations that included the geometric details of the porous plate bleed systems were also carried out to supplement the experimental data, and provide additional insights into the bleed flow physics. Overall, both bleed formulations fared well for the tests performed in this study. However, the sample of test problems considered in this effort was not large enough to permit a comprehensive validation of the models.

Understanding the Flow Physics of Shock Boundary-Layer Interactions Using CFD and Numerical Analyses

NASA Technical Reports Server (NTRS)

Friedlander, David J.

2013-01-01

Computational fluid dynamic (CFD) analyses of the University of Michigan (UM) Shock/Boundary-Layer Interaction (SBLI) experiments were performed as an extension of the CFD SBLI Workshop held at the 48th AIAA Aerospace Sciences Meeting in 2010. In particular, the UM Mach 2.75 Glass Tunnel with a semi-spanning 7.75deg wedge was analyzed in attempts to explore key physics pertinent to SBLI's, including thermodynamic and viscous boundary conditions as well as turbulence modeling. Most of the analyses were 3D CFD simulations using the OVERFLOW flow solver, with additional quasi-1D simulations performed with an in house MATLAB code interfacing with the NIST REFPROP code to explore perfect verses non-ideal air. A fundamental exploration pertaining to the effects of particle image velocimetry (PIV) on post-processing data is also shown. Results from the CFD simulations showed an improvement in agreement with experimental data with key contributions including adding a laminar zone upstream of the wedge and the necessity of mimicking PIV particle lag for comparisons. Results from the quasi-1D simulation showed that there was little difference between perfect and non-ideal air for the configuration presented.

Transition metal nitride coated with atomic layers of Pt as a low-cost, highly stable electrocatalyst for the oxygen reduction reaction

DOE PAGES

Tian, Xinlong; Adzic, Radoslav R.; Luo, Junming; ...

2016-02-10

Here, the main challenges to the commercial viability of polymer electrolyte membrane fuel cells are (i) the high cost associated with using large amounts of Pt in fuel cell cathodes to compensate for the sluggish kinetics of the oxygen reduction reaction, (ii) catalyst degradation, and (iii) carbon-support corrosion. To address these obstacles, our group has focused on robust, carbon-free transition metal nitride materials with low Pt content that exhibit tunable physical and catalytic properties. Here, we report on the high performance of a novel catalyst with low Pt content, prepared by placing several layers of Pt atoms on nanoparticles ofmore » titanium nickel binary nitride. For the ORR, the catalyst exhibited a more than 400% and 200% increase in mass activity and specific activity, respectively, compared with the commercial Pt/C catalyst. It also showed excellent stability/durability, experiencing only a slight performance loss after 10,000 potential cycles, while TEM results showed its structure had remained intact. The catalyst’s outstanding performance may have resulted from the ultrahigh dispersion of Pt (several atomic layers coated on the nitride nanoparticles), and the excellent stability/durability may have been due to the good stability of nitride and synergetic effects between ultrathin Pt layer and the robust TiNiN support.« less

HEPCloud, a New Paradigm for HEP Facilities: CMS Amazon Web Services Investigation

DOE PAGES

Holzman, Burt; Bauerdick, Lothar A. T.; Bockelman, Brian; ...

2017-09-29

Historically, high energy physics computing has been performed on large purpose-built computing systems. These began as single-site compute facilities, but have evolved into the distributed computing grids used today. Recently, there has been an exponential increase in the capacity and capability of commercial clouds. Cloud resources are highly virtualized and intended to be able to be flexibly deployed for a variety of computing tasks. There is a growing interest among the cloud providers to demonstrate the capability to perform large-scale scientific computing. In this paper, we discuss results from the CMS experiment using the Fermilab HEPCloud facility, which utilized bothmore » local Fermilab resources and virtual machines in the Amazon Web Services Elastic Compute Cloud. We discuss the planning, technical challenges, and lessons learned involved in performing physics workflows on a large-scale set of virtualized resources. Additionally, we will discuss the economics and operational efficiencies when executing workflows both in the cloud and on dedicated resources.« less

HEPCloud, a New Paradigm for HEP Facilities: CMS Amazon Web Services Investigation

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

Holzman, Burt; Bauerdick, Lothar A. T.; Bockelman, Brian

Historically, high energy physics computing has been performed on large purpose-built computing systems. These began as single-site compute facilities, but have evolved into the distributed computing grids used today. Recently, there has been an exponential increase in the capacity and capability of commercial clouds. Cloud resources are highly virtualized and intended to be able to be flexibly deployed for a variety of computing tasks. There is a growing interest among the cloud providers to demonstrate the capability to perform large-scale scientific computing. In this paper, we discuss results from the CMS experiment using the Fermilab HEPCloud facility, which utilized bothmore » local Fermilab resources and virtual machines in the Amazon Web Services Elastic Compute Cloud. We discuss the planning, technical challenges, and lessons learned involved in performing physics workflows on a large-scale set of virtualized resources. Additionally, we will discuss the economics and operational efficiencies when executing workflows both in the cloud and on dedicated resources.« less

Effect of dissolved oxygen manipulation on diffusive emissions from NAPL-impacted low permeability soil layers.

PubMed

Clifton, Lisa M; Dahlen, Paul R; Johnson, Paul C

2014-05-06

Aquifer physical model experiments were performed to investigate if diffusive emissions from nonaqueous phase liquid (NAPL)-impacted low-permeability layers into groundwater moving through adjacent NAPL-free high-permeability layers can be reduced by creating an aerobic biotreatment zone at the interface between the two, and if over time that leads to reduced emissions after treatment ceases. Experiments were performed in two 1.2-m long × 1.2-m high × 5.4 cm wide stainless steel tanks; each with a high-permeability sand layer overlying a low-permeability crushed granite layer containing a NAPL mixture of indane and benzene. Each tank was water-saturated with horizontal flow primarily through the sand layer. The influent water was initially deoxygenated and the emissions and concentration distributions were allowed to reach near-steady conditions. The influent dissolved oxygen (DO) level was increased stepwise to 6.5-8.5 mg/L and 17-20 mg/L, and then decreased back to deoxygenated conditions. Each condition was maintained for at least 45 days. Relative to the near-steady benzene emission at the initial deoxygenated condition, the emission was reduced by about 70% when the DO was 6.5-8.5 mg/L, 90% when the DO was 17-20 mg/L, and ultimately 60% when returning to low DO conditions. While the reductions were substantial during treatment, longer-term reductions after 120 d of elevated DO treatment, relative to an untreated condition predicted by theory, were low: 29% and 6% in Tank 1 and Tank 2, respectively. Results show a 1-2 month lag between the end of DO delivery and rebound to the final near-steady emissions level. This observation has implications for post-treatment performance monitoring sampling at field sites.

[Changes of soil physical properties during the conversion of cropland to agroforestry system].

PubMed

Wang, Lai; Gao, Peng Xiang; Liu, Bin; Zhong, Chong Gao; Hou, Lin; Zhang, Shuo Xin

2017-01-01

To provide theoretical basis for modeling and managing agroforestry systems, the influence of conversion of cropland to agroforestry system on soil physical properties was investigated via a walnut (Juglans regia)-wheat (Triticum aestivum) intercropping system, a wide spreading local agroforestry model in northern Weihe River of loess area, with the walnut and wheat monoculture systems as the control. The results showed that the improvement of the intercropping system on soil physical properties mainly appeared in the 0-40 cm soil layer. The intercropping system could prevent soil bulk density rising in the surface soil (0-20 cm), and the plow pan in the 20-40 cm soil layer could be significantly alleviated. The intercropping system had conti-nuous improvement on soil field capacity in each soil layer with the planting age increase, and the soil field capacity was higher than that of each monoculture system in each soil layer (except 20-40 cm soil layer) since the 5th year after planting. The intercropping system had continuous improvement on soil porosity in each soil layer, but mainly in the 0-20 and 20-40 cm soil layer, and the ratio of capillary porosity was also improved. The soil bulk density, field capacity and soil porosity obtained continuous improvement during the conversion of cropland to agroforestry system, and the improvement on soil physical properties was stronger in shallow soil layer than in deep soil.

A Resource Service Model in the Industrial IoT System Based on Transparent Computing.

PubMed

Li, Weimin; Wang, Bin; Sheng, Jinfang; Dong, Ke; Li, Zitong; Hu, Yixiang

2018-03-26

The Internet of Things (IoT) has received a lot of attention, especially in industrial scenarios. One of the typical applications is the intelligent mine, which actually constructs the Six-Hedge underground systems with IoT platforms. Based on a case study of the Six Systems in the underground metal mine, this paper summarizes the main challenges of industrial IoT from the aspects of heterogeneity in devices and resources, security, reliability, deployment and maintenance costs. Then, a novel resource service model for the industrial IoT applications based on Transparent Computing (TC) is presented, which supports centralized management of all resources including operating system (OS), programs and data on the server-side for the IoT devices, thus offering an effective, reliable, secure and cross-OS IoT service and reducing the costs of IoT system deployment and maintenance. The model has five layers: sensing layer, aggregation layer, network layer, service and storage layer and interface and management layer. We also present a detailed analysis on the system architecture and key technologies of the model. Finally, the efficiency of the model is shown by an experiment prototype system.

A Resource Service Model in the Industrial IoT System Based on Transparent Computing

PubMed Central

Wang, Bin; Sheng, Jinfang; Dong, Ke; Li, Zitong; Hu, Yixiang

2018-01-01

The Internet of Things (IoT) has received a lot of attention, especially in industrial scenarios. One of the typical applications is the intelligent mine, which actually constructs the Six-Hedge underground systems with IoT platforms. Based on a case study of the Six Systems in the underground metal mine, this paper summarizes the main challenges of industrial IoT from the aspects of heterogeneity in devices and resources, security, reliability, deployment and maintenance costs. Then, a novel resource service model for the industrial IoT applications based on Transparent Computing (TC) is presented, which supports centralized management of all resources including operating system (OS), programs and data on the server-side for the IoT devices, thus offering an effective, reliable, secure and cross-OS IoT service and reducing the costs of IoT system deployment and maintenance. The model has five layers: sensing layer, aggregation layer, network layer, service and storage layer and interface and management layer. We also present a detailed analysis on the system architecture and key technologies of the model. Finally, the efficiency of the model is shown by an experiment prototype system. PMID:29587450

Effectiveness of an intervention to facilitate the implementation of healthy eating and physical activity policies and practices in childcare services: a randomised controlled trial.

PubMed

Jones, Jannah; Wyse, Rebecca; Finch, Meghan; Lecathelinais, Christophe; Wiggers, John; Marshall, Josephine; Falkiner, Maryann; Pond, Nicole; Yoong, Sze Lin; Hollis, Jenna; Fielding, Alison; Dodds, Pennie; Clinton-McHarg, Tara; Freund, Megan; McElduff, Patrick; Gillham, Karen; Wolfenden, Luke

2015-10-25

The primary aim of this study was to evaluate the effectiveness of an intervention to increase the implementation of healthy eating and physical activity policies and practices by centre-based childcare services. The study also sought to determine if the intervention was effective in improving child dietary intake and increasing child physical activity levels while attending childcare. A parallel group, randomised controlled trial was conducted in a sample of 128 childcare services. Intervention strategies included provision of implementation support staff, securing executive support, staff training, consensus processes, academic detailing visits, tools and resources, performance monitoring and feedback and a communications strategy. The primary outcome of the trial was the proportion of services implementing all seven healthy eating and physical activity policies and practices targeted by the intervention. Outcome data were collected via telephone surveys with nominated supervisors and room leaders at baseline and immediately post-intervention. Secondary trial outcomes included the differences between groups in the number of serves consumed by children for each food group within the Australian Guide to Healthy Eating and in the proportion of children engaged in sedentary, walking or very active physical activity assessed via observation in a random subsample of 36 services at follow-up. There was no significant difference between groups for the primary trial outcome (p = 0.44). Relative to the control group, a significantly larger proportion of intervention group services reported having a written nutrition and physical activity policy (p = 0.05) and providing adult-guided activities to develop fundamental movement skills (p = 0.01). There were no significant differences between groups at follow-up on measures of child dietary intake or physical activity. The findings of the trial were equivocal. While there was no significant difference between groups for the primary trial outcome, the intervention did significantly increase the proportion of intervention group services implementing two of the seven healthy eating and physical activity policies and practices. High levels of implementation of a number of policies and practices at baseline, significant obesity prevention activity in the study region and higher than previously reported intra-class correlation of child behaviours may, in part, explain the trial findings. Australian Clinical Trials Registry (reference ACTRN12612000927820 ).

National survey of availability of physical rehabilitation services in Iran: A mixed methods study

PubMed Central

Shirazikhah, Marzieh; Mirabzadeh, Arash; Sajadi, Homeira; Joghataei, Mohammad Taghi; Biglarian, Akbar; Mousavi, Tahmineh; Shahboulaghi, Farahnaz Mohammadi

2017-01-01

Background The prevalence of disability in Iran has increased due to ageing of the population and the presence of chronic diseases. However, little is known about the availability of rehabilitation services in Iran. Objective To study the availability of physical rehabilitation services in Iran. Methods This was a mixed method study. In the first phase, a qualitative design was conducted for designing an instrument with focus groups based on Service Availability and Readiness Assessment (SARA) instrument (developed by World Health Organization). Content analysis was used for data analysis. Then, in the second phase, a cross-sectional study was performed to collect the data with census method in Iran. This study was formed from June to October 2015, and samples consisted of all governmental, public non-governmental and private facilities established for rehabilitation centers affiliated with the Ministry of Health and Medical Education, Ministry of Labor, Cooperative and Social Welfare and the Iranian Red Crescent Society. Data analyses were performed using SPSS software (version 16). Descriptive statistical analysis (percentage and frequency) were calculated for quantitative data. Results In the first phase, the content analysis of qualitative data identified a Master Facilities List (MFL) of rehabilitation services and service providers in Iran. Results of the second phase showed that the rate of inpatient, outpatient, community-based and long-term care centers per 1,000,000 populations in Iran were 1.68, 89.24, 66.21 and 3.6, respectively. Also, that the rate of rehabilitation professionals including physical medicine and rehabilitation specialists, physiotherapists, occupational therapists, speech therapists, and audiologists were 3.90, 64.65, 22.09, 22.83 and 24.18 per 1,000,000 populations, respectively. Conclusion There is a need to increase the availability of rehabilitation services and to promote rehabilitation referrals by using an interdisciplinary team approach. PMID:29403619

Graphene-like two-dimensional layered nanomaterials: applications in biosensors and nanomedicine.

PubMed

Yang, Guohai; Zhu, Chengzhou; Du, Dan; Zhu, Junjie; Lin, Yuehe

2015-09-14

The development of nanotechnology provides promising opportunities for various important applications. The recent discovery of atomically-thick two-dimensional (2D) nanomaterials can offer manifold perspectives to construct versatile devices with high-performance to satisfy multiple requirements. Many studies directed at graphene have stimulated renewed interest on graphene-like 2D layered nanomaterials (GLNs). GLNs including boron nitride nanosheets, graphitic-carbon nitride nanosheets and transition metal dichalcogenides (e.g. MoS2 and WS2) have attracted significant interest in numerous research fields from physics and chemistry to biology and engineering, which has led to numerous interdisciplinary advances in nano science. Benefiting from the unique physical and chemical properties (e.g. strong mechanical strength, high surface area, unparalleled thermal conductivity, remarkable biocompatibility and ease of functionalization), these 2D layered nanomaterials have shown great potential in biochemistry and biomedicine. This review summarizes recent advances of GLNs in applications of biosensors and nanomedicine, including electrochemical biosensors, optical biosensors, bioimaging, drug delivery and cancer therapy. Current challenges and future perspectives in these rapidly developing areas are also outlined. It is expected that they will have great practical foundation in biomedical applications with future efforts.

A Wideband Satcom Based Avionics Network with CDMA Uplink and TDM Downlink

NASA Technical Reports Server (NTRS)

Agrawal, D.; Johnson, B. S.; Madhow, U.; Ramchandran, K.; Chun, K. S.

2000-01-01

The purpose of this paper is to describe some key technical ideas behind our vision of a future satcom based digital communication network for avionics applications The key features of our design are as follows: (a) Packetized transmission to permit efficient use of system resources for multimedia traffic; (b) A time division multiplexed (TDM) satellite downlink whose physical layer is designed to operate the satellite link at maximum power efficiency. We show how powerful turbo codes (invented originally for linear modulation) can be used with nonlinear constant envelope modulation, thus permitting the satellite amplifier to operate in a power efficient nonlinear regime; (c) A code division multiple access (CDMA) satellite uplink, which permits efficient access to the satellite from multiple asynchronous users. Closed loop power control is difficult for bursty packetized traffic, especially given the large round trip delay to the satellite. We show how adaptive interference suppression techniques can be used to deal with the ensuing near-far problem; (d) Joint source-channel coding techniques are required both at the physical and the data transport layer to optimize the end-to-end performance. We describe a novel approach to multiple description image encoding at the data transport layer in this paper.

Graphene-like two-dimensional layered nanomaterials: applications in biosensors and nanomedicine

NASA Astrophysics Data System (ADS)

Yang, Guohai; Zhu, Chengzhou; Du, Dan; Zhu, Junjie; Lin, Yuehe

2015-08-01

The development of nanotechnology provides promising opportunities for various important applications. The recent discovery of atomically-thick two-dimensional (2D) nanomaterials can offer manifold perspectives to construct versatile devices with high-performance to satisfy multiple requirements. Many studies directed at graphene have stimulated renewed interest on graphene-like 2D layered nanomaterials (GLNs). GLNs including boron nitride nanosheets, graphitic-carbon nitride nanosheets and transition metal dichalcogenides (e.g. MoS2 and WS2) have attracted significant interest in numerous research fields from physics and chemistry to biology and engineering, which has led to numerous interdisciplinary advances in nano science. Benefiting from the unique physical and chemical properties (e.g. strong mechanical strength, high surface area, unparalleled thermal conductivity, remarkable biocompatibility and ease of functionalization), these 2D layered nanomaterials have shown great potential in biochemistry and biomedicine. This review summarizes recent advances of GLNs in applications of biosensors and nanomedicine, including electrochemical biosensors, optical biosensors, bioimaging, drug delivery and cancer therapy. Current challenges and future perspectives in these rapidly developing areas are also outlined. It is expected that they will have great practical foundation in biomedical applications with future efforts.

Guiding the Design of Radiation Imagers with Experimentally Benchmarked Geant4 Simulations for Electron-Tracking Compton Imaging

NASA Astrophysics Data System (ADS)

Coffer, Amy Beth

Radiation imagers are import tools in the modern world for a wide range of applications. They span the use-cases of fundamental sciences, astrophysics, medical imaging, all the way to national security, nuclear safeguards, and non-proliferation verification. The type of radiation imagers studied in this thesis were gamma-ray imagers that detect emissions from radioactive materials. Gamma-ray imagers goal is to localize and map the distribution of radiation within their specific field-of-view despite the fact of complicating background radiation that can be terrestrial, astronomical, and temporal. Compton imaging systems are one type of gamma-ray imager that can map the radiation around the system without the use of collimation. Lack of collimation enables the imaging system to be able to detect radiation from all-directions, while at the same time, enables increased detection efficiency by not absorbing incident radiation in non-sensing materials. Each Compton-scatter events within an imaging system generated a possible cone-surface in space that the radiation could have originated from. Compton imaging is limited in its reconstructed image signal-to-background due to these source Compton-cones overlapping with background radiation Compton-cones. These overlapping cones limit Compton imaging's detection-sensitivity in image space. Electron-tracking Compton imaging (ETCI) can improve the detection-sensitivity by measuring the Compton-scattered electron's initial trajectory. With an estimate of the scattered electron's trajectory, one can reduce the Compton-back-projected cone to a cone-arc, thus enabling faster radiation source detection and localization. However, the ability to measure the Compton-scattered electron-trajectories adds another layer of complexity to an already complex methodology. For a real-world imaging applications, improvements are needed in electron-track detection efficiency and in electron-track reconstruction. One way of measuring Compton-scattered electron-trajectories is with high-resolution Charged-Coupled Devices (CCDs). The proof-of-principle CCD-based ETCI experiment demonstrated the CCDs' ability to measure the Compton-scattered electron-tracks as a 2-dimensional image. Electron-track-imaging algorithms using the electron-track-image are able to determine the 3-dimensional electron-track trajectory within +/- 20 degrees. The work presented here is the physics simulations developed along side the experimental proof-of-principle experiment. The development of accurate physics modeling for multiple-layer CCDs based ETCI systems allow for the accurate prediction of future ETCI system performance. The simulations also enable quick development insights for system design, and they guide the development of electron-track reconstruction methods. The physics simulation efforts for this project looked closely at the accuracy of the Geant4 Monte Carlo methods for medium energy electron transport. In older version of Geant4 there were some discrepancies between the electron-tracking experimental measurements and the simulation results. It was determined that when comparing the electron dynamics of electrons at very high resolutions, Geant4 simulations must be fine tuned with careful choices for physics production cuts and electron physics stepping sizes. One result of this work is a CCDs Monte Carlo model that has been benchmarked to experimental findings and fully characterized for both photon and electron transport. The CCDs physics model now match to within 1 percent error of experimental results for scattered-electron energies below 500 keV. Following the improvements of the CCDs simulations, the performance of a realistic two-layer CCD-stack system was characterized. The realistic CCD-stack system looked at the effect of thin passive-layers on the CCDs' front face and back-contact. The photon interaction efficiency was calculated for the two-layer CCD-stack, and we found that there is a 90 percent probability of scattered-electrons from a 662 keV source to stay within a single active layer. This demonstrates the improved detection efficiency, which is one of the strengths of the CCDs' implementation as a ETCI system. The CCD-stack simulations also established that electron-tracks scattering from one CCDs layer to another could be reconstructed. The passive-regions on the CCD-stack mean that these inter-layer scattered-electron-tracks will always loose both angular information and energy information. Looking at the angular changes of these electrons scattering between the CCDs layers showed us there is not a strong energy dependence on the angular changes due to the passive-regions of the CCDs. The angular changes of the electron track are, for the most part, a function of the thickness of the thin back-layer of the CCDs. Lastly, an approach using CCD-stack simulations was developed to reconstruct the energy transport across dead-layers and its feasibility was demonstrated. Adding back this lost energy will limit the loss of energy resolution of the scatter-interactions. Energy resolution losses would negatively impacted the achievable image resolution from image reconstruction algorithms. Returning some of the energy back to the reconstructed electron-track will help retain the expected performance of the electron-track trajectory determination algorithm.

Grids, virtualization, and clouds at Fermilab

DOE PAGES

Timm, S.; Chadwick, K.; Garzoglio, G.; ...

2014-06-11

Fermilab supports a scientific program that includes experiments and scientists located across the globe. To better serve this community, in 2004, the (then) Computing Division undertook the strategy of placing all of the High Throughput Computing (HTC) resources in a Campus Grid known as FermiGrid, supported by common shared services. In 2007, the FermiGrid Services group deployed a service infrastructure that utilized Xen virtualization, LVS network routing and MySQL circular replication to deliver highly available services that offered significant performance, reliability and serviceability improvements. This deployment was further enhanced through the deployment of a distributed redundant network core architecture andmore » the physical distribution of the systems that host the virtual machines across multiple buildings on the Fermilab Campus. In 2010, building on the experience pioneered by FermiGrid in delivering production services in a virtual infrastructure, the Computing Sector commissioned the FermiCloud, General Physics Computing Facility and Virtual Services projects to serve as platforms for support of scientific computing (FermiCloud 6 GPCF) and core computing (Virtual Services). Lastly, this work will present the evolution of the Fermilab Campus Grid, Virtualization and Cloud Computing infrastructure together with plans for the future.« less

Grids, virtualization, and clouds at Fermilab

NASA Astrophysics Data System (ADS)

Timm, S.; Chadwick, K.; Garzoglio, G.; Noh, S.

2014-06-01

Fermilab supports a scientific program that includes experiments and scientists located across the globe. To better serve this community, in 2004, the (then) Computing Division undertook the strategy of placing all of the High Throughput Computing (HTC) resources in a Campus Grid known as FermiGrid, supported by common shared services. In 2007, the FermiGrid Services group deployed a service infrastructure that utilized Xen virtualization, LVS network routing and MySQL circular replication to deliver highly available services that offered significant performance, reliability and serviceability improvements. This deployment was further enhanced through the deployment of a distributed redundant network core architecture and the physical distribution of the systems that host the virtual machines across multiple buildings on the Fermilab Campus. In 2010, building on the experience pioneered by FermiGrid in delivering production services in a virtual infrastructure, the Computing Sector commissioned the FermiCloud, General Physics Computing Facility and Virtual Services projects to serve as platforms for support of scientific computing (FermiCloud 6 GPCF) and core computing (Virtual Services). This work will present the evolution of the Fermilab Campus Grid, Virtualization and Cloud Computing infrastructure together with plans for the future.

Scattering Models and Basic Experiments in the Microwave Regime

NASA Technical Reports Server (NTRS)

Fung, A. K.; Blanchard, A. J. (Principal Investigator)

1985-01-01

The objectives of research over the next three years are: (1) to develop a randomly rough surface scattering model which is applicable over the entire frequency band; (2) to develop a computer simulation method and algorithm to simulate scattering from known randomly rough surfaces, Z(x,y); (3) to design and perform laboratory experiments to study geometric and physical target parameters of an inhomogeneous layer; (4) to develop scattering models for an inhomogeneous layer which accounts for near field interaction and multiple scattering in both the coherent and the incoherent scattering components; and (5) a comparison between theoretical models and measurements or numerical simulation.

Model-Based Design of Tree WSNs for Decentralized Detection.

PubMed

Tantawy, Ashraf; Koutsoukos, Xenofon; Biswas, Gautam

2015-08-20

The classical decentralized detection problem of finding the optimal decision rules at the sensor and fusion center, as well as variants that introduce physical channel impairments have been studied extensively in the literature. The deployment of WSNs in decentralized detection applications brings new challenges to the field. Protocols for different communication layers have to be co-designed to optimize the detection performance. In this paper, we consider the communication network design problem for a tree WSN. We pursue a system-level approach where a complete model for the system is developed that captures the interactions between different layers, as well as different sensor quality measures. For network optimization, we propose a hierarchical optimization algorithm that lends itself to the tree structure, requiring only local network information. The proposed design approach shows superior performance over several contentionless and contention-based network design approaches.

Layer-by-Layer Assembled Architecture of Polyelectrolyte Multilayers and Graphene Sheets on Hollow Carbon Spheres/Sulfur Composite for High-Performance Lithium-Sulfur Batteries.

PubMed

Wu, Feng; Li, Jian; Su, Yuefeng; Wang, Jing; Yang, Wen; Li, Ning; Chen, Lai; Chen, Shi; Chen, Renjie; Bao, Liying

2016-09-14

In the present work, polyelectrolyte multilayers (PEMs) and graphene sheets are applied to sequentially coat on the surface of hollow carbon spheres/sulfur composite by a flexible layer-by-layer (LBL) self-assembly strategy. Owing to the strong electrostatic interactions between the opposite charged materials, the coating agents are very stable and the coating procedure is highly efficient. The LBL film shows prominent impact on the stability of the cathode by acting as not only a basic physical barrier, and more importantly, an ion-permselective film to block the polysulfides anions by Coulombic repulsion. Furthermore, the graphene sheets can help to stabilize the polyelectrolytes film and greatly reduce the inner resistance of the electrode by changing the transport of the electrons from a "point-to-point" mode to a more effective "plane-to-point'' mode. On the basis of the synergistic effect of the PEMs and graphene sheets, the fabricated composite electrode exhibits very stable cycling stability for over 200 cycles at 1 A g(-1), along with a high average Coulombic efficiency of 99%. With the advantages of rapid and controllable fabrication of the LBL coating film, the multifunctional architecture developed in this study should inspire the design of other lithium-sulfur cathodes with unique physical and chemical properties.

Hybrid Organic/Inorganic Materials Depth Profiling Using Low Energy Cesium Ions

NASA Astrophysics Data System (ADS)

Noël, Céline; Houssiau, Laurent

2016-05-01

The structures developed in organic electronics, such as organic light emitting diodes (OLEDs) or organic photovoltaics (OPVs) devices always involve hybrid interfaces, joining metal or oxide layers with organic layers. No satisfactory method to probe these hybrid interfaces physical chemistry currently exists. One promising way to analyze such interfaces is to use in situ ion beam etching, but this requires ion beams able to depth profile both inorganic and organic layers. Mono- or diatomic ion beams commonly used to depth profile inorganic materials usually perform badly on organics, while cluster ion beams perform excellently on organics but yield poor results when organics and inorganics are mixed. Conversely, low energy Cs+ beams (<500 eV) allow organic and inorganic materials depth profiling with comparable erosion rates. This paper shows a successful depth profiling of a model hybrid system made of metallic (Au, Cr) and organic (tyrosine) layers, sputtered with 500 eV Cs+ ions. Tyrosine layers capped with metallic overlayers are depth profiled easily, with high intensities for the characteristic molecular ions and other specific fragments. Metallic Au or Cr atoms are recoiled into the organic layer where they cause some damage near the hybrid interface as well as changes in the erosion rate. However, these recoil implanted metallic atoms do not appear to severely degrade the depth profile overall quality. This first successful hybrid depth profiling report opens new possibilities for the study of OLEDs, organic solar cells, or other hybrid devices.

The effects of temperature on service employees' customer orientation: an experimental approach.

PubMed

Kolb, Peter; Gockel, Christine; Werth, Lioba

2012-01-01

Numerous studies have demonstrated how temperature can affect perceptual, cognitive and psychomotor performance (e.g. Hancock, P.A., Ross, J., and Szalma, J., 2007. A meta-analysis of performance response under thermal stressors. Human Factors: The Journal of the Human Factors and Ergonomics Society, 49 (5), 851-877). We extend this research to interpersonal aspects of performance, namely service employees' and salespeople's customer orientation. We combine ergonomics with recent research on social cognition linking physical with interpersonal warmth/coldness. In Experiment 1, a scenario study in the lab, we demonstrate that student participants in rooms with a low temperature showed more customer-oriented behaviour and gave higher customer discounts than participants in rooms with a high temperature - even in zones of thermal comfort. In Experiment 2, we show the existence of alternative possibilities to evoke positive temperature effects on customer orientation in a sample of 126 service and sales employees using a semantic priming procedure. Overall, our results confirm the existence of temperature effects on customer orientation. Furthermore, important implications for services, retail and other settings of interpersonal interactions are discussed. Practitioner Summary: Temperature effects on performance have emerged as a vital research topic. Owing to services' increasing economic importance, we transferred this research to the construct of customer orientation, focusing on performance in service and retail settings. The demonstrated temperature effects are transferable to services, retail and other settings of interpersonal interactions.

Protective coatings for sensitive materials

DOEpatents

Egert, Charles M.

1997-01-01

An enhanced protective coating to prevent interaction between constituents of the environment and devices that can be damaged by those constituents. This coating is provided by applying a synergistic combination of diffusion barrier and physical barrier materials. These materials can be, for example, in the form of a plurality of layers of a diffusion barrier and a physical barrier, with these barrier layers being alternated. Further protection in certain instances is provided by including at least one layer of a getter material to actually react with one or more of the deleterious constituents. The coating is illustrated by using alternating layers of an organic coating (such as Parylene-C.TM.) as the diffusion barrier, and a metal coating (such as aluminum) as the physical barrier. For best results there needs to be more than one of at least one of the constituent layers.

The layered sensing operations center: a modeling and simulation approach to developing complex ISR networks

NASA Astrophysics Data System (ADS)

Curtis, Christopher; Lenzo, Matthew; McClure, Matthew; Preiss, Bruce

2010-04-01

In order to anticipate the constantly changing landscape of global warfare, the United States Air Force must acquire new capabilities in the field of Intelligence, Surveillance, and Reconnaissance (ISR). To meet this challenge, the Air Force Research Laboratory (AFRL) is developing a unifying construct of "Layered Sensing" which will provide military decision-makers at all levels with the timely, actionable, and trusted information necessary for complete battlespace awareness. Layered Sensing is characterized by the appropriate combination of sensors and platforms (including those for persistent sensing), infrastructure, and exploitation capabilities to enable this synergistic awareness. To achieve the Layered Sensing vision, AFRL is pursuing a Modeling & Simulation (M&S) strategy through the Layered Sensing Operations Center (LSOC). An experimental ISR system-of-systems test-bed, the LSOC integrates DoD standard simulation tools with commercial, off-the-shelf video game technology for rapid scenario development and visualization. These tools will help facilitate sensor management performance characterization, system development, and operator behavioral analysis. Flexible and cost-effective, the LSOC will implement a non-proprietary, open-architecture framework with well-defined interfaces. This framework will incentivize the transition of current ISR performance models to service-oriented software design for maximum re-use and consistency. This paper will present the LSOC's development and implementation thus far as well as a summary of lessons learned and future plans for the LSOC.

42 CFR 485.713 - Condition of participation: Physical therapy services.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 5 2011-10-01 2011-10-01 false Condition of participation: Physical therapy... Agencies as Providers of Outpatient Physical Therapy and Speech-Language Pathology Services § 485.713 Condition of participation: Physical therapy services. If the organization offers physical therapy services...

42 CFR 485.713 - Condition of participation: Physical therapy services.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 42 Public Health 5 2012-10-01 2012-10-01 false Condition of participation: Physical therapy... Agencies as Providers of Outpatient Physical Therapy and Speech-Language Pathology Services § 485.713 Condition of participation: Physical therapy services. If the organization offers physical therapy services...

"Self-Peel-Off" Transfer Produces Ultrathin Polyvinylidene-Fluoride-Based Flexible Nanodevices.

PubMed

Tai, Yanlong; Lubineau, Gilles

2017-04-01

Here, a new strategy, self-peel-off transfer, for the preparation of ultrathin flexible nanodevices made from polyvinylidene-fluoride (PVDF) is reported. In this process, a functional pattern of nanoparticles is transferred via peeling from a temporary substrate to the final PVDF film. This peeling process takes advantage of the differences in the work of adhesion between the various layers (the PVDF layer, the nanoparticle-pattern layer and the substrate layer) and of the high stresses generated by the differential thermal expansion of the layers. The work of adhesion is mainly guided by the basic physical/chemical properties of these layers and is highly sensitive to variations in temperature and moisture in the environment. The peeling technique is tested on a variety of PVDF-based functional films using gold/palladium nanoparticles, carbon nanotubes, graphene oxide, and lithium iron phosphate. Several PVDF-based flexible nanodevices are prepared, including a single-sided wireless flexible humidity sensor in which PVDF is used as the substrate and a double-sided flexible capacitor in which PVDF is used as the ferroelectric layer and the carrier layer. Results show that the nanodevices perform with high repeatability and stability. Self-peel-off transfer is a viable preparation strategy for the design and fabrication of flexible, ultrathin, and light-weight nanodevices.

Layered materials

NASA Astrophysics Data System (ADS)

Johnson, David; Clarke, Simon; Wiley, John; Koumoto, Kunihito

2014-06-01

Layered compounds, materials with a large anisotropy to their bonding, electrical and/or magnetic properties, have been important in the development of solid state chemistry, physics and engineering applications. Layered materials were the initial test bed where chemists developed intercalation chemistry that evolved into the field of topochemical reactions where researchers are able to perform sequential steps to arrive at kinetically stable products that cannot be directly prepared by other approaches. Physicists have used layered compounds to discover and understand novel phenomena made more apparent through reduced dimensionality. The discovery of charge and spin density waves and more recently the remarkable discovery in condensed matter physics of the two-dimensional topological insulating state were discovered in two-dimensional materials. The understanding developed in two-dimensional materials enabled subsequent extension of these and other phenomena into three-dimensional materials. Layered compounds have also been used in many technologies as engineers and scientists used their unique properties to solve challenging technical problems (low temperature ion conduction for batteries, easy shear planes for lubrication in vacuum, edge decorated catalyst sites for catalytic removal of sulfur from oil, etc). The articles that are published in this issue provide an excellent overview of the spectrum of activities that are being pursued, as well as an introduction to some of the most established achievements in the field. Clusters of papers discussing thermoelectric properties, electronic structure and transport properties, growth of single two-dimensional layers, intercalation and more extensive topochemical reactions and the interleaving of two structures to form new materials highlight the breadth of current research in this area. These papers will hopefully serve as a useful guideline for the interested reader to different important aspects in this field and an overview of current areas of research interest.

Resource Sharing via Planed Relay for [InlineEquation not available: see fulltext.

NASA Astrophysics Data System (ADS)

Shen, Chong; Rea, Susan; Pesch, Dirk

2008-12-01

We present an improved version of adaptive distributed cross-layer routing algorithm (ADCR) for hybrid wireless network with dedicated relay stations ([InlineEquation not available: see fulltext.]) in this paper. A mobile terminal (MT) may borrow radio resources that are available thousands mile away via secure multihop RNs, where RNs are placed at pre-engineered locations in the network. In rural places such as mountain areas, an MT may also communicate with the core network, when intermediate MTs act as relay node with mobility. To address cross-layer network layers routing issues, the cascaded ADCR establishes routing paths across MTs, RNs, and cellular base stations (BSs) and provides appropriate quality of service (QoS). We verify the routing performance benefits of [InlineEquation not available: see fulltext.] over other networks by intensive simulation.

Wearable ECG Based on Impulse-Radio-Type Human Body Communication.

PubMed

Wang, Jianqing; Fujiwara, Takuya; Kato, Taku; Anzai, Daisuke

2016-09-01

Human body communication (HBC) provides a promising physical layer for wireless body area networks (BANs) in healthcare and medical applications, because of its low propagation loss and high security characteristics. In this study, we have developed a wearable electrocardiogram (ECG) which employs impulse radio (IR)-type HBC technology for transmitting vital signals on the human body in a wearable BAN scenario. The HBC-based wearable ECG has two excellent features. First, the wideband performance of the IR scheme contributed to very low radiation power so that the transceiver is easy to satisfy the extremely weak radio laws, which does not need a license. This feature can provide big convenience in the use and spread of the wearable ECG. Second, the realization of common use of sensing and transmitting electrodes based on time sharing and capacitive coupling largely simplified the HBC-based ECG structure and contributed to its miniaturization. To verify the validity of the HBC-based ECG, we evaluated its communication performance and ECG acquisition performance. The measured bit error rate, smaller than 10 -3 at 1.25 Mb/s, showed a good physical layer communication performance, and the acquired ECG waveform and various heart-rate variability parameters in time and frequency domains exhibited good agreement with a commercially available radio-frequency ECG and a Holter ECG. These results sufficiently showed the validity and feasibility of the HBC-based ECG for healthcare applications. This should be the first time to have realized a real-time ECG transmission by using the HBC technology.

Laboratory-based observations of capillary barriers and preferential flow in layered snow

NASA Astrophysics Data System (ADS)

Avanzi, F.; Hirashima, H.; Yamaguchi, S.; Katsushima, T.; De Michele, C.

2015-12-01

Several evidences are nowadays available that show how the effects of capillary gradients and preferential flow on water transmission in snow may play a more important role than expected. To observe these processes and to contribute in their characterization, we performed observations on the development of capillary barriers and preferential flow patterns in layered snow during cold laboratory experiments. We considered three different layering (all characterized by a finer-over-coarser texture in grain size) and three different water input rates. Nine samples of layered snow were sieved in a cold laboratory, and subjected to a constant supply of dyed tracer. By means of visual inspection, horizontal sectioning and liquid water content measurements, the processes of ponding and preferential flow were characterized as a function of texture and water input rate. The dynamics of each sample were replicated using the multi-layer physically-based SNOWPACK model. Results show that capillary barriers and preferential flow are relevant processes ruling the speed of liquid water in stratified snow. Ponding is associated with peaks in LWC at the boundary between the two layers equal to ~ 33-36 vol. % when the upper layer is composed by fine snow (grain size smaller than 0.5 mm). The thickness of the ponding layer at the textural boundary is between 0 and 3 cm, depending on sample stratigraphy. Heterogeneity in water transmission increases with grain size, while we do not observe any clear dependency on water input rate. The extensive comparison between observed and simulated LWC profiles by SNOWPACK (using an approximation of Richards Equation) shows high performances by the model in estimating the LWC peak over the boundary, while water speed in snow is underestimated by the chosen water transport scheme.

42 CFR 410.60 - Outpatient physical therapy services: Conditions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 42 Public Health 2 2012-10-01 2012-10-01 false Outpatient physical therapy services: Conditions... Services § 410.60 Outpatient physical therapy services: Conditions. (a) Basic rule. Except as specified in paragraph (a)(3)(iii) of this section, Medicare Part B pays for outpatient physical therapy services only if...

42 CFR 410.60 - Outpatient physical therapy services: Conditions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 42 Public Health 2 2013-10-01 2013-10-01 false Outpatient physical therapy services: Conditions... Services § 410.60 Outpatient physical therapy services: Conditions. (a) Basic rule. Except as specified in paragraph (a)(3)(iii) of this section, Medicare Part B pays for outpatient physical therapy services only if...

42 CFR 410.60 - Outpatient physical therapy services: Conditions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 2 2011-10-01 2011-10-01 false Outpatient physical therapy services: Conditions... Services § 410.60 Outpatient physical therapy services: Conditions. (a) Basic rule. Except as specified in paragraph (a)(3)(iii) of this section, Medicare Part B pays for outpatient physical therapy services only if...

42 CFR 410.60 - Outpatient physical therapy services: Conditions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 2 2010-10-01 2010-10-01 false Outpatient physical therapy services: Conditions... Services § 410.60 Outpatient physical therapy services: Conditions. (a) Basic rule. Except as specified in paragraph (a)(3)(iii) of this section, Medicare Part B pays for outpatient physical therapy services only if...

42 CFR 410.60 - Outpatient physical therapy services: Conditions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 42 Public Health 2 2014-10-01 2014-10-01 false Outpatient physical therapy services: Conditions... Services § 410.60 Outpatient physical therapy services: Conditions. (a) Basic rule. Except as specified in paragraph (a)(3)(iii) of this section, Medicare Part B pays for outpatient physical therapy services only if...

11 CFR 6.103 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... learning disabilities. The term physical or mental impairment includes, but is not limited to, such... one's self, performing manual tasks, walking, seeing, hearing, speaking, breathing, learning, and... Stat. 1617), and the Rehabilitation, Comprehensive Services, and Developmental Disabilities Act of 1978...

A pragmatic randomised controlled trial of an implementation intervention to increase healthy eating and physical activity-promoting policies, and practices in centre-based childcare services: study protocol.

PubMed

Finch, Meghan; Yoong, Sze Lin; Thomson, Rebecca J; Seward, Kirsty; Cooney, Mairead; Jones, Jannah; Fielding, Alison; Wiggers, John; Gillham, Karen; Wolfenden, Luke

2015-05-21

Promotion of healthy eating and physical activity in early childhood is recommended as a global chronic disease prevention strategy. Centre-based childcare services represent a promising setting to provide children with opportunities to improve healthy eating and physical activity. Evidence to inform implementation of childcare obesity prevention guidelines into routine practice in childcare, however, is lacking. This study aims to assess the effectiveness of an intervention, delivered to childcare staff, aiming to increasing service implementation of healthy eating and physical activity-promoting policies and practices. A pragmatic parallel group randomised controlled trial will be undertaken with 165 childcare services in the Hunter New England region of New South Wales, Australia. Services will be randomised to receive either a 10-month evidence-based performance review intervention with other resources to support practice change, or to a waitlist control group. The primary trial outcome is the proportion of services implementing all of the following recommended healthy eating and physical activity promoting practices: written nutrition, physical activity and small screen recreation policies; providing information to families regarding healthy eating (including breastfeeding), physical activity and small screen time; providing twice weekly healthy eating learning experiences to children; providing water and only plain milk to children; providing fundamental movement skills activities for children every day; and limiting and using electronic screen time more for educational purposes and learning experiences. Effectiveness will be assessed using a telephone interview of practice implementation with childcare staff at baseline and 12 months following baseline. The study was approved by the Hunter New England Human Research Ethics Committee and the University of Newcastle Human Research Ethics Committee. Study findings will be disseminated widely through peer-reviewed publications and conference presentations. Australian New Zealand Clinical Trials Registry ACTRN12614000972628. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Toward Transparent Data Management in Multi-layer Storage Hierarchy for HPC Systems

DOE PAGES

Wadhwa, Bharti; Byna, Suren; Butt, Ali R.

2018-04-17

Upcoming exascale high performance computing (HPC) systems are expected to comprise multi-tier storage hierarchy, and thus will necessitate innovative storage and I/O mechanisms. Traditional disk and block-based interfaces and file systems face severe challenges in utilizing capabilities of storage hierarchies due to the lack of hierarchy support and semantic interfaces. Object-based and semantically-rich data abstractions for scientific data management on large scale systems offer a sustainable solution to these challenges. Such data abstractions can also simplify users involvement in data movement. Here, we take the first steps of realizing such an object abstraction and explore storage mechanisms for these objectsmore » to enhance I/O performance, especially for scientific applications. We explore how an object-based interface can facilitate next generation scalable computing systems by presenting the mapping of data I/O from two real world HPC scientific use cases: a plasma physics simulation code (VPIC) and a cosmology simulation code (HACC). Our storage model stores data objects in different physical organizations to support data movement across layers of memory/storage hierarchy. Our implementation sclaes well to 16K parallel processes, and compared to the state of the art, such as MPI-IO and HDF5, our object-based data abstractions and data placement strategy in multi-level storage hierarchy achieves up to 7 X I/O performance improvement for scientific data.« less

The Impact of Microphysics on Intensity and Structure of Hurricanes

NASA Technical Reports Server (NTRS)

Tao, Wei-Kuo; Shi, Jainn; Lang, Steve; Peters-Lidard, Christa

2006-01-01

During the past decade, both research and operational numerical weather prediction models, e.g. Weather Research and Forecast (WRF) model, have started using more complex microphysical schemes originally developed for high-resolution cloud resolving models (CRMs) with a 1-2 km or less horizontal resolutions. WFW is a next-generation mesoscale forecast model and assimilation system that has incorporated modern software framework, advanced dynamics, numeric and data assimilation techniques, a multiple moveable nesting capability, and improved physical packages. WFW model can be used for a wide range of applications, from idealized research to operational forecasting, with an emphasis on horizontal grid sizes in the range of 1-10 km. The current WRF includes several different microphysics options such as Lin et al. (1983), WSM 6-class and Thompson microphysics schemes. We have recently implemented three sophisticated cloud microphysics schemes into WRF. The cloud microphysics schemes have been extensively tested and applied for different mesoscale systems in different geographical locations. The performances of these schemes have been compared to those from other WRF microphysics options. We are performing sensitivity tests in using WW to examine the impact of six different cloud microphysical schemes on hurricane track, intensity and rainfall forecast. We are also performing the inline tracer calculation to comprehend the physical processes @e., boundary layer and each quadrant in the boundary layer) related to the development and structure of hurricanes.

Investigation on iterative multiuser detection physical layer network coding in two-way relay free-space optical links with turbulences and pointing errors.

PubMed

Abu-Almaalie, Zina; Ghassemlooy, Zabih; Bhatnagar, Manav R; Le-Minh, Hoa; Aslam, Nauman; Liaw, Shien-Kuei; Lee, It Ee

2016-11-20

Physical layer network coding (PNC) improves the throughput in wireless networks by enabling two nodes to exchange information using a minimum number of time slots. The PNC technique is proposed for two-way relay channel free space optical (TWR-FSO) communications with the aim of maximizing the utilization of network resources. The multipair TWR-FSO is considered in this paper, where a single antenna on each pair seeks to communicate via a common receiver aperture at the relay. Therefore, chip interleaving is adopted as a technique to separate the different transmitted signals at the relay node to perform PNC mapping. Accordingly, this scheme relies on the iterative multiuser technique for detection of users at the receiver. The bit error rate (BER) performance of the proposed system is examined under the combined influences of atmospheric loss, turbulence-induced channel fading, and pointing errors (PEs). By adopting the joint PNC mapping with interleaving and multiuser detection techniques, the BER results show that the proposed scheme can achieve a significant performance improvement against the degrading effects of turbulences and PEs. It is also demonstrated that a larger number of simultaneous users can be supported with this new scheme in establishing a communication link between multiple pairs of nodes in two time slots, thereby improving the channel capacity.

Toward Transparent Data Management in Multi-layer Storage Hierarchy for HPC Systems

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

Wadhwa, Bharti; Byna, Suren; Butt, Ali R.

Upcoming exascale high performance computing (HPC) systems are expected to comprise multi-tier storage hierarchy, and thus will necessitate innovative storage and I/O mechanisms. Traditional disk and block-based interfaces and file systems face severe challenges in utilizing capabilities of storage hierarchies due to the lack of hierarchy support and semantic interfaces. Object-based and semantically-rich data abstractions for scientific data management on large scale systems offer a sustainable solution to these challenges. Such data abstractions can also simplify users involvement in data movement. Here, we take the first steps of realizing such an object abstraction and explore storage mechanisms for these objectsmore » to enhance I/O performance, especially for scientific applications. We explore how an object-based interface can facilitate next generation scalable computing systems by presenting the mapping of data I/O from two real world HPC scientific use cases: a plasma physics simulation code (VPIC) and a cosmology simulation code (HACC). Our storage model stores data objects in different physical organizations to support data movement across layers of memory/storage hierarchy. Our implementation sclaes well to 16K parallel processes, and compared to the state of the art, such as MPI-IO and HDF5, our object-based data abstractions and data placement strategy in multi-level storage hierarchy achieves up to 7 X I/O performance improvement for scientific data.« less

Factors Associated With Civilian Employment, Work Satisfaction, and Performance Among National Guard Members.

PubMed

Nelson, C Beau; Zivin, Kara; Walters, Heather; Ganoczy, Dara; MacDermid Wadsworth, Shelley; Valenstein, Marcia

2015-12-01

Employment is a vital part of the postdeployment return to civilian life. This study investigated factors associated with employment-related outcomes (employment status, self-reported work performance, and self-reported work satisfaction) among National Guard members returning from Operation Enduring Freedom, Operation Iraqi Freedom, or Operation New Dawn deployments. The sample consisted of 1,151 National Guard service members who had returned from overseas deployments approximately six months earlier. Bivariate and multivariable analyses were performed to examine associations between predictors and employment-related outcome variables. Higher-risk alcohol use was associated with reduced odds of being employed as well as with lower ratings of work satisfaction, whereas psychiatric symptom load was associated with lower self-reported work performance and work satisfaction ratings. Perceived social resources were associated with higher self-reported work performance and work satisfaction, whereas better physical functioning was associated with better self-reported work performance. Policy makers and clinicians may need to consider and assess alcohol use among unemployed National Guard members. They may also need to consider psychiatric symptom load and physical functioning among employed service members who perceive poor work performance and have low work satisfaction. Further research is needed on causal links between these predictors and employment outcomes.

Circularly polarized Raman study on diamond structure crystals

NASA Astrophysics Data System (ADS)

Lee, Je-Ho; Kim, Sera; Seong, Maeng-Je

2018-01-01

Circularly polarized Raman and/or photoluminescence (PL) analyses have recently been very important in studying physical properties of many layered materials that were either mechanically exfoliated or grown by chemical-vapor-deposition (CVD) on silicon substrates. Since silicon Raman signal is always accompanied by the circularly polarized Raman and/or PL signal from the layered materials, observation of proper circularly polarized Raman selection rules on silicon substrates would be extremely good indicator that the circularly polarized Raman and/or PL measurements on the layered materials were done properly. We have performed circularly polarized Raman measurements on silicon substrates and compared the results with the Raman intensities calculated by using Raman tensors of the diamond crystal structure. Our experimental results were in excellent agreement with the calculation. Similar circularly polarized Raman analysis done on germanium substrate also showed good agreement.

Novel graphene-oxide-coated SPR interfaces for biosensing applications

NASA Astrophysics Data System (ADS)

Volkov, V. S.; Stebunov, Yu. V.; Yakubovsky, D. I.; Fedyanin, D. Yu.; Arsenin, A. V.

2017-09-01

Carbon allotropes-based nanomaterials possess unique physical and chemical properties including high surface area, the possibility of pi-stacking interaction with a wide range of biological objects, rich availability of oxygen-containing functional groups in graphene-oxide (GO), and excellent optical properties, which make them an ideal candidate for use as a universal immobilization platform in SPR biosensing. Here, we propose a new surface plasmon resonance (SPR) biosensing interface for sensitive and selective detection of small molecules. This interface is based on the GO linking layers deposited on the gold/copper surface of SPR sensor chips. To estimate the binding capacity of GO layers, modification of carboxyl groups to N-Hydroxysuccinimide esters was performed in the flow cell of SPR instrument. For comparison, the same procedure was applied to commercial sensor chips based on linking layers of carboxymethylated dextran.

Implementation of a Cross-Layer Sensing Medium-Access Control Scheme.

PubMed

Su, Yishan; Fu, Xiaomei; Han, Guangyao; Xu, Naishen; Jin, Zhigang

2017-04-10

In this paper, compressed sensing (CS) theory is utilized in a medium-access control (MAC) scheme for wireless sensor networks (WSNs). We propose a new, cross-layer compressed sensing medium-access control (CL CS-MAC) scheme, combining the physical layer and data link layer, where the wireless transmission in physical layer is considered as a compress process of requested packets in a data link layer according to compressed sensing (CS) theory. We first introduced using compressive complex requests to identify the exact active sensor nodes, which makes the scheme more efficient. Moreover, because the reconstruction process is executed in a complex field of a physical layer, where no bit and frame synchronizations are needed, the asynchronous and random requests scheme can be implemented without synchronization payload. We set up a testbed based on software-defined radio (SDR) to implement the proposed CL CS-MAC scheme practically and to demonstrate the validation. For large-scale WSNs, the simulation results show that the proposed CL CS-MAC scheme provides higher throughput and robustness than the carrier sense multiple access (CSMA) and compressed sensing medium-access control (CS-MAC) schemes.

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

PubMed

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

2016-10-01

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

Barriers to Translation of Physical Activity into the Lung Cancer Model of Care. A Qualitative Study of Clinicians' Perspectives.

PubMed

Granger, Catherine L; Denehy, Linda; Remedios, Louisa; Retica, Sarah; Phongpagdi, Pimsiri; Hart, Nicholas; Parry, Selina M

2016-12-01

Evidence-based clinical practice guidelines recommend physical activity for people with lung cancer, however evidence has not translated into clinical practice and the majority of patients do not meet recommended activity levels. To identify factors (barriers and enablers) that influence clinicians' translation of the physical activity guidelines into practice. Qualitative study involving 17 participants (three respiratory physicians, two thoracic surgeons, two oncologists, two nurses, and eight physical therapists) who were recruited using purposive sampling from five hospitals in Melbourne, Victoria, Australia. Nine semistructured interviews and a focus group were conducted, transcribed verbatim, and independently cross-checked by a second researcher. Thematic analysis was used to analyze data. Five consistent themes emerged: (1) the clinicians perception of patient-related physical and psychological influences (including symptoms and comorbidities) that impact on patient's ability to perform regular physical activity; (2) the influence of the patient's past physical activity behavior and their perceived relevance and knowledge about physical activity; (3) the clinicians own knowledge and beliefs about physical activity; (4) workplace culture supporting or hindering physical activity; and (5) environmental and structural influences in the healthcare system (included clinicians time, staffing, protocols and services). Clinicians described potential strategies, including: (1) the opportunity for nurse practitioners to act as champions of regular physical activity and triage referrals for physical activity services; (2) opportunistically using the time when patients are in hospital after surgery to discuss physical activity; and (3) for all members of the multidisciplinary team to provide consistent messages to patients about the importance of physical activity. Key barriers to implementation of the physical activity guidelines in lung cancer are diverse and include both clinician- and healthcare system-related factors. A combined approach to target a number of these factors should be used to inform research, improve clinical services, and develop policies aiming to increase physical activity and improve survivorship outcomes for patients with lung cancer.

Restoration of Worn Movable Bridge Props with Use of Bronze Claddings.

PubMed

Viňáš, Ján; Vrabeľ, Marek; Greš, Miroslav; Brezina, Jakub; Sabadka, Dušan; Fedorko, Gabriel; Molnár, Vieroslav

2018-03-21

This article examined the possibility of using CuSn6P claddings in sliding bearing renovation of movable pontoon bridge props. The bronze layer was welded on cylinders of the high-strength steel S355J0WP EN 10155-93, in an inert atmosphere using an automated welding method (gas tungsten arc welding). Pulsed arc welding was used to minimize the effects of heat on the cladding area, while also accounting for the differences in the physical properties of the joined metals. The sliding bearing was created in two layers. The quality of the cladding layer was evaluated by nondestructive and/or destructive tests. The quality of the surface was assessed by visual inspection (visual testing) in accordance with the EN ISO 17637 standard. The quality of the claddings was evaluated by metallographic analysis, performed using light microscopy. The microhardness values of a few weld areas were determined by Vickers tests, performed according to the EN ISO 9015-2 standard. The analyses confirmed that the welding parameters and filler material used resulted in high-quality weld joints with no internal (subsurface) or metallurgical defects.

Restoration of Worn Movable Bridge Props with Use of Bronze Claddings

PubMed Central

Viňáš, Ján; Vrabeľ, Marek; Greš, Miroslav; Brezina, Jakub; Sabadka, Dušan; Fedorko, Gabriel

2018-01-01

This article examined the possibility of using CuSn6P claddings in sliding bearing renovation of movable pontoon bridge props. The bronze layer was welded on cylinders of the high-strength steel S355J0WP EN 10155-93, in an inert atmosphere using an automated welding method (gas tungsten arc welding). Pulsed arc welding was used to minimize the effects of heat on the cladding area, while also accounting for the differences in the physical properties of the joined metals. The sliding bearing was created in two layers. The quality of the cladding layer was evaluated by nondestructive and/or destructive tests. The quality of the surface was assessed by visual inspection (visual testing) in accordance with the EN ISO 17637 standard. The quality of the claddings was evaluated by metallographic analysis, performed using light microscopy. The microhardness values of a few weld areas were determined by Vickers tests, performed according to the EN ISO 9015–2 standard. The analyses confirmed that the welding parameters and filler material used resulted in high-quality weld joints with no internal (subsurface) or metallurgical defects. PMID:29561762

Numerical modeling of time-lapse monitoring of CO2 sequestration in a layered basalt reservoir

USGS Publications Warehouse

Khatiwada, M.; Van Wijk, K.; Clement, W.P.; Haney, M.

2008-01-01

As part of preparations in plans by The Big Sky Carbon Sequestration Partnership (BSCSP) to inject CO2 in layered basalt, we numerically investigate seismic methods as a noninvasive monitoring technique. Basalt seems to have geochemical advantages as a reservoir for CO2 storage (CO2 mineralizes quite rapidly while exposed to basalt), but poses a considerable challenge in term of seismic monitoring: strong scattering from the layering of the basalt complicates surface seismic imaging. We perform numerical tests using the Spectral Element Method (SEM) to identify possibilities and limitations of seismic monitoring of CO2 sequestration in a basalt reservoir. While surface seismic is unlikely to detect small physical changes in the reservoir due to the injection of CO2, the results from Vertical Seismic Profiling (VSP) simulations are encouraging. As a perturbation, we make a 5%; change in wave velocity, which produces significant changes in VSP images of pre-injection and post-injection conditions. Finally, we perform an analysis using Coda Wave Interferometry (CWI), to quantify these changes in the reservoir properties due to CO2 injection.

ARINC 818 express for high-speed avionics video and power over coax

NASA Astrophysics Data System (ADS)

Keller, Tim; Alexander, Jon

2012-06-01

CoaXPress is a new standard for high-speed video over coax cabling developed for the machine vision industry. CoaXPress includes both a physical layer and a video protocol. The physical layer has desirable features for aerospace and defense applications: it allows 3Gbps (up to 6Gbps) communication, includes 21Mbps return path allowing for bidirectional communication, and provides up to 13W of power, all over a single coax connection. ARINC 818, titled "Avionics Digital Video Bus" is a protocol standard developed specifically for high speed, mission critical aerospace video systems. ARINC 818 is being widely adopted for new military and commercial display and sensor applications. The ARINC 818 protocol combined with the CoaXPress physical layer provide desirable characteristics for many aerospace systems. This paper presents the results of a technology demonstration program to marry the physical layer from CoaXPress with the ARINC 818 protocol. ARINC 818 is a protocol, not a physical layer. Typically, ARINC 818 is implemented over fiber or copper for speeds of 1 to 2Gbps, but beyond 2Gbps, it has been implemented exclusively over fiber optic links. In many rugged applications, a copper interface is still desired, by implementing ARINC 818 over the CoaXPress physical layer, it provides a path to 3 and 6 Gbps copper interfaces for ARINC 818. Results of the successful technology demonstration dubbed ARINC 818 Express are presented showing 3Gbps communication while powering a remote module over a single coax cable. The paper concludes with suggested next steps for bring this technology to production readiness.