Sample records for informal communication networks

  1. Information communication on complex networks

    NASA Astrophysics Data System (ADS)

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

    2013-02-01

    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.

  2. Information Delivery Through Broadcasting in Satellite Communication Networks

    E-print Network

    Tassiulas, Leandros

    Information Delivery Through Broadcasting in Satellite Communication Networks Leandros Tassiulas­range multicasting capability of satellites and the asymmetry of satellite communications (high bandwidth downlink. We consider a data broadcasting model that is encountered in most asymmetric satellite communication

  3. COMMUNICATION NETWORKS AND THE RISE OF AN INFORMATION ELITE

    E-print Network

    COMMUNICATION NETWORKS AND THE RISE OF AN INFORMATION ELITE CAN COMMUNICATION HELP THE INFORMATION shared. Thus universal access policies that provide only communication channels but do not also establish of communication channels and the levels of learning and sharing that take place, the model rigorously explains how

  4. Information concealing games in communication networks

    E-print Network

    ``minimum'' amount of information about the system state to the second entity. It can however choose in communication systems have lead to schemes that maximize the rate of exchange of information. An aspect that has entity (controller) has complete information about the state of the system, and must reveal a certain

  5. Directedness of information flow in mobile phone communication networks

    E-print Network

    Peruani, Fernando; 10.1371/journal.pone.0028860

    2013-01-01

    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 ...

  6. Library Participation in a Biomedical Communication and Information Network *

    PubMed Central

    Bridegam, Willis E.; Meyerhoff, Erich

    1970-01-01

    The experience of two libraries participating in the SUNY Biomedical Communication Network is described. The history of the Network is briefly given, together with its original aims and their current status. Use of the terminals and formulation of queries are explained. Figures are given for total costs, number of searches performed, and cost per search. There is an account of the internal structure of the administration of the Network. PMID:5439900

  7. David Meets Goliath on the Information Superhighway: Venezuela in the Context of the Electronic Communication Networks.

    ERIC Educational Resources Information Center

    Sanchez-Vegas, Saadia

    1995-01-01

    Discusses Venezuela's information and communications technology infrastructure and usage patterns; examines future networking plans; and addresses political and economic considerations linked to the information and technology problems in Venezuela and in Latin America in general. (LRW)

  8. Advanced information processing system: Authentication protocols for network communication

    NASA Technical Reports Server (NTRS)

    Harper, Richard E.; Adams, Stuart J.; Babikyan, Carol A.; Butler, Bryan P.; Clark, Anne L.; Lala, Jaynarayan H.

    1994-01-01

    In safety critical I/O and intercomputer communication networks, reliable message transmission is an important concern. Difficulties of communication and fault identification in networks arise primarily because the sender of a transmission cannot be identified with certainty, an intermediate node can corrupt a message without certainty of detection, and a babbling node cannot be identified and silenced without lengthy diagnosis and reconfiguration . Authentication protocols use digital signature techniques to verify the authenticity of messages with high probability. Such protocols appear to provide an efficient solution to many of these problems. The objective of this program is to develop, demonstrate, and evaluate intercomputer communication architectures which employ authentication. As a context for the evaluation, the authentication protocol-based communication concept was demonstrated under this program by hosting a real-time flight critical guidance, navigation and control algorithm on a distributed, heterogeneous, mixed redundancy system of workstations and embedded fault-tolerant computers.

  9. ContactMap: Integrating Communication and Information Through Visualizing Personal Social Networks

    Microsoft Academic Search

    Bonnie A. Nardi; Steve Whittaker; Ellen Isaacs; Mike Creech; Jeff Johnson; John Hainsworth

    What could provide an organizing principle for advanced user interfaces that afford information and communication services in a single integrated system? Based on our research on communication patterns in the workplace, our answer is models of personal social networks. Our research showed that people invest considerable effort in maintaining links with networks of colleagues, acquaintances and friends, and that these

  10. INFORMATION & COMMUNICATION

    E-print Network

    Jackson, Daniel

    .00/£23.95 · 978-0-262-01813-5 VENTURE LABOR Work and the Burden of Risk in Innovative Industries Gina Neff Why of Information Science series DIGITAL DEAD END Fighting for Social Justice in the Information Age Virginia) TRANSFORMING GLOBAL INFORMATION AND COMMUNICATION MARKETS The Political Economy of Innovation Peter F. Cowhey

  11. Information & Communication

    E-print Network

    Greenaway, Alan

    how visitors use a website. All information is anonymous and is used to improve how the website works by Google Inc. It allows us to recognise and count the number of visitors and to see how visitors moveInformation & Communication Services Understand how cookies are used on the University of Dundee

  12. Information -Communication Communication des entreprises

    E-print Network

    Sart, Remi

    Information - Communication 2 PARCOURS Communication des entreprises Communication et solidarité;2 Information - Communication UFR Langues Appliquées, Commerce et Communication PR?SENTATION Objectifs La Licence Information et communication est destinée aux étudiants qui souhaitent suivre un parcours

  13. System and method for information security in optical communication networks

    NASA Astrophysics Data System (ADS)

    Shemtoob, Dariush; Sadot, Dan

    2002-07-01

    A genuinely triple-security-level encryption module for optical communication systems is presented. The approach is practical and feasible supporting real-time encryption of data rates from 155.52 Mbit/s up to 2.4 Gbit/s, based on existing, commercially available electronic technologies. The system deploys a nonrestricted symmetric-key block algorithm with dynamic parallel-processing width according to the input data rates. The algorithm enables the system to support different key strengths according to dynamic key length and processing block size assignment. The operation principle is based on time-to-frequency translation of differentially coded data blocks from the input data stream after optical-to-electronic conversion and utilization of the resulting wideband multitone radio-frequency (RF) signal to modulate a laser source being fed back to the optical fiber network. An identical scheme implemented in time-reversed order is established during the decryption process to recover the wideband multitone RF signal from the optical fiber and decode the original data, based on a synchronized code generation scheme, before it is transferred back to the optical fiber. The total system bandwidth depends on data rates at input and expected encryption strength and can vary from 2020 MHz for an OC-3 link up to 12,900 MHz for an OC-48 link.

  14. ANALYZING THE EFFECT OF ATTITUDE IN FRIENDSHIP NETWORKS TO IMPROVE INFORMATION AND COMMUNICATION TECHNOLOGY KNOWLEDGE SHARING: A GENDER APPROACH

    Microsoft Academic Search

    Jose Esteves

    Based in 14 focus groups, this exploratory study attempts to analyze the way women and men perceive talking about information and communication technology in their same sex friendship networks and the way it impact in information and communication technology (ICT) attitude and knowledge sharing. Our research findings reveal that friendship networks play an important role in ICT knowledge sharing. There

  15. R-ALOHA protocol for SS inter-vehicle communication network using head spacing information

    Microsoft Academic Search

    Young-An Kim; Masao Nakagawa

    1996-01-01

    The purpose of the studies is to improve the safety of road traffic systems and the smooth control of the traffic flow by providing information to vehicles. This paper assumes that the vehicles incidentally close to each other, form and manage a locally autonomous decentralized dynamic network. An R-ALOHA (reservation-ALOHA) protocol for the spread spectrum (SS) inter-vehicle communication network using

  16. Information and Communication Technology

    NSDL National Science Digital Library

    Communication is a central aspect of all our lives. Today, our modes of communication are highly dependent on technologies such as the internet, wireless networks, phones, and computers. This issue of Topic in Depth explores the ways these forms of communication are part of our lives and highlights some new directions in communication technology.WordIQ Dictionary and Encyclopedia (1) offers this definition: "Communication is the process of exchanging information usually via a common system of symbols." The website explains some of the key process involved in communication and describes different forms of communication, such as animal communication, interpersonal communication, and computer-mediated communication. Also taking a broad view on communication, this world history website (2) provides some background on the mathematical theories that are used in designing telecommunications systems. The articles highlighted on this website from the Center for the Study of Technology and Society (4) attest to the far reaching influence of communication technology. As research on the MediaLab Europe website suggests (5), we have moved into not just developing technology that mediates interpersonal communication (such as phones) but also creating "intimate and personal connections with and through new technologies." This NSF website (6) also highlights some recent discoveries in Computer Information Science and Engineering. Finally, this article from First Monday (7) discusses the far-reaching effects these new developments in technology and globalization are having on language and learning.

  17. Regional-technical information network system by PC-based communication 'Kougi Net Niigata'

    NASA Astrophysics Data System (ADS)

    Tanaka, Koichi; Kitagawa, Yoichi; Hoshino, Kimiaki

    'Regional-technical information' database was constructed by Industrial research institute of Niigata prefecture. This is available for industries in our prefecture with our PC-based communication network system. And also, it provides communication measures called BBS and electronic mail service with which they can communicate each other. This system is considered to give three effects. First of all, they can get technical information required in regional industries that is not provided by commercial database at their office or factory speedy and correctly. Secondly, they can easily survey technical background of local industries they want to take into partnership in their extension of work. Thirdly, since it provides a place where they can exchange information each other, it promotes their development of new commercial products and partnership.

  18. To construct a communications network over the whole of Hokkaido - Vitality from an information network : NF212 plan -

    NASA Astrophysics Data System (ADS)

    Ishiko, Michimasu

    Hokkaido finds itself confronted with certain problems-how to strengthen the constitution of its industrial structure and how to build up wealthy local communities without regional differences. We think that information-orientation is indispensable for this purpose. What we now see materializing is a government policy of establishing information-oriented communities, and information allied businesses promoted by private industrial firms. If, however, these high-tech start-up ventures are carried out without any cooperation with each other, it would be impossible to realize an effective communication network-with each individual venture, for example, probably selecting a different kind of terminal. The Hokkaido government has searched for what information-oriented society should be in Hokkaido along with the private industrial firms, and also to make things ready for an information communication system. That means finding a way to apply this plan to the whole of Hokkaido. The Hokkaido government calls this plan NF212.

  19. Informing the network: Improving communication with interface communities during wildland fire

    USGS Publications Warehouse

    Taylor, J.G.; Gillette, S.C.; Hodgson, R.W.; Downing, J.L.; Burns, M.R.; Chavez, D.J.; Hogan, J.T.

    2007-01-01

    An interagency research team studied fire communications that took place during different stages of two wildfires in southern California: one small fire of short duration and one large fire of long duration. This "quick- response" research showed that pre-fire communication planning was particularly effective for smaller fire events and parts of that planning proved invaluable for the large fire event as well. Information seeking by the affected public relied on locally convenient sources during the small fire. During the large fire, widespread evacuations disrupted many of the local informal communication networks. Residents' needs were for "real-time, " place-specific information: precise location, severity, size, and direction of spread of the fires. Fire management agencies must contribute real-time, place-specific fire information when it is most needed by the affected public, as they try to make sense out of the chaos of a wildland fire. Disseminating fire information as broadly as possible through multiple pathways will maximize the probability of the public finding the information they need. ?? Society for Human Ecology.

  20. Sensor Networks Communication strategies

    E-print Network

    Chisci, Luigi

    Outline Sensor Networks Communication strategies Follow on Distributed estimation in sensor@dsi.unifi.it February 1, 2007 A. Benavoli Fully Decentralized Networks #12;Outline Sensor Networks Communication strategies Follow on Outline 1 Sensor Networks An introduction to Sensor Networks Network architectures

  1. International Journal of Communication Networks and Information Security (IJCNIS) Vol. 1, No. 2, August 2009 A Secured Service Level Negotiation

    E-print Network

    Paris-Sud XI, Université de

    9 International Journal of Communication Networks and Information Security (IJCNIS) Vol. 1, No. 2, August 2009 A Secured Service Level Negotiation In Ubiquitous Environments Mohamed Aymen Chalouf1 make the concerned communications vulnerable to security attacks because of the open medium on which

  2. Extracting information from informal communication

    E-print Network

    Rennie, Jason D. M. (Jason Daniel Malyutin), 1976-

    2007-01-01

    This thesis focuses on the problem of extracting information from informal communication. Textual informal communication, such as e-mail, bulletin boards and blogs, has become a vast information resource. However, such ...

  3. Communicability across evolving networks.

    PubMed

    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. PMID:21599253

  4. A universal quantum information processor for scalable quantum communication and networks

    PubMed Central

    Yang, Xihua; Xue, Bolin; Zhang, Junxiang; Zhu, Shiyao

    2014-01-01

    Entanglement provides an essential resource for quantum computation, quantum communication, and quantum networks. How to conveniently and efficiently realize the generation, distribution, storage, retrieval, and control of multipartite entanglement is the basic requirement for realistic quantum information processing. Here, we present a theoretical proposal to efficiently and conveniently achieve a universal quantum information processor (QIP) via atomic coherence in an atomic ensemble. The atomic coherence, produced through electromagnetically induced transparency (EIT) in the ?-type configuration, acts as the QIP and has full functions of quantum beam splitter, quantum frequency converter, quantum entangler, and quantum repeater. By employing EIT-based nondegenerate four-wave mixing processes, the generation, exchange, distribution, and manipulation of light-light, atom-light, and atom-atom multipartite entanglement can be efficiently and flexibly achieved in a deterministic way with only coherent light fields. This method greatly facilitates the operations in quantum information processing, and holds promising applications in realistic scalable quantum communication and quantum networks. PMID:25316514

  5. A universal quantum information processor for scalable quantum communication and networks.

    PubMed

    Yang, Xihua; Xue, Bolin; Zhang, Junxiang; Zhu, Shiyao

    2014-01-01

    Entanglement provides an essential resource for quantum computation, quantum communication, and quantum networks. How to conveniently and efficiently realize the generation, distribution, storage, retrieval, and control of multipartite entanglement is the basic requirement for realistic quantum information processing. Here, we present a theoretical proposal to efficiently and conveniently achieve a universal quantum information processor (QIP) via atomic coherence in an atomic ensemble. The atomic coherence, produced through electromagnetically induced transparency (EIT) in the ?-type configuration, acts as the QIP and has full functions of quantum beam splitter, quantum frequency converter, quantum entangler, and quantum repeater. By employing EIT-based nondegenerate four-wave mixing processes, the generation, exchange, distribution, and manipulation of light-light, atom-light, and atom-atom multipartite entanglement can be efficiently and flexibly achieved in a deterministic way with only coherent light fields. This method greatly facilitates the operations in quantum information processing, and holds promising applications in realistic scalable quantum communication and quantum networks. PMID:25316514

  6. Information and Communications Technologies Tutorials

    NSDL National Science Digital Library

    The Information and Communications Technologies Center (ICT) presents this collection of links to a number of online tutorials. The tutorials fall under the categories of electronics, fiber optics, general computing and programming, general telecommunications, java, math, matlab, networking and physics.

  7. Network information flow

    Microsoft Academic Search

    Rudolf Ahlswede; Ning Cai; Shuo-yen Robert Li; Raymond W. Yeung

    2000-01-01

    We introduce a new class of problems called network information flow which is inspired by computer network applica- tions. Consider a point-to-point communication network on which a number of information sources are to be mulitcast to certain sets of destinations. We assume that the information sources are mu- tually independent. The problem is to characterize the admissible coding rate region.

  8. General practice and the Internet revolution. Use of an Internet social network to communicate information on prevention in France.

    PubMed

    Veuillotte, Isabelle; Morel, Gilles; Pitois, Stephane; Haler, Renaud; Mercier, Patricia; Aubry, Catherine; Cannet, Didier

    2015-03-01

    The popularity of social networks and the huge number of exchanges have made them immensely important for the communication of information. This French study explored prevention in hereditary breast cancer using a social Internet network to communicate information. The principal objective was to inform French women aged from 20 to 50 years, using the social network Facebook, about the warning signs of breast cancer in cases of a predisposition to the disease due to a genetic mutation. The secondary objectives were to inform people about screening. An information page entitled "hereditary breast cancer: and if I was concerned?" was distributed in 3 different ways: from friend to friend, via groups of persons, and by targeted advertising. Four articles and 11 messages were distributed over 27 days. The total number of visits for this period amounted to 1019. A total of 81 percent of the Internauts were women and 55 percent of the visitors were aged between 25 and 44 years. Other information campaigns concerning public health issues could be conducted using this tool. A legal framework is necessary to preserve the quality of the medical information provided. This new means of communication, used for prevention purposes, will add to other frequently used methods of communication. PMID:25784641

  9. Resourcesharing computer communications networks

    Microsoft Academic Search

    ROBERT E. KAHN

    1972-01-01

    The development of resource-sharing networks can facilitate the provision of a wide range of economic and reliable computer services. Computer-communication networks allow the sharing of specialized computer resources such as data bases, programs, and hardware. Such a network consists of both the computer resources and a communications system interconnecting them and allowing their full utilization to be achieved. In addition,

  10. College of Communication and Information COM Communication

    E-print Network

    MacAdam, Keith

    College of Communication and Information COM Communication KEY: # = new course * = course changed TO COMMUNICATIONS. (3) Anintroductiontotheprocessofcommunicationasacriticalelementinhumaninteractionandinsociety.Designedtoenhanceeffective communication and informed use of the mass media. COM 181 BASIC PUBLIC SPEAKING. (3) A course designed to give

  11. Out of sight but not out of mind?: Informal networks, communication and media use in global software teams

    Microsoft Academic Search

    Klarissa T. Chang; Kate Ehrlich

    2007-01-01

    In an effort to reduce costs and improve staffing options, companies are going offshore to staff software projects. Although advances in communication technologies make it easier to share information, a growing number of studies have highlighted the disadvantages and hidden costs of distributed teams. This paper reports the results of a study that used social network analysis to study the

  12. A network information theory for wireless communication: scaling laws and optimal operation

    Microsoft Academic Search

    Liang-liang Xie; Panganamala R. Kumar

    2004-01-01

    How much information can be carried over a wireless network with a multiplicity of nodes, and how should the nodes cooperate to transfer information? To study these questions, we formulate a model of wireless networks that particularly takes into account the distances between nodes, and the resulting attenuation of radio signals, and study a performance measure that weights information by

  13. Digital information and communication networks and scientific research substance: An investigation of meteorology

    NASA Astrophysics Data System (ADS)

    Shen, Yi

    This study investigated research meteorologists' current usage and evaluation of information and communication technologies (ICT) in performing research tasks and the current relationship between meteorologists' ICT use and content characteristics of their research outputs. It surveyed research meteorologists working in three NOAA funded research institutes based at universities. Follow-up interviews with two selective samples of the survey participants were conducted to provide additional evidence to survey results and make suggestions for future measurement development work. Multiple regression analysis was performed to test the hypothesized relationships between meteorologists' ICT use and two substantive characteristics of their research---data integration and intra-/interdisciplinarity. Descriptive statistics were calculated to discern inferences of the scientists' current state of use and their degree of satisfaction with ICT tools. Follow-up interviews were transcribed and analyzed qualitatively with open coding and axial coding. The study findings contradicted the two assumptions of ICT effects on meteorological research by showing that the greater frequency of networked ICT use is not significantly associated with either greater data integration in research analysis, or greater intra- or interdisciplinary research. The major ICT barrier is the lack of a data and information infrastructure and support system for integrated, standardized, specialized, and easily accessible data and information from distributed servers. Suggestions were provided on the improvements of technical, social, political, and educational settings to promote large-scale date integration and intra-/interdisciplinary research. By moving further from theoretical assumptions to practical examinations, the research findings provide empirical evidence of Bowker's theories on the social shaping and social impact of infrastructure in sciences and affirmed some of Bowker's arguments regarding both social-political aspect and technical aspect of e-science practice. The results also provide implications for Computer-Mediated-Communication theories. The knowledge helps information system developers identify several important issues in current systems planning and development. The study also helps librarians, information scientists, and meteorologists both recognize the importance of and develop their collaboration in data, information, and knowledge management. Finally, the study could aid research institutes and government funding agencies to develop appropriate strategies to optimize the effective use of ICT resources and augment its positive impact on sciences.

  14. Overview of the Space Station communications networks

    NASA Technical Reports Server (NTRS)

    Smith, Joseph F.; Willett, Daniel; Paul, Sunil

    1990-01-01

    Within the Space Station Freedom program, the communications and data-processing capabilities that will be used to handle the operational and scientific information needs will be provided by a Space Station information and communications system. This system will be composed of a variety of elements, networks, and subnetworks. The networks and how they are interconnected are described. The discussion covers communications system elements and services, elements of the onboard systems, wide-area transport network elements, and command and control elements.

  15. Architecting space communication networks

    E-print Network

    Sanchez Net, Marc

    2014-01-01

    Reliable communication and navigation services are critical to robotic and human space missions. NASA currently provides them through three independent and uncoordinated network that consist of both Earth-based and space-based ...

  16. Communication in Neuronal Networks

    PubMed Central

    Laughlin, Simon B.; Sejnowski, Terrence J.

    2010-01-01

    Brains perform with remarkable efficiency, are capable of prodigious computation, and are marvels of communication. We are beginning to understand some of the geometric, biophysical, and energy constraints that have governed the evolution of cortical networks. To operate efficiently within these constraints, nature has optimized the structure and function of cortical networks with design principles similar to those used in electronic networks. The brain also exploits the adaptability of biological systems to reconfigure in response to changing needs. PMID:14512617

  17. Qudit communication network

    NASA Astrophysics Data System (ADS)

    Kim, Jaewan; Lee, Juhui; Ji, Sewan; Nha, Hyunchul; Anisimov, Petr M.; Dowling, Jonathan P.

    2012-10-01

    Optical coherent states can be interpreted as d-dimensional quantum systems, or qudits of even superposition of pseudo-number states. Cross-Kerr nonlinear interaction can generate the maximal entanglements of pseudo- phase and pseudo-number states from two opticl coherent states. Extended network of these entangled coherent states is a qudit cluster state and can be used as qudit communication network for d-dimensional teleportation or multi-user quantum cryptographic network.

  18. Social network analysis and dual rover communications

    NASA Astrophysics Data System (ADS)

    Litaker, Harry L.; Howard, Robert L.

    2013-10-01

    Social network analysis (SNA) refers to the collection of techniques, tools, and methods used in sociometry aiming at the analysis of social networks to investigate decision making, group communication, and the distribution of information. Human factors engineers at the National Aeronautics and Space Administration (NASA) conducted a social network analysis on communication data collected during a 14-day field study operating a dual rover exploration mission to better understand the relationships between certain network groups such as ground control, flight teams, and planetary science. The analysis identified two communication network structures for the continuous communication and Twice-a-Day Communication scenarios as a split network and negotiated network respectfully. The major nodes or groups for the networks' architecture, transmittal status, and information were identified using graphical network mapping, quantitative analysis of subjective impressions, and quantified statistical analysis using Sociometric Statue and Centrality. Post-questionnaire analysis along with interviews revealed advantages and disadvantages of each network structure with team members identifying the need for a more stable continuous communication network, improved robustness of voice loops, and better systems training/capabilities for scientific imagery data and operational data during Twice-a-Day Communications.

  19. Simulator of Space Communication Networks

    NASA Technical Reports Server (NTRS)

    Clare, Loren; Jennings, Esther; Gao, Jay; Segui, John; Kwong, Winston

    2005-01-01

    Multimission Advanced Communications Hybrid Environment for Test and Evaluation (MACHETE) is a suite of software tools that simulates the behaviors of communication networks to be used in space exploration, and predict the performance of established and emerging space communication protocols and services. MACHETE consists of four general software systems: (1) a system for kinematic modeling of planetary and spacecraft motions; (2) a system for characterizing the engineering impact on the bandwidth and reliability of deep-space and in-situ communication links; (3) a system for generating traffic loads and modeling of protocol behaviors and state machines; and (4) a system of user-interface for performance metric visualizations. The kinematic-modeling system makes it possible to characterize space link connectivity effects, including occultations and signal losses arising from dynamic slant-range changes and antenna radiation patterns. The link-engineering system also accounts for antenna radiation patterns and other phenomena, including modulations, data rates, coding, noise, and multipath fading. The protocol system utilizes information from the kinematic-modeling and link-engineering systems to simulate operational scenarios of space missions and evaluate overall network performance. In addition, a Communications Effect Server (CES) interface for MACHETE has been developed to facilitate hybrid simulation of space communication networks with actual flight/ground software/hardware embedded in the overall system.

  20. Information and Communications Infrastructure

    E-print Network

    Liskiewicz, Maciej

    Information and Communications Infrastructure Confidential Presidential Working Paper August 17, 2007 Copyright © 2007 Virginia Tech #12;PRESIDENTIAL WORKING PAPER: TELECOMMUNICATIONS WORKING GROUP Notification System______________________________________ 14 4.2 Infrastructure Challenges (What Needs Work

  1. Communication in Home Area Networks

    E-print Network

    Wang, Yubo

    2012-01-01

    Network PLC Power Line Communication HDR High Data Rate PSDPower Line Communication (PLC) is carrying data throughdata rate communication up to 200Mbps. All appliance/device are connected together through power line

  2. Quantum network communication -- the butterfly and beyond

    E-print Network

    Debbie Leung; Jonathan Oppenheim; Andreas Winter

    2009-12-03

    We study the k-pair communication problem for quantum information in networks of quantum channels. We consider the asymptotic rates of high fidelity quantum communication between specific sender-receiver pairs. Four scenarios of classical communication assistance (none, forward, backward, and two-way) are considered. (i) We obtain outer and inner bounds of the achievable rate regions in the most general directed networks. (ii) For two particular networks (including the butterfly network) routing is proved optimal, and the free assisting classical communication can at best be used to modify the directions of quantum channels in the network. Consequently, the achievable rate regions are given by counting edge avoiding paths, and precise achievable rate regions in all four assisting scenarios can be obtained. (iii) Optimality of routing can also be proved in classes of networks. The first class consists of directed unassisted networks in which (1) the receivers are information sinks, (2) the maximum distance from senders to receivers is small, and (3) a certain type of 4-cycles are absent, but without further constraints (such as on the number of communicating and intermediate parties). The second class consists of arbitrary backward-assisted networks with 2 sender-receiver pairs. (iv) Beyond the k-pair communication problem, observations are made on quantum multicasting and a static version of network communication related to the entanglement of assistance.

  3. NASA technology transfer network communications and information system: TUNS user survey

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Applied Expertise surveyed the users of the deployed Technology Utilization Network System (TUNS) and surveyed prospective new users in order to gather background information for developing the Concept Document of the system that will upgrade and replace TUNS. Survey participants broadly agree that automated mechanisms for acquiring, managing, and disseminating new technology and spinoff benefits information can and should play an important role in meeting NASA technology utilization goals. However, TUNS does not meet this need for most users. The survey describes a number of systematic improvements that will make it easier to use the technology transfer mechanism, and thus expedite the collection and dissemination of technology information. The survey identified 26 suggestions for enhancing the technology transfer system and related processes.

  4. The integration of communications networks in the intelligent building

    Microsoft Academic Search

    Stuart Smith

    1997-01-01

    An Intelligent Building Communications Network (IBN) is a ubiquitous network that integrates Telecommunications, an Intelligent Building Information System (IBIS) and Business Resources over a digital communications platform and has interoperability between systems. Implementation of an IBN is dependent on the migration of IBIS communications networks into the domain of telecommunication and the adoption of Open Systems Interconnection to standardise protocol

  5. Using Geospatial Information in Sensor Networks

    Microsoft Academic Search

    John Heidemann; Nirupama Bulusu

    2001-01-01

    This paper describes several ways sensor networks can ben- efit from geospatial information and identifies two research directions. First, better models of localization error, logi- cal location, and communications costs are required to un- derstand the interactions between spatial information and control and communications algorithms in sensor networks. Second, wider use of spatial information in densely de- ployed sensor networks

  6. information planning communication art

    E-print Network

    Illinois at Chicago, University of

    extremely high-resolution images developed in the EVL at UIC. Other display technologies discussed include on basic concepts of design to clarify abstractions and communicate salient relationships of statistical Basics Think conceptually about the internet and learn how to cross index information for searching

  7. COMMUNICATIONS AND NEURAL NETWORKS: THEORY AND PRACTICE Mark D. Plumbley

    E-print Network

    Plumbley, Mark

    COMMUNICATIONS AND NEURAL NETWORKS: THEORY AND PRACTICE Mark D. Plumbley Division of Engineering communication of information. One con­ crete example of this is the use of neural networks to ensure efficient network. Finally we exam­ ine what type of neural network solutions are suggested by this approach. 1

  8. GSM Mobile Phone Based Communication of Multimedia Information : A Case Study Through a practical application, this paper studies the capacity of the GSM network, a wireless mobile phone network

    E-print Network

    Wong, Kenneth K.Y.

    Title: GSM Mobile Phone Based Communication of Multimedia Information : A Case Study Abstract: Through a practical application, this paper studies the capacity of the GSM network, a wireless mobile the GSM network. The design and construction of the system are described with parameters of the equipment

  9. Bluetooth Sensor Network Communication

    Microsoft Academic Search

    You Ke; Liu Rui Qiang; Gao Run Quan

    2009-01-01

    The wireless sensor network discussed in this article is one with Web interface based on radio frequency connection, information-driven star topology and energy-saved mode are used, the energy of each sensor node is reduced and secure management of each sensor node is improved.

  10. Switch for serial or parallel communication networks

    DOEpatents

    Crosette, Dario B. (DeSoto, TX)

    1994-01-01

    A communication switch apparatus and a method for use in a geographically extensive serial, parallel or hybrid communication network linking a multi-processor or parallel processing system has a very low software processing overhead in order to accommodate random burst of high density data. Associated with each processor is a communication switch. A data source and a data destination, a sensor suite or robot for example, may also be associated with a switch. The configuration of the switches in the network are coordinated through a master processor node and depends on the operational phase of the multi-processor network: data acquisition, data processing, and data exchange. The master processor node passes information on the state to be assumed by each switch to the processor node associated with the switch. The processor node then operates a series of multi-state switches internal to each communication switch. The communication switch does not parse and interpret communication protocol and message routing information. During a data acquisition phase, the communication switch couples sensors producing data to the processor node associated with the switch, to a downlink destination on the communications network, or to both. It also may couple an uplink data source to its processor node. During the data exchange phase, the switch couples its processor node or an uplink data source to a downlink destination (which may include a processor node or a robot), or couples an uplink source to its processor node and its processor node to a downlink destination.

  11. Switch for serial or parallel communication networks

    DOEpatents

    Crosette, D.B.

    1994-07-19

    A communication switch apparatus and a method for use in a geographically extensive serial, parallel or hybrid communication network linking a multi-processor or parallel processing system has a very low software processing overhead in order to accommodate random burst of high density data. Associated with each processor is a communication switch. A data source and a data destination, a sensor suite or robot for example, may also be associated with a switch. The configuration of the switches in the network are coordinated through a master processor node and depends on the operational phase of the multi-processor network: data acquisition, data processing, and data exchange. The master processor node passes information on the state to be assumed by each switch to the processor node associated with the switch. The processor node then operates a series of multi-state switches internal to each communication switch. The communication switch does not parse and interpret communication protocol and message routing information. During a data acquisition phase, the communication switch couples sensors producing data to the processor node associated with the switch, to a downlink destination on the communications network, or to both. It also may couple an uplink data source to its processor node. During the data exchange phase, the switch couples its processor node or an uplink data source to a downlink destination (which may include a processor node or a robot), or couples an uplink source to its processor node and its processor node to a downlink destination. 9 figs.

  12. Towards Hybrid Quantum Communication Networks

    NASA Astrophysics Data System (ADS)

    Tittel, Wolfgang; Alibart, Olivier; Baldi, Pascal; Gisin, Nicolas; Halder, Matthaeus; Marcikic, Ivan; de Riedmatten, Hugues; Tanzilli, Sebastien; Zbinden, Hugo

    2007-06-01

    The last years have seen a remarkable advance of experimental realizations of applications of quantum communication. The most important example is quantum cryptography that is now at the verge of becoming an industrial application. One of the future challenges to make this technology widely available is the integration of point-to-point links into networks that may consist of hybrid quantum communication channels with fibre optic and free-space links. I will report on experiments that allow transferring quantum information between photons at different wavelengths, as required for different quantum channels, either based on quantum teleportation [1], or on parametric up-conversion in a non-linear crystal [2]. [1] I. Marcikic, H. de Riedmatten, W. Tittel, H. Zbinden, N. Gisin, Nature 421, 509 (2003). [2] S. Tanzilli, W. Tittel, M. Halder, O. Alibart, P. Baldi, N. Gisin, H. Zbinden, Nature 437, 116 (2005).

  13. Information Computer Communications Policy, 2: The Usage of International Data Networks in Europe.

    ERIC Educational Resources Information Center

    Organisation for Economic Cooperation and Development, Paris (France).

    This study of the development of international data networks, a phenomena of the 1970's, and policy issues arising from their use is an in depth investigation of 24 private and six public European networks commissioned from Logica Limited and sponsored by the governments of France, Germany, the Netherlands, Norway, Spain, and Sweden. The report

  14. The Impact of Synchronous Inter-Networked Teacher Training in Information and Communication Technology Integration

    ERIC Educational Resources Information Center

    Martin, Stewart; Vallance, Michael

    2008-01-01

    This paper summarises the outcomes of research that recorded and interpreted change in pre-service teachers' pedagogical beliefs when immersed in unique synchronous networked collaboration. The pre-service teachers were involved in the design and implementation of synchronous networked tasks, supported by the theoretical and pragmatic application

  15. Information Horizons in Complex Networks

    NASA Astrophysics Data System (ADS)

    Sneppen, Kim

    2005-03-01

    We investigate how the structure constrain specific communication in social-, man-made and biological networks. We find that human networks of governance and collaboration are predictable on teat-a-teat level, reflecting well defined pathways, but globally inefficient (1). In contrast, the Internet tends to have better overall communication abilities, more alternative pathways, and is therefore more robust. Between these extremes are the molecular network of living organisms. Further, for most real world networks we find that communication ability is favored by topology on small distances, but disfavored at larger distances (2,3,4). We discuss the topological implications in terms of modularity and the positioning of hubs in the networks (5,6). Finally we introduce some simple models which demonstarte how communication may shape the structure of in particular man made networks (7,8). 1) K. Sneppen, A. Trusina, M. Rosvall (2004). Hide and seek on complex networks [cond-mat/0407055] 2) M. Rosvall, A. Trusina, P. Minnhagen and K. Sneppen (2004). Networks and Cities: An Information Perspective [cond-mat/0407054]. In PRL. 3) A. Trusina, M. Rosvall, K. Sneppen (2004). Information Horizons in Networks. [cond-mat/0412064] 4) M. Rosvall, P. Minnhagen, K. Sneppen (2004). Navigating Networks with Limited Information. [cond-mat/0412051] 5) S. Maslov and K. Sneppen (2002). Specificity and stability in topology of protein networks Science 296, 910-913 [cond-mat/0205380]. 6) A. Trusina, S. Maslov, P. Minnhagen, K. Sneppen Hierarchy Measures in Complex Networks. Phys. Rev. Lett. 92, 178702 [cond-mat/0308339]. 7) M. Rosvall and K. Sneppen (2003). Modeling Dynamics of Information Networks. Phys. Rev. Lett. 91, 178701 [cond-mat/0308399]. 8) B-J. Kim, A. Trusina, P. Minnhagen, K. Sneppen (2003). Self Organized Scale-Free Networks from Merging and Regeneration. nlin.AO/0403006. In European Journal of Physics.

  16. Communication and information technology in medical education

    Microsoft Academic Search

    Jeremy PT Ward; Jill Gordon; Michael J Field; Harold P Lehmann

    2001-01-01

    The past few years have seen rapid advances in communication and information technology (C&IT), and the pervasion of the worldwide web into everyday life has important implications for education. Most medical schools provide extensive computer networks for their students, and these are increasingly becoming a central component of the learning and teaching environment. Such advances bring new opportunities and challenges

  17. Voice communications over zigbee networks

    Microsoft Academic Search

    Chonggang Wang; Kazem Sohraby; Rittwik Jana; Lusheng Ji; Mahmoud Daneshmand

    2008-01-01

    This article provides an overview of ZigBee-enabled wireless networks and discusses the feasibility of supporting voice communications over ZigBee networks. We begin by providing an overview of the ZigBee technology followed by an evaluation of voice quality and performance over such an impoverished wireless channel. Two types of voice communications, namely full-duplex voice over IP (VoIP) and half-duplex push-to-talk (PTT)

  18. Security in Advanced Optical Communication Networks

    Microsoft Academic Search

    Stamatios V. Kartalopoulos

    2009-01-01

    The increased demand of data services within the last few years has prompted a commensurate explosion in transportable bandwidth, most of which contain sensitive information, personal data, bank accounts, credit card numbers, proprietary documents, and more. As a result, there are two types of security in communications, securing user data and securing the physical network. The first is addressed with

  19. Communication Dynamics in Finite Capacity Social Networks

    NASA Astrophysics Data System (ADS)

    Haerter, Jan O.; Jamtveit, Bjrn; Mathiesen, Joachim

    2012-10-01

    In communication networks, structure and dynamics are tightly coupled. The structure controls the flow of information and is itself shaped by the dynamical process of information exchanged between nodes. In order to reconcile structure and dynamics, a generic model, based on the local interaction between nodes, is considered for the communication in large social networks. In agreement with data from a large human organization, we show that the flow is non-Markovian and controlled by the temporal limitations of individuals. We confirm the versatility of our model by predicting simultaneously the degree-dependent node activity, the balance between information input and output of nodes, and the degree distribution. Finally, we quantify the limitations to network analysis when it is based on data sampled over a finite period of time.

  20. Computing, Information and Communications Technology (CICT) Website

    NASA Technical Reports Server (NTRS)

    Hardman, John; Tu, Eugene (Technical Monitor)

    2002-01-01

    The Computing, Information and Communications Technology Program (CICT) was established in 2001 to ensure NASA's Continuing leadership in emerging technologies. It is a coordinated, Agency-wide effort to develop and deploy key enabling technologies for a broad range of mission-critical tasks. The NASA CICT program is designed to address Agency-specific computing, information, and communications technology requirements beyond the projected capabilities of commercially available solutions. The areas of technical focus have been chosen for their impact on NASA's missions, their national importance, and the technical challenge they provide to the Program. In order to meet its objectives, the CICT Program is organized into the following four technology focused projects: 1) Computing, Networking and Information Systems (CNIS); 2) Intelligent Systems (IS); 3) Space Communications (SC); 4) Information Technology Strategic Research (ITSR).

  1. Network and Index Coding with Application to Robust and Secure Communications

    E-print Network

    El Rouayheb, Salim Y.

    2011-02-22

    Since its introduction in the year 2000 by Ahlswede et al., the network coding paradigm has revolutionized the way we understand information flows in networks. Traditionally, information transmitted in a communication network was treated as a...

  2. Data communication network at the ASRM facility

    NASA Technical Reports Server (NTRS)

    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.

  3. Multiple-Ring Digital Communication Network

    NASA Technical Reports Server (NTRS)

    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.

  4. Analyzing and Communicating Scientific Information

    NSDL National Science Digital Library

    James Clements

    2001-05-01

    Using collaborative techniques, case studies, and extensive assessment, students in the Towson Transition Course at Towson University learned to access, evaluate, and communicate scientific information. A statistically significant increase in the average

  5. NASA Integrated Space Communications Network

    NASA Technical Reports Server (NTRS)

    Tai, Wallace; Wright, Nate; Prior, Mike; Bhasin, Kul

    2012-01-01

    The NASA Integrated Network for Space Communications and Navigation (SCaN) has been in the definition phase since 2010. It is intended to integrate NASA s three existing network elements, i.e., the Space Network, Near Earth Network, and Deep Space Network, into a single network. In addition to the technical merits, the primary purpose of the Integrated Network is to achieve a level of operating cost efficiency significantly higher than it is today. Salient features of the Integrated Network include (a) a central system element that performs service management functions and user mission interfaces for service requests; (b) a set of common service execution equipment deployed at the all stations that provides return, forward, and radiometric data processing and delivery capabilities; (c) the network monitor and control operations for the entire integrated network are conducted remotely and centrally at a prime-shift site and rotating among three sites globally (a follow-the-sun approach); (d) the common network monitor and control software deployed at all three network elements that supports the follow-the-sun operations.

  6. Discovering Hidden Groups in Communication Networks 1

    E-print Network

    Magdon-Ismail, Malik

    Discovering Hidden Groups in Communication Networks 1 Jeff BAUMES a , Mark K. GOLDBERG a,2 , Malik statistical and algorithmic approaches to discov­ ering groups of actors that hide their communications within the myriad of back­ ground communications in a large communication network. Our approach to dis­ covering

  7. Discovering Hidden Groups in Communication Networks1

    E-print Network

    Magdon-Ismail, Malik

    Discovering Hidden Groups in Communication Networks1 Jeff BAUMES a, Mark K. GOLDBERG a,2, Malik statistical and algorithmic approaches to discov- ering groups of actors that hide their communications within the myriad of back- ground communications in a large communication network. Our approach to dis- covering

  8. Communication in automation, including networking and wireless

    E-print Network

    Antsaklis, Panos

    Communication in automation, including networking and wireless Nicholas Kottenstette and Panos J and networking in automation is given. Digital communication fundamentals are reviewed and networked control are presented. 1 Introduction 1.1 Why communication is necessary in automated systems Automated systems use

  9. Extreme Simulation of C4ISR Communications and Networking

    Microsoft Academic Search

    Donald M. Leskiw; Donald R. Pflug; Alex F. Sisti

    The Internet is viewed by many to be the network of choice for worldwide communications. Indeed, as the Internet proliferates, one will have a global base from which to choose technologies and methods for building intra- and inter- network systems. This emerging information infrastructure comprises wire and wireless networks of vast complexity. A fundamental issue for military users, however, is

  10. Information and Communications Technologies (ICT) Center Print Publications

    NSDL National Science Digital Library

    This website from the Information and Communication Technology (ICT) Center provides a list of print publications from the ICT Center Delmar Learning Series, created by Delmar Learning and the ICT Center. Titles include Introduction to Telecommunications Networks, Basic Telecommunications: The Physical Layer, Fiber Optic Communications and Network Security. The listings for each book include links to information and sample chapters on Delmar Learning's website, as well as links to order the titles on Amazon.com.

  11. Research Networks and Libraries. Applications and Issues for a Global Information Network. UDT Series on Data Communication Technologies and Standards for Libraries, Report #1.

    ERIC Educational Resources Information Center

    Cleveland, Gary

    This paper is intended to provide interested librarians with a basic knowledge of research networks (as opposed to library networks), focusing specifically on the manner in which they can be used by the international library community to support library functions and improve access to bibliographic information, as well as the technical and policy

  12. ECE 333: Introduction to Communication Networks Lecture 1: Introduction

    E-print Network

    Berry, Randall

    information is sent in the form of electromagnetic waves. One example of a link is an optical fiber where is a radio link, where information is transmitted through the atmosphere as an electromagnetic wave radiated of communication networks/uses Course Goals History Classification of networks Related courses 2 Notes

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

    DOEpatents

    Buttles, John W. (Idaho Falls, ID)

    2011-12-20

    Wireless communication devices include a software-defined radio coupled to processing circuitry. The processing circuitry is configured to execute computer programming code. Storage media is coupled to the processing circuitry and includes computer programming code configured to cause the processing circuitry 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.

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

    DOEpatents

    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.

  15. Data communication network at the ASRM facility

    NASA Technical Reports Server (NTRS)

    Moorhead, Robert J., III; Smith, Wayne D.; Nirgudkar, Ravi; Dement, James

    1994-01-01

    This three-year project (February 1991 to February 1994) has involved analyzing and helping to design the communication network for the Advanced Solid Rocket Motor (ASRM) facility at Yellow Creek, near Iuka, MS. The principal concerns in the analysis were the bandwidth (both on average and in the worst case) and the expandability of the network. As the communication network was designed and modified, a careful evaluation of the bandwidth of the network, the capabilities of the protocol, and the requirements of the controllers and computers on the network was required. The overall network, which was heterogeneous in protocol and bandwidth, needed to be modeled, analyzed, and simulated to obtain some degree of confidence in its performance capabilities and in its performance under nominal and heavy loads. The results of our analysis did have an impact on the design and operation of the ASRM facility. During 1993 we analyzed many configurations of this basic network structure. The analyses are described in detail in Section 2 and 3 herein. Section 2 reports on an analysis of the whole network. The preliminary results of that research indicated that the most likely bottleneck as the network traffic increased would be the hubs. Thus a study of Cabletron hubs was initiated. The results of that study are in Section 3. Section 4 herein reports on the final network configuration analyzed. When the ASRM facility was mothballed in December of 1993, this was basically the planned and partially installed network. A briefing was held at NASA/MSFC on December 7, 1993, at which time our final analysis and conclusions were disseminated. This report contains a written record of most of the information disseminated at that briefing.

  16. Data communication network at the ASRM facility

    NASA Technical Reports Server (NTRS)

    Moorhead, Robert J., II; Smith, Wayne D.; Nirgudkar, Ravi; Zhu, Zhifan; Robinson, Walter

    1993-01-01

    The main objective of the report is to present the overall communication network structure for the Advanced Solid Rocket Motor (ASRM) facility being built at Yellow Creek near Iuka, Mississippi. This 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 critical and manufacturing non-critical. The manufacturing critical buildings will be connected via FDDI to the Operational Information System (OIS) in the main computing center in B 1000. The manufacturing non-critical buildings will be connected by 10BASE-FL to the Business Information System (BIS) in the main computing center. The workcells will be connected to the Area Supervisory Computers (ASCs) through the nearest manufacturing critical hub and one of the OIS hubs. The network structure described in this report will be the basis for simulations to be carried out next year. The Comdisco's Block Oriented Network Simulator (BONeS) will be used for the network simulation. The main aim of the simulations will be to evaluate the loading of the OIS, the BIS, the ASCs, and the network links by the traffic generated by the workstations and workcells throughout the site.

  17. Congenital Heart Information Network

    MedlinePLUS

    ... heart defects. Important Notice The Congenital Heart Information Network website is temporarily out of service. Please join ... and Uwe Baemayr for The Congenital Heart Information Network Exempt organization under Section 501(c)3. Copyright ...

  18. Communications for unattended sensor networks

    NASA Astrophysics Data System (ADS)

    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.

  19. Cognitive networking with software programmable intelligent networks for wireless and wireline critical communications

    Microsoft Academic Search

    S. M. Lake

    2005-01-01

    Given all the plans to use slightly modified IP network architectures as a basis for critical communications infrastructures such as network centric warfare (NCW), joint tactical radio (JTRS), ForceNet, future combat systems (FCS), the global information grid (GIG), the warfighter information network tactical (WIN-T), and many other high profile, life-critical networks, the inherent weaknesses of IP networking must be examined.

  20. Communication through Resonance in Spiking Neuronal Networks

    PubMed Central

    Frgnac, Yves; Aertsen, Ad; Kumar, Arvind

    2014-01-01

    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. PMID:25165853

  1. COOPERATIVE INFORMATION AGENTS AND COMMUNICATION

    E-print Network

    Dignum, Frank

    Information Agents. We describe an architecture for these CIA's in which the relations of a CIA with other CIA manager can also negotiate a contract with other CIA's. The contracts (which may include communication or transaction protocols) between agents are handled by the contract manager of the CIA responsible

  2. Information, Education, Communication in Population.

    ERIC Educational Resources Information Center

    Hawaii Univ., Honolulu. East-West Center.

    Programs and services of the Swedish International Development Authority (SIDA) are reviewed in this report on resources available for the support of population information, education, and communication activities. Four major sections describe in concise, outline form: (1) the agency and its programs, (2) the specific program in population/family

  3. Structure and tie strengths in mobile communication networks

    PubMed Central

    Onnela, J.-P.; Saramki, J.; Hyvnen, J.; Szab, G.; Lazer, D.; Kaski, K.; Kertsz, J.; Barabsi, A.-L.

    2007-01-01

    Electronic databases, from phone to e-mails logs, currently provide detailed records of human communication patterns, offering novel avenues to map and explore the structure of social and communication networks. Here we examine the communication patterns of millions of mobile phone users, allowing us to simultaneously study the local and the global structure of a society-wide communication network. We observe a coupling between interaction strengths and the network's local structure, with the counterintuitive consequence that social networks are robust to the removal of the strong ties but fall apart after a phase transition if the weak ties are removed. We show that this coupling significantly slows the diffusion process, resulting in dynamic trapping of information in communities and find that, when it comes to information diffusion, weak and strong ties are both simultaneously ineffective. PMID:17456605

  4. On traffic analysis in anonymous communication networks

    E-print Network

    Zhu, Ye

    2009-06-02

    In this dissertation, we address issues related to traffic analysis attacks and the engineering in anonymous communication networks. Mixes have been used in many anonymous communication systems and are supposed to provide countermeasures that can...

  5. Communications network design and costing model users manual

    NASA Technical Reports Server (NTRS)

    Logan, K. P.; Somes, S. S.; Clark, C. A.

    1983-01-01

    The information and procedures needed to exercise the communications network design and costing model for performing network analysis are presented. Specific procedures are included for executing the model on the NASA Lewis Research Center IBM 3033 computer. The concepts, functions, and data bases relating to the model are described. Model parameters and their format specifications for running the model are detailed.

  6. Exploiting Multiuser Diversity with Capture in Wireless Communication Networks

    Microsoft Academic Search

    Justin Foo; Defeng Huang; G. Mercankosk

    2007-01-01

    Multiuser diversity refers to the inherent diversity in channel quality across several mobile users in a wireless communication network. Multiuser diversity can be exploited through rate adaptation to increase system goodput, however the overhead incurred in polling channel state information in large networks can overshadow the multiuser diversity gain. In this paper, we propose a novel wireless medium access control

  7. Wireless Network Communications Overview for Space Mission Operations

    NASA Technical Reports Server (NTRS)

    Fink, Patrick W.

    2009-01-01

    The mission of the On-Board Wireless Working Group (WWG) is to serve as a general CCSDS focus group for intra-vehicle wireless technologies. The WWG investigates and makes recommendations pursuant to standardization of applicable wireless network protocols, ensuring the interoperability of independently developed wireless communication assets. This document presents technical background information concerning uses and applicability of wireless networking technologies for space missions. Agency-relevant driving scenarios, for which wireless network communications will provide a significant return-on-investment benefiting the participating international agencies, are used to focus the scope of the enclosed technical information.

  8. 2015 IEEE 5th International Conference on Electronics Information and Emergency Communication

    E-print Network

    Tam, Vincent W. L.

    of FPGA and DSP in Communication Devices and Networks Deep web technology Decision Support System Collaborative Business Systems Decision Making and Information Retrieval Data Analysis, Prediction and Model

  9. Efficient Reliable Communication over Partially Authenticated Networks

    E-print Network

    Beimel, Amos

    processors, then ev- ery pair of processors can communicate reliably if and only if the network in the network. In this pa- per we present a more efficient protocol obtained by exploiting the properties

  10. Network Connectivity under Probabilistic Communication Models in Sensor Networks

    E-print Network

    Zhang, Richard "Hao"

    1 Network Connectivity under Probabilistic Communication Models in Sensor Networks Mohamed Hefeeda that communication ranges of sensors are not regular disks. Rather, they follow probabilistic models. Yet, many current connectivity maintenance protocols assume the disk communication model for convenience and ease

  11. PIPELINES AS COMMUNICATION NETWORK LINKS

    SciTech Connect

    Kelvin T. Erickson; Ann Miller; E. Keith Stanek; C.H. Wu; Shari Dunn-Norman

    2005-03-14

    This report presents the results of an investigation into two methods of using the natural gas pipeline as a communication medium. The work addressed the need to develop secure system monitoring and control techniques between the field and control centers and to robotic devices in the pipeline. In the first method, the pipeline was treated as a microwave waveguide. In the second method, the pipe was treated as a leaky feeder or a multi-ground neutral and the signal was directly injected onto the metal pipe. These methods were tested on existing pipeline loops at UMR and Batelle. The results reported in this report indicate the feasibility of both methods. In addition, a few suitable communication link protocols for this network were analyzed.

  12. Exponential Separation of Information and Communication

    E-print Network

    Raz, Ran

    Exponential Separation of Information and Communication Anat Ganor Gillat Kol Ran Raz Abstract We show an exponential gap between communication complexity and information complexity, by giving an explicit example for a communication task (relation), with information complexity O(k), and distributional

  13. 75 FR 49870 - Effects on Broadband Communications Networks of Damage to or Failure of Network Equipment or...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-16

    ...Network Equipment or Severe Overload AGENCY: Federal Communications...submitting comments and additional information on the notice process, see the SUPPLEMENTARY INFORMATION section of this document. FOR FURTHER INFORMATION CONTACT: Jeffery...

  14. Communication via Quantum Neural Network

    E-print Network

    A. Al- Segher; Nasser Metwally

    2009-12-13

    In this study, the partially entangled neural networks is used to transfer information between two neurons, where the original teleportation protocol is employed this for this purpose. The effect of the network strength on the fidelity of the transported information is investigated. We show that as the strength of the network increases, the accuracy of the transformed information increases. As a practical application, we consider the spread of swine flu virus between two equivalent tranches of the community. In this treatment two factors are considered, one for humanity and the other for influence factor. The likelihood of infection between different age group is investigated, where we show that the strength of the neural network and the degree of infection plays an important role on transferring infection between different age group. From theoretical point of view, we show that it is possible to control the spread of the virus by controlling the network parameter. Also, by using local rotation, one can decrease the rate of infection between the young.

  15. Advances in vehicular communications networks [Guest Editorial

    Microsoft Academic Search

    Carlos Jesus Bernardos; Andreas Festag; Nicholas F. Maxemchuk; Carolina Pinart; Christian Weib

    2010-01-01

    The articles in this special issue focus on advances in vehicular communications networks. The first four deal with the refinement of several different important mechanisms in vehicular communication protocols, with the aim of controlling and reducing the overall network offered load, while guaranteeing a good level of accuracy, efficiency, and security. The last article proposes a system architecture, called VISIONS,

  16. PESTICIDE INFORMATION NETWORK

    EPA Science Inventory

    The Pesticide Information Network (PIN) is an interactive database containing information about pesticides. PIN is a free service offered by the USEPAs Office of Pesticide Programs which provides contacts on pesticide issues, has a bulletin board network for public and private us...

  17. Effective Protocols for Mobile Communications and Networking

    SciTech Connect

    Espinoza, J.; Sholander, P.; Van Leeuwen, B,

    1998-12-01

    This report examines methods of mobile communications with an emphasis on mobile computing and wireless communications. Many of the advances in communications involve the use of Internet Protocol (IP), Asynchronous Transfer Mode (ATM), and ad hoc network protocols. However, many of the advances in these protocols have been focused on wired communications. Recently much focus has been directed at advancing communication technology in the area of mobile wireless networks. This report discusses various protocols used in mobile communications and proposes a number of extensions to existing protocols. A detailed discussion is also included on desirable protocol characteristics and evaluation criteria. In addition, the report includes a discussion on several network simulation tools that maybe used to evaluate network protocols.

  18. Recent advances in underwater acoustic communications & networking

    Microsoft Academic Search

    Mandar Chitre; Shiraz Shahabudeen; Lee Freitag; Milica Stojanovic

    2008-01-01

    The past three decades have seen a growing interest in underwater acoustic communications. Continued research over the years has resulted in improved performance and robustness as compared to the initial communication systems. Research has expanded from point-to-point communications to include underwater networks as well. A series of review papers provide an excellent history of the development of the field until

  19. Validation of Network Communicability Metrics for the Analysis of Brain Structural Networks

    PubMed Central

    Andreotti, Jennifer; Jann, Kay; Melie-Garcia, Lester; Giezendanner, Stphanie; Abela, Eugenio; Wiest, Roland; Dierks, Thomas; Federspiel, Andrea

    2014-01-01

    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. PMID:25549088

  20. Scalable Hierarchical Network Management System for Displaying Network Information in Three Dimensions

    NASA Technical Reports Server (NTRS)

    George, Jude (Inventor); Schlecht, Leslie (Inventor); McCabe, James D. (Inventor); LeKashman, John Jr. (Inventor)

    1998-01-01

    A network management system has SNMP agents distributed at one or more sites, an input output module at each site, and a server module located at a selected site for communicating with input output modules, each of which is configured for both SNMP and HNMP communications. The server module is configured exclusively for HNMP communications, and it communicates with each input output module according to the HNMP. Non-iconified, informationally complete views are provided of network elements to aid in network management.

  1. Extracting association patterns in network communications.

    PubMed

    Portela, Javier; Villalba, Luis Javier Garca; 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

  2. Communication Defined as Complementary Informative Processes

    Microsoft Academic Search

    Robert M. Losee

    1999-01-01

    Given a set of requirements for a definition of communication, we can define a communication as information that enters a process and eventually leaves its inverse process. For example, information is transmitted by speak- ing and received after processing by its inverse, hearing. This definition can be used to precisely describe and explain communication phenomena in an inclusive and exact

  3. Entangled Network and Quantum Communication

    E-print Network

    Nasser Metwally

    2011-06-07

    A theoretical scheme is introduced to generate entangled network via Dzyaloshinskii- Moriya (DM)interaction. The dynamics of entanglement generated between different nodes by direct or indirect interaction is investigated. It is shown that, the direction of (DM) interaction and the location of the nodes have a sensational effect on the degree of entanglement. We quantify the minimum entanglement generated between all the nodes. The upper and lower bound of the entanglement of the generated network depends 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 we show that the fidelity of teleporting unknown information between the network members depends on the location of the members.

  4. The Geospatial Characteristics of a Social Movement Communication Network

    PubMed Central

    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 movements efforts to mobilize resources at the local level and to develop narrative frames that reinforce collective purpose at the national level. PMID:23483885

  5. Internetworking satellite and local exchange networks for personal communications applications

    NASA Technical Reports Server (NTRS)

    Wolff, Richard S.; Pinck, Deborah

    1993-01-01

    The demand for personal communications services has shown unprecedented growth, and the next decade and beyond promise an era in which the needs for ubiquitous, transparent and personalized access to information will continue to expand in both scale and scope. The exchange of personalized information is growing from two-way voice to include data communications, electronic messaging and information services, image transfer, video, and interactive multimedia. The emergence of new land-based and satellite-based wireless networks illustrates the expanding scale and trend toward globalization and the need to establish new local exchange and exchange access services to meet the communications needs of people on the move. An important issue is to identify the roles that satellite networking can play in meeting these new communications needs. The unique capabilities of satellites, in providing coverage to large geographic areas, reaching widely dispersed users, for position location determination, and in offering broadcast and multicast services, can complement and extend the capabilities of terrestrial networks. As an initial step in exploring the opportunities afforded by the merger of satellite-based and land-based networks, several experiments utilizing the NASA ACTS satellite and the public switched local exchange network were undertaken to demonstrate the use of satellites in the delivery of personal communications services.

  6. Great Lakes Information Network

    NSDL National Science Digital Library

    The Great Lakes Information Network (GLIN) is a partnership that has compiled information relating to the binational Great Lakes-St. Lawrence region of North America. Sections of the site include an overview of the Great Lakes, the environment of the Great Lakes, the economy of the Great Lakes, education, maps and Geographic Information Systems (GIS), and tourism.

  7. Chief Information & Networking

    E-print Network

    Operations / Data Center Systems Server Admin Web Services Building Management Helpdesk Desktop Services Director HPC & Research Computing Tim Kaiser Director Networking Telecommunications Information Security Databases Enterprise Applications Administrative Applications Academic Applications HPC Operations HPC

  8. Earth System Science Informal Education Network (ESSIEN)

    NSDL National Science Digital Library

    The Earth System Science Informal Education Network (ESSIEN) is dedicated to improving Earth system literacy through increased communication and collaboration among providers of informal Earth system education. The collection is designed for museum professionals (educators, exhibits designers, developers) as a resource of ideas, tools, traveling exhibits and online materials. The resources are web portals to organizations providing substantial informal Earth system science education. They describe educational programming, resources and exhibits that are pertinent to an informal educator.

  9. Laser satellite communication network-vibration effect and possible solutions

    Microsoft Academic Search

    SHLOMI ARNON; N. S. Kopeika

    1997-01-01

    A number of serious consortiums develop satellite communication networks. The objective of these communication projects is to service personal communication users almost everywhere on Earth. The intersatellite links in those projects use microwave radiation as the carrier. Free-space optical communication between satellites networked together can make possible high-speed communication between different places on Earth. Some advantages of an optical communication

  10. The Operation of a Specialized Scientific Information and Data Analysis Center With Computer Base and Associated Communications Network.

    ERIC Educational Resources Information Center

    Cottrell, William B.; And Others

    The Nuclear Safety Information Center (NSIC) is a highly sophisticated scientific information center operated at Oak Ridge National Laboratory (ORNL) for the U.S. Atomic Energy Commission. Its information file, which consists of both data and bibliographic information, is computer stored and numerous programs have been developed to facilitate the

  11. Integrated communication and information fabric for space applications

    NASA Technical Reports Server (NTRS)

    Maitan, J.; Walichiewicz, L.; Wealand, B.

    1990-01-01

    The results of preliminary research into infrastructures for integrated communication and information fabrics, which can meet the needs of space applications of the future, are presented. Technologies that foster scaleability and adaptability and support self-organizing mechanisms are needed to effectively integrate the working fabric of a large-scale distributed system. A multigrid network architecture that uses a completely distributed packet-routing scheme is derived. The first part of the paper introduces a simple model of a communication and information system for space applications, the second discusses the known limitations of the large-scale future communication and information systems, and the third part describes the results of preliminary research in this area. It is expected that this technology will result in inexpensive networks utilizing multigigabit-per-second data links.

  12. Communication Reliability in Network on Chip Designs

    E-print Network

    Kumar, Reeshav

    2012-10-19

    The performance of low latency Network on Chip (NoC) architectures, which incorporate fast bypass paths to reduce communication latency, is limited by crosstalk induced skewing of signal transitions on link wires. As a result of crosstalk...

  13. Supporting fault-tolerant communication in networks

    E-print Network

    Kanjani, Khushboo

    2009-05-15

    We address two problems dealing with fault-tolerant communication in networks. The first one is designing a distributed storage protocol tolerant to Byzantine failure of servers. The protocol implements a multi-writer multi-reader register which...

  14. Optimizing secure communication standards for disadvantaged networks

    E-print Network

    Okano, Stephen Hiroshi

    2009-01-01

    We present methods for optimizing standardized cryptographic message protocols for use on disadvantaged network links. We first provide an assessment of current secure communication message packing standards and their ...

  15. Information, Communication, and Educational Technologies in Rural Alaska

    ERIC Educational Resources Information Center

    Page, G. Andrew; Hill, Melissa

    2008-01-01

    Information, communication, and educational technologies hold promise to connect geographically isolated rural communities, offering adults greater access to educational, financial, and numerous other resources. The Internet and computer-based network technologies are often seen as remedies for communities in economic decline, but they also have

  16. THE INSTITUTE OF ELECTRONICS, INFORMATION AND COMMUNICATION ENGINEERS

    E-print Network

    Fukai, Tomoki

    THE INSTITUTE OF ELECTRONICS, INFORMATION AND COMMUNICATION ENGINEERS TECHNICAL REPORT OF IEICE network as pseudo-brain. At the method, we try to extract the image feature represented well by activity of pseudo-brain with kernel canonical correlation analysis. The extracted features are probably effective

  17. WIRELESS SENSOR NETWORK BASED CONTROL SYSTEM CONCIDERING COMMUNICATION COST

    E-print Network

    WIRELESS SENSOR NETWORK BASED CONTROL SYSTEM CONCIDERING COMMUNICATION COST Yutaka Iino* Takeshi for wireless sensor network based control system, minimizing communication energy consumption. Some control, wireless sensor network technology has been developed rapidly, and various applications to control system

  18. Structure and evolution of communication networks in organizations

    E-print Network

    Qian, Jichao, M. Eng. Massachusetts Institute of Technology

    2008-01-01

    We study three types of communication data--emails, phone calls, and meetings-in a modern IT firm. Using network descriptive statistics, we show how communication networks in an organization differ from random networks and ...

  19. Quantum secure direct communication network with hyperentanglement

    NASA Astrophysics Data System (ADS)

    Chang, Ho Hong; Jino, Heo; Jong In, Lim; Hyung, Jin Yang

    2014-09-01

    We propose a quantum secure direct communication protocol with entanglement swapping and hyperentanglement. Any two users, Alice and Bob, can communicate with each other in a quantum network, even though there is no direct quantum channel between them. The trust center, Trent, who provides a quantum channel to link them by performing entanglement swapping, cannot eavesdrop on their communication. This protocol provides a high channel capacity because it uses hyperentanglement, which can be generated using a beta barium borate crystal.

  20. State energy information networks

    SciTech Connect

    Tatar, J.; Ettinger, G.; Wrabel, M.

    1984-06-01

    In November 1983, Argonne National Laboratory (ANL) initiated a study under the sponsorship of the US Department of Energy (DOE) State Programs Branch to examine state energy information networks. Goal was to help DOE decide how best to allocate resources to assist states in acquiring information related to state energy programs and policies.

  1. Information transfer among widely spaced individuals: latrines as a basis for communication networks in the swift fox?

    Microsoft Academic Search

    Safi K. Darden; Lise K. Steffensen; Torben Dabelsteen

    2008-01-01

    In species where individuals are widely spaced instantaneous signals cannot readily form the basis of com- munication networks, that is several individuals within signalling range of each other. However, markings, signals that remain in the environment after the signaller has left, may fulfil this role. In this study, we have investigated the possible function of swift fox, Vulpes velox, latrines,

  2. Information Communication Highways in the 1990s: An Analysis of Their Potential Impact on Library Automation.

    ERIC Educational Resources Information Center

    Kibirige, Harry M.

    1991-01-01

    Discussion of the potential effects of fiber optic-based communication technology on information networks and systems design highlights library automation. Topics discussed include computers and telecommunications systems, the importance of information in national economies, microcomputers, local area networks (LANs), national computer networks,

  3. Information Systems and Business Communication.

    ERIC Educational Resources Information Center

    Beswick, Raymond W., Ed.; Williams, Alfred B., Ed.

    Intended to provide orientation about the integration of business communication, business systems, and the researching and teaching of business communication, this books offers articles on a variety of topics concerning business communication. Titles of the articles and their authors are as follows: (1) "Office Technology: Voice Store-and-Forward"

  4. Health information community networks.

    PubMed Central

    Duhl, L J

    2000-01-01

    The author supports the development of health information community networks (HICNs) as an important tool for use by individuals and community groups. HICNs can enable citizens, organizations, and communities to exchange geographically based information on community health status. Through HICNs, individuals and groups will be able to share information, prioritize issues, resolve conflicts, estimate the impact of policy initiatives, and plan, organize, manage, and evaluate programs and projects that deal with community health issues. PMID:10968768

  5. Informal Social Networks of People with Profound Intellectual and Multiple Disabilities: Relationship with Age, Communicative Abilities and Current Living Arrangements

    ERIC Educational Resources Information Center

    Kamstra, A.; van der Putten, A. A. J.; Post, W. J.; Vlaskamp, C.

    2015-01-01

    Background: People with profound intellectual and multiple disabilities (PIMD) have limited informal social contacts. Research to determine the factors which can positively influence establishing sound informal social contacts is required. Materials and Methods: Regression analysis for 200 people with PIMD was used to analyse how age,

  6. Tracking mobile users in wireless communications networks

    Microsoft Academic Search

    Amotz Bar-Noy; Ilan Kessler

    1993-01-01

    Tracking strategies for mobile wireless networks are studied. A cellular architecture in which base stations that are interconnected by a wired network communicate with mobile units via wireless links is assumed. The cost of utilizing the wireless links for the actual tracking of mobile users is considered. A tracking strategy in which a subset of all base stations is selected

  7. Predicting Employee Turnover from Communication Networks.

    ERIC Educational Resources Information Center

    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. Stress Testing of Data-Communication Networks

    NASA Technical Reports Server (NTRS)

    Leucht, Kurt; Bedette, Guy

    2006-01-01

    NetStress is a computer program that stress-tests a data-communication network and components thereof. NetStress comprises two components running, respectively, in a transmitting system and a receiving system connected to a network under test

  9. Communicating Centrality in Policy Network Drawings

    E-print Network

    Brandes, Ulrik

    policy making than private actors or that national actors are more important than local actors. ThusCommunicating Centrality in Policy Network Drawings Ulrik Brandes, Patrick Kenis, and Dorothea applied in the social sciences. Policy network analysis is an approach to study policy making structures

  10. Communication Network Research: An Examination of Controversies

    Microsoft Academic Search

    Alvin M. Snadowsky

    1972-01-01

    This study was concerned with the salient issues in communication network research. When the organizational phase was separated from the operational phase of problem-solving, centralization was adequate in both phases where the probems were simple symbol identification tasks. Although a centralized operational procedure also was adopted by all groups solving complex arithmetic tasks, the decentralized network permitted the organizational flexibility

  11. Efficient Reliable Communication over Partially Authenticated Networks

    E-print Network

    Beimel, Amos

    that if there are t faulty processors, then ev­ ery pair of processors can communicate reliably if and only if the network(n) rounds, where n is the number of processors in the network. In this pa­ per we present a more efficient

  12. The Lymphoma Information Network

    NSDL National Science Digital Library

    The Lymphoma Information Network website strives to "put a bit of humanity and understanding to this disease, to gather lymphoma information and resources in one place, and to present information in an easy to understand and logical format." The award-winning site offers information sections on Hodgkin's Lymphoma, Non-Hodgkin's Lymphoma, Fighting Lymphoma, and Surviving Lymphoma. The site also offers a special resource section for kids and teenagers, and information about childhood lymphoma. In addition, the site contains an extensive Glossary of Lymphoma Terms, The Lymphoma Blog, resources for independent research, book lists, and related links.

  13. Wireless Network Information Flow

    Microsoft Academic Search

    Amir Salman Avestimehr; Suhas N. Diggavi; David N. C. Tse

    2007-01-01

    We present an achievable rate for general deterministic relay networks, with broadcasting at the transmitters and interference at the receivers. In partic- ular we show that if the optimizing distribution for the information-theoretic cut-set bound is a product distri- bution, then we have a complete characterization of the achievable rates for such networks. For linear determinis- tic finite-field models discussed

  14. Environmental monitoring by wireless communication networks.

    PubMed

    Messer, Hagit; Zinevich, Artem; Alpert, Pinhas

    2006-05-01

    The global spread of wireless networks brings a great opportunity for their use in environmental studies. Weather, atmospheric conditions, and constituents cause propagation impairments on radio links. As such, while providing communication facilities, existing wireless communication systems can be used as a widely distributed, high-resolution atmospheric observation network, operating in real time with minimum supervision and without additional cost. Here we demonstrate how measurements of the received signal level, which are made in a cellular network, provide reliable measurements for surface rainfall. We compare the estimated rainfall intensity with radar and rain gauge measurements. PMID:16675693

  15. Communicating oscillatory networks: frequency domain analysis

    PubMed Central

    2011-01-01

    Background Constructing predictive dynamic models of interacting signalling networks remains one of the great challenges facing systems biology. While detailed dynamical data exists about individual pathways, the task of combining such data without further lengthy experimentation is highly nontrivial. The communicating links between pathways, implicitly assumed to be unimportant and thus excluded, are precisely what become important in the larger system and must be reinstated. To maintain the delicate phase relationships between signals, signalling networks demand accurate dynamical parameters, but parameters optimised in isolation and under varying conditions are unlikely to remain optimal when combined. The computational burden of estimating parameters increases exponentially with increasing system size, so it is crucial to find precise and efficient ways of measuring the behaviour of systems, in order to re-use existing work. Results Motivated by the above, we present a new frequency domain-based systematic analysis technique that attempts to address the challenge of network assembly by defining a rigorous means to quantify the behaviour of stochastic systems. As our focus we construct a novel coupled oscillatory model of p53, NF-kB and the mammalian cell cycle, based on recent experimentally verified mathematical models. Informed by online databases of protein networks and interactions, we distilled their key elements into simplified models containing the most significant parts. Having coupled these systems, we constructed stochastic models for use in our frequency domain analysis. We used our new technique to investigate the crosstalk between the components of our model and measure the efficacy of certain network-based heuristic measures. Conclusions We find that the interactions between the networks we study are highly complex and not intuitive: (i) points of maximum perturbation do not necessarily correspond to points of maximum proximity to influence; (ii) increased coupling strength does not necessarily increase perturbation; (iii) different perturbations do not necessarily sum and (iv) overall, susceptibility to perturbation is amplitude and frequency dependent and cannot easily be predicted by heuristic measures. Our methodology is particularly relevant for oscillatory systems, though not limited to these, and is most revealing when applied to the results of stochastic simulation. The technique is able to characterise precisely the distance in behaviour between different models, different systems and different parts within the same system. It can also measure the difference between different simulation algorithms used on the same system and can be used to inform the choice of dynamic parameters. By measuring crosstalk between subsystems it can also indicate mechanisms by which such systems may be controlled in experiments and therapeutics. We have thus found our technique of frequency domain analysis to be a valuable benchmark systems-biological tool. PMID:22192879

  16. Apparatus and method for data communication in an energy distribution network

    SciTech Connect

    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.

  17. Hidden Communication in P2P Networks: Steganographic Handshake and Broadcast

    E-print Network

    Hidden Communication in P2P Networks: Steganographic Handshake and Broadcast Raphael Eidenbenz ETH of how a conspiring subgroup of peers in a p2p network can find each other and communicate without that transmit hidden information by varying the block request sequence meaningfully. We find that a p2p protocol

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

    NASA Astrophysics Data System (ADS)

    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.

  19. Designing Satellite Communication Networks by Zero-One Quadratic Programming

    E-print Network

    Helme, Marcia P.

    In satellite communications networks, distinctive facilities called homing stations perform special transmission functions. Local demand nodes clustered around each homing station communicate with each other via a local ...

  20. Gordon's Information and Communications Technologies (ICT) Blog

    NSDL National Science Digital Library

    Snyder, Gordon F.

    This page presents the blog of Gordon F. Snyder of the National Center for Information and Communications Technologies, presenting perspectives on the Information and Communications Technology (ICT) Industries and Education. Gordon blogs about topics ranging from personal interests, technology and politics, the birth and death of new technologies, and industry developments. In addition to the blog's archives, visitors can find Snyder's photo stream, links to other bloggers of interest, and more information about Gordon himself.

  1. Evaluating video as a technology for informal communication

    Microsoft Academic Search

    Robert S. Fish; Robert E. Kraut; Robert W. Root; Ronald E. Rice

    1992-01-01

    Collaborations in organizations thrive on communication that is informal because informal communication is frequent, interactive, and expressive. Informal communication is crucial for the coordination of work, learning an organization's culture, the perpetuation of the social relations that underlie collaboration, and, in general, any situation that requires communication to resolve ambiguity. Informal communication is traditionally mediated by physical proximity, but physical

  2. WATERSHED INFORMATION NETWORK

    EPA Science Inventory

    Resource Purpose: The Watershed Information Network is a set of about 30 web pages that are organized by topic. These pages access existing databases like the American Heritage Rivers Services database and Surf Your Watershed. WIN in itself has no data or data sets. L...

  3. The NASA Space Communications Data Networking Architecture

    NASA Technical Reports Server (NTRS)

    Israel, David J.; Hooke, Adrian J.; Freeman, Kenneth; Rush, John J.

    2006-01-01

    The NASA Space Communications Architecture Working Group (SCAWG) has recently been developing an integrated agency-wide space communications architecture in order to provide the necessary communication and navigation capabilities to support NASA's new Exploration and Science Programs. A critical element of the space communications architecture is the end-to-end Data Networking Architecture, which must provide a wide range of services required for missions ranging from planetary rovers to human spaceflight, and from sub-orbital space to deep space. Requirements for a higher degree of user autonomy and interoperability between a variety of elements must be accommodated within an architecture that necessarily features minimum operational complexity. The architecture must also be scalable and evolvable to meet mission needs for the next 25 years. This paper will describe the recommended NASA Data Networking Architecture, present some of the rationale for the recommendations, and will illustrate an application of the architecture to example NASA missions.

  4. Organization of Communication in Information Systems.

    ERIC Educational Resources Information Center

    Datsenko, V. P.; Zaytsev, N. G.

    Organization of communication between the center of an automated system of information exchange and the subscribers to the system is described. The three requirements are: (1) those technical communication means must be chosen which will provide effective and convenient avenues for calls from the subscribers to the center, (2) the required

  5. The Cancer Information Network

    NSDL National Science Digital Library

    The Cancer Information Network is a noncommercial website that was "founded to provide support and information to cancer patients and their caregivers." The site offers access to a plethora of resources that can help patients and others find current high-quality information on many types of cancer. Resource links are provided for many specific cancer subject areas including Breast Cancer, Colorectal Cancer, Esophageal Cancer, Lung Cancer, and many more. The site includes sections on News & Features, Support, and Prevention as well. The site also offers lists of relevant websites, support organizations, and a dictionary of cancer-related terms.

  6. Universities Water Information Network

    NSDL National Science Digital Library

    The Universities Water Information Network (UWIN), located at Southern Illinois University in Carbondale, Illinois, "disseminates information of interest to the water resources community and all concerned with our water resources." Although much of the site is accessed by paid subscription only, several resources are offered free to anyone. A database of water related consulting firms contains contact information, including name, acronym, postal address, phone, fax, email, and contact person. Another helpful resource, the organizations database, lists water resource agencies, organizations, and institutions in the US, Caribbean, and Central America. Other items of interest include job listings, press releases, and more.

  7. Timber Wolf Information Network

    NSDL National Science Digital Library

    Wolves in the United States have suffered from human extermination efforts, habitat loss, and perhaps most significantly, a bad reputation. The Timber Wolf Information Network (TWIN) is working to reverse that reputation by increasing "public awareness and acceptance of the wolf in its natural habitat and its ecological role in the environment.� The award-winning TWIN website contains links to numerous references; news stories that feature wolves; information about global conservation efforts; a section for kids; and population updates for wolves across the country. The site also contains organizational information about TWIN, and hosts the cleverly titled online forum: Scent Post.

  8. The Deep Space Network. [tracking and communication functions and facilities

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The objectives, functions, and organization of the Deep Space Network are summarized. The Deep Space Instrumentation Facility, the Ground Communications Facility, and the Network Control System are described.

  9. Flexible Connectivity Management in Vehicular Communication Networks

    Microsoft Academic Search

    Roberto Baldessari; Andreas Festag; Alfredo Matos; Justino Santos; Rui Aguiar

    Vehicular communication, providing vehicle-to-vehicle and vehicle-to-roadside communica- tion, can considerably improve traffic safety and com- fort of driving and traveling. For communication in vehicular ad hoc networks, position-based routing has emerged as a promising candidate. For Internet ac- cess, Mobile IPv6 is a widely accepted solution to pro- vide session continuity and reachability to the Internet for mobile nodes. While

  10. Global Communications Network 2.9.1

    NSDL National Science Digital Library

    More and more individuals are turning to the Internet to communicate with colleagues, friends, and relatives and there are a number of helpful programs currently available for general use. This edition of the Global Communications Network application allows visitors to engage in video and voice chat and administer their own chat rooms, all within a secure format. This version is compatible with Windows 95 or newer.

  11. SECURITY AND COMMUNICATION NETWORKS Security Comm. Networks (2010)

    E-print Network

    Hu, Jiankun

    2010-01-01

    unauthorized access to secured facilities, such as hospital service. To protect patient's privacy and SECURITY AND COMMUNICATION NETWORKS Security Comm. Networks (2010) Published online in Wiley Inter delay for authenticating CVD patients, as time is critical for saving CVD affected patient's life

  12. Intelligent network concepts in mobile communications

    Microsoft Academic Search

    Bijan Jabbari

    1992-01-01

    A mobile cellular network architecture that is based on intelligent network concepts is presented. Subscriber service mobility and call management attributes of the network, including location information retrieval and updating, authentication, call routing, handover, charging, and operations and maintenance, are discussed

  13. Information and Communication in Lean Product Development

    E-print Network

    Graebsch, Martin

    In this thesis, the implications and influences that information and communication impose on lean product development in general, as well as the development of a lean Product Development Value Stream Display (lean PDVSD) ...

  14. Accelerating Communication in On-Chip Interconnection Networks

    E-print Network

    Ahn, Minseon

    2012-07-16

    are full. Second, a pseudo-circuit scheme is proposed to reduce network latency using communication temporal locality. Reducing per-hop router delay becomes more important for communication latency reduction in larger on-chip interconnection networks...

  15. INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING Int. J. Satell. Commun. Network. 2006; 24:261281

    E-print Network

    INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING Int. J. Satell. Commun. Network: 10.1002/sat.841 Turbo-coded APSK modulations design for satellite broadband communications Riccardo phase shift keying (APSK) modulation with application to satellite broadband communications. APSK

  16. Communication synthesis of networks-on-chip (noc)

    E-print Network

    Bhojwani, Praveen Sunder

    2009-05-15

    The emergence of networks-on-chip (NoC) as the communication infrastructure solution for complex multi-core SoCs presents communication synthesis challenges. This dissertation addresses the design and run-time management aspects of communication...

  17. Communication Gaps in Social Networks

    Microsoft Academic Search

    Naohiro Matsumura; David E. Goldberg; Xavier Llor

    2005-01-01

    In the paper, we first present an approach to extract social networks from message boards on the Internet. Then we measure\\u000a structural features of 3,000 social networks extracted from 3,000 message boards from 15 categories in Yahoo!Japan Message\\u000a Boards to prove the relationships between the features and the categories. Using hierarchical cluster analysis, we show three\\u000a types of social networks.

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

    NASA Technical Reports Server (NTRS)

    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.

  19. A Communications Network for Cislunar Operations

    NASA Technical Reports Server (NTRS)

    Burleigh, Scott

    2012-01-01

    Reliable and efficient communications will be critical to the success of commercial flight operations in cislunar space. The Internet is not well-suited to meeting this requirement. But the Delay-Tolerant Networking (DTN) architecture is. The DTN protocols are well-documented and implementations are mature. We think DTN will be ready to support low-cost, low-risk cislunar networking by the time the vehicles are in place.

  20. College of Communication and Information LIS Library and Information Science

    E-print Network

    MacAdam, Keith

    , bibliographic systems and methods of organizing and retrieving information sources. LIS 603 MANAGEMENT as well as the theories of management and the effective use of these in an information system. LIS 604College of Communication and Information LIS Library and Information Science KEY: # = new course

  1. Structure and tie strengths in mobile communication networks

    Microsoft Academic Search

    J.-P. Onnela; J. Saramaki; J. Hyvonen; G. Szabo; D. Lazer; K. Kaski; J. Kertesz; A.-L. Barabasi

    2007-01-01

    Electronic databases, from phone to emails logs, currently provide detailed records of human communication patterns, offering novel avenues to map and explore the structure of social and communication networks. Here we examine the communication patterns of millions of mobile phone users, allowing us to simultaneously study the local and the global structure of a society-wide communication network. We observe a

  2. Hybrid Mobile Communication Networks for Planetary Exploration

    NASA Technical Reports Server (NTRS)

    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.

  3. Graph analysis of cortical networks reveals complex anatomical communication substrate

    NASA Astrophysics Data System (ADS)

    Zamora-Lpez, Gorka; Zhou, Changsong; Kurths, Jrgen

    2009-03-01

    Sensory information entering the nervous system follows independent paths of processing such that specific features are individually detected. However, sensory perception, awareness, and cognition emerge from the combination of information. Here we have analyzed the corticocortical network of the cat, looking for the anatomical substrate which permits the simultaneous segregation and integration of information in the brain. We find that cortical communications are mainly governed by three topological factors of the underlying network: (i) a large density of connections, (ii) segregation of cortical areas into clusters, and (iii) the presence of highly connected hubs aiding the multisensory processing and integration. Statistical analysis of the shortest paths reveals that, while information is highly accessible to all cortical areas, the complexity of cortical information processing may arise from the rich and intricate alternative paths in which areas can influence each other.

  4. Lewis Information Network (LINK): Background and overview

    NASA Technical Reports Server (NTRS)

    Schulte, Roger R.

    1987-01-01

    The NASA Lewis Research Center supports many research facilities with many isolated buildings, including wind tunnels, test cells, and research laboratories. These facilities are all located on a 350 acre campus adjacent to the Cleveland Hopkins Airport. The function of NASA-Lewis is to do basic and applied research in all areas of aeronautics, fluid mechanics, materials and structures, space propulsion, and energy systems. These functions require a great variety of remote high speed, high volume data communications for computing and interactive graphic capabilities. In addition, new requirements for local distribution of intercenter video teleconferencing and data communications via satellite have developed. To address these and future communications requirements for the next 15 yrs, a project team was organized to design and implement a new high speed communication system that would handle both data and video information in a common lab-wide Local Area Network. The project team selected cable television broadband coaxial cable technology as the communications medium and first installation of in-ground cable began in the summer of 1980. The Lewis Information Network (LINK) became operational in August 1982 and has become the backbone of all data communications and video.

  5. Informal Communication in an Online Volunteer Community: Implications for

    E-print Network

    Fussell, Susan R.

    1 Informal Communication in an Online Volunteer Community: Implications for Supporting Virtual in which proximity benefits informal communication and relationship development and how technologies can opportunities for interpersonal communication and relationship development and then examine how dimensions

  6. A Privacy Preserving Reputation System for Mobile Information Dissemination Networks

    Microsoft Academic Search

    Marco Voss; Andreas Heinemann; Max Muhlhauser

    2005-01-01

    In a mobile information dissemination network mobile users, equipped with wireless devices, exchange information in a spontaneous manner whenever they come into communication range. Users have to specify what kind of information they are looking for and what kind of information they can offer. A priori there is no relation between users, literally spoken, they don?t know each other and

  7. Information & Communication Technology Emergency Instructions

    E-print Network

    de Leon, Alex R.

    the area for Campus Security or emergency services to arrive Evacuation Procedures Activate the NEARESTInformation & Communication Technology Emergency Instructions In the event of an EMERGENCY dial 403-220-5333 for Campus Security or dial 9-1-1 for Police, Fire or Ambulance Additional emergency instructions is found

  8. Providing Seamless Communication in Mobile Wireless Networks

    E-print Network

    Vaidya, Nitin

    -mail: fbbakshi,pkrishna,pradhan,vaidyag@cs.tamu.edu Phone: (409) 862-3411 Technical Report TR-96-015y May 1, 1996 communication, incurring heavy network bandwidth usage (multicast based approach), or do not provide any's cell. Each BS is responsible for forwarding data between the mobile user in it's cell, and the wired

  9. Opportunistic Communication for eNetworks Cyberengineering

    Microsoft Academic Search

    Mohsin Sohail; Mihaela Ulieru

    2007-01-01

    Within the broader context of the Adaptive Risk Management (ARM) Platform described in [27], the aim of this work is to show practically a proof of concept for a network architecture based on mobile code for Weiser's vision of ubiquitous computing [26] and opportunistic computing [22]. The proposed paradigm which animates the Opportunistic Communication Module (OCM) of the ARM Platform

  10. Graphene-enabled Wireless Communication Networks

    E-print Network

    Politècnica de Catalunya, Universitat

    Graphene-enabled Wireless Communication Networks at the Nanoscale 1 Ignacio Llatser Nanonetworking;Graphene Honeycomb lattice of carbon atoms 2-dimensional material Discovered by A. K. Geim and K. S. Novoselov 9 Graphene G. Liu, W. Stillman, S. Rumyantsev, Q. Shao, M. Shur, A. A. Balandin, "Low

  11. Communication Constrained Task Allocation For Robotic Networks

    E-print Network

    Lynch, Nancy

    Communication Constrained Task Allocation For Robotic Networks Stephen L. Smith Distibuted Robotics Lab CSAIL MIT 2010 TDS Talk March 19, 2010 Joint work with Francesco Bullo Stephen L. Smith Task: robots divide tasks among themselves Stephen L. Smith Task Allocation 2 #12;Task allocation Given

  12. Experience with Speech Communication in Packet Networks

    Microsoft Academic Search

    C. Weinstein; J. Forgie

    1983-01-01

    The integration of digital voice with data in a common packet-switched network system offers a number of potential benefits, including reduced systems cost through sharing of switching and transmission resources, flexible internetworking among systems utilizing different transmission media, and enhanced services for users requiring access to both voice and data communications. Issues which it has been necessary to address in

  13. Protocol for Communication Networking for Formation Flying

    NASA Technical Reports Server (NTRS)

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

    2009-01-01

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

  14. College Students' Nutrition Information Networks

    Microsoft Academic Search

    Ann A. Hertzler; Robert B. Frary

    1995-01-01

    Nutrition information networks accessible to or being accessed by college students were studied. Data were collected on the types of networks, the extent of their use, and the relationship of use tofood behavior. Undergraduate students (179 men, 300 women) in an introductory nutrition class rated their perceived use of nutrition information networks; provided frequency-of-use responses to a survey offood choicesfat

  15. Integrating Information & Communications Technologies into the Classroom

    ERIC Educational Resources Information Center

    Tomei, Lawrence, Ed.

    2007-01-01

    "Integrating Information & Communications Technologies Into the Classroom" examines topics critical to business, computer science, and information technology education, such as: school improvement and reform, standards-based technology education programs, data-driven decision making, and strategic technology education planning. This book also

  16. Communication services for advanced network applications.

    SciTech Connect

    Bresnahan, J.; Foster, I.; Insley, J.; Toonen, B.; Tuecke, S.

    1999-06-10

    Advanced network applications such as remote instrument control, collaborative environments, and remote I/O are distinguished by traditional applications such as videoconferencing by their need to create multiple, heterogeneous flows with different characteristics. For example, a single application may require remote I/O for raw datasets, shared controls for a collaborative analysis system, streaming video for image rendering data, and audio for collaboration. Furthermore, each flow can have different requirements in terms of reliability, network quality of service, security, etc. They argue that new approaches to communication services, protocols, and network architecture are required both to provide high-level abstractions for common flow types and to support user-level management of flow creation and quality. They describe experiences with the development of such applications and communication services.

  17. Southwest Environmental Information Network

    NSDL National Science Digital Library

    The Southwest Environmental Information Network (SEINet) is a series of linked databases and accompanying web software helpful in using those databases, which will be of interest to the environmental research community in Arizona, the Southwest, and elsewhere. SEINet allows users to locate, access, and work with a variety of data, including biological collections, ecological research data, GIS data, taxonomic information, bibliographies, and research protocols. Searchable databases include herbaria; pollen, fruit and seed collections; and mammal, bird, reptile, and amphibian collections. There is also a library of plant and lichen images; links to identification keys and species checklists from various research projects; information on NaviKey (a Java applet and application for accessing descriptive data); and Symbiota web tools (which integrate biological community knowledge and data in order to help identify plants).

  18. WindTalker: A P2P-Based Low-Latency Anonymous Communication Network

    NASA Astrophysics Data System (ADS)

    Zhang, Jia; Duan, Haixin; Liu, Wu; Wu, Jianping

    Compared with traditional static anonymous communication networks, the P2P architecture can provide higher anonymity in communication. However, the P2P architecture also leads to more challenges, such as route, stability, trust and so on. In this paper, we present WindTalker, a P2P-based low-latency anonymous communication network. It is a pure decentralized mix network and can provide low-latency services which help users hide their real identity in communication. In order to ensure stability and reliability, WindTalker imports seed nodes to help a peer join in the P2P network and the peer nodes can use gossip-based protocol to exchange active information. Moreover, WindTalker uses layer encryption to ensure the information of relayed messages cannot be leaked. In addition, malicious nodes in the network are the major threat to anonymity of P2P anonymous communication, so WindTalker imports a trust mechanism which can help the P2P network exclude malicious nodes and optimize the strategy of peer discovery, tunnel construction, and relaying etc. in anonymous communications. We deploy peer nodes of WindTalker in our campus network to test reliability and analyze anonymity in theory. The network measurement and simulation analysis shows that WindTalker can provide low-latency and reliable anonymous communication services.

  19. Networked sensor communications for the objective force

    NASA Astrophysics Data System (ADS)

    Nemeroff, Jay L.; Garcia, Luis; Hampel, Daniel; Di Pierro, Stefano

    2002-08-01

    The US Army's Future Combat Systems (FCS) and Objective Force will rely heavily on the use of unattended sensor networks to detect, locate and identify enemy targets in order to survive with less armor protection on the future battlefield. Successful implementation of these critical communication networks will require the collection of the sensor data, processing and collating it with available intelligence, then transporting it in a format conducive to make quick and accurate command decisions based on the latest tactical situational awareness. The networked communications must support both static deployed and mobile ground and air robotic sensors with secure, stealthy, and jam resistant links for sensor fusion and command and control. It is envisioned for broadest application that sensor networks can be deployed in a two-tiered architecture. The architecture includes a lower sensor sub-layer consisting of mixes of acoustic, magnetic and seismic detectors and an upper sub-layer consisting of infrared or visual imagers. The upper sub-layer can be cued by the lower sub-layer and provides a gateway link to the higher echelon tactical maneuver layer networks such as the Tactical Internet. The sensor deployments, networking constraints and reach back distances to Command and Control (C2) nodes will be mission scenario specific, however, the architecture will also apply to tactical unattended sensor, munition and robotic applications. Technologies from the Army Research Laboratory, Defense Advance Research Projects Agency (DARPA), and commercial will be leveraged for this effort.

  20. Fidelity and the communication of quantum information

    E-print Network

    Stephen M. Barnett; Claire R. Gilson; Masahide Sasaki

    2001-07-05

    We compare and contrast the error probability and fidelity as measures of the quality of the receiver's measurement strategy for a quantum communications system. The error probability is a measure of the ability to retrieve {\\it classical} information and the fidelity measures the retrieval of {\\it quantum} information. We present the optimal measurement strategies for maximising the fidelity given a source that encodes information on the symmetric qubit-states.

  1. Scholarly Information Network

    NASA Astrophysics Data System (ADS)

    Ginsparg, Paul

    I review the background and some recent trends of a particular scholarly information network, arXiv.org, and discuss some of its implications for new scholarly publication models. If we were to start from scratch today to design a quality-controlled archive and distribution system for scientific and technical information, it could take a very different form from what has evolved in the past decade from pre-existing print infrastructure. Near-term advances in automated classification systems, authoring tools, and document formats will facilitate efficient datamining and long-term archival stability, and I discuss how these could provide not only more efficient means of accessing and navigating the information, but also more cost-effective means of authentication and quality control. Finally, I illustrate the use of machine learning techniques to analyze, structure, maintain, and evolve a large online corpus of academic literature. An emerging field of research can be identified as part of an existing corpus, permitting the implementation of a more coherent community structure for its network of practitioners.

  2. Cell Multiprocessor Communication Network: Built for Speed

    SciTech Connect

    Kistler, Mike; Perrone, Michael; Petrini, Fabrizio

    2006-06-01

    The existence of major obstacles to the traditional path to processor performance improvement has led chip manufacturers to consider multi-core designs. These architectural solutions promise a variety of power/performance and area/performance benefits. But additional care must be taken to ensure that these benefits are not lost due to inadequate design of the on-chip communication network. This paper presents the design challenges of the on-chip network of the Cell Broadband Engine (Cell BE) processor, and describes in detail its architectural design and the network, communication and synchronization protocols. In the experimental evaluation, performed on an early prototype, we analyze the communication characteristics of the Cell BE processor, using a series of microbenchmarks involving various DMA traffic patterns and synchronization protocols. We find that the on-chip communication subsystem is well matched to the to computational capacity of the processor. A Synergistic Processing Element (SPE) can issue an internal direct memory access (DMA) operation in less than 4 nanoseconds, and a DMA of a single cache line can be executed in less the than 100 nanoseconds. SPEs can achieve the optimal bandwidth of 25.6 GB/second in point to point communication with surprisingly small messages ?only a few KB, using batches of non-blocking DMAs. The aggregate network behavior under heavy load is also remarkably efficient, reaching almost 200 GB/second with collective patterns and optimal contention resolution under hot-spot traffic. Additionally, we demonstrate the consistency of these hardware results with identical experiments carried out using the Mambo simulator software for Cell BE.

  3. Structural Changes in Data Communication in Wireless Sensor Networks

    E-print Network

    Cabral, Raquel S; Frery, Alejandro C; Rosso, Osvaldo A; Ramrez, Jaime A

    2013-01-01

    Wireless sensor networks are an important technology for making distributed autonomous measures in hostile or inaccessible environments. Among the challenges they pose, the way data travel among them is a relevant issue since their structure is quite dynamic. The operational topology of such devices can often be described by complex networks. In this work, we assess the variation of measures commonly employed in the complex networks literature applied to wireless sensor networks. Four data communication strategies were considered: geometric, random, small-world, and scale-free models, along with the shortest path length measure. The sensitivity of this measure was analyzed with respect to the following perturbations: insertion and removal of nodes in the geometric strategy; and insertion, removal and rewiring of links in the other models. The assessment was performed using the normalized Kullback-Leibler divergence and Hellinger distance quantifiers, both deriving from the Information Theory framework. The re...

  4. Structural changes in data communication in wireless sensor networks

    NASA Astrophysics Data System (ADS)

    da Silva Cabral, Raquel; Aquino, Andre L. L.; Frery, Alejandro C.; Rosso, Osvaldo A.; Ramrez, Jaime A.

    2013-12-01

    Wireless sensor networks are an important technology for making distributed autonomous measures in hostile or inaccessible environments. Among the challenges they pose, the way data travel among them is a relevant issue since their structure is quite dynamic. The operational topology of such devices can often be described by complex networks. In this work, we assess the variation of measures commonly employed in the complex networks literature applied to wireless sensor networks. Four data communication strategies were considered: geometric, random, small-world, and scale-free models, along with the shortest path length measure. The sensitivity of this measure was analyzed with respect to the following perturbations: insertion and removal of nodes in the geometric strategy; and insertion, removal and rewiring of links in the other models. The assessment was performed using the normalized Kullback-Leibler divergence and Hellinger distance quantifiers, both deriving from the Information Theory framework. The results reveal that the shortest path length is sensitive to perturbations.

  5. Essential elements of online information networks on invasive alien species

    USGS Publications Warehouse

    Simpson, A.; Sellers, E.; Grosse, A.; Xie, Y.

    2006-01-01

    In order to be effective, information must be placed in the proper context and organized in a manner that is logical and (preferably) standardized. Recently, invasive alien species (IAS) scientists have begun to create online networks to share their information concerning IAS prevention and control. At a special networking session at the Beijing International Symposium on Biological Invasions, an online Eastern Asia-North American IAS Information Network (EA-NA Network) was proposed. To prepare for the development of this network, and to provide models for other regional collaborations, we compare four examples of global, regional, and national online IAS information networks: the Global Invasive Species Information Network, the Invasives Information Network of the Inter-American Biodiversity Information Network, the Chinese Species Information System, and the Invasive Species Information Node of the US National Biological Information Infrastructure. We conclude that IAS networks require a common goal, dedicated leaders, effective communication, and broad endorsement, in order to obtain sustainable, long-term funding and long-term stability. They need to start small, use the experience of other networks, partner with others, and showcase benefits. Global integration and synergy among invasive species networks will succeed with contributions from both the top-down and the bottom-up. ?? 2006 Springer.

  6. The International Coral Reef Information Network

    NSDL National Science Digital Library

    International Coral Reef Action Network (ICRAN)

    This extensive site was originally created to support coral reef conservation by the International Coral Reef Initiative (ICRI). The site serves to provide general coral reef information, tools and resources, and a central coral reef communications and network hub. The site also provides a library which houses descriptions of brochures, books, videos and other items suitable for coral reef awareness and education efforts. Some publications are available for download directly from this site, while others are available for purchase.

  7. (CICT) Computing, Information, and Communications Technology Overview

    NASA Technical Reports Server (NTRS)

    VanDalsem, William R.

    2003-01-01

    The goal of the Computing, Information, and Communications Technology (CICT) program is to enable NASA's Scientific Research, Space Exploration, and Aerospace Technology Missions with greater mission assurance, for less cost, with increased science return through the development and use of advanced computing, information and communications technologies. This viewgraph presentation includes diagrams of how the political guidance behind CICT is structured. The presentation profiles each part of the NASA Mission in detail, and relates the Mission to the activities of CICT. CICT's Integrated Capability Goal is illustrated, and hypothetical missions which could be enabled by CICT are profiled. CICT technology development is profiled.

  8. Efficient QoS Provisioning for Adaptive Multimedia in Mobile Communication Networks by Reinforcement Learning

    E-print Network

    Wong, Vincent

    Efficient QoS Provisioning for Adaptive Multimedia in Mobile Communication Networks networks have motivated the development of adaptive multimedia services in mobile communication networks of the proposed scheme in adaptive multimedia mobile communication networks. 1. Introduction Recent years have

  9. Analyzing the Dynamics of Communication in Online Social Networks

    NASA Astrophysics Data System (ADS)

    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 function of attribute homophily existent among the participants. We believe that this chapter can make significant contribution into a better understanding of how we communicate online and how it is redefining our collective sociological behavior.

  10. Communication Networks in the Brain

    PubMed Central

    Lovinger, David M.

    2008-01-01

    Nerve cells (i.e., neurons) communicate via a combination of electrical and chemical signals. Within the neuron, electrical signals driven by charged particles allow rapid conduction from one end of the cell to the other. Communication between neurons occurs at tiny gaps called synapses, where specialized parts of the two cells (i.e., the presynaptic and postsynaptic neurons) come within nanometers of one another to allow for chemical transmission. The presynaptic neuron releases a chemical (i.e., a neurotransmitter) that is received by the postsynaptic neurons specialized proteins called neurotransmitter receptors. The neurotransmitter molecules bind to the receptor proteins and alter postsynaptic neuronal function. Two types of neurotransmitter receptors existligand-gated ion channels, which permit rapid ion flow directly across the outer cell membrane, and G-proteincoupled receptors, which set into motion chemical signaling events within the cell. Hundreds of molecules are known to act as neurotransmitters in the brain. Neuronal development and function also are affected by peptides known as neurotrophins and by steroid hormones. This article reviews the chemical nature, neuronal actions, receptor subtypes, and therapeutic roles of several transmitters, neurotrophins, and hormones. It focuses on neurotransmitters with important roles in acute and chronic alcohol effects on the brain, such as those that contribute to intoxication, tolerance, dependence, and neurotoxicity, as well as maintained alcohol drinking and addiction. PMID:23584863

  11. Performance evaluation of optical communication networks

    NASA Astrophysics Data System (ADS)

    Tafur Monroy, Idelfonso

    Optical communications networks are an essential part of the world wide telecommunication infrastructure. The number of users of present and future telecommunication services like Internet, web browsing and tele-education will increase dramatically. As a consequence there is an imminent demand for broadband high capacity communication systems. A promising solution is the concept of all- optical networks. Major research efforts in areas such as photonic integration and semiconductor technology, among others, are currently directed toward the development of key components that will enable the construction of all- optical networks. This thesis addresses the performance analysis of optical networks. Theoretical models are presented for a number of digital optical systems in the context of all-optical networking. The models account for the influence of significant noise arising from performance imperfections of optical devices that comprise an all-optical network. Modeling, apart from being applied to the performance assessment, gives insights into how to optimally operate the system so that a certain level of reliability is assured. The validity of the developed models has been confirmed by relevant experimental measurements. The main results of this thesis are as follows. Firstly, an accurate statistical description of filtered interferometric crosstalk is presented. Secondly, phase scrambling to reduce the effect of crosstalk in wavelength division multiplexing networks is theoretically investigated and experimentally assessed. Thirdly, original research on optically preamplified receivers, phase noise analysis, and scalability of optical networks is presented. Finally, based on theoretical and experimental studies, this work gives a series of recommendations on how to select the optimal operating regime for systems employing phase scrambling to reduce interferometric crosstalk.

  12. Position estimation of transceivers in communication networks

    DOEpatents

    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.

  13. An FPGA-based Torus Communication Network

    E-print Network

    Marcello Pivanti; Sebastiano Fabio Schifano; Hubert Simma

    2011-02-11

    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.

  14. Lecture Series in Mobile Telecommunications and Networks Wireless Communications

    E-print Network

    Toh, C-K.

    Lecture Series in Mobile Telecommunications and Networks Wireless Communications: Ideas that Change at the heart of this development, in particular in the field of mobile communications and networking in 1985. In academia, he has pioneered many of the major advances used in mobile communications today

  15. Route Optimization for Intra Communication of a Nested Mobile Network

    E-print Network

    Route Optimization for Intra Communication of a Nested Mobile Network Sungmin Baek Seoul National to retain the mobility transparency as the NEMO basic support protocol and to reduce the communication cost protocol efficiently supports communication within a nested mobile network. Categories and Subject

  16. ANALYSIS OF HANDOVER CHARACTERISTICS IN SHADOWED LEO SATELLITE COMMUNICATION NETWORKS

    E-print Network

    Sung, Dan Keun

    ANALYSIS OF HANDOVER CHARACTERISTICS IN SHADOWED LEO SATELLITE COMMUNICATION NETWORKS£ YOUNG HOON In the near future low earth orbit (LEO) satellite communication networks will partially substitute for fixed communication networks more than one satellite need to be simultaneously visible in order to hand over a call

  17. Essays on social networks and information worker productivity by Lynn Wu.

    E-print Network

    Wu, Lynn, 1981-

    2011-01-01

    In this thesis, I examine how information, information technology, and social networks affect information worker productivity. The work is divided into three essays based on tracking detailed communication patterns of ...

  18. Improve Communication Efficiency for the Physiological Information Monitor System Based on Zigbee

    Microsoft Academic Search

    Teng Jiao; Kun Zhang; Wen Zhang; Xiuzhen Dong

    2009-01-01

    This paper designs one physiological information monitor system based on the ZigBee wireless communication protocol. The hardware structure is presented. The network communication characteristic of this system was analyzed. The paper points out the disadvantage of the connection method in the ZigBee protocol. One improved connection method is proposed. Through carries on the comparison and the simulation to the routing

  19. Promoting Communication Skills for Information Systems Students in Australian and Portuguese Higher Education: Action Research Study

    ERIC Educational Resources Information Center

    Isaias, Pedro; Issa, Tomayess

    2014-01-01

    This paper aims to examine the value of communication skills learning process through various assessments in Information Systems (IS) postgraduate units in Australia and Portugal. Currently, communication skills are indispensable to students in expanding their social networks and their knowledge at university and in the future workplace, since

  20. Gas Main Sensor and Communications Network System

    Microsoft Academic Search

    Hagen Schempf

    2006-01-01

    Automatika, Inc. was contracted by the Department of Energy (DOE) and with co-funding from the Northeast Gas Association (NGA), to develop an in-pipe natural gas prototype measurement and wireless communications system for assessing and monitoring distribution networks. This projected was completed in April 2006, and culminated in the installation of more than 2 dozen GasNet nodes in both low- and

  1. An OFDMA communication protocol for wireless sensor networks used for leakage detection in underground water infrastructures

    Microsoft Academic Search

    Elias Yaacoub; Abdullah Kadri; Adnan Abu-Dayya

    2011-01-01

    In this paper, an application of wireless sensor networks for leakage detection in underground water pipes is considered. A mobile sensor immersed in the water pipe is assumed to communicate with relay nodes on the ground surface, relaying its measured information to a base station for processing. A communication protocol between the relay nodes and the base station is presented.

  2. Information Communication Technology Planning in Developing Countries

    ERIC Educational Resources Information Center

    Malapile, Sandy; Keengwe, Jared

    2014-01-01

    This article explores major issues related to Information Communication Technology (ICT) in education and technology planning. Using the diffusion of innovation theory, the authors examine technology planning opportunities and challenges in Developing countries (DCs), technology planning trends in schools, and existing technology planning models

  3. School Leadership and Information Communication Technology

    ERIC Educational Resources Information Center

    Afshari, Mojgan; Bakar, Kamariah Abu; Luan, Wong Su; Samah, Bahaman Abu; Fooi, Foo Say

    2008-01-01

    Leadership is an important component in guiding the teaching-learning process. Principal as school leaders have a major responsibility for initiating and implementing school change through the use of Information and Communication Technology (ICT) and can facilitate complex decision to integrate it into learning, teaching and school administration.

  4. Information and Communications Technologies Center Video Library

    NSDL National Science Digital Library

    The Information and Communications Technologies Center (ICT) presents this collection of useful videos. Most of the clips are from conferences such as the 2010 CTC Winter Retreat and feature talks given at the conferences. Several other clips involve discussions of ICT academics and technology. The clips vary in length.

  5. Understanding Science: Studies of Communication and Information.

    ERIC Educational Resources Information Center

    Griffith, Belver C.

    1989-01-01

    Sets bibliometrics in the context of the sociology of science by tracing the influences of Robert Merton, Thomas Kuhn, and D. J. Price. Explores the discovery of strong empirical relationships among measured communication and information that capture important features of social process and cognitive change in science. (SR)

  6. An Underwater Sensor Network with Dual Communications, Sensing, and

    E-print Network

    Farritor, Shane

    ], the current industry standard for ground sensor networks has fueled an explosion in the development of groundAn Underwater Sensor Network with Dual Communications, Sensing, and Mobility Carrick Detweiller an underwater sensor network with dual communication and sup- port for sensing and mobility. The nodes

  7. Africa in Global Communication Networks: from networks to concrete uses

    Microsoft Academic Search

    Annie ChNeau-Loquay

    2000-01-01

    Paper presented at the 9th General Conference of the European Association of Development Research and Training Institutes (EADI) Paris, France, 2225 September 1999, in a session of the EADI Information Management Working Group. The growing integration of Africa into the worldwide information and communications system gives rise to hopes that the continent will achieve a technological leap which will help

  8. Communication efficiency and congestion of signal traffic in large-scale brain networks.

    PubMed

    Mii?, Bratislav; Sporns, Olaf; McIntosh, Anthony R

    2014-01-01

    The complex connectivity of the cerebral cortex suggests that inter-regional communication is a primary function. Using computational modeling, we show that anatomical connectivity may be a major determinant for global information flow in brain networks. A macaque brain network was implemented as a communication network in which signal units flowed between grey matter nodes along white matter paths. Compared to degree-matched surrogate networks, information flow on the macaque brain network was characterized by higher loss rates, faster transit times and lower throughput, suggesting that neural connectivity may be optimized for speed rather than fidelity. Much of global communication was mediated by a "rich club" of hub regions: a sub-graph comprised of high-degree nodes that are more densely interconnected with each other than predicted by chance. First, macaque communication patterns most closely resembled those observed for a synthetic rich club network, but were less similar to those seen in a synthetic small world network, suggesting that the former is a more fundamental feature of brain network topology. Second, rich club regions attracted the most signal traffic and likewise, connections between rich club regions carried more traffic than connections between non-rich club regions. Third, a number of rich club regions were significantly under-congested, suggesting that macaque connectivity actively shapes information flow, funneling traffic towards some nodes and away from others. Together, our results indicate a critical role of the rich club of hub nodes in dynamic aspects of global brain communication. PMID:24415931

  9. GAS MAIN SENSOR AND COMMUNICATIONS NETWORK SYSTEM

    SciTech Connect

    Hagen Schempf, Ph.D.

    2003-02-27

    Automatika, Inc. was contracted by the Department of Energy (DOE) and with co-funding from the New York Gas Group (NYGAS), to develop an in-pipe natural gas prototype measurement and wireless communications system for assessing and monitoring distribution networks. A prototype system was built for low-pressure cast-iron mains and tested in a spider- and serial-network configuration in a live network in Long Island with the support of Keyspan Energy, Inc. The prototype unit combined sensors capable of monitoring pressure, flow, humidity, temperature and vibration, which were sampled and combined in data-packages in an in-pipe master-slave architecture to collect data from a distributed spider-arrangement, and in a master-repeater-slave configuration in serial or ladder-network arrangements. It was found that the system was capable of performing all data-sampling and collection as expected, yielding interesting results as to flow-dynamics and vibration-detection. Wireless in-pipe communications were shown to be feasible and valuable data was collected in order to determine how to improve on range and data-quality in the future.

  10. Effects of urban information and communication technology on sustainable development

    Microsoft Academic Search

    M. Navabakhsh; M. Motlaq

    2009-01-01

    This paper examines the urban information and communication technology and its impacts on sustainable development. The findings are based on the views represented in literature and the relationship between information and communication technology and sustainability in urban development. Therefore, information and communication technology as the main component of the information society should be taken into consideration in sustainable development. In

  11. Opportunistic Information Retrieval in Sparsely Connected Ad Hoc Networks

    NASA Astrophysics Data System (ADS)

    Chuah, Mooi-Choo; Han, Jian-Bin

    With the advancement in technology, many users carry wireless computing de-vices e.g., PDAs, cell-phones etc. Such devices can form mobile ad hoc networks and communicate with one another via the help of intermediate nodes. Such ad hoc networks are very useful in several scenarios e.g., battlefield operations, vehicular ad hoc networks and disaster response scenarios. The ability to access important information in these scenarios is highly critical. Many ad hoc routing schemes have been designed for ad hoc networks but such routing schemes are not useful in some challenging network scenarios where the nodes have intermittent connectivity and suffer frequent partitioning. Recently, disruption tolerant network technologies [5, 12] have been proposed to allow nodes in such extreme network-ing environment to communicate with one another. Several DTN routing schemes [4, 14] have been proposed.

  12. Research on a Heat-supply Network Dispatching System Based on Geographical Information System (GIS)

    E-print Network

    Zhou, Z.; Zou, P.; Tang, H.; Fang, X.; Wang, W.

    2006-01-01

    -supply Network Dispatching System (HNDS). The system, based on Oracle database and Mapgis 6.5, compiles with Visual C++ software. With computer and communication techniques, the system dynamic inspects parameters and information of a heat-supply network, achieves...

  13. Social networks and the communication of norms about prenatal care in rural Mexico.

    PubMed

    Lapinski, Maria Knight; Anderson, Jenn; Cruz, Shannon; Lapine, Peter

    2015-01-01

    Many normative beliefs are shared and learned through interpersonal communication, yet research on norms typically focuses on their effects rather than the communication that shapes them. This study focused on interpersonal communication during pregnancy to uncover (a) the nature of pregnancy-related communication and (b) normative information transmitted through such communication. Results from interviews with pregnant women living in rural Mexico revealed limited social networks; often, only a woman's mother or the baby's father were consulted about prenatal care decisions. However, women also indicated that communication with others during pregnancy provided important normative information regarding prenatal care. First, most referents believed that women should receive prenatal care (injunctive norm), which was conceptualized by participants as biomedical, nonmedical, or a blend of both. Second, family members often received prenatal care, whereas friends did not (descriptive norms). These findings highlight the key role of personal and social networks in shaping personal pregnancy-related beliefs and behaviors. PMID:25116348

  14. Acoustic Propagation Considerations for Underwater Acoustic Communications Network Development

    E-print Network

    Zhou, Shengli

    Acoustic Propagation Considerations for Underwater Acoustic Communications Network Development Woods Hole, MA 02543 jpreisig@whoi.edu ABSTRACT Underwater acoustic communications systems are challenged by the characteristics of acoustic propagation through the underwater environment

  15. Global Legal Information Network

    NSDL National Science Digital Library

    2005-01-01

    Legal scholars and those with an interest in the law will definitely want to take a look at the Global Legal Information Network (GLIN) website. Here visitors can search official full text legal documents, including judicial decisions, legislation, and laws. The database is provided courtesy of the Law Library of the United States Congress, and it draws from countries from around the world who wish to provide access to their own legal documents. Some of the countries who participate in the program include Brazil, Costa Rica, Kuwait, Peru, and Romania. Visitors will find that the ways to search the database are extremely helpful. Options include searching by jurisdiction, publication date, subject terms, and language. The site is rounded out by a section that provides answers to frequently asked questions about using the database.

  16. An Interdisciplinary Network Making Progress on Climate Change Communication

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

    Public understanding of climate change continues to lag far behind the scientific consensus not merely because the public lacks information, but because there is in fact too much complex and contradictory information available. Fortunately, we can now (1) build on careful empirical cognitive and social science research to understand what people already value, believe, and understand; and then (2) design and test strategies for translating complex science so that people can examine evidence, make well-informed inferences, and embrace science-based solutions. Informal science education institutions can help bridge the gap between climate scientists and the public. In the US, more than 1,500 informal science venues (science centers, museums, aquariums, zoos, nature centers, national parks, etc.) are visited annually by 61% of the population. Extensive research shows that these visitors are receptive to learning about climate change and trust these institutions as reliable sources. Ultimately, we need to take a strategic approach to the way climate change is communicated. An interdisciplinary approach is needed to bring together three key areas of expertise (as recommended by Pidgeon and Fischhoff, 2011): 1. Climate and decision science experts - who can summarize and explain what is known, characterize risks, and describe appropriate mitigation and adaptation strategies; 2. Social scientists - who can bring to bear research, theory, and best practices from cognitive, communication, knowledge acquisition, and social learning theory; and 3. Informal educators and program designers - who bring a practitioner perspective and can exponentially facilitate a learning process for additional interpreters. With support from an NSF CCEP Phase I grant, we have tested this approach, bringing together Interdisciplinary teams of colleagues for a five month "study circles" to develop skills to communicate climate change based on research in the social and cognitive sciences. In 2011, 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.

  17. Information and Communication Using Lasers

    NASA Astrophysics Data System (ADS)

    Alouini, Mehdi; Bretenaker, Fabien

    2015-10-01

    The applications of lasers in industry are numerous. It is of course beyond the scope of this book to give an overview of these applications. Rather than trying and failing in doing so, we have chosen in this chapter to illustrate the unique properties of lasers in four different fields. The two first applications described in this chapter, namely optical telecommunications (Section 3.1) and optical information storage (Section 3.2), highlight the contribution of the spatial coherence of the laser. The third one, namely the ring laser gyroscope (Section 3.3), illustrates the amazing spectral purity that can be provided by laser light. Finally, the fourth one, known under the generic acronym LIDAR (Section 3.4), can use different laser properties, depending on its implementation. It can be based on the laser spatial coherence, the laser temporal coherence, and/or on the laser ability to emit powerful short pulses.

  18. Information and Communications Technologies (ICT) Center

    NSDL National Science Digital Library

    The National Center for Information and Communications Technologies, an Advanced Technology Education (ATE) resource center, aims to "contribute to scientific and technological innovation in telecommunications education" as well as to "provide appropriately skilled technicians and technologists" to information and communication technologies (ICT) businesses, industry, and users. In the "Publications" section of this site, visitors will find links to ICT textbooks and a helpful glossary of telecommunications terms. In the "Resources" section, there are a number of ICT workforce development presentations and Flash simulations on topics such as shift keying and Ethernet switching. Also in this section, there is a web tutorial on designing accessible web pages. This site has a great deal of information to assist students and technologists in telecommunications fields, as well as ready-to-use instructional materials for educators.

  19. The Virtual Research and Extension Communication Network (VRECN): An Interactive Learning and Communication Network for Research and Extension Personnel. Concept Paper for the Food & Agriculture Organisation of the United Nations (FAO).

    ERIC Educational Resources Information Center

    Richardson, Don

    A Virtual Research and Extension Communication Network (VRECN) is a set of networked electronic tools facilitating improvement in communication processes and information sharing among stakeholders involved in agricultural development. In developing countries, research and extension personnel within a ministry of agriculture, in consultation and

  20. Cooperative Network Communications in Dynamic Channel Environments

    Microsoft Academic Search

    Yimin Zhang; Kehu Yang; Moeness G. Amin

    2006-01-01

    Coded space-time cooperation is a powerful approach to deliver information over a distributed network. Multiple transmit and receive nodes form a distributed multiple-input-multiple-output (MIMO) system, thus provide the capability of high data rate transmission with the support of high diversity gains. However, unlike co-located MIMO systems, it is impractical for distributed MIMO networks to maintain a perfect synchronization between different

  1. Human Communication and Information Science Division Introductory L e c t u r e s Seminars and Thesis Programs EducationVerbal Communication Human CommunicationInformation Technology

    E-print Network

    Banbara, Mutsunori

    s Seminars and Thesis Programs EducationVerbal Communication Human CommunicationInformation TechnologyHumanCommunication Neurolinguistics InterpersonalCommunication IntroductiontoInformationMethodology ComputerCommunications DataProcessingandMultimedia NumericalAnalysisforStatistics DataManagement ProgrammingFundamentals Issuesin

  2. Flows of Relations and Communication among Singapore Political Bloggers and Organizations: The Networked Public Sphere Approach

    Microsoft Academic Search

    Carol Soon; Hichang Cho

    2011-01-01

    Adopting Friedland, Hove, and Rojas's (2006) concept of the networked public sphere, we set out to achieve two key objectives: identify the key players concerned with Singapore politics in the cyberspace and examine the nature of the social network comprising these players. In spite of Singapore's recognized success in deploying information communication technologies for economic progress, the liberalizing effects of

  3. Communication Inequalities and Public Health Implications of Adult Social Networking Site Use in the United States

    Microsoft Academic Search

    Emily Z. Kontos; Karen M. Emmons; Elaine Puleo; K. Viswanath

    2010-01-01

    Social media, and specifically social networking sites (SNSs), are emerging as an important platform for communication and health information exchange. Yet, despite the increase in popularity and use, only a limited number of empirical studies document which segments of the adult population are and are not using social networking sites and with what, if any, affect on health. The purpose

  4. Child Rights Information Network

    NSDL National Science Digital Library

    Established in 1995 and based in London, the Children's Rights Information Network (CRIN) uses the United Nations Convention on the Rights of the Child (CRC) as their inspiration. Visitors unfamiliar with the reasons for the need for a group that advocates for the rights of children should check out the "Issues" tab. The CRIN Quiz section is a good place for visitors to learn about some of the specifics of children's rights in various countries, such as the "African Committee on the Rights and the Welfare of the Child" from 15/03/2010 and "Child Rights and the United States" from 05/11/2008. There are quizzes on some specific issues that involve children, such as "Child Slavery" from 28/03/2007 and "Quiz on Children Affected by Armed Conflict" from 24/11/2006. The "Information By Country", which can be accessed on the left hand side of the homepage, features International Law, National Law, and Regional Law related to the country, as well as the "Latest Resources", which include such valuable guides as the "Human Rights Watch: Global Report 2010".

  5. Communication Network Patterns and Employee Performance with New Technology.

    ERIC Educational Resources Information Center

    Papa, Michael J.

    1990-01-01

    Investigates the relationship between employee performance, new technology, employee communication network variables (activity, size, diversity, and integrativeness), and productivity at two corporate offices. Reports significant positive relationships between three of the network variables and employee productivity with new technology. Discusses

  6. Organizational structure and communication networks in a university environment

    NASA Astrophysics Data System (ADS)

    Mathiesen, Joachim; Jamtveit, Bjrn; Sneppen, Kim

    2010-07-01

    The six degrees of separation between any two individuals on Earth has become emblematic of the small world theme, even though the information conveyed via a chain of human encounters decays very rapidly with increasing chain length, and diffusion of information via this process may be very inefficient in large human organizations. The information flow on a communication network in a large organization, the University of Oslo, has been studied by analyzing email records. The records allow for quantification of communication intensity across organizational levels and between organizational units (referred to as modules). We find that the number of email messages within modules scales with module size to the power of 1.29.06 , and the frequency of communication between individuals decays exponentially with the number of links required upward in the organizational hierarchy before they are connected. Our data also indicates that the number of messages sent by administrative units is proportional to the number of individuals at lower levels in the administrative hierarchy, and the divergence of information within modules is associated with this linear relationship. The observed scaling is consistent with a hierarchical system in which individuals far apart in the organization interact little with each other and receive a disproportionate number of messages from higher levels in the administrative hierarchy.

  7. Proactive and adaptive reconfiguration for reliable communication in tactical networks

    NASA Astrophysics Data System (ADS)

    Zeng, Hui; Kwak, Kyung Joon; Deng, Julia; Fu, Bo; Xiao, Yang; Jeski, John

    2012-05-01

    Due to the layer-independency design, in current wireless networks, only after a complete failure occurs in one of the involved layers, is the next higher layer notified, and by then performance degradation may already be observed. Also, the new connection establishment process has to go through all the layers. It is time-consuming and usually results in an extra latency and resource unavailability within the transition region, which in turn leads to inefficient bandwidth usage and a poor user experience. Moreover, the root-cause of the connection termination is typically hidden, and not utilized for the repair or reestablishment. To mitigate the problem, in this paper, we propose a proactive and adaptive cross-layer reconfiguration (PACR) scheme for reliable communication in tactical networks. The PACR scheme allows the user (e.g., network operator) to adaptively reconfigure operating parameters in the corresponding layers through proactive prediction, root-cause identification, and cross-layer negotiations. The core of the PACR scheme is an integrated crosslayer information sharing architecture that expedites information exchange and inter-layer interactions between different network layers in a proactive manner. Through simulation and experiments, it has been shown that our proposed PACR scheme can significantly improve the network performance, and facilitate the nodes or users to make smart decisions accordingly in an adaptive manner.

  8. Models, Entropy and Information of Temporal Social Networks

    NASA Astrophysics Data System (ADS)

    Zhao, Kun; Karsai, Mrton; Bianconi, Ginestra

    Temporal social networks are characterized by heterogeneous duration of contacts, which can either follow a power-law distribution, such as in face-to-face interactions, or a Weibull distribution, such as in mobile-phone communication. Here we model the dynamics of face-to-face interaction and mobile phone communication by a reinforcement dynamics, which explains the data observed in these different types of social interactions. We quantify the information encoded in the dynamics of these networks by the entropy of temporal networks. Finally, we show evidence that human dynamics is able to modulate the information present in social network dynamics when it follows circadian rhythms and when it is interfacing with a new technology such as the mobile-phone communication technology.

  9. The network and transmission of based on the principle of laser multipoint communication

    NASA Astrophysics Data System (ADS)

    Fu, Qiang; Liu, Xianzhu; Jiang, Huilin; Hu, Yuan; Jiang, Lun

    2014-11-01

    Space laser communication is the perfectly choose to the earth integrated information backbone network in the future. This paper introduces the structure of the earth integrated information network that is a large capacity integrated high-speed broadband information network, a variety of communications platforms were densely interconnected together, such as the land, sea, air and deep air users or aircraft, the technologies of the intelligent high-speed processing, switching and routing were adopt. According to the principle of maximum effective comprehensive utilization of information resources, get accurately information, fast processing and efficient transmission through inter-satellite, satellite earth, sky and ground station and other links. Namely it will be a space-based, air-based and ground-based integrated information network. It will be started from the trends of laser communication. The current situation of laser multi-point communications were expounded, the transmission scheme of the dynamic multi-point between wireless laser communication n network has been carefully studied, a variety of laser communication network transmission schemes the corresponding characteristics and scope described in detail , described the optical multiplexer machine that based on the multiport form of communication is applied to relay backbone link; the optical multiplexer-based on the form of the segmentation receiver field of view is applied to small angle link, the optical multiplexer-based form of three concentric spheres structure is applied to short distances, motorized occasions, and the multi-point stitching structure based on the rotation paraboloid is applied to inter-satellite communications in detail. The multi-point laser communication terminal apparatus consist of the transmitting and receiving antenna, a relay optical system, the spectroscopic system, communication system and communication receiver transmitter system. The communication forms of optical multiplexer more than four goals or more, the ratio of received power and volume weight will be Obvious advantages, and can track multiple moving targets in flexible.It would to provide reference for the construction of earth integrated information networks.

  10. 76 FR 36154 - In the Matter of Certain Equipment for Communications Networks, Including Switches, Routers...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-21

    ...of Certain Equipment for Communications Networks, Including Switches...of certain equipment for communications networks, including switches...of certain equipment for communications networks, including switches...Consumer Products LLC, 120 Theory Drive, Irvine, CA...

  11. Architecting Communication Network of Networks for Space System of Systems

    NASA Technical Reports Server (NTRS)

    Bhasin, Kul B.; Hayden, Jeffrey L.

    2008-01-01

    The National Aeronautics and Space Administration (NASA) and the Department of Defense (DoD) are planning Space System of Systems (SoS) to address the new challenges of space exploration, defense, communications, navigation, Earth observation, and science. In addition, these complex systems must provide interoperability, enhanced reliability, common interfaces, dynamic operations, and autonomy in system management. Both NASA and the DoD have chosen to meet the new demands with high data rate communication systems and space Internet technologies that bring Internet Protocols (IP), routers, servers, software, and interfaces to space networks to enable as much autonomous operation of those networks as possible. These technologies reduce the cost of operations and, with higher bandwidths, support the expected voice, video, and data needed to coordinate activities at each stage of an exploration mission. In this paper, we discuss, in a generic fashion, how the architectural approaches and processes are being developed and used for defining a hypothetical communication and navigation networks infrastructure to support lunar exploration. Examples are given of the products generated by the architecture development process.

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

    PubMed

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

    2015-01-01

    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. PMID:25658394

  13. Information needs for risk management/communication

    SciTech Connect

    Bennett, D.A. [Environmental Protection Agency, Washington, DC (United States)

    1990-12-31

    The hazardous waste cleanup program under the Comprehensive Environmental Response, Compensation, and Liability Act (Superfund) is delegated to the ten Regions of the US Environmental Protection Agency (EPA) and has, to date, identified more than 33,000 sites for consideration. The size and complexity of the program places great demands on those who would provide information to achieve national consistency in application of risk assessment while meeting site-specific needs for risk management and risk communication.

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

    NASA Technical Reports Server (NTRS)

    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.

  15. Delay Sensitive Communications over Cognitive Radio Networks

    E-print Network

    Wang, Feng; Zhao, Yuping

    2012-01-01

    Supporting the quality of service of unlicensed users in cognitive radio networks is very challenging, mainly due to dynamic resource availability because of the licensed users' activities. In this paper, we study the optimal admission control and channel allocation decisions in cognitive overlay networks in order to support delay sensitive communications of unlicensed users. We formulate it as a Markov decision process problem, and solve it by transforming the original formulation into a stochastic shortest path problem. We then propose a simple heuristic control policy, which includes a threshold-based admission control scheme and and a largest-delay-first channel allocation scheme, and prove the optimality of the largest-delay-first channel allocation scheme. We further propose an improved policy using the rollout algorithm. By comparing the performance of both proposed policies with the upper-bound of the maximum revenue, we show that our policies achieve close-to-optimal performance with low complexities...

  16. Aquaculture Network Information Center

    NSDL National Science Digital Library

    Given the declining schools of fish in many of the world's oceans, interest in aquaculture has grown exponentially in the past few years. The Aquaculture Network Information Center (ANIC) serves as an electronic gateway to thousands of online aquaculture-related resources, and is hosted by Purdue University and the University of Illinois through the Illinois - Indiana Sea Grant College Program. ANIC was started in 1994, and currently contains links to hundreds of aquaculture publications from around the globe, visual media (such as Power Point presentations), calendars of germane conferences and events, and specialty sections for species and production systems. From the ANIC home page, visitors may join discussion groups about aquaculture (organized by species), learn about different aquaculture cultivation systems, and peruse recent and archive publications from the relevant federal, state, and international agencies. For aquaculture neophytes, a FAQ section will answer ever quandary possible about the world of pond management, the perplexity of pond construction, and the inevitable debates surrounding which form of aquaculture production is most appropriate for different regions of the world.

  17. GAS MAIN SENSOR AND COMMUNICATIONS NETWORK SYSTEM

    SciTech Connect

    Hagen Schempf

    2004-09-30

    Automatika, Inc. was contracted by the Department of Energy (DOE) and with co-funding from the New York Gas Group (NYGAS), to develop an in-pipe natural gas prototype measurement and wireless communications system for assessing and monitoring distribution networks. In Phase II of this three-phase program, an improved prototype system was built for low-pressure cast-iron and high-pressure steel (including a no-blow installation system) mains and tested in a serial-network configuration in a live network in Long Island with the support of Keyspan Energy, Inc. The experiment was carried out in several open-hole excavations over a multi-day period. The prototype units (3 total) combined sensors capable of monitoring pressure, flow, humidity, temperature and vibration, which were sampled and combined in data-packages in an in-pipe master-repeater-slave configuration in serial or ladder-network arrangements. It was verified that the system was capable of performing all data-sampling, data-storage and collection as expected, yielding interesting results as to flow-dynamics and vibration-detection. Wireless in-pipe communications were shown to be feasible and the system was demonstrated to run off in-ground battery- and above-ground solar power. The remote datalogger access and storage-card features were demonstrated and used to log and post-process system data. Real-time data-display on an updated Phase-I GUI was used for in-field demonstration and troubleshooting.

  18. Evaluations of gestural animations to convey feelings in asynchronous network communication

    Microsoft Academic Search

    Tomoo Inoue; Ken-ichi Okada; Y. Matsushita

    1995-01-01

    The paper deals with nonverbal communication in asynchronous networks. It is well known that nonverbal communication plays an important role in interpersonal communication. However, nonverbal communication has not been used in traditional character based network communication until now, yet the need for conveying feelings has increased. Due to the development of multimedia networks, it is thought that nonverbal communication can

  19. A correctness proof of a topology information maintenance protocol for a distributed computer network

    Microsoft Academic Search

    William D. Tajibnapis; D. Siewiorek

    1977-01-01

    In order for the nodes of a distributed computer network to communicate, each node must have information about the network's topology. Since nodes and links sometimes crash, a scheme is needed to update this information. One of the major constraints on such a topology information scheme is that it may not involve a central controller. The Topology Information Protocol that

  20. Cooperative Localization and Mapping in Sparsely-Communicating Robot Networks

    E-print Network

    Sislian, J. P.

    Cooperative Localization and Mapping in Sparsely-Communicating Robot Networks by Keith Yu Kit Leung #12;Abstract Cooperative Localization and Mapping in Sparsely-Communicating Robot Networks Keith Yu of Toronto 2012 This thesis examines the use of multiple robots in cooperative simultaneous localization

  1. LOCOMOTION (TERRESTRIAL AND AERIAL) AND COMMUNICATION OF AUTONOMOUS ROBOT NETWORKS

    E-print Network

    Kansas, University of

    1 LOCOMOTION (TERRESTRIAL AND AERIAL) AND COMMUNICATION OF AUTONOMOUS ROBOT NETWORKS Arvin Agah This report focuses on locomotion and communication aspects of mobile robot networks for harsh polar environments. The report is organized into seven sections: terrestrial locomotion, aerial locomotion, micro air

  2. Interplant Communication of Tomato Plants through Underground Common Mycorrhizal Networks

    E-print Network

    Bruns, Tom

    Interplant Communication of Tomato Plants through Underground Common Mycorrhizal Networks Yuan Yuan, plants can also communicate with each other through underground common mycorrhizal networks (CMNs movement and there is no evidence that defense signals can be exchanged through such mycorrhizal hyphal

  3. Statistically validated mobile communication networks: Evolution of motifs in European and Chinese data

    E-print Network

    Li, Ming-Xia; Jiang, Zhi-Qiang; Kaski, Kimmo; Kertsz, Janos; Miccich, Salvatore; Tumminello, Michele; Zhou, Wei-Xing; Mantegna, Rosario N

    2014-01-01

    Big data open up unprecedented opportunities to investigate complex systems including the society. In particular, communication data serve as major sources for computational social sciences but they have to be cleaned and filtered as they may contain spurious information due to recording errors as well as interactions, like commercial and marketing activities, not directly related to the social network. The network constructed from communication data can only be considered as a proxy for the network of social relationships. Here we apply a systematic method, based on multiple hypothesis testing, to statistically validate the links and then construct the corresponding Bonferroni network, generalized to the directed case. We study two large datasets of mobile phone records, one from Europe and the other from China. For both datasets we compare the raw data networks with the corresponding Bonferroni networks and point out significant differences in the structures and in the basic network measures. We show eviden...

  4. Design of base station's vehicular communication network for intelligent traffic control

    Microsoft Academic Search

    S. S. Dorle; P. Bajaj; A. G. Keskar; M. Chakole

    2009-01-01

    Vehicle to vehicle communication has recently increased attention with respect to traffic regulation\\/safety aspects. In this spontaneous information network, each vehicle can take on the role of a receiving the data from the base station allowing a chain of information to be built up that is capable of covering a substantial distance. However there is also the domain of general

  5. Nomadic Communications AA 2010/11 Vehicular Ad Hoc Networks

    E-print Network

    Lo Cigno, Renato Antonio

    Communications' AA10-11 A digression on Fatalities (EU 2005) Main Causes and driving errors: 95% of all road, Sept. 9, 2007 Renato Lo Cigno `Nomadic Communications' AA10-11 A digression on Fatalities (EU 2005) #12Nomadic Communications AA 2010/11 Vehicular Ad Hoc Networks 90% of this material is reproduced

  6. Nomadic Communications AA 2009/10 Vehicular Ad Hoc Networks

    E-print Network

    Lo Cigno, Renato Antonio

    Communications' AA07-08 A digression on Fatalities (EU 2005) Main Causes and driving errors: 95% of all road, Sept. 9, 2007 Renato Lo Cigno `Nomadic Communications' AA07-08 A digression on Fatalities (EU 2005) #12Nomadic Communications AA 2009/10 Vehicular Ad Hoc Networks 90% of this material is reproduced

  7. Nomadic Communications AA 2010/11 Vehicular Ad Hoc Networks

    E-print Network

    Lo Cigno, Renato Antonio

    Nomadic Communications AA 2010/11 Vehicular Ad Hoc Networks 90% of this material is reproduced at ACM MobiCom/MobiHoc 2007, Montreal, Canada, Sept. 9, 2007 Renato Lo Cigno `Nomadic Communications' AA, Sept. 9, 2007 Renato Lo Cigno `Nomadic Communications' AA10-11 Agenda 1. Applications and recent

  8. Nomadic Communications AA 2009/10 Vehicular Ad Hoc Networks

    E-print Network

    Lo Cigno, Renato Antonio

    Nomadic Communications AA 2009/10 Vehicular Ad Hoc Networks 90% of this material is reproduced at ACM MobiCom/MobiHoc 2007, Montreal, Canada, Sept. 9, 2007 Renato Lo Cigno `Nomadic Communications' AA, Sept. 9, 2007 Renato Lo Cigno `Nomadic Communications' AA07-08 Agenda 1. Applications and recent

  9. Information, education and communication for emergency contraception.

    PubMed

    Puri, Chander P; Hazari, Kamal; Kulkarni, Ragini

    2006-09-01

    The utilisation of the emergency contraception pills is very low both in the public and private sectors. The major reason for this under-utilisation is the lack of awareness about the method among the users or the providers. A real need arises to aware the potential users or the healthcare providers like obstetrician and gynaecologists, medical practitioners, family planning counsellors, nurses and ANMs. Wider dissemination of information, education and communication about emergency contraception relating to the proper usage, mode of action and provision is the need. The information, education and communication materials developed should always be in languages socioculturally appropriate to the target audience. Mass media like TV, newspapers and women's magazine should also be included for dissemination of messages. Service providers should be informed correctly about the method. Healthcare providers would need basic scientific information of the contents of the emergency contraception pills, mode of action, indications, contra-indications, etc. Emphasis should be put on the method for use only as an emergency or 'second chance' when a primary method is not used or has failed. PMID:17388009

  10. Visual communication - Information and fidelity. [of images

    NASA Technical Reports Server (NTRS)

    Huck, Freidrich O.; Fales, Carl L.; Alter-Gartenberg, Rachel; Rahman, Zia-Ur; Reichenbach, Stephen E.

    1993-01-01

    This assessment of visual communication deals with image gathering, coding, and restoration as a whole rather than as separate and independent tasks. The approach focuses on two mathematical criteria, information and fidelity, and on their relationships to the entropy of the encoded data and to the visual quality of the restored image. Past applications of these criteria to the assessment of image coding and restoration have been limited to the link that connects the output of the image-gathering device to the input of the image-display device. By contrast, the approach presented in this paper explicitly includes the critical limiting factors that constrain image gathering and display. This extension leads to an end-to-end assessment theory of visual communication that combines optical design with digital processing.

  11. Gas Main Sensor and Communications Network System

    SciTech Connect

    Hagen Schempf

    2006-05-31

    Automatika, Inc. was contracted by the Department of Energy (DOE) and with co-funding from the Northeast Gas Association (NGA), to develop an in-pipe natural gas prototype measurement and wireless communications system for assessing and monitoring distribution networks. This projected was completed in April 2006, and culminated in the installation of more than 2 dozen GasNet nodes in both low- and high-pressure cast-iron and steel mains owned by multiple utilities in the northeastern US. Utilities are currently logging data (off-line) and monitoring data in real time from single and multiple networked sensors over cellular networks and collecting data using wireless bluetooth PDA systems. The system was designed to be modular, using in-pipe sensor-wands capable of measuring, flow, pressure, temperature, water-content and vibration. Internal antennae allowed for the use of the pipe-internals as a waveguide for setting up a sensor network to collect data from multiple nodes simultaneously. Sensor nodes were designed to be installed with low- and no-blow techniques and tools. Using a multi-drop bus technique with a custom protocol, all electronics were designed to be buriable and allow for on-board data-collection (SD-card), wireless relaying and cellular network forwarding. Installation options afforded by the design included direct-burial and external polemounted variants. Power was provided by one or more batteries, direct AC-power (Class I Div.2) and solar-array. The utilities are currently in a data-collection phase and intend to use the collected (and processed) data to make capital improvement decisions, compare it to Stoner model predictions and evaluate the use of such a system for future expansion, technology-improvement and commercialization starting later in 2006.

  12. Distributed communications and control network for robotic mining

    NASA Technical Reports Server (NTRS)

    Schiffbauer, William H.

    1989-01-01

    The application of robotics to coal mining machines is one approach pursued to increase productivity while providing enhanced safety for the coal miner. Toward that end, a network composed of microcontrollers, computers, expert systems, real time operating systems, and a variety of program languages are being integrated that will act as the backbone for intelligent machine operation. Actual mining machines, including a few customized ones, have been given telerobotic semiautonomous capabilities by applying the described network. Control devices, intelligent sensors and computers onboard these machines are showing promise of achieving improved mining productivity and safety benefits. Current research using these machines involves navigation, multiple machine interaction, machine diagnostics, mineral detection, and graphical machine representation. Guidance sensors and systems employed include: sonar, laser rangers, gyroscopes, magnetometers, clinometers, and accelerometers. Information on the network of hardware/software and its implementation on mining machines are presented. Anticipated coal production operations using the network are discussed. A parallelism is also drawn between the direction of present day underground coal mining research to how the lunar soil (regolith) may be mined. A conceptual lunar mining operation that employs a distributed communication and control network is detailed.

  13. Conjoining Speeds up Information Diffusion in Overlaying Social-Physical Networks

    E-print Network

    Yagan, Osman; Zhang, Junshan; Cochran, Douglas

    2011-01-01

    We study information diffusion in an overlaying social-physical network. Specifically, we consider the following set-up: There is a physical information network where information spreads amongst people through conventional communication media (e.g., face-to-face communication, phone calls), and conjoint to this physical network, there are online social networks where information spreads via web sites such as Facebook, Twitter, FriendFeed, YouTube, etc. Capitalizing on the theory of inhomogeneous random graphs, we quantify the size and the critical threshold of information epidemics in this conjoint social-physical network by assuming that information diffuses according to the SIR epidemic model. One interesting finding is that even if there is no percolation in the individual networks, percolation (i.e., information epidemics) can take place in the conjoint social-physical network. We also show, both analytically and experimentally, that the fraction of individuals who receive an item of information (started ...

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

    PubMed Central

    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. PMID:22736978

  15. Information aggregation and communication in committees

    PubMed Central

    Austen-Smith, David; Feddersen, Timothy J.

    2008-01-01

    In this paper, we attempt to explain the underlying strategic incentives confronting individuals when they must make a collective decision over a set of alternatives and each has information that is decision-relevant for others. A significant literature has emerged in formal political theory over the past several years that focuses on such problems, paying particular attention, first, to the extent to which voting can be expected to aggregate committee members' information and, second, to the role of communication among committee members prior to voting. Inter alia, this literature reveals a surprisingly subtle interaction between the voting rules used to make decisions and the incentives for committee members to share information prior to voting. PMID:19073484

  16. The Research on Ad Hoc Network-Based Mobile Service of Geospatial Information Towards 4G

    Microsoft Academic Search

    Yun Zhang; Fuling Bian

    2011-01-01

    The mobile geographic information service involves the domain of mobile communication, mobile computing, geographic information service and other techniques. Ad Hoc networks are infrastructureless networks formed by neighboring equipments with limited life, and are now envisioned as cornerstones of future generation networking technologies (B3G and 4G). This paper researches on the integration of above technologies and proposes architecture of mobile

  17. Short communication: Use of genomic and metabolic information as well as milk performance records for prediction of subclinical ketosis risk via artificial neural networks.

    PubMed

    Ehret, A; Hochstuhl, D; Krattenmacher, N; Tetens, J; Klein, M S; Gronwald, W; Thaller, G

    2015-01-01

    Subclinical ketosis is one of the most prevalent metabolic disorders in high-producing dairy cows during early lactation. This renders its early detection and prevention important for both economical and animal-welfare reasons. Construction of reliable predictive models is challenging, because traits like ketosis are commonly affected by multiple factors. In this context, machine learning methods offer great advantages because of their universal learning ability and flexibility in integrating various sorts of data. Here, an artificial-neural-network approach was applied to investigate the utility of metabolic, genetic, and milk performance data for the prediction of milk levels of ?-hydroxybutyrate within and across consecutive weeks postpartum. Data were collected from 218 dairy cows during their first 5wk in milk. All animals were genotyped with a 50,000 SNP panel, and weekly information on the concentrations of the milk metabolites glycerophosphocholine and phosphocholine as well as milk composition data (milk yield, fat and protein percentage) was available. The concentration of ?-hydroxybutyric acid in milk was used as target variable in all prediction models. Average correlations between observed and predicted target values up to 0.643 could be obtained, if milk metabolite and routine milk recording data were combined for prediction at the same day within weeks. Predictive performance of metabolic as well as milk performance-based models was higher than that of models based on genetic information. PMID:25465566

  18. Information-Seeking Behavior in Intercultural and Intergroup Communication.

    ERIC Educational Resources Information Center

    Baldwin, John R.; Hunt, Stephen K.

    2002-01-01

    Reviews the current state of information-seeking research and theory in the field of intercultural communication. Draws distinctions between different types of intercultural communication research. Discusses how information seeking might be relevant across types and different between types of intercultural communication. Recommends directions for

  19. Information flow in interaction networks.

    PubMed

    Stojmirovi?, Aleksandar; Yu, Yi-Kuo

    2007-10-01

    Interaction networks, consisting of agents linked by their interactions, are ubiquitous across many disciplines of modern science. Many methods of analysis of interaction networks have been proposed, mainly concentrating on node degree distribution or aiming to discover clusters of agents that are very strongly connected between themselves. These methods are principally based on graph-theory or machine learning. We present a mathematically simple formalism for modelling context-specific information propagation in interaction networks based on random walks. The context is provided by selection of sources and destinations of information and by use of potential functions that direct the flow towards the destinations. We also use the concept of dissipation to model the aging of information as it diffuses from its source. Using examples from yeast protein-protein interaction networks and some of the histone acetyltransferases involved in control of transcription, we demonstrate the utility of the concepts and the mathematical constructs introduced in this paper. PMID:17985991

  20. Communication and cooperation in underwater acoustic networks

    NASA Astrophysics Data System (ADS)

    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 the grand coalition of transmitters using tools from cooperative game theory and show that the grand coalition in both the asymptotic regimes of high and low SNR. Towards studying the problem of receiver cooperation for a broadcast channel, we propose a game theoretic model for the broadcast channel and then derive a game theoretic duality between the multiple access and the broadcast channel and show that how the equilibria of the broadcast channel are related to the multiple access channel and vice versa.

  1. Workplace Learning in Informal Networks

    ERIC Educational Resources Information Center

    Milligan, Colin; Littlejohn, Allison; Margaryan, Anoush

    2014-01-01

    Learning does not stop when an individual leaves formal education, but becomes increasingly informal, and deeply embedded within other activities such as work. This article describes the challenges of informal learning in knowledge intensive industries, highlighting the important role of personal learning networks. The article argues that

  2. Power-law behavior in complex organizational communication networks during crisis

    NASA Astrophysics Data System (ADS)

    Uddin, Shahadat; Murshed, Shahriar Tanvir Hasan; Hossain, Liaquat

    2011-08-01

    Communication networks can be described as patterns of contacts which are created due to the flow of messages and information shared among participating actors. Contemporary organizations are now commonly viewed as dynamic systems of adaptation and evolution containing several parts, which interact with one another both in internal and in external environment. Although there is limited consensus among researchers on the precise definition of organizational crisis, there is evidence of shared meaning: crisis produces individual crisis, crisis can be associated with positive or negative conditions, crises can be situations having been precipitated quickly or suddenly or situations that have developed over time and are predictable etc. In this research, we study the power-law behavior of an organizational email communication network during crisis from complexity perspective. Power law simply describes that, the probability that a randomly selected node has k links (i.e. degree k) follows P(k)?k, where ? is the degree exponent. We used social network analysis tools and techniques to analyze the email communication dataset. We tested two propositions: (1) as organization goes through crisis, a few actors, who are prominent or more active, will become central, and (2) the daily communication network as well as the actors in the communication network exhibit power-law behavior. Our preliminary results support these two propositions. The outcome of this study may provide significant advancement in exploring organizational communication network behavior during crisis.

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

    NASA Astrophysics Data System (ADS)

    Gao, Gan

    2014-12-01

    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.

  4. Ethics of Clear Health Communication: applying the CLean Look approach to Communicate Biobanking Information for Cancer research

    PubMed Central

    Koskan, Alexis; Arevalo, Mariana; Gwede, Clement K.; Quinn, Gwendolyn P.; Noel-Thomas, Shalewa A.; Luque, John S.; Wells, Kristen J.; Meade, Cathy D.

    2013-01-01

    Cancer innovations, such as biobanking technologies, are continuously evolving to improve our understanding and knowledge about cancer prevention and treatment modalities. However, the public receives little communication about biobanking and is often unaware about this innovation until asked to donate biospecimens. It is the researchers ethical duty to provide clear communications about biobanking and biospecimen research. Such information allows the public to understand biobanking processes and facilitates informed decision making about biospecimen donation. The aims of this paper are 1) to examine the importance of clear communication as an ethical imperative when conveying information about cancer innovations and 2) to illustrate the use of an organizing framework, the CLEAN (Culture, Literacy, Education, Assessment, and Networking) Look approach for creating educational priming materials about the topic of biobanking. PMID:23124500

  5. Finding Quasi-Optimal Network Topologies for Information Transmission in Active Networks

    PubMed Central

    Baptista, Murilo S.; de Carvalho, Josu X.; Hussein, Mahir S.

    2008-01-01

    This work clarifies the relation between network circuit (topology) and behaviour (information transmission and synchronization) in active networks, e.g. neural networks. As an application, we show how one can find network topologies that are able to transmit a large amount of information, possess a large number of communication channels, and are robust under large variations of the network coupling configuration. This theoretical approach is general and does not depend on the particular dynamic of the elements forming the network, since the network topology can be determined by finding a Laplacian matrix (the matrix that describes the connections and the coupling strengths among the elements) whose eigenvalues satisfy some special conditions. To illustrate our ideas and theoretical approaches, we use neural networks of electrically connected chaotic Hindmarsh-Rose neurons. PMID:18941516

  6. LETTER Communicated by Dongsung Huh Hierarchical Control Using Networks Trained

    E-print Network

    Abbott, Laurence

    example of the successful solution of a nonlinear control problem by a neural network. We make through an environ- ment filled with static or moving obstacles. The final system consists of networksLETTER Communicated by Dongsung Huh Hierarchical Control Using Networks Trained with Higher

  7. TYMNET - A tutorial survey of a computer communications network

    Microsoft Academic Search

    M. Schwartz

    1976-01-01

    Describes the special features of TYMNET, a computer communications network developed in 1970 by Tymshare, Inc., of Cupertino, CA. Although originally developed for time-shared purposes, TYMNET has taken on a network function as well, much like the GE network [I]. In addition to providing connection to its own computer systems for interactive processing, remote job entry (RJE), and other user

  8. Communicated by Richard Lippmann A Spherical Basis Function Neural Network

    E-print Network

    Jenison, Rick L.

    Communicated by Richard Lippmann '" A Spherical Basis Function Neural Network for Modeling Auditory USA This paper describes a neural network for approximation problems on the sphere. The von Mises coordinates. The architecture of the von Mises Basis Function (VMBF) neural network is presented along

  9. Unreduced Dynamic Complexity: Towards the Unified Science of Intelligent Communication Networks and Software

    E-print Network

    Andrei P. Kirilyuk

    2006-03-16

    Operation of autonomic communication networks with complicated user-oriented functions should be described as unreduced many-body interaction process. The latter gives rise to complex-dynamic behaviour including fractally structured hierarchy of chaotically changing realisations. We recall the main results of the universal science of complexity (physics/9806002) based on the unreduced interaction problem solution and its application to various real systems, from nanobiosystems (physics/0412097, physics/0502133) and quantum devices (physics/0211071) to intelligent networks (physics/0412058) and emerging consciousness (physics/0409140). We concentrate then on applications to autonomic communication leading to fundamentally substantiated, exact science of intelligent communication and software. It aims at unification of the whole diversity of complex information system behaviour, similar to the conventional, "Newtonian" science order for sequential, regular models of system dynamics. Basic principles and first applications of the unified science of complex-dynamic communication networks and software are outlined to demonstrate its advantages and emerging practical perspectives.

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

    ERIC Educational Resources Information Center

    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

  11. Correlated Dynamics in Egocentric Communication Networks

    PubMed Central

    Karsai, Mrton; Kaski, Kimmo; Kertsz, Jnos

    2012-01-01

    We investigate the communication sequences of millions of people through two different channels and analyse the fine grained temporal structure of correlated event trains induced by single individuals. By focusing on correlations between the heterogeneous dynamics and the topology of egocentric networks we find that the bursty trains usually evolve for pairs of individuals rather than for the ego and his/her several neighbours, thus burstiness is a property of the links rather than of the nodes. We compare the directional balance of calls and short messages within bursty trains to the average on the actual link and show that for the trains of voice calls the imbalance is significantly enhanced, while for short messages the balance within the trains increases. These effects can be partly traced back to the technological constraints (for short messages) and partly to the human behavioural features (voice calls). We define a model that is able to reproduce the empirical results and may help us to understand better the mechanisms driving technology mediated human communication dynamics. PMID:22866176

  12. Pacific Islands Mass Communications; Selected Information Sources.

    ERIC Educational Resources Information Center

    Richstad, Jim; McMillan, Michael

    1977-01-01

    Presents a bibliography of materials on such area of mass communications in the Pacific Islands as broadcasting, radio and television, cinema, communication research, mass media in education, Honululu Media Council, newspapers and newspapermen, and printing and satellite communication. (JEG)

  13. 150 College of Communications and Information Studies 2007-2008 University of Kentucky Bulletin College of Communications and Information Studies

    E-print Network

    MacAdam, Keith

    in the allied areas of advertising, public relations, anddirectresponsecommunication.Thetele- communications College of Communications and Information Studies J. David Johnson, Ph.D., is Dean of the College

  14. Consensus in networks of mobile communicating agents

    NASA Astrophysics Data System (ADS)

    Baronchelli, Andrea; Daz-Guilera, Albert

    2012-01-01

    Populations of mobile and communicating agents describe a vast array of technological and natural systems, ranging from sensor networks to animal groups. Here, we investigate how a group-level agreement may emerge in the continuously evolving network defined by the local interactions of the moving individuals. We adopt a general scheme of motion in two dimensions and we let the individuals interact through the minimal naming game, a prototypical scheme to investigate social consensus. We distinguish different regimes of convergence determined by the emission range of the agents and by their mobility, and we identify the corresponding scaling behaviors of the consensus time. In the same way, we rationalize also the behavior of the maximum memory used during the convergence process, which determines the minimum cognitive/storage capacity needed by the individuals. Overall, we believe that the simple and general model presented in this paper can represent a helpful reference for a better understanding of the behavior of populations of mobile agents.

  15. Communicating Cancer Risk Information: The Challenges of Uncertainty.

    ERIC Educational Resources Information Center

    Bottorff, Joan L.; Ratner, Pamela A.; Johnson, Joy L.; Lovato, Chris Y.; Joab, S. Amanda

    1998-01-01

    Accurate and sensitive communication of cancer-risk information is important. Based on a literature review of 75 research reports, expert opinion papers, and clinical protocols, a synthesis of what is known about the communication of cancer-risk information is presented. Relevance of information to those not tested is discussed. (Author/EMK)

  16. Advanced Communication and Networking Technologies for Mars Exploration

    NASA Technical Reports Server (NTRS)

    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 activities.

  17. 76 FR 23812 - Reliability and Continuity of Communications Networks, Including Broadband Technologies; Effects...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-28

    ...Panel Reviewing the Impact of Hurricane Katrina on Communications Networks AGENCY...Panel Reviewing the Impact of Hurricane Katrina on Communications Networks...Panel Reviewing the Impact of Hurricane Katrina on Communications...

  18. Networked information resources: electronic opportunities for users and librarians

    Microsoft Academic Search

    Jane E. Klobas

    1996-01-01

    Many of the activities people perform with the Internet are new, and possibly could not have been conceived before the network became available. Describes innovative uses of the Internet by staff of two Australian universities. While the Internet provides opportunities for communication among its users, it poses challenges to the computing and information systems professionals who support them. It also

  19. ATM based transport architecture for multiservices wireless personal communication networks

    Microsoft Academic Search

    D. Raychaudhuri

    1994-01-01

    This paper presents an ATM based transport architecture for next-generation multiservices personal communication networks (PCN). Such multimedia capable integrated services wireless networks are motivated by an anticipated demand for wireless extensions to future broadband networks. An ATM based wireless network concept capable of supporting a mix of broadband ISDN services including constant bit-rate (CBR), variable, bit-rate (VBR) and packet data

  20. Network Information Management Subsystem

    NASA Technical Reports Server (NTRS)

    Chatburn, C. C.

    1985-01-01

    The Deep Space Network is implementing a distributed data base management system in which the data are shared among several applications and the host machines are not totally dedicated to a particular application. Since the data and resources are to be shared, the equipment must be operated carefully so that the resources are shared equitably. The current status of the project is discussed and policies, roles, and guidelines are recommended for the organizations involved in the project.

  1. Information Recovery In Behavioral Networks

    E-print Network

    Squartini, Tiziano; Garlaschelli, Diego; Judge, George

    2015-01-01

    In the context of agent based modeling and network theory, we focus on the problem of recovering micro behavior-related choice information from aggregate origin-destination data. As a basis for predicting agents' choices we emphasize the connection between adaptive intelligent behavior, causal entropy maximization and self-organized, equilibrium-seeking behavior in a dynamic system. We cast this problem in the form of a binary network and suggest information theoretic, entropy-driven methods to recover estimates of the unknown parameters connecting the behavioral data. Our objective is to recover the unknown behavioral binary parameters analytically, without explicitly sampling the configuration space. In order to do so, we enlarge the set of estimators commonly employed to make optimal use of the available information. More specifically, we consider the Cressie-Read family of entropic functionals and focus on three cases of particular interest. We then apply this information theoretic method to the analysis ...

  2. Predictive Compensation for Communication Outages in Networked Control Systems

    E-print Network

    Johansson, Karl Henrik

    Predictive Compensation for Communication Outages in Networked Control Systems Erik Henriksson if the current is lost) are special cases of the more general compensation scheme presented. The predictive Henrik Sandberg Karl Henrik Johansson Abstract-- A predictive outage compensator co

  3. Space Communications Networks Support MMS - Duration: 1:28.

    NASA Video Gallery

    All three of NASAs Space Communications Networks are excited to support the Magnetospheric Multiscale (MMS) Mission in its journey to study the microphysics of magnetic reconnection. The Near Eart...

  4. Computational Intelligence in Multimedia Networking and Communications: Trends and

    E-print Network

    Guturu, Parthasarathy

    Computational Intelligence in Multimedia Networking and Communications: Trends and Future multimedia researchers in recent times have developed computational intelligence (CI) based methods. From these applications, it appears that the various computa- tional intelligence frameworks

  5. Standard Ethernet as an Embedded Communication Network Project Report

    E-print Network

    Koopman, Philip

    polling station that can fail. There is no token that can be lost. Ethernet, in its most basic version-time communication networks are being implemented with standard 10 Mbit/s Ethernet for economy, famili

  6. Duality Quantum Information and Duality Quantum Communication

    SciTech Connect

    Li, C. Y.; Wang, W. Y.; Wang, C.; Song, S. Y.; Long, G. L. [Key Laboratory for Atomic and Molecular Nanosciences and Department of Physics, Tsinghua University, Beijing 100084 and Tsinghua National Laboratory for Information Science and Technology, Beijing 100084 (China)

    2011-03-28

    Quantum mechanical systems exhibit particle wave duality property. This duality property has been exploited for information processing. A duality quantum computer is a quantum computer on the move and passing through a multi-slits. It offers quantum wave divider and quantum wave combiner operations in addition to those allowed in an ordinary quantum computer. It has been shown that all linear bounded operators can be realized in a duality quantum computer, and a duality quantum computer with n qubits and d-slits can be realized in an ordinary quantum computer with n qubits and a qudit in the so-called duality quantum computing mode. The quantum particle-wave duality can be used in providing secure communication. In this paper, we will review duality quantum computing and duality quantum key distribution.

  7. 79 FR 3123 - Improving 9-1-1 Reliability; Reliability and Continuity of Communications Networks, Including...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2014-01-17

    ...Reliability and Continuity of Communications Networks, Including Broadband Technologies AGENCY...and resiliency of 911 communications networks nationwide by requiring that 911 service...devastating impact many telecommunications networks experienced as a result of the...

  8. Fiber-Optic Terahertz Data-Communication Networks

    NASA Technical Reports Server (NTRS)

    Chua, Peter L.; Lambert, James L.; Morookian, John M.; Bergman, Larry A.

    1994-01-01

    Network protocols implemented in optical domain. Fiber-optic data-communication networks utilize fully available bandwidth of single-mode optical fibers. Two key features of method: use of subpicosecond laser pulses as carrier signals and spectral phase modulation of pulses for optical implementation of code-division multiple access as multiplexing network protocol. Local-area network designed according to concept offers full crossbar functionality, security of data in transit through network, and capacity about 100 times that of typical fiber-optic local-area network in current use.

  9. Measuring the Diffusion of Information and Communication Technology in Society and its Effects: Canadian Experience

    Microsoft Academic Search

    G. PETERSON

    2007-01-01

    Statistics Canada has measured the use of information and communication technologies (ICTs) for close to 15 years in industry and more recently in households and it has developed a body on knowledge on the effects of the use off these technologies. While ICTs have long been used in manufacturing processes, the use of computers and networks, and a growing number

  10. Researching on Communication Efficiency for the Mobile Physiological Information Monitor System Based on Zigbee

    Microsoft Academic Search

    Teng Jiao; Kun Zhang; Yang Zhang; Hua Wang; Xinya Zhu; Xiuzhen Dong

    2009-01-01

    This paper designs one mobile physiological information monitor system based on the ZigBee protocol. The hardware structure is presented. The network communication characteristic of this system was analyzed. The paper points out the disadvantage of the connection method in the ZigBee protocol. One improved connection method is proposed. Through carries on the comparison and the simulation to the routing mechanism

  11. Needs for Developing Culturally Oriented Supportive Learning with the Aid of Information and Communication Technologies

    ERIC Educational Resources Information Center

    Palaiologou, Nektaria

    2009-01-01

    This article demonstrates the inadequacy of access and use of Information and Communication Technologies (ICTs) and networked learning for many people in non-Western societies and for those who belong to ethno-cultural minority groups. Especially, immigrants have great needs in the domain of learning the language of the host country as a foreign

  12. The Internet, Political Communications Research and the Search for a New Information Paradigm

    ERIC Educational Resources Information Center

    Chiu, William Franklin

    2013-01-01

    The Internet, as a digital record of human discourse, provides an opportunity to directly analyze political communicative behavior. The rapid emergence of social online networks augurs a transformation in the quality and quantity of information people have to evaluate their political system. Digital formats instantiate new categories of actors and

  13. Junior / Community College Students with Learning Disabilities and Their Use of Information and Communication Technologies (ICTs)

    ERIC Educational Resources Information Center

    Nguyen, Mai Nhu; Fichten, Catherine; King, Laura; Barile, Maria; Mimouni, Zohra; Havel, Alice; Raymond, Odette; Juhel, Jean-Charles; Jorgensen, Shirley; Chauvin, Alexandre; Gutberg, Jennifer; Budd, Jillian; Hewlett, Maureen; Heiman, Tali; Gaulin, Chris; Asuncion, Jennison

    2013-01-01

    Junior / community college students who have learning disabilities (LD), such as dyslexia, often do not maximize their use of information and communication technologies (ICTs) for school work. They do not use many of these technologies nor do they know as much about them as other students. These are the results of an Adaptech Research Network

  14. Performance study on delay tolerant networks in maritime communication environments

    Microsoft Academic Search

    Hao-Min Lin; Yu Ge; Ai-Chun Pang; Jaya Shankar Pathmasuntharam

    2010-01-01

    Today, it is still hard to form an alternative network in a maritime environment besides using costly satellite links because of the lack of wireless infrastructure at sea. In the TRITON project, we are exploring the use of WiMAX-based mesh technology for over the horizon ship-to-ship communications with Delay Tolerant Network (DTN) features to provide less expensive wireless communication services

  15. Information Security and Privacy in Network Environments.

    ERIC Educational Resources Information Center

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

    The use of information networks for business and government is expanding enormously. Government use of networks features prominently in plans to make government more efficient, effective, and responsive. But the transformation brought about by the networking also raises new concerns for the security and privacy of networked information. This

  16. The Role and Future Challenges of Wireless Communication Networks for

    E-print Network

    Boyer, Edmond

    The Role and Future Challenges of Wireless Communication Networks for Cooperative Autonomous City their safety and efficiency. Vehicle-to-Vehicle (V2V) communication allows nearby vehicles to exchange relevant is mainly only used for monitoring the autonomous vehicles and for safety reasons (emergency stopping

  17. Mitigating the Hospital Area Communication's Interference using Cognitive Radio Networks

    E-print Network

    Paris-Sud XI, Université de

    Mitigating the Hospital Area Communication's Interference using Cognitive Radio Networks Dramane.khalife@thalesgroup.com. Abstract--The communication infrastructures and devices in hospitals are becoming increasingly wireless because of doctors and nurses are mobile in their work. On the other hand, the hospital patient

  18. Study of teleoperation using realtime communication network emulation

    Microsoft Academic Search

    Sandra Hirche; Martin Buss

    2003-01-01

    The stability and performance of telepresence systems with kinesthetic (force) feedback operated via a communication network mainly depends on the quality (delay, bandwidth) of communication. The combined position\\/force control of teleoperation system with time delay using impedance matching filters to achieve robust passivity for the teleoperator\\/environment and transparency is discussed. The impedance matching filter design is the result of optimization

  19. Project Universe - Local area networks and satellite communications

    Microsoft Academic Search

    B. R. Ackroyd

    1983-01-01

    A high-speed digital communications system is discussed in which a satellite is used to link a number of local area networks which interconnect a variety of computer facilities. The advantages of satellite communications compared with terrestrial links are described, together with a historical survey of the use of the Orbital Test Satellite (OTS) for data experiments. A description of Project

  20. Accent: A Communication Oriented Network Operating System Kernel

    Microsoft Academic Search

    Richard F. Rashid; George G. Robertson

    1981-01-01

    Accent is a communication oriented operating system kernel being built at Carnegie-Mellon University to support the distributed personal computing project, Spice, and the development of a fault-tolerant distributed sensor network (DSN). Accent is. built around a single, powerful abstraction of communication between processes, with all kernel functions, such as device access and virtual memory management accessible through messages and distributable

  1. Exploring the Potential of Social Network Sites in Relation to Intercultural Communication

    ERIC Educational Resources Information Center

    Lang, Anouk

    2012-01-01

    This article reports on the results of a project which used a social network site to support students on a year abroad and foster informal learning, particularly in the area of intercultural communication. The project employed a peer-mentoring structure to solve the problem of role conflict, in which users of these sites may feel some tension as

  2. IEEE Communications Surveys & Tutorials 4th Quarter 20072 his survey focuses on measurements of the network

    E-print Network

    Bonaventure, Olivier

    IEEE Communications Surveys & Tutorials · 4th Quarter 20072 his survey focuses on measurements in the network. While some of this information can be gleaned from passive measurements, researchers largely obtain the topology and its characteristics from active measurements. There are three different levels

  3. Family Health History Communication Networks of Older Adults: Importance of Social Relationships and Disease Perceptions

    ERIC Educational Resources Information Center

    Ashida, Sato; Kaphingst, Kimberly A.; Goodman, Melody; Schafer, Ellen J.

    2013-01-01

    Older individuals play a critical role in disseminating family health history (FHH) information that can facilitate disease prevention among younger family members. This study evaluated the characteristics of older adults and their familial networks associated with two types of communication ("have shared" and "intend to share

  4. Information and communication technologies for promoting and sustaining quality of life, health and self-sufficiency in ageing societies--outcomes of the Lower Saxony Research Network Design of Environments for Ageing (GAL).

    PubMed

    Haux, Reinhold; Hein, Andreas; Kolb, Gerald; Knemund, Harald; Eichelberg, Marco; Appell, Jens-E; Appelrath, H-Jrgen; Bartsch, Christian; Bauer, Jrgen M; Becker, Marcus; Bente, Petra; Bitzer, Jrg; Boll, Susanne; Bsching, Felix; Dasenbrock, Lena; Deparade, Riana; Depner, Dominic; Elbers, Katharina; Fachinger, Uwe; Felber, Juliane; Feldwieser, Florian; Forberg, Anne; Gietzelt, Matthias; Goetze, Stefan; Gvercin, Mehmet; Helmer, Axel; Herzke, Tobias; Hesselmann, Tobias; Heuten, Wilko; Huber, Rainer; Hlsken-Giesler, Manfred; Jacobs, Gerold; Kalbe, Elke; Kerling, Arno; Klingeberg, Timo; Kltzsch, Yvonne; Lammel-Polchau, Christopher; Ludwig, Wolfram; Marschollek, Michael; Martens, Birger; Meis, Markus; Meyer, Eike Michael; Meyer, Jochen; Meyer Zu Schwabedissen, Hubertus; Moritz, Niko; Mller, Heiko; Nebel, Wolfgang; Neyer, Franz J; Okken, Petra-Karin; Rahe, Julia; Remmers, Hartmut; Rlker-Denker, Lars; Schilling, Meinhard; Schpke, Birte; Schrder, Jens; Schulze, Gisela C; Schulze, Mareike; Siltmann, Sina; Song, Bianying; Spehr, Jens; Steen, Enno-Edzard; Steinhagen-Thiessen, Elisabeth; Tanschus, Nele-Marie; Tegtbur, Uwe; Thiel, Andreas; Thoben, Wilfried; van Hengel, Peter; Wabnik, Stefan; Wegel, Sandra; Wilken, Olaf; Winkelbach, Simon; Wist, Thorben; Wolf, Klaus-Hendrik; Wolf, Lars; Zokoll-van der Laan, Melanie

    2014-01-01

    Many societies across the world are confronted with demographic changes, usually related to increased life expectancy and, often, relatively low birth rates. Information and communication technologies (ICT) may contribute to adequately support senior citizens in aging societies with respect to quality of life and quality and efficiency of health care processes. For investigating and for providing answers on whether new information and communication technologies can contribute to keeping, or even improving quality of life, health and self-sufficiency in ageing societies through new ways of living and new forms of care, the Lower Saxony Research Network Design of Environments for Ageing (GAL) had been established as a five years research project, running from 2008 to 2013. Ambient-assisted living (AAL) technologies in personal and home environments were especially important. In this article we report on the GAL project, and present some of its major outcomes after five years of research. We report on major challenges and lessons learned in running and organizing such a large, inter- and multidisciplinary project and discuss GAL in the context of related research projects. With respect to research outcomes, we have, for example, learned new knowledge about multimodal and speech-based human-machine-interaction mechanisms for persons with functional restrictions, and identified new methods and developed new algorithms for identifying activities of daily life and detecting acute events, particularly falls. A total of 79 apartments of senior citizens had been equipped with specific "GAL technology", providing new insights into the use of sensor data for smart homes. Major challenges we had to face were to deal constructively with GAL's highly inter- and multidisciplinary aspects, with respect to research into GAL's application scenarios, shifting from theory and lab experimentation to field tests, and the complexity of organizing and, in our view, successfully managing such a large project. Overall it can be stated that, from our point of view, the GAL research network has been run successfully and has achieved its major research objectives. Since we now know much more on how and where to use AAL technologies for new environments of living and new forms of care, a future focus for research can now be outlined for systematically planned studies, scientifically exploring the benefits of AAL technologies for senior citizens, in particular with respect to quality of life and the quality and efficiency of health care. PMID:25148556

  5. Design of Hybrid Mobile Communication Networks for Planetary Exploration

    NASA Technical Reports Server (NTRS)

    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.

  6. Software design of optical link for indoor wireless optical communication network used LEDs as source visible light communication

    NASA Astrophysics Data System (ADS)

    Liner, Andrej; Papes, Martin; Jaros, Jakub; Koudelka, Petr; Latal, Jan; Vitasek, Jan; Hajek, Lukas; Vasinek, Vladimir

    2015-01-01

    Nowadays, the conventional light sources are replaced progressively evolving LED (Light Emitting Diode) for their deficient properties. This technology recorded dynamic growth mainly due to effective research in increasing power density and choice the color shade on good color rendering CRI (Color Rendering Index). This extending the zone of used LEDs. Development of lighting technology by means of white power LEDs provided impulse to the idea of the development of optical wireless data networks based on optical radiation in the visible region of the spectrum VLC (Visible Light Communications). In the last years being recorded a turnover of research from transmission of information via optical fiber to the transmission of information through wireless networks. At the same time the concept of information transmission by indirect sight between transmitter and receiver NLOS (Non Line of Sight) is changing. Line of research focuses mainly on the direct line of sight LOS (Line of Sight). This is due to the development of the semiconductor lighting through the white power LED. This is connected with the idea of using them as a transmitter for communication purposes. This article deals with software design of optical link for indoor wireless optical network in LightTools software. Optimal optical source was designed for communication using LED as the first. For the proposed type of LEDs sources were used different shapes and distances distribution between LEDs in a single cell at the designed optical transmitter.

  7. Energy-Aware Secure Multicast Communication In Wireless Ad-Hoc Networks Loukas Lazos, and Radha Poovendran

    E-print Network

    Lazos, Loukas

    in hospitals, as well as mili- tary applications such as deployment of surveillance networks and real time information distribution to moving army units. Most of these applications rely on the capability of peer-to- peer collaboration in computation and/or communication. The extension of group communication

  8. Highly survivable communications: Complementary media packet switched networks

    NASA Astrophysics Data System (ADS)

    Yavuz, D.; Eken, F.; Karavassilis, N.

    1994-07-01

    The requirement for highly survivable communications (HSC) for essential command functions in military operations does not need any justification. The ability to communicate under extreme jamming levels and adverse propagation conditions, including high altitude nuclear events, is a very important requirement. There are also many natural disaster related requirements that also need such highly survivable communications. The prevalent and in a sense classical, approach to provide highly assured connectivity can be summarized as follows: Take a particular propagation medium and try to obtain the ultimate performance from it. There are many examples of this philosophy some successful, most not. Our approach, on the other hand, is to use complementary multi-media or mixed-media where communication links utilizing essentially commercial-off-the-shelf (COTS) equipment are integrated using packet radio (PR) techniques. There is also, in our view, an even more fundamental, recently discovered consideration why the expectation of continuous incremental refinement of a system using a given single media may be be achievable. This is derived from the theory of 'deterministic uncertainty' or more popularly known as 'theory of CHAOS', systems whose state space behavior has fractal characteristics. We will elaborate on this novel argument. Complementary multi-media approach has been the focus for all HSC communications activities at STC since 1982. The original STC studies and prototypes were in response to requirements of broadcasting (i.e., one-way transmission) information. A high frequency (HF)/meteorburst (MB) system was developed/prototyped/tested demonstrating the cost effectiveness of the approach. These results are reviewed. More recently, in 1992 STC has completed the development/test of an Open Systems Interconnection (OSI) HF packet radio protocol as no such open or non-proprietary protocol exists. This protocol has been fully tested, documented and made available to all NATO nations/industries. These extensive results show that significant improvements in throughput of up to many times are obtained. A similar development for an OSI MB protocol has also been completed and combined with the HF protocol to obtain an OSI HF/MB link layer protocol with unique properties for HSC networks. Description of these protocols and the relevant results are presented. networks using standard COTS transceivers/modems with OSI PRO protocols can provide highly survivable connectivity, by providing the most important ingredient of survivability, media diversity.

  9. Synchronization and a secure communication scheme using optical star network

    NASA Astrophysics Data System (ADS)

    Jeeva Sathya Theesar, S.; Ariffin, M. R. K.; Banerjee, Santo

    2013-12-01

    This work aims to show the effect of synchronization phenomena in multi-nodal star optical network topology as well as to develop an efficient symmetric cryptosystem utilizing available parameters. The optical network is based on chaotic semiconductor laser (SL) systems described by dimensionless modified Lang-Kobayashi's (L-K) delay differential equations. The network nodes are mutually connected with a central semiconductor laser hub with bidirectional linear optical feedback. It has been observed that the laser output can be modulated using a star network setup. The laser intensity increases with the number of nodes and its much more higher than the same for solitary laser, keeping all other inputs as constant. So the network topology is an effective way to optimize the output power. The process by each nodes into the network is illustrated graphically for three, five and seven SLs, respectively. Also the whole network can be implemented as an optical communication system for transmission of signals. Each SL can act as a transceiver during communication. The communication process is examined using a chaotic signal as a plaintext connected with the SL hub and successfully provided a symmetrically secure mechanism upon the communication protocol. The result shows the optimization of output power with the increment of the number of nodes. Also the communication scheme can successfully decode the encrypted signal from SL Hub, at each other nodes.

  10. Fast massive preventive security and information communication systems

    Microsoft Academic Search

    David Akopian; Philip Chen; Susheel Miryakar; Abhinav Kumar

    2008-01-01

    We present a fast massive information communication system for data collection from distributive sources such as cell phone users. As a very important application one can mention preventive notification systems when timely notification and evidence communication may help to improve safety and security through wide public involvement by ensuring easy-to-access and easy-to-communicate information systems. The technology significantly simplifies the response

  11. Information and Communication Technologies in Social Work

    PubMed Central

    Perron, Brian E.; Taylor, Harry O.; Glass, Joseph E.; Margerum-Leys, Jon

    2011-01-01

    Information and communication technologies (ICTs) are electronic tools used to convey, manipulate and store information. The exponential growth of Internet access and ICTs greatly influenced social, political, and economic processes in the United States, and worldwide. Regardless of the level of practice, ICTs will continue influencing the careers of social workers and the clients they serve. ICTs have received some attention in the social work literature and curriculum, but we argue that this level of attention is not adequate given their ubiquity, growth and influence, specifically as it relates to upholding social work ethics. Significant attention is needed to help ensure social workers are responsive to the technological changes in the health care system, including the health care infrastructure and use of technology among clients. Social workers also need ICT competencies in order to effectively lead different types of social change initiatives or collaborate with professionals of other disciplines who are using ICTs as part of existing strategies. This paper also identifies potential pitfalls and challenges with respect to the adoption of ICTs, with recommendations for advancing their use in practice, education, and research. PMID:21691444

  12. College of Communication & Information 1345 Circle Park Drive | Suite 302

    E-print Network

    Grissino-Mayer, Henri D.

    -0332 865.974.3031 E-mail: ccidevelopment@utk.edu What is special about UT's CCI? · Center for Information Media · Executive Education advanced learning options WWW.CCI.UTK.EDU Dean Mike Wirth College OF COMMUNICATION & INFORMATION The four schools of CCI · Advertising and Public Relations · Communication Studies

  13. Fading Channels: Information-Theoretic and Communication Aspects

    Microsoft Academic Search

    Ezio Biglieri; John G. Proakis; Shlomo Shamai

    1998-01-01

    In this paper we review the most peculiar and interesting information-theoretic and communications features of fading channels. We first describe the statistical models of fading channels which are frequently used in the analysis and design of communication systems. Next, we focus on the information theory of fading channels, by emphasizing capacity as the most important performance measure. Both single-user and

  14. Fading channels: information-theoretic and communications aspects

    Microsoft Academic Search

    Ezio Biglieri; John Proakis; Shlomo Shamai

    1998-01-01

    In this paper we review the most peculiar and interesting information-theoretic and communications features of fading channels. We first describe the statistical models of fading channels which are frequently used in the analysis and design of communication systems. Next, we focus on the information theory of fading channels, by emphasizing capacity as the most important performance measure. Both single-user and

  15. Information and Communications Technologies Center (ICT) YouTube Channel

    NSDL National Science Digital Library

    This page presents the YouTube channel of the National Center for Information and Communications Technologies (ICT Center). There is a growing collection of videos - focusing on information and communication technologies - on topics such as Second Life, the oscilloscope, digital media production, games and gaming, as well as a number of interviews with others in the telecommunications technology field.

  16. Towards Communication and Information Access for Deaf People

    E-print Network

    Blake, Edwin

    Towards Communication and Information Access for Deaf People Edwin Blake1 , William Tucker2 & Meryl Science, University of the Western Cape, South Africa 3 Deaf Community of Cape Town, South Africa device can assist Deaf people with their communication and information needs. The Deaf users considered

  17. Novel Quantum Virtual Private Network Scheme for PON via Quantum Secure Direct Communication

    NASA Astrophysics Data System (ADS)

    Gong, Li-Hua; Liu, Ye; Zhou, Nan-Run

    2013-09-01

    Two quantum secure direct communication (QSDC) protocols with quantum identification (QI) based on passive optical network (PON) architecture are proposed. One QSDC protocol can be implemented between two different optical network units just with simple configurations of PON by optical line terminal when they are in the same virtual private network after optical line terminal performing QI to the optical network units in the given PON architecture. The other QSDC protocol is also implemented between any two legitimated users in the virtual private network but with considerable reduction of workload of the optical line terminal. The security analysis shows that the proposed QSDC schemes with quantum identification are unconditionally secure and allow the legitimate users to exchange their secret information efficiently and to realize a quantum virtual private network in the PON networks ultimately.

  18. Adaptive protocols for information dissemination in wireless sensor networks

    Microsoft Academic Search

    Wendi Rabiner Heinzelman; Joanna Kulik; Hari Balakrishnan

    1999-01-01

    In this paper, we present a family of adaptive protocols, called SPIN (Sensor Protocols for Information via Negotia- tion), that efficiently disseminates information among sen- sors in an energy-constrained wireless sensor network. Nodes running a SPIN communication protocol name their data us- ing high-level data descriptors, called meta-data. They use meta-data negotiations to eliminate the transmission of re- dundant data

  19. Temporal motifs reveal homophily, gender-specific patterns and group talk in mobile communication networks

    E-print Network

    Kovanen, Lauri; Kertsz, Jnos; Saramki, Jari

    2013-01-01

    Electronic communication records provide detailed information about temporal aspects of human interaction. Previous studies have shown that individuals' communication patterns have complex temporal structure, and that this structure has system-wide effects. In this paper we use mobile phone records to show that interaction patterns involving multiple individuals have non-trivial temporal structure that cannot be deduced from a network presentation where only interaction frequencies are taken into account. We apply a recently introduced method, temporal motifs, to identify interaction patterns in a temporal network where nodes have additional attributes such as gender and age. We then develop a null model that allows identifying differences between various types of nodes so that these differences are independent of the network based on interaction frequencies. We find gender-related differences in communication patters, and show the existence of temporal homophily, the tendency of similar individuals to partic...

  20. Communications network design and costing model programmers manual

    NASA Technical Reports Server (NTRS)

    Logan, K. P.; Somes, S. S.; Clark, C. A.

    1983-01-01

    Otpimization algorithms and techniques used in the communications network design and costing model for least cost route and least cost network problems are examined from the programmer's point of view. All system program modules, the data structures within the model, and the files which make up the data base are described.

  1. Secure Group Communications over Combined Wired\\/Wireless Networks

    Microsoft Academic Search

    Junghyun Nam; Seungjoo Kim; Hyungkyu Yang; Dongho Won

    2004-01-01

    This paper considers the fundamental problem of key agreement among a group of parties communicating over an insecure public network. Over the years, a number of solutions to this problem have been proposed with varying degrees of com- plexity. However, there seems to have been no previous systematic look at the growing problem of key agreement over combined wired\\/wireless networks,

  2. Enabling Disconnected Transitive Communication in Mobile Ad Hoc Networks

    Microsoft Academic Search

    Xiangchuan Chen; Amy L. Murphy

    2001-01-01

    Recently, mobile ad hoc computing has attracted much at- tentionintheresearchcommunity. Difierentfrommostcur- rentwirelessnetworks,mobilead-hocnetworkshavenoflxed infrastructure, all hosts are capable of movement, and the network is continuously reconstructed into multiple discon- nected clusters. In such environments, connection is unsta- ble, and communication is unpredictable. Current research mainly focuses on providing the same models of communi- cation in this environment as in flxed networks,

  3. An Investigation of the Composition of Interpersonal Communication Networks.

    ERIC Educational Resources Information Center

    Blake, Reed H.

    Drawing on research by the author, this paper analyzes the composition of the interpersonal communication networks (auxiliary channels) which are pervasive in human society. These networks tend to be 1) primary in nature, containing four members from primary relationships and one from a secondary relationship, and 2) reflective of neighborhood and

  4. Routing protocol for anycast communications in a wireless sensor network

    E-print Network

    Paris-Sud XI, Universit de

    Routing protocol for anycast communications in a wireless sensor network Nancy El Rachkidy. 1 Introduction In the past few years, wireless sensor networks have been used in several moni University Complexe scientifique des Cezeaux, 63177 Aubi`ere cedex, France Abstract. In wireless sensor

  5. Robot Swarm Communication Networks: Architectures, Protocols, and Applications

    E-print Network

    Chen, Min

    Robot Swarm Communication Networks: Architectures, Protocols, and Applications Ming Li Department in deploying a team of robots, or robot swarms, to fulfill certain complicated tasks such as surveillance. Since robot swarms may move to areas of far distance, it is important to have a pervasive networking

  6. Preliminary Evaluation, Texas State Library Communication Network, 1968.

    ERIC Educational Resources Information Center

    Texas State Library, Austin. Field Services Div.

    In 1968 the Texas State Library established a library communications network under Title III of the Librar y Services and Construction Act. The objective of this study was to evaluate the network after six months of operation. Part I of the study consists of a general evaluation by Peat, Marwick, Mitchell and Co., based on operational data

  7. MEASUREMENT-BASED USAGE CHARGES IN COMMUNICATIONS NETWORKS

    E-print Network

    Weber, Richard

    -approximated by charges based on simple measurements. Charging and pricing are essential requirements in the operation will generate certain demands, uctuating on various time scales, e.g., daily. Network operators will makeMEASUREMENT-BASED USAGE CHARGES IN COMMUNICATIONS NETWORKS COSTAS COURCOUBETIS ICS

  8. Sounds for Communication How should sounds be constructed in order to communicate information effectively? Sounds convey

    E-print Network

    Miranda, Eduardo Reck

    effectively? Sounds convey information between distal objects; they have the advantage of not requiringSounds for Communication How should sounds be constructed in order to communicate information mates. However, listeners receive a signal that combines all of the sounds present in the environment

  9. Deep Space Network information system architecture study

    NASA Technical Reports Server (NTRS)

    Beswick, C. A.; Markley, R. W. (editor); Atkinson, D. J.; Cooper, L. P.; Tausworthe, R. C.; Masline, R. C.; Jenkins, J. S.; Crowe, R. A.; Thomas, J. L.; Stoloff, M. J.

    1992-01-01

    The purpose of this article is to describe an architecture for the Deep Space Network (DSN) information system in the years 2000-2010 and to provide guidelines for its evolution during the 1990s. The study scope is defined to be from the front-end areas at the antennas to the end users (spacecraft teams, principal investigators, archival storage systems, and non-NASA partners). The architectural vision provides guidance for major DSN implementation efforts during the next decade. A strong motivation for the study is an expected dramatic improvement in information-systems technologies, such as the following: computer processing, automation technology (including knowledge-based systems), networking and data transport, software and hardware engineering, and human-interface technology. The proposed Ground Information System has the following major features: unified architecture from the front-end area to the end user; open-systems standards to achieve interoperability; DSN production of level 0 data; delivery of level 0 data from the Deep Space Communications Complex, if desired; dedicated telemetry processors for each receiver; security against unauthorized access and errors; and highly automated monitor and control.

  10. Novel technology for enhanced security and trust in communication networks

    NASA Astrophysics Data System (ADS)

    Milovanov, Alexander; Bukshpun, Leonid; Pradhan, Ranjit; Jannson, Tomasz

    2011-06-01

    A novel technology that significantly enhances security and trust in wireless and wired communication networks has been developed. It is based on integration of a novel encryption mechanism and novel data packet structure with enhanced security tools. This novel data packet structure results in an unprecedented level of security and trust, while at the same time reducing power consumption and computing/communication overhead in networks. As a result, networks are provided with protection against intrusion, exploitation, and cyber attacks and posses self-building, self-awareness, self-configuring, self-healing, and self-protecting intelligence.

  11. 78 FR 66929 - Information Collection Being Reviewed by the Federal Communications Commission Under Delegated...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-07

    ...FEDERAL COMMUNICATIONS COMMISSION Information Collection Being Reviewed by the Federal Communications Commission Under Delegated Authority AGENCY: Federal Communications Commission. ACTION: Notice and...

  12. 78 FR 55254 - Information Collection Being Reviewed by the Federal Communications Commission Under Delegated...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-10

    ...FEDERAL COMMUNICATIONS COMMISSION Information Collection Being Reviewed by the Federal Communications Commission Under Delegated Authority AGENCY: Federal Communications Commission. ACTION: Notice and...

  13. 78 FR 34097 - Information Collections Being Reviewed by the Federal Communications Commission Under Delegated...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-06

    ...FEDERAL COMMUNICATIONS COMMISSION Information Collections Being Reviewed by the Federal Communications Commission Under Delegated Authority AGENCY: Federal Communications Commission. ACTION: Notice and...

  14. 77 FR 66838 - Information Collection Being Reviewed by the Federal Communications Commission for Extension...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-07

    ...FEDERAL COMMUNICATIONS COMMISSION Information Collection Being Reviewed by the Federal Communications Commission for Extension Under Delegated Authority AGENCY: Federal Communications Commission. ACTION: Notice;...

  15. 76 FR 49476 - Information Collection Being Reviewed by the Federal Communications Commission Under Delegated...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-10

    ...FEDERAL COMMUNICATIONS COMMISSION Information Collection Being Reviewed by the Federal Communications Commission Under Delegated Authority AGENCY: Federal Communications Commission. ACTION: Notice and...

  16. 78 FR 36185 - Information Collection(s) Being Reviewed by the Federal Communications Commission, Comments...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-17

    ...FEDERAL COMMUNICATIONS COMMISSION Information Collection(s) Being Reviewed by the Federal Communications Commission, Comments Requested AGENCY: Federal Communications Commission. ACTION: Notice;...

  17. 76 FR 67451 - Information Collections Being Reviewed by the Federal Communications Commission Under Delegated...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-01

    ...FEDERAL COMMUNICATIONS COMMISSION Information Collections Being Reviewed by the Federal Communications Commission Under Delegated Authority AGENCY: Federal Communications Commission. ACTION: Notice and...

  18. 76 FR 61699 - Information Collections Being Reviewed by the Federal Communications Commission Under Delegated...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-05

    ...FEDERAL COMMUNICATIONS COMMISSION Information Collections Being Reviewed by the Federal Communications Commission Under Delegated Authority AGENCY: Federal Communications Commission. ACTION: Notice and...

  19. 78 FR 6102 - Information Collection(s) Being Reviewed by the Federal Communications Commission, Comments...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-29

    ...FEDERAL COMMUNICATIONS COMMISSION Information Collection(s) Being Reviewed by the Federal Communications Commission, Comments Requested AGENCY: Federal Communications Commission. ACTION: Notice;...

  20. 78 FR 18338 - Information Collections Being Reviewed by the Federal Communications Commission, Comments Requested

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-26

    ...FEDERAL COMMUNICATIONS COMMISSION Information Collections Being Reviewed by the Federal Communications Commission, Comments Requested AGENCY: Federal Communications Commission. ACTION: Notice; request...

  1. 78 FR 28215 - Information Collection Being Reviewed by the Federal Communications Commission Under Delegated...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-14

    ...FEDERAL COMMUNICATIONS COMMISSION Information Collection Being Reviewed by the Federal Communications Commission Under Delegated Authority AGENCY: Federal Communications Commission. ACTION: Notice;...

  2. 77 FR 55838 - Information Collections Being Reviewed by the Federal Communications Commission Under Delegated...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-11

    ...FEDERAL COMMUNICATIONS COMMISSION Information Collections Being Reviewed by the Federal Communications Commission Under Delegated Authority AGENCY: Federal Communications Commission. ACTION: Notice and...

  3. 78 FR 37809 - Information Collections Being Reviewed by the Federal Communications Commission Under Delegated...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-24

    ...FEDERAL COMMUNICATIONS COMMISSION Information Collections Being Reviewed by the Federal Communications Commission Under Delegated Authority AGENCY: Federal Communications Commission. ACTION: Notice and...

  4. 78 FR 8528 - Information Collections Being Reviewed by the Federal Communications Commission Under Delegated...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-06

    ...FEDERAL COMMUNICATIONS COMMISSION Information Collections Being Reviewed by the Federal Communications Commission Under Delegated Authority AGENCY: Federal Communications Commission. ACTION: Notice and...

  5. Routing Techniques Used in Computer Communication Networks

    Microsoft Academic Search

    MISCHA SCHWARTZ; THOMSS E. STERN

    1980-01-01

    An overview is provided in this paper of the routing procedures used in a number of operating networks, as well as in two commercial network architectures. The networks include TYMNET, ARPANET, and TRANSPAC. The network architectures discussed are the IBM SNA and the DEC DNA. The routing algorithms all tend to fall in the shortest path class. In the introductory

  6. Performance-aware Security of Unicast Communication in Hybrid Satellite Networks

    E-print Network

    Baras, John S.

    Performance-aware Security of Unicast Communication in Hybrid Satellite Networks Ayan Roy for securing the end-to-end communication in hybrid satellite networks. Satellite networks use TCP and HTTP communication in hybrid satellite networks. We therefore propose the use of the Layered IPSEC (LES) protocol

  7. Enhanced Communication Network Solution for Positive Train Control Implementation

    NASA Technical Reports Server (NTRS)

    Fatehi, M. T.; Simon, J.; Chang, W.; Chow, E. T.; Burleigh, S. C.

    2011-01-01

    The commuter and freight railroad industry is required to implement Positive Train Control (PTC) by 2015 (2012 for Metrolink), a challenging network communications problem. This paper will discuss present technologies developed by the National Aeronautics and Space Administration (NASA) to overcome comparable communication challenges encountered in deep space mission operations. PTC will be based on a new cellular wireless packet Internet Protocol (IP) network. However, ensuring reliability in such a network is difficult due to the "dead zones" and transient disruptions we commonly experience when we lose calls in commercial cellular networks. These disruptions make it difficult to meet PTC s stringent reliability (99.999%) and safety requirements, deployment deadlines, and budget. This paper proposes innovative solutions based on space-proven technologies that would help meet these challenges: (1) Delay Tolerant Networking (DTN) technology, designed for use in resource-constrained, embedded systems and currently in use on the International Space Station, enables reliable communication over networks in which timely data acknowledgments might not be possible due to transient link outages. (2) Policy-Based Management (PBM) provides dynamic management capabilities, allowing vital data to be exchanged selectively (with priority) by utilizing alternative communication resources. The resulting network may help railroads implement PTC faster, cheaper, and more reliably.

  8. "I'll See You on IM, Text, or Call You": A Social Network Approach of Adolescents' Use of Communication Media

    ERIC Educational Resources Information Center

    Van Cleemput, Katrien

    2010-01-01

    This study explores some possibilities of social network analysis for studying adolescents' communication patterns. A full network analysis was conducted on third-grade high school students (15 year olds, 137 students) in Belgium. The results pointed out that face-to-face communication was still the most prominent way for information to flow

  9. Space-based Networking Technology Developments in the Interplanetary Network Directorate Information Technology Program

    NASA Technical Reports Server (NTRS)

    Clare, Loren; Clement, B.; Gao, J.; Hutcherson, J.; Jennings, E.

    2006-01-01

    Described recent development of communications protocols, services, and associated tools targeted to reduce risk, reduce cost and increase efficiency of IND infrastructure and supported mission operations. Space-based networking technologies developed were: a) Provide differentiated quality of service (QoS) that will give precedence to traffic that users have selected as having the greatest importance and/or time-criticality; b) Improve the total value of information to users through the use of QoS prioritization techniques; c) Increase operational flexibility and improve command-response turnaround; d) Enable new class of networked and collaborative science missions; e) Simplify applications interfaces to communications services; and f) Reduce risk and cost from a common object model and automated scheduling and communications protocols. Technologies are described in three general areas: communications scheduling, middleware, and protocols. Additionally developed simulation environment, which provides comprehensive, quantitative understanding of the technologies performance within overall, evolving architecture, as well as ability to refine & optimize specific components.

  10. The deep space network, volume 18. [Deep Space Instrumentation Facility, Ground Communication Facility, and Network Control System

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The objectives, functions, and organization of the Deep Space Network are summarized. The Deep Space Instrumentation Facility, the Ground Communications Facility, and the Network Control System are described.

  11. Control of communication networks: welfare maximization and multipath transfers.

    PubMed

    Key, Peter B; Massouli, Laurent

    2008-06-13

    We discuss control strategies for communication networks such as the Internet. We advocate the goal of welfare maximization as a paradigm for network resource allocation. We explore the application of this paradigm to the case of parallel network paths. We show that welfare maximization requires active balancing across paths by data sources, and potentially requires implementation of novel transport protocols. However, the only requirement from the underlying 'network layer' is to expose the marginal congestion cost of network paths to the 'transport layer'. We further illustrate the versatility of the corresponding layered architecture by describing transport protocols with the following properties: they welfare maximization, each communication may use an arbitrary collection of paths, where paths may be from an overlay, and paths may be combined in series and parallel. We conclude by commenting on incentives, pricing and open problems. PMID:18325871

  12. On effectiveness of routing algorithms for satellite communication networks

    NASA Astrophysics Data System (ADS)

    Yu, Wei; Wei, Sixiao; Xu, Guobin; Chen, Genshe; Pham, Khanh; Blasch, Erik P.; Lu, Chao

    2013-05-01

    For worldwide, a satellite communication network is an integral component of the global networking infrastructure. In this paper, we focus on developing effective routing techniques that consider both user preferences and network dynamic conditions. In particular, we develop a weighted-based route selection scheme for the core satellite communication network. Unlike the shortest path routing scheme, our scheme chooses the route from multiple matched entries based on the assigned weights that reflect the dynamic condition of networks. We also discuss how to derive the optimal weights for route assignment. To further meet user's preference, we implement the multiple path routing scheme to achieve the high rate of data transmission and the preemption based routing scheme to guarantee the data transmission for high priority users. Through extensive simulation studies, our data validates the effectiveness of our proposed routing schemes.

  13. Leveraging Information Technology. Track V: Communications.

    ERIC Educational Resources Information Center

    CAUSE, Boulder, CO.

    Seven papers from the 1987 CAUSE conference's Track V, Communications, are presented. They include: "University of Miami LAN: A Case Study" (Ruben Lopez and M. Lewis Temares); "Designing and Implementing an Integrated Communications Environment in a Small College" (Charles S. Garratt IV, Jack M. Lewis, and John L. Van Hemert); "Commonwealth of

  14. AeroTCP: A Splitting Transport Protocol for an IP-based Satellite Network Supporting Aeronautical Communications

    E-print Network

    Baras, John S.

    Communications Yadong Shang* , Michael Hadjitheodosiou and John Baras Center for Satellite & Hybrid Communication to establish broadband aeronautical communication networks. Satellite network is recognized as one- ocean coverage. The expected advantages of the satellite systems for aeronautical communications also

  15. Computational Inference of Neural Information Flow Networks

    E-print Network

    Jarvis, Erich D.

    Computational Inference of Neural Information Flow Networks V. Anne Smith1[¤ , Jing Yu1,2[¤ , Tom V, Hartemink AJ, Jarvis ED (2006) Computational inference of neural information flow networks. PLoS Comput Biol connectivity networks. But traffic congestion, power blackouts, packet routing, computation, and animal

  16. Graph Models for Library Information Networks.

    ERIC Educational Resources Information Center

    Korfhage, Robert R.; And Others

    The design and study of library information networks are enhanced by the use of the concepts which have been developed by graph theorists. In this paper this theme is expanded upon, proposing a general network structure which is believed to be a good model for a wide variety of library and other information networks. The basic concepts from graph

  17. 75 FR 26180 - Effects on Broadband Communications Networks of Damage To or Failure of Network Equipment or...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-11

    ...FEDERAL COMMUNICATIONS COMMISSION 47 CFR Chapter I [PS Docket...FCC 10-62] Effects on Broadband Communications Networks of Damage To or Failure of...or Severe Overload AGENCY: Federal Communications Commission. ACTION: Proposed...

  18. SIA: secure information aggregation in sensor networks

    Microsoft Academic Search

    Bartosz Przydatek; Dawn Xiaodong Song; Adrian Perrig

    2003-01-01

    Sensor networks promise viable solutions to many monitoring problems. However, the practical deployment of sensor networks faces many challenges imposed by real-world demands. Sensor nodes often have limited computation and communication resources and battery power. Moreover, in many applications sensors are deployed in open environments, and hence are vulnerable to physical attacks, potentially compromising the sensor's cryptographic keys.One of the

  19. Progress on the Development of Future Airport Surface Wireless Communications Network

    NASA Technical Reports Server (NTRS)

    Kerczewski, Robert J.; Budinger, James M.; Brooks, David E.; Franklin, Morgan; DeHart, Steve; Dimond, Robert P.; Borden, Michael

    2009-01-01

    Continuing advances in airport surface management and improvements in airport surface safety are required to enable future growth in air traffic throughout the airspace, as airport arrival and departure delays create a major system bottleneck. These airport management and safety advances will be built upon improved communications, navigation, surveillance, and weather sensing, creating an information environment supporting system automation. The efficient movement of the digital data generated from these systems requires an underlying communications network infrastructure to connect data sources with the intended users with the required quality of service. Current airport surface communications consists primarily of buried copper or fiber cable. Safety related communications with mobile airport surface assets occurs over 25 kHz VHF voice and data channels. The available VHF spectrum, already congested in many areas, will be insufficient to support future data traffic requirements. Therefore, a broadband wireless airport surface communications network is considered a requirement for the future airport component of the air transportation system. Progress has been made on defining the technology and frequency spectrum for the airport surface wireless communications network. The development of a test and demonstration facility and the definition of required testing and standards development are now underway. This paper will review the progress and planned future work.

  20. Scheduling algorithms for arbitrary communication networks

    E-print Network

    Jagabathula, Srikanth

    2008-01-01

    We consider the problem of designing scheduling schemes for networks with arbitrary topology and scheduling constraints. We address the optimality of scheduling schemes for packet networks in terms of throughput, delay and ...

  1. Communicating Centrality in Policy Network Drawings

    Microsoft Academic Search

    Ulrik Brandes; Patrick Kenis; Dorothea Wagner

    2003-01-01

    We introduce a network visualization technique that supports an analytical method applied in the social sciences. Policy network analysis is an approach to study policy making structures, processes, and outcomes, thereby concentrating on relations between policy actors. An important operational concept for the analysis of policy networks is the notion of centrality, i.e., the distinction of actors according to their

  2. Stochastically bounded burstiness for communication networks

    Microsoft Academic Search

    David Starobinski; Moshe Sidi

    2000-01-01

    Abstract - We develop a network calculus for processes whose burstiness is stochastically bounded by general decreasing functions This calculus en - ables us to prove the stability of feedforward networks and obtain statistical upper bounds on interesting performance measures such as delay, at each buffer in the network Our bounding methodology is useful for a large class of input

  3. CSCE 3030: Parallel Programming Communication Network Topologies

    E-print Network

    Kavi, Krishna

    Partitioning Checklist ·At least 10x more primitive tasks than processors in target computer ·Minimize an increasing function of problem size Communication Checklist ·Communication operations balanced among tasks concurrently ·Task can perform computations concurrently Agglomeration checklist ·Locality of parallel

  4. Communication, advice exchange and job satisfaction of nursing staff: a social network analyses of 35 long-term care units

    PubMed Central

    2011-01-01

    Background The behaviour of individuals is affected by the social networks in which they are embedded. Networks are also important for the diffusion of information and the influence of employees in organisations. Yet, at the moment little is known about the social networks of nursing staff in healthcare settings. This is the first study that investigates informal communication and advice networks of nursing staff in long-term care. We examine the structure of the networks, how they are related to the size of units and characteristics of nursing staff, and their relationship with job satisfaction. Methods We collected social network data of 380 nursing staff of 35 units in group projects and psychogeriatric units in nursing homes and residential homes in the Netherlands. Communication and advice networks were analyzed in a social network application (UCINET), focusing on the number of contacts (density) between nursing staff on the units. We then studied the correlation between the density of networks, size of the units and characteristics of nursing staff. We used multilevel analyses to investigate the relationship between social networks and job satisfaction of nursing staff, taking characteristics of units and nursing staff into account. Results Both communication and advice networks were negatively related to the number of residents and the number of nursing staff of the units. Communication and advice networks were more dense when more staff worked part-time. Furthermore, density of communication networks was positively related to the age of nursing staff of the units. Multilevel analyses showed that job satisfaction differed significantly between individual staff members and units and was influenced by the number of nursing staff of the units. However, this relationship disappeared when density of communication networks was added to the model. Conclusions Overall, communication and advice networks of nursing staff in long-term care are relatively dense. This fits with the high level of cooperation that is needed to provide good care to residents. Social networks are more dense in small units and are also shaped by characteristics of staff members. The results furthermore show that communication networks are important for staff's job satisfaction. PMID:21631936

  5. TRYPNET. New hemoparasite information network.

    PubMed

    Vokaty, S; Desquesnes, M; Applewhaite, L; Favre, J; Lieuw-A-Joe, R; Parris-Aaron, M; Bansse-Iisa, L

    1996-07-23

    Although Guyana, Suriname, and French Guiana share borders and climatic and geographic similarities, the countries have maintained little contact, due to language, political, and administrative differences. In 1993, two international organizations involved in the improvement of animal health, the Inter-American Institute for Cooperation on Agriculture (IICA) and CIRAD-EMVT (Centre de Cooperation Internationale en Recherche Agronomique pour le Developpement-Elevage et Medecine Veterinaire des Pays Tropicaux), jointly developed a collaborative project between the veterinary services of the three countries entitled "Hemoparasite Network for the Guianas." This project seeks to pool livestock, laboratory, and technical resources between the three countries in order to generate and exchange information on hemoparasites of livestock. A Hemoparasite Reference Laboratory for the Guianas has been created at the CIRAD-EMVT laboratory in Cayenne, French Guiana. Besides processing ruminant serum samples from the three countries, specialists from this organization conduct training in hemoparasite diagnostic techniques for laboratory personnel from Guyana and Suriname. A large-scale epidemiologic study of hemoparasites of cattle in the three countries is under way, to determine the prevalence, distribution, and clinical and economic significance of hemoparasites in the three countries, particularly Trypanosoma vivax and T. evansi. Preliminary results are presented and discussed. A Hemoparasite Information Network (TRYPNET) has been initiated, including a quarterly hemoparasite newsletter (TRYPNEWS), published in English and Spanish and disseminated to researchers in the Americas, Europe, and Africa. In 1995/96, it is proposed to expand the network's scope to include Venezuela and Brazil. PMID:8784498

  6. Universities Water Information Network (UWIN)

    NSDL National Science Digital Library

    Based at Southern Illinois University in Carbondale, Illinois, the Universities Water Information Network (UWIN) is a USGS-funded meta-resource that centralizes water information on the WWW. The heart of the site is the searchable WRSIC (Water Resources Scientific Information Center) research abstracts bibliographic database, containing over 265,000 research abstracts and citations covering "a wide variety of (international) topics that span the time period from 1967 to October, 1993." Research abstracts in the database include "the life, physical, and social sciences, as well as engineering and legal issues." In addition to the database, UWIN offers tips for finding Water Resources on the Web (see the WetList section), as well as professional announcements, directories, and employment-related tips.

  7. Enabling information management systems in tactical network environments

    NASA Astrophysics Data System (ADS)

    Carvalho, Marco; Uszok, Andrzej; Suri, Niranjan; Bradshaw, Jeffrey M.; Ceccio, Philip J.; Hanna, James P.; Sinclair, Asher

    2009-05-01

    Net-Centric Information Management (IM) and sharing in tactical environments promises to revolutionize forward command and control capabilities by providing ubiquitous shared situational awareness to the warfighter. This vision can be realized by leveraging the tactical and Mobile Ad hoc Networks (MANET) which provide the underlying communications infrastructure, but, significant technical challenges remain. Enabling information management in these highly dynamic environments will require multiple support services and protocols which are affected by, and highly dependent on, the underlying capabilities and dynamics of the tactical network infrastructure. In this paper we investigate, discuss, and evaluate the effects of realistic tactical and mobile communications network environments on mission-critical information management systems. We motivate our discussion by introducing the Advanced Information Management System (AIMS) which is targeted for deployment in tactical sensor systems. We present some operational requirements for AIMS and highlight how critical IM support services such as discovery, transport, federation, and Quality of Service (QoS) management are necessary to meet these requirements. Our goal is to provide a qualitative analysis of the impact of underlying assumptions of availability and performance of some of the critical services supporting tactical information management. We will also propose and describe a number of technologies and capabilities that have been developed to address these challenges, providing alternative approaches for transport, service discovery, and federation services for tactical networks.

  8. Networked Operations of Hybrid Radio Optical Communications Satellites

    NASA Technical Reports Server (NTRS)

    Hylton, Alan; Raible, Daniel

    2014-01-01

    In order to address the increasing communications needs of modern equipment in space, and to address the increasing number of objects in space, NASA is demonstrating the potential capability of optical communications for both deep space and near-Earth applications. The Integrated Radio Optical Communications (iROC) is a hybrid communications system that capitalizes on the best of both the optical and RF domains while using each technology to compensate for the other's shortcomings. Specifically, the data rates of the optical links can be higher than their RF counterparts, whereas the RF links have greater link availability. The focus of this paper is twofold: to consider the operations of one or more iROC nodes from a networking point of view, and to suggest specific areas of research to further the field. We consider the utility of Disruption Tolerant Networking (DTN) and the Virtual Mission Operation Center (VMOC) model.

  9. Project Universe - Local area networks and satellite communications

    NASA Astrophysics Data System (ADS)

    Ackroyd, B. R.

    1983-07-01

    A high-speed digital communications system is discussed in which a satellite is used to link a number of local area networks which interconnect a variety of computer facilities. The advantages of satellite communications compared with terrestrial links are described, together with a historical survey of the use of the Orbital Test Satellite (OTS) for data experiments. A description of Project Universe is given and the purpose of the project is described along with a more detailed description of the elements that make up the network such as satellite earth terminals, communication rings and terrestrial links. Future developments of such systems and their use as a means of business communication are considered, in particular, the factors affecting their growth, emphasis being placed on the specification and cost of equipment.

  10. Unmediated communication in games with complete and incomplete information

    Microsoft Academic Search

    Dino Gerardi

    2004-01-01

    We study the effects of adding unmediated communication to static, finite games of complete and incomplete information. We characterize SU(G), the set of outcomes of a game G, that are induced by sequential equilibria of cheap talk extensions. A cheap talk extension of G is an extensive-form game in which players communicate before playing G. A reliable mediator is not

  11. Child Welfare and Information and Communication Technology: Today's Challenge

    Microsoft Academic Search

    Susan Tregeagle; Michael Darcy

    2008-01-01

    Summary Information and communication technology (ICT) usage in contemporary child welfare practice reflects dominant managerial interests rather than those of the profession, and, importantly, of service users. Explicit use of ICT in the interests of service users remains embryonic, and professionals have been slow to capitalize on the communication poten- tial of new technologies. This contrasts with technology uptake in

  12. Securing against fraud in mobile communications : system design and development in 3G mobile networks

    E-print Network

    Mochizuki, Yujiro, 1973-

    2006-01-01

    Network security ensures the consistency, integrity, and reliability of telecommunications systems. Authorized network access prevents fraudulent communications and maintains the availability of the systems. However, limited ...

  13. Analyzing the Dynamics of Communication in Online Social Networks

    Microsoft Academic Search

    Munmun De Choudhury; Hari Sundaram; Ajita John; Doree Duncan Seligmann

    2010-01-01

    \\u000a This chapter deals with the analysis of interpersonal communication dynamics in online social networks and social media. Communication\\u000a is central to the evolution of social systems. Today, the different online social sites feature variegated interactional affordances,\\u000a ranging from blogging, micro-blogging, sharing media elements (i.e., image, video) as well as a rich set of social actions\\u000a such as tagging, voting, commenting

  14. Real-time fieldbus communications using Profibus networks

    Microsoft Academic Search

    Eduardo Tovar; Francisco Vasques

    1999-01-01

    This paper provides a comprehensive study on how to use Profibus fieldbus networks to support real-time industrial communications, that is, on how to ensure the transmission of real-time messages within a maximum bound time. Profibus is base on a simplified timed token (TT) protocol, which is a well-proved solution for real-time communication systems. However, Profibus differs with respect to the

  15. Impact of Community Structure on Network Efficiency and Communicability

    Microsoft Academic Search

    Gao-Xia Wang; Tai-Gui Qin

    2010-01-01

    To explore the impact of community structure on some measures of about the capability of information transfer and transformation occurring on such topologies, we set up a kind of network model with community structure which shows obvious local and global small world characteristics. Under the control of the parameters of the network generation, the networks with the different level on

  16. Community First Communication: Reversing Information Disparities to Achieve Environmental Justice.

    PubMed

    Emmett, Edward A; Desai, Chintan

    2010-09-01

    We address how information developed and effectively communicated through community based participatory research (CBPR) can reverse long-standing information disparities, empower a community, and be an agent for sustained change. Substantial information and power disparities existed between the polluted community and both the pollution industry and governmental regulators. An environmental justice partnership between a local community organization, physicians, and university performed CBPR and then developed a novel communication strategy to address a series of information disparities around a local water pollution issue. The community established a set of principles to govern the communication of results as soon as they were determined to be scientifically valid, including informing study participants and the community before other interested parties. CBPR results combined with a community-first communication strategy reversed the preexisting information disparities. The novel communication flow reversed the preferential information flow to industry and government associated with the usual scientific publication process. The community was empowered, and industry and government agencies responded positively to study recommendations. The CBPR results together with community first communication led to adoption of both community-wide and individual solutions and provided powerful motivation for behavioral change by industry and residents. PMID:21546988

  17. Community First Communication: Reversing Information Disparities to Achieve Environmental Justice

    PubMed Central

    Emmett, Edward A.; Desai, Chintan

    2011-01-01

    We address how information developed and effectively communicated through community based participatory research (CBPR) can reverse long-standing information disparities, empower a community, and be an agent for sustained change. Substantial information and power disparities existed between the polluted community and both the pollution industry and governmental regulators. An environmental justice partnership between a local community organization, physicians, and university performed CBPR and then developed a novel communication strategy to address a series of information disparities around a local water pollution issue. The community established a set of principles to govern the communication of results as soon as they were determined to be scientifically valid, including informing study participants and the community before other interested parties. CBPR results combined with a community-first communication strategy reversed the preexisting information disparities. The novel communication flow reversed the preferential information flow to industry and government associated with the usual scientific publication process. The community was empowered, and industry and government agencies responded positively to study recommendations. The CBPR results together with community first communication led to adoption of both community-wide and individual solutions and provided powerful motivation for behavioral change by industry and residents. PMID:21546988

  18. Analysis of adaptive algorithms for an integrated communication network

    NASA Technical Reports Server (NTRS)

    Reed, Daniel A.; Barr, Matthew; Chong-Kwon, Kim

    1985-01-01

    Techniques were examined that trade communication bandwidth for decreased transmission delays. When the network is lightly used, these schemes attempt to use additional network resources to decrease communication delays. As the network utilization rises, the schemes degrade gracefully, still providing service but with minimal use of the network. Because the schemes use a combination of circuit and packet switching, they should respond to variations in the types and amounts of network traffic. Also, a combination of circuit and packet switching to support the widely varying traffic demands imposed on an integrated network was investigated. The packet switched component is best suited to bursty traffic where some delays in delivery are acceptable. The circuit switched component is reserved for traffic that must meet real time constraints. Selected packet routing algorithms that might be used in an integrated network were simulated. An integrated traffic places widely varying workload demands on a network. Adaptive algorithms were identified, ones that respond to both the transient and evolutionary changes that arise in integrated networks. A new algorithm was developed, hybrid weighted routing, that adapts to workload changes.

  19. Network Communication as a Service-Oriented Capability

    SciTech Connect

    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.

  20. The landlocked island: Information access and communications policy in Nepal

    Microsoft Academic Search

    Robin Shields

    2009-01-01

    This paper examines information access in Nepal, its current limitations, and opportunities for expansion, particularly in rural areas. It argues that government policies and the regulatory environment have failed to create the competition necessary for rapid expansion of information access through information and communication technologies (ICTs), particularly in rural areas. Furthermore, restrictive approaches to licensing and exorbitant fees have hindered

  1. Information theory, animal communication, and the search for extraterrestrial intelligence

    Microsoft Academic Search

    Laurance R. Doyle; Brenda McCowan; Simon Johnston; Sean F. Hanser

    2011-01-01

    We present ongoing research in the application of information theory to animal communication systems with the goal of developing additional detectors and estimators for possible extraterrestrial intelligent signals. Regardless of the species, for intelligence (i.e., complex knowledge) to be transmitted certain rules of information theory must still be obeyed. We demonstrate some preliminary results of applying information theory to socially

  2. Defining Information Needs of Computer Users: A Human Communication Problem.

    ERIC Educational Resources Information Center

    Kimbrough, Kenneth L.

    This exploratory investigation of the process of defining the information needs of computer users and the impact of that process on information retrieval focuses on communication problems. Six sites were visited that used computers to process data or to provide information, including the California Department of Transportation, the California

  3. [Research on Zhejiang blood information network and management system].

    PubMed

    Yan, Li-Xing; Xu, Yan; Meng, Zhong-Hua; Kong, Chang-Hong; Wang, Jian-Min; Jin, Zhen-Liang; Wu, Shi-Ding; Chen, Chang-Shui; Luo, Ling-Fei

    2007-02-01

    This research was aimed to develop the first level blood information centralized database and real time communication network at a province area in China. Multiple technology like local area network database separate operation, real time data concentration and distribution mechanism, allopatric backup, and optical fiber virtual private network (VPN) were used. As a result, the blood information centralized database and management system were successfully constructed, which covers all the Zhejiang province, and the real time exchange of blood data was realised. In conclusion, its implementation promote volunteer blood donation and ensure the blood safety in Zhejiang, especially strengthen the quick response to public health emergency. This project lays the first stone of centralized test and allotment among blood banks in Zhejiang, and can serve as a reference of contemporary blood bank information systems in China. PMID:17490550

  4. A Secure Communication Suite for Underwater Acoustic Sensor Networks

    PubMed Central

    Dini, Gianluca; Duca, Angelica Lo

    2012-01-01

    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. PMID:23202204

  5. Communication synthesis of networks-on-chip (NoC)

    E-print Network

    Bhojwani, Praveen Sunder

    2008-10-10

    COMMUNICATION SYNTHESIS OF NETWORKS-ON-CHIP (NoC) A Dissertation by PRAVEEN SUNDER BHOJWANI Submitted to the O ce of Graduate Studies of Texas A&M University in partial ful llment of the requirements for the degree of DOCTOR OF PHILOSOPHY December... 2007 Major Subject: Computer Engineering COMMUNICATION SYNTHESIS OF NETWORKS-ON-CHIP (NoC) A Dissertation by PRAVEEN SUNDER BHOJWANI Submitted to the O ce of Graduate Studies of Texas A&M University in partial ful llment of the requirements...

  6. Communicating genetic risk information within families: a review

    Microsoft Academic Search

    Mel Wiseman; Caroline Dancyger; Susan Michie

    2010-01-01

    This review of family communication of genetic risk information addresses questions of what the functions and influences on\\u000a communication are; what, who and how family members are told about genetic risk information; what the impact for counsellee,\\u000a relative and relationships are; whether there are differences by gender and condition; and what theories and methodologies\\u000a are used. A systematic search strategy

  7. NASCOM network ground communications availability report

    NASA Technical Reports Server (NTRS)

    1983-01-01

    A performance analysis of NASCOM Network circuits is presented. An objective of 99.80 percent availability has been established for all network circuits and an acceptable level of 99.50. A network narrative summary for the current month includes changes in network configurations, current month's totals for modes of service and trouble category losses, a discussion of trends, and significant losses that affected the performance indexes of individual or groups of circuits. A table and narrative summary of those circuits that failed to meet the objective of 99.80% availability for all network circuits and an acceptable level of 99.50. Lost time and interruption tables showing all circuits affected by outages, by trouble category, with their total time and events, scheduled operating hours, and individual availability indexes also are included. Selected circuits whose availabilities have or continue to affect the overall network availability are also analyzed.

  8. BPSK & QPSK modulated data communication for biomedical monitoring sensor network.

    PubMed

    Wegmueller, Marc S; Fichtner, Wolfgang; Oberle, Michael; Kuster, Niels

    2006-01-01

    Data communication between body-mounted sensors is progressing towards wireless monitoring networks. In this work, digital data communication by galvanic coupling through the body is presented as a promising approach for wireless intra-body communication. The human body itself serves as the transmission medium of electrical current. Both binary and quadrature phase-shift-keying (BPSK and QPSK) modulated data transmissions are implemented and compared for galvanic coupled links between 2 differential electrode pairs. The adaptive system offers up to 1 mA maximum current amplitude between 10 kHz and 1MHz. Data communication at a rate of up to 64 kbit/s was realized with BER of 10(-4) corresponding to an SNR greater than 6 dB. The novel technology has shown its feasibility in clinical trials. Furthermore, such a low-current approach enables data communication that is more energy-saving than other wireless technologies. PMID:17946088

  9. Deep Space Network information system architecture study

    NASA Technical Reports Server (NTRS)

    Beswick, C. A.; Markley, R. W. (editor); Atkinson, D. J.; Cooper, L. P.; Tausworthe, R. C.; Masline, R. C.; Jenkins, J. S.; Crowe, R. A.; Thomas, J. L.; Stoloff, M. J.

    1992-01-01

    The purpose of this article is to describe an architecture for the DSN information system in the years 2000-2010 and to provide guidelines for its evolution during the 1990's. The study scope is defined to be from the front-end areas at the antennas to the end users (spacecraft teams, principal investigators, archival storage systems, and non-NASA partners). The architectural vision provides guidance for major DSN implementation efforts during the next decade. A strong motivation for the study is an expected dramatic improvement in information-systems technologies--i.e., computer processing, automation technology (including knowledge-based systems), networking and data transport, software and hardware engineering, and human-interface technology. The proposed Ground Information System has the following major features: unified architecture from the front-end area to the end user; open-systems standards to achieve interoperability; DSN production of level 0 data; delivery of level 0 data from the Deep Space Communications Complex, if desired; dedicated telemetry processors for each receiver; security against unauthorized access and errors; and highly automated monitor and control.

  10. Power, Avionics and Software Communication Network Architecture

    NASA Technical Reports Server (NTRS)

    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).

  11. Automotive suspension control through a computer communication network

    Microsoft Academic Search

    U. Ozguner; H. Goktas; H. Chant; J. Winkelman; M. Liubakka; R. Krtolica

    1992-01-01

    Closed-loop stability and performance-related studies performed on a multiplex communication network called Carlink, being considered for automotive applications, are discussed. Tests done on an automotive suspension control model, in which the active control signal is applied through the multiplex network as a real-time hybrid computer\\/hardware-in-the-loop experiment are outlined. The stability of the system is considered using analytical approaches developed by

  12. Real-time communication in packet-switched networks

    Microsoft Academic Search

    CAGLAN M. ARAS; JAMES F. KUROSE; DOUGLAS S. REEVES; HENNING SCHULZRINNE

    1994-01-01

    The dramatically increased bandwidths and processing capabilities of future high-speed networks make possible many distributed real-time applications, such as sensor-based applications and multimedia services. Since these applications will have traffic characteristics and performance requirements that differ dramatically from those of current data-oriented applications, new communication network architectures, and protocols will be required. In this paper we discuss the performance requirements

  13. Multimedia transport in next-generation personal communication networks

    Microsoft Academic Search

    D. Raychaudhuri; N. Wilson

    1993-01-01

    A discussion of issues related to the support of multimedia traffic in next-generation personal communication networks (PCNs) is presented. Broadband integrated services digital network\\/asynchronous transfer mode (B-ISDN\\/ATM) compatibility is proposed as a basis for next-generation PCN transport architectures. This implies that a multimedia-capable PCN should support ATM-type cell switching of constant bit-rate (CBR) and variable bit-rate (VBR) services, both real-time

  14. Capacity limits of information transport in fiber-optic networks.

    PubMed

    Essiambre, Ren-Jean; Foschini, Gerard J; Kramer, Gerhard; Winzer, Peter J

    2008-10-17

    The instantaneous optical Kerr effect in optical fibers is a nonlinear phenomenon that can impose limits on the ability of fiber-optic communication systems to transport information. We present here a conservative estimate of the "fiber channel" capacity in an optically routed network. We show that the fiber capacity per unit bandwidth for a given distance significantly exceeds current record experimental demonstrations. PMID:18999670

  15. Latin American Network Information Center

    NSDL National Science Digital Library

    Started in 1992 and affiliated with the Lozano Long Institute of Latin American Studies at the University of Texas at Austin, the Latin American Network Information Center (LANIC) is designed to "facilitate access to Internet-based information to, from, or on Latin America." Their site was redesigned in the spring of 2008, and currently their various directories contain over 12,000 unique URLs for use by the general public. These links can be browsed by subject headings or by country, and visitors can look into more discrete topical headings like "food", "political science", and "social work". Along with these high-quality links, visitors can then click on over to their "Digital Initiatives" area. Here they will find digital collections that cover documents from the New Mexican Revolution and the full-text Fidel Castro Speech database. Visitors will also appreciate that many of the site's resources are available in Spanish and Portuguese.

  16. Pseudo-Circuit: Accelerating Communication for On-Chip Interconnection Networks

    Microsoft Academic Search

    Minseon Ahn; Eun Jung Kim

    2010-01-01

    As the number of cores on a single chip increases with more recent technologies, a packet-switched on-chip interconnection network has become a de facto communication paradigm for chip multiprocessors (CMPs). However, it is inevitable to suffer from high communication latency due to the increasing number of hops. In this paper, we attempt to accelerate network communication by exploiting communication temporal

  17. Technology forecasting for space communication. [analysis of systems for application to Spacecraft Data and Tracking Network

    NASA Technical Reports Server (NTRS)

    1973-01-01

    A study was conducted to determine techniques for application to space communication. The subjects considered are as follows: (1) optical communication systems, (2) laser communications for data acquisition networks, (3) spacecraft data rate requirements, (4) telemetry, command, and data handling, (5) spacecraft tracking and data network antenna and preamplifier cost tradeoff study, and (6) spacecraft communication terminal evaluation.

  18. Minimizing Mobility and Communication Energy in Robotic Networks: an Optimal Control Approach

    E-print Network

    Egerstedt, Magnus

    Minimizing Mobility and Communication Energy in Robotic Networks: an Optimal Control Approach H of motion energy and communication energy in a network of mobile robots. The robotic network is charged to use mobility to reduce the energy required for sensing and communications; see [13] and references

  19. Multi-agent Communication Disorders: Dynamic Breeding Networks in Genetic Algorithms

    E-print Network

    Wilensky, Uri

    to peer computing Mobile and ad-hoc networks Swarm robots, smart dust? #12;Multi-agent CommunicationMulti-agent Communication Disorders: Dynamic Breeding Networks in Genetic Algorithms Forrest-Based Modeling http://ccl.northwestern.edu/ #12;Multi-agent Communication Disorders: Dynamic Breeding Networks

  20. A new communication paradigm for mobile TV over cellular network Dr. Hongxiang Li

    E-print Network

    A new communication paradigm for mobile TV over cellular network Dr. Hongxiang Li Electrical terrestrial TV network and propose a new mobile TV communication paradigm that is radically different from and communication theory (i.e., Network Coding and Dirty Paper Coding) in the new mobile TV system design. Despite

  1. Tracking Mobile Users in Wireless Communication Networks

    Microsoft Academic Search

    Amotz Bar-noy; Ilan Kessler

    1993-01-01

    Tracking strategies for mobile wireless networks are studied. We assume a cellulararchitecture where base stations that are interconnected by a wired network communicatewith mobile units via wireless links. Previous works focused on the cost of utilizing thewired links for management of directories. In this paper, the issue considered is thecost of utilizing the wireless links for the actual tracking of

  2. A New Network Architecture for Wireless Communications

    Microsoft Academic Search

    Chin-Tau Lea; Li-Chun Wang

    1998-01-01

    Current cellular systems are based on the concept of the cell. Although the cell allows channel reuse, it has also become a metaphor for channel con nement and leads to the thorny problem of handoff and call dropping. The problem will get much worse as wireless networks move toward smaller cells and multirate. A new network architecture for wireless comm

  3. A New Network Architecture for Wireless Communications

    Microsoft Academic Search

    Chin-Tau Lea; Li-Chun Wang

    1998-01-01

    Current cellular systems are based on theconcept of the cell. Although the cell allows channelreuse, it has also become a metaphor for channelconfinement and leads to the thorny problem of handoffand call dropping. The problem will get much worseas wireless networks move toward smaller cells andmultirate. A new network architecture for wirelesscommunications is presented in this paper. Thearchitecture called

  4. Management of the Western Union Communications Network

    Microsoft Academic Search

    J. W. Vancleve

    1980-01-01

    The paper describes the integrated transmission network and operational control of Western Union's combined satellite and terrestrial network. The WESTAR and microwave coast-to-coast radio beam installation is outlined. Bibtex entry for this abstract Preferred format for this abstract (see Preferences) Find Similar Abstracts: Use: Authors Title Keywords (in text query field) Abstract Text Return: Query Results Return items starting with

  5. Fast massive preventive security and information communication systems

    NASA Astrophysics Data System (ADS)

    Akopian, David; Chen, Philip; Miryakar, Susheel; Kumar, Abhinav

    2008-04-01

    We present a fast massive information communication system for data collection from distributive sources such as cell phone users. As a very important application one can mention preventive notification systems when timely notification and evidence communication may help to improve safety and security through wide public involvement by ensuring easy-to-access and easy-to-communicate information systems. The technology significantly simplifies the response to the events and will help e.g. special agencies to gather crucial information in time and respond as quickly as possible. Cellular phones are nowadays affordable for most of the residents and became a common personal accessory. The paper describes several ways to design such systems including existing internet access capabilities of cell phones or downloadable specialized software. We provide examples of such designs. The main idea is in structuring information in predetermined way and communicating data through a centralized gate-server which will automatically process information and forward it to a proper destination. The gate-server eliminates a need in knowing contact data and specific local community infrastructure. All the cell phones will have self-localizing capability according to FCC E911 mandate, thus the communicated information can be further tagged automatically by location and time information.

  6. Efficient data communication protocols for wireless networks

    NASA Astrophysics Data System (ADS)

    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 converge to pure strategy Nash equilibrium with high probability throughout the iterations in the interference impaired network. On the other hand, the regret-matching learning algorithm is noncooperative and requires minimum amount of overhead. The proposed cooperative and regret-matching based distributed algorithms are also compared with centralized solutions through simulation results.

  7. 75 FR 69439 - Notice of Public Information Collection(s) Being Reviewed by the Federal Communications...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-12

    ...FEDERAL COMMUNICATIONS COMMISSION Notice of Public Information...s) Being Reviewed by the Federal Communications Commission for Extension Under Delegated...November 3, 2010. SUMMARY: The Federal Communications Commission, as part of its...

  8. 76 FR 28843 - Meeting of Advisory Committee on International Communications and Information Policy

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-18

    ...foreign industrial and regulatory policy, the activities of international...Communications and Information Policy. The meeting's agenda will...importance to U.S. communications policy interests including information and communications technology (ICT) and international...

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

    NASA Technical Reports Server (NTRS)

    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 results and impact. We will highlight the insights gained by applying the Model Based System Engineering and provide recommendations for its applications and improvements.

  10. Progress Toward Standards for the Seamless Interoperability of Broadband Satellite Communication Networks

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

    The realization of the full potential of the National Information Infrastructure (NH) and Global Information Infrastructure (GII) requires seamless interoperability of emerging satellite networks with terrestrial networks. This requires a cooperative effort between industry, academia and government agencies to develop and advocate new, satellite-friendly communication protocols and modifications to existing communication protocol standards. These groups have recently come together to actively participating in a number of standards making bodies including: the Internet Engineering Task Force (IETF), the Asynchronous Transfer Mode (ATM) Forum, the International Telecommunication Union (ITU) and the Telecommunication Industry Association MA) to ensure that issues regarding efficient use of these protocols over satellite links are not overlooked. This paper will summarize the progress made toward standards development to achieve seamless integration and accelerate the deployment of multimedia applications.

  11. Signaling communication events in a computer network

    DOEpatents

    Bender, Carl A. (Highland, NY); DiNicola, Paul D. (Hurley, NY); Gildea, Kevin J. (Bloomington, NY); Govindaraju, Rama K. (Poughkeepsie, NY); Kim, Chulho (Poughkeepsie, NY); Mirza, Jamshed H. (Woodstock, NY); Shah, Gautam H. (Wappingers Falls, NY); Nieplocha, Jaroslaw (Richland, WA)

    2000-01-01

    A method, apparatus and program product for detecting a communication event in a distributed parallel data processing system in which a message is sent from an origin to a target. A low-level application programming interface (LAPI) is provided which has an operation for associating a counter with a communication event to be detected. The LAPI increments the counter upon the occurrence of the communication event. The number in the counter is monitored, and when the number increases, the event is detected. A completion counter in the origin is associated with the completion of a message being sent from the origin to the target. When the message is completed, LAPI increments the completion counter such that monitoring the completion counter detects the completion of the message. The completion counter may be used to insure that a first message has been sent from the origin to the target and completed before a second message is sent.

  12. Secure Group Communications over Combined Wired and Wireless Networks

    Microsoft Academic Search

    Junghyun Nam; Seungjoo Kim; Dongho Won

    2005-01-01

    Abstract This paper considers the fundamental problem of key agreement among a group of parties communicating over an insecure public network Over the years, a number of solutions to this problem have been proposed with varying degrees of com - plexity However, there seems to have been no previous systematic look at the growing problem of key agreement over combined

  13. What's Going On? Learning Communication Rules In Edge Networks

    E-print Network

    Rajamani, Sriram K.

    What's Going On? Learning Communication Rules In Edge Networks Srikanth Kandula MIT CSAIL kandula@mit.edu Ranveer Chandra Microsoft Research ranveer@microsoft.com Dina Katabi MIT CSAIL dk@mit.edu ABSTRACT what to look for. Going beyond rules involving ow pairs, eXpose introduces templates to systematically

  14. Speech signal recovery in packet-switched communication networks

    Microsoft Academic Search

    E. Ginters; V. Zagursky

    2000-01-01

    Interpolation approaches to shape recovery of a speech signal transmitted over packet switched communications networks are proposed. The samples of signal fragments are mixed and transmitted in correspondence with the standard procedure of packet-switched transmission. After reception a reverse permutation is made. In the case of packet losses missing samples are separated by several samples of the source signal. Correlation

  15. Speech signal recovery in packet-switched communication networks

    Microsoft Academic Search

    V. Zagursky; E. Ginters

    1999-01-01

    The interpolation approaches to shape recovery of a speech signal in transmission over packet-switched communications networks are proposed. The samples of a signal fragments are mixed and transmitted in correspondence with the standard procedure of packet-switched transmission. After reception a reverse permutation is made. In the case of packet losses, missing samples are separated by several samples of the source

  16. Speech signal recovery in packet-switched communication networks

    Microsoft Academic Search

    V. Zagursky; E. Ginters

    1999-01-01

    The interpolation approaches to the shape recovery of a speech signal in transmission over packet switched communications networks are proposed. The samples of a signal fragments are mixed and transmitted in correspondence with standard procedure of packet-switched transmission. After reception a reverse permutation is made. In the case of packet losses missing samples are separated by several samples of the

  17. A Ubiquitous, Infrastructure-Free Network for Interpersonal Communication

    E-print Network

    Biagioni, Edoardo S.

    in a number of situations: most notably in emergencies, but also for social networking, chatting, and other laptops and tablets to smartphones and potentially even lower-powered devices. The hardware of these units smartphones and tablets these days also have an 802.11 interface that is capable ad-hoc communication

  18. Data communication requirements for the advanced NAS network

    Microsoft Academic Search

    Eugene Levin; C. K. Eaton; Bruce Young

    1986-01-01

    The goal of the Numerical Aerodynamic Simulation (NAS) Program is to provide a powerful computational environment for advanced research and development in aeronautics and related disciplines. The present NAS system consists of a Cray 2 supercomputer connected by a data network to a large mass storage system, to sophisticated local graphics workstations, and by remote communications to researchers throughout the

  19. A Future Internet Architecture supporting Multipath Communication Networks

    E-print Network

    Dreibholz, Thomas

    A Future Internet Architecture supporting Multipath Communication Networks Martin Becke, Thomas.becke,dreibh,hakim.adhari,rathgeb}@iem.uni-due.de Abstract--The classic layered OSI reference model has reached its limits for the Internet of today discussion on the Future Internet. We address the shortcomings of the layered model by redesigning

  20. Applying mobile IP over wireless ATM communication networks

    Microsoft Academic Search

    J. Soldatos; D. D. Vergados; N. Protopsaltis; C. Lykou; G. Kormentzas; C. Anagnostopoulos; M. Theologou

    2001-01-01

    Advances in mobile devices' and networks' technology have set a challenging pace for all new proposals in the rapidly growing domain of mobile communications. The decade of the 90's brought a revolution in mobile computing. The explosion in sales of laptop PCs as well as personal digital assistants and cellular phones has marked the beginning of a new era in

  1. Energy-Efficient Communication Protocol for Wireless Microsensor Networks

    Microsoft Academic Search

    Wendi Rabiner Heinzelman; Anantha Chandrakasan; Hari Balakrishnan

    2000-01-01

    Wireless distributed microsensor systems will enable the reliable monitoring of a variety of environments for both civil and military applications. In this paper, we look at communication protocols, which can have significant im- pact on the overall energy dissipation of these networks. Based on our findings that the conventional protocols of direct transmission, minimum-transmission-energy, multi- hop routing, and static clustering

  2. COMMUNICATION Self-organizing Neural Networks Bridge the

    E-print Network

    Wriggers, Willy

    COMMUNICATION Self-organizing Neural Networks Bridge the Biomolecular Resolution Gap Willy Wriggers are employed to generate pseudo-atomic structures of large-scale protein assemblies by combining high at pseudo-atomic resolution. The successful construction of such hybrid models for viruses and cytoskeletal

  3. Swarm Intelligence for Routing in Communication Networks I. Kassabalidis*

    E-print Network

    Arabshahi, Payman

    Swarm Intelligence for Routing in Communication Networks I. Kassabalidis* , M.A. El-Sharkawi* , R.J.Marks II* , P. Arabshahi , A.A. Gray ,_ Abstract ­ Swarm intelligence, as demonstrated by natural analytically understanding and extending the design principles and operations exhibited by intelligent

  4. Electronic Communication Systems and Social Networking Employee Social Media Policy

    E-print Network

    Dasgupta, Dipankar

    /or bullying apply to content posted online. Violating any University policy while using social media couldElectronic Communication Systems and Social Networking Employee Social Media Policy The Fogelman impact. Beware of comments that could reflect poorly on you and the College. Social media sites

  5. Role of Communication Networks in Behavioral Systems Analysis

    ERIC Educational Resources Information Center

    Houmanfar, Ramona; Rodrigues, Nischal Joseph; Smith, Gregory S.

    2009-01-01

    This article provides an overview of communication networks and the role of verbal behavior in behavioral systems analysis. Our discussion highlights styles of leadership in the design and implementation of effective organizational contingencies that affect ways by which coordinated work practices are managed. We draw upon literature pertaining to

  6. Global Mobility Management by Replicated Databases in Personal Communication Networks*

    E-print Network

    Leung, Kin K.

    - 1 - Global Mobility Management by Replicated Databases in Personal Communication Networks* Kin K for the management of PCN is to develop an efficient database architecture so that customer data can be readily}@att.com October 1, 1996 April 18, 1997 (revised) ABSTRACT This paper explores the use of replicated databases

  7. The next frontier for communications networks: power management

    Microsoft Academic Search

    Kenneth J. Christensen; Chamara Gunaratne; Bruce Nordman; Alan D. George

    2004-01-01

    Abstract Storage, memory, processor, and communications bandwidth are all relatively plentiful and inexpensive. However, a growing expense in the operation of computer networks is electricity usage. Estimates place devices connected to the Internet as consuming about 2%, and growing, of the total electricity produced in the USAmuch of this power consumption is unnecessary. Power management is needed to reduce this

  8. The next frontier for communications networks: power management

    Microsoft Academic Search

    Kenneth J. Christensen; Chamara Gunaratne; Bruce Nordman; Alan D. George

    Storage, memory, processor, and communications bandwidth are all relatively plentiful and inexpensive. However, a growing expense in the operation of computer networks is electricity usage. Estimates place devices connected to the Internet as consuming about 2%, and growing, of the total electricity produced in the USAmuch of this power consumption is unnecessary. Power management is needed to reduce this large

  9. Information Spread of Emergency Events: Path Searching on Social Networks

    PubMed Central

    Hu, Hongzhi; Wu, Tunan

    2014-01-01

    Emergency has attracted global attentions of government and the public, and it will easily trigger a series of serious social problems if it is not supervised effectively in the dissemination process. In the Internet world, people communicate with each other and form various virtual communities based on social networks, which lead to a complex and fast information spread pattern of emergency events. This paper collects Internet data based on data acquisition and topic detection technology, analyzes the process of information spread on social networks, describes the diffusions and impacts of that information from the perspective of random graph, and finally seeks the key paths through an improved IBF algorithm. Application cases have shown that this algorithm can search the shortest spread paths efficiently, which may help us to guide and control the information dissemination of emergency events on early warning. PMID:24600323

  10. Exploring the Human Mesenchymal Stem Cell Tubule Communication Network through Electron Microscopy.

    PubMed

    Valente, Sabrina; Rossi, Roberta; Resta, Leonardo; Pasquinelli, Gianandrea

    2015-04-01

    Cells use several mechanisms to transfer information to other cells. In this study, we describe micro/nanotubular connections and exosome-like tubule fragments in multipotent mesenchymal stem cells (MSCs) from human arteries. Scanning and transmission electron microscopy allowed characterization of sinusoidal microtubular projections (700?nm average size, 200?m average length, with bulging mitochondria and actin microfilaments); short, uniform, variously shaped nanotubular projections (100?nm, bidirectional communication); and tubule fragments (50?nm). This is the first study demonstrating that MSCs from human arteries constitutively interact through an articulate and dynamic tubule network allowing long-range cell to cell communication. PMID:25268461

  11. Communications of the Association for Information Systems

    E-print Network

    Kurnia, Sherah

    and the individual levels, a lack of theoretical explanation of why and how social capital changes due to ICT and the individual levels, a lack of theoretical explanation of why and how social capital changes due to ICT and Communications Technology Research: Past, Present, and Future 184 Volume 25 Article 23 I. INTRODUCTION Social

  12. Specifying Communication in Distributed Information Systems #

    E-print Network

    Lisboa, Universidade Técnica de

    ­level logic. The latter corresponds with concepts incorporated in Troll3, a specification language research into a commercial product [Esp93]. In the academic realm, there are several related developments: Troll [JSHS96, HJ]. In the Oblog family, Troll3 [DH97] is the first to address problems of concurrency and communication

  13. Measuring the Diffusion of Information and Communication Technology in Society and its Effects: Canadian Experience

    Microsoft Academic Search

    Fred Gault; Greg Peterson

    2003-01-01

    Statistics Canada has measured the use of information and communication technologies (ICTs)\\u000afor close to 15 years in industry and more recently in households and it has developed a body of\\u000aknowledge on the effects of the use of these technologies. While ICTs have long been used in\\u000amanufacturing processes, the use of computers and networks, and a growing number

  14. A professional development project for improving the use of information and communication technologies in science teaching

    Microsoft Academic Search

    Jari Lavonen; Kalle Juuti; Maija Aksela; Veijo Meisalo

    2006-01-01

    This article describes a professional development project aiming to develop practical approaches for the integration of information and communication technologies (ICT) into science education. Altogether, 13 two?day face?to?face seminars and numerous computer network conferences were held during a three?year period. The goals for the project were based on the general goals of the Finnish national framework curriculum and ICT strategy.

  15. Direction gnrale des technologies de l'information et de la communication

    E-print Network

    Charette, André

    Direction générale des technologies de l'information et de la communication Service vpn.umontreal.ca Première utilisation de vpn.umontreal.ca sur un Mac... · Dans un navigateur web, aller à l'adresse http://vpn). · Une fois dans la page vpn.umontreal.ca, à la droite de Network Connect, cliquer sur le bouton

  16. Using Visual Analytics and Information Visualization to Investigate In-Car Communication Processes

    Microsoft Academic Search

    Michael Sedlmair; Andreas Butz

    Modern cars provide a large spectrum of electronic functional- ity which is realized by a great number of interconnected elec- tronic control units (ECUs). The constantly increasing complexity of these in-car communication networks challenges developers in terms of understandability. The goal of my PhD research is to find novel and suitable methods of visual analytics (VA) and information visualization (InfoVis)

  17. Testing Information Causality for General Quantum Communication Protocols

    E-print Network

    I-Ching Yu; Feng-Li Lin

    2013-08-13

    Information causality was proposed as a physical principle to put upper bound on the accessible information gain in a physical bi-partite communication scheme. Intuitively, the information gain cannot be larger than the amount of classical communication to avoid violation of causality. Moreover, it was shown that this bound is consistent with the Tsirelson bound for the binary quantum systems. In this paper, we test the information causality for the more general (non-binary) quantum communication schemes. In order to apply the semi-definite programming method to find the maximal information gain, we only consider the schemes in which the information gain is monotonically related to the Bell-type functions, i.e., the generalization of CHSH functions for Bell inequalities in a binary schemes. We determine these Bell-type functions by using the signal decay theorem. Our results support the proposal of information causality. We also find the maximal information gain by numerical brute-force method for the most general 2-level and 2-setting quantum communication schemes. Our results show that boundary for the information causality bound does not agree with the one for the Tsirelson bound.

  18. 75 FR 34802 - Meeting To Learn of U.S. Information and Communications Technologies (ICT) Industry Efforts To...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-18

    ...Communications Technologies (ICT) Industry Efforts...Communications and Information Policy (CIP) will hold...advocates international policies for expanded access...communication technologies (ICT), improved efficiency...Communications and Information Policy and facilitated by...communications technologies (ICT) industry...

  19. Sailor: Maryland's Online Public Information Network

    NSDL National Science Digital Library

    1999-01-01

    Sailor - Maryland's Information Network - provides general Maryland government information and a wide variety of Internet jump-points. The gopher is run by the Pratt Free Library and also has local dialup numbers in Maryland.

  20. Predicting Information Flows in Network Traffic.

    ERIC Educational Resources Information Center

    Hinich, Melvin J.; Molyneux, Robert E.

    2003-01-01

    Discusses information flow in networks and predicting network traffic and describes a study that uses time series analysis on a day's worth of Internet log data. Examines nonlinearity and traffic invariants, and suggests that prediction of network traffic may not be possible with current techniques. (Author/LRW)

  1. Department of Communications and Networking WORKING PAPERSSCIENCE +

    E-print Network

    Ott, Jörg

    . Keywords-best-effort security; opportunistic networks; frag- ment authentication I. INTRODUCTION of available contact opportunities [2]. Frag- mentation in the presence of resource hogs implies the need for publicly verifiable fragment authentication. Without frag- ment authentication, intermediaries assign

  2. Stochastically Bounded Burstiness for Communication Networks

    Microsoft Academic Search

    David Starobinski; Moshe Sidi

    1999-01-01

    A network calculus is developed for processes whose burstiness is stochastically bounded by general decreasing func- tions. This calculus is useful for a large class of input processes, including important processes exhibiting \\

  3. Trusted Networking Mobile Peer-Peer Communications

    E-print Network

    -network use. Contact Details Business Development David McKeague ATP Tel: +61 2 9376 2060 Email: david (47), Staff House Road, St Lucia QLD 4072 PO Box 6020 St Lucia QLD 4067 Australia Tel: + 61 7 3300

  4. Optimising Quality of Information in Data Collection for Mobile Sensor Networks

    E-print Network

    Flener, Pierre

    sensor is capable of communicating with every other node in range through Bluetooth or near fieldOptimising Quality of Information in Data Collection for Mobile Sensor Networks Farshid Hassani.Pearson}@it.uu.se Abstract--Wireless sensor networks have become increasingly popular for environmental and activity

  5. Contingency\\/disaster recovery planning for transmission systems of the Defense Information System Network

    Microsoft Academic Search

    D. R. Smith; W. J. Cybrowski; F. Zawislan; D. Arnstein; A. D. Dayton; T. D. Studwell

    1994-01-01

    The paper provides recommendations for the enhancement and protection of the Defense Information System Network (DISN) for disaster recovery and contingencies. The DISN is a worldwide Defense Department network designed to serve consolidated and integrated communication requirements of the defense services and agencies. The ability to recover from disasters and allow for contingencies must be inherent in the design of

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

    NASA Technical Reports Server (NTRS)

    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.

  7. College of Engineering, Boston University Spring 2013 EC541 Computer Communication Networks

    E-print Network

    Goldberg, Bennett

    College of Engineering, Boston University Spring 2013 EC541 Computer Communication Networks of fundamental concepts in computer networking o Queueing and delay models in communication networks o Little references: S. Keshav, An engineering approach to computer networking, Addison-Wesley 1997 L. Kleinrock

  8. Impact of imperfect information on network attack

    NASA Astrophysics Data System (ADS)

    Melchionna, Andrew; Caloca, Jesus; Squires, Shane; Antonsen, Thomas M.; Ott, Edward; Girvan, Michelle

    2015-03-01

    This paper explores the effectiveness of network attack when the attacker has imperfect information about the network. For Erd?s-Rnyi networks, we observe that dynamical importance and betweenness centrality-based attacks are surprisingly robust to the presence of a moderate amount of imperfect information and are more effective compared with simpler degree-based attacks even at moderate levels of network information error. In contrast, for scale-free networks the effectiveness of attack is much less degraded by a moderate level of information error. Furthermore, in the Erd?s-Rnyi case the effectiveness of network attack is much more degraded by missing links as compared with the same number of false links.

  9. Information and Communication Technologies in Development: a UNESCO Perspective.

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific, and Cultural Organization, Paris (France).

    The rapid development and use of information and communication technologies (ICTs) has a direct and dramatic impact on all aspects of life. The traditional distinctions among media, publishing, telecommunications, computing, and information services have become blurred, and new paradigms for creation, dissemination, and exploitation of knowledge

  10. Nonlinear limits to the information capacity of optical fibre communications

    Microsoft Academic Search

    Partha P. Mitra; Jason B. Stark

    2001-01-01

    The exponential growth in the rate at which information can be communicated through an optical fibre is a key element in the `information revolution'. However, as for all exponential growth laws, physical limits must be considered. The nonlinear nature of the propagation of light in optical fibre has made these limits difficult to elucidate. Here we use a key simplification

  11. Finding Community Through Information and Communication Technology During Disaster Events

    Microsoft Academic Search

    Irina Shklovski; Leysia Palen; Jeannette Sutton

    Disasters affect not only the welfare of individuals and family groups, but also the well-being of communities, and can serve as a catalyst for innovative uses of information and communication technology (ICT). In this paper, we present evidence of ICT use for re-orientation toward the community and for the production of public goods in the form of information dissemination during

  12. Finding community through information and communication technology in disaster response

    Microsoft Academic Search

    Irina Shklovski; Leysia Palen; Jeannette Sutton

    2008-01-01

    Disasters affect not only the welfare of individuals and family groups, but also the well-being of communities, and can serve as a catalyst for innovative uses of information and communication technology (ICT). In this paper, we present evidence of ICT use for re-orientation toward the community and for the production of public goods in the form of information dissemination during

  13. Communicating Ocean Sciences to Informal Audiences (COSIA): Final Evaluation Report

    ERIC Educational Resources Information Center

    Phillips, Michelle; St. John, Mark

    2010-01-01

    Communicating Ocean Sciences to Informal Audiences (COSIA) is a National Science Foundation (NSF)-funded project consisting of six three-way partnerships between the Lawrence Hall of Science (LHS) and an informal science education institution (ISEI) partnered with an institution of higher education (IHE). Together, educators from the ISEI (often

  14. Communicating Ocean Sciences to Informal Audiences (COSIA): Interim Evaluation Report

    ERIC Educational Resources Information Center

    St. John, Mark; Phillips, Michelle; Smith, Anita; Castori, Pam

    2009-01-01

    Communicating Ocean Sciences to Informal Audiences (COSIA) is a National Science Foundation (NSF)-funded project consisting of seven long-term three-way partnerships between the Lawrence Hall of Science (LHS) and an informal science education institution (ISEI) partnered with an institution of higher education (IHE). Together, educators from the

  15. On the assessment of visual communication by information theory

    NASA Technical Reports Server (NTRS)

    Huck, Friedrich O.; Fales, Carl L.

    1993-01-01

    This assessment of visual communication integrates the optical design of the image-gathering device with the digital processing for image coding and restoration. Results show that informationally optimized image gathering ordinarily can be relied upon to maximize the information efficiency of decorrelated data and the visual quality of optimally restored images.

  16. Information Services in the International Network Marketplace.

    ERIC Educational Resources Information Center

    Hepworth, Mark E.

    1987-01-01

    Examines the internationalism of the network marketplace through case studies of the London Stock Exchange and I. P. Sharp Associates, a Canadian computer service bureau. Discussion focuses on the importance of transnational computer networks to the production of information services and marketplace expansion, and global information policy issues.

  17. Informal Networks in a Dynamic Regional Cluster

    Microsoft Academic Search

    Michael S. Dahl; Christian ; R. Pedersen

    2002-01-01

    The role of informal networks in the development of regional clusters has received a lot of attention in the debate recently. Informal networks between employees in different firms are argued to be one of the main carriers of knowledge between firms in a cluster. As a result firms wish to locate in these clusters to more or less automatically participate

  18. Information theory, animal communication, and the search for extraterrestrial intelligence

    NASA Astrophysics Data System (ADS)

    Doyle, Laurance R.; McCowan, Brenda; Johnston, Simon; Hanser, Sean F.

    2011-02-01

    We present ongoing research in the application of information theory to animal communication systems with the goal of developing additional detectors and estimators for possible extraterrestrial intelligent signals. Regardless of the species, for intelligence (i.e., complex knowledge) to be transmitted certain rules of information theory must still be obeyed. We demonstrate some preliminary results of applying information theory to socially complex marine mammal species (bottlenose dolphins and humpback whales) as well as arboreal squirrel monkeys, because they almost exclusively rely on vocal signals for their communications, producing signals which can be readily characterized by signal analysis. Metrics such as Zipf's Law and higher-order information-entropic structure are emerging as indicators of the communicative complexity characteristic of an "intelligent message" content within these animals' signals, perhaps not surprising given these species' social complexity. In addition to human languages, for comparison we also apply these metrics to pulsar signalsperhaps (arguably) the most "organized" of stellar systemsas an example of astrophysical systems that would have to be distinguished from an extraterrestrial intelligence message by such information theoretic filters. We also look at a message transmitted from Earth (Arecibo Observatory) that contains a lot of meaning but little information in the mathematical sense we define it here. We conclude that the study of non-human communication systems on our own planet can make a valuable contribution to the detection of extraterrestrial intelligence by providing quantitative general measures of communicative complexity. Studying the complex communication systems of other intelligent species on our own planet may also be one of the best ways to deprovincialize our thinking about extraterrestrial communication systems in general.

  19. SECURITY AND COMMUNICATION NETWORKS Security Comm. Networks. 2008; 1:375388

    E-print Network

    Vouyioukas, Demosthenes

    It has been generally agreed that the security of electronic patient records and generally eSECURITY AND COMMUNICATION NETWORKS Security Comm. Networks. 2008; 1:375388 Published online 2 of secure web based m-health services utilizing XML based security models Demosthenes Vouyioukas*,y , George

  20. A Queueing Network Analysis of Computer Communication Networks with Window Flow Control

    Microsoft Academic Search

    MARTIN REISER

    1979-01-01

    A computer communication network with window flow control is modeled by a closed multichain queueing network. The severe computational limitation of previous solution algorithms is overcome with a heuristic derived from the recently found mean value analysis. A large numerical example is given.

  1. Space sensing, communications, and networking; Proceedings of the Meeting, LOS Angeles, CA, Jan. 16-18, 1989

    Microsoft Academic Search

    Monte Ross; Richard J. Temkin

    1989-01-01

    Various papers on space sensing, communications, and networking are presented. Individual topics addressed include: multiple satellite network architectures based on laser communications, mitigation of scintillation for high data rate communications links, space communication network issues for air defense, telecommunications and navigation systems design for manned Mars exploration missions, effect of double-ended beam tracking errors on optical PPM communication, estimation and

  2. Basics of perfect communication through quantum networks

    SciTech Connect

    Kay, Alastair [Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543, and Keble College, Parks Road, Oxford OX1 3PG (United Kingdom)

    2011-08-15

    Perfect transfer of a quantum state through a one-dimensional chain is now well understood, allowing one not only to decide whether a fixed Hamiltonian achieves perfect transfer but to design a suitable one. We are particularly interested in being able to design, or understand the limitations imposed upon, Hamiltonians subject to various naturally arising constraints such as a limited coupling topology with low connectivity (specified by a graph) and type of interaction. In this paper, we characterize the necessary and sufficient conditions for transfer through a network and describe some natural consequences such as the impossibility of routing between many different recipients for a large class of Hamiltonians and the limitations on transfer rate. We also consider some of the trade-offs that arise in uniformly coupled networks (both Heisenberg and XX models) between transfer distance and the size of the network as a consequence of the derived conditions.

  3. Involuntary Information Leakage in Social Network Services

    E-print Network

    Chen, Sheng-Wei

    the identified involuntary information leakage problem. 1 Introduction Social network services (SNS) represent personal information This work was supported in part by Taiwan Information Security Center (TWISC addressed the problems of privacy invasion and security threats raised by information exposure online, e

  4. 78 FR 17418 - Rural Health Information Technology Network Development Grant

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-21

    ...Administration Rural Health Information Technology Network Development Grant AGENCY: Health Resources...the Rural Health Information Technology Network Development Grant (RHITND) to Grace...the Rural Health Information Technology Network Development (RHITND) Grant to the...

  5. Passing crisis and emergency risk communications: The effects of communication channel, information type, and repetition.

    PubMed

    Edworthy, Judy; Hellier, Elizabeth; Newbold, Lex; Titchener, Kirsteen

    2015-05-01

    Three experiments explore several factors which influence information transmission when warning messages are passed from person to person. In Experiment 1, messages were passed down chains of participants using five different modes of communication. Written communication channels resulted in more accurate message transmission than verbal. In addition, some elements of the message endured further down the chain than others. Experiment 2 largely replicated these effects and also demonstrated that simple repetition of a message eliminated differences between written and spoken communication. In a final field experiment, chains of participants passed information however they wanted to, with the proviso that half of the chains could not use telephones. Here, the lack of ability to use a telephone did not affect accuracy, but did slow down the speed of transmission from the recipient of the message to the last person in the chain. Implications of the findings for crisis and emergency risk communication are discussed. PMID:25683552

  6. Protocol for a Delay-Tolerant Data-Communication Network

    NASA Technical Reports Server (NTRS)

    Torgerson, Jordan; Hooke, Adrian; Burleigh, Scott; Fall, Kevin

    2004-01-01

    As its name partly indicates, the Delay-Tolerant Networking (DTN) Bundle Protocol is a protocol for delay-tolerant transmission of data via communication networks. This protocol was conceived as a result of studies of how to adapt Internet protocols so that Internet-like services could be provided across interplanetary distances in support of deep-space exploration. The protocol, and software to implement the protocol, is being developed in collaboration among experts at NASA's Jet Propulsion Laboratory and other institutions. No current Internet protocols can accommodate long transmission delay times or intermittent link connectivity. The DTN Bundle Protocol represents a departure from the standard Internet assumption that a continuous path is available from a host computer to a client computer: It provides for routing of data through networks that may be disjointed and may be characterized by long transmission delays. In addition to networks that include deepspace communication links, examples of such networks include terrestrial ones within which branches are temporarily disconnected. The protocol is based partly on the definition of a message-based overlay above the transport layers of the networks on which it is hosted.

  7. Radar network communication through sensing of frequency hopping

    SciTech Connect

    Dowla, Farid; Nekoogar, Faranak

    2013-05-28

    In one embodiment, a radar communication system includes a plurality of radars having a communication range and being capable of operating at a sensing frequency and a reporting frequency, wherein the reporting frequency is different than the sensing frequency, each radar is adapted for operating at the sensing frequency until an event is detected, each radar in the plurality of radars has an identification/location frequency for reporting information different from the sensing frequency, a first radar of the radars which senses the event sends a reporting frequency corresponding to its identification/location frequency when the event is detected, and all other radars in the plurality of radars switch their reporting frequencies to match the reporting frequency of the first radar upon detecting the reporting frequency switch of a radar within the communication range. In another embodiment, a method is presented for communicating information in a radar system.

  8. Communications of the Association for Information Systems

    E-print Network

    Crowston, Kevin

    Report: Open Access Publishing to Nurture the Sprouts of Knowledge and the Future of Information Systems to Nurture the Sprouts of Knowledge and the Future of Information Systems Research Michel Avital, Bo of the Internet and the subsequent adoption of Open Access schemata are changing the nature of the scholarly

  9. Active Information Networks and XML Active Information Networks and XML

    E-print Network

    Marshall, Ian W.

    are identified; rapid introduction of new services, dynamic customisation of services by clients, and minimal realisable active network proposal, is a potential solution to all three. Combining eXtensible Markup Language and Application Layer Active Networking yields strong benefits for networked services. A Wide

  10. Three-Party Quantum Network Communication Protocols Based on Quantum Teleportation

    NASA Astrophysics Data System (ADS)

    Zhou, Nan-Run; Cheng, Hu-Lai; Gong, Li-Hua; Li, Chi-Sheng

    2014-04-01

    By utilizing the delocalized correlation of entangled states in quantum information theory, a novel method on acknowledgments of quantum information among three-party is presented, and then two three-party quantum network communication protocols based on quantum teleportation are presented, namely, three-party stop-wait quantum communication protocol and three-party selective automatic repeat quantum communication protocol. In the two proposed protocols, the data frames composed of qubits are teleported via three-party quantum teleportation, the two receivers simultaneously receive quantum frames from the sender, and then return quantum acknowledgment frames or quantum negative acknowledgment frames via quantum entanglement channels. The sender simultaneously receives and deals with quantum acknowledgment frames and quantum negative acknowledgment frames from the two receivers, thus the processing delay on returning quantum frames is reduced. And due to the transience of transferring quantum information, the returning of quantum acknowledgment frames and quantum negative acknowledgment frames are completed instantaneously, the proposed protocols reduce the transmission delay and improve the communication efficiency. During the whole course of communications, the classical channels are only used to transmit the measurement message, so the burdens of classical channels are reduced.

  11. Good Communication: The Other Social Network for Successful IT Organizations

    ERIC Educational Resources Information Center

    Trubitt, Lisa; Overholtzer, Jeff

    2009-01-01

    Social networks of the electronic variety have become thoroughly embedded in contemporary culture. People have woven these networks into their daily routines, using Facebook, Twitter, LinkedIn, online gaming environments, and other tools to build and maintain complex webs of professional and personal relationships. Chief Information Officers

  12. Fault-tolerant onboard digital information switching and routing for communications satellites

    NASA Technical Reports Server (NTRS)

    Shalkhauser, Mary JO; Quintana, Jorge A.; Soni, Nitin J.; Kim, Heechul

    1993-01-01

    The NASA Lewis Research Center is developing an information-switching processor for future meshed very-small-aperture terminal (VSAT) communications satellites. The information-switching processor will switch and route baseband user data onboard the VSAT satellite to connect thousands of Earth terminals. Fault tolerance is a critical issue in developing information-switching processor circuitry that will provide and maintain reliable communications services. In parallel with the conceptual development of the meshed VSAT satellite network architecture, NASA designed and built a simple test bed for developing and demonstrating baseband switch architectures and fault-tolerance techniques. The meshed VSAT architecture and the switching demonstration test bed are described, and the initial switching architecture and the fault-tolerance techniques that were developed and tested are discussed.

  13. Disclosure Control of Natural Language Information to Enable Secure and Enjoyable Communication over the Internet

    NASA Astrophysics Data System (ADS)

    Kataoka, Haruno; Utsumi, Akira; Hirose, Yuki; Yoshiura, Hiroshi

    Disclosure control of natural language information (DCNL), which we are trying to realize, is described. DCNL will be used for securing human communications over the internet, such as through blogs and social network services. Before sentences in the communications are disclosed, they are checked by DCNL and any phrases that could reveal sensitive information are transformed or omitted so that they are no longer revealing. DCNL checks not only phrases that directly represent sensitive information but also those that indirectly suggest it. Combinations of phrases are also checked. DCNL automatically learns the knowledge of sensitive phrases and the suggestive relations between phrases by using co-occurrence analysis and Web retrieval. The users' burden is therefore minimized, i.e., they do not need to define many disclosure control rules. DCNL complements the traditional access control in the fields where reliability needs to be balanced with enjoyment and objects classes for the access control cannot be predefined.

  14. Scaling of data communications for an advanced supercomputer network

    NASA Technical Reports Server (NTRS)

    Levin, E.; Eaton, C. K.; Young, Bruce

    1986-01-01

    The goal of NASA's Numerical Aerodynamic Simulation (NAS) Program is to provide a powerful computational environment for advanced research and development in aeronautics and related disciplines. The present NAS system consists of a Cray 2 supercomputer connected by a data network to a large mass storage system, to sophisticated local graphics workstations and by remote communication to researchers throughout the United States. The program plan is to continue acquiring the most powerful supercomputers as they become available. The implications of a projected 20-fold increase in processing power on the data communications requirements are described.

  15. Center for Networked Information Discovery and Retrieval

    NSDL National Science Digital Library

    The prototype AIDS patent library is a system designed by MCNC's Clearinghouse for Networked Information Discovery and Retrieval (CNIDR) for the U.S. Patent and Trademark Office (PTO) and will serve as a model for storing and disseminating government and other public documents in the future. The system uses CNIDR-developed information retrieval software and supports direct access to patents through a variety of popular network information services such as Z39.50, World Wide Web and electronic mail.

  16. [Communication of useful information from laboratory physicians to clinical physicians].

    PubMed

    Shimetani, Naoto

    2003-04-01

    In recent years increasing importance has been placed on the role of hospital clinical research, such as the promotion of intra-laboratory human, material and informational resources, previously restricted to the laboratory, to the whole hospital system, and the appropriate usage of laboratory findings via common consultation systems, or specialized informational consultants in the clinical laboratory department. The volume of clinical laboratory information, which plays an important role in the decision-making process of routine clinical practices, is enormous for each individual hospital, and appropriate use of this information has a major influence on institutional clinical practice efficiency. In response to the need for the communication of useful laboratory information to clinical physicians, departments of laboratory research consultants have been organized in individual hospitals as a way forward. In the near future, laboratory physicians will play a leading role in the communication of research information from the viewpoint of EBLM (evidence-based laboratory medicine). From the work of these laboratory research consultants, it becomes possible to obtain relevant EBLM-related information, such as frequently asked questions and opinions, from their users. By replying to these questions and opinions appropriately, laboratory research consultants can provide information that is both advantageous and useful, and which meets the needs of the clinical physician side. Effective communication of useful laboratory research information should not be restricted to either the laboratory physicians or the technicians; it is a job that needs the cooperation and teamwork of both sets of people. Also, they should always keep in mind that communication by itself is not sufficient; they should not assume the useful evaluation of information by the users, but rather ensure that they are presented with information that precisely meets their needs. PMID:12747256

  17. Aerial networking communication solutions using Micro Air Vehicle (MAV)

    NASA Astrophysics Data System (ADS)

    Balasubramanian, Shyam; de Graaf, Maurits; Hoekstra, Gerard; Corporaal, Henk; Wijtvliet, Mark; Cuadros Linde, Javier

    2014-10-01

    The application of a Micro Air Vehicle (MAV) for wireless networking is slowly gaining significance in the field of network robotics. Aerial transport of data requires efficient network protocols along with accurate positional adjustment of the MAV to minimize transaction times. In our proof of concept, we develop an Aerial networking protocol for data transfer using the technology of Disruption Tolerant Networks (DTN), a store-and-forward approach for environments that deals with disrupted connectivity. Our results show that close interaction between networking and flight behavior helps in efficient data exchange. Potential applications are in areas where network infrastructure is minimal or unavailable and distances may be large. For example, forwarding video recordings during search and rescue, agriculture, swarm communication, among several others. A practical implementation and validation, as described in this paper, presents the complex dynamics of wireless environments and poses new challenges that are not addressed in earlier work on this topic. Several tests are evaluated in a practical setup to display the networking MAV behavior during such an operation.

  18. Destination-directed, packet-switched architecture for a geostationary communications satellite network

    NASA Astrophysics Data System (ADS)

    Ivancic, William D.; Shalkhauser, Mary Jo; Bobinsky, Eric A.; Soni, Nitin J.; Quintana, Jorge A.; Kim, Heechul; Wager, Paul; Vanderaar, Mark

    1993-07-01

    A major goal of the Digital Systems Technology Branch at the NASA Lewis Research Center is to identify and develop critical digital components and technologies that either enable new commercial missions or significantly enhance the performance, cost efficiency, and/or reliability of existing and planned space communications systems. NASA envisions a need for low-data-rate, interactive, direct-to-the-user communications services for data, voice, facsimile, and video conferencing. The network would provide enhanced very-small-aperture terminal (VSAT) communications services and be capable of handling data rates of 64 kbps through 2.048 Mbps in 64-kbps increments. Efforts have concentrated heavily on the space segment; however, the ground segment has been considered concurrently to ensure cost efficiency and realistic operational constraints. The focus of current space segment developments is a flexible, high-throughput, fault-tolerant onboard information-switching processor (ISP) for a geostationary satellite communications network. The Digital Systems Technology Branch is investigating both circuit and packet architectures for the ISP. Destination-directed, packet-switched architectures for geostationary communications satellites are addressed.

  19. Future large broadband switched satellite communications networks

    NASA Technical Reports Server (NTRS)

    Staelin, D. H.; Harvey, R. R.

    1979-01-01

    Critical technical, market, and policy issues relevant to future large broadband switched satellite networks are summarized. Our market projections for the period 1980 to 2000 are compared. Clusters of switched satellites, in lieu of large platforms, etc., are shown to have significant advantages. Analysis of an optimum terrestrial network architecture suggests the proper densities of ground stations and that link reliabilities 99.99% may entail less than a 10% cost premium for diversity protection at 20/30 GHz. These analyses suggest that system costs increase as the 0.6 power of traffic. Cost estimates for nominal 20/30 GHz satellite and ground facilities suggest optimum system configurations might employ satellites with 285 beams, multiple TDMA bands each carrying 256 Mbps, and 16 ft ground station antennas. A nominal development program is outlined.

  20. Emerging Information and Communication Technologies and the Discipline of Project Information Management

    Microsoft Academic Search

    Thomas Froese

    2006-01-01

    Project Management for architecture, engineering, and construction projects could include a well-defined sub-discipline of\\u000a project information management. Not only might this improve project performance, particularly when new information and communication\\u000a technologies are used, but it could also improve the technology transfer processincreasing the potential of new information\\u000a and communication technologies being adopted into industry practice. An overall framework for project

  1. J. Douglas Streit, Information Security Officer Office of Computing and Communications Services

    E-print Network

    J. Douglas Streit, Information Security Officer Office of Computing and Communications Services Last updated February 6, 2012 Old Dominion University Information Technology Security Program #12;J. Douglas Streit, Information Security Officer Office of Computing and Communications Services Last updated

  2. Photon information efficient communication through atmospheric turbulence

    NASA Astrophysics Data System (ADS)

    Chandrasekaran, Nivedita; Shapiro, Jeffrey H.; Wang, Ligong

    2012-10-01

    High photon-efficiency (many bits/photon) optical communication is possible with pulse-position modulation and direct detection, and high spectral efficiency (many bits/sec-Hz) optical communication is possible with quadrature-amplitude modulation and coherent detection. These high efficiencies, however, cannot be achieved simultaneously unless multiple spatial modes are employed. Previous work for the vacuum-propagation channel has shown that achieving 10 bits/photon and 5 bits/sec-Hz is impossible with coherent detection, and it requires 189 low diffraction-loss spatial modes at the ultimate Holevo limit, and 4500 such modes at the Shannon limit for on-off keying with direct detection. For terrestrial propagation paths, however, the effects of atmospheric turbulence must be factored into the photon and spectral efficiency assessments. This paper accomplishes that goal by presenting upper and lower bounds on the turbulent channel's ergodic Holevo capacity for M-mode systems whose transmitters use either focused-beam, Hermite-Gaussian (HG), or Laguerre-Gaussian (LG) modes, and whose receivers do M-mode detection either with or without adaptive optics. The bounds show that use of adaptive optics will not be necessary for achieving high photon efficiency and high spectral efficiency through atmospheric turbulence, although receivers which do not use adaptive optics will need to cope with considerable crosstalk between the spatial patterns produced in their entrance pupils by the M-mode transmitter. The bounds also show the exact theoretical equivalence of the HG and LG mode sets for this application, generalizing a result previously established for the vacuum-propagation channel. Finally, our results show that the FB modes outperform the HG and LG modes in operation with and without adaptive optics.

  3. Impact of Information and Communication Technology on Information Seeking Behavior of Users in Astronomy and Astrophysics Centers of India: A Survey

    NASA Astrophysics Data System (ADS)

    Sahu, H. K.; Singh, S. N.

    2010-10-01

    This study is based on a survey designed to determine the Information Seeking Behavior (ISB) of Astronomy and Astrophysics users in India. The main objective of the study is to determine the sources consulted and the general pattern of the information-gathering system of users and the impact of Information and Communication Technology (ICT) on the Astronomy and Astrophysics user's Information Seeking Behavior. It examines various Information and Communication Technology-based resources and methods of access and use. A descriptive sample stratified method has been used and data was collected using a questionnaire as the main tool. The response rate was 72%. Descriptive statistics were also employed and data have been presented in tables and graphs. The study is supported by earlier studies. It shows that Astronomy and Astrophysics users have developed a unique Information Seeking Behavior to carry out their education and research. The vast majority of respondents reported that more information is available from a variety of e-resources. Consequently, they are able to devote more time to seek out relevant information in the current Information and Communication Technology scenario. The study also indicates that respondents use a variety of information resources including e-resources for teaching and research. Books and online databases such as the NASA Astrophysics Data System (ADS) were considered more important as formal sources of information. E-mail and face-to-face communications are used extensively by users as informal sources of information. It also reveals that despite the presence of electronic sources, Astronomy and Astrophysics users are still using printed materials. This study should to help to improve various Information and Communication Technology-based services. It also suggests that GOI should adopt Information and Communication Technology-based Information Centers and Libraries services and recommends a network-based model for Astronomy and Astrophysics users.

  4. Technology and Research Requirements for Combating Human Trafficking: Enhancing Communication, Analysis, Reporting, and Information Sharing

    SciTech Connect

    Kreyling, Sean J.; West, Curtis L.; Olson, Jarrod

    2011-03-17

    DHS Science & Technology Directorate directed PNNL to conduct an exploratory study on the domain of human trafficking in the Pacific Northwest in order to examine and identify technology and research requirements for enhancing communication, analysis, reporting, and information sharing activities that directly support efforts to track, identify, deter, and prosecute human trafficking including identification of potential national threats from smuggling and trafficking networks. This effort was conducted under the Knowledge Management Technologies Portfolio as part of the Integrated Federal, State, and Local/Regional Information Sharing (RISC) and Collaboration Program.

  5. A pricing scheme to maximize social welfare in communication networks

    NASA Astrophysics Data System (ADS)

    Estvez, J.; Xiong, H. G.; Gao, Q.; Guerrero, E.

    2009-12-01

    In this paper, we analyze switching from the current flat-rate Internet pricing to adopt usage-based pricing schemes. Even if flat rate pricing is one of the main reasons for the success of the Internet, the only way to prevent network congestion, differentiate services and maximizes social welfare is to adopt usage-based pricing schemes. Our scheme is highly related to an optimal congestion and cost-sharing pricing scheme for multiclass services applied to communication networks developed by Yezekael Hayel, Bruno Tuffin and design a pricing scheme that maximizes the social welfare which is the total gross value minus the total expected delay cost.

  6. ECS: Efficient Communication Scheduling for Underwater Sensor Networks

    PubMed Central

    Hong, Lu; Hong, Feng; Guo, Zhongwen; Li, Zhengbao

    2011-01-01

    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. PMID:22163775

  7. Practical issues in picture archiving and communication system and networking

    PubMed Central

    Kalyanpur, Arjun; Singh, Jasbir; Bedi, Ricky

    2010-01-01

    Picture Archiving and Communication System (PACS) is a key workflow tool in the functioning of radiology departments worldwide, today, and its utilization is rapidly growing in India. The key challenges in PACS implementation are related to vendor and feature selection, integration with the existing HIS, user training, maintenance and scalability to meet increasing demands. Additionally, the networking requirements that PACS imposes on hospital networks are not insignificant. This article attempts to review these issues from the standpoint of what a prospective or new user needs to know. PMID:20351983

  8. Multiply-agile encryption in high speed communication networks

    SciTech Connect

    Pierson, L.G. [Sandia National Labs., Albuquerque, NM (United States); Witzke, E.L. [RE/SPEC Inc., Albuquerque, NM (United States)

    1997-05-01

    Different applications have different security requirements for data privacy, data integrity, and authentication. Encryption is one technique that addresses these requirements. Encryption hardware, designed for use in high-speed communications networks, can satisfy a wide variety of security requirements if that hardware is key-agile, robustness-agile and algorithm-agile. Hence, multiply-agile encryption provides enhanced solutions to the secrecy, interoperability and quality of service issues in high-speed networks. This paper defines these three types of agile encryption. Next, implementation issues are discussed. While single-algorithm, key-agile encryptors exist, robustness-agile and algorithm-agile encryptors are still research topics.

  9. The World Information Network on Biodiversity

    NSDL National Science Digital Library

    1969-12-31

    The World Information Network on Biodiversity (REMIB) is organized and provided by Mexico's National Commission for the Knowledge and Use of the Biodiversity. REMIB is a network of shared biological information databases from research centers in Mexico, the US, Costa Rica, and Spain. The databases contain "curatorial, taxonomic, ecological, cartographic, bibliographic, ethno-biological type, use of catalogues on natural resources and other subject matters." Currently, REMIB gathers information on taxonomic groups of plants, as well as terrestrial and aquatic vertebrates, and invertebrates. The network contains information on over 6 million specimens from over 200 countries, and will be soon be incorporating collections from additional sources, such as the Smithsonian Institution and the Kew Herbarium. Users must first click on Access to the Information and accept the conditions for data use before reaching the network's search engine. The main page includes links to the home pages of partner institutions.

  10. Optimal Information Processing in Biochemical Networks

    NASA Astrophysics Data System (ADS)

    Wiggins, Chris

    2012-02-01

    A variety of experimental results over the past decades provide examples of near-optimal information processing in biological networks, including in biochemical and transcriptional regulatory networks. Computing information-theoretic quantities requires first choosing or computing the joint probability distribution describing multiple nodes in such a network --- for example, representing the probability distribution of finding an integer copy number of each of two interacting reactants or gene products while respecting the `intrinsic' small copy number noise constraining information transmission at the scale of the cell. I'll given an overview of some recent analytic and numerical work facilitating calculation of such joint distributions and the associated information, which in turn makes possible numerical optimization of information flow in models of noisy regulatory and biochemical networks. Illustrating cases include quantification of form-function relations, ideal design of regulatory cascades, and response to oscillatory driving.

  11. Communicating quantitative information about unexploded ordnance risks to the public.

    PubMed

    MacDonald Gibson, Jacqueline; Rowe, Aimee; Stone, Eric R; Bruine de Bruin, Wandi

    2013-05-01

    Military base closures have left 600,000 acres of U.S. land contaminated with unexploded ordnance (UXO). Recent research has demonstrated a method for quantifying the probability of residual UXO harming future land users. Here, we explore how a community neighboring a closed, UXO-contaminated military base responds to the probabilistic risk information this method produces. We explore how probabilistic information affects their risk understanding, risk management preferences, risk perceptions, and worry. We test eight different communication formats employing varying combinations of textual risk descriptions, comparative risk information, stacked bar graphs illustrating the proportion of future land users at risk, and textual summaries and/or graphical histograms presenting uncertainty. We find that stacked bar graphs double the odds of correctly reporting the probability of harm and decrease the perceived risk, compared to textual descriptions. Providing histograms or summary uncertainty information decreases the odds of correctly reporting the probability of harm by about one-half, compared to communications without uncertainty information. We also find that risk communication formats do not alter risk management preferences. We recommend that as EPA reevaluates its UXO risk management policies in the coming year, the agency shift to quantitative rather than its current qualitative approach to assessing and communicating UXO risks. PMID:23514101

  12. Asymmetries in commitment in an avian communication network

    NASA Astrophysics Data System (ADS)

    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.

  13. Asymmetries in commitment in an avian communication network.

    PubMed

    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. PMID:23325292

  14. Program Support Communications Network (PSCN) facsimile system directory

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This directory provides a system description, a station listing, and operating procedures for the Program Support Communications Network (PSCN) NASA Facsimile System. The NASA Facsimile System is a convenient and efficient means of spanning the distance, time, and cost of transmitting documents from one person to another. In the spectrum of communication techniques, facsimile bridges the gap between mail and data transmission. Facsimile can transmit in a matter of minutes or seconds what would take a day or more by mail delivery. The NASA Facsimile System is composed of several makes and models of facsimile machines. The system also supports the 3M FaxXchange network controllers located at Marshall Space Flight Center (MSFC).

  15. Modeling and Analysis of Mobility Management in Mobile Communication Networks

    PubMed Central

    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. PMID:24883368

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

    PubMed

    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. PMID:24883368

  17. Eavesdropping and communication networks revealed through playback and an acoustic location system

    Microsoft Academic Search

    Lauren P. Fitzsimmons; Jennifer R. Foote; Laurene M. Ratcliffe; Daniel J. Mennill

    2008-01-01

    Our understanding of animal communication is expanding from a dyadic framework of one signaler and one receiver to a broader communication network model, yet empirical studies of communication networks are scarce. To investigate whether territorial males eavesdrop on interactions occurring outside of their territory boundaries and to quantify the neighborhood-level effects of song contests, we simulated diurnal dyadic countersinging exchanges

  18. Online Social Networking by Patients with Diabetes: A Qualitative Evaluation of Communication with Facebook

    Microsoft Academic Search

    Jeremy A. Greene; Niteesh K. Choudhry; Elaine Kilabuk; William H. Shrank

    2011-01-01

    BackgroundSeveral disease-specific information exchanges now exist on Facebook and other online social networking sites. These new sources\\u000a of knowledge, support, and engagement have become important for patients living with chronic disease, yet the quality and\\u000a content of the information provided in these digital arenas are poorly understood.\\u000a \\u000a \\u000a \\u000a \\u000a ObjectiveTo qualitatively evaluate the content of communication in Facebook communities dedicated to diabetes.

  19. IEEE CAS Workshop on Wireless Communications and Networking

    NSDL National Science Digital Library

    In September 2002, researchers from universities and technical companies from around the world met for a Workshop on Wireless Communications and Networking. The documents that can be downloaded from this Web page consist of over twenty full papers presented at the event and several more one-page research summaries. Many of the papers address low-power design and issues, while others discuss applications of ultra-wideband technology.

  20. Energy efficient communication protocol for wireless sensor networks

    Microsoft Academic Search

    W. Rabiner Heinzelman; A. Chandrakasan; H. Balakrish-nan

    2000-01-01

    Abstract Wireless distributed microsensor systems will enable the reliable monitoring of a variety of environments,for both civil and military applications. In this paper, we look at communication protocols, which can have signicant im- pact on the overall energy dissipation of these networks. Based on our ndings,that the conventional protocols of direct transmission, minimum-transmission-energy, multi- hop routing, and static clustering may