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1

Information communication on complex networks  

NASA Astrophysics Data System (ADS)

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.

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

2013-02-01

2

Networking Paradigms: Information Technology and Communication Studies.  

ERIC Educational Resources Information Center

Communications media have long been acknowledged as the site of intense political struggle over issues of access to, control over, and representations in these media. That communications research is likewise the site of struggle between the various paradigms of the discipline is, however, troubling to the neophyte communication scholar. For well…

Howley, Kevin

3

The projects of Disaster-Resistant Information Communication Network at the Research Organization of Electrical Communication, Tohoku University  

NASA Astrophysics Data System (ADS)

After the East Japan Great Earthquake, Tohoku University has established Research Organization of Electrical Communication to achieve the most advanced disaster-resistant information communication network in the world. In this paper, we will introduce our projects of "Disaster-Resistant Information Communication Network" based on industry-academia-government collaboration.

Iwatsuki, Katsumi

2012-12-01

4

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

ERIC Educational Resources Information Center

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)

Sanchez-Vegas, Saadia

1995-01-01

5

Epidemic-style Communication Primitives Exploiting Network Topology Information  

Microsoft Academic Search

Gossip-based communication and epidemic-style routing al- gorithms have been proposed to achieve scalability in distributed systems and to support probabilistic communication when the application of the classic deterministic algorithms and protocols is impossible or unsuit- able. In this paper, we present a middleware for probabilistic communi- cation that relies on optimised epidemic-style information dissemination techniques for distributed systems, based on

Mirco Musolesi; Cecilia Mascolo

6

Electronic Communication Networks.  

ERIC Educational Resources Information Center

Discusses educational uses, types, operation, advantages, popular features, and subscription rates of electronic communication networks. Factors to consider when choosing a network are described, and a table listing networks designed for educators includes information on the network producer, target audience, features, subscription rates, and…

Raimondi, Sharon L.

1984-01-01

7

Communicability in temporal networks  

NASA Astrophysics Data System (ADS)

A first-principles approach to quantify the communicability between pairs of nodes in temporal networks is proposed. It corresponds to the imaginary-time propagator of a quantum random walk in the temporal network, which accounts for unique structural and temporal characteristics of both streaming and nonstreaming temporal networks. The influence of the system's temperature on the perdurability of information and how the communicability identifies patterns of communication hidden in the temporal and topological structure of the networks are also studied for synthetic and real-world systems.

Estrada, Ernesto

2013-10-01

8

Systems and methods for using verified information cards in a communications network  

US Patent & Trademark Office Database

Digital information cards associated with verified information about users are described. The cards can be used to optimize a network communications experience or interaction for a user and a commercial entity, such as a website provider. The cards can be user-centric in that the user can control access to information associated with the card. A website can access the information claim using a link of the information card and can customize a user's website experience based on the verified information claim.

2013-05-14

9

NASA Communications Augmentation network  

NASA Technical Reports Server (NTRS)

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

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

1990-01-01

10

Modeling the socially intelligent communication of health information to a patient's personal social network.  

PubMed

This study examined how emotional proximity and gender affect people's information requirements when someone that they know is chronically or critically ill. In an online study, participants were asked what information they would want to receive about members of their social network in three categories: someone who was very close, someone who was not so close, and someone who was not close at all. Our results show that the information that people want can be predicted from their gender and emotional proximity to the network member. The closer the relationship with the patient, the more information people want. Women want more information than men. We propose a model for the socially intelligent communication of health information across the social network, and discuss areas for its application. PMID:19887326

Moncur, Wendy; Reiter, Ehud; Masthoff, Judith; Carmichael, Alex

2010-03-01

11

Proceedings of the Conference: Universities in World Network of Information and Communication (3rd, Dubrovnik, May 20-23, 1980).  

ERIC Educational Resources Information Center

The study, exploration, and debate of relations between universities, world information systems, and communication networks seeking to establish a sustainable system to handle recent developments in information and communication, utilizing universities as focal points, was continued at this third annual conference attended by 31 information

Soucek, Branko, Ed.

1980-01-01

12

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

NASA Astrophysics Data System (ADS)

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.

Ishiko, Michimasu

13

Communicability across evolving networks.  

PubMed

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

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

2011-04-01

14

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.

15

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

USGS Publications Warehouse

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.

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

2007-01-01

16

Method, apparatus and system for management of information content for enhanced accessibility over wireless communication networks  

US Patent & Trademark Office Database

Information content is managed in a network-based communication system by providing a first web-based interface accessible to a first user, the first web-based interface being configured to permit the first user to designate at least one data source that is external to the first web-based interface, maintaining persistent information content on behalf of the first user including content obtained from the data source designated by the first user, and generating a second web-based interface different than the first web-based interface, wherein access to at least a portion of the persistent information content is provided to each of one or more additional users via the second web-based interface in a manner controlled by the first user via the first web-based interface to thereby facilitate interaction between the first and additional users. The first and second web-based interfaces may comprise respective content management and mobile web sites.

2014-07-29

17

Network information flow  

Microsoft Academic Search

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.

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

2000-01-01

18

An embedded TCP\\/IP hard core for Smart Grid information and communication networks  

Microsoft Academic Search

Embedded system cores for communications networks are becoming much important recently due to the demands placed by Smart Grid, sensor mobile networks, etc. However, embedded system designs have unique metrics such as cost, flexibility, and size. Tuning these metrics during embedded system designs will definitely impact the cost and performance of Smart Grid devices and systems. In this research, we

Rami Amiri; Omar Elkeelany

2012-01-01

19

Natural communication with information systems  

Microsoft Academic Search

Pervasive networking and sophisticated computing open opportunities for collaborative information processing independent of time and space. In this instance the information system becomes an enhancer of human intellect, as well as a mediator for communication among participants. The human user favors the sensory dimensions of sight, sound, and touch as primary channels of communication. Machines that can accommodate these modes

IVAN MARSIC; ATTILA MEDL; JAMES FLANAGAN

2000-01-01

20

Communicating Networked Control Systems.  

National Technical Information Service (NTIS)

This report describes research conducted over a twelve month period under support from a multi-university research grant whose focus is the technological foundations of Communicating Networked Control Systems. Coordinated efforts at four participating ins...

J. Baillieul P. R. Kumar P. S. Krishnaprasad R. W. Brockett

2007-01-01

21

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

Microsoft Academic Search

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

Liang-liang Xie; Panganamala R. Kumar

2004-01-01

22

The French communicable diseases computer network  

Microsoft Academic Search

The authors give a brief review of a seven-year experiment of national surveillance of communicable diseases in France using computer networking technology. The information system (IS), developed by the French Communicable Diseases Computer Network (FCDN), provides the large amount of epidemiological information needed for surveillance activities and permits the information exchanges necessary for efficient decision making. Besides the surveillance of

Philippe Garnerin; A.-J. Valleron

1992-01-01

23

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.

2012-12-17

24

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

Microsoft Academic Search

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

Klarissa T. Chang; Kate Ehrlich

2007-01-01

25

Reconsidering Social Networks for Enterprise Communication Services  

Microsoft Academic Search

Social networking applications leverage valuable information from social graphs and integrate communication capabilities to offer new services. However, currently, these applications are limited to communication capabilities such as click-to-call or click-to-conference. Once the communication session is established the social context and the communication context are not integrated in these services. For social network communication services such integration permits new and

Krishna Kishore Dhara; Venkatesh Krishnaswamy; Taranjeet Singh

2010-01-01

26

Information-Theoretic Integration of Sensing and Communication for Active Robot Networks  

Microsoft Academic Search

This paper presents an information-theoretic approach to sensor placement that incorporates communication capacity into an\\u000a optimal formulation. A new formulation is presented that maximizes the information rate achievable by a set of sensors communicating\\u000a wirelessly to a single collection node. Shannon capacity and the standard radio propagation model are used to model the throughput\\u000a achievable by a sensor configuration. Likewise,

Eric W. Frew

2009-01-01

27

Information-theoretic integration of sensing and communication for active robot networks  

Microsoft Academic Search

Abstract—This paper presents an information-theoretic approach,to sensor,placement,that incorporates,communication capacity,into an,optimal,formulation. A new,formulation,is presented,that maximizes,the information,rate achievable,by a set of sensors communicating,wirelessly to a single collection node. Shannon capacity and the standard,radio propagation model,are used to model,the throughput,achievable by a sensor configuration. Likewise, the d-optimality criterion from the active sensing literature is used to model,information,gain provided,by range and bearing sensors. The

Eric W. Frew

2007-01-01

28

Simulator of Space Communication Networks  

NASA Technical Reports Server (NTRS)

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.

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

2005-01-01

29

Neural Network Communications Signal Processing.  

National Technical Information Service (NTIS)

This final technical report describes the research and development results of the Neural Network Communications Signal Processing (NNCSP) Program. The objectives of the NNCSP program are to: (1) develop and implement a neural network and communications si...

D. Tebbe J. Doner T. Billhartz

1994-01-01

30

Idotai tsushin system no denryoku tsushinmo eno tekiyo. 1. Idotai tsushin system no genjo to PHS ni yoru juyo kakei network no teian. (Studies of an application of a mobile communication system to the private telecommunication network. Part 1. Present condition of mobile communication system and proposal of the customer information network by PHS).  

National Technical Information Service (NTIS)

An application of various mobile communication systems to the electric power telecommunication network has been investigated. Among these, the customer information network by PHS (personal handy-phone system) has been proposed. Although great numbers of b...

H. Iwasaki

1996-01-01

31

Social network analysis and dual rover communications  

NASA Astrophysics Data System (ADS)

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.

Litaker, Harry L.; Howard, Robert L.

2013-10-01

32

Spread spectrum communication networks  

NASA Astrophysics Data System (ADS)

One of the difficulties that arises in the analysis of codeword and packet error probabilities in asynchronous frequency-hop (FH) multiple-access communication systems and networks is the statistical dependence between symbol errors within a codeword or packet in FH communications with multiple symbols per dwell interval. The basic problem is that the hits by other transmissions are statistically dependent. In one paper, we developed improved bounds on the codeword error probability for such FH multiple-access systems and networks. This was accomplished by investigating models in which hits are conditionally independent given the number of interfering packets and choosing the conditional probability of a hit in such a way that a bound on the performance of the actual system can be obtained. We showed that if the ratio of the number of interfering packets to the number of frequency slots is held constant, hits the asynchronous FH networks are asymptotically independent in the limits as the number of frequency slots increases. Thus, when the number of frequency slots is large, the error probabilities can be closely approximated by using the simplified model with independent hits. We published a related paper which shows that, contrary to a paper published by another author, the sequence of hits in an asynchronous FH multiple-access communication system does not form a Markov process.

Pursley, Michael B.; Sarwate, Dilip V.

1991-02-01

33

Communicability betweenness in complex networks  

NASA Astrophysics Data System (ADS)

Betweenness measures provide quantitative tools to pick out fine details from the massive amount of interaction data that is available from large complex networks. They allow us to study the extent to which a node takes part when information is passed around the network. Nodes with high betweenness may be regarded as key players that have a highly active role. At one extreme, betweenness has been defined by considering information passing only through the shortest paths between pairs of nodes. At the other extreme, an alternative type of betweenness has been defined by considering all possible walks of any length. In this work, we propose a betweenness measure that lies between these two opposing viewpoints. We allow information to pass through all possible routes, but introduce a scaling so that longer walks carry less importance. This new definition shares a similar philosophy to that of communicability for pairs of nodes in a network, which was introduced by Estrada and Hatano [E. Estrada, N. Hatano, Phys. Rev. E 77 (2008) 036111]. Having defined this new communicability betweenness measure, we show that it can be characterized neatly in terms of the exponential of the adjacency matrix. We also show that this measure is closely related to a Fréchet derivative of the matrix exponential. This allows us to conclude that it also describes network sensitivity when the edges of a given node are subject to infinitesimally small perturbations. Using illustrative synthetic and real life networks, we show that the new betweenness measure behaves differently to existing versions, and in particular we show that it recovers meaningful biological information from a protein-protein interaction network.

Estrada, Ernesto; Higham, Desmond J.; Hatano, Naomichi

2009-03-01

34

The social network and the geo-hydrological information: the CNR IRPI Facebook page as example of communication.  

NASA Astrophysics Data System (ADS)

Good communication is a fundamental step for the spread of news and knowledge. The effectiveness and persuasiveness of a message is a function of the interaction of characteristics of the audience, the source of the message, and content of the message. Italian Research Institute for the Hydrogeological Protection (CNR-IRPI) has been publishing information on geo-hydrological events using the Internet (http://sici.irpi.cnr.it/, http://webmap.irpi.cnr.it/, http://geomorphology.irpi.cnr.it/, http://polaris.irpi.cnr.it/, http://giida.irpi.cnr.it/, http://events.irpi.cnr.it/ ). Our websites are mainly visited by experts and the information are used for technical purposes. The contents and the interface of the websites are designed for this type of users. Our intention is to increase the type of users, and we are testing the use of social network to catch the wide public's attention. Social networks have emerged as critical factor in information dissemination, search, marketing expertise and influence discovery, and are an important channel for people to share information. Social scientist have long recognized the importance of social networks in the spread of information. Facebook and Twitter are the most widely used social networking services. They make it simpler to communicate with multiple people at one time. Social media may also make it easier for users to monitor activities of people (friends or followers). An official Facebook page of the Italian Research Institute for the Hydrogeological Protection (CNR-IRPI, https://www.facebook.com/CNR.IRPI ), was created and linked to a Twitter account. The purpose of this page is to disseminate information on flood and landslide events and on our research activities, in order to raise awareness of geo-hydrological matters among users. This page publishes news on current or historical landslide and flood events involving the Italian territory, or news from around the world collected on the network. The news are published as text or links to videos or photos collected from the network. Facebook provides statistics regarding access the page and the interactions that users have with the news published. These statistics make it possible to quantify the interest of the users to the content of the news (post events, new publication institute, etc.). The way the news are published (only in text mode, with photographic or video images), the novelty (current event or historical) and the location (events in Italy or abroad) are all messages characteristic's that increase the audience attention. This work has highlighted the significance of the characteristics that can draw the attention of the public regarding landslide and flood information.

Fiorucci, Federica; Bianchi, Cinzia; Marchesini, Ivan; Salvati, Paola; Fugnoli, Federico; Guzzetti, Fausto

2014-05-01

35

Hyperswitch communication network  

NASA Technical Reports Server (NTRS)

The Hyperswitch Communication Network (HCN) is a large scale parallel computer prototype being developed at JPL. Commercial versions of the HCN computer are planned. The HCN computer being designed is a message passing multiple instruction multiple data (MIMD) computer, and offers many advantages in price-performance ratio, reliability and availability, and manufacturing over traditional uniprocessors and bus based multiprocessors. The design of the HCN operating system is a uniquely flexible environment that combines both parallel processing and distributed processing. This programming paradigm can achieve a balance among the following competing factors: performance in processing and communications, user friendliness, and fault tolerance. The prototype is being designed to accommodate a maximum of 64 state of the art microprocessors. The HCN is classified as a distributed supercomputer. The HCN system is described, and the performance/cost analysis and other competing factors within the system design are reviewed.

Peterson, J.; Pniel, M.; Upchurch, E.

1991-01-01

36

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

NASA Technical Reports Server (NTRS)

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.

1992-01-01

37

Mapping Efficient Communication Networks in Higher Education.  

ERIC Educational Resources Information Center

Some perspectives are presented that help explain communication networks in institutions of higher education and the factors that impede or facilitate their efficient functioning. The first theory that informs this exploration is that of K. Wieck (1969), which states that communication can be viewed through the lens of "sensemaking." The…

Lubinescu, E. S.; Prabhu, R. P.; Terheggen, S. L.

38

Switch for serial or parallel communication networks  

DOEpatents

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.

Crosette, D.B.

1994-07-19

39

Switch for serial or parallel communication networks  

DOEpatents

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.

Crosette, Dario B. (DeSoto, TX)

1994-01-01

40

Communication Dynamics of Blog Networks  

NASA Astrophysics Data System (ADS)

We study the communication dynamics of Blog networks, focusing on the Russian section of LiveJournal as a case study. Communication (blogger-to-blogger links) in such online communication networks is very dynamic: over 60% of the links in the network are new from one week to the next, though the set of bloggers remains approximately constant. Two fundamental questions are: (i) what models adequately describe such dynamic communication behavior; and (ii) how does one detect the phase transitions, i.e. the changes that go beyond the standard high-level dynamics? We approach these questions through the notion of stable statistics. We give strong experimental evidence to the fact that, despite the extreme amount of communication dynamics, several aggregate statistics are remarkably stable. We use stable statistics to test our models of communication dynamics postulating that any good model should produce values for these statistics which are both stable and close to the observed ones. Stable statistics can also be used to identify phase transitions, since any change in a normally stable statistic indicates a substantial change in the nature of the communication dynamics. We describe models of the communication dynamics in large social networks based on the principle of locality of communication: a node's communication energy is spent mostly within its own "social area," the locality of the node.

Goldberg, Mark; Kelley, Stephen; Magdon-Ismail, Malik; Mertsalov, Konstantin; Wallace, William (Al)

41

Specific Communication Network Measure Distribution Estimation.  

National Technical Information Service (NTIS)

A new method is proposed to estimate the probability distribution of specific communication network measures. Real world communication networks are dynamic and vary based on an underlying social network, thus reliably estimating network measures is challe...

D. P. Baller J. Lospinoso

2008-01-01

42

Information, education and communication.  

PubMed

China's information, education and communication (IEC) program plays an important role in the population program, because 180 million people were illiterate in 1990, 22% of the adult population. Since the 1980s, organizations have been popularizing family planning policies and information about childbearing and contraception. A national IEC network is set up in all family planning committees at the provincial and municipal levels. Timely counseling services are provided to people (for adolescents, newly-weds, pregnant women, breastfeeding mothers, and menopausal women). Certain villagers are selected as family planning contact households, and they provide reading rooms with a collection of books and periodicals about population and family planning. Population education for middle school students covers the relationships between population growth, natural resources, and the environment; population and modernization; and physiological health. China's In-depth Fertility Survey conducted in 1987 by the State Statistical Bureau in 1 municipality and 5 provinces, indicates that knowledge of contraception is widespread. People have a better understanding of safe and reliable methods such as the IUD and sterilization than of traditional methods. In 1953, the mean age of women at first marriage was 19 years; by 1987, the majority of Chinese women were getting married at 22 or 23 years of age. The 1987 Survey indicates that women married 25 years earlier desired to have 1 or 2 children more than women who married recently. The family planning program has seen acceptance of the small family norm by the majority of the Chinese people. In 1992, the State Education Commission made population education an obligatory course in the curriculum for senior middle schools. Survey results show that the proportions of early marriage and early childbearing as well as the fertility rate among graduates of the pilot schools are significantly lower than those among graduates from other schools. PMID:12288128

1994-07-01

43

Designing Efficient Communication Networks.  

National Technical Information Service (NTIS)

In recent years it has become clear that communication time between processors is one of the most severe limiting factors in designing high speed parallel computers. Further, for massively parallel machines unrestricted communication via such methods as d...

G. Carlsson

1983-01-01

44

Using Geospatial Information in Sensor Networks  

Microsoft Academic Search

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

John Heidemann; Nirupama Bulusu

2001-01-01

45

Mobile and wireless communications networks  

Microsoft Academic Search

The purpose of this tutorial is to highlight several aspects of mobile and wireless communications networks. A first part presents a brief overview of the market and technology evolution. The second part is devoted to the radio propagation channel characteristics. In the third section, we present an overview of the transmission techniques related to the definition of new mobile communications

Ghais El Zein

2004-01-01

46

Networking Sensors for Information Dominance - Joint Signal Processing and Communication Design.  

National Technical Information Service (NTIS)

Recent advances in sensor technology have created great interest in building networked sensor systems for both civilian and military applications employing low-cost, low-power, multi-functional sensor nodes which carry their own power sources. Our results...

R. S. Blum

2012-01-01

47

Optical space communications and networks  

NASA Astrophysics Data System (ADS)

Optical space communications is now a reality. It will be a key building block for wide-area space data networks of the future. This new technology will provide quantum-leap improvements to satellite network performance and cost and have profound transforming effects on space system architectures and applications.

Chan, Vincent W. S.

2006-09-01

48

A Communications Network Architecture for Future Mars Missions  

NASA Astrophysics Data System (ADS)

We propose a Mars communications network architecture incorporating the Internet Protocol, small communications relay satellites, laser communications, delay tolerant networking, mobile ad hoc networking, and wireless sensor networks.

Gilstrap, R.; Alena, R.; Stone, T.

2012-06-01

49

Hubless satellite communications networks  

NASA Technical Reports Server (NTRS)

Frequency Comb Multiple Access (FCMA) is a new combined modulation and multiple access method which will allow cheap hubless Very Small Aperture Terminal (VSAT) networks to be constructed. Theoretical results show bandwidth efficiency and power efficiency improvements over other modulation and multiple access methods. Costs of the VSAT network are reduced dramatically since a hub station is not required.

Robinson, Peter Alan

1994-01-01

50

AN APPROACH FOR NETWORK COMMUNICATIONS SYSTEMS RECOVERY  

Microsoft Academic Search

In this paper we e xamine the problem of f ailures within network communications and telecom systems and outline a localised Invisible Recovery solution to such systems. We introduce a new approach that makes use of an envelope surrounding an unchanged software protocol layer, which is running as an independent process. This envelope stores just sufficient information on each connection

GEORGE G. MITCHELL; STEPHEN BROWN

2000-01-01

51

Information and communication technology  

NASA Technical Reports Server (NTRS)

NASA and the National Science Foundation (NSF) commissioned a panel of U.S. experts to study the international status of satellite communications systems and technology. The study covers emerging systems concepts, applications, services, and the attendant technologies. The panel members traveled to Europe, Japan, and Russia to gather information firsthand. They visited 17 sites in Europe, 20 in Japan, and 4 in Russia. These included major manufacturers, government organizations, service providers, and associated research and development facilities. The panel's report was reviewed by the sites visited, by the panel, and by representatives of U.S. industry. The report details the information collected and compares it to U.S. activities.

Edelson, Burton I.; Pelton, Joseph N.; Bostian, Charles W.; Brandon, William T.; Chan, Vincent W. S.; Hager, E. Paul; Helm, Neil R.; Jennings, Raymond D.; Kwan, Robert K.; Mahle, Christoph E.

1994-01-01

52

Multiple-Ring Digital Communication Network  

NASA Technical Reports Server (NTRS)

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.

Kirkham, Harold

1992-01-01

53

Reliable Communication in Overlay Networks  

Microsoft Academic Search

Reliable point-to-point communication is usually achieved in overlay networks by applying TCP on the end nodes of a connection. This paper presents a hop-by-hop reliability approach that considerably reduces the latency and jitter of reliable connections. Our approach is feasible and beneficial in overlay networks that do not have the scalability and interoperability requirements of the global Internet. The effects

Yair Amir; Claudiu Danilov

2003-01-01

54

Data communication network at the ASRM facility  

NASA Technical Reports Server (NTRS)

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.

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

1993-01-01

55

Software Architecture for Network Communication.  

National Technical Information Service (NTIS)

A distributed system is based on a layered set of abstractions of network communication. At a low level, current distributed systems use primitives such as datagrams, request/reply message-passing, reliable virtual circuits, or a combination of these. Fut...

D. P. Anderson

1987-01-01

56

Information Horizons in Complex Networks  

NASA Astrophysics Data System (ADS)

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.

Sneppen, Kim

2005-03-01

57

Some Remarks on Digital Distributed Communications Networks.  

National Technical Information Service (NTIS)

The rapid evolution in the design of communication networks makes it possible to create new communications networks more reliable than the reliability of the links themselves. This becomes possible because of the advent of new digital computer technology ...

P. Baran

1967-01-01

58

Communications for unattended sensor networks  

NASA Astrophysics Data System (ADS)

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.

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

2004-07-01

59

A Full Automatic Identification of Faulty Links for Communication Networks  

Microsoft Academic Search

Conventionally the manual service is often required for fault diagnosis of network links with improper accuracy brought in. So, a full automatic fault diagnosis approach for communication links is proposed as follows. If the path information that which node are available or unavailable to communicate with from the node(s) taking charge of network management has both been known, a fault

Zhi-Gang Zhao; Jian-Hui Wang

2008-01-01

60

Vulnerability of de Bruijn Communications Networks.  

National Technical Information Service (NTIS)

The report studies de Bruijn communications networks with faulty nodes. A de Bruijn communications networks is a communications network based on a de Bruijn graph. The author shows a method for messages to by-pass a faulty node in at most six steps when t...

M. Schlumberger

1974-01-01

61

Geographical dispersal of mobile communication networks  

NASA Astrophysics Data System (ADS)

In this paper, we analyze statistical properties of a communication network constructed from the records of a mobile phone company. The network consists of 2.5 million customers that have placed 810 million communications (phone calls and text messages) over a period of 6 months and for whom we have geographical home localization information. It is shown that the degree distribution in this network has a power-law degree distribution k-5 and that the probability that two customers are connected by a link follows a gravity model, i.e. decreases as d-2, where d is the distance between the customers. We also consider the geographical extension of communication triangles and we show that communication triangles are not only composed of geographically adjacent nodes but that they may extend over large distances. This last property is not captured by the existing models of geographical networks and in a last section we propose a new model that reproduces the observed property. Our model, which is based on the migration and on the local adaptation of agents, is then studied analytically and the resulting predictions are confirmed by computer simulations.

Lambiotte, Renaud; Blondel, Vincent D.; de Kerchove, Cristobald; Huens, Etienne; Prieur, Christophe; Smoreda, Zbigniew; Van Dooren, Paul

2008-09-01

62

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

DOEpatents

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.

Buttles, John W

2013-04-23

63

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

DOEpatents

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.

Buttles, John W. (Idaho Falls, ID)

2011-12-20

64

On Information Assurance in Nanoscale Networks  

Microsoft Academic Search

An intersection of two worlds, emerging nano- technologies and network\\/communication theory, is poised to change the nature of information assurance. New communication paradigms will be derived from the transition from micro- to nano-scale devices. The related degrees of freedom and constraints associated with these new technologies will change our notions about efficient networks, system design and the nature of information

Stephen F. Bush

65

Data communication network at the ASRM facility  

NASA Technical Reports Server (NTRS)

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.

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

1993-01-01

66

[Sensitization: information, education and communication].  

PubMed

IEC programs increase the knowledge and motivation of decision makers with power over determinants of population growth and socioeconomic development. Information may improve the awareness of public and private officials of population questions and of the form in which they are treated. Information activities involve demographic growth and spatial distribution of the population, the demographic and health benefits of family planning, and the danger of sexually transmitted diseases and AIDS. The mass media are the main source of information, but in developing countries various forms of folk media enjoyed by the public may also be used. Technical journals and other information networks are available for the professional audience. Population communication promotes acceptance and use of family planning. Radio and television series that incorporate family planning themes, popular music that mentions population problems, and broadcasts of telephone question and answer programs have been influential in some countries. Such informational programs may be very important in regions with low levels of literacy. Programs targeted to adolescents may help resolve problems of early pregnancy. More than 80 countries include population education in their school curriculum. The objectives vary, but they generally include making students aware of population problems and of their own responsibilities. Population questions are also included in many professional training programs. PMID:12289051

1993-01-01

67

Space network support for lunar communications  

NASA Technical Reports Server (NTRS)

The space network can provide high data rate lunar communications as an alternative or adjunct to an expansion of the deep space network. Use of a space-based system can provide continuous coverage for lunar users and reduce terrestrial communication costs by delivering data directly to a single domestic location. Adapting the space network for lunar communications support would also maximize the use of the existing and planned space network and Space Station infrastructure. Several alternative architectures are evaluated.

Jordan, Michael A.

1991-01-01

68

A vision of network-centric military communications  

NASA Astrophysics Data System (ADS)

This paper presents a vision for a future capability-based military communications system that considers user requirements. Historically, the military has developed and fielded many specialized communications systems. While these systems solved immediate communications problems, they were not designed to operate with other systems. As information has become more important to the execution of war, the "stove-pipe" nature of the communications systems deployed by the military is no longer acceptable. Realizing this, the military has begun the transformation of communications to a network-centric communications paradigm. However, the specialized communications systems were developed in response to the widely varying environments related to military communications. These environments, and the necessity for effective communications within these environments, do not disappear under the network-centric paradigm. In fact, network-centric communications allows for one message to cross many of these environments by transiting multiple networks. The military would also like one communications approach that is capable of working well in multiple environments. This paper presents preliminary work on the creation of a framework that allows for a reconfigurable device that is capable of adapting to the physical and network environments. The framework returns to the Open Systems Interconnect (OSI) architecture with the addition of a standardized intra-layer control interface for control information exchange, a standardized data interface and a proposed device architecture based on the software radio.

Conklin, Ross, Jr.; Burbank, Jack; Nichols, Robert, Jr.

2005-05-01

69

Communication and information technology in medical education  

Microsoft Academic Search

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

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

2001-01-01

70

PIPELINES AS COMMUNICATION NETWORK LINKS  

SciTech Connect

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.

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

2005-03-14

71

Using Egocentric Networks to Understand Communication  

Microsoft Academic Search

Social-network analysis generally helps researchers understand how groups of people interact. In this article the author uses small-scale egocentric social networks, based on volitional, explicit connections, to understand how people manage their personal and group communications. Two research projects using this approach show that such networks can give researchers important insight into the people who communicate online. Soylent, a project

Danyel Fisher

2005-01-01

72

A scheme for the teleportation of multiqubit quantum information via the control of many agents in a network [rapid communication  

NASA Astrophysics Data System (ADS)

We present a new scheme for teleporting multiqubit quantum information from a sender to a distant receiver via the control of many agents in a network. We show that the receiver can successfully restore the original state of each qubit as long as all the agents cooperate. However, it is remarkable that for certain type of teleported states, the receiver cannot gain any amplitude information even if one agent does not collaborate. In addition, our analysis shows that for general input states of each message qubit, the average fidelity for the output states, when even one agent does not take action, is the same as that for the previous proposals.

Yang, Chui-Ping; Han, Siyuan

2005-08-01

73

Computing, Information and Communications Technology (CICT) Website  

NASA Technical Reports Server (NTRS)

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).

Hardman, John; Tu, Eugene (Technical Monitor)

2002-01-01

74

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 © ...

75

Communicability reveals a transition to coordinated behavior in multiplex networks  

NASA Astrophysics Data System (ADS)

We analyze the flow of information in multiplex networks by means of the communicability function. First, we generalize this measure from its definition from simple graphs to multiplex networks. Then, we study its relevance for the analysis of real-world systems by studying a social multiplex where information flows using formal-informal channels and an air transportation system where the layers represent different air companies. Accordingly, the communicability, which is essential for the good performance of these complex systems, emerges at a systemic operation point in the multiplex where the performance of the layers operates in a coordinated way very differently from the state represented by a collection of unconnected networks.

Estrada, Ernesto; Gómez-Gardeñes, Jesús

2014-04-01

76

The Lower Saxony research network design of environments for ageing: towards interdisciplinary research on information and communication technologies in ageing societies.  

PubMed

Worldwide, ageing societies are bringing challenges for independent living and healthcare. Health-enabling technologies for pervasive healthcare and sensor-enhanced health information systems offer new opportunities for care. In order to identify, implement and assess such new information and communication technologies (ICT) the 'Lower Saxony Research Network Design of Environments for Ageing' (GAL) has been launched in 2008 as interdisciplinary research project. In this publication, we inform about the goals and structure of GAL, including first outcomes, as well as to discuss the potentials and possible barriers of such highly interdisciplinary research projects in the field of health-enabling technologies for pervasive healthcare. Although GAL's high interdisciplinarity at the beginning slowed down the speed of research progress, we can now work on problems, which can hardly be solved by one or few disciplines alone. Interdisciplinary research projects on ICT in ageing societies are needed and recommended. PMID:21133766

Haux, Reinhold; Hein, Andreas; Eichelberg, Marco; Appell, Jens-E; Appelrath, Hans-Jürgen; Bartsch, Christian; Bisitz, Thomas; Bitzer, Jörg; Blau, Matthias; Boll, Susanne; Buschermöhle, Michael; Büsching, Felix; Erdmann, Birte; Fachinger, Uwe; Felber, Juliane; Fleuren, Tobias; Gietzelt, Matthias; Goetze, Stefan; Gövercin, Mehmet; Helmer, Axel; Heuten, Wilko; Hohmann, Volker; Huber, Rainer; Hülsken-Giesler, Manfred; Jacobs, Gerold; Kayser, Riana; Kerling, Arno; Klingeberg, Timo; Költzsch, Yvonne; Künemund, Harald; Kunze, Jennifer; Ludwig, Wolfram; Marschollek, Michael; Martens, Birger; Meis, Markus; Meyer, Eike Michael; Meyer, Jochen; Nebel, Wolfgang; Neyer, Franz J; Okken, Petra-Karin; Remmers, Hartmut; Rölker-Denker, Lars; Rohdenburg, Thomas; Schilling, Meinhard; Schulze, Gisela C; Song, Bianying; Spehr, Jens; Steinhagen-Thiessen, Elisabeth; Tegtbur, Uwe; Thoben, Wilfried; Van Hengel, Peter; Wabnik, Stefan; Wahl, Friedrich; Wegel, Sandra; Wilken, Olaf; Winkelbach, Simon; Wist, Thorben; Wittrock, Manfred; Wolf, Klaus-Hendrik; Wolf, Lars; Zokoll-Van Derlaan, Melanie

2010-01-01

77

Network Management in an Emergency Communications System.  

National Technical Information Service (NTIS)

This thesis begins with a synopsis of contemporary knowledge concerning network management as it has been implemented in a modern communications network, and as it has been postulated by experts in the fields of systems engineering and systems management....

R. L. DeLorey

1986-01-01

78

Distributed Beamforming in Man Portable Communication Networks.  

National Technical Information Service (NTIS)

The advancement in communication and networking technologies lead to the emergence of network centric systems adopted by military forces. Many military forces around the world are equipping their ground soldiers with man portable or mobile wireless commun...

C. M. Chan

2007-01-01

79

Distributed network protocols for wireless communication  

Microsoft Academic Search

This paper describes a network design strategy that focuses on energy conservation. This position-based network protocol is optimized for minimum energy consumption in wireless networks that support peer-to-peer communication. Given any number of randomly deployed communication nodes over an area, we show that a simple local optimization scheme executed at each node guarantees strong connectivity of the entire network and

Teresa H. Meng; Volkan Rodoplu

1998-01-01

80

Computer networks in communication survey research  

Microsoft Academic Search

The paper explores the feasibility of using computer networks as communication survey research instruments. Also covered are the use of computers and computer networks in survey studies; a listing of the advantages and disadvantages of network surveys as compared with mail, phone, and fax surveys; a description of the development steps of network surveys; and a comparison of differences in

Chien Chou

1997-01-01

81

Flow of affective information between communicating brains.  

PubMed

When people interact, affective information is transmitted between their brains. Modern imaging techniques permit to investigate the dynamics of this brain-to-brain transfer of information. Here, we used information-based functional magnetic resonance imaging (fMRI) to investigate the flow of affective information between the brains of senders and perceivers engaged in ongoing facial communication of affect. We found that the level of neural activity within a distributed network of the perceiver's brain can be successfully predicted from the neural activity in the same network in the sender's brain, depending on the affect that is currently being communicated. Furthermore, there was a temporal succession in the flow of affective information from the sender's brain to the perceiver's brain, with information in the perceiver's brain being significantly delayed relative to information in the sender's brain. This delay decreased over time, possibly reflecting some 'tuning in' of the perceiver with the sender. Our data support current theories of intersubjectivity by providing direct evidence that during ongoing facial communication a 'shared space' of affect is successively built up between senders and perceivers of affective facial signals. PMID:20624471

Anders, Silke; Heinzle, Jakob; Weiskopf, Nikolaus; Ethofer, Thomas; Haynes, John-Dylan

2011-01-01

82

A continuous state space model of multiple service, multiple resource communication networks  

Microsoft Academic Search

The merging of telephone and computer networks is introducing multiple resources into networks, and information is becoming increasingly distributed across the network. Related services are being integrated onto a single network rather than being offered on separate uncoordinated networks. We focus upon communication networks that integrate multiple services using multiple resources. In previous work, such networks have been modeled by

Scott Jordan

1995-01-01

83

Communication matters -- network constellations in entrepreneurship  

Microsoft Academic Search

This paper investigates the role of communication within network constellations in entrepreneurship research. To become and remain successful in increasingly turbulent times, SMEs and entrepreneurs need to obtain certain success factors. One of these might be the entrepreneur's communication competences within the networks he operates in. This paper, therefore, investigates on a conceptual-theoretical basis the key success conditions of the

Mark Euler; Bernhard H. Vollmar; Sascha Kraus

2011-01-01

84

Research Priorities in Networking and Communications.  

ERIC Educational Resources Information Center

A workshop focused on major research issues in networking and communications. This report defines the context for research priorities and initiatives and deals with issues in networking and communications. Fifteen major research priorities and four research specific initiatives were identified by participants as areas that should be pursued over…

National Science Foundation, Washington, DC.

85

Effective Protocols for Mobile Communications and Networking  

SciTech Connect

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.

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

1998-12-01

86

Recent advances in underwater acoustic communications & networking  

Microsoft Academic Search

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

Mandar Chitre; Shiraz Shahabudeen; Lee Freitag; Milica Stojanovic

2008-01-01

87

Communications network design and costing model users manual  

NASA Astrophysics Data System (ADS)

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.

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

1983-09-01

88

Communications network design and costing model users manual  

NASA Technical Reports Server (NTRS)

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.

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

1983-01-01

89

Combined Fountain Code with Network Coding in Cooperative Communication  

Microsoft Academic Search

In this paper, we will investigate the block error rate (BLER) performance in cooperative communication, through combining fountain code with network coding. Contrast to the fixed-rate code, the rate of fountain code is not determined in advance, since that varies according to the instant channel state information. Under the error-free channel condition, network coding can get the maximum possible rate

Jing Yang; Jianping An; Xiangming Li; Lei Yuan

2010-01-01

90

Wireless Network Communications Overview for Space Mission Operations  

NASA Technical Reports Server (NTRS)

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.

Fink, Patrick W.

2009-01-01

91

Sensor information networking architecture and applications  

Microsoft Academic Search

This article introduces a sensor information networking architecture, called SINA, that facilitates querying, monitoring, and tasking of sensor networks. SINA serves the role of middleware that abstracts a network of sensor nodes as a collection of massively distributed objects. SINA's execution environment provides a set of configuration and communication primitives that enable scalable and energy-efficient organization of and interactions among

Chien-Chung Shen; Chavalit Srisathapornphat; Chaiporn Jaikaeo

2001-01-01

92

Quantum Information, Computation and Communication  

NASA Astrophysics Data System (ADS)

Part I. Quantum Information: 1. Quantum bits and quantum gates; 2. An atom in a laser field; 3. Spins in magnetic fields; 4. Photon techniques; 5. Two qubits and beyond; 6. Measurement and entanglement; Part II. Quantum Computation: 7. Principles of quantum computing; 8. Elementary quantum algorithms; 9. More advanced quantum algorithms; 10. Trapped atoms and ions; 11. Nuclear magnetic resonance; 12. Large scale quantum computers; Part III. Quantum Communication: 13. Basics of information theory; 14. Quantum information; 15. Quantum communication; 16. Testing EPR; 17. Quantum cryptography; Appendixes; References; Index.

Jones, Jonathan A.; Jaksch, Dieter

2012-07-01

93

Toward in vivo nanoscale communication networks: utilizing an active network architecture  

Microsoft Academic Search

A safe and reliable in vivo nanoscale communication network will be of great benefit for medical diagnosis and monitoring as well as medical implant\\u000a communication. This review article provides a brief introduction to nanoscale and molecular networking in general and provides\\u000a opinions on the role of active networking for in vivo nanoscale information transport. While there are many in vivo

Stephen F. Bush

94

Military Information Networks as Complex Adaptive Systems.  

National Technical Information Service (NTIS)

New information technology now permits a vastly increased degree of connectivity in military communication networks. This more connected architecture should result in faster response times and greater efficiencies in military operations. A potential downs...

L. D. Miller

2001-01-01

95

NETWORK DRIVER FOR COMMUNICATION IN SPV INDUSTRIAL NETWORK  

Microsoft Academic Search

In the present paper the development of a network driver for communication in SPV industrial controllers has been discussed. The hardware\\/software approach for realisation of the network driver is offered. The network driver realises all functions of sending and receiving, protecting times in industrial network, the repeating of the message when an error occurs and the solving of the conflict

Georgy Slavchev Mihov; Stanimir Damyanov Mollov; Ratcho Marinov Ivanov; Stoyan Nikolov Jilov

96

A Community Information Network.  

National Technical Information Service (NTIS)

The possibility of creating in Canada a non-profit community information network (a set of linked data banks containing information for use by the general public) should be explored. A network to link together a set of data banks containing information fo...

1971-01-01

97

Efficient communication in stationary wireless sensor networks  

Microsoft Academic Search

Wireless sensor networks have become possible because of the on-going improvements in sensor technology and VLSI. ^ In this dissertation we focus on three major points toward an efficient communication for stationary sensor networks. First, we study the relationship between the choice of topology and the power dissipated in the network. Second, we evaluate the effect of power metrics on

Ayad Salhieh

2004-01-01

98

Modeling Information Flow in Biological Networks  

PubMed Central

Large scale molecular interaction networks are being increasingly used to provide a system level view of cellular processes. Modeling communications between nodes in such huge networks as information flows is useful for dissecting dynamical dependences between individual network components. In the information flow model, individual nodes are assumed to communicate with each other by propagating the signals through intermediate nodes in the network. In this paper, we first provide an overview of the state of the art of research in the network analysis based on information flow models. In the second part, we describe our computational method underlying our recent work on discovering dys-regulated pathways in glioma. Motivated by applications to inferring information flow from genotype to phenotype in a very large human interaction network, we generalized previous approaches to compute information flows for a large number of instances and also provided a formal proof for the method.

Kim, Yoo-Ah; Przytycki, Jozef H.; Wuchty, Stefan; Przytycka, Teresa M.

2011-01-01

99

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.

2012-10-29

100

The National Biomedical Communications Network as a Developing Structure *  

PubMed Central

The National Biomedical Communications Network has evolved both from a set of conceptual recommendations over the last twelve years and an accumulation of needs manifesting themselves in the requests of members of the medical community. With a short history of three years this network and its developing structure have exhibited most of the stresses of technology interfacing with customer groups, and of a structure attempting to build itself upon many existing fragmentary unconnected segments of a potentially viable resourcesharing capability. In addition to addressing these topics, the paper treats a design appropriate to any network devoted to information transfer in a special interest user community. It discusses fundamentals of network design, highlighting that network structure most appropriate to a national information network. Examples are given of cost analyses of information services and certain conjectures are offered concerning the roles of national networks.

Davis, Ruth M.

1971-01-01

101

Communicating Psychological Information in Writing.  

ERIC Educational Resources Information Center

The guide describes approaches and considerations involved in school psychologists' communication of information in reports. Following an initial tongue in cheek discussion ("On Skinning Cats, Choking Dogs, and Leaving Lovers") of principles of report writing (such as avoiding using the language of logic and not contaminating interpretations with…

Iowa State Dept. of Public Instruction, Des Moines. Div. of Pupil Personnel Services.

102

Information, Education, Communication in Population.  

ERIC Educational Resources Information 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…

Hawaii Univ., Honolulu. East-West Center.

103

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

Federal Register 2010, 2011, 2012, 2013

...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...

2010-08-16

104

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...

105

Information Network Development.  

ERIC Educational Resources Information Center

The International Bureau of Education (IBE) and Unesco, together with their member states, are faced with the task of implementing a proposed network--the International Network for Educational Information (INED)--for the better use of information resources for educational development. This review of issues that need to be considered in the…

Mahon, F. V.

106

The Geospatial Characteristics of a Social Movement Communication Network  

PubMed Central

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

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

2013-01-01

107

Ad Hoc Networks: Headline 2000 Communications Analysis.  

National Technical Information Service (NTIS)

This report examines unit location data and terrain from Headline 2000 to investigate communications networks within the manoeuvre units. Within the Enhanced Combat Force timeframe, such units would be supported by a Tactical Data Distribution Subsystem (...

W. D. Blair A. B. Reynolds

2002-01-01

108

Architecture Design and Implementation Methods of Heterogeneous Emergency Communication Network  

NASA Astrophysics Data System (ADS)

Efficient response and treatment of unexpected events relies on reliable, flexible and robust emergency communication network. In this paper, backgrounds of building emergency communication network are introduced. Then, architecture design of emergency communication network is explained, including design goals, ideas and other technical issues. Afterwards, in terms of requirements of emergency communication network, implementation methods of WiMAX based broadband emergency communication network are discussed. Meanwhile, network monitor and interconnection issues are considered.

Wang, Haitao; Song, Lihua

109

Network Management of Highly Adaptive Communication Networks.  

National Technical Information Service (NTIS)

This report documents networking models, network solutions, programming techniques for parallel processing, and parallelled algorithm comparisons. Several papers are contained in the report. An operational research model and associated mathematics are pre...

J. L. Kennington J. M. Colombi R. V. Helgason

1988-01-01

110

Internetworking satellite and local exchange networks for personal communications applications  

NASA Technical Reports Server (NTRS)

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.

Wolff, Richard S.; Pinck, Deborah

1993-01-01

111

Routing optimization techniques for communication networks  

Microsoft Academic Search

In this paper, routing optimization techniques for communication networks are discussed. Preventing data loss on overloaded communication links and utilizing link bandwidths efficiently are the main problems of routing techniques. Load balancing and routing problems are solved using genetic algorithms, and simulation techniques. These algorithms work on destination or flow based routing techniques and mainly change the link weight system

A. Emrah Demircan; M. Kemal Leblebiciolu

2005-01-01

112

The Changing Face of Africa's Information and Communication Scenario.  

ERIC Educational Resources Information Center

Provides a glimpse of the prevailing situation in the field of information and communication in African countries; reports on recent surveys and case studies which indicate both problems and encouraging efforts. Discusses developments of international and national electronic communication networks which indicate rapid changes in electronic…

Chowdhury, G. G.

1998-01-01

113

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

ERIC Educational Resources Information Center

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…

Cottrell, William B.; And Others

114

Artificial neural networks in optical communications  

Microsoft Academic Search

In this paper, novel design principles aimed to improve the performance of optical receivers by means of neural networks, for enhanced signal-to-noise ratio, are presented. Paradigms from the area of optical communication networks, with emphasis, on optical wireless imaging angle-diversity receivers are presented, and discussed.

B. Frackerton; G. C. Giakos; B. Sobczyk; V. Formica; N. Patnekar

2002-01-01

115

Neural networks for routing communication traffic  

Microsoft Academic Search

The use of neural network computational algorithms to determine optimal traffic routing for communication networks is introduced. The routing problem requires choosing multilink paths for node-to-node traffic to minimize loss, which is represented by expected delay or some other function of traffic. The minimization procedure is implemented using a modification of the neural network traveling-salesman algorithm. Illustrative simulation results on

Herbert E. Rauch; T. Winarske

1988-01-01

116

Managing Communication Networks by Monitoring Databases  

Microsoft Academic Search

The problem of managing large communication networks using statistical tests, alerts, and correlation among alerts is considered. The authors propose a model of these network management functions as data-manipulation operations. They argue that this approach can improve the flexibility of network management systems by providing a language that is declarative and set-oriented. These are properties of existing data-manipulation languages and

Ouri Wolfson; Soumitra Sengupta; Yechiam Yemini

1991-01-01

117

[Modern network technologies for data communication in the hospital].  

PubMed

Modern network technologies provide the basic infrastructure for information and communication systems in the hospital today. The goal to build up a universal network infrastructure which meets the broadly varied requirements. Analysis of data communication in the hospital and the evaluation of established network technologies, as well as new developments, leads to the switching concept as the suitable solution. Two technologies play the major role in building enterprise networks: the Ethernet family, based on frame switching, and ATM, based on cell switching. Orientation on established standards is the key to free system choice and grants interoperability between systems from different manufacturers. However, the network design must meet the application and system architecture of the information technology in order to achieve successful mapping of the involved communication profiles. This means scaling of the bandwidth as needed, suitable segmenting of the network and resilient links. In a further step, policy-based networking takes advantages of prioritizing critical applications and therefore reduces interdependencies across the network. PMID:10337699

Pelikan, E; Kotter, E; Jäger, D; Langer, M; Timmermann, U

1999-04-01

118

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.

2007-10-26

119

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.

120

Review and evaluation of security threats on the communication networks in the smart grid  

Microsoft Academic Search

The smart grid, generally referred to as the next-generation power electric system, relies on robust communication networks to provide efficient, secure, and reliable information delivery. Thus, the network security is of critical importance in the smart grid. In this paper, we aim at classifying and evaluating the security threats on the communication networks in the smart grid. Based on a

Zhuo Lu; Xiang Lu; Wenye Wang; C. Wang

2010-01-01

121

Communicating oscillatory networks: frequency domain analysis  

PubMed Central

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.

2011-01-01

122

Review and Evaluation of Security Threats on the Communication Networks in the Smart Grid.  

National Technical Information Service (NTIS)

The smart grid, generally referred to as the nextgeneration power electric system, relies on robust communication networks to provide efficient, secure, and reliable information delivery. Thus, the network security is of critical importance in the smart g...

C. Wang W. Wang X. Lu Z. Lu

2010-01-01

123

Bidirectional Quantum Secure Direct Communication Network Protocol with Hyperentanglement  

NASA Astrophysics Data System (ADS)

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

Gu, Bin; Huang, Yu-Gai; Fang, Xia; Chen, Yu-Lin

2011-10-01

124

Surgeon Information Transfer and Communication  

PubMed Central

Objective: To determine the nature of surgeon information transfer and communication (ITC) errors that lead to adverse events and near misses. To recommend strategies for minimizing or preventing these errors. Summary Background Data: Surgical hospital practice is changing from a single provider to a team-based approach. This has put a premium on effective ITC. The Information Transfer and Communication Practices (ITCP) Project is a multi-institutional effort to: 1) better understand surgeon ITCP and their patient care consequences, 2) determine what has been done to improve ITCP in other professions, and 3) recommend ways to improve these practices among surgeons. Methods: Separate, semi-structured focus group sessions were conducted with surgical residents (n = 59), general surgery attending physicians (n = 36), and surgical nurses (n = 42) at 5 medical centers. Case descriptions and general comments were classified by the nature of ITC lapses and their effects on patients and medical care. Information learned was combined with a review of ITC strategies in other professions to develop principles and guidelines for re-engineering surgeon ITCP. Results: A total of 328 case descriptions and general comments were obtained and classified. Incidents fell into 4 areas: blurred boundaries of responsibility (87 reports), decreased surgeon familiarity with patients (123 reports), diversion of surgeon attention (31 reports), and distorted or inhibited communication (67 reports). Results were subdivided into 30 contributing factors (eg, shift change, location change, number of providers). Consequences of ITC lapses included delays in patient care (77% of cases), wasted surgeon/staff time (48%), and serious adverse patient consequences (31%). Twelve principles and 5 institutional habit changes are recommended to guide ITCP re-engineering. Conclusions: Surgeon communication lapses are significant contributors to adverse patient consequences, and provider inefficiency. Re-engineering ITCP will require significant cultural changes.

Williams, Reed G.; Silverman, Ross; Schwind, Cathy; Fortune, John B.; Sutyak, John; Horvath, Karen D.; Van Eaton, Erik G.; Azzie, Georges; Potts, John R.; Boehler, Margaret; Dunnington, Gary L.

2007-01-01

125

A Security Architecture for Health Information Networks  

PubMed Central

Health information network security needs to balance exacting security controls with practicality, and ease of implementation in today’s healthcare enterprise. Recent work on ‘nationwide health information network’ architectures has sought to share highly confidential data over insecure networks such as the Internet. Using basic patterns of health network data flow and trust models to support secure communication between network nodes, we abstract network security requirements to a core set to enable secure inter-network data sharing. We propose a minimum set of security controls that can be implemented without needing major new technologies, but yet realize network security and privacy goals of confidentiality, integrity and availability. This framework combines a set of technology mechanisms with environmental controls, and is shown to be sufficient to counter commonly encountered network security threats adequately.

Kailar, Rajashekar

2007-01-01

126

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

NASA Technical Reports Server (NTRS)

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.

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

1998-01-01

127

Approximate Dynamic Programming for Communication-Constrained Sensor Network Management  

Microsoft Academic Search

Resource management in distributed sensor networks is a challenging problem. This can be attributed to the fundamental tradeoff between the value of information contained in a distributed set of measurements versus the energy costs of acquiring measurements, fusing them into the conditional probability density function (pdf) and transmitting the updated conditional pdf. Communications is commonly the highest contributor among these

Jason L. Williams; John W. Fisher III; Alan S. Willsky

2007-01-01

128

Modeling MAC layer for powerline communications networks  

NASA Astrophysics Data System (ADS)

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

Hrasnica, Halid; Haidine, Abdelfatteh

2001-02-01

129

The NASA Space Communications Data Networking Architecture  

NASA Technical Reports Server (NTRS)

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.

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

2006-01-01

130

Communication networks for medical image transmission.  

PubMed

Digital communication networks are of increasing importance for data exchange in health care environments. They may be used to transmit multi-media data, such as text, images, graphics, signals and sound. The essential characteristics of modern network technologies are summarized in this article and are seen in the context of local, metropolitan and wide area networks. Standardized technologies discussed are Ethernet, token oriented systems, FDDI, DQDB and ATM. Off-line communication media based on magnetic optical disk, such as IS&C, are briefly introduced. The conclusion reached is that therapy planning for radiation therapy or hyperthermia can make use of communication technologies, for example, to transmit patient images, modelling data and results of distribution calculations of physical phenomena. PMID:8211670

Lemke, H U

1993-09-01

131

Anonymous communications in mobile ad hoc networks  

Microsoft Academic Search

Abstract—Due to the broadcast nature of radio transmissions, communications in mobile ad hoc networks (MANETs) are more susceptible to malicious traffi ca nalysis. In this paper we propose a novel anonymous on-demand routing protocol, termed MASK, to enable anonymous,communications thereby thwarting possible traffic analysis attacks. Based on a new cryptographic concept called pairing, we first propose an anonymous neighborhood authentication

Yanchao Zhang; Wei Liu; Wenjing Lout

2005-01-01

132

Network Science for Decision-making: Impact of Distributed Information Quality on Performance of Decision-Making Groups.  

National Technical Information Service (NTIS)

Within tactical networks, communication networks support command and control organizations and social networks by enabling the flow of information. The connectivity and quality of service of the communication network results in a varying degree of mission...

B. Rivera K. Chan

2011-01-01

133

Child Rights Information Network Newsletter, 1996.  

ERIC Educational Resources Information Center

These two newsletter issues communicate activities of the newly formed Child Rights Information Network (CRIN) and report on emerging information resources and activities concerning children and child rights. The January 1996 issue describes the history of CRIN, provides updates on the activities of projects linked to CRIN, and summarizes…

Purbrick, Becky, Ed.

1996-01-01

134

Information Retrieval as a Network Application.  

ERIC Educational Resources Information Center

Describes the function of the Open Systems Interconnection (OSI) Z39.50 protocol, which allows for construction of information "servers"--i.e., resources attached to a computer communications network that can be accessed by client machines to retrieve information. The relationship of Z39.5 to other OSI protocols is explained. (23 references) (SD)

Lynch, Clifford A.

1990-01-01

135

Intelligent network concepts in mobile communications  

Microsoft Academic Search

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

Bijan Jabbari

1992-01-01

136

A Communications Network for Cislunar Operations  

NASA Technical Reports Server (NTRS)

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.

Burleigh, Scott

2012-01-01

137

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.

2007-04-09

138

Hybrid Mobile Communication Networks for Planetary Exploration  

NASA Technical Reports Server (NTRS)

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.

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

2007-01-01

139

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

NASA Astrophysics Data System (ADS)

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.

Montain, J.; Byrne, J. M.

2010-12-01

140

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.

2007-04-03

141

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.

142

Government Communications Network Engineering Feasibility Study.  

National Technical Information Service (NTIS)

The Government of the Philippines (GOP) conducted a feasibility study of a Government Communications Network (GCN). The purpose of the study is to provide the GOP with sufficient data to prove the concept of a GCN and then implement the system. The ultima...

1992-01-01

143

Biologically Inspired, Self Organizing Communication Networks  

Microsoft Academic Search

The rapid exploitation of communication networks in progressively more aspects and their associated complexity have critically driven the desire for autonomic self-organized capabilities to provide scalable adaptive, resilient and emergent behaviour to maintain their operational capability in dynamic situations. The principles of achieving autonomic capabilities are inspired from biological and ecological systems. In this paper, biological behaviour such as migration,

Yousef E. M. Hamouda; Chris Phillips

2008-01-01

144

Communication security in a distributed network  

Microsoft Academic Search

In order for a distributed network to function securely, the integrity of the data transmitted over the communication links must be maintained. The use of either link encryption or end-to-end encryption will help to maintain the integrity of transmitted data, although there are differences in the level of security which they provide. This paper begins with an analysis of link

Marie A. Wright

1990-01-01

145

Distributed averaging on asynchronous communication networks  

Microsoft Academic Search

Abstract— Distributed algorithms for averaging have at- tracted interest in the control and sensing literature. However, previous works have not addressed some practical concerns that will arise in actual implementations on packet-switched communication networks such as the Internet. In this paper, we present several implementable algorithms that are robust to asynchronism and dynamic topology changes. The algorithms do not require

M. Mehyar; D. Spanos; J. Pongsajapan; S. H. Low; R. M. Murray

2005-01-01

146

Network Security: Synchronization in Chaotic Communication Systems  

Microsoft Academic Search

As the number of communication security violations and the sophistication of intruders and bad actors increases, complex processes such as chaos and quantum theory become applicable to cryptographic systems and to network security. In this paper we demystify chaos and chaotic processes with simple examples; we provide examples of using chaos in cryptographic systems, and we identify synchronization issues in

Stamatios V. Kartalopoulos

2009-01-01

147

Information Communication System at Tsukuba EXPO'85  

NASA Astrophysics Data System (ADS)

At Tsukuba EXPO'85 information communication system which employs the most advanced technology such as optical technology, is operated to conduct EXPO information guide, environmental and security control at the site, and office management, which is effective for smooth management of Exposition and appropriate service to visitors. The author outlines the characteristics of the whole communication system, and also describes how communication system using optical technology is located in the whole communication system, and the system outline.

Sakagami, Yasuhiko

148

Communication Networks in the Brain  

PubMed Central

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 neuron’s specialized proteins called neurotransmitter receptors. The neurotransmitter molecules bind to the receptor proteins and alter postsynaptic neuronal function. Two types of neurotransmitter receptors exist—ligand-gated ion channels, which permit rapid ion flow directly across the outer cell membrane, and G-protein–coupled 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.

Lovinger, David M.

2008-01-01

149

Improving reliability in a stochastic communication network  

NASA Astrophysics Data System (ADS)

This research investigated the behavior of increasing the reliability of components in stochastic communication networks. A stochastic communication network is one in which the components, links and nodes, are not 100 percent reliable. In addition to the reliability value, each component also has a capacity value that limits the flow through the component. The throughput in a stochastic communication network can be improved by increasing the capacity or the reliability of the individual components. A set of linear and nonlinear models was developed to determine the best investment strategy for increasing the reliability of individual components. Once the models were developed, an experiment was designed to compare the output of the models to another set of existing models that calculated the best investment strategy for increasing the capacity of individual components. The experiment employed a Prolog program to: enumerate the paths, compute the reliability of each path, and formulate the linear and nonlinear models for direct input into mathematical programming packages. In addition, the linear models were reformulated as networks with side constraints and solved using a network flow package. The models and methodology are general and could easily be modified.

Gaught, William L.

1990-12-01

150

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...

151

Network analysis to uncover the structural communication in GPCRs.  

PubMed

Protein structure network (PSN) analysis is one of the graph theory-based approaches currently used to investigate the structural communication in biomolecular systems. Information on system dynamics can be provided by atomistic molecular dynamics simulations or coarse-grained Elastic Network Models paired with Normal Mode Analysis (ENM-NMA). This chapter describes the application of PSN analysis to uncover the structural communication in G protein-coupled receptors (GPCRs). Strategies to highlight changes in structural communication upon misfolding mutations, dimerization, and activation are described. Focus is put on the ENM-NMA-based strategy applied to the crystallographic structures of rhodopsin in its inactive (dark) and signaling active (meta II (MII)) states, highlighting clear changes in the PSN and the centrality of the retinal chromophore in differentiating the inactive and active states of the receptor. PMID:24143971

Fanelli, Francesca; Felline, Angelo; Raimondi, Francesco

2013-01-01

152

Networked sensor communications for the objective force  

NASA Astrophysics Data System (ADS)

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.

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

2002-08-01

153

Networked sensor communications for the objective force  

NASA Astrophysics Data System (ADS)

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 application. Technologies from the Army Research Laboratory, Defense Research Projects Agency (DARPA), and commercial will be leveraged for this effort.

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

2002-08-01

154

Cooperative UAV-Based Communications Backbone for Sensor Networks  

Microsoft Academic Search

The objective of this project is to investigate the use of unmanned air vehicles (UAVs) as mobile, adaptive communications backbones for ground-based sensor networks. In this type of network, the UAVs provide communication connectivity to sensors that cannot communicate with each other because of terrain, distance, or other geographical constraints. In these situations, UAVs provide a vertical communication path for

2001-01-01

155

Topology design and performance analysis of an integrated communication network  

NASA Technical Reports Server (NTRS)

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.

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

1985-01-01

156

Governing the sea rescue service in Sweden: communicating in networks  

Microsoft Academic Search

This paper discusses how various actors communicate about and coordinate sea rescue activities in networks. We combine a network approach with theories of inter?organization communication to understand how communication can facilitate or limit coordination in networks. Search and rescue officers retain the overall authority to direct rescue missions, and coordination with several other professions is central to this. When coordinating

Jenny Palm; Eva Törnqvist

2008-01-01

157

Cell Multiprocessor Communication Network: Built for Speed  

SciTech Connect

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.

Kistler, Mike; Perrone, Michael; Petrini, Fabrizio

2006-06-01

158

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.

159

Interactive Weather Information Network  

NSDL National Science Digital Library

Offered by the National Oceanic and Atmospheric Administration (NOAA), the Interactive Weather Information Network (IWIN) is a collection of interactive weather maps and satellite images that is updated every five seconds. Visitors can see cloud cover animation loops, NEXRAD Radar images of precipitation, a map of all current weather fronts, and an interactive national map to see information about any particular state. Other information on the site includes a listing of any active weather warnings, a link for world weather data, and more, making this a must-see site for all those users interested in the most current weather happenings anywhere.

2002-01-01

160

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.

2001-01-01

161

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

PubMed

Software defined networking (SDN) has become the focus in the current information and communication technology area because of its flexibility and programmability. It has been introduced into various network scenarios, such as datacenter networks, carrier networks, and wireless networks. Optical transport network is also regarded as an important application scenario for SDN, which is adopted as the enabling technology of data communication networks (DCN) instead of general multi-protocol label switching (GMPLS). However, the practical performance of SDN based DCN for large scale optical networks, which is very important for the technology selection in the future optical network deployment, has not been evaluated up to now. In this paper we have built a large scale flexi-grid optical network testbed with 1000 virtual optical transport nodes to evaluate the performance of SDN based DCN, including network scalability, DCN bandwidth limitation, and restoration time. A series of network performance parameters including blocking probability, bandwidth utilization, average lightpath provisioning time, and failure restoration time have been demonstrated under various network environments, such as with different traffic loads and different DCN bandwidths. The demonstration in this work can be taken as a proof for the future network deployment. PMID:24787842

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

2014-04-21

162

The Study of Communication Networks and Communication Structure in Large Organizations.  

National Technical Information Service (NTIS)

Communication networks consist of the regular patterns of interpersonal communication contacts which develop among people within an organization as they use various forms of communication (face-to-face meetings, memos, telephone calls, etc.) to accomplish...

G. N. Lindsey P. R. Monge

1974-01-01

163

Communication Network Activity: Network Attributes of the Young and Elderly.  

ERIC Educational Resources Information Center

Finds that the elderly, as compared to the young, engaged in greater communicative contact with their families, and that the level of contact with nonfamily network members is less; also, their level of solidarity with nonfamily members is lower than that for the young, but the levels of family solidarity do not differ between these groups. (SR)

Patterson, Brian R.

1995-01-01

164

Scaling of load in communications networks.  

PubMed

We show that the load at each node in a preferential attachment network scales as a power of the degree of the node. For a network whose degree distribution is p(k)?k{-?} , we show that the load is l(k)?k{?} with ?=?-1 , implying that the probability distribution for the load is p(l)?1/l{2} independent of ? . The results are obtained through scaling arguments supported by finite size scaling studies. They contradict earlier claims, but are in agreement with the exact solution for the special case of tree graphs. Results are also presented for real communications networks at the IP layer, using the latest available data. Our analysis of the data shows relatively poor power-law degree distributions as compared to the scaling of the load versus degree. This emphasizes the importance of the load in network analysis. PMID:21230134

Narayan, Onuttom; Saniee, Iraj

2010-09-01

165

A method of structuring communication data for in-vehicle information service  

Microsoft Academic Search

New in-vehicle information provision services have started according to the progress of data communication infrastructure surrounding vehicles, where the vehicles can connect to communication network outside. In such information services, a large amount of various data related to vehicles and\\/or drivers will be stored to the datacenter over the network in near future. Data and functions which are currently equipped

Keisuke OKAMOTO; Munehiko SASAJIMA; Naiwala P. CHANDRASIRI; Kazunari NAWA; Riichiro MIZOGUCHI

2010-01-01

166

Information Theory Methods in Communication Complexity  

Microsoft Academic Search

We use tools and techniques from information theory to study communication complexityproblems in the one-way and simultaneous communication models. Our results include:(1) A tight characterization of multi-party one-way communication complexity for productdistributions in terms of VC-dimension and shatter coefficients;(2) An equivalence of multi-party one-way and simultaneous communication models for productdistributions;(3) A suite of lower bounds for specific functions in the...

Ziv Bar-yossef; T. S. Jayram; Ravi Kumar; D. Sivakumar

2002-01-01

167

A swarm-assisted integrated communication and sensing network  

NASA Astrophysics Data System (ADS)

We present a design concept for an integrated communication and sensor network that employs swarms of Unmanned Aerial Vehicles (UAVs). UAVs are deployed in two types of swarms: sensor swarms or communication swarms. Sensor swarms are motivated by the belief that adversaries will force future confrontations into urban settings, where advantages in surveillance and weapons are diminished. A sensor system is needed which can provide high-resolution imagery and an unobstructed view of a hazardous environment fraught with obstructions. These requirements can be satisfied by a swarm of inexpensive UAVs which "work together" by arranging themselves into a flight configuration that optimizes their integrated sensing capability. If a UAV is shot down, the swarm reconfigures its topology to continue the mission with the surviving assets. We present a methodology that integrates the agents into a formation that enhances the sensing operations while minimizing the transmission of control information for topology adaptation. We demonstrate the performance tradeoff between search time and number of UAVs employed, and present an algorithm that determines the minimum swarm size necessary to meet a targeted search completion time within probabilistic guarantees. A communication swarm provides an infrastructure to distribute information provided by the sensor swarms, and enables communication between dispersed ground locations. UAVs are "guided" to locations that provide the best support for an underlying ground-based communication network and for dissemination of data collected by sensor swarms.

Vincent, Patrick J.; Rubin, Izhak

2004-07-01

168

Informant Accuracy in Social Network Data. II.  

National Technical Information Service (NTIS)

This paper repeats and confirms the results of a 1976 study, concerning informants' ability to report their communication accurately. A variety of self-monitoring, or nearly self-monitoring, networks are used for this study. The conclusion again appears t...

H. R. Bernard P. D. Killworth

1976-01-01

169

Position estimation of transceivers in communication networks  

DOEpatents

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.

Kent, Claudia A. (Pleasanton, CA); Dowla, Farid (Castro Valley, CA)

2008-06-03

170

Distributed communications resource management for tracking and surveillance networks  

NASA Astrophysics Data System (ADS)

We present a market-like method for distributed communications resource management in the context of networked tracking and surveillance systems. This method divides communication resources according to the expected utility provided by information of particular types. By formulating the problem as an optimization of the joint utility of information flow rates, the dual of the problem can be understood to provide a price for particular routes. Distributed rate control can be accomplished using primal-dual iteration in combination with communication of these route prices. We extend the previous work on the subject in a few important ways. First, we consider utility functions that are jointly-dependent on flow rates, to properly account for geometric synergy that can occur in sensor fusion problems. Second, we do not require that the rate-update algorithms have explicit knowledge of utility functions. Instead, our update algorithms involve transmitting marginal utility values. We present simulation results to demonstrate the effectiveness of the technique.

Chong, Edwin K. P.; Brewington, Brian

2005-09-01

171

NOVANET: communications network for a control system  

SciTech Connect

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

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

1983-05-23

172

Real-Time Communication in Multihop Networks  

Microsoft Academic Search

Communication in real-time systems has to be predictable, because unpredictable delaysin the delivery of messages can adversely affect the execution of tasks dependent onthese messages. We develop a scheme for providing predictable interprocesscommunication in real-time systems with (partially connected) point-to-pointinterconnection networks, which provide guarantees on the maximum delivery time formessages. This scheme is based on the concept of a real-time

Dilip D. Kandlur; Kang G. Shin; Domenico Ferrari

1994-01-01

173

Intelligent network requirements for personal communications services  

Microsoft Academic Search

It is shown that a moderate set of capabilities within the service switching point (SSP), service control point (SCP), and intelligent peripheral (IP), which are the intelligent network (IN) components directly responsible for the real-time execution and control of end-user services, can engender a wide range of end-user personal communication service (PCS) features. These capabilities could be used as the

J. Homa; S. Harris

1992-01-01

174

A Survey on Communication Networks for Electric System Automation  

Microsoft Academic Search

In today' s competitive electric utility marketplace, real-time information becomes the key factor for reliable delivery of power to the end-users, profitability of the electric utility and customer satisfaction. The operational and commercial demands of electric utilities require a high-performance data communi- cation network that supports both existing functionalities and future operational requirements. In this respect, since such a communication

V. Cagri; Frank C. Lambertz

175

Informal networks: the company behind the chart.  

PubMed

A glance at an organizational chart can show who's the boss and who reports to whom. But this formal chart won't reveal which people confer on technical matters or discuss office politics over lunch. Much of the real work in any company gets done through this informal organization with its complex networks of relationships that cross functions and divisions. According to consultants David Krackhardt and Jeffrey Hanson, managers can harness the true power in their companies by diagramming three types of networks: the advice network, which reveals the people to whom others turn to get work done; the trust network, which uncovers who shares delicate information; and the communication network, which shows who talks about work-related matters. Using employee questionnaires, managers can generate network maps that will get to the root of many organizational problems. When a task force in a computer company, for example, was not achieving its goals, the CEO turned to network maps to find out why. He discovered that the task force leader was central in the advice network but marginal in the trust network. Task force members did not believe he would look out for their interests, so the CEO used the trust map to find someone to share responsibility for the group. And when a bank manager saw in the network map that there was little communication between tellers and supervisors, he looked for ways to foster interaction among employees of all levels. As companies continue to flatten and rely on teams, managers must rely less on their authority and more on understanding these informal networks. Managers who can use maps to identify, leverage, and revamp informal networks will have the key to success. PMID:10127036

Krackhardt, D; Hanson, J R

1993-01-01

176

Information, Communication, and Educational Technologies in Rural Alaska  

ERIC Educational Resources Information Center

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…

Page, G. Andrew; Hill, Melissa

2008-01-01

177

The Usefulness of Information and Communication Technologies in Crisis Response  

PubMed Central

Information and communication technologies (ICTs) play a vital role in coordinating crisis response between pre-hospital services and emergency departments of hospitals. In spite of the advances in these technologies, there remain a variety of challenges to their usage during a crisis. To identify these challenges, we conducted focus group interviews with emergency department (ED) and emergency medical services (EMS) personnel. We found that ED and EMS personnel have widely varying perceptions about the usefulness and ease-of-use of information tools and communication tools used in crisis management. We discuss the importance of bringing together communication and information tools into integrated networks of ICTs for effective crisis response. We also highlight design features of ICTs which can support seamless and effective communication and coordination between ED and EMS teams.

Paul, Sharoda A.; Reddy, Madhu; Abraham, Joanna; DeFlitch, Christopher

2008-01-01

178

GAS MAIN SENSOR AND COMMUNICATIONS NETWORK SYSTEM  

SciTech Connect

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.

Hagen Schempf, Ph.D.

2003-02-27

179

Position Estimation of Tranceivers in Communication Networks  

SciTech Connect

With the rapid development in wireless sensor networks, there is an important need for transceiver position estimation independent of Global Positioning Systems (GPS) [1,3]. While GPS might be useful for outdoor sensor nodes, it is not for indoor node localization. In this case, position estimation is possible through network range estimates from time-of-flight (TOF) measurements, a technique well suited to large bandwidth physical links, such as in ultra-wideband (UWB) communications. For example, in our UWB systems, with pulse duration less than 200 pico-seconds, range can easily be resolved to less than a foot. Assuming an encoded UWB or spread spectrum physical layer, we developed algorithms and simulation tools to test transceiver position localization. Simulations were designed to lend insight into system characteristics such as position error sensitivities to network geometry, to range estimation errors, and to number of sensor nodes.

Kent, C A; Dowla, F U

2003-10-13

180

The Use of Communication Networks to Increase Personal Privacy In a Health Insurance Architecture  

Microsoft Academic Search

Recent advances in computing and communications make it reasonable to assemble and process the vast amounts of information that would be needed to administer and monitor a national health insurance network. Using computing and communications technology to operate on medical information has many side advantages, such as making an individual's complete health records available any place, almost instantaneously, and conducting

N. F. Maxemchuk

181

A telemetry and space communication network simulation for training  

Microsoft Academic Search

Telemetry and data communications network simulation training devices are described in terms of training mission controllers and spacecraft flight crews to manage the space-network's resources for consistent and reliable data flow between a user's spacecraft and control center. A space-communication-network simulation for communication controller training contains models for network configuration, resource scheduling, simulation of tracking data blocks, data quality monitoring,

Joey White; Joseph Policella

1991-01-01

182

Electrical communication in branching arterial networks.  

PubMed

Electrical communication and its role in blood flow regulation are built on an examination of charge movement in single, isolated vessels. How this process behaves in broader arterial networks remains unclear. This study examined the nature of electrical communication in arterial structures where vessel length and branching were varied. Analysis began with the deployment of an existing computational model expanded to form a variable range of vessel structures. Initial simulations revealed that focal endothelial stimulation generated electrical responses that conducted robustly along short unbranched vessels and to a lesser degree lengthened arteries or branching structures retaining a single branch point. These predictions matched functional observations from hamster mesenteric arteries and support the idea that an increased number of vascular cells attenuate conduction by augmenting electrical load. Expanding the virtual network to 31 branches revealed that electrical responses increasingly ascended from fifth- to first-order arteries when the number of stimulated distal vessels rose. This property enabled the vascular network to grade vasodilation and network perfusion as revealed through blood flow modeling. An elevation in endothelial-endothelial coupling resistance, akin to those in sepsis models, compromised this ascension of vasomotor/perfusion responses. A comparable change was not observed when the endothelium was focally disrupted to mimic disease states including atherosclerosis. In closing, this study highlights that vessel length and branching play a role in setting the conduction of electrical phenomenon along resistance arteries and within networks. It also emphasizes that modest changes in endothelial function can, under certain scenarios, impinge on network responsiveness and blood flow control. PMID:22796538

Tran, Cam Ha T; Vigmond, Edward J; Goldman, Daniel; Plane, France; Welsh, Donald G

2012-09-15

183

Structural changes in data communication in wireless sensor networks  

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

184

Research on optic antenna of space laser communication networking  

NASA Astrophysics Data System (ADS)

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

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

2013-08-01

185

Joint network coding and channel coding for cooperative relay communication system  

Microsoft Academic Search

This paper we propose a scheme of joint network coding and channel coding for cooperative relay communication system. With the proposed joint network coding and channel coding, the soft probability information can be combined with the redundancy contained in the relay transmission by the operation relationship in network coding and diversity gain can be obtained. Simulation results show that the

Rongdao Yu; Tao Wu

2010-01-01

186

Information transmission and recovery in neural communications channels  

SciTech Connect

Biological neural communications channels transport environmental information from sensors through chains of active dynamical neurons to neural centers for decisions and actions to achieve required functions. These kinds of communications channels are able to create information and to transfer information from one time scale to the other because of the intrinsic nonlinear dynamics of the component neurons. We discuss a very simple neural information channel composed of sensory input in the form of a spike train that arrives at a model neuron, then moves through a realistic synapse to a second neuron where the information in the initial sensory signal is read. Our model neurons are four-dimensional generalizations of the Hindmarsh-Rose neuron, and we use a model of chemical synapse derived from first-order kinetics. The four-dimensional model neuron has a rich variety of dynamical behaviors, including periodic bursting, chaotic bursting, continuous spiking, and multistability. We show that, for many of these regimes, the parameters of the chemical synapse can be tuned so that information about the stimulus that is unreadable at the first neuron in the channel can be recovered by the dynamical activity of the synapse and the second neuron. Information creation by nonlinear dynamical systems that allow chaotic oscillations is familiar in their autonomous oscillations. It is associated with the instabilities that lead to positive Lyapunov exponents in their dynamical behavior. Our results indicate how nonlinear neurons acting as input/output systems along a communications channel can recover information apparently ''lost'' in earlier junctions on the channel. Our measure of information transmission is the average mutual information between elements, and because the channel is active and nonlinear, the average mutual information between the sensory source and the final neuron may be greater than the average mutual information at an earlier neuron in the channel. This behavior is strikingly different than the passive role communications channels usually play, and the ''data processing theorem'' of conventional communications theory is violated by these neural channels. Our calculations indicate that neurons can reinforce reliable transmission along a chain even when the synapses and the neurons are not completely reliable components. This phenomenon is generic in parameter space, robust in the presence of noise, and independent of the discretization process. Our results suggest a framework in which one might understand the apparent design complexity of neural information transduction networks. If networks with many dynamical neurons can recover information not apparent at various waystations in the communications channel, such networks may be more robust to noisy signals, may be more capable of communicating many types of encoded sensory neural information, and may be the appropriate design for components, neurons and synapses, which can be individually imprecise, inaccurate ''devices.''

Eguia, M. C.; Rabinovich, M. I.; Abarbanel, H. D. I.

2000-11-01

187

Performance testing framework for smart grid communication network  

NASA Astrophysics Data System (ADS)

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

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

2013-06-01

188

Analyzing the Dynamics of Communication in Online Social Networks  

NASA Astrophysics Data System (ADS)

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.

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

189

Computing and Communications Infrastructure for Network-Centric Warfare: Exploiting COTS, Assuring Performance.  

National Technical Information Service (NTIS)

In network centric warfare (NCW), the effectiveness of warfighters and their platforms is enhanced by rapid and effective information flow. This requires a robust and flexible computing and communications software infrastructure, and a degree of system in...

J. P. Richardson L. Graba M. Agrawal

2004-01-01

190

Scholarly Information Network  

NASA Astrophysics Data System (ADS)

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.

Ginsparg, Paul

191

Performance of TCP protocols in deep space communication networks  

Microsoft Academic Search

The communication requirements for space missions necessitate to address the problems due to deep space communication networks. In this letter, the effects of slow start algorithm, propagation delay and the link errors on the throughput performance of transport layer protocols are investigated in deep space communication networks. The objective of this letter is to demonstrate through experimental results that existing

Özgür B. Akan; H. Fang; Ian F. Akyildiz

2002-01-01

192

Mixed integer programming & heuristic scheduling for space communication networks  

Microsoft Academic Search

We introduce mixed integer programming and heuristic scheduling for space communication networks in this paper. The considered communication network consists of space and ground assets with the link dynamics between any two assets vary with respect to time, distance, and telecom configurations. One asset could be communicating with another at very high data rates at one time and at other

Charles H. Lee; Kar-Ming Cheung

2012-01-01

193

Self-organizing hierarchies in sensor and communication networks.  

PubMed

We consider a hierarchical multicellular sensing and communication network, embedded in an ageless aerospace vehicle that is expected to detect and react to multiple impacts and damage over a wide range of impact energies. In particular, we investigate self-organization of impact boundaries enclosing critically damaged areas, and impact networks connecting remote cells that have detected noncritical impacts. Each level of the hierarchy is shown to have distinct higher-order emergent properties, desirable in self-monitoring and self-repairing vehicles. In addition, cells and communication messages are shown to need memory (hysteresis) in order to retain desirable emergent behavior within and between various hierarchical levels. Spatiotemporal robustness of self-organizing hierarchies is quantitatively measured with graph-theoretic and information-theoretic techniques, such as the Shannon entropy. This allows us to clearly identify phase transitions separating chaotic dynamics from ordered and robust patterns. PMID:16197671

Prokopenko, Mikhail; Wang, Peter; Valencia, Philip; Price, Don; Foreman, Mark; Farmer, Anthony

2005-01-01

194

Communications Network Architecture for Space-Based Sensor Networks  

Microsoft Academic Search

Numerous planned and proposed future space exploration missions will employ multiple spacecraft that perform multipoint sensing. Distributed space-based sensing missions can significantly benefit from incorporation of cross-link communications capabilities, thereby forming space-based networks, by enabling continuous access to any\\/all Spacecraft via single ground contact, real-time coordinated observations, and autonomous processing among in situ spacecraft. In this paper, we present a

Loren P. Clare; Jay L. Gao; Esther H. Jennings; Clayton Okino

2004-01-01

195

On cost-effective communication network designing  

NASA Astrophysics Data System (ADS)

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

Zhang, Guo-Qiang

2010-02-01

196

Queue-length synchronization in communication networks  

NASA Astrophysics Data System (ADS)

We study the synchronization in the context of network traffic on a 2-d communication network with local clustering and geographic separations. The network consists of nodes and randomly distributed hubs where the top five hubs ranked according to their coefficient of betweenness centrality (CBC) are connected by random assortative and gradient mechanisms. For multiple message traffic, messages can trap at the high CBC hubs, and congestion can build up on the network with long queues at the congested hubs. The queue lengths are seen to synchronize in the congested phase. Both complete and phase synchronization are seen, between pairs of hubs. In the decongested phase, the pairs start clearing and synchronization is lost. A cascading master-slave relation is seen between the hubs, with the slower hubs (which are slow to decongest) driving the faster ones. These are usually the hubs of high CBC. Similar results are seen for traffic of constant density. Total synchronization between the hubs of high CBC is also seen in the congested regime. Similar behavior is seen for traffic on a network constructed using the Waxman random topology generator. We also demonstrate the existence of phase synchronization in real internet traffic data.

Mukherjee, Satyam; Gupte, Neelima

2009-05-01

197

MODELING INFORMATION DEPENDENCIES IN CONSTRUCTION PROJECT NETWORK ORGANIZATIONS  

Microsoft Academic Search

This ongoing study intends to explore and formalize the information dependency patterns in network forms of organizations in construction project management. In construction projects, information is critical for seamless and cost-effective operations. Communication of project information and coordination of information exchanges between different project participants are essential for a project's success. On the other hand, a better understanding of information

Mehmet Koray Pekericli; Burcu Akinci; Itir Karaesmen

198

Throughput and outage for block-Markov encoding implementation with network coding for cooperative communications  

Microsoft Academic Search

In size constraint terminals like in cellular and sensor networks, cooperative communications have been proposed as one of the most efficient way to exploit the benefits of multiple antenna systems. The achievable rates and resulting diversity gains are dependent on information theoretic block-Markov coding. Practical implementation of this information theoretic code design with network coding, as an efficient and low

Gordhan Das Menghwar; Wajiha Shah; C. F. Mecklenbrauker

2009-01-01

199

Determinants of Communication Network Involvement: Connectedness and Integration.  

ERIC Educational Resources Information Center

Developed structural equation models of involvement in communication networks in organizations for communication network connectedness and for network integration. A questionnaire was administered to members of a naval training facility (N=125). Models showed acceptable goodness-of-fit for the connectedness model and excellent goodness-of-fit for…

Monge, Peter R.; And Others

1983-01-01

200

Route Optimization for Intra Communication of a Nested Mobile Network  

Microsoft Academic Search

Network mobility, i.e. Internet access services for a moving network as a single unit brings about new challenging issues. A nested mobile network is a hierarchical form of multiple mobile networks. Nested mobile networks sufier from a pin- ball routing problem. This problem becomes more serious in the case of a communication between any two nodes in the same nested

Sungmin Baek; Jinkyu Yoo; Hosik Cho

201

Multiphoton quantum communication in quantum networks  

NASA Astrophysics Data System (ADS)

We propose and analyze a multiphoton-state coherent transport protocol in a coupled-resonator quantum network. A multiphoton swap gate between two antipodes can be achieved with neither external modulation nor coupling strength engineering. Moreover, we extend this result to a coupled-resonator chain of arbitrary length with different coupling strengths. Effects of decoherence via quantum nondemolition interaction are studied with sources including vacuum quantum fluctuation and bath thermal excitations when the bath is in the thermal equilibrium state. These observations are helpful to understand the decoherence effects on quantum communication in quantum coupled-resonator systems.

Qin, Wei; Wang, Chuan; Cao, Ye; Long, Gui Lu

2014-06-01

202

Information Communication Technology (ICT) Shaping Student Affairs.  

ERIC Educational Resources Information Center

This paper opens with the following questions: "How prepared are you as a student affairs professional for information communication technology (ICT)? Do you understand such concepts as portals, e-business, Napster, computer use policies, and wireless communication? Will student affairs be shaped by ICT or will student affairs help shape ICT on…

Broughton, Elizabeth

203

Organization of Communication in Information Systems.  

ERIC Educational Resources Information Center

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…

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

204

An Information Theory of Visual Communication  

Microsoft Academic Search

The fundamental problem of visual communication is that of producing the best possible picture at the lowest data rate. We address this problem by extending information theory to the assessment of the visual communication channel as a whole, from image gathering to display. The extension unites two disciplines, the electro-optical design of image gathering and display devices and the digital

Friedrich O. Huck; Carl L. Fales; Zia-Ur Rahman

1996-01-01

205

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

NASA Astrophysics Data System (ADS)

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.

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

206

Literacy Information and Communication System (LINCS)  

MedlinePLUS

... professional development, and a connected network of practitioners. Information For Students OCTAE's America's Literacy Directory allows students ... directory of programs and other websites for students . Information About Family Literacy and Early Learning LINCS provides ...

207

GAS MAIN SENSOR AND COMMUNICATIONS NETWORK SYSTEM  

SciTech Connect

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.

Hagen Schempf

2004-09-30

208

Based on asynchronous communication protocol of geographic space information service access mechanism research  

NASA Astrophysics Data System (ADS)

At present, the traditional way of accessing to classified network in geographic spatial information services is using network gatekeeper and firewall etc. to ensure public and classified network communications links. However, the physical isolation between classified network and public network is crossed, which is bound to cause classified network potential security hazard. In Yunnan province space Land dynamic monitoring integration project, it proposed the point to point text message communication protocol and asynchronous transmission mechanism. Using geo-spatial information encryption processing and data compression processing method, it reduced the risk of data sensitivity and monitored, namely to ensure data security, which realized geographic spatial information services data communication effectively between classified network and public network in the rigid field conditions.

Chen, G.; Zhao, J.; Gu, M.; Li, D.

2014-04-01

209

'The Tsukuba Network' as a new medium for promoting research communications in Tsukuba  

NASA Astrophysics Data System (ADS)

The Science and Technology Agency constructed a PC-based communication network system named 'The Tsukuba Network' as a new medium for promoting the research communication in, and with, the Tsukuba City. For about a year prior to full operation, a pilot system was operated with the cooperation of some monitoring users to gain skill and experience for managing the PC-based communication network. The main service functions of the system are : bulletin board service; electronic mail ; construction of, and access to, the databases involving research information in Tsukuba City ; electronic conference; common use of softwares ; connection to other communication networks ( e.g., university and local network). The host computer is a work station EWS4800 and the network processor is a personal computer PC-9801 . These two computers are connected with LAN.

Taguchi, Masamichi

210

Research Priorities in Networking and Communications Research (Workshop Report)  

NSF Publications Database

Network interface architectures Network interfaces are responsible for connecting networks to hosts and other networks, and are critical to the performance and usefulness of networks. Examples of research topics in network interface architectures include; workstation I/O architectures to support high-speed network interfaces; low-latency (sub 10-microsecond) end-to-end inter-host communication; integration of architectural development of hosts, with that of local, metropolitan, and wide area ...

211

The Refugee Health Information Network  

Microsoft Academic Search

The Refugee Health Information Network is an electronic resource designed to make accessible culturally and linguistically appropriate health and medical information in order to improve health services for refugees and asylees. Much of this information will clearly be of value to immigrants as well. This is also a network designed to facilitate collaboration and sharing among state refugee health coordinators

Gale A. Dutcher; John C. Scott; Stacey J. Arnesen

2008-01-01

212

Communicability Graph and Community Structures in Complex Networks  

Microsoft Academic Search

Abstract Weuse the concept of network communicability (Phys. Rev. E 77, 036111 (2008)) to define communities,in a complex,network. The communities,are defined as the cliques of a “communicabilitygraph”. The communicability,graph is defined here as the graph having the same set of vertices as the complex,network and the connections between ,them are determined by the ,communicability ,function. Two nodes ,are connected in

Ernesto Estrada; Naomichi Hatano

2009-01-01

213

An Interdisciplinary Network Making Progress on Climate Change Communication  

NASA Astrophysics Data System (ADS)

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.

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

2012-12-01

214

Global Legal Information Network  

NSDL National Science Digital Library

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.

2005-01-01

215

Cooperative UAV-Based Communications Backbone for Sensor Networks  

SciTech Connect

The objective of this project is to investigate the use of unmanned air vehicles (UAVs) as mobile, adaptive communications backbones for ground-based sensor networks. In this type of network, the UAVs provide communication connectivity to sensors that cannot communicate with each other because of terrain, distance, or other geographical constraints. In these situations, UAVs provide a vertical communication path for the sensors, thereby mitigating geographic obstacles often imposed on networks. With the proper use of UAVs, connectivity to a widely disbursed sensor network in rugged terrain is readily achieved. Our investigation has focused on networks where multiple cooperating UAVs are used to form a network backbone. The advantage of using multiple UAVs to form the network backbone is parallelization of sensor connectivity. Many widely spaced or isolated sensors can be connected to the network at once using this approach. In these networks, the UAVs logically partition the sensor network into sub-networks (subnets), with one UAV assigned per subnet. Partitioning the network into subnets allows the UAVs to service sensors in parallel thereby decreasing the sensor-to-network connectivity. A UAV services sensors in its subnet by flying a route (path) through the subnet, uplinking data collected by the sensors, and forwarding the data to a ground station. An additional advantage of using multiple UAVs in the network is that they provide redundancy in the communications backbone, so that the failure of a single UAV does not necessarily imply the loss of the network.

Roberts, R S

2001-10-07

216

Exploring the Morphospace of Communication Efficiency in Complex Networks  

PubMed Central

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

Goni, Joaquin; Avena-Koenigsberger, Andrea; Velez de Mendizabal, Nieves; van den Heuvel, Martijn P.; Betzel, Richard F.; Sporns, Olaf

2013-01-01

217

Gas Main Sensor and Communications Network System  

SciTech Connect

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.

Hagen Schempf

2006-05-31

218

Proactive and adaptive reconfiguration for reliable communication in tactical networks  

NASA Astrophysics Data System (ADS)

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.

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

2012-05-01

219

A Hybrid Satellite-Terrestrial Approach to Aeronautical Communication Networks  

NASA Technical Reports Server (NTRS)

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.

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

2000-01-01

220

Weight-Control Information Network  

MedlinePLUS

... Resources About WIN Facebook Welcome to WIN The Weight-control Information Network provides the general public, health professionals, ... with up-to-date, science-based information on weight control, obesity, physical activity, and related nutritional issues. Be ...

221

The International Coral Reef Information Network  

NSDL National Science Digital Library

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.

International Coral Reef Action Network (ICRAN)

222

Service-Oriented Communications in Optical Networks Using Virtual Switching  

Microsoft Academic Search

I. NETWORK VIRTUAL SWITCHES A network consists of nodes connected by communication links. In this paper, we focus on wide-area wired networks, especially the Internet. The performance of such a network is mainly determined by the capacity (bandwidth) of its links, and the latency of transmit- ted data encountered at intermediate nodes, which include bridges, switches, routers, gateways, etc. These

S. Q. Zheng; Ashwin Gumaste; Jianping Wang

2009-01-01

223

Analysis of Inter-Vehicle Communication Using Network Simulator  

SciTech Connect

Inter-Vehicle Communication (IVC) could be an important component of next-generation Intelligent Transportation System (ITS). It provides wireless connectivity among traveling vehicles to exchange real-time road condition and traffic information to support safe driving and traffic management. IVC system can be considered as a special form of mobile ad-hoc network (MANET). The MANET and IVC are both hot issues for researches. However, there are few domestic literatures combining the two topics. Most of them are discussed separately. Thus, the studies on architecture and protocols of mobile ad-hoc network have great value for establishing vehicular networks. The simulating method is an available way to assess the performance of networks. This paper has a specific description about the network simulator NS-2 . Under the basic of simulating practices, the design method and procedure for MANET simulation are summarized in detail. In this report, two simple IVC scenarios are implemented on NS-2. The quantitative metrics like network throughput, delay and packet-loss are used to assess the performance of MANET for IVC under different vehicular speeds, transport layer protocols and routing protocols. The results indicate that MANET can be used for IVC well. The different speeds and protocols should be chosen based on specific IVC scenarios.

Lu, Wei [ORNL] [ORNL

2013-01-01

224

Communication Efficiency and Congestion of Signal Traffic in Large-Scale Brain Networks  

PubMed Central

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.

Misic, Bratislav; Sporns, Olaf; McIntosh, Anthony R.

2014-01-01

225

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

PubMed

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

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

2014-01-01

226

Integrating Information & Communications Technologies into the Classroom  

ERIC Educational Resources Information Center

"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…

Tomei, Lawrence, Ed.

2007-01-01

227

International Research Network in European Political Communications  

NSDL National Science Digital Library

EurPolCom was initially established in 2000, by Professor Paul Statham, and located at the University of Leeds. In 2007, it was re-launched as a 'network' which advances research in the fields of political communications, the public sphere and social movements and is now located at the University of Bristol. On their website visitors can learn more about this organization and their various research projects. In addition, there are a number of working papers available to the public including "Constitutionalism of the European Public Sphere" and "The Politics of Immigration and Asylum Policy in Western Europe" to name only a few. After getting acquainted, visitors may want to learn more about their grants and awards available as well as upcoming events. Lastly, a set of related links is provided for those interested in a specific aspect of the site.

228

Relaying Selection with Network-coded Cooperative Protocols in Aeronautical Communications  

Microsoft Academic Search

In this article, we exploit the idea of network-coded cooperative protocol in aeronautical communications which combines different source nodes'information at the relay and joint decoding at the destination. Recently, the network coding in cooperative communications has been categorized into two mainstreams, bit-level and signal-level combinations, which are both discussed in the article. And to be exclusively, multiple access relay channel(MARC)

Du Bing; Zhang Jun

2010-01-01

229

Analysis of optical coherence multiplexing networks for satellite communication  

Microsoft Academic Search

Free-space optical communication between satellites networked together can enable a high data rate between the satellites. Coherence multiplexing (CM) is an attractive tech- nique for satellite networking due to its ability to cope with the asynchronous nature of communication traffic and the dynamic changes taking place in the satellite constellation. The use of optical radiation for intersatellite links creates very

G. Kats; Schlomi Arnon

2004-01-01

230

Mass transit power traction networks as communication channels  

Microsoft Academic Search

The rapid progress of power line communications (PLC) for data transmission over electric power supply systems is now opening ways for special applications such as train automation in local transportation and mass transit (MT) systems. These DC-powered traction networks can be used as communication links between wayside equipment and the moving trains. As MT networks significantly differ from usual electricity

Pavels Karols; Klaus Dostert; Gerd Griepentrog; Simon Huettinger

2006-01-01

231

Low-Latency Communication Over ATM Networks Using Active Messages  

Microsoft Academic Search

Recent developments in communication architectures for parallel machines have made significant progress and reduced the communication overheads and latencies by over an order of magnitude as compared to earlier proposals. This paper examines whether these techniques can carry over to clusters of workstations connected by an ATM network even though clusters use standard operating system software, are equipped with network

Thorsten Von Eicken; Anindya Basu; Vineet Buch

1995-01-01

232

Low-latency communication over ATM Networks using Active Messages  

Microsoft Academic Search

Recent developments in communication architectures for parallel machines have made significant progress and reduced the communication overheads and latencies by over an order of magnitude as compared to earlier proposals. This paper examines whether these techniques can carry over to clusters of workstations connected by an ATM network even though clusters use standard operating system software, are equipped with network

Thorsten von Eicken; Veena Avula; Anindya Basu; Vineet Buch

1994-01-01

233

Multiple communication in multi-hop radio networks  

Microsoft Academic Search

Two tasks of communication in a multi-hop synchronous radio network are con- sidered: point-to-point communication and broadcast (sending a message to all nodes of a network). Efficient protocols for both problems are presented. Even though the protocols are probabilistic, it is shown how to acknowledge messages deterministically. Let n, D, and ? be the number of nodes, the diameter and

Reuven Bar-Yehudaf; Amos IsraeliS

1989-01-01

234

Enhancing the performance of wireless sensor networks with MIMO communications  

Microsoft Academic Search

Wireless sensor networks are an enabling technology for many future surveillance-oriented applications. Before a practical wireless sensor network is realized, however, significant challenges must be overcome. Chief among the obstacles to netted sensors is providing low power, robust communications between sensor nodes. Multiple input, multiple output (MIMO) communication promises performance enhancements over conventional single input, single output (SISO) technology for

Jared Burdin; J. Dunyak

2005-01-01

235

Near field magnetic induction Communication in Body Area Network  

Microsoft Academic Search

Next generation wireless communication system may be near filed magnetic induction Communication (NFMIC) which has major application in Body Area Network (BAN). Communication takes place in and around the body is called BAN. This Paper describes the working principle, power equation, its significance and application in NFMIC. It is compared with the other short range wireless technology such as Bluetooth,

Nithya Thilak; Robin Braun

2012-01-01

236

Towards Natural Communication in Networked Collaborative Virtual Environments  

Microsoft Academic Search

:Networked Collaborative Virtual Environments (NCVE) have been a hot topic of research forsome time now. However, most of the existing NCVE systems restrict the communication betweenthe participants to text messages or audio communication. The natural means of humancommunication are richer than this. Facial expressions, lip movements, body postures andgestures all play an important role in our everyday communication. Part of

Igor Sunday Pandzic; Tolga K. Capin

1996-01-01

237

Information assurance in sensor networks  

Microsoft Academic Search

Sensor networks are deployed to monitor the surroundings and keep the end-user informed about the events witnessed. Different types of events have different levels of importance for the user. Information Assurance is an ability to disseminate different information at different assurance levels to the end-user. The assurance level is determined by the criticality of the sensed phenomenon. Thus, information assurance

Budhaditya Deb; Sudeept Bhatnagar; Badri Nath

2003-01-01

238

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.

239

Communication protocols for underwater data collection using a robotic sensor network  

Microsoft Academic Search

We examine the problem of collecting data from an underwater sensor network using an autonomous underwater vehicle (AUV). The sensors in the network are equipped with acoustic modems that provide noisy, range-limited communication to the AUV. One challenge in this scenario is to plan paths that maximize the information collected and minimize travel time. While executing a path, the AUV

Geoffrey A. Hollinger; Sunav Choudhary; Parastoo Qarabaqi; Christopher Murphy; Urbashi Mitra; Gaurav S. Sukhatme; Milica Stojanovic; Hanumant Singh; Franz Hover

2011-01-01

240

Consensus in networks of mobile communicating agents  

NASA Astrophysics Data System (ADS)

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.

Baronchelli, Andrea; Díaz-Guilera, Albert

2012-01-01

241

Citations among communication journals and other disciplines: a network analysis  

Microsoft Academic Search

This article describes the results of a network analysis based on the citation among Communication journals and those academic\\u000a disciplines that are cited by those journals labeled as “Communication” by the Web of Science. The results indicate that the\\u000a journals indexed solely as Communication rather than those also tagged as another social science are more central in the citation\\u000a network.

George A. Barnett; Catherine Huh; Youngju Kim; Han Woo Park

242

The Study of Communication Networks and Communication Structure in Large Organizations.  

ERIC Educational Resources Information Center

This report describes a set of procedures for analyzing communication networks in large organizations. The procedures include the identification and evaluation of various kinds of networks, assessment of the organizational hierarchy, appraisal of various departments within the organization, and evaluation of individual communication behavior. The…

Monge, Peter R.; Lindsey, Georg N.

243

Distributed communications and control network for robotic mining  

NASA Technical Reports Server (NTRS)

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.

Schiffbauer, William H.

1989-01-01

244

[Forensic evidence-based medicine in computer communication networks].  

PubMed

As an important component of judicial expertise, forensic science is broad and highly specialized. With development of network technology, increasement of information resources, and improvement of people's legal consciousness, forensic scientists encounter many new problems, and have been required to meet higher evidentiary standards in litigation. In view of this, evidence-based concept should be established in forensic medicine. We should find the most suitable method in forensic science field and other related area to solve specific problems in the evidence-based mode. Evidence-based practice can solve the problems in legal medical field, and it will play a great role in promoting the progress and development of forensic science. This article reviews the basic theory of evidence-based medicine and its effect, way, method, and evaluation in the forensic medicine in order to discuss the application value of forensic evidence-based medicine in computer communication networks. PMID:24665620

Qiu, Yun-Liang; Peng, Ming-Qi

2013-12-01

245

(CICT) Computing, Information, and Communications Technology Overview  

NASA Technical Reports Server (NTRS)

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.

VanDalsem, William R.

2003-01-01

246

Information dissemination in self-organizing intervehicle networks  

Microsoft Academic Search

Intervehicle communication (IVC) is an emerging topic in research and application that is getting increasing attention from all major car manufacturers. In this paper, a novel method for scalable information dissemination in highly mobile ad hoc networks is proposed: segment-oriented data abstraction and dissemination (SODAD). With SODAD, information can be distributed in an information range multiple orders of magnitude larger

Lars Wischhof; André Ebner; Hermann Rohling

2005-01-01

247

Information thermodynamics on causal networks.  

PubMed

We study nonequilibrium thermodynamics of complex information flows induced by interactions between multiple fluctuating systems. Characterizing nonequilibrium dynamics by causal networks (i.e., Bayesian networks), we obtain novel generalizations of the second law of thermodynamics and the fluctuation theorem, which include an informational quantity characterized by the topology of the causal network. Our result implies that the entropy production in a single system in the presence of multiple other systems is bounded by the information flow between these systems. We demonstrate our general result by a simple model of biochemical adaptation. PMID:24237500

Ito, Sosuke; Sagawa, Takahiro

2013-11-01

248

Information Thermodynamics on Causal Networks  

NASA Astrophysics Data System (ADS)

We study nonequilibrium thermodynamics of complex information flows induced by interactions between multiple fluctuating systems. Characterizing nonequilibrium dynamics by causal networks (i.e., Bayesian networks), we obtain novel generalizations of the second law of thermodynamics and the fluctuation theorem, which include an informational quantity characterized by the topology of the causal network. Our result implies that the entropy production in a single system in the presence of multiple other systems is bounded by the information flow between these systems. We demonstrate our general result by a simple model of biochemical adaptation.

Ito, Sosuke; Sagawa, Takahiro

2013-11-01

249

The analysis of network transmission method for welding robot information  

NASA Astrophysics Data System (ADS)

On the asis of User Datagram Protocol (UserDatagram Protocol, UDP), to do some improvement and design a welding robot network communication protocol (welding robot network communicate protocol: WRNCP), working on the fields of the transport layer and application layer of TCP / IP protocol. According to the characteristics of video data, to design the radio push-type (Broadcast Push Model, BPM) transmission method, improving the efficiency and stability of video transmission.and to designed the network information transmission system, used for real-time control of welding robot network.

Cheng, Weide; Zhang, Hua; Liu, Donghua; Wang, Hongbo

2011-12-01

250

Time synchronization in wireless physiological information sensor network.  

PubMed

Time synchronization is necessary to a Wireless Sensor Network (WSN). Existing time synchronization methods are mostly designed for large scale ad hoc network and are not suitable for small star network like Wireless Physiological Information Sensor Network (WPISN). In this article we present a simple and power-efficient time synchronization method designed specially for WPISN, Reference on Demand Time Synchronization method (RDTS), which employs the Near-Field Magnetic Communication (NFMC) technology. NFMC offers significant power, cost, and size advantages over RF communication. PMID:17281413

Min, Chen; Jianmei, Lei; Chenglin, Peng; Xingming, Guo

2005-01-01

251

Local Data Communications Network for the Wilford Hall USAF Medical Center  

PubMed Central

Data Communication technology has progressed to the point that dissimilar computer systems conforming to a common communications protocol can effectively communicate with each other. Until recently this technology has been used in networks that cover a large geographic area. The requirement for local networks is currently coming into focus. Data automation support for the Wilford Hall USAF Medical Center (WHMC) will be provided by off-the-shelf systems under the Tri-Service Medical Information System (TRIMIS) program. A local network (cable bus) is one way to effectively interface these dissimilar computer systems. The MITRI Corporation is functioning as systems engineer to install a cable bus at WHMC. The need for local data communication networks is increasing, and the cable bus offers a potentially effective method to interface multiple dissimilar computers on a cost effective basis.

Jackson, Thames F.; Workman, Billy J.

1980-01-01

252

SCIENTOMETRICS AND COMMUNICATION THEORY: TOWARDS THEORETICALLY INFORMED INDICATORS  

Microsoft Academic Search

A theory of citations should not consider cited and\\/or citing agents as its sole subject of study. One is able to study also the dynamics in the networks of communications. While communicating agents (e.g., authors, laboratories, journals) can be made comparable in terms of their publication and citation counts, one would expect the communication networks not to be homogeneous. The

Loet Leydesdorff; Peter Van den Besselaar

253

A centrality measure for communication ability in weighted network  

NASA Astrophysics Data System (ADS)

This paper proposes a new node centrality measurement in a weighted network, the communication centrality, which is inspired by Hirsch’s h-index. We investigated the properties of the communication centrality, and proved that the distribution of the communication centrality has the power-law upper tail in weighted scale-free networks. Relevant measures for node and network are discussed as extensions. A case study of a scientific collaboration network indicates that the communication centrality is different from other common centrality measures and other h-type indexes. Communication centrality displays moderate correlation with other indexes, and contains a well-balanced mix of other centrality measures and cannot be replaced by any of them.

Zhai, Li; Yan, Xiangbin; Zhang, Guojing

2013-12-01

254

Efficient Communication Strategies for Ad Hoc Wireless Networks  

Microsoft Academic Search

An ad-hoc wireless network is a collection of wireless mobile hosts forming a temporary network without the aid of any established infrastructure or centralized administration. This type of network is of great importance in situations where it is very difficult to provide the necessary infrastructure, but it is a challenging task to enable fast and reliable communication within such a

Micah Adler; Christian Scheideler

2000-01-01

255

Evolving Perspectives of Human Information Behavior: Contexts, Situations, Social Networks and Information Horizons  

Microsoft Academic Search

This paper presents an evolving framework of human information behavior. The framework emerges from theories and empirical studies from a variety of research traditions, including information science, communication, sociology and psychology, that inform our understanding of human information behavior. First, fundamental concepts, such as context, situation, and social networks, are discussed. Using these concepts, a series of propositions that strive

Diane H. Sonnenwald

256

The ADAPTIVE Communication Environment An Object-Oriented Network Programming Toolkit for Developing Communication Software  

Microsoft Academic Search

The ADAPTIVE Communication Environment (ACE) is an object-oriented (OO) toolkit that implements fundamental design patterns for communication software. ACE is tar- geted for developers of high-performance communication services and applications on UNIX and Win32 platforms. ACE simplifies the development of OO network applications and services that utilize interprocess communication, event demultiplexing, explicit dynamic linking, and concurrency. ACE automates system configuration

Douglas C. Schmidt

1993-01-01

257

Network User Information Support.  

National Technical Information Service (NTIS)

With increasing interest in the development of computer networks and the proliferation of remote entry capability from user terminals, user support takes on new dimensions. Some user characteristics are outlined as they affect user support. User support r...

A. J. Neumann

1973-01-01

258

School Leadership and Information Communication Technology  

ERIC Educational Resources Information Center

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.…

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

2008-01-01

259

Training in Information Selection for Communication.  

ERIC Educational Resources Information Center

An analysis of communication difficulties experienced by Australian children of lower socio-economic status and/or immigrant background led to the development of a program aimed at helping 8-12 year olds develop linguistic selection rules necessary for effective information transfer and processing. (Author/MLW)

Evans, Glen; And Others

1980-01-01

260

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.

2011-08-09

261

Using Interactive Computer to Communicate Scientific Information.  

ERIC Educational Resources Information Center

Asks whether the computer is another channel of communication, if its interactive qualities make it an information source, or if it is an undefined hybrid. Concludes that computers are neither the medium nor the source but will in the future provide the possibility of a sophisticated interaction between human intelligence and artificial…

Selnow, Gary W.

1988-01-01

262

HUBNET: Wide Area Network utilization of Local Area Network medical reference and communication resources.  

PubMed Central

The State University of New York at Buffalo School of Medicine and Biomedical Sciences and its associated teaching sites have developed and partially implemented a regional Wide Area Network (WAN) in Buffalo and Western New York. The school wishes to use this WAN to deliver reference and communication resources to students, residents and faculty. The richest pool of easy to use reference and communication resources are PC software programs that are intended for individual workstations or at best, client-server, Local Area Network (LAN) implementation. HUBNET (Hospitals and University at Buffalo Library Resource Network), a project of the School of Medicine and the Library Consortium of Health Institutions in Buffalo offers integrated presentation of many such LAN resources over this regional WAN. The system crosses many institutional boundaries and reaches physically remote sites in a complex mix of information systems environments with few issues related to performance. The system design provides a level of ease of use that has brought many new users into active computer use while addressing integration into diverse information systems settings and networking environments.

Loonsk, J. W.; Schweigel, J. E.; Carr, D.

1994-01-01

263

Information mobility in complex networks.  

PubMed

The concept of information mobility in complex networks is introduced on the basis of a stochastic process taking place in the network. The transition matrix for this process represents the probability that the information arising at a given node is transferred to a target one. We use the fractional powers of this transition matrix to investigate the stochastic process at fractional time intervals. The mobility coefficient is then introduced on the basis of the trace of these fractional powers of the stochastic matrix. The fractional time at which a network diffuses 50% of the information contained in its nodes (1/k(50)) is also introduced. We then show that the scale-free random networks display a better spread of information than the non-scale-free ones. We study 38 real-world networks and analyze their performance in spreading information from their nodes. We find that some real-world networks perform even better than the scale-free networks with the same average degree and we point out some of the structural parameters that make this possible. PMID:19792197

Estrada, Ernesto

2009-08-01

264

New-age patient communications through social networks.  

PubMed

Suicide prevention continues to be a significant clinical challenge in the care of psychiatric patients, particularly among youth. New patterns of interactions and communications using online social networks create opportunities for persons to indicate their mood, their opinions, and also to express ideation and plans about suicide. We report a case of a suicide attempt and how communications through online social networks initiated treatment and affected its outcome. We discuss advantages and challenges to clinicians regarding use social networks and electronic communication in patient care. PMID:21596215

Ogburn, Kelin M; Messias, Erick; Buckley, Peter F

2011-01-01

265

Defining 'Anonymity' in Networked Communication, Version 1.  

National Technical Information Service (NTIS)

Support for anonymous communication in hostile environments is the main goal of DARPA's 'Safer Warfighter Communications' program (DARPA-BAA-10- 69: SAFER). Despite the fact that the word is regularly encountered in common parlance, 'anonymity' is actuall...

J. Feigenbaum

2011-01-01

266

A Bit More to It: Scholarly Communication Forums as Socio-Technical Interaction Networks.  

ERIC Educational Resources Information Center

Examines the conceptual models that help to understand the development and sustainability of scholarly and professional communication forums on the Internet. An alternative information processing model that considers information technologies as Socio-Technical Interaction Networks (STINs) and a method for modeling electronic forums as STINs are…

Kling, Rob; McKim, Geoffrey; King, Adam

2003-01-01

267

Automatic Generation of Social Network Data from Electronic-Mail Communications  

Microsoft Academic Search

Most organizations have formal and informal elements. Formal structures are usually documented in organizational charts showing chain of command, levels of authority, and personnel resources. The actual effectiveness of the organization or specific ind ividuals may actually depend on informal structures and internal communication networks. These are by definition personality-dependent and may provide significant insight into how work actually gets

Jason Yee; Robert F. Mills; Gilbert L. Peterson; Summer E. Bartczak

268

Advanced Communication and Networking Technologies for Mars Exploration  

NASA Technical Reports Server (NTRS)

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.

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

2001-01-01

269

Green upgrading power grid communication network using deployment of DWDM  

Microsoft Academic Search

More information should be gathered to make the power grid unified, robust and smart. Power grid transport network needs higher capacity and reliability. There are numerous SDH\\/PDH equipments employed in the present network. The requirement of upgrading from SDH network to WDM network is investigated. The specific features of power grid transport network are also studied in this paper. A

Liming Zhou; Mi Lin; Jinnan Zhang; Yangan Zhang; Minglun Zhang; Yongqing Huang

2010-01-01

270

Adaptive Routing Algorithm in Wireless Communication Networks Using Evolutionary Algorithm  

NASA Astrophysics Data System (ADS)

At present, mobile communications traffic routing designs are complicated because there are more systems inter-connecting to one another. For example, Mobile Communication in the wireless communication networks has two routing design conditions to consider, i.e. the circuit switching and the packet switching. The problem in the Packet Switching routing design is its use of high-speed transmission link and its dynamic routing nature. In this paper, Evolutionary Algorithms is used to determine the best solution and the shortest communication paths. We developed a Genetic Optimization Process that can help network planners solving the best solutions or the best paths of routing table in wireless communication networks are easily and quickly. From the experiment results can be noted that the evolutionary algorithm not only gets good solutions, but also a more predictable running time when compared to sequential genetic algorithm.

Yan, Xuesong; Wu, Qinghua; Cai, Zhihua

271

Optimal Distributed Routing Algorithms for Datagram Communication Networks.  

National Technical Information Service (NTIS)

We consider the problem of routing in a communication network with datagram service. Relationships among four optimality conditions are presented. Two distributed algorithms are derived. The main idea underlying the construction of these algorithms is the...

J. R. Yee

1989-01-01

272

Managing Communications with Experts in Geographically Distributed Collaborative Networks.  

National Technical Information Service (NTIS)

The idea of communication through collaboration is not new, however, the need to collaborate efficiently with subject matter experts has become essential towards establishing a competitive advantage among individuals, groups, and organizations. As network...

J. E. Delaney

2009-01-01

273

Trust-Based Collaborative Control for Teams on Communication Networks.  

National Technical Information Service (NTIS)

Grant objectives are to develop new cooperative control protocols and trust propagation mechanisms for networked teams of nonlinear dynamical systems on communication graphs. We developed a body of knowledge for optimal control and adaptive control on gra...

F. L. Lewis

2012-01-01

274

Emergence of Interorganizational Communication Networks Following Natural Disasters.  

National Technical Information Service (NTIS)

Research was undertaken to investigate the emergence of interorganizational communication networks following three natural disasters: a mini-tornado in Lake Pomona, Kansas; a maxi-tornado in Wichita Falls, Kansas; and a flash flood in the hills of Texas. ...

T. S. Kilijanek

1980-01-01

275

Routing Techniques Used in Computer Communication Networks  

Microsoft Academic Search

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

MISCHA SCHWARTZ; THOMSS E. STERN

1980-01-01

276

Power-law behavior in complex organizational communication networks during crisis  

NASA Astrophysics Data System (ADS)

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.

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

2011-08-01

277

A Spatiotemporal Communication Protocol for Wireless Sensor Networks  

Microsoft Academic Search

In this paper, we present a spatiotemporal communication protocol for sensor networks, called SPEED. SPEED is specifically tailored to be a localized algorithm with minimal control overhead. End-to-end soft real-time communication is achieved by maintaining a desired delivery speed across the sensor network through a novel combination of feedback control and nondeterministic geographic forwarding. SPEED is a highly efficient and

Tian He; John A. Stankovic; Chenyang Lu; Tarek F. Abdelzaher

2005-01-01

278

Transparent self-healing communication networks via diversity coding  

Microsoft Academic Search

The authors present an error control based approach, called diversity coding, to provide nearly instantaneous self-healing digital communication networks. This is achieved by constructing an error-correcting code across logically independent channels and by treating link failures within the framework of an erasure channel model. Diversity coding is more efficient than the existing approaches to self-healing communication networks since it is

Chih-Lin I; Ender Ayanoglu; R. D. Gitlin; J. E. Mazo

1990-01-01

279

Randomized parallel communications on an extension of the omega network  

Microsoft Academic Search

Parallel communication algorithms and networks are central to large-scale parallel computing and, also, data communications. This paper identifies adverse source-destination traffic patterns and proposes a scheme for obtaining relief by means of randomized routing of packets on simple extensions of the well-known omega networks. Valiant and Aleliunas have demonstrated randomized algorithms, for a certain context which we call nonrenewal, that

Debasis Mitra; Randall A. Cieslak

1987-01-01

280

Developing IEEE 1613 standards for communications network in substations  

Microsoft Academic Search

The widespread use of multifunctional intelligent electronic devices (IEDs) with advanced communications capabilities has resulted in a new trend in substation automation systems, i.e. the implementation of high-speed peer-to-peer communications-based control schemes. The IEDs exchange messages over the substation local area network (LAN). A number of industry experts had observed that an unambiguous standard for network devices when installed in

A. Apostolov; M. Dood; J. Tengdin

2004-01-01

281

Child Rights Information Network Newsletter, 2000-2002.  

ERIC Educational Resources Information Center

These five newsletter issues communicate activities of the Child Rights Information Network (CRIN) and report on information resources and world-wide activities concerning children and child rights. The March 2000 issue focuses on children's right to education, assessing the matter form a range of differing perspectives, at international and…

Khan, Andrea, Ed.; Greenwood, Laura, Ed.

282

Network information management subsystem  

NASA Technical Reports Server (NTRS)

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.

Chatburn, C. C.

1985-01-01

283

Use of Communication Resources in a Networked Collaborative Design Environment.  

ERIC Educational Resources Information Center

Examines student use of a prototype networked collaborative design environment to support or augment learning about engineering design. Finds that students use the channels for a variety of activities to increase depth of communication, increase breadth of communication, and overcome technical difficulty. Suggests that students need multiple…

Gay, Geri; Lentini, Marc

1995-01-01

284

Wireless Adhoc Networks for Inter-Vehicle Communication  

Microsoft Academic Search

Future enhancements in automobile technology will cope - besides tradi- tional aspects, like security and driving conditions or comfort aspects of passengers - especially with the ability of vehicles to communicate. The aspirated enhance- ments in the ability of communication of vehicles should not only focus on the use of existing wireless (cellular) networks, but should also concentrate on totally

Michael Meincke; Peter Tondl; María Dolores Pérez Guirao; Klaus Jobmann

2002-01-01

285

Performance of an industrial data communication protocol on ethernet network  

Microsoft Academic Search

One of the well known industrial data communication protocols is Modbus which is widely used in industrial automation due to its availability. Modbus protocol can be implemented in many ways according to its network. Performance metrics and tests for IT infrastructure equipment have been used for many years, but now with real-time communication being used more, users are asking whether

Endra Joelianto; Hosana

2008-01-01

286

Cooperative communications with relay selection in wireless sensor networks  

Microsoft Academic Search

Cooperative communications is a promising technology to improve the performance of wireless sensor networks. In this paper, we propose a novel relay selection scheme combined with feedback and adaptive forwarding in cooperative communication systems. A closed form expression for the tight lower bound of its outage probability is derived and a detailed analysis of its diversity-multiplexing-tradeoff (DMT) performance is presented.

Li Sun; Taiyi Zhang; Long Lu; Hao Niu

2009-01-01

287

Project Universe - Local area networks and satellite communications  

Microsoft Academic Search

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

B. R. Ackroyd

1983-01-01

288

Collaborative Networked Communication: MUDs as Systems Tools  

Microsoft Academic Search

A systems administration group is only as effective as its internal communication mechanisms. On-line communication has traditionally been managed via electronic mail or news, which are neither real-time nor truly collaborative. Communication tools which let multiple parties work together in real-time have become widespread on the Internet in the last several years. In an effort to keep a physically disjoint

Rémy Evard

1993-01-01

289

Interactive computer-graphics network monitor for a tactical communications network. Master's thesis  

Microsoft Academic Search

In order to apply modern networking technology, either circuit- or packet-switched, to tactical communications networks, network designers must develop (1) robust link-level protocols to handle broadcast media and node mobility, and (2) distributed, adaptive routing protocols to handle the rapid reconfigurations required by node mobility and mortality. In addition, from the network manager's point of view, combat imposes electronic order

1987-01-01

290

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

Microsoft Academic Search

Background  The behaviour of individuals is affected by the social networks in which they are embedded. Networks are also important for\\u000a the diffusion of information and the influence of employees in organisations. Yet, at the moment little is known about the\\u000a social networks of nursing staff in healthcare settings. This is the first study that investigates informal communication\\u000a and advice networks

Adriana PA van Beek; Cordula Wagner; Peter PM Spreeuwenberg; Dinnus HM Frijters; Miel W Ribbe; Peter P Groenewegen

2011-01-01

291

Technology Developments Integrating a Space Network Communications Testbed  

NASA Technical Reports Server (NTRS)

As future manned and robotic space explorations missions involve more complex systems, it is essential to verify, validate, and optimize such systems through simulation and emulation in a low cost testbed environment. The goal of such a testbed is to perform detailed testing of advanced space and ground communications networks, technologies, and client applications that are essential for future space exploration missions. We describe the development of new technologies enhancing our Multi-mission Advanced Communications Hybrid Environment for Test and Evaluation (MACHETE) that enable its integration in a distributed space communications testbed. MACHETE combines orbital modeling, link analysis, and protocol and service modeling to quantify system performance based on comprehensive considerations of different aspects of space missions. It can simulate entire networks and can interface with external (testbed) systems. The key technology developments enabling the integration of MACHETE into a distributed testbed are the Monitor and Control module and the QualNet IP Network Emulator module. Specifically, the Monitor and Control module establishes a standard interface mechanism to centralize the management of each testbed component. The QualNet IP Network Emulator module allows externally generated network traffic to be passed through MACHETE to experience simulated network behaviors such as propagation delay, data loss, orbital effects and other communications characteristics, including entire network behaviors. We report a successful integration of MACHETE with a space communication testbed modeling a lunar exploration scenario. This document is the viewgraph slides of the presentation.

Kwong, Winston; Jennings, Esther; Clare, Loren; Leang, Dee

2006-01-01

292

Synchronization and a secure communication scheme using optical star network  

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

293

Highly survivable communications: Complementary media packet switched networks  

NASA Astrophysics Data System (ADS)

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.

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

1994-07-01

294

Operations of the reconfigured Ground Communications Facility Central Communications Terminal and the Network Operations Control Center  

NASA Technical Reports Server (NTRS)

The ground communications facility (GCF) central communications terminal and network operations control center (NOCC) hardware was rearranged, supplemented, and modified, and software programs changed to provide an improved GCF and NOCC operational environment and capability. Control center operations section activities required to make the changeover from the old to the new GCF and NOCC configuration are addressed.

Santana, J. C.; Jennings, L. E.

1982-01-01

295

Epidemic and information co-spreading in adaptive social networks  

NASA Astrophysics Data System (ADS)

We model simultaneous evolution of an epidemic and information about the epidemic on an adaptive social network. The classical Susceptible-Infectious-Susceptible (SIS) model is extended. Susceptible and infectious nodes are each divided into informed and uninformed types. Informed nodes affect the network structure by rewiring their network connections adaptively to avoid disease exposure. The impacts of mass media information and communication on the disease spreading and network structure are explored, and stochastic simulations are compared with a moment closure approximation. When the rewiring rate is high, the infection and information levels of the population show periodic oscillations for certain ranges of contact rate, and the moment closure approximation predicts similar dynamics. The epidemic threshold in the presence of rewiring and information is considered. Our results indicate that information can play a significant role in minimizing disease spread.

Long, Yunhan

2012-02-01

296

Networking protocols for space data communications  

Microsoft Academic Search

Space communications organizations, both civil and military, have focused their attention primarily on the physical (layer 1) and data link (layer 2) layers of the Open Systems Interconnection (OSI) reference model. The need to reduce space operations costs, the expected availability of distributed communications architectures within space vehicles, and the design of increasingly complex space constellations have generated civil and

R. Ramirez

1997-01-01

297

Preliminary Evaluation, Texas State Library Communication Network, 1968.  

ERIC Educational Resources Information Center

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…

Texas State Library, Austin. Field Services Div.

298

The 3G wireless technology in tactical communication networks  

Microsoft Academic Search

Third generation mobile systems are seen as the technology to bring new broadband services to the mobile user. This paper discusses UMTS\\/GPRS technologies applying to tactical communication networks. A detailed description of the 3G technologies is provided, and their application in military environments is studied in depth. The paper discusses the introduction of new services into military networks, which improves

Dimitrios D. Vergados; Christos Gizelis; Dimitrios J. Vergados

2004-01-01

299

An introductory course in computer communication and networks  

Microsoft Academic Search

This paper reports on the curriculum contents and experience obtained in the teaching of a semester-long introductory course in computer communication networks. The course is aimed at first year graduate and senior undergraduate students and covers a broad survey of networking issues. We focus on all seven layers of the OSI reference model and assign four major programming projects to

Thomas Narten; Raj Yavatkar

1992-01-01

300

Performance analysis of communication network for the CBTC system  

Microsoft Academic Search

Communication based train control (CBTC) system is a safety critical system, and several factors in the system demand for new design and implementation solutions. Combining some software or hardware errors, a dual redundant network is proposed. Moreover, framework and working mode of the network are introduced. The paper evaluates the reliability in theory. A simulation is realized to test how

Yufei Xie; Tao Tang

2009-01-01

301

Self-Organizing Hierarchies in Sensor and Communication Networks  

Microsoft Academic Search

We consider a hierarchical multicellular sensing and communication network, embedded in an ageless aerospace vehicle, that is expected to detect and react to multiple impacts and damage over a wide range of impact energies. In particular, we investigate self-organization of impact boundaries enclosing critically damaged areas, and impact networks connecting remote cells that have detected noncritical impacts. Each level of

Mikhail Prokopenko; Peter Wang; Philip Valencia; Don Price; Mark Foreman; Anthony Farmer

2005-01-01

302

Average consensus problems in networks of agents with delayed communications  

Microsoft Academic Search

The present paper is devoted to the study of average consensus problems for undirected networks of dynamic agents having communication delays. The accent is put here on the study of the time-delays influence: both constant and time-varying delays are considered, as well as uniform and non uniform repartitions of the delays in the network. The main results provide sufficient conditions

Pierre-Alexandre Bliman; Giancarlo Ferrari-Trecate

2005-01-01

303

A MODEL FOR INVISIBLE RECOVERY APPLIED TO COMMUNICATIONS NETWORKS  

Microsoft Academic Search

In this paper we present the advances we have made in our network fault tolerant computing project (1). We examine the problems of f ailures within n etwork communications and telecom systems and o utline the usefulness of our localised Invisible Recovery (IR) solution. We e valuate the current techniques (2,3,8) that provide recovery within distributed \\/ network systems; by

GEORGE G. MITCHELL; STEPHEN BROWN

2001-01-01

304

Multilayer chaotic encryption for secure communications in packet switching networks  

Microsoft Academic Search

A new, efficient algorithm for secure digital communications in packet switching networks is presented. The symmetric cipher proposed exploits the intrinsic synchronization between sender and receiver offered by the network. The key is dynamically adapted by means of a multilayer architecture, the advantage of which is to provide a scalable degree of security. Several interesting features of the multilayer chaotic

F. Beritelli; E. Di Cola; L. Fortuna; F. Italia

2000-01-01

305

Mobile IP LAN for ARL Mobile Communications/Networking Testbed.  

National Technical Information Service (NTIS)

This report describes the protocol and implementation of a Mobile IP (Internet protocol) LAN (local area network) for the LAN of the U.S. Army Research Laboratory (ARL) Mobile Communications/Networking Testbed. Mobile IP LAN protocol is developed to allow...

B. B. Luu

2001-01-01

306

Functional communication within a perceptual network processing letters and pseudoletters.  

PubMed

Many studies have identified regions within human ventral visual stream to be important for object identification and categorization; however, knowledge of how perceptual information is communicated within the visual network is still limited. Current theories posit that if a high correspondence between incoming sensory information and internal representations exists, then the object is rapidly identified, and if there is not, then the object requires extra detailed processing. Event-related responses from the present magnetoencephalography study showed two main effects. The N1m peak latencies were approximately 15 milliseconds earlier to familiar letters than to unfamiliar pseudoletters, and the N2m was more negative to pseudoletters than to letters. Event-related beamforming analyses identified these effects to be within bilateral visual cortices with a right lateralization for the N2m effect. Furthermore, functional connectivity analyses revealed that gamma-band (50-80 Hz) oscillatory phase synchronizations among occipital regions were greater to letters than to pseudoletters (around 85 milliseconds). However, during a later time interval between 245 and 375 milliseconds, pseudoletters elicited greater gamma-band phase synchronizations among a more distributed occipital network than did letters. These findings indicate that familiar object processing begins by at least 85 milliseconds, which could represent an initial match to an internal template. In addition, unfamiliar object processing persisted longer than that for familiar objects, which could reflect greater attention to inexperienced objects to determine their identity and/or to consolidate a new template to aid in future identification. PMID:21946359

Herdman, Anthony T

2011-10-01

307

Network Centric Communications for Expeditionary or Carrier Strike Groups.  

National Technical Information Service (NTIS)

The Department of Defense (DoD) utilizes the Global Information Grid (GIG) to provide the capability for deployed forces to obtain and share information with users dispersed worldwide. In the current US Naval communications architecture, ships within a st...

A. Deguzman D. Nunez J. Ebken N. Ho R. Lai

2011-01-01

308

Hybrid evolving clique-networks and their communicability  

NASA Astrophysics Data System (ADS)

Aiming to understand real-world hierarchical networks whose degree distributions are neither power law nor exponential, we construct a hybrid clique network that includes both homogeneous and inhomogeneous parts, and introduce an inhomogeneity parameter to tune the ratio between the homogeneous part and the inhomogeneous one. We perform Monte-Carlo simulations to study various properties of such a network, including the degree distribution, the average shortest-path-length, the clustering coefficient, the clustering spectrum, and the communicability.

Ding, Yimin; Zhou, Bin; Chen, Xiaosong

2014-08-01

309

Finding quasi-optimal network topologies for information transmission in active networks.  

PubMed

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

Baptista, Murilo S; de Carvalho, Josué X; Hussein, Mahir S

2008-01-01

310

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

PubMed Central

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.

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

2008-01-01

311

Computing, information, and communications: Technologies for the 21. Century  

SciTech Connect

To meet the challenges of a radically new and technologically demanding century, the Federal Computing, Information, and Communications (CIC) programs are investing in long-term research and development (R and D) to advance computing, information, and communications in the United States. CIC R and D programs help Federal departments and agencies to fulfill their evolving missions, assure the long-term national security, better understand and manage the physical environment, improve health care, help improve the teaching of children, provide tools for lifelong training and distance learning to the workforce, and sustain critical US economic competitiveness. One of the nine committees of the National Science and Technology Council (NSTC), the Committee on Computing, Information, and Communications (CCIC)--through its CIC R and D Subcommittee--coordinates R and D programs conducted by twelve Federal departments and agencies in cooperation with US academia and industry. These R and D programs are organized into five Program Component Areas: (1) HECC--High End Computing and Computation; (2) LSN--Large Scale Networking, including the Next Generation Internet Initiative; (3) HCS--High Confidence Systems; (4) HuCS--Human Centered Systems; and (5) ETHR--Education, Training, and Human Resources. A brief synopsis of FY 1997 accomplishments and FY 1998 goals by PCA is presented. This report, which supplements the President`s Fiscal Year 1998 Budget, describes the interagency CIC programs.

NONE

1998-11-01

312

Free Space Optical and RF Communications Testbed for Research and Education in Scalable Networks.  

National Technical Information Service (NTIS)

We have procured advanced communications and test equipment to further our research on scalable communication networks, hybrid free-space- optical (FSO) RF links and networks, and directional within networks.

C. C. Davis S. D. Milner Q. Balzano

2005-01-01

313

Visual communication - Information and fidelity. [of images  

NASA Technical Reports Server (NTRS)

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.

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

1993-01-01

314

Enhanced Communication Network Solution for Positive Train Control Implementation  

NASA Technical Reports Server (NTRS)

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.

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

2011-01-01

315

Network Chip Design for Grid Communication.  

National Technical Information Service (NTIS)

A system includes a plurality of integrated circuits for propagating data between at least one central processing unit and another component of the system. The plurality of integrated circuits are configured for proximity I/O communication. The plurality ...

B. Tourancheau, C. Koch-Hofer, X. F. Vigouroux

2005-01-01

316

Use of communication architecture test bed to evaluate data network performance  

SciTech Connect

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

Clapp, N.E. Jr.; Swail, B.K. [Oak Ridge National Lab., TN (United States); Naser, J.A. [Electric Power Research Inst., Palo Alto, CA (United States)

1994-10-01

317

Communication Networks in Marine Recreational Fishing: Information-Seeking Behavior, Fishing Knowledge, and Diffusion of Fishing Innovations Among Marine Recreational Fisherman in North Carolina.  

National Technical Information Service (NTIS)

The project is an assessment and evaluation of the marine recreational fishing (MRF) information dissemination system in North Carolina. First, a content analysis and panel evaluation of MRF brochures was conducted to identify the primary informational co...

R. R. Perdue C. J. Betz

1991-01-01

318

Scientometrics and communication theory: Towards theoretically informed indicators  

Microsoft Academic Search

The theory of citations should not consider cited and\\/or citing agents as its sole subject of study. One is able to study\\u000a also the dynamics in the networks of communications. While communicating agents (e.g., authors, laboratories, journals) can\\u000a be made comparable in terms of their publication and citation counts, one would expect the communication networks not to be\\u000a homogeneous. The

L. Leydesdorff; P. Van Den Besselaar

1997-01-01

319

Scientometrics and Communication Theory: Towards Theoretically Informed Indicators  

Microsoft Academic Search

A theory of citations should not consider cited and\\/or citing agents as its\\u000asole subject of study. One is able to study also the dynamics in the networks\\u000aof communications. While communicating agents (e.g., authors, laboratories,\\u000ajournals) can be made comparable in terms of their publication and citation\\u000acounts, one would expect the communication networks not to be homogeneous. The

Loet Leydesdorff; Peter Van den Besselaar

2010-01-01

320

By-product information can stabilize the reliability of communication.  

PubMed

Although communication underpins many biological processes, its function and basic definition remain contentious. In particular, researchers have debated whether information should be an integral part of a definition of communication and how it remains reliable. So far the handicap principle, assuming signal costs to stabilize reliable communication, has been the predominant paradigm in the study of animal communication. The role of by-product information produced by mechanisms other than the communicative interaction has been neglected in the debate on signal reliability. We argue that by-product information is common and that it provides the starting point for ritualization as the process of the evolution of communication. Second, by-product information remains unchanged during ritualization and enforces reliable communication by restricting the options for manipulation and cheating. Third, this perspective changes the focus of research on communication from studying signal costs to studying the costs of cheating. It can thus explain the reliability of signalling in many communication systems that do not rely on handicaps. We emphasize that communication can often be informative but that the evolution of communication does not cause the evolution of information because by-product information often predates and stimulates the evolution of communication. Communication is thus a consequence but not a cause of reliability. Communication is the interplay of inadvertent, informative traits and evolved traits that increase the stimulation and perception of perceivers. Viewing communication as a complex of inadvertent and derived traits facilitates understanding of the selective pressures shaping communication and those shaping information and its reliability. This viewpoint further contributes to resolving the current controversy on the role of information in communication. PMID:23116421

Schaefer, H Martin; Ruxton, G D

2012-12-01

321

Tracking Mobile Users in Wireless Communication Networks  

Microsoft Academic Search

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

Amotz Bar-noy; Ilan Kessler

1993-01-01

322

To Talk or Not to Talk: Exploring Culturally Diverse Patients' Health Information Communication Choices  

PubMed Central

As care shifts from institutional to home- and community-based settings, consumer health information technology (IT) must be designed to support patients’ new health information management responsibilities. We developed and piloted a new methodology grounded in social network analysis and human factors engineering to explore two often overlooked aspects of this phenomenon: the task of health information communication with members of the social network and the context of culture. Such knowledge is necessary to inform the appropriate design of consumer health IT. We asked a culturally diverse sample of participants to describe what, to whom, why, and how they communicate health information and to provide direct feedback about the methodology. The methodology was acceptable to all participants and able to capture similarities and differences in their health information communication practices. Prior to the main study we will need to refine the methodology to further explore patients’ cultural context and IT use.

Valdez, Rupa; Patton, Tim; Brennan, Patricia

2010-01-01

323

Efficient and Reliable Broadcast in Intervehicle Communication Networks: A Cross-Layer Approach  

Microsoft Academic Search

Broadcast transmission is an effective way to disseminate safety-related information for cooperative driving in intervehicle communication (IVC). However, it is fraught with fundamental challenges such as message redundancy, link unreliability, hidden terminals, and broadcast storms, which greatly degrade network performance. In this paper, we introduce a cross-layer approach to design an efficient and reliable broadcast protocol for emergency message dissemination

Yuanguo Bi; Lin X. Cai; Hai Zhao

2010-01-01

324

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

ERIC Educational Resources Information Center

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…

Lang, Anouk

2012-01-01

325

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

ERIC Educational Resources Information Center

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…

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

2013-01-01

326

Efficient data communication protocols for wireless networks  

NASA Astrophysics Data System (ADS)

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.

Zeydan, Engin

327

Signaling communication events in a computer network  

DOEpatents

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.

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

328

Technical research aspect of the Pan-Pacific Information Network using satellite  

NASA Astrophysics Data System (ADS)

The Pan-Pacific Information Network would provide an important new mechanism for education, research, health service, emergency communication, and cultural exchange. The paper discusses the technical research items related to the Pan-Pacific Information Network, reviews small earth-station systems, and considers the system configuration pointed to the network in the Asia/Pacific region.

Iida, Takashi; Morikawa, Hisashi; Noguchi, Shoichi

329

Influence of a network structure on the network effect in the communication service market  

Microsoft Academic Search

In this study, we analyze the network effect in a model of a personal communication market, by using a multi-agent based simulation approach. We introduce into the simulation model complex network structures as the interaction patterns of agents. With complex network models, we investigate the dynamics of a market in which two providers are competing. We also examine the structure

Makoto Uchida; Susumu Shirayama

2008-01-01

330

Project Universe - Local area networks and satellite communications  

NASA Astrophysics Data System (ADS)

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.

Ackroyd, B. R.

1983-07-01

331

The Effect of Information Overlap on Communication Effectiveness  

ERIC Educational Resources Information Center

It makes sense that the more information people share, the better they communicate. To evaluate the effect of knowledge overlap on the effectiveness of communication, participants played a communication game where the "director" identified objects to the "addressee". Pairs either shared information about most objects' names (high overlap), or…

Wu, Shali; Keysar, Boaz

2007-01-01

332

Information Networks: Definitions and Message Transfer Models.  

ERIC Educational Resources Information Center

A mathematical definition of an information network is constructed with the purpose of developing a theory useful in answering practical questions concerning information transfer. An information network includes: (1) users, (2) information resources, (3) information centers, and (4) the total information transfer structure linking (1), (2), and…

Nance, Richard E.; And Others

333

Health care network communications infrastructure: an engineering design for the Military Health Service System.  

PubMed Central

The Military Health Service System (MHSS) provides health care for the Department of Defense (DOD). This system operates on an annual budget of $15 Billion, supports 127 medical treatment facilities (MTFs) and 500 clinics, and provides support to 8.7 million beneficiaries worldwide. To support these facilities and their patients, the MHSS uses more than 125 different networked automated medical systems. These systems rely on a heterogeneous telecommunications infrastructure for data communications. With the support of the Defense Medical Information Management (DMIM) Program Office, our goal was to identify the network requirements for DMIM migration and target systems and design a communications infrastructure to support all systems with an integrated network. This work used tools from Business Process Reengineering (BPR) and applied it to communications infrastructure design for the first time. The methodology and results are applicable to any health care enterprise, military or civilian.

Hoffman, P.; Kline, E.; George, L.; Price, K.; Clark, M.; Walasin, R.

1995-01-01

334

Resting-brain functional connectivity predicted by analytic measures of network communication  

PubMed Central

The complex relationship between structural and functional connectivity, as measured by noninvasive imaging of the human brain, poses many unresolved challenges and open questions. Here, we apply analytic measures of network communication to the structural connectivity of the human brain and explore the capacity of these measures to predict resting-state functional connectivity across three independently acquired datasets. We focus on the layout of shortest paths across the network and on two communication measures—search information and path transitivity—which account for how these paths are embedded in the rest of the network. Search information is an existing measure of information needed to access or trace shortest paths; we introduce path transitivity to measure the density of local detours along the shortest path. We find that both search information and path transitivity predict the strength of functional connectivity among both connected and unconnected node pairs. They do so at levels that match or significantly exceed path length measures, Euclidean distance, as well as computational models of neural dynamics. This capacity suggests that dynamic couplings due to interactions among neural elements in brain networks are substantially influenced by the broader network context adjacent to the shortest communication pathways.

Goni, Joaquin; van den Heuvel, Martijn P.; Avena-Koenigsberger, Andrea; Velez de Mendizabal, Nieves; Betzel, Richard F.; Griffa, Alessandra; Hagmann, Patric; Corominas-Murtra, Bernat; Thiran, Jean-Philippe; Sporns, Olaf

2014-01-01

335

Power Saving Techniques for Underwater Communication Networks.  

National Technical Information Service (NTIS)

This thesis proposes three techniques to reduce the power consumption in underwater acoustic networks with randomly placed fixed and mobile nodes. The transmission range is optimized so as to minimize the power consumption and/or to maximize the throughpu...

A. P. Dole

2007-01-01

336

The Integration of the Information and Communication Functions, and the Marketing of the Resulting Products.  

ERIC Educational Resources Information Center

Discusses the theoretical basis for integration of information functions and communication functions, the relevance of this integration in the scientific information cycle, and its positive effect on commodity research networks. The application of this theory is described using three commodity programs of the Centro Internacional de Agricultura…

Harris, Susan C.

1985-01-01

337

Wireless network coding for cooperative communications  

Microsoft Academic Search

Relay transmission has been incorporated in the 3rd Generation Partnership Project (3GPP) for Long-Term Evolution (LTE) Enhancements (LTE-Advanced, or LTE-A). To effectively harvest the performance gain introduced by the relay transmission, wireless network coding techniques can be adopted. In this paper, using a simple three-node cooperative relay channel model, based on the decode-and-forward protocol, we consider a few wireless network

Sumei Sun

2010-01-01

338

Real-time communication in multi-hop networks  

Microsoft Academic Search

Communication in real-time systems has to be predictable, because unpredictable delays inthe delivery of messages can adversely affect the execution of tasks dependent on these messages.In this paper, we develop a scheme for providing predictable inter-process communication inreal-time systems with (partially connected) point--to--point interconnection networks, whichprovides guarantees on the maximum delivery time for messages. This scheme is based on theconcept

Dilip D. Kandlur; Kang G. Shin; Domenico Ferrari

1991-01-01

339

Localization and Communication for UWB-based Wireless Sensor Networks  

Microsoft Academic Search

The great demand for location-aware wireless sensor networks (WSNs) motivates the research in this thesis. The unique characteristics of WSNs impose numerous challenges on localization and communication. In this thesis, we handle some key challenges and provide affordable solutions.\\u000a\\u000aImpulse radio ultra wideband (IR-UWB) is employed as the fundamental technology for both localization and communication due to its distinctive advantages

Y. Wang

2011-01-01

340

Cooperative OTH communications for airborne networks: Opportunities and challenges  

Microsoft Academic Search

We propose a distributed cooperative communication scheme for airborne networks allowing increased range and throughput for over-the-horizon (OTH) communication via the high-frequency (HF) band. By exploiting multiple airborne radios in a collaborative fashion, we can obtain diversity gains similar to Multiple Input Single Output (MISO) allowing increased link reliability and increased throughput for a given range and power. The scheme

Andrea Rueetschi; M. Sharp; A. Scaglione

2009-01-01

341

Multi-carrier network-centric satellite communications modem design  

Microsoft Academic Search

The paper presents concepts for network-centric communications that are matched to the planned wideband gapfiller satellite system (WGSS) and other transponder based satellite communications. Gapfiller satellites will digitally transpond uplinks and downlinks between X- and Ka-band beams using multiple 125 MHz transponders that can be subchannelized into as many as forty-eight 2.6 MHz band segments. The proposed concept is a

H. I. Paul

2002-01-01

342

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

NASA Technical Reports Server (NTRS)

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.

1973-01-01

343

Isochronal synchronization in networks and chaos-based TDMA communication  

NASA Astrophysics Data System (ADS)

Pairs of delay-coupled chaotic systems were shown to be able to achieve isochronal synchronization under bidirectional coupling and self-feedback. Such identical-in-time behavior was demonstrated to be stable under a set of conditions and to support simultaneous bidirectional communication between pairs of chaotic oscillators coupled with time-delay. More recently, it was shown that isochronal synchronization can emerge in networks with several hundreds of oscillators, which allows its exploitation for communication in distributed systems. In this paper, we introduce a conceptual framework for the application of isochronal synchronization to TDMA communication in networks of delay-coupled chaotic oscillators. On the basis of the stable and identical-in-time behavior of delay-coupled chaotic systems, the chaotic dynamics of distributed oscillators is used to support and sustain coordinate communication among nodes over the network. On the basis of the unique features of chaotic systems in isochronal synchronization, the chaotic signals are used to timestamp clock readings at the physical layer such that logical clock synchronization among the nodes (a prerequisite for TDMA) can be exploited using the same basic structure. The result is a standalone network communication scheme that can be advantageously applied in the context of ad-hoc networks or alike, especially short-ranged ones that yield low values of time-delay. As explored to its depths in practical implementations, this conceptual framework is argued to have potential to provide gain in simplicity, security and efficiency in communication schemes for autonomous/standalone network applications.

Grzybowski, J. M. V.; Macau, E. E. N.; Yoneyama, T.

2014-04-01

344

Free-space optical communication satellite networks-vibration effects and possible solutions  

Microsoft Academic Search

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 inter satellite links in those project use microwave radiation as the carrier. Free space optical communication between satellites networked together can make possible high speed communications between different places on earth. The advantages of

Shlomi Arnon; Norman S. Kopeika

1997-01-01

345

Information Security and Privacy in Network Environments.  

ERIC Educational Resources Information Center

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…

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

346

A survey of ring-building network protocols suitable for command and control group communications  

NASA Astrophysics Data System (ADS)

Multicasting is the enabling technology for group communication. However, network-layer multicasting (e.g., IP multicast) has not been widely adopted more than 10 years of its invention due to the concerns related to deployment, scalability and network management. Application-layer multicast (ALM) has been proposed as an alternative for IP multicast. In ALM, group communications take place on an overlay network in which each edge corresponds to a direct unicast path between two group members. ALM protocols differ in, among other aspects, the topology of the underlying overlay network (e.g., tree, mesh or ring). Ring-based ALM protocols have the advantages of providing a constant node degree, and enabling the implementation of reliable and totally-ordered message delivery through the use of a ring with a token that contains ordering and flow control information. In addition, a ring overlay network topology is inherently reliable to single node failures. In this paper, we provide a survey and a taxonomy of several ring-building group communication protocols. Investigating the major characteristics of ring-building network protocols is an important step towards understanding which of them are suitable for command and control group communications.

Sobeih, Ahmed; Yurcik, William

2005-05-01

347

Placement of UAVs as Communication Relays Aiding Mobile Ad Hoc Wireless Networks  

Microsoft Academic Search

Unmanned aerial vehicles (UAVs) have been used for surveillance and reconnaaissance operations. Such communications enabled platforms can also be effectively utilized to enhance the communications transport capabilitites of a mobile ad hoc wireless network. When properly embedded into the architecture of a communications network, the resultirng UAV aided terrestrial network architecture is expended into a multi-layered hierarchical network structure. The

Izhak Rubin; Runhe Zhang

2007-01-01

348

Secure Communication among Cell Phones and Sensor Networks  

Microsoft Academic Search

Numerous applications, ranging from disaster management to smart buildings, have been proposed for sensor networks. The practicality of these applications depends on the ability of users to interact with these networks, in many cases in real time. In this paper we propose that cell phones interact with sensor networks and obtain the relevant information in real time. Cell phones can

Arjan Durresi; Vamsi Paruchuri

2009-01-01

349

Multiple-User Cooperative Communications Based on Linear Network Coding  

Microsoft Academic Search

We propose a new scheme for cooperative wireless networking based on linear network codes. The network consists of multiple (M ? 2) users having independent information to be transmitted to a common basestation (BS), assuming block-fading channels with independent fading for different codewords. The users collaborate in relaying messages. Because of potential transmission errors in links, resulting in erasures, the

Ming Xiao; Mikael Skoglund

2010-01-01

350

Rate-distortion optimized multimedia communication in networks  

NASA Astrophysics Data System (ADS)

Large-scale, widespread distribution of high definition multimedia contents using IP networks is extremely resource intensive. Service providers have to employ an expensive network of servers, routers, link infrastructures and set-top boxes to accommodate the generated traffic. The goal in this paper is to develop network-aware media communication solutions that help service providers to efficiently utilize their deployed network infrastructures for media delivery. In particular, we investigate the following fundamental problem: given a fixed network infrastructure, what is the best strategy to multicast multiple multimedia contents from a set of server nodes to a set of clients, to realize the best reconstruction quality at the client nodes? We use rate-distortion to formalize the notion of media quality and to formulate the corresponding optimization problem. We show that current approaches in which multimedia compression and network delivery mechanisms are designed separately are inherently suboptimal. Thus, better utilization of network resources requires a joint consideration of media compression and network delivery. We develop one such approach based on optimized delivery of balanced Multiple Description Codes (MDC), in which the MDC itself is also optimized with respect to the optimized delivery strategy. Simulation results are reported, verifying that our solution can significantly outperform existing, layered, solutions. As a byproduct, our solutions introduces a fundamentally different use of MDC. Up until now, MDC has been adopted to combat losses, mostly in packet lossy networks. We show that MDC is an efficient tool for network communication, even in error-free networks. In particular MDC, when properly duplicated at routers, can exploit the rich topological structures in networks to maximize the utilization of the network resources, beyond conventional coding techniques.

Sarshar, Nima; Wu, Xiaolin

2008-01-01

351

Integration of Auditory and Visual Communication Information in the Primate Ventrolateral Prefrontal Cortex  

PubMed Central

The integration of auditory and visual stimuli is crucial for recognizing objects, communicating effectively, and navigating through our complex world. Although the frontal lobes are involved in memory, communication, and language, there has been no evidence that the integration of communication information occurs at the single-cell level in the frontal lobes. Here, we show that neurons in the macaque ventrolateral prefrontal cortex (VLPFC) integrate audiovisual communication stimuli. The multisensory interactions included both enhancement and suppression of a predominantly auditory or a predominantly visual response, although multisensory suppression was the more common mode of response. The multisensory neurons were distributed across the VLPFC and within previously identified unimodal auditory and visual regions (O’Scalaidhe et al., 1997; Romanski and Goldman-Rakic, 2002). Thus, our study demonstrates, for the first time, that single prefrontal neurons integrate communication information from the auditory and visual domains, suggesting that these neurons are an important node in the cortical network responsible for communication.

Sugihara, Tadashi; Diltz, Mark D.; Averbeck, Bruno B.; Romanski, Lizabeth M.

2009-01-01

352

Hybrid Communications Network Simulation-Independent Toolkit.  

National Technical Information Service (NTIS)

Net-centric warfare requires information superiority to enable decision superiority, culminating in insurmountable combat power against our enemies on the battlefield. Information superiority must be attained and retained for success in today's joint/coal...

D. M. Dines

2008-01-01

353

Optimal Multicast Communication in Wormhole-Routed Torus Networks  

Microsoft Academic Search

This paper presents efficient algorithms that implement one-to-many, or multicast, communication in wormhole-routed torus networks. By exploiting the properties of the switching technology and the use of virtual channels, a minimum-time multicast algorithm is presented for n-dimensional torus networks that use deterministic, dimension-ordered routing of unicast messages. The algorithm can deliver a multicast message to m-1 destinations in [log2 m

David F. Robinson; Philip K. McKinley; Betty H. C. Cheng

1995-01-01

354

Optimal Multicast Communication in a Wormhole-Routed Torus Networks  

Microsoft Academic Search

This paper presents efficient algorithms that implement one-to-many, or multicast, communication in wormhole-routed torus networks. By exploiting the properties of the switching technology and the use of virtual channels, a minimum-time multicast algorithm is presented for n-dimensional torus networks that use deterministic, dimension-ordered routing of unicast messages. The algorithm can deliver a multicast message to m - 1 destinations in

David F. Robinson; Philip K. Mckinley; Betty H. C. Cheng

1994-01-01

355

H.323: the multimedia communications standard for local area networks  

Microsoft Academic Search

This article provides an overview of ITU-T Recommendation H.323, “Visual telephone systems and equipment for local area networks which provide a non-guaranteed quality of service.” This recommendation applies to multimedia communications over packet-switched networks, such as Ethernet, which run TCP\\/IP, IXP\\/SPX, or other related protocols. In addition to the multimedia terminal, other H.323 components are defined which provide for conference

G. A. Thom

1996-01-01

356

Information Retrieval as a ReceiverControlled Communication System.  

National Technical Information Service (NTIS)

Information storage and retrieval systems are characterized as receiver-controlled systems for the communication of information through space and time. The conclusion is reached that in designing, evaluating, or operating an information retrieval system, ...

W. J. Paisley E. B. Parker

1965-01-01

357

Deep Space Network information system architecture study  

NASA Technical Reports Server (NTRS)

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.

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

358

Harnessing the Swarm Communications Policy in an Era of Ubiquitous Networks and Disruptive Technologies (*)  

Microsoft Academic Search

This paper examines the prospects and limits of policies on information and communications technologies (ICTs) that enable knowledge-based societies. Its main argument is that the co-evolution of technological, economic, and political factors, which unfolded during the past three decades, has transformed the information network infrastructure from a closed to an open system. This fundamental change has far-reaching implications for the

Johannes M. BAUER

359

Narratives of Self in Networked Communications.  

ERIC Educational Resources Information Center

Suggests that the revolutionary potentials of network technologies are not intrinsic to the technologies. Uses experiences of Daedalus Interchange in composition classrooms to argue for critical engagement with technologies. Suggests that unless writing teachers critically address students' perceptions of writing, they will replicate the same…

Webb, Patricia R.

1997-01-01

360

Communication services for secure building automation networks  

Microsoft Academic Search

Up to now, building automation systems were considered as virtually closed environments. If at all, they had to provide some well dedicated dial-in connections for remote management. With the introduction of interconnections to foreign networks (e.g., Web gateways to the Internet) and wireless technologies, the assumption of physical isolation is not longer valid. In parallel, building automation systems of the

Wolfgang Granzer; Wolfgang Kastner

2010-01-01

361

RF switch positioner for communications satellite network  

NASA Technical Reports Server (NTRS)

The RF switch positioner is a simple, lightweight, redundant positioning mechanism used to reconfigure the antenna beam on the INTELSAT VI satellite. It simultaneously rotates approximately 100 squareax waveguide switches through a full 360 deg. The RF switch positioner has been space qualified and has performed to expectations in conjunction with the feed networks in range testing.

Storaasli, A. G.; Griesser, H. P.; Grant, R. W.

1986-01-01

362

Columbus Crew Communication Subsystem and the on Board Local Area Network.  

National Technical Information Service (NTIS)

The Columbus local area network (LAN) and crew communication system is described. The architecture of the system consists of several independant network assemblies (including the onboard LAN, audio network, and video network) each dedicated to a particula...

A. Morando A. Francia M. Masci G. Montalto

1988-01-01

363

Redesigning and revitalizing two networking courses in an undergraduate information technology degree program  

Microsoft Academic Search

Information technology is a fast changing discipline and is being conceived as a practical discipline. Information technology graduates are expected to possess relevant, practical experience when dealing with many facets of computing systems, especially in the areas of data communication, network design and administration. An information technology program of a mid-sized state university redesigned and revitalized two networking courses. They

Kam Fui Lau

2010-01-01

364

Network security system for health and medical information using smart IC card  

NASA Astrophysics Data System (ADS)

A new network security protocol that uses smart IC cards has been designed to assure the integrity and privacy of medical information in communication over a non-secure network. Secure communication software has been implemented as a library based on this protocol, which is called the Integrated Secure Communication Layer (ISCL), and has been incorporated into information systems of the National Cancer Center Hospitals and the Health Service Center of the Tokyo Institute of Technology. Both systems have succeeded in communicating digital medical information securely.

Kanai, Yoichi; Yachida, Masuyoshi; Yoshikawa, Hiroharu; Yamaguchi, Masahiro; Ohyama, Nagaaki

1998-07-01

365

Time Allocation in Social Networks: Correlation Between Social Structure and Human Communication Dynamics  

NASA Astrophysics Data System (ADS)

Recent research has shown the deep impact of the dynamics of human interactions (or temporal social networks) on the spreading of information, opinion formation, etc. In general, the bursty nature of human interactions lowers the interaction between people to the extent that both the speed and reach of information diffusion are diminished. Using a large database of 20 million users of mobile phone calls we show evidence this effect is not homogeneous in the social network but in fact, there is a large correlation between this effect and the social topological structure around a given individual. In particular, we show that social relations of hubs in a network are relatively weaker from the dynamical point than those that are poorer connected in the information diffusion process. Our results show the importance of the temporal patterns of communication when analyzing and modeling dynamical process on social networks.

Miritello, Giovanna; Lara, Rubén; Moro, Esteban

366

Progress on the Development of Future Airport Surface Wireless Communications Network  

NASA Technical Reports Server (NTRS)

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.

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

2009-01-01

367

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

NASA Technical Reports Server (NTRS)

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.

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

2013-01-01

368

Communication Resource Use in a Networked Collaborative Design Environment.  

ERIC Educational Resources Information Center

The purpose of this exploratory study was to examine student use of a prototype networked collaborative design environment to support or augment learning about engineering design. The theoretical framework is based primarily on Vygotsky's social construction of knowledge and the belief that collaboration and communication are critical components…

Gay, Geri; Lentini, Marc

369

Indian-Spanish Communication Networks: Continuity in the Greater Southwest.  

ERIC Educational Resources Information Center

Trade and communication networks established by Indian groups in the 15th century A.D. linked the Southwest to Mesoamerica, the Plains and the Pacific littoral; these routes were later used by the Spanish and Americans, and today major highways follow ancient Indian routes. The main east-west route had major termini at Cibola (near Zuni) in the…

Riley, Carroll L.; Manson, Joni L.

370

The research on tactical communication network simulative training system  

Microsoft Academic Search

In order to meet the educating and training requirements of tactical communication network (TCN), one advanced means is to develop its simulative training system. Firstly, the general framework of TCN simulative training system was designed, which included the system constitution, software structure and application manner. Secondly, a single federation and multi federation architecture were proposed, which solved the distributed interactive

Jian-jun Shen; Jing-jing Li; Xiao-hu Yu

2010-01-01

371

Energy-Efficient Communication Protocol for Wireless Microsensor Networks  

Microsoft Academic Search

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

Wendi Rabiner Heinzelman; Anantha Chandrakasan; Hari Balakrishnan

2000-01-01

372

ICEBERG: an Internet core network architecture for integrated communications  

Microsoft Academic Search

In the ICEBERG project at UC Berkeley, we are developing an Internet-based integration of telephony and data services spanning diverse access networks. Our primary goals are extensibility, scalability, robustness, and personalized communication. We leverage the Internet's low cost of entry for service creation, provision, deployment, and integration. We present our solutions to signaling, easy service creation, resource reservation, admission control,

Helen J. Wang; Bhaskaran Raman; Chen-Nee Chuah; Rahul Biswas; Ramakrishna Gummadi; Barbara Hohlt; Xia Hong; Emre Kiciman; Zhuoqing Mao; Jimmy S. Shih; L. Subraimanian; B. Y. Zhno; Anthony D. Joseph; Randy H. Katz

2000-01-01

373

Synchronization of power networks without and with communication infrastructures  

Microsoft Academic Search

The synchronization of power grid is studied by employing a simple model for the dynamics of generators. The interactions among generators and feedback control are represented by terms in the swing equation. When there is no communication network feeding back the wide area measurement, the system stability is determined by the largest eigenvalue of the Laplacian matrix of the graph

Husheng Li; Zhu Han

2011-01-01

374

Verifying cell loss requirements in high-speed communication networks  

Microsoft Academic Search

In high-speed communication networks it is common to have requirements of very small cell lossprobabilities due to buffer overflow. Losses are measured to verify that the cell loss requirementsare being met, but it is not clear how to interpret such measurements. We propose methods fordetermining whether or not cell loss requirements are being met. A key idea is to look

Kerry W. Fendick; Ward Whitt

1998-01-01

375

Average consensus problems in networks of agents with delayed communications  

Microsoft Academic Search

The present paper is devoted to the study of average consensus problems for undirected networks of dynamic agents having communication delays. By focusing on agents with integrator dynamics, the accent is put here on the study of the time-delays influence: both constant and time-varying delays are considered, as well as uniform and non uniform repartitions of the delays in the

Pierre-alexandre Bliman; Giancarlo Ferrari-trecate

2008-01-01

376

High Performance Communication and Navigation Systems for Interplanetary Networks  

Microsoft Academic Search

The increasing development of technologies enabling efficient space exploration and data communications has recently fostered a number of scientific missions, aimed at supporting the research in the field of geology and astronomy. To this end, the design of an effective telecommunication infrastructure is the challenge offered to research scientists and space engineers. In particular, the definition of a network architecture

Tomaso de Cola; Mario Marchese

2008-01-01

377

A New Coded Cooperation Method in Wireless Communication Networks  

Microsoft Academic Search

Abstract We propose a new coded cooperation method for wireless communication to obtain transmit diversity in the scenarios that agents such as mobile handsets, sensor network nodes and etc., due to size, power or other constraints, cannot utilize multiple antennas. New method supports more than 2 cooperative users with high code rates and low cooperation levels. We evaluate the performance

Azizollah Jamshidi; Masoumeh Nasiri-kenari

378

Delay Tolerant Networking for free-space optical communication systems  

Microsoft Academic Search

Free-space optical communication (FSOC) systems will be an important part of future networking infrastructures. With the growth in demand from users - both commercial and military - and the scarcity of available RF spectrum, FSOC has the potential to offer a solution. FSOC capacity can easily reach 10psilas Gbps or more over useful ranges. However, the ability to construct an

Robert A. Nichols; A. Roger Hammons Jr; Daniel J. Tebben; Anurag Dwivedi

2007-01-01

379

Topological Design of Mesh Communication Networks Using Multiobjective Genetic Optimisation  

Microsoft Academic Search

Designing an optimal communication network is a complex, multi- constraint and multi-criterion optimisation problem . Previous work in this field has optimized a single objective or a combination o f multiple values into a sin- gle scalar value. In this work, we use the multiobj ective genetic optimisation technique along with the convergence to obtain a Pa reto front -

Rajeev Kumar; S. Prasanth; M. S. Sudarshan

380

AC Electric Field Communication for Human-Area Networking  

Microsoft Academic Search

We have proposed a human-area networking technology that uses the surface of the human body as a data transmission path and uses an AC electric field signal below the resonant frequency of the human body. This technology aims to achieve a ``touch and connect'' intuitive form of communication by using the electric field signal that propagates along the surface of

Yuichi Kado; Mitsuru Shinagawa

2010-01-01

381

Role of Communication Networks in Behavioral Systems Analysis  

ERIC Educational Resources Information Center

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…

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

2009-01-01

382

Control of Multiple Service, Multiple Resource Communication Networks  

Microsoft Academic Search

The authors focus upon communication networks that integrate multiple services using multiple resources. In particular, the authors address the decision of whether to accept or deny service requests in such a system. A conjecture for the optimal policy for a related system introduced by G.J. Foschini and B. Gopinath (1983) is proved, and the optimal coordinate convex policy for a

Scott Jordan; Pravin Varaiya

1991-01-01

383

Supporting Secure Communication and Data Collection in Mobile Sensor Networks  

Microsoft Academic Search

Abstract, Sensor deployments may be static, but researchers have recently been making a case for mobile collector nodes to enhance data acquisition. Since mobile nodes are often more privileged, their compromise can give the adversary a significant advantage. Hence, security mechanisms for such networks must tolerate mobile node compromises. Unlike static sensors, which communicate mostly with their neighbors, mobile nodes

Li Zhou; Jinfeng Ni; Chinya V. Ravishankar

2006-01-01

384

Communicating Cancer Risk Information: The Challenges of Uncertainty.  

ERIC Educational Resources Information Center

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)

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

1998-01-01

385

Future large broadband switched satellite communications networks  

NASA Technical Reports Server (NTRS)

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.

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

1979-01-01

386

An information statistics approach to data stream and communication complexity  

Microsoft Academic Search

Abstract We present a new method,for proving strong lower bounds,in communication,complexity. This method,is based on the notion of the conditional information complexity,of a function which is the minimum,amount of information,about the inputs that has to be revealed by a communication,protocol for the function. While conditional information complexity is a lower bound on communication complexity, we show that it also admits

Ziv Bar-yossef; T. S. Jayram; Ravi Kumar; D. Sivakumar

2004-01-01

387

Issues and Strategies of the Network Political Communication: On the Social-Oriented Construction of E-Government  

Microsoft Academic Search

Facing the opportunities and challenges of Internet age, Chinese government has initialized the system of network communication with civil society. However, there still exist some notable issues mainly as follows. First, the complexity of Internet information causes the disorders of network political participation. Second, the powers of Internet age are clearly shifted to the hands of technocrats, and thus the

Gao Meng; Fu Cuilian

2010-01-01

388

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.

389

Communications, Navigation, and Network Reconfigurable Test-bed Flight Hardware Compatibility Test S  

NASA Technical Reports Server (NTRS)

Communications, Navigation, and Network Reconfigurable Test-bed Flight Hardware Compatibility Test Sets and Networks Integration Management Office Testing for the Tracking and Data Relay Satellite System

2010-01-01

390

Communications performance of an undersea acoustic large-area network  

NASA Astrophysics Data System (ADS)

The U.S. Navy is developing Seaweb acoustic networking capability for integrating undersea systems. Seaweb architectures generally involve a wide-area network of fixed nodes consistent with future distributed autonomous sensors on the seafloor. Mobile nodes including autonomous undersea vehicles (AUVs) and submarines operate in the context of the grid by using the fixed nodes as both navigation reference points and communication access points. In October and November 2004, Theater Anti-Submarine Warfare Exercise (TASWEX04) showcased Seaweb in its first fleet appearance. This paper evaluates the TASWEX04 Seaweb performance in support of networked communications between a submarine and a surface ship. Considerations include physical-layer dependencies on the 9-14 kHz acoustic channel, such as refraction, wind-induced ambient noise, and submarine aspect angle. [Work supported by SSC San Diego.

Kriewaldt, Hannah A.; Rice, Joseph A.

2005-04-01

391

Adaptive protocols for information dissemination in wireless sensor networks  

Microsoft Academic Search

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

Wendi Rabiner Heinzelman; Joanna Kulik; Hari Balakrishnan

1999-01-01

392

Information processing techniques program. Volume 2: Communications-adaptive internetting  

Microsoft Academic Search

The goal of this program is the investigation and development of techniques for communications-adaptive internetting with particular emphasis on digital voice communications. The specific class of problems addressed relates to packet speech networks whose interconnecting links may be stressed as a result of traffic overloads or are time varying due to natural or hostile actions. This program extends the technology

B. Gold

1977-01-01

393

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

NASA Technical Reports Server (NTRS)

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.

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

2006-01-01

394

RAP: A Real-Time Communication Architecture for Large-Scale Wireless Sensor Networks.  

National Technical Information Service (NTIS)

Large-scale wireless sensor networks represent a new generation of real-time embedded systems with significantly different communication constraints from traditional networked systems. This paper presents RAP, a new real-time communication architecture fo...

C. Lu B. M. Blum T. F. Abdelzaher J. A. Stankovic T. He

2002-01-01

395

Admission Control in Variable Capacity Communication Networks  

NASA Astrophysics Data System (ADS)

This paper defines a theoretical framework based on Markov Decision Processes (MDP) to deal with call control algorithms in links with variable capacity supporting multiple classes of service. The variable capacity problem, which arises in wireless network scenarios, is addressed by incorporating the link model into the MDP formulation and by introducing, beside the standard call admission policy, a call dropping policy. In this way, the proposed approach is capable of controlling class-level quality of service in terms of both blocking and dropping probabilities.

Pietrabissa, A.; Priscoli, F. Delli

396

Networked sensors for the future force (NSFF) advanced technology demonstration (ATD) communications systems  

NASA Astrophysics Data System (ADS)

The U.S. Army"s Future Combat Systems (FCS) and Future Force Warrior (FFW) will rely on the use of unattended, tactical sensors to detect and identify enemy targets in order to avoid enemy fires and enable precise networked fire to survive on the future battlefield with less armor protection. Successful implementation of these critical sensor fields requires the development of a specialized communications network infrastructure needed to disseminate sensor data to provide relevant, timely and accurate situational awareness information to the tactical common operating picture. The sensor network communications must support both static deployed and mobile ground and air robotic sensor arrays with robust, secure, stealthy, and jam resistant links. It is envisioned that tactical sensor networks can be deployed in a two tiered communications architecture that includes a lower sensor sub-layer consisting of acoustic, magnetic, Chemical/Biological and seismic detectors and an upper sub-layer consisting of infrared or visual imaging cameras. The upper sub-layer can be cued by the lower sub-layer and provides a seamless gateway link to higher echelon backbone tactical networks. The NSFF Advanced Technology Demonstration (ATD) communications effort focuses on providing Future Force systems such as the FCS and the Future Force Warrior with critical situational awareness data needed for survivability. The communications systems supporting this functionality must be designed such that unattended ground sensor data can flow seamlessly from the lowest unattended tactical sensor echelons into the Army"s tactical backbone networks while also allowing the "fusing" of the data with other intelligence information for correlation within a tactical command and control node. NSFF is realizing this capability by using advanced communications technologies developed under the Soldier Level Integrated Communications Environment (SLICE) Soldier Radio Waveform (SRW) project. These technologies include robust, self-organizing/healing networking protocols, energy management techniques, and stealthy, secure, jam resistant radio equipment for a significantly enhanced communications capability for the Joint Tactical Radio System (JTRS). CERDEC laboratory and field demonstrations in 2004 will be reviewed to show early SRW development in preparation for the NSFF ATD as well as development of affordable systems for disposable sensor applications

Nemeroff, Jay; DiPierro, Stefano

2005-05-01

397

SIA: secure information aggregation in sensor networks  

Microsoft Academic Search

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

Bartosz Przydatek; Dawn Xiaodong Song; Adrian Perrig

2003-01-01

398

PREFACE: Quantum Information, Communication, Computation and Cryptography  

NASA Astrophysics Data System (ADS)

The application of quantum mechanics to information related fields such as communication, computation and cryptography is a fast growing line of research that has been witnessing an outburst of theoretical and experimental results, with possible practical applications. On the one hand, quantum cryptography with its impact on secrecy of transmission is having its first important actual implementations; on the other hand, the recent advances in quantum optics, ion trapping, BEC manipulation, spin and quantum dot technologies allow us to put to direct test a great deal of theoretical ideas and results. These achievements have stimulated a reborn interest in various aspects of quantum mechanics, creating a unique interplay between physics, both theoretical and experimental, mathematics, information theory and computer science. In view of all these developments, it appeared timely to organize a meeting where graduate students and young researchers could be exposed to the fundamentals of the theory, while senior experts could exchange their latest results. The activity was structured as a school followed by a workshop, and took place at The Abdus Salam International Center for Theoretical Physics (ICTP) and The International School for Advanced Studies (SISSA) in Trieste, Italy, from 12-23 June 2006. The meeting was part of the activity of the Joint European Master Curriculum Development Programme in Quantum Information, Communication, Cryptography and Computation, involving the Universities of Cergy-Pontoise (France), Chania (Greece), Leuven (Belgium), Rennes1 (France) and Trieste (Italy). This special issue of Journal of Physics A: Mathematical and Theoretical collects 22 contributions from well known experts who took part in the workshop. They summarize the present day status of the research in the manifold aspects of quantum information. The issue is opened by two review articles, the first by G Adesso and F Illuminati discussing entanglement in continuous variable systems, the second by T Prosen, discussing chaos and complexity in quantum systems. Both topics have theoretical as well as experimental relevance and are likely to witness a fast growing development in the near future. The remaining contributions present more specific and very recent results. They involve the study of the structure of quantum states and their estimation (B Baumgartner et al, C King et al, S Olivares et al, D Petz et al and W van Dam et al), of entanglement generation and its quantification (G Brida et al, F Ciccarello et al, G Costantini et al, O Romero-Isart et al, D Rossini et al, A Serafini et al and D Vitali et al), of randomness related effects on entanglement behaviour (I Akhalwaya et al, O Dahlsten et al and L Viola et al), and of abstract and applied aspects of quantum computation and communication (K Audenart, G M D'Ariano et al, N Datta et al, L C Kwek et al and M Nathanson et al). We would like to express our gratitude to the European Commission, the Abdus Salam ICTP, SISSA and Eurotech SpA (Amaro, Udine, Italy) for financial and/or logistic support. Special thanks also go to the workshop secretary Marina De Comelli, and the secretaries of the Department of Theoretical Physics, University of Trieste, Sabrina Gaspardis and Rosita Glavina for their precious help and assistance.

Benatti, F.; Fannes, M.; Floreanini, R.; Petritis, D.

2007-07-01

399

Information and Communication Technologies in Social Work  

PubMed Central

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.

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

2011-01-01

400

Dynamics of rumor-like information dissemination in complex networks  

NASA Astrophysics Data System (ADS)

An important dynamic process that takes place in complex networks is the spreading of information via rumor-like mechanisms. In addition to their relevance to propagation of rumors and fads in human society, such mechanism are also the basis of an important class of collective communication protocols in complex computer networks, such as the Internet and the peer-to-peer systems. In this talk we present results of our analytical, numerical and large-scale Monte Carlo simulation studies of this process on several classes of complex networks, including random graphs, scale-free networks, and random and small-world topological graphs. Our studies point out to important differences between the dynamics of rumor spreading and that of virus spreading in such networks, and provide new insights into the complex interplay between the spreading phenomena and network topology.

Nekovee, Maziar; Moreno, Yamir; Bianconi, Ginestra

2005-03-01

401

Sustainable patient information network (SPaIN) for primary care health center in Indonesia  

Microsoft Academic Search

Sustainable patient information network for primary care health center is needed for Indonesia. There are many of remote, isolated or urban area, which causes transportation problems and telecommunication problems, for example: necessity of wireless infrastructure. The Internet and its free software is the main agent for this system combining with information and communication technology. We develop low speed communication system

I. T. Pambudi; T. Hayasaka; T. Tsubota; S. Wada; T. Yamaguchi

2003-01-01

402

Graph Models for Library Information Networks.  

ERIC Educational Resources Information Center

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…

Korfhage, Robert R.; And Others

403

Protocol for a Delay-Tolerant Data-Communication Network  

NASA Technical Reports Server (NTRS)

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.

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

2004-01-01

404

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

NASA Technical Reports Server (NTRS)

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.

1973-01-01

405

"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

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…

Van Cleemput, Katrien

2010-01-01

406

Reliability analysis of power and communication network in coal mine monitoring system  

Microsoft Academic Search

Due to the special security requirements and abominable environment, researching in the high reliability of the communication network and power in coal mine monitoring system is become special important. The reliability of the communication network and power in the coal mine monitoring system has been studied. To assess the reliability of the underground power and communication network, the constant stress

Fengying Ma; Xinrong Zhang

2011-01-01

407

Radar network communication through sensing of frequency hopping  

DOEpatents

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.

Dowla, Farid; Nekoogar, Faranak

2013-05-28

408

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.

409

Distributed wireless quantum communication networks with partially entangled pairs  

NASA Astrophysics Data System (ADS)

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

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

2014-01-01

410

An Acoustic Communication Network for Monitoring of the Underwater Environment  

NASA Astrophysics Data System (ADS)

An Acoustic Communication network for Monitoring of underwater Environments in coastal areas (ACME) is being developed by a consortium of 6 partners within the EU's Fifth Framework Programme. These partners are TNO Physics and Electronics Laboratory (NL), Thales Underwater Systems (FR), ORCA Instrumentation (FR), the University of Newcastle (UK), TNO-TPD (NL), and the Dutch Ministry of Transport, Public Works and Water Management. The main goal of the project is the development and deployment of a prototype underwater acoustic communication network for the readout of a number of sensors in the Westerschelde in the south west of the Netherlands. The project focusses on coastal areas such as shipping lanes, fishing grounds and estuaries, when conventional data transport with cables or radio links is impossible. The challenges are numerous: multiple echoes of the sound give rise to inter-symbol interference and complicate data retrieval; noise of shipping traffic lowers the signal-to-noise ratio, in particular along busy freighter routes; practical matters such as battery lifetime and hardware for deployment must be dealt with as well. The results so far show that the point-to-point communication and the network protocols are functioning correctly, ready for the last phase of the project in which the autonomous working of the prototype network will be realized.

van Walree, P. A.; Driesenaar, M. L.

2003-04-01

411

Sensor network and information interoperability integrating IEEE 1451 with MIMOSA and OSA-CBM  

Microsoft Academic Search

The IEEE 1451 smart transducer interface for sensors and actuators standard was developed to facilitate sensor to network interoperability. It has defined a set of common communication interfaces for connecting transducers (sensors or actuators) to control networks and instruments in a network-independent environment. Concurrently, the Machinery Information Management Open Systems Alliance (MIMOSA) has established an open architecture and a set

Kang Lee; Robert X. Gao; Rick Schneeman

2002-01-01

412

Route Optimization Solution Based on Extended Prefix Information Option for Nested Mobility Network  

Microsoft Academic Search

NEMO basic support protocol (Devarapalli et al., 2005) enables mobile networks preserve communication with other nodes, while changing their point of attachment to the Internet. But in nested mobile network, Pinball routing problem appears. In this paper, a route optimization solution for mobile networks based on extended prefix information option in RA message is proposed to solve the suboptimal routing,

Lu Li-Hua; Liu Yuan-an

2007-01-01

413

Scaling of data communications for an advanced supercomputer network  

NASA Technical Reports Server (NTRS)

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.

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

1986-01-01

414

Networks, Netwar, and Information-Age Terrorism.  

National Technical Information Service (NTIS)

The rise of network forms of organization is a key consequence of the ongoing information revolution. Business organizations are being newly energized by networking, and many professional militaries are experimenting with flatter forms of organization. In...

D. Ronfeldt J. Arquilla M. Zanini

1999-01-01

415

Networking and Information Technology Research and Development. Supplement to the President's Budget for FY 2002.  

National Technical Information Service (NTIS)

Today, at the beginning of a new millennium, networking and information technologies are transforming our world, generating unprecedented American prosperity, and building revolutionary new infrastructures for commerce, communication, human development, n...

2001-01-01

416

Exploration of Oral/Informal Technical Communications Behavior. Final Report.  

ERIC Educational Resources Information Center

The report explores and defines the boundaries of informal scientific and technological communication, based on data from scientists and engineers. A major purpose of the report was to determine the kinds of management decisions needed to enhance research productivity by improving informal research communication. The report includes: (1) a survey…

Graham, Warren R.; And Others

417

Computing, Information, and Communications Technology (CICT) Program Overview  

NASA Technical Reports Server (NTRS)

The Computing, Information and Communications Technology (CICT) Program's goal 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 communication technologies

VanDalsem, William R.

2003-01-01

418

Communication and information: alternative uses of the Internet in households  

Microsoft Academic Search

The Internet has been characterized as a superhighway to information and as a high-tech extension of the home telephone. How are people really using the Internet? The history of previous technologies that support interpersonal communication suggests that communication may be a more important use and determinant of participants’ commitment to the Internet than is information acquisition and entertainment. Operationalizing interpersonal

Robert E. Kraut; Tridas Mukhopadhyay; Janusz Szczypula; Sara B. Kiesler; William L. Scherlis

1998-01-01

419

Fading channels: information-theoretic and communications aspects  

Microsoft Academic Search

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

Ezio Biglieri; John Proakis; Shlomo Shamai

1998-01-01

420

Fading Channels: Information-Theoretic and Communication Aspects  

Microsoft Academic Search

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

Ezio Biglieri; John G. Proakis; Shlomo Shamai

1998-01-01

421

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.

2008-09-08

422

An Information Statistics Approach to Data Stream and Communication Complexity  

Microsoft Academic Search

We present a new method for proving strong lower bounds in communication com- plexity. This method is based on the notion of the conditional information complexity of a function which is the minimum amount of information about the inputs that has to be revealed by a communication protocol for the function. While conditional infor- mation complexity is a lower bound

Ziv Bar-yossef; T. S. Jayram; Ravi Kumar; D. Sivakumar

2002-01-01

423

Good Communication: The Other Social Network for Successful IT Organizations  

ERIC Educational Resources Information Center

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…

Trubitt, Lisa; Overholtzer, Jeff

2009-01-01

424

A Professional Development Project for Improving the Use of Information and Communication Technologies in Science Teaching  

ERIC Educational Resources Information Center

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…

Lavonen, Jari; Juuti, Kalle; Aksela, Maija; Meisalo, Veijo

2006-01-01

425

Near-optimal sensor placements: maximizing information while minimizing communication cost  

Microsoft Academic Search

When monitoring spatial phenomena with wireless sensor networks, selecting the best sensor placements is a funda- mental task. Not only should the sensors be informative, but they should also be able to communicate efficiently. In this paper, we present a data-driven approach that addresses the three central aspects of this problem: measuring the predic- tive quality of a set of

Andreas Krause; Carlos Guestrin; Anupam Gupta; Jon M. Kleinberg

2006-01-01

426

The Implications of Information and Communications Technologies for Distance Education: Looking toward the Future. Final Report  

ERIC Educational Resources Information Center

One salient factor of increasing interest in distance education is advancement in information and communications technologies (ICTs). In particular, digital and networked technologies have had a wide range of effects on the educational materials, practices, and institutions involved in education, notably by improving time-and cost-efficient…

Arafeh, Sousan

2004-01-01

427

Challenges of Information and Communication Technology in Energy Efficient Smart Homes  

Microsoft Academic Search

Energy saving is an important issue in the times of increasing energy prices. Products and services provided by the information and communication technology (ICT) can support energy efficiency and emissions reductions. The synergy of ICT and a residential area gives rise to the smart home environment. Ecological and smart home network applications should not only improve the peoples life satisfaction

Dragan Markovic; Dragan Cvetkovic; Dejan Zivkovic; Ranko Popovic

2012-01-01

428

Source Journal List: Women's Educational Equity Communications Network.  

National Technical Information Service (NTIS)

Designed for use by information network users, this list of journals which publish material relevant to women's educational equity indicates the machine database or databases which cover each journal, as well as identifying those journals not processed by...

A. Wehren

1978-01-01

429

Network Information Flow in Navigable Small-World Networks  

Microsoft Academic Search

Small-world graphs, exhibiting high clustering co-efficients and small average path length, have been shown to capture fundamental properties of a large number of natural and man-made networks. In the context of communication networks, navigable small-world topologies, i.e. those which admit efficient distributed routing algorithms, are deemed particularly effective, for example in resource discovery tasks and peer-to-peer applications. Intrigued by the

Rui A. Costa; Joao Barros

2006-01-01

430

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

NASA Technical Reports Server (NTRS)

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.

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

1998-01-01

431

A Computer Network Protocol for Library and Information Science Applications. NCLIS/NBS Task Force on Computer Network Protocol.  

ERIC Educational Resources Information Center

This document describes a proposed computer to computer protocol for electronic communication of digital information over a nationwide library bibliographic network. The protocol allows application tasks at one site on the network to converse with application tasks at any other site, regardless of differences in computer architecture or operating…

National Commission on Libraries and Information Science, Washington, DC.

432

Adaptive swarm-based routing in communication networks.  

PubMed

Swarm intelligence inspired by the social behavior of ants boasts a number of attractive features, including adaptation, robustness and distributed, decentralized nature, which are well suited for routing in modern communication networks. This paper describes an adaptive swarm-based routing algorithm that increases convergence speed, reduces routing instabilities and oscillations by using a novel variation of reinforcement learning and a technique called momentum. Experiment on the dynamic network showed that adaptive swarm-based routing learns the optimum routing in terms of convergence speed and average packet latency. PMID:15495316

Lu, Yong; Zhao, Guang-Zhou; Su, Fan-Jun; Li, Xiao-Run

2004-07-01

433

Deep Space Network information system architecture study  

NASA Technical Reports Server (NTRS)

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.

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

434

Modeling and Analysis of Mobility Management in Mobile Communication Networks  

PubMed Central

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.

Yoon, Ji Hyun; Kim, Chesoong

2014-01-01

435

Program Support Communications Network (PSCN) facsimile system directory  

NASA Technical Reports Server (NTRS)

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).

1992-01-01

436

Technology developments integrating a space network communications testbed  

NASA Technical Reports Server (NTRS)

As future manned and robotic space explorations missions involve more complex systems, it is essential to verify, validate, and optimize such systems through simulation and emulation in a low cost testbed environment. The goal of such a testbed is to perform detailed testing of advanced space and ground communications networks, technologies, and client applications that are essential for future space exploration missions. We describe the development of new technologies enhancing our Multi-mission Advanced Communications Hybrid Environment for Test and Evaluation (MACHETE) that enables its integration in a distributed space communications testbed. MACHETE combines orbital modeling, link analysis, and protocol and service modeling to quantify system performance based on comprehensive considerations of different aspects of space missions.

Kwong, Winston; Jennings, Esther; Clare, Loren; Leang, Dee

2006-01-01

437

Low-earth orbit global cellular communications network  

NASA Astrophysics Data System (ADS)

Technical aspects of the recently announced Iridium satellite communications system are discussed. The Iridium system is a worldwide, digital, satellite-based, cellular, personal communications system primarily intended to provide commercial, low-density, mobile service via portable, mobile, or transportable user units, employing low-profile antennas, to millions of users throughout the world. Calls can be made and received anywhere in the world with a personal, portable unit. Seventy-seven small (340 kg), smart satellites are internetted to form the network's backbone. Small, battery-powered, cellular-telephone-like user units communicate directly to the satellites. Gateways (earth stations) interface from the satellites to the individual Postal, Telephone and Telegraph Authorities (PTTs). The system is intended to complement the terrestrial cellular telephone systems installed, or being installed, in densely populated areas by providing a similar service everywhere else in the world.

Leopold, Raymond J.

438

Computation-Communication Overlap on Network-of-Workstation Multiprocessors  

Microsoft Academic Search

This paper describes and evaluates a compiler trans- formation that improves the performance of parallel programs on Network-of-Workstation (NOW) shared- memory multiprocessors. The transformation overlaps the communication time resulting form non-local mem- ory accesses with the computation time in parallel loops to effectively hide the latency of the remote accesses. The transformation peels from a parallel loop iterations that access

Gary Liu; Tarek S. Abdelrahman

1998-01-01

439

Communications architecture for space-based sensor networks  

Microsoft Academic Search

Numerous planned and proposed future space exploration missions employ multiple spacecraft that perform multipoint sensing. Distributed space-based sensing missions can significantly benefit from incorporation of cross-link communications capabilities, thereby forming space-based networks, by enabling continuous access to any\\/all spacecraft via a single ground contact, real-time coordinated observations, and autonomous in situ processing within a spatial neighborhood of spacecraft. We present

Loren P. Clare; Jay L. Gao; Esther H. Jennings; Clayton Okino

2004-01-01

440

Lightweight Testing of Communication Networks with eMotions  

Microsoft Academic Search

\\u000a This paper illustrates the use of high-level domain specific models to specify and test some performance properties of complex\\u000a systems, in particular Communication Networks, using a light-weight approach. By following a Model-Driven Engineering (MDE)\\u000a approach, we show the benefits of constructing very abstract models of the systems under test, which can then be easily prototyped\\u000a and analysed to explore their

Javier Troya; Jose M. Bautista; Fernando López-Romero; Antonio Vallecillo

441

Performance analysis of Integrated Communication and Control System networks  

NASA Technical Reports Server (NTRS)

This paper presents statistical analysis of delays in Integrated Communication and Control System (ICCS) networks that are based on asynchronous time-division multiplexing. The models are obtained in closed form for analyzing control systems with randomly varying delays. The results of this research are applicable to ICCS design for complex dynamical processes like advanced aircraft and spacecraft, autonomous manufacturing plants, and chemical and processing plants.

Halevi, Y.; Ray, A.

1990-01-01

442

Adaptive rate controlled, robust video communication over packet wireless networks  

Microsoft Academic Search

Video transmission over wireless packet networks is gaining importance due to the concept of universal personal communication.\\u000a Further, it is considered an important step towards wireless multimedia. The challenge however is to achieve good video quality\\u000a over mobile channels, where typically the channel conditions vary due to signal fading. Hence this paper investigates adaptive\\u000a rate controlled video transmission for robust

G. R. Rajugopal; R. H. M. Hafez

1998-01-01

443

Improving physical layer multicast by cooperative communications in heterogeneous networks  

Microsoft Academic Search

Recently, heterogeneous networks (HetNets) have drawn significant attention from academia and industry as an efficient way to improve the capacity and coverage of cellular systems. In addition to unicast communication, many important applications in HetNets, such as video\\/audio conferencing and mobile TV, require the support of multicast. In this article, we study the deployment of HetNets from the perspective of

Xianzhong Xie; Bo Rong; Tao Zhang; Weijia Lei

2011-01-01

444

Remote Stabilization Via Communication Networks With a Distributed Control Law  

Microsoft Academic Search

In this note, we investigate the problem of remote stabilization via communication networks involving some time-varying delays of known average dynamics. This problem arises when the control law is remotely implemented and leads to the problem of stabilizing an open-loop unstable system with time-varying delay. We use a time-varying horizon predictor to design a stabilizing control law that sets the

Emmanuel Witrant; Carlos Canudas-de-Wit; Didier Georges; Mazen Alamir

2007-01-01

445

Congestion-free communication in broadband packet networks  

Microsoft Academic Search

A congestion control strategy for broadband packet networks is proposed. The strategy is aimed at connection-oriented services and provides congestion-free communications with guaranteed throughput and constant end-to-end delay per connection. It is composed of an admission policy imposed per connection at the source node, and a particular queuing scheme practised at the switching nodes. The admission policy requires the packet

S. J. Golestani

1990-01-01

446

An Energy Efficient Communication Protocol Based on Data Equilibrium in Mobile Wireless Sensor Network  

Microsoft Academic Search

This paper considers large-scale dense wireless sensor networks with path-constrained mobile sink. From the viewpoints of\\u000a improving data equilibrium and energy-saving, we propose an enhanced energy efficient communication protocol in which a partition\\u000a algorithm of overlapping time based on data equilibrium is designed to minimize the data variance and disequilibrium from\\u000a each node. We present a data equilibrium information diffusion

Shuai Gao; Yanchao Niu; Hongwei Huo; Hongke Zhang

2007-01-01

447

Adaptive channel access protocol for asynchronous inter-vehicle communication network using spread spectrum  

Microsoft Academic Search

Inter-vehicle communication (IVC) systems, where vehicles exchange information with each other, can decrease traffic accidents and promote smoother driving. To realize such systems, decentralized (i.e., base-station-less) network management is required because of the independent movement of vehicles. However, it is very difficult to achieve decentralized synchronization among unspecified vehicles. Therefore we propose an adaptive channel access protocol for an asynchronous

Mina Maeda; Masao Nakagawa

1997-01-01

448

Cooperative Communication Protocols in Wireless Networks: Performance Analysis and Optimum Power Allocation  

Microsoft Academic Search

In this paper, symbol-error-rate (SER) performance analysis and optimum power allocation are provided for uncoded cooperative\\u000a communications in wireless networks with either decode-and-forward (DF) or amplify-and-forward (AF) cooperation protocol,\\u000a in which source and relay send information to destination through orthogonal channels. In case of the DF cooperation systems,\\u000a closed-form SER formulation is provided for uncoded cooperation systems with PSK and

Weifeng Su; Ahmed K. Sadek; K. J. Ray Liu

2008-01-01

449

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

NASA Technical Reports Server (NTRS)

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

Hoder, Douglas; Bergamo, Marcos

1996-01-01

450

Influence of a network structure on the network effect in the communication service market  

NASA Astrophysics Data System (ADS)

In this study, we analyze the network effect in a model of a personal communication market, by using a multi-agent based simulation approach. We introduce into the simulation model complex network structures as the interaction patterns of agents. With complex network models, we investigate the dynamics of a market in which two providers are competing. We also examine the structure of networks that affect the complex behavior of the market. By a series of simulations, we show that the structural properties of complex networks, such as the clustering coefficient and degree correlation, have a major influence on the dynamics of the market. We find that the network effect is increased if the interaction pattern of agents is characterized by a high clustering coefficient, or a positive degree correlation. We also discuss a suitable model of the interaction pattern for reproducing market dynamics in the real world, by performing simulations using real data of a social network.

Uchida, Makoto; Shirayama, Susumu

2008-09-01

451

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

Federal Register 2010, 2011, 2012, 2013

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

2013-06-06

452

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

Federal Register 2010, 2011, 2012, 2013

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2013-01-29

453

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

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2011-08-10

454

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

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2013-03-26

455

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

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2011-11-01

456

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

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2012-11-07

457

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

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2013-05-14

458

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

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2013-09-10

459

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

Federal Register 2010, 2011, 2012, 2013

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2013-06-17

460

Predicting Information Flows in Network Traffic.  

ERIC Educational Resources Information Center

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)

Hinich, Melvin J.; Molyneux, Robert E.

2003-01-01

461

Information Assurance In Wireless Sensor Networks  

Microsoft Academic Search

Networking unattended wireless sensors is expected to have significant impact on the efficiency of a large array of military and non-military applications. The main goal of wireless sensor networks is to obtain globally meaningful information from strictly local gleaned by individual sensor nodes. The network is deployed such that the sensors are embedded, possibly at random, in a target environment.

Stephan Olariu; Qingwen Xu

2005-01-01

462

Academic Topographies: A Network Analysis of Disciplinarity among Communication Faculty.  

ERIC Educational Resources Information Center

Examines how theoretical and paradigmatic differences among interdisciplinary faculty are reflected in the ongoing work of a school with departments of communication, journalism, and library and information science. Reveals the presence of two groups of faculty whose members coparticipate more cohesively within themselves than between groups; and…

White, William J.

1999-01-01

463

The Social Side of Information Networking.  

ERIC Educational Resources Information Center

Explores the social issues, including manners, security, crime (fraud), and social control associated with information networking, with emphasis on the Internet. Also addresses the influence of cellular phones, the Internet and other information technologies on society. (GR)

Katz, James E.

1997-01-01

464

Information Product Quality in Network Centric Operations.  

National Technical Information Service (NTIS)

This study introduces a pragmatic methodology for examining the effectiveness of decision support information systems for Network Centric Operations based on the concept of manufacturing information products. We first develop the definitions and framework...

P. J. Driscoll M. Tortorella E. Pohl

2005-01-01

465

The performance limitations of free space optical communication satellite networks due to vibrations-analogs case  

Microsoft Academic Search

Free space optical communication between satellites networked together can make possible high speed communication between different places on Earth. In this work we derive mathematical models of signal, noise, and approximate bit-error-rates of optical communication satellite networks as functions of the system parameters. The optical inter-satellite network model considered includes transmitter satellite, repeater satellites, and receiver satellite all networked together.

S. Arnon; N. S. Kopeika

1996-01-01

466

The performance limitations of free space optical communication satellite networks due to vibrations-analog case  

Microsoft Academic Search

Free space optical communication between satellites networked together can make possible high speed communication between different places on Earth. We derive mathematical models of signal, noise, and approximate bit-error-rates of optical communication satellite networks as functions of the system parameters. The optical inter-satellite network model considered includes transmitter satellite, repeater satellites, and receiver satellite all networked together. From the analysis

S. Arnon; N. S. Kopeika

1996-01-01

467

Information-based decision making over a data fusion network  

Microsoft Academic Search

In a dynamic battlespace the utility of decisions is a sensitive function of their timeliness. The allocation of weapons, and assignment of sensing and communications resources are examples where timely decisions are crucial to long-term survival. In this paper, we investigate the application of information-based decision-making theory to a data fusion network in such an environment. Specifically, we examine the

Felicity Dormon; Valerie Leung; Dave Nicholson; Ellie Siva; Mark Williams

2005-01-01

468

Information-aware collaborative routing in wireless sensor network  

NASA Astrophysics Data System (ADS)

In this paper, we propose a new approach to routing protocol called information-aware collaborative routing for wireless sensor networks. Clustering and local data aggregation schemes have been developed to reduce the energy for transmitting redundant data in the wireless sensor network. Most existing approaches have been developed for the cases when there is direct communication between cluster head and base station. Even though these schemes are able to reduce data redundancy to be transmitted from the cluster heads to the base station, they have not exploited the data redundancy between neighboring clusters. In this research, we study a more general case when there are multi-hop communications from cluster heads to the base station. To exploit the potential redundancy between neighboring clusters, we propose to develop a routing protocol architecture that combines multi-hop routing with information-aware clustering based on the correlation of sensor data. The information-aware collaborative routing includes the re-clustering based on data correlation as well as the central-controlled clustering and cluster heads rotation to evenly distribute the energy load in the entire network. Extensive simulations show that the proposed information-aware collaborative routing can achieve better performance in terms of longer network lifetime and less energy dissipation comparing with the existing cluster-based routing.

Lee, Ji Sun; Chen, Chang Wen

2006-06-01

469

Three-Party Quantum Network Communication Protocols Based on Quantum Teleportation  

NASA Astrophysics Data System (ADS)

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.

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

2014-04-01

470

Efficient dissemination method for traffic jams information sharing based on inter-vehicle communication  

Microsoft Academic Search

In an Intelligent Transport System (ITS), data dissemination based on inter-vehicle communication is effective for acquiring real-time traffic jams information. In this paper, we propose a novel method for traffic jams information dissemination in vehicular ad-hoc networks. In our proposed method, vehicles already trapped in a traffic jams elect leaders according to their locations from upstream and downstream respectively. Then,

Hyeong-Jun Chang; Hwan-Joo Kwak; Gwi-Tae Park

2009-01-01

471

Communication policy, corporate language policy and corporate information portal : A Holy Trinity in corporate communications?  

Microsoft Academic Search

Purpose – The aim of this paper is to discuss a theoretical framework for increased integration of a company's communication policy, corporate language policy and corporate information portal with a view to facilitating communication management. Design\\/methodology\\/approach – The paper draws on selected theoretical contributions on corporate language policy with special emphasis on theoretical considerations on the type of language policies

Henrik Simonsen

2009-01-01

472

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

NASA Technical Reports Server (NTRS)

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