WorldWideScience

Sample records for network communications issue

  1. Study on networking issues of medium earth orbit satellite communications systems

    Science.gov (United States)

    Araki, Noriyuki; Shinonaga, Hideyuki; Ito, Yasuhiko

    1993-01-01

    Two networking issues of communications systems with medium earth orbit (MEO) satellites, namely network architectures and location determination and registration methods for hand-held terminals, are investigated in this paper. For network architecture, five candidate architectures are considered and evaluated in terms of signaling traffic. For location determination and registration, two methods are discussed and evaluated.

  2. Reliability issues of free-space communications systems and networks

    Science.gov (United States)

    Willebrand, Heinz A.

    2003-04-01

    Free space optics (FSO) is a high-speed point-to-point connectivity solution traditionally used in the enterprise campus networking market for building-to-building LAN connectivity. However, more recently some wire line and wireless carriers started to deploy FSO systems in their networks. The requirements on FSO system reliability, meaing both system availability and component reliability, are far more stringent in the carrier market when compared to the requirements in the enterprise market segment. This paper tries to outline some of the aspects that are important to ensure carrier class system reliability.

  3. Issues for the integration of satellite and terrestrial cellular networks for mobile communications

    Science.gov (United States)

    Delre, Enrico; Mistretta, Ignazio; Dellipriscoli, Francesco; Settimo, Franco

    1991-01-01

    Satellite and terrestrial cellular systems naturally complement each other for land mobile communications, even though present systems have been developed independently. The main advantages of the integrated system are a faster wide area coverage, a better management of overloading traffic conditions, an extension to geographical areas not covered by the terrestrial network and, in perspective, the provision of only one integrated system for all mobile communications (land, aeronautical, and maritime). To achieve these goals, as far as possible the same protocols of the terrestrial network should be used also for the satellite network. Discussed here are the main issues arising from the requirements of the main integrated system. Some results are illustrated, and possible future improvements due to technical solutions are presented.

  4. Special Issue on 5G Communications and Experimental Trials with Heterogeneous and Agile Mobile networks

    OpenAIRE

    Sejun Song; KyungHi Chang; Chanho Yoon; Jong‐Moon Chung

    2018-01-01

    5th generation mobile networks, 5G, are the proposed next‐generation communication network standards. In addition to providing more than 1 Gb per second faster speeds, 5G will be a global game changer from technological, economic, societal, and environmental perspectives by integrating multiple networks in diverse sectors for various up to date applications such as the Internet of Things (IoT), device‐to‐device direct communication (D2D), vehicular communications (V2X), and disaster resilient...

  5. Trusted Data Communication and Security Issues in Gnss Network of Turkey

    Science.gov (United States)

    Bakici, S.; Erkek, B.; Manti, V.; Altekin, A.

    2017-11-01

    There are three main activities of General Directorate of Land Registry and Cadastre. These are Mapping, Land Registry and Cadastre. Geomatic Department is responsible for mapping activities. The most important projects like TUSAGA-Aktif (CORS-Tr), Metadata Geoportal, Orthophoto Production and orthophoto web services and preparation of Turkish NSDI Feasibility Report have been conducted and completed by this department's specialists since 2005. TUSAGA-Aktif (CORS-Tr) System, serves location information at cm level accuracy in Turkey and TR Nortern Cyprus in few seconds, where adequate numbers of GNSS satellites are observed and communication possibilities are present. No ground control points and benchmarks are necessary. There are 146 permanent GNSS stations within the CORS-Tr System. Station data are transferred online to the main control center located in the Mapping Department of the General Directorate of Land Registry and Cadastre and to the control center located in the General Command of Mapping. Currently CORS-Tr has more than 9000 users. Most of them are private companies working for governmental organization. Providing data communication between control center and both GNSS station and users via trusted and good substructure is important. Additionally, protection of the system and data against cyber attacks from domestic and foreign sources is important. This paper focuses on data communication and security issues of GNSS network named TUSAGA-Aktif.

  6. TRUSTED DATA COMMUNICATION AND SECURITY ISSUES IN GNSS NETWORK OF TURKEY

    Directory of Open Access Journals (Sweden)

    S. Bakici

    2017-11-01

    Full Text Available There are three main activities of General Directorate of Land Registry and Cadastre. These are Mapping, Land Registry and Cadastre. Geomatic Department is responsible for mapping activities. The most important projects like TUSAGA-Aktif (CORS-Tr, Metadata Geoportal, Orthophoto Production and orthophoto web services and preparation of Turkish NSDI Feasibility Report have been conducted and completed by this department’s specialists since 2005. TUSAGA-Aktif (CORS-Tr System, serves location information at cm level accuracy in Turkey and TR Nortern Cyprus in few seconds, where adequate numbers of GNSS satellites are observed and communication possibilities are present. No ground control points and benchmarks are necessary. There are 146 permanent GNSS stations within the CORS-Tr System. Station data are transferred online to the main control center located in the Mapping Department of the General Directorate of Land Registry and Cadastre and to the control center located in the General Command of Mapping. Currently CORS-Tr has more than 9000 users. Most of them are private companies working for governmental organization. Providing data communication between control center and both GNSS station and users via trusted and good substructure is important. Additionally, protection of the system and data against cyber attacks from domestic and foreign sources is important. This paper focuses on data communication and security issues of GNSS network named TUSAGA-Aktif.

  7. Special Issue on 5G Communications and Experimental Trials with Heterogeneous and Agile Mobile networks

    Directory of Open Access Journals (Sweden)

    Sejun Song

    2018-02-01

    Full Text Available 5th generation mobile networks, 5G, are the proposed next‐generation communication network standards. In addition to providing more than 1 Gb per second faster speeds, 5G will be a global game changer from technological, economic, societal, and environmental perspectives by integrating multiple networks in diverse sectors for various up to date applications such as the Internet of Things (IoT, device‐to‐device direct communication (D2D, vehicular communications (V2X, and disaster resilient communication. Currently, millimeter‐wave (mmWave radio spectrum between 30 GHz and 300 GHz is critical for 5G rollout. Regulatory bodies around the world are now working towards opening up new spectrum bands from 6 GHz–100 GHz, and new technologies to overcome the challenges of these mmWave bands have been developed. It is envisioned that advanced 5G network infrastructure includes ultra‐broadband access, high‐speed backhaul and relay, softwarized flexible evolved packet core solutions for efficient system management, and satellite communications as an inherent component of 5G systems.

  8. The DOE transportation strategy: Public information, communications network and issue resolution

    International Nuclear Information System (INIS)

    Philpott, R.E.

    1986-01-01

    The OCRWM plans to issue a draft ''comprehensive transportation plan'' in the fall of 1987 that combines the Institutional Plan, the Transportation Business Plan (DOE/RW-0046, January 1986), and a framework for transportation operational procedures. This paper reviews the major elements of the OCRWM's institutional strategy. The OCRWM's strategy for addressing transportation issues relies on the development of public information to foster public understanding and acceptance of program activities and goals, and active communication and interaction with all parties having an interest in the development and operation of the NWPA transportation program. The OCRWM's goal in conducting such activities is to foster cooperative effort in addressing transportation issues, and to focus on communication and constructive interaction rather than conflict

  9. NASA Communications Augmentation network

    Science.gov (United States)

    Omidyar, Guy C.; Butler, Thomas E.; Laios, Straton C.

    1990-01-01

    The NASA Communications (Nascom) Division of the Mission Operations and Data Systems Directorate (MO&DSD) is to undertake a major initiative to develop the Nascom Augmentation (NAUG) network to achieve its long-range service objectives for operational data transport to support the Space Station Freedom Program, the Earth Observing System (EOS), and other projects. The NAUG is the Nascom ground communications network being developed to accommodate the operational traffic of the mid-1990s and beyond. The NAUG network development will be based on the Open Systems Interconnection Reference Model (OSI-RM). This paper describes the NAUG network architecture, subsystems, topology, and services; addresses issues of internetworking the Nascom network with other elements of the Space Station Information System (SSIS); discusses the operations environment. This paper also notes the areas of related research and presents the current conception of how the network will provide broadband services in 1998.

  10. Security Issues Threats and Challenges in Data Management of Wireless Communication & Sensor Network over Cloud: A Review

    OpenAIRE

    Padmaja R Ayachit,; N. G. Narole

    2014-01-01

    Cloud computing is a colloquial expression used to describe a variety of different computing concepts that involve a large number of computers that are connected through a real-time communication network. The five key characteristics of cloud computing are: location-independent resource pooling, on demand self-service, rapid elasticity, broad network access, and measured service. These five characteristics represent the first layer in the cloud environment. Wireless sensor net...

  11. Broadband network selection issues

    Science.gov (United States)

    Leimer, Michael E.

    1996-01-01

    Selecting the best network for a given cable or telephone company provider is not as obvious as it appears. The cost and performance trades between Hybrid Fiber Coax (HFC), Fiber to the Curb (FTTC) and Asymmetric Digital Subscriber Line networks lead to very different choices based on the existing plant and the expected interactive subscriber usage model. This paper presents some of the issues and trades that drive network selection. The majority of the Interactive Television trials currently underway or planned are based on HFC networks. As a throw away market trial or a short term strategic incursion into a cable market, HFC may make sense. In the long run, if interactive services see high demand, HFC costs per node and an ever shrinking neighborhood node size to service large numbers of subscribers make FTTC appear attractive. For example, thirty-three 64-QAM modulators are required to fill the 550 MHz to 750 MHz spectrum with compressed video streams in 6 MHz channels. This large amount of hardware at each node drives not only initial build-out costs, but operations and maintenance costs as well. FTTC, with its potential for digitally switching large amounts of bandwidth to an given home, offers the potential to grow with the interactive subscriber base with less downstream cost. Integrated telephony on these networks is an issue that appears to be an afterthought for most of the networks being selected at the present time. The major players seem to be videocentric and include telephony as a simple add-on later. This may be a reasonable view point for the telephone companies that plan to leave their existing phone networks untouched. However, a phone company planning a network upgrade or a cable company jumping into the telephony business needs to carefully weigh the cost and performance issues of the various network choices. Each network type provides varying capability in both upstream and downstream bandwidth for voice channels. The noise characteristics

  12. Advances and Challenges in Convergent Communication Networks

    DEFF Research Database (Denmark)

    Toral-Cruz, Homero; Mihovska, Albena

    2017-01-01

    Welcome to this special issue of Wireless Personal Communications on Advances and Challenges in Convergent Communication Networks. The main purpose of this special issue is to present new progresses and challenges in convergent networks. Communication networks play an important role in our daily...... life because they allow communicating and sharing contents between heterogeneous nodes around the globe. The emergence of multiple network architectures and emerging technologies have resulted in new applications and services over a heterogeneous network. This heterogeneous network has undergone...... significant challenges in recent years, such as the evolution to a converged network with the capability to support multiple services, while maintaining a satisfactory level of QoE/QoS, security, efficiency and trust. The special issue on Advances and Challenges in Convergent Communication Networks...

  13. Computer-communication networks

    CERN Document Server

    Meditch, James S

    1983-01-01

    Computer- Communication Networks presents a collection of articles the focus of which is on the field of modeling, analysis, design, and performance optimization. It discusses the problem of modeling the performance of local area networks under file transfer. It addresses the design of multi-hop, mobile-user radio networks. Some of the topics covered in the book are the distributed packet switching queuing network design, some investigations on communication switching techniques in computer networks and the minimum hop flow assignment and routing subject to an average message delay constraint

  14. Designing for Networked Communications

    DEFF Research Database (Denmark)

    Designing for Networked Communications: Strategies and Development explains how to plan, use, and understand the products and the dynamic social processes and tasks some of the most vital innovations in the knowledge society depend upon– social as well as technological. Focusing on various forms...... of design, implementation and integration of computer mediated communication, this book bridges the academic fields of computer science and communication studies. Designing for Networked Communications: Strategies and Development uses an interdisciplinary approach, and presents results from recent...... and important research in a variety of forms for networked communications. A constructive and critical view of the interplay between the new electronic and the more conventional modes of communication are utilized, while studies of organizational work practices demonstrate that the use of new technologies...

  15. Network Approach in Political Communication Studies

    Directory of Open Access Journals (Sweden)

    Нина Васильевна Опанасенко

    2013-12-01

    Full Text Available The article is devoted to issues of network approach application in political communication studies. The author considers communication in online and offline areas and gives the definition of rhizome, its characteristics, identifies links between rhizome and network approach. The author also analyses conditions and possibilities of the network approach in modern political communication. Both positive and negative features of the network approach are emphasized.

  16. Communication: an ophthalmic practice issue.

    Science.gov (United States)

    Whitton, S J

    1995-12-01

    In the 1990's communication becomes an ophthalmic practice issue. The present ophthalmic climate of cost containment, downsizing, budget cuts, and lack of appreciation of contributions, results in a low staff morale. Recognition of the effects of job satisfaction and productivity led one group to seek solutions. A communication task force was formed to identify problems and the appropriate interventions.

  17. Theme Issue on Mass Communication.

    Science.gov (United States)

    Anapol, Malthon M., Ed.

    1978-01-01

    Focusing on issues in mass communication, the six articles in this journal issue cover many facets and approaches to the topics. The first article offers a review of recent developments in the field and some comments about its future. The second article reviews feminism in comedies from the 1930s and in a current film, and the third analyzes the…

  18. Data communications and computer communications network

    International Nuclear Information System (INIS)

    Kim, Jang Gwon; Gu, Chang Hoe

    2005-03-01

    This textbook is composed of twelve chapters, which are communication network introduction, foundation of data communication, data link control, circuit switching system, packet switching system, multiple access communication system, protocol and architecture, LAN, MAN communication network, integrated service digital network, internet and Asymmetric digital subscriber Line and Wireless Local Loop. Each chapter has the introduction of the technique, structure, function and practice problems. It also has the appendix on electricity and communication standards organization, characteristic table and glossary.

  19. Communication Network Analysis Methods.

    Science.gov (United States)

    Farace, Richard V.; Mabee, Timothy

    This paper reviews a variety of analytic procedures that can be applied to network data, discussing the assumptions and usefulness of each procedure when applied to the complexity of human communication. Special attention is paid to the network properties measured or implied by each procedure. Factor analysis and multidimensional scaling are among…

  20. Connectivist Communication Networks

    Science.gov (United States)

    Waßmann, Ingolf; Nicolay, Robin; Martens, Alke

    2016-01-01

    Facing the challenges of the digital age concerning lifelong learning, this contribution presents an approach to dynamically establish Connectivist communication networks. According the statement "the pipe is more important than the content within the pipe" by Georg Siemens, learning in digital age includes the connection of people to…

  1. European environmental communication networks

    International Nuclear Information System (INIS)

    Plesnikova, T.

    2005-01-01

    The goal of this presentation is apprise of special community - representatives of state and public administration, self-administration, workers of scientific institutes, schools, private companies and next privies subjects of areas of the environment with possibilities of access to actual environmental information by the Internet. Web-sites of environmental communication networks with data about the environment are presented

  2. Communicability across evolving networks.

    Science.gov (United States)

    Grindrod, Peter; Parsons, Mark C; Higham, Desmond J; Estrada, Ernesto

    2011-04-01

    Many natural and technological applications generate time-ordered sequences of networks, defined over a fixed set of nodes; for example, time-stamped information about "who phoned who" or "who came into contact with who" arise naturally in studies of communication and the spread of disease. Concepts and algorithms for static networks do not immediately carry through to this dynamic setting. For example, suppose A and B interact in the morning, and then B and C interact in the afternoon. Information, or disease, may then pass from A to C, but not vice versa. This subtlety is lost if we simply summarize using the daily aggregate network given by the chain A-B-C. However, using a natural definition of a walk on an evolving network, we show that classic centrality measures from the static setting can be extended in a computationally convenient manner. In particular, communicability indices can be computed to summarize the ability of each node to broadcast and receive information. The computations involve basic operations in linear algebra, and the asymmetry caused by time's arrow is captured naturally through the noncommutativity of matrix-matrix multiplication. Illustrative examples are given for both synthetic and real-world communication data sets. We also discuss the use of the new centrality measures for real-time monitoring and prediction.

  3. Communication in Animal Social Networks

    NARCIS (Netherlands)

    Snijders, Lysanne; Naguib, Marc

    2017-01-01

    Animal social networks and animal communication networks are key disciplines for understanding animal social behavior, yet these disciplines remain poorly integrated. In this review, we show how communication and social networks are inherently linked, with social signals reflecting and affecting

  4. Communication Buses and Protocols for Sensor Networks

    Directory of Open Access Journals (Sweden)

    Andrew Mason

    2002-07-01

    Full Text Available This paper overviews existing digital communication buses which are commonly used in sensor networks, discusses sensor network architectures, and introduces a new sensor bus for low power microsystem applications. The new intra-module multi-element microsystem (IM2 bus is nine-line interface with 8b serial data which implements several advanced features such as power management and plug-n-play while maintaining minimum hardware overhead at the sensor node. Finally, some issues in wireless sensor networking are discussed. The coverage of these issues provides a guideline for choosing the appropriate bus for different sensor network applications.

  5. Fairness in Communication and Computer Network Design

    OpenAIRE

    Nilsson, Pål

    2006-01-01

    In communication networks, fair sharing of resources is an important issue for one main reason. The growth of network capacity is in general not matching the rapid growth of traffic. Consequently, the resources consumed by each user have to be limited. This implies that users cannot always be assigned the end-to-end bandwidth they ask for. Instead, the limited network resources should be distributed to users in a way that assures fair end-to-end bandwidth assignment among them. Obtaini...

  6. SOCIAL NETWORKS AND INTERPERSONAL COMMUNICATION

    Directory of Open Access Journals (Sweden)

    Veronica GHEORGHIȚĂ

    2014-11-01

    Full Text Available Social networks visible influence people's ability to interact and communicate. Extending social circles by establishing virtual links involves a number of positive aspects such as: instant access to options for interaction, sharing of information to large communities of people, intensification of acts of communication, high levels of feedback and trust with people with whom we communicate. On the other hand, social networks adversely affects communication by decreasing the interaction face to face, by imposing superficial communications experiences, grammatical and spelling erosion of the language. Therefore, the study aims to capture the spread of social networks, their use and impact on interpersonal communication. More specifically, they look for the answer to the question: what is the nature of interpersonal communication that is found on social networking sites: personal, emotional, private or shared, informal, and public?

  7. Topological Rankings in Communication Networks

    DEFF Research Database (Denmark)

    Aabrandt, Andreas; Hansen, Vagn Lundsgaard; Træholt, Chresten

    2015-01-01

    In the theory of communication the central problem is to study how agents exchange information. This problem may be studied using the theory of connected spaces in topology, since a communication network can be modelled as a topological space such that agents can communicate if and only...... if they belong to the same path connected component of that space. In order to study combinatorial properties of such a communication network, notions from algebraic topology are applied. This makes it possible to determine the shape of a network by concrete invariants, e.g. the number of connected components...

  8. Policy issues in interconnecting networks

    Science.gov (United States)

    Leiner, Barry M.

    1989-01-01

    To support the activities of the Federal Research Coordinating Committee (FRICC) in creating an interconnected set of networks to serve the research community, two workshops were held to address the technical support of policy issues that arise when interconnecting such networks. The workshops addressed the required and feasible technologies and architectures that could be used to satisfy the desired policies for interconnection. The results of the workshop are documented.

  9. Special issue on network coding

    Science.gov (United States)

    Monteiro, Francisco A.; Burr, Alister; Chatzigeorgiou, Ioannis; Hollanti, Camilla; Krikidis, Ioannis; Seferoglu, Hulya; Skachek, Vitaly

    2017-12-01

    Future networks are expected to depart from traditional routing schemes in order to embrace network coding (NC)-based schemes. These have created a lot of interest both in academia and industry in recent years. Under the NC paradigm, symbols are transported through the network by combining several information streams originating from the same or different sources. This special issue contains thirteen papers, some dealing with design aspects of NC and related concepts (e.g., fountain codes) and some showcasing the application of NC to new services and technologies, such as data multi-view streaming of video or underwater sensor networks. One can find papers that show how NC turns data transmission more robust to packet losses, faster to decode, and more resilient to network changes, such as dynamic topologies and different user options, and how NC can improve the overall throughput. This issue also includes papers showing that NC principles can be used at different layers of the networks (including the physical layer) and how the same fundamental principles can lead to new distributed storage systems. Some of the papers in this issue have a theoretical nature, including code design, while others describe hardware testbeds and prototypes.

  10. Social networks: communication and change

    Directory of Open Access Journals (Sweden)

    Gustavo Cardoso

    2011-01-01

    Full Text Available Virtual social networks have brought about the possibility for open and plural debate, where all those with the necessary literacy skills and means are able to participate in the creation and dissemination of information. By pressing political agents and determining the “agenda” of a lot of the media, users demonstrate that we stand at an ideal platform for creating both real social movements and more or less fleeting events, as manifestos or virtual campaigns. Nonetheless, in order to understand the role of virtual social networks in today’s world, we need to answer some prior questions. Are we facing a new communication model, whereby the product of “disinterested” interactivity creates an aura of confidence in disseminated information, often quite higher that that seen in the “old media”? Will that interactivity be a chance to fight-off citizens’ growing detachment with regard to the “res publica”? Will we find in citizen-made journalism, transmitted through virtual social networks, the consecration of a true fourth power? On the other hand, can we call the distinct collective movements we have seen emerging true “social movements”?The present article aims to examine this and other issues that come to the fore in the intricate social world of cyberspace.

  11. MIMO Communication for Cellular Networks

    CERN Document Server

    Huang, Howard; Venkatesan, Sivarama

    2012-01-01

    As the theoretical foundations of multiple-antenna techniques evolve and as these multiple-input multiple-output (MIMO) techniques become essential for providing high data rates in wireless systems, there is a growing need to understand the performance limits of MIMO in practical networks. To address this need, MIMO Communication for Cellular Networks presents a systematic description of MIMO technology classes and a framework for MIMO system design that takes into account the essential physical-layer features of practical cellular networks. In contrast to works that focus on the theoretical performance of abstract MIMO channels, MIMO Communication for Cellular Networks emphasizes the practical performance of realistic MIMO systems. A unified set of system simulation results highlights relative performance gains of different MIMO techniques and provides insights into how best to use multiple antennas in cellular networks under various conditions. MIMO Communication for Cellular Networks describes single-user,...

  12. Communication issues in migraine diagnosis.

    Science.gov (United States)

    Edmeads, John

    2002-06-01

    To examine the importance of good communication when informing the patient of the diagnosis of migraine; to review the essentials of successful communication between physician and patient on the aspect of diagnosis; to survey learning resources for physicians on communicating information to patients. This paper is based on observations made by the author of the successful interactions of numerous international "headache experts" with their patients, on a review of the medical education literature pertaining to the teaching of communication skills, and on 30 years of not always successful communication with patients. Communicating the diagnosis of migraine is an opportunity to educate and reassure the patient, to lay the foundation for rational treatment and to help establish the successful doctor-patient relationship which is essential for effective management. No matter how accurate the diagnosis, failure to communicate it effectively to the patient (and often to significant others) may impair interactions with the patient and compromise therapy. Effective communication of a diagnosis requires clarity, relevance to the patient, a positive attitude, and reinforcement through repetition, questioning and dialogue. In terms of using the diagnosis to lay a foundation for therapy, it is useful to explain the symptoms as transient physical dysfunction of normal tissues, to indicate that there are multiple mechanisms underlying the dysfunction of which only some may presently be susceptible to treatment and to stress the relevance of emotions as factors which may powerfully affect, for better or worse, the underlying disturbed physiology of migraine. Into this model can be "plugged" all the relevant therapies for migraine. This is the ideal, but every day experience in the headache consultant's office suggest that in both primary care and specialist practice, it is infrequently attained. There are scant resources other than example for physicians to learn communication of

  13. Emerging trends in communication networks

    CERN Document Server

    Hasan, Syed Faraz

    2014-01-01

    This book covers the state of the art in communication networks with the help of illustrative diagrams and recent references published in reputed journals and magazines. The book gives readers a glimpse into the next generation of communication networks. It explores topics that are currently in the research phase and/or are expected to be deployed in recent future such as LTE networks and IPv6 networks. This book is written for students/researchers who wish to come up to date with the recent trends in telecommunications.

  14. Hybrid Mobile Communication Networks for Planetary Exploration

    Science.gov (United States)

    Alena, Richard; Lee, Charles; Walker, Edward; Osenfort, John; Stone, Thom

    2007-01-01

    A paper discusses the continuing work of the Mobile Exploration System Project, which has been performing studies toward the design of hybrid communication networks for future exploratory missions to remote planets. A typical network could include stationary radio transceivers on a remote planet, mobile radio transceivers carried by humans and robots on the planet, terrestrial units connected via the Internet to an interplanetary communication system, and radio relay transceivers aboard spacecraft in orbit about the planet. Prior studies have included tests on prototypes of these networks deployed in Arctic and desert regions chosen to approximate environmental conditions on Mars. Starting from the findings of the prior studies, the paper discusses methods of analysis, design, and testing of the hybrid communication networks. It identifies key radio-frequency (RF) and network engineering issues. Notable among these issues is the study of wireless LAN throughput loss due to repeater use, RF signal strength, and network latency variations. Another major issue is that of using RF-link analysis to ensure adequate link margin in the face of statistical variations in signal strengths.

  15. EPA Library Network Communication Strategies

    Science.gov (United States)

    To establish Agency-wide procedures for the EPA National Library Network libraries to communicate, using a range of established mechanisms, with other EPA libraries, EPA staff, organizations and the public.

  16. Networked Constellation Communications Technologies

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop communications architectures and enabling technologies for mission concepts relying on multiple spatially distributed spacecraft to perform coordinated...

  17. BRAND COMMUNICATION ON SOCIAL NETWORKS

    Directory of Open Access Journals (Sweden)

    Otilia-Elena PLATON

    2015-07-01

    Full Text Available The communication represents a basic element for the marketing activity that helps companies to achieve their objectives. Building long-term relationships between brands and consumers is one of the most important objectives pursued by marketers. This involves brand communication and creating multiple connections with consumers, even in the online environment. From this point of view, social networks proved to be an effective way of linking brands and consumers online. This paper aims to present some aspects involved by the usage of social networks in brand communication by analyzing several examples of online marketing campaigns implemented on Facebook on the occasion of Valentine's Day by six different brands.

  18. Fourth international conference on Networks & Communications

    CERN Document Server

    Meghanathan, Natarajan; Nagamalai, Dhinaharan; Computer Networks & Communications (NetCom)

    2013-01-01

    Computer Networks & Communications (NetCom) is the proceedings from the Fourth International Conference on Networks & Communications. This book covers theory, methodology and applications of computer networks, network protocols and wireless networks, data communication technologies, and network security. The proceedings will feature peer-reviewed papers that illustrate research results, projects, surveys and industrial experiences that describe significant advances in the diverse areas of computer networks & communications.

  19. Communicating embedded systems networks applications

    CERN Document Server

    Krief, Francine

    2013-01-01

    Embedded systems become more and more complex and require having some knowledge in various disciplines such as electronics, data processing, telecommunications and networks. Without detailing all the aspects related to the design of embedded systems, this book, which was written by specialists in electronics, data processing and telecommunications and networks, gives an interesting point of view of communication techniques and problems in embedded systems. This choice is easily justified by the fact that embedded systems are today massively communicating and that telecommunications and network

  20. RELATIONSHIPS AND COMMUNICATION NETWORKS

    OpenAIRE

    Stefan VLADUTESCU

    2012-01-01

    The main feature of the present situation regarding communication is the impregnation of the social with technology. Computer-mediated communication systems has led to the crystallization of a strong specific interactions. This article describes how human relationships constitues the ontological pillar of society and social relations form the axis irradiance of sociology. Overall, as social agents in social space, people come in a variety of social relationships. Thus, a distinct note of the ...

  1. Issues in Text Design and Layout for Computer Based Communications.

    Science.gov (United States)

    Andresen, Lee W.

    1991-01-01

    Discussion of computer-based communications (CBC) focuses on issues involved with screen design and layout for electronic text, based on experiences with electronic messaging, conferencing, and publishing within the Australian Open Learning Information Network (AOLIN). Recommendations for research on design and layout for printed text are also…

  2. Ethical issues in communicating science.

    Science.gov (United States)

    Garrett, J M; Bird, S J

    2000-10-01

    Most of the publicized work on scientific ethics concentrates on establishing professional norms and avoiding misconduct. The successful communication of science is the responsibility of all involved in the process. In one study, the increased incidence of autism and other social developmental disorders in males was investigated by examining individuals with Turner's syndrome (XO females). In the national newspaper this became "Genetic X-factor explains why boys will always be boys". The steps by which a study on developmental disorders, published in a highly prestigious journal, was transformed into an article in the science section which 'explained' the socially expected gender-based behavior of genetically normal children are fascinating and, unfortunately far too typical. The scientists wrote an excellent article that has just one sentence at the end that hesitantly suggests that the findings might, with further study, have some relevance to understanding normal behavior. The general interest article in the front of the journal gave a good account of the research, but suggested more strongly that there could be an in-built biological dimorphism in social cognition. This was misrepresented in the press as proof of gender differences that "undermines the trend towards sexual equality", and both illustrates cultural bias and provides fodder for feminist critiques of science. The study has been made to appear to be biased in favor of justifying the social structure of society, and yet it was the translation from the scientific study to national news that produced this transformation to biased genetic determinism. It is poor communication of the actual science, coupled with a lack of skepticism on the part of the public, that contributes to such a misapplication of science. Scientists should resist the urge to generalize their results to make them more compelling. The science community should not allow misconstructions of scientific facts to go unchallenged

  3. Robust Networking Architecture and Secure Communication Scheme for Heterogeneous Wireless Sensor Networks

    Science.gov (United States)

    McNeal, McKenzie, III.

    2012-01-01

    Current networking architectures and communication protocols used for Wireless Sensor Networks (WSNs) have been designed to be energy efficient, low latency, and long network lifetime. One major issue that must be addressed is the security in data communication. Due to the limited capabilities of low cost and small sized sensor nodes, designing…

  4. Computer networks and advanced communications

    International Nuclear Information System (INIS)

    Koederitz, W.L.; Macon, B.S.

    1992-01-01

    One of the major methods for getting the most productivity and benefits from computer usage is networking. However, for those who are contemplating a change from stand-alone computers to a network system, the investigation of actual networks in use presents a paradox: network systems can be highly productive and beneficial; at the same time, these networks can create many complex, frustrating problems. The issue becomes a question of whether the benefits of networking are worth the extra effort and cost. In response to this issue, the authors review in this paper the implementation and management of an actual network in the LSU Petroleum Engineering Department. The network, which has been in operation for four years, is large and diverse (50 computers, 2 sites, PC's, UNIX RISC workstations, etc.). The benefits, costs, and method of operation of this network will be described, and an effort will be made to objectively weigh these elements from the point of view of the average computer user

  5. Content Delivery in Future Mobile Communication Networks

    Science.gov (United States)

    Jonas, Karl; Raber, Sergey

    2003-07-01

    With the fast progress in the deployment of wireless networks during the last few years, the global communication market requires the development of new methods for content delivery towards mobile users. It is currently characterised by the introduction of the 3rd generation of terrestrial mobile networks based on 3GPP's UMTS standard. It is expected that this will eventually lead to integrated all-IP-based infrastructures supporting a variety of radio access technologies (so-called beyond-3G-networks or 4th Generation networks). The integration of mobility support, security and accounting and provisioning of differentiated qualities of service are among the issues which are currently researched in the 4G framework.Since it is not possible to change network protocols and infrastructure at once in order to optimize them for mobile services, it is very important to find an appropriate way for the migration from the current infrastructure towards an integrated architecture, where fixed and mobile networks coexist and interoperate in the most effective and flexible way.The integration of satellite communication networks into the terrestrial mobile communication environment is the focus of R&D activities at the Competence Centre for Advanced Satellite Communication of the FhG FOKUS institute. These activities are presented in this article, with a focus on the CoDeSat Content Delivery over Satellite project.In the remainder of this article we first summarize services and service requirements as they are considered in our work. We then discuss the challenges derived from these requirements with respect to current network and protocol architectures. Finally, we describe our approach, and the current status of our prototype implementation.

  6. Multiple-Ring Digital Communication Network

    Science.gov (United States)

    Kirkham, Harold

    1992-01-01

    Optical-fiber digital communication network to support data-acquisition and control functions of electric-power-distribution networks. Optical-fiber links of communication network follow power-distribution routes. Since fiber crosses open power switches, communication network includes multiple interconnected loops with occasional spurs. At each intersection node is needed. Nodes of communication network include power-distribution substations and power-controlling units. In addition to serving data acquisition and control functions, each node acts as repeater, passing on messages to next node(s). Multiple-ring communication network operates on new AbNET protocol and features fiber-optic communication.

  7. Fifth International Conference on Networks & Communications

    CERN Document Server

    Nagamalai, Dhinaharan; Rajasekaran, Sanguthevar

    2014-01-01

    This book covers theory, methodology and applications of computer networks, network protocols and wireless networks, data communication technologies, and network security. The book is based on the proceedings from the Fifth International Conference on Networks & Communications (NetCom). The proceedings will feature peer-reviewed papers that illustrate research results, projects, surveys and industrial experiences that describe significant advances in the diverse areas of computer networks & communications.

  8. Uncertainty Communication. Issues and good practice

    International Nuclear Information System (INIS)

    Kloprogge, P.; Van der Sluijs, J.; Wardekker, A.

    2007-12-01

    In 2003 the Netherlands Environmental Assessment Agency (MNP) published the RIVM/MNP Guidance for Uncertainty Assessment and Communication. The Guidance assists in dealing with uncertainty in environmental assessments. Dealing with uncertainty is essential because assessment results regarding complex environmental issues are of limited value if the uncertainties have not been taken into account adequately. A careful analysis of uncertainties in an environmental assessment is required, but even more important is the effective communication of these uncertainties in the presentation of assessment results. The Guidance yields rich and differentiated insights in uncertainty, but the relevance of this uncertainty information may vary across audiences and uses of assessment results. Therefore, the reporting of uncertainties is one of the six key issues that is addressed in the Guidance. In practice, users of the Guidance felt a need for more practical assistance in the reporting of uncertainty information. This report explores the issue of uncertainty communication in more detail, and contains more detailed guidance on the communication of uncertainty. In order to make this a 'stand alone' document several questions that are mentioned in the detailed Guidance have been repeated here. This document thus has some overlap with the detailed Guidance. Part 1 gives a general introduction to the issue of communicating uncertainty information. It offers guidelines for (fine)tuning the communication to the intended audiences and context of a report, discusses how readers of a report tend to handle uncertainty information, and ends with a list of criteria that uncertainty communication needs to meet to increase its effectiveness. Part 2 helps writers to analyze the context in which communication takes place, and helps to map the audiences, and their information needs. It further helps to reflect upon anticipated uses and possible impacts of the uncertainty information on the

  9. Using networking and communications software in business

    CERN Document Server

    McBride, PK

    2014-01-01

    Using Networking and Communications Software in Business covers the importance of networks in a business firm, the benefits of computer communications within a firm, and the cost-benefit in putting up networks in businesses. The book is divided into six parts. Part I looks into the nature and varieties of networks, networking standards, and network software. Part II discusses the planning of a networked system, which includes analyzing the requirements for the network system, the hardware for the network, and network management. The installation of the network system and the network managemen

  10. Communication Policies in Knowledge Networks

    Science.gov (United States)

    Ioannidis, Evangelos; Varsakelis, Nikos; Antoniou, Ioannis

    2018-02-01

    Faster knowledge attainment within organizations leads to improved innovation, and therefore competitive advantage. Interventions on the organizational network may be risky or costly or time-demanding. We investigate several communication policies in knowledge networks, which reduce the knowledge attainment time without interventions. We examine the resulting knowledge dynamics for real organizational networks, as well as for artificial networks. More specifically, we investigate the dependence of knowledge dynamics on: (1) the Selection Rule of agents for knowledge acquisition, and (2) the Order of implementation of "Selection" and "Filtering". Significant decrease of the knowledge attainment time (up to -74%) can be achieved by: (1) selecting agents of both high knowledge level and high knowledge transfer efficiency, and (2) implementing "Selection" after "Filtering" in contrast to the converse, implicitly assumed, conventional prioritization. The Non-Commutativity of "Selection" and "Filtering", reveals a Non-Boolean Logic of the Network Operations. The results demonstrate that significant improvement of knowledge dynamics can be achieved by implementing "fruitful" communication policies, by raising the awareness of agents, without any intervention on the network structure.

  11. Towards risk-aware communications networking

    International Nuclear Information System (INIS)

    Chołda, Piotr; Følstad, Eirik L.; Helvik, Bjarne E.; Kuusela, Pirkko; Naldi, Maurizio; Norros, Ilkka

    2013-01-01

    We promote introduction of risk-awareness in the design and operation of communications networks and services. This means explicit and systematic consideration of uncertainties related to improper behavior of the web of interdependent networks and the resulting consequences for individuals, companies and a society as a whole. Central activities are the recognition of events challenging dependability together with the assessment of their probabilities and impacts. While recognizing the complex technical, business and societal issues, we employ an overall risk framing approach containing risk assessment, response and monitoring. Our paradigm gathers topics that are currently dispersed in various fields of network activities. We review the current state of risk-related activities in networks, identify deficiencies and challenges, and suggest techniques, procedures, and metrics towards higher risk-awareness.

  12. Communications for unattended sensor networks

    Science.gov (United States)

    Nemeroff, Jay L.; Angelini, Paul; Orpilla, Mont; Garcia, Luis; DiPierro, Stefano

    2004-07-01

    The future model of the US Army's Future Combat Systems (FCS) and the Future Force reflects a combat force that utilizes lighter armor protection than the current standard. Survival on the future battlefield will be increased by the use of advanced situational awareness provided by unattended tactical and urban sensors that detect, identify, and track enemy targets and threats. Successful implementation of these critical sensor fields requires the development of advanced sensors, sensor and data-fusion processors, and a specialized communications network. To ensure warfighter and asset survivability, the communications must be capable of near real-time dissemination of the sensor data using robust, secure, stealthy, and jam resistant links so that the proper and decisive action can be taken. Communications will be provided to a wide-array of mission-specific sensors that are capable of processing data from acoustic, magnetic, seismic, and/or Chemical, Biological, Radiological, and Nuclear (CBRN) sensors. Other, more powerful, sensor node configurations will be capable of fusing sensor data and intelligently collect and process data images from infrared or visual imaging cameras. The radio waveform and networking protocols being developed under the Soldier Level Integrated Communications Environment (SLICE) Soldier Radio Waveform (SRW) and the Networked Sensors for the Future Force Advanced Technology Demonstration are part of an effort to develop a common waveform family which will operate across multiple tactical domains including dismounted soldiers, ground sensor, munitions, missiles and robotics. These waveform technologies will ultimately be transitioned to the JTRS library, specifically the Cluster 5 requirement.

  13. A Hybrid Satellite-Terrestrial Approach to Aeronautical Communication Networks

    Science.gov (United States)

    Kerczewski, Robert J.; Chomos, Gerald J.; Griner, James H.; Mainger, Steven W.; Martzaklis, Konstantinos S.; Kachmar, Brian A.

    2000-01-01

    Rapid growth in air travel has been projected to continue for the foreseeable future. To maintain a safe and efficient national and global aviation system, significant advances in communications systems supporting aviation are required. Satellites will increasingly play a critical role in the aeronautical communications network. At the same time, current ground-based communications links, primarily very high frequency (VHF), will continue to be employed due to cost advantages and legacy issues. Hence a hybrid satellite-terrestrial network, or group of networks, will emerge. The increased complexity of future aeronautical communications networks dictates that system-level modeling be employed to obtain an optimal system fulfilling a majority of user needs. The NASA Glenn Research Center is investigating the current and potential future state of aeronautical communications, and is developing a simulation and modeling program to research future communications architectures for national and global aeronautical needs. This paper describes the primary requirements, the current infrastructure, and emerging trends of aeronautical communications, including a growing role for satellite communications. The need for a hybrid communications system architecture approach including both satellite and ground-based communications links is explained. Future aeronautical communication network topologies and key issues in simulation and modeling of future aeronautical communications systems are described.

  14. Applied data communications and networks

    CERN Document Server

    Buchanan, W

    1996-01-01

    The usage of data communications and computer networks are ever in­ creasing. It is one of the few technological areas which brings benefits to most of the countries and the peoples of the world. Without it many industries could not exist. It is the objective of this book to discuss data communications in a readable form that students and professionals all over the world can understand. As much as possible the text uses dia­ grams to illustrate key points. Most currently available data communications books take their view­ point from either a computer scientists top-down approach or from an electronic engineers bottom-up approach. This book takes a practical ap­ proach and supports it with a theoretical background to create a textbook which can be used by electronic engineers, computer engineers, computer scientists and industry professionals. It discusses most of the current and future key data communications technologies, including: • Data Communications Standards and Models; • Local Area Networks (...

  15. Communications in interference limited networks

    CERN Document Server

    2016-01-01

    This book offers means to handle interference as a central problem of operating wireless networks. It investigates centralized and decentralized methods to avoid and handle interference as well as approaches that resolve interference constructively. The latter type of approach tries to solve the joint detection and estimation problem of several data streams that share a common medium. In fact, an exciting insight into the operation of networks is that it may be beneficial, in terms of an overall throughput, to actively create and manage interference. Thus, when handled properly, "mixing" of data in networks becomes a useful tool of operation rather than the nuisance as which it has been treated traditionally. With the development of mobile, robust, ubiquitous, reliable and instantaneous communication being a driving and enabling factor of an information centric economy, the understanding, mitigation and exploitation of interference in networks must be seen as a centrally important task.

  16. VSAT communications networks - An overview

    Science.gov (United States)

    Chakraborty, D.

    1988-05-01

    The very-small-aperture-terminal (VSAT) fixed satellite communication network is a star network in which many dispersed micro terminals attempt to send data in a packet form through a random access/time-division multiple-access (RA/TDMA) satellite channel with transmission delay. The basic concept of the VSAT and its service potential are discussed. Two classes of traffic are addressed, namely, business-oriented low-rate-data traffic and bulk data traffic of corporate networks. Satellite access, throughput, and delay are considered. The size of the network population that can be served in an RA/TDMA environment is calculated. User protocols are examined. A typical VSAT business scenario is described.

  17. Information communication on complex networks

    International Nuclear Information System (INIS)

    Igarashi, Akito; Kawamoto, Hiroki; Maruyama, Takahiro; Morioka, Atsushi; Naganuma, Yuki

    2013-01-01

    Since communication networks such as the Internet, which is regarded as a complex network, have recently become a huge scale and a lot of data pass through them, the improvement of packet routing strategies for transport is one of the most significant themes in the study of computer networks. It is especially important to find routing strategies which can bear as many traffic as possible without congestion in complex networks. First, using neural networks, we introduce a strategy for packet routing on complex networks, where path lengths and queue lengths in nodes are taken into account within a framework of statistical physics. Secondly, instead of using shortest paths, we propose efficient paths which avoid hubs, nodes with a great many degrees, on scale-free networks with a weight of each node. We improve the heuristic algorithm proposed by Danila et. al. which optimizes step by step routing properties on congestion by using the information of betweenness, the probability of paths passing through a node in all optimal paths which are defined according to a rule, and mitigates the congestion. We confirm the new heuristic algorithm which balances traffic on networks by achieving minimization of the maximum betweenness in much smaller number of iteration steps. Finally, We model virus spreading and data transfer on peer-to-peer (P2P) networks. Using mean-field approximation, we obtain an analytical formulation and emulate virus spreading on the network and compare the results with those of simulation. Moreover, we investigate the mitigation of information traffic congestion in the P2P networks.

  18. Communication devices for network-hopping communications and methods of network-hopping communications

    Science.gov (United States)

    Buttles, John W

    2013-04-23

    Wireless communication devices include a software-defined radio coupled to processing circuitry. The system controller is configured to execute computer programming code. Storage media is coupled to the system controller and includes computer programming code configured to cause the system controller to configure and reconfigure the software-defined radio to operate on each of a plurality of communication networks according to a selected sequence. Methods for communicating with a wireless device and methods of wireless network-hopping are also disclosed.

  19. Contemporary Issues Impacting European Communication Competencies

    Directory of Open Access Journals (Sweden)

    Ana Tkalac Verčič

    2013-06-01

    Full Text Available Although there is research focusing on skills, knowledge and personal attributes of communication professionals, there is no definitive research that brings these elements together in a European study. The article examines: (1 how socio-economic issues have shaped the communications profession in Turkey; (2 the disconnect between the competencies required by professional associations and educational institutions in the Netherlands; (3 the competencies required by managers and the need for practitioners to invest in further education in Germany; (4 how crisis communication emerged as a dominant specialization in Spain and the necessary competencies associated with this role; (5 the professionalization of public relations in the UK; and (6 how communication gained a reputation for conspicuous consumption in government and the public sector in Croatia and the consequences for the profession and the challenges for practitioners. The findings are based on the work of the European Communication Professionals Skills and Innovation Programme – ECOPSI (ERASMUS 2011 Ref No: 517691-LLP-1-2011-1-UK-ERASMUS-ECUE.

  20. A Review on Human Body Communication: Signal Propagation Model, Communication Performance, and Experimental Issues

    Directory of Open Access Journals (Sweden)

    Jian Feng Zhao

    2017-01-01

    Full Text Available Human body communication (HBC, which uses the human body tissue as the transmission medium to transmit health informatics, serves as a promising physical layer solution for the body area network (BAN. The human centric nature of HBC offers an innovative method to transfer the healthcare data, whose transmission requires low interference and reliable data link. Therefore, the deployment of HBC system obtaining good communication performance is required. In this regard, a tutorial review on the important issues related to HBC data transmission such as signal propagation model, channel characteristics, communication performance, and experimental considerations is conducted. In this work, the development of HBC and its first attempts are firstly reviewed. Then a survey on the signal propagation models is introduced. Based on these models, the channel characteristics are summarized; the communication performance and selection of transmission parameters are also investigated. Moreover, the experimental issues, such as electrodes and grounding strategies, are also discussed. Finally, the recommended future studies are provided.

  1. Issue Professionals in Transnational Networks

    DEFF Research Database (Denmark)

    Henriksen, Lasse Folke; Seabrooke, Leonard

    Professionals and organizations both seek to exploit and cooperate with each other. Professionals seek alliances in their own peer networks while organizations do the same. These networks carry not only information that inform incentives but norms about appropriate forms of governance and practices...

  2. ACHP | News | ACHP Issues Program Comment to Streamline Communication

    Science.gov (United States)

    Program Comment to Streamline Communication Facilities Construction and Modification ACHP Issues Program Comment to Streamline Communication Facilities Construction and Modification The Advisory Council on

  3. The Structure of Online Consumer Communication Networks

    NARCIS (Netherlands)

    B.G.C. Dellaert (Benedict); M.J.W. Harmsen-van Hout (Marjolein); P.J.J. Herings (Jean-Jacques)

    2006-01-01

    textabstractIn this paper we study the structure of the bilateral communication links within Online Consumer Communication Networks (OCCNs), such as virtual communities. Compared to the offline world, consumers in online networks are highly flexible to choose their communication partners and little

  4. Ad-hoc networking towards seamless communications

    CERN Document Server

    Gavrilovska, Liljana

    2006-01-01

    Ad-Hoc Networking Towards Seamless Communications is dedicated to an area that attracts growing interest in academia and industry and concentrates on wireless ad hoc networking paradigm. The persistent efforts to acquire the ability to establish dynamic wireless connections from anywhere to anyone with any device without prerequisite imbedded infrastructure move the communications boundaries towards ad-hoc networks. Recently, ad hoc networking has attracted growing interest due to advances in wireless communications, and developed framework for running IP based protocols. The expected degree of penetration of these networks will depend on the successful resolution of the key features. Ad-hoc networks pose many complex and open problems for researchers. Ad-Hoc Networking Towards Seamless Communications reveals the state-of-the-art in wireless ad-hoc networking and discusses some of the key research topics that are expected to promote and accelerate the commercial applications of these networks (e.g., MAC, rout...

  5. Communication issues and engineering work stations

    International Nuclear Information System (INIS)

    Kriloff, H.Z.; Ganti, N.A.

    1986-01-01

    Computer systems are evolving into collections of processors that work together to execute specific functions. The advent of the new, more-powerful microprocessors have made it possible for the system designer to utilize modules consisting of hardware, software, firmware, and databases integrated building-blocks, and by connecting them to other building-blocks perform new tasks or sequences of operations. The cement that holds together this collection of separately developed modules is the network, an entity steadily expanding to include functions previously performed by operating systems, database managers, display graphics executives, dispatching and other types of application codes. Several computer and communication vendors (IBM/SNA, DEC/DECNET, WANG/WANGNET, AT and T/ The Network Is the Solution, etc.) have realized that, by controlling the structure of the network, they can influence many of the designer's choices, and thereby restrict their future options to implement systems using different architecture structures. Because of this, the user, manager and/or designer of such systems should understand these trade-offs, the longer-term implications of the choices that they are making, and how their options may be restricted when they select a specific network implementation. Therefore, these new network architectures have both opened new options for systems design while making the choice of specific vendor components and increasingly more complex process. This paper is an attempt to outline some of the trends in the technology, and the implications of some of the user choices, now being made, that will influence the designer's options with respect to future system expansion, control and integration. Of course, each system will have many of it's own peculiar requirements that may determine what trade-offs are most significant for a specific case, but some general principles are possible and are developed

  6. The network communication of BEPC control system

    International Nuclear Information System (INIS)

    Xu Jingwei

    1997-01-01

    The author introduces the application of network communication of BEPC control system. The authors use non-transparent communication to transfer the data and command information from node VAX750 to VAX4500

  7. Wireless communications networks for the smart grid

    CERN Document Server

    Ho, Quang-Dung; Rajalingham, Gowdemy; Le-Ngoc, Tho

    2014-01-01

    This brief presents a comprehensive review of the network architecture and communication technologies of the smart grid communication network (SGCN). It then studies the strengths, weaknesses and applications of two promising wireless mesh routing protocols that could be used to implement the SGCN. Packet transmission reliability, latency and robustness of these two protocols are evaluated and compared by simulations in various practical SGCN scenarios. Finally, technical challenges and open research opportunities of the SGCN are addressed. Wireless Communications Networks for Smart Grid provi

  8. Maritime wideband communication networks video transmission scheduling

    CERN Document Server

    Yang, Tingting

    2014-01-01

    This Springer Brief covers emerging maritime wideband communication networks and how they facilitate applications such as maritime distress, urgency, safety and general communications. It provides valuable insight on the data transmission scheduling and protocol design for the maritime wideband network. This brief begins with an introduction to maritime wideband communication networks including the architecture, framework, operations and a comprehensive survey on current developments. The second part of the brief presents the resource allocation and scheduling for video packet transmission wit

  9. Engineering Issues for an Adaptive Defense Network

    National Research Council Canada - National Science Library

    Piszcz, Alan; Orlans, Nicholas; Eyler-Walker, Zachary; Moore, David

    2001-01-01

    .... The primary issue was the capability to detect and defend against DDoS. Experimentation was performed with a packet filtering firewall, a network Quality of Service manager, multiple DDoS tools, and traffic generation tools...

  10. Security Issues in Networks with Internet Access

    National Research Council Canada - National Science Library

    Landwehr, Carl E; Goldschlag, David M

    1997-01-01

    .... The principles are illustrated by describing the security issues a hypothetical company faces as the networks that support its operations evolve from strictly private, through a mix of Internet...

  11. Communication and control for networked complex systems

    CERN Document Server

    Peng, Chen; Han, Qing-Long

    2015-01-01

    This book reports on the latest advances in the study of Networked Control Systems (NCSs). It highlights novel research concepts on NCSs; the analysis and synthesis of NCSs with special attention to their networked character; self- and event-triggered communication schemes for conserving limited network resources; and communication and control co-design for improving the efficiency of NCSs. The book will be of interest to university researchers, control and network engineers, and graduate students in the control engineering, communication and network sciences interested in learning the core principles, methods, algorithms and applications of NCSs.

  12. IAEA activities on communication of nuclear safety issues

    International Nuclear Information System (INIS)

    Wieland, P.

    2001-01-01

    The regulatory authorities in several countries have taken the initiative to overcome the renowned difficulties of communicating nuclear safety issues. They communicate with segments of the public specially in case of nuclear/radiological accidents, waste disposal, transport of radioactive material or food irradiation. This reflects the full recognition of the importance of the topic. However it is also recognized that there is hitherto a need of international assistance in order to develop a regulatory communication strategy that could be harmonized and at the same time customized to the different needs. Communications on nuclear, radiation, transport and radioactive waste safety are needed to: disseminate information on safety to the public in both routine and emergency situations ; be attentive to public concerns, and address them; maintain social trust and confidence by keeping society informed on the established safety standards and how they are enforced; facilitate the decision-making process on nuclear matters by promptly presenting factual information in a clear manner; integrate and maintain an information network at both the national and international levels; improve co-operation with other countries and international organizations; encourage the dissemination of factual information on nuclear issues in schools. A major factor in addressing all of these questions is understanding the audience(s). A two way communication process is needed to establish what particular audiences want to know and in what form they prefer to receive information. This will differ depending on the audience and circumstances. For example, the information on a routine day-to-day basis will be different from what might be needed at the time of an accident. Communication with the news media is a matter of particular importance, as they are both an audience in themselves and a channel for communicating with wider audiences. (author)

  13. Next generation satellite communications networks

    Science.gov (United States)

    Garland, P. J.; Osborne, F. J.; Streibl, I.

    The paper introduces two potential uses for new space hardware to permit enhanced levels of signal handling and switching in satellite communication service for Canada. One application involves increased private-sector services in the Ku band; the second supports new personal/mobile services by employing higher levels of handling and switching in the Ka band. First-generation satellite regeneration and switching experiments involving the NASA/ACTS spacecraft are described, where the Ka band and switching satellite network problems are emphasized. Second-generation satellite development is outlined based on demand trends for more packet-based switching, low-cost earth stations, and closed user groups. A demonstration mission for new Ka- and Ku-band technologies is proposed, including the payload configuration. The half ANIK E payload is shown to meet the demonstration objectives, and projected to maintain a fully operational payload for at least 10 years.

  14. The physics of communicability in complex networks

    International Nuclear Information System (INIS)

    Estrada, Ernesto; Hatano, Naomichi; Benzi, Michele

    2012-01-01

    A fundamental problem in the study of complex networks is to provide quantitative measures of correlation and information flow between different parts of a system. To this end, several notions of communicability have been introduced and applied to a wide variety of real-world networks in recent years. Several such communicability functions are reviewed in this paper. It is emphasized that communication and correlation in networks can take place through many more routes than the shortest paths, a fact that may not have been sufficiently appreciated in previously proposed correlation measures. In contrast to these, the communicability measures reviewed in this paper are defined by taking into account all possible routes between two nodes, assigning smaller weights to longer ones. This point of view naturally leads to the definition of communicability in terms of matrix functions, such as the exponential, resolvent, and hyperbolic functions, in which the matrix argument is either the adjacency matrix or the graph Laplacian associated with the network. Considerable insight on communicability can be gained by modeling a network as a system of oscillators and deriving physical interpretations, both classical and quantum-mechanical, of various communicability functions. Applications of communicability measures to the analysis of complex systems are illustrated on a variety of biological, physical and social networks. The last part of the paper is devoted to a review of the notion of locality in complex networks and to computational aspects that by exploiting sparsity can greatly reduce the computational efforts for the calculation of communicability functions for large networks.

  15. Distributed wireless quantum communication networks

    International Nuclear Information System (INIS)

    Yu Xu-Tao; Xu Jin; Zhang Zai-Chen

    2013-01-01

    The distributed wireless quantum communication network (DWQCN) has a distributed network topology and transmits information by quantum states. In this paper, we present the concept of the DWQCN and propose a system scheme to transfer quantum states in the DWQCN. The system scheme for transmitting information between any two nodes in the DWQCN includes a routing protocol and a scheme for transferring quantum states. The routing protocol is on-demand and the routing metric is selected based on the number of entangled particle pairs. After setting up a route, quantum teleportation and entanglement swapping are used for transferring quantum states. Entanglement swapping is achieved along with the process of routing set up and the acknowledgment packet transmission. The measurement results of each entanglement swapping are piggybacked with route reply packets or acknowledgment packets. After entanglement swapping, a direct quantum link between source and destination is set up and quantum states are transferred by quantum teleportation. Adopting this scheme, the measurement results of entanglement swapping do not need to be transmitted specially, which decreases the wireless transmission cost and transmission delay. (general)

  16. The Issue Network as a Deliberative Space

    DEFF Research Database (Denmark)

    Ørmen, Jacob

    2012-01-01

    to identify relevant political issues online, but it does not manage to bring together the various antagonistic actors in one deliberative space online. In a triangulation of the results from the two separate analyses, the study further finds evidence, which suggests that the relationship between hyperlinks......Through an analysis of the Danish asylum issue network on the Internet, this article discusses the possibilities of the online sphere as a deliberative space, where politics is happening. By assessing the hyperlink structure of the issue network and a subsequent content analysis of the claims...

  17. Availability Issues in Wireless Visual Sensor Networks

    Science.gov (United States)

    Costa, Daniel G.; Silva, Ivanovitch; Guedes, Luiz Affonso; Vasques, Francisco; Portugal, Paulo

    2014-01-01

    Wireless visual sensor networks have been considered for a large set of monitoring applications related with surveillance, tracking and multipurpose visual monitoring. When sensors are deployed over a monitored field, permanent faults may happen during the network lifetime, reducing the monitoring quality or rendering parts or the entire network unavailable. In a different way from scalar sensor networks, camera-enabled sensors collect information following a directional sensing model, which changes the notions of vicinity and redundancy. Moreover, visual source nodes may have different relevancies for the applications, according to the monitoring requirements and cameras' poses. In this paper we discuss the most relevant availability issues related to wireless visual sensor networks, addressing availability evaluation and enhancement. Such discussions are valuable when designing, deploying and managing wireless visual sensor networks, bringing significant contributions to these networks. PMID:24526301

  18. Key management issue in SCADA networks: A review

    Directory of Open Access Journals (Sweden)

    Abdalhossein Rezai

    2017-02-01

    Full Text Available Supervisory Control And Data Acquisition (SCADA networks have a vital role in Critical Infrastructures (CIs such as public transports, power generation systems, gas, water and oil industries, so that there are concerns on security issues in these networks. The utilized Remote Terminal Units (RTUs and Intelligence Electronic Devices (IEDs in these networks have resource limitations, which make security applications a challenging issue. Efficient key management schemes are required besides lightweight ciphers for securing the SCADA communications. Many key management schemes have been developed to address the tradeoff between SCADA constrain and security, but which scheme is the most effective is still debatable. This paper presents a review of the existing key management schemes in SCADA networks, which provides directions for further researches in this field.

  19. Real-Time Communication Networks Onboard Ships

    DEFF Research Database (Denmark)

    Nielsen, Jens Frederik Dalsgaard; Nielsen, Kirsten Mølgaard; Jørgensen, N.

    1995-01-01

    This paper describes the ATOMOS communication network project carried out within the EU project ATOMOS, to be used for ISC purposes.......This paper describes the ATOMOS communication network project carried out within the EU project ATOMOS, to be used for ISC purposes....

  20. Agricultural informational flow in informal communication networks ...

    African Journals Online (AJOL)

    Agricultural informational flow in informal communication networks of farmers in Ghana. ... should identify such farmers who can serve as intermediaries between actors to help disseminate information in rural communities. Keywords: key communicators, farmers, rural communities, social networks, extension agents ...

  1. Collaborative communication protocols for wireless sensor networks

    NARCIS (Netherlands)

    Dulman, S.O.; van Hoesel, L.F.W.; Nieberg, T.; Havinga, Paul J.M.

    In this document, the design of communication within a wireless sensor network is discussed. The resource limitations of such a network, especially in terms of energy, require an integrated approach for all (traditional) layers of communication. We present such an integrated, collaborative approach

  2. Network Communication for Low Level RF Control

    International Nuclear Information System (INIS)

    Liu Weiqing; Yin Chengke; Zhang Tongxuan; Fu Zechuan; Liu Jianfei

    2009-01-01

    Low Level RF (LLRF) control system for storage ring of Shanghai Synchrotron Radiation Facility (SSRF) has been built by digital technology. The settings of parameters and the feedback loop status are carried out through the network communication interface, and the local oscillation and clock, which is the important component of the digital LLRF control system, are also configured through network communication. NIOS II processor was employed as a core to build the embedded system with a real-time operating system MicroC/OS-II, finally Lightweight TCP/IP (LwIP) was used to achieve the communication interface. The communication network is stable after a long-term operation. (authors)

  3. Communication and Networking in Smart Grids

    CERN Document Server

    Xiao, Yang

    2012-01-01

    Appropriate for researchers, practitioners, and students alike, Communication and Networking in Smart Grids presents state-of-the-art approaches and novel technologies for communication networks in smart grids. It explains how contemporary grid networks are developed and deployed and presents a collection of cutting-edge advances to help improve current practice. Prominent researchers working on smart grids and in related fields around the world explain the fundamental aspects and applications of smart grids. Describing the role that communication and networking will play in future smart grids

  4. Protocol and networking design issues for local access WDM networks

    NARCIS (Netherlands)

    Salvador, M.R.; Heemstra de Groot, S.M.; Niemegeers, I.G.M.M.

    This report gives an overview of some of the protocol and networking design issues that have been addressed in Flamingo, a major ongoing project which investigates the use of WDM optical technology in local access networks. Quality of service delivery and wavelength assignment are focused on in this

  5. 78 FR 69018 - Improving the Resiliency of Mobile Wireless Communications Networks; Reliability and Continuity...

    Science.gov (United States)

    2013-11-18

    ... consumers value overall network reliability and quality in selecting mobile wireless service providers, they...-125] Improving the Resiliency of Mobile Wireless Communications Networks; Reliability and Continuity... (Reliability NOI) in 2011 to ``initiate a comprehensive examination of issues regarding the reliability...

  6. Network Restoration for Next-Generation Communication and Computing Networks

    Directory of Open Access Journals (Sweden)

    B. S. Awoyemi

    2018-01-01

    Full Text Available Network failures are undesirable but inevitable occurrences for most modern communication and computing networks. A good network design must be robust enough to handle sudden failures, maintain traffic flow, and restore failed parts of the network within a permissible time frame, at the lowest cost achievable and with as little extra complexity in the network as possible. Emerging next-generation (xG communication and computing networks such as fifth-generation networks, software-defined networks, and internet-of-things networks have promises of fast speeds, impressive data rates, and remarkable reliability. To achieve these promises, these complex and dynamic xG networks must be built with low failure possibilities, high network restoration capacity, and quick failure recovery capabilities. Hence, improved network restoration models have to be developed and incorporated in their design. In this paper, a comprehensive study on network restoration mechanisms that are being developed for addressing network failures in current and emerging xG networks is carried out. Open-ended problems are identified, while invaluable ideas for better adaptation of network restoration to evolving xG communication and computing paradigms are discussed.

  7. Protocol and networking design issues for local access WDM networks

    OpenAIRE

    Salvador, M.R.; Heemstra de Groot, S.M.; Niemegeers, I.G.M.M.

    1999-01-01

    This report gives an overview of some of the protocol and networking design issues that have been addressed in Flamingo, a major ongoing project which investigates the use of WDM optical technology in local access networks. Quality of service delivery and wavelength assignment are focused on in this report. A brief introduction to optical networks and WDM as well as a brief description of Flamingo are also included in this report.

  8. Applications of Coding in Network Communications

    Science.gov (United States)

    Chang, Christopher SungWook

    2012-01-01

    This thesis uses the tool of network coding to investigate fast peer-to-peer file distribution, anonymous communication, robust network construction under uncertainty, and prioritized transmission. In a peer-to-peer file distribution system, we use a linear optimization approach to show that the network coding framework significantly simplifies…

  9. Communication on the structure of biological networks

    Indian Academy of Sciences (India)

    Networks are widely used to represent interaction pattern among the components in complex systems. Structures of real networks from different domains may vary quite significantly. As there is an interplay between network architecture and dynamics, structure plays an important role in communication and spreading of ...

  10. Corporate Communication in the Network Economy

    DEFF Research Database (Denmark)

    Foss, Nicolai Juul; Kristensen, Tore; Wilke, Ricky

    This paper draws on ideas in economics and game theory to develop a new theory of marketing and corporate communication in the emerging network economy. We argue that in a network economy, firms and consumers will confront `coordination problems.' With the emerging network economy all this become...

  11. Minimizing communication cost among distributed controllers in software defined networks

    Science.gov (United States)

    Arlimatti, Shivaleela; Elbreiki, Walid; Hassan, Suhaidi; Habbal, Adib; Elshaikh, Mohamed

    2016-08-01

    Software Defined Networking (SDN) is a new paradigm to increase the flexibility of today's network by promising for a programmable network. The fundamental idea behind this new architecture is to simplify network complexity by decoupling control plane and data plane of the network devices, and by making the control plane centralized. Recently controllers have distributed to solve the problem of single point of failure, and to increase scalability and flexibility during workload distribution. Even though, controllers are flexible and scalable to accommodate more number of network switches, yet the problem of intercommunication cost between distributed controllers is still challenging issue in the Software Defined Network environment. This paper, aims to fill the gap by proposing a new mechanism, which minimizes intercommunication cost with graph partitioning algorithm, an NP hard problem. The methodology proposed in this paper is, swapping of network elements between controller domains to minimize communication cost by calculating communication gain. The swapping of elements minimizes inter and intra communication cost among network domains. We validate our work with the OMNeT++ simulation environment tool. Simulation results show that the proposed mechanism minimizes the inter domain communication cost among controllers compared to traditional distributed controllers.

  12. Modeling And Simulation Of Multimedia Communication Networks

    Science.gov (United States)

    Vallee, Richard; Orozco-Barbosa, Luis; Georganas, Nicolas D.

    1989-05-01

    In this paper, we present a simulation study of a browsing system involving radiological image servers. The proposed IEEE 802.6 DQDB MAN standard is designated as the computer network to transfer radiological images from file servers to medical workstations, and to simultaneously support real time voice communications. Storage and transmission of original raster scanned images and images compressed according to pyramid data structures are considered. Different types of browsing as well as various image sizes and bit rates in the DQDB MAN are also compared. The elapsed time, measured from the time an image request is issued until the image is displayed on the monitor, is the parameter considered to evaluate the system performance. Simulation results show that image browsing can be supported by the DQDB MAN.

  13. Silicon-based optical integrated circuits for terabit communication networks

    International Nuclear Information System (INIS)

    Svidzinsky, K K

    2003-01-01

    A brief review is presented of the development of silicon-based optical integrated circuits used as components in modern all-optical communication networks with the terabit-per-second transmission capacity. The designs and technologies for manufacturing these circuits are described and the problems related to their development and application in WDM communication systems are considered. (special issue devoted to the memory of academician a m prokhorov)

  14. 2nd International Conference on Green Communications and Networks 2012

    CERN Document Server

    Ma, Maode; GCN 2012

    2013-01-01

    The objective of the 2nd International Conference on Green Communications and Networks 2012 (GCN 2012) is to facilitate an exchange of information on best practices for the latest research advances in the area of communications, networks and intelligence applications. These mainly involve computer science and engineering, informatics, communications and control, electrical engineering, information computing, and business intelligence and management. Proceedings of the 2nd International Conference on Green Communications and Networks 2012 (GCN 2012) will focus on green information technology and applications, which will provide in-depth insights for engineers and scientists in academia, industry, and government. The book addresses the most innovative research developments including technical challenges, social and economic issues, and presents and discusses the authors’ ideas, experiences, findings, and current projects on all aspects of advanced green information technology and applications. Yuhang Yang is ...

  15. Ethical Issues in Network System Design

    Directory of Open Access Journals (Sweden)

    Duncan Langford

    1997-05-01

    Full Text Available Today, most desktop computers and PCs are networked that is, they have the ability to link to other machines, usually to access data and other information held remotely. Such machines may sometimes be connected directly to each other, as part of an office or company computer system. More frequently, however, connected machines are at a considerable distance from each other, typically connected through links to global systems such as the Internet, or World Wide Web (WWW. The networked machine itself may be anything from a powerful company computer with direct Internet connections, to a small hobbyist machine, accessing a bulletin board through telephone and modem. It is important to remember that, whatever the type or the location of networked machines, their access to the network, and the network itself, was planned and constructed following deliberate design considerations. In this paper I discuss some ways in which the technical design of computer systems might appropriately be influenced by ethical issues, and examine pressures on computer scientists and others to technically control network related actions perceived as 'unethical'. After examination of the current situation, I draw together the issues, and conclude by suggesting some ethically based recommendations for the future design of networked systems.

  16. Interpersonal communication and issues for autonomous vehicles.

    Science.gov (United States)

    2017-06-01

    Interpersonal roadway communication is a vital component of the transportation system. Road users communicate to coordinate movement and increase roadway safety. Future autonomous vehicle research needs to account for the role of interpersonal roadwa...

  17. Efficient Networks Communication Routing Using Swarm Intelligence

    OpenAIRE

    Koushal Kumar

    2012-01-01

    As demonstrated by natural biological swarm’s collective intelligence has an abundance of desirable properties for problem-solving like in network routing. The focus of this paper is in the applications of swarm based intelligence in information routing for communication networks. As we know networks are growing and adopting new platforms as new technologies comes. Also according to new demands and requirements networks topologies and its complexity is increasing with time. Thus it is becomin...

  18. The handbook of optical communication networks

    CERN Document Server

    Ilyas, Mohammad

    2003-01-01

    The Handbook of Optical Communication Networks presents comprehensive, up-to-date technical information on integrated, state-of-the-art optical networks. Beginning with an in-depth intoduction to the field, top international authorities explore every major aspect of optical networks, from basic concepts to research grade material. Their discussions cover all of the essential topics, including protocols, resource management, routing and wavelength assignment in WDM networks, connection management, survivability, enabling technologies, and future trends.

  19. Seamless and secure communications over heterogeneous wireless networks

    CERN Document Server

    Cao, Jiannong

    2014-01-01

    This brief provides an overview of the requirements, challenges, design issues and major techniques for seamless and secure communications over heterogeneous wireless networks. It summarizes and provides detailed insights into the latest research on handoff management, mobility management, fast authentication and security management to support seamless and secure roaming for mobile clients. The reader will also learn about the challenges in developing relevant technologies and providing ubiquitous Internet access over heterogeneous wireless networks. The authors have extensive experience in im

  20. Design Considerations for Multi-Channel Picture Communication Networks

    OpenAIRE

    Scheibe, Paul O.

    1983-01-01

    Design of networks intended for communication of digitally-encoded pictures involves considerations different from those used in the design of text or voice communication networks. This paper provides an overview of the elements useful in the design of picture communication networks by relation and contrast with other communication networks. Particular emphasis is given to picture communication systems useful in medical applications.

  1. Embedded generation and network management issues

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    This report focuses on the characteristics of power generators that are important to accommodation in a distribution system. Part 1 examines the differences between transmission and distribution systems, and issues such as randomness, diversity, predictability, and controllability associated with accommodation in a distribution system. Part 2 concentrates on technical and operational issues relating to embedded generation, and the possible impact of the New Electricity Trading Arrangements. Commercial issues, contractual relationships for network charging and provision of services, and possible ways forward are examined in the last three parts of the report.

  2. Optimization and Control of Communication Networks

    OpenAIRE

    Chiang, Mung; Low, Steven

    2005-01-01

    Recently, there has been a surge in research activities that utilize the power of recent developments in nonlinear optimization to tackle a wide scope of work in the analysis and design of communication systems, touching every layer of the layered network architecture, and resulting in both intellectual and practical impacts significantly beyond the earlier frameworks. These research activities are driven by both new demands in the areas of communications and networking, and n...

  3. Jana: Confidential Communications on Social Networks

    Science.gov (United States)

    2017-08-09

    consuming phone resources and privacy leakage ?” We address this challenge via an extensive user study. Next, we ask “How can we detect background apps...not support secret group communications. Furthermore, access to such social networks via mobile platforms raises a series of concerns like leakage of...not support secret group communications. Furthermore, access to such social networks via mobile platforms raises a series of concerns like leakage of

  4. Control and estimation methods over communication networks

    CERN Document Server

    Mahmoud, Magdi S

    2014-01-01

    This book provides a rigorous framework in which to study problems in the analysis, stability and design of networked control systems. Four dominant sources of difficulty are considered: packet dropouts, communication bandwidth constraints, parametric uncertainty, and time delays. Past methods and results are reviewed from a contemporary perspective, present trends are examined, and future possibilities proposed. Emphasis is placed on robust and reliable design methods. New control strategies for improving the efficiency of sensor data processing and reducing associated time delay are presented. The coverage provided features: ·        an overall assessment of recent and current fault-tolerant control algorithms; ·        treatment of several issues arising at the junction of control and communications; ·        key concepts followed by their proofs and efficient computational methods for their implementation; and ·        simulation examples (including TrueTime simulations) to...

  5. Communication networks beyond the capacity crunch.

    Science.gov (United States)

    Ellis, A D; Mac Suibhne, N; Saad, D; Payne, D N

    2016-03-06

    This issue of Philosophical Transactions of the Royal Society, Part A represents a summary of the recent discussion meeting 'Communication networks beyond the capacity crunch'. The purpose of the meeting was to establish the nature of the capacity crunch, estimate the time scales associated with it and to begin to find solutions to enable continued growth in a post-crunch era. The meeting confirmed that, in addition to a capacity shortage within a single optical fibre, many other 'crunches' are foreseen in the field of communications, both societal and technical. Technical crunches identified included the nonlinear Shannon limit, wireless spectrum, distribution of 5G signals (front haul and back haul), while societal influences included net neutrality, creative content generation and distribution and latency, and finally energy and cost. The meeting concluded with the observation that these many crunches are genuine and may influence our future use of technology, but encouragingly noted that research and business practice are already moving to alleviate many of the negative consequences. © 2016 The Authors.

  6. Reliability Analysis Techniques for Communication Networks in Nuclear Power Plant

    International Nuclear Information System (INIS)

    Lim, T. J.; Jang, S. C.; Kang, H. G.; Kim, M. C.; Eom, H. S.; Lee, H. J.

    2006-09-01

    The objectives of this project is to investigate and study existing reliability analysis techniques for communication networks in order to develop reliability analysis models for nuclear power plant's safety-critical networks. It is necessary to make a comprehensive survey of current methodologies for communication network reliability. Major outputs of this study are design characteristics of safety-critical communication networks, efficient algorithms for quantifying reliability of communication networks, and preliminary models for assessing reliability of safety-critical communication networks

  7. Predicting Employee Turnover from Communication Networks.

    Science.gov (United States)

    Feeley, Thomas H.; Barnett, George A.

    1997-01-01

    Investigates three social network models of employee turnover: a structural equivalence model, a social influence model, and an erosion model. Administers a communication network questionnaire to all 170 employees of an organization. Finds support for all three models of turnover, with the erosion model explaining more of the variance than do the…

  8. Network protocols. Special issue; Netwerkprotocollen. Themanummer

    Energy Technology Data Exchange (ETDEWEB)

    Jansen, G.A. [RTB Van Heugten, Nijmegen (Netherlands); Rooijakkers, G.W.J. [GTI Building Automation, Amsterdam (Netherlands); Peterse, A. [Regel Partners, Hoevelaken (Netherlands); Smits, P. [Konnex Nederland, Valkenswaard (Netherlands); Hamers, E.P. [Van Dorp Installaties, Breda (Netherlands); Van der Velden, J.A.J. [Kropman, Rijswijk (Netherlands); Van Lingen, G.; Wijn, D.M. [Engineer Johnson Controls, Gorinchem (Netherlands); Deckere, W.J.M.A. [Deerns raadgevende ingenieurs, Rijswijk (Netherlands); Driessen, B. [Saia Burgess, Gouda (Netherlands); Van Olst, K. [K en R Consultants, Deventer (Netherlands); Mosterman, F. [Wago Building Technology, Harderwijk (Netherlands); Staub, R. [BUS-House, Zuerich (Switzerland); Meiring, O.B.; Hut, W.H. [Sauter Building Control Nederland, Amsterdam (Netherlands); Tukker, A. [Webeasy Products, Sliedrecht (Netherlands); Bakker, L.G.; Soethout, L.L.; Elkhuizen, P.A. [TNO Bouw en Ondergrond, Delft (Netherlands); Haeseler, U. [TAC GmbH, Berlin (Germany); Kerdel, J.F. [Siemens Building Technologies, Zoetermeer (Netherlands); Lugt, G.L.; Draijer, G.W.

    2007-11-15

    In 20 articles attention is paid to several aspects of network protocols by means of which building automation systems can exchange data: building automation and management, history of technical installations management, the open communication standard BACnet (Building Automation and Control network), the so-called ISO/IEC domotics and communication standard KNX or Konnex, the integration of electrotechnical and engineering installations by the LonWorks technology, other standard protocols as Modbus, M-bus, OPC (OLE for Process Control), an outline of TCP/IP, smart design of networks, automation and networks and building owners, the use of BACnet and Ethernet in a renovated office building, the use of an open management network in buildings, wireless open integrated systems, terminology in network communication, the use of BACnet in combination with KNX, the impact of BACnet on building automation, the role of the installation sector in the ICT-environment, knowledge of building automation and management, regulations with respect to building automation, and BACnet MSTP (Multiple Spanning Tree Protocol) [Dutch] In 20 artikelen wordt in dit themanummer aandacht besteed aan diverse aspecten m.b.t. netwerkprotocollen waarmee verschillende automatiseringssystemen gegevens met elkaar uitwisselen: gebouwautomatisering en beheer, geschiedenis van technisch installatie beheer, de open communicatie standaard BACnet (Building Automation and Control network), de zogenaamde ISO/IEC domotica en communicatie standaard KNX of Konnex, de integratie van electrotechnische en werktuigbouwkundige installaties met behulp van de LonWorks technologie, andere standaard protocollen zoals Modbus, M-bus, OPC (OLE for Process Control), uitleg over TCP/IP, slim ontwerpen van netwerken, gebouweigenaren over automatisering en netwerken, het gebruik van BACnet en Ethernet in een tot kantoorgebouw gerenoveerd monumentaal gebouw, het gebruik van een open management netwerk in gebouwen, draadloos met

  9. Evolutionary dynamics of complex communications networks

    CERN Document Server

    Karyotis, Vasileios; Papavassiliou, Symeon

    2013-01-01

    Until recently, most network design techniques employed a bottom-up approach with lower protocol layer mechanisms affecting the development of higher ones. This approach, however, has not yielded fascinating results in the case of wireless distributed networks. Addressing the emerging aspects of modern network analysis and design, Evolutionary Dynamics of Complex Communications Networks introduces and develops a top-bottom approach where elements of the higher layer can be exploited in modifying the lowest physical topology-closing the network design loop in an evolutionary fashion similar to

  10. A Quantum Cryptography Communication Network Based on Software Defined Network

    Directory of Open Access Journals (Sweden)

    Zhang Hongliang

    2018-01-01

    Full Text Available With the development of the Internet, information security has attracted great attention in today’s society, and quantum cryptography communication network based on quantum key distribution (QKD is a very important part of this field, since the quantum key distribution combined with one-time-pad encryption scheme can guarantee the unconditional security of the information. The secret key generated by quantum key distribution protocols is a very valuable resource, so making full use of key resources is particularly important. Software definition network (SDN is a new type of network architecture, and it separates the control plane and the data plane of network devices through OpenFlow technology, thus it realizes the flexible control of the network resources. In this paper, a quantum cryptography communication network model based on SDN is proposed to realize the flexible control of quantum key resources in the whole cryptography communication network. Moreover, we propose a routing algorithm which takes into account both the hops and the end-to-end availible keys, so that the secret key generated by QKD can be used effectively. We also simulate this quantum cryptography communication network, and the result shows that based on SDN and the proposed routing algorithm the performance of this network is improved since the effective use of the quantum key resources.

  11. COMMUNICATION MANAGEMENT CRISIS IN SOCIAL NETWORKS

    OpenAIRE

    Ana Mª Enrique Jiménez

    2013-01-01

    It is often in the social networks where you detect the first signs of a potential crisis situation. Today, many companies decide to be present in social networks to communicate, listen and respond to their audiences openly with immediacy. A simple complaint is visible and propagates through the network in seconds, being capable of generating a negative impact on the corporate image of the organization. The same can happen to the contrary, ie, to praise the performance of a company, which may...

  12. Crosstalk in WDM communication networks

    NARCIS (Netherlands)

    Tafur Monroy, I.; Tangdiongga, E.

    2002-01-01

    The use of advanced transmission and switching techniques such as reconfigurable WDM optical crossconnects is enabling high capacity and flexible optical networking at ultra bit-rates reaching multi-terabits per second. These techniques also offer creative ways to improve the network connectivity

  13. Future networks and technologies supporting innovative communications

    DEFF Research Database (Denmark)

    Prasad, Ramjee

    2012-01-01

    -communications (WISDOM) that combines the aspects of personal- and cognitive radio- networks to let seamlessly bridge the virtual and physical worlds offering a constant level of all-senses, context-based, rich communication experience over fixed and wireless networks for the end users while realizing a new generation......Within a fully interconnected world, the distinct relationship between end users, consumers and providers rapidly changes towards a scenario of collaboration and competition of multiple parties within one system. ‘Convergence’, ‘ubiquitous’ and ‘smart’ are key words describing future networks...

  14. Scalable Optical-Fiber Communication Networks

    Science.gov (United States)

    Chow, Edward T.; Peterson, John C.

    1993-01-01

    Scalable arbitrary fiber extension network (SAFEnet) is conceptual fiber-optic communication network passing digital signals among variety of computers and input/output devices at rates from 200 Mb/s to more than 100 Gb/s. Intended for use with very-high-speed computers and other data-processing and communication systems in which message-passing delays must be kept short. Inherent flexibility makes it possible to match performance of network to computers by optimizing configuration of interconnections. In addition, interconnections made redundant to provide tolerance to faults.

  15. Challenges of Integrating NASA's Space Communications Networks

    Science.gov (United States)

    Reinert, Jessica; Barnes, Patrick

    2013-01-01

    The transition to new technology, innovative ideas, and resistance to change is something that every industry experiences. Recent examples of this shift are changing to using robots in the assembly line construction of automobiles or the increasing use of robotics for medical procedures. Most often this is done with cost-reduction in mind, though ease of use for the customer is also a driver. All industries experience the push to increase efficiency of their systems; National Aeronautics and Space Administration (NASA) and the commercial space industry are no different. NASA space communication services are provided by three separately designed, developed, maintained, and operated communications networks known as the Deep Space Network (DSN), Near Earth Network (NEN) and Space Network (SN). The Space Communications and Navigation (SCaN) Program is pursuing integration of these networks and has performed a variety of architecture trade studies to determine what integration options would be the most effective in achieving a unified user mission support organization, and increase the use of common operational equipment and processes. The integration of multiple, legacy organizations and existing systems has challenges ranging from technical to cultural. The existing networks are the progeny of the very first communication and tracking capabilities implemented by NASA and the Jet Propulsion Laboratory (JPL) more than 50 years ago and have been customized to the needs of their respective user mission base. The technical challenges to integrating the networks are many, though not impossible to overcome. The three distinct networks provide the same types of services, with customizable data rates, bandwidth, frequencies, and so forth. The differences across the networks have occurred in effort to satisfy their user missions' needs. Each new requirement has made the networks more unique and harder to integrate. The cultural challenges, however, have proven to be a

  16. Challenges of Integrating NASAs Space Communication Networks

    Science.gov (United States)

    Reinert, Jessica M.; Barnes, Patrick

    2013-01-01

    The transition to new technology, innovative ideas, and resistance to change is something that every industry experiences. Recent examples of this shift are changing to using robots in the assembly line construction of automobiles or the increasing use of robotics for medical procedures. Most often this is done with cost-reduction in mind, though ease of use for the customer is also a driver. All industries experience the push to increase efficiency of their systems; National Aeronautics and Space Administration (NASA) and the commercial space industry are no different. NASA space communication services are provided by three separately designed, developed, maintained, and operated communications networks known as the Deep Space Network (DSN), Near Earth Network (NEN) and Space Network (SN). The Space Communications and Navigation (SCaN) Program is pursuing integration of these networks and has performed a variety of architecture trade studies to determine what integration options would be the most effective in achieving a unified user mission support organization, and increase the use of common operational equipment and processes. The integration of multiple, legacy organizations and existing systems has challenges ranging from technical to cultural. The existing networks are the progeny of the very first communication and tracking capabilities implemented by NASA and the Jet Propulsion Laboratory (JPL) more than 50 years ago and have been customized to the needs of their respective user mission base. The technical challenges to integrating the networks are many, though not impossible to overcome. The three distinct networks provide the same types of services, with customizable data rates, bandwidth, frequencies, and so forth. The differences across the networks have occurred in effort to satisfy their user missions' needs. Each new requirement has made the networks more unique and harder to integrate. The cultural challenges, however, have proven to be a

  17. BAKNET - Communication network for radiation monitoring devices

    International Nuclear Information System (INIS)

    Cohen, Y.; Wengrowicz, U.; Tirosh, D.; Barak, D.

    1997-01-01

    A system, based on a new concept of controlling and monitoring distributed radiation monitors, has been developed and approved at the NRCN. The system, named B AKNET Network , consists of a series of communication adapters connected to a main PC via an RS-485 communication network (see Fig. 1). The network's maximal length is 1200 meters and it enables connection of up to 128 adapters. The BAKNET adapters are designed to interface output signals of different types of stationary radiation monitors to a main PC. The BAKNET adapters' interface type includes: digital, analog, RS-232, and mixed output signals. This allows versatile interfacing of different stationary radiation monitors to the main computer. The connection to the main computer is via an RS-485 network, utilizing an identical communication protocol. The PC software, written in C ++ under MS-Windows, consists of two main programs. The first is the data collection program and the second is the Human Machine Interface (HMI). (authors)

  18. System Design for Nano-Network Communications

    Science.gov (United States)

    ShahMohammadian, Hoda

    The potential applications of nanotechnology in a wide range of areas necessities nano-networking research. Nano-networking is a new type of networking which has emerged by applying nanotechnology to communication theory. Therefore, this dissertation presents a framework for physical layer communications in a nano-network and addresses some of the pressing unsolved challenges in designing a molecular communication system. The contribution of this dissertation is proposing well-justified models for signal propagation, noise sources, optimum receiver design and synchronization in molecular communication channels. The design of any communication system is primarily based on the signal propagation channel and noise models. Using the Brownian motion and advection molecular statistics, separate signal propagation and noise models are presented for diffusion-based and flow-based molecular communication channels. It is shown that the corrupting noise of molecular channels is uncorrelated and non-stationary with a signal dependent magnitude. The next key component of any communication system is the reception and detection process. This dissertation provides a detailed analysis of the effect of the ligand-receptor binding mechanism on the received signal, and develops the first optimal receiver design for molecular communications. The bit error rate performance of the proposed receiver is evaluated and the impact of medium motion on the receiver performance is investigated. Another important feature of any communication system is synchronization. In this dissertation, the first blind synchronization algorithm is presented for the molecular communication channels. The proposed algorithm uses a non-decision directed maximum likelihood criterion for estimating the channel delay. The Cramer-Rao lower bound is also derived and the performance of the proposed synchronization algorithm is evaluated by investigating its mean square error.

  19. MAC layer security issues in wireless mesh networks

    Science.gov (United States)

    Reddy, K. Ganesh; Thilagam, P. Santhi

    2016-03-01

    Wireless Mesh Networks (WMNs) have emerged as a promising technology for a broad range of applications due to their self-organizing, self-configuring and self-healing capability, in addition to their low cost and easy maintenance. Securing WMNs is more challenging and complex issue due to their inherent characteristics such as shared wireless medium, multi-hop and inter-network communication, highly dynamic network topology and decentralized architecture. These vulnerable features expose the WMNs to several types of attacks in MAC layer. The existing MAC layer standards and implementations are inadequate to secure these features and fail to provide comprehensive security solutions to protect both backbone and client mesh. Hence, there is a need for developing efficient, scalable and integrated security solutions for WMNs. In this paper, we classify the MAC layer attacks and analyze the existing countermeasures. Based on attacks classification and countermeasures analysis, we derive the research directions to enhance the MAC layer security for WMNs.

  20. Location of terminals in a communications network

    DEFF Research Database (Denmark)

    2015-01-01

    A method (400, 500) of identifying nodes in a communications network is disclosed, the nodes being for use in locating wireless terminals within the network based upon reports from the wireless terminals of transmissions received from the nodes. The method (400, 500) comprises prioritising...... combinations of nodes in which at least three nodes are located around a reference node in a configuration satisfying similarity criteria to an idealised star configuration, wherein an idealised star configuration comprises three nodes evenly angularly distributed around, and at the same distance from......, a reference node. Also disclosed is a method (100, 200) for locating a plurality of wireless terminals in a communications network, the network comprising a plurality of network nodes at known locations, wherein the nodes emit wireless transmissions in an unsynchronised manner, such that a time difference...

  1. Understanding librarians communication is the issue

    CERN Document Server

    Hull, Barbara

    2011-01-01

    Aimed at professionals and trainee professionals within the library and information service (LIS) fields, this book reminds the reader of the frequently ignored communication-gulf between the professional and the layman, and in particular the lack of true communication between LIS professionals and the user. It focuses especially on 'non-standard' users, such as non-native speakers or those with some disability. The author provides accessible examples of good practice, assesses their degree of success and suggests further ways to improve performance in information provision.written by a "poach

  2. Modeling MAC layer for powerline communications networks

    Science.gov (United States)

    Hrasnica, Halid; Haidine, Abdelfatteh

    2001-02-01

    The usage of electrical power distribution networks for voice and data transmission, called Powerline Communications, becomes nowadays more and more attractive, particularly in the telecommunication access area. The most important reasons for that are the deregulation of the telecommunication market and a fact that the access networks are still property of former monopolistic companies. In this work, first we analyze a PLC network and system structure as well as a disturbance scenario in powerline networks. After that, we define a logical structure of the powerline MAC layer and propose the reservation MAC protocols for the usage in the PLC network which provides collision free data transmission. This makes possible better network utilization and realization of QoS guarantees which can make PLC networks competitive to other access technologies.

  3. The entire network topology display system of terminal communication access network

    OpenAIRE

    An Yi

    2016-01-01

    Now order terminal communication access network is network technology in Shanxi Province is diversiform, device type complex, lack of unified technical standard, the terminal communication access network management system of construction constitutes a great obstacle. Need to build a “unified communication interface and communication standard, unified communications network management” of the terminal communication access network cut in the integrated network management system, for the termina...

  4. The issue of trust and modern information and communication technologies

    OpenAIRE

    Tulchinsky G. L.; Lisenkova A. A.

    2016-01-01

    In this article, the authors study the problem of balance of trust and mistrust associated with the turbulence of modern society, redundancy, and heterogeneity of information and communication flows creating a contradictory picture of the world. Social networks are considered as one of the basic modern information resources creating previously unavailable opportunities for communication, interaction, information sharing, and commonality construction. Social networks users broadcast the experi...

  5. Case studies of attacks on communication networks

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Sin Bok; Han, Eon Suk [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1996-06-15

    Recently, as the computer hardware and communications are developed, the data exchange through inter-networking has been highlighted and the data is being recognized as a great asset. Most of the organizations, businesses and enterprises are open to the external world-computer communication networks, attention must be focused on the securities of the information infrastructure. A government organization has been developing 'Circuits Analyzers', and 'Hacker-Tracking Program' and is struggling to track down sneakers. In this report, we analyze the contents of the cases where the communication network has been invaded, from the past up until now in Korea. This report also contains the result of a study on E-mail security, for the protection of KAERI Integrated Management Information System under which utilizes the CALS concepts and web services. (Author)

  6. Communication networks for medical image transmission

    International Nuclear Information System (INIS)

    Lemke, H.U.

    1993-01-01

    Digital communication networks are of increasing importance for data exchange in health care environments. They may be used to transmit multi-media data, such as text, images, graphics, signals and sound. The essential characteristics of modern network technologies are summarized in this article and are seen in the context of local, metropolitan and wide area networks. Standardized technologies discussed are Ethernet, token oriented systems, FDDI, DQDB and ATM. Off-line communication media based on magnetic optical disk, such as ISandC, are briefly introduced. The conclusion reached is that therapy planning for radiation therapy or hyperthermia can make use of communication technologies, for example, to transmit patient images, modelling data and results of distribution calculations of physical phenomena. (orig.) [de

  7. Case studies of attacks on communication networks

    International Nuclear Information System (INIS)

    Kang, Sin Bok; Han, Eon Suk

    1996-06-01

    Recently, as the computer hardware and communications are developed, the data exchange through inter-networking has been highlighted and the data is being recognized as a great asset. Most of the organizations, businesses and enterprises are open to the external world-computer communication networks, attention must be focused on the securities of the information infrastructure. A government organization has been developing 'Circuits Analyzers', and 'Hacker-Tracking Program' and is struggling to track down sneakers. In this report, we analyze the contents of the cases where the communication network has been invaded, from the past up until now in Korea. This report also contains the result of a study on E-mail security, for the protection of KAERI Integrated Management Information System under which utilizes the CALS concepts and web services. (Author)

  8. VLSI Based Multiprocessor Communications Networks.

    Science.gov (United States)

    1982-09-01

    Networks". The contract began on September 1,1980 and was approved on scientific /technical grounds for a duration of three years. Incremental funding was...values for the individual delays will vary from comunicating modules (ij) are shown in Figure 4 module to module due to processing and fabrication

  9. Underwater Optical Wireless Communications, Networking, and Localization: A Survey

    KAUST Repository

    Saeed, Nasir; Celik, Abdulkadir; Al-Naffouri, Tareq Y.; Alouini, Mohamed-Slim

    2018-01-01

    Underwater wireless communications can be carried out through acoustic, radio frequency (RF), and optical waves. Compared to its bandwidth limited acoustic and RF counterparts, underwater optical wireless communications (UOWCs) can support higher data rates at low latency levels. However, severe aquatic channel conditions (e.g., absorption, scattering, turbulence, etc.) pose great challenges for UOWCs and significantly reduce the attainable communication ranges, which necessitates efficient networking and localization solutions. Therefore, we provide a comprehensive survey on the challenges, advances, and prospects of underwater optical wireless networks (UOWNs) from a layer by layer perspective which includes: 1) Potential network architectures; 2) Physical layer issues including propagation characteristics, channel modeling, and modulation techniques 3) Data link layer problems covering link configurations, link budgets, performance metrics, and multiple access schemes; 4) Network layer topics containing relaying techniques and potential routing algorithms; 5) Transport layer subjects such as connectivity, reliability, flow and congestion control; 6) Application layer goals and state-of-the-art UOWN applications, and 7) Localization and its impacts on UOWN layers. Finally, we outline the open research challenges and point out the future directions for underwater optical wireless communications, networking, and localization research.

  10. Underwater Optical Wireless Communications, Networking, and Localization: A Survey

    KAUST Repository

    Saeed, Nasir

    2018-02-28

    Underwater wireless communications can be carried out through acoustic, radio frequency (RF), and optical waves. Compared to its bandwidth limited acoustic and RF counterparts, underwater optical wireless communications (UOWCs) can support higher data rates at low latency levels. However, severe aquatic channel conditions (e.g., absorption, scattering, turbulence, etc.) pose great challenges for UOWCs and significantly reduce the attainable communication ranges, which necessitates efficient networking and localization solutions. Therefore, we provide a comprehensive survey on the challenges, advances, and prospects of underwater optical wireless networks (UOWNs) from a layer by layer perspective which includes: 1) Potential network architectures; 2) Physical layer issues including propagation characteristics, channel modeling, and modulation techniques 3) Data link layer problems covering link configurations, link budgets, performance metrics, and multiple access schemes; 4) Network layer topics containing relaying techniques and potential routing algorithms; 5) Transport layer subjects such as connectivity, reliability, flow and congestion control; 6) Application layer goals and state-of-the-art UOWN applications, and 7) Localization and its impacts on UOWN layers. Finally, we outline the open research challenges and point out the future directions for underwater optical wireless communications, networking, and localization research.

  11. Green networking and communications ICT for sustainability

    CERN Document Server

    Khan, Shafiullah

    2013-01-01

    Although the information and communication technology (ICT) industry accounted for only 2 percent of global greenhouse gas emissions in 2007, the explosive increase in data traffic brought about by a rapidly growing user base of more than a billion wireless subscribers is expected to nearly double that number by 2020. It is clear that now is the time to rethink how we design and build our networks.Green Networking and Communications: ICT for Sustainability brings together leading academic and industrial researchers from around the world to discuss emerging developments in energy-efficient netw

  12. Entangled network and quantum communication

    Energy Technology Data Exchange (ETDEWEB)

    Metwally, Nasser, E-mail: Nmetwally@gmail.com [Math. Dept., Faculty of Science, South Valley University, Aswan (Egypt); Math. Dept., College of Science, University of Bahrain, P.O. Box 32038 (Bahrain)

    2011-11-21

    A theoretical scheme is introduced to generate entangled network via Dzyaloshinskii–Moriya (DM) interaction. The dynamics of entanglement between different nodes, which is generated by direct or indirect interaction, is investigated. It is shown that, the direction of (DM) interaction and the locations of the nodes have a sensational effect on the degree of entanglement. The minimum entanglement generated between all the nodes is quantified. The upper and lower bounds of the entanglement depend on the direction of DM interaction, and the repetition of the behavior depends on the strength of DM. The generated entangled nodes are used as quantum channel to perform quantum teleportation, where it is shown that the fidelity of teleporting unknown information between the network members depends on the locations of the members.

  13. Interoperable Communications for Hierarchical Heterogeneous Wireless Networks

    Science.gov (United States)

    2016-04-01

    International Conference on Advanced Networks and Telecommuncations Systems (ANTS). 14-DEC-13, Kattankulathur, India. : , Husheng Li, Qi Zeng , Lijun Qian. GPS...correlation in space is too large, which implies that the correlation is overestimated. Other methods may be more accurate, faster or less memory ...limited, an intelligent mechanism is needed for the information selection and signaling design of the cross-network communication for collaborative

  14. Development of IT-based data communication network technology

    International Nuclear Information System (INIS)

    Hong, Seok Boong; Jeong, K. I.; Yoo, Y. R.

    2010-10-01

    - Developing broadband high-reliability real-time communications technology for NPP - Developing reliability and performance validation technology for communications network - Developing security technology for NPP communications network - Developing field communications network for harsh environment of NPP - International standard registration(Oct. 28, 2009, IEC 61500

  15. AESJ: communicating about nuclear issues in Japan

    International Nuclear Information System (INIS)

    Anon.

    2016-01-01

    The AESJ (Atomic Energy Society of Japan) was founded in 1959 to promote the information of the Japanese public about nuclear energy and to develop exchanges between professionals of the sector. AESJ gathers about 7000 professionals and is organized around 8 regional groups and 10 technical sessions. AESJ has been publishing 2 journals: Journal of Nuclear Science and Technology since 1964 and ATOMOΣ since 1959. AESJ also awards several prizes for promoting communication and technical achievements in nuclear activities. AESJ takes part into numerous international events like for instance supporting conferences or organizing student exchanges between research centers or universities. (A.C.)

  16. Green Communications and Networks : Proceedings of the International Conference on Green Communications and Networks

    CERN Document Server

    Ma, Maode

    2012-01-01

    Green Communications and Networks presents 95 papers chosen for publication from among 190 reviewed papers accepted for presentation to the International Conference on Green Communications and Networks (GCN 2011), held in Chongqing, China, July 15-17, 2011. GCN 2011 provided a venue for leading academic and industrial researchers to exchange their views, ideas and research results on innovative technologies and sustainable solutions leading to greener communications and networks. In addition to paper presentations, the conference featured keynote speakers and a panel discussion. Reflecting the broad scope of the conference, the contents are organized in these topical categories: Communication Systems Data Management and Database System Digital Image Processing Education and Informatics Enabling Technologies Forensics, Recognition Technologies and Applications Fuzzy System and Control Graphics and Visualizing Green Computing Internet Growth Modelling and Virtualized Networks Network Components and Application ...

  17. ISSUES AND RECENT TRENDS IN VEHICLE SAFETY COMMUNICATION SYSTEMS

    Directory of Open Access Journals (Sweden)

    Sadayuki TSUGAWA

    2005-01-01

    Full Text Available This paper surveys the research on the applications of inter-vehicle communications, the issues of the deployment and technology, and the current status of inter-vehicle communications projects in Europe, the United States and Japan. The inter-vehicle communications, defined here as communications between on-board ITS computers, improve road traffic safety and efficiency by expanding the horizon of the drivers and on-board sensors. One of the earliest studies on inter-vehicle communications began in Japan in the early 1980s. The inter-vehicle communications play an essential role in automated platooning and cooperative driving systems developed since the 1990's by enabling vehicles to obtain data that would be difficult or impossible to measure with on-board sensors. During these years, interest in applications for inter-vehicle communications increased in the EU, the US and Japan, resulting in many national vehicle safety communications projects such as CarTALK2000 in the EU and VSCC in the US. The technological issues include protocol and communications media. Experiments employ various kinds of protocols and typically use infrared, microwave or millimeter wave media. The situation is ready for standardization. The deployment strategy is another issue. To be feasible, deployment should begin with multiple rather than single services that would work even at a low penetration rate of the communication equipment. In addition, non-technological, legal and institutional issues remained unsolved. Although inter-vehicle communications involve many issues, such applications should be promoted because they will lead to safer and more efficient automobile traffic.

  18. DC microgrids providing frequency regulation in electrical power system - imperfect communication issues

    DEFF Research Database (Denmark)

    Bašić, Hrvoje; Dragicevic, Tomislav; Pandžić, Hrvoje

    2017-01-01

    This paper presents a model of multiple DC microgrids with battery energy storage systems and demand response capability, taking part in primary frequency regulation of electrical power system. Although DC microgrids can contribute to stability and efficiency of frequency regulation, these complex...... systems may cause serious stability issues due to the imperfect communication. This work presents possible scenarios of unstable primary frequency regulation in a simplified model of electrical power system with DC microgrids, which are controlled through communication network....

  19. Social Networking and Smart Technology: Viable Environmental Communication Tools…?

    Science.gov (United States)

    Montain, J.; Byrne, J. M.

    2010-12-01

    To what extent do popular social networking channels represent a viable means for disseminating information regarding environmental change to the general public? Are new forms of communication such as YouTube™, Facebook™, MySpace™ and Twitter™ and smart devices such as iPhone™ and BlackBerry™ useful and effective in terms motivating people into social action and behavioural modification; or do they simply pay ‘lip service’ to these pressing environmental issues? This project will explore the background connections between social networking and environmental communication and education; and outline why such tools might be an appropriate way to connect to a broad audience in an efficient and unconventional manner. Further, research will survey the current prevalence of reliable environmental change information on social networking Internet-based media; and finally, suggestions for improved strategies and new directions will be provided.

  20. Agricultural information systems and communication networks: the ...

    African Journals Online (AJOL)

    The study examined the Agricultural Information and communication networks among poultry farmers in three (3) area councils of the Federal Capital Territory Abuja, Nigeria. Snow-ball sampling technique was adopted for the study, a total of One hundred and twenty-two (122) respondents were sampled for the study.

  1. Self-Organization in Communication Networks

    NARCIS (Netherlands)

    V. Bala; S. Goyal (Sanjeev)

    1997-01-01

    textabstractWe develop a dynamic model to study the formation of communication networks. In this model, individuals periodically make decisions concerning the continuation of existing information links and the formation of new information links, with their cohorts. These decisions trade off the

  2. Communication, knowledge, social network and family planning ...

    African Journals Online (AJOL)

    AJRH Managing Editor

    Tanzania; 2Centre for International Development Initiatives Nijmegen (CIDIN) and ... demographic variables, social networks, knowledge and communication among the couples, whereby a stratified sample of 440 ..... FP method varies with urban- rural and regional ...... Pile JM and Simbakalia C. Tanzania Case Study: A.

  3. Communication, knowledge, social network and family planning ...

    African Journals Online (AJOL)

    Family planning utilization in Tanzania is low. This study was cross sectional. It examined family planning use and socio demographic variables, social networks, knowledge and communication among the couples, whereby a stratified sample of 440 women of reproductive age (18-49), married or cohabiting was studied in ...

  4. AIDS communications through social networks: catalyst for ...

    African Journals Online (AJOL)

    Objective: To investigate distinctive communications through social networks which may be associated with population behaviour changes and HIV prevalence declines in Uganda compared to other countries. Methods: We undertook a comparative analysis of demographic and HIV behavioural data collected in ...

  5. Communication network for telemedicine | Debretsion | Zede Journal

    African Journals Online (AJOL)

    Telemedicine is the most promising one for improving the access to specialized health services to all remote, rural areas in all developing countries. Exploiting the technological advancements in the field of electronics, signal processing and software a communication network for telemedicine is proposedfor the existing ...

  6. Protocol for Communication Networking for Formation Flying

    Science.gov (United States)

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

    2009-01-01

    An application-layer protocol and a network architecture have been proposed for data communications among multiple autonomous spacecraft that are required to fly in a precise formation in order to perform scientific observations. The protocol could also be applied to other autonomous vehicles operating in formation, including robotic aircraft, robotic land vehicles, and robotic underwater vehicles. A group of spacecraft or other vehicles to which the protocol applies could be characterized as a precision-formation- flying (PFF) network, and each vehicle could be characterized as a node in the PFF network. In order to support precise formation flying, it would be necessary to establish a corresponding communication network, through which the vehicles could exchange position and orientation data and formation-control commands. The communication network must enable communication during early phases of a mission, when little positional knowledge is available. Particularly during early mission phases, the distances among vehicles may be so large that communication could be achieved only by relaying across multiple links. The large distances and need for omnidirectional coverage would limit communication links to operation at low bandwidth during these mission phases. Once the vehicles were in formation and distances were shorter, the communication network would be required to provide high-bandwidth, low-jitter service to support tight formation-control loops. The proposed protocol and architecture, intended to satisfy the aforementioned and other requirements, are based on a standard layered-reference-model concept. The proposed application protocol would be used in conjunction with conventional network, data-link, and physical-layer protocols. The proposed protocol includes the ubiquitous Institute of Electrical and Electronics Engineers (IEEE) 802.11 medium access control (MAC) protocol to be used in the datalink layer. In addition to its widespread and proven use in

  7. Science Communication for the Public Understanding of Nuclear Issues

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Seongkyung [Myungji Univ., Yongin (Korea, Republic of)

    2006-04-15

    Uncertainty, stigma, risk perception, and value judgment represent characteristics of nuclear issues in the public arena. Nuclear issue, in the public arena, is a kind of risk rather than technology that we are willing to use for good purpose. There are uncertainty, stigma, risk perception, and value judgment as characteristics of nuclear. The notion of the public, here is of active, sensitive, and sensible citizens, with power and influence. The public understands nuclear issues less through direct experience or education than through the filter of mass media. Trust has been a key issue on public understanding of nuclear issues. Trust belongs to human. The public understanding process includes perception, interpretation, and evaluation. Therefore, science communication is needed for public understanding. Unfortunately, science communication is rarely performed well, nowadays, There are three important actors-the public, experts, and media. Effective science communication means finding comprehensible ways of presenting opaque and complex nuclear issues. It makes new and strong demands on experts. In order to meet that requirement, experts should fulfill their duty about developing nuclear technology for good purpose, understand the public before expecting the public to understand nuclear issues, accept the unique culture of the media process, take the responsibility for any consequence which nuclear technologies give rise to, communicate with an access route based on sensibility and rationality, have a flexible angle in the science communication process, get creative leadership for the communication process with deliberation and disagreement, make efficient use of various science technologies for science communication. We should try to proceed with patience, because science communication makes for a more credible society.

  8. Science Communication for the Public Understanding of Nuclear Issues

    International Nuclear Information System (INIS)

    Cho, Seongkyung

    2006-01-01

    Uncertainty, stigma, risk perception, and value judgment represent characteristics of nuclear issues in the public arena. Nuclear issue, in the public arena, is a kind of risk rather than technology that we are willing to use for good purpose. There are uncertainty, stigma, risk perception, and value judgment as characteristics of nuclear. The notion of the public, here is of active, sensitive, and sensible citizens, with power and influence. The public understands nuclear issues less through direct experience or education than through the filter of mass media. Trust has been a key issue on public understanding of nuclear issues. Trust belongs to human. The public understanding process includes perception, interpretation, and evaluation. Therefore, science communication is needed for public understanding. Unfortunately, science communication is rarely performed well, nowadays, There are three important actors-the public, experts, and media. Effective science communication means finding comprehensible ways of presenting opaque and complex nuclear issues. It makes new and strong demands on experts. In order to meet that requirement, experts should fulfill their duty about developing nuclear technology for good purpose, understand the public before expecting the public to understand nuclear issues, accept the unique culture of the media process, take the responsibility for any consequence which nuclear technologies give rise to, communicate with an access route based on sensibility and rationality, have a flexible angle in the science communication process, get creative leadership for the communication process with deliberation and disagreement, make efficient use of various science technologies for science communication. We should try to proceed with patience, because science communication makes for a more credible society

  9. Lessons learned in communicating nuclear transportation issues - a case study

    International Nuclear Information System (INIS)

    Reilly, B.; Austin, P.

    1992-01-01

    Successful communication requires several key elements. They include a non-intimidating forum for exchanging information, two-way communication, advance preparation to identify what each party wants to learn, and feedback. There is no single approach that guarantees success. Factors such as technical complexity of the issue, level of support by the public, and trust and confidence among the parties all play a role in determining the most workable approach for any particular situation. This paper illustrates lessons learned by the US Department of Energy (DOE) in communicating nuclear waste disposal and transportation issues to the public

  10. Assessing communication on sexual and reproductive health issues ...

    African Journals Online (AJOL)

    Bernt Lindtjorn

    issues among high school students with their parents, Bullen ... through targeted family life education activities among students and parents. [Ethiop. J. ... sexual issues and impact of this communication on ..... Males were about five times more likely than females to .... Prevention and Control Office and Regional Health.

  11. Secure Network-Centric Aviation Communication (SNAC)

    Science.gov (United States)

    Nelson, Paul H.; Muha, Mark A.; Sheehe, Charles J.

    2017-01-01

    The existing National Airspace System (NAS) communications capabilities are largely unsecured, are not designed for efficient use of spectrum and collectively are not capable of servicing the future needs of the NAS with the inclusion of new operators in Unmanned Aviation Systems (UAS) or On Demand Mobility (ODM). SNAC will provide a ubiquitous secure, network-based communications architecture that will provide new service capabilities and allow for the migration of current communications to SNAC over time. The necessary change in communication technologies to digital domains will allow for the adoption of security mechanisms, sharing of link technologies, large increase in spectrum utilization, new forms of resilience and redundancy and the possibly of spectrum reuse. SNAC consists of a long term open architectural approach with increasingly capable designs used to steer research and development and enable operating capabilities that run in parallel with current NAS systems.

  12. Data communication network at the ASRM facility

    Science.gov (United States)

    Moorhead, Robert J., II; Smith, Wayne D.

    1993-01-01

    This report describes the simulation of the overall communication network structure for the Advanced Solid Rocket Motor (ASRM) facility being built at Yellow Creek near Iuka, Mississippi as of today. The report is compiled using information received from NASA/MSFC, LMSC, AAD, and RUST Inc. As per the information gathered, the overall network structure will have one logical FDDI ring acting as a backbone for the whole complex. The buildings will be grouped into two categories viz. manufacturing intensive and manufacturing non-intensive. The manufacturing intensive buildings will be connected via FDDI to the Operational Information System (OIS) in the main computing center in B_1000. The manufacturing non-intensive buildings will be connected by 10BASE-FL to the OIS through the Business Information System (BIS) hub in the main computing center. All the devices inside B_1000 will communicate with the BIS. The workcells will be connected to the Area Supervisory Computers (ASCs) through the nearest manufacturing intensive hub and one of the OIS hubs. Comdisco's Block Oriented Network Simulator (BONeS) has been used to simulate the performance of the network. BONeS models a network topology, traffic, data structures, and protocol functions using a graphical interface. The main aim of the simulations was to evaluate the loading of the OIS, the BIS, and the ASCs, and the network links by the traffic generated by the workstations and workcells throughout the site.

  13. Data communication network at the ASRM facility

    Science.gov (United States)

    Moorhead, Robert J., II; Smith, Wayne D.

    1993-08-01

    This report describes the simulation of the overall communication network structure for the Advanced Solid Rocket Motor (ASRM) facility being built at Yellow Creek near Iuka, Mississippi as of today. The report is compiled using information received from NASA/MSFC, LMSC, AAD, and RUST Inc. As per the information gathered, the overall network structure will have one logical FDDI ring acting as a backbone for the whole complex. The buildings will be grouped into two categories viz. manufacturing intensive and manufacturing non-intensive. The manufacturing intensive buildings will be connected via FDDI to the Operational Information System (OIS) in the main computing center in B_1000. The manufacturing non-intensive buildings will be connected by 10BASE-FL to the OIS through the Business Information System (BIS) hub in the main computing center. All the devices inside B_1000 will communicate with the BIS. The workcells will be connected to the Area Supervisory Computers (ASCs) through the nearest manufacturing intensive hub and one of the OIS hubs. Comdisco's Block Oriented Network Simulator (BONeS) has been used to simulate the performance of the network. BONeS models a network topology, traffic, data structures, and protocol functions using a graphical interface. The main aim of the simulations was to evaluate the loading of the OIS, the BIS, and the ASCs, and the network links by the traffic generated by the workstations and workcells throughout the site.

  14. Energy, Entropy and Exergy in Communication Networks

    Directory of Open Access Journals (Sweden)

    Slavisa Aleksic

    2013-10-01

    Full Text Available The information and communication technology (ICT sector is continuously growing, mainly due to the fast penetration of ICT into many areas of business and society. Growth is particularly high in the area of technologies and applications for communication networks, which can be used, among others, to optimize systems and processes. The ubiquitous application of ICT opens new perspectives and emphasizes the importance of understanding the complex interactions between ICT and other sectors. Complex and interacting heterogeneous systems can only properly be addressed by a holistic framework. Thermodynamic theory, and, in particular, the second law of thermodynamics, is a universally applicable tool to analyze flows of energy. Communication systems and their processes can be seen, similar to many other natural processes and systems, as dissipative transformations that level differences in energy density between participating subsystems and their surroundings. This paper shows how to apply thermodynamics to analyze energy flows through communication networks. Application of the second law of thermodynamics in the context of the Carnot heat engine is emphasized. The use of exergy-based lifecycle analysis to assess the sustainability of ICT systems is shown on an example of a radio access network.

  15. Full-Duplex Communications in Large-Scale Cellular Networks

    KAUST Repository

    Alammouri, Ahmad

    2016-01-01

    /downlink interference. This thesis presents a tractable framework, based on stochastic geometry, to study FD communications in multi-tier cellular networks. Particularly, we assess the FD communications effect on the network performance and quantify the associated gains

  16. Communication through resonance in spiking neuronal networks.

    Science.gov (United States)

    Hahn, Gerald; Bujan, Alejandro F; Frégnac, Yves; Aertsen, Ad; Kumar, Arvind

    2014-08-01

    The cortex processes stimuli through a distributed network of specialized brain areas. This processing requires mechanisms that can route neuronal activity across weakly connected cortical regions. Routing models proposed thus far are either limited to propagation of spiking activity across strongly connected networks or require distinct mechanisms that create local oscillations and establish their coherence between distant cortical areas. Here, we propose a novel mechanism which explains how synchronous spiking activity propagates across weakly connected brain areas supported by oscillations. In our model, oscillatory activity unleashes network resonance that amplifies feeble synchronous signals and promotes their propagation along weak connections ("communication through resonance"). The emergence of coherent oscillations is a natural consequence of synchronous activity propagation and therefore the assumption of different mechanisms that create oscillations and provide coherence is not necessary. Moreover, the phase-locking of oscillations is a side effect of communication rather than its requirement. Finally, we show how the state of ongoing activity could affect the communication through resonance and propose that modulations of the ongoing activity state could influence information processing in distributed cortical networks.

  17. Information systems outsourcing issues in the communication technology sector

    CSIR Research Space (South Africa)

    Smuts, H

    2010-03-01

    Full Text Available in the IS industry, the limited availability of human resources at the appropriate experience level, maintaining and improving quality, lack of effective communication in the offshore context and concerns around data privacy with outsourcing to India or other... IN THE COMMUNICATION TECHNOLOGY SECTOR Hanlie Smuts School of Computing, University of South Africa, and Telephone Networks (Pty) Ltd, Private Bag 9955, Cresta, 2118, South Africa Paula Kotzé and Alta van der Merwe Meraka Institute of the CSIR, and School...

  18. Communication via an entangled coherent quantum network

    Energy Technology Data Exchange (ETDEWEB)

    El Allati, A; Hassouni, Y [Faculte des Sciences, Departement de Physique, Laboratoire de Physique Theorique URAC 13, Universite Mohammed V Agdal Rabat, Avenue Ibn Battouta, B.P. 1014, Rabat (Morocco); Metwally, N, E-mail: Nmetwally@gmail.com [Mathematics Department, College of Science, University of Bahrain, PO Box 32038 (Bahrain)

    2011-06-01

    A quantum network (QN) is constructed via maximum entangled coherent states. The possibility of using this network to achieve quantum communication between multi-participants is investigated. We showed that the probability of the successful teleportation of an unknown state depends on the size of the used network. As the number of participants increases, the success probability does not depend on the intensity of the field. Implementing a quantum teleportation protocol via a noisy QN is discussed. The unknown state can be teleported perfectly with small values of the field intensity and larger values of the noise strength. The success probability of this suggested protocol increases abruptly for larger values of the noise strength and gradually for small values. For small-size QNs, the fidelity of the teleported state decreases smoothly, whereas it decreases abruptly for larger-sized networks.

  19. Scaling of load in communications networks.

    Science.gov (United States)

    Narayan, Onuttom; Saniee, Iraj

    2010-09-01

    We show that the load at each node in a preferential attachment network scales as a power of the degree of the node. For a network whose degree distribution is p(k)∼k{-γ} , we show that the load is l(k)∼k{η} with η=γ-1 , implying that the probability distribution for the load is p(l)∼1/l{2} independent of γ . The results are obtained through scaling arguments supported by finite size scaling studies. They contradict earlier claims, but are in agreement with the exact solution for the special case of tree graphs. Results are also presented for real communications networks at the IP layer, using the latest available data. Our analysis of the data shows relatively poor power-law degree distributions as compared to the scaling of the load versus degree. This emphasizes the importance of the load in network analysis.

  20. Space Link Extension (SLE) Emulation for High-Throughput Network Communication

    Science.gov (United States)

    Murawski, Robert W.; Tchorowski, Nicole; Golden, Bert

    2014-01-01

    As the data rate requirements for space communications increases, significant stress is placed not only on the wireless satellite communication links, but also on the ground networks which forward data from end-users to remote ground stations. These wide area network (WAN) connections add delay and jitter to the end-to-end satellite communication link, effects which can have significant impacts on the wireless communication link. It is imperative that any ground communication protocol can react to these effects such that the ground network does not become a bottleneck in the communication path to the satellite. In this paper, we present our SCENIC Emulation Lab testbed which was developed to test the CCSDS SLE protocol implementations proposed for use on future NASA communication networks. Our results show that in the presence of realistic levels of network delay, high-throughput SLE communication links can experience significant data rate throttling. Based on our observations, we present some insight into why this data throttling happens, and trace the probable issue back to non-optimal blocking communication which is sup-ported by the CCSDS SLE API recommended practices. These issues were presented as well to the SLE implementation developers which, based on our reports, developed a new release for SLE which we show fixes the SLE blocking issue and greatly improves the protocol throughput. In this paper, we also discuss future developments for our end-to-end emulation lab and how these improvements can be used to develop and test future space communication technologies.

  1. Anonymous communication networks protecting privacy on the web

    CERN Document Server

    Peng, Kun

    2014-01-01

    In today's interactive network environment, where various types of organizations are eager to monitor and track Internet use, anonymity is one of the most powerful resources available to counterbalance the threat of unknown spectators and to ensure Internet privacy.Addressing the demand for authoritative information on anonymous Internet usage, Anonymous Communication Networks: Protecting Privacy on the Web examines anonymous communication networks as a solution to Internet privacy concerns. It explains how anonymous communication networks make it possible for participants to communicate with

  2. Position estimation of transceivers in communication networks

    Science.gov (United States)

    Kent, Claudia A [Pleasanton, CA; Dowla, Farid [Castro Valley, CA

    2008-06-03

    This invention provides a system and method using wireless communication interfaces coupled with statistical processing of time-of-flight data to locate by position estimation unknown wireless receivers. Such an invention can be applied in sensor network applications, such as environmental monitoring of water in the soil or chemicals in the air where the position of the network nodes is deemed critical. Moreover, the present invention can be arranged to operate in areas where a Global Positioning System (GPS) is not available, such as inside buildings, caves, and tunnels.

  3. Capacity analysis of vehicular communication networks

    CERN Document Server

    Lu, Ning

    2013-01-01

    This SpringerBrief focuses on the network capacity analysis of VANETs, a key topic as fundamental guidance on design and deployment of VANETs is very limited. Moreover, unique characteristics of VANETs impose distinguished challenges on such an investigation. This SpringerBrief first introduces capacity scaling laws for wireless networks and briefly reviews the prior arts in deriving the capacity of VANETs. It then studies the unicast capacity considering the socialized mobility model of VANETs. With vehicles communicating based on a two-hop relaying scheme, the unicast capacity bound is deriv

  4. Local-area communication networks - An overview

    International Nuclear Information System (INIS)

    Kuemmerle, K.

    1982-01-01

    Local-area communication networks represent a new field of activity. In this paper we first describe three scenarios for the use of these networks, and then discuss various technical approaches. Particular emphasis is put on bus and ring systems with various media access control mechanisms. Specifically, we compare the delay-throughput characteristic of two access methods, carrier-sense multiple access with collision detection and token passing, and discuss some significant differences of bus and ring systems concerning wiring, media, transmission, and reliability. (orig.)

  5. Resource Management in Broadband Communication Networks

    DEFF Research Database (Denmark)

    Hansen, Mads Stenhuus

    2003-01-01

    . The first part gives a brief description of some of the existing protocols for routing and controlling resources, such as RSVP, OSPF, BGP, PNNI, etc. The remaining part concerns the following two fundamentally different approaches to resource management etc.: - Software agents - Simulated ants......This thesis - Resource Management in Broadband Communication Networks - deals with different ways of optimizing the available resources of data- or telecommunication networks. Especially topics like optimal routing, load balancing and fast recovery of routes in case of link failures are covered...

  6. Satellite communications network design and analysis

    CERN Document Server

    Jo, Kenneth Y

    2011-01-01

    This authoritative book provides a thorough understanding of the fundamental concepts of satellite communications (SATCOM) network design and performance assessments. You find discussions on a wide class of SATCOM networks using satellites as core components, as well as coverage key applications in the field. This in-depth resource presents a broad range of critical topics, from geosynchronous Earth orbiting (GEO) satellites and direct broadcast satellite systems, to low Earth orbiting (LEO) satellites, radio standards and protocols.This invaluable reference explains the many specific uses of

  7. Digital Networked Information Society and Public Health: Problems and Promises of Networked Health Communication of Lay Publics.

    Science.gov (United States)

    Kim, Jeong-Nam

    2018-01-01

    This special issue of Health Communication compiles 10 articles to laud the promise and yet confront the problems in the digital networked information society related to public health. We present this anthology of symphony and cacophony of lay individuals' communicative actions in a digital networked information society. The collection of problems and promise of the new digital world may be a cornerstone joining two worlds-pre- and postdigital network society-and we hope this special issue will help better shape our future states of public health.

  8. An FPGA-based torus communication network

    Energy Technology Data Exchange (ETDEWEB)

    Pivanti, Marcello; Schifano, Sebastiano Fabio [INFN, Ferrara (Italy); Ferrara Univ. (Italy); Simma, Hubert [DESY, Zeuthen (Germany). John von Neumann-Institut fuer Computing NIC

    2011-02-15

    We describe the design and FPGA implementation of a 3D torus network (TNW) to provide nearest-neighbor communications between commodity multi-core processors. The aim of this project is to build up tightly interconnected and scalable parallel systems for scientific computing. The design includes the VHDL code to implement on latest FPGA devices a network processor, which can be accessed by the CPU through a PCIe interface and which controls the external PHYs of the physical links. Moreover, a Linux driver and a library implementing custom communication APIs are provided. The TNW has been successfully integrated in two recent parallel machine projects, QPACE and AuroraScience. We describe some details of the porting of the TNW for the AuroraScience system and report performance results. (orig.)

  9. An FPGA-based torus communication network

    International Nuclear Information System (INIS)

    Pivanti, Marcello; Schifano, Sebastiano Fabio; Simma, Hubert

    2011-02-01

    We describe the design and FPGA implementation of a 3D torus network (TNW) to provide nearest-neighbor communications between commodity multi-core processors. The aim of this project is to build up tightly interconnected and scalable parallel systems for scientific computing. The design includes the VHDL code to implement on latest FPGA devices a network processor, which can be accessed by the CPU through a PCIe interface and which controls the external PHYs of the physical links. Moreover, a Linux driver and a library implementing custom communication APIs are provided. The TNW has been successfully integrated in two recent parallel machine projects, QPACE and AuroraScience. We describe some details of the porting of the TNW for the AuroraScience system and report performance results. (orig.)

  10. Analysis of NASA communications (Nascom) II network protocols and performance

    Science.gov (United States)

    Omidyar, Guy C.; Butler, Thomas E.

    1991-01-01

    The NASA Communications (Nascom) Division of the Mission Operations and Data Systems Directorate is to undertake a major initiative to develop the Nascom II (NII) network to achieve its long-range service objectives for operational data transport to support the Space Station Freedom Program, the Earth Observing System, and other projects. NII is the Nascom ground communications network being developed to accommodate the operational traffic of the mid-1990s and beyond. The authors describe various baseline protocol architectures based on current and evolving technologies. They address the internetworking issues suggested for reliable transfer of data over heterogeneous segments. They also describe the NII architecture, topology, system components, and services. A comparative evaluation of the current and evolving technologies was made, and suggestions for further study are described. It is shown that the direction of the NII configuration and the subsystem component design will clearly depend on the advances made in the area of broadband integrated services.

  11. NOVANET: communications network for a control system

    International Nuclear Information System (INIS)

    Hill, J.R.; Severyn, J.R.; VanArsdall, P.J.

    1983-01-01

    NOVANET is a control system oriented fiber optic local area network that was designed to meet the unique and often conflicting requirements of the Nova laser control system which will begin operation in 1984. The computers and data acquisition devices that form the distributed control system for a large laser fusion research facility need reliable, high speed communications. Both control/status messages and experimental data must be handled. A subset of NOVANET is currently operating on the two beam Novette laser system

  12. Biased trapping issue on weighted hierarchical networks

    Indian Academy of Sciences (India)

    archical networks which are based on the classic scale-free hierarchical networks. ... Weighted hierarchical networks; weight-dependent walks; mean first passage ..... The weighted networks can mimic some real-world natural and social systems to ... the Priority Academic Program Development of Jiangsu Higher Education ...

  13. Understanding communication networks in the emergency department

    Directory of Open Access Journals (Sweden)

    Braithwaite Jeffrey

    2009-12-01

    Full Text Available Abstract Background Emergency departments (EDs are high pressure health care settings involving complex interactions between staff members in providing and organising patient care. Without good communication and cooperation amongst members of the ED team, quality of care is at risk. This study examined the problem-solving, medication advice-seeking and socialising networks of staff working in an Australian hospital ED. Methods A social network survey (Response Rate = 94% was administered to all ED staff (n = 109 including doctors, nurses, allied health professionals, administrative staff and ward assistants. Analysis of the network characteristics was carried out by applying measures of density (the extent participants are concentrated, connectedness (how related they are, isolates (how segregated, degree centrality (who has most connections measured in two ways, in-degree, the number of ties directed to an individual and out-degree, the number of ties directed from an individual, betweenness centrality (who is important or powerful, degree of separation (how many ties lie between people and reciprocity (how bi-directional are interactions. Results In all three networks, individuals were more closely connected to colleagues from within their respective professional groups. The problem-solving network was the most densely connected network, followed by the medication advice network, and the loosely connected socialising network. ED staff relied on each other for help to solve work-related problems, but some senior doctors, some junior doctors and a senior nurse were important sources of medication advice for their ED colleagues. Conclusions Network analyses provide useful ways to assess social structures in clinical settings by allowing us to understand how ED staff relate within their social and professional structures. This can provide insights of potential benefit to ED staff, their leaders, policymakers and researchers.

  14. The use of electronic communication (social network) by open and ...

    African Journals Online (AJOL)

    The use of electronic communication (social network) by open and distance students, ... ODL students use face book and whatsapps as their preferred social networks. ... networks distract academic studies and it is expensive to use, also more ...

  15. COMMUNICATION MANAGEMENT CRISIS IN SOCIAL NETWORKS

    Directory of Open Access Journals (Sweden)

    Ana Mª Enrique Jiménez

    2013-04-01

    Full Text Available It is often in the social networks where you detect the first signs of a potential crisis situation. Today, many companies decide to be present in social networks to communicate, listen and respond to their audiences openly with immediacy. A simple complaint is visible and propagates through the network in seconds, being capable of generating a negative impact on the corporate image of the organization. The same can happen to the contrary, ie, to praise the performance of a company, which may affect the creation or strengthening of the good reputation of the company. However, we know that this does not happen with the same intensity. In this paper we analyze the decisions and actions of two opposing companies, Nestlé and Panrico, in front of a possible crisis situation.

  16. COMPREHENSIVE SURVEY OF POSSIBLE SECURITY ISSUES ON 4G NETWORKS

    OpenAIRE

    Sumant Ku Mohapatra; Biswa Ranjan Swain; Pravanjan Das

    2015-01-01

    This paper presents a brief study of recent advances in wireless network security issues. The paper makes a number of contributions to the wireless networking field. First, it studies the 4G mail threats and risk and their design decisions. Second, the security of 4G architecture with next generation network security and 8- security dimensions of 4G network. Third, security issues and possible threats on 4G are discussed. Finally, we proposed four layer security model which manage...

  17. In-Space Internet-Based Communications for Space Science Platforms Using Commercial Satellite Networks

    Science.gov (United States)

    Kerczewski, Robert J.; Bhasin, Kul B.; Fabian, Theodore P.; Griner, James H.; Kachmar, Brian A.; Richard, Alan M.

    1999-01-01

    The continuing technological advances in satellite communications and global networking have resulted in commercial systems that now can potentially provide capabilities for communications with space-based science platforms. This reduces the need for expensive government owned communications infrastructures to support space science missions while simultaneously making available better service to the end users. An interactive, high data rate Internet type connection through commercial space communications networks would enable authorized researchers anywhere to control space-based experiments in near real time and obtain experimental results immediately. A space based communications network architecture consisting of satellite constellations connecting orbiting space science platforms to ground users can be developed to provide this service. The unresolved technical issues presented by this scenario are the subject of research at NASA's Glenn Research Center in Cleveland, Ohio. Assessment of network architectures, identification of required new or improved technologies, and investigation of data communications protocols are being performed through testbed and satellite experiments and laboratory simulations.

  18. Mobility in Higher Education: Cross-Cultural Communication Issues.

    Science.gov (United States)

    Baumgratz, Gisela

    1993-01-01

    A study of the role of foreign languages in European higher education focused on the influence of institutional culture, including that of the discipline, on quality of professional communication. Findings are discussed, and related issues are examined, including student/professional mobility, interinstitutional cooperation, standards for…

  19. Communication in turbulent times : exploring issue arenas and crisis communication to enhance organisational resilience

    OpenAIRE

    Vos, Marita; Van der Molen, Irna; Mykkänen, Markus

    2017-01-01

    This book is characterised by a broad approach towards corporate communication, emphasising change and crisis. The focus is not on crises as an exceptional situation but rather on broader volatility in the environment. The purpose of this book is to increase the understanding of multi- stakeholder communication concerning organisational issues and crises. From the perspective of organisational management, this book clarifies how communication contributes to organisational resi...

  20. On cost-effective communication network designing

    Science.gov (United States)

    Zhang, Guo-Qiang

    2010-02-01

    How to efficiently design a communication network is a paramount task for network designing and engineering. It is, however, not a single objective optimization process as perceived by most previous researches, i.e., to maximize its transmission capacity, but a multi-objective optimization process, with lowering its cost to be another important objective. These two objectives are often contradictive in that optimizing one objective may deteriorate the other. After a deep investigation of the impact that network topology, node capability scheme and routing algorithm as well as their interplays have on the two objectives, this letter presents a systematic approach to achieve a cost-effective design by carefully choosing the three designing aspects. Only when routing algorithm and node capability scheme are elegantly chosen can BA-like scale-free networks have the potential of achieving good tradeoff between the two objectives. Random networks, on the other hand, have the built-in character for a cost-effective design, especially when other aspects cannot be determined beforehand.

  1. Marketing communications model for innovation networks

    Directory of Open Access Journals (Sweden)

    Tiago João Freitas Correia

    2015-10-01

    Full Text Available Innovation is an increasingly relevant concept for the success of any organization, but it also represents a set of internal and external considerations, barriers and challenges to overcome. Along the concept of innovation, new paradigms emerge such as open innovation and co-creation that are simultaneously innovation modifiers and intensifiers in organizations, promoting organizational openness and stakeholder integration within the value creation process. Innovation networks composed by a multiplicity of agents in co-creative work perform as innovation mechanisms to face the increasingly complexity of products, services and markets. Technology, especially the Internet, is an enabler of all process among organizations supported by co-creative platforms for innovation. The definition of marketing communication strategies that promote motivation and involvement of all stakeholders in synergic creation and external promotion is the central aspect of this research. The implementation of the projects is performed by participative workshops with stakeholders from Madan Parque through IDEAS(REVOLUTION methodology and the operational model LinkUp parameterized for the project. The project is divided into the first part, the theoretical framework, and the second part where a model is developed for the marketing communication strategies that appeal to the Madan Parque case study. Keywords: Marketing Communication; Open Innovation, Technology; Innovation Networks; Incubator; Co-Creation.

  2. Clustering and Beamforming for Efficient Communication in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Francisco Porcel-Rodríguez

    2016-08-01

    Full Text Available Energy efficiency is a critical issue for wireless sensor networks (WSNs as sensor nodes have limited power availability. In order to address this issue, this paper tries to maximize the power efficiency in WSNs by means of the evaluation of WSN node networks and their performance when both clustering and antenna beamforming techniques are applied. In this work, four different scenarios are defined, each one considering different numbers of sensors: 50, 20, 10, five, and two nodes per scenario, and each scenario is randomly generated thirty times in order to statistically validate the results. For each experiment, two different target directions for transmission are taken into consideration in the optimization process (φ = 0° and θ = 45°; φ = 45°, and θ = 45°. Each scenario is evaluated for two different types of antennas, an ideal isotropic antenna and a conventional dipole one. In this set of experiments two types of WSN are evaluated: in the first one, all of the sensors have the same amount of power for communications purposes; in the second one, each sensor has a different amount of power for its communications purposes. The analyzed cases in this document are focused on 2D surface and 3D space for the node location. To the authors’ knowledge, this is the first time that beamforming and clustering are simultaneously applied to increase the network lifetime in WSNs.

  3. Extracting Association Patterns in Network Communications

    Science.gov (United States)

    Portela, Javier; Villalba, Luis Javier García; Trujillo, Alejandra Guadalupe Silva; Orozco, Ana Lucila Sandoval; Kim, Tai-hoon

    2015-01-01

    In network communications, mixes provide protection against observers hiding the appearance of messages, patterns, length and links between senders and receivers. Statistical disclosure attacks aim to reveal the identity of senders and receivers in a communication network setting when it is protected by standard techniques based on mixes. This work aims to develop a global statistical disclosure attack to detect relationships between users. The only information used by the attacker is the number of messages sent and received by each user for each round, the batch of messages grouped by the anonymity system. A new modeling framework based on contingency tables is used. The assumptions are more flexible than those used in the literature, allowing to apply the method to multiple situations automatically, such as email data or social networks data. A classification scheme based on combinatoric solutions of the space of rounds retrieved is developed. Solutions about relationships between users are provided for all pairs of users simultaneously, since the dependence of the data retrieved needs to be addressed in a global sense. PMID:25679311

  4. Extracting Association Patterns in Network Communications

    Directory of Open Access Journals (Sweden)

    Javier Portela

    2015-02-01

    Full Text Available In network communications, mixes provide protection against observers hiding the appearance of messages, patterns, length and links between senders and receivers. Statistical disclosure attacks aim to reveal the identity of senders and receivers in a communication network setting when it is protected by standard techniques based on mixes. This work aims to develop a global statistical disclosure attack to detect relationships between users. The only information used by the attacker is the number of messages sent and received by each user for each round, the batch of messages grouped by the anonymity system. A new modeling framework based on contingency tables is used. The assumptions are more flexible than those used in the literature, allowing to apply the method to multiple situations automatically, such as email data or social networks data. A classification scheme based on combinatoric solutions of the space of rounds retrieved is developed. Solutions about relationships between users are provided for all pairs of users simultaneously, since the dependence of the data retrieved needs to be addressed in a global sense.

  5. Opportunistic spectrum utilization in vehicular communication networks

    CERN Document Server

    Cheng, Nan

    2016-01-01

    This brief examines current research on improving Vehicular Networks (VANETs), examining spectrum scarcity due to the dramatic growth of mobile data traffic and the limited bandwidth of dedicated vehicular communication bands and the use of opportunistic spectrum bands to mitigate congestion. It reviews existing literature on the use of opportunistic spectrum bands for VANETs, including licensed and unlicensed spectrum bands and a variety of related technologies, such as cognitive radio, WiFi and device-to-device communications. Focused on analyzing spectrum characteristics, designing efficient spectrum exploitation schemes, and evaluating the date delivery performance when utilizing different opportunistic spectrum bands, the results presented in this brief provide valuable insights on improving the design and deployment of future VANETs.

  6. Manual for WSPEEDI international data communication network

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Masatoshi; Nagai, Haruyasu; Chino, Masamichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2000-09-01

    Japan Atomic Energy Research Institute has developed a computer-based dose prediction system WSPEEDI (System for Prediction of Environmental Emergency Dose Information) for predicting the radiological impacts on the Japanese people of a nuclear accident abroad to meet the requirement caused by the Chernobyl accident. Because WSPEEDI reached on the practical stage through several verification studies, the development of international data communication network is started to exchange modeling products and environmental data quickly. This manual describes registration, search and management of modeling products and environmental data and handling of tele-conference tool. (author)

  7. Method of optimization onboard communication network

    Science.gov (United States)

    Platoshin, G. A.; Selvesuk, N. I.; Semenov, M. E.; Novikov, V. M.

    2018-02-01

    In this article the optimization levels of onboard communication network (OCN) are proposed. We defined the basic parameters, which are necessary for the evaluation and comparison of modern OCN, we identified also a set of initial data for possible modeling of the OCN. We also proposed a mathematical technique for implementing the OCN optimization procedure. This technique is based on the principles and ideas of binary programming. It is shown that the binary programming technique allows to obtain an inherently optimal solution for the avionics tasks. An example of the proposed approach implementation to the problem of devices assignment in OCN is considered.

  8. Communication security in open health care networks.

    Science.gov (United States)

    Blobel, B; Pharow, P; Engel, K; Spiegel, V; Krohn, R

    1999-01-01

    Fulfilling the shared care paradigm, health care networks providing open systems' interoperability in health care are needed. Such communicating and co-operating health information systems, dealing with sensitive personal medical information across organisational, regional, national or even international boundaries, require appropriate security solutions. Based on the generic security model, within the European MEDSEC project an open approach for secure EDI like HL7, EDIFACT, XDT or XML has been developed. The consideration includes both securing the message in an unsecure network and the transport of the unprotected information via secure channels (SSL, TLS etc.). Regarding EDI, an open and widely usable security solution has been specified and practically implemented for the examples of secure mailing and secure file transfer (FTP) via wrapping the sensitive information expressed by the corresponding protocols. The results are currently prepared for standardisation.

  9. Simulation technologies in networking and communications selecting the best tool for the test

    CERN Document Server

    Pathan, Al-Sakib Khan; Khan, Shafiullah

    2014-01-01

    Simulation is a widely used mechanism for validating the theoretical models of networking and communication systems. Although the claims made based on simulations are considered to be reliable, how reliable they really are is best determined with real-world implementation trials.Simulation Technologies in Networking and Communications: Selecting the Best Tool for the Test addresses the spectrum of issues regarding the different mechanisms related to simulation technologies in networking and communications fields. Focusing on the practice of simulation testing instead of the theory, it presents

  10. Performance testing framework for smart grid communication network

    International Nuclear Information System (INIS)

    Quang, D N; See, O H; Chee, L L; Xuen, C Y; Karuppiah, S

    2013-01-01

    Smart grid communication network is comprised of different communication mediums and technologies. Performance evaluation is one of the main concerns in smart grid communication system. In any smart grid communication implementation, to determine the performance factor of the network, a testing of an end-to-end process flow is required. Therefore, an effective and coordinated testing procedure plays a crucial role in evaluating the performance of smart grid communications. In this paper, a testing framework is proposed as a guideline to analyze and assess the performance of smart grid communication network.

  11. Effect of correlating adjacent neurons for identifying communications: Feasibility experiment in a cultured neuronal network

    OpenAIRE

    Yoshi Nishitani; Chie Hosokawa; Yuko Mizuno-Matsumoto; Tomomitsu Miyoshi; Shinichi Tamura

    2017-01-01

    Neuronal networks have fluctuating characteristics, unlike the stable characteristics seen in computers. The underlying mechanisms that drive reliable communication among neuronal networks and their ability to perform intelligible tasks remain unknown. Recently, in an attempt to resolve this issue, we showed that stimulated neurons communicate via spikes that propagate temporally, in the form of spike trains. We named this phenomenon “spike wave propagation”. In these previous studies, using ...

  12. SPECIAL ISSUE - “COMMUNICATION, DESIGN AND LEARNING”

    Directory of Open Access Journals (Sweden)

    Per Hetland

    2016-11-01

    - a case of students negotiating their social presence in an online course”. Their paperreports on a study of a higher education online course based on asynchronous communication. In the selection of technology for online discussions they aimed at creating a sense of togetherness among the teachers and the students. Their choice proved to be a insightful experience of how the differences of agency of a virtual learning environment (VLE are compared to social media when it comes to social presence.Anders I. Mørch of the University of Oslo has collaborated with Louise Mifsud and Bård Kjetil Engen, of Oslo and Akershus University College of Applied Sciences on the fourth paper, called “Problem-Based Learning in Synchronous Networked Environments: Comparing Adobe Connect and Second Life”. Their approach was to compare experiences from using two networked learning environments: Adobe Connect (AC and Second Life (SL for supporting teaching and learning in distance education courses. Data were collected from two separate case studies: one in Norway (AC and the other in the United States (SL, using different but comparable methods of data analysis. They focus on problem-based learning (PBL, using four application characteristics of PBL (learner activity, collaborative learning, feedback, and valuation of previous knowledge.General sectionIn addition to the four papers in the special issue of Seminar.net, we also contribute with two more papers.David Hallberg, representing both The Swedish Red Cross University College and the Stockholm University, has written a paper with Henrik Hansson and Anders G.Nilsson, also from Stockholm University called: “Immigrant Women's Reasoning and Use of Information and Communications Technology in Lifelong Learning”. The paper explores the reasoning and use of information and communications technology (ICT in lifelong learning by immigrant women. The researchers collected data from semi-structured and unstructured interviews. The

  13. Value-Creating Networks: Organizational Issues and Challenges

    Science.gov (United States)

    Allee, Verna

    2009-01-01

    Purpose: The purpose of this paper is to provide examples of evaluating value-creating networks and to address the organizational issues and challenges of a network orientation. Design/methodology/approach: Value network analysis was first developed in 1993 and was adapted in 1997 for intangible asset management. It has been applied from shopfloor…

  14. Development of Network Devices Supporting Communication Independence In NPP I and C Systems

    International Nuclear Information System (INIS)

    Jeong, K.-I.; Suh, Y.S.; Park, G.-O.; Park, J.-Y.

    2013-06-01

    As advanced digital I and C systems of nuclear power plants or research reactors are being introduced to replace analog systems, a data communication network is necessary for data exchanges between I and C systems of nuclear power plants or research reactors. Data communication network technology may have significant impact on I and C systems. As the safety I and C system is composed of redundant channels to enhance the performance of the safety functions and data communication system is used to transmit the data generated by the digital I and C systems, communication independence is required to mitigate the risk of safety I and C system failure. Therefore this paper mainly discusses the issues related to the communication independence and the current status of network devices we designed, developed, and validated to satisfy the requirements of function, performance, and communication independence. (authors)

  15. College Student Social Networking: Its Importance and Its Issues

    Science.gov (United States)

    Wihbey, Jean A.

    2010-01-01

    Most traditional age college students communicate regularly on social networking sites such as, MySpace, Facebook, Friendster, Bebo, and LiveJournal. These are member-based internet communities that allow users to create a username, enter personal profile information, post photographs and communicate with others in innovative ways. Since Facebook…

  16. Transnational organizing: Issue professionals in environmental sustainability networks.

    Science.gov (United States)

    Henriksen, Lasse Folke; Seabrooke, Leonard

    2016-09-01

    An ongoing question for institutional theory is how organizing occurs transnationally, where institution building occurs in a highly ambiguous environment. This article suggests that at the core of transnational organizing is competition and coordination within professional and organizational networks over who controls issues. Transnational issues are commonly organized through professional battles over how issues are treated and what tasks are involved. These professional struggles are often more important than what organization has a formal mandate over an issue. We highlight how 'issue professionals' operate in two-level professional and organizational networks to control issues. This two-level network provides the context for action in which professionals do their institutional work. The two-level network carries information about professional incentives and also norms about how issues should be treated and governed by organizations. Using network and career sequences methods, we provide a case of transnational organizing through professionals who attempt issue control and network management on transnational environmental sustainability certification. The article questions how transnational organizing happens, and how we can best identify attempts at issue control.

  17. fraud detection in mobile communications networks using user

    African Journals Online (AJOL)

    DEPT OF AGRICULTURAL ENGINEERING

    testing the methods with data from real mobile communications networks. Keywords: Call .... System. Monitoring. Database. Database. Fig. 3: Mobile communication detection tools ..... receiver operating characteristic curve (ROC). ROC is a ...

  18. Smart Control of Energy Distribution Grids over Heterogeneous Communication Networks

    DEFF Research Database (Denmark)

    Schwefel, Hans-Peter; Silva, Nuno; Olsen, Rasmus Løvenstein

    2018-01-01

    Off-the shelf wireless communication technologies reduce infrastructure deployment costs and are thus attractive for distribution system control. Wireless communication however may lead to variable network performance. Hence the impact of this variability on overall distribution system control be...

  19. Characterizing the sustainable forestry issue network in thc United States

    Science.gov (United States)

    Steverson O. Moffat; Frederick W. Cubbage; Thomas P. Holmes; Elizabethann O' Sullivan

    2001-01-01

    Issue network analysis techniques were applied to the issue sustainable forestry in the United States to identify potential public and private outcomes for the issue. A quantitative approach based on work by Laumann and Knoke [(The Organizational State (1987)] was utilized in conjunction with the Delphi method. Results suggest that the parity in the distribution of...

  20. Game theory in communication networks cooperative resolution of interactive networking scenarios

    CERN Document Server

    Antoniou, Josephina

    2012-01-01

    A mathematical tool for scientists and researchers who work with computer and communication networks, Game Theory in Communication Networks: Cooperative Resolution of Interactive Networking Scenarios addresses the question of how to promote cooperative behavior in interactive situations between heterogeneous entities in communication networking scenarios. It explores network design and management from a theoretical perspective, using game theory and graph theory to analyze strategic situations and demonstrate profitable behaviors of the cooperative entities. The book promotes the use of Game T

  1. ACTS TDMA network control. [Advanced Communication Technology Satellite

    Science.gov (United States)

    Inukai, T.; Campanella, S. J.

    1984-01-01

    This paper presents basic network control concepts for the Advanced Communications Technology Satellite (ACTS) System. Two experimental systems, called the low-burst-rate and high-burst-rate systems, along with ACTS ground system features, are described. The network control issues addressed include frame structures, acquisition and synchronization procedures, coordinated station burst-time plan and satellite-time plan changes, on-board clock control based on ground drift measurements, rain fade control by means of adaptive forward-error-correction (FEC) coding and transmit power augmentation, and reassignment of channel capacities on demand. The NASA ground system, which includes a primary station, diversity station, and master control station, is also described.

  2. Integration versus Outsourcing in Stable Industry Equilibrium with Communication Networks

    OpenAIRE

    Okamoto, Yusuke

    2006-01-01

    For the selection of a firm's structure between vertical integration and arm's-length outsourcing, the importance of the thickness of the market had been emphasized in the previous literature. Here we take account of communication networks such as telephone, telex, fax, and the Internet. By doing so, we could illustrate the relationship between communication networks and the make-or-buy decision. With communication network technology differing in each type of firm, both vertically integrated ...

  3. Discovery Monday - Behind the plug: communication networks

    CERN Multimedia

    2004-01-01

    Ever wondered what happens to your email when you click "send"? And when you make a phone call, how does your voice travel down the wire? Find out more about communication networks and their applications at the next Discovery Monday in Microcosm on 1 March. At CERN, networks are used for a multitude of reasons. Mobile phones, for example, are used in the laboratory's underground areas. Optical fibre cabling ensures that CERN's computers are connected to the rest of the world. But how do optical fibres work and what does the future have in store? CERN's experiments also need networks. Particle detectors are made of many layers, each relays complex information to a computer analysis centre which reconstitutes the passage of the particles resulting from collisions. Many billions of bytes are transmitted every second from a multitude of sources, to many computers.  No single computer can handle such a huge flow of information. The next Discovery Monday is your chance to find out how this works.  Participate i...

  4. Network Analysis as a Communication Audit Instrument: Uncovering Communicative Strengths and Weaknesses Within Organizations

    NARCIS (Netherlands)

    Koning, K.H.; de Jong, Menno D.T.

    2015-01-01

    Network analysis is one of the instruments in the communication audit toolbox to diagnose communication problems within organizations. To explore its contribution to a communication audit, the authors conducted a network analysis within three secondary schools, comparing its results with those of

  5. Exploring the morphospace of communication efficiency in complex networks.

    Directory of Open Access Journals (Sweden)

    Joaquín Goñi

    Full Text Available Graph theoretical analysis has played a key role in characterizing global features of the topology of complex networks, describing diverse systems such as protein interactions, food webs, social relations and brain connectivity. How system elements communicate with each other depends not only on the structure of the network, but also on the nature of the system's dynamics which are constrained by the amount of knowledge and resources available for communication processes. Complementing widely used measures that capture efficiency under the assumption that communication preferentially follows shortest paths across the network ("routing", we define analytic measures directed at characterizing network communication when signals flow in a random walk process ("diffusion". The two dimensions of routing and diffusion efficiency define a morphospace for complex networks, with different network topologies characterized by different combinations of efficiency measures and thus occupying different regions of this space. We explore the relation of network topologies and efficiency measures by examining canonical network models, by evolving networks using a multi-objective optimization strategy, and by investigating real-world network data sets. Within the efficiency morphospace, specific aspects of network topology that differentially favor efficient communication for routing and diffusion processes are identified. Charting regions of the morphospace that are occupied by canonical, evolved or real networks allows inferences about the limits of communication efficiency imposed by connectivity and dynamics, as well as the underlying selection pressures that have shaped network topology.

  6. fraud detection in mobile communications networks using user

    African Journals Online (AJOL)

    DEPT OF AGRICULTURAL ENGINEERING

    Fraud detection is an important application, since network operators lose a relevant portion of their revenue to fraud. ... testing the methods with data from real mobile communications networks. Keywords: Call data, fraud ...... Ph. D. thesis. Pur-.

  7. Communication and cooperation in underwater acoustic networks

    Science.gov (United States)

    Yerramalli, Srinivas

    In this thesis, we present a study of several problems related to underwater point to point communications and network formation. We explore techniques to improve the achievable data rate on a point to point link using better physical layer techniques and then study sensor cooperation which improves the throughput and reliability in an underwater network. Robust point-to-point communications in underwater networks has become increasingly critical in several military and civilian applications related to underwater communications. We present several physical layer signaling and detection techniques tailored to the underwater channel model to improve the reliability of data detection. First, a simplified underwater channel model in which the time scale distortion on each path is assumed to be the same (single scale channel model in contrast to a more general multi scale model). A novel technique, which exploits the nature of OFDM signaling and the time scale distortion, called Partial FFT Demodulation is derived. It is observed that this new technique has some unique interference suppression properties and performs better than traditional equalizers in several scenarios of interest. Next, we consider the multi scale model for the underwater channel and assume that single scale processing is performed at the receiver. We then derive optimized front end pre-processing techniques to reduce the interference caused during single scale processing of signals transmitted on a multi-scale channel. We then propose an improvised channel estimation technique using dictionary optimization methods for compressive sensing and show that significant performance gains can be obtained using this technique. In the next part of this thesis, we consider the problem of sensor node cooperation among rational nodes whose objective is to improve their individual data rates. We first consider the problem of transmitter cooperation in a multiple access channel and investigate the stability of

  8. Time concurrency/phase-time synchronization in digital communications networks

    Science.gov (United States)

    Kihara, Masami; Imaoka, Atsushi

    1990-01-01

    Digital communications networks have the intrinsic capability of time synchronization which makes it possible for networks to supply time signals to some applications and services. A practical estimation method for the time concurrency on terrestrial networks is presented. By using this method, time concurrency capability of the Nippon Telegraph and Telephone Corporation (NTT) digital communications network is estimated to be better than 300 ns rms at an advanced level, and 20 ns rms at final level.

  9. The Dynamics of Initiative in Communication Networks.

    Directory of Open Access Journals (Sweden)

    Anders Mollgaard

    Full Text Available Human social interaction is often intermittent. Two acquainted persons can have extended periods without social interaction punctuated by periods of repeated interaction. In this case, the repeated interaction can be characterized by a seed initiative by either of the persons and a number of follow-up interactions. The tendency to initiate social interaction plays an important role in the formation of social networks and is in general not symmetric between persons. In this paper, we study the dynamics of initiative by analysing and modeling a detailed call and text message network sampled from a group of 700 individuals. We show that in an average relationship between two individuals, one part is almost twice as likely to initiate communication compared to the other part. The asymmetry has social consequences and ultimately might lead to the discontinuation of a relationship. We explain the observed asymmetry by a positive feedback mechanism where individuals already taking initiative are more likely to take initiative in the future. In general, people with many initiatives receive attention from a broader spectrum of friends than people with few initiatives. Lastly, we compare the likelihood of taking initiative with the basic personality traits of the five factor model.

  10. Coverage and Connectivity Issue in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Rachit Trivedi

    2013-04-01

    Full Text Available Wireless sensor networks (WSNs are an emerging area of interest in research and development. It finds use in military surveillance, health care, environmental monitoring, forest fire detection and smart environments. An important research issue in WSNs is the coverage since cost, area and lifetime are directly validated to it.In this paper we present an overview of WSNs and try to refine the coverage and connectivity issues in wireless sensor networks.

  11. Collaborative Algortihms for Communication in Wireless Sensor Networks

    NARCIS (Netherlands)

    Nieberg, T.; Dulman, S.O.; Havinga, Paul J.M.; van Hoesel, L.F.W.; Wu Jian, W.J.

    In this paper, we present the design of the communication in a wireless sensor network. The resource limitations of a wireless sensor network, especially in terms of energy, require an integrated, and collaborative approach for the different layers of communication. In particular, energy-efficient

  12. Collaborative Algorithms for Communication in Wireless Sensor Networks

    NARCIS (Netherlands)

    Nieberg, T.; Dulman, S.O.; Havinga, Paul J.M.; van Hoesel, L.F.W.; Wu Jian, W.J.; Basten, Twan; Geilen, Marc; de Groot, Harmke

    2003-01-01

    In this paper, we present the design of the communication in a wireless sensor network. The resource limitations of a wireless sensor network, especially in terms of energy, require an integrated, and collaborative approach for the different layers of communication. In particular, energy-efficient

  13. Dialogue, Language and Identity: Critical Issues for Networked Management Learning

    Science.gov (United States)

    Ferreday, Debra; Hodgson, Vivien; Jones, Chris

    2006-01-01

    This paper draws on the work of Mikhail Bakhtin and Norman Fairclough to show how dialogue is central to the construction of identity in networked management learning. The paper is based on a case study of a networked management learning course in higher education and attempts to illustrate how participants negotiate issues of difference,…

  14. Learning as Issue Framing in Agricultural Innovation Networks

    Science.gov (United States)

    Tisenkopfs, Talis; Kunda, Ilona; Šumane, Sandra

    2014-01-01

    Purpose: Networks are increasingly viewed as entities of learning and innovation in agriculture. In this article we explore learning as issue framing in two agricultural innovation networks. Design/methodology/approach: We combine frame analysis and social learning theories to analyse the processes and factors contributing to frame convergence and…

  15. Classification framework of knowledge transfer issues across value networks

    NARCIS (Netherlands)

    Bagheri, S.; Kusters, R.J.; Trienekens, J.J.M.; van der Zandt, Hugo; Cavalieri, S.; Ceretti, E.; Tolio, T.; Pezzotta, G.

    2016-01-01

    Co-creating integrated solutions with customers requires collaboration of different partners within a value network. In this emerging context, knowledge is considered as a foundation for value co-creation. Therefore, identifying different types of issues, with which value network actors in knowledge

  16. Social Networks in the workplace - some data protection issues

    OpenAIRE

    Haynes, D.

    2011-01-01

    There are many benefits to be gained from using social networks in the workplace but there is a downside – a growing concern about privacy and misuse of personal information. Using the results from a survey he conducted to highlight the issues, David Haynes puts forward an approach to managing social networks through the introduction of organisational policy.

  17. Issues related to social network advertising

    Directory of Open Access Journals (Sweden)

    Tecău, A. S.

    2012-01-01

    Full Text Available The promotional activity is currently marked by major transformations due to the coming out and extremely fast development of certain new media of promotion much more suitable for the interaction with consumers, much more appropriate in developing long term relationships with them as compared to classic media. The most edifying example is the Internet with all that it provides, becoming an important part of everyone’s everyday life. Within the Internet, the social networking is constantly developing, becoming increasingly important.

  18. Ethernet image communication performance in a multimodal PACS network

    International Nuclear Information System (INIS)

    Lou, S.L.; Valentino, D.J.; Chan, K.K.; Huang, H.K.

    1989-01-01

    The authors have evaluated the performance of an Ethernet network in a multimodal picture archiving and communications system (PACS) environment. The study included measurements between Sun workstations and PC- AT computers running communication software at the TCP level. First they initiated image transfers between two workstations, a server and a client. Next, they successively added clients to transfer images to the server and they measured degradation in network performance. Finally, they initiated image transfers between pairs of workstations and again measured performance degradation. The results of the authors' experiments indicate that Ethernet is suitable for image communication only in limited network situations. They discuss how to maximize network performance given these constraints

  19. Fiber-wireless convergence in next-generation communication networks systems, architectures, and management

    CERN Document Server

    Chang, Gee-Kung; Ellinas, Georgios

    2017-01-01

    This book investigates new enabling technologies for Fi-Wi convergence. The editors discuss Fi-Wi technologies at the three major network levels involved in the path towards convergence: system level, network architecture level, and network management level. The main topics will be: a. At system level: Radio over Fiber (digitalized vs. analogic, standardization, E-band and beyond) and 5G wireless technologies; b. Network architecture level: NGPON, WDM-PON, BBU Hotelling, Cloud Radio Access Networks (C-RANs), HetNets. c. Network management level: SDN for convergence, Next-generation Point-of-Presence, Wi-Fi LTE Handover, Cooperative MultiPoint. • Addresses the Fi-Wi convergence issues at three different levels, namely at the system level, network architecture level, and network management level • Provides approaches in communication systems, network architecture, and management that are expected to steer the evolution towards fiber-wireless convergence • Contributions from leading experts in the field of...

  20. Distributed Optimization of Multi Beam Directional Communication Networks

    Science.gov (United States)

    2017-06-30

    Distributed Optimization of Multi-Beam Directional Communication Networks Theodoros Tsiligkaridis MIT Lincoln Laboratory Lexington, MA 02141, USA...based routing. I. INTRODUCTION Missions where multiple communication goals are of in- terest are becoming more prevalent in military applications...Multilayer communications may occur within a coalition; for example, a team consisting of ground vehicles and an airborne set of assets may desire to

  1. ON SECURE FULL DUPLEX COMMUNICATION IN MOBILE AD HOC NETWORK

    OpenAIRE

    S. C. Dutta; Sudha Singh; D. K. Singh

    2013-01-01

    This paper is to establish Ad Hoc network in mobile phones and start fully secured full duplex communication in any situation. This type of communication will be cost effective and it will be fastest way of communication in case of any server failure or server error.

  2. Validation of Bosch' Mobile Communication NetworkArchitecture with SPIN

    NARCIS (Netherlands)

    Ruys, T.C.; Langerak, Romanus

    This paper discusses validation projects carried out for the Mobile Communication Division of Robert Bosch GmbH. We verified parts of their Mobile Communication Network (MCNet), a communication system which is to be used in infotainment systems of future cars. The protocols of the MCNet have been

  3. Novel Concepts for Device to Device Communication using Network Coding

    DEFF Research Database (Denmark)

    Pahlevani, Peyman; Hundebøll, Martin; Pedersen, Morten Videbæk

    2014-01-01

    Device-to-device communication is currently a hot research topic within 3GPP. Even though D2D communication has been part of previous ad hoc, meshed and sensor networks proposals, the main contribution by 3GPP is that the direct communication among two devices is carried out over a dynamically as...

  4. Future cooperative communication systems driven by social mobile networks

    DEFF Research Database (Denmark)

    Blázovics, L.; Varga, C.; Bamford, W.

    2011-01-01

    In this work we are underlining the importance of social mobile networks for upcoming cooperative communication systems. The assumption of this work is that future mobile communication systems will incorporate user cooperation, i.e. a combination of cellular access in parallel with ongoing short...... cases. By the example of the Gedda-Headz gaming community, possible links between cooperative mobile communication and social mobile networks are shown....

  5. A fusion networking model for smart grid power distribution backbone communication network based on PTN

    Directory of Open Access Journals (Sweden)

    Wang Hao

    2016-01-01

    Full Text Available In current communication network for distribution in Chinese power grid systems, the fiber communication backbone network for distribution and TD-LTE power private wireless backhaul network of power grid are both bearing by the SDH optical transmission network, which also carries the communication network of transformer substation and main electric. As the data traffic of the distribution communication and TD-LTE power private wireless network grow rapidly in recent years, it will have a big impact with the SDH network’s bearing capacity which is mainly used for main electric communication in high security level. This paper presents a fusion networking model which use a multiple-layer PTN network as the unified bearing of the TD-LTE power private wireless backhaul network and fiber communication backbone network for distribution. Network dataflow analysis shows that this model can greatly reduce the capacity pressure of the traditional SDH network as well as ensure the reliability of the transmission of the communication network for distribution and TD-LTE power private wireless network.

  6. Networked publics: multi-disciplinary perspectives on big policy issues

    OpenAIRE

    William H. Dutton

    2018-01-01

    This special issue of Internet Policy Review is the first to bring together the best policy-oriented papers presented at the annual conference of the Association of Internet Researchers (AoIR). This issue is anchored in the 2017 conference in Tartu, Estonia, which was organised around the theme of networked publics. The seven papers span issues concerning whether and how technology and policy are reshaping access to information, perspectives on privacy and security online, and social and lega...

  7. Leveraging the NPS Femto Satellite for Alternative Satellite Communication Networks

    Science.gov (United States)

    2017-09-01

    programmed for eventual integration with the Iridium Network , which is then tested. C. THESIS ORGANIZATION The thesis addresses these questions...NPS FEMTO SATELLITE FOR ALTERNATIVE SATELLITE COMMUNICATION NETWORKS by Faisal S. Alshaya September 2017 Co-Advisors: Steven J. Iatrou...TYPE AND DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE LEVERAGING THE NPS FEMTO SATELLITE FOR ALTERNATIVE SATELLITE COMMUNICATION NETWORKS 5

  8. Communicating with the public on nuclear materials disposition issues

    International Nuclear Information System (INIS)

    Stevenson, G.B.; Wherley, P.

    1995-01-01

    The storage and disposition of weapons grade fissile materials involves complex technical issues. The goal of reaching consensus on the best method or methods for storing and ultimately disposing of these materials can only be achieved after an open public discussion of all reasonable alternatives. The US Department of Energy considered a number of factors in developing a program for public involvement. These factors included defining the affected public, public knowledge about the proposed action, decision to be made, availability of pertinent information, current public perceptions, and responding to public input. Based upon an analysis of these factors, three primary techniques were selected for communicating with the public. The techniques are distribution of a quarterly newsletter, establishment of an electronic bulletin board, and holding periodic conference calls and public meetings. The newsletter is designed to reach the widest segment of the public and to be meaningful regardless of the reader's level of familiarity with the project. Periodic conference calls and meeting are used to reach the members of the public who have a real but periodic interest in the issues. The electronic bulletin board is used to communicate with a core group of stakeholders who have a continuing high interest in the total storage and disposition program. Initial indications are that these techniques are effective in reaching a wide segment of the public on highly technical and complex questions related to weapons grade nuclear materials. The effectiveness is not the result of these being new techniques but rather using each technique, to the maximum extent possible, to provide open, on-going, two way communications

  9. Communication on the structure of biological networks

    Indian Academy of Sciences (India)

    Introduction. Over the past few years, network science has drawn attention from a large number of ... The qualitative properties of biological networks cannot ... Here, we study the underlying undirected structure of empirical biological networks.

  10. From networked publics to issue publics

    DEFF Research Database (Denmark)

    Birkbak, Andreas

    2013-01-01

    As an increasing part of everyday life becomes connected with the web in many areas of the globe, the question of how the web mediates political processes becomes still more urgent. Several scholars have started to address this question by thinking about the web in terms of a public space....... In this paper, we aim to make a twofold contribution towards the development of the concept of publics in web science. First, we propose that although the notion of publics raises a variety of issues, two major concerns continue to be user privacy and democratic citizenship on the web. Well-known arguments hold......, this paper points towards an alternative way to think about publics by proposing a pragmatist reorientation of the public/private distinction in web science, away from seeing two spheres that needs to be kept separate, towards seeing the public and the private as something that is continuously connected...

  11. Low power radio communication platform for wireless sensor network

    NARCIS (Netherlands)

    Dutta, R.; Bentum, Marinus Jan; van der Zee, Ronan A.R.; Kokkeler, Andre B.J.

    2009-01-01

    Wireless sensor networks are predicted to be the most versatile, popular and useful technology in the near future. A large number of applications are targeted which will hugely benefit from a network of tiny computers with few sensors, radio communication platform, intelligent networking and

  12. Consensus in the network with uniform constant communication delay

    NARCIS (Netherlands)

    Wang, Xu; Saberi, Ali; Stoorvogel, Antonie Arij; Grip, H°avard Fjær; Yang, Tao

    2013-01-01

    This paper studies consensus among identical agents that are at most critically unstable and coupled through networks with uniform constant communication delay. An upper bound for delay tolerance is obtained which explicitly depends on agent dynamics and network topology. The dependence on network

  13. Large deviations for Gaussian queues modelling communication networks

    CERN Document Server

    Mandjes, Michel

    2007-01-01

    Michel Mandjes, Centre for Mathematics and Computer Science (CWI) Amsterdam, The Netherlands, and Professor, Faculty of Engineering, University of Twente. At CWI Mandjes is a senior researcher and Director of the Advanced Communications Network group.  He has published for 60 papers on queuing theory, networks, scheduling, and pricing of networks.

  14. Implementation of neuromorphic systems: from discrete components to analog VLSI chips (testing and communication issues).

    Science.gov (United States)

    Dante, V; Del Giudice, P; Mattia, M

    2001-01-01

    We review a series of implementations of electronic devices aiming at imitating to some extent structure and function of simple neural systems, with particular emphasis on communication issues. We first provide a short overview of general features of such "neuromorphic" devices and the implications of setting up "tests" for them. We then review the developments directly related to our work at the Istituto Superiore di Sanità (ISS): a pilot electronic neural network implementing a simple classifier, autonomously developing internal representations of incoming stimuli; an output network, collecting information from the previous classifier and extracting the relevant part to be forwarded to the observer; an analog, VLSI (very large scale integration) neural chip implementing a recurrent network of spiking neurons and plastic synapses, and the test setup for it; a board designed to interface the standard PCI (peripheral component interconnect) bus of a PC with a special purpose, asynchronous bus for communication among neuromorphic chips; a short and preliminary account of an application-oriented device, taking advantage of the above communication infrastructure.

  15. Complex networks in the Euclidean space of communicability distances

    Science.gov (United States)

    Estrada, Ernesto

    2012-06-01

    We study the properties of complex networks embedded in a Euclidean space of communicability distances. The communicability distance between two nodes is defined as the difference between the weighted sum of walks self-returning to the nodes and the weighted sum of walks going from one node to the other. We give some indications that the communicability distance identifies the least crowded routes in networks where simultaneous submission of packages is taking place. We define an index Q based on communicability and shortest path distances, which allows reinterpreting the “small-world” phenomenon as the region of minimum Q in the Watts-Strogatz model. It also allows the classification and analysis of networks with different efficiency of spatial uses. Consequently, the communicability distance displays unique features for the analysis of complex networks in different scenarios.

  16. Using Social Network Analysis to Investigate Positive EOL Communication.

    Science.gov (United States)

    Xu, Jiayun; Yang, Rumei; Wilson, Andrew; Reblin, Maija; Clayton, Margaret F; Ellington, Lee

    2018-04-30

    End of life (EOL) communication is a complex process involving the whole family and multiple care providers. Applications of analysis techniques that account for communication beyond the patient and patient/provider, will improve clinical understanding of EOL communication. To introduce the use of social network analysis to EOL communication data, and to provide an example of applying social network analysis to home hospice interactions. We provide a description of social network analysis using social network analysis to model communication patterns during home hospice nursing visits. We describe three social network attributes (i.e. magnitude, directionality, and reciprocity) in the expression of positive emotion among hospice nurses, family caregivers, and hospice cancer patients. Differences in communication structure by primary family caregiver gender and across time were also examined. Magnitude (frequency) in the expression of positive emotion occurred most often between nurses and caregivers or nurses and patients. Female caregivers directed more positive emotion to nurses, and nurses directed more positive emotion to other family caregivers when the primary family caregiver was male. Reciprocity (mutuality) in positive emotion declined towards day of death, but increased on day of actual patient death. There was variation in reciprocity by the type of positive emotion expressed. Our example demonstrates that social network analysis can be used to better understand the process of EOL communication. Social network analysis can be expanded to other areas of EOL research, such as EOL decision-making and health care teamwork. Copyright © 2018. Published by Elsevier Inc.

  17. Research of the key technology in satellite communication networks

    Science.gov (United States)

    Zeng, Yuan

    2018-02-01

    According to the prediction, in the next 10 years the wireless data traffic will be increased by 500-1000 times. Not only the wireless data traffic will be increased exponentially, and the demand for diversified traffic will be increased. Higher requirements for future mobile wireless communication system had brought huge market space for satellite communication system. At the same time, the space information networks had been greatly developed with the depth of human exploration of space activities, the development of space application, the expansion of military and civilian application. The core of spatial information networks is the satellite communication. The dissertation presented the communication system architecture, the communication protocol, the routing strategy, switch scheduling algorithm and the handoff strategy based on the satellite communication system. We built the simulation platform of the LEO satellites networks and simulated the key technology using OPNET.

  18. Design issues and applications of wireless sensor networks ...

    African Journals Online (AJOL)

    ... using tiny wireless sensor motes known as “smart dusts”, which have been made possible by advances in micro-electromechanical systems (MEMS) technology, wireless communications and digital electronics. Design considerations for the hardware and the topology necessary to realize these networks were evaluated.

  19. Communicative Dynamics and the Polyphony of Corporate Social Responsibility in the Network Society

    DEFF Research Database (Denmark)

    Castello, Itziar; Morsing, Mette; Schultz, Friederike

    2013-01-01

    This paper develops a media theoretical extension of the communicative view on corporate social responsibility by elaborating on the characteristics of network societies, arguing that new media increase the speed and connectivity, and lead to higher plurality and the potential polarization...... of reality constructions. We discuss the implications for corporate social responsibility of becoming more polyphonic and sketch the contours of “communicative legitimacy.” Finally, we present this special issue and develop some questions for future research....

  20. International scientific communication in the context of social networking sites for scientists

    OpenAIRE

    Stachowiak, Beata

    2016-01-01

    In this paper, the author considers the alterations that occurred in the international scientific communication. It is mainly technological development that exerts the influence over these alterations – particularly the emergence of new media. The major part of this paper is dedicated to the issue of the use of social networking sites in scientific communication. In her considerations, the author refers to the world-wide research pertaining to social media in the meantime demonstrating the at...

  1. Do learning collaboratives strengthen communication? A comparison of organizational team communication networks over time.

    Science.gov (United States)

    Bunger, Alicia C; Lengnick-Hall, Rebecca

    Collaborative learning models were designed to support quality improvements, such as innovation implementation by promoting communication within organizational teams. Yet the effect of collaborative learning approaches on organizational team communication during implementation is untested. The aim of this study was to explore change in communication patterns within teams from children's mental health organizations during a year-long learning collaborative focused on implementing a new treatment. We adopt a social network perspective to examine intraorganizational communication within each team and assess change in (a) the frequency of communication among team members, (b) communication across organizational hierarchies, and (c) the overall structure of team communication networks. A pretest-posttest design compared communication among 135 participants from 21 organizational teams at the start and end of a learning collaborative. At both time points, participants were asked to list the members of their team and rate the frequency of communication with each along a 7-point Likert scale. Several individual, pair-wise, and team level communication network metrics were calculated and compared over time. At the individual level, participants reported communicating with more team members by the end of the learning collaborative. Cross-hierarchical communication did not change. At the team level, these changes manifested differently depending on team size. In large teams, communication frequency increased, and networks grew denser and slightly less centralized. In small teams, communication frequency declined, growing more sparse and centralized. Results suggest that team communication patterns change minimally but evolve differently depending on size. Learning collaboratives may be more helpful for enhancing communication among larger teams; thus, managers might consider selecting and sending larger staff teams to learning collaboratives. This study highlights key future

  2. Communication Network Architectures Based on Ethernet Passive Optical Network for Offshore Wind Power Farms

    Directory of Open Access Journals (Sweden)

    Mohamed A. Ahmed

    2016-03-01

    Full Text Available Nowadays, with large-scale offshore wind power farms (WPFs becoming a reality, more efforts are needed to maintain a reliable communication network for WPF monitoring. Deployment topologies, redundancy, and network availability are the main items to enhance the communication reliability between wind turbines (WTs and control centers. Traditional communication networks for monitoring and control (i.e., supervisory control and data acquisition (SCADA systems using switched gigabit Ethernet will not be sufficient for the huge amount of data passing through the network. In this paper, the optical power budget, optical path loss, reliability, and network cost of the proposed Ethernet Passive Optical Network (EPON-based communication network for small-size offshore WPFs have been evaluated for five different network architectures. The proposed network model consists of an optical network unit device (ONU deployed on the WT side for collecting data from different internal networks. All ONUs from different WTs are connected to a central optical line terminal (OLT, placed in the control center. There are no active electronic elements used between the ONUs and the OLT, which reduces the costs and complexity of maintenance and deployment. As fiber access networks without any protection are characterized by poor reliability, three different protection schemes have been configured, explained, and discussed. Considering the cost of network components, the total implementation expense of different architectures with, or without, protection have been calculated and compared. The proposed network model can significantly contribute to the communication network architecture for next generation WPFs.

  3. New Communication Network Protocol for a Data Acquisition System

    Science.gov (United States)

    Uchida, T.; Fujii, H.; Nagasaka, Y.; Tanaka, M.

    2006-02-01

    An event builder based on communication networks has been used in high-energy physics experiments, and various networks have been adopted, for example, IEEE 802.3 (Ethernet), asynchronous transfer mode (ATM), and so on. In particular, Ethernet is widely used because its infrastructure is very cost effective. Many systems adopt standard protocols that are designed for a general network. However, in the case of an event builder, the communication pattern between stations is different from that in a general network. The unique communication pattern causes congestion, and thus makes it difficulty to quantitatively design the network. To solve this problem, we have developed a simple network protocol for a data acquisition (DAQ) system. The protocol is designed to keep the sequence of senders so that no congestion occurs. We implemented the protocol on a small hardware component [a field programmable gate array (FPGA)] and measured the performance, so that it will be ready for a generic DAQ system

  4. Communication networks and spatial ecology in nightingales

    NARCIS (Netherlands)

    Naguib, M.; Kunc, H.P.; Sprau, P.; Roth, T.; Amrhein, V.

    2011-01-01

    In most animals, communication plays a central role in a variety of contexts. In this chapter, we synthesize studies on vocal communication and spatial behavior in nightingales, Luscinia megarhynchos, with other research on songbirds to emphasize the need to integrate studies on communication with

  5. Use of communication architecture test bed to evaluate data network performance

    International Nuclear Information System (INIS)

    Clapp, N.E. Jr.; Swail, B.K.; Naser, J.A.

    1994-01-01

    Local area networks (LANs) are becoming more prevalent in nuclear power plants. Traditionally, LANs were only used as information highways, providing office automation services. LANs are now being used as data highways for applications in plant data acquisition and control systems. A communication architecture test bed, which contains network simulators, is needed to allow network performance studies and to resolve design issues prior to equipment purchase. Two levels of granularity of simulation are needed to provide the dynamic information about network performance. A coarse-grain simulator is used to estimate the dynamic performance of the network due to major resources such as workstations, gateways, and data acquisition systems. A fine-grain simulator allows a greater level of detail about the underlying network protocol and resources to be simulated. The combination of coarse-grain and fine-grain simulation packages provides the network designer with the required tools to thoroughly understand the behavior of the modeled network. This paper describes the development of a communication architecture test bed using commercial network simulation packages. Network simulators allow the resolution of major design issues in software without the expense of purchasing costly hardware components

  6. 5th International Conference on Electronics, Communications and Networks

    CERN Document Server

    2016-01-01

    This book comprises peer-reviewed contributions presented at the 5th International Conference on Electronics, Communications and Networks (CECNet 2015), held in Shanghai, China, 12-15 December, 2015. It includes new multi-disciplinary topics spanning a unique depth and breadth of cutting-edge research areas in Electronic Engineering, Communications and Networks, and Computer Technology. More generally, it is of interest to academics, students and professionals involved in Consumer Electronics Technology, Communication Engineering and Technology, Wireless Communication Systems and Technology, and Computer Engineering and Technology.

  7. Communication and Health - themes, issues and Latin American perspectives

    OpenAIRE

    Araujo, Inesita Soares de; Cabrera, Jesús Arroyave

    2012-01-01

    Editorial Reciis Vol 6, No. 4 -. Communication and Health - themes, issues and Latin American perspectives Editorial Vol Reciis 6, No. 4 -. De Comunicación y Salud - temas, problemas y perspectivas de América Latina A Comunicação e Saúde vem conhecendo nas duas últimas décadas uma grande expansão. Formada na interface de dois campos solidamente constituídos – o da Comunicação e o da Saúde – e frequentemente articulada com os da Ciência &Tecnologia e da Educação, a Comunicação e Saúd...

  8. An Interdisciplinary Network Making Progress on Climate Change Communication

    Science.gov (United States)

    Spitzer, W.; Anderson, J. C.; Bales, S.; Fraser, J.; Yoder, J. A.

    2012-12-01

    , social scientists, Ph.D. students studying oceanography, and staff from more than 20 institutions that teach science to the public came together in these learning groups. Most participants were motivated to create new or revised training or public programs based on lessons learned together. The success of this program rests on a twofold approach that combines collaborative learning with a cognitive and social sciences research based approach to communications. The learning process facilitated trust and experimentation among co-learners to practice applications for communications that has continued beyond the study circle experience through the networks established during the process. Examples drawn from the study circle outputs suggest that this approach could have a transformative impact on informal science education on a broad scale. Ultimately, we envision informal science interpreters as "vectors" for effective science communication, ocean and climate scientists with enhanced communication skills, and increased public demand for explanation and dialogue about global issues.

  9. Advanced Communication and Networking Technologies for Mars Exploration

    Science.gov (United States)

    Bhasin, Kul; Hayden, Jeff; Agre, Jonathan R.; Clare, Loren P.; Yan, Tsun-Yee

    2001-01-01

    Next-generation Mars communications networks will provide communications and navigation services to a wide variety of Mars science vehicles including: spacecraft that are arriving at Mars, spacecraft that are entering and descending in the Mars atmosphere, scientific orbiter spacecraft, spacecraft that return Mars samples to Earth, landers, rovers, aerobots, airplanes, and sensing pods. In the current architecture plans, the communication services will be provided using capabilities deployed on the science vehicles as well as dedicated communication satellites that will together make up the Mars network. This network will evolve as additional vehicles arrive, depart or end their useful missions. Cost savings and increased reliability will result from the ability to share communication services between missions. This paper discusses the basic architecture that is needed to support the Mars Communications Network part of NASA's Space Science Enterprise (SSE) communications architecture. The network may use various networking technologies such as those employed in the terrestrial Internet, as well as special purpose deep-space protocols to move data and commands autonomously between vehicles, at disparate Mars vicinity sites (on the surface or in near-Mars space) and between Mars vehicles and earthbound users. The architecture of the spacecraft on-board local communications is being reconsidered in light of these new networking requirements. The trend towards increasingly autonomous operation of the spacecraft is aimed at reducing the dependence on resource scheduling provided by Earth-based operators and increasing system fault tolerance. However, these benefits will result in increased communication and software development requirements. As a result, the envisioned Mars communications infrastructure requires both hardware and protocol technology advancements. This paper will describe a number of the critical technology needs and some of the ongoing research

  10. Northern emporia and maritime networks. Modelling past communication using archaeological network analysis

    DEFF Research Database (Denmark)

    Sindbæk, Søren Michael

    2015-01-01

    preserve patterns of thisinteraction. Formal network analysis and modelling holds the potential to identify anddemonstrate such patterns, where traditional methods often prove inadequate. Thearchaeological study of communication networks in the past, however, calls for radically different analytical...... this is not a problem of network analysis, but network synthesis: theclassic problem of cracking codes or reconstructing black-box circuits. It is proposedthat archaeological approaches to network synthesis must involve a contextualreading of network data: observations arising from individual contexts, morphologies...

  11. A network architecture for International Business Satellite communications

    Science.gov (United States)

    Takahata, Fumio; Nohara, Mitsuo; Takeuchi, Yoshio

    Demand Assignment (DA) control is expected to be introduced in the International Business Satellte communications (IBS) network in order to cope with a growing international business traffic. The paper discusses the DA/IBS network from the viewpoints of network configuration, satellite channel configuration and DA control. The network configuration proposed here consists of one Central Station with network management function and several Network Coordination Stations with user management function. A satellite channel configuration is also presented along with a tradeoff study on transmission bit rate, high power amplifier output power requirement, and service quality. The DA control flow and protocol based on CCITT Signalling System No. 7 are also proposed.

  12. Design issues for semi-passive optical communication devices

    Science.gov (United States)

    Glaser, I.

    2007-09-01

    Optical smart cards are devices containing a retro-reflector, light modulator, and some computing and data storage capabilities to affect semi-passive communication. They do not produce light; instead they modulate and send back light received from a stationary unit. These devices can replace contact-based smart cards as well as RF based ones for applications ranging from identification to transmitting and validating data. Since their transmission is essentially focused on the receiving unit, they are harder to eavesdrop than RF devices, yet need no physical contact or alignment. In this paper we explore optical design issues of these devices and estimate their optical behavior. Specifically, we analyze how these compact devices can be optimized for selected application profiles. Some of the key parameters addressed are effective light efficiency (how much modulated signal can be received by the stationary unit given the amount of light it transmits), range of tilt angles (angle between device surface normal to the line connecting the optical smart card with the stationary unit) through which the device would be effective, and power requirements of the semi-passive unit. In addition, issues concerning compact packaging of this device are discussed. Finally, results of the analysis are employed to produce a comparison of achievable capabilities of these optical smart cards, as opposed to alternative devices, and discuss potential applications were they can be best utilized.

  13. Cryptanalysis and improvement of quantum secure communication network protocol with entangled photons for mobile communications

    International Nuclear Information System (INIS)

    Gao, Gan

    2014-01-01

    Recently, a communication protocol called controlled bidirectional quantum secret direct communication for mobile networks was proposed by Chou et al (2014 Mobile Netw. Appl. 19 121). We study the security of the proposed communication protocol and find that it is not secure. The controller, Telecom Company, may eavesdrop secret messages from mobile devices without being detected. Finally, we give a possible improvement of the communication protocol. (paper)

  14. Communication networks of men facing a diagnosis of prostate cancer.

    Science.gov (United States)

    Brown, Dot; Oetzel, John; Henderson, Alison

    2016-11-01

    This study seeks to identify the factors that shape the communication networks of men who face a potential diagnosis of prostate cancer, and how these factors relate to their disclosure about their changing health status. Men facing a potential diagnosis of prostate cancer are in a challenging situation; the support benefits of disclosing their changing health status to others in their communication networks is set against a backdrop of the potential stigma and uncertainty of the diagnosis. All men on a prostate biopsy waiting list were eligible for inclusion in an exploratory and interpretive study. Semi-structured interviews with 40 men explored their network structures and disclosure of health information. Thematic analysis highlighted the factors which contributed to their network structures and their disclosure about their health status. Four network factors shaped men's perspectives about disclosing their health status: (1) tie strength, comprising both strong and weak ties; (2) knowledgeable others, with a focus on medical professionals in the family; (3) homophily, which included other individuals with a similar medical condition; and (4) geographical proximity, with a preference for face-to-face communication. Communication networks influence men's disclosure of their health status and in particular weak ties with medical knowledge have an important role. Men who use the potential for support in their networks may experience improved psychosocial outcomes. Using these four network factors-tie strength, knowledgeable others, homophily or geographical proximity-to forecast men's willingness to disclose helps identify men who lack potential support and so are at risk of poor psychosocial health. Those with few strong ties or knowledgeable others in their networks may be in the at-risk cohort. The support provided in communication networks complements formal medical care from nurses and other health professionals, and encouraging patients to use their

  15. Tactical Voice Communications Over Shipboard Local Area Networks

    National Research Council Canada - National Science Library

    Urie, Glenn

    2001-01-01

    The United States Navy's next generation ship(s) scheduled for commissioning in the year 2004 and beyond will integrate tactical shipboard voice communications system into the local area network (LAN...

  16. Wideband autonomous cognitive radios for networked satellites communications, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — There is growing recognition that success in a variety of space mission types can be greatly enhanced by making current communication transceivers and networks...

  17. Stabilization of Networked Control Systems Under Feedback-based Communication

    National Research Council Canada - National Science Library

    Zhang, Lei; Hristu-Varsakelis, Dimitrios

    2004-01-01

    We study the stabilization of a networked control system (NSC) in which multiple sensors and actuators of a physical plant share a communication medium to exchange information with a remote controller...

  18. Synchronization of Switched Neural Networks With Communication Delays via the Event-Triggered Control.

    Science.gov (United States)

    Wen, Shiping; Zeng, Zhigang; Chen, Michael Z Q; Huang, Tingwen

    2017-10-01

    This paper addresses the issue of synchronization of switched delayed neural networks with communication delays via event-triggered control. For synchronizing coupled switched neural networks, we propose a novel event-triggered control law which could greatly reduce the number of control updates for synchronization tasks of coupled switched neural networks involving embedded microprocessors with limited on-board resources. The control signals are driven by properly defined events, which depend on the measurement errors and current-sampled states. By using a delay system method, a novel model of synchronization error system with delays is proposed with the communication delays and event-triggered control in the unified framework for coupled switched neural networks. The criteria are derived for the event-triggered synchronization analysis and control synthesis of switched neural networks via the Lyapunov-Krasovskii functional method and free weighting matrix approach. A numerical example is elaborated on to illustrate the effectiveness of the derived results.

  19. 2014 International Conference on Wireless Communications, Networking and Applications

    CERN Document Server

    2016-01-01

    This book is based on a series of conferences on Wireless Communications, Networking and Applications that have been held on December 27-28, 2014 in Shenzhen, China. The meetings themselves were a response to technological developments in the areas of wireless communications, networking and applications and facilitate researchers, engineers and students to share the latest research results and the advanced research methods of the field. The broad variety of disciplines involved in this research and the differences in approaching the basic problems are probably typical of a developing field of interdisciplinary research. However, some main areas of research and development in the emerging areas of wireless communication technology can now be identified. The contributions to this book are mainly selected from the papers of the conference on wireless communications, networking and applications and reflect the main areas of interest: Section 1 - Emerging Topics in Wireless and Mobile Computing and Communications...

  20. Wireless Sensor Network Based Smart Grid Communications: Cyber Attacks, Intrusion Detection System and Topology Control

    Directory of Open Access Journals (Sweden)

    Lipi Chhaya

    2017-01-01

    Full Text Available The existing power grid is going through a massive transformation. Smart grid technology is a radical approach for improvisation in prevailing power grid. Integration of electrical and communication infrastructure is inevitable for the deployment of Smart grid network. Smart grid technology is characterized by full duplex communication, automatic metering infrastructure, renewable energy integration, distribution automation and complete monitoring and control of entire power grid. Wireless sensor networks (WSNs are small micro electrical mechanical systems that are deployed to collect and communicate the data from surroundings. WSNs can be used for monitoring and control of smart grid assets. Security of wireless sensor based communication network is a major concern for researchers and developers. The limited processing capabilities of wireless sensor networks make them more vulnerable to cyber-attacks. The countermeasures against cyber-attacks must be less complex with an ability to offer confidentiality, data readiness and integrity. The address oriented design and development approach for usual communication network requires a paradigm shift to design data oriented WSN architecture. WSN security is an inevitable part of smart grid cyber security. This paper is expected to serve as a comprehensive assessment and analysis of communication standards, cyber security issues and solutions for WSN based smart grid infrastructure.

  1. Mesh Network Architecture for Enabling Inter-Spacecraft Communication

    Science.gov (United States)

    Becker, Christopher; Merrill, Garrick

    2017-01-01

    To enable communication between spacecraft operating in a formation or small constellation, a mesh network architecture was developed and tested using a time division multiple access (TDMA) communication scheme. The network is designed to allow for the exchange of telemetry and other data between spacecraft to enable collaboration between small spacecraft. The system uses a peer-to-peer topology with no central router, so that it does not have a single point of failure. The mesh network is dynamically configurable to allow for addition and subtraction of new spacecraft into the communication network. Flight testing was performed using an unmanned aerial system (UAS) formation acting as a spacecraft analogue and providing a stressing environment to prove mesh network performance. The mesh network was primarily devised to provide low latency, high frequency communication but is flexible and can also be configured to provide higher bandwidth for applications desiring high data throughput. The network includes a relay functionality that extends the maximum range between spacecraft in the network by relaying data from node to node. The mesh network control is implemented completely in software making it hardware agnostic, thereby allowing it to function with a wide variety of existing radios and computing platforms..

  2. Successive lag synchronization on dynamical networks with communication delay

    International Nuclear Information System (INIS)

    Zhang Xin-Jian; Wei Ai-Ju; Li Ke-Zan

    2016-01-01

    In this paper, successive lag synchronization (SLS) on a dynamical network with communication delay is investigated. In order to achieve SLS on the dynamical network with communication delay, we design linear feedback control and adaptive control, respectively. By using the Lyapunov function method, we obtain some sufficient conditions for global stability of SLS. To verify these results, some numerical examples are further presented. This work may find potential applications in consensus of multi-agent systems. (paper)

  3. Utility communication networks and services specification, deployment and operation

    CERN Document Server

    2017-01-01

    This CIGRE green book begins by addressing the specification and provision of communication services in the context of operational applications for electrical power utilities, before subsequently providing guidelines on the deployment or transformation of networks to deliver these specific communication services. Lastly, it demonstrates how these networks and their services can be monitored, operated, and maintained to ensure that the requisite high level of service quality is consistently achieved.

  4. Advances in neural networks computational and theoretical issues

    CERN Document Server

    Esposito, Anna; Morabito, Francesco

    2015-01-01

    This book collects research works that exploit neural networks and machine learning techniques from a multidisciplinary perspective. Subjects covered include theoretical, methodological and computational topics which are grouped together into chapters devoted to the discussion of novelties and innovations related to the field of Artificial Neural Networks as well as the use of neural networks for applications, pattern recognition, signal processing, and special topics such as the detection and recognition of multimodal emotional expressions and daily cognitive functions, and  bio-inspired memristor-based networks.  Providing insights into the latest research interest from a pool of international experts coming from different research fields, the volume becomes valuable to all those with any interest in a holistic approach to implement believable, autonomous, adaptive, and context-aware Information Communication Technologies.

  5. Advanced communication and network requirements in Europe

    DEFF Research Database (Denmark)

    Falch, Morten; Enemark, Rasmus

    The report address diffusion of new tele-application, focusing on potential use and potential tele-trafic genrated as a consequense. The applications investigated are: Teleworking, distance learning, research and university network, applications aimed at SMEs, health networks, a trans European pu...... public administation network, city information highway, road-trafic manegement, air traffic control and electronic quotation.......The report address diffusion of new tele-application, focusing on potential use and potential tele-trafic genrated as a consequense. The applications investigated are: Teleworking, distance learning, research and university network, applications aimed at SMEs, health networks, a trans European...

  6. Design of Hybrid Mobile Communication Networks for Planetary Exploration

    Science.gov (United States)

    Alena, Richard L.; Ossenfort, John; Lee, Charles; Walker, Edward; Stone, Thom

    2004-01-01

    The Mobile Exploration System Project (MEX) at NASA Ames Research Center has been conducting studies into hybrid communication networks for future planetary missions. These networks consist of space-based communication assets connected to ground-based Internets and planetary surface-based mobile wireless networks. These hybrid mobile networks have been deployed in rugged field locations in the American desert and the Canadian arctic for support of science and simulation activities on at least six occasions. This work has been conducted over the past five years resulting in evolving architectural complexity, improved component characteristics and better analysis and test methods. A rich set of data and techniques have resulted from the development and field testing of the communication network during field expeditions such as the Haughton Mars Project and NASA Mobile Agents Project.

  7. True Nature of Supply Network Communication Structure

    Directory of Open Access Journals (Sweden)

    Lokhman Hakim bin Osman

    2016-04-01

    Full Text Available Globalization of world economy has altered the definition of organizational structure. Global supply chain can no longer be viewed as an arm-length structure. It has become more complex. The complexity demands deeper research and understanding. This research analyzed a structure of supply network in an attempt to elucidate the true structure of the supply network. Using the quantitative Social Network Analysis methodology, findings of this study indicated that, the structure of the supply network differs depending on the types of network relations. An important implication of these findings would be a more focus resource management upon network relationship development that is based on firms’ positions in the different network structure. This research also contributes to the various strategies of effective and efficient supply chain management.

  8. Using Social Networking Sites for Communicable Disease Control: Innovative Contact Tracing or Breach of Confidentiality?

    Science.gov (United States)

    Mandeville, Kate L; Harris, Matthew; Thomas, H Lucy; Chow, Yimmy; Seng, Claude

    2014-04-01

    Social media applications such as Twitter, YouTube and Facebook have attained huge popularity, with more than three billion people and organizations predicted to have a social networking account by 2015. Social media offers a rapid avenue of communication with the public and has potential benefits for communicable disease control and surveillance. However, its application in everyday public health practice raises a number of important issues around confidentiality and autonomy. We report here a case from local level health protection where the friend of an individual with meningococcal septicaemia used a social networking site to notify potential contacts.

  9. Emergency Communications Network for Disasters Management in Venezuela

    Science.gov (United States)

    Burguillos, C.; Deng, H.

    2018-04-01

    The integration and use of different space technology applications for disasters management, play an important role at the time of prevents the causes and mitigates the effects of the natural disasters. Nevertheless, the space technology counts with the appropriate technological resources to provide the accurate and timely information required to support in the decision making in case of disasters. Considering the aforementioned aspects, in this research is presented the design and implementation of an Emergency Communications Network for Disasters Management in Venezuela. Network based on the design of a topology that integrates the satellites platforms in orbit operation under administration of Venezuelan state, such as: the communications satellite VENESAT-1 and the remote sensing satellites VRSS-1 and VRSS-2; as well as their ground stations with the aim to implement an emergency communications network to be activated in case of disasters which affect the public and private communications infrastructures in Venezuela. In this regard, to design the network several technical and operational specifications were formulated, between them: Emergency Strategies to Maneuver the VRSS-1 and VRSS-2 satellites for optimal images capture and processing, characterization of the VENESAT-1 transponders and radiofrequencies for emergency communications services, technologies solutions formulation and communications links design for disaster management. As result, the emergency network designed allows to put in practice diverse communications technologies solutions and different scheme or media for images exchange between the areas affected for disasters and the entities involved in the disasters management tasks, providing useful data for emergency response and infrastructures recovery.

  10. Understanding Team Communication Characteristics using Social Network Analysis

    International Nuclear Information System (INIS)

    Kim, Ar Ryum; Lee, Seung Woo; Seong, Poong Hyun; Park, Jin Kyun

    2011-01-01

    An important aspect of human behavior in nuclear power plants (NPPs) is team interaction since operating NPPs involves the coordination of several team members among and within workplaces. Since operators in main control room (MCR) get a great deal of information through communication to perform a task, communication is one of the important characteristics for team characteristics. Many researchers have been studying how to understand the characteristics of communication. Social network analysis (SNA) which is considered as an objective and easily applicable method has been already applied in many fields to investigate characteristics of team communication. Henttonen (2010) has struggled to perform the research on the impact of social networks in a team and he found some team communication characteristics could be obtained using some properties of SNA. In this paper, SNA is used to understand communication characteristics within operators in NPPs

  11. Single-shot secure quantum network coding on butterfly network with free public communication

    Science.gov (United States)

    Owari, Masaki; Kato, Go; Hayashi, Masahito

    2018-01-01

    Quantum network coding on the butterfly network has been studied as a typical example of quantum multiple cast network. We propose a secure quantum network code for the butterfly network with free public classical communication in the multiple unicast setting under restricted eavesdropper’s power. This protocol certainly transmits quantum states when there is no attack. We also show the secrecy with shared randomness as additional resource when the eavesdropper wiretaps one of the channels in the butterfly network and also derives the information sending through public classical communication. Our protocol does not require verification process, which ensures single-shot security.

  12. The communications model of using social network by sports clubs

    OpenAIRE

    S. Kowalski

    2012-01-01

    This article presents a model of marketing communications using social network by sports clubs. It presents the links between the sports club and its environment and uses of the Internet to promote it. The model of communication is composed of the elements responsible for the success of marketing in the web. Article also includes recommendations for using the model in practice.

  13. Analyzing Human Communication Networks in Organizations: Applications to Management Problems.

    Science.gov (United States)

    Farace, Richard V.; Danowski, James A.

    Investigating the networks of communication in organizations leads to an understanding of efficient and inefficient information dissemination as practiced in large systems. Most important in organizational communication is the role of the "liaison person"--the coordinator of intercommunication. When functioning efficiently, coordinators maintain…

  14. Does the upgrading of the radio communications network in health ...

    African Journals Online (AJOL)

    In an attempt to strengthen the obstetric referral system, the Safe Motherhood Project installed a repeater-based VHF radio communication system in three pilot districts. The overall goal of the new network was to enable the health centers to communicate directly to their district health offices (DHOs) for an ambulance when ...

  15. Synchrophasor Sensor Networks for Grid Communication and Protection.

    Science.gov (United States)

    Gharavi, Hamid; Hu, Bin

    2017-07-01

    This paper focuses primarily on leveraging synchronized current/voltage amplitudes and phase angle measurements to foster new categories of applications, such as improving the effectiveness of grid protection and minimizing outage duration for distributed grid systems. The motivation for such an application arises from the fact that with the support of communication, synchronized measurements from multiple sites in a grid network can greatly enhance the accuracy and timeliness of identifying the source of instabilities. The paper first provides an overview of synchrophasor networks and then presents techniques for power quality assessment, including fault detection and protection. To achieve this we present a new synchrophasor data partitioning scheme that is based on the formation of a joint space and time observation vector. Since communication is an integral part of synchrophasor networks, the newly adopted wireless standard for machine-to-machine (M2M) communication, known as IEEE 802.11ah, has been investigated. The paper also presents a novel implementation of a hardware in the loop testbed for real-time performance evaluation. The purpose is to illustrate the use of both hardware and software tools to verify the performance of synchrophasor networks under more realistic environments. The testbed is a combination of grid network modeling, and an Emulab-based communication network. The combined grid and communication network is then used to assess power quality for fault detection and location using the IEEE 39-bus and 390-bus systems.

  16. Approaching socio-technical issues in Knowledge Communication

    DEFF Research Database (Denmark)

    Kampf, Constance; Islas Sedano, Carolina

    2008-01-01

    This paper looks at the connection between technology, knowledge management and knowledge communication theory from a process perspective. Knowledge management and knowledge communication processes are examined through the iterations in creating project goals and objectives which connect the social...... and objectives with respect to knowledge communication theory, demonstrating the potential of knowledge communication concepts for socio-technical design processes, as well as the implications of socio-technical design processes in extending our understanding of knowledge communication....

  17. Network analysis of team communication in a busy emergency department

    Science.gov (United States)

    2013-01-01

    Background The Emergency Department (ED) is consistently described as a high-risk environment for patients and clinicians that demands colleagues quickly work together as a cohesive group. Communication between nurses, physicians, and other ED clinicians is complex and difficult to track. A clear understanding of communications in the ED is lacking, which has a potentially negative impact on the design and effectiveness of interventions to improve communications. We sought to use Social Network Analysis (SNA) to characterize communication between clinicians in the ED. Methods Over three-months, we surveyed to solicit the communication relationships between clinicians at one urban academic ED across all shifts. We abstracted survey responses into matrices, calculated three standard SNA measures (network density, network centralization, and in-degree centrality), and presented findings stratified by night/day shift and over time. Results We received surveys from 82% of eligible participants and identified wide variation in the magnitude of communication cohesion (density) and concentration of communication between clinicians (centralization) by day/night shift and over time. We also identified variation in in-degree centrality (a measure of power/influence) by day/night shift and over time. Conclusions We show that SNA measurement techniques provide a comprehensive view of ED communication patterns. Our use of SNA revealed that frequency of communication as a measure of interdependencies between ED clinicians varies by day/night shift and over time. PMID:23521890

  18. Human-Centric Wireless Communication Networks

    OpenAIRE

    Cavallari, Riccardo

    2016-01-01

    This thesis covers two main topics: the design and performance evaluation of Wireless Body Area Networks (WBANs), and the simulation and mathematical modeling of Delay Tolerant Networks (DTNs). Different Medium Access Control (MAC) protocols for WBANs are implemented on dedicated hardware in order to evaluate, through extensive measurement campaigns, the performance of the network in terms of packet loss rate, delay and energy consumption. Novel solutions to cope with bo...

  19. Cognitive Radio Networks for Tactical Wireless Communications

    Science.gov (United States)

    2014-12-01

    exists. Instead, security is an evolving process, as we have seen in the context of WLANs and 2G / 3G networks. New system vulnerabilities continue to...in the network configuration and radio parameters take place due to mobility of platforms, and variation in other users of the RF environment. CRNs...dynamic spectrum access experimentally, and it represents the largest military Mobile Ad hoc Network (MANET) as of today. The WNaN demonstrator has been

  20. Comparative Analysis of Human Communication Networks in Selected Formal Organizations.

    Science.gov (United States)

    Farace, Richard V.; Johnson, Jerome David

    This paper briefly describes the organization of a "data bank" containing research on communication networks, specifies the kinds of information compiled about various network properties, discusses some specific results of the work done to date, and presents some general conclusions about the overall project and its potential advantages to…

  1. Real-Time Communication in Wireless Home Networks

    NARCIS (Netherlands)

    Scholten, Johan; Jansen, P.G.

    This paper describes a medium access protocol for real-time communication in wireless networks. Medium access is controlled by a scheduler, which utilizes a pre-emptive earliest deadline first (PEDF) scheduling algorithm. The scheduler prevents collisions in the network, where normally only

  2. Seamless integrated network system for wireless communication systems

    NARCIS (Netherlands)

    Wu, Gang; Mizuno, Mitsuhiko; Hase, Yoshihiro; Havinga, Paul J.M.

    2006-01-01

    To create a network that connects a plurality of wireless communication systems to create optimal systems for various environments, and that seamlessly integrates the resulting systems together in order to provide more efficient and advanced service in general. A network system that can seamlessly

  3. Seamless integrated network system for wireless communication systems

    NARCIS (Netherlands)

    Wu, Gang; Mizuno, Mitsuhiko; Hase, Yoshihiro; Havinga, Paul J.M.

    2002-01-01

    To create a network that connects a plurality of wireless communication systems to create optimal systems for various environments, and that seamlessly integrates the resulting systems together in order to provide more efficient and advanced service in general. A network system that can seamlessly

  4. Designing communication and remote controlling of virtual instrument network system

    Science.gov (United States)

    Lei, Lin; Wang, Houjun; Zhou, Xue; Zhou, Wenjian

    2005-01-01

    In this paper, a virtual instrument network through the LAN and finally remote control of virtual instruments is realized based on virtual instrument and LabWindows/CVI software platform. The virtual instrument network system is made up of three subsystems. There are server subsystem, telnet client subsystem and local instrument control subsystem. This paper introduced virtual instrument network structure in detail based on LabWindows. Application procedure design of virtual instrument network communication, the Client/the programming mode of the server, remote PC and server communication far realizing, the control power of the workstation is transmitted, server program and so on essential technical were introduced. And virtual instruments network may connect to entire Internet on. Above-mentioned technology, through measuring the application in the electronic measurement virtual instrument network that is already built up, has verified the actual using value of the technology. Experiment and application validate that this design is resultful.

  5. Designing communication and remote controlling of virtual instrument network system

    International Nuclear Information System (INIS)

    Lei Lin; Wang Houjun; Zhou Xue; Zhou Wenjian

    2005-01-01

    In this paper, a virtual instrument network through the LAN and finally remote control of virtual instruments is realized based on virtual instrument and LabWindows/CVI software platform. The virtual instrument network system is made up of three subsystems. There are server subsystem, telnet client subsystem and local instrument control subsystem. This paper introduced virtual instrument network structure in detail based on LabWindows. Application procedure design of virtual instrument network communication, the Client/the programming mode of the server, remote PC and server communication far realizing, the control power of the workstation is transmitted, server program and so on essential technical were introduced. And virtual instruments network may connect to entire Internet on. Above-mentioned technology, through measuring the application in the electronic measurement virtual instrument network that is already built up, has verified the actual using value of the technology. Experiment and application validate that this design is resultful

  6. Quantum communication network utilizing quadripartite entangled states of optical field

    International Nuclear Information System (INIS)

    Shen Heng; Su Xiaolong; Jia Xiaojun; Xie Changde

    2009-01-01

    We propose two types of quantum dense coding communication networks with optical continuous variables, in which a quadripartite entangled state of the optical field with totally three-party correlations of quadrature amplitudes is utilized. In the networks, the exchange of information between any two participants can be manipulated by one or two of the remaining participants. The channel capacities for a variety of communication protocols are numerically calculated. Due to the fact that the quadripartite entangled states applied in the communication systems have been successfully prepared already in the laboratory, the proposed schemes are experimentally accessible at present.

  7. Converting serial networks to Ethernet communications

    Energy Technology Data Exchange (ETDEWEB)

    Rosado, Elroy [Freewave Technologies, Inc., Boulder, CO (United States). Latin America

    2008-07-01

    Many oil and gas producers and pipeline companies find themselves in an awkward position. They have invested millions of dollars in legacy serial communications systems and in most cases, millions more in older SCADA remote terminal units and electronic flow meters. There is a desire throughout most of the industry to convert these systems to Ethernet. This presentation will explore how Ethernet protocol offers advantages over the older serial communications in terms of peer to peer communication, faster polling cycles, and the ability to poll multiple devices at the same time. (author)

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

    Science.gov (United States)

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

    2013-01-01

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

  9. Message transfer in a communication network

    Indian Academy of Sciences (India)

    Examples of transport processes on networks include the traffic of informa- tion packets [1–4], transport processes on biological networks [5,6], and road traffic. ... for this system. In the case of single message transfer, we study the dependence of average travel times on the hub density, and find that travel times fall off as a.

  10. Network Coding Protocols for Smart Grid Communications

    DEFF Research Database (Denmark)

    Prior, Rui; Roetter, Daniel Enrique Lucani; Phulpin, Yannick

    2014-01-01

    We propose a robust network coding protocol for enhancing the reliability and speed of data gathering in smart grids. At the heart of our protocol lies the idea of tunable sparse network coding, which adopts the transmission of sparsely coded packets at the beginning of the transmission process b...

  11. Quantum Communication Through a Two-Dimensional Spin Network

    International Nuclear Information System (INIS)

    Wang Zhaoming; Gu Yongjian

    2012-01-01

    We investigate the state or entanglement transfer through a two-dimensional spin network. We show that for state transfer, better fidelity can be gained along the diagonal direction but for entanglement transfer, when the initial entanglement is created along the boundary, the concurrence is more inclined to propagate along the boundary. This behavior is produced by quantum mechanical interference and the communication quality depends on the precise size of the network. For some number of sites, the fidelity in a two-dimensional channel is higher than one-dimensional case. This is an important result for realizing quantum communication through high dimension spin chain networks.

  12. Space Mobile Network: A Near Earth Communication and Navigation Architecture

    Science.gov (United States)

    Israel, Dave J.; Heckler, Greg; Menrad, Robert J.

    2016-01-01

    This paper describes a Space Mobile Network architecture, the result of a recently completed NASA study exploring architectural concepts to produce a vision for the future Near Earth communications and navigation systems. The Space Mobile Network (SMN) incorporates technologies, such as Disruption Tolerant Networking (DTN) and optical communications, and new operations concepts, such as User Initiated Services, to provide user services analogous to a terrestrial smartphone user. The paper will describe the SMN Architecture, envisioned future operations concepts, opportunities for industry and international collaboration and interoperability, and technology development areas and goals.

  13. Online social networking issues within academia and pharmacy education.

    Science.gov (United States)

    Cain, Jeff

    2008-02-15

    Online social networking sites such as Facebook and MySpace are extremely popular as indicated by the numbers of members and visits to the sites. They allow students to connect with users with similar interests, build and maintain relationships with friends, and feel more connected with their campus. The foremost criticisms of online social networking are that students may open themselves to public scrutiny of their online personas and risk physical safety by revealing excessive personal information. This review outlines issues of online social networking in higher education by drawing upon articles in both the lay press and academic publications. New points for pharmacy educators to consider include the possible emergence of an "e-professionalism" concept; legal and ethical implications of using online postings in admission, discipline, and student safety decisions; how online personas may blend into professional life; and the responsibility for educating students about the risks of online social networking.

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

    Science.gov (United States)

    Le, Nam-Tuan

    2017-05-01

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

  15. Development of network communication function for digitalized neutron flux monitoring instrument

    International Nuclear Information System (INIS)

    Li Kai; Zhang Liangju; Chen Xiaojun; Li Baoxiang

    2002-01-01

    It is essential for a digitalized Neutron Flux Monitoring Instrument to communicate with other parts of Instrumentation and Control System in a network environment, and it is fairly different from the case of traditional analogue nuclear instrumentation. How to satisfy all the requirements of different network structure and communication protocol, which might be adopted in different target nuclear power plant, is a key issue in the design and development of a digitalized neutron flux monitoring instrument. The author describes the overall communication scheme, mainly discusses the design idea and the requirements of the communication interfaces and the implementation of the RS-485 interface as an example of the digitalized neutron flux monitoring instrument, which is under development in the institute

  16. Emergence of communication in socio-biological networks

    CERN Document Server

    Berea, Anamaria

    2018-01-01

    This book integrates current advances in biology, economics of information and linguistics research through applications using agent-based modeling and social network analysis to develop scenarios of communication and language emergence in the social aspects of biological communications. The book presents a model of communication emergence that can be applied both to human and non-human living organism networks. The model is based on economic concepts and individual behavior fundamental for the study of trust and reputation networks in social science, particularly in economics; it is also based on the theory of the emergence of norms and historical path dependence that has been influential in institutional economics. Also included are mathematical models and code for agent-based models to explore various scenarios of language evolution, as well as a computer application that explores language and communication in biological versus social organisms, and the emergence of various meanings and grammars in human ...

  17. Power, Avionics and Software Communication Network Architecture

    Science.gov (United States)

    Ivancic, William D.; Sands, Obed S.; Bakula, Casey J.; Oldham, Daniel R.; Wright, Ted; Bradish, Martin A.; Klebau, Joseph M.

    2014-01-01

    This document describes the communication architecture for the Power, Avionics and Software (PAS) 2.0 subsystem for the Advanced Extravehicular Mobile Unit (AEMU). The following systems are described in detail: Caution Warn- ing and Control System, Informatics, Storage, Video, Audio, Communication, and Monitoring Test and Validation. This document also provides some background as well as the purpose and goals of the PAS project at Glenn Research Center (GRC).

  18. Proceedings of International Conference on Communication and Networks

    CERN Document Server

    Verma, Pramode; Trivedi, Bhushan

    2017-01-01

    The volume contains 75 papers presented at International Conference on Communication and Networks (COMNET 2015) held during February 19–20, 2016 at Ahmedabad Management Association (AMA), Ahmedabad, India and organized by Computer Society of India (CSI), Ahmedabad Chapter, Division IV and Association of Computing Machinery (ACM), Ahmedabad Chapter. The book aims to provide a forum to researchers to propose theory and technology on the networks and services, share their experience in IT and telecommunications industries and to discuss future management solutions for communication systems, networks and services. It comprises of original contributions from researchers describing their original, unpublished, research contribution. The papers are mainly from 4 areas – Security, Management and Control, Protocol and Deployment, and Applications. The topics covered in the book are newly emerging algorithms, communication systems, network standards, services, and applications. .

  19. Efficient data communication protocols for wireless networks

    Science.gov (United States)

    Zeydan, Engin

    In this dissertation, efficient decentralized algorithms are investigated for cost minimization problems in wireless networks. For wireless sensor networks, we investigate both the reduction in the energy consumption and throughput maximization problems separately using multi-hop data aggregation for correlated data in wireless sensor networks. The proposed algorithms exploit data redundancy using a game theoretic framework. For energy minimization, routes are chosen to minimize the total energy expended by the network using best response dynamics to local data. The cost function used in routing takes into account distance, interference and in-network data aggregation. The proposed energy-efficient correlation-aware routing algorithm significantly reduces the energy consumption in the network and converges in a finite number of steps iteratively. For throughput maximization, we consider both the interference distribution across the network and correlation between forwarded data when establishing routes. Nodes along each route are chosen to minimize the interference impact in their neighborhood and to maximize the in-network data aggregation. The resulting network topology maximizes the global network throughput and the algorithm is guaranteed to converge with a finite number of steps using best response dynamics. For multiple antenna wireless ad-hoc networks, we present distributed cooperative and regret-matching based learning schemes for joint transmit beanformer and power level selection problem for nodes operating in multi-user interference environment. Total network transmit power is minimized while ensuring a constant received signal-to-interference and noise ratio at each receiver. In cooperative and regret-matching based power minimization algorithms, transmit beanformers are selected from a predefined codebook to minimize the total power. By selecting transmit beamformers judiciously and performing power adaptation, the cooperative algorithm is shown to

  20. Introduction to focus issue: quantitative approaches to genetic networks.

    Science.gov (United States)

    Albert, Réka; Collins, James J; Glass, Leon

    2013-06-01

    All cells of living organisms contain similar genetic instructions encoded in the organism's DNA. In any particular cell, the control of the expression of each different gene is regulated, in part, by binding of molecular complexes to specific regions of the DNA. The molecular complexes are composed of protein molecules, called transcription factors, combined with various other molecules such as hormones and drugs. Since transcription factors are coded by genes, cellular function is partially determined by genetic networks. Recent research is making large strides to understand both the structure and the function of these networks. Further, the emerging discipline of synthetic biology is engineering novel gene circuits with specific dynamic properties to advance both basic science and potential practical applications. Although there is not yet a universally accepted mathematical framework for studying the properties of genetic networks, the strong analogies between the activation and inhibition of gene expression and electric circuits suggest frameworks based on logical switching circuits. This focus issue provides a selection of papers reflecting current research directions in the quantitative analysis of genetic networks. The work extends from molecular models for the binding of proteins, to realistic detailed models of cellular metabolism. Between these extremes are simplified models in which genetic dynamics are modeled using classical methods of systems engineering, Boolean switching networks, differential equations that are continuous analogues of Boolean switching networks, and differential equations in which control is based on power law functions. The mathematical techniques are applied to study: (i) naturally occurring gene networks in living organisms including: cyanobacteria, Mycoplasma genitalium, fruit flies, immune cells in mammals; (ii) synthetic gene circuits in Escherichia coli and yeast; and (iii) electronic circuits modeling genetic networks

  1. Data management issues in mobile ad hoc networks.

    Science.gov (United States)

    Hara, Takahiro

    2017-01-01

    Research on mobile ad hoc networks (MANETs) has become a hot research topic since the middle 1990's. Over the first decade, most research focused on networking techniques, ignoring data management issues. We, however, realized early the importance of data management in MANETs, and have been conducting studies in this area for 15 years. In this review, we summarize some key technical issues related to data management in MANETs, and the studies we have done in addressing these issues, which include placement of data replicas, update management, and query processing with security management. The techniques proposed in our studies have been designed with deep considerations of MANET features including network partitioning, node participation/disappearance, limited network bandwidth, and energy efficiency. Our studies published in early 2000's have developed a new research field as data management in MANETs. Also, our recent studies are expected to be significant guidelines of new research directions. We conclude the review by discussing some future directions for research.

  2. Introduction to Focus Issue: Complex network perspectives on flow systems.

    Science.gov (United States)

    Donner, Reik V; Hernández-García, Emilio; Ser-Giacomi, Enrico

    2017-03-01

    During the last few years, complex network approaches have demonstrated their great potentials as versatile tools for exploring the structural as well as dynamical properties of dynamical systems from a variety of different fields. Among others, recent successful examples include (i) functional (correlation) network approaches to infer hidden statistical interrelationships between macroscopic regions of the human brain or the Earth's climate system, (ii) Lagrangian flow networks allowing to trace dynamically relevant fluid-flow structures in atmosphere, ocean or, more general, the phase space of complex systems, and (iii) time series networks unveiling fundamental organization principles of dynamical systems. In this spirit, complex network approaches have proven useful for data-driven learning of dynamical processes (like those acting within and between sub-components of the Earth's climate system) that are hidden to other analysis techniques. This Focus Issue presents a collection of contributions addressing the description of flows and associated transport processes from the network point of view and its relationship to other approaches which deal with fluid transport and mixing and/or use complex network techniques.

  3. On the Effect of Security and Communication Factors in the Reliability of Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Damian Rusinek

    2014-03-01

    Full Text Available The ensuring reliability of wireless sensor networks (WSN is one of most important problems to be solved. In this article, the influence of the security and communication factors in the reliability of Wireless Sensor Networks was analyzed. Balancing security against performance in WSN is another issue to be solved. These factors should be considered during security analysis of quality of protection of realized protocol. In the article, we analyze wireless sensor network where hierarchical topologies is implemented with high performance routing sensors that forward big amount of data. We present the experiment results which were performed by high-performance Imote2 sensor platform and TinyOS operating system.

  4. Dehumanizing Communication Reified among Undergraduates and Lecturers: Issues and Suggestions

    Science.gov (United States)

    Duvie, Adanma Nnekwu; Modebelu, Melody Ndidi

    2014-01-01

    This paper discusses dehumanizing communication reified among undergraduates and lecturers. Dehumanization is the act of degrading people with respect to their best qualities and denial of humanness to others. On the other hand, communication is human interaction and learning. Communication becomes rude when it is deliberately directed resulting…

  5. Validation of network communicability metrics for the analysis of brain structural networks.

    Directory of Open Access Journals (Sweden)

    Jennifer Andreotti

    Full Text Available Computational network analysis provides new methods to analyze the brain's structural organization based on diffusion imaging tractography data. Networks are characterized by global and local metrics that have recently given promising insights into diagnosis and the further understanding of psychiatric and neurologic disorders. Most of these metrics are based on the idea that information in a network flows along the shortest paths. In contrast to this notion, communicability is a broader measure of connectivity which assumes that information could flow along all possible paths between two nodes. In our work, the features of network metrics related to communicability were explored for the first time in the healthy structural brain network. In addition, the sensitivity of such metrics was analysed using simulated lesions to specific nodes and network connections. Results showed advantages of communicability over conventional metrics in detecting densely connected nodes as well as subsets of nodes vulnerable to lesions. In addition, communicability centrality was shown to be widely affected by the lesions and the changes were negatively correlated with the distance from lesion site. In summary, our analysis suggests that communicability metrics that may provide an insight into the integrative properties of the structural brain network and that these metrics may be useful for the analysis of brain networks in the presence of lesions. Nevertheless, the interpretation of communicability is not straightforward; hence these metrics should be used as a supplement to the more standard connectivity network metrics.

  6. A Communication network for LHC detector readout

    International Nuclear Information System (INIS)

    Romero, L.

    1993-01-01

    This paper describe a network architecture for data taking in LHC environment. The network is composed of 64 rings of point to point links working at 100 Mbytes/s. The network connect the front end electronics, computer farms and two data switches. The efficiency of the system is discussed. Using extracted 1 Kbyte events for the 2nd level trigger and whole 1 Mbyte events for the 3rd level trigger, then the system can sustain working rates of 2 x 10''5 and 2 x 10''3 events/s going into the 2nd and 3rd level triggers. System resistance to errors is discussed. (Author) 3 refs

  7. A communication network for LHC detector readout

    International Nuclear Information System (INIS)

    Romero, L.

    1993-01-01

    This paper describe a network architecture for data taking in LHC environment. The network is composed of 64 rings of point to point links working at 100 Mbytes/s. The network connect the front end electronics, computer farms and two data switches. The efficiency of the system is discussed. Using extracted 1 kbyte events for the 2nd level trigger and whole 1 Mbyte events for the 3rd level trigger, then the system can sustain working rates of 2 x 10''5 and 2 x 10''3events/s going into the 2nd and 3rd level triggers. System resistance to errors is discussed. (Author)

  8. A Communication network for LHC detector readout

    Energy Technology Data Exchange (ETDEWEB)

    Romero, L

    1993-07-01

    This paper describe a network architecture for data taking in LHC environment. The network is composed of 64 rings of point to point links working at 100 Mbytes/s. The network connect the front end electronics, computer farms and two data switches. The efficiency of the system is discussed. Using extracted 1 Kbyte events for the 2nd level trigger and whole 1 Mbyte events for the 3rd level trigger, then the system can sustain working rates of 2 x 10''5 and 2 x 10''3 events/s going into the 2nd and 3rd level triggers. System resistance to errors is discussed. (Author) 3 refs.

  9. Reliable Communication in Wireless Meshed Networks using Network Coding

    DEFF Research Database (Denmark)

    Pahlevani, Peyman; Paramanathan, Achuthan; Hundebøll, Martin

    2012-01-01

    The advantages of network coding have been extensively studied in the field of wireless networks. Integrating network coding with existing IEEE 802.11 MAC layer is a challenging problem. The IEEE 802.11 MAC does not provide any reliability mechanisms for overheard packets. This paper addresses...... this problem and suggests different mechanisms to support reliability as part of the MAC protocol. Analytical expressions to this problem are given to qualify the performance of the modified network coding. These expressions are confirmed by numerical result. While the suggested reliability mechanisms...

  10. Energy Efficient Four Level Cooperative Opportunistic Communication for Wireless Personal Area Networks (WPAN)

    DEFF Research Database (Denmark)

    Rohokale, Vandana M.; Inamdar, Sandeep; Prasad, Neeli R.

    2013-01-01

    For wireless sensor networks (WSN),energy is a scarce resource. Due to limited battery resources, the energy consumption is the critical issue for the transmission as well as reception of the signals in the wireless communication. WSNs are infrastructure-less shared network demanding more energy...... consumption due to collaborative transmissions. This paper proposes a new cooperative opportunistic four level model for IEEE 802.15.4 Wireless Personal Area Network (WPAN).The average per node energy consumption is observed merely about 0.17mJ for the cooperative wireless communication which proves...... the proposed mechanism to be energy efficient. This paper further proposes four levels of cooperative data transmission from source to destination to improve network coverage with energy efficiency....

  11. Demand Moderation in Military Communication Networks

    National Research Council Canada - National Science Library

    Blackmore, Perry

    2002-01-01

    .... Demand moderation is the term used to encompass the array of mechanisms aimed at achieving this end. Integrated Defence networks of the future should benefit enormously from demand moderation mechanisms.

  12. A Survey of Routing Issues and Associated Protocols in Underwater Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Muhammad Khalid

    2017-01-01

    Full Text Available Underwater wireless sensor networks are a newly emerging wireless technology in which small size sensors with limited energy and limited memory and bandwidth are deployed in deep sea water and various monitoring operations like tactical surveillance, environmental monitoring, and data collection are performed through these tiny sensors. Underwater wireless sensor networks are used for the exploration of underwater resources, oceanographic data collection, flood or disaster prevention, tactical surveillance systems, and unmanned underwater vehicles. Sensor nodes consist of a small memory, a central processing unit, and an antenna. Underwater networks are much different from terrestrial sensor networks as radio waves cannot be used in underwater wireless sensor networks. Acoustic channels are used for communication in deep sea water. Acoustic signals have many limitations, such as limited bandwidth, higher end-to-end delay, network path loss, higher propagation delay, and dynamic topology. Usually, these limitations result in higher energy consumption with a smaller number of packets delivered. The main aim nowadays is to operate sensor nodes having a smaller battery for a longer time in the network. This survey has discussed the state-of-the-art localization based and localization-free routing protocols. Routing associated issues in the area of underwater wireless sensor networks have also been discussed.

  13. Advanced Communication for Wireless Sensor Networks

    Science.gov (United States)

    2016-08-22

    strategies that could be used to increase the single-hop transmission range of a wireless sensor network, increase energy efficiency (improve battery...substance placed within the reach of the network. Sensor measurements were quantized to save energy and bandwidth during transmission of the...the problem of assigning transmission powers to every node in order to maintain connectivity while minimizing the energy consumption of the whole

  14. On imperfect node protection in complex communication networks

    International Nuclear Information System (INIS)

    Xiao Shi; Xiao Gaoxi

    2011-01-01

    Motivated by recent research on complex networks, we study enhancing complex communication networks against intentional attack which takes down network nodes in a decreasing order of their degrees. Specifically, we evaluate an effect which has been largely ignored in existing studies; many real-life systems, especially communication systems, have protection mechanisms for their important components. Due to the existence of such protection, it is generally quite difficult to totally crash a protected node, though partially paralyzing it may still be feasible. Our analytical and simulation results show that such 'imperfect' protections generally speaking still help significantly enhance network robustness. Such insight may be helpful for the future developments of efficient network attack and protection schemes.

  15. Ninth International Conference on Wireless Communication and Sensor Networks

    CERN Document Server

    Tiwari, Murlidhar; Arora, Anish

    2014-01-01

    Wireless communication and sensor networks would form the backbone to create pervasive and ubiquitous environments that would have profound influence on the society and thus are important to the society. The wireless communication technologies and wireless sensor networks would encompass a wide range of domains such as HW devices such as motes, sensors and associated instrumentation, actuators, transmitters, receivers, antennas, etc., sensor network aspects such as topologies, routing algorithms, integration of heterogeneous network elements and topologies, designing RF devices and systems for energy efficiency and reliability etc. These sensor networks would provide opportunity to continuously and in a distributed manner monitor the environment and generate the necessary warnings and actions. However most of the developments have been demonstrated only in controlled and laboratory environments. So we are yet to see those powerful, ubiquitous applications for the benefit of the society. The conference and con...

  16. Overlapping coalition formation games in wireless communication networks

    CERN Document Server

    Wang, Tianyu; Saad, Walid; Han, Zhu

    2017-01-01

    This brief introduces overlapping coalition formation games (OCF games), a novel mathematical framework from cooperative game theory that can be used to model, design and analyze cooperative scenarios in future wireless communication networks. The concepts of OCF games are explained, and several algorithmic aspects are studied. In addition, several major application scenarios are discussed. These applications are drawn from a variety of fields that include radio resource allocation in dense wireless networks, cooperative spectrum sensing for cognitive radio networks, and resource management for crowd sourcing. For each application, the use of OCF games is discussed in detail in order to show how this framework can be used to solve relevant wireless networking problems. Overlapping Coalition Formation Games in Wireless Communication Networks provides researchers, students and practitioners with a concise overview of existing works in this emerging area, exploring the relevant fundamental theories, key techniqu...

  17. Business communication in social networks: Content management and experiences

    Directory of Open Access Journals (Sweden)

    Miguel Ángel Nicolás

    2014-11-01

    Full Text Available Currently, management of communication in social networks has become an indispensable strategic activity and contributes directly to change the mode of relationship between business and its stakeholders. The first section of this paper presents a brief analysis of the results reported in different specialized national studies in social networks. We analyse the general activities that users prefer to do and activities that users value most brands on networks. If an organization wants to successfully manage their communication in social networks is very important to know the behaviour of the users and design strategies based on their status and economic activity. This paper presents a brief analysis of social branding through the classification of different corporate content posted on their networks.

  18. On imperfect node protection in complex communication networks

    Energy Technology Data Exchange (ETDEWEB)

    Xiao Shi [Hubei Province Key Laboratory of Intelligent Robot and School of Computer Science and Engineering, Wuhan Institute of Technology, Wuhan 430073 (China); Xiao Gaoxi, E-mail: xiao_moon2002@yahoo.com.cn, E-mail: egxxiao@ntu.edu.sg [Division of Communication Engineering, School of Electrical and Electronic Engineering, Nanyang Technological University, 639798 (Singapore)

    2011-02-04

    Motivated by recent research on complex networks, we study enhancing complex communication networks against intentional attack which takes down network nodes in a decreasing order of their degrees. Specifically, we evaluate an effect which has been largely ignored in existing studies; many real-life systems, especially communication systems, have protection mechanisms for their important components. Due to the existence of such protection, it is generally quite difficult to totally crash a protected node, though partially paralyzing it may still be feasible. Our analytical and simulation results show that such 'imperfect' protections generally speaking still help significantly enhance network robustness. Such insight may be helpful for the future developments of efficient network attack and protection schemes.

  19. Perception of Communication Network Fraud Dynamics by Network ...

    African Journals Online (AJOL)

    In considering the implications of the varied nature of the potential targets, the paper identifies the view to develop effective intelligence analysis methodologies for network fraud detection and prevention by network administrators and stakeholders. The paper further notes that organizations are fighting an increasingly ...

  20. Heeding the Rebel Yell: Identification and Communication in Managing Organizational Issues

    Science.gov (United States)

    Collins, McLean

    2005-01-01

    In applying an issue development model, it is suggested that strategic identification and communication of the Colonel Reb issue would have helped the University of Mississippi to smoother transition to a new athletic mascot.

  1. 76 FR 10072 - Proposed Generic Communications; Draft NRC Regulatory Issue Summary 2011-XX, Adequacy of Station...

    Science.gov (United States)

    2011-02-23

    ... NUCLEAR REGULATORY COMMISSION [NRC-2011-0013] Proposed Generic Communications; Draft NRC Regulatory Issue Summary 2011-XX, Adequacy of Station Electric Distribution System Voltages; Reopening of... (NRC's) Draft Regulatory Issue Summary 2011-XX, Adequacy of Station Electric Distribution System...

  2. Some Practical Issues in the Design and Implementation of Group Communication Services

    National Research Council Canada - National Science Library

    Mishra, Shivakant

    2000-01-01

    The main objective of the proposed research was to investigate four important practical issues in the understanding, design, and implementation of group communication services. These issues were (1) Performance...

  3. Hierarchical Communication Network Architectures for Offshore Wind Power Farms

    Directory of Open Access Journals (Sweden)

    Mohamed A. Ahmed

    2014-05-01

    Full Text Available Nowadays, large-scale wind power farms (WPFs bring new challenges for both electric systems and communication networks. Communication networks are an essential part of WPFs because they provide real-time control and monitoring of wind turbines from a remote location (local control center. However, different wind turbine applications have different requirements in terms of data volume, latency, bandwidth, QoS, etc. This paper proposes a hierarchical communication network architecture that consist of a turbine area network (TAN, farm area network (FAN, and control area network (CAN for offshore WPFs. The two types of offshore WPFs studied are small-scale WPFs close to the grid and medium-scale WPFs far from the grid. The wind turbines are modelled based on the logical nodes (LN concepts of the IEC 61400-25 standard. To keep pace with current developments in wind turbine technology, the network design takes into account the extension of the LNs for both the wind turbine foundation and meteorological measurements. The proposed hierarchical communication network is based on Switched Ethernet. Servers at the control center are used to store and process the data received from the WPF. The network architecture is modelled and evaluated via OPNET. We investigated the end-to-end (ETE delay for different WPF applications. The results are validated by comparing the amount of generated sensing data with that of received traffic at servers. The network performance is evaluated, analyzed and discussed in view of end-to-end (ETE delay for different link bandwidths.

  4. Bidirectional Quantum Secure Direct Communication Network Protocol with Hyperentanglement

    International Nuclear Information System (INIS)

    Gu Bin; Chen Yulin; Huang Yugai; Fang Xia

    2011-01-01

    We propose a bidirectional quantum secure direct communication (QSDC) network protocol with the hyperentanglment in both the spatial-mode ad the polarization degrees of freedom of photon pairs which can in principle be produced with a beta barium borate crystal. The secret message can be encoded on the photon pairs with unitary operations in these two degrees of freedom independently. Compared with other QSDC network protocols, our QSDC network protocol has a higher capacity as each photon pair can carry 4 bits of information. Also, we discuss the security of our QSDC network protocol and its feasibility with current techniques. (general)

  5. VIRTUAL NETWORK COMMUNICATION AND ITS IMPACT ON INTERPERSONAL RELATIONS

    Directory of Open Access Journals (Sweden)

    Сергей Николаевич Хуторной

    2013-08-01

    Full Text Available The Internet was playing an increasing role in human life. Increasingly popular sites, where visitors can interact with other visitors through this site. Becoming popular communication "online", partially displacing the real-мире. There arises a problem of Internet addiction, or dependence on the Internet, which includes not only the dependence on virtual communication in social networks, but also addiction to gambling, online games, electronic purchases, and so on. Virtual reality acts not only as an intermediary virtual communication, but also significantly affect the nature, means and methods of communication, which ultimately has a significant effect on identity, often negatively, transforming it. The article dedicated to the analysis  of intercourse in virtual reality. The specification of net communication in comparing of real social communication is researching. The concept of Internet addicion is examined.DOI: http://dx.doi.org/10.12731/2218-7405-2013-6-9

  6. Demystifying communication signal lost for network redundancy ...

    African Journals Online (AJOL)

    These studies report on the communication signal lost factors that were analyzed and supported by evidences on coverage analysis activities for Automatic Meter Reading (AMR) systems. We have categorized the influential signal lost factors into four core elements that were concluded based on our field measurement ...

  7. Secure Communication in Vehicular Networks - PRESERVE Demo

    NARCIS (Netherlands)

    Lagana, M.; Feiri, Michael; Sall, M.; Lange, M.; Tomatis, A.; Papadimitratos, P.

    2012-01-01

    Security and privacy are fundamental prerequisites for the deployment of vehicular communications. The near-deployment status of Safety Applications for Intelligent Transport Systems (ITS) calls for strong evidence on the applicability of proposed research solutions, notably close-to-reality

  8. A Communication network for LHC detector readout

    Energy Technology Data Exchange (ETDEWEB)

    Romero, L.

    1993-07-01

    This paper describe a network architecture for data taking in LHC environment. The network is composed of 64 rings of point to point links working at 100 Mbytes/s. The network connect the front end electronics, computer farms and two data switches. The efficiency of the system is discussed. Using extracted 1 Kbyte events for the 2nd level trigger and whole 1 Mbyte events for the 3rd level trigger, then the system can sustain working rates of 2 x 10''5 and 2 x 10''3 events/s going into the 2nd and 3rd level triggers. System resistance to errors is discussed. (Author) 3 refs.

  9. Topological networks for quantum communication between distant qubits

    Science.gov (United States)

    Lang, Nicolai; Büchler, Hans Peter

    2017-11-01

    Efficient communication between qubits relies on robust networks, which allow for fast and coherent transfer of quantum information. It seems natural to harvest the remarkable properties of systems characterized by topological invariants to perform this task. Here, we show that a linear network of coupled bosonic degrees of freedom, characterized by topological bands, can be employed for the efficient exchange of quantum information over large distances. Important features of our setup are that it is robust against quenched disorder, all relevant operations can be performed by global variations of parameters, and the time required for communication between distant qubits approaches linear scaling with their distance. We demonstrate that our concept can be extended to an ensemble of qubits embedded in a two-dimensional network to allow for communication between all of them.

  10. Couples' communication on sexual and relational issues among the ...

    African Journals Online (AJOL)

    Interference by extended family members, especially husbands' mothers, and male authoritarian roles emerged as hindrances to effective communication between couples. The implications for HIV prevention regarding gender differences and the role of families in couples' communication are discussed. African Journal of ...

  11. Wireless ad hoc networks access for aeronautical communications

    OpenAIRE

    Besse , Frédéric; Garcia , Fabien; Pirovano , Alain; Radzik , José

    2010-01-01

    International audience; There is an increasing interest in the current aeronautical context to offer new services for civil aircraft passengers. For example, airlines want to offer their customers the opportunity to access the Internet, to manage their mails, to watch video on demand, to access corporate VPNs.... All these services represent a new type of air-ground communications called APC (Aeronautical Passenger Communications) in the ATN (Aeronautical Telecommunication Network) context. I...

  12. Data-Driven Handover Optimization in Next Generation Mobile Communication Networks

    Directory of Open Access Journals (Sweden)

    Po-Chiang Lin

    2016-01-01

    Full Text Available Network densification is regarded as one of the important ingredients to increase capacity for next generation mobile communication networks. However, it also leads to mobility problems since users are more likely to hand over to another cell in dense or even ultradense mobile communication networks. Therefore, supporting seamless and robust connectivity through such networks becomes a very important issue. In this paper, we investigate handover (HO optimization in next generation mobile communication networks. We propose a data-driven handover optimization (DHO approach, which aims to mitigate mobility problems including too-late HO, too-early HO, HO to wrong cell, ping-pong HO, and unnecessary HO. The key performance indicator (KPI is defined as the weighted average of the ratios of these mobility problems. The DHO approach collects data from the mobile communication measurement results and provides a model to estimate the relationship between the KPI and features from the collected dataset. Based on the model, the handover parameters, including the handover margin and time-to-trigger, are optimized to minimize the KPI. Simulation results show that the proposed DHO approach could effectively mitigate mobility problems.

  13. A Secure Communication Suite for Underwater Acoustic Sensor Networks

    Directory of Open Access Journals (Sweden)

    Angelica Lo Duca

    2012-11-01

    Full Text Available In this paper we describe a security suite for Underwater Acoustic Sensor Networks comprising both fixed and mobile nodes. The security suite is composed of a secure routing protocol and a set of cryptographic primitives aimed at protecting the confidentiality and the integrity of underwater communication while taking into account the unique characteristics and constraints of the acoustic channel. By means of experiments and simulations based on real data, we show that the suite is suitable for an underwater networking environment as it introduces limited, and sometimes negligible, communication and power consumption overhead.

  14. Communication-Free Distributed Coverage for Networked Systems

    KAUST Repository

    Yazicioglu, A. Yasin

    2016-01-15

    In this paper, we present a communication-free algorithm for distributed coverage of an arbitrary network by a group of mobile agents with local sensing capabilities. The network is represented as a graph, and the agents are arbitrarily deployed on some nodes of the graph. Any node of the graph is covered if it is within the sensing range of at least one agent. The agents are mobile devices that aim to explore the graph and to optimize their locations in a decentralized fashion by relying only on their sensory inputs. We formulate this problem in a game theoretic setting and propose a communication-free learning algorithm for maximizing the coverage.

  15. DoMUS a model to communicate energy issues in households

    NARCIS (Netherlands)

    Benders, René; Kok, Rixt

    1999-01-01

    Simulation models and games can be a valuable tool to communicate complex issues. Environmental problems in general and the problem described here in particular, are not always easily to explain. To communicate the issue of household energy use, energy reduction and shifting of energy expenditures

  16. Security Issues in Healthcare Applications Using Wireless Medical Sensor Networks: A Survey

    Directory of Open Access Journals (Sweden)

    Hoon-Jae Lee

    2011-12-01

    Full Text Available Healthcare applications are considered as promising fields for wireless sensor networks, where patients can be monitored using wireless medical sensor networks (WMSNs. Current WMSN healthcare research trends focus on patient reliable communication, patient mobility, and energy-efficient routing, as a few examples. However, deploying new technologies in healthcare applications without considering security makes patient privacy vulnerable. Moreover, the physiological data of an individual are highly sensitive. Therefore, security is a paramount requirement of healthcare applications, especially in the case of patient privacy, if the patient has an embarrassing disease. This paper discusses the security and privacy issues in healthcare application using WMSNs. We highlight some popular healthcare projects using wireless medical sensor networks, and discuss their security. Our aim is to instigate discussion on these critical issues since the success of healthcare application depends directly on patient security and privacy, for ethic as well as legal reasons. In addition, we discuss the issues with existing security mechanisms, and sketch out the important security requirements for such applications. In addition, the paper reviews existing schemes that have been recently proposed to provide security solutions in wireless healthcare scenarios. Finally, the paper ends up with a summary of open security research issues that need to be explored for future healthcare applications using WMSNs.

  17. Security issues in healthcare applications using wireless medical sensor networks: a survey.

    Science.gov (United States)

    Kumar, Pardeep; Lee, Hoon-Jae

    2012-01-01

    Healthcare applications are considered as promising fields for wireless sensor networks, where patients can be monitored using wireless medical sensor networks (WMSNs). Current WMSN healthcare research trends focus on patient reliable communication, patient mobility, and energy-efficient routing, as a few examples. However, deploying new technologies in healthcare applications without considering security makes patient privacy vulnerable. Moreover, the physiological data of an individual are highly sensitive. Therefore, security is a paramount requirement of healthcare applications, especially in the case of patient privacy, if the patient has an embarrassing disease. This paper discusses the security and privacy issues in healthcare application using WMSNs. We highlight some popular healthcare projects using wireless medical sensor networks, and discuss their security. Our aim is to instigate discussion on these critical issues since the success of healthcare application depends directly on patient security and privacy, for ethic as well as legal reasons. In addition, we discuss the issues with existing security mechanisms, and sketch out the important security requirements for such applications. In addition, the paper reviews existing schemes that have been recently proposed to provide security solutions in wireless healthcare scenarios. Finally, the paper ends up with a summary of open security research issues that need to be explored for future healthcare applications using WMSNs.

  18. Dynamic Pathloss Model for Future Mobile Communication Networks

    DEFF Research Database (Denmark)

    Kumar, Ambuj; Mihovska, Albena Dimitrova; Prasad, Ramjee

    2016-01-01

    that are essentially static. Therefore, once the signal level drops beyond the predicted values due to any variance in the environmental conditions, very crowded areas may not be catered well enough by the deployed network that had been designed with the static path loss model. This paper proposes an approach......— Future mobile communication networks (MCNs) are expected to be more intelligent and proactive based on new capabilities that increase agility and performance. However, for any successful mobile network service, the dexterity in network deployment is a key factor. The efficiency of the network...... planning depends on how congruent the chosen path loss model and real propagation are. Various path loss models have been developed that predict the signal propagation in various morphological and climatic environments; however they consider only those physical parameters of the network environment...

  19. Video Games in Volcanic Hazard Communications: Methods & Issues

    Science.gov (United States)

    Mani, Lara; Cole, Paul; Stewart, Iain

    2016-04-01

    Educational outreach plays a vital role in improving the resilience of vulnerable populations at risk from natural disasters. Currently, that activity is undertaken in many guises including the distribution of leaflets and posters, maps, presentations, education sessions and through radio and TV broadcasts. Such tried-and-tested communication modes generally target traditional stakeholder groups, but it is becoming increasingly important to engage with the new generation of learners who, due to advancements in technology, obtain information in ways different to their predecessors. That new generation is defined by a technological way of life and it remains a challenge to keep them motivated. On the eastern Caribbean island of St. Vincent, the La Soufriere Volcano lies in quiescence since the last eruption in 1979. Since then, an entire generation - over 56% of the population (Worldbank, 2015) - has little or no direct experience of a volcanic eruption. The island experiences, more frequently, other hazards (hurricanes, flooding, earthquakes landsliding), such that disaster preparedness measures give less priority to volcanic threats, which are deemed to pose less of a risk. With no accurate predictions to warn of the next eruption, it is especially important to educate residents about the potential of future volcanic hazards on the island, and to motivate them to prepare to mitigate their risk. This research critically examines the application of video games in supporting and enhancing existing public education and outreach programmes for volcanic hazards. St. Vincent's Volcano is a computer game designed to improve awareness and knowledge of the eruptive phenomena from La Soufriere that could pose a threat to residents. Within an interactive and immersive environment, players become acquainted with a 3D model of St. Vincent together with an overlay of the established volcanic hazard map (Robertson, 2005). Players are able to view visualisations of two historical

  20. Topology design and performance analysis of an integrated communication network

    Science.gov (United States)

    Li, V. O. K.; Lam, Y. F.; Hou, T. C.; Yuen, J. H.

    1985-01-01

    A research study on the topology design and performance analysis for the Space Station Information System (SSIS) network is conducted. It is begun with a survey of existing research efforts in network topology design. Then a new approach for topology design is presented. It uses an efficient algorithm to generate candidate network designs (consisting of subsets of the set of all network components) in increasing order of their total costs, and checks each design to see if it forms an acceptable network. This technique gives the true cost-optimal network, and is particularly useful when the network has many constraints and not too many components. The algorithm for generating subsets is described in detail, and various aspects of the overall design procedure are discussed. Two more efficient versions of this algorithm (applicable in specific situations) are also given. Next, two important aspects of network performance analysis: network reliability and message delays are discussed. A new model is introduced to study the reliability of a network with dependent failures. For message delays, a collection of formulas from existing research results is given to compute or estimate the delays of messages in a communication network without making the independence assumption. The design algorithm coded in PASCAL is included as an appendix.

  1. CSR communication: Quo vadis? A systematic review of the literature and introduction to the special issue

    NARCIS (Netherlands)

    Golob, U.; Elving, W.; Thomsen, C.; Podnar, K.; Nielsen, A.; Schultz, F.

    2013-01-01

    This paper aims to introduce the special issue on CSR communication attached to the First International CSR Communication Conference held in Amsterdam in October 2011. The aim of the introduction is also to review CSR communication papers published in scholarly journals in order to make a summary of

  2. Distributed fusion estimation for sensor networks with communication constraints

    CERN Document Server

    Zhang, Wen-An; Song, Haiyu; Yu, Li

    2016-01-01

    This book systematically presents energy-efficient robust fusion estimation methods to achieve thorough and comprehensive results in the context of network-based fusion estimation. It summarizes recent findings on fusion estimation with communication constraints; several novel energy-efficient and robust design methods for dealing with energy constraints and network-induced uncertainties are presented, such as delays, packet losses, and asynchronous information... All the results are presented as algorithms, which are convenient for practical applications.

  3. Tight Network Topology Dependent Bounds on Rounds of Communication

    OpenAIRE

    Chattopadhyay, Arkadev; Langberg, Michael; Li, Shi; Rudra, Atri

    2016-01-01

    We prove tight network topology dependent bounds on the round complexity of computing well studied $k$-party functions such as set disjointness and element distinctness. Unlike the usual case in the CONGEST model in distributed computing, we fix the function and then vary the underlying network topology. This complements the recent such results on total communication that have received some attention. We also present some applications to distributed graph computation problems. Our main contri...

  4. Reliability of Broadcast Communications Under Sparse Random Linear Network Coding

    OpenAIRE

    Brown, Suzie; Johnson, Oliver; Tassi, Andrea

    2018-01-01

    Ultra-reliable Point-to-Multipoint (PtM) communications are expected to become pivotal in networks offering future dependable services for smart cities. In this regard, sparse Random Linear Network Coding (RLNC) techniques have been widely employed to provide an efficient way to improve the reliability of broadcast and multicast data streams. This paper addresses the pressing concern of providing a tight approximation to the probability of a user recovering a data stream protected by this kin...

  5. Networked Airborne Communications Using Adaptive Multi Beam Directional Links

    Science.gov (United States)

    2016-03-05

    Networked Airborne Communications Using Adaptive Multi-Beam Directional Links R. Bruce MacLeod Member, IEEE, and Adam Margetts Member, IEEE MIT...provide new techniques for increasing throughput in airborne adaptive directional net- works. By adaptive directional linking, we mean systems that can...techniques can dramatically increase the capacity in airborne networks. Advances in digital array technology are beginning to put these gains within reach

  6. A demand assignment control in international business satellite communications network

    Science.gov (United States)

    Nohara, Mitsuo; Takeuchi, Yoshio; Takahata, Fumio; Hirata, Yasuo

    An experimental system is being developed for use in an international business satellite (IBS) communications network based on demand-assignment (DA) and TDMA techniques. This paper discusses its system design, in particular from the viewpoints of a network configuration, a DA control, and a satellite channel-assignment algorithm. A satellite channel configuration is also presented along with a tradeoff study on transmission rate, HPA output power, satellite resource efficiency, service quality, and so on.

  7. perception of communication network fraud dynamics by network ...

    African Journals Online (AJOL)

    ES Obe

    work fraud dynamics by network administrators and stakeholders. In considering ... cyber crime within the last two years. How- ever, two-thirds of the ... ˆ increased exposure to unpredictable fi- nancial losses ... The intentions of the customers are reflected ..... 'There is a 95% confidence that the differ- ence between the ...

  8. Scientific risk communication about controversial issues influences public perceptions of scientists' political orientations and credibility.

    Science.gov (United States)

    Vraga, Emily; Myers, Teresa; Kotcher, John; Beall, Lindsey; Maibach, Ed

    2018-02-01

    Many scientists communicate with the public about risks associated with scientific issues, but such communication may have unintended consequences for how the public views the political orientations and the credibility of the communicating scientist. We explore this possibility using an experiment with a nationally representative sample of Americans in the fall of 2015. We find that risk communication on controversial scientific issues sometimes influences perceptions of the political orientations and credibility of the communicating scientist when the scientist addresses the risks of issues associated with conservative or liberal groups. This relationship is moderated by participant political ideology, with liberals adjusting their perceptions of the scientists' political beliefs more substantially when the scientist addressed the risks of marijuana use when compared with other issues. Conservatives' political perceptions were less impacted by the issue context of the scientific risk communication but indirectly influenced credibility perceptions. Our results support a contextual model of audience interpretation of scientific risk communication. Scientists should be cognizant that audience members may make inferences about the communicating scientist's political orientations and credibility when they engage in risk communication efforts about controversial issues.

  9. Applying Model Based Systems Engineering to NASA's Space Communications Networks

    Science.gov (United States)

    Bhasin, Kul; Barnes, Patrick; Reinert, Jessica; Golden, Bert

    2013-01-01

    System engineering practices for complex systems and networks now require that requirement, architecture, and concept of operations product development teams, simultaneously harmonize their activities to provide timely, useful and cost-effective products. When dealing with complex systems of systems, traditional systems engineering methodology quickly falls short of achieving project objectives. This approach is encumbered by the use of a number of disparate hardware and software tools, spreadsheets and documents to grasp the concept of the network design and operation. In case of NASA's space communication networks, since the networks are geographically distributed, and so are its subject matter experts, the team is challenged to create a common language and tools to produce its products. Using Model Based Systems Engineering methods and tools allows for a unified representation of the system in a model that enables a highly related level of detail. To date, Program System Engineering (PSE) team has been able to model each network from their top-level operational activities and system functions down to the atomic level through relational modeling decomposition. These models allow for a better understanding of the relationships between NASA's stakeholders, internal organizations, and impacts to all related entities due to integration and sustainment of existing systems. Understanding the existing systems is essential to accurate and detailed study of integration options being considered. In this paper, we identify the challenges the PSE team faced in its quest to unify complex legacy space communications networks and their operational processes. We describe the initial approaches undertaken and the evolution toward model based system engineering applied to produce Space Communication and Navigation (SCaN) PSE products. We will demonstrate the practice of Model Based System Engineering applied to integrating space communication networks and the summary of its

  10. Communication for Influence : Building ICTD Networks in Central ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    This project seeks to help achieve universal affordable access to broadband information and communication technology (ICT) infrastructure in a number of countries on the East and West coasts of Africa. It will do so by building regional ICT for development (ICTD) research and advocacy networks in Central, East and West ...

  11. High speed switching for computer and communication networks

    NARCIS (Netherlands)

    Dorren, H.J.S.

    2014-01-01

    The role of data centers and computers are vital for the future of our data-centric society. Historically the performance of data-centers is increasing with a factor 100-1000 every ten years and as a result of this the capacity of the data-center communication network has to scale accordingly. This

  12. Localization and Communication for UWB-based Wireless Sensor Networks

    NARCIS (Netherlands)

    Wang, Y.

    2011-01-01

    The great demand for location-aware wireless sensor networks (WSNs) motivates the research in this thesis. The unique characteristics of WSNs impose numerous challenges on localization and communication. In this thesis, we handle some key challenges and provide affordable solutions. Impulse radio

  13. Computer-mediated-communication and social networking tools at work

    NARCIS (Netherlands)

    Ou, C.X.J.; Sia, C.L.; Hui, C.K.

    2013-01-01

    Purpose – Advances in information technology (IT) have resulted in the development of various computer‐mediated communication (CMC) and social networking tools. However, quantifying the benefits of utilizing these tools in the organizational context remains a challenge. In this study, the authors

  14. Test experience on an ultrareliable computer communication network

    Science.gov (United States)

    Abbott, L. W.

    1984-01-01

    The dispersed sensor processing mesh (DSPM) is an experimental, ultra-reliable, fault-tolerant computer communications network that exhibits an organic-like ability to regenerate itself after suffering damage. The regeneration is accomplished by two routines - grow and repair. This paper discusses the DSPM concept for achieving fault tolerance and provides a brief description of the mechanization of both the experiment and the six-node experimental network. The main topic of this paper is the system performance of the growth algorithm contained in the grow routine. The characteristics imbued to DSPM by the growth algorithm are also discussed. Data from an experimental DSPM network and software simulation of larger DSPM-type networks are used to examine the inherent limitation on growth time by the growth algorithm and the relationship of growth time to network size and topology.

  15. Satellite communications for the next generation telecommunication services and networks

    Science.gov (United States)

    Chitre, D. M.

    1991-01-01

    Satellite communications can play an important role in provisioning the next-generation telecommunication services and networks, provided the protocols specifying these services and networks are satellite-compatible and the satellite subnetworks, consisting of earth stations interconnected by the processor and the switch on board the satellite, interwork effectively with the terrestrial networks. The specific parameters and procedures of frame relay and broadband integrated services digital network (B-ISDN) protocols which are impacted by a satellite delay. Congestion and resource management functions for frame relay and B-ISDN are discussed in detail, describing the division of these functions between earth stations and on board the satellite. Specific onboard and ground functions are identified as potential candidates for their implementation via neural network technology.

  16. The 30/20 GHz communications satellite trunking network study

    Science.gov (United States)

    Kolb, W.

    1981-01-01

    Alternative transmission media for a CONUS-wide trunking network in the years 1990 and 2000 are examined. The alternative technologies comprised fiber optic cable, conventional C- and Ku-band satellites, and 30/20 GHz satellites. Three levels of implementation were considered - a 10-city network, a 20-city network, and a 40-city network. The cities selected were the major metropolitan areas with the greatest communications demand. All intercity voice, data, and video traffic carried more than 40 miles was included in the analysis. In the optimized network, traffic transmitted less than 500 miles was found to be better served by fiber optic cable in 1990. By the year 2000, the crossover point would be down to 200 miles, assuming availability of 30/20 GHz satellites.

  17. Network Coding for Hop-by-Hop Communication Enhancement in Multi-hop Networks

    DEFF Research Database (Denmark)

    Pahlevani, Peyman; Khamfroush, Hana; Roetter, Daniel Enrique Lucani

    2016-01-01

    In our recent study, we introduced the PlayNCool protocol that increases the throughput of the wireless networks by enabling a helper node to strengthen the communication link between two neighboring nodes and using random linear network coding. This paper focuses on design and implementation adv...

  18. Persian Linguistic and Rhetorical Pathology in The Telegram Communication Network

    Directory of Open Access Journals (Sweden)

    M. Hedayat Mofidi

    2017-12-01

    Full Text Available Today, the mobile phone, with its wide range of features, is an inexpensive, easy to use, and most modern communication tool. One of the special applications of smart phones is providing spaces and facilities such as SMS services, virtual networks, and interactive groups that link people and groups from different linguistic and cultural background. In this paper, we tried to study the messages of the Farsi-speaking users of the Telegram communication network from the linguistics perspective. In this regard, the linguistics and rhetorical correspondence of short messages in Persian language was studied by the content-analysis method. The statistical population consisted of 150 messages which contained 327 sentences. These messages were randomly selected from 5 different groups. Persian language used in cyberspace differs from standard Persian language. The first step in correcting communication language errors in cyberspace is to inform the users about the type of errors.

  19. Reliability Improved Cooperative Communication over Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Zhuangbin Chen

    2017-10-01

    Full Text Available With the development of smart devices and connection technologies, Wireless Sensor Networks (WSNs are becoming increasingly intelligent. New or special functions can be obtained by receiving new versions of program codes to upgrade their software systems, forming the so-called smart Internet of Things (IoT. Due to the lossy property of wireless channels, data collection in WSNs still suffers from a long delay, high energy consumption, and many retransmissions. Thanks to wireless software-defined networks (WSDNs, software in sensors can now be updated to help them transmit data cooperatively, thereby achieving more reliable communication. In this paper, a Reliability Improved Cooperative Communication (RICC data collection scheme is proposed to improve the reliability of random-network-coding-based cooperative communications in multi-hop relay WSNs without reducing the network lifetime. In WSNs, sensors in different positions can have different numbers of packets to handle, resulting in the unbalanced energy consumption of the network. In particular, nodes in non-hotspot areas have up to 90% of their original energy remaining when the network dies. To efficiently use the residual energy, in RICC, high data transmission power is adopted in non-hotspot areas to achieve a higher reliability at the cost of large energy consumption, and relatively low transmission power is adopted in hotspot areas to maintain the long network lifetime. Therefore, high reliability and a long network lifetime can be obtained simultaneously. The simulation results show that compared with other scheme, RICC can reduce the end-to-end Message Fail delivering Ratio (MFR by 59.4%–62.8% under the same lifetime with a more balanced energy utilization.

  20. Communicating systems with UML 2 modeling and analysis of network protocols

    CERN Document Server

    Barrera, David Garduno

    2013-01-01

    This book gives a practical approach to modeling and analyzing communication protocols using UML 2. Network protocols are always presented with a point of view focusing on partial mechanisms and starting models. This book aims at giving the basis needed for anybody to model and validate their own protocols. It follows a practical approach and gives many examples for the description and analysis of well known basic network mechanisms for protocols.The book firstly shows how to describe and validate the main protocol issues (such as synchronization problems, client-server interactions, layer

  1. Experimental performance evaluation of software defined networking (SDN) based data communication networks for large scale flexi-grid optical networks.

    Science.gov (United States)

    Zhao, Yongli; He, Ruiying; Chen, Haoran; Zhang, Jie; Ji, Yuefeng; Zheng, Haomian; Lin, Yi; Wang, Xinbo

    2014-04-21

    Software defined networking (SDN) has become the focus in the current information and communication technology area because of its flexibility and programmability. It has been introduced into various network scenarios, such as datacenter networks, carrier networks, and wireless networks. Optical transport network is also regarded as an important application scenario for SDN, which is adopted as the enabling technology of data communication networks (DCN) instead of general multi-protocol label switching (GMPLS). However, the practical performance of SDN based DCN for large scale optical networks, which is very important for the technology selection in the future optical network deployment, has not been evaluated up to now. In this paper we have built a large scale flexi-grid optical network testbed with 1000 virtual optical transport nodes to evaluate the performance of SDN based DCN, including network scalability, DCN bandwidth limitation, and restoration time. A series of network performance parameters including blocking probability, bandwidth utilization, average lightpath provisioning time, and failure restoration time have been demonstrated under various network environments, such as with different traffic loads and different DCN bandwidths. The demonstration in this work can be taken as a proof for the future network deployment.

  2. Information and Communication Technology: Gender Issues in Developing Nations

    Directory of Open Access Journals (Sweden)

    Kimberly Betz Leahy

    2003-01-01

    Full Text Available As Developing Nations seek to leverage scarce resources toward the goal of achieving a developed status they must reevaluate past practices and explore available and affordable technologies. Where in-formation and communication infrastructures are weak, use of low-cost, easily distributed technologies have proven effective. Still, many developing nations have failed to incorporate a resource in great abundance, their women, to use these new technologies to greatest advantage. This paper will address the implications of women's lack of economic and educational parity, and offer examples of how the education of women through the use of information and communication technology can enhance a nation's gross domestic product (GDP.

  3. Geoscience communication in Namibia: YES Network Namibia spreading the message to young scientists

    Science.gov (United States)

    Mhopjeni, Kombada

    2015-04-01

    The Young Earth Scientists (YES) Network is an international association for early-career geoscientists under the age of 35 years that was formed as a result of the International Year of Planet Earth (IYPE) in 2007. YES Network aims to establish an interdisciplinary global network of early-career geoscientists to solve societal issues/challenges using geosciences, promote scientific research and interdisciplinary networking, and support professional development of early-career geoscientists. The Network has several National Chapters including one in Namibia. YES Network Namibia (YNN) was formed in 2009, at the closing ceremony of IYPE in Portugal and YNN was consolidated in 2013 with the current set-up. YNN supports the activities and goals of the main YES Network at national level providing a platform for young Namibian scientists with a passion to network, information on geoscience opportunities and promoting earth sciences. Currently most of the members are geoscientists from the Geological Survey of Namibia (GSN) and University of Namibia. In 2015, YNN plans to carry out two workshops on career guidance, establish a mentorship program involving alumni and experienced industry experts, and increase involvement in outreach activities, mainly targeting high school pupils. Network members will participate in a range of educational activities such as school career and science fairs communicating geoscience to the general public, learners and students. The community outreach programmes are carried out to increase awareness of the role geosciences play in society. In addition, YNN will continue to promote interactive collaboration between the University of Namibia, Geological Survey of Namibia (GSN) and Geological Society of Namibia. Despite the numerous potential opportunities YNN offers young scientists in Namibia and its presence on all major social media platforms, the Network faces several challenges. One notable challenge the Network faces is indifference among

  4. The Study on the Communication Network of Wide Area Measurement System in Electricity Grid

    Science.gov (United States)

    Xiaorong, Cheng; Ying, Wang; Yangdan, Ni

    Wide area measurement system(WAMS) is a fundamental part of security defense in Smart Grid, and the communication system of WAMS is an important part of Electric power communication network. For a large regional network is concerned, the real-time data which is transferred in the communication network of WAMS will affect the safe operation of the power grid directly. Therefore, WAMS raised higher requirements for real-time, reliability and security to its communication network. In this paper, the architecture of WASM communication network was studied according to the seven layers model of the open systems interconnection(OSI), and the network architecture was researched from all levels. We explored the media of WAMS communication network, the network communication protocol and network technology. Finally, the delay of the network were analyzed.

  5. Security in Nano Communication: Challenges and Open Research Issues

    NARCIS (Netherlands)

    Dressler, Falko; Kargl, Frank

    Nano communication is one of the fastest growing emerging research fields. In recent years, much progress has been achieved in developing nano machines supporting our needs in health care and other scenarios. However, experts agree that only the interaction among nano machines allows to address the

  6. Agricultural Communications Students' Awareness and Perceptions of Biotechnology Issues.

    Science.gov (United States)

    Wingenbach, Gary J.; Rutherford, Tracy A.; Dunsford, Deborah W.

    2003-01-01

    Agricultural communications students (n=330) from 11 universities were most aware of biotechnology effects on food, less aware of effects on health and the environment. They were somewhat accepting of genetic modifications for plants, not humans. Sources of biotechnology knowledge were science classes, labs, and university professors' beliefs.…

  7. Practices in communicating technical issues to the general public

    International Nuclear Information System (INIS)

    Drabova, D.; Storey, P.

    2006-01-01

    The conclusions and recommendations of this session can be summarized this way. - Basic goal for the regulator is to protect the public and communication is a must to fully achieve this goal. - Regulator should become the prime source of information to the public and the media, regulator should base its actions upon values of competence, independence, transparency and stringency. - Set up of a Information and Communication Policy will help for consistency and efficiency. Policy will include setting goals, strategies, organisational aspects, procedures, and tools. Practices should be developed in accordance with local culture. - Challenges will consider transparency, public involvement and consultation with the stakeholders. - Practices will include in general: - Interactions with the media like press releases, news conferences, media workshops. Printed materials from plant periodical status reports, to periodical and annual reports and specific reports. Audio-visual materials. Use of radio and TV. Web site and electronic mail. - Method chosen depends on the targeted audience and the relevance of the topic. - Messages should be clearly understandable. Do not dehumanize the message by making it technically unintelligible. - Two excellent examples presented. How local culture and social characteristics were taken into account in designing and implementing plans is key for success. - Municipalities are to be considered as front line stakeholders. - Communicators role is relevant to meet regulatory needs. Good collaboration between communicators and technical staff produces benefits for the nuclear regulator and the public. (authors)

  8. Prevention, communication and equity in environmental epidemiology: ethical issues.

    Science.gov (United States)

    Pagliarani, Giovanna; Botti, Caterina

    2011-01-01

    In environmental epidemiology research, decisions about when and how to intervene requires adequate ethical reflection. In fact, different kinds of issues may arise about: research methods and knowledge production; management of the results in terms of their overall assessments or for the implementation of preventive actions; reclamation intervention. In this contribution we propose to consider three topics we regard as crucial to this ethical debate: the reporting of conclusive research data; the correct application of the precautionary principle; and the environmental equity issues.

  9. Simulation of Routing Protocol with CoS/QoS Enhancements in Heterogeneous Communication Network

    National Research Council Canada - National Science Library

    Kubera, Emil; Sliwa, Joanna; Zubel, Krzysztof; Mroczko, Adrian

    2006-01-01

    The article describes the subject of QoS routing mechanism in tactical heterogeneous communication network consisting of network elements built in different technologies and connected following rules...

  10. Utilization of Selected Data Mining Methods for Communication Network Analysis

    Directory of Open Access Journals (Sweden)

    V. Ondryhal

    2011-06-01

    Full Text Available The aim of the project was to analyze the behavior of military communication networks based on work with real data collected continuously since 2005. With regard to the nature and amount of the data, data mining methods were selected for the purpose of analyses and experiments. The quality of real data is often insufficient for an immediate analysis. The article presents the data cleaning operations which have been carried out with the aim to improve the input data sample to obtain reliable models. Gradually, by means of properly chosen SW, network models were developed to verify generally valid patterns of network behavior as a bulk service. Furthermore, unlike the commercially available communication networks simulators, the models designed allowed us to capture nonstandard models of network behavior under an increased load, verify the correct sizing of the network to the increased load, and thus test its reliability. Finally, based on previous experience, the models enabled us to predict emergency situations with a reasonable accuracy.

  11. Architecture for Cognitive Networking within NASAs Future Space Communications Infrastructure

    Science.gov (United States)

    Clark, Gilbert J., III; Eddy, Wesley M.; Johnson, Sandra K.; Barnes, James; Brooks, David

    2016-01-01

    Future space mission concepts and designs pose many networking challenges for command, telemetry, and science data applications with diverse end-to-end data delivery needs. For future end-to-end architecture designs, a key challenge is meeting expected application quality of service requirements for multiple simultaneous mission data flows with options to use diverse onboard local data buses, commercial ground networks, and multiple satellite relay constellations in LEO, MEO, GEO, or even deep space relay links. Effectively utilizing a complex network topology requires orchestration and direction that spans the many discrete, individually addressable computer systems, which cause them to act in concert to achieve the overall network goals. The system must be intelligent enough to not only function under nominal conditions, but also adapt to unexpected situations, and reorganize or adapt to perform roles not originally intended for the system or explicitly programmed. This paper describes architecture features of cognitive networking within the future NASA space communications infrastructure, and interacting with the legacy systems and infrastructure in the meantime. The paper begins by discussing the need for increased automation, including inter-system collaboration. This discussion motivates the features of an architecture including cognitive networking for future missions and relays, interoperating with both existing endpoint-based networking models and emerging information-centric models. From this basis, we discuss progress on a proof-of-concept implementation of this architecture as a cognitive networking on-orbit application on the SCaN Testbed attached to the International Space Station.

  12. Architecture for Cognitive Networking within NASA's Future Space Communications Infrastructure

    Science.gov (United States)

    Clark, Gilbert; Eddy, Wesley M.; Johnson, Sandra K.; Barnes, James; Brooks, David

    2016-01-01

    Future space mission concepts and designs pose many networking challenges for command, telemetry, and science data applications with diverse end-to-end data delivery needs. For future end-to-end architecture designs, a key challenge is meeting expected application quality of service requirements for multiple simultaneous mission data flows with options to use diverse onboard local data buses, commercial ground networks, and multiple satellite relay constellations in LEO, GEO, MEO, or even deep space relay links. Effectively utilizing a complex network topology requires orchestration and direction that spans the many discrete, individually addressable computer systems, which cause them to act in concert to achieve the overall network goals. The system must be intelligent enough to not only function under nominal conditions, but also adapt to unexpected situations, and reorganize or adapt to perform roles not originally intended for the system or explicitly programmed. This paper describes an architecture enabling the development and deployment of cognitive networking capabilities into the envisioned future NASA space communications infrastructure. We begin by discussing the need for increased automation, including inter-system discovery and collaboration. This discussion frames the requirements for an architecture supporting cognitive networking for future missions and relays, including both existing endpoint-based networking models and emerging information-centric models. From this basis, we discuss progress on a proof-of-concept implementation of this architecture, and results of implementation and initial testing of a cognitive networking on-orbit application on the SCaN Testbed attached to the International Space Station.

  13. Joint Preprocesser-Based Detectors for One-Way and Two-Way Cooperative Communication Networks

    KAUST Repository

    Abuzaid, Abdulrahman I.

    2014-01-01

    Efficient receiver designs for cooperative communication networks are becoming increasingly important. In previous work, cooperative networks communicated with the use of L relays. As the receiver is constrained, channel shortening and reduced

  14. A note on the consensus finding problem in communication networks with switching topologies

    KAUST Repository

    Haskovec, Jan

    2014-01-01

    In this note, we discuss the problem of consensus finding in communication networks of agents with dynamically switching topologies. In particular, we consider the case of directed networks with unbalanced matrices of communication rates. We

  15. Multilevel Approximations of Markovian Jump Processes with Applications in Communication Networks

    KAUST Repository

    Vilanova, Pedro

    2015-01-01

    for modeling networks of smart devices —tiny, abundant microprocessors with integrated sensors and wireless communication abilities— that form highly complex and diverse communication networks. During 2010, the number of devices connected to the Internet

  16. Distributed wireless quantum communication networks with partially entangled pairs

    International Nuclear Information System (INIS)

    Yu Xu-Tao; Zhang Zai-Chen; Xu Jin

    2014-01-01

    Wireless quantum communication networks transfer quantum state by teleportation. Existing research focuses on maximal entangled pairs. In this paper, we analyse the distributed wireless quantum communication networks with partially entangled pairs. A quantum routing scheme with multi-hop teleportation is proposed. With the proposed scheme, is not necessary for the quantum path to be consistent with the classical path. The quantum path and its associated classical path are established in a distributed way. Direct multi-hop teleportation is conducted on the selected path to transfer a quantum state from the source to the destination. Based on the feature of multi-hop teleportation using partially entangled pairs, if the node number of the quantum path is even, the destination node will add another teleportation at itself. We simulated the performance of distributed wireless quantum communication networks with a partially entangled state. The probability of transferring the quantum state successfully is statistically analyzed. Our work shows that multi-hop teleportation on distributed wireless quantum networks with partially entangled pairs is feasible. (general)

  17. Network Communication as a Service-Oriented Capability

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, William; Johnston, William; Metzger, Joe; Collins, Michael; Burrescia, Joseph; Dart, Eli; Gagliardi, Jim; Guok, Chin; Oberman, Kevin; O' Conner, Mike

    2008-01-08

    In widely distributed systems generally, and in science-oriented Grids in particular, software, CPU time, storage, etc., are treated as"services" -- they can be allocated and used with service guarantees that allows them to be integrated into systems that perform complex tasks. Network communication is currently not a service -- it is provided, in general, as a"best effort" capability with no guarantees and only statistical predictability. In order for Grids (and most types of systems with widely distributed components) to be successful in performing the sustained, complex tasks of large-scale science -- e.g., the multi-disciplinary simulation of next generation climate modeling and management and analysis of the petabytes of data that will come from the next generation of scientific instrument (which is very soon for the LHC at CERN) -- networks must provide communication capability that is service-oriented: That is it must be configurable, schedulable, predictable, and reliable. In order to accomplish this, the research and education network community is undertaking a strategy that involves changes in network architecture to support multiple classes of service; development and deployment of service-oriented communication services, and; monitoring and reporting in a form that is directly useful to the application-oriented system so that it may adapt to communications failures. In this paper we describe ESnet's approach to each of these -- an approach that is part of an international community effort to have intra-distributed system communication be based on a service-oriented capability.

  18. Communication Skills–Core of Employability Skills: Issues & Concerns

    Directory of Open Access Journals (Sweden)

    A.V. Bharathi

    2016-12-01

    Full Text Available Based on a case study conducted by the researcher on a sample of 618 UG students, this paper focuses on identifying certain flaws in the present educational communication. The researcher after presenting the data analysis of the survey, attempts to highlight the present ELT scenario and its relevance to the present day needs of the society. It also emphasizes on the need to focus on practical dimensions of learning. It substantiates that inadequate language proficiency, lack of presentation skills knowledge and unawareness about life skills are the main reasons for the educated unemployment.  Finally, the researcher concludes this paper with some suggestions and recommendations which will help the learners to enhance their communication skills.                           

  19. Public communication activities of JAPC on the issue of radiation

    International Nuclear Information System (INIS)

    Ogawa, Junko

    2000-01-01

    Hiroshima occasionally but inevitably reminds the Japanese nation of the A-bomb casualties in terms of radiation hazards with mass-destruction. Even peaceful use of nuclear energy is easily perceived as a synonym of menacing nuke'. Firstly, nuclear PA is to get rid of concerns among the general public by credibility to be established by bi-directional communications and common sense as well as technical integrity. JAPC is in direct contacts with the people by such means as guiding tours to nuclear plants, sitting together for exchange of opinions, or having every employee to be a PA person with his or her neighbors. It is our lesson that PA success definitely depends on the authentic person-to-person bond of trust and credibility with right communications. The general public tends to get excessively concerned, once they are put in process of their perception of nuclear information, all of sudden from daily indifference, via mass-media or education in various forms. Such concerns override nuclear benefits and precipitate especially against invisible phenomena, technical complexity, black boxes, probability of risks. For example, radiologists or law-makers do not mind 10 digit numbers of radiation expressed in Becquerel (rather than Curie). Mass media simply report 5-6 digit higher spikes than normal level even if it is well below permissible level. But the general public is overwhelmed by such gigantic spike ratio. Right communications for nuclear PA shall be made on common sense of the society. (author)

  20. Research on optic antenna of space laser communication networking

    Science.gov (United States)

    Meng, Li-Xin; Li, Long; Zhang, Li-zhong; Zhao, Shan-shan; Jiang, Hui-lin

    2013-08-01

    With the highlights of the high transmission rate, large capacity, strong anti-interference and anti-capture ability, good security and small light, space laser communication becomes an important hotspot. At present, the focus of research of the laser communication system is point to point communication structure. However, from the application point of view, both the realization of space laser communication among multiple points and the establishment of the information transmission network can really have the practical value. Aiming at the problem of space laser communication network, this article puts forward the general idea about optical antenna to achieve multiple tracking goals at the same time. Through the analysis of the optical antenna, and the comparing of the current commonly used mirror driving mechanism, a new mirror driving mechanism is designed. The azimuth motion, containing circular grating feedback, is driven by torque motor,voice coil motor of fan produces pitch motion that has fan-shaped grating feedback, so that compression of the structure size to improve the efficiency of the reflector assembly. Through the establishment of the driving mechanism and the kinematic model of 3D entity, the relationship between the single drive azimuth and pitch angle following the angle of incident light is explained. The biggest ideal view area affecting the optical antenna is obtained by the simulation analysis of the kinematics model using MATLAB. The several factors of field overlap area and blind area offers a theoretical basis for structure optimization and control system for the subsequent optical antenna design.

  1. Capacity of Wireless Ad Hoc Networks with Opportunistic Collaborative Communications

    Directory of Open Access Journals (Sweden)

    Simeone O

    2007-01-01

    Full Text Available Optimal multihop routing in ad hoc networks requires the exchange of control messages at the MAC and network layer in order to set up the (centralized optimization problem. Distributed opportunistic space-time collaboration (OST is a valid alternative that avoids this drawback by enabling opportunistic cooperation with the source at the physical layer. In this paper, the performance of OST is investigated. It is shown analytically that opportunistic collaboration outperforms (centralized optimal multihop in case spatial reuse (i.e., the simultaneous transmission of more than one data stream is not allowed by the transmission protocol. Conversely, in case spatial reuse is possible, the relative performance between the two protocols has to be studied case by case in terms of the corresponding capacity regions, given the topology and the physical parameters of network at hand. Simulation results confirm that opportunistic collaborative communication is a promising paradigm for wireless ad hoc networks that deserves further investigation.

  2. Capacity of Wireless Ad Hoc Networks with Opportunistic Collaborative Communications

    Directory of Open Access Journals (Sweden)

    O. Simeone

    2007-03-01

    Full Text Available Optimal multihop routing in ad hoc networks requires the exchange of control messages at the MAC and network layer in order to set up the (centralized optimization problem. Distributed opportunistic space-time collaboration (OST is a valid alternative that avoids this drawback by enabling opportunistic cooperation with the source at the physical layer. In this paper, the performance of OST is investigated. It is shown analytically that opportunistic collaboration outperforms (centralized optimal multihop in case spatial reuse (i.e., the simultaneous transmission of more than one data stream is not allowed by the transmission protocol. Conversely, in case spatial reuse is possible, the relative performance between the two protocols has to be studied case by case in terms of the corresponding capacity regions, given the topology and the physical parameters of network at hand. Simulation results confirm that opportunistic collaborative communication is a promising paradigm for wireless ad hoc networks that deserves further investigation.

  3. Prevention, communication and equity in environmental epidemiology: ethical issues

    Directory of Open Access Journals (Sweden)

    Giordana Pagliarani

    2011-01-01

    Full Text Available In environmental epidemiology research, decisions about when and how to intervene requires adequate ethical reflection. In fact, different kinds of issues may arise about: research methods and knowledge production; management of the results in terms of their overall assessments or for the implementation of preventive actions; reclamation intervention. In this contribution we propose to consider three topics we regard as crucial to this ethical debate: the reporting of conclusive research data; the correct application of the precautionary principle; and the environmental equity issues.

  4. A reference model for the development of networked organizational communication: A communication perspective.

    NARCIS (Netherlands)

    de Vries, Sjoerd A.; Isaias, P.

    2002-01-01

    Organizational communication is increasingly based on electronic networks. The growth is seldom the result of a planned organizational development of these technologies, but mostly driven by 'rapid' technology developments and best user practices. To enable organizations to understand and to steer

  5. Ultra-Reliable Communications in Failure-Prone Realistic Networks

    DEFF Research Database (Denmark)

    Gerardino, Guillermo Andrés Pocovi; Lauridsen, Mads; Alvarez, Beatriz Soret

    2016-01-01

    We investigate the potential of different diversity and interference management techniques to achieve the required downlink SINR outage probability for ultra-reliable communications. The evaluation is performed in a realistic network deployment based on site-specific data from a European capital....... Micro and macroscopic diversity techniques are proved to be important enablers of ultra-reliable communications. Particularly, it is shown how a 4x4 MIMO scheme with three orders of macroscopic diversity can achieve the required SINR outage performance. Smaller gains are obtained from interference...

  6. Pertinent Strategy Issues in Scientific Information and Communication in 2004

    NARCIS (Netherlands)

    Roosendaal, Hans E.; Geurts, Petrus A.T.M.; Hilf, E.R.; Hauke, P.

    2005-01-01

    In this article we will discuss some broader developments in the field of scientific information with the aim to determine and analyse some of the pertinent strategic issues that the stakeholders will face at present time. The stakeholders in the value chain of scientific information are: the user

  7. Advanced Categorical Statistics: Issues and Applications in Communication Research.

    Science.gov (United States)

    Denham, Bryan E.

    2002-01-01

    Discusses not only the procedures, assumptions, and applications of advanced categorical statistics, but also covers some common misapplications, from which a great deal can be learned. Addresses the use and limitations of cross-tabulation and chi-square analysis, as well as issues such as observation independence and artificial inflation of a…

  8. Verbal working memory-related neural network communication in schizophrenia.

    Science.gov (United States)

    Kustermann, Thomas; Popov, Tzvetan; Miller, Gregory A; Rockstroh, Brigitte

    2018-04-19

    Impaired working memory (WM) in schizophrenia is associated with reduced hemodynamic and electromagnetic activity and altered network connectivity within and between memory-associated neural networks. The present study sought to determine whether schizophrenia involves disruption of a frontal-parietal network normally supporting WM and/or involvement of another brain network. Nineteen schizophrenia patients (SZ) and 19 healthy comparison subjects (HC) participated in a cued visual-verbal Sternberg task while dense-array EEG was recorded. A pair of item arrays each consisting of 2-4 consonants was presented bilaterally for 200 ms with a prior cue signaling the hemifield of the task-relevant WM set. A central probe letter 2,000 ms later prompted a choice reaction time decision about match/mismatch with the target WM set. Group and WM load effects on time domain and time-frequency domain 11-15 Hz alpha power were assessed for the cue-to-probe time window, and posterior 11-15 Hz alpha power and frontal 4-8 Hz theta power were assessed during the retention period. Directional connectivity was estimated via Granger causality, evaluating group differences in communication. SZ showed slower responding, lower accuracy, smaller overall time-domain alpha power increase, and less load-dependent alpha power increase. Midline frontal theta power increases did not vary by group or load. Network communication in SZ was characterized by temporal-to-posterior information flow, in contrast to bidirectional temporal-posterior communication in HC. Results indicate aberrant WM network activity supporting WM in SZ that might facilitate normal load-dependent and only marginally less accurate task performance, despite generally slower responding. © 2018 Society for Psychophysiological Research.

  9. High-Throughput Network Communication with NetIO

    CERN Document Server

    Schumacher, J\\"orn; The ATLAS collaboration; Vandelli, Wainer

    2016-01-01

    HPC network technologies like Infiniband, TrueScale or OmniPath provide low-latency and high-throughput communication between hosts, which makes them attractive options for data-acquisition systems in large-scale high-energy physics experiments. Like HPC networks, DAQ networks are local and include a well specified number of systems. Unfortunately traditional network communication APIs for HPC clusters like MPI or PGAS target exclusively the HPC community and are not suited well for DAQ applications. It is possible to build distributed DAQ applications using low-level system APIs like Infiniband Verbs (and this has been done), but it requires a non negligible effort and expert knowledge. On the other hand, message services like 0MQ have gained popularity in the HEP community. Such APIs allow to build distributed applications with a high-level approach and provide good performance. Unfortunately their usage usually limits developers to TCP/IP-based networks. While it is possible to operate a TCP/IP stack on to...

  10. 77 FR 12089 - Proposed Generic Communication; Regulatory Issue Summary 2012-XX: Developing Inservice Testing...

    Science.gov (United States)

    2012-02-28

    ... NUCLEAR REGULATORY COMMISSION [NRC-2012-0048] Proposed Generic Communication; Regulatory Issue... CFR) Part 52, ``Licenses, Certifications, and Approvals for Nuclear Power Plants,'' to satisfy the... inservice testing programs during the initial 120-month program interval following nuclear power plant...

  11. Radio propagation and adaptive antennas for wireless communication networks

    CERN Document Server

    Blaunstein, Nathan

    2014-01-01

    Explores novel wireless networks beyond 3G, and advanced 4G technologies, such as MIMO, via propagation phenomena and the fundamentals of adapted antenna usage.Explains how adaptive antennas can improve GoS and QoS for any wireless channel, with specific examples and applications in land, aircraft and satellite communications.Introduces new stochastic approach based on several multi-parametric models describing various terrestrial scenarios, which have been experimentally verified in different environmental conditionsNew chapters on fundamentals of wireless networks, cellular and non-cellular,

  12. Network secure communications based on beam halo-chaos

    International Nuclear Information System (INIS)

    Liu Qiang; Fang Jinqing; Li Yong

    2010-01-01

    Based on beam halo-chaos synchronization in the beam transport network (line)with small-world effect, using three synchronization methods:the driver-response synchronization, small-world topology coupling synchronization and multi-local small-world topology coupling synchronization, three kinds of secure communication projects were designed respectively, and were studied numerically by the Simulink tool of the Matlab software. Numerical experimental results demonstrate that encryption and decryption of the original signal are realized successfully. It provides effective theoretical foundation and reference for the next engineering design and network experiment. (authors)

  13. Stochastic network optimization with application to communication and queueing systems

    CERN Document Server

    Neely, Michael

    2010-01-01

    This text presents a modern theory of analysis, control, and optimization for dynamic networks. Mathematical techniques of Lyapunov drift and Lyapunov optimization are developed and shown to enable constrained optimization of time averages in general stochastic systems. The focus is on communication and queueing systems, including wireless networks with time-varying channels, mobility, and randomly arriving traffic. A simple drift-plus-penalty framework is used to optimize time averages such as throughput, throughput-utility, power, and distortion. Explicit performance-delay tradeoffs are prov

  14. ECS: Efficient Communication Scheduling for Underwater Sensor Networks

    Directory of Open Access Journals (Sweden)

    Lu Hong

    2011-03-01

    Full Text Available TDMA protocols have attracted a lot of attention for underwater acoustic sensor networks (UWSNs, because of the unique characteristics of acoustic signal propagation such as great energy consumption in transmission, long propagation delay and long communication range. Previous TDMA protocols all allocated transmission time to nodes based on discrete time slots. This paper proposes an efficient continuous time scheduling TDMA protocol (ECS for UWSNs, including the continuous time based and sender oriented conflict analysis model, the transmission moment allocation algorithm and the distributed topology maintenance algorithm. Simulation results confirm that ECS improves network throughput by 20% on average, compared to existing MAC protocols.

  15. Study on Communication Mode of Wireless Sensor Networks Based on Effective Result

    International Nuclear Information System (INIS)

    Shi, J F; Zhong, X X; Chen, S

    2006-01-01

    The key challenge in wireless sensor networks is maximizing network lifetime. It will significantly reduce energy consumption of communication and prolong networks lifetime to choose appropriate communication mode. In this paper, energy model and communication topology are proposed, and then from the viewpoint of effective result, expression for communication energy cost of single sensor node and overall system in different communication mode is derived, impact that sensor nodes amount, communication radius and propagation loss exponent pose on communication mode based on simulations is analyzed, and the justification for choosing communication mode is summarized

  16. The construction of corporate social responsibility in network societies: A communication view

    NARCIS (Netherlands)

    Schultz, F.; Castello, I.; Morsing, M.

    2013-01-01

    The paper introduces the communication view on Corporate Social Responsibility (CSR), which regards CSR as communicatively constructed in dynamic interaction processes in today's networked societies. Building on the idea that communication constitutes organizations we discuss the potentially

  17. Gigabit Satellite Network for NASA's Advanced Communication Technology Satellite (ACTS)

    Science.gov (United States)

    Hoder, Douglas; Bergamo, Marcos

    1996-01-01

    The advanced communication technology satellite (ACTS) gigabit satellite network provides long-haul point-to-point and point-to-multipoint full-duplex SONET services over NASA's ACTS. at rates up to 622 Mbit/s (SONET OC-12), with signal quality comparable to that obtained with terrestrial fiber networks. Data multiplexing over the satellite is accomplished using time-division multiple access (TDMA) techniques coordinated with the switching and beam hopping facilities provided by ACTS. Transmissions through the satellite are protected with Reed-Solomon encoding. providing virtually error-free transmission under most weather conditions. Unique to the system are a TDMA frame structure and satellite synchronization mechanism that allow: (a) very efficient utilization of the satellite capacity: (b) over-the-satellite dosed-loop synchronization of the network in configurations with up to 64 ground stations: and (c) ground station initial acquisition without collisions with existing signalling or data traffic. The user interfaces are compatible with SONET standards, performing the function of conventional SONET multiplexers and. as such. can be: readily integrated with standard SONET fiber-based terrestrial networks. Management of the network is based upon the simple network management protocol (SNMP). and includes an over-the-satellite signalling network and backup terrestrial internet (IP-based) connectivity. A description of the ground stations is also included.

  18. Conference communication. Managing change in tourism destinations: Key issues and current trends.

    OpenAIRE

    Mariani, M.M.; Buhalis, Dimitrios; Longhi, C.; Vitouladiti, O.

    2013-01-01

    This conference communication illustrates the major outcomes emerging from the EIASM Conference on Tourism Management and Tourism Related Issues held in Nice (France), September 20-21, 2012. While a number of managerial issues pertaining to the tourism field were dealt with, this communication covers three specific areas of interest for destination management and marketing: (1) the increasing competition among tourism destinations and the rise and consolidation of BRIC countries as outbound t...

  19. Nanoscale molecular communication networks: a game-theoretic perspective

    Science.gov (United States)

    Jiang, Chunxiao; Chen, Yan; Ray Liu, K. J.

    2015-12-01

    Currently, communication between nanomachines is an important topic for the development of novel devices. To implement a nanocommunication system, diffusion-based molecular communication is considered as a promising bio-inspired approach. Various technical issues about molecular communications, including channel capacity, noise and interference, and modulation and coding, have been studied in the literature, while the resource allocation problem among multiple nanomachines has not been well investigated, which is a very important issue since all the nanomachines share the same propagation medium. Considering the limited computation capability of nanomachines and the expensive information exchange cost among them, in this paper, we propose a game-theoretic framework for distributed resource allocation in nanoscale molecular communication systems. We first analyze the inter-symbol and inter-user interference, as well as bit error rate performance, in the molecular communication system. Based on the interference analysis, we formulate the resource allocation problem as a non-cooperative molecule emission control game, where the Nash equilibrium is found and proved to be unique. In order to improve the system efficiency while guaranteeing fairness, we further model the resource allocation problem using a cooperative game based on the Nash bargaining solution, which is proved to be proportionally fair. Simulation results show that the Nash bargaining solution can effectively ensure fairness among multiple nanomachines while achieving comparable social welfare performance with the centralized scheme.

  20. Asymmetries in commitment in an avian communication network

    Science.gov (United States)

    Randler, Christoph; Vollmer, Christian

    2013-02-01

    Mobbing of predators occurs within a conspecific and heterospecific context but has not been quantified within the framework of a communication network and analysed with respect to heterospecific reciprocity. Here, we used playbacks of mobbing calls to show that mobbing is unequally distributed within a community of deciduous forest birds. Five species (great tit Parus major, blue tit Cyanistes caeruleus, marsh tit Poecile palustris, nuthatch Sitta europaea and chaffinch Fringilla coelebs) responded to each other's playbacks of mobbing calls. Commitment to mob was measured by minimum distance, response latency and uttering of calls. Commitment was higher when conspecific calls were broadcast. Yet, responses to heterospecific calls were significantly different between the five species. Chaffinches had the lowest commitment, and blue tits tended to have the highest. The communication network is asymmetric. Some species invest more than they receive from other species. As mobbing might incur costs, these are unequally distributed across the community.

  1. Modeling and analysis of mobility management in mobile communication networks.

    Science.gov (United States)

    Baek, Woon Min; Yoon, Ji Hyun; Kim, Chesoong

    2014-01-01

    Many strategies have been proposed to reduce the mobility management cost in mobile communication networks. This paper studies the zone-based registration methods that have been adopted by most mobile communication networks. We focus on two special zone-based registration methods, called two-zone registration (2Z) and two-zone registration with implicit registration by outgoing calls (2Zi). We provide a new mathematical model to analyze the exact performance of 2Z and 2Zi. We also present various numerical results, to compare the performance of 2Zi with those of 2Z and one-zone registration (1Z), and show that 2Zi is superior to 2Z as well as 1Z in most cases.

  2. Capitalist Crisis, Communication, & Culture – Introduction to the Special Issue of tripleC

    OpenAIRE

    Christian Fuchs; Matthias Schafranek; David Hakken; Marcus Breen

    2010-01-01

    The worldwide economic downturn is indicative for a new large crisis of capitalism. The future of capitalism is in this situation not determined, but depends on collective human agency. This introduction to the special issue of tripleC on “Capitalist Crisis, Communication & Culture” presents general arguments about the crisis, a general model of the political economy of capitalist communication, and a systematic typology of literature about capitalist crisis & communication. The introduced mo...

  3. Key issues of public relations of Europe: findings from the European Communication Monitor 2007-2014

    NARCIS (Netherlands)

    Verčič, D.; Verhoeven, P.; Zerfass, A.

    2014-01-01

    European Communication Monitor is the largest longitudinal research project in public relations practice in the world. Data collected annually from 2007 to 2014 show that practitioners perceive five issues as the most important for their work: linking business strategy and communication, coping with

  4. Enhancing Students' Communication Skills in the Science Classroom through Socioscientific Issues

    Science.gov (United States)

    Chung, Yoonsook; Yoo, Jungsook; Kim, Sung-Won; Lee, Hyunju; Zeidler, Dana L.

    2016-01-01

    Communication skills are one of the most important competencies for 21st century global citizens. Our guiding presupposition was that socioscientific issues (SSIs) could be used as an effective pedagogical tool for promoting students' communication skills by increasing peer interactions, stimulating students' reasoning, and in constructing shared…

  5. Analyzing the Dynamics of Communication in Online Social Networks

    Science.gov (United States)

    de Choudhury, Munmun; Sundaram, Hari; John, Ajita; Seligmann, Doree Duncan

    This chapter deals with the analysis of interpersonal communication dynamics in online social networks and social media. Communication is central to the evolution of social systems. Today, the different online social sites feature variegated interactional affordances, ranging from blogging, micro-blogging, sharing media elements (i.e., image, video) as well as a rich set of social actions such as tagging, voting, commenting and so on. Consequently, these communication tools have begun to redefine the ways in which we exchange information or concepts, and how the media channels impact our online interactional behavior. Our central hypothesis is that such communication dynamics between individuals manifest themselves via two key aspects: the information or concept that is the content of communication, and the channel i.e., the media via which communication takes place. We present computational models and discuss large-scale quantitative observational studies for both these organizing ideas. First, we develop a computational framework to determine the "interestingness" property of conversations cented around rich media. Second, we present user models of diffusion of social actions and study the impact of homophily on the diffusion process. The outcome of this research is twofold. First, extensive empirical studies on datasets from YouTube have indicated that on rich media sites, the conversations that are deemed "interesting" appear to have consequential impact on the properties of the social network they are associated with: in terms of degree of participation of the individuals in future conversations, thematic diffusion as well as emergent cohesiveness in activity among the concerned participants in the network. Second, observational and computational studies on large social media datasets such as Twitter have indicated that diffusion of social actions in a network can be indicative of future information cascades. Besides, given a topic, these cascades are often a

  6. Development and Analyses of Privacy Management Models in Online Social Networks Based on Communication Privacy Management Theory

    Science.gov (United States)

    Lee, Ki Jung

    2013-01-01

    Online social networks (OSNs), while serving as an emerging means of communication, promote various issues of privacy. Users of OSNs encounter diverse occasions that lead to invasion of their privacy, e.g., published conversation, public revelation of their personally identifiable information, and open boundary of distinct social groups within…

  7. Role of information and communication networks in malaria survival

    Directory of Open Access Journals (Sweden)

    Marathe Achla

    2007-10-01

    Full Text Available Abstract Background Quite often symptoms of malaria go unrecognized or untreated. According to the Multilateral Initiative on Malaria, 70% of the malaria cases that are treated at home are mismanaged. Up to 82% of all malaria episodes in sub-Saharan Africa are treated outside the formal health sector. Fast and appropriate diagnosis and treatment of malaria is extremely important in reducing morbidity and mortality. Method Data from 70 different countries is pooled together to construct a panel dataset of health and socio-economic variables for a time span of (1960–2004. The generalized two-stage least squares and panel data models are used to investigate the impact of information and communication network (ICN variables on malaria death probability. The intensity of ICN is represented by the number of telephone main lines per 1,000 people and the number of television sets per 1,000 people. Results The major finding is that the intensity of ICN is associated with reduced probability of deaths of people that are clinically identified as malaria infected. The results are robust for both indicators i.e. interpersonal and mass communication networks and for all model specifications examined. Conclusion The results suggest that information and communication networks can substantially scale up the effectiveness of the existing resources for malaria prevention. Resources spent in preventing malaria are far less than needed. Expanded information and communication networks will widen the avenues for community based "participatory development", that encourages the use of local information, knowledge and decision making. Timely information, immediate care and collective knowledge based treatment can be extremely important in reducing child mortality and achieving the millennium development goal.

  8. Information communications technologies that surpass the global communications network. Sekai tsushinmo o koeru joho tsushin gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    1990-05-01

    Development of information communications technologies that surpass the global communications network is being pushed forward in order to establish the global village that McLuhan foretold in 1964. Effects of hybrid intensification with the intensification of communications technologies and computer technologies have become evident as facsimiles, automated teller machines of banks, home videos, automatic response telephones with synthetic voices, compact disks, portable telephones, video games and high-definition televisions were developed and put to use in a wide range. Intensification and integration of computer technologies and communications technologies has every possibility, but it also has a peculiar aspect of lacking guiding principles. Uncertain factors of the values of informations in the market are ever increasing, and their true values are yet to be found. Anyhow, it is a long way to the goal of the global village.

  9. Experience on the FMS Communication module Development for an Application to Safety- Critical Communication Network

    Energy Technology Data Exchange (ETDEWEB)

    Son, Kwang Seop; Lee, Jang Soo; Kim, Jung Heon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2009-05-15

    The field bus has been developed for a network system which supports the real-time communication of various controls and automation equipment. It is known for Profibus in the field of a production automation environment. The Profibus standard uses open communication based on the ISO/OSI model. The Probibus standard uses layer 1, layer 2, layer 7. Layer 7 of Probibus FMS(Fieldbus Message Specification) provides a information and the user of a station. The high-level communication of the safety-grade PLC (POSAFE-Q) developed through the KNICS(Korea Nuclear I and C System) project is the FMS This paper describes the design, the configuration, and the test method of the FMS communication module.

  10. Experience on the FMS Communication module Development for an Application to Safety- Critical Communication Network

    International Nuclear Information System (INIS)

    Son, Kwang Seop; Lee, Jang Soo; Kim, Jung Heon

    2009-01-01

    The field bus has been developed for a network system which supports the real-time communication of various controls and automation equipment. It is known for Profibus in the field of a production automation environment. The Profibus standard uses open communication based on the ISO/OSI model. The Probibus standard uses layer 1, layer 2, layer 7. Layer 7 of Probibus FMS(Fieldbus Message Specification) provides a information and the user of a station. The high-level communication of the safety-grade PLC (POSAFE-Q) developed through the KNICS(Korea Nuclear I and C System) project is the FMS This paper describes the design, the configuration, and the test method of the FMS communication module

  11. How Networked Communication Has Changed the Ways We Tell Stories

    Directory of Open Access Journals (Sweden)

    Anna Notaro

    2014-12-01

    Full Text Available In the midst of the digital revolution, we are confronted with the task of defining how media will change our lives and how we communicate with each other in the years to come. Narrative, as one of the most ancient communication tools, has undergone substantial structural changes. This paper addresses how these changes impact the way we read and write. Does the same story conveyed through different media channels signify in the same manner? In other words, what are the differences between a printed story and a digitally presented one? Have electronic reader devices altered the way stories are told and created? And how is networked communication changing the ways we tell stories?

  12. Security Policy for a Generic Space Exploration Communication Network Architecture

    Science.gov (United States)

    Ivancic, William D.; Sheehe, Charles J.; Vaden, Karl R.

    2016-01-01

    This document is one of three. It describes various security mechanisms and a security policy profile for a generic space-based communication architecture. Two other documents accompany this document- an Operations Concept (OpsCon) and a communication architecture document. The OpsCon should be read first followed by the security policy profile described by this document and then the architecture document. The overall goal is to design a generic space exploration communication network architecture that is affordable, deployable, maintainable, securable, evolvable, reliable, and adaptable. The architecture should also require limited reconfiguration throughout system development and deployment. System deployment includes subsystem development in a factory setting, system integration in a laboratory setting, launch preparation, launch, and deployment and operation in space.

  13. REDISTRIBUTION OF BASE STATIONS LOAD IN MOBILE COMMUNICATION NETWORKS

    Directory of Open Access Journals (Sweden)

    Igor Ruban

    2017-09-01

    Full Text Available The subject matter of the article is the processes of load distribution in mobile communication networks. The object of research is the handover. The goal is to develop a method for redistributing the load between neighboring areas for mobile nodes. The considered base stations are supposed to have the signal-to-noise ratios that are equal or close. The methods that are used: methods of system analysis, methods of digital signal processing. The following results are obtained. The method that allows mobile nodes, whose signal-to-noise ratios are equal or close, to switch to a less loaded base station. This method allows the base station to launch the handover process enabling more even distribution of the load from mobile nodes among neighboring base stations in wireless and mobile networks. In the suggested modification of the method, the function assessing the bandwidth of the uplink channel is added to the base stations, as well a threshold value for using its bandwidth. Thus, when the current value of bandwidth reaches the threshold, the base station starts sending out a message to all mobile nodes and verifies free neighboring areas for switching over mobile nodes. If there are adjacent areas with a lower load, the base station notifies all potential candidates about the necessity of their switching over. The handover process is launched when the available bandwidth of the base station decreases below a certain threshold. Therefore, it is possible to optimize the operation of the WiMAX network with respect to the criterion of the total bandwidth capacity of the base stations. Besides, the results of the comparative analysis of the handover process in networks based on the WiMAX technology that are obtained using the OpNet simulation environment are presented. Conclusions.The suggested approach can be used to improve the basic software of mobile communication networks. When moving a node from one area to another one in access servers, the

  14. Neural Networks and Fault Probability Evaluation for Diagnosis Issues

    Science.gov (United States)

    Lefebvre, Dimitri; Guersi, Noureddine

    2014-01-01

    This paper presents a new FDI technique for fault detection and isolation in unknown nonlinear systems. The objective of the research is to construct and analyze residuals by means of artificial intelligence and probabilistic methods. Artificial neural networks are first used for modeling issues. Neural networks models are designed for learning the fault-free and the faulty behaviors of the considered systems. Once the residuals generated, an evaluation using probabilistic criteria is applied to them to determine what is the most likely fault among a set of candidate faults. The study also includes a comparison between the contributions of these tools and their limitations, particularly through the establishment of quantitative indicators to assess their performance. According to the computation of a confidence factor, the proposed method is suitable to evaluate the reliability of the FDI decision. The approach is applied to detect and isolate 19 fault candidates in the DAMADICS benchmark. The results obtained with the proposed scheme are compared with the results obtained according to a usual thresholding method. PMID:25132845

  15. Communication and cooperation in networked environments: an experimental analysis.

    Science.gov (United States)

    Galimberti, C; Ignazi, S; Vercesi, P; Riva, G

    2001-02-01

    Interpersonal communication and cooperation do not happen exclusively face to face. In work contexts, as in private life, there are more and more situations of mediated communication and cooperation in which new online tools are used. However, understanding how to use the Internet to support collaborative interaction presents a substantial challenge for the designers and users of this emerging technology. First, collaborative Internet environments are designed to serve a purpose, so must be designed with intended users' tasks and goals explicitly considered. Second, in cooperative activities the key content of communication is the interpretation of the situations in which actors are involved. So, the most effective way of clarifying the meaning of messages is to connect them to a shared context of meaning. However, this is more difficult in the Internet than in other computer-based activities. This paper tries to understand the characteristics of cooperative activities in networked environments--shared 3D virtual worlds--through two different studies. The first used the analysis of conversations to explore the characteristics of the interaction during the cooperative task; the second analyzed whether and how the level of immersion in the networked environments influenced the performance and the interactional process. The results are analyzed to identify the psychosocial roots used to support cooperation in a digital interactive communication.

  16. 75 FR 26180 - Effects on Broadband Communications Networks of Damage To or Failure of Network Equipment or...

    Science.gov (United States)

    2010-05-11

    ... FEDERAL COMMUNICATIONS COMMISSION 47 CFR Chapter I [PS Docket No. 10-92; FCC 10-62] Effects on... the National Broadband Plan, the Federal Communications Commission (Commission or FCC) adopted this... networks and to explore potential measures to reduce network vulnerability to failures in network equipment...

  17. SDN-Enabled Communication Network Framework for Energy Internet

    Directory of Open Access Journals (Sweden)

    Zhaoming Lu

    2017-01-01

    Full Text Available To support distributed energy generators and improve energy utilization, energy Internet has attracted global research focus. In China, energy Internet has been proposed as an important issue of government and institutes. However, managing a large amount of distributed generators requires smart, low-latency, reliable, and safe networking infrastructure, which cannot be supported by traditional networks in power grids. In order to design and construct smart and flexible energy Internet, we proposed a software defined network framework with both microgrid cluster level and global grid level designed by a hierarchical manner, which will bring flexibility, efficiency, and reliability for power grid networks. Finally, we evaluate and verify the performance of this framework in terms of latency, reliability, and security by both theoretical analysis and real-world experiments.

  18. Network Gateway Technology: The Issue of Redundancy towards ...

    African Journals Online (AJOL)

    The Internet has provided advancement in the areas of network and networking facilities. Everyone connected to the Internet is concerned about two basic things: the availability of network services and the speed of the network. Network gateway redundancy technology falls within these categories and happens to be one of ...

  19. Chain-based communication in cylindrical underwater wireless sensor networks.

    Science.gov (United States)

    Javaid, Nadeem; Jafri, Mohsin Raza; Khan, Zahoor Ali; Alrajeh, Nabil; Imran, Muhammad; Vasilakos, Athanasios

    2015-02-04

    Appropriate network design is very significant for Underwater Wireless Sensor Networks (UWSNs). Application-oriented UWSNs are planned to achieve certain objectives. Therefore, there is always a demand for efficient data routing schemes, which can fulfill certain requirements of application-oriented UWSNs. These networks can be of any shape, i.e., rectangular, cylindrical or square. In this paper, we propose chain-based routing schemes for application-oriented cylindrical networks and also formulate mathematical models to find a global optimum path for data transmission. In the first scheme, we devise four interconnected chains of sensor nodes to perform data communication. In the second scheme, we propose routing scheme in which two chains of sensor nodes are interconnected, whereas in third scheme single-chain based routing is done in cylindrical networks. After finding local optimum paths in separate chains, we find global optimum paths through their interconnection. Moreover, we develop a computational model for the analysis of end-to-end delay. We compare the performance of the above three proposed schemes with that of Power Efficient Gathering System in Sensor Information Systems (PEGASIS) and Congestion adjusted PEGASIS (C-PEGASIS). Simulation results show that our proposed 4-chain based scheme performs better than the other selected schemes in terms of network lifetime, end-to-end delay, path loss, transmission loss, and packet sending rate.

  20. Chain-Based Communication in Cylindrical Underwater Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Nadeem Javaid

    2015-02-01

    Full Text Available Appropriate network design is very significant for Underwater Wireless Sensor Networks (UWSNs. Application-oriented UWSNs are planned to achieve certain objectives. Therefore, there is always a demand for efficient data routing schemes, which can fulfill certain requirements of application-oriented UWSNs. These networks can be of any shape, i.e., rectangular, cylindrical or square. In this paper, we propose chain-based routing schemes for application-oriented cylindrical networks and also formulate mathematical models to find a global optimum path for data transmission. In the first scheme, we devise four interconnected chains of sensor nodes to perform data communication. In the second scheme, we propose routing scheme in which two chains of sensor nodes are interconnected, whereas in third scheme single-chain based routing is done in cylindrical networks. After finding local optimum paths in separate chains, we find global optimum paths through their interconnection. Moreover, we develop a computational model for the analysis of end-to-end delay. We compare the performance of the above three proposed schemes with that of Power Efficient Gathering System in Sensor Information Systems (PEGASIS and Congestion adjusted PEGASIS (C-PEGASIS. Simulation results show that our proposed 4-chain based scheme performs better than the other selected schemes in terms of network lifetime, end-to-end delay, path loss, transmission loss, and packet sending rate.

  1. Reliable and Efficient Communications in Wireless Sensor Networks

    International Nuclear Information System (INIS)

    Abdelhakim, M.M.

    2014-01-01

    Wireless sensor network (WSN) is a key technology for a wide range of military and civilian applications. Limited by the energy resources and processing capabilities of the sensor nodes, reliable and efficient communications in wireless sensor networks are challenging, especially when the sensors are deployed in hostile environments. This research aims to improve the reliability and efficiency of time-critical communications in WSNs, under both benign and hostile environments. We start with wireless sensor network with mobile access points (SENMA), where the mobile access points traverse the network to collect information from individual sensors. Due to its routing simplicity and energy efficiency, SENMA has attracted lots of attention from the research community. Here, we study reliable distributed detection in SENMA under Byzantine attacks, where some authenticated sensors are compromised to report fictitious information. The q-out-of-m rule is considered. It is popular in distributed detection and can achieve a good trade-off between the miss detection probability and the false alarm rate. However, a major limitation with this rule is that the optimal scheme parameters can only be obtained through exhaustive search. By exploiting the linear relationship between the scheme parameters and the network size, we propose simple but effective sub-optimal linear approaches. Then, for better flexibility and scalability, we derive a near-optimal closed-form solution based on the central limit theorem. It is proved that the false alarm rate of the q-out-of-m scheme diminishes exponentially as the network size increases, even if the percentage of malicious nodes remains fixed. This implies that large-scale sensor networks are more reliable under malicious attacks. To further improve the performance under time varying attacks, we propose an effective malicious node detection scheme for adaptive data fusion; the proposed scheme is analyzed using the entropy-based trust model

  2. The communications in early warning network for radiation monitoring

    International Nuclear Information System (INIS)

    Oyoun, M.B.; Al-Hussin, Mohamad; Fares, Adnan; Al-Oulabi, Yasser; Othman, Ibrahim

    1992-07-01

    The objectives of early warning network are: The determination of gamma radiation (background) levels in air which depend on location and time, evaluation of any situation resulting from radiation or nuclear accident out of boarder, and after that reporting the emergency situation to relevant authorities on the national and international levels. Monitoring stations were installed using Gm tubes to cover boarder lines from south to north and east to west as follows: Damascus, Darra, Latakia, Tartous, Aleppo, Kamishly, Ragaa, and Qunitra. The following modes of communication: Telephone line, leased line, direct connection, and Syrian data network were used in the Syrian early network. This project was carried out in cooperation with IAEA under project no. RER/9/003. (author). 22 figs., 1 tab

  3. Ethical Issues Associated with Information and Communication Technology in Counseling and Guidance

    Science.gov (United States)

    Sampson, James P., Jr.; Makela, Julia Panke

    2014-01-01

    For more than 50 years, literature on the use of information and communication technology in counseling and guidance has presented ethical issues related to the development and use of technologies in practice. This paper reviews the ethical issues raised, organizing them into three categories: Social equity, resources, and services. Career…

  4. Altered network communication following a neuroprotective drug treatment.

    Directory of Open Access Journals (Sweden)

    Kathleen Vincent

    Full Text Available Preconditioning is defined as a range of stimuli that allow cells to withstand subsequent anaerobic and other deleterious conditions. While cell protection under preconditioning is well established, this paper investigates the influence of neuroprotective preconditioning drugs, 4-aminopyridine and bicuculline (4-AP/bic, on synaptic communication across a broad network of in vitro rat cortical neurons. Using a permutation test, we evaluated cross-correlations of extracellular spiking activity across all pairs of recording electrodes on a 64-channel multielectrode array. The resulting functional connectivity maps were analyzed in terms of their graph-theoretic properties. A small-world effect was found, characterized by a functional network with high clustering coefficient and short average path length. Twenty-four hours after exposure to 4-AP/bic, small-world properties were comparable to control cultures that were not treated with the drug. Four hours following drug washout, however, the density of functional connections increased, while path length decreased and clustering coefficient increased. These alterations in functional connectivity were maintained at four days post-washout, suggesting that 4-AP/bic preconditioning leads to long-term effects on functional networks of cortical neurons. Because of their influence on communication efficiency in neuronal networks, alterations in small-world properties hold implications for information processing in brain systems. The observed relationship between density, path length, and clustering coefficient is captured by a phenomenological model where connections are added randomly within a spatially-embedded network. Taken together, results provide information regarding functional consequences of drug therapies that are overlooked in traditional viability studies and present the first investigation of functional networks under neuroprotective preconditioning.

  5. The issue of communication in the nuclear technology

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, A.B.; Ferreira, W. [Instituto de Radioprotecao e Dosimetria (IRD), Rio de Janeiro, RJ (Brazil). Dept. de Emergencias Radiologicas

    2001-07-01

    Surveys carried out on samples of the population of the city of Goiania, during the years of 1990 and between the years 1992 and 1996, shed light on how the population, after the Goiania accident, perceives radiation as a high risk over which they have no control. Radiation is perceived as the representation of the environment's contamination, destruction, cancer, genetic degeneration and death. As such, using a psychology terminology, nuclear energy could be considered the symbol of death. Other research results prove that this fear of radiation is so high as to provoke alterations in the individuals organism started by biochemical and neuro-physiological processes that provoke health hazards much higher that radiation itself. Only aggressive educational campaigns and explanation given to the population through the regulatory authorities on the risks and benefits of nuclear energy, employing people with credibility over the communities, can minimize this risk perception. These communication processes are of extreme importance in order that nuclear energy can have adequate public acceptance. This is a recommendation that has already been being made for a couple of decades. Providence about educational programs should be considered priority by governments. (author)

  6. The issue of communication in the nuclear technology

    International Nuclear Information System (INIS)

    Carvalho, A.B.; Ferreira, W.

    2001-01-01

    Surveys carried out on samples of the population of the city of Goiania, during the years of 1990 and between the years 1992 and 1996, shed light on how the population, after the Goiania accident, perceives radiation as a high risk over which they have no control. Radiation is perceived as the representation of the environment's contamination, destruction, cancer, genetic degeneration and death. As such, using a psychology terminology, nuclear energy could be considered the symbol of death. Other research results prove that this fear of radiation is so high as to provoke alterations in the individuals organism started by biochemical and neuro-physiological processes that provoke health hazards much higher that radiation itself. Only aggressive educational campaigns and explanation given to the population through the regulatory authorities on the risks and benefits of nuclear energy, employing people with credibility over the communities, can minimize this risk perception. These communication processes are of extreme importance in order that nuclear energy can have adequate public acceptance. This is a recommendation that has already been being made for a couple of decades. Providence about educational programs should be considered priority by governments. (author)

  7. Risk communication, geoethics and decision science issues in Japan's disaster management system

    Science.gov (United States)

    Sugimoto, M.

    2014-12-01

    Issues in Japan's disaster management system were revealed by the 2011 Tohoku earthquake and tsunami, and by the Fukushima Dai-ichi nuclear power station accident. Many important decisions were based on scientific data, but appear not to have sufficiently considered the uncertainties of the data and the societal aspects of the problems. The issues that arose show the need for scientists to appropriately deal with risk communication and geoethics and issues. This paper discusses necessity of education for risk communication, geoethics and decisions science in school before students become sicentific decision makers in future.

  8. Decomposing issue patterns in crisis communication : the case of the lost airliner

    OpenAIRE

    Zhang, Boyang; Vos, Marita; Veijalainen, Jari

    2018-01-01

    This research explores the relation between a crisis and public discussion on related issues. In organisational crisis communication, a singleissue strategy is often proposed. Such a strategy, however, may not be adequate in more complex crises where the crisis lifecycle is likely to encompass shorter lifecycles of issues that generate media attention. Decomposing the online crisis debate into a pattern of issues supports understanding of public perceptions, and hence of cri...

  9. Space Mobile Network: A Near Earth Communications and Navigation Architecture

    Science.gov (United States)

    Israel, David J.; Heckler, Gregory W.; Menrad, Robert J.

    2016-01-01

    This paper shares key findings of NASA's Earth Regime Network Evolution Study (ERNESt) team resulting from its 18-month effort to define a wholly new architecture-level paradigm for the exploitation of space by civil space and commercial sector organizations. Since the launch of Sputnik in October 1957 spaceflight missions have remained highly scripted activities from launch through disposal. The utilization of computer technology has enabled dramatic increases in mission complexity; but, the underlying premise that the diverse actions necessary to meet mission goals requires minute-by-minute scripting, defined weeks in advance of execution, for the life of the mission has remained. This archetype was appropriate for a "new frontier" but now risks overtly constraining the potential market-based opportunities for the innovation considered necessary to efficiently address the complexities associated with meeting communications and navigation requirements projected to be characteristics of the next era of space exploration: a growing number of missions in simultaneous execution, increased variance of mission types and growth in location/orbital regime diversity. The resulting ERNESt architectural cornerstone - the Space Mobile Network (SMN) - was envisioned as critical to creating an environment essential to meeting these future challenges in political, programmatic, technological and budgetary terms. The SMN incorporates technologies such as: Disruption Tolerant Networking (DTN) and optical communications, as well as new operations concepts such as User Initiated Services (UIS) to provide user services analogous to today's terrestrial mobile network user. Results developed in collaboration with NASA's Space Communications and Navigation (SCaN) Division and field centers are reported on. Findings have been validated via briefings to external focus groups and initial ground-based demonstrations. The SMN opens new niches for exploitation by the marketplace of mission

  10. Full-Duplex Communications in Large-Scale Cellular Networks

    KAUST Repository

    AlAmmouri, Ahmad

    2016-04-01

    In-band full-duplex (FD) communications have been optimistically promoted to improve the spectrum utilization and efficiency. However, the penetration of FD communications to the cellular networks domain is challenging due to the imposed uplink/downlink interference. This thesis presents a tractable framework, based on stochastic geometry, to study FD communications in multi-tier cellular networks. Particularly, we assess the FD communications effect on the network performance and quantify the associated gains. The study proves the vulnerability of the uplink to the downlink interference and shows that the improved FD rate gains harvested in the downlink (up to 97%) comes at the expense of a significant degradation in the uplink rate (up to 94%). Therefore, we propose a novel fine-grained duplexing scheme, denoted as α-duplex scheme, which allows a partial overlap between the uplink and the downlink frequency bands. We derive the required conditions to harvest rate gains from the α-duplex scheme and show its superiority to both the FD and half-duplex (HD) schemes. In particular, we show that the α-duplex scheme provides a simultaneous improvement of 28% for the downlink rate and 56% for the uplink rate. We also show that the amount of the overlap can be optimized based on the network design objective. Moreover, backward compatibility is an essential ingredient for the success of new technologies. In the context of in-band FD communication, FD base stations (BSs) should support HD users\\' equipment (UEs) without sacrificing the foreseen FD gains. The results show that FD-UEs are not necessarily required to harvest rate gains from FD-BSs. In particular, the results show that adding FD-UEs to FD-BSs offers a maximum of 5% rate gain over FD-BSs and HD-UEs case, which is a marginal gain compared to the burden required to implement FD transceivers at the UEs\\' side. To this end, we shed light on practical scenarios where HD-UEs operation with FD-BSs outperforms the

  11. Network security with openSSL cryptography for secure communications

    CERN Document Server

    Viega, John; Chandra, Pravir

    2002-01-01

    Most applications these days are at least somewhat network aware, but how do you protect those applications against common network security threats? Many developers are turning to OpenSSL, an open source version of SSL/TLS, which is the most widely used protocol for secure network communications.The OpenSSL library is seeing widespread adoption for web sites that require cryptographic functions to protect a broad range of sensitive information, such as credit card numbers and other financial transactions. The library is the only free, full-featured SSL implementation for C and C++, and it can be used programmatically or from the command line to secure most TCP-based network protocols.Network Security with OpenSSL enables developers to use this protocol much more effectively. Traditionally, getting something simple done in OpenSSL could easily take weeks. This concise book gives you the guidance you need to avoid pitfalls, while allowing you to take advantage of the library?s advanced features. And, inst...

  12. Strategies for Power Line Communications Smart Metering Network Deployment

    Directory of Open Access Journals (Sweden)

    Alberto Sendin

    2014-04-01

    Full Text Available Smart Grids are becoming a reality all over the world. Nowadays, the research efforts for the introduction and deployment of these grids are mainly focused on the development of the field of Smart Metering. This emerging application requires the use of technologies to access the significant number of points of supply (PoS existing in the grid, covering the Low Voltage (LV segment with the lowest possible costs. Power Line Communications (PLC have been extensively used in electricity grids for a variety of purposes and, of late, have been the focus of renewed interest. PLC are really well suited for quick and inexpensive pervasive deployments. However, no LV grid is the same in any electricity company (utility, and the particularities of each grid evolution, architecture, circumstances and materials, makes it a challenge to deploy Smart Metering networks with PLC technologies, with the Smart Grid as an ultimate goal. This paper covers the evolution of Smart Metering networks, together with the evolution of PLC technologies until both worlds have converged to project PLC-enabled Smart Metering networks towards Smart Grid. This paper develops guidelines over a set of strategic aspects of PLC Smart Metering network deployment based on the knowledge gathered on real field; and introduces the future challenges of these networks in their evolution towards the Smart Grid.

  13. Emulation Platform for Cyber Analysis of Wireless Communication Network Protocols

    Energy Technology Data Exchange (ETDEWEB)

    Van Leeuwen, Brian P. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Eldridge, John M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-11-01

    Wireless networking and mobile communications is increasing around the world and in all sectors of our lives. With increasing use, the density and complexity of the systems increase with more base stations and advanced protocols to enable higher data throughputs. The security of data transported over wireless networks must also evolve with the advances in technologies enabling more capable wireless networks. However, means for analysis of the effectiveness of security approaches and implementations used on wireless networks are lacking. More specifically a capability to analyze the lower-layer protocols (i.e., Link and Physical layers) is a major challenge. An analysis approach that incorporates protocol implementations without the need for RF emissions is necessary. In this research paper several emulation tools and custom extensions that enable an analysis platform to perform cyber security analysis of lower layer wireless networks is presented. A use case of a published exploit in the 802.11 (i.e., WiFi) protocol family is provided to demonstrate the effectiveness of the described emulation platform.

  14. AC Electric Field Communication for Human-Area Networking

    Science.gov (United States)

    Kado, Yuichi; Shinagawa, Mitsuru

    We have proposed a human-area networking technology that uses the surface of the human body as a data transmission path and uses an AC electric field signal below the resonant frequency of the human body. This technology aims to achieve a “touch and connect” intuitive form of communication by using the electric field signal that propagates along the surface of the human body, while suppressing both the electric field radiating from the human body and mutual interference. To suppress the radiation field, the frequency of the AC signal that excites the transmitter electrode must be lowered, and the sensitivity of the receiver must be raised while reducing transmission power to its minimally required level. We describe how we are developing AC electric field communication technologies to promote the further evolution of a human-area network in support of ubiquitous services, focusing on three main characteristics, enabling-transceiver technique, application-scenario modeling, and communications quality evaluation. Special attention is paid to the relationship between electro-magnetic compatibility evaluation and regulations for extremely low-power radio stations based on Japan's Radio Law.

  15. Traditional Art in the Age of Multimedia and Network Communications

    Directory of Open Access Journals (Sweden)

    Željko Rutović

    2013-09-01

    Full Text Available The digital age has opened up enormous possibilities of expression, perception and reading of art. Aesthetic criteria immanent to the models of traditional art transforming into a new conceptuality which is in conformity with the techniques of rapid production and distribution. World of multi-network communications and major technological shift resulting in the metamorphosis of the concept and experience of the definition of art. That means that art is outgoing from the traditional framework of standards and ways of expression, ie. aesthetic and values position of the sense of art. Outside the emblematic of the media traditional linear progress, modern network, according to its ontology, deconstructs forced poetics structure formalism, defining the phenomenology innovative problem-solving discourse situated in the self-reflection plurality as a sign of communication currency of man’s perception of (sur real. The multimedia art is in direct way with aesthetic and communication constructs that reformulating the mediating role, it is a dimension of openness and shifting boundaries seen in the image of the antipode of unquestionable durability.

  16. Interplant communication of tomato plants through underground common mycorrhizal networks.

    Science.gov (United States)

    Song, Yuan Yuan; Zeng, Ren Sen; Xu, Jian Feng; Li, Jun; Shen, Xiang; Yihdego, Woldemariam Gebrehiwot

    2010-10-13

    Plants can defend themselves to pathogen and herbivore attack by responding to chemical signals that are emitted by attacked plants. It is well established that such signals can be transferred through the air. In theory, plants can also communicate with each other through underground common mycorrhizal networks (CMNs) that interconnect roots of multiple plants. However, until now research focused on plant-to-plant carbon nutrient movement and there is no evidence that defense signals can be exchanged through such mycorrhizal hyphal networks. Here, we show that CMNs mediate plant-plant communication between healthy plants and pathogen-infected tomato plants (Lycopersicon esculentum Mill.). After establishment of CMNs with the arbuscular mycorrhizal fungus Glomus mosseae between tomato plants, inoculation of 'donor' plants with the pathogen Alternaria solani led to increases in disease resistance and activities of the putative defensive enzymes, peroxidase, polyphenol oxidase, chitinase, β-1,3-glucanase, phenylalanine ammonia-lyase and lipoxygenase in healthy neighbouring 'receiver' plants. The uninfected 'receiver' plants also activated six defence-related genes when CMNs connected 'donor' plants challenged with A. solani. This finding indicates that CMNs may function as a plant-plant underground communication conduit whereby disease resistance and induced defence signals can be transferred between the healthy and pathogen-infected neighbouring plants, suggesting that plants can 'eavesdrop' on defence signals from the pathogen-challenged neighbours through CMNs to activate defences before being attacked themselves.

  17. Implementation Issues of Adaptive Energy Detection in Heterogeneous Wireless Networks

    Science.gov (United States)

    Sobron, Iker; Eizmendi, Iñaki; Martins, Wallace A.; Diniz, Paulo S. R.; Ordiales, Juan Luis; Velez, Manuel

    2017-01-01

    Spectrum sensing (SS) enables the coexistence of non-coordinated heterogeneous wireless systems operating in the same band. Due to its computational simplicity, energy detection (ED) technique has been widespread employed in SS applications; nonetheless, the conventional ED may be unreliable under environmental impairments, justifying the use of ED-based variants. Assessing ED algorithms from theoretical and simulation viewpoints relies on several assumptions and simplifications which, eventually, lead to conclusions that do not necessarily meet the requirements imposed by real propagation environments. This work addresses those problems by dealing with practical implementation issues of adaptive least mean square (LMS)-based ED algorithms. The paper proposes a new adaptive ED algorithm that uses a variable step-size guaranteeing the LMS convergence in time-varying environments. Several implementation guidelines are provided and, additionally, an empirical assessment and validation with a software defined radio-based hardware is carried out. Experimental results show good performance in terms of probabilities of detection (Pd>0.9) and false alarm (Pf∼0.05) in a range of low signal-to-noise ratios around [-4,1] dB, in both single-node and cooperative modes. The proposed sensing methodology enables a seamless monitoring of the radio electromagnetic spectrum in order to provide band occupancy information for an efficient usage among several wireless communications systems. PMID:28441751

  18. Implementing new technologies for public safety communication: competing frequency demands and standardization issues

    Science.gov (United States)

    Stevens, Kathryn J.

    1997-01-01

    Attempting to incorporate new technology into an existing environment is often very difficult. The problems are lengthy to resolve, wrought with confusion and seldom turn out like anyone expected. This document represents an overview of one such attempt. It outlines the general areas of concern which could be affected by a transition, and potential problems that may be encountered as a result of the effort. Over the past several decades, many local, state and federal agencies are pressing for more efficient use of frequency spectrums. The urgency of this issue has grown due to the demands of several groups wanting access to these channels for commercial use. Pager systems, cellular telephones, radio systems for private businesses all demand more space. Public safety agencies are starting to fear their needs will diminish in importance as the available channel spectrums are consumed by commercial ventures. How to share these channels, purchase appropriate equipment to meet your needs, and stay within a reasonable budget are not easy tasks. Public safety agencies who rely on communication networks in the performance of their jobs also know why encryption is important. Protecting the rights of citizens as police exchange information over the air, maintaining the integrity of an investigation and officer safety are all concerns police must address each time they use a radio.

  19. Networking Alone? Digital Communications and Collective Action in Vietnam

    Directory of Open Access Journals (Sweden)

    Sandra Kurfürst

    2015-01-01

    Full Text Available This article explores the potential for the formation of collective action in Vietnam. Referring to land and labour protests, bauxite mining, anti-China demonstrations, as well as the revision of the 1992 Constitution, the article examines the social movement repertoires diverse groups have adopted to reach their objectives. Drawing on social movement theory and communication power, this contribution shows that apart from access to the technology, citizens’ opportunities to participate in digital networks as well as access to the default communication network of the state are necessary prerequisites in order to attain public attention and possibly to achieve social change. Moreover, this article shows that existing power differentials in Vietnam are reproduced in digital space. It concludes that for different collective behaviours to result in a social movement, it is essential to “switch” and to connect the different networks. For the moment, the call to protect Vietnam’s sovereignty offers common ground for collective action.

  20. Use of Social Network Sites for Communication Among Health Professionals: Systematic Review.

    Science.gov (United States)

    Chan, Windy Sy; Leung, Angela Ym

    2018-03-28

    Although much research has been done investigating the roles of social network sites (SNSs) in linking patients and health professionals, there is a lack of information about their uses, benefits, and limitations in connecting health professions only for professional communication. This review aimed to examine the utilization of SNSs for communication among health professionals in (1) frontline clinical practice, (2) professional networks, and (3) education and training to identify areas for future health communication research. This review followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. A systematic search of the literature published in the last 10 years (January 1, 2007, to March 1, 2017) was performed in March 2017, using the following electronic databases: MEDLINE via OvidSP, EMBASE, CINAHL Complete, and InfoSci-Journals. The searches were conducted using the following defined search terms: "social media" OR "social network" OR "social network site" OR "Facebook" OR "Twitter" OR "Linkedin" OR "Instagram" OR "Weibo" OR "Whatsapp" OR "Telegram" OR "WeChat" AND "health" OR "health profession." Of the 6977 papers retrieved, a total of 33 studies were included in this review. They were exploratory in nature, and the majority used surveys (n=25) and interviews (n=6). All retrieved studies stated that SNSs enhanced effective communication and information sharing. SNSs were used for supporting delivering of clinical services, making referrals, and sharing information. They were beneficial to network building and professional collaboration. SNSs were novel tools to enhance educational interactions among peers, students, instructors, and preceptors. The application of SNSs came with restraints in technical knowledge, concerns on data protection, privacy and liability, issues in professionalism, and data protection. SNSs provide platforms facilitating efficient communication, interactions, and connections among health

  1. Patients' Perspectives on Information and Communication About Sexual and Relational Issues in Rheumatology Health Care.

    Science.gov (United States)

    Helland, Ylva; Dagfinrud, Hanne; Haugen, Mona-Iren; Kjeken, Ingvild; Zangi, Heidi

    2017-06-01

    Men and women with rheumatic diseases report a significantly negative impact on multiple areas of life, including sexuality. Research indicates that patients want to discuss sexual issues with health professionals (HPs) in rheumatology care but these issues are rarely addressed in consultations. The objective of the present study was to explore patients' experiences of communication with HPs about disease-related sexual issues, their perceptions of the relevance of these issues in rheumatology care and their preferences for how these topics should be handled. A qualitative design was used and 18 semi-structured interviews were performed, including eight women and ten men with inflammatory rheumatic joint diseases, aged 29-62 years. The interviews were recorded and transcribed verbatim. Data were analysed thematically. Four main themes were derived from the interviews: (i) relevance of sexual issues; (ii) vital conditions for communication; (iii) individual preferences in mode and timing of information and communication; and (iv) benefits of information and communication. The participants expressed that, although sexual issues are relevant, necessary conditions for good communication are largely lacking. HPs' knowledge, experience and personal skills, as well as having sufficient time were essential. HPs lack of initiating sexual topics contributed to uncertainty about whether their sexual challenges were disease related and whether it was a legitimate topic to discuss in rheumatology care. Patients wanted HPs to possess knowledge about possible disease-related challenges in sexual life and intimate relationships, and to facilitate communication about these aspects. There is a need to develop practice guidelines to enable HPs to integrate sexual issues as an aspect of healthcare delivery in a patient-friendly manner. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  2. Young men's health promotion and new information communication technologies: illuminating the issues and research agendas.

    Science.gov (United States)

    Robinson, Mark; Robertson, Steve

    2010-09-01

    The article examines the use of newer, interactive information and communication technologies (ICTs) in young men's health promotion (HP), drawing on gender theory, HP research and evidence on young men's Internet usage. The focus is on highlighting an agenda for research in terms of emerging issues. New forms of social media ICT (for example 'web 2'-based on-line social networking sites, micro-blogging services, i-phones and podcasts) have the potential to enable young men to engage with health information in new and interesting ways. Given concerns about young men's engagement with health services, innovative ICT formats, particularly using the Internet, have been tried. However, issues persist around surfing 'addiction', quality control and equal access. Approaches to HP using new ICTs offer distributed control over information content and quality and a lay social context for accessing information. Online communities can potentially legitimize young men's participation in discourses around health, and support sustained engagement. The article discusses how this could support young men to re-conceptualize healthy choices in the context of masculine imperatives and responsible citizenship if specific conditions are met (for trusting engagement) and risks addressed (such as commercial disinformation). The skill requirements for young men to engage effectively with new ICTs are explored, focusing on health literacy (HL). It is predicted that social marketing approaches to HP for young men will increasingly include new ICTs, making specific requirements for HL. These approaches may appeal narrowly to hegemonic masculinities or broadly to multiple masculinities, including those historically marginalized. Recommendations are made for future research.

  3. Collocational Networks Supporting Strategic Planning of Brand Communication: Analysis of Quarterly Reports of Telecommunication Companies

    Directory of Open Access Journals (Sweden)

    Pentti Järvi

    2004-10-01

    Full Text Available This study addresses analysing quarterly reports from a brandtheoretical viewpoint. The study addresses the issue through a method which introduces both a quantitative tool based on linguistic theory and qualitative decisions of the researchers. The research objects of this study are two quarterly reports each of three telecommunications companies: Ericsson, Motorola and Nokia. The method used is a collocational network. The analyses show that there are differences in communication and message strategies among investigated companies and also changes during a quite short period in each company

  4. Optimal Time Allocation in Backscatter Assisted Wireless Powered Communication Networks

    Science.gov (United States)

    Lyu, Bin; Yang, Zhen; Gui, Guan; Sari, Hikmet

    2017-01-01

    This paper proposes a wireless powered communication network (WPCN) assisted by backscatter communication (BackCom). This model consists of a power station, an information receiver and multiple users that can work in either BackCom mode or harvest-then-transmit (HTT) mode. The time block is mainly divided into two parts corresponding to the data backscattering and transmission periods, respectively. The users first backscatter data to the information receiver in time division multiple access (TDMA) during the data backscattering period. When one user works in the BackCom mode, the other users harvest energy from the power station. During the data transmission period, two schemes, i.e., non-orthogonal multiple access (NOMA) and TDMA, are considered. To maximize the system throughput, the optimal time allocation policies are obtained. Simulation results demonstrate the superiority of the proposed model. PMID:28587171

  5. Secure and Authenticated Data Communication in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Omar Alfandi

    2015-08-01

    Full Text Available Securing communications in wireless sensor networks is increasingly important as the diversity of applications increases. However, even today, it is equally important for the measures employed to be energy efficient. For this reason, this publication analyzes the suitability of various cryptographic primitives for use in WSNs according to various criteria and, finally, describes a modular, PKI-based framework for confidential, authenticated, secure communications in which most suitable primitives can be employed. Due to the limited capabilities of common WSN motes, criteria for the selection of primitives are security, power efficiency and memory requirements. The implementation of the framework and the singular components have been tested and benchmarked in our testbed of IRISmotes.

  6. Analysis, Synthesis and Experiments of Networked Platoons with Communication Constraints

    Directory of Open Access Journals (Sweden)

    Ligang Wu

    2017-02-01

    Full Text Available This paper investigates the analysis and synthesis of networked vehicle platoons with communication delays, packet dropouts and disorders. In order to deal with the effects of the communication constraints, we introduce a novel Smart Data Processor (SDP for each vehicle, by which the latest data packets from logic Data Packet Processor and the matched data packet from its Buffer can be obtained. Based on this mechanism, a leader-predecessor-follower control strategy is proposed. In order to guarantee the asymptotic and string stability, the platoon control problem is transformed into a multi-objective H∞-type synthesis problem with the multiple time-varying delays. A sufficient condition for designing the controller gain is derived by solving a set of linear matrix inequalities. Numerous simulations and experiments with laboratory scale Arduino cars show the efficiency of the proposed methods.

  7. Quality Utilization Aware Based Data Gathering for Vehicular Communication Networks

    Directory of Open Access Journals (Sweden)

    Yingying Ren

    2018-01-01

    Full Text Available The vehicular communication networks, which can employ mobile, intelligent sensing devices with participatory sensing to gather data, could be an efficient and economical way to build various applications based on big data. However, high quality data gathering for vehicular communication networks which is urgently needed faces a lot of challenges. So, in this paper, a fine-grained data collection framework is proposed to cope with these new challenges. Different from classical data gathering which concentrates on how to collect enough data to satisfy the requirements of applications, a Quality Utilization Aware Data Gathering (QUADG scheme is proposed for vehicular communication networks to collect the most appropriate data and to best satisfy the multidimensional requirements (mainly including data gathering quantity, quality, and cost of application. In QUADG scheme, the data sensing is fine-grained in which the data gathering time and data gathering area are divided into very fine granularity. A metric named “Quality Utilization” (QU is to quantify the ratio of quality of the collected sensing data to the cost of the system. Three data collection algorithms are proposed. The first algorithm is to ensure that the application which has obtained the specified quantity of sensing data can minimize the cost and maximize data quality by maximizing QU. The second algorithm is to ensure that the application which has obtained two requests of application (the quantity and quality of data collection, or the quantity and cost of data collection could maximize the QU. The third algorithm is to ensure that the application which aims to satisfy the requirements of quantity, quality, and cost of collected data simultaneously could maximize the QU. Finally, we compare our proposed scheme with the existing schemes via extensive simulations which well justify the effectiveness of our scheme.

  8. 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

  9. Artificial Neural Network for Location Estimation in Wireless Communication Systems

    Directory of Open Access Journals (Sweden)

    Chien-Sheng Chen

    2012-03-01

    Full Text Available In a wireless communication system, wireless location is the technique used to estimate the location of a mobile station (MS. To enhance the accuracy of MS location prediction, we propose a novel algorithm that utilizes time of arrival (TOA measurements and the angle of arrival (AOA information to locate MS when three base stations (BSs are available. Artificial neural networks (ANN are widely used techniques in various areas to overcome the problem of exclusive and nonlinear relationships. When the MS is heard by only three BSs, the proposed algorithm utilizes the intersections of three TOA circles (and the AOA line, based on various neural networks, to estimate the MS location in non-line-of-sight (NLOS environments. Simulations were conducted to evaluate the performance of the algorithm for different NLOS error distributions. The numerical analysis and simulation results show that the proposed algorithms can obtain more precise location estimation under different NLOS environments.

  10. Artificial neural network for location estimation in wireless communication systems.

    Science.gov (United States)

    Chen, Chien-Sheng

    2012-01-01

    In a wireless communication system, wireless location is the technique used to estimate the location of a mobile station (MS). To enhance the accuracy of MS location prediction, we propose a novel algorithm that utilizes time of arrival (TOA) measurements and the angle of arrival (AOA) information to locate MS when three base stations (BSs) are available. Artificial neural networks (ANN) are widely used techniques in various areas to overcome the problem of exclusive and nonlinear relationships. When the MS is heard by only three BSs, the proposed algorithm utilizes the intersections of three TOA circles (and the AOA line), based on various neural networks, to estimate the MS location in non-line-of-sight (NLOS) environments. Simulations were conducted to evaluate the performance of the algorithm for different NLOS error distributions. The numerical analysis and simulation results show that the proposed algorithms can obtain more precise location estimation under different NLOS environments.

  11. Integrating Space Communication Network Capabilities via Web Portal Technologies

    Science.gov (United States)

    Johnston, Mark D.; Lee, Carlyn-Ann; Lau, Chi-Wung; Cheung, Kar-Ming; Levesque, Michael; Carruth, Butch; Coffman, Adam; Wallace, Mike

    2014-01-01

    We have developed a service portal prototype as part of an investigation into the feasibility of using Java portlet technology as a means of providing integrated access to NASA communications network services. Portal servers provide an attractive platform for this role due to the various built-in collaboration applications they can provide, combined with the possibility to develop custom inter-operating portlets to extent their functionality while preserving common presentation and behavior. This paper describes various options for integration of network services related to planning and scheduling, and results based on use of a popular open-source portal framework. Plans are underway to develop an operational SCaN Service Portal, building on the experiences reported here.

  12. Network coding multiuser scheme for indoor visible light communications

    Science.gov (United States)

    Zhang, Jiankun; Dang, Anhong

    2017-12-01

    Visible light communication (VLC) is a unique alternative for indoor data transfer and developing beyond point-to-point. However, for realizing high-capacity networks, VLC is facing challenges including the constrained bandwidth of the optical access point and random occlusion. A network coding scheme for VLC (NC-VLC) is proposed, with increased throughput and system robustness. Based on the Lambertian illumination model, theoretical decoding failure probability of the multiuser NC-VLC system is derived, and the impact of the system parameters on the performance is analyzed. Experiments demonstrate the proposed scheme successfully in the indoor multiuser scenario. These results indicate that the NC-VLC system shows a good performance under the link loss and random occlusion.

  13. Research of the self-healing technologies in the optical communication network of distribution automation

    Science.gov (United States)

    Wang, Hao; Zhong, Guoxin

    2018-03-01

    Optical communication network is the mainstream technique of the communication networks for distribution automation, and self-healing technologies can improve the in reliability of the optical communication networks significantly. This paper discussed the technical characteristics and application scenarios of several network self-healing technologies in the access layer, the backbone layer and the core layer of the optical communication networks for distribution automation. On the base of the contrastive analysis, this paper gives an application suggestion of these self-healing technologies.

  14. Unavailability of critical SCADA communication links interconnecting a power grid and a Telco network

    International Nuclear Information System (INIS)

    Bobbio, A.; Bonanni, G.; Ciancamerla, E.; Clemente, R.; Iacomini, A.; Minichino, M.; Scarlatti, A.; Terruggia, R.; Zendri, E.

    2010-01-01

    The availability of power supply to power grid customers depends upon the availability of services of supervision, control and data acquisition (SCADA) system, which constitutes the nervous system of a power grid. In turn, SCADA services depend on the availability of the interconnected networks supporting such services. We propose a service oriented stochastic modelling methodology to investigate the availability of large interconnected networks, based on the hierarchical application of different modelling formalisms to different parts of the networks. Interconnected networks are decomposed according to the specific services delivered until the failure and repair mechanisms of the decomposed elementary blocks can be identified. We represent each network by a convenient stochastic modelling formalism, able to capture the main technological issues and to cope with realistic assumptions about failure and recovery mechanisms. This procedure confines the application of the more intensive computational techniques to those subsystems that actually require it. The paper concentrates on an actual failure scenario, occurred in Rome in January 2004 that involved the outage of critical SCADA communication links, interconnecting a power grid and a Telco network.

  15. Unavailability of critical SCADA communication links interconnecting a power grid and a Telco network

    Energy Technology Data Exchange (ETDEWEB)

    Bobbio, A. [Dipartimento di Informatica, Universita del Piemonte Orientale, Viale Michel 11, 15121 Alessandria (Italy); Bonanni, G.; Ciancamerla, E. [ENEA - CRE Casaccia, Via Anguillarese 301, 00060 Roma (Italy); Clemente, R. [Telecom Italia Mobile, Via Isonzo112, 10141 Torino (Italy); Iacomini, A. [ACEA, Pl. Ostiense 2, 00154 Roma (Italy); Minichino, M., E-mail: minichino@casaccia.enea.i [ENEA - CRE Casaccia, Via Anguillarese 301, 00060 Roma (Italy); Scarlatti, A. [ACEA, Pl. Ostiense 2, 00154 Roma (Italy); Terruggia, R. [Dipartimento di Informatica, Universita del Piemonte Orientale, Viale Michel 11, 15121 Alessandria (Italy); Zendri, E. [ACEA, Pl. Ostiense 2, 00154 Roma (Italy)

    2010-12-15

    The availability of power supply to power grid customers depends upon the availability of services of supervision, control and data acquisition (SCADA) system, which constitutes the nervous system of a power grid. In turn, SCADA services depend on the availability of the interconnected networks supporting such services. We propose a service oriented stochastic modelling methodology to investigate the availability of large interconnected networks, based on the hierarchical application of different modelling formalisms to different parts of the networks. Interconnected networks are decomposed according to the specific services delivered until the failure and repair mechanisms of the decomposed elementary blocks can be identified. We represent each network by a convenient stochastic modelling formalism, able to capture the main technological issues and to cope with realistic assumptions about failure and recovery mechanisms. This procedure confines the application of the more intensive computational techniques to those subsystems that actually require it. The paper concentrates on an actual failure scenario, occurred in Rome in January 2004 that involved the outage of critical SCADA communication links, interconnecting a power grid and a Telco network.

  16. The communicative process of weather forecasts issued in the probabilistic form

    Directory of Open Access Journals (Sweden)

    Alessio Raimondi

    2009-03-01

    Full Text Available One of the main purposes of weather forecasting is that of protecting weather-sensitive human activities. Forecasts issued in the probabilistic form have a higher informative content, as opposed to deterministic one, since they bear information that give also a measure of their own uncertainty. However, in order to make an appropriate and effective use of this kind of forecasts in an operational setting, communication becomes significatively relevant.The present paper, after having briefly examined the weather forecasts concerning Hurricane Charley (August 2004, tackles the issue of the communicative process in detail.The bottom line of this study is that for the weather forecast to achieve its best predictive potential, an in-depth analysis of communication issues is necessary.

  17. The communicative process of weather forecasts issued in the probabilistic form (Italian original version

    Directory of Open Access Journals (Sweden)

    Alessio Raimondi

    2009-03-01

    Full Text Available One of the main purposes of weather forecasting is that of protecting weather-sensitive human activities. Forecasts issued in the probabilistic form have a higher informative content, as opposed to deterministic one, since they bear information that give also a measure of their own uncertainty. However, in order to make an appropriate and effective use of this kind of forecasts in an operational setting, communication becomes significatively relevant.The present paper, after having briefly examined the weather forecasts concerning Hurricane Charley (August 2004, tackles the issue of the communicative process in detail.The bottom line of this study is that for the weather forecast to achieve its best predictive potential, an in-depth analysis of communication issues is necessary.

  18. An Identification of Communication Skills, Problems and Issues for the Business and Professional Communication Course.

    Science.gov (United States)

    Di Salvo, Vincent S.; And Others

    In order to identify the demands, the skills, and the various contexts that students can expect to face in their chosen professions, organizational communication researchers need to conduct studies that will lead educators to make intelligent decisions regarding what should and should not be taught in business and professional communication…

  19. Conference proceedings on science communication addressing women's issues

    International Nuclear Information System (INIS)

    Deshpande, A.P.

    2013-03-01

    One of the most dynamic campaigns of National Centre for Science Communicators (NCSC) is its intensive interaction with teaching community to inculcate excitement regarding science education and scientific method of knowledge transfer. The conference focused on the theme engaging women in science and science communication, challenges -education, gender differences etc., myths and misconceptions: women related issues, and health awareness in women. Papers relevant to INIS are indexed separately

  20. COMMUNICATING REDD+ ISSUES AT LOCAL LEVEL: CREATING LATENT AND MANIFEST CONFLICT

    Directory of Open Access Journals (Sweden)

    Lukas Rumboko Wibowo

    2013-10-01

    Full Text Available ”Carbon offsetting”in forestry-related projects is widely regarded as the ideal solution to the three challenges of   the  21st Century:  climate change, biodiversity conservation  andsocio-economic development. At the same time, there is scepticism about the Reducing Emissions from Deforestation and  Forest  Degradation (REDD  proposal  particularly because of   the  weak  governance and institutional capacities in many developing countries, which could jeopardize the delivery of benefits at the local level. One major problem is that most people have little knowledge on the causes and consequences of the climate change. This is partly because the information  is largely scattered among scientific journals, and obscured by jargon and sophisticated  mathematical  models. Consequently, REDD+ is beyond thereach of  manyof the people affected by REDD+. This  paper examines the efforts and the capacity of  the local governments and other development  agents in explaining the REDD + issues and its impacts on the local people, especially customary communities. The research shows that lack of  policy communication and promotion, as well as consultations with the affected groups arethe main contributing factors to latent and manifest conflicts. In turn, this conflicth as proven that NGOs,  district governments and scientists have not been successful intermediaries. Thus, in the future policy communication on REDD+ should beaimed at improved network formation (i.e. between farmer groups with business partners and NGOs  and other related actors, learning, negotiation and relationship building (i.e. between members of farmer groups,  not only withtheir leaders within the farmer groups but also with governmental and business sectors. Policy communication should also create a  new  configuration of   support  and  services in  form  of   advocacy, empowerment and management skills and technical skills for conserving their

  1. Network Gateway Technology: The Issue of Redundancy towards ...

    African Journals Online (AJOL)

    Everyone connected to the Internet is concerned about two basic things: the availability of network services and the speed of the network. Network gateway redundancy technology falls within these categories and happens to be one of the newest technologies which only few companies, such as mobile companies and ...

  2. Doing Projects in a Foreign Language — Communications Management, Issues and Strategies

    Science.gov (United States)

    Xian, Deling

    The Qinghai Salt Lake Industry Co. Ltd. (QSLIC) smelter project involves a Chinese state-owned client, a Canadian engineering company, their American technology partner, several Chinese design institutes and international vendors. Proper technical communication plays an important role during the development of a project in a foreign language and across cultures. Using the QSLIC project as an example, this paper presents the role of Communications Manager and personal qualifications required, as well as technical communications management, issues and strategies, lessons learnt while doing smelter projects in China and Chinese business culture and etiquette.

  3. Issue on NPP-I and C important to safety-Data Communication

    International Nuclear Information System (INIS)

    Koo, I. S.; Hong, S. B.; Cho, J. W.; Choi, Y. S.; Lee, J. C.

    2010-01-01

    1. Issue on CDV and FDIS of IEC61500 - Nuclear Power Plants - Instrumentation and control important to safety -Data communication - Activities on IEC TC45, SC45A/WGA3. 2. As issue the requirements for safety data communication which is essential part of digital I and C systems, the fundamental technology for IT based nuclear I and C is established. 3. Approval and circulation of IED61500 CDV and FDIS - Issue of the international standard, IEC 61500. 4. Issue one IEC61500, three interim documents, three presentations and five technical support to industry, and participation in IEC TC45 and SC45A plenary meeting and intermediate meeting on SC45A/WGA3. 5. Based on IEC61500, an new project on wireless technologyes application to NPP will be proceeded

  4. 75 FR 49870 - Effects on Broadband Communications Networks of Damage to or Failure of Network Equipment or...

    Science.gov (United States)

    2010-08-16

    ... FEDERAL COMMUNICATIONS COMMISSION 47 CFR Chapter I [PS Docket No. 10-92; DA 10-1357] Effects on Broadband Communications Networks of Damage to or Failure of Network Equipment or Severe Overload AGENCY... with rubber bands or fasteners. Any envelopes must be disposed of before entering the building...

  5. TAM AIRLINES ON TWITTER: COMMUNICATION CHANNEL OR SOCIAL NETWORK?

    Directory of Open Access Journals (Sweden)

    Cynthia Harumy Watanabe Corrêa

    2010-12-01

    Full Text Available The research emphasizes the social appropriation of Information and Communication Technologies by the Brazilian aviation industry, through a case study of communication strategies of TAM on the social networking site Twitter. TAM is a leader in the Brazilian domestic market and gradually conquering its space in Mercosul. This is an exploratory research, based on content analysis of messages sent to the company profile on Twitter, in order to check whether indeed the consolidation of a social network between TAM and its followers. We analyzed all messages posted since July 3, 2009, the date of the first post in the company profile, until the day January 31, 2010. Among the subjects discussed, there was the predominance of information and promotions. The study concludes that, under Twitter, TAM has yet reached a high degree of social interaction with his followers, because the major number of messages is directed to promotional marketing.

  6. Alternative Path Communication in Wide-Scale Cluster-Tree Wireless Sensor Networks Using Inactive Periods.

    Science.gov (United States)

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

    2017-05-06

    The IEEE 802.15.4/ZigBee cluster-tree topology is a suitable technology to deploy wide-scale Wireless Sensor Networks (WSNs). These networks are usually designed to support convergecast traffic, where all communication paths go through the PAN (Personal Area Network) coordinator. Nevertheless, peer-to-peer communication relationships may be also required for different types of WSN applications. That is the typical case of sensor and actuator networks, where local control loops must be closed using a reduced number of communication hops. The use of communication schemes optimised just for the support of convergecast traffic may result in higher network congestion and in a potentially higher number of communication hops. Within this context, this paper proposes an Alternative-Route Definition (ARounD) communication scheme for WSNs. The underlying idea of ARounD is to setup alternative communication paths between specific source and destination nodes, avoiding congested cluster-tree paths. These alternative paths consider shorter inter-cluster paths, using a set of intermediate nodes to relay messages during their inactive periods in the cluster-tree network. Simulation results show that the ARounD communication scheme can significantly decrease the end-to-end communication delay, when compared to the use of standard cluster-tree communication schemes. Moreover, the ARounD communication scheme is able to reduce the network congestion around the PAN coordinator, enabling the reduction of the number of message drops due to queue overflows in the cluster-tree network.

  7. CSRQ: Communication-Efficient Secure Range Queries in Two-Tiered Sensor Networks

    Directory of Open Access Journals (Sweden)

    Hua Dai

    2016-02-01

    Full Text Available In recent years, we have seen many applications of secure query in two-tiered wireless sensor networks. Storage nodes are responsible for storing data from nearby sensor nodes and answering queries from Sink. It is critical to protect data security from a compromised storage node. In this paper, the Communication-efficient Secure Range Query (CSRQ—a privacy and integrity preserving range query protocol—is proposed to prevent attackers from gaining information of both data collected by sensor nodes and queries issued by Sink. To preserve privacy and integrity, in addition to employing the encoding mechanisms, a novel data structure called encrypted constraint chain is proposed, which embeds the information of integrity verification. Sink can use this encrypted constraint chain to verify the query result. The performance evaluation shows that CSRQ has lower communication cost than the current range query protocols.

  8. Communicative Planning As Institutional Capacity Building: From Discourse/Network To Opportunity

    Directory of Open Access Journals (Sweden)

    Delik Hudalah

    2013-05-01

    Full Text Available The paper redefines the ideas about communicative planning as not only participatory and democratic practice but also capacity building oriented toward the improvement of governance styles and consciousness. So far capacity building has focused on the exploitation of social resources internal to actors. These internal resources include knowledge (argumentation, debate, discourse formation etc and relational (network, coalition, alliance etc building. The paper argues that in dealing with very complex planning problems characterized by fragmented and uncertain institutional systems, the internal resources need to be coupled with the exploration of resources external to actors, namely the political opportunity structure and moment of opportunity. The analysis implies that the performance of communicative decision-making process as capacity building can be assessed in three aspects: strategic and inclusive actors’ involvement, the building of actors’ awareness on neglected but important planning issues and agendas, and consistency and deliberation in realizing and delivering agreed planning ideas, frameworks and decisions.

  9. Apparatus and method for data communication in an energy distribution network

    Science.gov (United States)

    Hussain, Mohsin; LaPorte, Brock; Uebel, Udo; Zia, Aftab

    2014-07-08

    A system for communicating information on an energy distribution network is disclosed. In one embodiment, the system includes a local supervisor on a communication network, wherein the local supervisor can collect data from one or more energy generation/monitoring devices. The system also includes a command center on the communication network, wherein the command center can generate one or more commands for controlling the one or more energy generation devices. The local supervisor can periodically transmit a data signal indicative of the data to the command center via a first channel of the communication network at a first interval. The local supervisor can also periodically transmit a request for a command to the command center via a second channel of the communication network at a second interval shorter than the first interval. This channel configuration provides effective data communication without a significant increase in the use of network resources.

  10. Myths on Bi-direction Communication of Web 2.0 Based Social Networks: Is Social Network Truly Interactive?

    Science.gov (United States)

    2011-03-10

    more and more social interactions are happening on the on-line. Especially recent uptake of the social network sites (SNSs), such as Facebook (http...Smart phones • Live updates within social networks • Facebook & Twitters Solution: WebMon for Risk Management Need for New WebMon for Social Networks ...Title: Myths on bi-direction communication of Web 2.0 based social networks : Is social network truly interactive

  11. A cross-layer communication framework for wireless networked control systems

    NARCIS (Netherlands)

    Israr, N.; Scanlon, W.G.; Irwin, G.W.

    2009-01-01

    This paper presents a robust, dynamic cross-layer wireless communication architecture for wireless networked control systems. Each layer in the proposed protocol architecture contributes to the overall goal of reliable, energy efficient communication. The protocol stack also features a

  12. A Review on Sensor Network Issues and Robotics

    Directory of Open Access Journals (Sweden)

    Ji Hyoung Ryu

    2015-01-01

    Full Text Available The interaction of distributed robotics and wireless sensor networks has led to the creation of mobile sensor networks. There has been an increasing interest in building mobile sensor networks and they are the favored class of WSNs in which mobility plays a key role in the execution of an application. More and more researches focus on development of mobile wireless sensor networks (MWSNs due to its favorable advantages and applications. In WSNs robotics can play a crucial role, and integrating static nodes with mobile robots enhances the capabilities of both types of devices and enables new applications. In this paper we present an overview on mobile sensor networks in robotics and vice versa and robotic sensor network applications.

  13. Detailed temporal structure of communication networks in groups of songbirds.

    Science.gov (United States)

    Stowell, Dan; Gill, Lisa; Clayton, David

    2016-06-01

    Animals in groups often exchange calls, in patterns whose temporal structure may be influenced by contextual factors such as physical location and the social network structure of the group. We introduce a model-based analysis for temporal patterns of animal call timing, originally developed for networks of firing neurons. This has advantages over cross-correlation analysis in that it can correctly handle common-cause confounds and provides a generative model of call patterns with explicit parameters for the influences between individuals. It also has advantages over standard Markovian analysis in that it incorporates detailed temporal interactions which affect timing as well as sequencing of calls. Further, a fitted model can be used to generate novel synthetic call sequences. We apply the method to calls recorded from groups of domesticated zebra finch (Taeniopygia guttata) individuals. We find that the communication network in these groups has stable structure that persists from one day to the next, and that 'kernels' reflecting the temporal range of influence have a characteristic structure for a calling individual's effect on itself, its partner and on others in the group. We further find characteristic patterns of influences by call type as well as by individual. © 2016 The Authors.

  14. Directedness of information flow in mobile phone communication networks.

    Directory of Open Access Journals (Sweden)

    Fernando Peruani

    Full Text Available Without having direct access to the information that is being exchanged, traces of information flow can be obtained by looking at temporal sequences of user interactions. These sequences can be represented as causality trees whose statistics result from a complex interplay between the topology of the underlying (social network and the time correlations among the communications. Here, we study causality trees in mobile-phone data, which can be represented as a dynamical directed network. This representation of the data reveals the existence of super-spreaders and super-receivers. We show that the tree statistics, respectively the information spreading process, are extremely sensitive to the in-out degree correlation exhibited by the users. We also learn that a given information, e.g., a rumor, would require users to retransmit it for more than 30 hours in order to cover a macroscopic fraction of the system. Our analysis indicates that topological node-node correlations of the underlying social network, while allowing the existence of information loops, they also promote information spreading. Temporal correlations, and therefore causality effects, are only visible as local phenomena and during short time scales. Consequently, the very idea that there is (intentional information spreading beyond a small vecinity is called into question. These results are obtained through a combination of theory and data analysis techniques.

  15. Design and analysis of communication protocols for quantum repeater networks

    International Nuclear Information System (INIS)

    Jones, Cody; Kim, Danny; Rakher, Matthew T; Ladd, Thaddeus D; Kwiat, Paul G

    2016-01-01

    We analyze how the performance of a quantum-repeater network depends on the protocol employed to distribute entanglement, and we find that the choice of repeater-to-repeater link protocol has a profound impact on entanglement-distribution rate as a function of hardware parameters. We develop numerical simulations of quantum networks using different protocols, where the repeater hardware is modeled in terms of key performance parameters, such as photon generation rate and collection efficiency. These parameters are motivated by recent experimental demonstrations in quantum dots, trapped ions, and nitrogen-vacancy centers in diamond. We find that a quantum-dot repeater with the newest protocol (‘MidpointSource’) delivers the highest entanglement-distribution rate for typical cases where there is low probability of establishing entanglement per transmission, and in some cases the rate is orders of magnitude higher than other schemes. Our simulation tools can be used to evaluate communication protocols as part of designing a large-scale quantum network. (paper)

  16. 76 FR 57006 - Proposed Generic Communications; Draft NRC Regulatory Issue Summary 2011-XX; NRC Regulation of...

    Science.gov (United States)

    2011-09-15

    ... NUCLEAR REGULATORY COMMISSION 10 CFR Parts 30 and 150 [NRC-2011-0146] Proposed Generic Communications; Draft NRC Regulatory Issue Summary 2011-XX; NRC Regulation of Military Operational Radium-226... published for public comment the proposed draft RIS 2011-XX; NRC Regulation of Military Operational Radium...

  17. Communication on radiation risk as an area of conflict between radiological, sociological and perceptional issues

    Energy Technology Data Exchange (ETDEWEB)

    Tschurlovits, M.; Taghizadegan, R. [University of Technology Vienna, Atominstitute of Austrian Universities, Vienna (Austria)

    2006-07-01

    Risk communication in radiation protection must not be considered as a single discipline, but is based upon an effective interaction of different scientific fields. This implies that radiological and sociological issues as well as risk perception are to be taken into account. However, communication is not straightforward, as the fields have different objectives, are different in terminology, apply different approaches to solve problems, and are using different languages. Issues to be addressed in this paper are among others: possible meanings and definitions of the term 'risk', handling of uncertainty and variability of parameters as risk factors, importance of doses delivered in the far future, reasonable application of the dose commitment concept, and perception of small numbers. Other issues are sociological issues as interests of stakeholders and involved parties, importance of public opinion, media and cultural prototypes, bias in different groups of advocate. As communication will become effective only if the different contributing parties adjust their way of thinking and their language to the requirements of others without modification of their knowledge, guidance for interaction is important. The paper will review possible approaches suitable for better communication. (authors)

  18. Communication on radiation risk as an area of conflict between radiological, sociological and perceptional issues

    International Nuclear Information System (INIS)

    Tschurlovits, M.; Taghizadegan, R.

    2006-01-01

    Risk communication in radiation protection must not be considered as a single discipline, but is based upon an effective interaction of different scientific fields. This implies that radiological and sociological issues as well as risk perception are to be taken into account. However, communication is not straightforward, as the fields have different objectives, are different in terminology, apply different approaches to solve problems, and are using different languages. Issues to be addressed in this paper are among others: possible meanings and definitions of the term 'risk', handling of uncertainty and variability of parameters as risk factors, importance of doses delivered in the far future, reasonable application of the dose commitment concept, and perception of small numbers. Other issues are sociological issues as interests of stakeholders and involved parties, importance of public opinion, media and cultural prototypes, bias in different groups of advocate. As communication will become effective only if the different contributing parties adjust their way of thinking and their language to the requirements of others without modification of their knowledge, guidance for interaction is important. The paper will review possible approaches suitable for better communication. (authors)

  19. Cross-Layer Design for Energy-Efficient Secure Multicast Communications in Ad Hoc Networks

    National Research Council Canada - National Science Library

    Lazos, Loukas; Poovendran, Radha

    2004-01-01

    .... They present an analytical formulation of the energy expenditure associated with the communication overhead of key management, and highlight its dependence on network topology and key distribution method...

  20. Locating relationship and communication issues among stressors associated with breast cancer.

    Science.gov (United States)

    Weber, Kirsten M; Solomon, Denise Haunani

    2008-11-01

    This article clarifies how the social contexts in which breast cancer survivors live can contribute to the stress they experience because of the disease. Guided by Solomon and Knobloch's (2004) relational turbulence model and Petronio's (2002) communication privacy management theory, this study explores personal relationship and communication boundary issues within stressors that are associated with the diagnosis, treatment, and early survivorship of breast cancer. A qualitative analysis of discourse posted on breast cancer discussion boards and weblogs using the constant comparative method and open-coding techniques revealed 12 sources of stress. Using axial coding methods and probing these topics for underlying relationship and communication issues yielded 5 themes. The discussion highlights the implications of the findings for the theories that guided this investigation and for breast cancer survivorship more generally.

  1. Engineering applications of fpgas chaotic systems, artificial neural networks, random number generators, and secure communication systems

    CERN Document Server

    Tlelo-Cuautle, Esteban; de la Fraga, Luis Gerardo

    2016-01-01

    This book offers readers a clear guide to implementing engineering applications with FPGAs, from the mathematical description to the hardware synthesis, including discussion of VHDL programming and co-simulation issues. Coverage includes FPGA realizations such as: chaos generators that are described from their mathematical models; artificial neural networks (ANNs) to predict chaotic time series, for which a discussion of different ANN topologies is included, with different learning techniques and activation functions; random number generators (RNGs) that are realized using different chaos generators, and discussions of their maximum Lyapunov exponent values and entropies. Finally, optimized chaotic oscillators are synchronized and realized to implement a secure communication system that processes black and white and grey-scale images. In each application, readers will find VHDL programming guidelines and computer arithmetic issues, along with co-simulation examples with Active-HDL and Simulink. Readers will b...

  2. The usage of Internet social networking as a tool of linguist students' intercultural communication competence growth

    Directory of Open Access Journals (Sweden)

    Сергей Владимирович Сороколетов

    2009-06-01

    Full Text Available In work concepts «the intercultural communicative competence», «a social network», possibilities of use social the Internet of network FaceBook in training of students-linguists are described.

  3. MmWave Vehicle-to-Infrastructure Communication :Analysis of Urban Microcellular Networks

    Science.gov (United States)

    2017-05-01

    Vehicle-to-infrastructure (V2I) communication may provide high data rates to vehicles via millimeterwave (mmWave) microcellular networks. This report uses stochastic geometry to analyze the coverage of urban mmWave microcellular networks. Prior work ...

  4. Virtualized cloud data center networks issues in resource management

    CERN Document Server

    Tsai, Linjiun

    2016-01-01

    This book discusses the characteristics of virtualized cloud networking, identifies the requirements of cloud network management, and illustrates the challenges in deploying virtual clusters in multi-tenant cloud data centers. The book also introduces network partitioning techniques to provide contention-free allocation, topology-invariant reallocation, and highly efficient resource utilization, based on the Fat-tree network structure. Managing cloud data center resources without considering resource contentions among different cloud services and dynamic resource demands adversely affects the performance of cloud services and reduces the resource utilization of cloud data centers. These challenges are mainly due to strict cluster topology requirements, resource contentions between uncooperative cloud services, and spatial/temporal data center resource fragmentation. Cloud data center network resource allocation/reallocation which cope well with such challenges will allow cloud services to be provisioned with ...

  5. Issues in the use of neural networks in information retrieval

    CERN Document Server

    Iatan, Iuliana F

    2017-01-01

    This book highlights the ability of neural networks (NNs) to be excellent pattern matchers and their importance in information retrieval (IR), which is based on index term matching. The book defines a new NN-based method for learning image similarity and describes how to use fuzzy Gaussian neural networks to predict personality. It introduces the fuzzy Clifford Gaussian network, and two concurrent neural models: (1) concurrent fuzzy nonlinear perceptron modules, and (2) concurrent fuzzy Gaussian neural network modules. Furthermore, it explains the design of a new model of fuzzy nonlinear perceptron based on alpha level sets and describes a recurrent fuzzy neural network model with a learning algorithm based on the improved particle swarm optimization method.

  6. A mars communication constellation for human exploration and network science

    Science.gov (United States)

    Castellini, Francesco; Simonetto, Andrea; Martini, Roberto; Lavagna, Michèle

    2010-01-01

    This paper analyses the possibility of exploiting a small spacecrafts constellation around Mars to ensure a complete and continuous coverage of the planet, for the purpose of supporting future human and robotic operations and taking advantage of optical transmission techniques. The study foresees such a communications mission to be implemented at least after 2020 and a high data-rate requirement is imposed for the return of huge scientific data from massive robotic exploration or to allow video transmissions from a possible human outpost. In addition, the set-up of a communication constellation around Mars would give the opportunity of exploiting this multi-platform infrastructure to perform network science, that would largely increase our knowledge of the planet. The paper covers all technical aspects of a feasibility study performed for the primary communications mission. Results are presented for the system trade-offs, including communication architecture, constellation configuration and transfer strategy, and the mission analysis optimization, performed through the application of a multi-objective genetic algorithm to two models of increasing difficulty for the low-thrust trajectory definition. The resulting communication architecture is quite complex and includes six 530 kg spacecrafts on two different orbital planes, plus one redundant unit per plane, that ensure complete coverage of the planet’s surface; communications between the satellites and Earth are achieved through optical links, that allow lower mass and power consumption with respect to traditional radio-frequency technology, while inter-satellite links and spacecrafts-to-Mars connections are ensured by radio transmissions. The resulting data-rates for Earth-Mars uplink and downlink, satellite-to-satellite and satellite-to-surface are respectively 13.7 Mbps, 10.2 Mbps, 4.8 Mbps and 4.3 Mbps, in worst-case. Two electric propulsion modules are foreseen, to be placed on a C3˜0 escape orbit with two

  7. Car-to-Pedestrian Communication Safety System Based on the Vehicular Ad-Hoc Network Environment: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Peng Jing

    2017-10-01

    Full Text Available With the unparalleled growth of motor vehicles, traffic accident between pedestrians and vehicles is one of the most serious issues in the word-wild. Plenty of injuries and fatalities are caused by the traffic accidents and crashes. The connected vehicular ad hoc network as an emerging approach which has the potential to reduce and even avoid accidents have been focused on by many researchers. A large number of car-to-pedestrian communication safety systems based on the vehicular ad hoc network are researching and developing. However, to our limited knowledge, a systematic review about the car-to-pedestrian communication safety system based on the vehicular ad-hoc network has not be written. The purpose and goal of this review is to systematically evaluate and access the reliability of car-to-pedestrian communication safety system based on the vehicular ad-hoc network environment and provide some recommendations for the future works according to throwing some light on the previous literatures. A quality evaluation was developed through established items and instruments tailored to this review. Future works are needed to focus on developing a valid as well as effective communication safety system based on the vehicular ad hoc network to protect the vulnerable road users.

  8. Government information collections in the networked environment new issues and models

    CERN Document Server

    Cheverie, Joan F

    2013-01-01

    This insightful book explores the challenging issues related to effective access to government information.Amidst all the chaos of today's dynamic information transition period, the only constants related to government information are change and inconsistency, yet with Government Information Collections in the Networked Environment: New Issues and Models, you will defeat the challenging issues and take advantage of the opportunities that networked government information collections have to offer. This valuable book gives you a fresh opportunity to rethink collecting activities and to

  9. Network Coded Cooperative Communication in a Real-Time Wireless Hospital Sensor Network.

    Science.gov (United States)

    Prakash, R; Balaji Ganesh, A; Sivabalan, Somu

    2017-05-01

    The paper presents a network coded cooperative communication (NC-CC) enabled wireless hospital sensor network architecture for monitoring health as well as postural activities of a patient. A wearable device, referred as a smartband is interfaced with pulse rate, body temperature sensors and an accelerometer along with wireless protocol services, such as Bluetooth and Radio-Frequency transceiver and Wi-Fi. The energy efficiency of wearable device is improved by embedding a linear acceleration based transmission duty cycling algorithm (NC-DRDC). The real-time demonstration is carried-out in a hospital environment to evaluate the performance characteristics, such as power spectral density, energy consumption, signal to noise ratio, packet delivery ratio and transmission offset. The resource sharing and energy efficiency features of network coding technique are improved by proposing an algorithm referred as network coding based dynamic retransmit/rebroadcast decision control (LA-TDC). From the experimental results, it is observed that the proposed LA-TDC algorithm reduces network traffic and end-to-end delay by an average of 27.8% and 21.6%, respectively than traditional network coded wireless transmission. The wireless architecture is deployed in a hospital environment and results are then successfully validated.

  10. Innovation and communicative action: health management networks and technologies.

    Science.gov (United States)

    Rivera, Francisco Javier Uribe; Artmann, Elizabeth

    2016-11-03

    This article discusses elements of a theory of innovation from the perspective of innovation networks and social construction of technology, based on Habermas' Theory of Communicative Action and authors from the Sociology of Innovation. Based on the theoretical framework of the communicative production of scientific facts, we focus on innovation management as a basic dimension that must meet some organizational and methodological requirements in order to power its results. We present and discuss instruments such as Situational Planning, Prospective Analysis, Strategic Portfolio Management, and Networks Management that can help deal with the challenge of innovation and exploration of the future. We conclude that network organizational formats centered on reflexivity of interdisciplinary groups and planning approaches that encourage innovation criteria in assessing the attractiveness of activities and that help anticipate forms of innovation through systematic prospective analysis can potentiate the process of generating innovation as a product of networks. Resumo: No artigo são discutidos elementos de uma teoria da inovação numa perspectiva de redes de inovação e de construção social da tecnologia, a partir da Teoria do Agir Comunicativo de Habermas e de autores da Sociologia da Inovação. Com base no marco teórico da produção comunicativa de fatos científicos, focamos a gestão da inovação como uma dimensão fundamental que deve contemplar alguns requisitos, tanto de natureza organizacional quanto metodológica, para potencializar seus resultados. Apresentamos e discutimos instrumentos como o Planejamento Situacional, a Análise Prospectiva, a Gestão Estratégica de Portfólios e a Gestão de Redes que podem contribuir para o desafio da inovação e exploração do futuro. Conclui-se que formas organizativas em rede, centradas na reflexividade de grupos interdisciplinares, e enfoques de planejamento que estimulem o uso de critérios de inovação na

  11. DOE waste information network: Data management and communications

    International Nuclear Information System (INIS)

    Fore, C.S.

    1986-01-01

    The U.S. Department of Energy's Waste Information Network (WIN) is an integral part of DOE's Hazardous Waste Remedial Actions Program. WIN has played an active role in the national program's mission to identify the magnitude and nature of existing DOE hazardous chemical and mixed radioactive waste streams and inventories and to provide a mechanism for disseminating pertinent information on technology activities. The information systems activity is structured into three key areas: data base development, data analysis, and data dissemination. As a result of this effort, several key data bases have been developed. Data dissemination is important to the use and management of the diversity of information and communication features developed by the program

  12. Capacity gain with an alternative LTE railway communication network

    DEFF Research Database (Denmark)

    Sniady, Aleksander; Soler, José

    2014-01-01

    , such as 3GPP Long Term Evolution (LTE). T his paper describe s how to adapt the reversible multi - chain/channel queuing system to model an LTE cell serving ETCS - equipped trains . It is proposed to use the multiple user chains available in the model to represent varying bitrate in LTE radio access network....... Usin g this model , LTE and GSM - R are compare d in terms of capacity on an example at Copenhagen Main Train Station . The purpose of this work is to demonstrate the benefits that railway operators and infrastructure managers can expect from the introduc tion of LTE , as a telecommunication technology...... Control System (ETCS) signaling , the capacity of GSM - R turns out to be insufficient . GSM - R cannot ful fill the railway requirements , in terms of the number of simultaneous ETCS connections . This is why , alternative , more efficient communication technologies should be considered by railways...

  13. Energy Harvesting in Heterogeneous Networks with Hybrid Powered Communication Systems

    KAUST Repository

    Alsharoa, Ahmad

    2018-02-12

    In this paper, we investigate an energy efficient and energy harvesting (EH) system model in heterogeneous networks (HetNets) where all base stations (BSS) are equipped to harvest energy from renewable energy sources. We consider a hybrid power supply of green (renewable) and traditional micro-grid, such that traditional micro-grid is not exploited as long as the BSS can meet their power demands from harvested and stored green energy. Therefore, our goal is to minimize the networkwide energy consumption subject to users\\' certain quality of service and BSS\\' power consumption constraints. As a result of binary BS sleeping status and user-cell association variables, proposed is formulated as a binary linear programming (BLP) problem. A green communication algorithm based on binary particle swarm optimization is implemented to solve the problem with low complexity time.

  14. Increasing capacity of baseband digital data communication networks

    Science.gov (United States)

    Frankel, Robert S.; Herman, Alexander

    1985-01-01

    This invention provides broadband network capabilities for baseband digital collision detection transceiver equipment for communication between a plurality of data stations by affording simultaneous transmission of multiple channels over a broadband pass transmission link such as a coaxial cable. Thus, a fundamental carrier wave is transmitted on said link, received at local data stations and used to detect signals on different baseband channels for reception. For transmission the carrier wave typically is used for segregating a plurality of at least two transmission channels into typically single sideband upper and lower pass bands of baseband bandwidth capability adequately separated with guard bands to permit simple separation for receiving by means of pass band filters, etc.

  15. Increasing capacity of baseband digital data communication networks

    International Nuclear Information System (INIS)

    Frankel, R. S.; Herman, A.

    1985-01-01

    This invention provides broadband network capabilities for baseband digital collision detection transceiver equipment for communication between a plurality of data stations by affording simultaneous transmission of multiple channels over a broadband pass transmission link such as a coaxial cable. Thus, a fundamental carrier wave is transmitted on said link, received at local data stations and used to detect signals on different baseband channels for reception. For transmission the carrier wave typically is used for segregating a plurality of at least two transmission channels into typically single sideband upper and lower pass bands of baseband bandwidth capability adequately separated with guard bands to permit simple separation for receiving by means of pass band filters, etc

  16. Network-Assisted Distributed Fairness-Aware Interference Coordination for Device-to-Device Communication Underlaid Cellular Networks

    Directory of Open Access Journals (Sweden)

    Francis Boabang

    2017-01-01

    Full Text Available Device-to-device (D2D communication underlaid cellular network is considered a key integration feature in future cellular network. However, without properly designed interference management, the interference from D2D transmission tends to degrade the performance of cellular users and D2D pairs. In this work, we proposed a network-assisted distributed interference mitigation scheme to address this issue. Specifically, the base station (BS acts as a control agent that coordinates the cross-tier interference from D2D transmission through a taxation scheme. The cotier interference is controlled by noncooperative game amongst D2D pairs. In general, the outcome of noncooperative game is inefficient due to the selfishness of each player. In our game formulation, reference user who is the victim of cotier interference is factored into the payoff function of each player to obtain fair and efficient outcome. The existence, uniqueness of the Nash Equilibrium (NE, and the convergence of the proposed algorithm are characterized using Variational Inequality theory. Finally, we provide simulation results to evaluate the efficiency of the proposed algorithm.

  17. Compatibility Issues of IPSec and TCP in Wireless Networks

    Institute of Scientific and Technical Information of China (English)

    ZHAO Hai-yang; XIN Yang

    2004-01-01

    Due to the problems arising when the Transmission Control Protocol (TCP) is applied over wireless networks, many TCP performance enhancement mechanisms have been proposed. However, such mechanisms aren't compatible with IPSec protocol. The paper reviews the TCP performance enhancement mechanisms in wireless networks. Then the conflicts between them are analyzed. Several proposals for solving theconflicts are discussed, and their benefit and limitations are examined.

  18. Flash floods warning technique based on wireless communication networks data

    Science.gov (United States)

    David, Noam; Alpert, Pinhas; Messer, Hagit

    2010-05-01

    Flash floods can occur throughout or subsequent to rainfall events, particularly in cases where the precipitation is of high-intensity. Unfortunately, each year these floods cause severe property damage and heavy casualties. At present, there are no sufficient real time flash flood warning facilities found to cope with this phenomenon. Here we show the tremendous potential of flash floods advanced warning based on precipitation measurements of commercial microwave links. As was recently shown, wireless communication networks supply high resolution precipitation measurements at ground level while often being situated in flood prone areas, covering large parts of these hazardous regions. We present the flash flood warning potential of the wireless communication system for two different cases when floods occurred at the Judean desert and at the northern Negev in Israel. In both cases, an advanced warning regarding the hazard could have been announced based on this system. • This research was supported by THE ISRAEL SCIENCE FOUNDATION (grant No. 173/08). This work was also supported by a grant from the Yeshaya Horowitz Association, Jerusalem. Additional support was given by the PROCEMA-BMBF project and by the GLOWA-JR BMBF project.

  19. Performance Analysis of Mobile Ad Hoc Unmanned Aerial Vehicle Communication Networks with Directional Antennas

    Directory of Open Access Journals (Sweden)

    Abdel Ilah Alshbatat

    2010-01-01

    Full Text Available Unmanned aerial vehicles (UAVs have the potential of creating an ad hoc communication network in the air. Most UAVs used in communication networks are equipped with wireless transceivers using omnidirectional antennas. In this paper, we consider a collection of UAVs that communicate through wireless links as a mobile ad-hoc network using directional antennas. The network design goal is to maximize the throughput and minimize the end-to-end delay. In this respect, we propose a new medium access control protocol for a network of UAVs with directional antennas. We analyze the communication channel between the UAVs and the effect of aircraft attitude on the network performance. Using the optimized network engineering tool (OPNET, we compare our protocol with the IEEE 802.11 protocol for omnidirectional antennas. The simulation results show performance improvement in end-to-end delay as well as throughput.

  20. Key issues of multiple access technique for LEO satellite communication systems

    Institute of Scientific and Technical Information of China (English)

    温萍萍; 顾学迈

    2004-01-01

    The large carrier frequency shift caused by the high-speed movement of satellite (Doppler effects) and the propagation delay on the up-down link are very critical issues in an LEO satellite communication system, which affects both the selection and the implementation of a suitable access method. A Doppler based multiple access technique is used here to control the flow and an MPRMA-HS protocol is proposed for the application in LEO satellite communication systems. The extended simulation trials prove that the proposed scheme seems to be a very promising access method.