WorldWideScience

Sample records for network performance characteristics

  1. A Hierarchy of Network Performance Characteristics for Grid Applications and Services

    Energy Technology Data Exchange (ETDEWEB)

    Lowekamp, B

    2004-07-06

    This document describes a standard set of network characteristics that are useful for Grid applications and services as well as a classification hierarchy for these characteristics. The goal of this work is to identify the various types of network measurements according to the network characteristic they measure and the network entity on which they are taken. This document defines standard terminology to describe those measurements, but it does not attempt to define new standard measurement methodologies or attempt to define the best measurement methodologies to use for grid applications. However, it does attempt to point out the advantages and disadvantages of different measurement methodologies. This document was motivated by the need for the interchange of measurements taken by various systems in the Grid and to develop a common dictionary to facilitate discussions about and specifications for measurement systems. The application of this naming system will facilitate the creation of common schemata for describing network monitoring data in Grid Monitoring and Discovery Services, and thus help to address portability issues between the wide variety of network measurements used between sites of a Grid.

  2. Network Characteristics of Successful Performance in Association Football. A Study on the UEFA Champions League

    Directory of Open Access Journals (Sweden)

    Tiago J. Pina

    2017-07-01

    Full Text Available The synergistic interaction between teammates in association football has properties that can be captured by Social Network Analysis (SNA. The analysis of networks formed by team players passing a ball in a match shows that team success is correlated with high network density and clustering coefficient, as well as with reduced network centralization. However, oversimplification needs to be avoided, as network metrics events associated with success should not be considered equally to those that are not. In the present study, we investigated whether network density, clustering coefficient and centralization can predict successful or unsuccessful team performance. We analyzed 12 games of the Group Stage of UEFA Champions League 2015/2016 Group C by using public records from TV broadcasts. Notational analyses were performed to categorize attacking sequences as successful or unsuccessful, and to collect data on the ball-passing networks. The network metrics were then computed. A hierarchical logistic-regression model was used to predict the successfulness of the offensive plays from network density, clustering coefficient and centralization, after controlling for the effect of total passes on successfulness of offensive plays. Results confirmed the independent effect of network metrics. Density, but not clustering coefficient or centralization, was a significant predictor of the successfulness of offensive plays. We found a negative relation between density and successfulness of offensive plays. However, reduced density was associated with a higher number of offensive plays, albeit mostly unsuccessful. Conversely, high density was associated with a lower number of successful offensive plays (SOPs, but also with overall fewer offensive plays and “ball possession losses” before the attacking team entered the finishing zone. Independent SNA of team performance is important to minimize the limitations of oversimplifying effective team synergies.

  3. Analyzing the impact of relay station characteristics on uplink performance in cellular network

    NARCIS (Netherlands)

    Dimitrova, D.C.; van den Berg, Hans Leo; Heijenk, Geert

    2009-01-01

    Uplink users in cellular networks, such as UMTS/ HSPA, located at the edge of the cell generally suffer from poor channel conditions. Deploying intermediate relay nodes is seen as a promising approach towards extending cell coverage. This paper focuses on the role of packet scheduling in cellular

  4. Characteristics of Effective Leadership Networks

    Science.gov (United States)

    Leithwood, Kenneth; Azah, Vera Ndifor

    2016-01-01

    Purpose: The purpose of this paper is to inquire about the characteristics of effective school leadership networks and the contribution of such networks to the development of individual leaders' professional capacities. Design/methodology/approach: The study used path-analytic techniques with survey data provided by 450 school and district leaders…

  5. Understand boiler performance characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Ganapathy, V. (ABCO Industries, Abilene, TX (United States))

    1994-08-01

    An understanding of the major differences in performance characteristics of steam generators is essential to better use and integrate them into plant steam systems. Process and cogeneration plants widely use gas- or oil-fired packaged steam generators and gas-turbine-exhaust, heat-recovery steam generators to meet steam demands. The most important differences are efficiency versus load characteristics, gas/steam temperature profiles and partial load behavior. Also, steaming in the economizer is a concern at low steam flows for HRSGs, but not for packaged boilers. The paper describes packaged boilers, how emissions impact design of packaged boilers, completely water-cooled furnace, superheater design, packaged boiler performance characteristics, heat-recovery steam generators, and basic differences between HRSGs and packaged boilers.

  6. Wireless networked music performance

    CERN Document Server

    Gabrielli, Leonardo

    2016-01-01

    This book presents a comprehensive overview of the state of the art in Networked Music Performance (NMP) and a historical survey of computer music networking. It introduces current technical trends in NMP and technical issues yet to be addressed. It also lists wireless communication protocols and compares these to the requirements of NMP. Practical use cases and advancements are also discussed.

  7. High-Performance Networking

    CERN Document Server

    CERN. Geneva

    2003-01-01

    The series will start with an historical introduction about what people saw as high performance message communication in their time and how that developed to the now to day known "standard computer network communication". It will be followed by a far more technical part that uses the High Performance Computer Network standards of the 90's, with 1 Gbit/sec systems as introduction for an in depth explanation of the three new 10 Gbit/s network and interconnect technology standards that exist already or emerge. If necessary for a good understanding some sidesteps will be included to explain important protocols as well as some necessary details of concerned Wide Area Network (WAN) standards details including some basics of wavelength multiplexing (DWDM). Some remarks will be made concerning the rapid expanding applications of networked storage.

  8. Network performance analysis

    CERN Document Server

    Bonald, Thomas

    2013-01-01

    The book presents some key mathematical tools for the performance analysis of communication networks and computer systems.Communication networks and computer systems have become extremely complex. The statistical resource sharing induced by the random behavior of users and the underlying protocols and algorithms may affect Quality of Service.This book introduces the main results of queuing theory that are useful for analyzing the performance of these systems. These mathematical tools are key to the development of robust dimensioning rules and engineering methods. A number of examples i

  9. Radial-Basis-Function-Network-Based Prediction of Performance and Emission Characteristics in a Bio Diesel Engine Run on WCO Ester

    Directory of Open Access Journals (Sweden)

    Shiva Kumar

    2012-01-01

    Full Text Available Radial basis function neural networks (RBFNNs, which is a relatively new class of neural networks, have been investigated for their applicability for prediction of performance and emission characteristics of a diesel engine fuelled with waste cooking oil (WCO. The RBF networks were trained using the experimental data, where in load percentage, compression ratio, blend percentage, injection timing, and injection pressure were taken as the input parameters, and brake thermal efficiency (BTE, brake specific energy consumption (BSEC, exhaust gas temperature (, and engine emissions were used as the output parameters. The number of RBF centers was selected randomly. The network was initially trained using variable width values for the RBF units using a heuristic and then was trained by using fixed width values. Studies showed that RBFNN predicted results matched well with the experimental results over a wide range of operating conditions. Prediction accuracy for all the output parameters was above 90% in case of performance parameters and above 70% in case of emission parameters.

  10. Experimental and artificial neural network based prediction of performance and emission characteristics of DI diesel engine using Calophyllum inophyllum methyl ester at different nozzle opening pressure

    Science.gov (United States)

    Vairamuthu, G.; Thangagiri, B.; Sundarapandian, S.

    2017-07-01

    The present work investigates the effect of varying Nozzle Opening Pressures (NOP) from 220 bar to 250 bar on performance, emissions and combustion characteristics of Calophyllum inophyllum Methyl Ester (CIME) in a constant speed, Direct Injection (DI) diesel engine using Artificial Neural Network (ANN) approach. An ANN model has been developed to predict a correlation between specific fuel consumption (SFC), brake thermal efficiency (BTE), exhaust gas temperature (EGT), Unburnt hydrocarbon (UBHC), CO, CO2, NOx and smoke density using load, blend (B0 and B100) and NOP as input data. A standard Back-Propagation Algorithm (BPA) for the engine is used in this model. A Multi Layer Perceptron network (MLP) is used for nonlinear mapping between the input and the output parameters. An ANN model can predict the performance of diesel engine and the exhaust emissions with correlation coefficient (R2) in the range of 0.98-1. Mean Relative Errors (MRE) values are in the range of 0.46-5.8%, while the Mean Square Errors (MSE) are found to be very low. It is evident that the ANN models are reliable tools for the prediction of DI diesel engine performance and emissions. The test results show that the optimum NOP is 250 bar with B100.

  11. Experimental and artificial neural network based prediction of performance and emission characteristics of DI diesel engine using Calophyllum inophyllum methyl ester at different nozzle opening pressure

    Science.gov (United States)

    Vairamuthu, G.; Thangagiri, B.; Sundarapandian, S.

    2018-01-01

    The present work investigates the effect of varying Nozzle Opening Pressures (NOP) from 220 bar to 250 bar on performance, emissions and combustion characteristics of Calophyllum inophyllum Methyl Ester (CIME) in a constant speed, Direct Injection (DI) diesel engine using Artificial Neural Network (ANN) approach. An ANN model has been developed to predict a correlation between specific fuel consumption (SFC), brake thermal efficiency (BTE), exhaust gas temperature (EGT), Unburnt hydrocarbon (UBHC), CO, CO2, NOx and smoke density using load, blend (B0 and B100) and NOP as input data. A standard Back-Propagation Algorithm (BPA) for the engine is used in this model. A Multi Layer Perceptron network (MLP) is used for nonlinear mapping between the input and the output parameters. An ANN model can predict the performance of diesel engine and the exhaust emissions with correlation coefficient (R2) in the range of 0.98-1. Mean Relative Errors (MRE) values are in the range of 0.46-5.8%, while the Mean Square Errors (MSE) are found to be very low. It is evident that the ANN models are reliable tools for the prediction of DI diesel engine performance and emissions. The test results show that the optimum NOP is 250 bar with B100.

  12. High Performance Network Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Jesse E [Los Alamos National Laboratory

    2012-08-10

    Network Monitoring requires a substantial use of data and error analysis to overcome issues with clusters. Zenoss and Splunk help to monitor system log messages that are reporting issues about the clusters to monitoring services. Infiniband infrastructure on a number of clusters upgraded to ibmon2. ibmon2 requires different filters to report errors to system administrators. Focus for this summer is to: (1) Implement ibmon2 filters on monitoring boxes to report system errors to system administrators using Zenoss and Splunk; (2) Modify and improve scripts for monitoring and administrative usage; (3) Learn more about networks including services and maintenance for high performance computing systems; and (4) Gain a life experience working with professionals under real world situations. Filters were created to account for clusters running ibmon2 v1.0.0-1 10 Filters currently implemented for ibmon2 using Python. Filters look for threshold of port counters. Over certain counts, filters report errors to on-call system administrators and modifies grid to show local host with issue.

  13. Performance Analysis of 3G Communication Network

    Directory of Open Access Journals (Sweden)

    Toni Anwar

    2013-09-01

    Full Text Available In this project, third generation (3G technologies research had been carried out to design and optimization conditions for 3G network. The 3G wireless mobile communication networks are growing at an ever faster rate, and this is likely to continue in the foreseeable future. Some services such as e-mail, web browsing etc allow the transition of the network from circuit switched to packet switched operation, resulting in increased overall network performance. Higher reliability, better coverage and services, higher capacity, mobility management, and wireless multimedia are all parts of the network performance. Throughput and spectral efficiency are fundamental parameters in capacity planning for 3G cellular network deployments. This project investigates also the downlink (DL and uplink (UL throughput and spectral efficiency performance of the standard Universal Mobile Telecommunications system (UMTS system for different scenarios of user and different technologies. Power consumption comparison for different mobile technology is also discussed. The analysis can significantly help system engineers to obtain crucial performance characteristics of 3G network. At the end of the paper, coverage area of 3G from one of the mobile network in Malaysia is presented.

  14. Performance of Networked Control Systems

    Directory of Open Access Journals (Sweden)

    Yingwei Zhang

    2013-01-01

    Full Text Available Data packet dropout is a special kind of time delay problem. In this paper, predictive controllers for networked control systems (NCSs with dual-network are designed by model predictive control method. The contributions are as follows. (1 The predictive control problem of the dual-network is considered. (2 The predictive performance of the dual-network is evaluated. (3 Compared to the popular networked control systems, the optimal controller of the new NCSs with data packets dropout is designed, which can minimize infinite performance index at each sampling time and guarantee the closed-loop system stability. Finally, the simulation results show the feasibility and effectiveness of the controllers designed.

  15. Characteristics of networks of interventions: a description of a database of 186 published networks.

    Directory of Open Access Journals (Sweden)

    Adriani Nikolakopoulou

    Full Text Available Systematic reviews that employ network meta-analysis are undertaken and published with increasing frequency while related statistical methodology is evolving. Future statistical developments and evaluation of the existing methodologies could be motivated by the characteristics of the networks of interventions published so far in order to tackle real rather than theoretical problems. Based on the recently formed network meta-analysis literature we aim to provide an insight into the characteristics of networks in healthcare research. We searched PubMed until end of 2012 for meta-analyses that used any form of indirect comparison. We collected data from networks that compared at least four treatments regarding their structural characteristics as well as characteristics of their analysis. We then conducted a descriptive analysis of the various network characteristics. We included 186 networks of which 35 (19% were star-shaped (treatments were compared to a common comparator but not between themselves. The median number of studies per network was 21 and the median number of treatments compared was 6. The majority (85% of the non-star shaped networks included at least one multi-arm study. Synthesis of data was primarily done via network meta-analysis fitted within a Bayesian framework (113 (61% networks. We were unable to identify the exact method used to perform indirect comparison in a sizeable number of networks (18 (9%. In 32% of the networks the investigators employed appropriate statistical methods to evaluate the consistency assumption; this percentage is larger among recently published articles. Our descriptive analysis provides useful information about the characteristics of networks of interventions published the last 16 years and the methods for their analysis. Although the validity of network meta-analysis results highly depends on some basic assumptions, most authors did not report and evaluate them adequately. Reviewers and editors need

  16. Complexity Characteristics of Currency Networks

    Science.gov (United States)

    Gorski, A. Z.; Drozdz, S.; Kwapien, J.; Oswiecimka, P.

    2006-11-01

    A large set of daily FOREX time series is analyzed. The corresponding correlation matrices (CM) are constructed for USD, EUR and PLN used as the base currencies. The triangle rule is interpreted as constraints reducing the number of independent returns. The CM spectrum is computed and compared with the cases of shuffled currencies and a fictitious random currency taken as a base currency. The Minimal Spanning Tree (MST) graphs are calculated and the clustering effects for strong currencies are found. It is shown that for MSTs the node rank has power like, scale free behavior. Finally, the scaling exponents are evaluated and found in the range analogous to those identified recently for various complex networks.

  17. Social Networks and Sales Performance

    Directory of Open Access Journals (Sweden)

    Danny Pimentel Claro

    2011-05-01

    Full Text Available This paper argues that an informal network can itself be a basis for the increase in a sales manager’s performance. Informal networks create a structure that surpasses the formal hierarchical structure defined by the firm. We concentrated on the advice network and considered two different views of network structure that claim to have impact on performance. To explore this claim, we examined whether sales managers develop either a highly cohesive network structure (i.e. Coleman’s view or one containing structural holes (i.e. Burt’s view in order to achieve higher sales. We also investigated the matter of tie strength put forward by Granovetter in his seminal 1973 work. Census data was collected from about 500 personnel from an agricultural input retailer having 23 divisions. Estimates from a sample of 101 sales managers showed the importance of a highly cohesive structure (degree centrality for the three measures of sales manager’s performance. The strong ties have a positive impact on performance, suggesting the importance of building up strong bonds with network contacts. Sales managers’ age, time within the retailer and education also influence performance. These results imply that firms should stimulate contacts among personnel to spread technical and commercial information.

  18. Developing countries SMEs innovation characteristics and performance

    DEFF Research Database (Denmark)

    Rezaei, Shahamak; Brambini-Pedersen, Jan Vang; Baklanov, Nikita

    An econometric study analysing developing countries’ SMEs innovation characteristics and their correlation with performance.......An econometric study analysing developing countries’ SMEs innovation characteristics and their correlation with performance....

  19. Adaptive NetworkProfiler for Identifying Cancer Characteristic-Specific Gene Regulatory Networks.

    Science.gov (United States)

    Park, Heewon; Shimamura, Teppei; Imoto, Seiya; Miyano, Satoru

    2017-10-20

    There is currently much discussion about sample (patient)-specific gene regulatory network identification, since the efficiently constructed sample-specific gene networks lead to effective personalized cancer therapy. Although statistical approaches have been proposed for inferring gene regulatory networks, the methods cannot reveal sample-specific characteristics because the existing methods, such as an L1-type regularization, provide averaged results for all samples. Thus, we cannot reveal sample-specific characteristics in transcriptional regulatory networks. To settle on this issue, the NetworkProfiler was proposed based on the kernel-based L1-type regularization. The NetworkProfiler imposes a weight on each sample based on the Gaussian kernal function for controlling effect of samples on modeling a target sample, where the amount of weight depends on similarity of cancer characteristics between samples. The method, however, cannot perform gene regulatory network identification well for a target sample in a sparse region (i.e., for a target sample, there are only a few samples having a similar characteristic of the target sample, where the characteristic is considered as a modulator in sample-specific gene network construction), since a constant bandwidth in the Gaussian kernel function cannot effectively group samples for modeling a target sample in sparse region. The cancer characteristics, such as an anti-cancer drug sensitivity, are usually nonuniformly distributed, and thus modeling for samples in a sparse region is also a crucial issue. We propose a novel kernel-based L1-type regularization method based on a modified k-nearest neighbor (KNN)-Gaussian kernel function, called an adaptive NetworkProfiler. By using the modified KNN-Gaussian kernel function, our method provides robust results against the distribution of modulators, and properly groups samples according to a cancer characteristic for sample-specific analysis. Furthermore, we propose a sample

  20. Organizing NPD networks for high innovation performance: the case of Dutch medical devices SMEs

    NARCIS (Netherlands)

    Pullen, A.J.J.; Groen, Arend J.; de Weerd-Nederhof, Petronella C.; Fisscher, O.A.M.

    2010-01-01

    This research examines which combination of network characteristics (the network configuration) leads to high innovation performance for small and medium sized companies (SMEs). Even though research has paid significant attention to the relation between the external network and the innovation

  1. Network characteristics and open innovation in SMEs

    DEFF Research Database (Denmark)

    Pedersen, Maja; Søndergaard, Helle Alsted; Esbjerg, Lars

    The open innovation literature has primarily been concentrating on open innovation (OI) in large companies. Hence it is very unclear whether these findings can be generalized to small and medium-sized enterprises (SMEs). This paper begins filling in this knowledge gap. In doing so, we focus...... explicitly on understanding network characteristics and the unfolding of OI in SMEs. Case studies were used and empirical data was mainly generated through semi-structured interviews. Cases selected for study were companies in the Danish food industry with less than 499 employees. In this paper we report our...

  2. The Homogeneity Research of Urban Rail Transit Network Performance

    Directory of Open Access Journals (Sweden)

    Wang Fu-jian

    2016-01-01

    Full Text Available Urban Rail Transit is an important part of the public transit, it is necessary to carry out the corresponding network function analysis. Previous studies mainly about network performance analysis of a single city rail transit, lacking of horizontal comparison between the multi-city, it is difficult to find inner unity of different Urban Rail Transit network functions. Taking into account the Urban Rail Transit network is a typical complex networks, so this paper proposes the application of complex network theory to research the homogeneity of Urban Rail Transit network performance. This paper selects rail networks of Beijing, Shanghai, Guangzhou as calculation case, gave them a complex network mapping through the L, P Space method and had a static topological analysis using complex network theory, Network characteristics in three cities were calculated and analyzed form node degree distribution and node connection preference. Finally, this paper studied the network efficiency changes of Urban Rail Transit system under different attack mode. The results showed that, although rail transport network size, model construction and construction planning of the three cities are different, but their network performance in many aspects showed high homogeneity.

  3. Performance Modeling for Heterogeneous Wireless Networks with Multiservice Overflow Traffic

    DEFF Research Database (Denmark)

    Huang, Qian; Ko, King-Tim; Iversen, Villy Bæk

    2009-01-01

    Performance modeling is important for the purpose of developing efficient dimensioning tools for large complicated networks. But it is difficult to achieve in heterogeneous wireless networks, where different networks have different statistical characteristics in service and traffic models....... Multiservice loss analysis based on multi-dimensional Markov chain becomes intractable in these networks due to intensive computations required. This paper focuses on performance modeling for heterogeneous wireless networks based on a hierarchical overlay infrastructure. A method based on decomposition...... of the correlated traffic is used to achieve an approximate performance modeling for multiservice in hierarchical heterogeneous wireless networks with overflow traffic. The accuracy of the approximate performance obtained by our proposed modeling is verified by simulations....

  4. Generalization performance of regularized neural network models

    DEFF Research Database (Denmark)

    Larsen, Jan; Hansen, Lars Kai

    1994-01-01

    Architecture optimization is a fundamental problem of neural network modeling. The optimal architecture is defined as the one which minimizes the generalization error. This paper addresses estimation of the generalization performance of regularized, complete neural network models. Regularization...

  5. Network Performance Improvement under Epidemic Failures in Optical Transport Networks

    DEFF Research Database (Denmark)

    Fagertun, Anna Manolova; Ruepp, Sarah Renée

    2013-01-01

    In this paper we investigate epidemic failure spreading in large- scale GMPLS-controlled transport networks. By evaluating the effect of the epidemic failure spreading on the network, we design several strategies for cost-effective network performance improvement via differentiated repair times....... First we identify the most vulnerable and the most strategic nodes in the network. Then, via extensive simulations we show that strategic placement of resources for improved failure recovery has better performance than randomly assigning lower repair times among the network nodes. Our OPNET simulation...

  6. Network Detection Theory and Performance

    OpenAIRE

    Smith, Steven T.; Senne, Kenneth D.; Philips, Scott; Kao, Edward K.; Bernstein, Garrett

    2013-01-01

    Network detection is an important capability in many areas of applied research in which data can be represented as a graph of entities and relationships. Oftentimes the object of interest is a relatively small subgraph in an enormous, potentially uninteresting background. This aspect characterizes network detection as a "big data" problem. Graph partitioning and network discovery have been major research areas over the last ten years, driven by interest in internet search, cyber security, soc...

  7. Performance modeling of network data services

    Energy Technology Data Exchange (ETDEWEB)

    Haynes, R.A.; Pierson, L.G.

    1997-01-01

    Networks at major computational organizations are becoming increasingly complex. The introduction of large massively parallel computers and supercomputers with gigabyte memories are requiring greater and greater bandwidth for network data transfers to widely dispersed clients. For networks to provide adequate data transfer services to high performance computers and remote users connected to them, the networking components must be optimized from a combination of internal and external performance criteria. This paper describes research done at Sandia National Laboratories to model network data services and to visualize the flow of data from source to sink when using the data services.

  8. Relations between mental health team characteristics and work role performance.

    Science.gov (United States)

    Fleury, Marie-Josée; Grenier, Guy; Bamvita, Jean-Marie; Farand, Lambert

    2017-01-01

    Effective mental health care requires a high performing, interprofessional team. Among 79 mental health teams in Quebec (Canada), this exploratory study aims to 1) determine the association between work role performance and a wide range of variables related to team effectiveness according to the literature, and to 2) using structural equation modelling, assess the covariance between each of these variables as well as the correlation with other exogenous variables. Work role performance was measured with an adapted version of a work role questionnaire. Various independent variables including team manager characteristics, user characteristics, team profiles, clinical activities, organizational culture, network integration strategies and frequency/satisfaction of interactions with other teams or services were analyzed under the structural equation model. The later provided a good fit with the data. Frequent use of standardized procedures and evaluation tools (e.g. screening and assessment tools for mental health disorders) and team manager seniority exerted the most direct effect on work role performance. While network integration strategies had little effect on work role performance, there was a high covariance between this variable and those directly affecting work role performance among mental health teams. The results suggest that the mental healthcare system should apply standardized procedures and evaluation tools and, to a lesser extent, clinical approaches to improve work role performance in mental health teams. Overall, a more systematic implementation of network integration strategies may contribute to improved work role performance in mental health care.

  9. Social Networking and Academic Performance: A Review

    Science.gov (United States)

    Doleck, Tenzin; Lajoie, Susanne

    2018-01-01

    The ubiquitous use of social networking sites by students and the potential impacts of such use on academic performance are of both theoretical and practical importance. Hence, this paper addresses the question: how does the use of social networking sites influence academic performance? The present review synthesizes the empirical findings of the…

  10. Performance Evaluation of Coded Meshed Networks

    DEFF Research Database (Denmark)

    Krigslund, Jeppe; Hansen, Jonas; Pedersen, Morten Videbæk

    2013-01-01

    We characterize the performance of intra- and inter-session network coding (NC) in wireless networks using real-life implementations. We compare this performance to a recently developed hybrid approach, called CORE, which combines intra- and inter-session NC exploiting the code structure...

  11. Performance enhancement of OSPF protocol in the private network

    Science.gov (United States)

    Yang, Yang; Lu, Yang; Lin, Xiaokang

    2005-11-01

    The private network serves as an information exchange platform to support the integrated services via microwave channels and accordingly selects the open shortest path first (OSPF) as the IP routing protocol. But the existing OSPF can't fit the private network very well for its special characteristics. This paper presents our modifications to the standard protocol in such aspects as the single-area scheme, link state advertisement (LSA) types and formats, OSPF packet formats, important state machines, setting of protocol parameters and link flap damping. Finally simulations are performed in various scenarios and the results indicate that our modifications can enhance the OSPF performance in the private network effectively.

  12. How Friendship Network Characteristics Influence Subjective Well-Being

    Science.gov (United States)

    van der Horst, Mariska; Coffe, Hilde

    2012-01-01

    This article explores how friendship network characteristics influence subjective well-being (SWB). Using data from the 2003 General Social Survey of Canada, three components of the friendship network are differentiated: number of friends, frequency of contact, and heterogeneity of friends. We argue that these characteristics shape SWB through the…

  13. Characteristics of Family/Friend Care Networks of Frail Seniors

    Science.gov (United States)

    Fast, Janet; Keating, Norah Christine; Derksen, Linda; Otfinowski, Pam

    2004-01-01

    This paper tests assumptions often made by policy makers and practitioners that networks of family, friends, and neighbours are able to provide sustained care to frail elderly Canadians. Using national survey data, we examined characteristics of the care networks of 1,104 seniors living with a long-term health problem. Care networks were found to…

  14. Board characteristics, governance objectives, and hospital performance

    DEFF Research Database (Denmark)

    Thiel, Andrea; Winter, Vera; Büchner, Vera Antonia

    2017-01-01

    membership relates to board characteristics and financial performance. METHODOLOGY: Using factor analysis, we identify latent classes of governance objectives and use hierarchical cluster analysis to detect distinct clusters with varying emphasis on the classes. We then use multinomial regression to explore...... the associations between cluster membership and board characteristics (size, gender diversity, and occupational diversity) and examine the associations between clusters and financial performance using OLS regression. RESULTS: Classes of objectives reflecting three governance theories-agency theory, stewardship...... and hospital financial performance, with two of three groups performing significantly better than the reference group. CONCLUSION: High performance in hospitals can be the result of governance logics, which, compared to simple board characteristics, are associated with better financial outcomes. PRACTICE...

  15. Cost and Demand Characteristics of Telecom Networks

    DEFF Research Database (Denmark)

    Falch, Morten

    1997-01-01

    The Chapter presents the general characteristics of the cost and demand profiles for telecommunication services and identifies the barriers towards a free competitive market for telecommunication services related to these characteristics.......The Chapter presents the general characteristics of the cost and demand profiles for telecommunication services and identifies the barriers towards a free competitive market for telecommunication services related to these characteristics....

  16. Student Collaborative Networks and Academic Performance

    Science.gov (United States)

    Schmidt, David; Bridgeman, Ariel; Kohl, Patrick

    2013-04-01

    Undergraduate physics students commonly collaborate with one another on homework assignments, especially in more challenging courses. However, there currently exists a dearth of empirical research directly comparing the structure of students' collaborative networks to their academic performances in lower and upper division physics courses. We investigate such networks and associated performances through a mandated collaboration reporting system in two sophomore level and three junior level physics courses during the Fall 2012 and Spring 2013 semesters. We employ social network analysis to quantify the structure and time evolution of networks involving approximately 140 students. Analysis includes analytical and numerical assignments in addition to homework and exam scores. Preliminary results are discussed.

  17. Performance characteristics of anthropomorphic prosthetic hands.

    Science.gov (United States)

    Belter, Joseph T; Dollar, Aaron M

    2011-01-01

    In this paper we set forth a review of performance characteristics for both common commercial prosthetics as well as anthropomorphic research devices. Based on these specifications as well as surveyed results from prosthetic users, ranges of hand attributes are evaluated and discussed. End user information is used to describe the performance requirements for prosthetic hands for clinical use. © 2011 IEEE

  18. Artificial astrocytes improve neural network performance.

    Science.gov (United States)

    Porto-Pazos, Ana B; Veiguela, Noha; Mesejo, Pablo; Navarrete, Marta; Alvarellos, Alberto; Ibáñez, Oscar; Pazos, Alejandro; Araque, Alfonso

    2011-04-19

    Compelling evidence indicates the existence of bidirectional communication between astrocytes and neurons. Astrocytes, a type of glial cells classically considered to be passive supportive cells, have been recently demonstrated to be actively involved in the processing and regulation of synaptic information, suggesting that brain function arises from the activity of neuron-glia networks. However, the actual impact of astrocytes in neural network function is largely unknown and its application in artificial intelligence remains untested. We have investigated the consequences of including artificial astrocytes, which present the biologically defined properties involved in astrocyte-neuron communication, on artificial neural network performance. Using connectionist systems and evolutionary algorithms, we have compared the performance of artificial neural networks (NN) and artificial neuron-glia networks (NGN) to solve classification problems. We show that the degree of success of NGN is superior to NN. Analysis of performances of NN with different number of neurons or different architectures indicate that the effects of NGN cannot be accounted for an increased number of network elements, but rather they are specifically due to astrocytes. Furthermore, the relative efficacy of NGN vs. NN increases as the complexity of the network increases. These results indicate that artificial astrocytes improve neural network performance, and established the concept of Artificial Neuron-Glia Networks, which represents a novel concept in Artificial Intelligence with implications in computational science as well as in the understanding of brain function.

  19. Differential Characteristics Based Iterative Multiuser Detection for Wireless Sensor Networks.

    Science.gov (United States)

    Chen, Xiaoguang; Jiang, Xu; Wu, Zhilu; Zhuang, Shufeng

    2017-02-16

    High throughput, low latency and reliable communication has always been a hot topic for wireless sensor networks (WSNs) in various applications. Multiuser detection is widely used to suppress the bad effect of multiple access interference in WSNs. In this paper, a novel multiuser detection method based on differential characteristics is proposed to suppress multiple access interference. The proposed iterative receive method consists of three stages. Firstly, a differential characteristics function is presented based on the optimal multiuser detection decision function; then on the basis of differential characteristics, a preliminary threshold detection is utilized to find the potential wrongly received bits; after that an error bit corrector is employed to correct the wrong bits. In order to further lower the bit error ratio (BER), the differential characteristics calculation, threshold detection and error bit correction process described above are iteratively executed. Simulation results show that after only a few iterations the proposed multiuser detection method can achieve satisfactory BER performance. Besides, BER and near far resistance performance are much better than traditional suboptimal multiuser detection methods. Furthermore, the proposed iterative multiuser detection method also has a large system capacity.

  20. Estimation of Anonymous Email Network Characteristics through Statistical Disclosure Attacks

    Directory of Open Access Journals (Sweden)

    Javier Portela

    2016-11-01

    Full Text Available Social network analysis aims to obtain relational data from social systems to identify leaders, roles, and communities in order to model profiles or predict a specific behavior in users’ network. Preserving anonymity in social networks is a subject of major concern. Anonymity can be compromised by disclosing senders’ or receivers’ identity, message content, or sender-receiver relationships. Under strongly incomplete information, a statistical disclosure attack is used to estimate the network and node characteristics such as centrality and clustering measures, degree distribution, and small-world-ness. A database of email networks in 29 university faculties is used to study the method. A research on the small-world-ness and Power law characteristics of these email networks is also developed, helping to understand the behavior of small email networks.

  1. High Performance Networks for High Impact Science

    Energy Technology Data Exchange (ETDEWEB)

    Scott, Mary A.; Bair, Raymond A.

    2003-02-13

    This workshop was the first major activity in developing a strategic plan for high-performance networking in the Office of Science. Held August 13 through 15, 2002, it brought together a selection of end users, especially representing the emerging, high-visibility initiatives, and network visionaries to identify opportunities and begin defining the path forward.

  2. WiMAX network performance monitoring & optimization

    DEFF Research Database (Denmark)

    Zhang, Qi; Dam, H

    2008-01-01

    In this paper we present our WiMAX (worldwide interoperability for microwave access) network performance monitoring and optimization solution. As a new and small WiMAX network operator, there are many demanding issues that we have to deal with, such as limited available frequency resource, tight ...

  3. Competitive Learning Neural Network Ensemble Weighted by Predicted Performance

    Science.gov (United States)

    Ye, Qiang

    2010-01-01

    Ensemble approaches have been shown to enhance classification by combining the outputs from a set of voting classifiers. Diversity in error patterns among base classifiers promotes ensemble performance. Multi-task learning is an important characteristic for Neural Network classifiers. Introducing a secondary output unit that receives different…

  4. Performance Measures of a Fuzzy Product Form Queueing Network

    Directory of Open Access Journals (Sweden)

    J. P. Mukeba Kanyinda

    2015-04-01

    Full Text Available This paper introduces the performance measures computation of a product form queueing network with fuzzy parameters. In this first study, we focus our objective to find the customers number and the customer sojourn time in the system at the stationary state. Values of these characteristics are provided. A didactical example is used to illustrate the process.

  5. Social Network Analysis and Qualitative Interviews for Assessing Geographic Characteristics of Tourism Business Networks

    National Research Council Canada - National Science Library

    Kelman, Ilan; Luthe, Tobias; Wyss, Romano; Tørnblad, Silje H; Evers, Yvette; Curran, Marina Martin; Williams, Richard J; Berlow, Eric L

    2016-01-01

    This study integrates quantitative social network analysis (SNA) and qualitative interviews for understanding tourism business links in isolated communities through analysing spatial characteristics...

  6. SDL-based network performance simulation

    Science.gov (United States)

    Yang, Yang; Lu, Yang; Lin, Xiaokang

    2005-11-01

    Specification and description language (SDL) is an object-oriented formal language defined as a standard by ITU-T. Though SDL is mainly used in describing communication protocols, it is an efficient way to simulate the network performance with SDL tools according to our experience. This paper presents our methodology of SDL-based network performance simulation in such aspects as the simulation platform, the simulation modes and the integrated simulation environment. Note that Telelogic Tau 4.3 SDL suite is used here as the simulation environment though our methodology isn't limited to the software. Finally the SDL-based open shortest path first (OSPF) performance simulation in the wireless private network is illustrated as an example of our methodology, which indicates that SDL is indeed an efficient language in the area of the network performance simulation.

  7. Physical Growth Characteristics And Cognitive Performance Of ...

    African Journals Online (AJOL)

    This study assesses the effect of the physical growth characteristics on cognitive performance of preschool school children in Owerri Municipality aged 2-5 years. A cross-sectional study was conducted on sample of 369 preschool children from 3 Nursery/kindergarten schools. All the subjects were measured for weight and ...

  8. Performance, Economics of Production and Carcass Characteristics ...

    African Journals Online (AJOL)

    A study was conducted to ascertain the performance, economics of production and carcass characteristics of broilers exposed to different levels of restricted feeding in a humid tropical environment. Four (4) dietary feed restriction treatments: T0- full or ad libitum fed - control, T75%, T50% and T25% of full or ad libitum ...

  9. Performance nutrient digestibility and carcass characteristics of ...

    African Journals Online (AJOL)

    A study was conducted using one hundred and eighty (180) day-old Hubbard broiler chicks to determine growth performance, nutrient digestibility and carcass characteristics of broiler chickens fed replacement levels of rumen filtrate fermented shea nut (Vitellaria paradoxa, Gaertn.) meal for groundnut meal. The chicks ...

  10. Growth performance, blood parameters and carcass characteristics ...

    African Journals Online (AJOL)

    This study was carried out with one hundred and twenty (120) day-old marshal chicks to investigate the effect of Maxigrain® enzyme supplementation of corn bran based diets on growth performance, carcass characteristics, haematology and serum biochemistry of broilers in an eight weeks experiment. Four experimental ...

  11. Performance, Carcass Characteristics and Haematology of Grower ...

    African Journals Online (AJOL)

    A total of two hundred seventy growing Japanese male quail birds were fed with parboiled (PB) and varying boiling time of African Breadfruit, ABF (Treculia africana) seed to evaluate the performance, carcass characteristics and haematological parameters of the growing male quail fed the African Breadfruit seed. Six dietary ...

  12. Anthropometric and performance characteristics of Turkey National ...

    African Journals Online (AJOL)

    The main objective of this research was to determine the anthropometric, somatotype and performance characteristics of the Turkish National U-14 Female Volleyball Team that participated in the national team selection session. Fifty- eight (58) female volleyball players from various towns in Turkey camped to compete in ...

  13. Performance Characteristics of an Isothermal Freeze Valve

    Energy Technology Data Exchange (ETDEWEB)

    Hailey, A.E.

    2001-08-22

    This document discusses performance characteristics of an isothermal freeze valve. A freeze valve has been specified for draining the DWPF melter at the end of its lifetime. Two freeze valve designs have been evaluated on the Small Cylindrical Melter-2 (SCM-2). In order to size the DWPF freeze valve, the basic principles governing freeze valve behavior need to be identified and understood.

  14. Performance, Nutrient Digestibility and Carcass Characteristics of ...

    African Journals Online (AJOL)

    The study examined the effect of replacing maize with cocoa pod husk (CPH) in the diets of broilers on the performance, nutrient digestibility and carcass characteristics of the birds. CPH was sun-dried, milled and incorporated in the diets at 0, 20, 40, 60 and 80% replacement levels for maize. There was a significant ...

  15. Performance characteristics and nutrient digestibility of Finisher ...

    African Journals Online (AJOL)

    An experiment was conducted to determine the performance characteristics, nutrient digestibility and blood chemistry of Finishing (84-112d) turkeys fed diets containing 100 g/kg MSP supplemented with varying combinations of enzyme and yeast. A total of 100 day-old, British United Turkeys (BUT) turkeys were reared for ...

  16. Performance Monitoring Techniques Supporting Cognitive Optical Networking

    DEFF Research Database (Denmark)

    Caballero Jambrina, Antonio; Borkowski, Robert; Zibar, Darko

    2013-01-01

    to solve this issue by realizing a network that can observe, act, learn and optimize its performance, taking into account end-to-end goals. In this letter we present the approach of cognition applied to heterogeneous optical networks developed in the framework of the EU project CHRON: Cognitive...... Heterogeneous Reconfigurable Optical Network. We focus on the approaches developed in the project for optical performance monitoring, which enable the feedback from the physical layer to the cognitive decision system by providing accurate description of the performance of the established lightpaths.......High degree of heterogeneity of future optical networks, such as services with different quality-of-transmission requirements, modulation formats and switching techniques, will pose a challenge for the control and optimization of different parameters. Incorporation of cognitive techniques can help...

  17. How Friendship Network Characteristics Influence Subjective Well-Being

    OpenAIRE

    van der Horst, Mariska; Coffé, Hilde

    2011-01-01

    This article explores how friendship network characteristics influence subjective well-being (SWB). Using data from the 2003 General Social Survey of Canada, three components of the friendship network are differentiated: number of friends, frequency of contact, and heterogeneity of friends. We argue that these characteristics shape SWB through the benefits they bring. Benefits considered are more social trust, less stress, better health, and more social support. Results confirm that higher fr...

  18. Comparing Community Structure to Characteristics in Online Collegiate Social Networks

    OpenAIRE

    Traud, Amanda L.; Kelsic, Eric D.; Mucha, Peter J; Porter, Mason A.

    2008-01-01

    We study the structure of social networks of students by examining the graphs of Facebook "friendships" at five American universities at a single point in time. We investigate each single-institution network's community structure and employ graphical and quantitative tools, including standardized pair-counting methods, to measure the correlations between the network communities and a set of self-identified user characteristics (residence, class year, major, and high school). We review the bas...

  19. Effect of mean network coordination number on dispersivity characteristics

    NARCIS (Netherlands)

    Vasilyev, L.; Raoof, A.; Nordbotten, J.M.

    2012-01-01

    In this study, we investigate the role of topology on the macroscopic (centimeter scale) dispersion characteristics derived from pore-network models.We consider 3D random porous networks extracted from a regular cubic lattice with coordination number distributed in accordance with real porous

  20. Public Cardiac Arrest Characteristics in Enclosed Pedestrian Networks

    NARCIS (Netherlands)

    Lee, Minha; Demirtas, Derya; Buick, Jason E.; Ng, Amy; Feldman, Michael J.; Cheskes, Sheldon; Morrison, Laurie J.; Chan, Timothy C.Y.

    2015-01-01

    Background: Cities around the world have underground or above-ground enclosed networks for pedestrian travel, representing unique environments for studying out-of-hospital cardiac arrest (OHCA) and resuscitation. The characteristics of OHCAs that occur in such networks are unknown. Objective: To

  1. Applying a social network analysis (SNA) approach to understanding radiologists' performance in reading mammograms

    Science.gov (United States)

    Tavakoli Taba, Seyedamir; Hossain, Liaquat; Heard, Robert; Brennan, Patrick; Lee, Warwick; Lewis, Sarah

    2017-03-01

    Rationale and objectives: Observer performance has been widely studied through examining the characteristics of individuals. Applying a systems perspective, while understanding of the system's output, requires a study of the interactions between observers. This research explains a mixed methods approach to applying a social network analysis (SNA), together with a more traditional approach of examining personal/ individual characteristics in understanding observer performance in mammography. Materials and Methods: Using social networks theories and measures in order to understand observer performance, we designed a social networks survey instrument for collecting personal and network data about observers involved in mammography performance studies. We present the results of a study by our group where 31 Australian breast radiologists originally reviewed 60 mammographic cases (comprising of 20 abnormal and 40 normal cases) and then completed an online questionnaire about their social networks and personal characteristics. A jackknife free response operating characteristic (JAFROC) method was used to measure performance of radiologists. JAFROC was tested against various personal and network measures to verify the theoretical model. Results: The results from this study suggest a strong association between social networks and observer performance for Australian radiologists. Network factors accounted for 48% of variance in observer performance, in comparison to 15.5% for the personal characteristics for this study group. Conclusion: This study suggest a strong new direction for research into improving observer performance. Future studies in observer performance should consider social networks' influence as part of their research paradigm, with equal or greater vigour than traditional constructs of personal characteristics.

  2. The Application of Social Characteristic and L1 Optimization in the Error Correction for Network Coding in Wireless Sensor Networks.

    Science.gov (United States)

    Zhang, Guangzhi; Cai, Shaobin; Xiong, Naixue

    2018-02-03

    One of the remarkable challenges about Wireless Sensor Networks (WSN) is how to transfer the collected data efficiently due to energy limitation of sensor nodes. Network coding will increase network throughput of WSN dramatically due to the broadcast nature of WSN. However, the network coding usually propagates a single original error over the whole network. Due to the special property of error propagation in network coding, most of error correction methods cannot correct more than C/2 corrupted errors where C is the max flow min cut of the network. To maximize the effectiveness of network coding applied in WSN, a new error-correcting mechanism to confront the propagated error is urgently needed. Based on the social network characteristic inherent in WSN and L1 optimization, we propose a novel scheme which successfully corrects more than C/2 corrupted errors. What is more, even if the error occurs on all the links of the network, our scheme also can correct errors successfully. With introducing a secret channel and a specially designed matrix which can trap some errors, we improve John and Yi's model so that it can correct the propagated errors in network coding which usually pollute exactly 100% of the received messages. Taking advantage of the social characteristic inherent in WSN, we propose a new distributed approach that establishes reputation-based trust among sensor nodes in order to identify the informative upstream sensor nodes. With referred theory of social networks, the informative relay nodes are selected and marked with high trust value. The two methods of L1 optimization and utilizing social characteristic coordinate with each other, and can correct the propagated error whose fraction is even exactly 100% in WSN where network coding is performed. The effectiveness of the error correction scheme is validated through simulation experiments.

  3. Diversity Performance Analysis on Multiple HAP Networks

    Directory of Open Access Journals (Sweden)

    Feihong Dong

    2015-06-01

    Full Text Available One of the main design challenges in wireless sensor networks (WSNs is achieving a high-data-rate transmission for individual sensor devices. The high altitude platform (HAP is an important communication relay platform for WSNs and next-generation wireless networks. Multiple-input multiple-output (MIMO techniques provide the diversity and multiplexing gain, which can improve the network performance effectively. In this paper, a virtual MIMO (V-MIMO model is proposed by networking multiple HAPs with the concept of multiple assets in view (MAV. In a shadowed Rician fading channel, the diversity performance is investigated. The probability density function (PDF and cumulative distribution function (CDF of the received signal-to-noise ratio (SNR are derived. In addition, the average symbol error rate (ASER with BPSK and QPSK is given for the V-MIMO model. The system capacity is studied for both perfect channel state information (CSI and unknown CSI individually. The ergodic capacity with various SNR and Rician factors for different network configurations is also analyzed. The simulation results validate the effectiveness of the performance analysis. It is shown that the performance of the HAPs network in WSNs can be significantly improved by utilizing the MAV to achieve overlapping coverage, with the help of the V-MIMO techniques.

  4. Performance benchmarking of core optical networking paradigms.

    Science.gov (United States)

    Drakos, Andreas; Orphanoudakis, Theofanis G; Stavdas, Alexandros

    2012-07-30

    The sustainability of Future Internet critically depends on networking paradigms able to provide optimum and balanced performance over an extended set of efficiency and Quality of Service (QoS) metrics. In this work we benchmark the most established networking modes through appropriate performance metrics for three network topologies. The results demonstrate that the static reservation of WDM channels, as used in IP/WDM schemes, is severely limiting scalability, since it cannot efficiently adapt to the dynamic traffic fluctuations that are frequently observed in today's networks. Optical Burst Switching (OBS) schemes do provide dynamic resource reservation but their performance is compromised due to high burst loss. It is shown that the CANON (Clustered Architecture for Nodes in an Optical Network) architecture exploiting statistical multiplexing over a large scale core optical network and efficient grooming at appropriate granularity levels could be a viable alternative to existing static as well as dynamic wavelength reservation schemes. Through extensive simulation results we quantify performance gains and we show that CANON demonstrates the highest efficiency achieving both targets for statistical multiplexing gains and QoS guarantees.

  5. Refining ensembles of predicted gene regulatory networks based on characteristic interaction sets.

    Directory of Open Access Journals (Sweden)

    Lukas Windhager

    Full Text Available Different ensemble voting approaches have been successfully applied for reverse-engineering of gene regulatory networks. They are based on the assumption that a good approximation of true network structure can be derived by considering the frequencies of individual interactions in a large number of predicted networks. Such approximations are typically superior in terms of prediction quality and robustness as compared to considering a single best scoring network only. Nevertheless, ensemble approaches only work well if the predicted gene regulatory networks are sufficiently similar to each other. If the topologies of predicted networks are considerably different, an ensemble of all networks obscures interesting individual characteristics. Instead, networks should be grouped according to local topological similarities and ensemble voting performed for each group separately. We argue that the presence of sets of co-occurring interactions is a suitable indicator for grouping predicted networks. A stepwise bottom-up procedure is proposed, where first mutual dependencies between pairs of interactions are derived from predicted networks. Pairs of co-occurring interactions are subsequently extended to derive characteristic interaction sets that distinguish groups of networks. Finally, ensemble voting is applied separately to the resulting topologically similar groups of networks to create distinct group-ensembles. Ensembles of topologically similar networks constitute distinct hypotheses about the reference network structure. Such group-ensembles are easier to interpret as their characteristic topology becomes clear and dependencies between interactions are known. The availability of distinct hypotheses facilitates the design of further experiments to distinguish between plausible network structures. The proposed procedure is a reasonable refinement step for non-deterministic reverse-engineering applications that produce a large number of candidate

  6. Refining Ensembles of Predicted Gene Regulatory Networks Based on Characteristic Interaction Sets

    Science.gov (United States)

    Windhager, Lukas; Zierer, Jonas; Küffner, Robert

    2014-01-01

    Different ensemble voting approaches have been successfully applied for reverse-engineering of gene regulatory networks. They are based on the assumption that a good approximation of true network structure can be derived by considering the frequencies of individual interactions in a large number of predicted networks. Such approximations are typically superior in terms of prediction quality and robustness as compared to considering a single best scoring network only. Nevertheless, ensemble approaches only work well if the predicted gene regulatory networks are sufficiently similar to each other. If the topologies of predicted networks are considerably different, an ensemble of all networks obscures interesting individual characteristics. Instead, networks should be grouped according to local topological similarities and ensemble voting performed for each group separately. We argue that the presence of sets of co-occurring interactions is a suitable indicator for grouping predicted networks. A stepwise bottom-up procedure is proposed, where first mutual dependencies between pairs of interactions are derived from predicted networks. Pairs of co-occurring interactions are subsequently extended to derive characteristic interaction sets that distinguish groups of networks. Finally, ensemble voting is applied separately to the resulting topologically similar groups of networks to create distinct group-ensembles. Ensembles of topologically similar networks constitute distinct hypotheses about the reference network structure. Such group-ensembles are easier to interpret as their characteristic topology becomes clear and dependencies between interactions are known. The availability of distinct hypotheses facilitates the design of further experiments to distinguish between plausible network structures. The proposed procedure is a reasonable refinement step for non-deterministic reverse-engineering applications that produce a large number of candidate predictions for a gene

  7. Effects of Performers' External Characteristics on Performance Evaluations.

    Science.gov (United States)

    Bermingham, Gudrun A.

    2000-01-01

    States that fairness has been a major concern in the field of music adjudication. Reviews the research literature to reveal information about three external characteristics (race, gender, and physical attractiveness) that may affect judges' performance evaluations and influence fairness of music adjudication. Includes references. (CMK)

  8. Dismissing attachment characteristics dynamically modulate brain networks subserving social aversion.

    Directory of Open Access Journals (Sweden)

    Anna Linda eKrause

    2016-03-01

    Full Text Available Attachment patterns influence actions, thoughts and feeling through a person’s ‘Inner Working Model’. Speech charged with attachment-dependent content was proposed to modulate the activation of cognitive-emotional schemata in listeners. We performed a 7 Tesla rest-task-rest fMRI-experiment, presenting auditory narratives prototypical of dismissing attachment representations to investigate their effect on 23 healthy males. We then examined effects of participants’ attachment style and childhood trauma on brain state changes using seed-based functional connectivity (FC analyses, and finally tested whether subjective differences in responsivity to narratives could be predicted by baseline network states. In comparison to a baseline state, we observed increased FC in a previously described ‘social aversion network’ including dorsal anterior cingulated cortex (dACC and left anterior middle temporal gyrus (aMTG specifically after exposure to insecure-dismissing attachment narratives. Increased dACC-seeded FC within the social aversion network was positively related to the participants’ avoidant attachment style and presence of a history of childhood trauma. Anxious attachment style on the other hand was positively correlated with FC between the dACC and a region outside of the ‘social aversion network’, namely the dorsolateral prefrontal cortex, which suggests decreased network segregation as a function of anxious attachment. Finally, the extent of subjective experience of friendliness towards the dismissing narrative was predicted by low baseline FC-values between hippocampus and inferior parietal lobule. Taken together, our study demonstrates an activation of networks related to social aversion in terms of increased connectivity after listening to insecure-dismissing attachment narratives. A causal interrelation of brain state changes and subsequent changes in social reactivity was further supported by our observation of direct

  9. Integrated System for Performance Monitoring of the ATLAS TDAQ Network

    CERN Document Server

    Savu, DO; The ATLAS collaboration; Martin, B; Sjoen, R; Batraneanu, SM; Stancu, S

    2011-01-01

    The ATLAS TDAQ Network consists of three separate networks spanning four levels of the experimental building. Over 200 edge switches and 5 multi-blade chassis routers are used to interconnect 2000 processors, adding up to more than 7000 high speed interfaces. In order to substantially speed-up ad-hoc and post mortem analysis, a scalable, yet flexible, integrated system for monitoring both network statistics and environmental conditions, processor parameters and data taking characteristics was required. For successful up-to-the-minute monitoring, information from many SNMP compliant devices, independent databases and custom APIs was gathered, stored and displayed in an optimal way. Easy navigation and compact aggregation of multiple data sources were the main requirements; characteristics not found in any of the tested products, either open-source or commercial. This paper describes how performance, scalability and display issues were addressed and what challenges the project faced during development and deplo...

  10. Integrated System for Performance Monitoring of ATLAS TDAQ Network

    CERN Document Server

    Savu, D; The ATLAS collaboration; Martin, B; Sjoen, R; Batraneanu, S; Stancu, S

    2010-01-01

    The ATLAS TDAQ Network consists of three separate networks spanning four levels of the experimental building. Over 200 edge switches and 5 multi-blade chassis routers are used to interconnect 2000 processors, adding up to more than 7000 high speed interfaces. In order to substantially speed-up ad-hoc and post mortem analysis, a scalable, yet flexible, integrated system for monitoring both network statistics and environmental conditions, processor parameters and data taking characteristics was required. For successful up-to-the-minute monitoring, information from many SNMP compliant devices, independent databases and custom APIs was gathered, stored and displayed in an optimal way. Easy navigation and compact aggregation of multiple data sources were the main requirements; characteristics not found in any of the tested products, either open-source or commercial. This paper describes how performance, scalability and display issues were addressed and what challenges the project faced during development and deplo...

  11. TCP Performance Enhancement for UMTS Access Network

    DEFF Research Database (Denmark)

    Hu, Liang

    2008-01-01

    is between UMTS access network and Internet. The split proxy divides the bandwidth delay product into two parts, resulting in two TCP connections with smaller bandwidth delay products. Simulation results show, the split TCP proxy can significantly improve the TCP performance under high bit rate DCH channel......We aim at optimize the TCP performance over UMTS access network challenged by the large delay bandwidth product that is mainly caused by the latency from the link layer ARQ retransmissions and diversity technique at physical layer. We propose to place a split TCP proxy at GGSN nodes which...

  12. NetBench. Automated Network Performance Testing

    CERN Document Server

    Cadeddu, Mattia

    2016-01-01

    In order to evaluate the operation of high performance routers, CERN has developed the NetBench software to run benchmarking tests by injecting various traffic patterns and observing the network devices behaviour in real-time. The tool features a modular design with a Python based console used to inject traffic and collect the results in a database, and a web user

  13. A review of hospital characteristics associated with improved performance.

    Science.gov (United States)

    Brand, Caroline A; Barker, Anna L; Morello, Renata T; Vitale, Michael R; Evans, Sue M; Scott, Ian A; Stoelwinder, Johannes U; Cameron, Peter A

    2012-10-01

    The objective of this review was to critically appraise the literature relating to associations between high-level structural and operational hospital characteristics and improved performance. The Cochrane Library, MEDLINE (Ovid), CINAHL, proQuest and PsychINFO were searched for articles published between January 1996 and May 2010. Reference lists of included articles were reviewed and key journals were hand searched for relevant articles. and data extraction Studies were included if they were systematic reviews or meta-analyses, randomized controlled trials, controlled before and after studies or observational studies (cohort and cross-sectional) that were multicentre, comparative performance studies. Two reviewers independently extracted data, assigned grades of evidence according to the Australian National Health and Medical Research Council guidelines and critically appraised the included articles. Data synthesis Fifty-seven studies were reported within 12 systematic reviews and 47 observational articles. There was heterogeneity in use and definition of performance outcomes. Hospital characteristics investigated were environment (incentives, market characteristics), structure (network membership, ownership, teaching status, geographical setting, service size) and operational design (innovativeness, leadership, organizational culture, public reporting and patient safety practices, information technology systems and decision support, service activity and planning, workforce design, staff training and education). The strongest evidence for an association with overall performance was identified for computerized physician order entry systems. Some evidence supported the associations with workforce design, use of financial incentives, nursing leadership and hospital volume. There is limited, mainly low-quality evidence, supporting the associations between hospital characteristics and healthcare performance. Further characteristic-specific systematic reviews are

  14. THE USE OF NEURAL NETWORK TECHNOLOGY TO MODEL SWIMMING PERFORMANCE

    Directory of Open Access Journals (Sweden)

    António José Silva

    2007-03-01

    Full Text Available The aims of the present study were: to identify the factors which are able to explain the performance in the 200 meters individual medley and 400 meters front crawl events in young swimmers, to model the performance in those events using non-linear mathematic methods through artificial neural networks (multi-layer perceptrons and to assess the neural network models precision to predict the performance. A sample of 138 young swimmers (65 males and 73 females of national level was submitted to a test battery comprising four different domains: kinanthropometric evaluation, dry land functional evaluation (strength and flexibility, swimming functional evaluation (hydrodynamics, hydrostatic and bioenergetics characteristics and swimming technique evaluation. To establish a profile of the young swimmer non-linear combinations between preponderant variables for each gender and swim performance in the 200 meters medley and 400 meters font crawl events were developed. For this purpose a feed forward neural network was used (Multilayer Perceptron with three neurons in a single hidden layer. The prognosis precision of the model (error lower than 0.8% between true and estimated performances is supported by recent evidence. Therefore, we consider that the neural network tool can be a good approach in the resolution of complex problems such as performance modeling and the talent identification in swimming and, possibly, in a wide variety of sports

  15. Social Network Characteristics and Salivary Cortisol in Healthy Older People

    Directory of Open Access Journals (Sweden)

    Julian C. L. Lai

    2012-01-01

    Full Text Available Psychobiological research on aging in humans has been confounded by individual differences that have not been adequately characterized in the literature. This paper is an attempt to shed light on this issue by examining the impact of social network characteristics predictive of successful aging on salivary cortisol among 78 older Chinese people in Hong Kong. Eight salivary cortisol samples were collected each day for two consecutive days from immediately after awakening to 12 hours later. Two components of the cortisol diurnal cycle, response to awakening and diurnal decline, were examined in relation to social network characteristics including size, emotional support, and cultivation. ANOVAs with repeated measured were run to examine influences of the three social network characteristics on the cortisol awakening response and diurnal decline, with the effects of gender, age, socioeconomic status, and waking time controlled. Results indicated that those who spent more time and effort in developing and strengthening their social ties (i.e., those high in “cultivation” exhibited a significantly greater rise in cortisol in the morning and a significantly steeper decline over the day, thus attesting to more effective activation and deactivation of the HPA axis. Network cultivation reflected a positive motivation to nurture social relationships more than the other two network characteristics. Its effect on cortisol might stem from the positivity underlying the motivation.

  16. Characteristics explaining performance in downhill mountain biking.

    Science.gov (United States)

    Chidley, Joel B; MacGregor, Alexandra L; Martin, Caoimhe; Arthur, Calum A; Macdonald, Jamie H

    2015-03-01

    To identify physiological, psychological, and skill characteristics that explain performance in downhill (DH) mountain-bike racing. Four studies were used to (1) identify factors potentially contributing to DH performance (using an expert focus group), (2) develop and validate a measure of rider skill (using video analysis and expert judge evaluation), (3) evaluate whether physiological, psychological, and skill variables contribute to performance at a DH competition, and (4) test the specific contribution of aerobic capacity to DH performance. STUDY 1 identified aerobic capacity, handgrip endurance, anaerobic power, rider skill, and self-confidence as potentially important for DH. In study 2 the rider-skill measure displayed good interrater reliability. Study 3 found that rider skill and handgrip endurance were significantly related to DH ride time (β=-0.76 and -0.14, respectively; R2=.73), with exploratory analyses suggesting that DH ride time may also be influenced by self-confidence and aerobic capacity. Study 4 confirmed aerobic capacity as an important variable influencing DH performance (for a DH ride, mean oxygen uptake was 49±5 mL·kg(-1)·min(-1), and 90% of the ride was completed above the 1st ventilatory threshold). In order of importance, rider skill, handgrip endurance, self-confidence, and aerobic capacity were identified as variables influencing DH performance. Practically, this study provides a novel assessment of rider skill that could be used by coaches to monitor training and identify talent. Novel intervention targets to enhance DH performance were also identified, including self-confidence and aerobic capacity.

  17. Gender differences in predicting loneliness from social network characteristics.

    Science.gov (United States)

    Stokes, J; Levin, I

    1986-11-01

    In two studies we examined gender differences in predicting loneliness from measures of social network structure and a measure of perceived social support. The results showed that social network characteristics, especially density, were consistently better predictors of perceived loneliness for men than for women. Study 1 used the traditional measure of network density in which the number of relationships among network members was determined. Study 2 used a newly developed index of density that assessed the extent of closeness of relationships between pairs of network members. Uniformly, male subjects with more highly interconnected, cohesive sets of friends reported themselves to be less lonely, whereas density had little relation to loneliness in female subjects. These results are discussed as possibly indicating that men and women use different standards in evaluating whether they are lonely. It is suggested that men may use more group-oriented criteria in evaluating loneliness, whereas women focus more on the qualities of dyadic relationships.

  18. Performance modeling, stochastic networks, and statistical multiplexing

    CERN Document Server

    Mazumdar, Ravi R

    2013-01-01

    This monograph presents a concise mathematical approach for modeling and analyzing the performance of communication networks with the aim of introducing an appropriate mathematical framework for modeling and analysis as well as understanding the phenomenon of statistical multiplexing. The models, techniques, and results presented form the core of traffic engineering methods used to design, control and allocate resources in communication networks.The novelty of the monograph is the fresh approach and insights provided by a sample-path methodology for queueing models that highlights the importan

  19. Performance Analysis of RF-FSO Multi-Hop Networks

    KAUST Repository

    Makki, Behrooz

    2017-05-12

    We study the performance of multi-hop networks composed of millimeter wave (MMW)-based radio frequency (RF) and free-space optical (FSO) links. The results are obtained in the cases with and without hybrid automatic repeat request (HARQ). Taking the MMW characteristics of the RF links into account, we derive closed-form expressions for the network outage probability. We also evaluate the effect of various parameters such as power amplifiers efficiency, number of antennas as well as different coherence times of the RF and the FSO links on the system performance. Finally, we present mappings between the performance of RF- FSO multi-hop networks and the ones using only the RF- or the FSO-based communication, in the sense that with appropriate parameter settings the same outage probability is achieved in these setups. The results show the efficiency of the RF-FSO setups in different conditions. Moreover, the HARQ can effectively improve the outage probability/energy efficiency, and compensate the effect of hardware impairments in RF-FSO networks. For common parameter settings of the RF-FSO dual- hop networks, outage probability 10^{-4} and code rate 3 nats-per-channel-use, the implementation of HARQ with a maximum of 2 and 3 retransmissions reduces the required power, compared to the cases with no HARQ, by 13 and 17 dB, respectively.

  20. Analysis of the Air Transport Network Characteristics of Major Airports

    Directory of Open Access Journals (Sweden)

    Min Geun Song

    2017-09-01

    Full Text Available The world's major airports are directly connected to hundreds of airports without intermediate routes. This connectivity can be described as the network in which the airport becomes a node and the route becomes a connection line. In this regard, this study analyzes the air transport network of 1,060 airports using the social network analysis (SNA methodology. We consolidated the data from three airline alliances and established a network of 1,060 airports and 5,580 routes in 173 countries. Many previous studies on air transport network examined several specific airports or regions and mainly utilized the internal indicators of airports. Conversely, this study conducted a comprehensive analysis covering 173 countries by using air route, which is an external indicator of airports. This study presented the general characteristics of major countries and regions from the perspective of SNA and compared the individual networks of the United States and China, which have the greatest influence on international air logistics within the scope of the entire network analysis. This study can aid in the understanding of air transport networks and logistics connectivity in inter-city and inter-country transport.

  1. Performance of TCP variants over LTE network

    Science.gov (United States)

    Nor, Shahrudin Awang; Maulana, Ade Novia

    2016-08-01

    One of the implementation of a wireless network is based on mobile broadband technology Long Term Evolution (LTE). LTE offers a variety of advantages, especially in terms of access speed, capacity, architectural simplicity and ease of implementation, as well as the breadth of choice of the type of user equipment (UE) that can establish the access. The majority of the Internet connections in the world happen using the TCP (Transmission Control Protocol) due to the TCP's reliability in transmitting packets in the network. TCP reliability lies in the ability to control the congestion. TCP was originally designed for wired media, but LTE connected through a wireless medium that is not stable in comparison to wired media. A wide variety of TCP has been made to produce a better performance than its predecessor. In this study, we simulate the performance provided by the TCP NewReno and TCP Vegas based on simulation using network simulator version 2 (ns2). The TCP performance is analyzed in terms of throughput, packet loss and end-to-end delay. In comparing the performance of TCP NewReno and TCP Vegas, the simulation result shows that the throughput of TCP NewReno is slightly higher than TCP Vegas, while TCP Vegas gives significantly better end-to-end delay and packet loss. The analysis of throughput, packet loss and end-to-end delay are made to evaluate the simulation.

  2. Neurodynamics of learning and network performance

    Science.gov (United States)

    Wilson, Charles L.; Blue, James L.; Omidvar, Omid M.

    1997-07-01

    A simple dynamic model of a neural network is presented. Using the dynamic model of a neural network, we improve the performance of a three-layer multilayer perceptron (MLP). The dynamic model of a MLP is used to make fundamental changes in the network optimization strategy. These changes are: neuron activation functions are used, which reduces the probability of singular Jacobians; successive regularization is used to constrain the volume of the weight space being minimized; Boltzmann pruning is used to constrain the dimension of the weight space; and prior class probabilities are used to normalize all error calculations, so that statistically significant samples of rare but important classes can be included without distortion of the error surface. All four of these changes are made in the inner loop of a conjugate gradient optimization iteration and are intended to simplify the training dynamics of the optimization. On handprinted digits and fingerprint classification problems, these modifications improve error-reject performance by factors between 2 and 4 and reduce network size by 40 to 60%.

  3. Characteristics of road network forms in historic districts of Japan

    Directory of Open Access Journals (Sweden)

    Ze Liu

    2015-12-01

    Full Text Available This study focused on the structure and the platform of the road space of historic districts. We analyzed the road networks of 16 historic districts in Japan from the perspectives of circularity, accessibility and indirection based on graph theory. By calculating and comparing the indexes of each road network (NW1 and NW2 forms, we quantitatively describe the effects of the main prefectural roads (more than 4 m in width and narrow streets (less than 4 m in width on the spatial characteristics. And it turned out that we could divided the 16 objective historic districts into 4 types. Moreover, we qualitatively studied the characteristics of each type of historic districts based on their development background and the structure of road network.

  4. Laser Microprobe Mass Spectrometry 1: Basic Principles and Performance Characteristics.

    Science.gov (United States)

    Denoyer, Eric; And Others

    1982-01-01

    Describes the historical development, performance characteristics (sample requirements, analysis time, ionization characteristics, speciation capabilities, and figures of merit), and applications of laser microprobe mass spectrometry. (JN)

  5. A Fluid Model for Performance Analysis in Cellular Networks

    Directory of Open Access Journals (Sweden)

    Coupechoux Marceau

    2010-01-01

    Full Text Available We propose a new framework to study the performance of cellular networks using a fluid model and we derive from this model analytical formulas for interference, outage probability, and spatial outage probability. The key idea of the fluid model is to consider the discrete base station (BS entities as a continuum of transmitters that are spatially distributed in the network. This model allows us to obtain simple analytical expressions to reveal main characteristics of the network. In this paper, we focus on the downlink other-cell interference factor (OCIF, which is defined for a given user as the ratio of its outer cell received power to its inner cell received power. A closed-form formula of the OCIF is provided in this paper. From this formula, we are able to obtain the global outage probability as well as the spatial outage probability, which depends on the location of a mobile station (MS initiating a new call. Our analytical results are compared to Monte Carlo simulations performed in a traditional hexagonal network. Furthermore, we demonstrate an application of the outage probability related to cell breathing and densification of cellular networks.

  6. Research on complex networks' repairing characteristics due to cascading failure

    Science.gov (United States)

    Chaoqi, Fu; Ying, Wang; Xiaoyang, Wang

    2017-09-01

    In reality, most of the topological structures of complex networks are not ideal. Considering the restrictions from all aspects, we cannot timely adjust and improve network defects. Once complex networks collapse under cascading failure, an appropriate repair strategy must be implemented. This repair process is divided into 3 kinds of situations. Based on different types of opening times, we presented 2 repair modes, and researched 4 kinds of repair strategies. Results showed that network efficiency recovered faster when the repair strategies were arranged in descending order by parameters under the immediate opening condition. However, the risk of secondary failure and additional expansion capacity were large. On the contrary, when repair strategies were in ascending order, the demand for additional capacity caused by secondary failure was greatly saved, but the recovery of network efficiency was relatively slow. Compared to immediate opening, delayed opening alleviated the contradiction between network efficiency and additional expansion capacity, particularly to reduce the risk of secondary failure. Therefore, different repair methods have different repair characteristics. This paper investigates the impact of cascading effects on the network repair process, and by presenting a detailed description of the status of each repaired node, helps us understand the advantages and disadvantages of different repair strategies.

  7. Performance modeling, loss networks, and statistical multiplexing

    CERN Document Server

    Mazumdar, Ravi

    2009-01-01

    This monograph presents a concise mathematical approach for modeling and analyzing the performance of communication networks with the aim of understanding the phenomenon of statistical multiplexing. The novelty of the monograph is the fresh approach and insights provided by a sample-path methodology for queueing models that highlights the important ideas of Palm distributions associated with traffic models and their role in performance measures. Also presented are recent ideas of large buffer, and many sources asymptotics that play an important role in understanding statistical multiplexing. I

  8. Characteristics of High-Performing School Districts

    Science.gov (United States)

    Leithwood, Kenneth; Azah, Vera N.

    2017-01-01

    This mixed-methods study inquired about characteristics of districts which influence changes in student achievement and how those characteristics are developed. Staff in 49 Ontario districts were surveyed to estimate the status of nine district characteristics on changes in provincial tests of math and language achievement over five years. A…

  9. Student network centrality and academic performance: evidence from United Nations University

    OpenAIRE

    Zhang, Y.; Rajabzadeh, I.; Lauterbach, R

    2009-01-01

    In this paper we empirically studied the relationship between network centrality and academic performance among a group of 47 PhD students from UNU-MERIT institute. We conducted an independent email survey and relied on social networks theory as well as standard econometric procedures to analyse the data. We found a significant reversed U-shaped relation between network centrality and students' academic performance. We controlled our results by several node's characteristics such as age, acad...

  10. Evaluation of the performance characteristics of the European Lightning Detection Network EUCLID in the Alps region for upward negative flashes using direct measurements at the instrumented Säntis Tower

    Science.gov (United States)

    Azadifar, Mohammad; Rachidi, Farhad; Rubinstein, Marcos; Paolone, Mario; Diendorfer, Gerhard; Pichler, Hannes; Schulz, Wolfgang; Pavanello, Davide; Romero, Carlos

    2016-01-01

    In this paper, we present a performance analysis of the European Cooperation for Lightning Detection (EUCLID) lightning detection network using data obtained on lightning currents measured at the Säntis Tower (located in northeastern of Switzerland) from June 2010 to December 2013. In the considered period of analysis, a total number of 269 upward negative flashes were recorded at the Säntis Tower. The performance of the EUCLID lightning detection network is evaluated in terms of detection efficiency, location accuracy, and peak current estimates for upward flashes. Excluding flashes containing only an initial continuous current with no superimposed pulses exceeding 2 kA, the flash detection efficiency for upward flashes is estimated to be 97%. The recorded flashes contained a total of 2795 pulses (including return strokes and International Conference on Communications pulses characterized by risetimes lower than 8 µs and peaks greater than 2 kA). The overall pulse detection efficiency was found to be 73%. For pulses with peak values higher than 5 kA, the pulse detection efficiency was found to be about 83%. Peak current estimates provided by the EUCLID network were found to be significantly larger than their directly measured counterparts. This overestimation might be attributed to the enhancement of the radiated electromagnetic fields associated with the presence of the tower and the mountain. The median of the absolute distance error, defined as the median distance between the Säntis Tower location and the EUCLID's stroke locations, was found to be 186 m, the majority of large location errors being associated with measured current peaks lower than 10 kA. The analysis revealed also that the location accuracy of the EUCLID network improved significantly in 2013 as a result of an upgrade in the location algorithms to take into account propagation effects.

  11. The Applications for the Calculation and Optimization of Passive Optical Networks Attenuation Characteristics

    Directory of Open Access Journals (Sweden)

    Pavel Lafata

    2010-01-01

    Full Text Available The passive optical networks represent modern and promising solution to meet the increasing demands on the transmission speed in access networks. These optical networks consist only of passive optical components, essential role play mainly the passive optical splitters. Therefore, it is not possible to perform additional adjustments with the optical signal, such as its amplifying, dropping, routing, etc. It is necessary in early stage of planning the optical network to comply with its parameters for its proper operation, especially the values of total attenuation, optical return loss, delay, etc. It is therefore necessary to accomplish the detailed analysis and the calculation of total attenuation characteristics of proposed optical network. The program for the purposes of rapid calculation of the passive optical network attenuation was designed. It supports various network topologies and it enables to enter initial parameters of optical network. The outputs in the tabular form also include the assessment of the suitability of proposed optical network for the different variants of passive optical networks.

  12. Nanotechnological inventions considerably improve performance characteristics

    Directory of Open Access Journals (Sweden)

    VLASOV Vladimir Alexeevich

    2014-06-01

    Full Text Available The invention «The method of production of carbon nanomaterial (RU 2509053» can be used as an additive for concretes and polymers which significantly improves their performance characteristics. The method of production of carbon nanomaterial consists of the following stages: preliminary preparation of sphagnous moss when it is refined from foreign admixtures, dried up to 10% humidity and ground, then ground material is exposed to pyrolysis under the temperature 850–950оC for 1–2 hours and cooled up to the environment temperature. After that amorphous carbon obtained in pyrolysis is treated with mechanical activation in the variable planetary mill for 7–10 hours. The invention makes it possible to provide increased outcome of nanotubes with high cleanliness. The invention «The method of production of nanodispersed metal powders and alloys of them (RU 2509626» relates to the powder metallurgy. Powder metal chloride or powder mixture at least of two metal chlorides is treated in the environment of the water steam which is supplied in reaction space at the rate of 50–100 ml/min at the temperature 400–800оC at the presence of absorbent carbon or introducing carbon oxide (II obtained during dissolution of formic acid HCOOH. The invention provides reliable production of nanodispersed metal powders and alloys of them from 3-d metal range: Ni, Co, Cu, Fe, Zn which can be used in powder metallurgy to improve baking process, in chemical industry as the fillers of polymers and reaction catalysts; as additives to anticorrosive covers, etc.

  13. Data center networks topologies, architectures and fault-tolerance characteristics

    CERN Document Server

    Liu, Yang; Veeraraghavan, Malathi; Lin, Dong; Hamdi, Mounir

    2013-01-01

    This SpringerBrief presents a survey of data center network designs and topologies and compares several properties in order to highlight their advantages and disadvantages. The brief also explores several routing protocols designed for these topologies and compares the basic algorithms to establish connections, the techniques used to gain better performance, and the mechanisms for fault-tolerance. Readers will be equipped to understand how current research on data center networks enables the design of future architectures that can improve performance and dependability of data centers. This con

  14. Copercolating Networks: An Approach for Realizing High-Performance Transparent Conductors using Multicomponent Nanostructured Networks

    Directory of Open Access Journals (Sweden)

    Das Suprem R.

    2016-06-01

    Full Text Available Although transparent conductive oxides such as indium tin oxide (ITO are widely employed as transparent conducting electrodes (TCEs for applications such as touch screens and displays, new nanostructured TCEs are of interest for future applications, including emerging transparent and flexible electronics. A number of twodimensional networks of nanostructured elements have been reported, including metallic nanowire networks consisting of silver nanowires, metallic carbon nanotubes (m-CNTs, copper nanowires or gold nanowires, and metallic mesh structures. In these single-component systems, it has generally been difficult to achieve sheet resistances that are comparable to ITO at a given broadband optical transparency. A relatively new third category of TCEs consisting of networks of 1D-1D and 1D-2D nanocomposites (such as silver nanowires and CNTs, silver nanowires and polycrystalline graphene, silver nanowires and reduced graphene oxide have demonstrated TCE performance comparable to, or better than, ITO. In such hybrid networks, copercolation between the two components can lead to relatively low sheet resistances at nanowire densities corresponding to high optical transmittance. This review provides an overview of reported hybrid networks, including a comparison of the performance regimes achievable with those of ITO and single-component nanostructured networks. The performance is compared to that expected from bulk thin films and analyzed in terms of the copercolation model. In addition, performance characteristics relevant for flexible and transparent applications are discussed. The new TCEs are promising, but significant work must be done to ensure earth abundance, stability, and reliability so that they can eventually replace traditional ITO-based transparent conductors.

  15. Performance of wireless sensor networks under random node failures

    Energy Technology Data Exchange (ETDEWEB)

    Bradonjic, Milan [Los Alamos National Laboratory; Hagberg, Aric [Los Alamos National Laboratory; Feng, Pan [Los Alamos National Laboratory

    2011-01-28

    Networks are essential to the function of a modern society and the consequence of damages to a network can be large. Assessing network performance of a damaged network is an important step in network recovery and network design. Connectivity, distance between nodes, and alternative routes are some of the key indicators to network performance. In this paper, random geometric graph (RGG) is used with two types of node failure, uniform failure and localized failure. Since the network performance are multi-facet and assessment can be time constrained, we introduce four measures, which can be computed in polynomial time, to estimate performance of damaged RGG. Simulation experiments are conducted to investigate the deterioration of networks through a period of time. With the empirical results, the performance measures are analyzed and compared to provide understanding of different failure scenarios in a RGG.

  16. Developing countries SMEs innovation characteristics and performance

    DEFF Research Database (Denmark)

    Rezaei, Shahamak; Brambini-Pedersen, Jan Vang; Baklanov, Nikita

    This paper aims at reducing this research gap by conducting a survey based econometric assessment of Vietnamese SMEs innovation performance and the relationship between specific innovation traits and firm performance.......This paper aims at reducing this research gap by conducting a survey based econometric assessment of Vietnamese SMEs innovation performance and the relationship between specific innovation traits and firm performance....

  17. [Numerical analysis on network characteristics of communities in herb-pairs network].

    Science.gov (United States)

    Cao, Jia; Xin, Juan-juan; Wang, Yun

    2015-06-01

    To interpret the traditional Chinese medicine (TCM) theory by the network technology, in order to promote the modernization and programming of studies on compatibility of TCMs. In this paper, efforts were made to express the direct interactions between drugs through the herb-pair network, analyze the community characteristics of the network and its relations with blood-Qi theory, and study the expression of blood-Qi theory on the herb-pair network through prescriptions. According to the findings, the herb-pairs network showed a strong community structure characteristics; Each community is composed of a series of herb pairs with close correlations, and either blood efficacy or Qi efficacy but not both of them. Based on that, the 386 single TCM ingredients involved by the herb-pair network were divided into three types of communities: Blood (B) community, Qi (Q) community and uncertain community. According to the statistical results of 262 prescriptions mapped onto the three types of communities, if a prescription contains single herbs of the Q community, the probability that it contains single herbs o the B community is 99.84%; Meanwhile, there are 140 prescriptions containing single herbs of both the Q community and the B community. The result is completely coincident with the TCM Blood-Qi theory that single herbs belong to both Q and B communities or the B community, because Qi regulation leads to blood regulation, but not vice versa. For example, a patient with hemorrhage due to trauma or blood-heat, Qi tonifying prescriptions may aggravate hemorrhage. In this paper, authors found high-recognition macroscopic network numerical characteristics to network data reference for judging rationality of new prescriptions, and proved human blood and Qi relations from the perspective of data analysis.

  18. Performance of the surface observation network during MAP

    Energy Technology Data Exchange (ETDEWEB)

    Haeberli, C. [Dept. of Meteorology and Geophysics, Univ. of Vienna (Austria); Federal Office of Meteorology and Climatology (MeteoSwiss), Zurich (Switzerland); Groehn, I.; Steinacker, R.; Poettschacher, W.; Dorninger, M. [Dept. of Meteorology and Geophysics, Univ. of Vienna (Austria)

    2004-04-01

    The comprehensive data collection effort in the framework of the mesoscale alpine programme (MAP) offers the unprecedented possibility to carry out a careful evaluation of the performance of one of the densest surface observational networks of the world. Quality control of meteorological data today is usually seen as an integrated step of prognostic model initialization. If mesoscale models should be validated independently, however, a model independent quality checking procedure becomes important, especially when operating over complex terrain. For that reason DAQUAMAP, a project sponsored by the EUMETNET programme MAP-NWS, was conducted to make a high quality data set available to the scientific community testing high resolution numerical weather forecast models as well as performing diagnostic studies. The applied method of quality control consists of an automatic spatial consistency check of primary atmospheric variables. It allows to recognize gross errors and biases of individual station data and to derive station characteristics as well. The latter is especially important when validating model results with single station data. Due to a separate treatment of GTS and combined GTS and non-GTS station data a distinction of the performance of both networks could be achieved. Also a comparison between a similar exercise done with the ALPEX data set in 1982 and the MAP data set has been carried out. This allows to assess the effect of automatization in the meteorological observation networks which has taken place during the last 20 years. (orig.)

  19. Analysis of interference performance of tactical radio network

    Science.gov (United States)

    Nie, Hao; Cai, Xiaoxia; Chen, Hong

    2017-08-01

    Mobile Ad hoc network has a strong military background for its development as the core technology of the backbone network of US tactical Internet. And which tactical radio network, is the war in today's tactical use of the Internet more mature form of networking, mainly used in brigade and brigade following forces. This paper analyzes the typical protocol AODV in the tactical radio network, and then carries on the networking. By adding the interference device to the whole network, the battlefield environment is simulated, and then the throughput, delay and packet loss rate are analyzed, and the performance of the whole network and the single node before and after the interference is obtained.

  20. A network characteristic that correlates environmental and genetic robustness.

    Directory of Open Access Journals (Sweden)

    Zeina Shreif

    2014-02-01

    Full Text Available As scientific advances in perturbing biological systems and technological advances in data acquisition allow the large-scale quantitative analysis of biological function, the robustness of organisms to both transient environmental stresses and inter-generational genetic changes is a fundamental impediment to the identifiability of mathematical models of these functions. An approach to overcoming this impediment is to reduce the space of possible models to take into account both types of robustness. However, the relationship between the two is still controversial. This work uncovers a network characteristic, transient responsiveness, for a specific function that correlates environmental imperturbability and genetic robustness. We test this characteristic extensively for dynamic networks of ordinary differential equations ranging up to 30 interacting nodes and find that there is a power-law relating environmental imperturbability and genetic robustness that tends to linearity as the number of nodes increases. Using our methods, we refine the classification of known 3-node motifs in terms of their environmental and genetic robustness. We demonstrate our approach by applying it to the chemotaxis signaling network. In particular, we investigate plausible models for the role of CheV protein in biochemical adaptation via a phosphorylation pathway, testing modifications that could improve the robustness of the system to environmental and/or genetic perturbation.

  1. Performance Analysis of Gsm Networks in Minna Metropolis of Nigeria

    African Journals Online (AJOL)

    The performance of a cellular network is assessed in terms of key performance indicators (KPI) based on statistics generated from drive tests or network management systems. However, drive tests give the 'feel' of the designed network as it is experienced by the subscribers. Therefore, it is used in this study to compare ...

  2. Network characteristics emerging from agent interactions in balanced distributed system.

    Science.gov (United States)

    Salman, Mahdi Abed; Bertelle, Cyrille; Sanlaville, Eric

    2015-01-01

    A distributed computing system behaves like a complex network, the interactions between nodes being essential information exchanges and migrations of jobs or services to execute. These actions are performed by software agents, which behave like the members of social networks, cooperating and competing to obtain knowledge and services. The load balancing consists in distributing the load evenly between system nodes. It aims at enhancing the resource usage. A load balancing strategy specifies scenarios for the cooperation. Its efficiency depends on quantity, accuracy, and distribution of available information. Nevertheless, the distribution of information on the nodes, together with the initial network structure, may create different logical network structures. In this paper, different load balancing strategies are tested on different network structures using a simulation. The four tested strategies are able to distribute evenly the load so that the system reaches a steady state (the mean response time of the jobs is constant), but it is shown that a given strategy indeed behaves differently according to structural parameters and information spreading. Such a study, devoted to distributed computing systems (DCSs), can be useful to understand and drive the behavior of other complex systems.

  3. Network performance and fault analytics for LTE wireless service providers

    CERN Document Server

    Kakadia, Deepak; Gilgur, Alexander

    2017-01-01

     This book is intended to describe how to leverage emerging technologies big data analytics and SDN, to address challenges specific to LTE and IP network performance and fault management data in order to more efficiently manage and operate an LTE wireless networks. The proposed integrated solutions permit the LTE network service provider to operate entire integrated network, from RAN to Core , from UE to application service, as one unified system and correspondingly collect and align disparate key metrics and data, using an integrated and holistic approach to network analysis. The LTE wireless network performance and fault involves the network performance and management of network elements in EUTRAN, EPC and IP transport components, not only as individual components, but also as nuances of inter-working of these components. The key metrics for EUTRAN include radio access network accessibility, retainability, integrity, availability and mobility. The key metrics for EPC include MME accessibility, mobility and...

  4. Network characteristics for server selection in online games

    Science.gov (United States)

    Claypool, Mark

    2008-01-01

    Online gameplay is impacted by the network characteristics of players connected to the same server. Unfortunately, the network characteristics of online game servers are not well-understood, particularly for groups that wish to play together on the same server. As a step towards a remedy, this paper presents analysis of an extensive set of measurements of game servers on the Internet. Over the course of many months, actual Internet game servers were queried simultaneously by twenty-five emulated game clients, with both servers and clients spread out on the Internet. The data provides statistics on the uptime and populations of game servers over a month long period an an in-depth look at the suitability for game servers for multi-player server selection, concentrating on characteristics critical to playability--latency and fairness. Analysis finds most game servers have latencies suitable for third-person and omnipresent games, such as real-time strategy, sports and role-playing games, providing numerous server choices for game players. However, far fewer game servers have the low latencies required for first-person games, such as shooters or race games. In all cases, groups that wish to play together have a greatly reduced set of servers from which to choose because of inherent unfairness in server latencies and server selection is particularly limited as the group size increases. These results hold across different game types and even across different generations of games. The data should be useful for game developers and network researchers that seek to improve game server selection, whether for single or multiple players.

  5. Performance characteristics of a manually operated plantain ...

    African Journals Online (AJOL)

    A manually operated machine was designed and fabricated for chipping plantain. Experiments were conducted to model the performance of the machine. The crop parameters varied during the experiments include plantain diameter or size (X1), plantain ripeness (X2) and chip thickness (X3). The performance ...

  6. Destination Characteristics that Drive Hotel Performance

    DEFF Research Database (Denmark)

    Assaf, A. George; Josiassen, Alexander; Woo, Linda

    2017-01-01

    The increased market saturation and competition in both domestic and international tourism destinations have renewed interest among hotel operators in identifying the key drivers of hotel performance. This paper presents a comprehensive analysis of the determinants of hotel performance and their ...

  7. Scholastic performance and functional connectivity of brain networks in children.

    Directory of Open Access Journals (Sweden)

    Laura Chaddock-Heyman

    Full Text Available One of the keys to understanding scholastic success is to determine the neural processes involved in school performance. The present study is the first to use a whole-brain connectivity approach to explore whether functional connectivity of resting state brain networks is associated with scholastic performance in seventy-four 7- to 9-year-old children. We demonstrate that children with higher scholastic performance across reading, math and language have more integrated and interconnected resting state networks, specifically the default mode network, salience network, and frontoparietal network. To add specificity, core regions of the dorsal attention and visual networks did not relate to scholastic performance. The results extend the cognitive role of brain networks in children as well as suggest the importance of network connectivity in scholastic success.

  8. Sire influence on reproductive, performance characteristics and ...

    African Journals Online (AJOL)

    , Panda White x Cinnamon Brown (PWxCB) and Silver Brown x Cinnamon Brown (SBxCB). The experiment was a randomized complete block design. Parameters measured include: fertility and hatchability traits, growth performance traits and ...

  9. Organsweight and performance characteristics of broiler chickens ...

    African Journals Online (AJOL)

    Key Words: Broiler chickens, burning, flames and fumes, organ weights and performance, simulated crude petroleum. La performance des poulets de chair exposé aux flammes et aux fumées de la combustion du pétrole brut à des distances variables au cours d'une période quotidienne de 16 heures a été évaluée pendant ...

  10. Optical Networks Solutions planning - performances - management

    DEFF Research Database (Denmark)

    Fenger, Christian

    2002-01-01

    are kept optical and not converted into the optical domain. The focus is on the scientific results achieved throughout the Ph.D. period. Five subjects – all increasing the understanding of optical networks – are studied. Static wavelength routed optical networks are studied. Management on terms....... An explicit solution for network blocking probability has been derived, and fixed point equations for alternate routing are derived. Secondly is self similar traffic studied and the effect on optical networks considered. The Synchronous Optical Hierarchy is suggested as a new type of network to overcome...

  11. Performance Characteristics of Silane Silica Modified Asphalt

    Directory of Open Access Journals (Sweden)

    Xuedong Guo

    2016-01-01

    Full Text Available At present there are many kinds of fillers and modifier used for modified asphalt, but the effect of modifier differs in thousands of ways; most of them can increase the high temperature performance of asphalt, but the modified effect of low-temperature crack resistance, water stability, and antifatigue performance is different. Aiming at the subsistent problems, this paper innovatively puts forward the idea of taking the silane silica (nanosilica modified with silane coupling agent as filler to develop one kind of modified asphalt concrete which has excellent comprehensive performance based on the idea of enhance the whole performance of asphalt concrete and interface consolidation strength between aggregate and asphalt at the same time. The best mixing amount of silane silica and the production process of modified asphalt were conducted by contrasting the test date as penetration, viscosity, and softening point; the aging of asphalt and modified asphalt was analyzed by TG test, the superiority of silane silica modified asphalt is more clearly understandable by chemical analysis results. Meanwhile it is proved that silane silica has positive effect to improve the mixture of high and low temperature performance, water stability, and aging resistance through a series of road performance tests.

  12. ‘Down-Stream’ Network Characteristics, Broker Functions and New Product Development Success

    DEFF Research Database (Denmark)

    Smed, Marie; Salomo, Søren; Li, Ying

    2011-01-01

    knowledge sharing as main motivator for engaging in cooperative network or alliance efforts. Extending this perspective, not the least the user-driven innovation research has emphasized the important input to new product development provided by users. While integration with this ‘down-stream’ partner can...... discuss how recent developments of management practice, with respect to integrating broker functions in network and alliance management, alter the relationships between network characteristics and new product development and performance, and (3) We focus ‘down-stream networks’ and, thus, develop research......Success of product development measured by new product introductions to the market is a key performance indicator for business today. Often internal processes are mentioned in relation to product development optimization. However, the external environment is also critical for product development...

  13. Coexistence: Threat to the Performance of Heterogeneous Network

    Science.gov (United States)

    Sharma, Neetu; Kaur, Amanpreet

    2010-11-01

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

  14. Multidimensional performance characteristics in selected and deselected talented soccer players.

    Science.gov (United States)

    Huijgen, Barbara C H; Elferink-Gemser, Marije T; Lemmink, Koen A P M; Visscher, Chris

    2014-01-01

    The present study examined whether performance characteristics discriminated between selected and deselected players in talent development programmes. This examination was carried out in talented soccer players, aged 16-18 years using objective measurement instruments. Four domains of multidimensional performance characteristics (physiological, technical, tactical and psychological) were assessed by using a test battery consisting of soccer-specific field tests and questionnaires. Multivariate analyses of covariance revealed that the physiological characteristics peak and repeated shuttle sprint, the technical characteristics of peak and repeated shuttle dribble and the tactical characteristic of 'positioning and deciding', significantly differed between the selected (n=76) and deselected players (n=37), with selected players performing better (Pskill performances. Sports research can play an essential role in investigating the club's perception of important performance characteristics in talented players.

  15. performance characteristics of a cam turning attachment

    African Journals Online (AJOL)

    Dr Obe

    ABSTRACT. A modification of a cylindrical turning unit has been done to give a non- cylindrical turning attachment for production of irregular shapes, like cams on the lathe machine. To assess the performance of the attachment, cutting forces have been measured using a 'Sigma' Cutting Tool. Dynamometer. Furthermore ...

  16. Data characteristics that determine classifier performance

    CSIR Research Space (South Africa)

    Van der Walt, Christiaan M

    2006-11-01

    Full Text Available The relationship between the distribution of data, on the one hand, and classifier performance, on the other, for non-parametric classifiers has been studied. It is shown that predictable factors such as the available amount of training data...

  17. Growth performance, carcass and hematological characteristics of ...

    African Journals Online (AJOL)

    This experiment was conducted with the aim of investigating the effect of tiger nuts (Cypers esculentus) rejects on the growth performance, carcass weight and hematological parameters of weaner rabbits. Three experimental diets were formulated with Diets A being a commercial growers' mash as control diet; Diet B: 5% ...

  18. A survey of performance enhancement of transmission control protocol (TCP in wireless ad hoc networks

    Directory of Open Access Journals (Sweden)

    Mast Noor

    2011-01-01

    Full Text Available Abstract Transmission control protocol (TCP, which provides reliable end-to-end data delivery, performs well in traditional wired network environments, while in wireless ad hoc networks, it does not perform well. Compared to wired networks, wireless ad hoc networks have some specific characteristics such as node mobility and a shared medium. Owing to these specific characteristics of wireless ad hoc networks, TCP faces particular problems with, for example, route failure, channel contention and high bit error rates. These factors are responsible for the performance degradation of TCP in wireless ad hoc networks. The research community has produced a wide range of proposals to improve the performance of TCP in wireless ad hoc networks. This article presents a survey of these proposals (approaches. A classification of TCP improvement proposals for wireless ad hoc networks is presented, which makes it easy to compare the proposals falling under the same category. Tables which summarize the approaches for quick overview are provided. Possible directions for further improvements in this area are suggested in the conclusions. The aim of the article is to enable the reader to quickly acquire an overview of the state of TCP in wireless ad hoc networks.

  19. Fin-and-tube condenser performance evaluation using neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Ling-Xiao [Institute of Refrigeration and Cryogenics, Shanghai Jiaotong University, Shanghai 200240 (China); Zhang, Chun-Lu [China R and D Center, Carrier Corporation, No. 3239 Shen Jiang Road, Shanghai 201206 (China)

    2010-05-15

    The paper presents neural network approach to performance evaluation of the fin-and-tube air-cooled condensers which are widely used in air-conditioning and refrigeration systems. Inputs of the neural network include refrigerant and air-flow rates, refrigerant inlet temperature and saturated temperature, and entering air dry-bulb temperature. Outputs of the neural network consist of the heating capacity and the pressure drops on both refrigerant and air sides. The multi-input multi-output (MIMO) neural network is separated into multi-input single-output (MISO) neural networks for training. Afterwards, the trained MISO neural networks are combined into a MIMO neural network, which indicates that the number of training data sets is determined by the biggest MISO neural network not the whole MIMO network. Compared with a validated first-principle model, the standard deviations of neural network models are less than 1.9%, and all errors fall into {+-}5%. (author)

  20. Management Practices, Environmental Characteristics and Organizational Performance.

    Science.gov (United States)

    1981-02-01

    organizations: Toward a machine-scored standarized questionnarie instrument. Ann Arbor: Institute for Social Research, 1972. Terhorg, J.R., Richardson, P...8217&-78-C-0756 UNCLASSIFIED NL I.EVEL 0 IJTIC MAR 2 5 1981. 0 F Graduate School of Management University of Oregon Eugene, Oregon 97403 DISTMiBUT1O1N Sm...process Climate supervisory practices Likert organization practices Organization Performance aggregate attitudes Turnover 20. ABSTRACT (ContInua an revere

  1. Predicting Expressive Dynamics in Piano Performances using Neural Networks

    NARCIS (Netherlands)

    van Herwaarden, Sam; Grachten, Maarten; de Haas, W. Bas

    2014-01-01

    This paper presents a model for predicting expressive accentuation in piano performances with neural networks. Using Restricted Boltzmann Machines (RBMs), features are learned from performance data, after which these features are used to predict performed loudness. During feature learning, data

  2. Artificial neural network simulator for SOFC performance prediction

    Science.gov (United States)

    Arriagada, Jaime; Olausson, Pernilla; Selimovic, Azra

    This paper describes the development of a novel modelling tool for evaluation of solid oxide fuel cell (SOFC) performance. An artificial neural network (ANN) is trained with a reduced amount of data generated by a validated cell model, and it is then capable of learning the generic functional relationship between inputs and outputs of the system. Once the network is trained, the ANN-driven simulator can predict different operational parameters of the SOFC (i.e. gas flows, operational voltages, current density, etc.) avoiding the detailed description of the fuel cell processes. The highly parallel connectivity within the ANN further reduces the computational time. In a real case, the necessary data for training the ANN simulator would be extracted from experiments. This simulator could be suitable for different applications in the fuel cell field, such as, the construction of performance maps and operating point optimisation and analysis. All this is performed with minimum time demand and good accuracy. This intelligent model together with the operational conditions may provide useful insight into SOFC operating characteristics and improved means of selecting operating conditions, reducing costs and the need for extensive experiments.

  3. Analysis of complex network performance and heuristic node removal strategies

    Science.gov (United States)

    Jahanpour, Ehsan; Chen, Xin

    2013-12-01

    Removing important nodes from complex networks is a great challenge in fighting against criminal organizations and preventing disease outbreaks. Six network performance metrics, including four new metrics, are applied to quantify networks' diffusion speed, diffusion scale, homogeneity, and diameter. In order to efficiently identify nodes whose removal maximally destroys a network, i.e., minimizes network performance, ten structured heuristic node removal strategies are designed using different node centrality metrics including degree, betweenness, reciprocal closeness, complement-derived closeness, and eigenvector centrality. These strategies are applied to remove nodes from the September 11, 2001 hijackers' network, and their performance are compared to that of a random strategy, which removes randomly selected nodes, and the locally optimal solution (LOS), which removes nodes to minimize network performance at each step. The computational complexity of the 11 strategies and LOS is also analyzed. Results show that the node removal strategies using degree and betweenness centralities are more efficient than other strategies.

  4. [Analysis of gene effects on performance characteristics].

    Science.gov (United States)

    Geldermann, H

    1996-10-01

    In farm animals, associations between individually identified genotypes and the values of performance traits were investigated since more than 30 years. The topic of research was largely determined by the Veterinary Institute of the University of Göttingen. For the experimental analysis of gene loci, for which allelic variants are connected with alterations of trait values, new techniques of DNA diagnostic were of crucial significance. Thereby, two approaches of analysis of quantitative trait loci (QTL) can be distinguished. By considering informative groups of animals, the first approach uses marker loci in order to trace the inheritance of their alleles and thus simultaneously the transfer of specific chromosome sections to individuals of the offspring generation. By this manner, the associations between the marked chromosome regions and trait values are calculated. Results are shown for examples from experiments with milk performance in cattle and with fatting and carcass traits in pigs. In the second approach, genetic effects of trait values are assigned to distinct genes or gene clusters. For this purpose, variants of the gene structure are identified and then analysed for their effects on the formation of specific trait values. As an example of such a functional analysis of single gene positions, the milk protein coding genes in cattle are given. From the data we see that DNA techniques allow a direct access to genotypic information and so far-reaching potential for tracing back effects on trait values to single nucleotide differences. However, such a functional analysis need specific test systems which are able to consider the complex net work between single gene effects and the multifactorially caused values of performance traits. This will be possible by proceedings, which identify the gene effects in vivo and the balancing forces of haplotype combinations in populations. Genetic parameters of such investigations are needed for farm animal populations

  5. Wireless Local Area Network Performance Inside Aircraft Passenger Cabins

    Science.gov (United States)

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

    2005-01-01

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

  6. Social Network Analysis and Qualitative Interviews for Assessing Geographic Characteristics of Tourism Business Networks.

    Science.gov (United States)

    Kelman, Ilan; Luthe, Tobias; Wyss, Romano; Tørnblad, Silje H; Evers, Yvette; Curran, Marina Martin; Williams, Richard J; Berlow, Eric L

    2016-01-01

    This study integrates quantitative social network analysis (SNA) and qualitative interviews for understanding tourism business links in isolated communities through analysing spatial characteristics. Two case studies are used, the Surselva-Gotthard region in the Swiss Alps and Longyearbyen in the Arctic archipelago of Svalbard, to test the spatial characteristics of physical proximity, isolation, and smallness for understanding tourism business links. In the larger Surselva-Gotthard region, we found a strong relationship between geographic separation of the three communities on compartmentalization of the collaboration network. A small set of businesses played a central role in steering collaborative decisions for this community, while a group of structurally 'peripheral' actors were less influential. By contrast, the business community in Svalbard showed compartmentalization that was independent of geographic distance between actors. Within towns of similar size and governance scale, Svalbard is more compartmentalized, and those compartments are not driven by geographic separation of the collaboration clusters. This compartmentalization in Svalbard was reflected in a lower density of formal business collaboration ties compared to the communities of the Alps. We infer that the difference is due to Svalbard having higher cultural diversity and population turnover than the Alps communities. We propose that integrating quantitative network analysis from simple surveys with qualitative interviews targeted from the network results is an efficient general approach to identify regionally specific constraints and opportunities for effective governance.

  7. Social Network Analysis and Qualitative Interviews for Assessing Geographic Characteristics of Tourism Business Networks.

    Directory of Open Access Journals (Sweden)

    Ilan Kelman

    Full Text Available This study integrates quantitative social network analysis (SNA and qualitative interviews for understanding tourism business links in isolated communities through analysing spatial characteristics. Two case studies are used, the Surselva-Gotthard region in the Swiss Alps and Longyearbyen in the Arctic archipelago of Svalbard, to test the spatial characteristics of physical proximity, isolation, and smallness for understanding tourism business links. In the larger Surselva-Gotthard region, we found a strong relationship between geographic separation of the three communities on compartmentalization of the collaboration network. A small set of businesses played a central role in steering collaborative decisions for this community, while a group of structurally 'peripheral' actors were less influential. By contrast, the business community in Svalbard showed compartmentalization that was independent of geographic distance between actors. Within towns of similar size and governance scale, Svalbard is more compartmentalized, and those compartments are not driven by geographic separation of the collaboration clusters. This compartmentalization in Svalbard was reflected in a lower density of formal business collaboration ties compared to the communities of the Alps. We infer that the difference is due to Svalbard having higher cultural diversity and population turnover than the Alps communities. We propose that integrating quantitative network analysis from simple surveys with qualitative interviews targeted from the network results is an efficient general approach to identify regionally specific constraints and opportunities for effective governance.

  8. Moving Large Data Sets Over High-Performance Long Distance Networks

    Energy Technology Data Exchange (ETDEWEB)

    Hodson, Stephen W [ORNL; Poole, Stephen W [ORNL; Ruwart, Thomas [ORNL; Settlemyer, Bradley W [ORNL

    2011-04-01

    In this project we look at the performance characteristics of three tools used to move large data sets over dedicated long distance networking infrastructure. Although performance studies of wide area networks have been a frequent topic of interest, performance analyses have tended to focus on network latency characteristics and peak throughput using network traffic generators. In this study we instead perform an end-to-end long distance networking analysis that includes reading large data sets from a source file system and committing large data sets to a destination file system. An evaluation of end-to-end data movement is also an evaluation of the system configurations employed and the tools used to move the data. For this paper, we have built several storage platforms and connected them with a high performance long distance network configuration. We use these systems to analyze the capabilities of three data movement tools: BBcp, GridFTP, and XDD. Our studies demonstrate that existing data movement tools do not provide efficient performance levels or exercise the storage devices in their highest performance modes. We describe the device information required to achieve high levels of I/O performance and discuss how this data is applicable in use cases beyond data movement performance.

  9. Image Filtering with Neural Networks: applications and performance evaluation

    NARCIS (Netherlands)

    Spreeuwers, Lieuwe Jan

    1992-01-01

    A simple and elegant method to design image filters with neural networks is proposed: using small networks that scan the image and perform position invariant filtering. In the theses examples of image filtering with error backpropagation networks for edge detection, image deblurring and noise

  10. In-Network Performance of Handheld Mobile Terminals

    DEFF Research Database (Denmark)

    Nielsen, Jesper Ødum; Pedersen, Gert Frølund

    2006-01-01

    are compared with the equivalent performance obtained in a live GSM network using data from the Abis network interface. This method does not require altering of the handsets and the testing uses normal calls in the network. The investigation is based on measurements with four different commercially available...

  11. Personal and Network Dynamics in Performance of Knowledge Workers: A Study of Australian Breast Radiologists.

    Science.gov (United States)

    Tavakoli Taba, Seyedamir; Hossain, Liaquat; Heard, Robert; Brennan, Patrick; Lee, Warwick; Lewis, Sarah

    2016-01-01

    In this paper, we propose a theoretical model based upon previous studies about personal and social network dynamics of job performance. We provide empirical support for this model using real-world data within the context of the Australian radiology profession. An examination of radiologists' professional network topology through structural-positional and relational dimensions and radiologists' personal characteristics in terms of knowledge, experience and self-esteem is provided. Thirty one breast imaging radiologists completed a purpose designed questionnaire regarding their network characteristics and personal attributes. These radiologists also independently read a test set of 60 mammographic cases: 20 cases with cancer and 40 normal cases. A Jackknife free response operating characteristic (JAFROC) method was used to measure the performance of the radiologists' in detecting breast cancers. Correlational analyses showed that reader performance was positively correlated with the social network variables of degree centrality and effective size, but negatively correlated with constraint and hierarchy. For personal characteristics, the number of mammograms read per year and self-esteem (self-evaluation) positively correlated with reader performance. Hierarchical multiple regression analysis indicated that the combination of number of mammograms read per year and network's effective size, hierarchy and tie strength was the best fitting model, explaining 63.4% of the variance in reader performance. The results from this study indicate the positive relationship between reading high volumes of cases by radiologists and expertise development, but also strongly emphasise the association between effective social/professional interactions and informal knowledge sharing with high performance.

  12. Novel Estimation of Pilot Performance Characteristics

    Science.gov (United States)

    Bachelder, Edward N.; Aponso, Bimal

    2017-01-01

    Two mechanisms internal to the pilot that affect performance during a tracking task are: 1) Pilot equalization (i.e. lead/lag); and 2) Pilot gain (i.e. sensitivity to the error signal). For some applications McRuer's Crossover Model can be used to anticipate what equalization will be employed to control a vehicle's dynamics. McRuer also established approximate time delays associated with different types of equalization - the more cognitive processing that is required due to equalization difficulty, the larger the time delay. However, the Crossover Model does not predict what the pilot gain will be. A nonlinear pilot control technique, observed and coined by the authors as 'amplitude clipping', is shown to improve stability, performance, and reduce workload when employed with vehicle dynamics that require high lead compensation by the pilot. Combining linear and nonlinear methods a novel approach is used to measure the pilot control parameters when amplitude clipping is present, allowing precise measurement in real time of key pilot control parameters. Based on the results of an experiment which was designed to probe workload primary drivers, a method is developed that estimates pilot spare capacity from readily observable measures and is tested for generality using multi-axis flight data. This paper documents the initial steps to developing a novel, simple objective metric for assessing pilot workload and its variation over time across a wide variety of tasks. Additionally, it offers a tangible, easily implementable methodology for anticipating a pilot's operating parameters and workload, and an effective design tool. The model shows promise in being able to precisely predict the actual pilot settings and workload, and observed tolerance of pilot parameter variation over the course of operation. Finally, an approach is proposed for generating Cooper-Harper ratings based on the workload and parameter estimation methodology.

  13. MODEL OF EMERGENCY DEPARTMENT NURSE PERFORMANCE IMPROVEMENT BASED ON ASSOCIATION OF INDIVIDUAL CHARACTERISTIC, ORGANIZATION CHARACTERISTIC AND JOB CHARACTERISTIC

    Directory of Open Access Journals (Sweden)

    Maria Margaretha Bogar

    2017-04-01

    Full Text Available Introduction: Nursing care is integral part of health care and having important role in management of patient with emergency condition. The purpose of this research was to develop nurse performance improvement model based on individual, organization and job characteristics association in Emergency Department of RSUD dr TC Hillers Maumere. Method: This was an explanative survey by cross sectional approach held on July -August 2012. Respondents in this study were 22 nurses and 44 patients were obtained by purposive sampling technique. Data were analyzed by partial least square test and signi fi cant t value > 1.64 (alpha 10%. Result: Results showed that individual characteristic had effect on nurse performance (t = 7.59, organization characteristic had effect on nurse performance (t = 2.03 and job characteristic didn’t have effect on nurse performance (t = 0.88. Nurse performance had effect on patient satisfaction (t = 6.54 but nurse satisfaction didn’t have effect on nurse performance (t = 1.31, and nurse satisfaction didn’t have effect either on patient satisfaction (t = 0.94. Discussion: This research concluded that individual characteristics which in fl uence nurse performance in nursing care were ability and skill, experience, age, sex, attitude and motivation. Organization characteristic that influence nurse performance was reward while job characteristic that include job design and feedback didn’t influence nurse performance in nursing care. Nurse performance influenced patient satisfaction but nurse satisfaction didn’t influence patient satisfaction and nurse performance.

  14. Study on multiple-hops performance of MOOC sequences-based optical labels for OPS networks

    Science.gov (United States)

    Zhang, Chongfu; Qiu, Kun; Ma, Chunli

    2009-11-01

    In this paper, we utilize a new study method that is under independent case of multiple optical orthogonal codes to derive the probability function of MOOCS-OPS networks, discuss the performance characteristics for a variety of parameters, and compare some characteristics of the system employed by single optical orthogonal code or multiple optical orthogonal codes sequences-based optical labels. The performance of the system is also calculated, and our results verify that the method is effective. Additionally it is found that performance of MOOCS-OPS networks would, negatively, be worsened, compared with single optical orthogonal code-based optical label for optical packet switching (SOOC-OPS); however, MOOCS-OPS networks can greatly enlarge the scalability of optical packet switching networks.

  15. Spectral characteristics of fiber couplers for FTTx networks

    Science.gov (United States)

    Vitasek, Jan; Latal, Jan; Koudelka, Petr; Vasinek, Vladimir; Bocheza, Jiri; Hejduk, Stanislav

    2012-06-01

    This article deals with spectral characteristics measurement of fiber couplers which are used for FTTx networks. Due to WDM systems we are able to communicate with several wavelengths at a time. In xPON systems the data transmission runs at wavelengths 1310 nm, 1490 and 1550 nm, in case of using singlemode fibers, or at 850 nm and 1300 nm in case of using multimode fibers. The target of this work is a testing how the individual parameters of fiber coupler behave whether broad spectrum light source is connected to the input. In sum it was measured four most often used fiber couplers, fiber coupler in port configuration 1x2 with coupling ratio 50/50%, fiber coupler in port configuration 1x2 with coupling ratio 30/70%, fiber coupler in port configuration 1x2 with coupling ratio 10/90% and fiber coupler in port configuration 1×4 with coupling ratio 4×25%. For these fiber couplers it was set insertion losses, coupling ratios, homogeneities and total losses by using a broad spectrum light source. The results are valuable information for companies which deal with optical networks.

  16. Identification and adaptive neural network control of a DC motor system with dead-zone characteristics.

    Science.gov (United States)

    Peng, Jinzhu; Dubay, Rickey

    2011-10-01

    In this paper, an adaptive control approach based on the neural networks is presented to control a DC motor system with dead-zone characteristics (DZC), where two neural networks are proposed to formulate the traditional identification and control approaches. First, a Wiener-type neural network (WNN) is proposed to identify the motor DZC, which formulates the Wiener model with a linear dynamic block in cascade with a nonlinear static gain. Second, a feedforward neural network is proposed to formulate the traditional PID controller, termed as PID-type neural network (PIDNN), which is then used to control and compensate for the DZC. In this way, the DC motor system with DZC is identified by the WNN identifier, which provides model information to the PIDNN controller in order to make it adaptive. Back-propagation algorithms are used to train both neural networks. Also, stability and convergence analysis are conducted using the Lyapunov theorem. Finally, experiments on the DC motor system demonstrated accurate identification and good compensation for dead-zone with improved control performance over the conventional PID control. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

  17. Application of Bayesian Networks for Estimation of Individual Psychological Characteristics

    KAUST Repository

    Litvinenko, Alexander

    2017-07-19

    In this paper we apply Bayesian networks for developing more accurate final overall estimations of psychological characteristics of an individual, based on psychological test results. Psychological tests which identify how much an individual possesses a certain factor are very popular and quite common in the modern world. We call this value for a given factor -- the final overall estimation. Examples of factors could be stress resistance, the readiness to take a risk, the ability to concentrate on certain complicated work and many others. An accurate qualitative and comprehensive assessment of human potential is one of the most important challenges in any company or collective. The most common way of studying psychological characteristics of each single person is testing. Psychologists and sociologists are constantly working on improvement of the quality of their tests. Despite serious work, done by psychologists, the questions in tests often do not produce enough feedback due to the use of relatively poor estimation systems. The overall estimation is usually based on personal experiences and the subjective perception of a psychologist or a group of psychologists about the investigated psychological personality factors.

  18. Topological Effects and Performance Optimization in Transportation Continuous Network Design

    Directory of Open Access Journals (Sweden)

    Jianjun Wu

    2014-01-01

    Full Text Available Because of the limitation of budget, in the planning of road works, increased efforts should be made on links that are more critical to the whole traffic system. Therefore, it would be helpful to model and evaluate the vulnerability and reliability of the transportation network when the network design is processing. This paper proposes a bilevel transportation network design model, in which the upper level is to minimize the performance of the network under the given budgets, while the lower level is a typical user equilibrium assignment problem. A new solution approach based on particle swarm optimization (PSO method is presented. The topological effects on the performance of transportation networks are studied with the consideration of three typical networks, regular lattice, random graph, and small-world network. Numerical examples and simulations are presented to demonstrate the proposed model.

  19. Social Network Characteristics Associated with Weight Loss among Black and Hispanic Adults with Overweight and Obesity

    OpenAIRE

    Winston, Ginger; Phillips, Erica G.; Wethington, Elaine; Devine, Carol; Wells, Martin; Peterson, Janey C.; Hippolyte, Jessica; Ramos, Rosio; Martinez, Guillerma; Eldridge, Johanna; Charlson, Mary

    2015-01-01

    Objective To examine social network member characteristics associated with weight loss. Methods Cross-sectional examination of egocentric network data from 245 Black and Hispanic adults with BMI ? 25 kg/m2 enrolled in a small change weight loss study. The relationship between weight loss at 12 months and characteristics of helpful and harmful network members (relationship, contact frequency, living proximity and body size) were examined. Results There were 2,571 network members identified. Me...

  20. Library Network Statistics and Performance Measures: Approaches and Issues

    Directory of Open Access Journals (Sweden)

    John Carlo Bertot

    2001-07-01

    Full Text Available Library networked statistics and performance measures are important indicators of the use, uses, and users of networked services that libraries offer their patrons. This article focuses on three efforts to develop and standardize library network statistics and performance measures. In particular, the article discusses, compares, and contrasts selected aspects of the International Standards Organization (ISO, U.S. public library network statistics, and Association of Research Library (ARL efforts. The three approaches attempt to capture, describe, and present library networked activities in similar ways through similar approaches – yet they differ in key areas. It is important to note that there are a number of national and international efforts underway that continue to research the library network statistics and performance measure environment.

  1. Building and measuring a high performance network architecture

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, William T.C.; Toole, Timothy; Fisher, Chuck; Dugan, Jon; Wheeler, David; Wing, William R; Nickless, William; Goddard, Gregory; Corbato, Steven; Love, E. Paul; Daspit, Paul; Edwards, Hal; Mercer, Linden; Koester, David; Decina, Basil; Dart, Eli; Paul Reisinger, Paul; Kurihara, Riki; Zekauskas, Matthew J; Plesset, Eric; Wulf, Julie; Luce, Douglas; Rogers, James; Duncan, Rex; Mauth, Jeffery

    2001-04-20

    Once a year, the SC conferences present a unique opportunity to create and build one of the most complex and highest performance networks in the world. At SC2000, large-scale and complex local and wide area networking connections were demonstrated, including large-scale distributed applications running on different architectures. This project was designed to use the unique opportunity presented at SC2000 to create a testbed network environment and then use that network to demonstrate and evaluate high performance computational and communication applications. This testbed was designed to incorporate many interoperable systems and services and was designed for measurement from the very beginning. The end results were key insights into how to use novel, high performance networking technologies and to accumulate measurements that will give insights into the networks of the future.

  2. Job Characteristics, Work Involvement, and Job Performance of Public Servants

    Science.gov (United States)

    Johari, Johanim; Yahya, Khulida Kirana

    2016-01-01

    Purpose: The primary purpose of this study is to assess the predicting role of job characteristics on job performance. Dimensions in the job characteristics construct are skill variety, task identity, task significance, autonomy and feedback. Further, work involvement is tested as a mediator in the hypothesized link. Design/methodology/approach: A…

  3. Design and performance characteristics of a krypton chloride (λ ...

    Indian Academy of Sciences (India)

    2014-01-07

    Jan 7, 2014 ... Home; Journals; Pramana – Journal of Physics; Volume 82; Issue 1. Design and performance characteristics of a krypton chloride ( = 222 nm) excimer laser. N S Benerji N ... In this paper the design, successful realization and operating characteristics of KrCl excimer laser are reported. The laser is driven ...

  4. Force10 networks performance in world's first transcontinental 10 gigabit ethernet network verified by Ixia

    CERN Multimedia

    2003-01-01

    Force10 Networks, Inc., today announced that the performance of the Force10 E-Series switch/routers deployed in a transcontinental network has been verified as line-rate 10 GE throughput by Ixia, a leading provider of high-speed, network performance and conformance analysis systems. The network, the world's first transcontinental 10 GE wide area network, consists of a SURFnet OC-192 lambda between Geneva and the StarLight facility in Chicago via Amsterdam and another OC-192 lambda between this same facility in Chicago and Carleton University in Ottawa, Canada provided by CANARIE and ORANO (1/2 page).

  5. Performance and carcass characteristics of broilers fed boiled ...

    African Journals Online (AJOL)

    Performance and carcass characteristics of broilers fed boiled cowpea (Vigna unguiculata L Walp) and or black common bean (Phaseolus vulgaris) meal diets. HF Defang, A Teguia, J Awah-Ndukum, A Kenfack, F Ngoula, F Metuge ...

  6. Multidimensional performance characteristics in selected and deselected talented soccer players

    NARCIS (Netherlands)

    B.C. Huijgen; Koen A.P.M. Lemmink; C. Visscher; M.T. Elferink-Gemser

    2014-01-01

    Abstract: The present study examined whether performance characteristics discriminated between selected and deselected players in talent development programmes. This examination was carried out in talented soccer players, aged 16-18 years using objective measurement instruments. Four domains of

  7. Evaluation of the productive performance characteristics of red ...

    African Journals Online (AJOL)

    Evaluation of the productive performance characteristics of red tilapia ( Oreochromis sp.) injected with shark DNA into skeletal muscles and maintained diets containing different levels of probiotic and amino yeast.

  8. Correlation Between Resting-state Electroencephalographic Characteristics and Shooting Performance.

    Science.gov (United States)

    Gong, Anmin; Liu, Jianping; Li, Fangbo; Liu, Fangyi; Jiang, Changhao; Fu, Yunfa

    2017-12-16

    According to the theories of neural plasticity and neural efficiency, professional skill training improves performance by strengthening the underlying neural mechanisms. Therefore, subjects trained professionally may exhibit changes in resting-state neurophysiological characteristics closely related to performance. To test this notion, the resting-state electroencephalogram (EEG) was measured from 35 rifle shooters after the same training regimen, and resting-state EEG characteristics were analyzed for correlations with shooting performance. The results showed a significant linear correlation between shooting performance and the coherence of electrode channels C3 and T3 in the beta1 band (r = 0.74, P shooting performance (r = 0.56, P shooting and a new method for predicting and evaluating performance based on EEG characteristics. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

  9. Wireless ad hoc and sensor networks management, performance, and applications

    CERN Document Server

    He, Jing

    2013-01-01

    Although wireless sensor networks (WSNs) have been employed across a wide range of applications, there are very few books that emphasize the algorithm description, performance analysis, and applications of network management techniques in WSNs. Filling this need, Wireless Ad Hoc and Sensor Networks: Management, Performance, and Applications summarizes not only traditional and classical network management techniques, but also state-of-the-art techniques in this area. The articles presented are expository, but scholarly in nature, including the appropriate history background, a review of current

  10. Performers and performance : how to investigate the contribution of the operational network to operational performance

    NARCIS (Netherlands)

    Wijngaard, J.; Vries, J. de; Nauta, A.

    2006-01-01

    Purpose This paper seeks to explore the question of how to investigate the contribution of the operational network (comprising sales service, logistics, planning, production, etc.) to operational performance. In doing so, the paper aims to link concepts from organisational and social psychology to

  11. Performers and performance : How to investigate the contribution of the operational network to operational performance

    NARCIS (Netherlands)

    Wijngaard, J.; de Vries, J.; Nauta, Aukje

    2006-01-01

    Purpose - This paper seeks to explore the question of how to investigate the contribution of the operational network (comprising sales service, logistics, planning, production, etc.) to operational performance. In doing so, the paper aims to link concepts from organisational and social psychology to

  12. The Influence of Top Management Team Characteristics on BPD Performance

    Directory of Open Access Journals (Sweden)

    Joy Elly Tulung

    2015-12-01

    Full Text Available Based on ”upper echelons theory”, this paper investigates the relation between top management team composition and BPD performance. For top management team characteristics, we employ age, level of education, background of education, gender, and functional background, while for measured the BPD performance we employ return on asset (ROA, return on equity (ROE, capital adequacy ratio (CAR, net interest margin (NIM, loan to deposit ratio (LDR, non-performing loan (NPL and operation expenses to operation income (BOPO. The results show that all characteristics have positive significant influences on BPD performance.

  13. Human Navigational Performance in a Complex Network with Progressive Disruptions

    CERN Document Server

    Ramesh, Amitash; Iyengar, Sudarshan; Sekhar, Vinod

    2012-01-01

    The current paper is an investigation towards understanding the navigational performance of humans on a network when the "landmark" nodes are blocked. We observe that humans learn to cope up, despite the continued introduction of blockages in the network. The experiment proposed involves the task of navigating on a word network based on a puzzle called the wordmorph. We introduce blockages in the network and report an incremental improvement in performance with respect to time. We explain this phenomenon by analyzing the evolution of the knowledge in the human participants of the underlying network as more and more landmarks are removed. We hypothesize that humans learn the bare essentials to navigate unless we introduce blockages in the network which would whence enforce upon them the need to explore newer ways of navigating. We draw a parallel to human problem solving and postulate that obstacles are catalysts for humans to innovate techniques to solve a restricted variant of a familiar problem.

  14. A comprehensive approach for evaluating network performance in surface and borehole seismic monitoring

    Science.gov (United States)

    Stabile, T. A.; Iannaccone, G.; Zollo, A.; Lomax, A.; Ferulano, M. F.; Vetri, M. L. V.; Barzaghi, L. P.

    2013-02-01

    The accurate determination of locations and magnitudes of seismic events in a monitored region is important for many scientific, industrial and military studies and applications; for these purposes a wide variety of seismic networks are deployed throughout the world. It is crucial to know the performance of these networks not only in detecting and locating seismic events of different sizes throughout a specified source region, but also by evaluating their location errors as a function of the magnitude and source location. In this framework, we have developed a method for evaluating network performance in surface and borehole seismic monitoring. For a specified network geometry, station characteristics and a target monitoring volume, the method determines the lowest magnitude of events that the seismic network is able to detect (Mwdetect), and locate (Mwloc) and estimates the expected location and origin time errors for a specified magnitude. Many of the features related to the seismic signal recorded at a single station are considered in this methodology, including characteristics of the seismic source, the instrument response, the ambient noise level, wave propagation in a layered, anelastic medium and uncertainties on waveform measures and the velocity model. We applied this method to two different network typologies: a local earthquake monitoring network, Irpinia Seismic Network (ISNet), installed along the Campania-Lucania Apennine chain in Southern Italy, and a hypothetic borehole network for monitoring microfractures induced during the hydrocarbon extraction process in an oil field. The method we present may be used to aid in enhancing existing networks and/or understanding their capabilities, such as for the ISNet case study, or to optimally design the network geometry in specific target regions, as for the borehole network example.

  15. Structure of Small World Innovation Network and Learning Performance

    Directory of Open Access Journals (Sweden)

    Shuang Song

    2014-01-01

    Full Text Available This paper examines the differences of learning performance of 5 MNCs (multinational corporations that filed the largest number of patents in China. We establish the innovation network with the patent coauthorship data by these 5 MNCs and classify the networks by the tail of distribution curve of connections. To make a comparison of the learning performance of these 5 MNCs with differing network structures, we develop an organization learning model by regarding the reality as having m dimensions, which denotes the heterogeneous knowledge about the reality. We further set n innovative individuals that are mutually interactive and own unique knowledge about the reality. A longer (shorter distance between the knowledge of the individual and the reality denotes a lower (higher knowledge level of that individual. Individuals interact with and learn from each other within the small-world network. By making 1,000 numerical simulations and averaging the simulated results, we find that the differing structure of the small-world network leads to the differences of learning performance between these 5 MNCs. The network monopolization negatively impacts and network connectivity positively impacts learning performance. Policy implications in the conclusion section suggest that to improve firm learning performance, it is necessary to establish a flat and connective network.

  16. End-to-end network/application performance troubleshooting methodology

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Wenji; Bobyshev, Andrey; Bowden, Mark; Crawford, Matt; Demar, Phil; Grigaliunas, Vyto; Grigoriev, Maxim; Petravick, Don; /Fermilab

    2007-09-01

    The computing models for HEP experiments are globally distributed and grid-based. Obstacles to good network performance arise from many causes and can be a major impediment to the success of the computing models for HEP experiments. Factors that affect overall network/application performance exist on the hosts themselves (application software, operating system, hardware), in the local area networks that support the end systems, and within the wide area networks. Since the computer and network systems are globally distributed, it can be very difficult to locate and identify the factors that are hurting application performance. In this paper, we present an end-to-end network/application performance troubleshooting methodology developed and in use at Fermilab. The core of our approach is to narrow down the problem scope with a divide and conquer strategy. The overall complex problem is split into two distinct sub-problems: host diagnosis and tuning, and network path analysis. After satisfactorily evaluating, and if necessary resolving, each sub-problem, we conduct end-to-end performance analysis and diagnosis. The paper will discuss tools we use as part of the methodology. The long term objective of the effort is to enable site administrators and end users to conduct much of the troubleshooting themselves, before (or instead of) calling upon network and operating system 'wizards,' who are always in short supply.

  17. TCP Performance over Gigabit-Capable Passive Optical Networks

    Science.gov (United States)

    Orozco, Julio; Ros, David

    The deployment of optical access networks is considered by many as the sole solution able to cope with the ever-increasing bandwidth needs of data and media applications. Gigabit-capable Passive Optical Networks (GPON) are being adopted by many operators worldwide as their preferred fiber-to-the-home network architecture. In such systems, the Medium Access Control (MAC) layer is a key aspect of their operation and performance.

  18. High Performance Networks From Supercomputing to Cloud Computing

    CERN Document Server

    Abts, Dennis

    2011-01-01

    Datacenter networks provide the communication substrate for large parallel computer systems that form the ecosystem for high performance computing (HPC) systems and modern Internet applications. The design of new datacenter networks is motivated by an array of applications ranging from communication intensive climatology, complex material simulations and molecular dynamics to such Internet applications as Web search, language translation, collaborative Internet applications, streaming video and voice-over-IP. For both Supercomputing and Cloud Computing the network enables distributed applicati

  19. Gender and Peer Effects on Performance in Social Networks

    OpenAIRE

    Beugnot, Julie; Fortin, Bernard; Lacroix, Guy; Villeval, Marie Claire

    2017-01-01

    We investigate whether peer effects at work differ by gender and whether gender differences in peer effects -if any- depend on work organization. We develop a social network model with gender heterogeneity that we test in a real-effort laboratory experiment. We compare sequential networks in which information flows from peers to the worker and simultaneous networks where it disseminates bi-directionally. We identify strong gender differences as females disregard their peers’ performance in si...

  20. The Current Performance of the Third Interplanetary Network

    OpenAIRE

    Hurley, K.; Cline, T.; Mitrofanov, I.; Mazets, E.; Golenetskii, S.; Frontera, F.; Montanari, E; Guidorzi, C; Feroci, M.

    2002-01-01

    The 3rd Interplanetary Network (IPN) has been operating since April 2001 with two distant spacecraft, Ulysses and Mars Odyssey, and numerous near-Earth spacecraft, such as BeppoSAX, Wind, and HETE-II. Mars Odyssey is presently in orbit about Mars, and the network has detected approximately 30 cosmic, SGR, and solar bursts. We discuss the results obtained to date and use them to predict the future performance of the network.

  1. Academic Performance and the Use of Social Networks

    Directory of Open Access Journals (Sweden)

    Jéssica Ribeiro Rangel

    2016-08-01

    Full Text Available This study aimed to investigate whether the use of social networks influences on the academic performance of students in the undergraduate program in accounting. Data were collected from 322 students of the course of a federal University of the State of Minas Gerais, Brazil. The regression results show that the variables "gender", "motivation" and "classification in the University entrance examination" are significant in explaining students' academic performance measured by the Grade Point Average (GPA. The results show that the performance of male students is lower than that of female students at the level of 5%. Also was identified that the greater the student's motivation level, the greater your academic performance (at the level of 1 percent. Finally, it was observed that the best ranked students in the University entrance examination, the higher their academic performance. However, none of the variables relating to the use of social networks ("familiarity with technological resources", "hours", "Internet hours on social networks" and "use of social networks to study" presented relation with academic performance. In other words, these results show that the use of social networks does not have positive or negative impacts directly on academic performance. We can conclude for the sample analyzed, that use of social networks during the academic period does not influence significantly the performance of the students. However, you can verify that the motivation is directly related to the academic performance of the Accounting student with regard to perception of motivation, to familiarity with technological resources and the use of applications.

  2. Analysis of Spatial Characteristics of Rainfall for Optimal Observation Network in Korea

    Science.gov (United States)

    Park, Sojung; Lee, Ebony; Park, Seon Ki; Park, Yunho; Lee, Jeung Whan

    2017-04-01

    Accurate prediction of high impact weather phenomena can reduce damages to people as well as property. Among the meteorological disasters occurred in Korea, heavy rainfall causes the second largest damage, next to typhoons. Therefore, proper observation network of rainfall is important for better understanding of the rainfall characteristics and for more accurate rainfall forecast over Korea. Precipitating weather systems in Korea are highly influenced by East Asian Monsoon, hence they have not only high seasonal variation in rainfall, but also high spatial variation due to complex topographic characteristics. In this study, we identify the spatial characteristics of rainfall in Korea with the geostatistical analyses, including autocorrelogram, variogram, Moran's I, and general G. We develop a testbed system to design an appropriate observation network for rainfall, which can be applied to other high impact weather systems. Geostatistical analyses are conducted using data sets collected from Automatic Weather Stations (AWS; 600 rain gauge data), global/regional numerical weather prediction outputs (i.e., temperature, geopotential height and humidity), Himawari satellite measurements (i.e., water vapor) over Korea in a period of 2013 - 2015. A heavy rainfall is defined as a case with the rainfall rate larger than 80 mm/24 hr over at least one station. In order to consider different characteristics of heavy rainfall systems, we have classified them into several groups: isolated thunderstorms, convective bands, squall lines, cloud clusters, migratory cyclones, typhoons, Changma (monsoon) frontal systems, and showers. We also perform the spatial analyses of rainfall by dividing Korea into several areas based on topographic characteristics. Our results show different properties for different heavy rainfall systems in terms of correlation distances, separation distances, clustered vs. random patterns, and hot vs. cold spots; thus suggesting clues for optimal observation

  3. A Mathematical Model to Improve the Performance of Logistics Network

    Directory of Open Access Journals (Sweden)

    Muhammad Izman Herdiansyah

    2012-01-01

    Full Text Available The role of logistics nowadays is expanding from just providing transportation and warehousing to offering total integrated logistics. To remain competitive in the global market environment, business enterprises need to improve their logistics operations performance. The improvement will be achieved when we can provide a comprehensive analysis and optimize its network performances. In this paper, a mixed integer linier model for optimizing logistics network performance is developed. It provides a single-product multi-period multi-facilities model, as well as the multi-product concept. The problem is modeled in form of a network flow problem with the main objective to minimize total logistics cost. The problem can be solved using commercial linear programming package like CPLEX or LINDO. Even in small case, the solver in Excel may also be used to solve such model.Keywords: logistics network, integrated model, mathematical programming, network optimization

  4. IT Performance Dashboard: Network/Security Dashboard

    Data.gov (United States)

    Department of Veterans Affairs — The IT Performance Dashboard is a trusted source for IT performance information across VA. This is available only on the VA intranet. The dashboard is a collection...

  5. Relationship Between Job Characteristics And Job Performance Of ...

    African Journals Online (AJOL)

    The agricultural extension agent is a key stakeholder in extension systems. The nature of their work is so important that it has overriding effect on their job performance. This study investigates the relationship between job characteristics and job performance of agricultural extension agents in Imo and Rivers States, Nigeria.

  6. Towards a Social Networks Model for Online Learning & Performance

    Science.gov (United States)

    Chung, Kon Shing Kenneth; Paredes, Walter Christian

    2015-01-01

    In this study, we develop a theoretical model to investigate the association between social network properties, "content richness" (CR) in academic learning discourse, and performance. CR is the extent to which one contributes content that is meaningful, insightful and constructive to aid learning and by social network properties we…

  7. Next generation network performance management: a business perspective

    CSIR Research Space (South Africa)

    Harding, C

    2010-08-01

    Full Text Available This paper addresses a Next Generation Network (NGN) performance management model in a business context. The CSIR is currently in the process of the concept design for the new Next Generation Communications Network (NGCN) for a large South African...

  8. Managing the Environment : Effects of network ambition on agency performance

    NARCIS (Netherlands)

    Akkerman, A.; Torenvlied, R.

    2011-01-01

    The literature on network management in the public sector reports positive effects of network activity on agency performance. Current studies show however no differences between specific types of contacts in an agency's environment. The present article adopts an explorative design to study the

  9. Mitigating the controller performance bottlenecks in Software Defined Networks

    DEFF Research Database (Denmark)

    Caba, Cosmin Marius; Soler, José

    2016-01-01

    The centralization of the control plane decision logic in Software Defined Networking (SDN) has raised concerns regarding the performance of the SDN Controller (SDNC) when the network scales up. A number of solutions have been proposed in the literature to address these concerns. This paper...

  10. Comparative performance of some popular artificial neural network ...

    Indian Academy of Sciences (India)

    Comparative performance of some popular artificial neural network algorithms on benchmark and function approximation problems ... dynamic range of these functions, it is suggested that these functions can also be considered as standard benchmark problems for function approximation using artificial neural networks.

  11. Nonlinear Performance Characteristics of Flux-Switching PM Motors

    Directory of Open Access Journals (Sweden)

    E. Ilhan

    2013-01-01

    Full Text Available Nonlinear performance characteristics of 3-phase flux-switching permanent magnet motors (FSPM are overviewed. These machines show advantages of a robust rotor structure and a high energy density. Research on the FSPM is predominated by topics such as modeling and machine comparison, with little emphasis given on its performance and limits. Performance characteristics include phase flux linkage, phase torque, and phase inductance. In the paper, this analysis is done by a cross-correlation of rotor position and armature current. Due to the high amount of processed data, which cannot be handled analytically within an acceptable time period, a multistatic 2D finite element model (FEM is used. For generalization, the most commonly discussed FSPM topology, 12/10 FSPM, is chosen. Limitations on the motor performance due to the saturation are discussed on each characteristic. Additionally, a focused overview is given on energy conversion loops and dq-axes identification for the FSPM.

  12. Network performance of a wireless sensor network for temperature monitoring in vineyards

    DEFF Research Database (Denmark)

    Liscano, Ramiro; Jacoub, John Khalil; Dersingh, Anand

    2011-01-01

    Wireless sensor networks (WSNs) are an emerging technology which can be used for outdoor environmental monitoring. This paper presents challenges that arose from the development and deployment of a WSN for environmental monitoring as well as network performance analysis of this network. Different...... components in our sensor network architecture are presented like the physical nodes, the sensor node code, and two messaging protocols; one for collecting sensor and network values and the other for sensor node commands. An information model for sensor nodes to support plug-and-play capabilities in sensor...

  13. Synthetic Event Reconstruction Experiments for Defining Sensor Network Characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Lundquist, J K; Kosovic, B; Belles, R

    2005-12-15

    An event reconstruction technology system has been designed and implemented at Lawrence Livermore National Laboratory (LLNL). This system integrates sensor observations, which may be sparse and/or conflicting, with transport and dispersion models via Bayesian stochastic sampling methodologies to characterize the sources of atmospheric releases of hazardous materials. We demonstrate the application of this event reconstruction technology system to designing sensor networks for detecting and responding to atmospheric releases of hazardous materials. The quantitative measure of the reduction in uncertainty, or benefit of a given network, can be utilized by policy makers to determine the cost/benefit of certain networks. Herein we present two numerical experiments demonstrating the utility of the event reconstruction methodology for sensor network design. In the first set of experiments, only the time resolution of the sensors varies between three candidate networks. The most ''expensive'' sensor network offers few advantages over the moderately-priced network for reconstructing the release examined here. The second set of experiments explores the significance of the sensors detection limit, which can have a significant impact on sensor cost. In this experiment, the expensive network can most clearly define the source location and source release rate. The other networks provide data insufficient for distinguishing between two possible clusters of source locations. When the reconstructions from all networks are aggregated into a composite plume, a decision-maker can distinguish the utility of the expensive sensor network.

  14. IBM SP high-performance networking with a GRF.

    Energy Technology Data Exchange (ETDEWEB)

    Navarro, J.P.

    1999-05-27

    Increasing use of highly distributed applications, demand for faster data exchange, and highly parallel applications can push the limits of conventional external networking for IBM SP sites. In technical computing applications we have observed a growing use of a pipeline of hosts and networks collaborating to collect, process, and visualize large amounts of realtime data. The GRF, a high-performance IP switch from Ascend and IBM, is the first backbone network switch to offer a media card that can directly connect to an SP Switch. This enables switch attached hosts in an SP complex to communicate at near SP Switch speeds with other GRF attached hosts and networks.

  15. The effects of traffic structure on application and network performance

    CERN Document Server

    Aikat, Jay; Smith, F Donelson

    2012-01-01

    Over the past three decades, the Internet's rapid growth has spurred the development of new applications in mobile computing, digital music, online video, gaming and social networks. These applications rely heavily upon various underlying network protocols and mechanisms to enable, maintain and enhance their Internet functionalityThe Effects of Traffic Structure on Application and Network Performance provides the necessary tools for maximizing the network efficiency of any Internet application, and presents ground-breaking research that will influence how these applications are built in the fu

  16. Network Characteristics, Perceived Social Support, and Psychological Adjustment in Mothers of Children with Autism Spectrum Disorder

    Science.gov (United States)

    Benson, Paul R.

    2012-01-01

    This study examined the characteristics of the support networks of 106 mothers of children with ASD and their relationship to perceived social support, depressed mood, and subjective well-being. Using structural equation modeling, two competing sets of hypotheses were assessed: (1) that network characteristics would impact psychological adjustment…

  17. Social Network Characteristics of Urban Adolescents in Brief Substance Abuse Treatment

    Science.gov (United States)

    Mason, Michael

    2009-01-01

    In this study, the social network characteristics of 102 urban adolescents in brief substance abuse treatment are described and analyzed longitudinally to examine risk and protective mechanisms. The treatment intervention had one session devoted to social support and networks. Social networks were conceptualized and measured along two dimensions…

  18. Networked Mobilities and Performative Urban Environments

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    Physical mobility has an important cultural dimension to contemporary life. The movement of objects, signs, and people constitutes material sites of networked relationships. However, as an increasing number of mobility practices are making up our everyday life experiences the movement is much mor...... a field of explorations into broader issues of democracy, multiple publics, and new mobile (electronic and material) agoras pointing towards a critical re-interpretation of contemporary politics of space and mobility.......Physical mobility has an important cultural dimension to contemporary life. The movement of objects, signs, and people constitutes material sites of networked relationships. However, as an increasing number of mobility practices are making up our everyday life experiences the movement is much more...... than a travel from point A to point B. The mobile experiences of the contemporary society are practices that are meaningful and normatively embedded. That is to say, mobility is seen as a cultural phenomenon shaping notions of self and other as well as the relationship to sites and places. Furthermore...

  19. Social networks : Effects on Identification, Performance and Satisfaction Effects on identification, performance and satisfaction

    NARCIS (Netherlands)

    Stormbroek-Burgers, van R.G.B.M.; Montfort, van K.; Sluis, van der E.C. (Lidewey)

    2011-01-01

    This study contributes to research on the impact of social networks on organizational outcomes in the context of the increasing number of professionals in the Netherlands. The aim of this study was to get insight into the characteristics of professionals’ social networks and to examine the effect of

  20. The performance analysis of linux networking - packet receiving

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Wenji; Crawford, Matt; Bowden, Mark; /Fermilab

    2006-11-01

    The computing models for High-Energy Physics experiments are becoming ever more globally distributed and grid-based, both for technical reasons (e.g., to place computational and data resources near each other and the demand) and for strategic reasons (e.g., to leverage equipment investments). To support such computing models, the network and end systems, computing and storage, face unprecedented challenges. One of the biggest challenges is to transfer scientific data sets--now in the multi-petabyte (10{sup 15} bytes) range and expected to grow to exabytes within a decade--reliably and efficiently among facilities and computation centers scattered around the world. Both the network and end systems should be able to provide the capabilities to support high bandwidth, sustained, end-to-end data transmission. Recent trends in technology are showing that although the raw transmission speeds used in networks are increasing rapidly, the rate of advancement of microprocessor technology has slowed down. Therefore, network protocol-processing overheads have risen sharply in comparison with the time spent in packet transmission, resulting in degraded throughput for networked applications. More and more, it is the network end system, instead of the network, that is responsible for degraded performance of network applications. In this paper, the Linux system's packet receive process is studied from NIC to application. We develop a mathematical model to characterize the Linux packet receiving process. Key factors that affect Linux systems network performance are analyzed.

  1. How coordination trajectories influence the performance of interorganizational project networks

    NARCIS (Netherlands)

    Barros de Oliveira, N.R.; Lumineau, Fabrice

    2017-01-01

    This study examines how the joint use of integrators and contracts either enables or hampers coordination and, in turn, the performance of interorganizational project networks. Using extensive qualitative analyses and socio-metric techniques, we investigated coordination among organizations during

  2. Performance Analysis on the Coexistence of Multiple Cognitive Radio Networks

    Directory of Open Access Journals (Sweden)

    Lijun Qian

    2015-05-01

    Full Text Available The demand for wireless services is growing on a daily basis while spectral resources to support this growth are static. Therefore, there is need for the adoption of a new spectrum sharing paradigm. Cognitive Radio (CR is a revolutionary technology aiming to increase spectrum utilization through dynamic spectrum access, as well as mitigating interference among multiple coexisting wireless networks. In many practical scenarios, multiple CR networks may coexist in the same geographical area, and they may interfere with each other and also have to yield to the primary user (PU. In this study, we investigate how much throughput a node in a CR network can achieve in the presence of another CR network and a PU. The results of this study illustrate how the transmission probability and sensing performance affect the achievable throughput of a node in coexisting CR networks. In addition, these results may serve as guidance for the deployment of multiple CR networks.

  3. Leveraging Structure to Improve Classification Performance in Sparsely Labeled Networks

    Energy Technology Data Exchange (ETDEWEB)

    Gallagher, B; Eliassi-Rad, T

    2007-10-22

    We address the problem of classification in a partially labeled network (a.k.a. within-network classification), with an emphasis on tasks in which we have very few labeled instances to start with. Recent work has demonstrated the utility of collective classification (i.e., simultaneous inferences over class labels of related instances) in this general problem setting. However, the performance of collective classification algorithms can be adversely affected by the sparseness of labels in real-world networks. We show that on several real-world data sets, collective classification appears to offer little advantage in general and hurts performance in the worst cases. In this paper, we explore a complimentary approach to within-network classification that takes advantage of network structure. Our approach is motivated by the observation that real-world networks often provide a great deal more structural information than attribute information (e.g., class labels). Through experiments on supervised and semi-supervised classifiers of network data, we demonstrate that a small number of structural features can lead to consistent and sometimes dramatic improvements in classification performance. We also examine the relative utility of individual structural features and show that, in many cases, it is a combination of both local and global network structure that is most informative.

  4. Factors Influencing the Performance of German Food SME Formal Networks

    Directory of Open Access Journals (Sweden)

    Jivka Deiters

    2014-08-01

    Full Text Available The food sector in Europe can be characterized as a complex, global and dynamically changing network of trade streams, food supply network relations and related product flows which offers a big spectrum for economic output and employment. Innovation is important for the competitiveness of the food industry that is to a large extent comprised of small and medium sized enterprises (SMEs. For them, innovation has grown extremely subordinate to interaction in networks. Network initiatives that could provide appropriate support involve social interaction and knowledge exchange, learning and competence development, and coordination (organization and management ofimplementation. This paper is designed to assess the factors that affect the performance of German food SME formal networks. It also addresses the consequences at the network and macro level. The analysis was explored by using the laddering technique based on the means‐end chain theory. The findings will help to build up a “network learning toolbox” that is adapted to the particular requirements of the different target groups such as of SMEs, network managers and policy makers. The “network learning toolbox” should improve network learning, which is adriver for improvements in innovation, economic growth and sustainable competitive advantage for food SMEs.

  5. Cross Deployment Networking and Systematic Performance Analysis of Underwater Wireless Sensor Networks.

    Science.gov (United States)

    Wei, Zhengxian; Song, Min; Yin, Guisheng; Wang, Hongbin; Ma, Xuefei; Song, Houbing

    2017-07-12

    Underwater wireless sensor networks (UWSNs) have become a new hot research area. However, due to the work dynamics and harsh ocean environment, how to obtain an UWSN with the best systematic performance while deploying as few sensor nodes as possible and setting up self-adaptive networking is an urgent problem that needs to be solved. Consequently, sensor deployment, networking, and performance calculation of UWSNs are challenging issues, hence the study in this paper centers on this topic and three relevant methods and models are put forward. Firstly, the normal body-centered cubic lattice to cross body-centered cubic lattice (CBCL) has been improved, and a deployment process and topology generation method are built. Then most importantly, a cross deployment networking method (CDNM) for UWSNs suitable for the underwater environment is proposed. Furthermore, a systematic quar-performance calculation model (SQPCM) is proposed from an integrated perspective, in which the systematic performance of a UWSN includes coverage, connectivity, durability and rapid-reactivity. Besides, measurement models are established based on the relationship between systematic performance and influencing parameters. Finally, the influencing parameters are divided into three types, namely, constraint parameters, device performance and networking parameters. Based on these, a networking parameters adjustment method (NPAM) for optimized systematic performance of UWSNs has been presented. The simulation results demonstrate that the approach proposed in this paper is feasible and efficient in networking and performance calculation of UWSNs.

  6. Safety performance indicators for the road network.

    NARCIS (Netherlands)

    Weijermars, W. Gitelman, V. Papadimitriou, E. Lima De & Azevedo, C.

    2010-01-01

    Within the 6th FP European project SafetyNet, a team has worked on the development of Safety Performance Indicators (SPIs) on seven road safety related areas. These SPIs reflect the operational conditions of the road traffic system that influence the system's safety performance. SPIs were developed

  7. Optical interconnection networks for high-performance computing systems.

    Science.gov (United States)

    Biberman, Aleksandr; Bergman, Keren

    2012-04-01

    Enabled by silicon photonic technology, optical interconnection networks have the potential to be a key disruptive technology in computing and communication industries. The enduring pursuit of performance gains in computing, combined with stringent power constraints, has fostered the ever-growing computational parallelism associated with chip multiprocessors, memory systems, high-performance computing systems and data centers. Sustaining these parallelism growths introduces unique challenges for on- and off-chip communications, shifting the focus toward novel and fundamentally different communication approaches. Chip-scale photonic interconnection networks, enabled by high-performance silicon photonic devices, offer unprecedented bandwidth scalability with reduced power consumption. We demonstrate that the silicon photonic platforms have already produced all the high-performance photonic devices required to realize these types of networks. Through extensive empirical characterization in much of our work, we demonstrate such feasibility of waveguides, modulators, switches and photodetectors. We also demonstrate systems that simultaneously combine many functionalities to achieve more complex building blocks. We propose novel silicon photonic devices, subsystems, network topologies and architectures to enable unprecedented performance of these photonic interconnection networks. Furthermore, the advantages of photonic interconnection networks extend far beyond the chip, offering advanced communication environments for memory systems, high-performance computing systems, and data centers.

  8. Structural integration and performance of inter-sectoral public health-related policy networks: An analysis across policy phases.

    Science.gov (United States)

    Peters, D T J M; Raab, J; Grêaux, K M; Stronks, K; Harting, J

    2017-12-01

    Inter-sectoral policy networks may be effective in addressing environmental determinants of health with interventions. However, contradictory results are reported on relations between structural network characteristics (i.e., composition and integration) and network performance, such as addressing environmental determinants of health. This study examines these relations in different phases of the policy process. A multiple-case study was performed on four public health-related policy networks. Using a snowball method among network actors, overall and sub-networks per policy phase were identified and the policy sector of each actor was assigned. To operationalise the outcome variable, interventions were classified by the proportion of environmental determinants they addressed. In the overall networks, no relation was found between structural network characteristics and network performance. In most effective cases, the policy development sub-networks were characterised by integration with less interrelations between actors (low cohesion), more equally distributed distances between the actors (low closeness centralisation), and horizontal integration in inter-sectoral cliques. The most effective case had non-public health central actors with less connections in all sub-networks. The results suggest that, to address environmental determinants of health, sub-networks should be inter-sectorally composed in the policy development rather than in the intervention development and implementation phases, and that policy development actors should have the opportunity to connect with other actors, without strong direction from a central actor. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Identifying protein complex by integrating characteristic of core-attachment into dynamic PPI network.

    Directory of Open Access Journals (Sweden)

    Xianjun Shen

    Full Text Available How to identify protein complex is an important and challenging task in proteomics. It would make great contribution to our knowledge of molecular mechanism in cell life activities. However, the inherent organization and dynamic characteristic of cell system have rarely been incorporated into the existing algorithms for detecting protein complexes because of the limitation of protein-protein interaction (PPI data produced by high throughput techniques. The availability of time course gene expression profile enables us to uncover the dynamics of molecular networks and improve the detection of protein complexes. In order to achieve this goal, this paper proposes a novel algorithm DCA (Dynamic Core-Attachment. It detects protein-complex core comprising of continually expressed and highly connected proteins in dynamic PPI network, and then the protein complex is formed by including the attachments with high adhesion into the core. The integration of core-attachment feature into the dynamic PPI network is responsible for the superiority of our algorithm. DCA has been applied on two different yeast dynamic PPI networks and the experimental results show that it performs significantly better than the state-of-the-art techniques in terms of prediction accuracy, hF-measure and statistical significance in biology. In addition, the identified complexes with strong biological significance provide potential candidate complexes for biologists to validate.

  10. High electromechanical performance of electroelastomers based on interpenetrating polymer networks

    Science.gov (United States)

    Ha, Soon Mok; Park, Il Seok; Wissler, Michael; Pelrine, Ron; Stanford, Scott; Kim, Kwang J.; Kovacs, Gabor; Pei, Qibing

    2008-03-01

    The electromechanical performance of interpenetrating polymer networks (IPN) in which one elastomer network is under high tension balanced by compression of the second network, were investigated. Uniaxial stress relaxation analysis confirmed significant decrease in viscoelasticity in comparison with 3M VHB films, the primary component network in the IPN films. In dynamic mechanical analysis, the IPN composite showed a higher mechanical efficiency, suggesting delayed relaxation of the acrylic chains in the presence of IPN formation. This improvement was found to be dependant on the contents of poly(TMPTMA). Actuation performance without mechanical prestrain showed that these IPN electroelastomers had demonstrated high elastic strain energy density (3.5 MJ/m 3) and a high electromechanical coupling factor (93.7%). These enhanced electromechanical performances indicate that IPN electroelastomer should be suitable for diverse applications.

  11. Modeling Travel Time Reliability of Road Network Considering Connected Vehicle Guidance Characteristics Indexes

    Directory of Open Access Journals (Sweden)

    Jiangfeng Wang

    2017-01-01

    Full Text Available Travel time reliability (TTR is one of the important indexes for effectively evaluating the performance of road network, and TTR can effectively be improved using the real-time traffic guidance information. Compared with traditional traffic guidance, connected vehicle (CV guidance can provide travelers with more timely and accurate travel information, which can further improve the travel efficiency of road network. Five CV characteristics indexes are selected as explanatory variables including the Congestion Level (CL, Penetration Rate (PR, Compliance Rate (CR, release Delay Time (DT, and Following Rate (FR. Based on the five explanatory variables, a TTR model is proposed using the multilogistic regression method, and the prediction accuracy and the impact of characteristics indexes on TTR are analyzed using a CV guidance scenario. The simulation results indicate that 80% of the RMSE is concentrated within the interval of 0 to 0.0412. The correlation analysis of characteristics indexes shows that the influence of CL, PR, CR, and DT on the TTR is significant. PR and CR have a positive effect on TTR, and the average improvement rate is about 77.03% and 73.20% with the increase of PR and CR, respectively, while CL and DT have a negative effect on TTR, and TTR decreases by 31.21% with the increase of DT from 0 to 180 s.

  12. Analysis of networking characteristics of different personality types

    OpenAIRE

    Charilaos, Mylonas

    2014-01-01

    The MBTI personality test and a personal facebook network were used in order to gain some insights on the relationship of social network centrality and path length measures and different personality types. Although the personality classification data were scarce, there were some intuitive quantitative results supporting anecdotal statements, based on empirical observations, about the expected social behavior of personality types.

  13. Personal and Network Dynamics in Performance of Knowledge Workers: A Study of Australian Breast Radiologists.

    Directory of Open Access Journals (Sweden)

    Seyedamir Tavakoli Taba

    Full Text Available In this paper, we propose a theoretical model based upon previous studies about personal and social network dynamics of job performance. We provide empirical support for this model using real-world data within the context of the Australian radiology profession. An examination of radiologists' professional network topology through structural-positional and relational dimensions and radiologists' personal characteristics in terms of knowledge, experience and self-esteem is provided. Thirty one breast imaging radiologists completed a purpose designed questionnaire regarding their network characteristics and personal attributes. These radiologists also independently read a test set of 60 mammographic cases: 20 cases with cancer and 40 normal cases. A Jackknife free response operating characteristic (JAFROC method was used to measure the performance of the radiologists' in detecting breast cancers.Correlational analyses showed that reader performance was positively correlated with the social network variables of degree centrality and effective size, but negatively correlated with constraint and hierarchy. For personal characteristics, the number of mammograms read per year and self-esteem (self-evaluation positively correlated with reader performance. Hierarchical multiple regression analysis indicated that the combination of number of mammograms read per year and network's effective size, hierarchy and tie strength was the best fitting model, explaining 63.4% of the variance in reader performance. The results from this study indicate the positive relationship between reading high volumes of cases by radiologists and expertise development, but also strongly emphasise the association between effective social/professional interactions and informal knowledge sharing with high performance.

  14. Multiplex network analysis of employee performance and employee social relationships

    Science.gov (United States)

    Cai, Meng; Wang, Wei; Cui, Ying; Stanley, H. Eugene

    2018-01-01

    In human resource management, employee performance is strongly affected by both formal and informal employee networks. Most previous research on employee performance has focused on monolayer networks that can represent only single categories of employee social relationships. We study employee performance by taking into account the entire multiplex structure of underlying employee social networks. We collect three datasets consisting of five different employee relationship categories in three firms, and predict employee performance using degree centrality and eigenvector centrality in a superimposed multiplex network (SMN) and an unfolded multiplex network (UMN). We use a quadratic assignment procedure (QAP) analysis and a regression analysis to demonstrate that the different categories of relationship are mutually embedded and that the strength of their impact on employee performance differs. We also use weighted/unweighted SMN/UMN to measure the predictive accuracy of this approach and find that employees with high centrality in a weighted UMN are more likely to perform well. Our results shed new light on how social structures affect employee performance.

  15. Performance requirements for integrated voice/data networks

    Science.gov (United States)

    Gruber, J. G.; Le, N. H.

    1983-12-01

    This paper addresses top-down end-to-end user-oriented performance requirements pertaining primarily to voice and digital data services. The discussion of requirements for voice parameters accounts for the performance of existing analog and mixed analog/digital networks, as well as the likely effects on performance of short, medium, and long term evolution toward the ultimate all digital ISDN. The requirements for digital data parameters necessarily reflect an evolutionary process which is less consistent than for voice, and therefore these requirements are less definitive in nature. The discussions of voice and digital data performance apply largely to a wide variety of appropriate network designs, transmission schemes, and switching architectures. Both traditional parameters, as well as contemporary parameters associated with new and evolving systems, are considered. The emphasis is on the performance of nation-wide public and private networks, but the paper also considers the constraints of international connections.

  16. Facebook use, personality characteristics and academic performance: A correlational study

    OpenAIRE

    Sapsani, Georgia; Tselios, Nikolaos

    2017-01-01

    The present paper examines the relationship between the students personality, use of social media and their academic performance and engagement. In specific, the aim of this study is to examine the relationship of students facebook (fb) use and personality characteristics using the Big Five Personality Test with (a) student engagement, (b) time spent preparing for class, (c) time spent in co-curricular activities and (d) academic performance. Results illustrate that fb time was significantly ...

  17. Evaluation of corn meal on performance, carcass characteristics and ...

    African Journals Online (AJOL)

    To study the effect of corn meal (CM) on performance, carcass characteristics and nutrient digestibility of chickens in a completely randomized design experiment with 4 × 2 factorial arrangement and 4 replicates per treatment, 384 Ross male broiler chickens in a 49 days period were evaluated. Treatments were 0 (CM0), ...

  18. The effects of docking on performance and carcass characteristics of ...

    African Journals Online (AJOL)

    The effects of tail docking at birth on growth performance and carcass characteristics of fat-tailed male Karakas lambs were investigated. A total of 23 Karakas single-born male lambs was used in this study. Nine were docked at one day of age using rubber elastrator rings and the rest was left intact. After weaning, the lambs ...

  19. Influence of Personal Characteristics on Job Performance Among ...

    African Journals Online (AJOL)

    This paper examined the influence of personal characteristics of extension agents and researchers on their job performance. The results indicate that extension agents had a mean of 36. 5 years with majority being male and married as well as having HND certificates. They have also spent between 21 and 30 years in ...

  20. performance characteristics of an armature voltage controlled dc motor

    African Journals Online (AJOL)

    Dr Obe

    types. To each of these two control arrangements is added an inner current controller loop. Using developed motor equations, the performance characteristics of a test motor are obtained by digital computer analysis. The results show that closed loop operation, with appropriate control gains, give improved speed regulation ...

  1. Aggregate packing characteristics of good and poor performing asphalt mixes

    CSIR Research Space (South Africa)

    Denneman, E

    2007-07-01

    Full Text Available and related techniques for determining the porosity of the Dominant Aggregate Size Range (DASR) and the permeability characteristics of the mix. The aim is to assess the potential benefits of these new gradation analysis techniques for HMA performance in South...

  2. Performance And Carcass Characteristics Of Broiler Chicken Fed ...

    African Journals Online (AJOL)

    Performance And Carcass Characteristics Of Broiler Chicken Fed High Fibre Sunflower Seed Cake Diets. ... 05) differences were in liveweight, plucked and dressing percentages at the starter and finisher phases. Reduction in abdominal fat deposition was obtained at the starter and finisher phases while gizzard weights ...

  3. Performance characteristics of growing rabbits fed diet based on a ...

    African Journals Online (AJOL)

    A feeding trial using twenty four cross bred 8-9 weeks old rabbits was conducted to investigate the effect of feeding cerelac waste - CW (a by-product of the infant food industry considered as waste) on the performance and organ characteristics of growing rabbits. Three experimental diets were formulated with diet 1 serving ...

  4. Performance Characteristics of an Armature Voltage Controlled D.C. ...

    African Journals Online (AJOL)

    In this paper, the performance study of a separately excited d. c. motor whose speed is controlled by armature voltage variation is presented. Both the open loop and the closed loop steady state and transient characteristics are reported. The speed controllers considered in the closed loop mode are the proportional and the ...

  5. Effect of Multi-Response Performance Characteristics on Optimum ...

    African Journals Online (AJOL)

    The resulting optimal combination was further investigated by applying the Analysis of Variance, ANOVA, to show which welding process parameter significantly affected the performance characteristic of the welding process. From the ANOVA, the torch stand-off, welding speed and plasma flow rate were found to be the ...

  6. Network characteristics, perceived social support, and psychological adjustment in mothers of children with autism spectrum disorder.

    Science.gov (United States)

    Benson, Paul R

    2012-12-01

    This study examined the characteristics of the support networks of 106 mothers of children with ASD and their relationship to perceived social support, depressed mood, and subjective well-being. Using structural equation modeling, two competing sets of hypotheses were assessed: (1) that network characteristics would impact psychological adjustment directly, and (2) that network effects on adjustment would be indirect, mediated by perceived social support. Results primarily lent support to the latter hypotheses, with measures of network structure (network size) and function (proportion of network members providing emotional support) predicting increased levels of perceived social support which, in turn, predicted decreased depressed mood and increased well-being. Results also indicated that increased interpersonal strain in the maternal network was directly and indirectly associated with increased maternal depression, while being indirectly linked to reduced well-being. Study limitations and implications are discussed.

  7. Effects of the bipartite structure of a network on performance of recommenders

    Science.gov (United States)

    Wang, Qing-Xian; Li, Jian; Luo, Xin; Xu, Jian-Jun; Shang, Ming-Sheng

    2018-02-01

    Recommender systems aim to predict people's preferences for online items by analyzing their historical behaviors. A recommender can be modeled as a high-dimensional and sparse bipartite network, where the key issue is to understand the relation between the network structure and a recommender's performance. To address this issue, we choose three network characteristics, clustering coefficient, network density and user-item ratio, as the analyzing targets. For the cluster coefficient, we adopt the Degree-preserving rewiring algorithm to obtain a series of bipartite network with varying cluster coefficient, while the degree of user and item keep unchanged. Furthermore, five state-of-the-art recommenders are applied on two real datasets. The performances of recommenders are measured by both numerical and physical metrics. These results show that a recommender's performance is positively related to the clustering coefficient of a bipartite network. Meanwhile, higher density of a bipartite network can provide more accurate but less diverse or novel recommendations. Furthermore, the user-item ratio is positively correlated with the accuracy metrics but negatively correlated with the diverse and novel metrics.

  8. Effects of Network Capabilities on Firm Performance across Cultures

    Directory of Open Access Journals (Sweden)

    Papastamatelou Julie

    2016-03-01

    Full Text Available The purpose of this study is to identify key factors related to network capabilities that enhance the performance of Chinese, Turkish and German firms. Chinese (n = 107, Turkish (n = 129 and German (n = 109 MBA-students completed a questionnaire, based on an earlier version developed by Kenny [2009], which included questions on the respective firm, its performance and network capabilities. The predictors of firm performance varied by country: in China “information sharing” and “trust” were important, in Turkey “network coordination” and in Germany “human capital resources.” In addition, each country had its own specific drivers of firm performance. The findings of this paper should enhance understanding of the cross-cultural differences and assist managers when planning to join foreign corporations.

  9. Using AQM to improve TCP performance over wireless networks

    Science.gov (United States)

    Li, Victor H.; Liu, Zhi-Qiang; Low, Steven H.

    2002-07-01

    TCP flow control algorithms have been designed for wireline networks where congestion is measured by packet loss due to buffer overflow. However, wireless networks also suffer from significant packet losses due to bit errors and handoffs. TCP responds to all the packet losses by invoking congestion control and avoidance algorithms and this results in degraded end-to-end performance in wireless networks. In this paper, we describe an Wireless Random Exponential Marking(WREM) scheme which effectively improves TCP performance over wireless networks by decoupling loss recovery from congestion control. Moreover, WREM is capable of handling the coexistence of both ECN-Capable and Non-ECN-Capable routers. We present simulation results to show its effectiveness and compatibility.

  10. FLUXNET Research Network Site Characteristics, Investigators, and Bibliography, 2016

    Data.gov (United States)

    National Aeronautics and Space Administration — FLUXNET is a global network of micrometeorological tower sites that use eddy covariance methods to measure the exchanges of carbon dioxide, water vapor, and energy...

  11. Packet throughput performance of multiservice, multirate OCDMA in elastic networks

    DEFF Research Database (Denmark)

    Raddo, Thiago R.; Sanches, Anderson L.; Tafur Monroy, Idelfonso

    2016-01-01

    In this paper, the packet throughput performance of multiservice, multirate optical code-division multiple-access (OCDMA) networks is addressed based on two distinct multirate techniques, namely multilength code and multicode. A new analytical formalism to evaluate the packet throughput performance...

  12. Optimizing the performance of a data vortex interconnection network

    Science.gov (United States)

    Shacham, Assaf; Bergman, Keren

    2007-04-01

    The definition of the data vortex architecture leaves broad room for decisions regarding the exact design point required for achieving a desired performance level. A detailed simulation-based study of various parameters that affect a data vortex interconnection network's performance is reported. Three implementations are compared by acceptance rate, latency, and cost.

  13. Sustainable Performance in Energy Harvesting - Wireless Sensor Networks

    DEFF Research Database (Denmark)

    Fafoutis, Xenofon; Di Mauro, Alessio; Dragoni, Nicola

    2013-01-01

    In this practical demo we illustrate the concept of "sustainable performance" in Energy-Harvesting Wireless Sensor Networks (EH-WSNs). In particular, for different classes of applications and under several energy harvesting scenarios, we show how it is possible to have sustainable performance when...

  14. The Enhancing Impact of Friendship Networks on Sales Managers’ Performance

    Directory of Open Access Journals (Sweden)

    Danny Pimentel Claro

    2013-04-01

    Full Text Available This paper examines how relationships with friends moderate the impact of professional networks on sales performance. Based on a sample of 204 sales managers in a professional service company, this study presents evidence that friendship networks amplify the effect of sales forces’ professional networks on new product sales as well as on prospecting and converting new deals. Our results offer important insights into the socio-cognitive perspective of sales management literature and suggest that firms should encourage managers to improve their friendships in order to access valuable information that will enhance customer knowledge and support their sales efforts.

  15. The performance of multichannel, multihop packet radio networks

    Science.gov (United States)

    Shacham, Nachum; King, Peter J. B.

    The architecture for a packet radio network which utilizes parallel multihop multiple-access channels is proposed. Consideration is given to single and multichannel transmissions, routing in single and multichannel transmission systems, the quiescent channel, and nodes. The performance of multihop multichannel packet radio networks is evaluated; throughput and average packet progress per hop under slotted ALOHA and CSMA protocols are analyzed. It is noted that multichannel transmission provides no significant advantages over single channel transmission.

  16. Computational studies on small wind turbine performance characteristics

    Science.gov (United States)

    Karthikeyan, N.; Suthakar, T.

    2016-10-01

    To optimize the selection of suitable airfoils for small wind turbine applications, computational investigation on aerodynamic characteristics of low Re airfoils MID321a, MID321d, SG6040, SG6041, SG6042 and SG6043 are carried out for the Reynolds number range of (0.5- 2)×105. The BEM method is used to determine the power coefficient of the rotor from the airfoil characteristics; in addition, the blade parameters like chord and twist are also determined. The newly designed MID321a airfoil shows better aerodynamic performance and maximum power coefficient as compared with other investigated airfoils for wider operating ranges.

  17. Auditory virtual environment with dynamic room characteristics for music performances

    Science.gov (United States)

    Choi, Daniel Dhaham

    A room-adaptive system was designed to simulate an electro-acoustic space that changes room characteristics in real-time according to the content of sound. In this specific case, the focus of the sound components is on the different styles and genres of music. This system is composed of real-time music recognition algorithms that analyze the different elements of music, determine the desired room characteristics, and output the acoustical parameters via multi-channel room simulation mechanisms. The system modifies the acoustic properties of a space and enables it to "improvise" its acoustical parameters based on the sounds of the music performances.

  18. Social Network Characteristics Associated with Weight Loss among Black and Hispanic Adults with Overweight and Obesity

    Science.gov (United States)

    Winston, Ginger; Phillips, Erica G.; Wethington, Elaine; Devine, Carol; Wells, Martin; Peterson, Janey C.; Hippolyte, Jessica; Ramos, Rosio; Martinez, Guillerma; Eldridge, Johanna; Charlson, Mary

    2015-01-01

    Objective To examine social network member characteristics associated with weight loss. Methods Cross-sectional examination of egocentric network data from 245 Black and Hispanic adults with BMI ≥ 25 kg/m2 enrolled in a small change weight loss study. The relationship between weight loss at 12 months and characteristics of helpful and harmful network members (relationship, contact frequency, living proximity and body size) were examined. Results There were 2,571 network members identified. Mean weight loss was -4.8 (±11.3) lbs. among participants with network help and no harm with eating goals vs. +3.4 (±7.8) lbs. among participants with network harm alone. In a multivariable regression model, greater weight loss was associated with help from a child with eating goals (p=.0002) and coworker help with physical activity (p=.01). Weight gain was associated with having network members with obesity living in the home (p=.048) and increased network size (p=.002). Conclusions There was greater weight loss among participants with support from children and coworkers. Weight gain was associated with harmful network behaviors and having network members with obesity in the home. Incorporating child and co-worker support, and evaluating network harm and the body size of network members should be considered in future weight loss interventions. PMID:26179578

  19. Social network characteristics associated with weight loss among black and hispanic adults.

    Science.gov (United States)

    Winston, Ginger J; Phillips, Erica G; Wethington, Elaine; Devine, Carol; Wells, Martin; Peterson, Janey C; Hippolyte, Jessica; Ramos, Rosio; Martinez, Guillerma; Eldridge, Johanna; Charlson, Mary

    2015-08-01

    To examine social network member characteristics associated with weight loss. A cross-sectional examination included egocentric network data from 245 Black and Hispanic adults with BMI ≥ 25 kg/m(2) enrolled in a small change weight loss study. The relationships between weight loss at 12 months and characteristics of helpful and harmful network members (relationship, contact frequency, living proximity, and body size) were examined. There were 2,571 network members identified. Mean weight loss was -4.8 (±11.3) lbs. among participants with network help and no harm with eating goals vs. +3.4 (±7.8) lbs. among participants with network harm alone. In a multivariable regression model, greater weight loss was associated with help from a child with eating goals (P = 0.0002) and coworker help with physical activity (P = 0.01). Weight gain was associated with having network members with obesity living in the home (P = 0.048) and increased network size (P = 0.002). There was greater weight loss among participants with support from children and coworkers. Weight gain was associated with harmful network behaviors and having network members with obesity in the home. Incorporating child and coworker support and evaluating network harm and the body size of network members should be considered in future weight loss interventions. © 2015 The Obesity Society.

  20. General performance characteristics of an irreversible ferromagnetic Stirling refrigeration cycle

    Science.gov (United States)

    Lin, G.; Tegus, O.; Zhang, L.; Brück, E.

    2004-02-01

    A new magnetic-refrigeration-cycle model using ferromagnetic materials as a cyclic working substance is set up, in which finite-rate heat transfer, heat leak and regeneration time are taken into account. On the basis of the thermodynamic properties of a ferromagnetic material, the general performance characteristics of the ferromagnetic Stirling refrigeration cycle are investigated and the effects of some key irreversibilities on the performance of the cycle are revealed. By using the optimal-control theory, the optimal relation between the coefficient of performance and the cooling rate is derived and some important performance bounds, e.g., the maximum cooling rate, the maximum coefficient of performance, are determined. Moreover, the optimal operating regions for cooling rate, coefficient of performance and the optimal operating temperatures of a cyclic working substance in the two heat-transfer processes are obtained. Furthermore, the influences of magnetization and magnetic field on the performance characteristics of the cycle are discussed. The results obtained here have general significance and can be deduced to the related ones of the Stirling refrigeration cycle using paramagnetic salt as a cyclic working substance.

  1. The geospatial characteristics of a social movement communication network.

    Directory of Open Access Journals (Sweden)

    Michael D Conover

    Full Text Available Social movements rely in large measure on networked communication technologies to organize and disseminate information relating to the movements' objectives. In this work we seek to understand how the goals and needs of a protest movement are reflected in the geographic patterns of its communication network, and how these patterns differ from those of stable political communication. To this end, we examine an online communication network reconstructed from over 600,000 tweets from a thirty-six week period covering the birth and maturation of the American anticapitalist movement, Occupy Wall Street. We find that, compared to a network of stable domestic political communication, the Occupy Wall Street network exhibits higher levels of locality and a hub and spoke structure, in which the majority of non-local attention is allocated to high-profile locations such as New York, California, and Washington D.C. Moreover, we observe that information flows across state boundaries are more likely to contain framing language and references to the media, while communication among individuals in the same state is more likely to reference protest action and specific places and times. Tying these results to social movement theory, we propose that these features reflect the movement's efforts to mobilize resources at the local level and to develop narrative frames that reinforce collective purpose at the national level.

  2. The geospatial characteristics of a social movement communication network.

    Science.gov (United States)

    Conover, Michael D; Davis, Clayton; Ferrara, Emilio; McKelvey, Karissa; Menczer, Filippo; Flammini, Alessandro

    2013-01-01

    Social movements rely in large measure on networked communication technologies to organize and disseminate information relating to the movements' objectives. In this work we seek to understand how the goals and needs of a protest movement are reflected in the geographic patterns of its communication network, and how these patterns differ from those of stable political communication. To this end, we examine an online communication network reconstructed from over 600,000 tweets from a thirty-six week period covering the birth and maturation of the American anticapitalist movement, Occupy Wall Street. We find that, compared to a network of stable domestic political communication, the Occupy Wall Street network exhibits higher levels of locality and a hub and spoke structure, in which the majority of non-local attention is allocated to high-profile locations such as New York, California, and Washington D.C. Moreover, we observe that information flows across state boundaries are more likely to contain framing language and references to the media, while communication among individuals in the same state is more likely to reference protest action and specific places and times. Tying these results to social movement theory, we propose that these features reflect the movement's efforts to mobilize resources at the local level and to develop narrative frames that reinforce collective purpose at the national level.

  3. Virtual Networking Performance in OpenStack Platform for Network Function Virtualization

    Directory of Open Access Journals (Sweden)

    Franco Callegati

    2016-01-01

    Full Text Available The emerging Network Function Virtualization (NFV paradigm, coupled with the highly flexible and programmatic control of network devices offered by Software Defined Networking solutions, enables unprecedented levels of network virtualization that will definitely change the shape of future network architectures, where legacy telco central offices will be replaced by cloud data centers located at the edge. On the one hand, this software-centric evolution of telecommunications will allow network operators to take advantage of the increased flexibility and reduced deployment costs typical of cloud computing. On the other hand, it will pose a number of challenges in terms of virtual network performance and customer isolation. This paper intends to provide some insights on how an open-source cloud computing platform such as OpenStack implements multitenant network virtualization and how it can be used to deploy NFV, focusing in particular on packet forwarding performance issues. To this purpose, a set of experiments is presented that refer to a number of scenarios inspired by the cloud computing and NFV paradigms, considering both single tenant and multitenant scenarios. From the results of the evaluation it is possible to highlight potentials and limitations of running NFV on OpenStack.

  4. Network Signaling Channel for Improving ZigBee Performance in Dynamic Cluster-Tree Networks

    Directory of Open Access Journals (Sweden)

    Kohvakka Mikko

    2008-01-01

    Full Text Available Abstract ZigBee is one of the most potential standardized technologies for wireless sensor networks (WSNs. Yet, sufficient energy-efficiency for the lowest power WSNs is achieved only in rather static networks. This severely limits the applicability of ZigBee in outdoor and mobile applications, where operation environment is harsh and link failures are common. This paper proposes a network channel beaconing (NCB algorithm for improving ZigBee performance in dynamic cluster-tree networks. NCB reduces the energy consumption of passive scans by dedicating one frequency channel for network beacon transmissions and by energy optimizing their transmission rate. According to an energy analysis, the power consumption of network maintenance operations reduces by 70%–76% in dynamic networks. In static networks, energy overhead is negligible. Moreover, the service time for data routing increases up to 37%. The performance of NCB is validated by ns-2 simulations. NCB can be implemented as an extension on MAC and NWK layers and it is fully compatible with ZigBee.

  5. Network Signaling Channel for Improving ZigBee Performance in Dynamic Cluster-Tree Networks

    Directory of Open Access Journals (Sweden)

    D. Hämäläinen

    2008-03-01

    Full Text Available ZigBee is one of the most potential standardized technologies for wireless sensor networks (WSNs. Yet, sufficient energy-efficiency for the lowest power WSNs is achieved only in rather static networks. This severely limits the applicability of ZigBee in outdoor and mobile applications, where operation environment is harsh and link failures are common. This paper proposes a network channel beaconing (NCB algorithm for improving ZigBee performance in dynamic cluster-tree networks. NCB reduces the energy consumption of passive scans by dedicating one frequency channel for network beacon transmissions and by energy optimizing their transmission rate. According to an energy analysis, the power consumption of network maintenance operations reduces by 70%–76% in dynamic networks. In static networks, energy overhead is negligible. Moreover, the service time for data routing increases up to 37%. The performance of NCB is validated by ns-2 simulations. NCB can be implemented as an extension on MAC and NWK layers and it is fully compatible with ZigBee.

  6. Multidimensional performance characteristics and standard of performance in talented youth field hockey players : A longitudinal study

    NARCIS (Netherlands)

    Elferink-Gemser, Marije T.; Visscher, Chris; Lemmink, Koen A. P. M.; Mulder, Theo

    2007-01-01

    To identify performance characteristics that could help predict future elite field hockey players, we measured the anthropometric, physiological, technical, tactical, and psychological characteristics of 30 elite and 35 sub-elite youth players at the end of three consecutive seasons. The mean age of

  7. RELATIONSHIPS BETWEEN MUSCLE FATIGUE CHARACTERISTICS AND MARKERS OF ENDURANCE PERFORMANCE

    Directory of Open Access Journals (Sweden)

    Martyn G. Morris

    2008-12-01

    Full Text Available The aim of this study was to examine the relationship of a range of in-vivo whole muscle characteristics to determinants of endurance performance. Eleven healthy males completed a cycle ergometer step test to exhaustion for the determination of the lactate threshold, gross mechanical efficiency, peak power and VO2max. On two separate occasions, contractile and fatigue characteristics of the quadriceps femoris were collected using a specially designed isometric strength-testing chair. Muscle fatigue was then assessed by stimulating the muscle for 3 minutes. Force, rate of force development and rates of relaxation were calculated at the beginning and end of the 3 minute protocol and examined for reliability and in relation to lactate threshold, VO2max, gross mechanical efficiency and peak power. Muscle characteristics, rate of force development and relaxation rate were demonstrated to be reliable measures. Force drop off over the 3 minutes (fatigue index was related to lactate threshold (r = -0.72 p < 0.01 but not to VO2max. The rate of force development related to the peak power at the end of the cycle ergometer test (r = -0.75 p < 0.01. Rates of relaxation did not relate to any of the performance markers. We found in-vivo whole muscle characteristics, such as the fatigue index and rate of force development, relate to specific markers of peripheral, but not to central, fitness components. Our investigation suggests that muscle characteristics assessed in this way is reliable and could be feasibly utilised to further our understanding of the peripheral factors underpinning performance

  8. Crystal networks in silk fibrous materials: from hierarchical structure to ultra performance.

    Science.gov (United States)

    Nguyen, Anh Tuan; Huang, Qiao-Ling; Yang, Zhen; Lin, Naibo; Xu, Gangqin; Liu, Xiang Yang

    2015-03-01

    This review provides a comprehensive survey of the structural characteristics of crystal networks of silk soft fibrous materials in correlation with the macroscopic properties/performance and the network formation mechanisms. The correlation between the hierarchical mesoscopic structures and the mechanical properties of silk soft fibrous materials including silk fibroin hydrogels and naturally spun silk fibers are addressed based on the hierarchical crystal network models. Namely, two types of hierarchical networks are identified: the weak nanofibril-nanofibril interaction case (i.e., silk fibroin hydrogels), and the strong nanofibril-nanofibril interaction case (i.e., silk fibers). The macroscopic properties, i.e., the rheological/mechanical properties, can be controlled in terms of tuning different levels of hierarchical network structures by ultrasonication-induced gelation, introducing the initial nucleation centers, etc. Such controls take effect by different mesoscale assembly pathways, which are found to occur via different routes of the nucleation and growth processes. Furthermore, the hierarchical network model of soft fibrous materials can be applied to explain the superior mechanical properties and the unique strain-hardening behaviors of spider silk fibers within the framework of hierarchical breaking mechanism. Obviously, a knowledge of crystal networks will allow the prediction of the performance and engineering strategy of silk fibrous materials in generals. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Quantifying the multi-scale performance of network inference algorithms.

    Science.gov (United States)

    Oates, Chris J; Amos, Richard; Spencer, Simon E F

    2014-10-01

    Graphical models are widely used to study complex multivariate biological systems. Network inference algorithms aim to reverse-engineer such models from noisy experimental data. It is common to assess such algorithms using techniques from classifier analysis. These metrics, based on ability to correctly infer individual edges, possess a number of appealing features including invariance to rank-preserving transformation. However, regulation in biological systems occurs on multiple scales and existing metrics do not take into account the correctness of higher-order network structure. In this paper novel performance scores are presented that share the appealing properties of existing scores, whilst capturing ability to uncover regulation on multiple scales. Theoretical results confirm that performance of a network inference algorithm depends crucially on the scale at which inferences are to be made; in particular strong local performance does not guarantee accurate reconstruction of higher-order topology. Applying these scores to a large corpus of data from the DREAM5 challenge, we undertake a data-driven assessment of estimator performance. We find that the "wisdom of crowds" network, that demonstrated superior local performance in the DREAM5 challenge, is also among the best performing methodologies for inference of regulation on multiple length scales.

  10. Impact of tasks and users' characteristics on virtual reality performance.

    Science.gov (United States)

    Tyndiuk, F; Lespinet-Najib, V; Thomas, G; Schlick, C

    2007-06-01

    A better understanding of how users perform virtual reality (VR) tasks may help build better VR interfaces. In this study, we concentrated on the compensatory behavior in VR depending on the tasks and users' characteristics. The tasks characteristics considered were display size (large display vs. desktop monitor) and tasks types (manipulation and travel). The users' characteristics studied were the visual attention abilities and users' satisfaction. Ninety-five subjects participated in the experimentation composed of two parts: the first one consisted in cognitive tests used to evaluate visual attention abilities, and the second one was based on a set of VR tasks. Our result showed that large displays positively affect on performance for some kinds of VR tasks. Moreover, this impact was linked to users' satisfaction and visual attention abilities. Indeed, users with low-level attention abilities and users who preferred the large display took more advantage of large displays. We concluded that large displays can be considered cognitive aids depending on the tasks and users' characteristics.

  11. Research on Harmonic Characteristics Influence for Distribution Network with Renewable Energy

    Directory of Open Access Journals (Sweden)

    Huang Wei

    2016-01-01

    Full Text Available In order to study the influence on harmonic characteristics of distribution network with renewable energy, a simplified model of distribution network is established to analyse theory while considering the influence of cable on the system capacitive current. Establishing an actual distribution network model by Digsilent to research the harmonic characteristics impact when photovoltaic power with PV incorporated the distribution network in a variety of different access , while using constant current source model as harmonic source model which often been used in engineering practices. The simulation results show that: optimizing the access location and dispersion of PV can decrease the waveform distortion levels in distribution network and a certain number of high-order harmonic will magnify by a specific grid structure, deteriorating the distribution network power quality.

  12. Adolescent social networks: general and smoking-specific characteristics associated with smoking.

    Science.gov (United States)

    Roberts, Megan E; Nargiso, Jessica E; Gaitonde, Linda Brazil; Stanton, Cassandra A; Colby, Suzanne M

    2015-03-01

    Converging lines of research suggest that adolescents' smoking behaviors are strongly influenced by the characteristics of their social network and the social processes their network facilitates. The primary goal of this study was to conduct a detailed comparison of the social networks of adolescent smokers and nonsmokers to determine what aspects relate the most to smoking status. A secondary goal was to conduct within-group analyses to examine relationships between key measures of behavior-specific social support and (a) smoking susceptibility among nonsmokers, and (b) readiness to quit smoking among smokers. A matched sample of 190 adolescent smokers and nonsmokers (Mage = 16.8 years; 51% female) completed a questionnaire in which they nominated and reported on up to 10 important people in their lives. This measure allowed us to examine adolescents' overall networks (both peers and family) and to investigate numerous aspects, including general network characteristics (e.g., size of network, average contact with network members), social support (e.g., importance of people in the network), and the pervasiveness of smoking in the network (e.g., percentage of smoking peers). The pervasiveness of smoking in adolescents' social network was the strongest distinguisher of smokers versus nonsmokers. In addition, behavior-specific social support was strongly associated with susceptibility to initiate smoking among nonsmokers and readiness to quit among smokers. This research offers insight into potential targets for prevention and early intervention by demonstrating how social networks can both promote and attenuate risk for smoking.

  13. Adolescent Social Networks: General and Smoking-Specific Characteristics Associated With Smoking

    Science.gov (United States)

    Roberts, Megan E.; Nargiso, Jessica E.; Gaitonde, Linda Brazil; Stanton, Cassandra A.; Colby, Suzanne M.

    2015-01-01

    Objective: Converging lines of research suggest that adolescents’ smoking behaviors are strongly influenced by the characteristics of their social network and the social processes their network facilitates. The primary goal of this study was to conduct a detailed comparison of the social networks of adolescent smokers and nonsmokers to determine what aspects relate the most to smoking status. A secondary goal was to conduct within-group analyses to examine relationships between key measures of behavior-specific social support and (a) smoking susceptibility among nonsmokers, and (b) readiness to quit smoking among smokers. Method: A matched sample of 190 adolescent smokers and nonsmokers (Mage = 16.8 years; 51% female) completed a questionnaire in which they nominated and reported on up to 10 important people in their lives. This measure allowed us to examine adolescents’ overall networks (both peers and family) and to investigate numerous aspects, including general network characteristics (e.g., size of network, average contact with network members), social support (e.g., importance of people in the network), and the pervasiveness of smoking in the network (e.g., percentage of smoking peers). Results: The pervasiveness of smoking in adolescents’ social network was the strongest distinguisher of smokers versus nonsmokers. In addition, behavior-specific social support was strongly associated with susceptibility to initiate smoking among nonsmokers and readiness to quit among smokers. Conclusions: This research offers insight into potential targets for prevention and early intervention by demonstrating how social networks can both promote and attenuate risk for smoking. PMID:25785800

  14. EXPERIMENTAL ANALYSIS OF THE CHARACTERISTIC PERFORMANCE OF STANDALONE PHOTOVOLTAIC SYSTEM

    OpenAIRE

    Birendra Kishore; Anirban Nandy*; O. P. Pandey

    2016-01-01

    This paper demonstrates an insight solar PV Stand Alone system which is a practical model with a halogen light source. At different situations the performance of solar PV cells are analyzed. The system produces power with depending on the change in halogen light intensity & temperature. A theoretical & experimental analysis of the PV cell can be achieved. In this paper the I-V & P-V characteristic of the solar photovoltaic cells with changes in temperature and isolation have been ...

  15. Growth performance, carcass and organ characteristics of growing ...

    African Journals Online (AJOL)

    Growth performance, carcass and organ characteristics of growing rabbits fed graded levels of Moringa oleifera leaf meal in diets. ... Similarly, the weight of liver (40.35-57.05g), lungs (10.22-11.24g), heart (2.95-4.10g), kidney (8.30-10.70g), kidney fat (11.10-12.65g), small intestine (81.25-99.80g), large intestine ...

  16. Relationships between Isometric Force-Time Characteristics and Dynamic Performance

    Directory of Open Access Journals (Sweden)

    Thomas Dos’Santos

    2017-09-01

    Full Text Available The purpose of this study was to explore the relationships between isometric mid-thigh pull (IMTP force-time characteristics (peak force and time-specific force vales (100–250 ms and dynamic performance and compare dynamic performance between stronger and weaker athletes. Forty-three athletes from different sports (rowing, soccer, bicycle motocross, and hockey performed three trials of the squat jump (SJ, countermovement jump (CMJ, and IMTP, and performed a one repetition maximum power clean (PC. Reactive strength index modified (RSImod was also calculated from the CMJ. Statistically significant large correlations between IMTP force-time characteristics and PC (ρ = 0.569–0.674, p < 0.001, and moderate correlations between IMTP force-time characteristics (excluding force at 100 ms and RSImod (ρ = 0.389–0.449, p = 0.013–0.050 were observed. Only force at 250 ms demonstrated a statistically significant moderate correlation with CMJ height (ρ = 0.346, p = 0.016 and no statistically significant associations were observed between IMTP force-time characteristics and SJ height. Stronger athletes (top 10 demonstrated statistically significantly greater CMJ heights, RSImods, and PCs (p ≤ 0.004, g = 1.32–1.89 compared to weaker (bottom 10 athletes, but no differences in SJ height were observed (p = 0.871, g = 0.06. These findings highlight that the ability to apply rapidly high levels of force in short time intervals is integral for PC, CMJ height, and reactive strength.

  17. Error performance analysis in downlink cellular networks with interference management

    KAUST Repository

    Afify, Laila H.

    2015-05-01

    Modeling aggregate network interference in cellular networks has recently gained immense attention both in academia and industry. While stochastic geometry based models have succeeded to account for the cellular network geometry, they mostly abstract many important wireless communication system aspects (e.g., modulation techniques, signal recovery techniques). Recently, a novel stochastic geometry model, based on the Equivalent-in-Distribution (EiD) approach, succeeded to capture the aforementioned communication system aspects and extend the analysis to averaged error performance, however, on the expense of increasing the modeling complexity. Inspired by the EiD approach, the analysis developed in [1] takes into consideration the key system parameters, while providing a simple tractable analysis. In this paper, we extend this framework to study the effect of different interference management techniques in downlink cellular network. The accuracy of the proposed analysis is verified via Monte Carlo simulations.

  18. Characteristics of Key Update Strategies for Wireless Sensor Networks

    DEFF Research Database (Denmark)

    Yuksel, Ender; Nielson, Hanne Riis; Nielson, Flemming

    2011-01-01

    Wireless sensor networks offer the advantages of simple and low-resource communication. Challenged by this simplicity and low-resources, security is of particular importance in many cases such as transmission of sensitive data or strict requirements of tamper-resistance. Updating the security keys...

  19. Characteristics of file sharing and peer to peer networking | Opara ...

    African Journals Online (AJOL)

    A peer-to-peer (p2p) network allows computer hardware and software to function without the need for special server devices. While file sharing is the practice of distributing or providing access to digitally stored information, such as computer programs, multi-media (audio, video) resources, documents, or electronic books.

  20. Bandwidth characteristics of multimedia data traffic on a local area network

    Science.gov (United States)

    Chuang, Shery L.; Doubek, Sharon; Haines, Richard F.

    1993-01-01

    Limited spacecraft communication links call for users to investigate the potential use of video compression and multimedia technologies to optimize bandwidth allocations. The objective was to determine the transmission characteristics of multimedia data - motion video, text or bitmap graphics, and files transmitted independently and simultaneously over an ethernet local area network. Commercial desktop video teleconferencing hardware and software and Intel's proprietary Digital Video Interactive (DVI) video compression algorithm were used, and typical task scenarios were selected. The transmission time, packet size, number of packets, and network utilization of the data were recorded. Each data type - compressed motion video, text and/or bitmapped graphics, and a compressed image file - was first transmitted independently and its characteristics recorded. The results showed that an average bandwidth of 7.4 kilobits per second (kbps) was used to transmit graphics; an average bandwidth of 86.8 kbps was used to transmit an 18.9-kilobyte (kB) image file; a bandwidth of 728.9 kbps was used to transmit compressed motion video at 15 frames per second (fps); and a bandwidth of 75.9 kbps was used to transmit compressed motion video at 1.5 fps. Average packet sizes were 933 bytes for graphics, 498.5 bytes for the image file, 345.8 bytes for motion video at 15 fps, and 341.9 bytes for motion video at 1.5 fps. Simultaneous transmission of multimedia data types was also characterized. The multimedia packets used transmission bandwidths of 341.4 kbps and 105.8kbps. Bandwidth utilization varied according to the frame rate (frames per second) setting for the transmission of motion video. Packet size did not vary significantly between the data types. When these characteristics are applied to Space Station Freedom (SSF), the packet sizes fall within the maximum specified by the Consultative Committee for Space Data Systems (CCSDS). The uplink of imagery to SSF may be performed at

  1. Structure and Topology Dynamics of Hyper-Frequency Networks during Rest and Auditory Oddball Performance.

    Science.gov (United States)

    Müller, Viktor; Perdikis, Dionysios; von Oertzen, Timo; Sleimen-Malkoun, Rita; Jirsa, Viktor; Lindenberger, Ulman

    2016-01-01

    Resting-state and task-related recordings are characterized by oscillatory brain activity and widely distributed networks of synchronized oscillatory circuits. Electroencephalographic recordings (EEG) were used to assess network structure and network dynamics during resting state with eyes open and closed, and auditory oddball performance through phase synchronization between EEG channels. For this assessment, we constructed a hyper-frequency network (HFN) based on within- and cross-frequency coupling (WFC and CFC, respectively) at 10 oscillation frequencies ranging between 2 and 20 Hz. We found that CFC generally differentiates between task conditions better than WFC. CFC was the highest during resting state with eyes open. Using a graph-theoretical approach (GTA), we found that HFNs possess small-world network (SWN) topology with a slight tendency to random network characteristics. Moreover, analysis of the temporal fluctuations of HFNs revealed specific network topology dynamics (NTD), i.e., temporal changes of different graph-theoretical measures such as strength, clustering coefficient, characteristic path length (CPL), local, and global efficiency determined for HFNs at different time windows. The different topology metrics showed significant differences between conditions in the mean and standard deviation of these metrics both across time and nodes. In addition, using an artificial neural network approach, we found stimulus-related dynamics that varied across the different network topology metrics. We conclude that functional connectivity dynamics (FCD), or NTD, which was found using the HFN approach during rest and stimulus processing, reflects temporal and topological changes in the functional organization and reorganization of neuronal cell assemblies.

  2. Throughput Performance Evaluation of Multiservice Multirate OCDMA in Flexible Networks

    DEFF Research Database (Denmark)

    Raddo, Thiago R.; Sanches, Anderson L.; Tafur Monroy, Idelfonso

    2016-01-01

    packet arrivals distributions, with the latter defined as benchmark. A throughput performance evaluation is carried out for two distinct user code sequences separately, namely, 1-D and 2-D multiweight multilength optical orthogonal code (MWML-OOC). Numerical results show that the Poisson approach......In this paper, new analytical formalisms to evaluate the packet throughput of multiservice multirate slotted ALOHA optical code-division multiple-access (OCDMA) networks are proposed. The proposed formalisms can be successfully applied to 1-D and 2-D OCDMA networks with any number of user classes...... underestimates the throughput performance in unacceptable levels and incorrectly predicts the number of successfully received packets for most offered load values even in favorable conditions, such as for the 2-D MWML-OOC OCDMA network with a considerably large number of simultaneous users. On the other hand...

  3. Performance verification of network function virtualization in software defined optical transport networks

    Science.gov (United States)

    Zhao, Yongli; Hu, Liyazhou; Wang, Wei; Li, Yajie; Zhang, Jie

    2017-01-01

    With the continuous opening of resource acquisition and application, there are a large variety of network hardware appliances deployed as the communication infrastructure. To lunch a new network application always implies to replace the obsolete devices and needs the related space and power to accommodate it, which will increase the energy and capital investment. Network function virtualization1 (NFV) aims to address these problems by consolidating many network equipment onto industry standard elements such as servers, switches and storage. Many types of IT resources have been deployed to run Virtual Network Functions (vNFs), such as virtual switches and routers. Then how to deploy NFV in optical transport networks is a of great importance problem. This paper focuses on this problem, and gives an implementation architecture of NFV-enabled optical transport networks based on Software Defined Optical Networking (SDON) with the procedure of vNFs call and return. Especially, an implementation solution of NFV-enabled optical transport node is designed, and a parallel processing method for NFV-enabled OTN nodes is proposed. To verify the performance of NFV-enabled SDON, the protocol interaction procedures of control function virtualization and node function virtualization are demonstrated on SDON testbed. Finally, the benefits and challenges of the parallel processing method for NFV-enabled OTN nodes are simulated and analyzed.

  4. The influence of passenger flow on the topology characteristics of urban rail transit networks

    Science.gov (United States)

    Hu, Yingyue; Chen, Feng; Chen, Peiwen; Tan, Yurong

    2017-05-01

    Current researches on the network characteristics of metro networks are generally carried out on topology networks without passenger flows running on it, thus more complex features of the networks with ridership loaded on it cannot be captured. In this study, we incorporated the load of metro networks, passenger volume, into the exploration of network features. Thus, the network can be examined in the context of operation, which is the ultimate purpose of the existence of a metro network. To this end, section load was selected as an edge weight to demonstrate the influence of ridership on the network, and a weighted calculation method for complex network indicators and robustness were proposed to capture the unique behaviors of a metro network with passengers flowing in it. The proposed method was applied on Beijing Subway. Firstly, the passenger volume in terms of daily origin and destination matrix was extracted from exhausted transit smart card data. Using the established approach and the matrix as weighting, common indicators of complex network including clustering coefficient, betweenness and degree were calculated, and network robustness were evaluated under potential attacks. The results were further compared to that of unweighted networks, and it suggests indicators of the network with consideration of passenger volumes differ from that without ridership to some extent, and networks tend to be more vulnerable than that without load on it. The significance sequence for the stations can be changed. By introducing passenger flow weighting, actual operation status of the network can be reflected more accurately. It is beneficial to determine the crucial stations and make precautionary measures for the entire network’s operation security.

  5. Study on the complex network characteristics of urban road system based on GIS

    Science.gov (United States)

    Gao, Zhonghua; Chen, Zhenjie; Liu, Yongxue; Huang, Kang

    2007-06-01

    Urban road system is the basic bone of urban transportation and one of the most important factors that influent and controls the urban configuration. In this paper, an approach of modeling, analyzing and optimizing urban road system is described based on complex network theory and GIS technology. The urban road system is studied on three focuses: building the urban road network, modeling the computational procedures based on urban road networks and analyzing the urban road system of Changzhou City as the study case. The conclusion is that the urban road network is a scale-free network with small-world characteristic, and there is still space for development of the whole network as a small-world network, also the key road crosses should be kept expedite.

  6. Impact of sensor installation techniques on seismic network performance

    Science.gov (United States)

    Bainbridge, Geoffrey; Laporte, Michael; Baturan, Dario; Greig, Wesley

    2015-04-01

    The magnitude of completeness (Mc) of a seismic network is determined by a number of factors including station density, self-noise and passband of the sensor used, ambient noise environment and sensor installation method and depth. Sensor installation techniques related to depth are of particular importance due to their impact on overall monitoring network deployment costs. We present a case study which evaluates performance of Trillium Compact Posthole seismometers installed using different methods as well as depths, and evaluate its impact on seismic network operation in terms of the target area of interest average magnitude of completeness in various monitoring applications. We evaluate three sensor installation methods: direct burial in soil at 0.5 m depth, 5 m screwpile and 15 m cemented casing borehole at sites chosen to represent high, medium and low ambient noise environments. In all cases, noise performance improves with depth with noise suppression generally more prominent at higher frequencies but with significant variations from site to site. When extended to overall network performance, the observed noise suppression results in improved (decreased) target area average Mc. However, the extent of the improvement with depth varies significantly, and can be negligible. The increased cost associated with installation at depth uses funds that could be applied to the deployment of additional stations. Using network modelling tools, we compare the improvement in magnitude of completeness and location accuracy associated with increasing installation depth to those associated with increased number of stations. The appropriate strategy is applied on a case-by-case and driven by network-specific performance requirements, deployment constraints and site noise conditions.

  7. Performance and Characteristics of Heat Pump Clothes Drier

    Science.gov (United States)

    Ambarita, H.; Nasution, D. M.; Gunawan, S.; Nasution, A. H.

    2017-03-01

    In this paper, a study of clothes drying using a heat pump drier has been carried out. The objective is to examine the performance and drying characteristics of the heat pump clothes dryer. The result of performances and drying characteristics were compared with waste heat drying system of split-type residential air conditioner (RAC). A drying chamber with volume 1 m3 integrated with heat pump component had been designed and fabricated. The heat pump operated by vapor compression cycle with power input of 800W and refrigerant R22 as a working fluid. The clothes dried made of pure cotton with initial weight varied from 3.00 kg, 5.25 kg, and 6.38 kg, respectively. The results shown that the drying time and drying rate of heat pump drier are faster than waste heat drying system. The average total performance of heat pump clothes drier is 6.56. On the other hand, SMER which is obtained 1.492 kg/kWh. These values are lower than the SMER of waste heat drying system which shown the average value of 2.492 kg/kWh. In the case of drying clothes, waste heat drying of RAC shows a better performance in comparison with heat pump drying system.

  8. Social network characteristics and body mass index in an elderly Korean population.

    Science.gov (United States)

    Lee, Won Joon; Youm, Yoosik; Rhee, Yumie; Park, Yeong-Ran; Chu, Sang Hui; Kim, Hyeon Chang

    2013-11-01

    Research has shown that obesity appears to spread through social ties. However, the association between other characteristics of social networks and obesity is unclear. This study aimed to identify the association between social network characteristics and body mass index (BMI, kg/m(2)) in an elderly Korean population. This cross-sectional study analyzed data from 657 Koreans (273 men, 384 women) aged 60 years or older who participated in the Korean Social Life, Health, and Aging Project. Network size is a count of the number of friends. Density of communication network is the number of connections in the social network reported as a fraction of the total links possible in the personal (ego-centric) network. Average frequency of communication (or meeting) measures how often network members communicate (or meet) each other. The association of each social network measure with BMI was investigated by multiple linear regression analysis. After adjusting for potential confounders, the men with lower density (0.83) and lower size (1-2), but not in the women (p=0.393). The lowest tertile of communication frequency was associated with higher BMI in the women (β=0.885, p=0.049), but not in the men (p=0.140). Our study suggests that social network structure (network size and density) and activation (communication frequency and meeting frequency) are associated with obesity among the elderly. There may also be gender differences in this association.

  9. Characteristics of Social Network Gamers: Results of an Online Survey.

    Science.gov (United States)

    Geisel, Olga; Panneck, Patricia; Stickel, Anna; Schneider, Michael; Müller, Christian A

    2015-01-01

    Current research on Internet addiction (IA) reported moderate to high prevalence rates of IA and comorbid psychiatric symptoms in users of social networking sites (SNS) and online role-playing games. The aim of this study was to characterize adult users of an Internet multiplayer strategy game within a SNS. Therefore, we conducted an exploratory study using an online survey to assess sociodemographic variables, psychopathology, and the rate of IA in a sample of adult social network gamers by Young's Internet Addiction Test (IAT), the Toronto Alexithymia Scale (TAS-26), the Beck Depression Inventory-II (BDI-II), the Symptom Checklist-90-R (SCL-90-R), and the WHO Quality of Life-BREF (WHOQOL-BREF). All participants were listed gamers of "Combat Zone" in the SNS "Facebook." In this sample, 16.2% of the participants were categorized as subjects with IA and 19.5% fulfilled the criteria for alexithymia. Comparing study participants with and without IA, the IA group had significantly more subjects with alexithymia, reported more depressive symptoms, and showed poorer quality of life. These findings suggest that social network gaming might also be associated with maladaptive patterns of Internet use. Furthermore, a relationship between IA, alexithymia, and depressive symptoms was found that needs to be elucidated by future studies.

  10. Improving Dense Network Performance through Centralized Scheduling and Interference Coordination

    DEFF Research Database (Denmark)

    Lopez, Victor Fernandez; Pedersen, Klaus I.; Alvarez, Beatriz Soret

    2017-01-01

    and the receiver sides. As a network coordination scheme, we apply a centralized joint cell association and scheduling mechanism based on dynamic cell switching, by which users are not always served by the strongest perceived cell. The method simultaneously resultsin more balanced loads and increased performance...

  11. Assessment of neural networks performance in modeling rainfall ...

    African Journals Online (AJOL)

    This paper presents the evaluation of performance of Neural Network (NN) model in predicting the behavioral pattern of rainfall depths of some locations in the North Central zones of Nigeria. The input to the model is the consecutive rainfall depths data obtained from the Nigerian Meteorological (NiMET) Agency. The neural ...

  12. Road safety performance indicators for the interurban road network.

    NARCIS (Netherlands)

    Yannis, G. Weijermars, W.A.M. Gitelman, V. Vis, M. Chazirisa, A. Papadimitriou, E. & Lima Azevedo, C.

    2013-01-01

    Various road safety performance indicators (SPIs) have been proposed for different road safety research areas, mainly as regards driver behaviour (e.g. seat belt use, alcohol, drugs, etc.) and vehicles (e.g. passive safety); however, no SPIs for the road network and design have been developed. The

  13. High Performance Computing and Networking for Science--Background Paper.

    Science.gov (United States)

    Congress of the U.S., Washington, DC. Office of Technology Assessment.

    The Office of Technology Assessment is conducting an assessment of the effects of new information technologies--including high performance computing, data networking, and mass data archiving--on research and development. This paper offers a view of the issues and their implications for current discussions about Federal supercomputer initiatives…

  14. The Influence of Social Networks on High School Students' Performance

    Science.gov (United States)

    Abu-Shanab, Emad; Al-Tarawneh, Heyam

    2015-01-01

    Social networks are becoming an integral part of people's lives. Students are spending much time on social media and are considered the largest category that uses such application. This study tries to explore the influence of social media use, and especially Facebook, on high school students' performance. The study used the GPA of students in four…

  15. Metrics for evaluating performance and uncertainty of Bayesian network models

    Science.gov (United States)

    Bruce G. Marcot

    2012-01-01

    This paper presents a selected set of existing and new metrics for gauging Bayesian network model performance and uncertainty. Selected existing and new metrics are discussed for conducting model sensitivity analysis (variance reduction, entropy reduction, case file simulation); evaluating scenarios (influence analysis); depicting model complexity (numbers of model...

  16. Public Management and Educational Performance: The Impact of Managerial Networking.

    Science.gov (United States)

    Meier, Kenneth J.; O'Toole, Laurence J., Jr.

    2003-01-01

    A 5-year performance analysis of managers in more than 500 school districts used a nonlinear, interactive, contingent model of management. Empirical support was found for key elements of the network-management portion of the model. Results showed that public management matters in policy implementation, but its impact is often nonlinear. (Contains…

  17. Model of Emergency Department Nurse Performance Improvement Based on Association of Individual Characteristic, Organization Characteristic and Job Characteristic

    OpenAIRE

    Bogar, Maria Margaretha; Nursalam, Nursalam; Dewi, Yulis Setiya

    2013-01-01

    Introduction: Nursing care is integral part of health care and having important role in management of patient with emergency condition. The purpose of this research was to develop nurse performance improvement model based on individual, organization and job characteristics association in Emergency Department of RSUD dr TC Hillers Maumere. Method: This was an explanative survey by cross sectional approach held on July -August 2012. Respondents in this study were 22 nurses and 44 patients were ...

  18. Hierarchical neural networks perform both serial and parallel processing.

    Science.gov (United States)

    Agliari, Elena; Barra, Adriano; Galluzzi, Andrea; Guerra, Francesco; Tantari, Daniele; Tavani, Flavia

    2015-06-01

    In this work we study a Hebbian neural network, where neurons are arranged according to a hierarchical architecture such that their couplings scale with their reciprocal distance. As a full statistical mechanics solution is not yet available, after a streamlined introduction to the state of the art via that route, the problem is consistently approached through signal-to-noise technique and extensive numerical simulations. Focusing on the low-storage regime, where the amount of stored patterns grows at most logarithmical with the system size, we prove that these non-mean-field Hopfield-like networks display a richer phase diagram than their classical counterparts. In particular, these networks are able to perform serial processing (i.e. retrieve one pattern at a time through a complete rearrangement of the whole ensemble of neurons) as well as parallel processing (i.e. retrieve several patterns simultaneously, delegating the management of different patterns to diverse communities that build network). The tune between the two regimes is given by the rate of the coupling decay and by the level of noise affecting the system. The price to pay for those remarkable capabilities lies in a network's capacity smaller than the mean field counterpart, thus yielding a new budget principle: the wider the multitasking capabilities, the lower the network load and vice versa. This may have important implications in our understanding of biological complexity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Performance Evaluation of Hybrid Acoustic-Optical Underwater Swarm Networks

    Directory of Open Access Journals (Sweden)

    Samuela PERSIA

    2016-04-01

    Full Text Available The Underwater Swarm is a particular Underwater Network configuration characterized by nodes very close one to each other, with mobility capability. The structure of the network is that of a distributed network, in which the nodes, through the exchange of control information, will take decisions in collaborative manner. This type of network raises challenges for its effective design and development, for which the only use of acoustic communication as traditionally suggested in underwater communication could be not enough. A new emerging solution could be a hybrid solution that combines the use of acoustic and optical channel in order to overcome the acoustic channel limitations in underwater environment. In this work, we want to investigate how the acoustic and optical communications influence the Underwater Swarm performance by considering the Low Layers Protocols (Physical Layer, Data Link Layer and Network Layer effects over the two different propagation technologies. Performance simulations have been carried out to suggest how the new hybrid system could be designed. This study will permit to provide useful analysis for the real implementation of an Underwater Swarm based on hybrid communication technology.

  20. Performance evaluation of two highly interconnected Data Center networks

    DEFF Research Database (Denmark)

    Andrus, Bogdan-Mihai; Mihai Poncea, Ovidiu; Vegas Olmos, Juan José

    2015-01-01

    In this paper we present the analysis of highly interconnected topologies like hypercube and torus and how they can be implemented in data centers in order to cope with the rapid increase and demands for performance of the internal traffic. By replicating the topologies and subjecting them...... of the network was increased by a factor of 32. The performance measurements are supported by abstract metrics that also give a cost and complexity indication in choosing the right topology for the required application....

  1. Using Critical Systems thinking to Improve Student Performance in Networking

    OpenAIRE

    Albertus G. Joubert; Roelien Goede

    2012-01-01

    This paper explores how Critical Systems Thinking and Action Research can be used to improve student performance in Networking. When describing a system from a systems thinking perspective, the following aspects can be identified: the total system performance, the systems environment, the resources, the components and the management of the system. Following the history of system thinking we observe three emerged methodologies namely, hard systems, soft systems, and critical systems. This pape...

  2. The Impact of Social Networks on Students’ Performance

    OpenAIRE

    Jusuf Zekiri

    2016-01-01

    The objective of this study is to determine the impact of using social media and its impact on students’ performance and success. This research tries to identify the relationship between students’ use of social networks and their success in their studies. It tries also to find out whether time spent impacts students’ performance and success. Whether students use social media more for entertainment or for teaching and information sharing purposes. The paper uses a quantitative approach for col...

  3. Performance characteristics of a quantum Diesel refrigeration cycle

    Energy Technology Data Exchange (ETDEWEB)

    He Jizhou [Department of Physics, Nanchang University, Nanchang 330031 (China)], E-mail: hjzhou@ncu.edu.cn; Wang Hao; Liu Sanqiu [Department of Physics, Nanchang University, Nanchang 330031 (China)

    2009-04-15

    The Diesel refrigeration cycle using an ideal quantum gas as the working substance is called quantum Diesel refrigeration cycle, which is different from Carnot, Ericsson, Brayton, Otto and Stirling refrigeration cycles. For ideal quantum gases, a corrected equation of state, which considers the quantum behavior of gas particles, is used instead of the classical one. The purpose of this paper is to investigate the effect of quantum gas as the working substance on the performance of a quantum Diesel refrigeration cycle. It is found that coefficients of performance of the cycle are not affected by the quantum degeneracy of the working substance, which is the same as that of the classical Diesel refrigeration cycle. However, the refrigeration load is different from those of the classical Diesel refrigeration cycle. Lastly, the influence of the quantum degeneracy on the performance characteristics of the quantum Diesel refrigeration cycle operated in different temperature regions is discussed.

  4. Performance characteristics of a quantum Diesel refrigeration cycle

    Energy Technology Data Exchange (ETDEWEB)

    He, Jizhou; Wang, Hao; Liu, Sanqiu [Department of Physics, Nanchang University, Nanchang 330031 (China)

    2009-04-15

    The Diesel refrigeration cycle using an ideal quantum gas as the working substance is called quantum Diesel refrigeration cycle, which is different from Carnot, Ericsson, Brayton, Otto and Stirling refrigeration cycles. For ideal quantum gases, a corrected equation of state, which considers the quantum behavior of gas particles, is used instead of the classical one. The purpose of this paper is to investigate the effect of quantum gas as the working substance on the performance of a quantum Diesel refrigeration cycle. It is found that coefficients of performance of the cycle are not affected by the quantum degeneracy of the working substance, which is the same as that of the classical Diesel refrigeration cycle. However, the refrigeration load is different from those of the classical Diesel refrigeration cycle. Lastly, the influence of the quantum degeneracy on the performance characteristics of the quantum Diesel refrigeration cycle operated in different temperature regions is discussed. (author)

  5. IDI diesel engine performance and exhaust emission analysis using biodiesel with an artificial neural network (ANN)

    OpenAIRE

    K. Prasada Rao; T. Victor Babu; Anuradha, G.; B.V. Appa Rao

    2016-01-01

    Biodiesel is receiving increasing attention each passing day because of its fuel properties and compatibility. This study investigates the performance and emission characteristics of single cylinder four stroke indirect diesel injection (IDI) engine fueled with Rice Bran Methyl Ester (RBME) with Isopropanol additive. The investigation is done through a combination of experimental data analysis and artificial neural network (ANN) modeling. The study used IDI engine experimental data to evaluat...

  6. Temperature Effect on Uncooled Semiconductor Laser Diode to the Network Performance System

    OpenAIRE

    Mohammad S. Ab-Rahman; Nurain I. Shuhaimi

    2012-01-01

    Problem statement: The characteristics of a laser diode are highly dependent on the temperature of the laser chip. Thus, the effect of temperature on the network performance of uncooled semiconductor laser diode are studied by simulating its equivalent electrical circuit, developed from the rate equations that governing optical components directly into an electrical simulation framework. Approach: The simulations are carried out using circuit analysis program named OptiSPICE and OptiSystem. I...

  7. COMPARATIVE ANALYSIS OF PERFORMANCE CHARACTERISTICS OF JET VORTEX TYPE SUPERCHAGES

    Directory of Open Access Journals (Sweden)

    A. Rogovyi

    2016-06-01

    Full Text Available On the basis of mathematical modeling there was carried out a comparative analysis of characteristics of jet vortex type superchargers. Dependences of the energy performance of vortex ejector on the geometry parameters and the largest values in terms of efficiency as well as the coefficient of ejection are analyzed. There were built combined characteristics of vortex chamber pumps and vortex ejectors. Vortex chamber pump has advantage pressure in an exit channel over the vortex ejector, consequently there is a more effective power transmission from a working medium, besides the withdrawal of pumping medium in a tangential channel allows to avoid energy losses owing to rotation of a stream in an exit channel.

  8. Performance and emission characteristics of double biodiesel blends with diesel

    Directory of Open Access Journals (Sweden)

    Kuthalingam Arun Balasubramanian

    2013-01-01

    Full Text Available Recent research on biodiesel focused on performance of single biodiesel and its blends with diesel. The present work aims to investigate the possibilities of the application of mixtures of two biodiesel and its blends with diesel as a fuel for diesel engines. The combinations of Pongamia pinnata biodiesel, Mustard oil biodiesel along with diesel (PMD and combinations of Cotton seed biodiesel, Pongamia pinnata biodiesel along with diesel (CPD are taken for the experimental analysis. Experiments are conducted using a single cylinder direct-injection diesel engine with different loads at rated 3000 rpm. The engine characteristics of the two sets of double biodiesel blends are compared. For the maximum load, the value of Specific Fuel consumption and thermal efficiency of CPD-1 blend (10:10:80 is close to the diesel values. CPD blends give better engine characteristics than PMD blends. The blends of CPD are suitable alternative fuel for diesel in stationary/agricultural diesel engines.

  9. Prediction of flow characteristics using multiple regression and neural networks: A case study in Zimbabwe

    NARCIS (Netherlands)

    Mazvimavi, D.; Meijerink, A.M.J.; Savenije, H.H.G.; Stein, A.

    2005-01-01

    The feasibility of predicting flow characteristics from basin descriptors using multiple regression and neural networks has been investigated on 52 basins in Zimbabwe. Flow characteristics considered were average annual runoff, base flow index, flow duration curve, and average monthly runoff . Mean

  10. Characteristics and Performance of Existing Load Disaggregation Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Mayhorn, Ebony T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sullivan, Greg P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Butner, Ryan S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hao, He [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Baechler, Michael C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-04-10

    Non-intrusive load monitoring (NILM) or non-intrusive appliance load monitoring (NIALM) is an analytic approach to disaggregate building loads based on a single metering point. This advanced load monitoring and disaggregation technique has the potential to provide an alternative solution to high-priced traditional sub-metering and enable innovative approaches for energy conservation, energy efficiency, and demand response. However, since the inception of the concept in the 1980’s, evaluations of these technologies have focused on reporting performance accuracy without investigating sources of inaccuracies or fully understanding and articulating the meaning of the metrics used to quantify performance. As a result, the market for, as well as, advances in these technologies have been slowly maturing.To improve the market for these NILM technologies, there has to be confidence that the deployment will lead to benefits. In reality, every end-user and application that this technology may enable does not require the highest levels of performance accuracy to produce benefits. Also, there are other important characteristics that need to be considered, which may affect the appeal of NILM products to certain market targets (i.e. residential and commercial building consumers) and the suitability for particular applications. These characteristics include the following: 1) ease of use, the level of expertise/bandwidth required to properly use the product; 2) ease of installation, the level of expertise required to install along with hardware needs that impact product cost; and 3) ability to inform decisions and actions, whether the energy outputs received by end-users (e.g. third party applications, residential users, building operators, etc.) empower decisions and actions to be taken at time frames required for certain applications. Therefore, stakeholders, researchers, and other interested parties should be kept abreast of the evolving capabilities, uses, and characteristics

  11. Performance of SON for RSRP-based LTE/WLAN access network selection

    NARCIS (Netherlands)

    Kovács, I.Z.; Laselva, D.; Michaelsen, P.H.; Wang, Y.; Djapic, R.; Spaey, K.

    2014-01-01

    Carrier-grade Wireless Local Area Network (WLAN) is becoming an important complementary system to cellular networks for Mobile Network Operators (MNOs). Network controlled access network selection between cellular and WLAN is an essential functionality to optimize network performance and user

  12. Study on hydraulic characteristics of mine dust-proof water supply network

    Science.gov (United States)

    Deng, Quanlong; Jiang, Zhongan; Han, Shuo; Fu, Enqi

    2018-01-01

    In order to study the hydraulic characteristics of mine dust-proof water supply network and obtain the change rule of water consumption and water pressure, according to the similarity principle and the fluid continuity equation and energy equation, the similarity criterion of mine dust-proof water supply network is deduced, and a similar model of dust-proof water supply network is established based on the prototype of Kailuan Group, the characteristics of hydraulic parameters in water supply network are studied experimentally. The results show that water pressure at each point is a dynamic process, and there is a negative correlation between water pressure and water consumption. With the increase of water consumption, the pressure of water points show a decreasing trend. According to the structure of the pipe network and the location of the water point, the influence degree on the pressure of each point is different.

  13. Traffic characteristics analysis in optical burst switching networks with optical label processing

    Directory of Open Access Journals (Sweden)

    Edson Moschim

    2007-03-01

    Full Text Available An analysis is carried out with burst-switching optical networks which use label processing consisting of orthogonal optical codes (OOC, considering traffic characteristics such as length/duration and arrival rate of bursts. Main results show that the use of OOC label processing influences on the decrease of burst loss probability, especially for short-lived bursts. Therefore, short bursts that would be blocked in conventional electronic processing networks are transmitted when the OOC label processing is used. Thus, an increase in the network use occurs as well as a decrease in the burst transmission latency, reaching a granularity close to packets networks.

  14. State network approach to characteristics of financial crises

    Science.gov (United States)

    Qiu, Lu; Gu, Changgui; Xiao, Qin; Yang, Huijie; Wu, Guolin

    2018-02-01

    Extensive works have reported that a financial crisis can induce significant changes to topological structure of a stock network constructed with cross-correlations between stocks. But there are still some problems to be answered, such as what is the relationship between different crises in history and how to classify them? In the present work, we propose a new network-based solution to extract and display the relationships between the crises. The Dow Jones stock market is investigated as a typical example. The cross-correlation matrix between stocks is used to measure the state of stock market, called state matrix. All the states cluster into six sub-categories. A state network is constructed further to display the relationships between all the states, which contains a total of nine communities. It is found that three crises C , D and E (refer to the Lehman's bankruptcy in 2008, the Euro-zone and International Monetary Fund decide the first bailout for Greece in 2010, and the European sovereign debt crisis in 2011, respectively) belong to a specific sub-category and cluster in a single community. The mid-stage of C is closely linked with E, while the other stages with D. The other two crises A and B (refer to the financial crisis in Asia in 1997, and the burst of "dot-com bubble" in 2002, respectively) belong to another sub-category and gather in a corner of another single community. A and B are linked directly with C and D by two edges. By this way, we give a clear picture of the relationships between the crises.

  15. PERFORMANCE CHARACTERISTIC MEMS-BASED IMUs FOR UAVs NAVIGATION

    Directory of Open Access Journals (Sweden)

    H. A. Mohamed

    2015-08-01

    Full Text Available Accurate 3D reconstruction has become essential for non-traditional mapping applications such as urban planning, mining industry, environmental monitoring, navigation, surveillance, pipeline inspection, infrastructure monitoring, landslide hazard analysis, indoor localization, and military simulation. The needs of these applications cannot be satisfied by traditional mapping, which is based on dedicated data acquisition systems designed for mapping purposes. Recent advances in hardware and software development have made it possible to conduct accurate 3D mapping without using costly and high-end data acquisition systems. Low-cost digital cameras, laser scanners, and navigation systems can provide accurate mapping if they are properly integrated at the hardware and software levels. Unmanned Aerial Vehicles (UAVs are emerging as a mobile mapping platform that can provide additional economical and practical advantages. However, such economical and practical requirements need navigation systems that can provide uninterrupted navigation solution. Hence, testing the performance characteristics of Micro-Electro-Mechanical Systems (MEMS or low cost navigation sensors for various UAV applications is important research. This work focuses on studying the performance characteristics under different manoeuvres using inertial measurements integrated with single point positioning, Real-Time-Kinematic (RTK, and additional navigational aiding sensors. Furthermore, the performance of the inertial sensors is tested during Global Positioning System (GPS signal outage.

  16. Performance characteristics of CdTe drift ring detector

    Science.gov (United States)

    Alruhaili, A.; Sellin, P. J.; Lohstroh, A.; Veeramani, P.; Kazemi, S.; Veale, M. C.; Sawhney, K. J. S.; Kachkanov, V.

    2014-03-01

    CdTe and CdZnTe material is an excellent candidate for the fabrication of high energy X-ray spectroscopic detectors due to their good quantum efficiency and room temperature operation. The main material limitation is associated with the poor charge transport properties of holes. The motivation of this work is to investigate the performance characteristics of a detector fabricated with a drift ring geometry that is insensitive to the transport of holes. The performance of a prototype Ohmic CdTe drift ring detector fabricated by Acrorad with 3 drift rings is reported; measurements include room temperature current voltage characteristics (IV) and spectroscopic performance. The data shows that the energy resolution of the detector is limited by leakage current which is a combination of bulk and surface leakage currents. The energy resolution was studied as a function of incident X-ray position with an X-ray microbeam at the Diamond Light Source. Different ring biasing schemes were investigated and the results show that by increasing the lateral field (i.e. the bias gradient across the rings) the active area, evaluated by the detected count rate, increased significantly.

  17. The establishment of heterogeneous networks in performative spaces

    DEFF Research Database (Denmark)

    Suenson, Valinka; Harder, Henrik

    2010-01-01

    This paper presents an empirical research combining the Actor Network Theory with a development of RFID (Radio Frequency Identification) technology for tracking indoor movement behavior. The aim of the paper is to disucss the value of RFID technology as a method for observing heterogeneous networks...... and architecture through this theoretical perspective, it highlights the importance of the user involvement in the performative spaces where materiality becomes an actant on equal terms with the users. This paper discusses the use of RFID technology for tracking indoor movenment behavior as a method for examining...

  18. Value networks in manufacturing sustainability and performance excellence

    CERN Document Server

    Uusitalo, Teuvo

    2017-01-01

    This book highlights innovative solutions together with various techniques and methods that can help support the manufacturing sector to excel in economic, social, and environmental terms in networked business environments. The book also furthers understanding of sustainable manufacturing from the perspective of value creation in manufacturing networks, by capitalizing on the outcomes of the European ‘Sustainable Value Creation in Manufacturing Networks’ project. New dynamics and uncertainties in modern markets call for innovative solutions in the global manufacturing sector. While the manufacturing sector is traditionally driven by technology, it also requires other managerial and organizational solutions in terms of network governance, business models, sustainable solution development for products and services, performance management portals, etc., which can provide major competitive advantages for companies. At the same time, the manufacturing industry is subject to a change process, where business net...

  19. Analysis of convergence performance of neural networks ranking algorithm.

    Science.gov (United States)

    Zhang, Yongquan; Cao, Feilong

    2012-10-01

    The ranking problem is to learn a real-valued function which gives rise to a ranking over an instance space, which has gained much attention in machine learning in recent years. This article gives analysis of the convergence performance of neural networks ranking algorithm by means of the given samples and approximation property of neural networks. The upper bounds of convergence rate provided by our results can be considerably tight and independent of the dimension of input space when the target function satisfies some smooth condition. The obtained results imply that neural networks are able to adapt to ranking function in the instance space. Hence the obtained results are able to circumvent the curse of dimensionality on some smooth condition. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

  20. Performance characteristics of lumped nonevaporable getter (NEG) pump

    Energy Technology Data Exchange (ETDEWEB)

    In, Sang-Ryul; Yokouchi, Shigeru; Be, Suck-Hee (JAERI-RIKEN SPring-8 Project Team, Wako, Saitama (Japan)); Maruyama, Takashi

    1991-12-01

    A prototype of the lumped NEG pump (LNP) designed as a main pump of the crotches and absorbers of the SPring-8 storage ring was manufactured with 14 nonevaporable getter (NEG) modules and a cylindrical pump body made of aluminum alloy. Vacuum Performance and operating characteristics of the LNP have been tested. Initial pumping speeds of the LNP for H{sub 2}, CO, N{sub 2} and CO{sub 2} were typically 3 m{sup 3}/s, 1.7 m{sup 3}/s, 1 m{sup 3}/s and 1.3 m{sup 3}/s, respectively. The experimental results were compared with the pumping speeds calculated by the Monte Carlo method. Equilibrium characteristics of the LNP in the activation period were studies to obtain basic data for the design of the auxiliary pumping system, and to set a pertinent activation schedule for the LNP. Operating characteristics such as the power consumption of the NEG modules and the temperature rise of the adjacent chambers including the aluminum alloy pump body during the NEG activation were also investigated. (author).

  1. Performance assessment of Beijing Lightning Network (BLNET) and comparison with other lightning location networks across Beijing

    Science.gov (United States)

    Srivastava, Abhay; Tian, Ye; Qie, Xiushu; Wang, Dongfang; Sun, Zhuling; Yuan, Shanfeng; Wang, Yu; Chen, Zhixiong; Xu, Wenjing; Zhang, Hongbo; Jiang, Rubin; Su, Debin

    2017-11-01

    The performances of Beijing Lightning Network (BLNET) operated in Beijing-Tianjin-Hebei urban cluster area have been evaluated in terms of detection efficiency and relative location accuracy. A self-reference method has been used to show the detection efficiency of BLNET, for which fast antenna waveforms have been manually examined. Based on the fast antenna verification, the average detection efficiency of BLNET is 97.4% for intracloud (IC) flashes, 73.9% for cloud-to-ground (CG) flashes and 93.2% for the total flashes. Result suggests the CG detection of regional dense network is highly precise when the thunderstorm passes over the network; however it changes day to day when the thunderstorms are outside the network. Further, the CG stroke data from three different lightning location networks across Beijing are compared. The relative detection efficiency of World Wide Lightning Location Network (WWLLN) and Chinese Meteorology Administration - Lightning Detection Network (CMA-LDN, also known as ADTD) are approximately 12.4% (16.8%) and 36.5% (49.4%), respectively, comparing with fast antenna (BLNET). The location of BLNET is in middle, while WWLLN and CMA-LDN average locations are southeast and northwest, respectively. Finally, the IC pulses and CG return stroke pulses have been compared with the S-band Doppler radar. This type of study is useful to know the approximate situation in a region and improve the performance of lightning location networks in the absence of ground truth. Two lightning flashes occurred on tower in the coverage of BLNET show that the horizontal location error was 52.9 m and 250 m, respectively.

  2. Performance characteristics of continuously grated multicore sensor fiber

    Science.gov (United States)

    Westbrook, Paul S.; Kremp, Tristan; Feder, Kenneth S.; Ko, Wing; Monberg, Eric M.; Wu, Hongchao; Simoff, Debra A.; Shenk, Scott; Ortiz, Roy M.

    2017-04-01

    We describe the fabrication and performance of a continuously grated twisted multicore fiber sensor array. The grated fiber sensor comprises nearly continuous Bragg gratings along its entire length. The gratings are inscribed over lengths in excess of 10m in fibers with UV transparent coating using a flexible and scalable reel to reel processing system. The arrays are tested using optical frequency domain reflectometry (OFDR). We report on automated analysis routines applied to these OFDR measurements that allow for characterization of 100s of individual grating exposures that make up a continuously grated fiber length. We also report on the spectral loss of the continuously grated fiber, showing that it is suitable for applications with sensors in excess of 100m. Finally, we report on the fiber sensing characteristics by performing measurements of fiber bend using a fiber shape reconstruction algorithm on OFDR traces obtained from four of the fiber cores.

  3. Performance Modeling of Communication Networks with Markov Chains

    CERN Document Server

    Mo, Jeonghoon

    2010-01-01

    This book is an introduction to Markov chain modeling with applications to communication networks. It begins with a general introduction to performance modeling in Chapter 1 where we introduce different performance models. We then introduce basic ideas of Markov chain modeling: Markov property, discrete time Markov chain (DTMe and continuous time Markov chain (CTMe. We also discuss how to find the steady state distributions from these Markov chains and how they can be used to compute the system performance metric. The solution methodologies include a balance equation technique, limiting probab

  4. Data assimilation for identification of cardiovascular network characteristics.

    Science.gov (United States)

    Lal, Rajnesh; Mohammadi, Bijan; Nicoud, Franck

    2017-05-01

    A method to estimate the hemodynamics parameters of a network of vessels using an Ensemble Kalman filter is presented. The elastic moduli (Young's modulus) of blood vessels and the terminal boundary parameters are estimated as the solution of an inverse problem. Two synthetic test cases and a configuration where experimental data are available are presented. The sensitivity analysis confirms that the proposed method is quite robust even with a few numbers of observations. The simulations with the estimated parameters recovers target pressure or flow rate waveforms at given specific locations, improving the state-of-the-art predictions available in the literature. This shows the effectiveness and efficiency of both the parameter estimation algorithm and the blood flow model. Copyright © 2016 John Wiley & Sons, Ltd.

  5. Generalized Performance Characteristics of Refrigeration and Heat Pump Systems

    Directory of Open Access Journals (Sweden)

    Mahmoud Huleihil

    2010-01-01

    Full Text Available A finite-time generic model to describe the behavior of real refrigeration systems is discussed. The model accounts for finite heat transfer rates, heat leaks, and friction as different sources of dissipation. The performance characteristics are cast in terms of cooling rate (r versus coefficient of performance (w. For comparison purposes, various types of refrigeration/heat pump systems are considered: the thermoelectric refrigerator, the reverse Brayton cycle, and the reverse Rankine cycle. Although the dissipation mechanisms are different (e.g., heat leak and Joule heating in the thermoelectric refrigerator, isentropic losses in the reverse Brayton cycle, and limits arising from the equation of state in the reverse Rankine cycle, the r−w characteristic curves have a general loop shape. There are four limiting types of operation: open circuit in which both r and w vanish in the limit of slow operation; short circuit in which again r and w vanish but in the limit of fast operation; maximum r; maximum w. The behavior of the considered systems is explained by means of the proposed model. The derived formulae could be used for a quick estimation of w and the temperatures of the working fluid at the hot and cold sides.

  6. A diagnosis model for early Tourette syndrome children based on brain structural network characteristics

    Science.gov (United States)

    Wen, Hongwei; Liu, Yue; Wang, Jieqiong; Zhang, Jishui; Peng, Yun; He, Huiguang

    2016-03-01

    Tourette syndrome (TS) is a childhood-onset neurobehavioral disorder characterized by the presence of multiple motor and vocal tics. Tic generation has been linked to disturbed networks of brain areas involved in planning, controlling and execution of action. The aim of our work is to select topological characteristics of structural network which were most efficient for estimating the classification models to identify early TS children. Here we employed the diffusion tensor imaging (DTI) and deterministic tractography to construct the structural networks of 44 TS children and 48 age and gender matched healthy children. We calculated four different connection matrices (fiber number, mean FA, averaged fiber length weighted and binary matrices) and then applied graph theoretical methods to extract the regional nodal characteristics of structural network. For each weighted or binary network, nodal degree, nodal efficiency and nodal betweenness were selected as features. Support Vector Machine Recursive Feature Extraction (SVM-RFE) algorithm was used to estimate the best feature subset for classification. The accuracy of 88.26% evaluated by a nested cross validation was achieved on combing best feature subset of each network characteristic. The identified discriminative brain nodes mostly located in the basal ganglia and frontal cortico-cortical networks involved in TS children which was associated with tic severity. Our study holds promise for early identification and predicting prognosis of TS children.

  7. On the Performance of TCP Spoofing in Satellite Networks

    Science.gov (United States)

    Ishac, Joseph; Allman, Mark

    2001-01-01

    In this paper, we analyze the performance of Transmission Control Protocol (TCP) in a network that consists of both satellite and terrestrial components. One method, proposed by outside research, to improve the performance of data transfers over satellites is to use a performance enhancing proxy often dubbed 'spoofing.' Spoofing involves the transparent splitting of a TCP connection between the source and destination by some entity within the network path. In order to analyze the impact of spoofing, we constructed a simulation suite based around the network simulator ns-2. The simulation reflects a host with a satellite connection to the Internet and allows the option to spoof connections just prior to the satellite. The methodology used in our simulation allows us to analyze spoofing over a large range of file sizes and under various congested conditions, while prior work on this topic has primarily focused on bulk transfers with no congestion. As a result of these simulations, we find that the performance of spoofing is dependent upon a number of conditions.

  8. Performance Analysis of Cluster Formation in Wireless Sensor Networks.

    Science.gov (United States)

    Montiel, Edgar Romo; Rivero-Angeles, Mario E; Rubino, Gerardo; Molina-Lozano, Heron; Menchaca-Mendez, Rolando; Menchaca-Mendez, Ricardo

    2017-12-13

    Clustered-based wireless sensor networks have been extensively used in the literature in order to achieve considerable energy consumption reductions. However, two aspects of such systems have been largely overlooked. Namely, the transmission probability used during the cluster formation phase and the way in which cluster heads are selected. Both of these issues have an important impact on the performance of the system. For the former, it is common to consider that sensor nodes in a clustered-based Wireless Sensor Network (WSN) use a fixed transmission probability to send control data in order to build the clusters. However, due to the highly variable conditions experienced by these networks, a fixed transmission probability may lead to extra energy consumption. In view of this, three different transmission probability strategies are studied: optimal, fixed and adaptive. In this context, we also investigate cluster head selection schemes, specifically, we consider two intelligent schemes based on the fuzzy C-means and k-medoids algorithms and a random selection with no intelligence. We show that the use of intelligent schemes greatly improves the performance of the system, but their use entails higher complexity and selection delay. The main performance metrics considered in this work are energy consumption, successful transmission probability and cluster formation latency. As an additional feature of this work, we study the effect of errors in the wireless channel and the impact on the performance of the system under the different transmission probability schemes.

  9. Design and implementation of a high performance network security processor

    Science.gov (United States)

    Wang, Haixin; Bai, Guoqiang; Chen, Hongyi

    2010-03-01

    The last few years have seen many significant progresses in the field of application-specific processors. One example is network security processors (NSPs) that perform various cryptographic operations specified by network security protocols and help to offload the computation intensive burdens from network processors (NPs). This article presents a high performance NSP system architecture implementation intended for both internet protocol security (IPSec) and secure socket layer (SSL) protocol acceleration, which are widely employed in virtual private network (VPN) and e-commerce applications. The efficient dual one-way pipelined data transfer skeleton and optimised integration scheme of the heterogenous parallel crypto engine arrays lead to a Gbps rate NSP, which is programmable with domain specific descriptor-based instructions. The descriptor-based control flow fragments large data packets and distributes them to the crypto engine arrays, which fully utilises the parallel computation resources and improves the overall system data throughput. A prototyping platform for this NSP design is implemented with a Xilinx XC3S5000 based FPGA chip set. Results show that the design gives a peak throughput for the IPSec ESP tunnel mode of 2.85 Gbps with over 2100 full SSL handshakes per second at a clock rate of 95 MHz.

  10. Integration and the performance of healthcare networks: do integration strategies enhance efficiency, profitability, and image?

    Directory of Open Access Journals (Sweden)

    Thomas T.H. Wan

    2001-06-01

    Full Text Available Purpose: This study examines the integration effects on efficiency and financial viability of the top 100 integrated healthcare networks (IHNs in the United States. Theory: A contingency- strategic theory is used to identify the relationship of IHNs' performance to their structural and operational characteristics and integration strategies. Methods: The lists of the top 100 IHNs ranked in two years, 1998 and 1999, by the SMG Marketing Group were merged to create a database for the study. Multiple indicators were used to examine the relationship between IHNs' characteristics and their performance in efficiency and financial viability. A path analytical model was developed and validated by the Mplus statistical program. Factors influencing the top 100 IHNs' images, represented by attaining ranking among the top 100 in two consecutive years, were analysed. Results and conclusion: No positive associations were found between integration and network performance in efficiency or profits. Longitudinal data are needed to investigate the effect of integration on healthcare networks' financial performance.

  11. Board Characteristics and Firm Performance: Evidence from Indonesia

    Directory of Open Access Journals (Sweden)

    Athalia Ariati Hidayat

    2015-12-01

    Full Text Available This research examines the effect of board characteristics (comprising in different sized proportions: family commissioners, family directors, independent commissioners, ex-government officer commissioners, and board of commissioners size to firm performance. Using fixed-effects data panel regression, this research investigates 293 firms listed on the Indonesian Stock Exchange during 2008-2012. Firm performance is proxied by market measure (Tobin’s Q and accounting measure (ROA. The findings of this research suggest that the proportion of family commissioners and family directors have positive impact only to Tobin’s Q value, while the proportion of independent directors can increase both Tobin’s Q and ROA. On the other hand, this research finds that the proportion of ex-government officers in the board gives no impact to firm performance. This research also finds that the board size has U-shaped non-linear relationship with firm performance as proxied by Tobin’s Q and ROA.

  12. Network characteristics of individual pigments in cyanobacterial photosystem II core complexes

    Science.gov (United States)

    Lee, Eun; Holme, Petter

    2013-12-01

    Part of the excitation energy transfer (EET) characteristics of the photosystem II (PSII) comes from the interconnection between pigments. To understand the correlation between the EET and the pigments' interaction structure, we construct a network from the EET rates which are related to both the distance between the pigments (chlorophylls and pheophytins) and their spatial orientations. Especially, we investigate how well the PS II core complex's EET functionality can be explained by using only the network topology in Thermosynechococcus vulcanus 1.9 °A. Starting from the Förster theory, we construct a network of EET pathways. For an analysis of the network structure, we calculate common network-structural measures like betweenness centrality, eigenvector centrality and weighted clustering. These measures can reflect the role of individual pigments in the EET network. In our work, we found that some well-known properties were reproduced by the network analysis of the simplified network, which means that the topology of the network encodes functionally relevant information. For example, from the network structural analysis, we can infer that most of the chlorophyll molecules (clorophylls) in the pigment-protein complex CP47 have heightened probability to transfer energy compared with other chlorophylls. We also see that the active branch chlorophylls in the reaction center are characterized by a high eigenvector centrality, a high betweenness centrality and a low weighted clustering coefficient. This is indicative of functionally important vertices.

  13. The Gain of Performance of Optical WDM Networks

    Directory of Open Access Journals (Sweden)

    Miroslav Bahleda

    2008-01-01

    Full Text Available We study the blocking probability and performance of single-fiber and multifiber optical networks with wavelength division multiplexing (WDM. We extend the well-known analytical blocking probability model by Barry and Humblet to the general model, which is proposed for both single-fiber and multifiber network paths with any kind of wavelength conversion (no, limited, or full wavelength conversion and for uniform and nonuniform link loads. We investigate the effect of the link load, wavelength conversion degree, and the number of wavelengths, fibers, and hops on blocking probability. We also extend the definition of the gain of wavelength conversion by Barry and Humblet to the gain of performance, which is fully general. Thanks to this definition and implementation of our model, we compare different WDM node architectures and present interesting results.

  14. Wide area network performance study of a distribution management system

    Energy Technology Data Exchange (ETDEWEB)

    Su, C.-L.; Lu, C.-N. [National Sun Yat-Sen University, Kaohsiung (Taiwan). Dept. of Electrical Engineering; Lin, M.-C. [Taiwan Power Company, Kaohsiung (Taiwan). Kaoping Regional Office

    2000-01-01

    Distribution automation is considered a necessity for providing better power service in a more competitive environment. When new automatic functions are included in a distribution management system (DMS), loadings of the data links in the supervisory control and data acquisition (SCADA) system will become very heavy. In order to maintain a proper performance, system upgrade or migration will need to be considered. Two wide area network (WAN) architectures for a Taiwan Power Company's regional DMS are investigated. The WAN modeling presented in this paper is aimed to verify whether the hardware design could accommodate the communications load and to avoid overpaying for network equipment. Simulation results indicate that, to cover feeder automation functions, a WAN with distributed processing capability would provide better SCADA performance than an extension of the old centralized system. (author)

  15. Depth-dependent flow and pressure characteristics in cortical microvascular networks.

    Directory of Open Access Journals (Sweden)

    Franca Schmid

    2017-02-01

    Full Text Available A better knowledge of the flow and pressure distribution in realistic microvascular networks is needed for improving our understanding of neurovascular coupling mechanisms and the related measurement techniques. Here, numerical simulations with discrete tracking of red blood cells (RBCs are performed in three realistic microvascular networks from the mouse cerebral cortex. Our analysis is based on trajectories of individual RBCs and focuses on layer-specific flow phenomena until a cortical depth of 1 mm. The individual RBC trajectories reveal that in the capillary bed RBCs preferentially move in plane. Hence, the capillary flow field shows laminar patterns and a layer-specific analysis is valid. We demonstrate that for RBCs entering the capillary bed close to the cortical surface (< 400 μm the largest pressure drop takes place in the capillaries (37%, while for deeper regions arterioles are responsible for 61% of the total pressure drop. Further flow characteristics, such as capillary transit time or RBC velocity, also vary significantly over cortical depth. Comparison of purely topological characteristics with flow-based ones shows that a combined interpretation of topology and flow is indispensable. Our results provide evidence that it is crucial to consider layer-specific differences for all investigations related to the flow and pressure distribution in the cortical vasculature. These findings support the hypothesis that for an efficient oxygen up-regulation at least two regulation mechanisms must be playing hand in hand, namely cerebral blood flow increase and microvascular flow homogenization. However, the contribution of both regulation mechanisms to oxygen up-regulation likely varies over depth.

  16. Depth-dependent flow and pressure characteristics in cortical microvascular networks.

    Science.gov (United States)

    Schmid, Franca; Tsai, Philbert S; Kleinfeld, David; Jenny, Patrick; Weber, Bruno

    2017-02-01

    A better knowledge of the flow and pressure distribution in realistic microvascular networks is needed for improving our understanding of neurovascular coupling mechanisms and the related measurement techniques. Here, numerical simulations with discrete tracking of red blood cells (RBCs) are performed in three realistic microvascular networks from the mouse cerebral cortex. Our analysis is based on trajectories of individual RBCs and focuses on layer-specific flow phenomena until a cortical depth of 1 mm. The individual RBC trajectories reveal that in the capillary bed RBCs preferentially move in plane. Hence, the capillary flow field shows laminar patterns and a layer-specific analysis is valid. We demonstrate that for RBCs entering the capillary bed close to the cortical surface (pressure drop takes place in the capillaries (37%), while for deeper regions arterioles are responsible for 61% of the total pressure drop. Further flow characteristics, such as capillary transit time or RBC velocity, also vary significantly over cortical depth. Comparison of purely topological characteristics with flow-based ones shows that a combined interpretation of topology and flow is indispensable. Our results provide evidence that it is crucial to consider layer-specific differences for all investigations related to the flow and pressure distribution in the cortical vasculature. These findings support the hypothesis that for an efficient oxygen up-regulation at least two regulation mechanisms must be playing hand in hand, namely cerebral blood flow increase and microvascular flow homogenization. However, the contribution of both regulation mechanisms to oxygen up-regulation likely varies over depth.

  17. Using a Bayesian network to predict barrier island geomorphologic characteristics

    Science.gov (United States)

    Gutierrez, Ben; Plant, Nathaniel G.; Thieler, E. Robert; Turecek, Aaron

    2015-01-01

    Quantifying geomorphic variability of coastal environments is important for understanding and describing the vulnerability of coastal topography, infrastructure, and ecosystems to future storms and sea level rise. Here we use a Bayesian network (BN) to test the importance of multiple interactions between barrier island geomorphic variables. This approach models complex interactions and handles uncertainty, which is intrinsic to future sea level rise, storminess, or anthropogenic processes (e.g., beach nourishment and other forms of coastal management). The BN was developed and tested at Assateague Island, Maryland/Virginia, USA, a barrier island with sufficient geomorphic and temporal variability to evaluate our approach. We tested the ability to predict dune height, beach width, and beach height variables using inputs that included longer-term, larger-scale, or external variables (historical shoreline change rates, distances to inlets, barrier width, mean barrier elevation, and anthropogenic modification). Data sets from three different years spanning nearly a decade sampled substantial temporal variability and serve as a proxy for analysis of future conditions. We show that distinct geomorphic conditions are associated with different long-term shoreline change rates and that the most skillful predictions of dune height, beach width, and beach height depend on including multiple input variables simultaneously. The predictive relationships are robust to variations in the amount of input data and to variations in model complexity. The resulting model can be used to evaluate scenarios related to coastal management plans and/or future scenarios where shoreline change rates may differ from those observed historically.

  18. Performance Analysis on the Coexistence of Multiple Cognitive Radio Networks

    Science.gov (United States)

    2015-05-28

    Multiple Cognitive Radio Networks The demand for wireless services is growing on a daily basis while spectral resources to support this growth are...static. Therefore, there is need for the adoption of a new spectrum sharing paradigm. Cognitive Radio (CR) is a revolutionary technology aiming to...27709-2211 Cognitive Radio REPORT DOCUMENTATION PAGE 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 10. SPONSOR/MONITOR’S ACRONYM(S) ARO 8. PERFORMING

  19. Performance evaluation of coherent Ising machines against classical neural networks

    Science.gov (United States)

    Haribara, Yoshitaka; Ishikawa, Hitoshi; Utsunomiya, Shoko; Aihara, Kazuyuki; Yamamoto, Yoshihisa

    2017-12-01

    The coherent Ising machine is expected to find a near-optimal solution in various combinatorial optimization problems, which has been experimentally confirmed with optical parametric oscillators and a field programmable gate array circuit. The similar mathematical models were proposed three decades ago by Hopfield et al in the context of classical neural networks. In this article, we compare the computational performance of both models.

  20. The Algerian Seismic Network: Performance from data quality analysis

    Science.gov (United States)

    Yelles, Abdelkarim; Allili, Toufik; Alili, Azouaou

    2013-04-01

    densify the network and to enhance performance of the Algerian Digital Seismic Network.

  1. Capacitance-Voltage Characteristics of Thin-film Transistors Fabricated with Solution-Processed Semiconducting Carbon Nanotube Networks.

    Science.gov (United States)

    Cai, Le; Zhang, Suoming; Miao, Jinshui; Wei, Qinqin; Wang, Chuan

    2015-12-01

    We report the capacitance-voltage (C-V) measurements on thin-film transistors (TFTs) using solution-processed semiconducting carbon nanotube networks with different densities and channel lengths. From the measured C-V characteristics, gate capacitance and field-effect mobility (up to ~50 cm(2) V(-1) s(-1)) of the TFTs were evaluated with better precision compared with the results obtained from calculated gate capacitance. The C-V characteristics measured under different frequencies further enabled the extraction and analysis of the interface trap density at the nanotube-dielectric layer interface, which was found to increase significantly as the network density increases. The results presented here indicate that C-V measurement is a powerful tool to assess the electrical performance and to investigate the carrier transport mechanism of TFTs based on carbon nanotubes.

  2. Passive and Active Monitoring on a High Performance Research Network.

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, Warren

    2001-05-01

    The bold network challenges described in ''Internet End-to-end Performance Monitoring for the High Energy and Nuclear Physics Community'' presented at PAM 2000 have been tackled by the intrepid administrators and engineers providing the network services. After less than a year, the BaBar collaboration has collected almost 100 million particle collision events in a database approaching 165TB (Tera=10{sup 12}). Around 20TB has been exported via the Internet to the BaBar regional center at IN2P3 in Lyon, France, for processing and around 40 TB of simulated events have been imported to SLAC from Lawrence Livermore National Laboratory (LLNL). An unforseen challenge has arisen due to recent events and highlighted security concerns at DoE funded labs. New rules and regulations suggest it is only a matter of time before many active performance measurements may not be possible between many sites. Yet, at the same time, the importance of understanding every aspect of the network and eradicating packet loss for high throughput data transfers has become apparent. Work at SLAC to employ passive monitoring using netflow and OC3MON is underway and techniques to supplement and possibly replace the active measurements are being considered. This paper will detail the special needs and traffic characterization of a remarkable research project, and how the networking hurdles have been resolved (or not!) to achieve the required high data throughput. Results from active and passive measurements will be compared, and methods for achieving high throughput and the effect on the network will be assessed along with tools that directly measure throughput and applications used to actually transfer data.

  3. The Impact of Social Networks on Students’ Performance

    Directory of Open Access Journals (Sweden)

    Jusuf Zekiri

    2016-11-01

    Full Text Available The objective of this study is to determine the impact of using social media and its impact on students’ performance and success. This research tries to identify the relationship between students’ use of social networks and their success in their studies. It tries also to find out whether time spent impacts students’ performance and success. Whether students use social media more for entertainment or for teaching and information sharing purposes. The paper uses a quantitative approach for collecting the primary data. The data was collected by surveying 255 respondents from South East European University. The data analyses were done by SPSS so" ware program. Cronbach alpha is used for testing the validity and reliability of variables used in this study. The hypotheses were tested using One Simple T-test. The obtained empirical results show that a great number of students are aware of advantages and disadvantages by the social media. Thus, due to a great percent of times spent on social networking activities, the performance and the success of students suffer setbacks which could lead to a poor performance and they might fail to create a balance between the social media and academic activities. Furthermore, it is about their addiction, the loss of time leading to consequences in their academic development, and they are also influenced to a great extent negatively by the social networking sites, because their attention is focused on chatting and music while their academic activities are neglected. Finally, based on the results of survey, we can conclude that impact of social media on the academic performance of students should focus more on the positive side than on the negative side to achieve balance. Hence, creating more pages for research and academic activities will enable students to improve their performance, thereby avoiding a distraction which leads to deviation from their academic work.

  4. Social Network Characteristics and Daily Smoking among Young Adults in Sweden

    Directory of Open Access Journals (Sweden)

    Mikael Rostila

    2013-11-01

    Full Text Available A large number of studies have shown that friends’ smoking behavior is strongly associated with an individual’s own risk for smoking. However, few studies have examined whether other features of social networks, independently or conjointly with friends’ smoking behavior, may influence the risk for smoking. Because it is characterized by the growing importance of friendship networks, the transition from adolescence to young adulthood may constitute a particularly relevant period on which to focus our investigation of network influences on smoking behavior. The aim of this study was therefore to examine the consequences of peer smoking as well as other network characteristics (friends’ other health behaviors, relationship content, and structural aspects of the network on the risk for smoking among young adults. The data was based on a cross-sectional survey of Swedish 19-year-olds carried out in 2009 (n = 5,695 with a response rate of 51.6%. Logistic regression was the primary method of analysis. The results show that having a large percentage of smokers in one’s network was by far the most important risk factor for daily smoking. The risk of daily smoking was 21.20 (CI 14.24. 31.54 if 76%–100% of the network members smoked. Having a high percentage of physically active friends was inversely associated with daily smoking. The risk of smoking was 0.65 (CI 0.42. 1.00 if 76%–100% of the network members were physically active. No main associations between the other network characteristics (relationship content and structural aspects of the network and smoking were found. However, there was an interaction between the percentage of smokers in the network and relationship content (i.e., trust, relationship quality and propensity to discuss problems: positive relationship content in combination with peer smoking may increase the risk of smoking. Women with a high percentage of smokers in their networks were also at higher risk of daily

  5. Top-Performing Students’ Use of Social Networking Sites

    OpenAIRE

    Afendi Hamat; Mohamed Amin Embi; Haslinda Abu Hassan

    2013-01-01

    This study aims to identify patterns in Internet and Social Networking Site (SNS) usage among topperforming students at Malaysian universities. Data were gathered from 6358 public and private university students through an online survey. The top performers (reported CGPA of 3.6 and above) were found to be the most likely to have an SNS account and they spent more time using the Internet than other students. The findings also show that in terms of SNS usage, top-performing students display pat...

  6. Modeling Nanoscale FinFET Performance by a Neural Network Method

    Directory of Open Access Journals (Sweden)

    Jin He

    2017-07-01

    Full Text Available This paper presents a neural network method to model nanometer FinFET performance. The principle of this method is firstly introduced and its application in modeling DC and conductance characteristics of nanoscale FinFET transistor is demonstrated in detail. It is shown that this method does not need parameter extraction routine while its prediction of the transistor performance has a small relative error within 1 % compared with measured data, thus this new method is as accurate as the physics based surface potential model.

  7. Distributed utility technology cost, performance, and environmental characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Y; Adelman, S

    1995-06-01

    Distributed Utility (DU) is an emerging concept in which modular generation and storage technologies sited near customer loads in distribution systems and specifically targeted demand-side management programs are used to supplement conventional central station generation plants to meet customer energy service needs. Research has shown that implementation of the DU concept could provide substantial benefits to utilities. This report summarizes the cost, performance, and environmental and siting characteristics of existing and emerging modular generation and storage technologies that are applicable under the DU concept. It is intended to be a practical reference guide for utility planners and engineers seeking information on DU technology options. This work was funded by the Office of Utility Technologies of the US Department of Energy.

  8. Performance Characteristics of a Vertical Axis Hydrokinetic Turbine

    Science.gov (United States)

    Bailin, Benjamin; Flack, Karen; Lust, Ethan

    2016-11-01

    Performance characteristics are presented for a vertical axis hydrokinetic turbine designed for use in a riverine environment. The test turbine is a 1:6 scale model of a three-bladed device (9.5 m span, 6.5 m diameter) that has been proposed by the Department of Energy. Experiments are conducted in the large towing tank (116 m long, 7.9 m wide, 5 m deep) at the United States Naval Academy. The large scale facility allows for scale independent results. The turbine is towed beneath a moving carriage at a constant speed in combination with a shaft brake to achieve the desired tip speed ratio (TSR) range. The measured quantities of turbine thrust, torque and RPM result in power and thrust coefficients for a range of TSR. Results will be presented for cases with quiescent flow and flow with mild surface waves, representative of riverine environments.

  9. Roasted sesame hulls improve broiler performance without affecting carcass characteristics

    Directory of Open Access Journals (Sweden)

    Kamel Z. Mahmoud

    2015-09-01

    Full Text Available An experiment was conducted to evaluate the effect of using graded levels of roasted sesame hulls (RSH on growth performance and meat quality characteristics in broiler chickens. A total of 360 day-old Lohmann chicks were randomly allocated into 24 floor pens and raised over 42 days. One of four dietary treatments was assigned to each group of six pens in a completely randomized fashion. The chicks in the control group were fed a corn-soybean based diet (RSH-0, while the chicks in treatments two, three, and four were fed graded levels of RSH at 4% (RSH-4, 8% (RSH-8, and 12% (RSH-12, respectively. Diets were formulated to meet broiler chicks’ requirements according to the National Research Council for both starter and finisher rations. The results showed that RSH inclusion increased (P<0.05 feed intake and final body weight without adversely affecting the feed conversion ratio. Broiler chicks fed RSH-12 had heavier (P<0.05 breast and leg cuts compared to the control-fed group with no change to their chemical composition. Water holding capacity (WHC, cooking loss (CL, and shear force (SF reported similar results in all dietary groups. The chemical composition of both thigh and breast cuts was not affected by the RSH. After one day of thawing, colour coordinates of breast cuts behaved similarly in all dietary groups. The results of this study suggest that the addition of RSH to broiler diets up to 12% improves their growth performance; nevertheless, carcass characteristics and meat quality showed no alterations compared to the control-fed group.

  10. Science collaboration networks in sociology and their general characteristics in Serbia

    Directory of Open Access Journals (Sweden)

    Lazar Zsolt

    2012-01-01

    Full Text Available Science collaboration networks occupy an important place in the analysis of social networks. There are several directions of concern in this kind of research: one attempts to explain the structure of science collaboration networks, the second one analyses the invisible scientific communities and the third one is dealing with the problems of different citation forms which function as a base from which many of the conclusions concerning these networks are being derived. However, the results of recent research in science collaboration networks indicate that there are a number of idiosyncratic characteristics of collaboration networks in sociology. In the first part of the paper the author analyzes the results of previous research of sociological social networks, published in scientific papers available in the following databases: JSTOR, ScienceDirect and SpringerLink. The authors then proceeds with the analysis of social networks of sociologists in Serbia and gives guidelines of the first research project dedicated to the analysis of social networks in Serbia.

  11. SON for LTE-WLAN access network selection : design and performance

    NARCIS (Netherlands)

    Willemen, P.; Laselva, D.; Wang, Y.; Kovács, I.; Djapic, R.; Moerman, I.

    2016-01-01

    Mobile network operators (MNOs) are deploying carrier-grade Wireless Local Area Network (WLAN) as an important complementary system to cellular networks. Access network selection (ANS) between cellular and WLAN is an essential component to improve network performance and user quality-of-service

  12. Network DEA: an application to analysis of academic performance

    Science.gov (United States)

    Saniee Monfared, Mohammad Ali; Safi, Mahsa

    2013-05-01

    As governmental subsidies to universities are declining in recent years, sustaining excellence in academic performance and more efficient use of resources have become important issues for university stakeholders. To assess the academic performances and the utilization of the resources, two important issues need to be addressed, i.e., a capable methodology and a set of good performance indicators as we consider in this paper. In this paper, we propose a set of performance indicators to enable efficiency analysis of academic activities and apply a novel network DEA structure to account for subfunctional efficiencies such as teaching quality, research productivity, as well as the overall efficiency. We tested our approach on the efficiency analysis of academic colleges at Alzahra University in Iran.

  13. Anti-correlations in the degree distribution increase stimulus detection performance in noisy spiking neural networks.

    Science.gov (United States)

    Martens, Marijn B; Houweling, Arthur R; E Tiesinga, Paul H

    2017-02-01

    Neuronal circuits in the rodent barrel cortex are characterized by stable low firing rates. However, recent experiments show that short spike trains elicited by electrical stimulation in single neurons can induce behavioral responses. Hence, the underlying neural networks provide stability against internal fluctuations in the firing rate, while simultaneously making the circuits sensitive to small external perturbations. Here we studied whether stability and sensitivity are affected by the connectivity structure in recurrently connected spiking networks. We found that anti-correlation between the number of afferent (in-degree) and efferent (out-degree) synaptic connections of neurons increases stability against pathological bursting, relative to networks where the degrees were either positively correlated or uncorrelated. In the stable network state, stimulation of a few cells could lead to a detectable change in the firing rate. To quantify the ability of networks to detect the stimulation, we used a receiver operating characteristic (ROC) analysis. For a given level of background noise, networks with anti-correlated degrees displayed the lowest false positive rates, and consequently had the highest stimulus detection performance. We propose that anti-correlation in the degree distribution may be a computational strategy employed by sensory cortices to increase the detectability of external stimuli. We show that networks with anti-correlated degrees can in principle be formed by applying learning rules comprised of a combination of spike-timing dependent plasticity, homeostatic plasticity and pruning to networks with uncorrelated degrees. To test our prediction we suggest a novel experimental method to estimate correlations in the degree distribution.

  14. Performance evaluation of cellular phone network based portable ECG device.

    Science.gov (United States)

    Hong, Joo-Hyun; Cha, Eun-Jong; Lee, Tae-Soo

    2008-01-01

    In this study, cellular phone network based portable ECG device was developed and three experiments were performed to evaluate the accuracy, reliability and operability, applicability during daily life of the developed device. First, ECG signals were measured using the developed device and Biopac device (reference device) during sitting and marking time and compared to verify the accuracy of R-R intervals. Second, the reliable data transmission to remote server was verified on two types of simulated emergency event using patient simulator. Third, during daily life with five types of motion, accuracy of data transmission to remote server was verified on two types of event occurring. By acquiring and comparing subject's biomedical signal and motion signal, the accuracy, reliability and operability, applicability during daily life of the developed device were verified. Therefore, cellular phone network based portable ECG device can monitor patient with inobtrusive manner.

  15. High Performance Data mining by Genetic Neural Network

    Directory of Open Access Journals (Sweden)

    Dadmehr Rahbari

    2013-10-01

    Full Text Available Data mining in computer science is the process of discovering interesting and useful patterns and relationships in large volumes of data. Most methods for mining problems is based on artificial intelligence algorithms. Neural network optimization based on three basic parameters topology, weights and the learning rate is a powerful method. We introduce optimal method for solving this problem. In this paper genetic algorithm with mutation and crossover operators change the network structure and optimized that. Dataset used for our work is stroke disease with twenty features that optimized number of that achieved by new hybrid algorithm. Result of this work is very well incomparison with other similar method. Low present of error show that our method is our new approach to efficient, high-performance data mining problems is introduced.

  16. Characteristics of frequent emergency department presenters to an Australian emergency medicine network

    Directory of Open Access Journals (Sweden)

    Markham Donna

    2011-12-01

    Full Text Available Abstract Background To describe the characteristics of emergency department (ED patients defined as frequent presenters (FP presenting to an Australian emergency department network and compare these with a cohort of non-frequent presenters (NFP. Method A retrospective chart review utilising an electronic emergency medicine patient medical record database was performed on patients presenting to Southern Health EDs from March 2009 to March 2010. Non-frequent presenters were defined as patients presenting less than 5 times and frequent presenters as presenting 8 or more times in the study period. Characteristics of both groups were described and compared. Results During the 12-month study period there were 540 FP patients with 4549 admissions and 73,089 NFP patients with 100,943 admissions. FP patients were slightly older with a significant increase in frequency of patients between the ages of 70 to 79 years and they were more likely to be divorced or separated than NFP patients. Frequent presenters to the emergency department were more likely to utilise the ambulance service to arrive at the hospital, or in the custody of police than NFP patients. FPs were more likely to be admitted to hospital, more likely to have an admission to a mental health bed than NFP patients and more likely to self-discharge from the emergency department while waiting for care. Conclusions There are major implications for the utilisation of limited ED resources by frequent presenters. By further understanding the characteristics of FP we may be able to address the specific health care needs of this population in more efficient and cost effective ways. Further research analysing the effectiveness of targeted multidisciplinary interventions aiming to reduce the frequency of ED attendances may be warranted.

  17. An exploratory analysis of network characteristics and quality of interactions among public health collaboratives

    Directory of Open Access Journals (Sweden)

    Danielle M. Varda

    2012-06-01

    Full Text Available While the benefits of collaboration have become widely accepted and the practice of collaboration is growing within the public health system, a paucity of research exists that examines factors and mechanisms related to effective collaboration between public health and their partner organizations. The purpose of this paper is to address this gap by exploring the structural and organizational characteristics of public health collaboratives. Design and Methods. Using both social network analysis and traditional statistical methods, we conduct an exploratory secondary data analysis of 11 public health collaboratives chosen from across the United States. All collaboratives are part of the PARTNER (www.partnertool.net database. We analyze data to identify relational patterns by exploring the structure (the way that organizations connect and exchange relationships, in relation to perceptions of value and trust, explanations for varying reports of success, and factors related to outcomes. We describe the characteristics of the collaboratives, types of resource contributions, outcomes of the collaboratives, perceptions of success, and reasons for success. We found high variation and significant differences within and between these collaboratives including perceptions of success. There were significant relationships among various factors such as resource contributions, reasons cited for success, and trust and value perceived by organizations. We find that although the unique structure of each collaborative makes it challenging to identify a specific set of factors to determine when a collaborative will be successful, the organizational characteristics and interorganizational dynamics do appear to impact outcomes. We recommend a quality improvement process that suggests matching assessment to goals and developing action steps for performance improvement.

  18. Network Performance and Quality of Experience of Remote Access Laboratories

    Directory of Open Access Journals (Sweden)

    Alexander A. Kist

    2012-11-01

    Full Text Available Remote Access Laboratories (RAL have become important learning and teaching tools. This paper presents a performance study that targets a specific remote access architecture implemented within a universities operational environment. This particular RAL system provides globally authenticated and arbitrated remote access to virtualized computers as well as computer controlled hardware experiments. This paper presents system performance results that have been obtained utilizing both a set of automated and human subject tests. Principle objectives of the study were: To gain a better understanding of the nature of network traffic caused by experimental activity usage; to obtain an indication of user expectations of activity performance; and to develop a measure to predict Quality of Experience, based on easily measurable Quality of Service parameters. The study emulates network layer variation of access-bandwidth and round-trip-time of typical usage scenarios and contrasts against user perception results that allow classifying expected user performance. It demonstrates that failure rate is excellent measure of usability, and that round-trip-time predominantly affects user experience. Thin-client and remote desktop architectures are popular to separate the location of users and the actual data processing and use similar structures, hence results of this study to be applied in these application areas as well.

  19. A Framework to Implement IoT Network Performance Modelling Techniques for Network Solution Selection

    Directory of Open Access Journals (Sweden)

    Declan T. Delaney

    2016-12-01

    Full Text Available No single network solution for Internet of Things (IoT networks can provide the required level of Quality of Service (QoS for all applications in all environments. This leads to an increasing number of solutions created to fit particular scenarios. Given the increasing number and complexity of solutions available, it becomes difficult for an application developer to choose the solution which is best suited for an application. This article introduces a framework which autonomously chooses the best solution for the application given the current deployed environment. The framework utilises a performance model to predict the expected performance of a particular solution in a given environment. The framework can then choose an apt solution for the application from a set of available solutions. This article presents the framework with a set of models built using data collected from simulation. The modelling technique can determine with up to 85% accuracy the solution which performs the best for a particular performance metric given a set of solutions. The article highlights the fractured and disjointed practice currently in place for examining and comparing communication solutions and aims to open a discussion on harmonising testing procedures so that different solutions can be directly compared and offers a framework to achieve this within IoT networks.

  20. A Framework to Implement IoT Network Performance Modelling Techniques for Network Solution Selection †

    Science.gov (United States)

    Delaney, Declan T.; O’Hare, Gregory M. P.

    2016-01-01

    No single network solution for Internet of Things (IoT) networks can provide the required level of Quality of Service (QoS) for all applications in all environments. This leads to an increasing number of solutions created to fit particular scenarios. Given the increasing number and complexity of solutions available, it becomes difficult for an application developer to choose the solution which is best suited for an application. This article introduces a framework which autonomously chooses the best solution for the application given the current deployed environment. The framework utilises a performance model to predict the expected performance of a particular solution in a given environment. The framework can then choose an apt solution for the application from a set of available solutions. This article presents the framework with a set of models built using data collected from simulation. The modelling technique can determine with up to 85% accuracy the solution which performs the best for a particular performance metric given a set of solutions. The article highlights the fractured and disjointed practice currently in place for examining and comparing communication solutions and aims to open a discussion on harmonising testing procedures so that different solutions can be directly compared and offers a framework to achieve this within IoT networks. PMID:27916929

  1. A Framework to Implement IoT Network Performance Modelling Techniques for Network Solution Selection.

    Science.gov (United States)

    Delaney, Declan T; O'Hare, Gregory M P

    2016-12-01

    No single network solution for Internet of Things (IoT) networks can provide the required level of Quality of Service (QoS) for all applications in all environments. This leads to an increasing number of solutions created to fit particular scenarios. Given the increasing number and complexity of solutions available, it becomes difficult for an application developer to choose the solution which is best suited for an application. This article introduces a framework which autonomously chooses the best solution for the application given the current deployed environment. The framework utilises a performance model to predict the expected performance of a particular solution in a given environment. The framework can then choose an apt solution for the application from a set of available solutions. This article presents the framework with a set of models built using data collected from simulation. The modelling technique can determine with up to 85% accuracy the solution which performs the best for a particular performance metric given a set of solutions. The article highlights the fractured and disjointed practice currently in place for examining and comparing communication solutions and aims to open a discussion on harmonising testing procedures so that different solutions can be directly compared and offers a framework to achieve this within IoT networks.

  2. Performance and flow characteristics of MHD seawater thruster

    Energy Technology Data Exchange (ETDEWEB)

    Doss, E.D.

    1990-01-01

    The main goal of the research is to investigate the effects of strong magnetic fields on the electrical and flow fields inside MHD thrusters. The results of this study is important in the assessment of the feasibility of MHD seawater propulsion for the Navy. To accomplish this goal a three-dimensional fluid flow computer model has been developed and applied to study the concept of MHD seawater propulsion. The effects of strong magnetic fields on the current and electric fields inside the MHD thruster and their interaction with the flow fields, particularly those in the boundary layers, have been investigated. The results of the three-dimensional computations indicate that the velocity profiles are flatter over the sidewalls of the thruster walls in comparison to the velocity profiles over the electrode walls. These nonuniformities in the flow fields give rise to nonuniform distribution of the skin friction along the walls of the thrusters, where higher values are predicted over the sidewalls relative to those over the electrode walls. Also, a parametric study has been performed using the three-dimensional MHD flow model to analyze the performance of continuous electrode seawater thrusters under different operating parameters. The effects of these parameters on the fluid flow characteristics, and on the thruster efficiency have been investigated. Those parameters include the magnetic field (10--20 T), thruster diameter, surface roughness, flow velocity, and the electric load factor. The results show also that the thruster performance improves with the strength of the magnetic field and thruster diameter, and the efficiency decreases with the flow velocity and surface roughness.

  3. Analyzing topological characteristics of neuronal functional networks in the rat brain

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Hu [School of Computer Science and Communication Engineering, Jiangsu University, Jiangsu 212003 (China); School of Computer Science, Fudan University, Shanghai 200433 (China); Yang, Shengtao [Institutes of Brain Science, Fudan University, Shanghai 200433 (China); Song, Yuqing [School of Computer Science and Communication Engineering, Jiangsu University, Jiangsu 212003 (China); Wei, Hui [School of Computer Science, Fudan University, Shanghai 200433 (China)

    2014-08-28

    In this study, we recorded spike trains from brain cortical neurons of several behavioral rats in vivo by using multi-electrode recordings. An NFN was constructed in each trial, obtaining a total of 150 NFNs in this study. The topological characteristics of NFNs were analyzed by using the two most important characteristics of complex networks, namely, small-world structure and community structure. We found that the small-world properties exist in different NFNs constructed in this study. Modular function Q was used to determine the existence of community structure in NFNs, through which we found that community-structure characteristics, which are related to recorded spike train data sets, are more evident in the Y-maze task than in the DM-GM task. Our results can also be used to analyze further the relationship between small-world characteristics and the cognitive behavioral responses of rats. - Highlights: • We constructed the neuronal function networks based on the recorded neurons. • We analyzed the two main complex network characteristics, namely, small-world structure and community structure. • NFNs which were constructed based on the recorded neurons in this study exhibit small-world properties. • Some NFNs have community structure characteristics.

  4. Performance Characteristics of Plane-Wall Two-Dimensional Diffusers

    Science.gov (United States)

    Reid, Elliott G

    1953-01-01

    Experiments have been made at Stanford University to determine the performance characteristics of plane-wall, two-dimensional diffusers which were so proportioned as to insure reasonable approximation of two-dimensional flow. All of the diffusers had identical entrance cross sections and discharged directly into a large plenum chamber; the test program included wide variations of divergence angle and length. During all tests a dynamic pressure of 60 pounds per square foOt was maintained at the diffuser entrance and the boundary layer there was thin and fully turbulent. The most interesting flow characteristics observed were the occasional appearance of steady, unseparated, asymmetric flow - which was correlated with the boundary-layer coalescence - and the rapid deterioration of flow steadiness - which occurred as soon as the divergence angle for maximum static pressure recovery was exceeded. Pressure efficiency was found to be controlled almost exclusively by divergence angle, whereas static pressure recovery was markedly influenced by area ratio (or length) as well as divergence angle. Volumetric efficiency. diminished as area ratio increased, and at a greater rate with small lengths than with large ones. Large values of the static-pressure-recovery coefficient were attained only with long diffusers of large area ratio; under these conditions pressure efficiency was high and. volumetric efficiency low. Auxiliary tests with asymmetric diffusers demonstrated that longitudinal pressure gradient, rather than wall divergence angle, controlled flow separation. Others showed that the addition of even a short exit duct of uniform section augmented pressure recovery. Finally, it was found that the installation of a thin, central, longitudinal partition suppressed flow separation in short diffusers and thereby improved pressure recovery

  5. Data center network performance evaluation in ns3

    DEFF Research Database (Denmark)

    Andrus, Bogdan-Mihai; Vegas Olmos, Juan José

    2015-01-01

    In the following paper we present the analysis of highly interconnected topologies like hypercube and torus and how they can be implemented in data centers in order to cope with the rapid increase and demands for performance of the internal traffic. By replicating the topologies in NS3 and subjec......In the following paper we present the analysis of highly interconnected topologies like hypercube and torus and how they can be implemented in data centers in order to cope with the rapid increase and demands for performance of the internal traffic. By replicating the topologies in NS3...... we scale the network from 16 to 512 switches. The performance measurements are supported by abstract metrics that that also give a cost and complexity indication in choosing the right topology for the required application....

  6. Optimizing the ASC WAN: evaluating network performance tools for comparing transport protocols.

    Energy Technology Data Exchange (ETDEWEB)

    Lydick, Christopher L.

    2007-07-01

    The Advanced Simulation & Computing Wide Area Network (ASC WAN), which is a high delay-bandwidth network connection between US Department of Energy National Laboratories, is constantly being examined and evaluated for efficiency. One of the current transport-layer protocols which is used, TCP, was developed for traffic demands which are different from that on the ASC WAN. The Stream Control Transport Protocol (SCTP), on the other hand, has shown characteristics which make it more appealing to networks such as these. Most important, before considering a replacement for TCP on any network, a testing tool that performs well against certain criteria needs to be found. In order to try to find such a tool, two popular networking tools (Netperf v.2.4.3 & v.2.4.6 (OpenSS7 STREAMS), and Iperf v.2.0.6) were tested. These tools implement both TCP and SCTP and were evaluated using four metrics: (1) How effectively can the tool reach a throughput near the bandwidth? (2) How much of the CPU does the tool utilize during operation? (3) Is the tool freely and widely available? And, (4) Is the tool actively developed? Following the analysis of those tools, this paper goes further into explaining some recommendations and ideas for future work.

  7. The Relationship of Policymaking and Networking Characteristics among Leaders of Large Urban Health Departments.

    Science.gov (United States)

    Leider, Jonathon P; Castrucci, Brian C; Harris, Jenine K; Hearne, Shelley

    2015-08-06

    The relationship between policy networks and policy development among local health departments (LHDs) is a growing area of interest to public health practitioners and researchers alike. In this study, we examine policy activity and ties between public health leadership across large urban health departments. This study uses data from a national profile of local health departments as well as responses from a survey sent to three staff members (local health official, chief of policy, chief science officer) in each of 16 urban health departments in the United States. Network questions related to frequency of contact with health department personnel in other cities. Using exponential random graph models, network density and centrality were examined, as were patterns of communication among those working on several policy areas using exponential random graph models. All 16 LHDs were active in communicating about chronic disease as well as about use of alcohol, tobacco, and other drugs (ATOD). Connectedness was highest among local health officials (density = .55), and slightly lower for chief science officers (d = .33) and chiefs of policy (d = .29). After accounting for organizational characteristics, policy homophily (i.e., when two network members match on a single characteristic) and tenure were the most significant predictors of formation of network ties. Networking across health departments has the potential for accelerating the adoption of public health policies. This study suggests similar policy interests and formation of connections among senior leadership can potentially drive greater connectedness among other staff.

  8. The Relationship of Policymaking and Networking Characteristics among Leaders of Large Urban Health Departments

    Directory of Open Access Journals (Sweden)

    Jonathon P. Leider

    2015-08-01

    Full Text Available Background: The relationship between policy networks and policy development among local health departments (LHDs is a growing area of interest to public health practitioners and researchers alike. In this study, we examine policy activity and ties between public health leadership across large urban health departments. Methods: This study uses data from a national profile of local health departments as well as responses from a survey sent to three staff members (local health official, chief of policy, chief science officer in each of 16 urban health departments in the United States. Network questions related to frequency of contact with health department personnel in other cities. Using exponential random graph models, network density and centrality were examined, as were patterns of communication among those working on several policy areas using exponential random graph models. Results: All 16 LHDs were active in communicating about chronic disease as well as about use of alcohol, tobacco, and other drugs (ATOD. Connectedness was highest among local health officials (density = .55, and slightly lower for chief science officers (d = .33 and chiefs of policy (d = .29. After accounting for organizational characteristics, policy homophily (i.e., when two network members match on a single characteristic and tenure were the most significant predictors of formation of network ties. Conclusion: Networking across health departments has the potential for accelerating the adoption of public health policies. This study suggests similar policy interests and formation of connections among senior leadership can potentially drive greater connectedness among other staff.

  9. Predicting Retweeting Behavior on Breast Cancer Social Networks: Network and Content Characteristics.

    Science.gov (United States)

    Kim, Eunkyung; Hou, Jiran; Han, Jeong Yeob; Himelboim, Itai

    2016-01-01

    This study explored how social media, especially Twitter, serves as a viable place for communicating about cancer. Using a 2-step analytic method that combined social network analysis and computer-aided content analysis, this study investigated (a) how different types of network structures explain retweeting behavior and (b) which types of tweets are retweeted and why some messages generate more interaction among users. The analysis revealed that messages written by users who had a higher number of followers, a higher level of personal influence over the interaction, and closer relationships and similarities with other users were retweeted. In addition, a tweet with a higher level of positive emotion was more likely to be retweeted, whereas a tweet with a higher level of tentative words was less likely to be retweeted. These findings imply that Twitter can be an effective tool for the dissemination of health information. Theoretical and practical implications for psychosocial interventions for people with health concerns are discussed.

  10. Characteristics of Social Network Gamers: in between Social Networking and Online Role-Playing Games

    Directory of Open Access Journals (Sweden)

    Olga eGeisel

    2015-07-01

    Full Text Available Current research on internet addiction (IA reported moderate to high prevalence rates of IA and comorbid psychiatric symptoms in users of social networking sites (SNS and online role-playing games. The aim of this study was to characterise adult users of an internet multiplayer strategy game within a SNS. Therefore, we conducted an exploratory study using an online survey to assess sociodemographic variables, psychopathology and the rate of IA in a sample of adult social network gamers by Young´s Internet Addiction Test (IAT, the Toronto Alexithymia Scale (TAS, the Beck Depression Inventory II (BDI-II, the Symptom Checklist-90-R (SCL-90-R and the WHO Quality of Life-BREF (WHOQOL-BREF. All participants were listed gamers of combat zone in the SNS Facebook. In the IAT analysis, 16.2 % of the participants (n = 60 were categorized as subjects with IA and 19.5 % (n = 72 fulfilled the criteria for alexithymia. Comparing study participants with and without IA, the IA group had significantly more subjects with alexithymia, reported more depressive symptoms, and showed poorer quality of life. These findings suggest that social network gaming might also be associated with maladaptive patterns of internet use. Furthermore, a relationship between IA, alexithymia and depressive symptoms was found that needs to be elucidated by future studies.

  11. The technical CCDs in ESPRESSO: usage, performances, and network requirements

    Science.gov (United States)

    Calderone, G.; Baldini, V.; Cirami, R.; Coretti, I.; Cristiani, S.; Di Marcantonio, P.; Landoni, M.; Mégevand, D.; Riva, M.; Santin, P.

    2016-07-01

    The Echelle Spectrograph for Rocky Exoplanets and Stable Spectral Observations (ESPRESSO) requires active-loop stabilization of the light path from the telescope to the spectrograph, in order to achieve its centimeter-per- second precision goal. This task is accomplished by moving the mirrors placed along the light path by means of piezoelectric actuators. Two cameras are used to acquire the field and pupil images, and the required corrections are dynamically calculated and applied to the piezos. In this paper we will discuss the camera usage, performance and network bandwidth requirements for the ESPRESSO scientific operations.

  12. Physiological and performance characteristics of adolescent club volleyball players.

    Science.gov (United States)

    Melrose, Donald R; Spaniol, Frank J; Bohling, Mark E; Bonnette, Randy A

    2007-05-01

    The objective of this investigation was to examine the physical and performance characteristics of adolescent club volleyball players. Twenty-nine adolescent girls, aged 12 to 17 years (14.31 +/- 1.37) were participants in this investigation. All athletes were members of a competitive volleyball club. The following group values were obtained: height (HT) = 1.69 +/- 0.08 m, weight (WT) = 59.6 +/- 8.2 kg, body fat percentage (BF%) = 20.9 +/- 4.5, lean body mass (LBM) = 46.7 +/- 4.9 kg, modified sit-and-reach (MSR) = 38.7 +/- 7.1 cm, shoulder rotation (SR) = 29.4 +/- 5.6 cm, isometric hand grip (IHG) = 34.5 +/- 5.5 kg, isometric leg strength (ILS) = 77.4 +/- 18.1 kg, vertical jump (VJ) = 35.5 +/- 6.2 cm, standing broad jump (SBJ) =178.8 +/- 20.3 cm, 1-minute sit-ups (SU) = 47.0 +/- 6.7, T-test (TT) = 11.2 +/- 0.8 seconds., shuttle test (SHT) = 9.7 +/- 0.4 seconds, stork stand (SS) = 8.1 +/- 4.1 seconds, serving velocity (SVV) =16.1 +/- 4.5 m.s(-1), and spiking velocity (SKV) = 16.9 +/- 2.4 m.s(-1). For purposes of analysis, players were divided into 2 age groups: 12 to 14 years (group A) and 15 to 17 years (group B). Significant differences (p volleyball. Potentially, this type of information will allow coaches and athletes to identify physical and performance data specific to age groups for purposes of evaluation and player development.

  13. Key Performance Characteristics of Organic Shrimp Aquaculture in Southwest Bangladesh

    Directory of Open Access Journals (Sweden)

    Christian Reinhard Vogl

    2012-05-01

    Full Text Available In Bangladesh, black tiger shrimp (Penaeus monodon; Fabricius, 1798 aquaculture has come to be one of the most important sectors in both the rural and national economies. Likewise, organic shrimp aquaculture has emerged as an alternative farming enterprise for farmers especially in the southwestern districts of Bangladesh. The present study aims to show key performance characteristics of organic shrimp farmers and farming in a prototypical shrimp farming area in Bangladesh. Data was collected in 2009 from organic shrimp farmers in the Kaligonj and Shyamnagar sub-districts through questionnaire interviews, transect walks and focus group discussions. The mean productivity of organic shrimp farming in the area is 320 kg ha−1 yr−1 (ranging from 120 to 711 kg ha−1year−1. Organic farmers are more likely to have a higher monthly income and less aquaculture experience. Moreover, suitable landholdings and classified labor distribution have been found to play an important role in the development of organic shrimp aquaculture. The most common assets of organic shrimp aquaculture are high yield, low production cost, available post larvae and high market prices. Small business farmers are likely to earn more income benefits from organic shrimp aquaculture than their larger-scale counterparts. Finally, the paper suggests that more research is needed to stimulate the success of organic shrimp aquaculture.

  14. Multi-objective optimal power flow for active distribution network considering the stochastic characteristic of photovoltaic

    Science.gov (United States)

    Zhou, Bao-Rong; Liu, Si-Liang; Zhang, Yong-Jun; Yi, Ying-Qi; Lin, Xiao-Ming

    2017-05-01

    To mitigate the impact on the distribution networks caused by the stochastic characteristic and high penetration of photovoltaic, a multi-objective optimal power flow model is proposed in this paper. The regulation capability of capacitor, inverter of photovoltaic and energy storage system embedded in active distribution network are considered to minimize the expected value of active power the T loss and probability of voltage violation in this model. Firstly, a probabilistic power flow based on cumulant method is introduced to calculate the value of the objectives. Secondly, NSGA-II algorithm is adopted for optimization to obtain the Pareto optimal solutions. Finally, the best compromise solution can be achieved through fuzzy membership degree method. By the multi-objective optimization calculation of IEEE34-node distribution network, the results show that the model can effectively improve the voltage security and economy of the distribution network on different levels of photovoltaic penetration.

  15. Performance Analysis of CDMA Wireless Sensor Networks in Shadowed Environment

    Directory of Open Access Journals (Sweden)

    U. DATTA

    2010-07-01

    Full Text Available This paper evaluates the performance of a CDMA based wireless sensor networks (WSN with layered architecture in terms of QoS like outage probability, bit error rate (BER, throughput, and delay, considering correlation amongst interferers in shadowed environment. Energy consumption for successful delivery of information is also evaluated at different channel conditions. Two kinds of interference namely multiple access interference (MAI and node interference (NI are considered and an infinite ARQ is assumed at link layer between a sending node and sink till successful transmission of packetized data. An appropriate analytical model of interference considering correlation amongst interferers, power control error and shadowing is developed for evaluating bit error rate (BER, packet error rate (PER, average number of retransmission for successful delivery of information, throughput, and delay in a single hop communication. A simple energy model is used for evaluating the consumption of energy for successful delivery of information between source and sink. We also evaluate the sink capacity of wireless CDMA sensor networks considering a threshold BER. Sink capacity is defined as the maximum number of sensor nodes transmitting concurrently to the sink and located within one hop layer. The impact of NI on the sink capacity is also indicated. The effects of node density, correlation amongst interferers and power control error (pce on performance of WSN are investigated. Analytical results are supported by simulation results.

  16. Performance Analysis of a Finite Capacity Femtocell Network

    Directory of Open Access Journals (Sweden)

    Wanod Kumar

    2014-01-01

    Full Text Available A feasible solution to wireless spectrum scarcity is the deployment of femtocells along with already existing or new macrocells. This hybrid architecture not only helps to increase the system capacity but also improves the wireless signal quality for indoor users. Moreover, these femtocells can offer higher data rates to indoor users. In this paper, we analyze the performance of a finite capacity femtocell network. The transmission of data from M communicating nodes to a FAP (Femtocell Access Point is modelled as M/M/1/K queue. The access point in this case can hold a maximum of K-I packets in its buffer, hence the system represents a finite capacity network. The performance of the system is evaluated in term of QoS (Quality of Service parameters such as packet blocking probability, average packet delay and utilization for different buffer sizes. The results reveal that with an increase in buffer size, the packet blocking probability decreases however at the cost of increased average delay

  17. The challenges of archiving networked-based multimedia performances (Performance cryogenics)

    Science.gov (United States)

    Cohen, Elizabeth; Cooperstock, Jeremy; Kyriakakis, Chris

    2002-11-01

    Music archives and libraries have cultural preservation at the core of their charters. New forms of art often race ahead of the preservation infrastructure. The ability to stream multiple synchronized ultra-low latency streams of audio and video across a continent for a distributed interactive performance such as music and dance with high-definition video and multichannel audio raises a series of challenges for the architects of digital libraries and those responsible for cultural preservation. The archiving of such performances presents numerous challenges that go beyond simply recording each stream. Case studies of storage and subsequent retrieval issues for Internet2 collaborative performances are discussed. The development of shared reality and immersive environments generate issues about, What constitutes an archived performance that occurs across a network (in multiple spaces over time)? What are the families of necessary metadata to reconstruct this virtual world in another venue or era? For example, if the network exhibited changes in latency the performers most likely adapted. In a future recreation, the latency will most likely be completely different. We discuss the parameters of immersive environment acquisition and rendering, network architectures, software architecture, musical/choreographic scores, and environmental acoustics that must be considered to address this problem.

  18. A Generic Framework of Performance Measurement in Networked Enterprises

    Science.gov (United States)

    Kim, Duk-Hyun; Kim, Cheolhan

    Performance measurement (PM) is essential for managing networked enterprises (NEs) because it greatly affects the effectiveness of collaboration among members of NE.PM in NE requires somewhat different approaches from PM in a single enterprise because of heterogeneity, dynamism, and complexity of NE’s. This paper introduces a generic framework of PM in NE (we call it NEPM) based on the Balanced Scorecard (BSC) approach. In NEPM key performance indicators and cause-and-effect relationships among them are defined in a generic strategy map. NEPM could be applied to various types of NEs after specializing KPIs and relationships among them. Effectiveness of NEPM is shown through a case study of some Korean NEs.

  19. Messaging Performance of FIPA Interaction Protocols in Networked Embedded Controllers

    Directory of Open Access Journals (Sweden)

    Omar Jehovani López Orozco

    2007-12-01

    Full Text Available Agent-based technologies in production control systems could facilitate seamless reconfiguration and integration of mechatronic devices/modules into systems. Advances in embedded controllers which are continuously improving computational capabilities allow for software modularization and distribution of decisions. Agent platforms running on embedded controllers could hide the complexity of bootstrap and communication. Therefore, it is important to investigate the messaging performance of the agents whose main motivation is the resource allocation in manufacturing systems (i.e., conveyor system. The tests were implemented using the FIPA-compliant JADE-LEAP agent platform. Agent containers were distributed through networked embedded controllers, and agents were communicating using request and contract-net FIPA interaction protocols. The test scenarios are organized in intercontainer and intracontainer communications. The work shows the messaging performance for the different test scenarios using both interaction protocols.

  20. ESTABLISHED MODES AND STATIC CHARACTERISTICS OF THREE-PHASE ASYNCHRONOUS MOTOR POWERED WITH SINGLE PHASE NETWORK

    Directory of Open Access Journals (Sweden)

    V. S. Malyar

    2016-01-01

    Full Text Available A mathematical model is developed to study the operation of three-phase asynchronous motor with squirrel-cage rotor when the stator winding is powered from a single phase network. To create a rotating magnetic field one of the phases is fed through the capacitor. Due to the asymmetry of power feed not only transients, but the steady-state regimes are dynamic, so they are described by differential equations in any coordinate system. Their study cannot be carried out with sufficient adequacy on the basis of known equivalent circuits and require the use of dynamic parameters. In the mathematical model the state equations of the circuits of the stator and rotor are composed in the stationary three phase coordinate system. Calculation of the established mode is performed by solving the boundary problem that makes it possible to obtain the coordinate dependences over the period, without calculation of the transient process. In order to perform it, the original nonlinear differential equations are algebraized by approximating the variables with the use of cubic splines. The resulting nonlinear system of algebraic equations is a discrete analogue of the initial system of differential equations. It is solved by parameter continuation method. To calculate the static characteristics as a function of a certain variable, the system is analytically differentiated, and then numerically integrated over this variable. In the process of integration, Newton's refinement is performed at each step or at every few steps, making it possible to implement the integration in just a few steps using Euler's method. Jacobi matrices in both cases are the same. To account for the current displacement in the rods of the squirrel-cage rotor, each of them, along with the squirrel-cage rings, is divided in height into several elements. This results in several squirrel-cage rotor windings which are represented by three-phase windings with magnetic coupling between them.

  1. Analysis of TCP performance in data center networks

    CERN Document Server

    Kulkarni, Santosh

    2014-01-01

    This book addresses the need to improve TCP’s performance inside data centers by providing solutions that are both practical and backward compatible with standard TCP versions. The authors approach this challenge first by deriving an analytical model for TCP’s performance under typical data center workload traffic.  They then discuss some solutions that are designed to improve TCP performance by either proactively detecting network congestion through probabilistic retransmission or by avoiding timeout penalty through dynamic resizing of TCP segments. Experimental results show that each of techniques discussed outperforms standard TCP inside a data center.  ·         Analyzes the reasons behind TCP performance slump inside data centers when operating under synchronized workload traffic; ·         Introduces solutions to TCP performance slump inside data centers that are both practical and backward compatible; ·         Describes mechanisms that are responsible for TCP’s relia...

  2. Social Network Characteristics, Social Support, and Cigarette Smoking among Asian/Pacific Islander Young Adults.

    Science.gov (United States)

    Pokhrel, Pallav; Fagan, Pebbles; Cassel, Kevin; Trinidad, Dennis R; Kaholokula, Joseph Keawe'aimoku; Herzog, Thaddeus A

    2016-06-01

    Cigarette smoking may be one of the factors contributing to the high levels of cancer-related mortality experienced by certain Asian/Pacific Islander (A/PI) subgroups (e.g., Native Hawaiian). Given the collectivist cultural orientation attributed to A/PI groups, social strategies are recommended for substance abuse or smoking cessation treatment among A/PI. However, research examining how social network characteristics and social support relate to smoking across A/PI subgroups has been lacking. This study investigated the associations between social network characteristics (e.g., size, composition), perceived social support, and recent cigarette use across Native Hawaiian, Filipino, and East Asian (e.g., Japanese, Chinese) young adults (18-35 year old). Cross-sectional, self-report data were collected from N = 435 participants (M age = 25.6, SD = 8.3; 61% women). Ethnic differences were found in a number of pathways linking social network characteristics, perceived social support, and cigarette smoking. Larger network size was strongly associated with higher perceived social support and lower recent cigarette smoking among Native Hawaiians but not Filipinos or East Asians. Higher perceived social support was associated with lower recent smoking among East Asians and Filipinos but not Native Hawaiians. Implications are discussed with regard to smoking prevention and cessation among A/PI. © Society for Community Research and Action 2016.

  3. The geometrical effect of single walled carbon nanotube network transistors on low frequency noise characteristics.

    Science.gov (United States)

    Kim, Un Jeong; Kil, Joon Pyo; Park, Wanjun

    2011-07-01

    The noise characteristics of randomly networked single walled carbon nanotubes grown directly by plasma enhanced chemical vapor deposition with field effect transistor. Geometrical complexity due to the large number of tube-tube junctions in the nanotube network is expected to be one of the key factors for the noise power of 1/f dependence. We investigated low frequency noise as a function of channel length (2-10 microm) and found that increased with longer channel length. Percolational behaviors of nanotube network that differs from ordinary semiconducting and metallic materials can be characterized by a geometrical picture with electrical homo- and hetero-junctions. Fixed nanotube density provides a test conditions to evaluate the contributions of junctions as a noise center. Hooge's empirical law is applied to investigate the low frequency noise characteristics of single walled carbon nanotube random network transistors. The noise power shows the dependence of the transistor channel length. It is understood that nanotube/nanotube junctions act as a noise center. However, the differences induced by channel length in the noise power are observed as not so significant. We conclude that tolerance of low frequency noise is important property for SWNT networks as an electronic device application.

  4. Sexual Networking and Partner Characteristics Among Single, African, Caribbean, and Black Youth in Windsor, Ontario.

    Science.gov (United States)

    Kerr, Jelani; Maticka-Tyndale, Eleanor; Bynum, Shalanda; Mihan, Robert

    2017-10-01

    The disproportionate HIV burden shared by African, Caribbean, and Black (ACB) populations in Canada has not been explained by unique sexual behaviors in this population. This study investigates partner selection and sexual networking as potential contributors to HIV vulnerability. The study examines variations in the characteristics of sexual partners and sexual networking across groups based on differences in ethno-religious identity, gender, and length of Canadian residency among single, 16- to 27-year old, heterosexual-identified, ACB individuals living in Windsor, Ontario, Canada. Respondent-driven sampling maximized the representativeness of the sample of 250 (45 % male; 55 % female) youth with penile-vaginal intercourse experience who completed surveys. Logistic regression and analysis of variance compared groups with respect to number of lifetime partners, concurrency of sexual relationships, non-relational and age disparate partnering, and intra-ethnic sexual networking. For vulnerability associated with number of partners, concurrency and non-relational sex, women, newcomers to Canada, and African-Muslim participants were at lower vulnerability for HIV infection than their comparator groups. For vulnerability associated with sexual networking within a group with higher HIV prevalence, women and newcomers to Canada were at higher vulnerability to HIV infection than their comparator groups. There were insufficient data on age disparate partnering to support analysis. These results point to the importance of considering characteristics of partners and sexual networking both in further research and in developing policies and programs to curtail the spread of HIV and other sexually transmitted infections.

  5. Sex Differences in Virtual Network Characteristics and Sexual Risk Behavior among Emerging Adults

    Science.gov (United States)

    Cook, Stephanie H.; Bauermeister, José A.; Zimmerman, Marc A.

    2016-01-01

    Emerging adults (EAs)ages 18 to 24 account for a large proportion of all sexually transmitted infections (STIs), HIV infections, and unintended pregnancies in the United States. Given the increased influence of online media on decision-making, we examined how EA online networks were associated with sexual risk behaviors. We used egocentric network data collected from EAs aged 18 to 24 years old across the United States (N=1,687) to examine how online norms (e.g., acceptance of HIV infections, other STIs, and pregnancy) and network characteristics (i.e., network size and density; ties' closeness, race, age, and sex similarities) were associated with participants' unprotected vaginal intercourse (UVI) in the last 30 days. Findings suggested that in male EAs, there was a strong association between sexual norms, structural characteristics, and sexual risk behavior compared to females. Researchers and practitioners may wish to address online peer norms and EAs' online network composition when developing online sexual risk prevention tools. PMID:28083447

  6. Comparative Performance Evaluation of TCP Variants in WiMAX (and WLANs Network Configurations

    Directory of Open Access Journals (Sweden)

    Konstantinos Tsiknas

    2012-01-01

    Full Text Available An important application for the IEEE 802.16 technology (also called WiMAX is to provide high-speed access to the Internet where the transmission control protocol (TCP is the core transport protocol. In this paper we study through extensive simulation scenarios the performance characteristics of five representative TCP schemes, namely, TCP New Reno, Vegas, Veno, Westwood, and BIC, in WiMAX (and WLANs networks, under the conditions of correlated wireless errors, asymmetric end-to-end capabilities, and link congestion. The target is to evaluate how the above conditions would affect the TCP congestion control and suggest the best schemes to be employed in WiMAX networks.

  7. Social networks of people with mild intellectual disabilities: characteristics, satisfaction, wishes and quality of life.

    Science.gov (United States)

    van Asselt-Goverts, A E; Embregts, P J C M; Hendriks, A H C

    2015-05-01

    A supportive social network is crucial for facilitating social inclusion, which can, in turn, contribute to the quality of life (QOL) for people with intellectual disabilities (ID). In this study, we investigate how people with mild ID perceive their social networks and which network characteristics relate to satisfaction with the network and perceived QOL. Data were gathered from 33 young adults with a mild to borderline ID using structured questionnaires: the MSNA to map the social network, the IDQOL-16 to assess QOL, and a questionnaire to determine satisfaction and wishes with regard to the social network. The majority of the participants (73.1%) were satisfied with their social networks. Improvement in the area of strengthening existing ties (e.g. more frequent contact, better contact) was desired as opposed to expansion of the network. Affection--especially towards family and professionals--was most strongly related to perceived QOL. It appears to be essential that relatives live in the same town, can frequently meet up and provide both emotional and practical support. The significance of family and the importance of high-quality interpersonal relationships between professional and client in the lives of young adults with ID cannot be overestimated. Although measures of satisfaction and wishes can have limitations, in actual practice it is considered useful to assess the opinions of clients with respect to their social networks. Interventions can then be tailored to the needs and wishes of the persons themselves. © 2014 MENCAP and International Association of the Scientific Study of Intellectual and Developmental Disabilities and John Wiley & Sons Ltd.

  8. Workplace social networks and their relationship with job outcomes and other employment characteristics for people with severe mental illness.

    Science.gov (United States)

    Rollins, Angela L; Bond, Gary R; Jones, Amanda M; Kukla, Marina; Collins, Linda A

    2011-07-01

    Clients with severe mental illness (SMI) often struggle in their efforts to maintain employment. One cause of early job terminations is interpersonal difficulties in the workplace. This study explored workplace social networks and their relationship with job outcomes and other employment characteristics for people with SMI. Results indicated that clients generally had positive experiences with both supervisors and coworkers. Contrary to our hypothesis, employment model was not associated with better workplace network characteristics. Also contrary to our hypothesis, clients employed in group placements did not differ in workplace network characteristics from those in competitive employment settings. Workplace network characteristics were robustly correlated with job satisfaction, but not strongly related to hourly wages or overall job tenure. Job tenure at the time of the workplace network assessment did show a few modest negative correlations with supervisor and coworker support, indicating declining perceived social network support with increasing job tenure. Study limitations and future directions for research using this methodology are discussed.

  9. Addressing the Influence of Hidden State on Wireless Network Optimizations using Performance Maps

    DEFF Research Database (Denmark)

    Højgaard-Hansen, Kim; Madsen, Tatiana Kozlova; Schwefel, Hans-Peter

    2015-01-01

    Performance of wireless connectivity for network client devices is location dependent. It has been shown that it can be beneficial to collect network performance metrics along with location information to generate maps of the location dependent network performance. These performance maps can...... be used to optimize the use of the wireless net- work by predicting future network performance and scheduling the net- work communication for certain applications on mobile devices. However, other important factors influence the performance of the wireless communication such as changes in the propagation...... environment and resource sharing. In this work we extend the framework of performance maps for wireless networks by introducing network state as an abstraction for all other factors than location that influence the performance. Since network state might not always be directly observable the framework...

  10. Network Degradation Effects on Different Codec Types and Characteristics of Video Streaming

    Directory of Open Access Journals (Sweden)

    Jaroslav Frnda

    2014-01-01

    Full Text Available Nowadays, there is a quickly growing demand for the transmission of voice, video and data over an IP based network. Multimedia, whether we are talking about broadcast, audio and video transmission and others, from a global perspective is growing exponentially with time. With incoming requests from users, new technologies for data transfer are continually developing. Data must be delivered reliably and with the fewest losses at such high speed. Video quality as part of multimedia technology has a very important role nowadays. It is influenced by several factors, where each of them can have many forms and processing. Network performance is the major degradation effect that influences the quality of resulting image. Poor network performance (lack of link capacity, high network load… causes data packet losses or different delivery time for each packet. This work focuses exactly on these network phenomena. It examines the impact of different delays and packet losses on the quality parameters of triple play services, to evaluate the results using objective methods. The aim of this work is to bring a detailed view on the performance of video streaming over IP-based networks.

  11. Prediction of roadheaders' performance using artificial neural network approaches (MLP and KOSFM

    Directory of Open Access Journals (Sweden)

    Arash Ebrahimabadi

    2015-10-01

    Full Text Available Application of mechanical excavators is one of the most commonly used excavation methods because it can bring the project more productivity, accuracy and safety. Among the mechanical excavators, roadheaders are mechanical miners which have been extensively used in tunneling, mining and civil industries. Performance prediction is an important issue for successful roadheader application and generally deals with machine selection, production rate and bit consumption. The main aim of this research is to investigate the cutting performance (instantaneous cutting rates (ICRs of medium-duty roadheaders by using artificial neural network (ANN approach. There are different categories for ANNs, but based on training algorithm there are two main kinds: supervised and unsupervised. The multi-layer perceptron (MLP and Kohonen self-organizing feature map (KSOFM are the most widely used neural networks for supervised and unsupervised ones, respectively. For gaining this goal, a database was primarily provided from roadheaders' performance and geomechanical characteristics of rock formations in tunnels and drift galleries in Tabas coal mine, the largest and the only fully-mechanized coal mine in Iran. Then the database was analyzed in order to yield the most important factor for ICR by using relatively important factor in which Garson equation was utilized. The MLP network was trained by 3 input parameters including rock mass properties, rock quality designation (RQD, intact rock properties such as uniaxial compressive strength (UCS and Brazilian tensile strength (BTS, and one output parameter (ICR. In order to have more validation on MLP outputs, KSOFM visualization was applied. The mean square error (MSE and regression coefficient (R of MLP were found to be 5.49 and 0.97, respectively. Moreover, KSOFM network has a map size of 8 × 5 and final quantization and topographic errors were 0.383 and 0.032, respectively. The results show that MLP neural networks

  12. The social support and social network characteristics of smokers in methadone maintenance treatment.

    Science.gov (United States)

    de Dios, Marcel Alejandro; Stanton, Cassandra A; Caviness, Celeste M; Niaura, Raymond; Stein, Michael

    2013-01-01

    Previous studies have shown social support and social network variables to be important factors in smoking cessation treatment. Tobacco use is highly prevalent among individuals in methadone maintenance treatment (MMT). However, smoking cessation treatment outcomes in this vulnerable subpopulation have been poor and social support and social network variables may contribute. The current study examined the social support and social network characteristics of 151 MMT smokers involved in a randomized clinical trial of smoking cessation treatments. Participants were 50% women and 78% Caucasian. A high proportion (57%) of MMT smokers had spouses or partners who smoke and over two-thirds of households (68.5%) included at least one smoker. Our sample was characterized by relatively small social networks, but high levels of general social support and quitting support. The number of cigarettes per day was found to be positively associated with the number of smokers in the social network (r = .239, p < .05) and quitting self-efficacy was negatively associated with partner smoking (r = -.217, p < .001). Findings are discussed in the context of developing smoking cessation interventions that address the influential role of social support and social networks of smokers in MMT.

  13. Networks of ultrasmall Pd/Cr bilayer nanowires as high performance hydrogen sensors.

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, X.-Q.; Wang, Y.-L.; Deng, H.; Latimer, M. L.; Xiao, Z.-L.; Pearson, J.; Xu, T.; Wang, H.-H.; Welp, U.; Crabtree, G. W.; Kwok, W.-K. (Center for Nanoscale Materials); ( MSD); (Northern Illinois Univ.); (Illinois Math and Science Academy); (Univ. of Illinois at Chicago)

    2011-01-01

    The newly developed hydrogen sensor, based on a network of ultrasmall pure palladium nanowires sputter-deposited on a filtration membrane, takes advantage of single palladium nanowires' characteristics of high speed and sensitivity while eliminating their nanofabrication obstacles. However, this new type of sensor, like the single palladium nanowires, cannot distinguish hydrogen concentrations above 3%, thus limiting the potential applications of the sensor. This study reports hydrogen sensors based on a network of ultrasmall Cr-buffered Pd (Pd/Cr) nanowires on a filtration membrane. These sensors not only are able to outperform their pure Pd counterparts in speed and durability but also allow hydrogen detection at concentrations up to 100%. The new networks consist of a thin layer of palladium deposited on top of a Cr adhesion layer 1-3 nm thick. Although the Cr layer is insensitive to hydrogen, it enables the formation of a network of continuous Pd/Cr nanowires with thicknesses of the Pd layer as thin as 2 nm. The improved performance of the Pd/Cr sensors can be attributed to the increased surface area to volume ratio and to the confinement-induced suppression of the phase transition from Pd/H solid solution ({alpha}-phase) to Pd hydride ({beta}-phase).

  14. Prediction of biopore- and matrix-dominated flow from X-ray CT-derived macropore network characteristics

    Directory of Open Access Journals (Sweden)

    M. Naveed

    2016-10-01

    Full Text Available Prediction and modeling of localized flow processes in macropores is of crucial importance for sustaining both soil and water quality. However, currently there are no reliable means to predict preferential flow due to its inherently large spatial variability. The aim of this study was to investigate the predictive performance of previously developed empirical models for both water and air flow and to explore the potential applicability of X-ray computed tomography (CT-derived macropore network characteristics. For this purpose, 65 cylindrical soil columns (6 cm diameter and 3.5 cm height were extracted from the topsoil (5 cm to 8.5 cm depth in a 15 m  ×  15 m grid from an agricultural field located in Silstrup, Denmark. All soil columns were scanned with an industrial X-ray CT scanner (129 µm resolution and later employed for measurement of saturated hydraulic conductivity, air permeability at −30 and −100 cm matric potential, and gas diffusivity at −30 and −100 cm matric potential. Distribution maps for saturated hydraulic conductivity, air permeability, and gas diffusivity reflected no autocorrelation irrespective of soil texture and organic matter content. Existing empirical predictive models for saturated hydraulic conductivity and air permeability showed poor performance, as they were not able to realistically capture macropore flow. The tested empirical model for gas diffusivity predicted measurements at −100 cm matric potential reasonably well, but failed at −30 cm matric potential, particularly for soil columns with biopore-dominated flow. X-ray CT-derived macroporosity matched the measured air-filled porosity at −30 cm matric potential well. Many of the CT-derived macropore network characteristics were strongly interrelated. Most of the macropore network characteristics were also significantly correlated with saturated hydraulic conductivity, air permeability, and gas diffusivity. The

  15. Enhancing the Performance of Random Access Networks with Random Packet CDMA and Joint Detection

    Directory of Open Access Journals (Sweden)

    Behrouz Farhang-Boroujeny

    2008-09-01

    Full Text Available Random packet CDMA (RP-CDMA is a recently proposed random transmission scheme which has been designed from the beginning as a cross-layer method to overcome the restrictive nature of the Aloha protocol. Herein, we more precisely model its performance and investigate throughput and network stability. In contrast to previous works, we adopt the spread Aloha model for header transmission, and the performance of different joint detection methods for the payload data is investigated. Furthermore, we introduce performance measures for multiple access systems based on the diagonal elements of a modified multipacket reception matrix, and show that our measures describe the upper limit of the vector of stable arrival rates for a finite number of users. Finally, we simulate queue sizes and throughput characteristics of RP-CDMA with various receiver structures and compare them to spread Aloha.

  16. Enhancing the Performance of Random Access Networks with Random Packet CDMA and Joint Detection

    Science.gov (United States)

    Kempter, Roland; Amini, Peiman; Farhang-Boroujeny, Behrouz

    2008-12-01

    Random packet CDMA (RP-CDMA) is a recently proposed random transmission scheme which has been designed from the beginning as a cross-layer method to overcome the restrictive nature of the Aloha protocol. Herein, we more precisely model its performance and investigate throughput and network stability. In contrast to previous works, we adopt the spread Aloha model for header transmission, and the performance of different joint detection methods for the payload data is investigated. Furthermore, we introduce performance measures for multiple access systems based on the diagonal elements of a modified multipacket reception matrix, and show that our measures describe the upper limit of the vector of stable arrival rates for a finite number of users. Finally, we simulate queue sizes and throughput characteristics of RP-CDMA with various receiver structures and compare them to spread Aloha.

  17. Cooperative cognitive radio networking system model, enabling techniques, and performance

    CERN Document Server

    Cao, Bin; Mark, Jon W

    2016-01-01

    This SpringerBrief examines the active cooperation between users of Cooperative Cognitive Radio Networking (CCRN), exploring the system model, enabling techniques, and performance. The brief provides a systematic study on active cooperation between primary users and secondary users, i.e., (CCRN), followed by the discussions on research issues and challenges in designing spectrum-energy efficient CCRN. As an effort to shed light on the design of spectrum-energy efficient CCRN, they model the CCRN based on orthogonal modulation and orthogonally dual-polarized antenna (ODPA). The resource allocation issues are detailed with respect to both models, in terms of problem formulation, solution approach, and numerical results. Finally, the optimal communication strategies for both primary and secondary users to achieve spectrum-energy efficient CCRN are analyzed.

  18. The role of networks in firms' multi-characteristics competition and market-share inequality

    CERN Document Server

    Garas, Antonios

    2016-01-01

    We develop a location analysis spatial model of firms' competition in multi-characteristics space, where consumers' opinions about the firms' products are distributed on multilayered networks. Firms do not compete on price but only on location upon the products' multi-characteristics space, and they aim to attract the maximum number of consumers. Boundedly rational consumers have distinct ideal points/tastes over the possible available firm locations but, crucially, they are affected by the opinions of their neighbors. Our central argument is that the consolidation of a dense underlying consumers' opinion network is the key for the firm to enlarge its market-share. Proposing a dynamic agent-based analysis on firms' location choice we characterize multi-dimensional product differentiation competition as adaptive learning by firms' managers and we argue that such a complex systems approach advances the analysis in alternative ways, beyond game-theoretic calculations.

  19. Friendship Network Characteristics Are Associated with Physical Activity and Sedentary Behavior in Early Adolescence.

    Directory of Open Access Journals (Sweden)

    Jennifer Marks

    Full Text Available There is limited understanding of the association between peer social networks and physical activity (PA, sedentary and screen-related behaviors. This study reports on associations between personal network characteristics and these important health behaviors for early adolescents.Participants were 310 students, aged 11-13 years, from fifteen randomly selected Victorian primary schools (43% response rate. PA and sedentary behaviors were collected via accelerometer and self-report questionnaire, and anthropometric measures via trained researchers. Participants nominated up to fifteen friends, and described the frequency of interaction and perceived activity intensity of these friends. Personal network predictors were examined using regression modelling for PA and sedentary/screen behavior.Perceived activity levels of friends, and friendships with very frequent interaction were associated with outside-of-school PA and/or sedentary/screen time. Differences according to sex were also observed in the association between network characteristics and PA and sedentary time. A higher number of friends and greater proportion of same sex friends were associated with boys engaging in more moderate-to-vigorous PA outside of school hours. PA intensity during school-day breaks was positively associated with having a greater proportion of friends who played sports for girls, and a greater proportion of male friends for boys.Friendship network characteristics are associated with PA and sedentary/screen time in late childhood/early adolescence, and these associations differ by sex. The positive influence of very active peers may be a promising avenue to strengthen traditional interventions for the promotion of PA and reduction in screen time.

  20. Friendship Network Characteristics Are Associated with Physical Activity and Sedentary Behavior in Early Adolescence.

    Science.gov (United States)

    Marks, Jennifer; de la Haye, Kayla; Barnett, Lisa M; Allender, Steven

    2015-01-01

    There is limited understanding of the association between peer social networks and physical activity (PA), sedentary and screen-related behaviors. This study reports on associations between personal network characteristics and these important health behaviors for early adolescents. Participants were 310 students, aged 11-13 years, from fifteen randomly selected Victorian primary schools (43% response rate). PA and sedentary behaviors were collected via accelerometer and self-report questionnaire, and anthropometric measures via trained researchers. Participants nominated up to fifteen friends, and described the frequency of interaction and perceived activity intensity of these friends. Personal network predictors were examined using regression modelling for PA and sedentary/screen behavior. Perceived activity levels of friends, and friendships with very frequent interaction were associated with outside-of-school PA and/or sedentary/screen time. Differences according to sex were also observed in the association between network characteristics and PA and sedentary time. A higher number of friends and greater proportion of same sex friends were associated with boys engaging in more moderate-to-vigorous PA outside of school hours. PA intensity during school-day breaks was positively associated with having a greater proportion of friends who played sports for girls, and a greater proportion of male friends for boys. Friendship network characteristics are associated with PA and sedentary/screen time in late childhood/early adolescence, and these associations differ by sex. The positive influence of very active peers may be a promising avenue to strengthen traditional interventions for the promotion of PA and reduction in screen time.

  1. Friendship Network Characteristics Are Associated with Physical Activity and Sedentary Behavior in Early Adolescence

    Science.gov (United States)

    Marks, Jennifer; de la Haye, Kayla; Barnett, Lisa M; Allender, Steven

    2015-01-01

    Introduction There is limited understanding of the association between peer social networks and physical activity (PA), sedentary and screen-related behaviors. This study reports on associations between personal network characteristics and these important health behaviors for early adolescents. Methods Participants were 310 students, aged 11–13 years, from fifteen randomly selected Victorian primary schools (43% response rate). PA and sedentary behaviors were collected via accelerometer and self-report questionnaire, and anthropometric measures via trained researchers. Participants nominated up to fifteen friends, and described the frequency of interaction and perceived activity intensity of these friends. Personal network predictors were examined using regression modelling for PA and sedentary/screen behavior. Results Perceived activity levels of friends, and friendships with very frequent interaction were associated with outside-of-school PA and/or sedentary/screen time. Differences according to sex were also observed in the association between network characteristics and PA and sedentary time. A higher number of friends and greater proportion of same sex friends were associated with boys engaging in more moderate-to-vigorous PA outside of school hours. PA intensity during school-day breaks was positively associated with having a greater proportion of friends who played sports for girls, and a greater proportion of male friends for boys. Conclusion Friendship network characteristics are associated with PA and sedentary/screen time in late childhood/early adolescence, and these associations differ by sex. The positive influence of very active peers may be a promising avenue to strengthen traditional interventions for the promotion of PA and reduction in screen time. PMID:26709924

  2. VMware vSphere performance designing CPU, memory, storage, and networking for performance-intensive workloads

    CERN Document Server

    Liebowitz, Matt; Spies, Rynardt

    2014-01-01

    Covering the latest VMware vSphere software, an essential book aimed at solving vSphere performance problems before they happen VMware vSphere is the industry's most widely deployed virtualization solution. However, if you improperly deploy vSphere, performance problems occur. Aimed at VMware administrators and engineers and written by a team of VMware experts, this resource provides guidance on common CPU, memory, storage, and network-related problems. Plus, step-by-step instructions walk you through techniques for solving problems and shed light on possible causes behind the problems. Divu

  3. Characteristics of Social Networks and Mortality Risk: Evidence From Two Prospective Cohort Studies.

    Science.gov (United States)

    Kauppi, Maarit; Kawachi, Ichiro; Batty, George David; Oksanen, Tuula; Elovainio, Marko; Pentti, Jaana; Aalto, Ville; Virtanen, Marianna; Koskenvuo, Markku; Vahtera, Jussi; Kivimäki, Mika

    2017-08-23

    The size of social network is linked to health and longevity, but it is unclear whether the number of strong or weak social ties is most influential for health. We examined social network characteristics as predictors of mortality in the Finnish Public Sector (n = 7,617) and the Health and Social Support (n = 20,816) studies. Social network characteristics were surveyed at baseline in 1998. Information about mortality was obtained from the national death registry. During a mean follow-up of 16 years participants with a small social network (≤10 members) were more likely to die than those with a large social network (≥21 members) (adjusted hazard ratio (HR) = 1.23, 95% confidence interval (CI): 1.04, 1.46). Mortality risk was increased among participants with small number of both strong (≤2 members) and weak ties (≤5 members) (hazard ratio = 1.55, 95% confidence interval: 1.26, 1.79), and among those with large number of strong ties and small number of weak ties (hazard ratio = 1.28, 95% confidence interval: 1.08, 1.52), but not among those with small number of strong ties and large number of weak ties (HR = 1.04, 95%CI: 0.87, 1.25). These findings suggest that in terms of mortality risk the number of weak ties may be an important component of social networks. © The Author(s) 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. Bridging Social Circles: Need for Cognition, Prejudicial Judgments, and Personal Social Network Characteristics

    Science.gov (United States)

    Curşeu, Petru L.; de Jong, Jeroen P.

    2017-01-01

    Various factors pertaining to the social context (availability of plausible social contacts) as well as personality traits influence the emergence of social ties that ultimately compose one’s personal social network. We build on a situational selection model to argue that personality traits influence the cognitive processing of social cues that in turn influences the preference for particular social ties. More specifically, we use a cross-lagged design to test a mediation model explaining the effects of need for cognition (NFC) on egocentric network characteristics. We used the data available in the LISS panel, in which a probabilistic sample of Dutch participants were asked to fill in surveys annually. We tested our model on data collected in three successive years and our results show that people scoring high in NFC tend to revolve in information-rich egocentric networks, characterized by high demographic diversity, high interpersonal dissimilarity, and high average education. The results also show that the effect of NFC on social network characteristics is mediated by non-prejudicial judgments. PMID:28790948

  5. Performance evaluation of wavelet-based ECG compression algorithms for telecardiology application over CDMA network.

    Science.gov (United States)

    Kim, Byung S; Yoo, Sun K

    2007-09-01

    The use of wireless networks bears great practical importance in instantaneous transmission of ECG signals during movement. In this paper, three typical wavelet-based ECG compression algorithms, Rajoub (RA), Embedded Zerotree Wavelet (EZ), and Wavelet Transform Higher-Order Statistics Coding (WH), were evaluated to find an appropriate ECG compression algorithm for scalable and reliable wireless tele-cardiology applications, particularly over a CDMA network. The short-term and long-term performance characteristics of the three algorithms were analyzed using normal, abnormal, and measurement noise-contaminated ECG signals from the MIT-BIH database. In addition to the processing delay measurement, compression efficiency and reconstruction sensitivity to error were also evaluated via simulation models including the noise-free channel model, random noise channel model, and CDMA channel model, as well as over an actual CDMA network currently operating in Korea. This study found that the EZ algorithm achieves the best compression efficiency within a low-noise environment, and that the WH algorithm is competitive for use in high-error environments with degraded short-term performance with abnormal or contaminated ECG signals.

  6. An investigation of 'sparse channel networks'. Characteristic behaviours and their causes

    Energy Technology Data Exchange (ETDEWEB)

    Black, J.H. (In Situ Solutions, East Bridgford (GB)); Barker, J.A.; Woodman, N.D. (Univ. of Southampton (GB))

    2007-09-15

    This report represents a third study in a series concerned with groundwater flow in poorly permeable fractured crystalline rocks. The study has brought together three linked, but distinct, elements; a mathematical analysis of the intersection of ellipses, a review of field measurements associated with nuclear waste repository investigations and probabilistic simulations using a lattice network numerical model. We conclude that the model of channels that traverse fracture intersections without necessarily branching is a very likely representation of reality. More generally, assembling all the lines of evidence, it is suggested that groundwater flow systems in fractured crystalline rocks in the environs of underground laboratories have the following characteristics: Groundwater flows within a sparse network of channels just above the percolation limit. The frequency of intersections is low in that individual channels extend considerable distances between significant junctions. Individual channels often extend over many fracture surfaces and the resulting flow system is only weakly related to the density or size of mappable fractures. The sparseness of systems compared to the size of drifts and tunnels means that only a very few flow channels are intersected by drifts and tunnels. Highly convergent flow is required to connect to the rest of the network and this is misinterpreted as a skin of low hydraulic conductivity. Systems are so sparse that they are controlled by a few 'chokes' that give rise to compartments of head, and probably, of groundwater chemistry. Channels occur on all fracture planes, including those within fracture zones, and although the characteristics of the fracture zone channel networks may differ from those in surrounding rocks, they are nonetheless still channel networks. The actively flowing sparse channel network, occurring within any particular rock, is a naturally selected, small sub-set of the available channels. Hence, there are

  7. modeling the effect of bandwidth allocation on network performance

    African Journals Online (AJOL)

    Keywords: Coverage capacity, CDMA, mobile network, network throughput. INTRODUCTION. Wireless network is one of the rapidly growing aspects in today's communication technology. Advances in interactive multimedia applications such as audio phone, movie/video on demand, video conferencing, video gaming, etc., ...

  8. Performance Evaluation of Resilience using Service Relocation for GMPLS Networks

    DEFF Research Database (Denmark)

    Wessing, Henrik; Herrmann, Sven; Ruepp, Sarah Renée

    2015-01-01

    path when providing resiliency to cloud services in the network. The control plane of a GMPLSenabled optical network is simulated, thus evaluating the proposed Path Computation Element architecture for service relocation. The results show that for increased offered traffic in the network, the overall...

  9. Social Networks Use, Loneliness and Academic Performance among University Students

    Science.gov (United States)

    Stankovska, Gordana; Angelkovska, Slagana; Grncarovska, Svetlana Pandiloska

    2016-01-01

    The world is extensively changed by Social Networks Sites (SNSs) on the Internet. A large number of children and adolescents in the world have access to the internet and are exposed to the internet at a very early age. Most of them use the Social Networks Sites with the purpose of exchanging academic activities and developing a social network all…

  10. Growth performance, carcass characteristics and meat quality of ...

    African Journals Online (AJOL)

    At the end of the 56 days feeding trial, three animals per treatment were slaughtered after being starved for 16 hours and evaluated for carcass characteristics and meat quality. Average daily weight gain, average daily feed intake and feed efficiency were significantly (P<0.05) higher in YS/NF compared to other treatments.

  11. Growth performance and carcass characteristics of three Ethiopian ...

    African Journals Online (AJOL)

    Growth and carcass characteristics of three Ethiopian goat breeds, the Afar, Central Highland (CHG) and Long-eared Somali (LES) were evaluated using three grainless diets varying in concentrate:roughage ratios (diet 1 was 50:50, diet 2, 65:35 and diet 3, 80:20) under feedlot conditions. The roughage was native grass ...

  12. Predicting Microbial Fuel Cell Biofilm Communities and Bioreactor Performance using Artificial Neural Networks.

    Science.gov (United States)

    Lesnik, Keaton Larson; Liu, Hong

    2017-09-19

    The complex interactions that occur in mixed-species bioelectrochemical reactors, like microbial fuel cells (MFCs), make accurate predictions of performance outcomes under untested conditions difficult. While direct correlations between any individual waste stream characteristic or microbial community structure and reactor performance have not been able to be directly established, the increase in sequencing data and readily available computational power enables the development of alternate approaches. In the current study, 33 MFCs were evaluated under a range of conditions including eight separate substrates and three different wastewaters. Artificial Neural Networks (ANNs) were used to establish mathematical relationships between wastewater/solution characteristics, biofilm communities, and reactor performance. ANN models that incorporated biotic interactions predicted reactor performance outcomes more accurately than those that did not. The average percent error of power density predictions was 16.01 ± 4.35%, while the average percent error of Coulombic efficiency and COD removal rate predictions were 1.77 ± 0.57% and 4.07 ± 1.06%, respectively. Predictions of power density improved to within 5.76 ± 3.16% percent error through classifying taxonomic data at the family versus class level. Results suggest that the microbial communities and performance of bioelectrochemical systems can be accurately predicted using data-mining, machine-learning techniques.

  13. The Effect of Board Characteristics on Firm Performance in Japan

    Directory of Open Access Journals (Sweden)

    Oona Cha

    2009-06-01

    Full Text Available This paper analyzes the effect of similarity among board members on firm performance in Japanese manufacturing firms. The similarity measures regarding age and educational background of individual directors were used to predict firm performance. The analyses revealed that similarity of age among board members had adverse effects on firm performance. In addition, greater variation in educational background among board members predicted better firm performance. It seems that homogeneity among board members in terms of age and education can affect the firm negatively by impeding exchange of diverse ideas. These findings emphasize that promoting diversity in terms of age and education in the board of directors is crucial for firm performance.

  14. Hypothesis generation using network structures on community health center cancer-screening performance.

    Science.gov (United States)

    Carney, Timothy Jay; Morgan, Geoffrey P; Jones, Josette; McDaniel, Anna M; Weaver, Michael T; Weiner, Bryan; Haggstrom, David A

    2015-10-01

    cohesion, and connectedness varied by community health center performance level. Visual assessment of both the agent-to-agent knowledge sharing network and agent-to-resource knowledge use network diagrams demonstrated that community health centers labeled as high performers typically showed higher levels of collaboration and cohesiveness among agent classes, faster knowledge-absorption rates, and fewer agents that were unconnected to key knowledge resources. Conclusions and research implications: Using the point-in-time survey data outlining community health center cancer-screening practices, our computational model successfully distinguished between high and low performers. Results indicated that high-performance environments displayed distinctive network characteristics in patterns of interaction among agents, as well as in the access and utilization of key knowledge resources. Our study demonstrated how non-network-specific data obtained from a point-in-time survey can be employed to forecast community health center performance over time, thereby enhancing the sustainability of long-term strategic-improvement efforts. Our results revealed a strategic profile for community health center cancer-screening improvement via simulation over a projected 10-year period. The use of computational modeling allows additional inferential knowledge to be drawn from existing data when examining organizational performance in increasingly complex environments. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Understanding characteristics in multivariate traffic flow time series from complex network structure

    Science.gov (United States)

    Yan, Ying; Zhang, Shen; Tang, Jinjun; Wang, Xiaofei

    2017-07-01

    Discovering dynamic characteristics in traffic flow is the significant step to design effective traffic managing and controlling strategy for relieving traffic congestion in urban cities. A new method based on complex network theory is proposed to study multivariate traffic flow time series. The data were collected from loop detectors on freeway during a year. In order to construct complex network from original traffic flow, a weighted Froenius norm is adopt to estimate similarity between multivariate time series, and Principal Component Analysis is implemented to determine the weights. We discuss how to select optimal critical threshold for networks at different hour in term of cumulative probability distribution of degree. Furthermore, two statistical properties of networks: normalized network structure entropy and cumulative probability of degree, are utilized to explore hourly variation in traffic flow. The results demonstrate these two statistical quantities express similar pattern to traffic flow parameters with morning and evening peak hours. Accordingly, we detect three traffic states: trough, peak and transitional hours, according to the correlation between two aforementioned properties. The classifying results of states can actually represent hourly fluctuation in traffic flow by analyzing annual average hourly values of traffic volume, occupancy and speed in corresponding hours.

  16. The impacts of network competence, knowledge sharing on service innovation performance: Moderating role of relationship quality

    Directory of Open Access Journals (Sweden)

    Zaoquan Jian

    2013-03-01

    Full Text Available Purpose: To examine how network competence, knowledge sharing and relationship quality affect service innovation performanceDesign/methodology/approach: Empirical ResearchFindings: 1 Both enterprise’s network competence and knowledge sharing have distinct positive impact on SIP; (2 Knowledge sharing partially mediates the effect of network competence on SIP. (3 Relationship quality positively moderates the effect of network competence on knowledge sharing, and the effect of knowledge sharing on SIP. (4 Relationship quality does not positively moderate the effect of network competence on SIP.Originality/value: This study has enriched current understanding of the relationship among network competence, knowledge sharing, relationship quality and service innovation performance.

  17. Loss Performance Modeling for Hierarchical Heterogeneous Wireless Networks With Speed-Sensitive Call Admission Control

    DEFF Research Database (Denmark)

    Huang, Qian; Huang, Yue-Cai; Ko, King-Tim

    2011-01-01

    A hierarchical overlay structure is an alternative solution that integrates existing and future heterogeneous wireless networks to provide subscribers with better mobile broadband services. Traffic loss performance in such integrated heterogeneous networks is necessary for an operator's network...... dimensioning and planning. This paper investigates the computationally efficient loss performance modeling for multiservice in hierarchical heterogeneous wireless networks. A speed-sensitive call admission control (CAC) scheme is considered in our model to assign overflowed calls to appropriate tiers...

  18. Performance and antrhropometric characteristics of Elite Rugby Players.

    Science.gov (United States)

    Pasin, Federico; Caroli, Barbara; Spigoni, Valentina; Dei Cas, Alessandra; Volpi, Riccardo; Galli, Carlo; Passeri, Giovanni

    2017-08-23

    Physical performance is the result of a complex combination of several factors such as genetic and anthropometric aspects, nutrition and hormonal status. In the past few years many studies have considered the impact of vitamin D on muscular strength and athletic performance.The aim of the present study was to assess the anthropometric measures impacting on physical performance in a group of professional rugby athletes.  As a secondary aim we investigated a possible relationship between baseline vitamin D status and athletic performance status in these subjects. All rugby players completed a test-retest reliability study on performance measures, as 70kg jump squat and body weight (BW) jump squat to assess musculoskeletal performance. Additionally at the time point we collected a blood sample of every athletes for the assessment of serum vitamin D. We found that lean mass was an important independent predictor of performance score in 70kg jump squat (p=0.007, R2=0.74) and BW jump squat (p=0.010, R2=0.66) in these well trained athletes. No statistically significant association was present between performance score and serum vitamin D in this specific setting. We demonstrate a positive interaction between lower limb lean mass and performance score, but we have not been able to identify any statistically significant association between worsening in performance measures and decrease of serum 25 OH Vitamin D.

  19. Evaluating the Performance of Taiwan Homestay Using Analytic Network Process

    Directory of Open Access Journals (Sweden)

    Yi-Chung Hu

    2012-01-01

    Full Text Available Homestay industry in Taiwan is not only thriving, but also its operation is moving gradually toward elaboration strategy and in a specialized-operation manner these years. Nevertheless, the evaluation frameworks of the earlier studies were sporadically constructed from an overall perspective of homestays. Moreover, the functions, operational model, and natures of homestays are dissimilar to those of hotels; therefore, if the evaluation criteria of homestays employ the ones of hotels, it would appear to be incoherent and incompatible. This study has accordingly developed and constructed a set of evaluation indicators tailor-made for homestay sector through discussion of literatures and interviewing experts so that the evaluation framework would be more comprehensive and more practical. In the process of interviewing experts, it was discovered that dependences lay on the aspects and criteria. Consequently, this research chose the ANP (analytic network process to get the weights and, further, to acquire the homestay business performance through fuzzy theory. The result reveals, as regards key aspects, homestay proprietors and customer groups both weight the surroundings of the building and features, service quality, operation, and management most. In respect to overall homestay performance, customer groups consider it has reached the satisfactory level.

  20. Performance of a Rain Barrel Sharing Network under Climate Change

    Directory of Open Access Journals (Sweden)

    Seong Jin Noh

    2015-07-01

    Full Text Available Rain barrels can be technically shared through social practices or mutual agreement between individual households. This study proposes the evaluation system for a rain barrel sharing network (RBSN considering three performance criteria of reliability, resiliency, and vulnerability, under plausible climate change scenarios. First, this study shows how the system can be improved in terms of the performance criteria using historical daily rainfall data based on the storage-reliability-yield relationship. This study then examined how the benefits from RBSN are affected by climate change after 100 years. Three climate change scenarios (A1B, A2 and B2 and three global circulation models were used for this purpose. The results showed that the reliability and vulnerability are improved due to sharing and their improvements become larger under climate change conditions. In contrast, the resiliency reduces slightly due to sharing and its reduction is attenuated under climate change conditions. In particular, vulnerability will be reduced significantly under climate change. These results suggest that the sharing of various water resources systems can be an effective climate change adaptation strategy that reduces vulnerability and increases the reliability of the system.

  1. Testing the Performance Characteristics of Manipulating Industrial Robots

    Directory of Open Access Journals (Sweden)

    Darina Kumičáková

    2016-09-01

    Full Text Available The article is aimed at an issue of assessment of performance criteria of manipulating industrial robots with focusing on positioning performance. There are presented: the testing of one-directional pose accuracy and repeatability on Robot Fanuc LR Mate 200iC within the Laboratory of the Department of Automation and Production Systems and processing of the measured data. The laser interferometer Renishaw and digital indicator Mitutoyo Digimatic were used for performing the testing experiments.

  2. MANAGEMENT TEAM CHARACTERISTICS: EVIDENCE FROM UNIVERSITY GOVERNANCE AND SCHOOL PERFORMANCE

    OpenAIRE

    Hsiang-Tsai Chiang; Mei-Chih Lin

    2013-01-01

    The paper examines cognition from the viewpoint of internal management teams of private universities against satisfaction with school performance, applying the SEM model. Empirical results show that the board’s operational effectiveness and attendance rate for internal important meetings held on campus have a significantly positive relationship with implementing effectiveness and satisfaction with school administrative performance. The satisfaction with school administrative performance and...

  3. Laying performance and egg qualities characteristics of Japanese ...

    African Journals Online (AJOL)

    There were also significantly higher values for the internal and external egg quality traits (egg weight, egg width, yolk index, Haugh unit, albumen height, albumen %, and yolk width) in T1, T2 and T3 compare to T4(10.00, 2.11, 0.17, 75.42, 1.55, 49.01and 37.3,). Key words: Egg quality, Japanese quail, laying characteristics, ...

  4. PGF2α induced estrus characteristics and reproductive performance ...

    African Journals Online (AJOL)

    Further, 40 cycling local breed does were selected and randomly assigned into PGF2α treatment (n=20) and control (n=20) groups to study estrus characteristics. Age at puberty was 6.5±1.22 and 6.7±1.22 months for male and female goats, respectively. The mean (±sd) kidding interval was 252.35±31.46 days with a mean ...

  5. Performance-related characteristics of water reactor fuel

    Science.gov (United States)

    Bairiot, H.; Vanderborck, Y.; Dumbruch, G.

    1982-04-01

    The most widely utilized manufacturing routes are based on different conversion processes: precipitation from aqueous solutions ("wet processes") and dry processes. The characteristics of the resulting powders (grain size, flowability, etc…) influence the pellet fabrication steps and even the sintered pellet characteristics. Depending on the powder characteristics, the pelletizing can be done directly or requires a previous conditioning. This preconditioning may include blending additives for further processing, for modifying the final pellet structure or for incorporating fissile or poison material. Controls at this stage are usually limited to homogeneity of the dispersion of additives. The sintering process parameters are monitored to insure that the pellet structure presents adequate densification stability. As a final product, the pellet is also subjected to all the controls required to demonstrate that the specifications are met. The paper reviews the controls applied for what regards the major components, the structural features and the geometry. Rather than the presentation of control techniques, the paper discusses the subject in the light of methods and procedures, typically applied in todays industrial fabrication.

  6. Effects of dehydration methods on the characteristics of fibrous networks from un-tanned hides

    Science.gov (United States)

    To improve prospective markets and to secure a viable future for the hides and leather industries, it is important to develop new uses and novel biobased products from hides. We hypothesize collagen fiber networks derived from un-tanned hides can be utilized to prepare high performance green compos...

  7. Effects of dehydration methods on characteristics of fibrous networks from un-tanned hides

    Science.gov (United States)

    To improve prospective markets and to secure a viable future for the hides and leather industries, it is important to develop new uses and novel biobased products from hides. We hypothesize collagen fiber networks derived from un-tanned hides can be utilized to prepare high performance green compos...

  8. Effect of landslides on the structural characteristics of land-cover based on complex networks

    Science.gov (United States)

    He, Jing; Tang, Chuan; Liu, Gang; Li, Weile

    2017-09-01

    Landslides have been widely studied by geologists. However, previous studies mainly focused on the formation of landslides and never considered the effect of landslides on the structural characteristics of land-cover. Here we define the modeling of the graph topology for the land-cover, using the satellite images of the earth’s surface before and after the earthquake. We find that the land-cover network satisfies the power-law distribution, whether the land-cover contains landslides or not. However, landslides may change some parameters or measures of the structural characteristics of land-cover. The results show that the linear coefficient, modularity and area distribution are all changed after the occurence of landslides, which means the structural characteristics of the land-cover are changed.

  9. The Influence of Social Network Characteristics on Peer Clustering in Smoking: A Two-Wave Panel Study of 19- and 23-Year-Old Swedes.

    Science.gov (United States)

    Miething, Alexander; Rostila, Mikael; Edling, Christofer; Rydgren, Jens

    2016-01-01

    The present study examines how the composition of social networks and perceived relationship content influence peer clustering in smoking, and how the association changes during the transition from late adolescence to early adulthood. The analysis was based on a Swedish two-wave survey sample comprising ego-centric network data. Respondents were 19 years old in the initial wave, and 23 when the follow-up sample was conducted. 17,227 ego-alter dyads were included in the analyses, which corresponds to an average response rate of 48.7 percent. Random effects logistic regression models were performed to calculate gender-specific average marginal effects of social network characteristics on smoking. The association of egos' and alters' smoking behavior was confirmed and found to be stronger when correlated in the female sample. For females, the associations decreased between age 19 and 23. Interactions between network characteristics and peer clustering in smoking showed that intense social interactions with smokers increase egos' smoking probability. The influence of network structures on peer clustering in smoking decreased during the transition from late adolescence to early adulthood. The study confirmed peer clustering in smoking and revealed that females' smoking behavior in particular is determined by social interactions. Female smokers' propensity to interact with other smokers was found to be associated with the quality of peer relationships, frequent social interactions, and network density. The influence of social networks on peer clustering in smoking decreased during the transition from late adolescence to early adulthood.

  10. The performance characteristics of groundnut (Arachis hypogea, L ...

    African Journals Online (AJOL)

    JOHN ONIYA

    methanol as the alcohol for transesterification (Yusuf and. Sirajo, 2009), no work was reported in literature on the performance of groundnut biodiesel in any diesel engine. The main objective of this work was to evaluate the performance of a 2.46 kW diesel engine using groundnut biodiesel. MATERIALS AND METHODS.

  11. Comparison of performance and emission characteristics of diesel ...

    African Journals Online (AJOL)

    The present work is focused on comparison of diesel and diesel-water blend on emissions and performance parameters of the diesel engine. The emission parameters such as NO, CO and soot are investigated numerically by using commercially available CFD software AVL FIRE. In addition to that, performance parameters ...

  12. Performance and carcass characteristics of Japanese quail as ...

    African Journals Online (AJOL)

    p2486547

    Keywords: Prebiotic, acidifier, Coturnix japonica, performance, meat quality, fatty acids profile. # Corresponding author. E-mail: ... et al., 2004). Organic acids such as formic and propionic acid have mainly been used to sanitize animal feed. ...... Effect of malic acid on performance and some digestive tract traits of Japanese ...

  13. Is functional integration of resting state brain networks an unspecific biomarker for working memory performance?

    Science.gov (United States)

    Alavash, Mohsen; Doebler, Philipp; Holling, Heinz; Thiel, Christiane M; Gießing, Carsten

    2015-03-01

    Is there one optimal topology of functional brain networks at rest from which our cognitive performance would profit? Previous studies suggest that functional integration of resting state brain networks is an important biomarker for cognitive performance. However, it is still unknown whether higher network integration is an unspecific predictor for good cognitive performance or, alternatively, whether specific network organization during rest predicts only specific cognitive abilities. Here, we investigated the relationship between network integration at rest and cognitive performance using two tasks that measured different aspects of working memory; one task assessed visual-spatial and the other numerical working memory. Network clustering, modularity and efficiency were computed to capture network integration on different levels of network organization, and to statistically compare their correlations with the performance in each working memory test. The results revealed that each working memory aspect profits from a different resting state topology, and the tests showed significantly different correlations with each of the measures of network integration. While higher global network integration and modularity predicted significantly better performance in visual-spatial working memory, both measures showed no significant correlation with numerical working memory performance. In contrast, numerical working memory was superior in subjects with highly clustered brain networks, predominantly in the intraparietal sulcus, a core brain region of the working memory network. Our findings suggest that a specific balance between local and global functional integration of resting state brain networks facilitates special aspects of cognitive performance. In the context of working memory, while visual-spatial performance is facilitated by globally integrated functional resting state brain networks, numerical working memory profits from increased capacities for local processing

  14. Performance Analysis with Network-Enhanced Complexities: On Fading Measurements, Event-Triggered Mechanisms, and Cyber Attacks

    Directory of Open Access Journals (Sweden)

    Derui Ding

    2014-01-01

    Full Text Available Nowadays, the real-world systems are usually subject to various complexities such as parameter uncertainties, time-delays, and nonlinear disturbances. For networked systems, especially large-scale systems such as multiagent systems and systems over sensor networks, the complexities are inevitably enhanced in terms of their degrees or intensities because of the usage of the communication networks. Therefore, it would be interesting to (1 examine how this kind of network-enhanced complexities affects the control or filtering performance; and (2 develop some suitable approaches for controller/filter design problems. In this paper, we aim to survey some recent advances on the performance analysis and synthesis with three sorts of fashionable network-enhanced complexities, namely, fading measurements, event-triggered mechanisms, and attack behaviors of adversaries. First, these three kinds of complexities are introduced in detail according to their engineering backgrounds, dynamical characteristic, and modelling techniques. Then, the developments of the performance analysis and synthesis issues for various networked systems are systematically reviewed. Furthermore, some challenges are illustrated by using a thorough literature review and some possible future research directions are highlighted.

  15. Macropore flow at the field scale: predictive performance of empirical models and X-ray CT analyzed macropore characteristics

    Science.gov (United States)

    Naveed, M.; Moldrup, P.; Schaap, M.; Tuller, M.; Kulkarni, R.; Vögel, H.-J.; Wollesen de Jonge, L.

    2015-11-01

    Predictions of macropore flow is important for maintaining both soil and water quality as it governs key related soil processes e.g. soil erosion and subsurface transport of pollutants. However, macropore flow currently cannot be reliably predicted at the field scale because of inherently large spatial variability. The aim of this study was to perform field scale characterization of macropore flow and investigate the predictive performance of (1) current empirical models for both water and air flow, and (2) X-ray CT derived macropore network characteristics. For this purpose, 65 cylindrical soil columns (6 cm diameter and 3.5 cm height) were extracted from the topsoil (5 to 8.5 cm depth) in a 15 m × 15 m grid from an agricultural loamy field located in Silstrup, Denmark. All soil columns were scanned with an industrial CT scanner (129 μm resolution) and later used for measurements of saturated water permeability, air permeability and gas diffusivity at -30 and -100 cm matric potentials. Distribution maps for both water and air permeabilities and gas diffusivity reflected no spatial correlation irrespective of the soil texture and organic matter maps. Empirical predictive models for both water and air permeabilities showed poor performance as they were not able to realistically capture macropore flow because of poor correlations with soil texture and bulk density. The tested empirical model predicted well gas diffusivity at -100 cm matric potential, but relatively failed at -30 cm matric potential particularly for samples with biopore flow. Image segmentation output of the four employed methods was nearly the same, and matched well with measured air-filled porosity at -30 cm matric potential. Many of the CT derived macropore network characteristics were strongly interrelated. Most of the macropore network characteristics were also strongly correlated with saturated water permeability, air permeability, and gas diffusivity. The correlations between macropore

  16. Site response and station performance of the newly-upgraded Myanmar National Seismic Network

    Science.gov (United States)

    Wolin, E.; Thiam, H. N.; MIN Htwe, Y. M.; Kyaw, T. L.; Tun, P. P.; Min, Z.; Htwe, S. H.; Aung, T. M.; Lin, K. K.; Aung, M. M.; De Cristofaro, J. L.; Franke, M.; Hough, S. E.

    2016-12-01

    Myanmar is in a tectonically complex region between the eastern edge of the Himalayan collision zone and the northern end of the Sunda megathrust. Faults accommodating the oblique motion between India and Southeast Asia pose a hazard to the population of Myanmar, with few Mw>7 events in recent decades, but a number of Mw7-8 events documented in the historical record. A primary concern is the right-lateral Sagaing fault stretching more than 1000 km through the center of Myanmar in proximity to large cities such as Yangon, Mandalay, and the capital Nay Pyi Taw. Until recently, earthquake monitoring and research efforts have been hampered by a lack of modern instrumentation and communication infrastructure. In January of 2016, a major upgrade of the Myanmar National Seismic Network (MNSN; network code MM) was undertaken to improve earthquake monitoring capability. We installed five permanent broadband/strong-motion seismic stations and real-time data telemetry using newly improved cellular networks. Data are telemetered to the MNSN hub in Nay Pyi Taw and archived at the Incorporated Research Institutions for Seismology Data Management Center. We analyzed station performance and site response using noise and events recorded over the first six months of station operation. Background noise characteristics vary across the array, but indicate that the new stations are performing well. With data from the upgraded stations, the MNSN is able to lower the event detection threshold relative to the threshold provided by the global network, improving the ability of the MNSN to report on locally felt events, and improving significantly the monitoring of ground motions within the country. MM stations have recorded more than 20 earthquakes of M≥4.5 within Myanmar and its immediate surroundings, including a M6.8 earthquake located northwest of Mandalay on 13 April 2016. We use this new dataset to calculate horizontal-to-vertical spectral ratios and evaluate the site response of MM

  17. Performance characteristics, plasma lipids and copper residue in ...

    African Journals Online (AJOL)

    Copper proteinate) and inorganic (Copper sulphate) Cu source on growth performance, plasma lipids and copper residue in organs and tissues of cockerel chickens. 240 day-old commercial Black-Harco cockerel chicks were randomly distributed to ...

  18. Familism, Social Network Characteristics, and Well-being among Older Adults in Mexico.

    Science.gov (United States)

    Fuller-Iglesias, Heather R; Antonucci, Toni C

    2016-03-01

    Familism, is a cultural value considered to be central to Mexican culture. Older generations are thought to more strongly adhere to familistic values; however, little is known about the implications of familism in late-life. The goal of the current study was to examine links between familism, social network characteristics, and well-being among Mexican older adults. A sample of 556 older adults (50-99 years old) was drawn from the Study of Social Relations and Well-being in Mexico. Various aspects of social network characteristics and familism varied by age, gender, and education status. Familism was correlated with contact frequency and geographic proximity, but not proportion of family in network. Regression analyses indicated higher familism was associated with better psychological and physical well-being, yet familism interacted with proportion of family to predict both self-rated health and chronic conditions indicating that a discrepancy between familistic values and actual family support may be detrimental for older Mexicans' physical health. The discussion highlights the complex interrelationships and potential protective effects of familism. Future research should continue to examine the implications of familism and family relationships in the Mexican context; in particular, how generational shifts in familism influence intergenerational relations and well-being.

  19. A Study of Coaxial Rotor Performance and Flow Field Characteristics

    Science.gov (United States)

    2016-01-22

    Inc. Ames, Iowa, USA ABSTRACT As a precursor to studying the acoustics of a coaxial rotor system, the aerodynamics and flow field of a coaxial rotor... aerodynamics model, was used to predict coaxial rotor performance in hover and forward flight. RotUNS steady hover calculations showed improved performance...small unmanned aerial vehicles ( UAVs ) market. As with all rotorcraft, the rotor noise generated by a coaxial rotor system must be mitigated to minimize

  20. IDI diesel engine performance and exhaust emission analysis using biodiesel with an artificial neural network (ANN

    Directory of Open Access Journals (Sweden)

    K. Prasada Rao

    2017-09-01

    Full Text Available Biodiesel is receiving increasing attention each passing day because of its fuel properties and compatibility. This study investigates the performance and emission characteristics of single cylinder four stroke indirect diesel injection (IDI engine fueled with Rice Bran Methyl Ester (RBME with Isopropanol additive. The investigation is done through a combination of experimental data analysis and artificial neural network (ANN modeling. The study used IDI engine experimental data to evaluate nine engine performance and emission parameters including Exhaust Gas Temperature (E.G.T, Brake Specific Fuel Consumption (BSFC, Brake Thermal Efficiency (B.The and various emissions like Hydrocarbons (HC, Carbon monoxide (CO, Carbon dioxide (CO2, Oxygen (O2, Nitrogen oxides (NOX and smoke. For the ANN modeling standard back propagation algorithm was found to be the optimum choice for training the model. A multi-layer perception (MLP network was used for non-linear mapping between the input and output parameters. It was found that ANN was able to predict the engine performance and exhaust emissions with a correlation coefficient of 0.995, 0.980, 0.999, 0.985, 0.999, 0.999, 0.980, 0.999, and 0.999 for E.G.T, BSFC, B.The, HC, O2, CO2, CO, NOX, smoke respectively.

  1. Social network characteristics and cervical cancer screening among Quechua women in Andean Peru

    Directory of Open Access Journals (Sweden)

    John S. Luque

    2016-02-01

    Full Text Available Abstract Background Peru has high cervical cancer incidence and mortality rates compared to other Andean countries. Therefore, partnerships between governmental and international organizations have targeted rural areas of Peru to receive cervical cancer screening via outreach campaigns. Previous studies have found a relationship between a person’s social networks and cancer screening behaviors. Screening outreach campaigns conducted by the nonprofit organization CerviCusco created an opportunity for a social network study to examine cervical cancer screening history and social network characteristics in a rural indigenous community that participated in these campaigns in 2012 and 2013. The aim of this study was to explore social network characteristics in this community related to receipt of cervical cancer screening following the campaigns. Methods An egocentric social network questionnaire was used to collect cross-sectional network data on community participants. Each survey participant (ego was asked to name six other women they knew (alters and identify the nature of their relationship or tie (family, friend, neighbor, other, residential closeness (within 5 km, length of time known, frequency of communication, topics of conversation, and whether they lent money to the person, provided childcare or helped with transportation. In addition, each participant was asked to report the nature of the relationship between all alters identified (e.g., friend, family, or neighbor. Bivariate and multivariate analyses were used to explore the relationship between Pap test receipt at the CerviCusco outreach screening campaigns and social network characteristics. Results Bivariate results found significant differences in percentage of alter composition for neighbors and family, and for mean number of years known, mean density, and mean degree centrality between women who had received a Pap test (n = 19 compared to those who had not (n = 50 (p

  2. Investigation of transfer characteristics of high performance graphene flakes.

    Science.gov (United States)

    Venugopal, Gunasekaran; Krishnamoorthy, Karthikeyan; Kim, Sang-Jae

    2013-05-01

    In this article, we attempted a study on field effect transport characteristics of graphene flakes. These graphene flakes were exfoliated by mechanical peeling-off technique and the electrical contacts were patterned by photo-lithographic method. Graphene devices have shown better transfer characteristics which was obtained even in low-voltage (graphene transistors were patterned on oxidized silicon wafers. A clear n-type to p-type transition at Dirac point and higher electron drain-current modulation in positive back-gate field with current minimum (the Dirac point) were observed at V(GS) = -1.7 V. The carrier mobility was determined from the measured transconductance. The transconductance of the graphene transistors was observed as high as 18.6 microS with a channel length of 68 microm. A maximum electron mobility of 1870 +/- 143 cm2/V x s and hole mobility of 1050 +/- 35 cm2/V x s were achieved at a drain bias 2.1 V which are comparatively higher values among reported for mechanically exfoliated graphene using lithographic method. The fabricated devices also sustained with high-current density for 40 hr in continuous operation without any change in device resistance, which could be applied for robust wiring applications.

  3. Computing by Robust Transience: How the Fronto-Parietal Network Performs Sequential, Category-Based Decisions.

    Science.gov (United States)

    Chaisangmongkon, Warasinee; Swaminathan, Sruthi K; Freedman, David J; Wang, Xiao-Jing

    2017-03-22

    Decision making involves dynamic interplay between internal judgements and external perception, which has been investigated in delayed match-to-category (DMC) experiments. Our analysis of neural recordings shows that, during DMC tasks, LIP and PFC neurons demonstrate mixed, time-varying, and heterogeneous selectivity, but previous theoretical work has not established the link between these neural characteristics and population-level computations. We trained a recurrent network model to perform DMC tasks and found that the model can remarkably reproduce key features of neuronal selectivity at the single-neuron and population levels. Analysis of the trained networks elucidates that robust transient trajectories of the neural population are the key driver of sequential categorical decisions. The directions of trajectories are governed by network self-organized connectivity, defining a "neural landscape" consisting of a task-tailored arrangement of slow states and dynamical tunnels. With this model, we can identify functionally relevant circuit motifs and generalize the framework to solve other categorization tasks. Published by Elsevier Inc.

  4. Proposal and Performance Evaluation of a Multicast Routing Protocol for Wireless Mesh Networks Based on Network Load

    Directory of Open Access Journals (Sweden)

    Kiyotaka Oe

    2015-01-01

    Full Text Available Wireless Mesh Networks (WMNs can provide wide range Wireless Local Area Networks (WLANs area by connecting Access Points (APs of WLANs with each other using radio communications. A routing protocol is very important to keep communication quality over radio multihop communications because radio waves are impacted much by surrounding environment. When we use multiuser shared applications like a video conference and an IP phone, it is predicted that large amount of traffic flows on network. Therefore, we should consider network loads to use these applications. In this paper, we propose a multicast routing protocol for WMNs which considers network loads and hop count. Furthermore, we evaluate performance by simulation. In the simulation results, we show that the proposed protocol has better performance than a conventional protocol (MAODV at high loaded scenario.

  5. Qualitative performance characteristics differentiate dementia with Lewy bodies and Alzheimer's disease

    OpenAIRE

    Doubleday, E; Snowden, J.; A.; Varma; Neary, D

    2002-01-01

    Objectives: To determine whether dementia with Lewy bodies (DLB) and Alzheimer's disease (AD) can be differentiated on the basis of qualitative performance characteristics during neuropsychological evaluation.

  6. Anthropometric, Physiological and Performance Characteristics of Elite and Sub-elite Fencers

    National Research Council Canada - National Science Library

    Tsolakis, Charilaos; Vagenas, George

    2010-01-01

    The present study aimed at investigating the differences in selected anthropometric, strength-power parameters and functional characteristics of fencing performance between elite and sub-elite fencers...

  7. Aerodynamic characteristics and heat radiation performance of sportswear fabrics

    Science.gov (United States)

    Koga, H.; Hiratsuka, M.; Ito, S.; Konno, A.

    2017-10-01

    Sports such as swimming, speed skating, and marathon are sports competing for time. In recent years, reduction of the fluid drag of sportswear is required for these competitions in order to improve the record. In addition, sweating and discomfort due to body temperature rise during competition are thought to affect competitor performance, and heat radiation performance is also an important factor for sportswear. The authors have measured fluid force drag by wrapping cloth around a cylinder and have confirmed their differences due to the roughness of the fabric surface, differences in sewing. The authors could be verified the drag can be reduced by the position of the wear stitch. This time, we measured the heat radiation performance of 14 types of cloths whose aero dynamic properties are known using cylinders which are regarded as human fuselages, and found elements of cloth with heat radiation performance. It was found to be important for raising the heat radiation performance of sportswear that the fabric is thin and flat surface processing.

  8. Modelling and structural characteristics analysis of gene networks for prostate cancer.

    Science.gov (United States)

    Zhang, Yulin; Wang, Shudong; Meng, Dazhi

    2015-01-01

    Analysing structure of gene networks is an important way to understand regulatory mechanisms of organism at the molecular level. In this work, gene mutual information networks are constructed based on gene expression profiles in prostate tissues with and without cancer. In order to contrast structural difference of normal and diseased networks, curves of four structural parameters are given with the change of thresholds. Then threshold discrimination intervals and discrimination weights are defined. A method of finding structural key genes with significant degree-difference is proposed. The finding of key genes will help the biomedical scientists to further research the pathogenesis of prostate cancer. Finally randomisation test is performed to prove that these structural parameters can distinguish normal and prostate cancer in their structures compared with these results in real data.

  9. 172 Networks, Micro Small Enterprises (MSE'S) and Performance ...

    African Journals Online (AJOL)

    User

    were in the urban employment in 2002 (Karekezi and Majoro 2002). In terms ... market behavior (Granovetter 1985, Uzzi 1996). A small firm without networking with its external actors is bound to fail. Networking is the best solution for small firm ..... been seen as an effective vehicle for obtaining necessary resources for small.

  10. 172 Networks, Micro Small Enterprises (MSE'S) and Performance ...

    African Journals Online (AJOL)

    User

    Abstract. This paper examines the role of informal personal networks in determining. Micro Small Enterprises (MSE's) success in Kenya. It adopts the network perspective theoretical approach. Empirically, the paper finds that MSE's in. Kenya get around market failures and lack of formal institutions through entrepreneurial ...

  11. Performance of Flow-Aware Networking in LTE backbone

    DEFF Research Database (Denmark)

    Sniady, Aleksander; Soler, José

    2012-01-01

    technologies, such as Long Term Evolution (LTE). This paper proposes usage of a modified Flow Aware Networking (FAN) technique for enhancing Quality of Service (QoS) in the all-IP transport networks underlying LTE backbone. The results obtained with OPNET Modeler show that FAN, in spite of being relatively...

  12. Assessing the implications of cellular network performance on mobile content access

    DEFF Research Database (Denmark)

    Kaup, Fabian; Michelinakis, Foivos; Bui, Nicola

    2016-01-01

    quality is affected by a number of factors, including network operator and available technologies. However, most studies measuring the cellular network do not consider the performance implications of network configuration and management. To this end, this paper reports about an extensive data set...

  13. From Network to Research – Ten Years of Music Informatics, Performance and Aesthetics

    DEFF Research Database (Denmark)

    Frimodt-Møller, Søren; Grund, Cynthia M.; Jensen, Kristoffer

    2011-01-01

    This article briefly chronicles the history of the Nordic Network of Music Informatics, Performance and Aesthetics (NNIMIPA) and its roots in previous research networks and milieus. It explains how a cross-disciplinary network works and gives rise to research projects that bridge the gap between...

  14. A Bayesian Network Approach to Modeling Learning Progressions and Task Performance. CRESST Report 776

    Science.gov (United States)

    West, Patti; Rutstein, Daisy Wise; Mislevy, Robert J.; Liu, Junhui; Choi, Younyoung; Levy, Roy; Crawford, Aaron; DiCerbo, Kristen E.; Chappel, Kristina; Behrens, John T.

    2010-01-01

    A major issue in the study of learning progressions (LPs) is linking student performance on assessment tasks to the progressions. This report describes the challenges faced in making this linkage using Bayesian networks to model LPs in the field of computer networking. The ideas are illustrated with exemplar Bayesian networks built on Cisco…

  15. The Impact of Increases in Subsidiary Autonomy and Network Relationships on Performance

    DEFF Research Database (Denmark)

    Gammelgaard, Jens; McDonald, Frank; Stephan, Andreas

    2012-01-01

    This paper uses network approaches to subsidiary theory to investigate the performance impacts of interactions among the factors of autonomy, intra-organizational network relationships, and inter-organizational network relationships. The paper offers an analysis of both direct and indirect intera...

  16. Individual, contextual and network characteristics of blood donors and non-donors: a systematic review of recent literature

    NARCIS (Netherlands)

    Piersma, Tjeerd W.; Bekkers, René; Klinkenberg, Elisabeth F.; de Kort, Wim L. A. M.; Merz, Eva-Maria

    2017-01-01

    Background. The ageing population and recent migration flows may negatively affect the blood supply in the long term, increasing the importance of targeted recruitment and retention strategies to address donors. This review sought to identify individual, network and contextual characteristics

  17. Performance Analysis of Economic Model and Radio Resource Management in Heterogeneous Wireless Networks

    OpenAIRE

    Nilkantha Chakraborty

    2013-01-01

    Radio resource management (RRM) is the system level control of co-channel interference and other radio transmission characteristics in wireless communication systems. In this paper we first analyze a utility function based access selection (UFAS) method. Thenwe investigate a radio resource management and network selection scheme in heterogeneous wireless network. We propose an economic model to allocate radio resources for Code Division Multiple Access (CDMA) Networks and Wireless local Area ...

  18. Optimization of observation plan based on the stochastic characteristics of the geodetic network

    Directory of Open Access Journals (Sweden)

    Pachelski Wojciech

    2016-06-01

    Full Text Available Optimal design of geodetic network is a basic subject of many engineering projects. An observation plan is a concluding part of the process. Any particular observation within the network has through adjustment a different contribution and impact on values and accuracy characteristics of unknowns. The problem of optimal design can be solved by means of computer simulation. This paper presents a new method of simulation based on sequential estimation of individual observations in a step-by-step manner, by means of the so-called filtering equations. The algorithm aims at satisfying different criteria of accuracy according to various interpretations of the covariance matrix. Apart of them, the optimization criterion is also amount of effort, defined as the minimum number of observations required.

  19. Performance evaluation of power control algorithms in wireless cellular networks

    Science.gov (United States)

    Temaneh-Nyah, C.; Iita, V.

    2014-10-01

    Power control in a mobile communication network intents to control the transmission power levels in such a way that the required quality of service (QoS) for the users is guaranteed with lowest possible transmission powers. Most of the studies of power control algorithms in the literature are based on some kind of simplified assumptions which leads to compromise in the validity of the results when applied in a real environment. In this paper, a CDMA network was simulated. The real environment was accounted for by defining the analysis area and the network base stations and mobile stations are defined by their geographical coordinates, the mobility of the mobile stations is accounted for. The simulation also allowed for a number of network parameters including the network traffic, and the wireless channel models to be modified. Finally, we present the simulation results of a convergence speed based comparative analysis of three uplink power control algorithms.

  20. Performance Characteristics And Muscle Fat Contents Of Broiler ...

    African Journals Online (AJOL)

    ... 8.08, 12.12 and 16.16% dietary inclusion of POS. it was concluded that 8% dietary inclusion of POS was most beneficial considering muscle fat and economic returns. Keywords: Palm oil sludge, maize, broiler chickens, performance, carcass fat. Journal of Agriculture, Forestry and the Social Sciences Vol. 4 (2) 2006: pp.

  1. Design, development and performance characteristics of a large ...

    Indian Academy of Sciences (India)

    A large aperture disc amplifier has been designed, set-up and characterized for its performance on small signal gain, spatial variation of gain, and thermal recovery time. This amplifier, consisting of three elliptical Nd: phosphate glass discs of size 214 × 114 × 20 mm mounted at Brewster angle and pumped by ten xenon ...

  2. Performance characteristics of a gelled-electrolyte valve-regulated ...

    Indian Academy of Sciences (India)

    12 V/25 AH gelled-electrolyte valve-regulated lead-acid batteries have been assembled in-house and their performance studied in relation to the absorptive glass-microfibre valve-regulated and flooded-electrolyte counterparts at various discharge rates and temperatures between –40°C and 40°C. Although the ...

  3. Performance and carcass characteristics of Japanese quail as ...

    African Journals Online (AJOL)

    The effect of sex and the supplementation of the prebiotic, mannan oligosaccharides (MOS), the acidifier, calcium propionate (CPr) or their combination in the feed of Japanese quail (Coturnix japonica) on their performance and carcass quality was examined in this experimentation. Three hundred, 1-day old Japanese quail ...

  4. Performance gaps in energy consumption : household groups and building characteristics

    NARCIS (Netherlands)

    van den Brom, P.I.; Meijer, A.; Visscher, H.J.

    2017-01-01

    The difference between actual and calculated energy is called the ‘energy-performance gap’. Possible explanations for this gap are construction mistakes, improper adjusting of equipment, excessive simplification in simulation models and occupant behaviour. Many researchers and governmental

  5. Personality characteristics that predict effective performance of sales people

    NARCIS (Netherlands)

    W.J.M.I. Verbeke (Willem)

    1993-01-01

    textabstractIn sales literature the role of personality traits in the prediction of salespeople's performance is a hot topic. This study, based upon an administered personality test, suggests that salespeople's personality traits — specifically, the ability to elicit information from others, to

  6. Performance and carcass characteristics of Japanese quail as ...

    African Journals Online (AJOL)

    p2486547

    Abstract. The effect of sex and the supplementation of the prebiotic, mannan oligosaccharides (MOS), the acidifier, calcium propionate (CPr) or their combination in the feed of Japanese quail (Coturnix japonica) on their performance and carcass quality was examined in this experimentation. Three hundred, 1-day old.

  7. Performance and behavioural characteristics of Pigs as affected by ...

    African Journals Online (AJOL)

    However, effects of hourly exposure to evaporative cooling on gilts have not been adequately documented. Hence, behavioral attributes and performance of pigs given access to evaporative cooling were studied. In a completely randomized design, cross bred gilts (n=40) (Landrace x Large White) weighing 25.00±2.5kg ...

  8. Performance Characteristics of a Cam Turning Attachment | Tuleun ...

    African Journals Online (AJOL)

    A modification of a cylindrical turning unit has been done to give a non-cylindrical turning attachment for production of irregular shapes, like cams on the lathe machine. To assess the performance of the attachment, cutting forces have been measured using a 'Sigma' Cutting Tool Dynamometer. Furthermore, the effect of ...

  9. Performance and carcass characteristics of finisher broilers fed ...

    African Journals Online (AJOL)

    A total of 96, four weeks old broiler birds of Anak strain were subjected to 42 days feeding trial at the poultry unit of Imo State Polytechnic Teaching and Research Farm, Umuagwo in Ohaji/Egbema LGA of Imo State, Nigeria to determine the effect of sun-dried cattle plasma (SDCP) on their performance and carcass ...

  10. Performance characteristics and blood profile of West African dwarf ...

    African Journals Online (AJOL)

    A twelve week trial was investigated to evaluate performance and blood profile of West African dwarf (WAD) goats fed malted sorghum sprout with pineapple waste (MSPW) based diet. The malted sorghum sprout and pineapple waste was at ratio 1:2 (weight/weight) respectively. Sixteen WAD goats with average initial ...

  11. Performance characteristics of a gelled-electrolyte valve-regulated ...

    Indian Academy of Sciences (India)

    Unknown

    12 V/25 AH gelled-electrolyte valve-regulated lead-acid batteries have been assembled in-house ... 1997). In the technical literature, the debate over the rela- ... in-house. It is found that while the performance of the gelled-electrolyte VRLA battery is similar to both the. AGM–VRLA and flooded-electrolyte lead-acid batteries.

  12. Heterotic performance of quality characteristics of bread wheat ...

    African Journals Online (AJOL)

    Heterosis has made a significant contribution to the improvement of many crops regarding yield, quality and resistance to pests. The low wheat (Triticum aestivum L.) productivity in Lesotho has necessitated exploitation of heterosis in commercial cultivars. Heterotic performance of 38 F1 and F2 progenies from 5 x 5 diallel ...

  13. Predicting Performance Under Acute Stress : The Role of Individual Characteristics

    NARCIS (Netherlands)

    Delahaij, R.; Dam, K. van; Gaillard, A.W.K.; Soeters, J.

    2011-01-01

    This prospective study examined how differences in coping style, coping self-efficacy, and metacognitive awareness influence coping behavior and performance during a realistic acute stressful exercise in 2 military samples (n = 122 and n = 132). Results showed that coping self-efficacy and coping

  14. Evaluation of Techniques to Detect Significant Network Performance Problems using End-to-End Active Network Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Cottrell, R.Les; Logg, Connie; Chhaparia, Mahesh; /SLAC; Grigoriev, Maxim; /Fermilab; Haro, Felipe; /Chile U., Catolica; Nazir, Fawad; /NUST, Rawalpindi; Sandford, Mark

    2006-01-25

    End-to-End fault and performance problems detection in wide area production networks is becoming increasingly hard as the complexity of the paths, the diversity of the performance, and dependency on the network increase. Several monitoring infrastructures are built to monitor different network metrics and collect monitoring information from thousands of hosts around the globe. Typically there are hundreds to thousands of time-series plots of network metrics which need to be looked at to identify network performance problems or anomalous variations in the traffic. Furthermore, most commercial products rely on a comparison with user configured static thresholds and often require access to SNMP-MIB information, to which a typical end-user does not usually have access. In our paper we propose new techniques to detect network performance problems proactively in close to realtime and we do not rely on static thresholds and SNMP-MIB information. We describe and compare the use of several different algorithms that we have implemented to detect persistent network problems using anomalous variations analysis in real end-to-end Internet performance measurements. We also provide methods and/or guidance for how to set the user settable parameters. The measurements are based on active probes running on 40 production network paths with bottlenecks varying from 0.5Mbits/s to 1000Mbit/s. For well behaved data (no missed measurements and no very large outliers) with small seasonal changes most algorithms identify similar events. We compare the algorithms' robustness with respect to false positives and missed events especially when there are large seasonal effects in the data. Our proposed techniques cover a wide variety of network paths and traffic patterns. We also discuss the applicability of the algorithms in terms of their intuitiveness, their speed of execution as implemented, and areas of applicability. Our encouraging results compare and evaluate the accuracy of our

  15. The financial performance of hospitals belonging to health networks and systems.

    Science.gov (United States)

    Bazzoli, G J; Chan, B; Shortell, S M; D'Aunno, T

    2000-01-01

    The U.S. health industry is experiencing substantial restructuring through ownership consolidation and development of new forms of interorganizational relationships. Using an established taxonomy of health networks and systems, this paper develops and tests four hypotheses related to hospital financial performance. Consistent with our predictions, we find that hospitals in health systems that had unified ownership generally had better financial performance than hospitals in contractually based health networks. Among health network hospitals, those belonging to highly centralized networks had better financial performance than those belonging to more decentralized networks. However, health system hospitals in moderately centralized systems performed better than those in highly centralized systems. Finally, hospitals in networks or systems with little differentiation or centralization experienced the poorest financial performance. These results are consistent with resource dependence, transaction cost economics, and institutional theories of organizational behavior, and provide a conceptual and empirical baseline for future research.

  16. Back-propagation operation for analog neural network hardware with synapse components having hysteresis characteristics.

    Directory of Open Access Journals (Sweden)

    Michihito Ueda

    Full Text Available To realize an analog artificial neural network hardware, the circuit element for synapse function is important because the number of synapse elements is much larger than that of neuron elements. One of the candidates for this synapse element is a ferroelectric memristor. This device functions as a voltage controllable variable resistor, which can be applied to a synapse weight. However, its conductance shows hysteresis characteristics and dispersion to the input voltage. Therefore, the conductance values vary according to the history of the height and the width of the applied pulse voltage. Due to the difficulty of controlling the accurate conductance, it is not easy to apply the back-propagation learning algorithm to the neural network hardware having memristor synapses. To solve this problem, we proposed and simulated a learning operation procedure as follows. Employing a weight perturbation technique, we derived the error change. When the error reduced, the next pulse voltage was updated according to the back-propagation learning algorithm. If the error increased the amplitude of the next voltage pulse was set in such way as to cause similar memristor conductance but in the opposite voltage scanning direction. By this operation, we could eliminate the hysteresis and confirmed that the simulation of the learning operation converged. We also adopted conductance dispersion numerically in the simulation. We examined the probability that the error decreased to a designated value within a predetermined loop number. The ferroelectric has the characteristics that the magnitude of polarization does not become smaller when voltages having the same polarity are applied. These characteristics greatly improved the probability even if the learning rate was small, if the magnitude of the dispersion is adequate. Because the dispersion of analog circuit elements is inevitable, this learning operation procedure is useful for analog neural network hardware.

  17. Performance Evaluation of 5G Millimeter-Wave Cellular Access Networks Using a Capacity-Based Network Deployment Tool

    Directory of Open Access Journals (Sweden)

    Michel Matalatala

    2017-01-01

    Full Text Available The next fifth generation (5G of wireless communication networks comes with a set of new features to satisfy the demand of data-intensive applications: millimeter-wave frequencies, massive antenna arrays, beamforming, dense cells, and so forth. In this paper, we investigate the use of beamforming techniques through various architectures and evaluate the performance of 5G wireless access networks, using a capacity-based network deployment tool. This tool is proposed and applied to a realistic area in Ghent, Belgium, to simulate realistic 5G networks that respond to the instantaneous bit rate required by the active users. The results show that, with beamforming, 5G networks require almost 15% more base stations and 4 times less power to provide more capacity to the users and the same coverage performances, in comparison with the 4G reference network. Moreover, they are 3 times more energy efficient than the 4G network and the hybrid beamforming architecture appears to be a suitable architecture for beamforming to be considered when designing a 5G cellular network.

  18. Performance in wireless networks and industrial wireless networks on control processes in real time under industrial environments

    Directory of Open Access Journals (Sweden)

    Juan F. Monsalve-Posada

    2015-01-01

    Full Text Available The growing use of Ethernet networks on the industrial automation pyramid has led many companies to develop new devices to operate in requirements of this level, nowadays it is called Industrial Ethernet network, on the market there are various sensors and actuators to industrial scale equipped with this technology, many of these devices are very expensive. In this paper, the performance of two wireless networks is evaluated, the first network has conventional Ethernet devices, and the second network has Industrial Ethernet devices. For the process we vary four parameters such as distance, number of bytes, the signal to noise ratio, and the packet error rate, and then we measure delays and compare with metric statistics results, Box Plot graphs were used for the analysis. Finally, we conclude that under the parameters and conditions tested, wireless networks can serve as a communication system in control applications with allowable delays of up to 50 ms, in addition, the results show a better performance of Industrial Ethernet networks over conventional networks, with differences in the RTT of milliseconds. Therefore, it is recommended to establish what risk is for the process to control these delays to determine if the equipment conventional applies, since under certain features like humidity and temperature can operate properly for a considerable time and at lower cost than devices to Industrial Ethernet.

  19. Performance characteristics of aerodynamically optimum turbines for wind energy generators

    Science.gov (United States)

    Rohrbach, C.; Worobel, R.

    1975-01-01

    This paper presents a brief discussion of the aerodynamic methodology for wind energy generator turbines, an approach to the design of aerodynamically optimum wind turbines covering a broad range of design parameters, some insight on the effect on performance of nonoptimum blade shapes which may represent lower fabrication costs, the annual wind turbine energy for a family of optimum wind turbines, and areas of needed research. On the basis of the investigation, it is concluded that optimum wind turbines show high performance over a wide range of design velocity ratios; that structural requirements impose constraints on blade geometry; that variable pitch wind turbines provide excellent power regulation and that annual energy output is insensitive to design rpm and solidity of optimum wind turbines.

  20. myCourse: An Educational Content Management Platform with Social Networking Characteristics

    Directory of Open Access Journals (Sweden)

    Ioannis Ignatiadis

    2010-12-01

    Full Text Available We adopt the direction towards new educational and pedagogic paradigms, where learning is a process of emergence and co-evolution of the individual, the social group and the wider society. In this direction, Service-Oriented Architectures are becoming a popular system paradigm for e-learning. In this article, we present our research and development efforts to provide a social networking learning platform for developing services which address the personal learning needs of the users and enable them to create value. We also present the specific characteristics of our community driven service framework and discuss our approach in comparison to other similar approaches and frameworks.

  1. Can Network Characteristics Detect Spam Effectively in a Stand-Alone Enterprise?

    Science.gov (United States)

    Ouyang, Tu; Ray, Soumya; Rabinovich, Michael; Allman, Mark

    Previous work has shown that the network dynamics experienced by both the initial packet and an entire connection carrying an email can be leveraged to classify the email as spam or ham. In the case of packet properties, the prior work has investigated their efficacy based on models of traffic collected from around the world. In this paper, we first revisit the techniques when only using information from a single enterprise's vantage point and find packet properties to be less useful. We also show that adding flow characteristics to a model of packet features adds modest discriminating power, and some flow features' information is captured by packet features.

  2. Design, development and performance characteristics of a large ...

    Indian Academy of Sciences (India)

    Zapata L E, Erlandson A E 1998 3D gain modelling of LMJ and NIF amplifiers, Proc. of SPIE. 3492: 630–637. Wonterghem B M V, Murray J R, Campbell J H, Speck R D, Barker C E, Smith I C, Browning D F,. Behrendt W C 1997 Performance of prototype of a large-aperture multi-pass Nd: glass laser for inertial confinement ...

  3. Vocal Characteristics and Laryngoscopic Findings in Future Musical Theater Performers.

    Science.gov (United States)

    D'haeseleer, Evelien; Claeys, Sofie; Meerschman, Iris; Bettens, Kim; Degeest, Sofie; Dijckmans, Caroline; De Smet, Joke; Luyten, Anke; Van Lierde, Kristiane

    2017-07-01

    Musical theater performers are a special group of elite vocal performers with a high vocal load as they combine singing, acting, and physical performance. As they are absolutely depending on their voice quality and vocal capacities for their studies and their future profession, an optimal voice production is very important. The purpose of this study was to determine the voice quality of musical theater students. The voice quality of seven students was then reevaluated 1 year after the first assessment. Observational study. Thirty-one musical students (7 men and 24 women) with a mean age of 20 years participated in the study. To determine the voice quality, objective (aerodynamic measurements, voice range profile, acoustic analysis, and Dysphonia Severity Index) and subjective (videolaryngostroboscopy, Voice Handicap Indexes, and questionnaires regarding voice symptoms and risk factors) voice measurements were performed. The median Dysphonia Severity Index in male and female musical students was respectively 5.3 and 5.7, both corresponding with an overall good voice quality. The questionnaires revealed the presence of vocal fatigue, dryness of the throat, vocal tract discomfort, and harmful vocal habits in the majority of students. In 45% of the subjects, videolaryngostroboscopic evaluation of the vocal folds showed an organic lesion. The majority of these lesions are inflammatory lesions (26%). In 68% of the subjects, a certain degree of supraglottic constriction was observed. Despite the overall good voice quality, videolaryngostroboscopy showed a high presence of vocal fold lesions and supraglottic constriction during phonation. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  4. Performance characteristics of mill rolls from graphite chromium cast iron

    OpenAIRE

    Lecomte-Beckers, Jacqueline; Terziev, L.; Breyer, J. P.

    2000-01-01

    The main requirements for the development of a new grade for the later finishing section of the mill are : good oxidation and thermal behaviour, high wear resistance, good resistance to rolling incidents. The approach of Marichal Ketin to improve the rolling performances in the last finishing stands is presented. The Hi-Cr cast iron possesses excellent wear resistance due to the presence of hard chromium carbides, but its thermal conductivity and sticking properties are fairly low. A graphite...

  5. the steady-state performance characteristics of single phase transfer

    African Journals Online (AJOL)

    2012-11-03

    Nov 3, 2012 ... field (SPTF) machine operating in the asynchronous mode from which the performance charac- .... three phase ABC system and by using the operator j ... IOS. RS. VO. /. 2LLr. 1. T. , r. (c) O-axis circuit. 1. U. 5. ' ωλ. G. U 1. ) (λωω -. Figure 2: Dynamic equivalent circuits of the polyphase TF machine, (a) q-axis ...

  6. The Effects of Ratee Characteristics on Rater Performance Appraisal Behavior.

    Science.gov (United States)

    1983-11-01

    personality types such as extrovert or introvert ; social roles, such as parent or lover; or occupational roles, such as politician or banker. Categorization...positive or negative (such as extrovert , an emotionally unstable person, or a criminal madman). Given the evaluative nature of appraising performance, it...were made across groups or time. For these comparisons , the true score and possible range of accuracy scores remained constant for each dimension

  7. The performance characteristics of groundnut ( Arachis hypogea , L ...

    African Journals Online (AJOL)

    The ethyl-esters were blended with automotive gas oil at (0 to 20%) mix with 5% increment of groundnut ethyl-esters to produce biodiesel. The performance of a 2.46 kW diesel engine was evaluated using the groundnut biodiesel at five loading conditions (0, 25, 50, 75 and 100% of full load). Automotive gas oil was used as ...

  8. Performance Enhancement of Distribution Network with DG Integration Using Modified PSO Algorithm

    Directory of Open Access Journals (Sweden)

    Ramadoni Syahputra

    2016-03-01

    Full Text Available This paper addresses performance enhancement of distribution network with distributed generator (DG integration using modified particle swarm optimization (PSO algorithm. The effort of performance enhancement is done by using optimization of distribution network configuration. The objective of the optimization is minimizing active power loss and improving voltage profile while the distribution network is maintained in the radial structure. In this study, configuration optimization method is based on a modified PSO algorithm. The method has been tested in an IEEE model of 33-bus radial distribution network test system and a reallife radial distribution network of 60-bus Bantul distribution system, Indonesia. The simulation results show the importance of reconfiguring the network for enhancing the distribution network performance in the presence of DG.

  9. PERFORMANCE COMPARISON FOR INTRUSION DETECTION SYSTEM USING NEURAL NETWORK WITH KDD DATASET

    Directory of Open Access Journals (Sweden)

    S. Devaraju

    2014-04-01

    Full Text Available Intrusion Detection Systems are challenging task for finding the user as normal user or attack user in any organizational information systems or IT Industry. The Intrusion Detection System is an effective method to deal with the kinds of problem in networks. Different classifiers are used to detect the different kinds of attacks in networks. In this paper, the performance of intrusion detection is compared with various neural network classifiers. In the proposed research the four types of classifiers used are Feed Forward Neural Network (FFNN, Generalized Regression Neural Network (GRNN, Probabilistic Neural Network (PNN and Radial Basis Neural Network (RBNN. The performance of the full featured KDD Cup 1999 dataset is compared with that of the reduced featured KDD Cup 1999 dataset. The MATLAB software is used to train and test the dataset and the efficiency and False Alarm Rate is measured. It is proved that the reduced dataset is performing better than the full featured dataset.

  10. Characteristics and Performance of Minority-Serving Dialysis Facilities

    Science.gov (United States)

    Hall, Yoshio N; Xu, Ping; Chertow, Glenn M; Himmelfarb, Jonathan

    2014-01-01

    Objective To examine the structure, processes, and outcomes of American dialysis facilities that predominantly treat racial-ethnic minority patients. Data Sources/Study Setting Secondary analysis of data from all patients who initiated dialysis during 2005–2008 in the United States. Study Design In this retrospective cohort study, we examined the associations of the racial-ethnic composition of the dialysis facility with facility-level survival and achievement of performance targets for anemia and dialysis adequacy. Data Collection/Extraction Methods We obtained dialysis facility- and patient-level data from the national data registry of patients with end-stage renal disease. We linked these data with clinical performance measures from the Centers for Medicare and Medicaid Services. Principal Findings Overall, minority-serving facilities were markedly larger, more often community based, and less likely to offer home dialysis than facilities serving predominantly white patients. A significantly higher proportion of minority-serving dialysis facilities exhibited worse than expected survival as compared with facilities serving predominantly white patients (p dialysis adequacy were similar across minority-serving status. Conclusions While minority-serving facilities generally met dialysis performance targets mandated by Medicare, they exhibited worse than expected patient survival. PMID:24354718

  11. Physiological and performance characteristics of United States championship class orienteers.

    Science.gov (United States)

    Knowlton, R G; Ackerman, K J; Fitzgerald, P I; Wilde, S W; Tahamont, M V

    1980-01-01

    The purpose of this investigation was to study the anaerobic and aerobic power of female and male United States championship orienteers and relate these data to competitive performance. In addition, it was considered valuable to obtain a general physical description of the athletes. Anthropometrically, neither the females (n=5) nor the males (n=13) conformed to a somatotype classification typical of endurance athletes. Although the mean anaerobic power values for the females (76.6 kg.m.sec-1) and the males (106.6 kg.m.sec-1) were consistent with what is known for distance runners, the respective aerobic powers of 46.1 and 61.6 ml.kg-1.min-1 were considerably below expectations for national class competitors. The explanation for this latter finding was attributed to their reported training programs. Partial residual plots and multiple regression procedures were used to determine the relationship between aerobic power and gender, respectively, with speed of competitive performance. The final equation to predict performance was P = -13.10 + 0.62(VO2max) + 0.26 (Experience, years) - 0.03 (Anaerobic power) + 1.21 (gender) - 0.01 (VO2max)2 with an R-square of 0.73 and P less than 0.01.

  12. Calculation of the Characteristic Performance Indicators in an Electrochemical Process

    Science.gov (United States)

    Sánchez-Sánchez, C. M.; Expósito, E.; Solla-Gullón, J.; García-García, V.; Montiel, V.; Aldaz, A.

    2003-05-01

    Electrochemical engineering, a relatively young discipline, has important interrelationships with chemical engineering and electrochemistry. The main objectives of electrochemical engineering are the characterization and optimization, both in design and operation mode, of the mechanisms and the processes related to the conversion of chemical and electrical energies. Among the examples of electrochemical synthesis implemented at an industry scale are the synthesis of chlor alkali, aluminium, adiponitrile (an intermediate compound in the manufacture of Nylon). It is feasible to review the systems of electric energy generation (batteries and fuel cells) and sewage treatment. The definition of figures of merit is focused on the electrochemical process and is related to its yield. This concept constitutes a very useful tool to optimize the cost and the economic balance of this process. In this paper, the most characteristic figures of merit in an electrochemical process are defined. They are applied using experimental data obtained in an organic electrosynthesis process: the reduction of L-cystine to L-cysteine in acid media.

  13. Characteristics and lessons learned from practice-based research networks (PBRNs in the United States

    Directory of Open Access Journals (Sweden)

    Keller S

    2012-09-01

    Full Text Available Melinda M Davis,1,2 Sara Keller,1 Jennifer E DeVoe,1,3 Deborah J Cohen11Department of Family Medicine, 2Oregon Rural Practice-based Research Network, Oregon Health & Science University, Portland, OR, USA; 3OCHIN Practice-based Research Network, Portland, OR, USAAbstract: Practice-based research networks (PBRNs are organizations that involve practicing clinicians in asking and answering clinically relevant research questions. This review explores the origins, characteristics, funding, and lessons learned through practice-based research in the United States. Primary care PBRNs emerged in the USA in the 1970s. Early studies explored the etiology of common problems encountered in primary care practices (eg, headache, miscarriage, demonstrating the gap between research conducted in controlled specialty settings and real-world practices. Over time, national initiatives and an evolving funding climate have shaped PBRN development, contributing to larger networks, a push for shared electronic health records, and the use of a broad range of research methodologies (eg, observational studies, pragmatic randomized controlled trials, continuous quality improvement, participatory methods. Today, there are over 160 active networks registered with the Agency for Healthcare Research and Quality's PBRN Resource Center that engage primary care clinicians, pharmacists, dentists, and other health care professionals in research and quality-improvement initiatives. PBRNs provide an important laboratory for encouraging collaborative research partnerships between academicians and practices or communities to improve population health, conduct comparative effectiveness and patient-centered outcomes research, and study health policy reform. PBRNs continue to face critical challenges that include: (1 adapting to a changing landscape; (2 recruiting and retaining membership; (3 securing infrastructure support; (4 straddling two worlds (academia and community and managing

  14. Performance evaluation of a Software-Defined Network (SDN) controller

    OpenAIRE

    Casas Moreno, Xavier

    2016-01-01

    The 5th generation of mobile networks (5G) will enable access to information anywhere and anytime to anyone and anything, i.e., the so-called Networked Society. The details of 5G are still the subject of ongoing research and debate, mostly focused on understanding the radio technologies that can enable the 5G vision. On the other hand, less work has been dedicated so far to address the challenges that 5G will pose to the transport network infrastructure. These challenges include: (i) the capa...

  15. Performance analyses of hybrid WDM/OCDM optical networks

    Directory of Open Access Journals (Sweden)

    Fábio Renan Durand

    2005-02-01

    Full Text Available In this work, optical networks using the hybrid technology of wavelength division multiplexing and optical code division multiplexing (WDM/OCDM are investigated. The architecture of the network is described and it is shown the main advantages of applied optical paths with wavelengths and optical orthogonal codes (OOC to routing and switching virtual optical paths. The main results show that the use of OOC codes together with optical codes converters have a great impact on the decrease of blocking probability for establishing virtual optical paths, increasing network use.

  16. The Current State of Human Performance Technology: A Citation Network Analysis of "Performance Improvement Quarterly," 1988-2010

    Science.gov (United States)

    Cho, Yonjoo; Jo, Sung Jun; Park, Sunyoung; Kang, Ingu; Chen, Zengguan

    2011-01-01

    This study conducted a citation network analysis (CNA) of human performance technology (HPT) to examine its current state of the field. Previous reviews of the field have used traditional research methods, such as content analysis, survey, Delphi, and citation analysis. The distinctive features of CNA come from using a social network analysis…

  17. Supramolecular Polymer Network-Mediated Self-Assembly of Semicrystalline Polymers with Excellent Crystalline Performance.

    Science.gov (United States)

    Cheng, Chih-Chia; Chuang, Wei-Tsung; Lee, Duu-Jong; Xin, Zhong; Chiu, Chih-Wei

    2017-03-01

    A novel application of supramolecular interactions within semicrystalline polymers, capable of self-assembling into supramolecular polymer networks via self-complementary multiple hydrogen-bonded complexes, is demonstrated for efficient construction of highly controlled self-organizing hierarchical structures to offer a direct, efficient nucleation pathway resulting in superior crystallization performance. Herein, a novel functionalized poly(ε-caprolactone) containing self-complementary sextuple hydrogen-bonded uracil-diamidopyridine (U-DPy) moieties is successfully developed and demonstrated excellent thermal and viscoelastic properties as well as high dynamic structural stability in the bulk state due to physical cross-linking created by reversible sextuple hydrogen bonding between U-DPy units. Due to the ability to vary the extent of the reversible network by tuning the U-DPy content, this newly developed material can be readily adjusted to obtain the desired crystalline products with specific characteristics. Importantly, incorporating only 0.1% U-DPy resulted in a polymer with a high crystallization rate constant, short crystallization half-time, and much more rapid crystallization kinetics than pristine PCL, indicating a low content of U-DPy moieties provides highly efficient nucleation sites that manipulate the nucleation and growth processes of polymer crystals to promote crystallization and chain alignment in bulk. This new system is suggested as a potential new route to substantially improve the performance of polymer crystallization. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Linking Belgian employee performance management system characteristics with performance management system effectiveness : Exploring the mediating role of fairness

    NARCIS (Netherlands)

    Dewettinck, K.; van Dijk, J.

    2013-01-01

    Based on expectancy theory, goal-setting theory and control theory, we propose a model in which perceived fairness mediates the relationship between characteristics of employee performance management (PM) systems and their perceived effectiveness by employees. PM system characteristics we propose

  19. The HARP resistive plate chambers: Characteristics and physics performance

    CERN Document Server

    Ammosov, V; Chelkov, G; Dedovitch, D; Dydak, F; Elagin, A; Gapienko, V; Gostkin, M; Guskov, A; Koreshev, V; Kroumchtein, Z; Nefedov, Yu; Nikolaev, K; Semak, A; Sviridov, Yu; Usenko, E; Wotschack, J; Zaets, V; Zhemchugov, A

    2009-01-01

    The HARP resistive plate chamber (RPC) system was designed for time-of-flight measurement in the large-angle acceptance region of the HARP spectrometer. It comprised 46 four-gap glass RPCs covering an area of . The design of the RPCs, their operation, intrinsic properties, and system performance are described. The intrinsic time resolution of the RPCs is 127 ps leading to a system time-of-flight resolution of 175 ps. It is argued that gross differences between pion and proton timing in multi-gap timing RPCs, reported recently in the literature, do not exist.

  20. Knowledge sharing and work performance: a network perspective

    National Research Council Canada - National Science Library

    Wu, Wei-Li; Yeh, Ryh-Song; Hung, Hao-Kai

    2012-01-01

    .... Participants were 170 employees from 4 companies in Taiwan, and it was found that in-degree and in-closeness centralities within a knowledge-sharing network had significant and positive effects...

  1. Enabling Secure High-Performance Wireless Ad Hoc Networking

    Science.gov (United States)

    2003-05-29

    Carl Meyer, and Jonathan Oseas. Generating Strong One-Way Functions with Cryptographic Algorithm. 27:5658–5659, 1985. [119] Marshall Kirk McKusick... Culler , and J. D. Tygar. SPINS: Security Protocols for Sensor Networks. In Proceedings of the Seventh Annual International Conference on Mobile...David L. Tennenhouse, Jonathan M. Smith, W. David Sincoskie, David J. Wetherall, and Gary J. Minden. A Survey of Active Network Research. IEEE

  2. Performance Analysis of Authentication Protocols in Vehicular Ad Hoc Networks

    OpenAIRE

    Aboobaker, Abdul Kalam Kunnel

    2009-01-01

    Traditionally traffic safety was addressed by traffic awareness and passive safety measures like solid chassis, seat belts, air bags etc. With the recent breakthroughs in the domain of mobile ad hoc networks, the concept of vehicular ad hoc networks (VANET) was realised. Safety messaging is the most important aspect of VANETs, where the passive safety (accident readiness) in vehicles was reinforced with the idea of active safety (accident prevention). In safety messaging vehicles will message...

  3. Performance characteristics of the ARCHITECT Galectin-3 assay.

    Science.gov (United States)

    La'ulu, Sonia L; Apple, Fred S; Murakami, Maryann M; Ler, Ranka; Roberts, William L; Straseski, Joely A

    2013-01-01

    Galectin-3 is an emerging biomarker that is commonly increased in patients with heart failure and/or patients at risk for cardiovascular disease. We evaluated the Galectin-3 assay on the Abbott ARCHITECT i1000(SR) and ARCHITECT i2000(SR) at 2 testing sites. Imprecision (%CV), interference, limits of blank (LoB), detection (LoD), and quantitation (LoQ), linearity, method comparison to an ELISA method, comparisons between plasma and serum, and reference intervals were evaluated. Imprecision was performed based on two runs of duplicate testing conducted daily. Verification of LoB, LoD, and LoQ was performed according to Clinical and Laboratory Standards Institute guidelines. Linearity was evaluated by making 5 dilutions of a high patient EDTA plasma pool with a low patient pool. Reference intervals were established using EDTA plasma collected from self-reported healthy volunteers. A second lot of reagent was used at one site for method comparison and imprecision studies. Total CV's were ≤6.0%. A positive interference was observed for hemolyzed samples over 2.0 g/L hemolysate. The LoB ranged from 0.1 to 0.3 ng/mL, the LoD from 1.4 to 2.1 ng/mL and the LoQ from 3.0 to 3.3 ng/mL. Linearity studies had slopes and correlation coefficients equal to 1.0. Comparison of the i1000(SR) and i2000(SR) to the ELISA method demonstrated slopes of 1.0 to 1.2 and correlation coefficients of 0.93 to 0.97. The 97.5th percentile of the reference interval was 18.7 and 17.9 ng/mL for the i1000(SR) and i2000(SR), respectively. The Abbott Galectin-3 assay demonstrated acceptable analytical performance on both the ARCHITECT i1000(SR) and ARCHITECT i2000(SR). Copyright © 2012 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  4. An efficient approach to understanding and predicting the effects of multiple task characteristics on performance.

    Science.gov (United States)

    Richardson, Miles

    2017-04-01

    In ergonomics there is often a need to identify and predict the separate effects of multiple factors on performance. A cost-effective fractional factorial approach to understanding the relationship between task characteristics and task performance is presented. The method has been shown to provide sufficient independent variability to reveal and predict the effects of task characteristics on performance in two domains. The five steps outlined are: selection of performance measure, task characteristic identification, task design for user trials, data collection, regression model development and task characteristic analysis. The approach can be used for furthering knowledge of task performance, theoretical understanding, experimental control and prediction of task performance. Practitioner Summary: A cost-effective method to identify and predict the separate effects of multiple factors on performance is presented. The five steps allow a better understanding of task factors during the design process.

  5. USE OF SOCIAL NETWORKS AND ACADEMIC PERFORMANCE IN EXACT SCIENCES IN UNIVERSITY STUDENTS

    OpenAIRE

    Ph.D. Irma Leticia Chávez Márquez *

    2017-01-01

    The increase use of social networks gives way to new didactic strategies in university students. The objective of the research was to analyze the relationship between the use of the social network Facebook and academic performance in the subject Statistics in university students. The way the research was descriptive and correlational between the variables (use of social networks and academic performance). The research focus was mixed, applied type, the design was quasi-experimental. The resea...

  6. Performance evaluation of wavelet scattering network in image texture classification in various color spaces

    OpenAIRE

    Wu, Jiasong; Jiang, Longyu,; Han, Xu; Senhadji, Lotfi; Shu, Huazhong

    2014-01-01

    Texture plays an important role in many image analysis applications. In this paper, we give a performance evaluation of color texture classification by performing wavelet scattering network in various color spaces. Experimental results on the KTH_TIPS_COL database show that opponent RGB based wavelet scattering network outperforms other color spaces. Therefore, when dealing with the problem of color texture classification, opponent RGB based wavelet scattering network is recommended.

  7. Influence of course characteristics, student characteristics, and behavior in learning management systems on student performance

    NARCIS (Netherlands)

    Conijn, Rianne; Kleingeld, Ad; Matzat, Uwe; Snijders, Chris; van Zaanen, Menno

    2016-01-01

    The use of learning management systems (LMS) in education make it possible to track students’ online behavior. This data can be used for educational data mining and learning analytics, for example, by predicting student performance. Although LMS data might contain useful predictors, course

  8. Fibrillar organization in tendons: A pattern revealed by percolation characteristics of the respective geometric network

    Directory of Open Access Journals (Sweden)

    Daniel Andres Dos Santos

    2014-06-01

    Full Text Available Since the tendon is composed by collagen fibrils of various sizes connected between them through molecular cross-links, it sounds logical to model it via a heterogeneous network of fibrils. Using cross sectional images, that network is operatively inferred from the respective Gabriel graph of the fibril mass centers. We focus on network percolation characteristics under an ordered activation of fibrils (progressive recruitment going from the smallest to the largest fibril. Analyses of percolation were carried out on a repository of images of digital flexor tendons obtained from samples of lizards and frogs. Observed percolation thresholds were compared against values derived from hypothetical scenarios of random activation of nodes. Strikingly, we found a significant delay for the occurrence of percolation in actual data. We interpret this finding as the consequence of some non-random packing of fibrillar units into a size-constrained geometric pattern. We erect an ideal geometric model of balanced interspersion of polymorphic units that accounts for the delayed percolating instance. We also address the circumstance of being percolation curves mirrored by the empirical curves of stress-strain obtained from the same studied tendons. By virtue of this isomorphism, we hypothesize that the inflection points of both curves are different quantitative manifestations of a common transitional process during mechanical load transference.

  9. Separator Characteristics for Increasing Performance of Microbial Fuel Cells

    KAUST Repository

    Zhang, Xiaoyuan

    2009-11-01

    Two challenges for improving the performance of air cathode, single-chamber microbial fuel cells (MFCs) include increasing Coulombic efficiency (CE) and decreasing internal resistance. Nonbiodegradable glass fiber separators between the two electrodes were shown to increase power and CE, compared to cloth separators (J-cloth) that were degraded over time. MFCtestswereconductedusing glass fibermatswith thicknesses of 1.0mm (GF1) or 0.4 mm (GF0.4), a cation exchange membrane (CEM), and a J-cloth (JC), using reactors with different configurations. Higher power densities were obtained with either GF1 (46 ± 4 W/m3) or JC (46 ± 1 W/m3) in MFCs with a 2 cm electrode spacing, when the separator was placed against the cathode (S-configuration), rather than MFCs with GF0.4 (36 ± 1 W/m3) or CEM (14 ± 1 W/m3). Power was increased to 70 ± 2 W/m3 by placing the electrodes on either side of the GF1 separator (single separator electrode assembly, SSEA) and further to 150 ± 6 W/m3 using two sets of electrodes spaced 2 cm a part (double separator electrode assembly, DSEA). Reducing the DSEA electrode spacing to 0.3 cm increased power to 696 ± 26 W/m3 as a result of a decrease in the ohmic resistance from 5.9 to 2.2 Ω. The main advantages of a GF1 separator compared to JC were an improvement in the CE from 40% to 81% (S-configuration), compared to only 20-40% for JC under similar conditions, and the fact that GF1 was not biodegradable. The high CE for the GF1 separator was attributed to a low oxygen mass transfer coefficient (ko ) 5.0 x 10-5 cm/s). The GF1 andJCmaterials differed in the amount of biomass that accumulated on the separator and its biodegradability, which affected long-term power production and oxygen transport. These results show that materials and mass transfer properties of separators are important factors for improving power densities, CE, and long-term performance of MFCs. © 2009 American Chemical Society.

  10. NEXT Long-Duration Test Neutralizer Performance and Erosion Characteristics

    Science.gov (United States)

    Herman, Daniel A.; Soulas, George C.; Patterson, Michael J.

    2009-01-01

    The NASA's Evolutionary Xenon Thruster (NEXT) program is developing the next-generation ion propulsion system with significant enhancements beyond the state-of-the-art to provide future NASA science missions with enhanced capabilities at a low total development cost. A Long-Duration Test (LDT) was initiated in June 2005, to verify the NEXT propellant throughput capability to a qualification-level of 450 kg, 1.5 times the anticipated throughput requirement of 300 kg per thruster based on mission analyses. As of September 2, 2009, the thruster has accumulated 24,400 hr of operation with extensive durations at the following input powers: 6.9, 4.7, 1.1, and 0.5 kW. The thruster has processed 434 kg of xenon, surpassing the NASA Solar Technology Application Readiness (NSTAR) program thruster propellant throughput demonstrated during the extended life testing of the Deep Space 1 flight spare ion thruster and approaching the NEXT development qualification throughput goal of 450 kg. The NEXT LDT has demonstrated a total impulse of 16.1 10(exp 6zzz0 N s; the highest total impulse ever demonstrated by an ion thruster. A reduction in neutralizer flow margin has been the only appreciable source of thruster performance degradation. The behavior of the neutralizer is not easily predicted due to both erosion and deposition observed in previous wear tests. Spot-to-plume mode transition flow data and in-situ erosion results for the LDT neutralizer are discussed. This loss of flow margin has been addressed through a combination of a design change in the prototype-model neutralizer to increase flow margin at low emission current and to update the NEXT throttle table to ensure adequate flow margin as a function of propellant throughput processed. The new throttle table will be used for future LDT operations. The performance of the NEXT LDT neutralizer is consistent with that observed for long-life hollow cathodes. The neutralizer life-limiting failure modes are progressing as expected

  11. Prediction of biopore- and matrix-dominated flow from X-ray CT-derived macropore network characteristics

    DEFF Research Database (Denmark)

    Naveed, Muhammad; Møldrup, Per; Schaap, Marcel G

    2016-01-01

    Prediction and modeling of localized flow processes in macropores is of crucial importance for sustaining both soil and water quality. However, currently there are no reliable means to predict preferential flow due to its inherently large spatial variability. The aim of this study...... was to investigate the predictive performance of previously developed empirical models for both water and air flow and to explore the potential applicability of X-ray computed tomography (CT)-derived macropore network characteristics. For this purpose, 65 cylindrical soil columns (6 cm diameter and 3.5 cm height......) were extracted from the topsoil (5 cm to 8.5 cm depth) in a 15m15m grid from an agricultural field located in Silstrup, Denmark. All soil columns were scanned with an industrial X-ray CT scanner (129 μm resolution) and later employed for measurement of saturated hydraulic conductivity, air permeability...

  12. Dissemination stability and phase noise characteristics in a cascaded, fiber-based long-haul radio frequency dissemination network.

    Science.gov (United States)

    Gao, C; Wang, B; Zhu, X; Yuan, Y B; Wang, L J

    2015-09-01

    To study the dissemination stability and phase noise characteristics of the cascaded fiber-based RF dissemination, we perform an experiment using three sets of RF modulated frequency dissemination systems. The experimental results show that the total transfer stability of the cascaded system can be given by σ(T)(2)=∑(i=1)(N)σ(i)(2) (σ(i) is the frequency dissemination stability of the ith segment and N is the quantity of segments). Furthermore, for each segment, the phase noise of recovered frequency signal is also measured. The results show that for an N-segment, cascaded dissemination system, its stability degrades only by a factor of N. This sub-linear relation makes the cascaded, RF-dissemination method a very attractive one for long-haul, time and frequency dissemination network.

  13. Characteristics of Primer of High Performance Bismaleimide Resin

    Directory of Open Access Journals (Sweden)

    LI Hong-feng

    2016-06-01

    Full Text Available A primer of the bismaleimide resin toughened with block copolymer was prepared. The properties of the primer, such as adhesion, pencil hardness, impact resistance, environment resistant, ageing resistant performance and etc. meet the requirements of the technical specifications of GJB1388. The thermal property of the primer was characterized by differential scanning calorimeter (DSC, thermal gravity analysis (TG, and dynamic mechanical analysis (DMA. The results show that the primer possesses good heat resistance, the glass transition temperature of the primer reach 238℃, 5% mass heat lost temperature is 384℃ after 200℃ cured, and the glass transition temperature of the primer reach 268℃, 5% mass heat lost temperature is 407℃ after 230℃ heat treatment respectively. Bonding strength will increase when the bismaleimide primer doubled with bismaleimide film adhesive, when the primer doubled with J-188 bismaleimide film adhesive, peel strength increases to 107%, the room temperature shear strength and high temperature shear strength increase by 10%.The primer can also be used with other bismaleimide film structural adhesives, which are suitable for the bonding between metals or bismaleimide composites with metals.

  14. Sibsize, family environment, cognitive performance, and affective characteristics.

    Science.gov (United States)

    Marjoribanks, K

    1976-11-01

    The study examined to what extent relationships between sibsize and the cognitive and affective chaarcteristics of children were mediated by family environments. The Alice Heim nonverbal intelligence test (AH4), the Watts Vernon English test, and the Vernon graded mathematics test were used to assess the cognitive performance of 15-year-old children (383 boys and 396 girls). The Ss formed part of a longitudinal national study of English school children. Also schedules were administered to measure children's educational and occupational aspirations, self-concepts, and attitudes toward school. From parental interviews a family environment index consisting of both distal and proximal measures was constructed. The Jackknife technique was used in the analysis to adjust significance levels. Regression surface analysis indicated that at each environment level, sibsize was related only to the English achievement of girls and boys and to the aspirations of girls. However, the shapes of the surfaces suggest that if parents create differential learning environments for different siblings then the behaviors of the siblings are likely to vary, which provides tentative support for the confluence model of sibsize influences on the behaviors of children.

  15. Performance characteristics of the novel PETRRA positron camera

    CERN Document Server

    Ott, R J; Erlandsson, K; Reader, A; Duxbury, D; Bateman, J; Stephenson, R; Spill, E

    2002-01-01

    The PETRRA positron camera consists of two 60 cmx40 cm annihilation photon detectors mounted on a rotating gantry. Each detector contains large BaF sub 2 scintillators interfaced to large area multiwire proportional chambers filled with a photo-sensitive vapour (tetrakis-(dimethylamino)-ethylene). The spatial resolution of the camera has been measured as 6.5+-1.0 mm FWHM throughout the sensitive field-of-view (FoV), the timing resolution is between 7 and 10 ns FWHM and the detection efficiency for annihilation photons is approx 30% per detector. The count-rates obtained, from a 20 cm diameter by 11 cm long water filled phantom containing 90 MBq of sup 1 sup 8 F, were approx 1.25x10 sup 6 singles and approx 1.1x10 sup 5 cps raw coincidences, limited only by the read-out system dead-time of approx 4 mu s. The count-rate performance, sensitivity and large FoV make the camera ideal for whole-body imaging in oncology.

  16. Comparison of Analytical and Measured Performance Results on Network Coding in IEEE 802.11 Ad-Hoc Networks

    DEFF Research Database (Denmark)

    Zhao, Fang; Médard, Muriel; Hundebøll, Martin

    2012-01-01

    CATWOMAN that can run on standard WiFi hardware. We present an analytical model to evaluate the performance of COPE in simple networks, and our results show the excellent predictive quality of this model. By closely examining the performance in two simple topologies, we observe that the coding gain results...

  17. The performance evaluation of a new neural network based traffic management scheme for a satellite communication network

    Science.gov (United States)

    Ansari, Nirwan; Liu, Dequan

    1991-01-01

    A neural-network-based traffic management scheme for a satellite communication network is described. The scheme consists of two levels of management. The front end of the scheme is a derivation of Kohonen's self-organization model to configure maps for the satellite communication network dynamically. The model consists of three stages. The first stage is the pattern recognition task, in which an exemplar map that best meets the current network requirements is selected. The second stage is the analysis of the discrepancy between the chosen exemplar map and the state of the network, and the adaptive modification of the chosen exemplar map to conform closely to the network requirement (input data pattern) by means of Kohonen's self-organization. On the basis of certain performance criteria, whether a new map is generated to replace the original chosen map is decided in the third stage. A state-dependent routing algorithm, which arranges the incoming call to some proper path, is used to make the network more efficient and to lower the call block rate. Simulation results demonstrate that the scheme, which combines self-organization and the state-dependent routing mechanism, provides better performance in terms of call block rate than schemes that only have either the self-organization mechanism or the routing mechanism.

  18. Application of time-hopping UWB range-bit rate performance in the UWB sensor networks

    NARCIS (Netherlands)

    Nascimento, J.R.V. do; Nikookar, H.

    2008-01-01

    In this paper, the achievable range-bit rate performance is evaluated for Time-Hopping (TH) UWB networks complying with the FCC outdoor emission limits in the presence of Multiple Access Interference (MAI). Application of TH-UWB range-bit rate performance is presented for UWB sensor networks.

  19. Network meta-analyses performed by contracting companies and commissioned by industry

    NARCIS (Netherlands)

    Schuit, Ewoud|info:eu-repo/dai/nl/341652385; Ioannidis, John P A

    2016-01-01

    Background: Industry commissions contracting companies to perform network meta-analysis for health technology assessment (HTA) and reimbursement submissions. Our objective was to estimate the number of network meta-analyses performed by consulting companies contracted by industry, to assess whether

  20. Relationship between patient panel characteristics and primary care physician clinical performance rankings.

    Science.gov (United States)

    Hong, Clemens S; Atlas, Steven J; Chang, Yuchiao; Subramanian, S V; Ashburner, Jeffrey M; Barry, Michael J; Grant, Richard W

    2010-09-08

    Physicians have increasingly become the focus of clinical performance measurement. To investigate the relationship between patient panel characteristics and relative physician clinical performance rankings within a large academic primary care network. Cohort study using data from 125,303 adult patients who had visited any of the 9 hospital-affiliated practices or 4 community health centers between January 1, 2003, and December 31, 2005, (162 primary care physicians in 1 physician organization linked by a common electronic medical record system in Eastern Massachusetts) to determine changes in physician quality ranking based on an aggregate of Health Plan Employer and Data Information Set (HEDIS) measures after adjusting for practice site, visit frequency, and patient panel characteristics. Composite physician clinical performance score based on 9 HEDIS quality measures (reported by percentile, with lower scores indicating higher quality). Patients of primary care physicians in the top quality performance tertile compared with patients of primary care physicians in the bottom quality tertile were older (51.1 years [95% confidence interval {CI}, 49.6-52.6 years] vs 46.6 years [95% CI, 43.8-49.5 years], respectively; P care practice visits (71.0% [95% CI, 68.5%-73.5%] vs 61.8% [95% CI, 57.3%-66.3%] with >3 visits/year; P = .003). Top tertile primary care physicians compared with the bottom tertile physicians had fewer minority patients (13.7% [95% CI, 10.6%-16.7%] vs 25.6% [95% CI, 20.2%-31.1%], respectively; P patients (3.2% [95% CI, 0.7%-5.6%] vs 10.2% [95% CI, 5.5%-14.9%]; P patients with Medicaid coverage or without insurance (9.6% [95% CI, 7.5%-11.7%] vs 17.2% [95% CI, 13.5%-21.0%]; P patient panel factors resulted in a relative mean change in physician rankings of 7.6 percentiles (95% CI, 6.6-8.7 percentiles) per primary care physician, with more than one-third (36%) of primary care physicians (59/162) reclassified into different quality tertiles. Among primary

  1. ARTIFICIAL NEURAL NETWORK OPTIMIZATION MODELING ON ENGINE PERFORMANCE OF DIESEL ENGINE USING BIODIESEL FUEL

    National Research Council Canada - National Science Library

    M R Shukri; M M Rahman; D Ramasamy; K Kadirgama

    2015-01-01

      This paper presents a study of engine performance using a mixture of palm oil methyl ester blends with diesel oil as biodiesel in a diesel engine, and optimizes the engine performance using artificial neural network (ANN) modeling...

  2. Enhancing the Innovativeness of Food SMEs through the Management of Strategic Network Behavior and Network Learning Performance

    Directory of Open Access Journals (Sweden)

    Bianka Kühne

    2013-02-01

    Full Text Available The European project NetGrow stands for Enhancing the innovativeness of food SMEs through the management of strategic network behavior and network learning performance. It is a FP7 Cooperation project in the theme Food, Agriculture and Fisheries, and Biotechnology with an EC contribution of 3M €. The project has a duration of 4 years and will be finished in April 2014. The project coordinator is Prof. dr. Xavier Gellynck from Ghent University, Belgium. The aim of Netgrow is to enhance network learning leading to increased innovation, economic growth andsustainable competitive advantage for food small and medium enterprises (SMEs.

  3. Characteristics of nitrogen retention along the river network of upper Xin'anjiang catchment in China

    Science.gov (United States)

    Wang, A.; Yang, D.; Tang, L.

    2014-12-01

    Nitrogen (N) originates mainly from the non-point source (NPS) in the headwaters of many rivers. Understanding the nitrogen retention characteristics along the river network is important for land management in order to implement water resources protection. This study employs a geomorphology based non-point source pollution (GBNP) model to simulate the hillslope hydrological processes, sediment and pollutants transportation in the upper Xin'anjiang catchment in recent 10 years from 2001 to 2010. Calibration and validation of the GBNP model are carried out carefully using the observed discharge, sediment and total nitrogen (TN) concentrations at several hydrological gauges, and then the simulated results of the whole catchment are used to analyze the spatial and temporal distribution of nitrogen along the river networks with emphasis on its retention characteristics. The simulated results indicate that annual TN loaded from the hillslopes in the study catchment ranges from nearly 4000 ton to 11,000 ton and relatively higher TN load occurred in spring and summer. Average TN loads from hillslopes have significant positive correlation with the irrigated-cropland area (correlation coefficient =0.820), and significant negative correlation with the area of forest and grassland (correlation coefficient =-0.427 and -0.246). Seasonal nitrogen retention ratio in the river networks of study catchment in last 10 years varies from 0%-81%, and the streams of order 1 in the Horton-Strahler ordering system has the highest retention ratio and is followed by order 2, order 3 and order 4. The results also indicate that nitrogen retention ratio has positive correlation with river length and negative correlation with discharge and velocity. Scenario analysis of fertilizer application demonstrates that the nitrogen retention ratio increases logarithmically with the TN load and reach a maximum value rapidly.

  4. Performance Analysis of Cell-Phone Worm Spreading in Cellular Networks through Opportunistic Communications

    Directory of Open Access Journals (Sweden)

    YAHUI, W.

    2012-05-01

    Full Text Available Worms spreading directly between cell-phones over short-range radio (Bluetooth, WiFi, etc. are increasing rapidly. Communication by these technologies is opportunistic and has very close relation with the social characteristics of the phone carriers. In this paper, we try to evaluate the impact of different characteristics on the spreading performance of worms. On the other hand, the behaviors of worms may have certain impact, too. For example, worms may make phones be completely dysfunctional and these phones can be seen as killed. We study the impact of the killing speed. Using the Markov model, we propose some theoretical models to evaluate the spreading performance in different cases. Simulation results show the accuracy of our models. Numerical results show that if users do not believe the data coming from others easily, the worms may bring less damage. Surprisingly, if the users are more willing to install the anti-virus software, the worms may bring bigger damage when the software becomes to be outdated with high probability. Though the worms can bring big damage on the network temporarily by killing phones rapidly, numerical results show that this behavior may decrease the total damage in the long time. Therefore, killing nodes more rapidly may be not optimal for worms.

  5. Design, deployment and performance of 4G-LTE networks a practical approach

    CERN Document Server

    ElNashar, Ayman; Sherif, Mahmoud

    2014-01-01

    This book provides an insight into the key practical aspects and best practice of 4G-LTE network design, performance, and deployment Design, Deployment and Performance of 4G-LTE Networks addresses the key practical aspects and best practice of 4G networks design, performance, and deployment. In addition, the book focuses on the end-to-end aspects of the LTE network architecture and different deployment scenarios of commercial LTE networks. It describes the air interface of LTE focusing on the access stratum protocol layers: PDCP, RLC, MAC, and Physical Layer. The air interface described in this book covers the concepts of LTE frame structure, downlink and uplink scheduling, and detailed illustrations of the data flow across the protocol layers. It describes the details of the optimization process including performance measurements and troubleshooting mechanisms in addition to demonstrating common issues and case studies based on actual field results. The book provides detailed performance analysis of key fe...

  6. The Characteristics of a Research Network for Radiation Oncology in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jin Hyun; Park, Seo Hyun; Kang, Jin Oh [Kyung Hee University School of Medicine, Seoul (Korea, Republic of)

    2010-11-15

    To evaluate the structural characteristics of a scientific network of radiation oncology society A total of 1,512 articles published from 1986 to April 2010 with the terms 'radiation oncology' or 'therapeutic radiology' were obtained in the Korea Med database. The co-authors were analyzed according to their affiliation, and their relationship was used to build a matrix. With the matrix, centralization indices and the Key Player index were analyzed. We used UCINET 6.0 for the network analysis, Netdraw for determining a sociogram and Key Player 1.44 for the key player analysis. The centralization of the radiation oncology field decreased from 8.29% for the period from 1986-1990 to 1.84% from 2006-2010. However, when the Korean Journal of Medical Physics was excluded, centralization increased from 2.32% for the period from 2001-2005 to 3.80% from 2006-2010. This suggested that the communication in the clinical research field of radiation oncology is decreasing. In a node centralization analysis, Seoul National University was found to be the highest at 7.9%. Seoul National University showed the highest indices in the Outdegree (6.50%) and Indegree (8.54%), in addition to Betweenness (14.94%) and Eigenvector (135.234%). The Key Player analysis indicated that Inha University had the highest index at 0.491, but when the Korean Journal of Medical Physics was excluded, Yonsei University had the highest Key Player index at 0.584. The degree centrality in the network of radiation oncology decreased in the most recent period as more institutions are participating in network. However, the Betweenness centrality is still increasing, suggesting that the communications among research groups (clique) in radiation oncology is warranted.

  7. Performance of Implementation IBR-DTN and Batman-Adv Routing Protocol in Wireless Mesh Networks

    Directory of Open Access Journals (Sweden)

    Herman Yuliandoko

    2016-03-01

    Full Text Available Wireless mesh networks is a network which has high mobility and flexibility network. In Wireless mesh networks nodes are free to move and able to automatically build a network connection with other nodes. High mobility, heterogeneous condition and intermittent network connectivity cause data packets drop during wireless communication and it becomes a problem in the wireless mesh networks. This condition can happen because wireless mesh networks use connectionless networking type such as IP protocol which it is not tolerant to delay. To solve this condition it is needed a technology to keep data packets when the network is disconnect. Delay tolerant technology is a technology that provides store and forward mechanism and it can prevent packet data dropping during communication. In our research, we proposed a test bed wireless mesh networks implementation by using proactive routing protocol and combining with delay tolerant technology. We used Batman-adv routing protocol and IBR-DTN on our research. We measured some particular performance aspect of networking such as packet loss, delay, and throughput of the network. We identified that delay tolerant could keep packet data from dropping better than current wireless mesh networks in the intermittent network condition. We also proved that IBR-DTN and Batman-adv could run together on the wireless mesh networks. In The experiment throughput test result of IBR-DTN was higher than Current TCP on the LoS (Line of Side and on environment with obstacle. Keywords: Delay Tolerant, IBR-DTN, Wireless Mesh, Batman-adv, Performance

  8. Runtime Performance and Virtual Network Control Alternatives in VM-Based High-Fidelity Network Simulations

    Science.gov (United States)

    2012-12-01

    network emulation systems have been proposed, such as V-eM (Apostolopoulos and Hasapis 2006), DieCast (Gupta et al. 2008), VENICE (Liu, Raju, and...Proceedings of the 2006 3rd Symposium on Networked Systems Design and Implementation (NSDI’06), San Jose, CA, USA. Gupta, D., et al. 2008. “ DieCast

  9. Network performance analysis of the Limpopo TV white space (TVWS) trial network

    CSIR Research Space (South Africa)

    Masonta, MT

    2015-09-01

    Full Text Available the spectrum allocation is managed appropriately, SUs can co-exist on the same radio frequency (RF) spectrum band with licensed networks. This paper introduces the Limpopo TVWS trial network, which provides a point-to-point Internet connectivity to five rural...

  10. Testing the Feasibility of a Low-Cost Network Performance Measurement Infrastructure

    Energy Technology Data Exchange (ETDEWEB)

    Chevalier, Scott [Indiana Univ., Bloomington, IN (United States). International Networks; Schopf, Jennifer M. [Indiana Univ., Bloomington, IN (United States). International Networks; Miller, Kenneth [Pennsylvania State Univ., University Park, PA (United States). Telecommunications and Networking Services; Zurawski, Jason [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Sciences Network

    2016-07-01

    Todays science collaborations depend on reliable, high performance networks, but monitoring the end-to-end performance of a network can be costly and difficult. The most accurate approaches involve using measurement equipment in many locations, which can be both expensive and difficult to manage due to immobile or complicated assets. The perfSONAR framework facilitates network measurement making management of the tests more reasonable. Traditional deployments have used over-provisioned servers, which can be expensive to deploy and maintain. As scientific network uses proliferate, there is a desire to instrument more facets of a network to better understand trends. This work explores low cost alternatives to assist with network measurement. Benefits include the ability to deploy more resources quickly, and reduced capital and operating expenditures. Finally, we present candidate platforms and a testing scenario that evaluated the relative merits of four types of small form factor equipment to deliver accurate performance measurements.

  11. Performance of the hybrid wireless mesh protocol for wireless mesh networks

    DEFF Research Database (Denmark)

    Boye, Magnus; Staalhagen, Lars

    2010-01-01

    Wireless mesh networks offer a new way of providing end-user access and deploying network infrastructure. Though mesh networks offer a price competitive solution to wired networks, they also come with a set of new challenges such as optimal path selection, channel utilization, and load balancing....... These challenges must first be overcome before satisfactory network stability and throughput can be achieved. This paper studies the performance of the Hybrid Wireless Mesh Protocol, the proposed routing protocol for the upcoming IEEE 802.11s standard. HWMP supports two modes of path selection: reactive...

  12. Research about reactor operator's personability characteristics and performance

    Energy Technology Data Exchange (ETDEWEB)

    Wei Li; He Xuhong; Zhao Bingquan [Tsinghua Univ., Institute of Nuclear Energy Technology, Beijing (China)

    2003-03-01

    To predict and evaluate the reactor operator's performance by personality characteristics is an important part of reactor operator safety assessment. Using related psychological theory combined with the Chinese operator's fact and considering the effect of environmental factors to personality analysis, paper does the research about the about the relationships between reactor operator's performance and personality characteristics, and offers the reference for operator's selection, using and performance in the future. (author)

  13. Association between Social Network Characteristics and Lifestyle Behaviours in Adults at Risk of Diabetes and Cardiovascular Disease.

    Science.gov (United States)

    Bot, Sandra D; Mackenbach, Joreintje D; Nijpels, Giel; Lakerveld, Jeroen

    2016-01-01

    In this exploratory study we examined the associations between several social network characteristics and lifestyle behaviours in adults at increased risk of diabetes and cardiovascular diseases. In addition, we explored whether similarities in lifestyle between individuals and their network members, or the level of social support perceived by these individuals, could explain these associations. From the control group of the Hoorn Prevention Study, participants with high and low educational attainment were approached for a structured interview between April and August 2010. Inclusion was stopped when fifty adults agreed to participate. Participants and a selection of their network members (e.g. spouses, best friends, neighbours, colleagues) completed a questionnaire on healthy lifestyle that included questions on fruit and vegetable intake, daily physical activity and leisure-time sedentary behaviour. We first examined associations between network characteristics and lifestyle using regression analyses. Second, we assessed associations between network characteristics and social support, social support and lifestyle, and compared the participants' lifestyles to those of their network members using concordance correlation coefficients. Fifty adults (50/83 x 100 = 62% response) and 170 of their network members (170/192 x 100 = 89% response) participated in the study. Individuals with more close-knit relationships, more friends who live nearby, and a larger and denser network showed higher levels of vegetable consumption and physical activity, and lower levels of sedentary behaviour. Perceived social norms or perceived support for behavioural change were not related to healthy lifestyle. Except for spousal concordance for vegetable intake, the lifestyle of individuals and their network members were not alike. Study results suggest that adults with a larger and denser social network have a healthier lifestyle. Underlying mechanisms for these associations should be

  14. Artificial neural network approach to predicting engine-out emissions and performance parameters of a turbo charged diesel engine

    Directory of Open Access Journals (Sweden)

    Özener Orkun

    2013-01-01

    Full Text Available This study details the artificial neural network (ANN modelling of a diesel engine to predict the torque, power, brake-specific fuel consumption and pollutant emissions, including carbon dioxide, carbon monoxide, nitrogen oxides, total hydrocarbons and filter smoke number. To collect data for training and testing the neural network, experiments were performed on a four cylinder, four stroke compression ignition engine. A total of 108 test points were run on a dynamometer. For the first part of this work, a parameter packet was used as the inputs for the neural network, and satisfactory regression was found with the outputs (over ~95%, excluding total hydrocarbons. The second stage of this work addressed developing new networks with additional inputs for predicting the total hydrocarbons, and the regression was raised from 75 % to 90 %. This study shows that the ANN approach can be used for accurately predicting characteristic values of an internal combustion engine and that the neural network performance can be increased using additional related input data.

  15. Prediction of deformation characteristics of sintered aluminium preforms using neural networks

    Science.gov (United States)

    Selvakumar, N.; Radha, P.; Narayanasamy, R.; Davidson, M. Joseph

    2004-07-01

    Neural networks (NNs) are employed to study the deformation characteristics of sintered aluminium preforms. The proposed NN model has used the measured parameters, namely the load, the aspect ratio and the initial preform fractional density ratio to predict multiple material characteristics, namely the axial stress, the hoop stress, the hydrostatic stress, the axial strain, the hoop strain and the Poisson's ratio. The model is based on a 'four layered NN' with back propagation learning algorithm. The experimental set-up available in the laboratory has been used to get the training data for the sintered aluminium with various preform densities and different aspect ratios (0.50, 0.75 and 1.00) using MoS2 as lubricant. The predicted values from the proposed NN coincide well with the experimental values. In addition, a comparative study between the regression analysis and the NN revealed that the NN can predict the material characteristics of sintered aluminium preform better than regression polynomials within a few per cent error.

  16. Outage and ser performance of an opportunistic multi-user underlay cognitive network

    KAUST Repository

    Khan, Fahd Ahmed

    2012-10-01

    Consider a multi-user underlay cognitive network where multiple cognitive users concurrently share the spectrum with a primary network and a single secondary user is selected for transmission. The channel is assumed to have independent but not identical Nakagami-m fading. Closed form expressions for the outage performance and the symbol-error-rate performance of the opportunistic multi-user secondary network are derived when a peak interference power constraint is imposed on the secondary network in addition to the limited peak transmit power of each secondary user. © 2012 IEEE.

  17. An Efficient Scheme for Aggregation and Presentation of Network Performance in Distributed Brokering Systems

    Directory of Open Access Journals (Sweden)

    Gurhan Gunduz

    2003-12-01

    Full Text Available The Internet is presently being used to support increasingly complex interaction models as a result of more and more applications, services and frameworks becoming network centric. Efficient utilization of network and networkedresources is of paramount importance. Network performance gathering is a precursor to any scheme that seeks to provide adaptive routing capabilities for interactions. In this paper we present a network performance aggregation framework that is extensible and appropriate for distributed messaging systems that span multiple realms, disparate communication protocols and support different applications.

  18. Social Networks and Performance in Distributed Learning Communities

    Science.gov (United States)

    Cadima, Rita; Ojeda, Jordi; Monguet, Josep M.

    2012-01-01

    Social networks play an essential role in learning environments as a key channel for knowledge sharing and students' support. In distributed learning communities, knowledge sharing does not occur as spontaneously as when a working group shares the same physical space; knowledge sharing depends even more on student informal connections. In this…

  19. Software defined networking to improve mobility management performance

    NARCIS (Netherlands)

    Karimzadeh Motallebi Azar, Morteza; Sperotto, Anna; Pras, Aiko; Sperotto, Anna; Doyen, Guillaume; Latré, Steven; Charalambides, Marinos; Stiller, Burkhard

    2014-01-01

    n mobile networks, efficient IP mobility management is a crucial issue for the mobile users changing their mobility anchor points during handover. In this regard several mobility management methods have been proposed. However, those are insufficient for the future mobile Internet in terms of

  20. Cooperative driving in mixed traffic networks - Optimizing for performance

    NARCIS (Netherlands)

    Calvert, S.C.; Broek, T.H.A. van den; Noort, M. van

    2012-01-01

    This paper discusses a cooperative adaptive cruise control application and its effects on the traffic system. In previous work this application has been tested on the road, and traffic simulation has been used to scale up the results of the field test to larger networks and more vehicles. The