WorldWideScience

Sample records for network equipment performance

  1. Deep Space Network equipment performance, reliability, and operations management information system

    Science.gov (United States)

    Cooper, T.; Lin, J.; Chatillon, M.

    2002-01-01

    The Deep Space Mission System (DSMS) Operations Program Office and the DeepSpace Network (DSN) facilities utilize the Discrepancy Reporting Management System (DRMS) to collect, process, communicate and manage data discrepancies, equipment resets, physical equipment status, and to maintain an internal Station Log. A collaborative effort development between JPL and the Canberra Deep Space Communication Complex delivered a system to support DSN Operations.

  2. ENERGY STAR Certified Small Network Equipment

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 1.0 ENERGY STAR Program Requirements for Small Networking Equipment that are effective as...

  3. Computer Network Equipment for Intrusion Detection Research

    National Research Council Canada - National Science Library

    Ye, Nong

    2000-01-01

    .... To test the process model, the system-level intrusion detection techniques and the working prototype of the intrusion detection system, a set of computer and network equipment has been purchased...

  4. Heterogeneous information network model for equipment-standard system

    Science.gov (United States)

    Yin, Liang; Shi, Li-Chen; Zhao, Jun-Yan; Du, Song-Yang; Xie, Wen-Bo; Yuan, Fei; Chen, Duan-Bing

    2018-01-01

    Entity information network is used to describe structural relationships between entities. Taking advantage of its extension and heterogeneity, entity information network is more and more widely applied to relationship modeling. Recent years, lots of researches about entity information network modeling have been proposed, while seldom of them concentrate on equipment-standard system with properties of multi-layer, multi-dimension and multi-scale. In order to efficiently deal with some complex issues in equipment-standard system such as standard revising, standard controlling, and production designing, a heterogeneous information network model for equipment-standard system is proposed in this paper. Three types of entities and six types of relationships are considered in the proposed model. Correspondingly, several different similarity-measuring methods are used in the modeling process. The experiments show that the heterogeneous information network model established in this paper can reflect relationships between entities accurately. Meanwhile, the modeling process has a good performance on time consumption.

  5. Neural network based system for equipment surveillance

    Science.gov (United States)

    Vilim, R.B.; Gross, K.C.; Wegerich, S.W.

    1998-04-28

    A method and system are disclosed for performing surveillance of transient signals of an industrial device to ascertain the operating state. The method and system involves the steps of reading into a memory training data, determining neural network weighting values until achieving target outputs close to the neural network output. If the target outputs are inadequate, wavelet parameters are determined to yield neural network outputs close to the desired set of target outputs and then providing signals characteristic of an industrial process and comparing the neural network output to the industrial process signals to evaluate the operating state of the industrial process. 33 figs.

  6. Lack of security of networked medical equipment in radiology.

    Science.gov (United States)

    Moses, Vinu; Korah, Ipeson

    2015-02-01

    OBJECTIVE. There are few articles in the literature describing the security and safety aspects of networked medical equipment in radiology departments. Most radiologists are unaware of the security issues. We review the security of the networked medical equipment of a typical radiology department. MATERIALS AND METHODS. All networked medical equipment in a radiology department was scanned for vulnerabilities with a port scanner and a network vulnerability scanner, and the vulnerabilities were classified using the Common Vulnerability Scoring System. A network sniffer was used to capture and analyze traffic on the radiology network for exposure of confidential patient data. We reviewed the use of antivirus software and firewalls on the networked medical equipment. USB ports and CD and DVD drives in the networked medical equipment were tested to see whether they allowed unauthorized access. Implementation of the virtual private network (VPN) that vendors use to access the radiology network was reviewed. RESULTS. Most of the networked medical equipment in our radiology department used vulnerable software with open ports and services. Of the 144 items scanned, 64 (44%) had at least one critical vulnerability, and 119 (83%) had at least one high-risk vulnerability. Most equipment did not encrypt traffic and allowed capture of confidential patient data. Of the 144 items scanned, two (1%) used antivirus software and three (2%) had a firewall enabled. The USB ports were not secure on 49 of the 58 (84%) items with USB ports, and the CD or DVD drive was not secure on 17 of the 31 (55%) items with a CD or DVD drive. One of three vendors had an insecure implementation of VPN access. CONCLUSION. Radiologists and the medical industry need to urgently review and rectify the security issues in existing networked medical equipment. We hope that the results of our study and this article also raise awareness among radiologists about the security issues of networked medical equipment.

  7. Dental CBCT equipment and performance issues.

    Science.gov (United States)

    Horner, K; Jacobs, R; Schulze, R

    2013-02-01

    Dental cone beam computed tomography (CBCT), also known as digital volumetric tomography was developed in the late 1990s and is now increasingly available in clinical practice. It can provide high resolution cross-sectional images of teeth and the maxillofacial region with applications in all branches of dentistry. As a new imaging modality, there were no established suspension levels at a European level. A literature review, encompassing scientific, professional publications and existing national guidelines was performed in an attempt to develop a set of suspension levels for dental CBCT, using additional expert opinion from the members of the European Academy of dento-maxillo-facial radiology. A limited set of suspension levels has been devised for aspects of the X-ray tube and generator, dosimetry, field-of-view, alignment and image quality. These should be kept under review in the light of growing experience of testing equipment in practice.

  8. 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.

  9. Performativity and the Politics of Equipping for Calculation

    DEFF Research Database (Denmark)

    Henriksen, Lasse Folke

    2013-01-01

    This article argues that the concept of performativity deepens our understanding of contemporary, expertise-driven processes of global economic governance. Tracing the World Bank's role in constructing a global market for microfinance, the paper suggests that the World Bank was instrumental...... in translating selected parts of economic models into practice, thereby changing microfinance practices globally. Socio-technical networks centered on the World Bank were created to equip actors to become part of a global market, which incorporated not only donors but also commercial investors. The paper makes...

  10. Equipment to Support Development of Neuronal Network Controlled Robots

    Science.gov (United States)

    2016-06-25

    Equipment to Support Development of Neuronal Network Controlled Robots With this award, our team purchased an ALA 2-channel stimulus generator, an...34 laser cutter, and a Rethink Robotics Baxter Robot . This equipment supported two ARO awards, a DARPA award and two NSF-funded projects. The views...Controlled Robots Report Title With this award, our team purchased an ALA 2-channel stimulus generator, an ALA 60-channel amplifier with pre-filter

  11. RTOL: design and implementation of an network equipment testing tool

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J.Y.; Kim, H.J.; Kim, B.S.; Park, K.H.; An, S.S [Korea University, Seoul (Korea, Republic of); Choi, H.S.; Yu, S.H. [Samsung Electronics, Suwon (Korea, Republic of)

    1997-11-01

    As the infrastructure of information communication network becomes larger and more complicated, many network equipment are being developed. To verify the reliability of such equipment, many test methods have been proposed. But those require a lot of cost and efforts. In this paper, we designed and implemented a test tool, called RTOL(Router Testing command Language system), to verify the functions of network equipment, especially router. RTOL can be used to test OSPF, Appletalk, DecNet, as well as IP and supports the functions of SNMP manager. By using the virtual router functions of RTOL, we can operate many virtual routers with only one router. Finally, we present test results of specific routers by using RTOL. (author). 17 refs., 8 figs., 5 tabs.

  12. 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.

  13. Scaling sporting equipment for children promotes implicit processes during performance.

    Science.gov (United States)

    Buszard, Tim; Farrow, Damian; Reid, Machar; Masters, Rich S W

    2014-11-01

    This study investigated whether children who used scaled equipment compared to full size equipment during a motor task demonstrated reduced conscious involvement in performance. Children (9-11 years) performed a tennis hitting task in two attention conditions (single-task and dual-task) using two types of equipment (scaled and full size). A more skilled group and a less skilled group were formed using hitting performance scores. The more skilled group displayed greater working memory capacity than the less skilled group. For both groups, hitting performance and technique were better when scaled equipment was used. Hitting performance when using scaled equipment was not disrupted in either group by a cognitively demanding secondary task; however, performance was disrupted in the less skilled group when using full size equipment. We conclude that equipment scaling may reduce working memory engagement in motor performance and discuss the findings in the context of implicit motor learning theory. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Fleet equipment performance measure preventive maintenance model.

    Science.gov (United States)

    2013-02-28

    The Texas Department of Transportation : (TxDOT) operates a large fleet of on-road and : off-road equipment. Consequently, fleet : maintenance procedures (specifically preventive : maintenance such as oil changes) represent a : significant cost to th...

  15. 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

  16. Performance of FACTS equipment in Meshed systems

    Energy Technology Data Exchange (ETDEWEB)

    Lerch, E.; Povh, D. [Siemens AG, Berlin (Germany)

    1994-12-31

    Modern power electronic devices such as thyristors and GTOs have made it possible to design controllable network elements, which will play a considerable role in ensuring reliable economic operation of transmission systems as a result of their capability to rapidly change active and reactive power. A number of FACTS elements for high-speed active and reactive power control will be described. Control of power system fluctuations in meshed systems by modulation of active and reactive power will be demonstrated using a number of examples. (author) 7 refs., 11 figs.

  17. Basic equipments for improved practical performance in creative arts ...

    African Journals Online (AJOL)

    This paper addresses the issue of adequate provision equipment for improved practical performance of ceramics study in Nigerian higher institutions. It was noted that ceramics equipments are very expensive yet they are indispensable to the study of ceramics. Nigerian Journal of Technology and Education in Nigeria Vol.

  18. Sporting Equipment and Students\\' Academic Performance in the ...

    African Journals Online (AJOL)

    Also, the facilitating influence of sporting equipment on students' academic performance in the concept of projectile in Physics is about the same at all levels of gender. It is recommended that teachers should adopt the use of sporting equipment in the teaching of the concept of projectile in secondary school Physics.

  19. Performance Measurement of Mining Equipments by Utilizing OEE

    Directory of Open Access Journals (Sweden)

    Sermin Elevli

    2010-10-01

    Full Text Available Over the past century, open pit mines have steadily increased their production rate by using larger equipments which requireintensive capital investment. Low commodity prices have forced companies to decrease their unit cost by improving productivity. Oneway to improve productivity is to utilize equipment as effectively as possible. Therefore, the accurate estimation of equipmenteffectiveness is very important so that it can be increased. Overall Equipment Effectiveness (OEE is a well-known measurementmethod, which combines availability, performance and quality, for the evaluation of equipment effectiveness in manufacturing industry.However, there isn’t any study in literature about how to use this metric for mining equipments such as shovel, truck, drilling machineetc. This paper will discuss the application of OEE to measure effectiveness of mining equipment. It identifies causes of time losses forshovel and truck operations and introduces procedure to record time losses. The procedure to estimate OEE of shovels and trucks hasalso been presented via numerical example.

  20. 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.

  1. Sporting Equipment and Students\\' Academic Performance in the ...

    African Journals Online (AJOL)

    This study investigated the effect of sporting equipment on students academic performance in the concept of projectile in Nigerian senior secondary school Physics in Uyo Local Government Area of Akwa Ibom State, Nigeria. A total of 183 senior secondary two (SS2) Physics students were involved in the study. The design ...

  2. The importance of social networks in their association to drug equipment sharing among injection drug users: a review.

    Science.gov (United States)

    De, Prithwish; Cox, Joseph; Boivin, Jean-François; Platt, Robert W; Jolly, Ann M

    2007-11-01

    To examine the scientific evidence regarding the association between characteristics of social networks of injection drug users (IDUs) and the sharing of drug injection equipment. A search was performed on MEDLINE, EMBASE, BIOSIS, Current Contents, PsycINFO databases and other sources to identify published studies on social networks of IDUs. Papers were selected based on their examination of social network factors in relation to the sharing of syringes and drug preparation equipment (e.g. containers, filters, water). Additional relevant papers were found from the reference list of identified articles. Network correlates of drug equipment sharing are multi-factorial and include structural factors (network size, density, position, turnover), compositional factors (network member characteristics, role and quality of relationships with members) and behavioural factors (injecting norms, patterns of drug use, severity of drug addiction). Factors appear to be related differentially to equipment sharing. Social network characteristics are associated with drug injection risk behaviours and should be considered alongside personal risk behaviours in prevention programmes. Recommendations for future research into the social networks of IDUs are proposed.

  3. 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.

  4. Interchat - New channel equipment for the Intersputnik satellite network

    Science.gov (United States)

    Baranyi, A.; Uhereczky, L.; Henk, T.; Kantor, L. Ia.; Dorofeev, V. M.

    The Interchat SCPC channel equipment, developed for the Intersputnik satellite and meeting the Intelsat SCPC requirements, is described. In the Interchat channel equipment, the SPPC-FDMA principle is used for the transmission of voice signals or voice-band telegraph or data signals. For the transmission of individual carriers, the standard IF bandwidth of 36 MHz is utilized, which can be shared with other equipment connected to the same up/down converter configuration. A schematic diagram of the Interchat equipment configuration is presented.

  5. 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.

  6. Theoretical performances of double Gurney Flap equipped the VAWTs

    Directory of Open Access Journals (Sweden)

    Horia DUMITRESCU

    2012-12-01

    Full Text Available A Gurney flap is simply a flat plate attached perpendicularly to the lower surface of an airfoil or wing trailing edge. A T-strip or double Gurney flap is attached to both the upper and lower surfaces. T-strips are used to modify the lifting characteristics of the baseline airfoil for vertical axis wind rotor turbines. Generally, T-strips have been used during developmental flight test as simple add-on “fixes” to improve the performances of existing aircraft vertical tails. This paper aims to investigate the performances of VAWTs equipped with T-strip on blades trailing edge.

  7. A Study on Performance and Safety Tests of Electrosurgical Equipment.

    Science.gov (United States)

    Tavakoli Golpaygani, A; Movahedi, M M; Reza, M

    2016-09-01

    Modern medicine employs a wide variety of instruments with different physiological effects and measurements. Periodic verifications are routinely used in legal metrology for industrial measuring instruments. The correct operation of electrosurgical generators is essential to ensure patient's safety and management of the risks associated with the use of high and low frequency electrical currents on human body. The metrological reliability of 20 electrosurgical equipment in six hospitals (3 private and 3 public) was evaluated in one of the provinces of Iran according to international and national standards. The achieved results show that HF leakage current of ground-referenced generators are more than isolated generators and the power analysis of only eight units delivered acceptable output values and the precision in the output power measurements was low. Results indicate a need for new and severe regulations on periodic performance verifications and medical equipment quality control program especially in high risk instruments. It is also necessary to provide training courses for operating staff in the field of meterology in medicine to be acquianted with critical parameters to get accuracy results with operation room equipment.

  8. A Study on Performance and Safety Tests of Electrosurgical Equipment

    Directory of Open Access Journals (Sweden)

    Tavakoli Golpaygani A.

    2016-09-01

    Full Text Available Introduction: Modern medicine employs a wide variety of instruments with different physiological effects and measurements. Periodic verifications are routinely used in legal metrology for industrial measuring instruments. The correct operation of electrosurgical generators is essential to ensure patient’s safety and management of the risks associated with the use of high and low frequency electrical currents on human body. Material and Methods: The metrological reliability of 20 electrosurgical equipment in six hospitals (3 private and 3 public was evaluated in one of the provinces of Iran according to international and national standards. Results: The achieved results show that HF leakage current of ground-referenced generators are more than isolated generators and the power analysis of only eight units delivered acceptable output values and the precision in the output power measurements was low. Conclusion: Results indicate a need for new and severe regulations on periodic performance verifications and medical equipment quality control program especially in high risk instruments. It is also necessary to provide training courses for operating staff in the field of meterology in medicine to be acquianted with critical parameters to get accuracy results with operation room equipment.

  9. 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.

  10. Electromagnetic interference of Equipment in power supply networks

    NARCIS (Netherlands)

    Timens, R.B.

    2013-01-01

    Electromagnetic Compatibility (EMC) is defined by the European Directive on EMC as the ‘ability of an equipment or system to function satisfactorily in its electromagnetic environment without producing intolerable electromagnetic disturbances to anything in that environment’. EMC means that

  11. A Study on Performance and Safety Tests of Defibrillator Equipment

    Directory of Open Access Journals (Sweden)

    Tavakoli Golpaygani A.

    2017-12-01

    Full Text Available Introduction: Nowadays, more than 10,000 different types of medical devices can be found in hospitals. This way, medical electrical equipment is being employed in a wide variety of fields in medical sciences with different physiological effects and measurements. Hospitals and medical centers must ensure that their critical medical devices are safe, accurate, reliable and operational at the required level of performance. Defibrillators are critical resuscitation devices. The use of reliable defibirillators has led to more effective treatments and improved patient safety through better control and management of complications during Cardiopulmonary Resuscitation (CPR. Materials and Methods: The metrological reliability of twenty frequent use, manual defibrillators in use ten hospitals (4 private and 6 public in one of the provinces of Iran according to international and national standards was evaluated. Results: Quantitative analysis of control and instrument accuracy showed the amount of the obtained results in many units are critical which had less value over the standard limitations especially in devices with poor battery. For the accuracy of delivered energy analysis, only twelve units delivered acceptable output values and the precision in the output energy measurements especialy in weak battry condition, after activation of discharge alarm, were low. Conclusion: Obtained results indicate a need for new and severe regulations on periodic performance verifications and medical equipment quality control program especially for high risk instruments. It is also necessary to provide training courses on the fundumentals of operation and performane parameters for medical staff in the field of meterology in medicine and how one can get good accuracy results especially in high risk medical devices.

  12. Performance of Very Small Robotic Fish Equipped with CMOS Camera

    Directory of Open Access Journals (Sweden)

    Yang Zhao

    2015-10-01

    Full Text Available Underwater robots are often used to investigate marine animals. Ideally, such robots should be in the shape of fish so that they can easily go unnoticed by aquatic animals. In addition, lacking a screw propeller, a robotic fish would be less likely to become entangled in algae and other plants. However, although such robots have been developed, their swimming speed is significantly lower than that of real fish. Since to carry out a survey of actual fish a robotic fish would be required to follow them, it is necessary to improve the performance of the propulsion system. In the present study, a small robotic fish (SAPPA was manufactured and its propulsive performance was evaluated. SAPPA was developed to swim in bodies of freshwater such as rivers, and was equipped with a small CMOS camera with a wide-angle lens in order to photograph live fish. The maximum swimming speed of the robot was determined to be 111 mm/s, and its turning radius was 125 mm. Its power consumption was as low as 1.82 W. During trials, SAPPA succeeded in recognizing a goldfish and capturing an image of it using its CMOS camera.

  13. Sectoral Innovation Performance in the Electrical and Optical Equipment Sector

    NARCIS (Netherlands)

    Broek, T. van den; Giessen, A.M. van der

    2010-01-01

    The Electrical and Optical equipment sector is a high-tech manufacturing sector. It is one of the most innovative sectors in Europe with investments and advances in fundamental research, applied R&D and innovation in the actual use of equipment. This sector is also one of the most global sectors

  14. Fleet equipment performance measurement preventive maintenance model : final report.

    Science.gov (United States)

    2014-04-01

    The concept of preventive maintenance is very important in the effective management and deployment of : vehicle fleets. The Texas Department of Transportation (TxDOT) operates a large fleet of on-road and offroad : equipment. Newer engines and vehicl...

  15. Performance test of nutrient control equipment for hydroponic plants

    Science.gov (United States)

    Rahman, Nurhaidar; Kuala, S. I.; Tribowo, R. I.; Anggara, C. E. W.; Susanti, N. D.

    2017-11-01

    Automatic control equipment has been made for the nutrient content in irrigation water for hydroponic plants. Automatic control equipment with CCT53200E conductivity controller to nutrient content in irrigation water for hydroponic plants, can be used to control the amount of TDS of nutrient solution in the range of TDS numbers that can be set according to the range of TDS requirements for the growth of hydroponically cultivated crops. This equipment can minimize the work time of hydroponic crop cultivators. The equipment measurement range is set between 1260 ppm up to 1610 ppm for spinach plants. Caisim plants were included in this experiment along with spinach plants with a spinach plants TDS range. The average of TDS device is 1450 ppm, while manual (conventional) is 1610 ppm. Nutrient solution in TDS controller has pH 5,5 and temperature 29,2 °C, while manual is pH 5,6 and temperature 31,3 °C. Manually treatment to hydroponic plant crop, yields in an average of 39.6 grams/plant, greater than the yield of spinach plants with TDS control equipment, which is in an average of 24.6 grams / plant. The yield of caisim plants by manual treatment is in an average of 32.3 grams/crop, less than caisim crop yields with TDS control equipment, which is in an average of 49.4 grams/plant.

  16. 10 CFR 34.20 - Performance requirements for industrial radiography equipment.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Performance requirements for industrial radiography equipment. 34.20 Section 34.20 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND... requirements for industrial radiography equipment. Equipment used in industrial radiographic operations must...

  17. 47 CFR 68.110 - Compatibility of the public switched telephone network and terminal equipment.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Compatibility of the public switched telephone... Conditions on Use of Terminal Equipment § 68.110 Compatibility of the public switched telephone network and... maintain uninterrupted service. (c) Availability of inside wiring information. Any available technical...

  18. Equipment Management for Sensor Networks: Linking Physical Infrastructure and Actions to Observational Data

    Science.gov (United States)

    Jones, A. S.; Horsburgh, J. S.; Matos, M.; Caraballo, J.

    2015-12-01

    Networks conducting long term monitoring using in situ sensors need the functionality to track physical equipment as well as deployments, calibrations, and other actions related to site and equipment maintenance. The observational data being generated by sensors are enhanced if direct linkages to equipment details and actions can be made. This type of information is typically recorded in field notebooks or in static files, which are rarely linked to observations in a way that could be used to interpret results. However, the record of field activities is often relevant to analysis or post-processing of the observational data. We have developed an underlying database schema and deployed a web interface for recording and retrieving information on physical infrastructure and related actions for observational networks. The database schema for equipment was designed as an extension to the Observations Data Model 2 (ODM2), a community-developed information model for spatially discrete, feature based earth observations. The core entities of ODM2 describe location, observed variable, and timing of observations, and the equipment extension contains entities to provide additional metadata specific to the inventory of physical infrastructure and associated actions. The schema is implemented in a relational database system for storage and management with an associated web interface. We designed the web-based tools for technicians to enter and query information on the physical equipment and actions such as site visits, equipment deployments, maintenance, and calibrations. These tools were implemented for the iUTAH (innovative Urban Transitions and Aridregion Hydrosustainability) ecohydrologic observatory, and we anticipate that they will be useful for similar large-scale monitoring networks desiring to link observing infrastructure to observational data to increase the quality of sensor-based data products.

  19. 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...

  20. 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...

  1. 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.

  2. Equipment and performance upgrade of compact nuclear simulator

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jae Chang; Kwon, Kee Choon; Cha, Hyung Ho; Park, Won Man; Song, Soon Ja; Seh, Kyung Won; Joo, Young Chang

    1998-12-01

    In this project, the techniques to upgrade obsolescent nuclear power plant simulation were developed: the simulation code operated in Macro-VAX II has been transplanted to the HP workstation: commercial equipment PLC was adopted for the interface system: the protection logic was developed in the prototype level: and the display system was strengthened. These techniques can be directly used to upgrade other obsolescent simulators.

  3. 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...

  4. Performance characterization of night vision equipment based on Triangle Orientation Discrimination (TOD) methodology

    OpenAIRE

    Laurent, N.; Lejard, C.; Deltel, G.; Bijl, P.

    2013-01-01

    Night vision equipment is crucial in order to accomplish supremacy and safety of the troops on the battlefield. Evidently, system integrators, MODs and end-users need access to reliable quantitative characterization of the expected field performance when using night vision equipment. The Image Intensifier tube is one of the most important engines driving the performance for night vision equipment. As a major tube manufacturer, PHOTONIS has investigated the link between its products physical d...

  5. 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.

  6. 49 CFR 232.309 - Equipment and devices used to perform single car air brake tests.

    Science.gov (United States)

    2010-10-01

    ... (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRAKE SYSTEM SAFETY STANDARDS FOR... Testing Requirements § 232.309 Equipment and devices used to perform single car air brake tests. (a) Equipment and devices used to perform single car air brake tests shall be tested for correct operation at...

  7. SOM neural network fault diagnosis method of polymerization kettle equipment optimized by improved PSO algorithm.

    Science.gov (United States)

    Wang, Jie-sheng; Li, Shu-xia; Gao, Jie

    2014-01-01

    For meeting the real-time fault diagnosis and the optimization monitoring requirements of the polymerization kettle in the polyvinyl chloride resin (PVC) production process, a fault diagnosis strategy based on the self-organizing map (SOM) neural network is proposed. Firstly, a mapping between the polymerization process data and the fault pattern is established by analyzing the production technology of polymerization kettle equipment. The particle swarm optimization (PSO) algorithm with a new dynamical adjustment method of inertial weights is adopted to optimize the structural parameters of SOM neural network. The fault pattern classification of the polymerization kettle equipment is to realize the nonlinear mapping from symptom set to fault set according to the given symptom set. Finally, the simulation experiments of fault diagnosis are conducted by combining with the industrial on-site historical data of the polymerization kettle and the simulation results show that the proposed PSO-SOM fault diagnosis strategy is effective.

  8. SOM Neural Network Fault Diagnosis Method of Polymerization Kettle Equipment Optimized by Improved PSO Algorithm

    Directory of Open Access Journals (Sweden)

    Jie-sheng Wang

    2014-01-01

    Full Text Available For meeting the real-time fault diagnosis and the optimization monitoring requirements of the polymerization kettle in the polyvinyl chloride resin (PVC production process, a fault diagnosis strategy based on the self-organizing map (SOM neural network is proposed. Firstly, a mapping between the polymerization process data and the fault pattern is established by analyzing the production technology of polymerization kettle equipment. The particle swarm optimization (PSO algorithm with a new dynamical adjustment method of inertial weights is adopted to optimize the structural parameters of SOM neural network. The fault pattern classification of the polymerization kettle equipment is to realize the nonlinear mapping from symptom set to fault set according to the given symptom set. Finally, the simulation experiments of fault diagnosis are conducted by combining with the industrial on-site historical data of the polymerization kettle and the simulation results show that the proposed PSO-SOM fault diagnosis strategy is effective.

  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. Complex Network Analysis for Characterizing Global Value Chains in Equipment Manufacturing.

    Directory of Open Access Journals (Sweden)

    Hao Xiao

    Full Text Available The rise of global value chains (GVCs characterized by the so-called "outsourcing", "fragmentation production", and "trade in tasks" has been considered one of the most important phenomena for the 21st century trade. GVCs also can play a decisive role in trade policy making. However, due to the increasing complexity and sophistication of international production networks, especially in the equipment manufacturing industry, conventional trade statistics and the corresponding trade indicators may give us a distorted picture of trade. This paper applies various network analysis tools to the new GVC accounting system proposed by Koopman et al. (2014 and Wang et al. (2013 in which gross exports can be decomposed into value-added terms through various routes along GVCs. This helps to divide the equipment manufacturing-related GVCs into some sub-networks with clear visualization. The empirical results of this paper significantly improve our understanding of the topology of equipment manufacturing-related GVCs as well as the interdependency of countries in these GVCs that is generally invisible from the traditional trade statistics.

  12. Complex Network Analysis for Characterizing Global Value Chains in Equipment Manufacturing

    Science.gov (United States)

    Meng, Bo; Cheng, Lihong

    2017-01-01

    The rise of global value chains (GVCs) characterized by the so-called “outsourcing”, “fragmentation production”, and “trade in tasks” has been considered one of the most important phenomena for the 21st century trade. GVCs also can play a decisive role in trade policy making. However, due to the increasing complexity and sophistication of international production networks, especially in the equipment manufacturing industry, conventional trade statistics and the corresponding trade indicators may give us a distorted picture of trade. This paper applies various network analysis tools to the new GVC accounting system proposed by Koopman et al. (2014) and Wang et al. (2013) in which gross exports can be decomposed into value-added terms through various routes along GVCs. This helps to divide the equipment manufacturing-related GVCs into some sub-networks with clear visualization. The empirical results of this paper significantly improve our understanding of the topology of equipment manufacturing-related GVCs as well as the interdependency of countries in these GVCs that is generally invisible from the traditional trade statistics. PMID:28081201

  13. Complex Network Analysis for Characterizing Global Value Chains in Equipment Manufacturing.

    Science.gov (United States)

    Xiao, Hao; Sun, Tianyang; Meng, Bo; Cheng, Lihong

    2017-01-01

    The rise of global value chains (GVCs) characterized by the so-called "outsourcing", "fragmentation production", and "trade in tasks" has been considered one of the most important phenomena for the 21st century trade. GVCs also can play a decisive role in trade policy making. However, due to the increasing complexity and sophistication of international production networks, especially in the equipment manufacturing industry, conventional trade statistics and the corresponding trade indicators may give us a distorted picture of trade. This paper applies various network analysis tools to the new GVC accounting system proposed by Koopman et al. (2014) and Wang et al. (2013) in which gross exports can be decomposed into value-added terms through various routes along GVCs. This helps to divide the equipment manufacturing-related GVCs into some sub-networks with clear visualization. The empirical results of this paper significantly improve our understanding of the topology of equipment manufacturing-related GVCs as well as the interdependency of countries in these GVCs that is generally invisible from the traditional trade statistics.

  14. 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.

  15. Performance Evaluation of Bucket based Excavating, Loading and Transport (BELT) Equipment - An OEE Approach

    Science.gov (United States)

    Mohammadi, Mousa; Rai, Piyush; Gupta, Suprakash

    2017-03-01

    Overall Equipment Effectiveness (OEE) has been used since last over two decades as a measure of performance in manufacturing industries. Unfortunately, enough, application of OEE in mining and excavation industry has not been duly adopted. In this paper an effort has been made to identify the OEE for performance evaluation of Bucket based Excavating, Loading and Transport (BELT) equipment. The conceptual model of OEE, as used in the manufacturing industries, has been revised to adapt to the BELT equipment. The revised and adapted model considered the operational time, speed and bucket capacity utilization losses as the key OEE components for evaluating the performance of BELT equipment. To illustrate the efficacy of the devised model on real-time basis, a case study was undertaken on the biggest single bucket excavating equipment - the dragline, in a large surface coal mine. One-year data was collected in order to evaluate the proposed OEE model.

  16. 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.

  17. Performance characterization of night vision equipment based on the triangle orientation discrimination methodology

    NARCIS (Netherlands)

    Laurent, N.; Bijl, P.; Deltel, G.

    2015-01-01

    Night vision equipment is crucial in order to accomplish supremacy and safety of the troops on the battlefield. Evidently, system integrators, ministry of defenses and end-users need access to reliable quantitative characterization of the expected field performance when using night vision equipment.

  18. Performance characterization of night vision equipment based on Triangle Orientation Discrimination (TOD) methodology

    NARCIS (Netherlands)

    Laurent, N.; Lejard, C.; Deltel, G.; Bijl, P.

    2013-01-01

    Night vision equipment is crucial in order to accomplish supremacy and safety of the troops on the battlefield. Evidently, system integrators, MODs and end-users need access to reliable quantitative characterization of the expected field performance when using night vision equipment. The Image

  19. Root cause analysis underscores the importance of understanding, addressing, and communicating cold chain equipment failures to improve equipment performance.

    Science.gov (United States)

    Lennon, Pat; Atuhaire, Brian; Yavari, Shahrzad; Sampath, Vidya; Mvundura, Mercy; Ramanathan, Nithya; Robertson, Joanie

    2017-04-19

    Vaccine cold chain equipment (CCE) in developing countries is often exposed to harsh environmental conditions, such as extreme temperatures and humidity, and is subject to many additional challenges, including intermittent power supply, insufficient maintenance capacity, and a scarcity of replacement parts. Together, these challenges lead to high failure rates for refrigerators, potentially damaging vaccines and adversely affecting immunization coverage. Providing a sustainable solution for improving CCE performance requires an understanding of the root causes of failure. Project teams conducted small-scale studies to determine the root causes of CCE failure in selected locations in Uganda and Mozambique. The evaluations covered 59 failed refrigerators and freezers in Uganda and 27 refrigerators in Mozambique. In Uganda, the vast majority of failures were due to a cooling unit fault in one widely used refrigerator model. In Mozambique, 11 of the 27 problems were attributable to solar refrigerators with batteries that were unable to hold a charge, and another eight problems were associated with a need to adjust thermostat settings. The studies showed that tracking and evaluation of equipment performance and failure can yield important, actionable information for a range of stakeholders, including local CCE technicians, the ministry of health, equipment manufacturers, and international partners such as the United Nations Children's Fund, World Health Organization, and Gavi, the Vaccine Alliance. Collaborative efforts to systematically collect and communicate data on CCE performance and causes of failure will help to improve the efficiency and reach of immunization programs in low- and middle-income countries. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  20. Optimal positioning of protection and remote control equipment in medium voltage networks; Optimale Positionierung von Schutz- und Fernwirktechnik in Mittelspannungsnetzen

    Energy Technology Data Exchange (ETDEWEB)

    Schroeders, Christian; Moser, Albert [RWTH Aachen Univ. (Germany). IAEW; Lewtschenko, Daniel [RWTH Aachen Univ. (Germany)

    2012-07-01

    Since 2012 the introduced German quality regulation provides an economic incentive for network operators to realize cost-efficient measures that improve supply reliability. The use of protection and remote control devices in medium-voltage stations has rarely been considered as a measure to increase supply reliability. Falling prices for digital control and protection devices enhance the economic competitiveness of these measures against conventional network structure expansion. While many existing computer-based methods approach the optimization of network structure in the medium-voltage level, equipping medium-voltage stations with additional protection and remote control devices is rarely considered. It is the purpose of this paper to present a new computer-based method that optimizes the use of protection and remote control devices in medium-voltage stations considering the quality regulation. The developed method performs an optimization based on a genetic algorithm and is applicable to all typical medium-voltage network structures. A case study illustrates the operational capability of the developed method with an urban medium-voltage network. (orig.)

  1. A Study on the Fluid Mechanics Performance of Aquatics Equipment

    Directory of Open Access Journals (Sweden)

    Jiao Jian

    2015-01-01

    Based on the theoretical foundation of fluid mechanics performance, this paper carries out an analysis on mechanical characteristics of aquatic sports. First, basic features of windsurfing are studied in this paper. Performance of windsurfing changes with its parameters, requiring a lot for windsurfers. It can be known from variance analysis that the best performance of NP plate and a relatively small resistance should be the direction of sail-board design. Meanwhile, by building up a mathematical model with fuzzy comprehensive evaluation and correlation analysis, it can be also found that the fluid resistance characteristic is a key factor that influences the performance of windsurfers. Besides, this paper also takes into account external factors, including the influences of regional difference on aquatic events. Different regions with various geographical conditions have different influences on aquatic events.

  2. 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.

  3. The improvement of maintenance service for traction networks equipment on the base of process approach

    Directory of Open Access Journals (Sweden)

    D. V. Mironov

    2014-12-01

    Full Text Available Purpose. The new methods development for improving the maintenance service for equipment of traction networks in order to increase its efficiency and quality. Methodology. In world practice of solving problems related to the quality of products and services is usually achieved by introducing quality management system in to the enterprises. The provisions of quality management system were used for solving the problem. The technologies of process engineering were used for describing the main stages of maintenance service. Findings. The development of high-speed movement and growth of its intensity, the use of electric rolling stock of a new generation require the introduction of new methods diagnostics of equipment technical state and improvement of the existing maintenance system and repair of power supply. Developing a model of business-processes, their optimization with using techniques of process engineering and system management is needed for the transition to the management system based on the process approach. From the standpoint of the process approach and in accordance with the requirements of the quality management system (ISO 9001-2009, the operation of the E (Department of electrification and power supply infrastructure sector is represented as a scheme of business-processes in which the guaranteed supply with electricity of railway and third-party consumers is defined as the main business-process of management. Each of the sub-process of power supply for consumers is described in details. The use methods and main stages of process approach for sample management system reorganization were investigated. The methodology and the application method of PDCA (Plan-Do-Check-Act closed loop to the equipment maintenance system were described. The monitoring process of traction networks maintenance using the process approach was divided into components after investigations. The technical documentation of maintenance service was investigated in

  4. A Decision Support System For Equipment Allocation In A Telemedicine Referral Network

    Directory of Open Access Journals (Sweden)

    Treurnicht, Maria J.

    2014-05-01

    Full Text Available Telemedicine applications have had much success in strengthening health systems worldwide. Unfortunately, many systems are implemented without decisions based on proper needs assessments. In South Africa, this technology push approach has led to a large amount of equipment standing dormant. It is proposed that the potential of telemedicine be measured prior to implementation, thus pulling the technology towards a clinical need. A decision support system is developed that uses health informatics and computational intelligence to determine the need for telemedicine and to allocate equipment in a network of facilities to achieve the best cost benefit. The system facilitates the collection and storage of electronic health record (EHR data in a data warehouse. A linear programming model is used with a genetic algorithm. The system was developed and tested for the South African public health sector, using data from 27 hospitals in the Western Cape Province. Results have shown that if telemedicine workstations with specific peripheral equipment, as determined by the algorithm, were implemented in the given period, an estimated R8.7 million in referral costs could have been saved for the 27 hospitals. Thus the case study provided evidence for the benefits of implementation in the chosen network of hospitals. This new application of health informatics could provide telemedicine management with a useful tool for making implementation decisions based on evidence. Future work would include the development of similar systems for other markets.

  5. 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.

  6. 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.

  7. 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 ...

  8. Estimation of Visual Maps with a Robot Network Equipped with Vision Sensors

    Directory of Open Access Journals (Sweden)

    Arturo Gil

    2010-05-01

    Full Text Available In this paper we present an approach to the Simultaneous Localization and Mapping (SLAM problem using a team of autonomous vehicles equipped with vision sensors. The SLAM problem considers the case in which a mobile robot is equipped with a particular sensor, moves along the environment, obtains measurements with its sensors and uses them to construct a model of the space where it evolves. In this paper we focus on the case where several robots, each equipped with its own sensor, are distributed in a network and view the space from different vantage points. In particular, each robot is equipped with a stereo camera that allow the robots to extract visual landmarks and obtain relative measurements to them. We propose an algorithm that uses the measurements obtained by the robots to build a single accurate map of the environment. The map is represented by the three-dimensional position of the visual landmarks. In addition, we consider that each landmark is accompanied by a visual descriptor that encodes its visual appearance. The solution is based on a Rao-Blackwellized particle filter that estimates the paths of the robots and the position of the visual landmarks. The validity of our proposal is demonstrated by means of experiments with a team of real robots in a office-like indoor environment.

  9. Sporting Equipment and Students' Academic Performance in the ...

    African Journals Online (AJOL)

    Administrator

    students academic performance in the concept of projectile in. Nigerian senior ... To arouse the students' interest in the subject, Physics should be ..... Influence of feedback at the item level. Educational and. Psychological Measurement, 43, 106 – 107. Uche, S. C. & Umoren, G. U. (1998). Integrated science teaching: ...

  10. 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.

  11. 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.

  12. Node localization algorithm of wireless sensor network for large electrical equipment monitoring application

    DEFF Research Database (Denmark)

    Chen, Qinyin; Hu, Y.; Chen, Zhe

    2016-01-01

    Node localization technology is an important technology for the Wireless Sensor Networks (WSNs) applications. An improved 3D node localization algorithm is proposed in this paper, which is based on a Multi-dimensional Scaling (MDS) node localization algorithm for large electrical equipment...... monitoring applications. The proposed algorithm utilizes the relative information of anchor nodes to calculate the distance of two nodes with two hops in a non-line of sight (NLOS) condition. This proposed algorithm improves the positioning accuracy and reduces the effect of the measurement error, which...

  13. 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)

  14. 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...

  15. Performance characterization of night vision equipment based on triangle orientation discrimination (TOD) methodology

    Science.gov (United States)

    Laurent, N.; Lejard, C.; Deltel, G.; Bijl, P.

    2013-06-01

    Night vision equipment is crucial in order to accomplish supremacy and safety of the troops on the battlefield. Evidently, system integrators, MODs and end-users need access to reliable quantitative characterization of the expected field performance when using night vision equipment. The Image Intensifier tube is one of the most important engines driving the performance for night vision equipment. As a major tube manufacturer, PHOTONIS has investigated the link between its products physical design parameters and the actual end-user field performance. The developments include 1) an end-to-end performance measurement method and test facility, 2) an image-based night vision simulation and 3) a range estimation model. The purpose is twofold: i) being able to support the need of the integrators and end users, and ii) further systematic improvement of night vision equipment design. For the end-to-end test, PHOTONIS and TNO cooperated in the implementation of the TOD (Triangle Orientation Discrimination) test for night vision equipment. This test provides a clear and rigorous ranking of the products with respect to their target acquisition performance level. With respect to the image-based simulation, PHOTONIS performs physical and performance comparisons between artificial and real imagery, promising exciting further development of a model based on the merging of the different approaches of night vision evaluation and modelling. In this paper, we present the PHOTONIS night vision test laboratory, provide TOD results for a set of night vision devices and show range prediction examples.

  16. 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.

  17. 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.

  18. Analysis of harmonics in the power supply networks of electric welding equipment of alternating voltage

    Directory of Open Access Journals (Sweden)

    Василь Ількович Гудим

    2015-11-01

    Full Text Available Electric arc welding is widely used in construction and engineering for rigid connections of metal elements. Substantial nonlinearity of dynamic voltage-current characteristics of electric arcs in such equipment is a source of distortion in current and voltage sinusoids at the points of other electric receivers parallel joints. The voltage fluctuations from the nominal value result in changing luminous flux of bulbs, while current higher harmonics result in additional losses in electric motors. However, the problem of electric welding equipment influence on power lines wasn’t paid proper attention to. Therefore, this work is to research electric arc equipment influence on power lines in order to find out the values and the spectrum of higher harmonics, and the prevailing amplitudes dynamics of change. In this paper the results of experimental researches of harmonics spectrum in electrical circuits of electric arc welding machine of alternating voltage that it generates during the technological process and the main energy parameters, that influence negatively on the power supply networks of 0,4/0,23 kV. Analyzing the results of the measurements we come to the conclusion that if the load factor is about 35% the power coefficient of the welding machine is 0,46, that is rather low. Such a result is economically disadvantageous since high reactive power results in a significant increase of active power losses in the elements of power supply. That’s why reactive power compensation as well as higher harmonics filtration are necessitated

  19. Operational Risk Assessment of Distribution Network Equipment Based on Rough Set and D-S Evidence Theory

    Directory of Open Access Journals (Sweden)

    Cunbin Li

    2013-01-01

    Full Text Available With the increasing complication, compaction, and automation of distribution network equipment, a small failure will cause an outbreak chain reaction and lead to operational risk in the power distribution system, even in the whole power system. Therefore, scientific assessment of power distribution equipment operation risk is significant to the security of power distribution system. In order to get the satisfactory assessment conclusions from the complete and incomplete information and improve the assessment level, an operational risk assessment model of distribution network equipment based on rough set and D-S evidence theory was built. In this model, the rough set theory was used to simplify and optimize the operation risk assessment indexes of distribution network equipment and the evidence D-S theory was adopted to combine the optimal indexes. At last, the equipment operational risk level was obtained from the basic probability distribution decision. Taking the transformer as an example, this paper compared the assessment result obtained from the method proposed in this paper with that from the ordinary Rogers ratio method and discussed the application of the proposed method. It proved that the method proposed in this paper is feasible, efficient, and provides a new way to assess the distribution network equipment operational risk.

  20. High Precision Testbed to Evaluate Ethernet Performance for In-Car Networks

    DEFF Research Database (Denmark)

    Revsbech, Kasper; Madsen, Tatiana Kozlova; Schiøler, Henrik

    2012-01-01

    Validating safety-critical real-time systems such as in-car networks often involves a model-based performance analysis of the network. An important issue performing such analysis is to provide precise model parameters, matching the actual equipment. One way to obtain such parameters is to derive...... them by measurements of the equipment. In this work we describe the design of a testbed enabling active measurements on up to 1 [Gb=Sec] Copper based Ethernet Switches. By use of the testbed it self, we conduct a series of tests where the precision of the testbed is estimated. We find a maximum error...

  1. Comparison of approaches to weighting of multiple criteria for selecting equipment to optimize performance and safety.

    Science.gov (United States)

    Agarski, Boris; Hadzistevic, Miodrag; Budak, Igor; Moraca, Slobodan; Vukelic, Djordje

    2017-12-08

    Nowadays every piece of working equipment and tools has to comply with safety standards and laws. This study investigated multi-criteria methods for selecting working equipment in order to optimize performance and occupational safety. The multi-criteria decision-making (MDCM) method was applied to the problem of selecting optimal working equipment using four different criterion weighting approaches (direct weighting, revised Simos procedure, Fuller's triangle and analytic hierarchy process). Groups of economic, technical and safety criteria were defined and five weighting scenarios were developed. Although the four weighting methods produced similar results, in some situations they produced different criterion weighting factors. The final output of the MCDM method was the identification of the optimal forklift in the five weighting scenarios. Although we have applied the MCDM method to a forklift selection problem, it can be applied to all sorts of working equipment in contexts where economic, technical and safety selection criteria can be identified.

  2. 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...

  3. 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.

  4. Analysis of performance reliability of electrical and electronic equipment of car-tractor

    Directory of Open Access Journals (Sweden)

    Kravchenko О.Р.

    2016-08-01

    Full Text Available The analysis of the operational reliability of electrical and electronic equipment of vehicles, trucks Mercedes-Benz Actros 1844 LS and Volvo FH 1242, conducting international cargo transportation is performed. It is established that the equipment is reliable, which meets modern requirements, but where there is a violation of the resolution. The reason for repair work is constructive and operational factors. Distribution of efficiency and overall performance of operational reliability is retrieved. Items with more bounce are found. Common factors of violation of efficiency cars, trucks in operation, are largely different stages in warranty runs are obtained.

  5. The prediction of the residual life of electromechanical equipment based on the artificial neural network

    Science.gov (United States)

    Zhukovskiy, Yu L.; Korolev, N. A.; Babanova, I. S.; Boikov, A. V.

    2017-10-01

    This article is devoted to the prediction of the residual life based on an estimate of the technical state of the induction motor. The proposed system allows to increase the accuracy and completeness of diagnostics by using an artificial neural network (ANN), and also identify and predict faulty states of an electrical equipment in dynamics. The results of the proposed system for estimation the technical condition are probability technical state diagrams and a quantitative evaluation of the residual life, taking into account electrical, vibrational, indirect parameters and detected defects. Based on the evaluation of the technical condition and the prediction of the residual life, a decision is made to change the control of the operating and maintenance modes of the electric motors.

  6. 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

  7. 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

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

    Science.gov (United States)

    Yelles, Abdelkarim; Allili, Toufik; Alili, Azouaou

    2013-04-01

    Seismic monitoring in Algeria has seen a great change after the Boumerdes earthquake of May 21st, 2003. Indeed the installation of a New Digital seismic network (ADSN) upgrade drastically the previous analog telemetry network. During the last four years, the number of stations in operation has greatly increased to 66 stations with 15 Broad Band, 02 Very Broad band, 47 Short period and 21 accelerometers connected in real time using various mode of transmission ( VSAT, ADSL, GSM, ...) and managed by Antelope software. The spatial distribution of these stations covers most of northern Algeria from east to west. Since the operation of the network, significant number of local, regional and tele-seismic events was located by the automatic processing, revised and archived in databases. This new set of data is characterized by the accuracy of the automatic location of local seismicity and the ability to determine its focal mechanisms. Periodically, data recorded including earthquakes, calibration pulse and cultural noise are checked using PSD (Power Spectral Density) analysis to determine the noise level. ADSN Broadband stations data quality is controlled in quasi real time using the "PQLX" software by computing PDFs and PSDs of the recordings. Some other tools and programs allow the monitoring and the maintenance of the entire electronic system for example to check the power state of the system, the mass position of the sensors and the environment conditions (Temperature, Humidity, Air Pressure) inside the vaults. The new design of the network allows management of many aspects of real time seismology: seismic monitoring, rapid determination of earthquake, message alert, moment tensor estimation, seismic source determination, shakemaps calculation, etc. The international standards permit to contribute in regional seismic monitoring and the Mediterranean warning system. The next two years with the acquisition of new seismic equipment to reach 50 new BB stations led to

  9. 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%.

  10. Performance of on-site Medical waste disinfection equipment in hospitals of Tabriz, Iran

    Directory of Open Access Journals (Sweden)

    Hassan Taghipour

    2016-10-01

    Full Text Available Background: The number of studies available on the performance of on-site medical waste treatment facilities is rare, to date. The aim of this study was to evaluate the performance of onsite medical waste treatment equipment in hospitals of Tabriz, Iran. Methods: A various range of the on-site medical waste disinfection equipment (autoclave, chemical disinfection, hydroclave, and dry thermal treatment was considered to select 10 out of 22 hospitals in Tabriz to be included in the survey. The apparatus were monitored mechanically, chemically, and biologically for a six months period in all of the selected hospitals. Results: The results of the chemical monitoring (Bowie-Dick tests indicated that 38.9% of the inspected autoclaves had operational problems in pre-vacuum, air leaks, inadequate steam penetration into the waste, and/or vacuum pump. The biological indicators revealed that about 55.55% of the samples were positive. The most of applied devices were not suitable for treating anatomical, pharmaceutical, cytotoxic, and chemical waste. Conclusion: Although on-site medical waste treating facilities have been installed in all the hospitals, the most of infectious-hazardous medical waste generated in the hospitals were deposited into a municipal solid waste landfill, without enough disinfection. The responsible authorities should stringently inspect and evaluate the operation of on-site medical waste treating equipment. An advanced off-site central facility with multi-treatment and disinfection equipment and enough capacity is recommended as an alternative.

  11. 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

  12. OPERATIONAL FACTORS AFFECTING THE PERFORMANCE OF CONTINUOUS MONITORING SYSTEM OF TRANSFORMER EQUIPMENT INSULATION

    Directory of Open Access Journals (Sweden)

    A. G. Spitsa

    2013-07-01

    Full Text Available To ensure the required level of high voltage electrical networks reliability, special attention should be paid to the equipment technical condition monitoring and diagnosis. The periodic monitoring can only reduce the probability of device damaging. The time period between the insulation defect appearance and the device damage can be considerably less than the time interval between measurements recommended by the Testing norms and recommendations for each type of equipment. This demonstrates the lack of effectiveness of the systems of technical diagnostics and large time interval between tests. Continuous monitoring systems are free from these disadvantages. The article covers the results of the insulation continuous monitoring of current transformers and bushings at substation 330 kV «Dnipro-Donbass» Dnieper Power System. Operational factors affecting the reliability of the results are considered, and detailed analysis of errors caused by isolating transformers is given. The article describes methods and recommendations elaborated for mitigation of operational factors impact on the insulation continuous monitoring system. It should be noted that systems of continuous monitoring of transformer equipment under operating voltage are relatively new. Their implementation at the power facilities is at the initial stage. As a result, there is no reliable information on such systems operating experience. Therefore, the investigations covered by this article can be of practical value for both continuous monitoring system developers and operating personnel.

  13. How the reverse supply chain impacts the financial performance of original equipment manufacturers

    OpenAIRE

    Larsen, Samuel; Jacobsen, Peter

    2017-01-01

    This thesis examines the financial impact of a firm’s reverse supply chain (RSC). Specifically, the thesis examines the two questions of how the RSC can contribute to the financial performance of the firm and which factors are decisive for the RSC’s financial contribution. The thesis focuses on original equipment manufacturers. The thesis results show that the RSC can contribute to the financial performance of the firm in more than 20 different ways, which the thesis defines as functions of t...

  14. Analysis of the performance of the SPS extraction channel equipment in 1997

    CERN Document Server

    Balhan, B; CERN. Geneva. SPS and LEP Division

    1998-01-01

    In 1997 the SPS ran with high proton intensities (peak above 4.8x1013 protons per pulse) at 450 GeV/c, essential for the neutrino physics program. The SPS also provided lepton beams at 22 GeV for injection into LEP. The equipment used to extract the proton beams is generally very sensitive to the set-up and state of both the SPS machine and the hardware itself; this note contains an analysis of the performance of this extraction equipment in 1997. We describe the modifications to the hardware installations made during the 1996-1997 shutdown, the problems encountered in operation in 1997, the measurements and investigations undertaken, and the conclusions reached. Recommendations are made concerning changes to the hardware installations and operation.

  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. Intubation performance using different laryngoscopes while wearing chemical protective equipment: a manikin study

    Science.gov (United States)

    Schröder, H; Zoremba, N; Rossaint, R; Deusser, K; Stoppe, C; Coburn, M; Rieg, A; Schälte, G

    2016-01-01

    Objectives This study aimed to compare visualisation of the vocal cords and performance of intubation by anaesthetists using four different laryngoscopes while wearing full chemical protective equipment. Setting Medical simulation center of a university hospital, department of anaesthesiology. Participants 42 anaesthetists (15 females and 27 males) completed the trial. The participants were grouped according to their professional education as anaesthesiology residents with experience of 5 years. Interventions In a manikin scenario, participants performed endotracheal intubations with four different direct and indirect laryngoscopes (Macintosh (MAC), Airtraq (ATQ), Glidescope (GLS) and AP Advance (APA)), while wearing chemical protective gear, including a body suit, rubber gloves, a fire helmet and breathing apparatus. Primary and secondary outcome measures With respect to the manikin, setting time to complete ‘endotracheal intubation’ was defined as primary end point. Glottis visualisation (according to the Cormack-Lehane score (CLS) and impairments caused by the protective equipment, were defined as secondary outcome measures. Results The times to tracheal intubation were calculated using the MAC (31.4 s; 95% CI 26.6 to 36.8), ATQ (37.1 s; 95% CI 28.3 to 45.9), GLS (35.4 s; 95% CI 28.7 to 42.1) and APA (23.6 s; 95% CI 19.1 to 28.1), respectively. Intubation with the APA was significantly faster than with all the other devices examined among the total study population (pvisualisation of the vocal cords was reported for the APA compared with the GLS. Conclusions Despite the restrictions caused by the equipment, the anaesthetists intubated the manikin successfully within adequate time. The APA outperformed the other devices in the time to intubation, and it has been evaluated as an easily manageable device for anaesthetists with varying degrees of experience (low to high), providing good visualisation in scenarios that require the use of chemical

  17. 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.

  18. Network effects in the operation of electrical equipment; Efectos de la red en la operacion del equipo electrico

    Energy Technology Data Exchange (ETDEWEB)

    Garcia T, Arturo; Rosales S, Inocente; Garcia P, Job; Ruiz F, L. Ivan; Robles P, Edgar [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2005-07-01

    In the nineties, the Instituto de Investigaciones Electricas (IIE) Electrical Equipment Management (GEE) was restricted to make the diagnosis of generators, transformers, switch boards and cables, without considering the global operating conditions. With the experience acquired in different services it was verified that, inclusively when this equipment is correctly designed, it can be subjected to unfavorable operative conditions, which causes an accelerated deterioration to the degree of producing a fault. In agreement with this, the GEE settled down new line of development named Analysis of the network effect on the electrical equipment, that analyzes the behavior of the equipment originated by work abnormal causes, including the network configuration effect. [Spanish] En la decada de los noventa, la Gerencia de Equipos Electricos (GEE) del IIE se limitaba a realizar el diagnostico de generadores, transformadores, tableros de distribucion y cables, sin considerar las condiciones globales de operacion. Con la experiencia adquirida en diferentes servicios se comprobo que, inclusive cuando estos equipos esten correctamente disenados, pueden verse sometidos a condiciones de operacion desfavorables, lo que ocasiona un deterioro acelerado al grado de producir una falla. De acuerdo con esto, la GEE establecio una nueva linea de desarrollo de nominada Analisis del efecto de la red en los equipos electricos, que analiza el comportamiento de los equipos originado por causas anormales de trabajo, incluido el efecto de la configuracion de la red.

  19. MONITORING OF THE PERFORMANCE EFFICIENCY OF THE EQUIPMENT AT THE ENTERPRISES OF AVIATION INSTRUMENTATION

    Directory of Open Access Journals (Sweden)

    Petr P. Dobrov

    2016-01-01

    Full Text Available The article elaborates the proposals to improve the systems for monitoring performance of the equipment at the enterprises of aviation instrument. The relevance of the study due to the fact that the aviation instrument-making industry of the Russian Federation can play a role as a key factor in enhancing the competitiveness of the national economy. Currently, the global aviation market is fairly saturated, it competition is not between individual companies and between the aviation powers. The role of an efficient industrial production is largely dependent on the amount, structure, technical condition and the level of utilization of fixed assets. Specificity of high-tech high-tech production presupposes the existence of a specific fleet of expensive and unique equipment; a high degree of novelty products, single or small-scale type of production that determines the high cost of production of a unit of production; high demands on the staff . The paper noted that the production capacity is an essential tool for production planning process, which allows to determine the optimal work shifts Park main technological equipment and production program to justify the enterprises of sphere of aviation instrument. On the basis of the modification of OEE method, a stochastic model is proposed, which allows to display the efficiency of the productive capacity of the high-tech enterprises of sphere of aviation instrument in the form of multi-dimensional size and much more accurately identify the relationship between its elements.

  20. 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 ...

  1. 75 FR 49870 - Effects on Broadband Communications Networks of Damage to or Failure of Network Equipment or...

    Science.gov (United States)

    2010-08-16

    ... Equipment or Severe Overload AGENCY: Federal Communications Commission ACTION: Proposed rule; extension of... information on the notice process, see the SUPPLEMENTARY INFORMATION section of this document. FOR FURTHER INFORMATION CONTACT: Jeffery Goldthorp, Chief, Communications Systems Analysis Division, Public Safety and...

  2. 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...

  3. 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.

  4. 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...

  5. The effect of plant aging on equipment qualification and human performance issues related to license renewal

    Energy Technology Data Exchange (ETDEWEB)

    Gunther, W.E.; Higgins, J.C. [Brookhaven National Lab., Upton, NY (United States); Aggarwal, S.K. [Nuclear Regulatory Commission, Washington, DC (United States)

    1991-12-31

    The aging of nuclear power plants is one of the most important issues facing the nuclear industry worldwide. Aging encompasses as forms of degradation to nuclear power plant components, systems, and structures that result from exposure to environmental conditions or from operational stresses. Both the degradation from aging and actions taken to address the aging, such as increased maintenance and testing, can significantly impact human performance in the plant. Research into the causes and effects of aging as obtained through the assessment of operating experience and testing have raised questions regarding the adequacy of existing industry standards for addressing the concerns raised by this research. This paper discusses these issues, with particular emphasis in the area of equipment qualification and human performance.

  6. The effect of plant aging on equipment qualification and human performance issues related to license renewal

    Energy Technology Data Exchange (ETDEWEB)

    Gunther, W.E.; Higgins, J.C. (Brookhaven National Lab., Upton, NY (United States)); Aggarwal, S.K. (Nuclear Regulatory Commission, Washington, DC (United States))

    1991-01-01

    The aging of nuclear power plants is one of the most important issues facing the nuclear industry worldwide. Aging encompasses as forms of degradation to nuclear power plant components, systems, and structures that result from exposure to environmental conditions or from operational stresses. Both the degradation from aging and actions taken to address the aging, such as increased maintenance and testing, can significantly impact human performance in the plant. Research into the causes and effects of aging as obtained through the assessment of operating experience and testing have raised questions regarding the adequacy of existing industry standards for addressing the concerns raised by this research. This paper discusses these issues, with particular emphasis in the area of equipment qualification and human performance.

  7. Understanding the Dehumidification Performance of Air-Conditioning Equipment at Part-Load Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Don B. Shirey III; Hugh I. Henderson Jr; Richard A. Raustad

    2006-01-01

    Air conditioner cooling coils typically provide both sensible cooling and moisture removal. Data from a limited number of field studies (Khattar et al. 1985; Henderson and Rengarajan 1996; Henderson 1998) have demonstrated that the moisture removal capacity of a cooling coil degrades at part-load conditions--especially when the supply fan operates continuously while the cooling coil cycles on and off. Degradation occurs because moisture that condenses on the coil surfaces during the cooling cycle evaporates back into air stream when the coil is off. This degradation affects the ability of cooling equipment to maintain proper indoor humidity levels and may negatively impact indoor air quality. This report summarizes the results of a comprehensive project to better understand and quantify the moisture removal (dehumidification) performance of cooling coils at part-load conditions. A review of the open literature was initially conducted to learn from previous research on this topic. Detailed performance measurements were then collected for eight cooling coils in a controlled laboratory setting to understand the impact of coil geometry and operating conditions on transient moisture condensation and evaporation by the coils. Measurements of cooling coil dehumidification performance and space humidity levels were also collected at seven field test sites. Finally, an existing engineering model to predict dehumidification performance degradation for single-stage cooling equipment at part-load conditions (Henderson and Rengarajan 1996) was enhanced to include a broader range of fan control strategies and an improved theoretical basis for modeling off-cycle moisture evaporation from cooling coils. The improved model was validated with the laboratory measurements, and this report provides guidance for users regarding proper model inputs. The model is suitable for use in computerized calculation procedures such as hourly or sub-hourly building energy simulation programs (e

  8. 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.

  9. 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)

  10. 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

  11. Improving SCTP Performance by Jitter-Based Congestion Control over Wired-Wireless Networks

    Directory of Open Access Journals (Sweden)

    Chen Jyh-Ming

    2011-01-01

    Full Text Available With the advances of wireless communication technologies, wireless networks gradually become the most adopted communication networks in the new generation Internet. Computing devices and mobile devices may be equipped with multiple wired and/or wireless network interfaces. Stream Control Transmission Protocol (SCTP has been proposed for reliable data transport and its multihoming feature makes use of network interfaces effectively to improve performance and reliability. However, like TCP, SCTP suffers unnecessary performance degradation over wired-wireless heterogeneous networks. The main reason is that the original congestion control scheme of SCTP cannot differentiate loss events so that SCTP reduces the congestion window inappropriately. In order to solve this problem and improve performance, we propose a jitter-based congestion control scheme with end-to-end semantics over wired-wireless networks. Besides, we solved ineffective jitter ratio problem which may cause original jitter-based congestion control scheme to misjudge congestion loss as wireless loss. Available bandwidth estimation scheme will be integrated into our congestion control mechanism to make the bottleneck more stabilized. Simulation experiments reveal that our scheme (JSCTP gives prominence to improve performance effectively over wired-wireless networks.

  12. 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.

  13. 75 FR 26180 - Effects on Broadband Communications Networks of Damage To or Failure of Network Equipment or...

    Science.gov (United States)

    2010-05-11

    ... networks for voice, video, data, and other communications services, the reliability and survivability of... rely on broadband communications networks to supply voice, video, and data service to fixed and mobile... survivability to three broad classes of harm: (1) Physical damage (whether due to malevolent acts, accidents, or...

  14. 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.

  15. 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

  16. 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...

  17. 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....

  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. New networks of technological creation in energy industries: reassessment of the roles of equipment suppliers and operators

    Energy Technology Data Exchange (ETDEWEB)

    Jacquier-Roux, V. [Institut de Recherche Economique sur la Production et le Developpement -IREPD, Universite Pierre Mendes-France, 38 - Grenoble (France); Bourgeois, B. [Institut d' Economie et de Politique de l' Energie - IEPE-CNRS/ Universite Pierre Mendes-France, 38 - Grenoble (France)

    2002-12-01

    Within a financial context of selection inducing either a decrease or a drop of their home research and development expenditures, energy industries companies have succeeded to maintain and even to increase their knowledge production during the last 15 years (1985 - 1998). To understand these apparently paradoxical changes, elements of analysis are looked for within an evolutionary framework, and more specially referring to the related developments to network-firms, user-supplier relationship, and interactive nature of innovation processes. Empirical data are set on granted patents to a sample of the top 15 world largest companies on both sides of operators and equipment suppliers, and for the two industries of oil production and power generation. Interpretation of the results suggests that two dynamics ought to be distinguished. On one side, dynamics of the networks of technological creation is characterized by an upstream going-up of the head of the network towards suppliers. On the other side networks of creation of competitive advantages and bargaining power continues to be based on the operators and their strategies of adaptation to the constraints and opportunities of their institutional, financial and competitive environment. (author)

  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. 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).

  3. Employing RFID for an Equipment Management System via Wireless Sensor Network

    OpenAIRE

    Jui-Ho Chen; Wen-Tsai Sung; Hsi-Chun Wang

    2014-01-01

    This paper is mainly in combination with RFID to construct a set of power system equipment remote control, used first on the reader tags received after the use of Visual Basic in order to determine the signal and then transmits the signal via the RS232 cable to control circuit 8051 to control the instrument power switch. The topic is written in the Visual Basic RFID and uses features, such as personnel control systems, and access control systems, which are derived from the time of access cont...

  4. 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

  5. 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

  6. 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

  7. Performance Analysis of a Solar Dryer Equipped with a Recycling Air System and Desiccant Chamber

    Directory of Open Access Journals (Sweden)

    M.H Aghkhani

    2013-09-01

    Full Text Available Drying is a high energy consuming process. Solar drying is one of the most popular methods for dehydration of agricultural products. In the present study, the performance of a forced convection solar dryer equipped with recycling air system and desiccant chamber was investigated. The solar dryer is comprised of solar collector, drying chamber, silica jell desiccant chamber, air ducts, fan and measuring and controlling system. Drying rate and energy consumption in three levels of air temperature (40, 45 and 50 oC and two modes of drying (with recycling air and no-recycling with open duct system were measured and compared. The results showed that increasing the drying air temperature decreased the drying time and increased the energy consumption in the mode of non-recycling air system. The dryer efficiency and drying rate were better in the mode of recycling air system than open duct system. The highest dryer efficiency was obtained from drying air temperature of 50 oC and the mode of recycling air system. In general, the efficiency of solar collector and the highest efficiency of the dryer were 0.34 and 0.41, respectively.

  8. Equipment and operator training denote manual ventilation performance in neonatal resuscitation.

    Science.gov (United States)

    Roehr, Charles C; Kelm, Marcus; Proquitté, Hans; Schmalisch, Gerd

    2010-10-01

    High peak inspiratory pressure (PIP) and tidal volume (V(T)) from manual ventilation are hazardous to the neonatal lung. We investigated the influence of operator training on the extent of applied PIP and V(T) between two manual ventilation devices. We performed a prospective, crossover study of 84 medical professionals using a neonatal mannequin. Participants were classified into four groups, according to experience in neonatal resuscitation and previous training in manual ventilation. Provision of PIP, V(T), and inspiratory time (Ti) were compared between groups and equipment used, either a self-inflating bag (SI-bag) or a T-piece resuscitator (Neopuff). Using SI-bags, operator training significantly affected provision of PIP ( P piece device, PIP and V(T) provision was independent of operator training ( P = 0.55 and P = 0.66, respectively). Twenty-five participants (30%) had previous experience with T-piece devices; this correlated significantly with lower PIP and lower V(T) provision ( P > 0.001 for PIP and V(T)). Operator training level and device-specific experience had a significant impact on PIP and V(T) provision when using SI-bags for manual ventilation. For operators with no specific training in manual ventilation, use of T-piece devices is advised to control for excessive PIP and V(T) application. © Thieme Medical Publishers.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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...

  15. 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.

  16. 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.

  17. Performance management in the internal supply chain of an industry of equipment for refrigeration

    Directory of Open Access Journals (Sweden)

    Emílio Della Bruna Junior

    2013-05-01

    Full Text Available Supply chains are complex, conflicting and uncertain management environments, where the best alternatives are usually not previously know, they need to be built based on the managers objectives. For this reason, its decision-makers have been looking for management tools that expand their understanding in order to identify which objectives best represent their values regarding the decision context. With this in mind, this paper aims to develop a Performance Evaluation Model for the operations of the internal supply chain of an organization of the refrigeration equipment sector. The study adopts a mixture of qualitative and quantitative approaches and applies them through a case study. The data collection was conducted through unstructured interviews with the decision-maker as well as specialists appointed by him and supplemented by documentary research. The applied intervention instrument is the Multricriteria Decision Aid – Constructivist (MCDA-C due to its capacity of expanding the knowledge in the decision-maker about the consequences of his decisions on the criteria that he deems critical to the success of the company. One of the results of this research was the identification of the objectives that, according to the decision-maker perception, should drive the alternative definition process, as well as their organization, ordinal and cardinal measurement and integration. In addition, it can be highlighted the current situation diagnosis and elaboration of improvement actions, where the implementation effects of the Lean Philosophy and an Advanced Planning System are evaluated. The main contributions made by the article resides in the proposal of solutions for fulfilling gaps identified within the Supply Chain Performance Evaluation area and in the application of the MCDA-C to a real case.

  18. The performance investigation of a temperature cascaded cogeneration system equipped with adsorption desalination unit

    KAUST Repository

    Myat, Aung

    2013-02-01

    This paper presents the performance investigation of a temperature cascaded cogeneration plant, shortly in TCCP, equipped with an efficient waste heat recovery system. The TCCP or cogeneration system produces four types of useful energy namely (i) electricity, (ii) steam, (iii) cooling, and (iv) dehumidification and distilled water by utilizing single energy source. The TCCP comprises a Capstone C30 micro-turbine that generates nominal capacity of 26 kW of electricity, a compact and efficient waste heat recovery system and a host of waste heatactivated devices namely (i) a steam generator, (ii) an absorption chiller, (iii) an adsorption desalination system, and (iv) a multi-bed desiccant dehumidifier. The analysis is performed under different operation conditions such as heat source temperatures, flow rates of heat transfer fluids and chilled water inlet temperatures. The only single heat source for TCCP is obtained from exhaust gas of micro-turbine and it is channeled to a series of waste heat recovery heat exchangers to steam and hot water at different temperatures. Hot water produced by such a compact heat exchangers is the driving heat source to produce steam of 15 kg/h, cooling of 2 Rton, dehumidification of 2 Rton, and distilled water of 0.7 m3/day. A set of experiments, both part load and full load, of micro-turbine is conducted to examine the electricity generation and the exhaust gas temperature. It is observed that energy utilization factor could achieve as high as 70% while fuel energy saving ratio is found to be 28%. © 2013 Desalination Publications. All rights reserved.

  19. Equipping Network Warfare: Industrial-Era Bureaucracies for Information-Era Weapons

    Science.gov (United States)

    2009-04-01

    to operational shortfalls. Clearly, there are benefits in following known methods in organizing the cyberspace mission and its capabilities...sid26_gci853845,00.html (accessed 15 December 2008). 9 BX.com Terminology Reference, “Web Year,” http://www.bx.com/dictionary/ ecommerce /Web_year.cfm... benefits of the process, while amplifying the negative aspects of the bureaucracy. Network warfare capabilities are much more vulnerable to

  20. Employing RFID for an Equipment Management System via Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Jui-Ho Chen

    2014-01-01

    Full Text Available This paper is mainly in combination with RFID to construct a set of power system equipment remote control, used first on the reader tags received after the use of Visual Basic in order to determine the signal and then transmits the signal via the RS232 cable to control circuit 8051 to control the instrument power switch. The topic is written in the Visual Basic RFID and uses features, such as personnel control systems, and access control systems, which are derived from the time of access control systems, several instrument control systems, and uses records stored in the form of functions, where the other circuit transmits signals to Visual Basic 8051, and then, by 8051, controls the instrument power switch.

  1. 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

  2. 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...

  3. Analysis of embedded CORBA middleware performance on urban distributed transportation equipments

    OpenAIRE

    S. L. Toral; Barrero, Federico; Cortés, Francisco; Gregor Recalde, Derlis

    2013-01-01

    The increasing number of ITS (Intelligent Transportation Systems) equipment spread across cities offers tre- mendous possibilities in the development of distributed smart environments. A middleware layer located be- tween the operating system and the fi nal application can be used for the communication among the equipment to spontaneously act and cooperate among themselves. However, this middleware layer has also a computational cost that should be quanti fi ed as it c...

  4. 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…

  5. 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...

  6. 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

  7. 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...

  8. 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.

  9. 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...

  10. Optimising reverse logistics network to support policy-making in the case of Electrical and Electronic Equipment.

    Science.gov (United States)

    Achillas, Ch; Vlachokostas, Ch; Aidonis, D; Moussiopoulos, N; Iakovou, E; Banias, G

    2010-12-01

    Due to the rapid growth of Waste Electrical and Electronic Equipment (WEEE) volumes, as well as the hazardousness of obsolete electr(on)ic goods, this type of waste is now recognised as a priority stream in the developed countries. Policy-making related to the development of the necessary infrastructure and the coordination of all relevant stakeholders is crucial for the efficient management and viability of individually collected waste. This paper presents a decision support tool for policy-makers and regulators to optimise electr(on)ic products' reverse logistics network. To that effect, a Mixed Integer Linear Programming mathematical model is formulated taking into account existing infrastructure of collection points and recycling facilities. The applicability of the developed model is demonstrated employing a real-world case study for the Region of Central Macedonia, Greece. The paper concludes with presenting relevant obtained managerial insights. Copyright © 2010 Elsevier Ltd. All rights reserved.

  11. 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.

  12. 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

  13. 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...

  14. SCinet Architecture: Featured at the International Conference for High Performance Computing,Networking, Storage and Analysis 2016

    Energy Technology Data Exchange (ETDEWEB)

    Lyonnais, Marc; Smith, Matt; Mace, Kate P.

    2017-02-06

    SCinet is the purpose-built network that operates during the International Conference for High Performance Computing,Networking, Storage and Analysis (Super Computing or SC). Created each year for the conference, SCinet brings to life a high-capacity network that supports applications and experiments that are a hallmark of the SC conference. The network links the convention center to research and commercial networks around the world. This resource serves as a platform for exhibitors to demonstrate the advanced computing resources of their home institutions and elsewhere by supporting a wide variety of applications. Volunteers from academia, government and industry work together to design and deliver the SCinet infrastructure. Industry vendors and carriers donate millions of dollars in equipment and services needed to build and support the local and wide area networks. Planning begins more than a year in advance of each SC conference and culminates in a high intensity installation in the days leading up to the conference. The SCinet architecture for SC16 illustrates a dramatic increase in participation from the vendor community, particularly those that focus on network equipment. Software-Defined Networking (SDN) and Data Center Networking (DCN) are present in nearly all aspects of the design.

  15. 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

  16. Academic Performance of Indigenous Issues- Taking Original Equipment Manufacturer Research as an Example

    Directory of Open Access Journals (Sweden)

    Hong-Jiang Yue

    2017-06-01

    Full Text Available Advocated for the localization of international issues under the voice of meaningful research has become increasingly high, after 30 years of development, original equipment manufacturer (OEM phenomenon as a living localization issues exist. This paper is a systematic review of the bibliometrics, which is a typical indigenous topic, which can be traced to the interpretation of Chinese scholars and its unique performance. The study found: (1 The academic community on the local issues - OEM phenomenon is response, but far from showing a prosperous situation; (2 Intensive units engaged in OEM research mainly concentrated in the Pearl River Delta and the Yangtze River Delta region of several key universities, which is with other research topics throughout the country blossom everywhere in the different characteristics; (3 Collaborative research is the main theme of foundry research, in the middle-aged scholars and young students in the mode of cooperation, the formation of “student first” and “professor second” two common modes of cooperation; (4 OEM research results are distributed in the field of industrial industries, but also covers business management and other economic management areas; (5 OEM research mainly formed a “global value chain” as the center of the macro-level expansion of economic research-oriented trends and “OEM enterprises” as the center of the expansion of business management level of management research-oriented trends; (6 The academic achievements of OEM research more from the English literature to find the theoretical basis for research, independent discovery and construction of the foundry “Chinese theory” is more than the lack of; (7 OEM research, both empirical research and case studies are more deductive way to verify the Western theory, the lack of a paradigm of the development of local unique theoretical contribution; (8 The state and central departments funding is an important research model of OEM

  17. Gender differences in work performance on the Baltimore Therapeutic Equipment work simulator.

    Science.gov (United States)

    Esmail, S; Bhambhani, Y; Brintnell, S

    1995-05-01

    The purposes of this study were to (a) establish biomechanical and physiological normative data for healthy young women performing three tasks on the Baltimore Therapeutic Equipment work simulator (BTE): wheel-turn, push-pull, and overhead-reach; and (b) compare these data with previously reported values for healthy men of a similar age group. Twenty women completed five test sessions: (a) task familiarization on the BTE to determine the work intensity that was perceived as hard on the Borg scale, (b) incremental test on an arm crank ergometer to measure peak oxygen uptake (VO2) and peak heart rate (HR), and (c) one of the three tasks in random order for 4 min during the next three sessions. Physiological responses were monitored with a metabolic cart interfaced with an electrocardiogram. Torque, work, and power during the three tasks were significantly higher (p men than in women. The absolute VO2 (L.min-1) during these tasks was higher in men, but when the VO2 was calculated relative to body weight (ml.kg-1.min-1), no significant (p > .05) gender differences were observed. Computation of energy expenditure relative to body weight and power output (cal.kg-1.W-1) indicated that women expended significantly (p men. No significant (p > .05) gender differences were observed for VO2 and HR when the values were expressed as a percentage of their respective peaks. Findings indicated that (a) the functional work capacity is significantly lower in women than in men, (b) women are less efficient than men when the energy expenditure is expressed per unit of body weight and power output, and (c) the relative physiological stress in men and women is similar under these conditions.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. A review on equipped hospital beds with wireless sensor networks for reducing bedsores.

    Science.gov (United States)

    Ajami, Sima; Khaleghi, Lida

    2015-10-01

    At present, the solutions to prevent bedsore include using various techniques for movement and displacement of patients, which is not possible for some patients or dangerous for some of them while it also poses problems for health care providers. On the other hand, development of information technology in the health care system including application of wireless sensor networks (WSNs) has led to easy and quick service-providing. It can provide a solution to prevent bedsore in motionless and disabled patients. Hence, the aim of this article was first to introduce WSNs in hospital beds and second, to identify the benefits and challenges in implementing this technology. This study was a nonsystematic review. The literature was searched for WSNs to reduce and prevent bedsores with the help of libraries, databases (PubMed, SCOPUS, and EMBASE), and also searches engines available at Google Scholar including during 1974-2014 while the inclusion criteria were applied in English and Persian. In our searches, we employed the following keywords and their combinations: "wireless sensor network," "smart bed," "information technology," "smart mattress," and "bedsore" in the searching areas of titles, keywords, abstracts, and full texts. In this study, more than 45 articles and reports were collected and 37 of them were selected based on their relevance. Therefore, identification and implementation of this technology will be a step toward mechanization of traditional procedures in providing care for hospitalized patients and disabled people. The smart bed and mattress, either alone or in combination with the other technologies, should be capable of providing all of the novel features while still providing the comfort and safety features usually associated with traditional and hospital mattresses. It can eliminate the expense of bedsore in the intensive care unit (ICU) department in the hospital and save much expense there.

  6. A review on equipped hospital beds with wireless sensor networks for reducing bedsores

    Directory of Open Access Journals (Sweden)

    Sima Ajami

    2015-01-01

    Full Text Available At present, the solutions to prevent bedsore include using various techniques for movement and displacement of patients, which is not possible for some patients or dangerous for some of them while it also poses problems for health care providers. On the other hand, development of information technology in the health care system including application of wireless sensor networks (WSNs has led to easy and quick service-providing. It can provide a solution to prevent bedsore in motionless and disabled patients. Hence, the aim of this article was first to introduce WSNs in hospital beds and second, to identify the benefits and challenges in implementing this technology. This study was a nonsystematic review. The literature was searched for WSNs to reduce and prevent bedsores with the help of libraries, databases (PubMed, SCOPUS, and EMBASE, and also searches engines available at Google Scholar including during 1974-2014 while the inclusion criteria were applied in English and Persian. In our searches, we employed the following keywords and their combinations: "wireless sensor network," "smart bed," "information technology," "smart mattress," and "bedsore" in the searching areas of titles, keywords, abstracts, and full texts. In this study, more than 45 articles and reports were collected and 37 of them were selected based on their relevance. Therefore, identification and implementation of this technology will be a step toward mechanization of traditional procedures in providing care for hospitalized patients and disabled people. The smart bed and mattress, either alone or in combination with the other technologies, should be capable of providing all of the novel features while still providing the comfort and safety features usually associated with traditional and hospital mattresses. It can eliminate the expense of bedsore in the intensive care unit (ICU department in the hospital and save much expense there.

  7. Modelling of synchronisation and energy performance of FBE- and LBE-based standalone LTE-U networks

    Directory of Open Access Journals (Sweden)

    Jiamin Li

    2017-06-01

    Full Text Available Without the aid of licensed channel, deploying long-term evolution (LTE networks over unlicensed spectrum (named standalone LTE-U networks faces the difficulty of establishing and maintaining synchronisation between user equipments and base stations. In this work, considering the two modes of listen-before-talk-based channel access scheme, frame-based equipment (FBE and load-based equipment (LBE, the authors propose analytical frameworks to study the successful probability of synchronisation and the energy consumption of synchronisation in a standalone LTE-U network. Specifically, for the LBE mode, the authors also propose a Lattice-Poisson algorithm-based approach to derive the distribution of the channel non-occupancy period of a standalone LTE-U network. Furthermore, the authors explore the impact of diverse protocol parameters of both FBE and LBE modes on the two studied performance metrics. Simulation results demonstrate the accuracy of the analysis, and shed some light on the selection of FBE and LBE for standalone LTE-U networks, in terms of synchronisation, energy consumption, and throughput of standalone LTE-U and Wi-Fi networks.

  8. 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.

  9. The LHC's equipment all in step

    CERN Multimedia

    2005-01-01

    Over 80% of the control equipment for the LHC will be connected by a special communication network known as WorldFIP, which has been chosen for its very precise timing, excellent operating performance and robustness in difficult environments. Over 350 kilometres of this network are currently being installed in the LHC tunnel and checked for compliance with the required standards.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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...

  15. 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.

  16. 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...

  17. A Neural Network-Based Gait Phase Classification Method Using Sensors Equipped on Lower Limb Exoskeleton Robots

    Science.gov (United States)

    Jung, Jun-Young; Heo, Wonho; Yang, Hyundae; Park, Hyunsub

    2015-01-01

    An exact classification of different gait phases is essential to enable the control of exoskeleton robots and detect the intentions of users. We propose a gait phase classification method based on neural networks using sensor signals from lower limb exoskeleton robots. In such robots, foot sensors with force sensing registers are commonly used to classify gait phases. We describe classifiers that use the orientation of each lower limb segment and the angular velocities of the joints to output the current gait phase. Experiments to obtain the input signals and desired outputs for the learning and validation process are conducted, and two neural network methods (a multilayer perceptron and nonlinear autoregressive with external inputs (NARX)) are used to develop an optimal classifier. Offline and online evaluations using four criteria are used to compare the performance of the classifiers. The proposed NARX-based method exhibits sufficiently good performance to replace foot sensors as a means of classifying gait phases. PMID:26528986

  18. A Neural Network-Based Gait Phase Classification Method Using Sensors Equipped on Lower Limb Exoskeleton Robots

    Directory of Open Access Journals (Sweden)

    Jun-Young Jung

    2015-10-01

    Full Text Available An exact classification of different gait phases is essential to enable the control of exoskeleton robots and detect the intentions of users. We propose a gait phase classification method based on neural networks using sensor signals from lower limb exoskeleton robots. In such robots, foot sensors with force sensing registers are commonly used to classify gait phases. We describe classifiers that use the orientation of each lower limb segment and the angular velocities of the joints to output the current gait phase. Experiments to obtain the input signals and desired outputs for the learning and validation process are conducted, and two neural network methods (a multilayer perceptron and nonlinear autoregressive with external inputs (NARX are used to develop an optimal classifier. Offline and online evaluations using four criteria are used to compare the performance of the classifiers. The proposed NARX-based method exhibits sufficiently good performance to replace foot sensors as a means of classifying gait phases.

  19. A Neural Network-Based Gait Phase Classification Method Using Sensors Equipped on Lower Limb Exoskeleton Robots.

    Science.gov (United States)

    Jung, Jun-Young; Heo, Wonho; Yang, Hyundae; Park, Hyunsub

    2015-10-30

    An exact classification of different gait phases is essential to enable the control of exoskeleton robots and detect the intentions of users. We propose a gait phase classification method based on neural networks using sensor signals from lower limb exoskeleton robots. In such robots, foot sensors with force sensing registers are commonly used to classify gait phases. We describe classifiers that use the orientation of each lower limb segment and the angular velocities of the joints to output the current gait phase. Experiments to obtain the input signals and desired outputs for the learning and validation process are conducted, and two neural network methods (a multilayer perceptron and nonlinear autoregressive with external inputs (NARX)) are used to develop an optimal classifier. Offline and online evaluations using four criteria are used to compare the performance of the classifiers. The proposed NARX-based method exhibits sufficiently good performance to replace foot sensors as a means of classifying gait phases.

  20. 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.

  1. 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.

  2. Performance Analysis of enhanced Inter-cell Interference Coordination in LTE-Advanced Heterogeneous Networks

    DEFF Research Database (Denmark)

    Wang, Yuanye; Pedersen, Klaus I.

    2012-01-01

    The performance of enhanced Inter-Cell Interference Coordination (eICIC) for Long Term Evolution (LTE)- Advanced with co-channel deployment of both macro and pico is analyzed. The use of pico-cell Range Extension (RE) and time domain eICIC (TDM muting) is combined. The performance is evaluated...... in the downlink by means of extensive system level simulations that follow the 3GPP guidelines. The overall network performance is analyzed for different number of pico-eNBs, transmit power levels, User Equipment (UE) distributions, and packet schedulers. Recommended settings of the RE offset and TDM muting ratio...... in different scenarios are identified. The presented performance results and findings can serve as input to guidelines for co-channel deployment of macro and pico-eNBs with eICIC....

  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. 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

  7. 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.

  8. 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.

  9. 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.

  10. Influence of impurities on the performances of HIPS recycled from Waste Electric and Electronic Equipment (WEEE).

    Science.gov (United States)

    Perrin, Didier; Mantaux, Olivier; Ienny, Patrick; Léger, Romain; Dumon, Michel; Lopez-Cuesta, José-Marie

    2016-10-01

    In order to produce a high quality recycled material from real deposits of electric and electronic equipment, the rate of impurities in different blended grades of reclaimed materials has to be reduced. Setting up industrial recycling procedures requires to deal with the main types of polymers presents in WEEE (Waste Electric and Electronic Equipment), particularly High Impact Polystyrene (HIPS) as well as other styrenic polymers such as Acrylonitrile-Butadiene-Styrene (ABS), Polystyrene (PS) but also polyolefin which are present into WEEE deposit as Polypropylene (PP). The production of a substantial quantity of recycled materials implies to improve and master the compatibility of different HIPS grades. The influence of polymeric impurities has to be studied since automatic sorting techniques are not able to remove completely these fractions. Investigation of the influence of minor ABS, PS and PP polymer fractions as impurities has been done on microstructure and mechanical properties of HIPS using environmental scanning electron microscopy (ESEM) in order to determine the maximum tolerated rate for each of them into HIPS after sorting and recycling operations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. 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...

  12. 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.

  13. 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...

  14. 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…

  15. 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 ...

  16. 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.

  17. 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

  18. 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…

  19. 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…

  20. 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...

  1. 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…

  2. Radon removal equipment based on aeration: A literature study of tests performed in Sweden between 1981 and 1996

    Energy Technology Data Exchange (ETDEWEB)

    Mjoenes, L

    2000-02-01

    In Sweden some principles to reduce the radon concentration in drinking water were tested in the beginning of the 1980s. Spray aeration under atmospheric pressure, diffused bubble aeration, aeration in the pressure tank and different combinations of these principles were studied. Aeration in the drill hole and adsorption on granulated activated char-coal were also tested. The best results, about 70 % reduction, were obtained with aeration in the pressure tank with a spray system combined with diffused air bubbling. The Oerebro project in the beginning of the 1990s included on site testing of five different aeration solutions: Aeration in the drill hole, aeration in the storage tank, ejector aeration, shallow tray aeration and packed column aeration. The radon removal efficiency varied between 20 % and 99 %. In 1994 a study intended to test the radon removal capacity of different water treatment equipment was performed. Six units of radon separators were included but most of the tested equipment was installed for other water treatment purposes. The performed measurements showed that the only types of equipment that reduce the radon concentration efficiently are radon separators and reverse osmosis filters. The radon removal capacity of the radon separators varied between 23 % and 97 %. In 1996 the nine most common radon separators on the Swedish market were tested. The results showed that the tested radon removal equipment worked well, although the technical quality and chosen technical solutions were not always the best. The radon removal capacity of the units participating in this test was in most cases between 96 and 99 %. In some cases the capacity exceeded 99 %. In order to reach this radon removal capacity the water must be recirculated in a storage tank under atmospheric pressure.

  3. 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.

  4. Impact of Users Identities and Access Conditions on Downlink Performance in Closed Small-Cell Networks

    KAUST Repository

    Radaydeh, Redha

    2015-05-26

    This paper investigates the effect of various operation parameters on the downlink user performance in overlaid small-cell networks. The case study considers closed-access small cells (e.g., femtocells), wherein only active authorized user equipments (UEs) can be served, and each of which is allocated single downlink channel at a time. On the other hand, the macrocell base station can unconditionally serve macrocell UEs that exist inside its coverage space. The available channels can be shared simultaneously in the macrocell network and the femtocell network. Moreover, a channel can be reused only at the macrocell base station. The analysis provides quantitative approaches to model UEs identities, their likelihoods of being active, and their likelihoods of producing interference, considering UEs classifications, locations, and access capabilities. Moreover, it develops models for various interference sources observed from effective interference femtocells, considering femtocells capacities and operation conditions. The associated formulations to describe a desired UE performance and the impact of the number of available channels as well as the adopted channel assignment approach are thoroughly investigated. The results are generally presented for any channel models of interference sources as well as the desired source of the served UE. Moreover, specific channel models are then adopted, for which generalized closedform analytical results for the desired UE outage probability performance are obtained. Numerical and simulation results are presented to further clarify the main outcomes of the developed analysis.

  5. The Mirror Fusion Test Facility cryogenic system: Performance, management approach, and present equipment status

    Energy Technology Data Exchange (ETDEWEB)

    Slack, D.S.; Chronis, W.C.

    1987-06-08

    The cryogenic system for the Mirror Fusion Test Facility (MFTF) is a 14-kW, 4.35-K helium refrigeration system that proved to be highly successful and cost-effective. All operating objectives were met, while remaining within a few percent of initial cost and schedule plans. The management approach used in MFTF allowed decisions to be made quickly and effectively, and it helped keep costs down. Manpower levels, extent and type of industrial participation, key aspects of subcontractor specifications, and subcontractor interactions are reviewed, as well as highlights of the system tests, operation, and present equipment status. Organizations planning large, high-technology systems may benefit from this experience with the MFTF cryogenic system.

  6. 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.

  7. 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.

  8. 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....

  9. 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...

  10. 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...

  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. 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...

  13. Performance of a resistive plate chamber equipped with a new prototype of amplified front-end electronics

    CERN Document Server

    Marchisone, Massimiliano

    2016-01-01

    ALICE is the LHC experiment dedicated to the study of heavy-ion collisions. At forward rapidity a muon spectrometer detects muons from low mass mesons, quarkonia, open heavy-flavor hadrons as well as weak bosons. A muon selection based on transverse momentum is made by a trigger system composed of 72 resistive plate chambers (RPCs). For the LHC Run 1 and the ongoing Run 2 the RPCs have been equipped with a non-amplified FEE called ADULT. However, in view of an increase in luminosity expected for Run 3 (2021-2023) the possibility to use an amplified FEE has been explored in order to improve the counting rate limitation and to prevent the aging of the detector, by reducing the charge per hit. A prototype of this new electronics (FEERIC) has been developed and tested first with cosmic rays before equipping one RPC in the ALICE cavern with it. In this talk the most important performance indicators - efficiency, dark current, dark rate, cluster size and total charge - of an RPC equipped with this new FEE will be r...

  14. Element nodes of sports equipment double back flip factions and double back flip hunched performed gymnast in floor exercise

    Directory of Open Access Journals (Sweden)

    Potop V.A.

    2014-04-01

    Full Text Available Purpose: to identify the node elements of sports equipment double back somersault tuck and double back flip bent. To compare the two types of nodes for double somersault. Material : the study involved eight gymnasts (age 12 - 14 years. All finalists in the competition floor exercise - reserve team Romania. The method of video - computer research and method of postural orientation movements. Results : identified nodal elements of sports equipment double back somersault tuck and double back flip bent. In the preparatory phase of motor actions - launcher body posture for reaching is repulsive to flip. In the phase of basic motor action - animation body postures (double back somersault tuck and bent (bent double back flip. Exercises are performed on the ascending and descending parts of the flight path of the demonstration of individual maximum lift height common center of mass. In the final phase of motor actions - final body posture - steady landing. Conclusions : indicators of key elements of sports equipment acrobatic exercises contain new scientific facts kinematic and dynamic structures of motor actions. They are necessary for the development of modern training programs acrobatic exercises in step specialized base preparation.

  15. 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...

  16. 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...

  17. 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...

  18. 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.

  19. 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.

  20. 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

  1. Performance of a cluster of Multi-anode Photomultipliers equipped with lenses for use in a prototype RICH detector

    CERN Document Server

    Albrecht, E; Barber, G J; Bibby, J; Calvi, M; Charles, M J; Duane, A; Easo, S; Eisenhardt, S; Eklund, L; French, M; Gibson, V; Halley, A; Halsall, R; Harnew, N; John, M J J; Katvars, S G; Libby, J; Muheim, F; Paganoni, M; Petrolini, A; Playfer, S; Price, D; Rademacker, J; Smale, N J; Topp-Jørgensen, S; Websdale, David M; Wilkinson, G R; Wooton, S A

    2002-01-01

    A cluster of Multi--anode Photomultiplier Tubes (MaPMTs) equipped with focusing lenses in front of the tubes was tested in a prototype Ring Imaging \\v{C}erenkov detector in a charged particle beam. The readout electronics were capable of capturing the data at 40~MHz. The effects due to charged particles and magnetic field on the MaPMT performance were also studied. The results are used to evaluate the MaPMT as a possible photodetector for the LHCb RICH detectors.

  2. Delay performance of a broadcast spectrum sharing network in Nakagami-m fading

    KAUST Repository

    Khan, Fahd Ahmed

    2014-03-01

    In this paper, we analyze the delay performance of a point-to-multipoint secondary network (P2M-SN), which is concurrently sharing the spectrum with a point-to-multipoint primary network (P2M-PN). The channel is assumed to be independent but not identically distributed (i.n.i.d.) and has Nakagami-m fading. A constraint on the peak transmit power of the secondary-user transmitter (SU-Tx) is considered, in addition to the peak interference power constraint. The SU-Tx is assumed to be equipped with a buffer and is modeled using the M/G/1 queueing model. The performance of this system is analyzed for two scenarios: 1) P2M-SN does not experience interference from the primary network (denoted by P2M-SN-NI), and 2) P2M-SN does experience interference from the primary network (denoted by P2M-SN-WI). The performance of both P2M-SN-NI and P2M-SN-WI is analyzed in terms of the packet transmission time, and the closed-form cumulative density function (cdf) of the packet transmission time is derived for both scenarios. Furthermore, by utilizing the concept of timeout, an exact closed-form expression for the outage probability of the P2M-SN-NI is obtained. In addition, an accurate approximation for the outage probability of the P2M-SN-WI is also derived. Furthermore, for the P2M-SN-NI, the analytic expressions for the total average waiting time (TAW-time) of packets and the average number of packets waiting in the buffer of the SU-Tx are also derived. Numerical simulations are also performed to validate the derived analytical results. © 1967-2012 IEEE.

  3. The effect of equipment scaling on children's sport performance: the case for tennis

    NARCIS (Netherlands)

    Timmerman, E.; de Water, J.; Kachel, K.; Savelsbergh, G.J.P.

    2015-01-01

    Abstract: The influence of scaling court-size and net height on children’s tennis performance was examined. Sixteen boys (9.7 ± 0.5 years) had to perform a 30-min match in four different conditions, where court-size and/or net height were scaled by using a scaling ratio based on the differences in

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Novel Scanning Lens Instrument for Evaluating Fresnel Lens Performance: Equipment Development and Initial Results (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Herrero, R.; Miller, D. C.; Kurtz, S. R.; Anton, I.; Sala, G.

    2013-07-01

    A system dedicated to the optical transmittance characterization of Fresnel lenses has been developed at NREL, in collaboration with the UPM. The system quantifies the optical efficiency of the lens by generating a performance map. The shape of the focused spot may also be analyzed to understand change in the lens performance. The primary instrument components (lasers and CCD detector) have been characterized to confirm their capability for performing optical transmittance measurements. Measurements performed on SoG and PMMA lenses subject to a variety of indoor conditions (e.g., UV and damp heat) identified differences in the optical efficiency of the evaluated lenses, demonstrating the ability of the Scanning Lens Instrument (SLI) to distinguish between the aged lenses.

  9. Double-shell tank integrity assessments ultrasonic test equipment performance test

    Energy Technology Data Exchange (ETDEWEB)

    Pfluger, D.C.

    1996-09-26

    A double-shell tank (DST) inspection (DSTI) system was performance tested over three months until August 1995 at Pittsburgh, Pennsylvania, completing a contract initiated in February 1993 to design, fabricate, and test an ultrasonic inspection system intended to provide ultrasonic test (UT) and visual data to determine the integrity of 28 DSTs at Hanford. The DSTs are approximately one-million-gallon underground radioactive-waste storage tanks. The test was performed in accordance with a procedure (Jensen 1995) that included requirements described in the contract specification (Pfluger 1995). This report documents the results of tests conducted to evaluate the performance of the DSTI system against the requirements of the contract specification. The test of the DSTI system also reflects the performance of qualified personnel and operating procedures.

  10. 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.

  11. 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

  12. 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.

  13. 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.)

  14. 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.

  15. The North East Italy (NI) broadband seismic network run by OGS: experience in improving the long period performances

    Science.gov (United States)

    Pesaresi, D.

    2009-04-01

    The NI broadband seismic network is designed to monitor regional seismic activity of North East Italy and surroundings as well as to provide high quality data for various research projects in regional and global broadband seismology, like moment tensor determination. The network, grown during the last 30 years within local Civil Defence agencies and neighbouring scientific institutions cooperation, currently consists of 11 digital broadband stations equipped with Streckeisen STS-2 and STS-1, Nanometrics Trillium 40 and Guralp CMG-3T seismometers with 120 and 40 seconds long period corners; most of the seismic stations are also equipped with accelerometers. Waveforms and parametric data of the NI seismic network are transmitted in real time to the Friuli-Venezia Giulia,Veneto and Provincia di Trento Civil Defence Agencies, to the Italian National Institute for Geophysics and Volcanology (INGV) and to the Earth Science Department (DST) of the Trieste University in Italy, to the Austrian Central Institute for Meteorology and Geodynamics (ZAMG) in Vienna, Austria and to the Environmental Agency of the Republic of Slovenia (ARSO) in Ljubljana, Slovenia to support emergency management and seismological studies in the whole Alps-Dinarides junction zone. The commercial Antelope software suite from BRTT has been chosen as the common basis for real time data exchange, rapid location of earthquakes and alerting. In order to guarantee high quality installations, we sustain a continuous effort that involves searches for appropriate sites, away from sources of long period noise, improvements in installation procedures and insulation techniques, maintenance of transfer function files and routine monitoring of noise conditions at individual existing station. The quality of the seismic data is checked through the noise Power Spectral Density (PSD) analysis. The insulation equipment that we designed for our network is a local adaptation of the pressure-thermal insulation

  16. 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

  17. 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.

  18. THE EFFECTS OF SCALING TENNIS EQUIPMENT ON THE FOREHAND GROUNDSTROKE PERFORMANCE OF CHILDREN

    Directory of Open Access Journals (Sweden)

    Emma J. Larson

    2013-06-01

    Full Text Available The modifications that have taken place within youth sports have made games, such as basketball, soccer, or tennis, easier for children to play. The purpose of this study was to determine the effects low compression (LC tennis balls and scaled tennis courts had on the forehand groundstroke performance of children. The forehand groundstroke performances of eight subjects' (8.10 ± 0.74 yrs using LC tennis balls were measured on a scaled tennis court and standard compression balls (SC on a standard court. Forehand groundstroke performance was assessed by the ForeGround test which measures Velocity Precision Success Index (VPS and Velocity Precision Index (VP. Participants attempted three different forehand rally patterns on two successive days, using LC balls on the 18.3m court one day and SC balls on the 23.8m court the other. When using LC balls, participants' recorded higher overall VPS performance scores (p < 0.001 for each non-error stroke as well as higher VP scores (p = 0.01. The results of this study confirmed that the use of modified balls and modified court size may increase the control, velocity and overall success rate of the tennis forehand groundstroke of children

  19. The Effects of Equipment Modification on Children's Self-Efficacy and Basketball Shooting Performance.

    Science.gov (United States)

    Chase, Melissa A.; And Others

    1994-01-01

    Reports a study that examined the effects of modification of basketball size and basket height on shooting performance and self-efficacy of children ages 9-12 years. Subjects completed a self-efficacy questionnaire before and after shooting 10 baskets under 4 conditions. Self-efficacy was highest when children shot at a lower basket. (SM)

  20. The effect of equipment scaling on children's sport performance: the case for tennis.

    Science.gov (United States)

    Timmerman, Ewout; De Water, Joel; Kachel, Kim; Reid, Machar; Farrow, Damian; Savelsbergh, Geert

    2015-01-01

    The influence of scaling court-size and net height on children's tennis performance was examined. Sixteen boys (9.7 ± 0.5 years) had to perform a 30-min match in four different conditions, where court-size and/or net height were scaled by using a scaling ratio based on the differences in temporal demands between the children and the adult game. These 30-min matches were analysed using Tennis Analyst (FairPlay Ltd., Jindalee, QLD, Australia) software to determine typical tennis match performance characteristics. Children hit more winners, more forced errors, played more volleys, struck more shots from a comfortable height and played in a more forward court position when the net was scaled. Scaling both the court and net lead to a faster children's game, more closely approximating what is typical of the adult game. The differences between the typical tennis performance variables recorded suggested that scaling the net led to a more aggressive way of playing. Further, children enjoyed playing on the standard court-scaled net condition more than standard adult conditions. It is suggested that optimising the scaling of net height may be as critical as other task constraints, such as racquet length or court-size, as it leads to a more engaging learning environment for experienced children.

  1. 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...

  2. 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

  3. A study on the establishment of component/equipment performance criteria considering Heavy Water Reactor characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Keun Sun; Kwon, Young Chul; Lee, Min Kyu; Lee, Yun Soo [Sunmoon Univ., Asan (Korea, Republic of); Chang, Seong Hoong; Ryo, Chang Hyun [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of); Kim, Soong Pyung; Hwnag, Jung Rye; Chung, Chul Kee [Chosun Univ., Gwangju (Korea, Republic of)

    2002-03-15

    Foreign and domestic technology trends, regulatory requirements, design and researches for heavy water reactors are analyzed. Safety design guides of Canada industry and regulatory documents and consultative documents of Canada regulatory agency are reviewed. Applicability of MOST guidance 16 Revision 'guidance for technical criteria of nuclear reactor facility' is reviewed. Specific performance criteria are established for components and facilities for heavy water reactor.

  4. How the reverse supply chain impacts the financial performance of original equipment manufacturers

    DEFF Research Database (Denmark)

    Larsen, Samuel

    This thesis examines the financial impact of a firm’s reverse supply chain (RSC). Specifically, the thesis examines the two questions of how the RSC can contribute to the financial performance of the firm and which factors are decisive for the RSC’s financial contribution. The thesis focuses...... the traditional perception of the RSC in academic literature as well as with logistics practitioners....

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. Performance evaluation of aprons according to lead equipment and form types

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Won; Choi, Sung Hyun; Kim, Ki Yeol; Lee, Ik Pyo; Hwang, Sun Gwang [Dept. of Radiology, Kyung Hee University Hostpital at Gangdong, Seoul (Korea, Republic of); Dong, Kyung Rae [Dept. of of Radiological Technology, Gwangju Health University, Gwangju (Korea, Republic of)

    2017-02-15

    The apron is one of the essential protectors to reduce the exposure dose of radiological technologists. This study is to provide a guideline for purchasing the aprons with excellent performance and to help reducing the exposure dose by measuring the shielding ration and uniformity of aprons according to lead equivalent and form types. The shielding ratio of aprons were measured by using radiation generator and dosimeter. Exposure conditions were 81 kVp, 25 mAs, source to image receptor distance (SID) 100 cm and field of view (FOV) 17{sup ×}17{sup .} Exposure areas for front type and around type aprons were divided into 9 areas and for 2 pieces type aprons were divided into 3 areas of top and 4 areas of skirt. The uniformity of aprons were measured by using fluoroscopy and Image J. The 4 regions of interest (ROI) were set into acquired images and measured uniformity by measuring the standard deviation of pixel intensity in ROIs. In continuous shielding ration measurement of aprons according to exposure area, there was not statistical significance (P>0.05). In ANOVA test of aprons, there was statistical significance (P<0.01). In the results of shielding ratio, although the aprons had equal lead equivalent, there were difference in shielding ratio from 83.59% to 98.15%. In the results of uniformity, the front type aprons with equal lead equivalent indicated the similar uniformity. However, the around type and 2 pieces type apron with equal lead equivalent indicated the different uniformity each other, from 1.8 to 22.2. If the performance evaluation in this study were conducted regularly before and after purchase the aprons, the exposure does to patients and radiological technologists could be reduced.

  14. Performance Evaluation of sUAS Equipped with Velodyne HDL-32E LiDAR Sensor

    Science.gov (United States)

    Jozkow, G.; Wieczorek, P.; Karpina, M.; Walicka, A.; Borkowski, A.

    2017-08-01

    The Velodyne HDL-32E laser scanner is used more frequently as main mapping sensor in small commercial UASs. However, there is still little information about the actual accuracy of point clouds collected with such UASs. This work evaluates empirically the accuracy of the point cloud collected with such UAS. Accuracy assessment was conducted in four aspects: impact of sensors on theoretical point cloud accuracy, trajectory reconstruction quality, and internal and absolute point cloud accuracies. Theoretical point cloud accuracy was evaluated by calculating 3D position error knowing errors of used sensors. The quality of trajectory reconstruction was assessed by comparing position and attitude differences from forward and reverse EKF solution. Internal and absolute accuracies were evaluated by fitting planes to 8 point cloud samples extracted for planar surfaces. In addition, the absolute accuracy was also determined by calculating point 3D distances between LiDAR UAS and reference TLS point clouds. Test data consisted of point clouds collected in two separate flights performed over the same area. Executed experiments showed that in tested UAS, the trajectory reconstruction, especially attitude, has significant impact on point cloud accuracy. Estimated absolute accuracy of point clouds collected during both test flights was better than 10 cm, thus investigated UAS fits mapping-grade category.

  15. 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....

  16. Equipment Grafting in Telecommunication Industry (Case Study ...

    African Journals Online (AJOL)

    ... existing network in the form of Upgrades and Expansion efforts. This paper appraises these grafting processes. It introduces the subject matter, highlights the performance capabilities and usage constraints of a variety of switching and transmission equipment. It also gives insight into the on-going grafting efforts in NITEL.

  17. 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.

  18. 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.

  19. Space Heating Equipment

    Energy Technology Data Exchange (ETDEWEB)

    Rafferty, Kevin D.

    1998-01-01

    The performance evaluation of space heating equipment for a geothermal application is generally considered from either of two perspectives: (a) selecting equipment for installation in new construction, or (b) evaluating the performance and retrofit requirements of an existing system. With regard to new construction, the procedure is relatively straightforward. Once the heating requirements are determined, the process need only involve the selection of appropriately sized hot water heating equipment based on the available water temperature. It is important to remember that space heating equipment for geothermal applications is the same equipment used in non-geothermal applications. What makes geothermal applications unique is that the equipment is generally applied at temperatures and flow rates that depart significantly from traditional heating system design. This chapter presents general considerations for the performance of heating equipment at non-standard temperature and flow conditions, retrofit of existing systems, and aspects of domestic hot water heating.

  20. 78 FR 79649 - Energy Conservation Program: Proposed Determination of Set-Top Boxes and Network Equipment as a...

    Science.gov (United States)

    2013-12-31

    ... Equipment as a Covered Consumer Product AGENCY: Office of Energy Efficiency and Renewable Energy, Department... Dommu, U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Building... the maximum economic benefits and energy savings occur through increasing the efficiency of STBs. DOE...

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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...

  7. The Design and Implementation of Smart Monitoring System for Large-Scale Railway Maintenance Equipment Cab Based on ZigBee Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Hairui Wang

    2014-06-01

    Full Text Available In recent years, organizations use IEEE 802.15.4 and ZigBee technology to deliver solution in variety areas including home environment monitoring. ZigBee technology has advantages on low-cost, low power consumption and self-forming. With the rapid expansion of the Internet, there is the requirement for remote monitoring large-scale railway maintenance equipment cab. This paper discusses the disadvantages of the existing smart monitoring system, and proposes a solution. A ZigBee wireless sensor network smart monitoring system and Wi-Fi network is integrated through a home gateway to increase the system flexibility. At the same time the home gateway cooperated with a pre- processing system provide a flexible user interface, and the security and safety of the smart monitoring system. To testify the efficiency of the proposed system, the temperature and humidity sensors and light sensors have developed and evaluated in the smart monitoring system.

  8. 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...

  9. Is it the athlete or the equipment? An analysis of the top swim performances from 1990 to 2010.

    Science.gov (United States)

    O'connor, Lanty M; Vozenilek, John A

    2011-12-01

    O'Connor, LM and Vozenilek, JA. Is it the athlete or the equipment? An analysis of the top swim performances from 1990 to 2010. J Strength Cond Res 25(12): 3239-3241, 2011-Forty-three world record swims were recorded at the 2009 Fédération Internationale de Natation (FINA) World Championship meet in Rome. Of the 20 FINA recognized long-course (50-m pool) swimming events, men set new world records in 15 of those events, whereas women did the same in 17 events. Each of the men's world records and 14 of the 17 women's records still stand. These performances were unprecedented; never before had these many world records been broken in such a short period of time. There was much speculation that full-body, polyurethane, technical swimsuits were the reason for the conspicuous improvement in world records. Further analysis led the FINA to institute new rules on January 1, 2010, that limited the types of technical swimsuits that could be worn by athletes. No long-course world record has been broken since then. We sought to understand this phenomenon by analyzing publicly available race data and exploring other possible causes including improvements in other sports, improvements in training science, changes in rules and regulations, gender differences, anaerobic vs. aerobic events, unique talent, and membership data.

  10. 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.

  11. 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

  12. 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., ...

  13. 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...

  14. 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…

  15. Quality of mammography equipment in Health Public Network; Calidad de proceso generador de imagenes mamograficas de equipos instalados en la Red Publica de Salud

    Energy Technology Data Exchange (ETDEWEB)

    Ruberti Filha, E. M.; Pires, S. R.; Medeiros, R. B.

    2006-07-01

    In spite of the requirements of the Brazilian Regulatory Organization to ensure that quality control verifications are made in the radiological equipment, further actions should also be carried out in order to guarantee the quality of the images and of the diagnosis. This study has as its objective to analyze the failures of the image generation system using instruments to control the quality of the radiological equipment, verify the processing image conditions and, finally, classify the mammographic findings as unacceptable, suitable and acceptable. A statistical phantom was used in which the fibers and the microcalcifications were randomly positioned. The images were then read by specialists and the level of agreement was measured by the Kappa value. It was possible to check that most of the tested equipment parameters presented a good performance, although the film processing did not generate satisfactory results and caused reading difficulties. Many of the results of these reading were classified as unacceptable. Among these images, only a small percentage of them presented the fibers and microcalcifications of the sizes required by the Brazilian legislation. We concluded that it is only possible to generate good quality images if all the steps of the process are properly controlled. Therefore, it is relevant to invest in training, calibration and maintenance of the mammographic equipment. (Author)

  16. Performance and evaluation of gas engine driven rooftop air conditioning equipment at the Willow Grove (PA) Naval Air Station

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, P.R.; Conover, D.R.

    1993-05-01

    In a field evaluation conducted for the US Department of Energy (DOE) Office of Federal Energy Management Program (FEMP), the Pacific Northwest Laboratory (PNL) examined the performance of a new US energy-related technology under the FEMP Test Bed Demonstration Program. The technology was a 15-ton natural gas engine driven roof top air conditioning unit. Two such units were installed on a naval retail building to provide space conditioning to the building. Under the Test Bed Demonstration Program, private and public sector interests are focused to support the installation and evaluation of new US technologies in the federal sector. Participating in this effort under a Cooperative Research and Development Agreement (CRADA) with DOE were the American Gas Cooling Center, Philadelphia Electric Company, Thermo King Corporation, and the US Naval Air Station at Willow Grove, Pennsylvania. Equipment operating and service data as well as building interior and exterior conditions were secured for the 1992 cooling season. Based on a computer assessment of the building using standard weather data, a comparison was made with the energy and operating costs associated with the previous space conditioning system. Based on performance during the 1992 cooling season and adjusted to a normal weather year, the technology will save the site $6,000/yr in purchased energy costs. An additional $9,000 in savings due to electricity demand ratchet charge reductions will also be realized. Detailed information on the technology, the installation, and the results of the technology test are provided to illustrate the advantages to the federal sector of using this technology. A history of the CRADA development process is also reported.

  17. 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.

  18. 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...

  19. Intelligent cruise control field operational test. Vol III, Performance of a string or cluster of ACC-equipped cars

    Science.gov (United States)

    1998-07-01

    This report is one element of a cooperative agreement between NHTSA and UMTRI entitled Intelligent Cruise Control (ICC) Field Operational Test (FOT). It addresses the operation of a serial string or dense cluster of passenger cars equipped with a new...

  20. 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.

  1. 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.

  2. 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

  3. The performance of the stations of the Romanian seismic network in monitoring the local seismic activity

    Science.gov (United States)

    Ardeleanu, Luminita Angela; Neagoe, Cristian

    2014-05-01

    The seismic survey of the territory of Romania is mainly performed by the national seismic network operated by the National Institute for Earth Physics of Bucharest. After successive developments and upgrades, the network consists at present of 123 permanent stations equipped with high quality digital instruments (Kinemetrics K2, Quantera Q330, Quantera Q330HR, PS6-24 and Basalt digitizers) - 102 real time and 20 off-line stations - which cover the whole territory of the country. All permanent stations are supplied with 3 component accelerometers (episenzor type), while the real time stations are in addition provided with broadband (CMG3ESP, CMG40T, KS2000, KS54000, KS2000, CMG3T, STS2) or short period (SH-1, S13, Mark l4c, Ranger, GS21, L22_VEL) velocity sensors. Several communication systems are currently used for the real time data transmission: an analog line in UHF band, a line through GPRS (General Packet Radio Service), a dedicated line through satellite, and a dedicated line provided by the Romanian Special Telecommunication Service. During the period January 1, 2006 - June 30, 2013, 5936 shallow depth seismic events - earthquakes and quarry blasts - with local magnitude ML ≥ 1.2 were localized on the Romanian territory, or in its immediate vicinity, using the records of the national seismic network; 1467 subcrustal earthquakes (depth ≥ 60 km) with magnitude ML ≥ 1.9 were also localized in the Vrancea region, at the bend of the Eastern Carpathians. The goal of the present study is to evaluate the individual contribution of the real time seismic stations to the monitoring of the local seismicity. The performance of each station is estimated by taking into consideration the fraction of events that are localised using the station records, compared to the total number of events of the catalogue, occurred during the time of station operation. Taking into account the nonuniform space distribution of earthquakes, the location of the site and the recovery

  4. EO-Performance relationships in Reverse Internationalization by Chinese Global Startup OEMs: Social Networks and Strategic Flexibility

    Science.gov (United States)

    Chin, Tachia; Tsai, Sang-Bing; Fang, Kai; Zhu, Wenzhong; Yang, Dongjin; Liu, Ren-huai; Tsuei, Richard Ting Chang

    2016-01-01

    Due to the context-sensitive nature of entrepreneurial orientation (EO), it is imperative to in-depth explore the EO-performance mechanism in China at its critical, specific stage of economic reform. Under the context of “reverse internationalization” by Chinese global startup original equipment manufacturers (OEMs), this paper aims to manifest the unique links and complicated interrelationships between the individual EO dimensions and firm performance. Using structural equation modeling, we found that during reverse internationalization, proactiveness is positively related to performance; risk taking is not statistically associated with performance; innovativeness is negatively related to performance. The proactiveness-performance relationship is mediated by Strategic flexibility and moderated by social networking relationships. The dynamic and complex institutional setting, coupled with the issues of overcapacity and rising labor cost in China may explain why our distinctive results occur. This research advances the understanding of how contingent factors (social network relationships and strategic flexibility) facilitate entrepreneurial firms to break down institutional barriers and reap the most from EO. It brings new insights into how Chinese global startup OEMs draw on EO to undertake reverse internationalization, responding the calls for unraveling the heterogeneous characteristics of EO sub-dimensions and for more contextually-embedded treatment of EO-performance associations. PMID:27631368

  5. EO-Performance relationships in Reverse Internationalization by Chinese Global Startup OEMs: Social Networks and Strategic Flexibility.

    Science.gov (United States)

    Chin, Tachia; Tsai, Sang-Bing; Fang, Kai; Zhu, Wenzhong; Yang, Dongjin; Liu, Ren-Huai; Tsuei, Richard Ting Chang

    2016-01-01

    Due to the context-sensitive nature of entrepreneurial orientation (EO), it is imperative to in-depth explore the EO-performance mechanism in China at its critical, specific stage of economic reform. Under the context of "reverse internationalization" by Chinese global startup original equipment manufacturers (OEMs), this paper aims to manifest the unique links and complicated interrelationships between the individual EO dimensions and firm performance. Using structural equation modeling, we found that during reverse internationalization, proactiveness is positively related to performance; risk taking is not statistically associated with performance; innovativeness is negatively related to performance. The proactiveness-performance relationship is mediated by Strategic flexibility and moderated by social networking relationships. The dynamic and complex institutional setting, coupled with the issues of overcapacity and rising labor cost in China may explain why our distinctive results occur. This research advances the understanding of how contingent factors (social network relationships and strategic flexibility) facilitate entrepreneurial firms to break down institutional barriers and reap the most from EO. It brings new insights into how Chinese global startup OEMs draw on EO to undertake reverse internationalization, responding the calls for unraveling the heterogeneous characteristics of EO sub-dimensions and for more contextually-embedded treatment of EO-performance associations.

  6. Quality assessment in in vivo NMR spectroscopy: V. Multicentre evaluation of prototype test objects and protocols for performance assessment in small bore MRS equipment

    DEFF Research Database (Denmark)

    Howe, F.A.; Canese, R; Podo, F

    1995-01-01

    This paper reports the results of multicentre studies aimed at designing, constructing, and evaluating prototype test objects for performance assessment in small-bore MRS systems, by utilizing the test protocols already proposed by the EEC COMAC-BME Concerted Action for clinical MRS equipment...

  7. 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.

  8. 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.

  9. 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 ...

  10. 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...

  11. 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...

  12. 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...

  13. 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…

  14. 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...

  15. 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.

  16. 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.

  17. Statistical Analysis of Wireless Networks: Predicting Performance in Multiple Environments

    Science.gov (United States)

    2006-06-01

    integration of “satellite in a suitcase ” (portable satellite communication equipment) technology, enhanced unattended ground and water-based sensors...transition between night and day and the addition of solar energy always plays an effect on how humidity and temperature respond. Since solar radiation

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. [Design of a medical equipment purchasing system].

    Science.gov (United States)

    Zeng, Li; Chen, Xiao-hua

    2008-09-01

    This paper introduces the network data dynamic exchange technology applied to the design of the medical equipment purchase system according to the process of the medical equipment purchasing. The new system adopts B/S structure based on .net technology, to realize the medical equipment purchasing information's dynamic management of network purchase application and verification, suppliers qualification examination and the contact file inquiry etc.

  4. Early science with the Korean VLBI network: evaluation of system performance

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang-Sung; Byun, Do-Young; Kim, Jongsoo; Jung, Taehyun; Song, Min-Gyu; Oh, Chung Sik; Roh, Duk-Gyoo; Je, Do-Heung; Wi, Seog-Oh; Sohn, Bong Won; Oh, Se-Jin; Kim, Kee-Tae; Yeom, Jae-Hwan; Chung, Moon-Hee; Kang, Jiman; Han, Seog-Tae; Lee, Jung-Won; Kim, Bong Gyu; Chung, Hyunsoo [Korea Astronomy and Space Science Institute, Daedeokdae-ro 776, Yuseong-gu, Daejeon 305-348 (Korea, Republic of); Petrov, Leonid, E-mail: sslee@kasi.re.kr [Astrogeo Center, Falls Church, VA 22043 (United States); and others

    2014-04-01

    We report the very long baseline interferometry (VLBI) observing performance of the Korean VLBI Network (KVN). The KVN is the first millimeter-dedicated VLBI network in East Asia. The KVN consists of three 21 m radio telescopes with baseline lengths in a range of 305-476 km. The quasi-optical system equipped on the antennas allows simultaneous observations at 22, 43, 86, and 129 GHz. The first fringes of the KVN were obtained at 22 GHz on 2010 June 8. Test observations at 22 and 43 GHz on 2010 September 30 and 2011 April 4 confirmed that the full cycle of VLBI observations works according to specification: scheduling, antenna control system, data recording, correlation, post-correlation data processing, astrometry, geodesy, and imaging analysis. We found that decorrelation due to instability in the hardware at times up to 600 s is negligible. The atmosphere fluctuations at KVN baseline are partly coherent, which allows us to extend integration time under good winter weather conditions up to 600 s without significant loss of coherence. The post-fit residuals at KVN baselines do not exhibit systematic patterns, and the weighted rms of the residuals is 14.8 ps. The KVN is ready to image compact radio sources both in snapshot and full-track modes with residual noise in calibrated phases of less than 2 deg at 22 and 43 GHz and with dynamic ranges of ∼300 for snapshot mode and ∼1000 for full-track mode. With simultaneous multi-frequency observations, the KVN can be used to make parsec-scale spectral index maps of compact radio sources.

  5. Erosion of wind turbine blade coatings - Design and analysis of jet-based laboratory equipment for performance evaluation

    DEFF Research Database (Denmark)

    Zhang, Shizhong; Dam-Johansen, Kim; Nørkjær, Sten

    2015-01-01

    of the blades in such equipment. To reduce expensive blade maintenance repairs and to avoid out-of-service periods, energy-absorbing blade coatings are required to protect rotor blades from rain erosion. In this work we describe the design, construction and evaluation of a laboratory setup for fast screening...

  6. 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...

  7. 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.

  8. Network interruptions

    CERN Document Server

    2005-01-01

    On Sunday 12 June 2005, a site-wide security software upgrade will be performed on all CERN network equipment. This maintenance operation will cause at least 2 short network interruptions of 2 minutes on each equipment item. There are hundreds of such items across the CERN site (Meyrin, Prévessin and all SPS and LHC pits), and it will thus take the whole day to treat them all. All network users and services will be affected. Central batch computing services will be interrupted during this period, expected to last from 8 a.m. until late evening. Job submission will still be possible but no jobs will actually be run. It is hoped to complete the computer centre upgrades in the morning so that stable access can be restored to lxplus, afs and nice services as soon as possible; this cannot be guaranteed, however. The opportunity will be used to interrupt and perform upgrades on the CERN Document Servers.

  9. 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…

  10. 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...

  11. 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

  12. 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...

  13. Análise das redes interpessoais: aplicação na realidade de uma equipe de enfermagem atuando em unidade de hematologia Interpersonal network analysis: application to the reality of a nursing team working in a hematology unit

    Directory of Open Access Journals (Sweden)

    Fátima Luna Pinheiro Landim

    2010-12-01

    Full Text Available A equipe de Enfermagem do Serviço de Hematologia depara-se constantemente com situações de sofrimento intenso, podendo afetar sua homeostase. Considerando o postulado acerca da tendência à atualização do ser humano, as redes interpessoais podem ser benéficas, disponibilizando suportes para atualização da pessoa, que passa a transformar sua energia em comportamento útil, favorecendo o desempenho de funções e promovendo saúde. Este estudo foi realizado sobre a metodologia de análise das redes sociais, com o objetivo de analisar a rede interpessoal dos componentes de uma equipe de Enfermagem, que atua em unidade de hematologia de um hospital-escola na cidade de Fortaleza-CE. Foi realizado no ano de 2009, com 10 informantes-chaves. Os dados foram coletados no questionário gerador de nomes e qualificador da relação, processados nos programas: UCINET 6.123 e NETDRAW 2.38. O emprego da metodologia de análise de redes sociais permitiu reunir elementos elucidativos acerca da estrutura do grupo, sendo possível, a partir daí, tecer considerações acerca da posição ocupada pelos indivíduos, bem como do núcleo de relações constituído ao redor de cada um.The nursing team of the Hematology Service are constantly facing situations of intense suffering and this can affect their homeostasis. Considering the premise according to which human beings tend to upgrade themselves, interpersonal networks may be beneficial, providing support so that the person can upgrade herself, and starts to transform her energy into useful behavior, favoring the performance of duties and promoting health. This study employed the methodology of Social Network Analysis, and it aimed to analyze the interpersonal network of the members of a nursing team that work in the hematology unit of a hospital-school in the city of Fortaleza, Northeastern Brazil. The study was conducted in 2006, with ten key informants. Data were collected through a questionnaire that

  14. Equipment repaired is equipment gained

    Directory of Open Access Journals (Sweden)

    V Srinivasan

    2009-06-01

    Full Text Available According to WHO, at any one time, around 50 per cent of medical equipment in low- and middle-income countries cannot be used because of lack of maintenance or spare parts. We have found that unwillingness or inability to repair equipment and put it back in use is also a major cause.

  15. 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...

  16. 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...

  17. 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.

  18. 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...

  19. 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.

  20. 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.

  1. 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

  2. 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...

  3. 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.

  4. Improvements in Thermal Performance of Mango Hot-water Treatment Equipments: Data Analysis, Mathematical Modelling and Numerical-computational Simulation

    OpenAIRE

    Mendoza Orbegoso, Elder M.; Paul Villar-Yacila; Daniel Marcelo; Justo Oquelis

    2017-01-01

    Mango is one of the most popular and best paid tropical fruits in worldwide markets, its exportation is regulated within a phytosanitary quality control for killing the “fruit fly”. Thus, mangoes must be subject to hot-water treatment process that involves their immersion in hot water over a period of time. In this work, field measurements, analytical and simulation studies are developed on available hot-water treatment equipment called “Original” that only complies wi...

  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. 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

  7. 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

  8. 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...

  9. Antenna Calibration and Measurement Equipment

    Science.gov (United States)

    Rochblatt, David J.; Cortes, Manuel Vazquez

    2012-01-01

    A document describes the Antenna Calibration & Measurement Equipment (ACME) system that will provide the Deep Space Network (DSN) with instrumentation enabling a trained RF engineer at each complex to perform antenna calibration measurements and to generate antenna calibration data. This data includes continuous-scan auto-bore-based data acquisition with all-sky data gathering in support of 4th order pointing model generation requirements. Other data includes antenna subreflector focus, system noise temperature and tipping curves, antenna efficiency, reports system linearity, and instrument calibration. The ACME system design is based on the on-the-fly (OTF) mapping technique and architecture. ACME has contributed to the improved RF performance of the DSN by approximately a factor of two. It improved the pointing performances of the DSN antennas and productivity of its personnel and calibration engineers.

  10. 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...

  11. 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.

  12. 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.

  13. 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…

  14. 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

  15. 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

  16. Performance Assessment of Network Intrusion-Alert Prediction

    Science.gov (United States)

    2012-09-01

    through honeypots, machines explicitly designated solely to learn the methods used by black-hats to probe and hack a system so that a network...Maintaining access Miscellanous Reverse engineering RFID tools Table 3. BackTrack Intrusion-detection System/Intrusion-prevention System Penetration

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

    Indian Academy of Sciences (India)

    Written in Java environ- ment, this dedicated ANN package contains a variety of neural network algorithms such as the standard backpropagation, resilient, scale ...... Likewise, a compilation of useful approximations used for evaluating the upper tail integrals for the Gaussian and χ2 distributions can be found in [42] and [43], ...

  18. Performance analysis of data retrieval in wireless sensor networks

    NARCIS (Netherlands)

    Mitici, M.A.

    2015-01-01

    Wireless sensor networks are currently revolutionizing the way we live, work, and interact with the surrounding environment. Due to their ease of deployment, cost effectiveness and versatile functionality, sensors are employed in a wide range of areas such as environmental monitoring, surveillance

  19. Acoustic Performance of Exhaust Muffler based Genetic Algorithms and Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Wang Xiao Li

    2013-07-01

    Full Text Available The noise level was one of the important indicators as a measure of the quality and performance of the diesel engine, exhaust noise in diesel engines machine noise accounted for an important proportion of installed performance exhaust mufflerwas an effective way to control exhaust noise. This article using orthogonal test program was to the muffler structure parameters as input to the sound pressure level and diesel fuel each output artificial neural network (BP network learning sample. Matlab artificial neural network toolbox to complete the training of the network, and better noise performance and fuel consumption rate performance muffler internal structure parameters combination was obtained through genetic algorithm gifted collaborative validation of artificial neural networks and genetic algorithms to optimize application exhaust muffler design is entirely feasible

  20. LEARNING ALGORITHM EFFECT ON MULTILAYER FEED FORWARD ARTIFICIAL NEURAL NETWORK PERFORMANCE IN IMAGE CODING

    Directory of Open Access Journals (Sweden)

    OMER MAHMOUD

    2007-08-01

    Full Text Available One of the essential factors that affect the performance of Artificial Neural Networks is the learning algorithm. The performance of Multilayer Feed Forward Artificial Neural Network performance in image compression using different learning algorithms is examined in this paper. Based on Gradient Descent, Conjugate Gradient, Quasi-Newton techniques three different error back propagation algorithms have been developed for use in training two types of neural networks, a single hidden layer network and three hidden layers network. The essence of this study is to investigate the most efficient and effective training methods for use in image compression and its subsequent applications. The obtained results show that the Quasi-Newton based algorithm has better performance as compared to the other two algorithms.

  1. 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.

  2. Highway Maintenance Equipment Operator. Specialized Equipment. Training Materials.

    Science.gov (United States)

    Perky, Sandra Dutreau; And Others

    This curriculum guide provides instructional materials to assist in training equipment operators in the safe and effective use of highway maintenance equipment. It includes 18 units of instruction covering the large equipment used in maintenance operations. Each unit of instruction consists of eight basic components: performance objectives,…

  3. Network performance measurements as part of feasibility studies on moving an ATLAS event filter to off-site institutes

    CERN Document Server

    Korcyl, K; Dobinson, Robert W; Ivanovici, M; Losada-Maia, Marcia; Meirosu, C; Sladowski, G

    2004-01-01

    We present a system for measuring network performance as part of the feasibility studies for locating the ATLAS third level trigger, the event filter (EF), in remote locations. Part of the processing power required to run the EF algorithms, the current estimate is 2000 state off the art processors, can be provided in remote, CERN-affiliated institutes, if a suitable network connection between CERN and the remote site could be achieved. The system is composed of two PCs equipped with GPS systems, CERN-designed clock cards and Alteon gigabit programmable network interface cards. In the first set of measurements we plan to quantify connection in terms of end-to-end latency, throughput, jitter and packet loss. Running streaming tests and study throughput, IP QoS, routing testing and traffic shaping follows this. Finally, we plan to install the event filter software in a remote location and feed it with data from test beams at CERN. Each of these tests should be preformed with the test traffic treated in the netwo...

  4. Model Integrating Fuzzy Argument with Neural Network Enhancing the Performance of Active Queue Management

    Directory of Open Access Journals (Sweden)

    Nguyen Kim Quoc

    2015-08-01

    Full Text Available The bottleneck control by active queue management mechanisms at network nodes is essential. In recent years, some researchers have used fuzzy argument to improve the active queue management mechanisms to enhance the network performance. However, the projects using the fuzzy controller depend heavily on professionals and their parameters cannot be updated according to changes in the network, so the effectiveness of this mechanism is not high. Therefore, we propose a model combining the fuzzy controller with neural network (FNN to overcome the limitations above. Results of the training of the neural networks will find the optimal parameters for the adaptive fuzzy controller well to changes of the network. This improves the operational efficiency of the active queue management mechanisms at network nodes.

  5. Application of Neural Network and Simulation Modeling to Evaluate Russian Banks’ Performance

    OpenAIRE

    Sharma, Satish; Shebalkov, Mikhail

    2013-01-01

    This paper presents an application of neural network and simulation modeling to analyze and predict the performance of 883 Russian Banks over the period 2000-2010. Correlation analysis was performed to obtain key financial indicators which reflect the leverage, liquidity, profitability and size of Banks. Neural network was trained over the entire dataset, and then simulation modeling was performed generating values which are distributed with Largest Extreme Value and Loglogistic distributions...

  6. Hydrogen Bond Nanoscale Networks Showing Switchable Transport Performance

    Science.gov (United States)

    Long, Yong; Hui, Jun-Feng; Wang, Peng-Peng; Xiang, Guo-Lei; Xu, Biao; Hu, Shi; Zhu, Wan-Cheng; Lü, Xing-Qiang; Zhuang, Jing; Wang, Xun

    2012-08-01

    Hydrogen bond is a typical noncovalent bond with its strength only one-tenth of a general covalent bond. Because of its easiness to fracture and re-formation, materials based on hydrogen bonds can enable a reversible behavior in their assembly and other properties, which supplies advantages in fabrication and recyclability. In this paper, hydrogen bond nanoscale networks have been utilized to separate water and oil in macroscale. This is realized upon using nanowire macro-membranes with pore sizes ~tens of nanometers, which can form hydrogen bonds with the water molecules on the surfaces. It is also found that the gradual replacement of the water by ethanol molecules can endow this film tunable transport properties. It is proposed that a hydrogen bond network in the membrane is responsible for this switching effect. Significant application potential is demonstrated by the successful separation of oil and water, especially in the emulsion forms.

  7. GEECS (Generalized Equipment and Experiment Control System)

    Energy Technology Data Exchange (ETDEWEB)

    2017-01-12

    GEECS (Generalized Equipment and Experiment Control System) monitors and controls equipment distributed across a network, performs experiments by scanning input variables, and collects and stores various types of data synchronously from devices. Examples of devices include cameras, motors and pressure gauges. GEEKS is based upon LabView graphical object oriented programming (GOOP), allowing for a modular and scalable framework. Data is published for subscription of an arbitrary number of variables over TCP. A secondary framework allows easy development of graphical user interfaces for a combined control of any available devices on the control system without the need of programming knowledge. This allows for rapid integration of GEECS into a wide variety of systems. A database interface provides for devise and process configuration while allowing the user to save large quantities of data to local or network drives.

  8. A performance study of unmanned aerial vehicle-based sensor networks under cyber attack

    Science.gov (United States)

    Puchaty, Ethan M.

    In UAV-based sensor networks, an emerging area of interest is the performance of these networks under cyber attack. This study seeks to evaluate the performance trade-offs from a System-of-Systems (SoS) perspective between various UAV communications architecture options in the context two missions: tracking ballistic missiles and tracking insurgents. An agent-based discrete event simulation is used to model a sensor communication network consisting of UAVs, military communications satellites, ground relay stations, and a mission control center. Network susceptibility to cyber attack is modeled with probabilistic failures and induced data variability, with performance metrics focusing on information availability, latency, and trustworthiness. Results demonstrated that using UAVs as routers increased network availability with a minimal latency penalty and communications satellite networks were best for long distance operations. Redundancy in the number of links between communication nodes helped mitigate cyber-caused link failures and add robustness in cases of induced data variability by an adversary. However, when failures were not independent, redundancy and UAV routing were detrimental in some cases to network performance. Sensitivity studies indicated that long cyber-caused downtimes and increasing failure dependencies resulted in build-ups of failures and caused significant degradations in network performance.

  9. Traffic Dimensioning and Performance Modeling of 4G LTE Networks

    Science.gov (United States)

    Ouyang, Ye

    2011-01-01

    Rapid changes in mobile techniques have always been evolutionary, and the deployment of 4G Long Term Evolution (LTE) networks will be the same. It will be another transition from Third Generation (3G) to Fourth Generation (4G) over a period of several years, as is the case still with the transition from Second Generation (2G) to 3G. As a result,…

  10. Overhead-Performance Tradeoffs in Distributed Wireless Networks

    Science.gov (United States)

    2015-06-26

    inspired by cooperative commu- nications in mobile ad hoc networks. For this reason, the problem of users selection in cooperative relaying, as depicted...access methods are considered to ensure the receiver is able to recover the user information: Code Division Multiple Access ( CDMA ), linear MMSE access...codes and opportunistic access. CDMA allows the orthogonal transmission of the user data requiring only Channel State Information (CSI) at reception. On

  11. Predicting Deficient Condition Performance of Water Distribution Networks

    Directory of Open Access Journals (Sweden)

    Rajesh Gupta

    2013-12-01

    Full Text Available A water distribution network is subjected to various abnormal conditions such as pipe breaks, pump failures, excessive demands etc. in the design period. Under such conditions, the network may not be able to meet required demands at desired pressures, and becomes deficient. Traditional network analysis assumes nodal demands to be satisfied and available nodal pressures are calculated. However, assumption that demands are satisfied at all nodes is not true under deficient conditions. Therefore, under deficient conditions nodal demands and pressures are considered simultaneously through head-flow relationships to calculate available nodal flows. This type of analysis that determines available flows is termed as node flow analysis or pressure-driven or dependent wherein, outflows are considered as function of available pressure. Various node head-flow relationships (NHFR have been suggested by researchers to correlate available flow and available pressure based on required flow and required pressure. Methods using these NHFRs have been classified herein as direct and indirect approaches. Applications of these approaches have been shown with two illustrative examples and results are compared.

  12. 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.

  13. Improving the Performance Metric of Wireless Sensor Networks with Clustering Markov Chain Model and Multilevel Fusion

    Directory of Open Access Journals (Sweden)

    Saeed Havedanloo

    2013-01-01

    Full Text Available The paper proposes a performance metric evaluation for a distributed detection wireless sensor network with respect to IEEE 802.15.4 standard. A distributed detection scheme is considered with presence of the fusion node and organized sensors into the clustering and non-clustering networks. Sensors are distributed in clusters uniformly and nonuniformly and network has multilevel fusion centers. Fusion centers act as heads of clusters for decision making based on majority-like received signal strength (RSS with comparison the optimized value of the common threshold. IEEE 802.15.4 Markov chain model derived the performance metric of proposed network architecture with MAC, PHY cross-layer parameters, and Channel State Information (CSI specifications while it is including Path-loss, Modulation, Channel coding and Rayleigh fading. Simulation results represent significant enhancement on performance of network in terms of reliability, packet failure, average delay, power consumption, and throughput.

  14. 21 CFR 225.30 - Equipment.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Equipment. 225.30 Section 225.30 Food and Drugs... Equipment § 225.30 Equipment. (a) Equipment which is designed to perform its intended function and is properly installed and used is essential to the manufacture of medicated feeds. Such equipment permits...

  15. Communication, opponents, and clan performance in online games: a social network approach.

    Science.gov (United States)

    Lee, Hong Joo; Choi, Jaewon; Kim, Jong Woo; Park, Sung Joo; Gloor, Peter

    2013-12-01

    Online gamers form clans voluntarily to play together and to discuss their real and virtual lives. Although these clans have diverse goals, they seek to increase their rank in the game community by winning more battles. Communications among clan members and battles with other clans may influence the performance of a clan. In this study, we compared the effects of communication structure inside a clan, and battle networks among clans, with the performance of the clans. We collected battle histories, posts, and comments on clan pages from a Korean online game, and measured social network indices for communication and battle networks. Communication structures in terms of density and group degree centralization index had no significant association with clan performance. However, the centrality of clans in the battle network was positively related to the performance of the clan. If a clan had many battle opponents, the performance of the clan improved.

  16. Evaluation on the Collection Efficiency and Performance of the Sound Pressure Machine Equipped with a HEPA Filter Eliminating Asbestos Particles

    Directory of Open Access Journals (Sweden)

    Park Wha Me

    2016-01-01

    Full Text Available When the one-pass collection efficiency of each size of particles of the sound pressure machine equipped with a glass fiber HEPA filter to get rid of friable asbestos at the asbestos elimination field was evaluated, the collection efficiency of those with the size of 0.3um was examined to be 98.91%. That of the particles of 0.5um size was proved to be 99.21% on average, which is a little bit higher than that of 0.3um size. The 1.0um particles showed 100% of efficiency, and the collection efficiency of each size had statistically meaningful differences.

  17. Solar Equipment

    Science.gov (United States)

    1983-01-01

    A medical refrigeration and a water pump both powered by solar cells that convert sunlight directly into electricity are among the line of solar powered equipment manufactured by IUS (Independent Utility Systems) for use in areas where conventional power is not available. IUS benefited from NASA technology incorporated in the solar panel design and from assistance provided by Kerr Industrial Applications Center.

  18. Network performance, hub connectivity potential, and competitive position of primary airports in Asia/Pacific region

    NARCIS (Netherlands)

    Matsumoto, H.; Veldhuis, J.; de Wit, J.; Burghouwt, G.

    2008-01-01

    Recently, hub-and-spoke network configurations are more and more developed in the Asia/Pacific region. In this paper, it is argued that the measurement of network performance in hub-and-spoke systems should take into account the quantity and quality of both direct and indirect connections. The

  19. Comparing Performance of Different Neural Networks for Early Detection of Cancer from Benign Hyperplasia of Prostate

    Directory of Open Access Journals (Sweden)

    Mustafa GHADERZADEH

    2013-09-01

    Full Text Available Prostate cancer is one of the most common types of cancer found in men. Presenting a classifier in order classifies between Prostate Cancer (PCa and benign hyperplasia of prostate (BPH, has been great challenge among computer experts and medical specialists. There are a number of techniques proposed to perform such classification. Neural networks are one of the artificial intelligent techniques that have successful examples when applying to such problems. The increasing demand of Artificial Neural Network applications for predicting the disease shows better performance in the field of medical decision-making. This paper presents a comparison of neural network techniques for classification prostate neoplasia diseases. The classification performance obtained by four different types of neural networks for comparison are Back Propagation Neural Network (BPNN, General Regression Neural Network(GRNN, Probabilistic Neural Network (PNN and Radial Basis Function Neural Network (RBFNN. Result of these evaluation show that the overall performance of RBFNN can be apply successfully for detecting and diagnosing the cancer from benign hyperplasia of prostate.

  20. Social Networks and Students' Performance in Secondary Schools: Lessons from an Open Learning Centre, Kenya

    Science.gov (United States)

    Muhingi, Wilkins Ndege; Mutavi, Teresia; Kokonya, Donald; Simiyu, Violet Nekesa; Musungu, Ben; Obondo, Anne; Kuria, Mary Wangari

    2015-01-01

    Given the known positive and negative effects of uncontrolled social networking among secondary school students worldwide, it is necessary to establish the relationship between social network sites and academic performances among secondary school students. This study, therefore, aimed at establishing the relationship between secondary school…

  1. A comparative performance evaluation of neural network based approach for sentiment classification of online reviews

    Directory of Open Access Journals (Sweden)

    G. Vinodhini

    2016-01-01

    Full Text Available The aim of sentiment classification is to efficiently identify the emotions expressed in the form of text messages. Machine learning methods for sentiment classification have been extensively studied, due to their predominant classification performance. Recent studies suggest that ensemble based machine learning methods provide better performance in classification. Artificial neural networks (ANNs are rarely being investigated in the literature of sentiment classification. This paper compares neural network based sentiment classification methods (back propagation neural network (BPN, probabilistic neural network (PNN & homogeneous ensemble of PNN (HEN using varying levels of word granularity as features for feature level sentiment classification. They are validated using a dataset of product reviews collected from the Amazon reviews website. An empirical analysis is done to compare results of ANN based methods with two statistical individual methods. The methods are evaluated using five different quality measures and results show that the homogeneous ensemble of the neural network method provides better performance. Among the two neural network approaches used, probabilistic neural networks (PNNs outperform in classifying the sentiment of the product reviews. The integration of neural network based sentiment classification methods with principal component analysis (PCA as a feature reduction technique provides superior performance in terms of training time also.

  2. Performance of artificial neural networks and genetical evolved artificial neural networks unfolding techniques

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz R, J. M. [Escuela Politecnica Superior, Departamento de Electrotecnia y Electronica, Avda. Menendez Pidal s/n, Cordoba (Spain); Martinez B, M. R.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Gallego D, E.; Lorente F, A. [Universidad Politecnica de Madrid, Departamento de Ingenieria Nuclear, ETSI Industriales, C. Jose Gutierrez Abascal 2, 28006 Madrid (Spain); Mendez V, R.; Los Arcos M, J. M.; Guerrero A, J. E., E-mail: morvymm@yahoo.com.m [CIEMAT, Laboratorio de Metrologia de Radiaciones Ionizantes, Avda. Complutense 22, 28040 Madrid (Spain)

    2011-02-15

    With the Bonner spheres spectrometer neutron spectrum is obtained through an unfolding procedure. Monte Carlo methods, Regularization, Parametrization, Least-squares, and Maximum Entropy are some of the techniques utilized for unfolding. In the last decade methods based on Artificial Intelligence Technology have been used. Approaches based on Genetic Algorithms and Artificial Neural Networks (Ann) have been developed in order to overcome the drawbacks of previous techniques. Nevertheless the advantages of Ann still it has some drawbacks mainly in the design process of the network, vg the optimum selection of the architectural and learning Ann parameters. In recent years the use of hybrid technologies, combining Ann and genetic algorithms, has been utilized to. In this work, several Ann topologies were trained and tested using Ann and Genetically Evolved Artificial Neural Networks in the aim to unfold neutron spectra using the count rates of a Bonner sphere spectrometer. Here, a comparative study of both procedures has been carried out. (Author)

  3. 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

  4. Social networks and small businesses performance in West African border regions

    DEFF Research Database (Denmark)

    Kuépié, Mathias; Tenikue, Michel; Walther, Olivier

    2016-01-01

    burden that leads to a negative economic impact. Testing the effect of social networks between small traders and three categories of actors, we find that the most well-connected actors are also the most successful in terms of monthly profit. The effects of social networks are, however, dependent...... with traditional religious leaders has a negative effect on economic performance. Our work has two implications: first, collecting data on social networks remains challenging due to endogeneity. Second, network-enhancing policies should aim at improving both the internal connectivity of economic actors...

  5. Performance Analysis of On-Demand Routing Protocols in Wireless Mesh Networks

    Directory of Open Access Journals (Sweden)

    Arafatur RAHMAN

    2009-01-01

    Full Text Available Wireless Mesh Networks (WMNs have recently gained a lot of popularity due to their rapid deployment and instant communication capabilities. WMNs are dynamically self-organizing, self-configuring and self-healing with the nodes in the network automatically establishing an adiej hoc network and preserving the mesh connectivity. Designing a routing protocol for WMNs requires several aspects to consider, such as wireless networks, fixed applications, mobile applications, scalability, better performance metrics, efficient routing within infrastructure, load balancing, throughput enhancement, interference, robustness etc. To support communication, various routing protocols are designed for various networks (e.g. ad hoc, sensor, wired etc.. However, all these protocols are not suitable for WMNs, because of the architectural differences among the networks. In this paper, a detailed simulation based performance study and analysis is performed on the reactive routing protocols to verify the suitability of these protocols over such kind of networks. Ad Hoc On-Demand Distance Vector (AODV, Dynamic Source Routing (DSR and Dynamic MANET On-demand (DYMO routing protocol are considered as the representative of reactive routing protocols. The performance differentials are investigated using varying traffic load and number of source. Based on the simulation results, how the performance of each protocol can be improved is also recommended.

  6. Chapter 12. Space Heating Equipment

    Energy Technology Data Exchange (ETDEWEB)

    Rafferty, Kevin D.

    1998-01-01

    The performance evaluation of space heating equipment for a geothermal application is generally considered from either of two perspectives: (a) selecting equipment for installation in new construction, or (b) evaluating the performance and retrofit requirements of an existing system. With regard to new construction, the procedure is relatively straightforward. Once the heating requirements are determined, the process need only involve the selection of appropriately sized hot water heating equipment based on the available water temperature. It is important to remember that space heating equipment for geothermal applications is the same equipment used in non-geothermal applications. What makes geothermal applications unique is that the equipment is generally applied at temperatures and flow rates that depart significantly from traditional heating system design. This chapter presents general considerations for the performance of heating equipment at non-standard temperature and flow conditions, retrofit of existing systems, and aspects of domestic hot water heating.

  7. Enhanced Effective Filtering Approach (eEFA for Improving HSR Network Performance in Smart Grids

    Directory of Open Access Journals (Sweden)

    Nguyen Xuan Tien

    2018-01-01

    Full Text Available The effective filtering approach (EFA is one of the most effective approaches for improving the network traffic performance of high-availability seamless redundancy (HSR networks. However, because EFA uses port locking (PL for detecting nondestination doubly-attached nodes with HSR protocol (DANH rings in HSR networks, it forwards the first sent frame to all DANH rings in the network. In addition, it uses a control message for discovering passive QuadBox rings in both unidirectional and bidirectional communications. In this study, we propose an enhanced version of EFA called enhanced-EFA (eEFA that does not forward unicast frames to nondestination DANH rings. eEFA does not use any control message to discover passive QuadBox rings in bidirectional communications. eEFA thus reduces the network traffic in HSR networks compared with EFA. Analytical and simulation results for a sample network show that the traffic reduction of eEFA was 4–26% and 2–20% for unidirectional and bidirectional communications, respectively, compared to EFA. eEFA, thus, clearly saves network bandwidth and improves the network performance.

  8. The Innovation Network Scoreboard: Towards key Performance Indicators for the Assessment of Innovation Networks

    NARCIS (Netherlands)

    Kohl, Holger; Cap, Jan-Patrick; Blaich, Erik; von Raesfeld Meijer, Ariane M.; Dameri, R.P.; Garelli, R.; Resta, M.; Beltrametti, L.

    2015-01-01

    This work operationalizes a framework for the assessment of innovation networks. While a theoretical framework provides value to scholars, practitioners require concrete methods and indicators that they can apply to their projects. Scholars face the same demand when conducting empirical research.

  9. Analysis on the performance dependency of channel models in a wireless peer-to-peer network

    Science.gov (United States)

    Wang, Yupeng; Liu, Tianlong; Yu, Zelong; Li, Yufeng

    2017-08-01

    In order to reduce the simulation complexity and time of peer-to-peer network such as Ad Hoc network, most simulations only use the simplified Free Space Model or Two Ray Ground model to approximate the attenuation due to the wireless transmission without considering the dependency between system performance and channel models. In this paper, the effects of channel models on the wireless peer-to-peer network performance is analyzed in more details by using the conventional routing and medium access control algorithm to find the system performance sensitivity to different channel models. Through the computer simulation using network simulator 2, we found that some aspects of the system performance is only sensitive to the large scale fading effects, while others are not.

  10. Significant performance improvement obtained in a wireless mesh network using a beamswitching antenna

    CSIR Research Space (South Africa)

    Lysko, AA

    2012-09-01

    Full Text Available The paper describes the performance enhancement obtained by adding an electronically controlled beamswitching antenna to a laboratory set up of a wireless mesh network. The antenna permits several modes offering several beam shapes and directions...

  11. Performance analysis of selective cooperation in underlay cognitive networks over Rayleigh channels

    KAUST Repository

    Hussain, Syed Imtiaz

    2011-06-01

    Underlay cognitive networks should follow strict interference thresholds to operate in parallel with primary networks. This constraint limits their transmission power and eventually the area of coverage. Therefore, it is very likely that the underlay networks will make use of relays to transmit signals to the distant secondary users. In this paper, we propose a secondary relay selection scheme which maximizes the end-to-end signal to noise ratio (SNR) for the secondary link while keeping the interference levels to the primary network below a certain threshold. We derive closed form expressions for the probability density function (PDF) of the SNR at the secondary destination, average bit error probability and outage probability. Analytical results are verified through simulations which also give insight about the benefits and tradeoffs of the selective cooperation in underlay cognitive networks. It is shown that, in contrast to non-cognitive selective cooperation, this scheme performs better in low SNR region for cognitive networks. © 2011 IEEE.

  12. Heat transfer equipment performance diagnosis of auxiliary systems in electric power stations; Diagnostico de comportamiento de equipo de transferencia de calor de sistemas auxiliares de centrales termoelectricas

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz Esparza Gutierrez, Rogelio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1990-12-31

    In this article the methodology followed to diagnose the performance of the equipment where heat is transferred from the feed water, condensate and circulation water systems in fossil power plants (FPP). The data collection is made with the unit in normal operation, using local instrumentation without taking the equipment out of service for its installation. The equipment diagnosis is made through the analysis of the collected data in actual operation and the design data; for this purpose a thermal balance of the interested systems is performed to obtain all the conditions an operation data. Later on the performance indicative parameters (PIP) of actual operation and design are calculated and compared one against the other. Such a comparison reveals the performance deterioration and the possible equipment faults. The data obtained and the supplementary information are stored in a data base whose objective is that Comision Federal de Electricidad has on hand a prompt access to them in order to control the performance, compare them among similar units and power stations, and inclusively verify possible recurrent causes of low availability in the referred systems. [Espanol] En este articulo se presenta la metodologia seguida para diagnosticar el comportamiento de equipos en los que se transfiere calor de los sistemas de agua de alimentacion, condensado y circulacion de las centrales termoelectricas (CTE). La toma de datos se realiza con la unidad en operacion normal, utilizando instrumentacion local sin necesidad de sacar de servicio a los equipos para su instalacion, ya que se ocupan los mismos puntos para instrumentos con que cuentan por diseno. El diagnostico de los equipos se realiza mediante el analisis de los datos recopilados, tanto de operacion real como de diseno; para ello, se efectua un balance termico de los sistemas de interes para obtener todas las condiciones y los datos de operacion. Posteriormente, se calculan los parametros indicativos de

  13. A comparison of back propagation and generalized regression neural networks performance in neutron spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz R, J. M.; Martinez B, M. R.; Solis S, L. O.; Castaneda M, R. [Universidad Autonoma de Zacatecas, Unidad Academica de Ingenieria Electrica, Av. Ramon Lopez Velarde 801, Col. Centro, 98000 Zacatecas, Zac. (Mexico); Vega C, H. R., E-mail: morvymm@yahoo.com.mx [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico)

    2015-10-15

    The process of unfolding the neutron energy spectrum has been the subject of research for many years. Monte Carlo, iterative methods, the bayesian theory, the principle of maximum entropy are some of the methods used. The drawbacks associated with traditional unfolding procedures have motivated the need of complementary approaches. Back Propagation Neural Networks (BPNN), have been applied with success in the neutron spectrometry and dosimetry domains, however, the structure and the learning parameters are factors that contribute in a significant way in the networks performance. In artificial neural network domain, Generalized Regression Neural Network (GRNN) is one of the simplest neural networks in term of network architecture and learning algorithm. The learning is instantaneous, which mean require no time for training. Opposite to BPNN, a GRNN would be formed instantly with just a 1-pass training with the development data. In the network development phase, the only hurdle is to tune the hyper parameter, which is known as sigma, governing the smoothness of the network. The aim of this work was to compare the performance of BPNN and GRNN in the solution of the neutron spectrometry problem. From results obtained can be observed that despite the very similar results, GRNN performs better than BPNN. (Author)

  14. Performance comparison of multi-domain routing schemes in GMPLS networks with BGP

    DEFF Research Database (Denmark)

    Manolova, Anna Vasileva; Ruepp, Sarah Renée; Dittmann, Lars

    2009-01-01

    We compare an enhancement of the BGP protocol for TE support in GMPLS networks with a simple TE extension of BGP in terms of signaling overhead and connection blocking ratio. Our results show increased performance of the enhanced BGP.......We compare an enhancement of the BGP protocol for TE support in GMPLS networks with a simple TE extension of BGP in terms of signaling overhead and connection blocking ratio. Our results show increased performance of the enhanced BGP....

  15. Hardware Neural Networks Modeling for Computing Different Performance Parameters of Rectangular, Circular, and Triangular Microstrip Antennas

    Directory of Open Access Journals (Sweden)

    Taimoor Khan

    2014-01-01

    Full Text Available In the last one decade, neural networks-based modeling has been used for computing different performance parameters of microstrip antennas because of learning and generalization features. Most of the created neural models are based on software simulation. As the neural networks show massive parallelism inherently, a parallel hardware needs to be created for creating faster computing machine by taking the advantages of the parallelism of the neural networks. This paper demonstrates a generalized neural networks model created on field programmable gate array- (FPGA- based reconfigurable hardware platform for computing different performance parameters of microstrip antennas. Thus, the proposed approach provides a platform for developing low-cost neural network-based FPGA simulators for microwave applications. Also, the results obtained by this approach are in very good agreement with the measured results available in the literature.

  16. 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.

  17. High-performance image communication network with asynchronous transfer mode technology

    Science.gov (United States)

    Wong, Albert W. K.; Huang, H. K.; Lee, Joseph K.; Bazzill, Todd M.; Zhu, Xiaoming

    1996-05-01

    Asynchronous transfer mode (ATM) technology has been implemented within our radiology department's hospital-wide PACS as well as in a wide area network (WAN) connecting affiliated hospitals. This paper describes our implementation strategies and the network performance observed in a clinical setting. The image communication network for our PACS is composed of two network interfaces: ATM (OC-3, 155 Mbps) and Ethernet (10 Mbps). This communication network connects four major campus buildings and two remote hospitals, providing intra- and interbuilding communication for radiologic images including CT, MR, CR, US, and digitized screen-film images. The network links these modalities via their acquisition computers to the PACS controller and to display workstations. The ATM serves as the primary network for transmission of radiologic images and relevant data within the entire PACS. The standard Ethernet is used as a backup network for ATM. It interconnects all PACS components including radiologic imaging systems, acquisition computers, display workstations, the PACS controller, the database servers, and the RIS and HIS. Our communication network operates on a 24 hrs/day, 7 days/week basis. Performance of the ATM network was evaluated in terms of disk-to-disk, disk-to-memory, and memory-to- memory transmission rates. The average memory-to-memory transmission rate over the wide area ATM network was 8.3 MByte/s, which corresponds to transferring a 40-slice (or, 20- MByte) CT examination to a remote site in less than 3 seconds. With the emerging ATM technology, we believe that ATM-based digital communication network is a suitable choice for large-scale PACS involving both LAN and WAN.

  18. Evaluating the Effects of Clothing and Individual Equipment on Marksmanship Performance Using a Novel Five Target Methodology

    Science.gov (United States)

    2016-11-01

    NUMBER 13-137, 15-025 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION...Reprint of a paper presented at Proceedings of the Human Factors and Ergonomics Society (HFE) Annual Meeting 2016. 19-23 September, 2016. Washington...provide insight into how a product will perform in an operational environment (Johnson, McMenemy & Dauphinee, 1990; Johnson & Kobrick, 1997; Bensel

  19. Performance Improvement of Membrane Stress Measurement Equipment through Evaluation of Added Mass of Membrane and Error Correction

    Directory of Open Access Journals (Sweden)

    Sang-Wook Jin

    2017-01-01

    Full Text Available One of the most important issues in keeping membrane structures in stable condition is to maintain the proper stress distribution over the membrane. However, it is difficult to determine the quantitative real stress level in the membrane after the completion of the structure. The stress relaxation phenomenon of the membrane and the fluttering effect due to strong wind or ponding caused by precipitation may cause severe damage to the membrane structure itself. Therefore, it is very important to know the magnitude of the existing stress in membrane structures for their maintenance. The authors have proposed a new method for separately estimating the membrane stress in two different directions using sound waves instead of directly measuring the membrane stress. The new method utilizes the resonance phenomenon of the membrane, which is induced by sound excitations given through an audio speaker. During such experiment, the effect of the surrounding air on the vibrating membrane cannot be overlooked in order to assure high measurement precision. In this paper, an evaluation scheme for the added mass of membrane with the effect of air on the vibrating membrane and the correction of measurement error is discussed. In addition, three types of membrane materials are used in the experiment in order to verify the expandability and accuracy of the membrane measurement equipment.

  20. LTE, WiMAX and WLAN network design, optimization and performance analysis

    CERN Document Server

    Korowajczuk, Leonhard

    2011-01-01

    A technological overview of LTE and WiMAX LTE, WiMAX and WLAN Network Design, Optimization and Performance Analysis provides a practical guide to LTE and WiMAX technologies introducing various tools and concepts used within. In addition, topics such as traffic modelling of IP-centric networks, RF propagation, fading, mobility, and indoor coverage are explored; new techniques which increase throughput such as MIMO and AAS technology are highlighted; and simulation, network design and performance analysis are also examined. Finally, in the latter part of the book Korowajczuk gives a step-by-step

  1. Long-term effects of attentional performance on functional brain network topology.

    Directory of Open Access Journals (Sweden)

    Thomas P K Breckel

    Full Text Available Individuals differ in their cognitive resilience. Less resilient people demonstrate a greater tendency to vigilance decrements within sustained attention tasks. We hypothesized that a period of sustained attention is followed by prolonged changes in the organization of "resting state" brain networks and that individual differences in cognitive resilience are related to differences in post-task network reorganization. We compared the topological and spatial properties of brain networks as derived from functional MRI data (N = 20 recorded for 6 mins before and 12 mins after the performance of an attentional task. Furthermore we analysed changes in brain topology during task performance and during the switches between rest and task conditions. The cognitive resilience of each individual was quantified as the rate of increase in response latencies over the 32-minute time course of the attentional paradigm. On average, functional networks measured immediately post-task demonstrated significant and prolonged changes in network organization compared to pre-task networks with higher connectivity strength, more clustering, less efficiency, and shorter distance connections. Individual differences in cognitive resilience were significantly correlated with differences in the degree of recovery of some network parameters. Changes in network measures were still present in less resilient individuals in the second half of the post-task period (i.e. 6-12 mins after task completion, while resilient individuals already demonstrated significant reductions of functional connectivity and clustering towards pre-task levels. During task performance brain topology became more integrated with less clustering and higher global efficiency, but linearly decreased with ongoing time-on-task. We conclude that sustained attentional task performance has prolonged, "hang-over" effects on the organization of post-task resting-state brain networks; and that more cognitively

  2. Sales Managers’ Performance and Social Capital: the Impact of an Advice Network

    Directory of Open Access Journals (Sweden)

    Danny Pimentel Claro

    2009-10-01

    Full Text Available The aim of this study is to research a sales manager’s social network and demonstrate that sales managers who are central in closure structures of an advice network achieve high sales performance. Considering the results obtained and the discussion provided in the hypotheses presentation, we argue that sales managers must have accurate perceptions of their network. Two different networks were analyzed: friendship and advice; and we also considered two different views of network structure that claim to make an impact on performance and, to explore this claim, we examined whether sales managers, in order to improve sales performance, develop either a highly cohesive network or one containing structural holes. Census data was collected from over 500 personnel of an agricultural input retailer with 23 divisions. Estimates from a sample of 101 sales managers demonstrated, in the advice network, how important a highly cohesive structure is to a sales manager’s performance. These results suggest that firms should encourage contacts among their personnel to disseminate and share technical and commercial information. By stimulating cohesive structures of contacts for the purpose of receiving advice, firms create an environment for sales managers to develop relationships of trust in which social norms prevail.

  3. Alternative methods for internal quality control in research laboratories for environmental analysis: a programme for the performance evaluation of equipment, methods and staff

    Energy Technology Data Exchange (ETDEWEB)

    Wieling, J. (Inst. of Environmental Sciences (IMW-TWO), Dept. of Analytical Chemistry, TNO, Delft (Netherlands)); Bakkeren, H.A. (Inst. of Environmental Sciences (IMW-TWO), Dept. of Analytical Chemistry, TNO, Delft (Netherlands)); Peters, R.J.B. (Inst. of Environmental Sciences (IMW-TWO), Dept. of Analytical Chemistry, TNO, Delft (Netherlands)); Gils, W.J.C.G. van (Inst. of Environmental Sciences (IMW-TWO), Dept. of Analytical Chemistry, TNO, Delft (Netherlands)); Leer, E.W.B. de (Inst. of Environmental Sciences (IMW-TWO), Dept. of Analytical Chemistry, TNO, Delft (Netherlands)); Mulder, S.A. (Inst. of Environmental Sciences (IMW-TWO), Dept. of Analytical Chemistry, TNO, Delft (Netherlands)); Burg, P.A. van der (Inst. of Environmental Sciences (IMW-TWO), Dept. of Analytical Chemistry, TNO, Delft (Netherlands)); Renesse van Duivenbode, J.A.D. van (Inst. of Environmental Sciences (IMW-TWO), Dept. of Analytical Chemistry, TNO, Delft (Netherlands))

    1994-04-01

    In analytical research laboratories, the problem of quality assurance is more difficult to solve than in laboratories devoted exclusively to routine analysis: The former usually have to deal with a much geater variety of samples and may have to develop entirely new methods of analysis. For research laboratories we have developed several alternative methods of quality assurance. These methods can be used to distinguish between different analytical methods, between different types of equipment, between different levels of skill among laboratory technicians, or even between the performance of technicians of the same level of skill. (orig.)

  4. Physiological, Biomechanical, and Maximal Performance Comparisons of Female Soldiers Carrying Loads Using Prototype U.S. Marine Corps Modular Lightweight Load-Carrying Equipment (MOLLE) with Interceptor Body Armor and U.S. Army All-Purpose Lightweight Individual Carrying Equipment (ALICE) with PASGT Body Armor

    National Research Council Canada - National Science Library

    Harman, Everett

    1999-01-01

    The experiment evaluated the physiological, biomechanical, and maximal performance responses of 12 female soldiers carrying loads with prototype Modular Lightweight Load-Carrying Equipment with Interceptor body armor (MOLLE...

  5. 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.

  6. Interplant coordination, supply chain integration, and operational performance of a plant in a manufacturing network

    DEFF Research Database (Denmark)

    Yang, Cheng; Chaudhuri, Atanu; Farooq, Sami

    2016-01-01

    Purpose The objective of this paper is to investigate the relationships at the level of plant in a manufacturing network, labelled as networked plant in the paper, between (1) inter-plant coordination and operational performance, (2) supply chain integration (SCI) and operational performance......, and (3) inter-plant coordination and SCI. Design/methodology/approach This paper is developed based on the data obtained from the sixth version of International Manufacturing Strategy Survey (IMSS VI). Specifically, this paper uses a subset of the IMSS VI data set from the 606 plants that identified...... themselves as one of the plants in a manufacturing network. Findings This paper finds that external integration is significantly related to operational performance of networked plant, whereas internal integration is not. As an enabler for external integration, the influence of internal integration...

  7. Hybrid Neural-Network: Genetic Algorithm Technique for Aircraft Engine Performance Diagnostics Developed and Demonstrated

    Science.gov (United States)

    Kobayashi, Takahisa; Simon, Donald L.

    2002-01-01

    As part of the NASA Aviation Safety Program, a unique model-based diagnostics method that employs neural networks and genetic algorithms for aircraft engine performance diagnostics has been developed and demonstrated at the NASA Glenn Research Center against a nonlinear gas turbine engine model. Neural networks are applied to estimate the internal health condition of the engine, and genetic algorithms are used for sensor fault detection, isolation, and quantification. This hybrid architecture combines the excellent nonlinear estimation capabilities of neural networks with the capability to rank the likelihood of various faults given a specific sensor suite signature. The method requires a significantly smaller data training set than a neural network approach alone does, and it performs the combined engine health monitoring objectives of performance diagnostics and sensor fault detection and isolation in the presence of nominal and degraded engine health conditions.

  8. Analysis of Latency Performance of Bluetooth Low Energy (BLE Networks

    Directory of Open Access Journals (Sweden)

    Keuchul Cho

    2014-12-01

    Full Text Available Bluetooth Low Energy (BLE is a short-range wireless communication technology aiming at low-cost and low-power communication. The performance evaluation of classical Bluetooth device discovery have been intensively studied using analytical modeling and simulative methods, but these techniques are not applicable to BLE, since BLE has a fundamental change in the design of the discovery mechanism, including the usage of three advertising channels. Recently, there several works have analyzed the topic of BLE device discovery, but these studies are still far from thorough. It is thus necessary to develop a new, accurate model for the BLE discovery process. In particular, the wide range settings of the parameters introduce lots of potential for BLE devices to customize their discovery performance. This motivates our study of modeling the BLE discovery process and performing intensive simulation. This paper is focused on building an analytical model to investigate the discovery probability, as well as the expected discovery latency, which are then validated via extensive experiments. Our analysis considers both continuous and discontinuous scanning modes. We analyze the sensitivity of these performance metrics to parameter settings to quantitatively examine to what extent parameters influence the performance metric of the discovery processes.

  9. Analysis of latency performance of bluetooth low energy (BLE) networks.

    Science.gov (United States)

    Cho, Keuchul; Park, Woojin; Hong, Moonki; Park, Gisu; Cho, Wooseong; Seo, Jihoon; Han, Kijun

    2014-12-23

    Bluetooth Low Energy (BLE) is a short-range wireless communication technology aiming at low-cost and low-power communication. The performance evaluation of classical Bluetooth device discovery have been intensively studied using analytical modeling and simulative methods, but these techniques are not applicable to BLE, since BLE has a fundamental change in the design of the discovery mechanism, including the usage of three advertising channels. Recently, there several works have analyzed the topic of BLE device discovery, but these studies are still far from thorough. It is thus necessary to develop a new, accurate model for the BLE discovery process. In particular, the wide range settings of the parameters introduce lots of potential for BLE devices to customize their discovery performance. This motivates our study of modeling the BLE discovery process and performing intensive simulation. This paper is focused on building an analytical model to investigate the discovery probability, as well as the expected discovery latency, which are then validated via extensive experiments. Our analysis considers both continuous and discontinuous scanning modes. We analyze the sensitivity of these performance metrics to parameter settings to quantitatively examine to what extent parameters influence the performance metric of the discovery processes.

  10. On the MAC/Network/Energy Performance Evaluation of Wireless Sensor Networks: Contrasting MPH, AODV, DSR and ZTR Routing Protocols

    Science.gov (United States)

    Del-Valle-Soto, Carolina; Mex-Perera, Carlos; Orozco-Lugo, Aldo; Lara, Mauricio; Galván-Tejada, Giselle M.; Olmedo, Oscar

    2014-01-01

    Wireless Sensor Networks deliver valuable information for long periods, then it is desirable to have optimum performance, reduced delays, low overhead, and reliable delivery of information. In this work, proposed metrics that influence energy consumption are used for a performance comparison among our proposed routing protocol, called Multi-Parent Hierarchical (MPH), the well-known protocols for sensor networks, Ad hoc On-Demand Distance Vector (AODV), Dynamic Source Routing (DSR), and Zigbee Tree Routing (ZTR), all of them working with the IEEE 802.15.4 MAC layer. Results show how some communication metrics affect performance, throughput, reliability and energy consumption. It can be concluded that MPH is an efficient protocol since it reaches the best performance against the other three protocols under evaluation, such as 19.3% reduction of packet retransmissions, 26.9% decrease of overhead, and 41.2% improvement on the capacity of the protocol for recovering the topology from failures with respect to AODV protocol. We implemented and tested MPH in a real network of 99 nodes during ten days and analyzed parameters as number of hops, connectivity and delay, in order to validate our simulator and obtain reliable results. Moreover, an energy model of CC2530 chip is proposed and used for simulations of the four aforementioned protocols, showing that MPH has 15.9% reduction of energy consumption with respect to AODV, 13.7% versus DSR, and 5% against ZTR. PMID:25474377

  11. Network Performance Evaluation of Abis Interface over DVB-S2 in the GSM over Satellite Network

    Directory of Open Access Journals (Sweden)

    S. B. Musabekov

    2010-01-01

    Full Text Available This paper deals with establishing a GSM link over Satellite. Abis interface, which is defined between Base Transceiver Station (BTS and Base Station Controller (BSC, in a GSM network is considered here to be routed over the Satellite. The satellite link enables a quick and cost-effective GSM link in meagerly populated areas. A different scenario comparison was done to understand the impact of Satellite environment on network availability comparing to terrestrial scenario. We have implemented an Abis interface over DVB S2 in NS2 and evaluated the performance over the high delay and loss satellite channel. Network performance was evaluated with respect to Satellite channel delay and DVB S2 encapsulation efficiency under different amount of user traffic and compared with the terrestrial scenario. The results clearly showed an increased amount of SDCCH and TCH channels required in the case of satellite scenario for the same amount of traffic in comparison to conventional terrestrial scenario. We have optimized the parameters based on the simulation results. Link budget estimation considering DVB-S2 platform was done to find satellite bandwidth and cost requirements for different network setups.

  12. Team Sports Performance Analysed Through the Lens of Social Network Theory: Implications for Research and Practice.

    Science.gov (United States)

    Ribeiro, João; Silva, Pedro; Duarte, Ricardo; Davids, Keith; Garganta, Júlio

    2017-09-01

    This paper discusses how social network analyses and graph theory can be implemented in team sports performance analyses to evaluate individual (micro) and collective (macro) performance data, and how to use this information for designing practice tasks. Moreover, we briefly outline possible limitations of social network studies and provide suggestions for future research. Instead of cataloguing discrete events or player actions, it has been argued that researchers need to consider the synergistic interpersonal processes emerging between teammates in competitive performance environments. Theoretical assumptions on team coordination prompted the emergence of innovative, theoretically driven methods for assessing collective team sport behaviours. Here, we contribute to this theoretical and practical debate by re-conceptualising sports teams as complex social networks. From this perspective, players are viewed as network nodes, connected through relevant information variables (e.g. a ball-passing action), sustaining complex patterns of interaction between teammates (e.g. a ball-passing network). Specialised tools and metrics related to graph theory could be applied to evaluate structural and topological properties of interpersonal interactions of teammates, complementing more traditional analysis methods. This innovative methodology moves beyond the use of common notation analysis methods, providing a richer understanding of the complexity of interpersonal interactions sustaining collective team sports performance. The proposed approach provides practical applications for coaches, performance analysts, practitioners and researchers by establishing social network analyses as a useful approach for capturing the emergent properties of interactions between players in sports teams.

  13. A Step towards Developing a Sustainability Performance Measure within Industrial Networks

    Directory of Open Access Journals (Sweden)

    Samaneh Shokravi

    2014-04-01

    Full Text Available Despite the plethora of literature in sustainability and supply chain management in the recent years, a quantitative tool that measures the sustainability performance of an industrial supply network, considering the uncertainties of existing data, is hard to find. This conceptual paper is aimed at establishing a quantitative measure for the sustainability performance of industrial supply networks that considers aleatory and epistemic uncertainties in its environmental performance evaluation. The measure is built upon economic, environmental and social performance evaluation models. These models address a number of shortcomings in the literature, such as incomplete and inaccurate calculation of environmental impacts, as well as the disregard for aleatory and epistemic uncertainties in the input data and, more importantly, the scarce number of quantitative social sustainability measures. Dyadic interactions are chosen for the network, while the network members have a revenue-sharing relationship. This relationship promotes sharing of the required information for the use of the proposed model. This measure provides an approach to quantify the environmental, social and economic sustainability performances of a supply network. Moreover, as this measure is not specifically designed for an industrial sector, it can be employed over an evolving and diverse industrial network.

  14. High-performance parallel interface to synchronous optical network gateway

    Science.gov (United States)

    St. John, Wallace B.; DuBois, David H.

    1996-01-01

    A system of sending and receiving gateways interconnects high speed data interfaces, e.g., HIPPI interfaces, through fiber optic links, e.g., a SONET network. An electronic stripe distributor distributes bytes of data from a first interface at the sending gateway onto parallel fiber optics of the fiber optic link to form transmitted data. An electronic stripe collector receives the transmitted data on the parallel fiber optics and reforms the data into a format effective for input to a second interface at the receiving gateway. Preferably, an error correcting syndrome is constructed at the sending gateway and sent with a data frame so that transmission errors can be detected and corrected in a real-time basis. Since the high speed data interface operates faster than any of the fiber optic links the transmission rate must be adapted to match the available number of fiber optic links so the sending and receiving gateways monitor the availability of fiber links and adjust the data throughput accordingly. In another aspect, the receiving gateway must have sufficient available buffer capacity to accept an incoming data frame. A credit-based flow control system provides for continuously updating the sending gateway on the available buffer capacity at the receiving gateway.

  15. 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.

  16. THE IMPROVEMENT OF COMPUTER NETWORK PERFORMANCE WITH BANDWIDTH MANAGEMENT IN KEMURNIAN II SENIOR HIGH SCHOOL

    Directory of Open Access Journals (Sweden)

    Bayu Kanigoro

    2012-05-01

    Full Text Available This research describes the improvement of computer network performance with bandwidth management in Kemurnian II Senior High School. The main issue of this research is the absence of bandwidth division on computer, which makes user who is downloading data, the provided bandwidth will be absorbed by the user. It leads other users do not get the bandwidth. Besides that, it has been done IP address division on each room, such as computer, teacher and administration room for supporting learning process in Kemurnian II Senior High School, so wireless network is needed. The method is location observation and interview with related parties in Kemurnian II Senior High School, the network analysis has run and designed a new topology network including the wireless network along with its configuration and separation bandwidth on microtic router and its limitation. The result is network traffic on Kemurnian II Senior High School can be shared evenly to each user; IX and IIX traffic are separated, which improve the speed on network access at school and the implementation of wireless network.Keywords: Bandwidth Management; Wireless Network

  17. Electrical signature analysis to quantify human and animal performance on fitness and therapy equipment such as a treadmill

    Science.gov (United States)

    Cox, Daryl F.; Hochanadel, Charles D.; Haynes, Howard D.

    2010-05-18

    The invention is a human and animal performance data acquisition, analysis, and diagnostic system for fitness and therapy devices having an interface box removably disposed on incoming power wiring to a fitness and therapy device, at least one current transducer removably disposed on said interface box for sensing current signals to said fitness and therapy device, and a means for analyzing, displaying, and reporting said current signals to determine human and animal performance on said device using measurable parameters.

  18. 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.

  19. Dynamic Social Networks in High Performance Football Coaching

    Science.gov (United States)

    Occhino, Joseph; Mallett, Cliff; Rynne, Steven

    2013-01-01

    Background: Sports coaching is largely a social activity where engagement with athletes and support staff can enhance the experiences for all involved. This paper examines how high performance football coaches develop knowledge through their interactions with others within a social learning theory framework. Purpose: The key purpose of this study…

  20. Performance evaluation of routing metrics for wireless mesh networks

    CSIR Research Space (South Africa)

    Nxumalo, SL

    2009-08-01

    Full Text Available for WMN. The routing metrics have not been compared with QoS parameters. This paper is a work in progress of the project in which researchers want to compare the performance of different routing metrics in WMN using a wireless test bed. Researchers...

  1. Modeling the Effect of Bandwidth Allocation on Network Performance

    African Journals Online (AJOL)

    Our findings revealed that the uplink and downlink throughputs of the existing system were not impressive even when there was uniform sharing of bottlenecks across the BSs. Using MATLAB, simulations were then performed by extending these data, subject to ideal environmental constraints. Results obtained revealed the ...

  2. Implementation and Performance Evaluation Using the Fuzzy Network Balanced Scorecard

    Science.gov (United States)

    Tseng, Ming-Lang

    2010-01-01

    The balanced scorecard (BSC) is a multi-criteria evaluation concept that highlights the importance of performance measurement. However, although there is an abundance of literature on the BSC framework, there is a scarcity of literature regarding how the framework with dependence and interactive relationships should be properly implemented in…

  3. Experimental analysis on filter press and energy consumption performance of diaphragm press drying device in chemical post-processing integrated equipment

    Directory of Open Access Journals (Sweden)

    Yin-Fa Zhu

    2016-03-01

    Full Text Available Higher efficiency, lower energy consumption and less pollution are become more and more important in chemical engineering. Post-process is one of the key parts for producing chemical productions. Thus, we develop a novel device, Chemical Post-Processing Integrated Equipment (CPPIE, which can deal with crystallization, filtration, washing and drying in the same tank by changing the position of it. Without the transfer during these processes, CPPIE have meaningful advantages compared to conventional devices. In this paper, the structure and the working procedure of CPPIE are introduced, and Diaphragm press drying device (DPDD in CPPIE is further described. Then, the experimental setup is arranged. Its drying and energy consumption performances are experimentally investigated. The performance of DPDD is analyzed experimentally with theory to validate it can meet the requirements of industrial applications. Furthermore, the energy consumption for the whole processes is calculated with experimental data. Compared to CPPIE without DPDD, CPPIE with DPDD has energy conservation about 25%. This work presents the feasibility of CPPIE, the advantage of DPDD for drying process with lower energy consumption, which can be referenced for designing similar integrated equipment.

  4. The association between self-perceived proficiency of personal protective equipment and objective performance: An observational study during a bioterrorism simulation drill.

    Science.gov (United States)

    Fogel, Itay; David, Osant; Balik, Chaya H; Eisenkraft, Arik; Poles, Lion; Shental, Omri; Kassirer, Michael; Brosh-Nissimov, Tal

    2017-11-01

    The recent Ebola virus disease outbreak emphasized the potential misuse of personal protective equipment (PPE) by health care workers (HCWs) during such an event. We aimed to compare self-perceived proficiency of PPE use and objective performance, and identify predictors of low compliance and PPE misuse. An observational study combined with subjective questionnaires were carried out during a bioterror simulation drill. Forty-two observers evaluated performance under PPE. Mistakes were recorded and graded using a structured observational format and were correlated with the subjective questionnaires and with demographic parameters. One hundred seventy-eight HCWs from community clinics and hospitals were included. The mean self-perceived proficiency was high (6.1 out of 7), mean level of comfort was moderate (4.0 out of 7), and mean objective performance was intermediate (9.5 out of 13). There was no correlation between comfort and objective performance scores. Self-perceived proficiency was in correlation with donning and continuous performance with PPE but not with doffing. Clinic personnel performed better than personnel in hospitals (40.3% vs 67.8% with 3 or more mistakes, respectively; P = .001). Demographic characteristics had no correlation with objective or self-perceived performance. Self-perceived proficiency is a poor predictor of appropriate PPE use. The results suggest poor awareness of the possibility of PPE misuse. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  5. Cooperative decoding in femtocell networks: Performance-complexity tradeoff

    KAUST Repository

    Benkhelifa, Fatma

    2012-06-01

    Femtocells, which are low cost low power, stand alone cellular access points, are a potential solution to provide good indoor coverage with high data rate. However, the femtocell deployment may also increase the co-channel interference (CCI) by reducing the distance reuse of the spectrum. In this paper, we introduce methods to cancel out the interference among the femtocells while considering that macrocells operate orthogonally to the femtocells. The femtocells may also cooperate through joint detection of the received signal and improve the overall error performance at the expense of an increased computational complexity. In this paper, the performance-complexity tradeoff of cooperative detection is investigated for uplink transmissions. Numerical results show that the cooperative detection gain may reach 10 dB at a Bit-Error Rate (BER) of 10 -2 when compared to the case without cooperation. © 2012 IEEE.

  6. A User-Oriented Performance Index for Packet Switched Networks.

    Science.gov (United States)

    1986-03-01

    Philipines , as well as several NATO countries [Ref. 5: p. 3,4]. The ARPANET still exists as a subnetwork of the DDN, devoted to research and...3.1 Summary of ANSI X3.102 Performance Parameters. the form of a chronological event history . These events observed at each interface provide the basis...consists of a set of standard ASCII character files which record the the real-time event histories from the Data Extraction susbsystem. They are

  7. Performance and Scalability of Blockchain Networks and Smart Contracts

    OpenAIRE

    Scherer, Mattias

    2017-01-01

    The blockchain technology started as the innovation that powered the cryptocurrency Bitcoin. But in recent years, leaders in finance, banking, and many more companies has given this new innovation more attention than ever before. They seek a new technology to replace their system which are often inefficient and costly to operate. However, one of the reasons why it not possible to use a blockchain right away is because of the poor performance. Public blockchains, where anyone can participate, ...

  8. The shortest path algorithm performance comparison in graph and relational database on a transportation network

    Directory of Open Access Journals (Sweden)

    Mario Miler

    2014-02-01

    Full Text Available In the field of geoinformation and transportation science, the shortest path is calculated on graph data mostly found in road and transportation networks. This data is often stored in various database systems. Many applications dealing with transportation network require calculation of the shortest path. The objective of this research is to compare the performance of Dijkstra shortest path calculation in PostgreSQL (with pgRouting and Neo4j graph database for the purpose of determining if there is any difference regarding the speed of the calculation. Benchmarking was done on commodity hardware using OpenStreetMap road network. The first assumption is that Neo4j graph database would be well suited for the shortest path calculation on transportation networks but this does not come without some cost. Memory proved to be an issue in Neo4j setup when dealing with larger transportation networks.

  9. A Formal Verification Model for Performance Analysis of Reinforcement Learning Algorithms Applied t o Dynamic Networks

    Directory of Open Access Journals (Sweden)

    Shrirang Ambaji KULKARNI

    2017-04-01

    Full Text Available Routing data packets in a dynamic network is a difficult and important problem in computer networks. As the network is dynamic, it is subject to frequent topology changes and is subject to variable link costs due to congestion and bandwidth. Existing shortest path algorithms fail to converge to better solutions under dynamic network conditions. Reinforcement learning algorithms posses better adaptation techniques in dynamic environments. In this paper we apply model based Q-Routing technique for routing in dynamic network. To analyze the correctness of Q-Routing algorithms mathematically, we provide a proof and also implement a SPIN based verification model. We also perform simulation based analysis of Q-Routing for given metrics.

  10. INCITE: Edge-based Traffic Processing and Inference for High-Performance Networks

    Energy Technology Data Exchange (ETDEWEB)

    Baraniuk, Richard G.; Feng, Wu-chun; Cottrell, Les; Knightly, Edward; Nowak, Robert; Riedi, Rolf

    2005-06-20

    The INCITE (InterNet Control and Inference Tools at the Edge) Project developed on-line tools to characterize and map host and network performance as a function of space, time, application, protocol, and service. In addition to their utility for trouble-shooting problems, these tools will enable a new breed of applications and operating systems that are network aware and resource aware. Launching from the foundation provided our recent leading-edge research on network measurement, multifractal signal analysis, multiscale random fields, and quality of service, our effort consisted of three closely integrated research thrusts that directly attack several key networking challenges of DOE's SciDAC program. These are: Thrust 1, Multiscale traffic analysis and modeling techniques; Thrust 2, Inference and control algorithms for network paths, links, and routers, and Thrust 3, Data collection tools.

  11. Impact of the environment and the topology on the performance of hierarchical body area networks

    Directory of Open Access Journals (Sweden)

    Ferrari Gianluigi

    2011-01-01

    Full Text Available Abstract Personal area networks and, more specifically, body area networks (BANs are key building blocks of future generation networks and of the Internet of Things as well. In this article, we present a novel analytical framework for network performance analysis of body sensor networks with hierarchical (tree topologies. This framework takes into account the specificities of the on-body channel modeling and the impact of the surrounding environment. The obtained results clearly highlight the differences between indoor and outdoor scenarios, and provide several insights on BAN design and analysis. In particular, it will be shown that the BAN topology should be selected according to the foreseen medical application and the deployment environment.

  12. Performance Analysis of an Energy Efficient Femtocell Network Using Queuing Theory

    Directory of Open Access Journals (Sweden)

    Wanod Kumar

    2013-07-01

    Full Text Available The energy expenditure of cellular networks is increasing rapidly due to high demand of data services by the subscribers. This subsequently gives rise to the CO2 emission which is a critical issue nowadays. A hybrid cellular network comprised of macrocell and several femtocells is required to achieve reliability, continuous connectivity, and energy efficiency. To address the issue of energy efficiency, in this paper we present a queuing model of an energy efficient femtocell network. The transmission of data traffic in this type of network is modeled using M/M/1 queue where server FAP (Femtocell Access Point takes vacation to save energy during inactivity period. The network model is solved using a MGM (Matrix Geometric Method. The performance of the system is evaluated in terms of average system delay and power savings for different sleep cycle durations. Results reveal that the maximum energy can be saved with higher sleep cycle duration at a cost of increased system delay

  13. 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.

  14. 40 CFR Appendix B1 to Subpart F of... - Performance of Refrigerant Recovery, Recycling and/or Reclaim Equipment

    Science.gov (United States)

    2010-07-01

    ... contaminant have the following approximate particle size analysis: Wt. % in various size ranges, pm. Size..., test mixtures, sampling and analysis techniques that will be used to determine the performance of... Figure 1 consists of a 3 cubic foot mixing chamber with a conical-shaped bottom, although a larger mixing...

  15. Spouted bed drying of Bauhinia forficata link extract: the effects of feed atomizer position and operating conditions on equipment performance and product properties

    Directory of Open Access Journals (Sweden)

    C. R. F. Souza

    2005-06-01

    Full Text Available In this paper the effects of feed atomizer position and operating conditions on equipment performance (accumulation rate, product recovery, elutriation and thermal efficiency and product properties (moisture content, size distribution, flavonoid degradation and flow properties during spouted bed drying of Bauhinia forficata Link extract are evaluated. The parameters studied were the position of the atomizer system (top spray or bottom spray, the inlet temperature of the spouting gas (80 and 150oC and the feed mass flow rate of concentrated extract relative to the evaporation capacity of the dryer, Ws/Wmax (15 to 100%. Higher accumulation rate values were obtained with the atomizer placed at the bottom of the bed. In this configuration, the accumulation rate increases with the increase in the Ws/Wmax ratio. The best drying performance was obtained for the top spray configuration.

  16. Subjective Evaluation of Packet Service Performance in UMTS and Heterogeneous Networks

    DEFF Research Database (Denmark)

    Teyeb, Oumer Mohammed; Sørensen, Troels Bundgaard; Mogensen, Preben

    2006-01-01

    Quality of Service (QoS) in mobile telecommunication systems is usually identified by some basic performance metrics such as delay, throughput and jitter. However, the main impact of service quality is on the end user, and as such a detailed study of service performance should involve the end user....... In this paper, such an approach is taken where subjective performance evaluation is undertaken for web browsing and video streaming services in Universal Mobile Telecommunication System (UMTS) and a heterogeneous network comprised of UMTS and Wireless LAN (WLAN). Using a real-time network emulation testbed...

  17. Throughput performance analysis of multirate, multiclass S-ALOHA OFFH-CDMA packet networks

    DEFF Research Database (Denmark)

    Raddo, Thiago R.; Sanches, Anderson L.; Borges, Ben Hur V

    2015-01-01

    In this paper, we propose a new throughput expression for multirate, multiclass slotted-ALOHA optical fast frequency hopping code-division multiple-access (OFFH-CDMA) packet networks considering a Poisson distribution for packet composite arrivals. We analyze the packet throughput performance...... of a three-class OFFH-CDMA network, where multirate transmissions are achieved via manipulation of the user's code parameters. It is shown that users transmitting at low rates interfere considerably in the performance of high rate users. Finally, we perform a validation procedure to demonstrate...

  18. Scalable software-defined optical networking with high-performance routing and wavelength assignment algorithms.

    Science.gov (United States)

    Lee, Chankyun; Cao, Xiaoyuan; Yoshikane, Noboru; Tsuritani, Takehiro; Rhee, June-Koo Kevin

    2015-10-19

    The feasibility of software-defined optical networking (SDON) for a practical application critically depends on scalability of centralized control performance. The paper, highly scalable routing and wavelength assignment (RWA) algorithms are investigated on an OpenFlow-based SDON testbed for proof-of-concept demonstration. Efficient RWA algorithms are proposed to achieve high performance in achieving network capacity with reduced computation cost, which is a significant attribute in a scalable centralized-control SDON. The proposed heuristic RWA algorithms differ in the orders of request processes and in the procedures of routing table updates. Combined in a shortest-path-based routing algorithm, a hottest-request-first processing policy that considers demand intensity and end-to-end distance information offers both the highest throughput of networks and acceptable computation scalability. We further investigate trade-off relationship between network throughput and computation complexity in routing table update procedure by a simulation study.

  19. A performance analysis of DS-CDMA and SCPC VSAT networks

    Science.gov (United States)

    Hayes, David P.; Ha, Tri T.

    1990-01-01

    Spread-spectrum and single-channel-per-carrier (SCPC) transmission techniques work well in very small aperture terminal (VSAT) networks for multiple-access purposes while allowing the earth station antennas to remain small. Direct-sequence code-division multiple-access (DS-CDMA) is the simplest spread-spectrum technique to use in a VSAT network since a frequency synthesizer is not required for each terminal. An examination is made of the DS-CDMA and SCPC Ku-band VSAT satellite systems for low-density (64-kb/s or less) communications. A method for improving the standardf link analysis of DS-CDMA satellite-switched networks by including certain losses is developed. The performance of 50-channel full mesh and star network architectures is analyzed. The selection of operating conditions producing optimum performance is demonstrated.

  20. Evaluating the Performance of TCP Stacks for High-Speed Networks.

    OpenAIRE

    Even, B.; Li, Y.; Leith, D.J.

    2006-01-01

    In this paper we present experimental results evaluating the performance of the Scalable-TCP, HS-TCP, BICTCP, FAST-TCP and H-TCP proposals for changes to the TCP congestion control algorithm to improve performance in highspeed network paths.

  1. HPNAIDM: The High-Performance Network Anomaly/Intrusion Detection and Mitigation System

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yan [Northwesten University

    2013-12-05

    Identifying traffic anomalies and attacks rapidly and accurately is critical for large network operators. With the rapid growth of network bandwidth, such as the next generation DOE UltraScience Network, and fast emergence of new attacks/virus/worms, existing network intrusion detection systems (IDS) are insufficient because they: • Are mostly host-based and not scalable to high-performance networks; • Are mostly signature-based and unable to adaptively recognize flow-level unknown attacks; • Cannot differentiate malicious events from the unintentional anomalies. To address these challenges, we proposed and developed a new paradigm called high-performance network anomaly/intrustion detection and mitigation (HPNAIDM) system. The new paradigm is significantly different from existing IDSes with the following features (research thrusts). • Online traffic recording and analysis on high-speed networks; • Online adaptive flow-level anomaly/intrusion detection and mitigation; • Integrated approach for false positive reduction. Our research prototype and evaluation demonstrate that the HPNAIDM system is highly effective and economically feasible. Beyond satisfying the pre-set goals, we even exceed that significantly (see more details in the next section). Overall, our project harvested 23 publications (2 book chapters, 6 journal papers and 15 peer-reviewed conference/workshop papers). Besides, we built a website for technique dissemination, which hosts two system prototype release to the research community. We also filed a patent application and developed strong international and domestic collaborations which span both academia and industry.

  2. Energy Efficiency and Network Performance: A Reality Check in SDN-Based 5G Systems

    Directory of Open Access Journals (Sweden)

    Leonardo Ochoa-Aday

    2017-12-01

    Full Text Available The increasing power consumption and related environmental implications currently generated by large data networks have become a major concern over the last decade. Given the drastic traffic increase expected in 5G dense environments, the energy consumption problem becomes even more concerning and challenging. In this context, Software-Defined Networks (SDN, a key technology enabler for 5G systems, can be seen as an attractive solution. In these programmable networks, an energy-aware solution could be easily implemented leveraging the capabilities provided by control and data plane separation. This paper investigates the impact of energy-aware routing on network performance. To that end, we propose a novel energy-aware mechanism that reduces the number of active links in SDN with multiple controllers, considering in-band control traffic. The proposed strategy exploits knowledge of the network topology combined with traffic engineering techniques to reduce the overall power consumption. Therefore, two heuristic algorithms are designed: a static network configuration and a dynamic energy-aware routing. Significant values of switched-off links are reached in the simulations where real topologies and demands data are used. Moreover, the obtained results confirm that crucial network parameters such as control traffic delay, data path latency, link utilization and Ternary Content Addressable Memory (TCAM occupation are affected by the performance-agnostic energy-aware model.

  3. Performance of an artificial neural network for vertical root fracture detection: an ex vivo study.

    Science.gov (United States)

    Kositbowornchai, Suwadee; Plermkamon, Supattra; Tangkosol, Tawan

    2013-04-01

    To develop an artificial neural network for vertical root fracture detection. A probabilistic neural network design was used to clarify whether a tooth root was sound or had a vertical root fracture. Two hundred images (50 sound and 150 vertical root fractures) derived from digital radiography--used to train and test the artificial neural network--were divided into three groups according to the number of training and test data sets: 80/120,105/95 and 130/70, respectively. Either training or tested data were evaluated using grey-scale data per line passing through the root. These data were normalized to reduce the grey-scale variance and fed as input data of the neural network. The variance of function in recognition data was calculated between 0 and 1 to select the best performance of neural network. The performance of the neural network was evaluated using a diagnostic test. After testing data under several variances of function, we found the highest sensitivity (98%), specificity (90.5%) and accuracy (95.7%) occurred in Group three, for which the variance of function in recognition data was between 0.025 and 0.005. The neural network designed in this study has sufficient sensitivity, specificity and accuracy to be a model for vertical root fracture detection. © 2012 John Wiley & Sons A/S.

  4. A Study of Complex Deep Learning Networks on High Performance, Neuromorphic, and Quantum Computers

    Energy Technology Data Exchange (ETDEWEB)

    Potok, Thomas E [ORNL; Schuman, Catherine D [ORNL; Young, Steven R [ORNL; Patton, Robert M [ORNL; Spedalieri, Federico [University of Southern California, Information Sciences Institute; Liu, Jeremy [University of Southern California, Information Sciences Institute; Yao, Ke-Thia [University of Southern California, Information Sciences Institute; Rose, Garrett [University of Tennessee (UT); Chakma, Gangotree [University of Tennessee (UT)

    2016-01-01

    Current Deep Learning models use highly optimized convolutional neural networks (CNN) trained on large graphical processing units (GPU)-based computers with a fairly simple layered network topology, i.e., highly connected layers, without intra-layer connections. Complex topologies have been proposed, but are intractable to train on current systems. Building the topologies of the deep learning network requires hand tuning, and implementing the network in hardware is expensive in both cost and power. In this paper, we evaluate deep learning models using three different computing architectures to address these problems: quantum computing to train complex topologies, high performance computing (HPC) to automatically determine network topology, and neuromorphic computing for a low-power hardware implementation. Due to input size limitations of current quantum computers we use the MNIST dataset for our evaluation. The results show the possibility of using the three architectures in tandem to explore complex deep learning networks that are untrainable using a von Neumann architecture. We show that a quantum computer can find high quality values of intra-layer connections and weights, while yielding a tractable time result as the complexity of the network increases; a high performance computer can find optimal layer-based topologies; and a neuromorphic computer can represent the complex topology and weights derived from the other architectures in low power memristive hardware. This represents a new capability that is not feasible with current von Neumann architecture. It potentially enables the ability to solve very complicated problems unsolvable with current computing technologies.

  5. 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.

  6. Performance and evaluation of gas-engine-driven split-system cooling equipment at the Willow Grove Naval Air Station

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, P.R.; Schmelzer, J.R.

    1997-01-01

    DOE`s Federal Energy Management Program supports efforts to reduce energy use and associated expenditures within the federal sector; one such effort, the New Technology Demonstration Program (NTDP)(formerly the Test Bed Demonstration program), seeks to evaluate new energy saving US technologies and secure their more timely adoption by the federal government. This report describes the field evaluation conducted to examine the performance of a 15-ton natural-gas-engine- driven, split-system, air-conditioning unit. The unit was installed at a multiple-use building at Willow Grove Naval Air Station, a regular and reserve training facility north of Philadelphia, and its performance was monitored under the NTDP.

  7. Cost Benefit Analysis of Performing a Pilot Project for Hydrogen-Powered Ground Support Equipment at Lemoore Naval Air Station

    Science.gov (United States)

    2006-12-01

    Benefits of Fuel Cells." Bullnet eCommerce Solutions, Bull Group. http://www.bullnet.co.uk/ (accessed November 25, 2006). "Hydrogen Production and...NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA MBA PROFESSIONAL REPORT Cost Benefit Analysis of Performing a Pilot Project for...blank) 2. REPORT DATE December 2006 3. REPORT TYPE AND DATES COVERED MBA Professional Report 4. TITLE AND SUBTITLE: Cost Benefit Analysis of

  8. Real-Time Performance of a Self-Powered Environmental IoT Sensor Network System.

    Science.gov (United States)

    Wu, Fan; Rüdiger, Christoph; Yuce, Mehmet Rasit

    2017-02-01

    Wireless sensor networks (WSNs) play an increasingly important role in monitoring applications in many areas. With the emergence of the Internet-of-Things (IoT), many more lowpower sensors will need to be deployed in various environments to collect and monitor data about environmental factors in real time. Providing power supply to these sensor nodes becomes a critical challenge for realizations of IoT applications as sensor nodes are normally battery-powered and have a limited lifetime. This paper proposes a wireless sensor network that is powered by solar energy harvesting. The sensor network monitors the environmental data with low-power sensor electronics and forms a network using multiple XBee wireless modules. A detailed performance analysis of the network system under solar energy harvesting has been presented. The sensor network system and the proposed energy-harvesting techniques are configured to achieve a continuous energy source for the sensor network. The proposed energy-harvesting system has been successfully designed to enable an energy solution in order to keep sensor nodes active and reliable for a whole day. The paper also outlines some of our experiences in real-time implementation of a sensor network system with energy harvesting.

  9. Real-Time Performance of a Self-Powered Environmental IoT Sensor Network System

    Directory of Open Access Journals (Sweden)

    Fan Wu

    2017-02-01

    Full Text Available Wireless sensor networks (WSNs play an increasingly important role in monitoring applications in many areas. With the emergence of the Internet-of-Things (IoT, many more lowpower sensors will need to be deployed in various environments to collect and monitor data about environmental factors in real time. Providing power supply to these sensor nodes becomes a critical challenge for realizations of IoT applications as sensor nodes are normally battery-powered and have a limited lifetime. This paper proposes a wireless sensor network that is powered by solar energy harvesting. The sensor network monitors the environmental data with low-power sensor electronics and forms a network using multiple XBee wireless modules. A detailed performance analysis of the network system under solar energy harvesting has been presented. The sensor network system and the proposed energy-harvesting techniques are configured to achieve a continuous energy source for the sensor network. The proposed energy-harvesting system has been successfully designed to enable an energy solution in order to keep sensor nodes active and reliable for a whole day. The paper also outlines some of our experiences in real-time implementation of a sensor network system with energy harvesting.

  10. D-LiTE: A platform for evaluating DASH performance over a simulated LTE network

    OpenAIRE

    Quinlan, Jason J.; Raca, Darijo; Zahran, Ahmed H.; Khalid, Ahmed; Ramakrishnan, K. K.; Sreenan, Cormac J.

    2015-01-01

    In this demonstration we present a platform that encompasses all of the components required to realistically evaluate the performance of Dynamic Adaptive Streaming over HTTP (DASH) over a real-time NS-3 simulated network. Our platform consists of a network-attached storage server with DASH video clips and a simulated LTE network which utilises the NS-3 LTE module provided by the LENA project. We stream to clients running an open-source player with a choice of adaptation algorithms. By providi...

  11. The performance of immune-based neural network with financial time series prediction

    Directory of Open Access Journals (Sweden)

    Dhiya Al-Jumeily

    2015-12-01

    Full Text Available This paper presents the use of immune-based neural networks that include multilayer perceptron (MLP and functional neural network for the prediction of financial time series signals. Extensive simulations for the prediction of one- and five-steps-ahead of stationary and non-stationary time series were performed which indicate that immune-based neural networks in most cases demonstrated advantages in capturing chaotic movement in the financial signals with an improvement in the profit return and rapid convergence over MLPs.

  12. Laser ranging network performance and routine orbit determination at D-PAF

    Science.gov (United States)

    Massmann, Franz-Heinrich; Reigber, C.; Li, H.; Koenig, Rolf; Raimondo, J. C.; Rajasenan, C.; Vei, M.

    1993-01-01

    ERS-1 is now about 8 months in orbit and has been tracked by the global laser network from the very beginning of the mission. The German processing and archiving facility for ERS-1 (D-PAF) is coordinating and supporting the network and performing the different routine orbit determination tasks. This paper presents details about the global network status, the communication to D-PAF and the tracking data and orbit processing system at D-PAF. The quality of the preliminary and precise orbits are shown and some problem areas are identified.

  13. Control Policies Approaching HGI Performance in Heavy Traffic for Resource Sharing Networks

    OpenAIRE

    Budhiraja, Amarjit; Johnson, Dane

    2017-01-01

    We consider resource sharing networks of the form introduced in the work of Massouli\\'{e} and Roberts(2000) as models for Internet flows. The goal is to study the open problem, formulated in Harrison et al. (2014), of constructing simple form rate allocation policies for broad families of resource sharing networks with associated costs converging to the Hierarchical Greedy Ideal performance in the heavy traffic limit. We consider two types of cost criteria, an infinite horizon discounted cost...

  14. AN ENERGY MODEL FOR ACHIEVING HIGH PERFORMANCE BURST TRANSMISSION IN OBCS NETWORKS

    OpenAIRE

    Renuka, R.; Kavitha, V.

    2013-01-01

    Optical burst switching is a promising solution for all optical WDM networks. It combines the benefits of optical circuit switching and optical packet switching. In OBS, the user data is collected at the edge of the network, sorted based on the destination address and grouped into variable size bursts. The OBS framework has been widely used in past years, for recent work use Optical Burst Chain switching (OBCS) to achieve high performance. Here switching unit is burst chain it consist of non-...

  15. Applying Artificial Neural Networks to Evaluate Export Performance: A Relational Approach

    OpenAIRE

    Antonio CORREIA de BARROS; Hortensia BARANDAS; Paulo Alexandre PIRES

    2009-01-01

    The paper applies artificial neural networks to investigate the effect of the exporter’s relationship orientation on the export performance, mediated by the relationship quality, taking into account the supplier’s strategic orientation and the foreign customer’s approach to purchasing. The proposed model is supported mainly by the Second Networking Marketing Paradox, the Commitment-Trust Theory, the Relationship Marketing Paradigm and International Marketing fundamentals. The model developed,...

  16. Very high precision survey equipment for great distances Surface surveys used to map out the surface network and the tunnelling machines then gyroscopically steered underground.

    CERN Multimedia

    1983-01-01

    At the beginning of the 1980s, CERN embarked on the enormous Large Electron-Positron Collider construction project. The excavation of the 27-kilometre LEP tunnel was a huge technical challenge. The tunnel-boring machines excavated the tunnel in 3.3 km octants and had to be operated with extraordinary precision to ensure that they reached their destination - the bottom of the next vertical shaft - precisely on target. The tunnel was excavated before high-performance instruments were developed for the construction of the Channel Tunnel. As no firms were willing to perform the surveying work, CERN's own surveyors, with experience from the SPS behind them, took up the challenge. At the surface, the surveyors established the world's most accurate geodetic network, performing measurements to an accuracy of 10-7, or 1mm per 10 km, using the Terrameter (see photo). The excavation of the tunnel was completed in 1988 and the finished tunnel's trajectory was found to diverge from the theoretical value specified by the p...

  17. Experimental validation of optical layer performance monitoring using an all-optical network testbed

    Science.gov (United States)

    Vukovic, Alex; Savoie, Michel J.; Hua, Heng

    2004-11-01

    Communication transmission systems continue to evolve towards higher data rates, increased wavelength densities, longer transmission distances and more intelligence. Further development of dense wavelength division multiplexing (DWDM) and all-optical networks (AONs) will demand ever-tighter monitoring to assure a specified quality of service (QoS). Traditional monitoring methods have been proven to be insufficient. Higher degree of self-control, intelligence and optimization for functions within next generation networks require new monitoring schemes to be developed and deployed. Both perspective and challenges of performance monitoring, its techniques, requirements and drivers are discussed. It is pointed out that optical layer monitoring is a key enabler for self-control of next generation optical networks. Aside from its real-time feedback and the safeguarding of neighbouring channels, optical performance monitoring ensures the ability to build and control complex network topologies while maintaining an efficiently high QoS. Within an all-optical network testbed environment, key performance monitoring parameters are identified, assessed through real-time proof-of-concept, and proposed for network applications for the safeguarding of neighbouring channels in WDM systems.

  18. A Holistic Approach to ZigBee Performance Enhancement for Home Automation Networks

    Directory of Open Access Journals (Sweden)

    August Betzler

    2014-08-01

    Full Text Available Wireless home automation networks are gaining importance for smart homes. In this ambit, ZigBee networks play an important role. The ZigBee specification defines a default set of protocol stack parameters and mechanisms that is further refined by the ZigBee Home Automation application profile. In a holistic approach, we analyze how the network performance is affected with the tuning of parameters and mechanisms across multiple layers of the ZigBee protocol stack and investigate possible performance gains by implementing and testing alternative settings. The evaluations are carried out in a testbed of 57 TelosB motes. The results show that considerable performance improvements can be achieved by using alternative protocol stack configurations. From these results, we derive two improved protocol stack configurations for ZigBee wireless home automation networks that are validated in various network scenarios. In our experiments, these improved configurations yield a relative packet delivery ratio increase of up to 33.6%, a delay decrease of up to 66.6% and an improvement of the energy efficiency for battery powered devices of up to 48.7%, obtainable without incurring any overhead to the network.

  19. A holistic approach to ZigBee performance enhancement for home automation networks.

    Science.gov (United States)

    Betzler, August; Gomez, Carles; Demirkol, Ilker; Paradells, Josep

    2014-08-14

    Wireless home automation networks are gaining importance for smart homes. In this ambit, ZigBee networks play an important role. The ZigBee specification defines a default set of protocol stack parameters and mechanisms that is further refined by the ZigBee Home Automation application profile. In a holistic approach, we analyze how the network performance is affected with the tuning of parameters and mechanisms across multiple layers of the ZigBee protocol stack and investigate possible performance gains by implementing and testing alternative settings. The evaluations are carried out in a testbed of 57 TelosB motes. The results show that considerable performance improvements can be achieved by using alternative protocol stack configurations. From these results, we derive two improved protocol stack configurations for ZigBee wireless home automation networks that are validated in various network scenarios. In our experiments, these improved configurations yield a relative packet delivery ratio increase of up to 33.6%, a delay decrease of up to 66.6% and an improvement of the energy efficiency for battery powered devices of up to 48.7%, obtainable without incurring any overhead to the network.

  20. Performance Analysis of TCP Enhancements in Satellite Data Networks

    Science.gov (United States)

    Broyles, Ren H.

    1999-01-01

    This research examines two proposed enhancements to the well-known Transport Control Protocol (TCP) in the presence of noisy communication links. The Multiple Pipes protocol is an application-level adaptation of the standard TCP protocol, where several TCP links cooperate to transfer data. The Space Communication Protocol Standard - Transport Protocol (SCPS-TP) modifies TCP to optimize performance in a satellite environment. While SCPS-TP has inherent advantages that allow it to deliver data more rapidly than Multiple Pipes, the protocol, when optimized for operation in a high-error environment, is not compatible with legacy TCP systems, and requires changes to the TCP specification. This investigation determines the level of improvement offered by SCPS-TP's Corruption Mode, which will help determine if migration to the protocol is appropriate in different environments. As the percentage of corrupted packets approaches 5 %, Multiple Pipes can take over five times longer than SCPS-TP to deliver data. At high error rates, SCPS-TP's advantage is primarily caused by Multiple Pipes' use of congestion control algorithms. The lack of congestion control, however, limits the systems in which SCPS-TP can be effectively used.

  1. CFC and HFC recycling equipments: Test performances; Qualificazione di dispositivi per il riciclaggio dei CFC e degli HFC

    Energy Technology Data Exchange (ETDEWEB)

    Picini, P.; Caropreso, G.; Cicoli, G.; Posarelli, M. [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dipt. Ambiente; Pallotti, P. [ICF, Industria Componenti Frigoriferi Srl, Bologna (Italy)

    1996-12-01

    Actual regulatory conditions about ozone layer depleting chemicals set problems on their disposal and on the management of plants still using illegal CFCs. Anyway fluids that will replace CFCs (i.e. HFCs) will not be allowed to be spread into the atmosphere, due to their high costs and to the greenhouse effect. A viable solution would be the recovery, purification and recycle of contaminated fluids. ENEA (National Agency for New Technology, Energy and the Environment), in cooperation with ICF (Industria Componenti Frigoriferi) Company leader in the field of air refrigerating and conditioning, patented a device able to extract, to clean and to recycle CFC 12 and HFC 134a in the refrigerating systems. This paper presents experimental data from the qualification tests on a device performing the above mentioned operations regarding systems that use HFC 134a as process fluid.

  2. Basal functional connectivity within the anterior temporal network is associated with performance on declarative memory tasks.

    Science.gov (United States)

    Gour, Natalina; Ranjeva, Jean-Philippe; Ceccaldi, Mathieu; Confort-Gouny, Sylviane; Barbeau, Emmanuel; Soulier, Elisabeth; Guye, Maxime; Didic, Mira; Felician, Olivier

    2011-09-15

    Spontaneous fluctuations in the blood oxygenation level-dependent (BOLD) signal, as measured by functional magnetic resonance imaging (fMRI) at rest, exhibit a temporally coherent activity thought to reflect functionally relevant networks. Antero-mesial temporal structures are the site of early pathological changes in Alzheimer's disease and have been shown to be critical for declarative memory. Our study aimed at exploring the functional impact of basal connectivity of an anterior temporal network (ATN) on declarative memory. A heterogeneous group of subjects with varying performance on tasks assessing memory was therefore selected, including healthy subjects and patients with isolated memory complaint, amnestic Mild Cognitive Impairment (aMCI) and mild Alzheimer's disease (AD). Using Independent Component Analysis on resting-state fMRI, we extracted a relevant anterior temporal network (ATN) composed of the perirhinal and entorhinal cortex, the hippocampal head, the amygdala and the lateral temporal cortex extending to the temporal pole. A default mode network and an executive-control network were also selected to serve as control networks. We first compared basal functional connectivity of the ATN between patients and control subjects. Relative to controls, patients exhibited significantly increased functional connectivity in the ATN during rest. Specifically, voxel-based analysis revealed an increase within the inferior and superior temporal gyrus and the uncus. In the patient group, positive correlations between averaged connectivity values of ATN and performance on anterograde and retrograde object-based memory tasks were observed, while no correlation was found with other evaluated cognitive measures. These correlations were specific to the ATN, as no correlation between performance on memory tasks and the other selected networks was found. Taken together, these findings provide evidence that basal connectivity inside the ATN network has a functional role in

  3. Performance of an opportunistic multi-user cognitive network with multiple primary users

    KAUST Repository

    Khan, Fahd Ahmed

    2014-04-01

    Consider a multi-user underlay cognitive network where multiple cognitive users, having limited peak transmit power, concurrently share the spectrum with a primary network with multiple users. The channel between the secondary network is assumed to have independent but not identical Nakagami-m fading. The interference channel between the secondary users and the primary users is assumed to have Rayleigh fading. The uplink scenario is considered where a single secondary user is selected for transmission. This opportunistic selection depends on the transmission channel power gain and the interference channel power gain as well as the power allocation policy adopted at the users. Exact closed form expressions for the momentgenerating function, outage performance and the symbol-error-rate performance are derived. The outage performance is also studied in the asymptotic regimes and the generalized diversity gain of this scheduling scheme is derived. Numerical results corroborate the derived analytical results.

  4. Classification of non-performing loans portfolio using Multilayer Perceptron artificial neural networks

    Directory of Open Access Journals (Sweden)

    Flávio Clésio Silva de Souza

    2014-06-01

    Full Text Available The purpose of the present research is to apply a Multilayer Perceptron (MLP neural network technique to create classification models from a portfolio of Non-Performing Loans (NPLs to classify this type of credit derivative. These credit derivatives are characterized as the amount of loans that were not paid and are already overdue more than 90 days. Since these titles are, because of legislative motives, moved by losses, Credit Rights Investment Funds (FDIC performs the purchase of these debts and the recovery of the credits. Using the Multilayer Perceptron (MLP architecture of Artificial Neural Network (ANN, classification models regarding the posterior recovery of these debts were created. To evaluate the performance of the models, evaluation metrics of classification relating to the neural networks with different architectures were presented. The results of the classifications were satisfactory, given the classification models were successful in the presented economics costs structure.

  5. New Created Enterprise Value Network Embeddedness, Strategic Positioning and Enterprise Growth Performance

    OpenAIRE

    Huabai BU

    2013-01-01

    The study found that: the new created enterprise value network structure embedding and relationships embedded have significant direct impact on entrepreneurial performance, but the impact mechanisms is different; the one of mediating variables of the structure embedded and the entrepreneurial performance is Relations embedded. Strategic positioning and structure embedded in the impact of entrepreneurial performance have significant interaction effects, the interaction effect of strategic posi...

  6. Centrality and charisma: comparing how leader networks and attributions affect team performance.

    Science.gov (United States)

    Balkundi, Prasad; Kilduff, Martin; Harrison, David A

    2011-11-01

    When leaders interact in teams with their subordinates, they build social capital that can have positive effects on team performance. Does this social capital affect team performance because subordinates come to see the leader as charismatic? We answered this question by examining 2 models. First, we tested the charisma-to-centrality model according to which the leader's charisma facilitates the occupation of a central position in the informal advice network. From this central position, the leader positively influences team performance. Second, we examined the centrality-to-charisma model according to which charisma is attributed to those leaders who are socially active in terms of giving and receiving advice. Attributed charisma facilitates increased team performance. We tested these 2 models in 2 different studies. In the first study, based on time-separated, multisource data emanating from members of 56 work teams, we found support for the centrality-to-charisma model. Formal leaders who were central within team advice networks were seen as charismatic by subordinates, and this charisma was associated with high team performance. To clarify how leader network centrality affected the emergence of charismatic leadership, we designed Study 2 in which, for 79 student teams, we measured leader networking activity and leader charisma at 2 different points in time and related these variables to team performance measured at a third point in time. On the basis of this temporally separated data set, we again found support for the centrality-to-charisma model. (c) 2011 APA, all rights reserved.

  7. Lumen claims of the STERRAD 100NX sterilizer: testing performance limits when processing equipment containing long, narrow lumens.

    Science.gov (United States)

    Diab-Elschahawi, Magda; Blacky, Alexander; Bachhofner, Nicole; Koller, Walter

    2011-11-01

    According to manufacturers information, the STERRAD 100NX sterilizer-a low temperature H(2)O(2) gas plasma sterilizer-can adequately process single channel stainless steel lumens with an inside diameter of 0.7 mm or larger and a maximum length of 500 mm using standard cycle sterilizing conditions. The aim of this study was to qualify the performance of this H(2)O(2) gas plasma sterilizer under different experimental settings representing worst case conditions. Inoculated carriers were placed at the midpoint position of specified lumens and then submitted to flex scope sterilizing conditions. To simulate insufficient cleaning or crystalline residues, we added organic and inorganic challenges to our inoculated carriers. For experiments done with unchallenged carriers, quantitative analysis reached a log(10) reduction rate of ≥5.71, whereas qualitative results showed no growth in 24 out of 30 biologic indicators tested using flex scope half cycle conditions. Any additional kind of challenge significantly impaired the sterilization outcome. The findings of our current study emphasize the importance of a thorough validated cleaning of medical devices as well as timing for cleaning and decontamination before being exposed to the H(2)O(2) sterilization process and, furthermore, the need for strict adherence to manufacturer's recommendations. Copyright © 2011 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

  8. Does network board capital matter? A study of innovative performance in strategic SME networks

    National Research Council Canada - National Science Library

    Wincent, Joakim; Anokhin, Sergey; Örtqvist, Daniel

    2010-01-01

    ..., 1995; Human and Provan, 2000 ), which are intentionally formed groups of partly independent, profit-oriented SMEs that cooperate to improve innovative performance both through multilateral, intranetwork technology and through know-how exchange and the development of new products or services ( Human and Provan, 1997; Wincent, 2008 ). Al...

  9. Transforming Input Into Output : How Downward Networking Mediates the Effect of External Networking on Organizational Performance

    NARCIS (Netherlands)

    van den Bekerom, Petra; Schalk, Jelmer; Torenvlied, René

    2017-01-01

    One of the core assumptions of the open systems perspective is that management facilitates the technical flows that transform resources and demands into output, which ultimately affects the organization’s performance. This article sheds light on the managerial throughput hypothesis by testing the

  10. Visualizing Network Traffic to Understand the Performance of Massively Parallel Simulations

    KAUST Repository

    Landge, A. G.

    2012-12-01

    The performance of massively parallel applications is often heavily impacted by the cost of communication among compute nodes. However, determining how to best use the network is a formidable task, made challenging by the ever increasing size and complexity of modern supercomputers. This paper applies visualization techniques to aid parallel application developers in understanding the network activity by enabling a detailed exploration of the flow of packets through the hardware interconnect. In order to visualize this large and complex data, we employ two linked views of the hardware network. The first is a 2D view, that represents the network structure as one of several simplified planar projections. This view is designed to allow a user to easily identify trends and patterns in the network traffic. The second is a 3D view that augments the 2D view by preserving the physical network topology and providing a context that is familiar to the application developers. Using the massively parallel multi-physics code pF3D as a case study, we demonstrate that our tool provides valuable insight that we use to explain and optimize pF3D-s performance on an IBM Blue Gene/P system. © 1995-2012 IEEE.

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

    Science.gov (United States)

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

    2011-09-01

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

  12. On end-to-end performance of MIMO multiuser in cognitive radio networks

    KAUST Repository

    Yang, Yuli

    2011-12-01

    In this paper, a design for the multiple-input-multiple-output (MIMO) multiuser transmission in the cognitive radio network is developed and its end-to-end performance is investigated under spectrum-sharing constraints. Firstly, the overall average packet error rate is analyzed by considering the channel state information feedback delay and the multiuser scheduling. Then, we provide corresponding numerical results to measure the performance evaluation for several separate scenarios, which presents a convenient tool for the cognitive radio network design with multiple secondary MIMO users. © 2011 IEEE.

  13. Small businesses performance in West African border regions: Do social networks pay off?

    DEFF Research Database (Denmark)

    Kuepié, Mathias; Tenikué, Michel; Walther, Olivier

    This paper studies the link between economic performance and social networks in West Africa. Using first-hand data collected on 358 small-scale traders in five border markets between Niger, Nigeria and Benin, we are particularly interested in testing whether the most well-connected actors of trade...... networks are also the most successful in terms of monthly sales and profit. The paper shows that the overall economic performance of traders is affected by the socio-professional position of the actors with whom they are connected. While social ties with local religious leaders have no effect...

  14. Networks of dissipative systems compositional certification of stability, performance, and safety

    CERN Document Server

    Arcak, Murat; Packard, Andrew

    2016-01-01

    This book addresses a major problem for today’s large-scale networked systems: certification of the required stability and performance properties using analytical and computational models. On the basis of illustrative case studies, it demonstrates the applicability of theoretical methods to biological networks, vehicle fleets, and Internet congestion control. Rather than tackle the network as a whole —an approach that severely limits the ability of existing methods to cope with large numbers of physical components— the book develops a compositional approach that derives network-level guarantees from key structural properties of the components and their interactions. The foundational tool in this approach is the established dissipativity theory, which is reviewed in the first chapter and supplemented with modern computational techniques. The book blends this theory with the authors’ recent research efforts at a level that is accessible to graduate students and practising engineers familiar with only th...

  15. Study on the IoT application network performance optimization based on Mobile Internet

    Directory of Open Access Journals (Sweden)

    ZHAO Jiarong

    2015-02-01

    Full Text Available The Internet of Things is an important part of the new generation of information technology,following the development of computer and the Internet.The core of the development of IoT is application innovation,while innovation focusing on user experience is the most important.In this paper we research two applications including ″Mega Eyes network video monitoring system″ and ″Internet of Vehicles″ based on CDMA mobile network.In order to improve user experience,we analyze network performance of the applications and establish a multidimensional system model.We enhance the reliability,timeliness and safety of network access phase and transmission phase of IoT applications.

  16. Exact Outage Performance Analysis of Multiuser Multi-relay Spectrum Sharing Cognitive Networks

    Directory of Open Access Journals (Sweden)

    T. Zhang

    2015-04-01

    Full Text Available In this paper, we investigate the outage performance of dual-hop multiuser multi-relay cognitive radio networks under spectrum sharing constraints. Using an efficient relay-destination selection scheme, the exact and asymptotic closed-form expressions for the outage probability are derived. From these expressions it is indicated that the achieved diversity order is only determined by the number of secondary user (SU relays and destinations, and equals to M+N (where M and N are the number of destination nodes and relay nodes, respectively. Further, we find that the coding gain of the SU network will be affected by the interference threshold $bar I$ at the primary user (PU receiver. Specifically, as the increases of the interference threshold, the coding gain of the considered network approaches to that of the multiuser multi-relay system in the non-cognitive network. Finally, our study is corroborated by representative numerical examples.

  17. Prioritizing equipment for replacement.

    Science.gov (United States)

    Capuano, Mike

    2010-01-01

    It is suggested that clinical engineers take the lead in formulating evaluation processes to recommend equipment replacement. Their skill, knowledge, and experience, combined with access to equipment databases, make them a logical choice. Based on ideas from Fennigkoh's scheme, elements such as age, vendor support, accumulated maintenance cost, and function/risk were used.6 Other more subjective criteria such as cost benefits and efficacy of newer technology were not used. The element of downtime was also omitted due to the data element not being available. The resulting Periop Master Equipment List and its rationale was presented to the Perioperative Services Program Council. They deemed the criteria to be robust and provided overwhelming acceptance of the list. It was quickly put to use to estimate required capital funding, justify items already thought to need replacement, and identify high-priority ranked items for replacement. Incorporating prioritization criteria into an existing equipment database would be ideal. Some commercially available systems do have the basic elements of this. Maintaining replacement data can be labor-intensive regardless of the method used. There is usually little time to perform the tasks necessary for prioritizing equipment. However, where appropriate, a clinical engineering department might be able to conduct such an exercise as shown in the following case study.

  18. Comparative analysis of the performance of One-Way and Two-Way urban road networks

    Science.gov (United States)

    Gheorghe, Carmen

    2017-10-01

    The fact that the number of vehicles is increasing year after year represents a challenge in road traffic management because it is necessary to adjust the road traffic, in order to prevent any incidents, using mostly the same road infrastructure. At this moment one-way road network provides efficient traffic flow for vehicles but it is not ideal for pedestrians. Therefore, a proper solution must be found and applied when and where it is necessary. Replacing one-way road network with two-way road network may be a viable solution especially if in the area is high pedestrian traffic. The paper aims to highlight the influence of both, one-way and two-way urban road networks through an experimental research which was performed by using traffic data collected in the field. Each of the two scenarios analyzed were based on the same traffic data, the same geometrical conditions of the road (lane width, total road segment width, road slopes, total length of the road network) and also the same signaling conditions (signalised intersection or roundabout). The analysis which involves two-way scenario reveals changes in the performance parameters like delay average, stops average, delay stop average and vehicle speed average. Based on the values obtained, it was possible to perform a comparative analysis between the real, one-way, scenario and the theoretical, two-way, scenario.

  19. Advanced Communication Technology Satellite (ACTS) Very Small Aperture Terminal (VSAT) Network Control Performance

    Science.gov (United States)

    Coney, T. A.

    1996-01-01

    This paper discusses the performance of the network control function for the Advanced Communications Technology Satellite (ACTS) very small aperture terminal (VSAT) full mesh network. This includes control of all operational activities such as acquisition, synchronization, timing and rain fade compensation as well as control of all communications activities such as on-demand integrated services (voice, video, and date) connects and disconnects Operations control is provided by an in-band orderwire carried in the baseboard processor (BBP) control burst, the orderwire burst, the reference burst, and the uplink traffic burst. Communication services are provided by demand assigned multiple access (DAMA) protocols. The ACTS implementation of DAMA protocols ensures both on-demand and integrated voice, video and data services. Communications services control is also provided by the in-band orderwire but uses only the reference burst and the uplink traffic burst. The performance of the ACTS network control functions have been successfully tested during on-orbit checkout and in various VSAT networks in day to day operations. This paper discusses the network operations and services control performance.

  20. 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.

  1. Performance Estimation of Networked Business Models: Case Study on a Finnish eHealth Service Project

    Directory of Open Access Journals (Sweden)

    Marikka Heikkilä

    2014-08-01

    Full Text Available Purpose: The objective of this paper is to propose and demonstrate a framework for estimating performance in a networked business model. Design/methodology/approach: Our approach is design science, utilising action research in studying a case of four independent firms in Health & Wellbeing sector aiming to jointly provide a new service for business and private customers. The duration of the research study is 3 years. Findings: We propose that a balanced set of performance indicators can be defined by paying attention to all main components of the business model, enriched with of network collaboration. The results highlight the importance of measuring all main components of the business model and also the business network partners’ view on trust, contracts and fairness. Research implications: This article contributes to the business model literature by combining business modelling with performance evaluation. The article points out that it is essential to create metrics that can be applied to evaluate and improve the business model blueprints, but it is also important to measure business collaboration aspects. Practical implications: Companies have already adopted Business model canvas or similar business model tools to innovate new business models. We suggest that companies continue their business model innovation work by agreeing on a set of performance metrics, building on the business model components model enriched with measures of network collaboration. Originality/value: This article contributes to the business model literature and praxis by combining business modelling with performance evaluation.

  2. Performing particle image velocimetry using artificial neural networks: a proof-of-concept

    Science.gov (United States)

    Rabault, Jean; Kolaas, Jostein; Jensen, Atle

    2017-12-01

    Traditional programs based on feature engineering are underperforming on a steadily increasing number of tasks compared with artificial neural networks (ANNs), in particular for image analysis. Image analysis is widely used in fluid mechanics when performing particle image velocimetry (PIV) and particle tracking velocimetry (PTV), and therefore it is natural to test the ability of ANNs to perform such tasks. We report for the first time the use of convolutional neural networks (CNNs) and fully connected neural networks (FCNNs) for performing end-to-end PIV. Realistic synthetic images are used for training the networks and several synthetic test cases are used to assess the quality of each network’s predictions and compare them with state-of-the-art PIV software. In addition, we present tests on real-world data that prove ANNs can be used not only with synthetic images but also with more noisy, imperfect images obtained in a real experimental setup. While the ANNs we present have slightly higher root mean square error than state-of-the-art cross-correlation methods, they perform better near edges and allow for higher spatial resolution than such methods. In addition, it is likely that one could with further work develop ANNs which perform better that the proof-of-concept we offer.

  3. Distinct Aging Effects on Functional Networks in Good and Poor Cognitive Performers

    Directory of Open Access Journals (Sweden)

    Annie Lee

    2016-09-01

    Full Text Available Brain network hubs are susceptible to normal aging processes and disruptions of their functional connectivity are detrimental to decline in cognitive functions in older adults. However, it remains unclear how the functional connectivity of network hubs cope with cognitive heterogeneity in an aging population. This study utilized cognitive and resting-state functional magnetic resonance imaging (fMRI data, cluster analysis, and graph network analysis to examine age-related alterations in the network hubs’ functional connectivity of good and poor cognitive performers. Our results revealed that poor cognitive performers showed age-dependent disruptions in the functional connectivity of the right insula and posterior cingulate cortex (PCC, while good cognitive performers showed age-related disruptions in the functional connectivity of the left insula and PCC. Additionally, the left PCC had age-related declines in the functional connectivity with the left medial prefrontal cortex (mPFC and anterior cingulate cortex (ACC. Most interestingly, good cognitive performers showed age-related declines in the functional connectivity of the left insula and PCC with their right homotopic structures. These results may provide insights of neuronal correlates for understanding individual differences in aging. In particular, our study suggests prominent protection roles of the left insula and PCC and bilateral ACC in good performers.

  4. Cleaning supplies and equipment

    Science.gov (United States)

    ... gov/ency/patientinstructions/000443.htm Cleaning supplies and equipment To use the sharing features on this page, ... to clean supplies and equipment. Disinfecting Supplies and Equipment Start by wearing the right personal protective equipment ( ...

  5. Error performance analysis in K-tier uplink cellular networks using a stochastic geometric approach

    KAUST Repository

    Afify, Laila H.

    2015-09-14

    In this work, we develop an analytical paradigm to analyze the average symbol error probability (ASEP) performance of uplink traffic in a multi-tier cellular network. The analysis is based on the recently developed Equivalent-in-Distribution approach that utilizes stochastic geometric tools to account for the network geometry in the performance characterization. Different from the other stochastic geometry models adopted in the literature, the developed analysis accounts for important communication system parameters and goes beyond signal-to-interference-plus-noise ratio characterization. That is, the presented model accounts for the modulation scheme, constellation type, and signal recovery techniques to model the ASEP. To this end, we derive single integral expressions for the ASEP for different modulation schemes due to aggregate network interference. Finally, all theoretical findings of the paper are verified via Monte Carlo simulations.

  6. Data-flow Performance Optimisation on Unreliable Networks: the ATLAS Data-Acquisition Case

    Science.gov (United States)

    Colombo, Tommaso; ATLAS Collaboration

    2015-05-01

    The ATLAS detector at CERN records proton-proton collisions delivered by the Large Hadron Collider (LHC). The ATLAS Trigger and Data-Acquisition (TDAQ) system identifies, selects, and stores interesting collision data. These are received from the detector readout electronics at an average rate of 100 kHz. The typical event data size is 1 to 2 MB. Overall, the ATLAS TDAQ system can be seen as a distributed software system executed on a farm of roughly 2000 commodity PCs. The worker nodes are interconnected by an Ethernet network that at the restart of the LHC in 2015 is expected to experience a sustained throughput of several 10 GB/s. A particular type of challenge posed by this system, and by DAQ systems in general, is the inherently burstynature of the data traffic from the readout buffers to the worker nodes. This can cause instantaneous network congestion and therefore performance degradation. The effect is particularly pronounced for unreliable network interconnections, such as Ethernet. In this paper we report on the design of the data-flow software for the 2015-2018 data-taking period of the ATLAS experiment. This software will be responsible for transporting the data across the distributed Data-Acquisition system. We will focus on the strategies employed to manage the network congestion and therefore minimisethe data-collection latency and maximisethe system performance. We will discuss the results of systematic measurements performed on different types of networking hardware. These results highlight the causes of network congestion and the effects on the overall system performance.

  7. Strategies for a better performance of RPL under mobility in wireless sensor networks

    Science.gov (United States)

    Latib, Z. A.; Jamil, A.; Alduais, N. A. M.; Abdullah, J.; Audah, L. H. M.; Alias, R.

    2017-09-01

    A Wireless Sensor Network (WSN) is usually stationary, which the network comprises of static nodes. The increase demand for mobility in various applications such as environmental monitoring, medical, home automation, and military, raises the question how IPv6 Routing Protocol for Low-Power and Lossy Networks (RPL) would perform under these mobility applications. This paper aims to understand performance of RPL and come out with strategies for a better performance of RPL in mobility scenarios. Because of this, this paper evaluates the performance of the RPL protocol under three different scenarios: sink and sensor nodes are static, static sink and mobile sensor nodes, and sink and sensor nodes are mobile. The network scenarios are implemented in Cooja simulator. A WSN consists of 25 sensor nodes and one sink node is configured in the simulation environment. The simulation is varied over different packet rates and ContikiMAC's Clear Channel Assessment (CCA) rate. As the performance metric, RPL is evaluated in term of packet delivery ratio (PDR), power consumption and packet rates. The simulation results show RPL provides a poor PDR in the mobility scenarios when compared to the static scenario. In addition, RPL consumes more power and increases duty-cycle rate to support mobility when compared to the static scenario. Based on the findings, we suggest three strategies for a better performance of RPL in mobility scenarios. First, RPL should operates at a lower packet rates when implemented in the mobility scenarios. Second, RPL should be implemented with a higher duty-cycle rate. Lastly, the sink node should be positioned as much as possible in the center of the mobile network.

  8. 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.

  9. Medical applications for high-performance computers in SKIF-GRID network.

    Science.gov (United States)

    Zhuchkov, Alexey; Tverdokhlebov, Nikolay

    2009-01-01

    The paper presents a set of software services for massive mammography image processing by using high-performance parallel computers of SKIF-family which are linked into a service-oriented grid-network. An experience of a prototype system implementation in two medical institutions is also described.

  10. A Cross-cultural Qualitative Examination of Social-networking Sites and Academic Performance

    NARCIS (Netherlands)

    Ozer, Ipek; Karpinski, Aryn; Kirschner, Paul A.

    2018-01-01

    Social-networking site (SNS) use, specifically Facebook®, has remained a controversial subject for many educators and media. Recent studies discuss the negative and positive impacts of SNSs on students’ academic performance. This qualitative study examines the impact of SNSs on students’ academic

  11. Modelling the Cost Performance of a Given Logistics Network Operating Under Regular and Irregular Conditions

    NARCIS (Netherlands)

    Janic, M.

    2009-01-01

    This paper develops an analytical model for the assessment of the cost performance of a given logistics network operating under regular and irregular (disruptive) conditions. In addition, the paper aims to carry out a sensitivity analysis of this cost with respect to changes of the most influencing

  12. Performance Evaluation and Parameter Optimization of Wavelength Division Multiplexing Networks with Importance Sampling Techniques

    NARCIS (Netherlands)

    Remondo Bueno, D.; Srinivasan, R.; Nicola, V.F.; van Etten, Wim; Tattje, H.E.P.

    1998-01-01

    In this paper new adaptive importance sampling techniques are applied to the performance evaluation and parameter optimization of wavelength division multiplexing (WDM) network impaired by crosstalk in an optical cross-connect. Worst-case analysis is carried out including all the beat noise terms

  13. Entrepreneurial networking: A blessing or a curse? : Differential effects for low, medium and high performing franchisees

    NARCIS (Netherlands)

    Croonen, Evelien; Brand, Maryse; Leenders, R.T.A.J.

    2017-01-01

    Recent studies have called for a better understanding of the link between networking and entrepreneurial performance. We provide such understanding in three ways: by focusing on a specific entrepreneurial context (franchise systems), by developing a multi-faceted theoretical framework, and by

  14. Performance Evaluation of a Cluster-Based Service Discovery Protocol for Heterogeneous Wireless Sensor Networks

    NARCIS (Netherlands)

    Marin Perianu, Raluca; Scholten, Johan; Havinga, Paul J.M.; Hartel, Pieter H.

    2006-01-01

    Abstract—This paper evaluates the performance in terms of resource consumption of a service discovery protocol proposed for heterogeneous Wireless Sensor Networks (WSNs). The protocol is based on a clustering structure, which facilitates the construction of a distributed directory. Nodes with higher

  15. Downlink Performance of a Multi-Carrier MIMO System in a Bursty Traffic Cellular Network

    DEFF Research Database (Denmark)

    Nguyen, Hung Tuan; Kovacs, Istvan; Wang, Yuanye

    2011-01-01

    In this paper we analyse the downlink performance of a rank adaptive multiple input multiple output (MIMO) system in a busty traffic cellular network. A LTE-Advanced system with multiple component carriers was selected as a study case. To highlight the advantage of using MIMO techniques, we used...

  16. Collaboration in Action: Measuring and Improving Contracting Performance in the University of California Contracting Network

    Science.gov (United States)

    Tran, Tam; Bowman-Carpio, LeeAnna; Buscher, Nate; Davidson, Pamela; Ford, Jennifer J.; Jenkins, Erick; Kalay, Hillary Noll; Nakazono, Terry; Orescan, Helene; Sak, Rachael; Shin, Irene

    2017-01-01

    In 2013, the University of California, Biomedical Research, Acceleration, Integration, and Development (UC BRAID) convened a regional network of contracting directors from the five University of California (UC) health campuses to: (i) increase collaboration, (ii) operationalize and measure common metrics as a basis for performance improvement…

  17. Modeling the cooling performance of vortex tube using a genetic algorithm-based artificial neural network

    Directory of Open Access Journals (Sweden)

    Pouraria Hassan

    2016-01-01

    Full Text Available In this study, artificial neural networks (ANNs have been used to model the effects of four important parameters consist of the ratio of the length to diameter(L/D, the ratio of the cold outlet diameter to the tube diameter(d/D, inlet pressure(P, and cold mass fraction (Y on the cooling performance of counter flow vortex tube. In this approach, experimental data have been used to train and validate the neural network model with MATLAB software. Also, genetic algorithm (GA has been used to find the optimal network architecture. In this model, temperature drop at the cold outlet has been considered as the cooling performance of the vortex tube. Based on experimental data, cooling performance of the vortex tube has been predicted by four inlet parameters (L/D, d/D, P, Y. The results of this study indicate that the genetic algorithm-based artificial neural network model is capable of predicting the cooling performance of vortex tube in a wide operating range and with satisfactory precision.

  18. A Public-Private Partnership Improves Clinical Performance In A Hospital Network In Lesotho.

    Science.gov (United States)

    McIntosh, Nathalie; Grabowski, Aria; Jack, Brian; Nkabane-Nkholongo, Elizabeth Limakatso; Vian, Taryn

    2015-06-01

    Health care public-private partnerships (PPPs) between a government and the private sector are based on a business model that aims to leverage private-sector expertise to improve clinical performance in hospitals and other health facilities. Although the financial implications of such partnerships have been analyzed, few studies have examined the partnerships' impact on clinical performance outcomes. Using quantitative measures that reflected capacity, utilization, clinical quality, and patient outcomes, we compared a government-managed hospital network in Lesotho, Africa, and the new PPP-managed hospital network that replaced it. In addition, we used key informant interviews to help explain differences in performance. We found that the PPP-managed network delivered more and higher-quality services and achieved significant gains in clinical outcomes, compared to the government-managed network. We conclude that health care public-private partnerships may improve hospital performance in developing countries and that changes in management and leadership practices might account for differences in clinical outcomes. Project HOPE—The People-to-People Health Foundation, Inc.

  19. Performance estimation of networked business models : Case study on a Finnish eHealth Service Project

    NARCIS (Netherlands)

    Heikkilä, M.; Solaimani, H. (Sam); Kuivaniemi, L.; Suoranta, M.

    2014-01-01

    Purpose: The objective of this paper is to propose and demonstrate a framework for estimating performance in a networked business model. Design/methodology/approach: Our approach is design science, utilising action research in studying a case of four independent firms in Health & Wellbeing sector

  20. Entrepreneurial networking: A blessing or a curse? : Differential effects for low, medium and high performing franchisees

    NARCIS (Netherlands)

    Croonen, Evelien; Brand, Maryse; Leenders, R.T.A.J.

    2018-01-01

    Recent studies have called for a better understanding of the link between networking and entrepreneurial performance. We provide such understanding in three ways: by focusing on a specific entrepreneurial context (franchise systems), by developing a multi-faceted theoretical framework, and by

  1. Early detection monitoring of aquatic invasive species: Measuring performance success in a Lake Superior pilot network

    Science.gov (United States)

    The Great Lakes Water Quality Agreement, Annex 6 calls for a U.S.-Canada, basin-wide aquatic invasive species early detection network by 2015. The objective of our research is to explore survey design strategies that can improve detection efficiency, and to develop performance me...

  2. Sustainability performance measurement with Analytic Network Process and balanced scorecard: Cuban practical case

    Directory of Open Access Journals (Sweden)

    Frank Medel-González

    2016-01-01

    Full Text Available Abstract The recent years has arisen a global discussion in relation with how to incorporate sustainability at a business level. Corporate sustainability is a multidimensional concept, is the translation of Sustainable Development concept at a business level. Sustainability in organizations must be managed and assessed by decision makers, for that reason a multi-criteria sustainability performance measurement is necessary. The aim of this paper is combine different important tools that helps to make operative corporate sustainability and sustainability performance measurement in Cuban organizations. The combination of Sustainability Balanced Scorecard, multi-criteria decisions models like: Analytic Network Process, and Matrix of Sustainable Strategic Alignment, can help managers in sustainability performance measurement and assessment. The result of this paper focus in a Corporate Sustainability Measurement Network design as a first approach for further sustainability performance measurement systems development emphasizing in multi-criteria analysis.

  3. Aquatic Equipment Information.

    Science.gov (United States)

    Sova, Ruth

    Equipment usually used in water exercise programs is designed for variety, intensity, and program necessity. This guide discusses aquatic equipment under the following headings: (1) equipment design; (2) equipment principles; (3) precautions and contraindications; (4) population contraindications; and (5) choosing equipment. Equipment is used…

  4. A comparative performance evaluation of neural network based approach for sentiment classification of online reviews

    OpenAIRE

    Vinodhini, G.; Chandrasekaran, R.M.

    2016-01-01

    The aim of sentiment classification is to efficiently identify the emotions expressed in the form of text messages. Machine learning methods for sentiment classification have been extensively studied, due to their predominant classification performance. Recent studies suggest that ensemble based machine learning methods provide better performance in classification. Artificial neural networks (ANNs) are rarely being investigated in the literature of sentiment classification. This paper compare...

  5. Performances of Neural Networks and LDPC Decoders for OFDM High Speed Transmission in Optical Fiber

    OpenAIRE

    Sanou Serge Roland 1, 2 * , Zougmoré François 1 , Kébré Marcel 1 , Koalaga Zacharie 1 , Doumounia Ali

    2013-01-01

    This paper presents a comparison of the performances of coded OFDM (Orthogonal Frequency Division Multiplexing) for optical broadband transmission using Random Neural Network (RNN), a variant of RNN, Soft Decision Decoding (SDD) and LDPC channel decoding techniques. The performance evaluation is based firstly on the Error Vector Magnitude (EVM) to assess the effects of imperfections in the optical channel, and secondly on the estimated Bit Error Rate (BER) base...

  6. ANALYTIC NETWORK PROCESS AND BALANCED SCORECARD APPLIED TO THE PERFORMANCE EVALUATION OF PUBLIC HEALTH SYSTEMS

    Directory of Open Access Journals (Sweden)

    Marco Aurélio Reis dos Santos

    2015-08-01

    Full Text Available The performance of public health systems is an issue of great concern. After all, to assure people's quality of life, public health systems need different kinds of resources. Balanced Scorecard provides a multi-dimensional evaluation framework. This paper presents the application of the Analytic Network Process and Balanced Scorecard in the performance evaluation of a public health system in a typical medium-sized Southeastern town in Brazil.

  7. 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.

  8. Changes in Brain Network Efficiency and Working Memory Performance in Aging

    Science.gov (United States)

    Stanley, Matthew L.; Simpson, Sean L.; Dagenbach, Dale; Lyday, Robert G.; Burdette, Jonathan H.; Laurienti, Paul J.

    2015-01-01

    Working memory is a complex psychological construct referring to the temporary storage and active processing of information. We used functional connectivity brain network metrics quantifying local and global efficiency of information transfer for predicting individual variability in working memory performance on an n-back task in both young (n = 14) and older (n = 15) adults. Individual differences in both local and global efficiency during the working memory task were significant predictors of working memory performance in addition to age (and an interaction between age and global efficiency). Decreases in local efficiency during the working memory task were associated with better working memory performance in both age cohorts. In contrast, increases in global efficiency were associated with much better working performance for young participants; however, increases in global efficiency were associated with a slight decrease in working memory performance for older participants. Individual differences in local and global efficiency during resting-state sessions were not significant predictors of working memory performance. Significant group whole-brain functional network decreases in local efficiency also were observed during the working memory task compared to rest, whereas no significant differences were observed in network global efficiency. These results are discussed in relation to recently developed models of age-related differences in working memory. PMID:25875001

  9. Ansiedade e desempenho: um estudo com uma equipe infantil de voleibol feminino Anxiety and performance: a study of an infant female volleyball team

    Directory of Open Access Journals (Sweden)

    Christi Noriko Sonoo

    2010-09-01

    Full Text Available O objetivo deste estudo foi analisar a 'ansiedade traço' e 'ansiedade estado' e sua relação com o desempenho pré-competitivo e competitivo no voleibol. O caso estudado foi uma equipe de voleibol feminina infantil. Utilizou-se como instrumentos de medida os protocolos CSAI-II e o SCAT. A coleta de dados ocorreu nos locais de treinamento e durante os Jogos Colegiais 2005. Para a análise dos dados utilizou-se estatística descritiva e o teste "t" de Student. Os resultados indicaram: 'ansiedade traço' pré-competitiva e competitiva sem diferenças significativas, porém na 'ansiedade estado' observou-se diferença significativa (P=0,05 para o componente cognitivo. Verificou-se um equilíbrio entre os componentes da 'ansiedade estado' na fase preparatória pelas vitórias em todos os jogos, o que se mostrou diferente na fase competitiva, onde a equipe sofreu duas derrotas. Conclui-se que a ansiedade pode afetar o desempenho das atletas na situação competitiva nesta modalidade e categoria estudada.The objective of this study was to analyze trait anxiety and state anxiety and their relation with pre-competitive and competitive performance in volleyball. The case studied was a infantile female volleyball team. The measure instruments used were the CSAI-II and SCAT protocols. Data collection occurred in training stations and during High School games 2005. Data analysis was performed through descriptive statistics and Student's "t" test. The results indicated: pre-competitive and competitive trait anxiety with no significant differences, however in relation to state anxiety a significant difference was observed (P=0,05 in the cognitive component. A balance was verified between state anxiety components in preparation phase because of the winnings in all games, fact that was different in the competitive phase, where the team lost two times. It is concluded that anxiety can affect athletes' performance in competitive situation in the modality and

  10. Modeling radio link performance in UMTS W-CDMA network simulations

    DEFF Research Database (Denmark)

    Klingenbrunn, Thomas; Mogensen, Preben Elgaard

    2000-01-01

    This article presents a method to model the W-CDMA radio receiver performance, which is usable in network simulation tools for third generation mobile cellular systems. The method represents a technique to combine link level simulations with network level simulations. The method is derived from [1......], which defines a stochastic mapping function from a Signal-to-Interference Ratio into a Bit-Error-Rate for a TDMA system. However, in order to work in a W-CDMA based system, the fact that the Multiple-Access Interference in downlink consists of both Gaussian inter-cell interference and orthogonal intra...

  11. Performance Evaluation of Survivability Strategies for Elastic Optical Networks under Physical Layer Impairments

    Directory of Open Access Journals (Sweden)

    Jurandir Lacerda Jr

    2017-08-01

    Full Text Available This paper carried out a performance evaluation study that compares two survivability strategies (DPP and SM-RSA for elastic optical networks with and without physical layer impairments. The evaluated scenarios include three representative topologies for elastic optical network, NSFNET, EON and USA. It also analyzes the increase of blocking probability when the survivability strategies are evaluated under the realistic scenario that assumes physical layer impairments. For all studied topologies under physical layer impairments, the survivability strategies achieved blocking probability above 80%.

  12. Network coding and evolutionary theory for performance enhancement in wireless cooperative clusters

    DEFF Research Database (Denmark)

    Militano, Leonardo; Fitzek, Frank; Iera, Antonio

    2010-01-01

    , portions of a file to be successively exchanged among all cluster members over wireless local area network (WLAN) links. Besides showing the beneficial effects of cooperation, this paper also focuses on the performance enhancement that can be achieved when using the network coding paradigm, whose...... are investigated and an ad hoc conceived Genetic Algorithm (GA) designed. Either the service time (the time needed for all nodes to receive the complete file) or the energy consumption for the nodes is used as objective function, showing in both cases the fast convergence for the algorithm that makes it preferable...

  13. Performance analysis of coordination strategies in two-tier Heterogeneous Networks

    KAUST Repository

    Boukhedimi, Ikram

    2016-08-11

    Large scale multi-tier Heterogeneous Networks (HetNets) are expected to ensure a consistent quality of service (QoS) in 5G systems. Such networks consist of a macro base station (BS) equipped with a large number of antennas and a dense overlay of small cells. The small cells could be deployed within the same coverage of the macro-cell BS, thereby causing high levels of inter-cell interference. In this regard, coordinated beamforming techniques are considered as a viable solution to counteract the arising interference. The goal of this work is to analyze the efficiency of coordinated beamforming techniques in mitigating both intra-cell and inter-cell interference. In particular, we consider the downlink of a Time-division duplexing (TDD) massive multiple-input-multiple-output (MIMO) tier-HetNet and analyze different beamforming schemes together with different degrees of coordination between the BSs. We exploit random matrix theory tools in order to provide, in explicit form, deterministic equivalents for the average achievable rates in the macro-cell and the micro-cells. We prove that our theoretical derivations allow us to draw some conclusions regarding the role played by coordination strategies in reducing the inter-cell interference. These findings are finally validated by a selection of some numerical results. © 2016 IEEE.

  14. Performance Analysis of a Cluster-Based MAC Protocol for Wireless Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Jesús Alonso-Zárate

    2010-01-01

    Full Text Available An analytical model to evaluate the non-saturated performance of the Distributed Queuing Medium Access Control Protocol for Ad Hoc Networks (DQMANs in single-hop networks is presented in this paper. DQMAN is comprised of a spontaneous, temporary, and dynamic clustering mechanism integrated with a near-optimum distributed queuing Medium Access Control (MAC protocol. Clustering is executed in a distributed manner using a mechanism inspired by the Distributed Coordination Function (DCF of the IEEE 802.11. Once a station seizes the channel, it becomes the temporary clusterhead of a spontaneous cluster and it coordinates the peer-to-peer communications between the clustermembers. Within each cluster, a near-optimum distributed queuing MAC protocol is executed. The theoretical performance analysis of DQMAN in single-hop networks under non-saturation conditions is presented in this paper. The approach integrates the analysis of the clustering mechanism into the MAC layer model. Up to the knowledge of the authors, this approach is novel in the literature. In addition, the performance of an ad hoc network using DQMAN is compared to that obtained when using the DCF of the IEEE 802.11, as a benchmark reference.

  15. Performance analysis of an opportunistic multi-user cognitive network with multiple primary users

    KAUST Repository

    Khan, Fahd Ahmed

    2014-03-01

    Consider a multi-user underlay cognitive network where multiple cognitive users concurrently share the spectrum with a primary network with multiple users. The channel between the secondary network is assumed to have independent but not identical Nakagami-m fading. The interference channel between the secondary users (SUs) and the primary users is assumed to have Rayleigh fading. A power allocation based on the instantaneous channel state information is derived when a peak interference power constraint is imposed on the secondary network in addition to the limited peak transmit power of each SU. The uplink scenario is considered where a single SU is selected for transmission. This opportunistic selection depends on the transmission channel power gain and the interference channel power gain as well as the power allocation policy adopted at the users. Exact closed form expressions for the moment-generating function, outage performance, symbol error rate performance, and the ergodic capacity are derived. Numerical results corroborate the derived analytical results. The performance is also studied in the asymptotic regimes, and the generalized diversity gain of this scheduling scheme is derived. It is shown that when the interference channel is deeply faded and the peak transmit power constraint is relaxed, the scheduling scheme achieves full diversity and that increasing the number of primary users does not impact the diversity order. © 2014 John Wiley & Sons, Ltd.

  16. A novel nature inspired firefly algorithm with higher order neural network: Performance analysis

    Directory of Open Access Journals (Sweden)

    Janmenjoy Nayak

    2016-03-01

    Full Text Available The applications of both Feed Forward Neural network and Multilayer perceptron are very diverse and saturated. But the linear threshold unit of feed forward networks causes fast learning with limited capabilities, while due to multilayering, the back propagation of errors exhibits slow training speed in MLP. So, a higher order network can be constructed by correlating between the input variables to perform nonlinear mapping using the single layer of input units for overcoming the above drawbacks. In this paper, a Firefly based higher order neural network has been proposed for data classification for maintaining fast learning and avoids the exponential increase of processing units. A vast literature survey has been conducted to review the state of the art of the previous developed models. The performance of the proposed method has been tested with various benchmark datasets from UCI machine learning repository and compared with the performance of other established models. Experimental results imply that the proposed method is fast, steady, reliable and provides better classification accuracy than others.

  17. 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.

  18. Analysis of integrated healthcare networks' performance: a contingency-strategic management perspective.

    Science.gov (United States)

    Lin, B Y; Wan, T T

    1999-12-01

    Few empirical analyses have been done in the organizational researches of integrated healthcare networks (IHNs) or integrated healthcare delivery systems. Using a contingency derived contact-process-performance model, this study attempts to explore the relationships among an IHN's strategic direction, structural design, and performance. A cross-sectional analysis of 100 IHNs suggests that certain contextual factors such as market competition and network age and tax status have statistically significant effects on the implementation of an IHN's service differentiation strategy, which addresses coordination and control in the market. An IHN's service differentiation strategy is positively related to its integrated structural design, which is characterized as integration of administration, patient care, and information system across different settings. However, no evidence supports that the development of integrated structural design may benefit an IHN's performance in terms of clinical efficiency and financial viability.

  19. Prediction of the Styrene Butadiene Rubber Performance by Emulsion Polymerization Using Backpropagation Neural Network

    Directory of Open Access Journals (Sweden)

    Yan-jiang Jin

    2013-01-01

    Full Text Available The effect of the amounts of initiator, emulsifier, and molecular weight regulator on the styrene butadiene rubber performance was investigated, based on the industrial original formula. It was found that the polymerization rate was increased with the increased dosage of initiator and emulsifier, and together with replenishing molecular weight regulator will make the Mooney viscosity of rubber meet the national standard when the conversion rate reaches 70%. The backpropagation neural network was trained by the original formula and ameliorated formula on the basis of Levenberg-Marquardt algorithm, and the relative error between the simulation results and experimental data is less than 1%. The good consistency shows that the BP neural network could predict the product performances in different formula conditions. It would pave the way for adjustment of the SBR formulation and prediction of the product performances.

  20. Evaluating the Impact of Communication Network Performance on Supervisory Supermarket Control

    DEFF Research Database (Denmark)

    Madsen, Jacob Theilgaard; Minko, Tomasz; Madsen, Tatiana Kozlova

    2017-01-01

    scenarios of variable electricity prices. Based on the structure of the message exchanges between supervisory and local controllers, first the impact of deterministic delays on the information age that is used by the controller to calculate set-points is analyzed. Subsequently we investigate the impact......This paper addresses the evaluation of the impact of non-ideal communication networks on system performance of hierarchical control systems. It develops a stepwise evaluation approach that is applied to the example scenario of a supervisory controller for supermarket temperature control, addressing...... of communication network performance on the supermarket refrigeration control and resulting energy costs using simulation models. The results show that the controller is resilient to downstream information delays, however upstream delays or up- and downstream information loss can cause significant performance...