WorldWideScience

Sample records for network communication capabilities

  1. Network Communication as a Service-Oriented Capability

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-01-08

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

  2. Integrating Space Communication Network Capabilities via Web Portal Technologies

    Science.gov (United States)

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

    2014-01-01

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

  3. Advanced Measurements of the Aggregation Capability of the MPT Network Layer Multipath Communication Library

    Directory of Open Access Journals (Sweden)

    Gábor Lencse

    2015-05-01

    Full Text Available The MPT network layer multipath communicationlibrary is a novel solution for several problems including IPv6transition, reliable data transmission using TCP, real-time transmissionusing UDP and also wireless network layer routingproblems. MPT can provide an IPv4 or an IPv6 tunnel overone or more IPv4 or IPv6 communication channels. MPT canalso aggregate the capacity of multiple physical channels. In thispaper, the channel aggregation capability of the MPT libraryis measured up to twelve 100Mbps speed channels. Differentscenarios are used: both IPv4 and IPv6 are used as the underlyingand also as the encapsulated protocols and also both UDP andTCP are used as transport protocols. In addition, measurementsare taken with both 32-bit and 64-bit version of the MPT library.In all cases, the number of the physical channels is increased from1 to 12 and the aggregated throughput is measured.

  4. On the Capability of Smartphones to Perform as Communication Gateways in Medical Wireless Personal Area Networks

    Directory of Open Access Journals (Sweden)

    María José Morón

    2014-01-01

    Full Text Available This paper evaluates and characterizes the technical performance of medicalwireless personal area networks (WPANs that are based on smartphones. For this purpose,a prototype of a health telemonitoring system is presented. The prototype incorporates acommercial Android smartphone, which acts as a relay point, or “gateway”, between a setof wireless medical sensors and a data server. Additionally, the paper investigates if theconventional capabilities of current commercial smartphones can be affected by their useas gateways or “Holters” in health monitoring applications. Specifically, the profiling hasfocused on the CPU and power consumption of the mobile devices. These metrics havebeen measured under several test conditions modifying the smartphone model, the type ofsensors connected to the WPAN, the employed Bluetooth profile (SPP (serial port profile orHDP (health device profile, the use of other peripherals, such as a GPS receiver, the impactof the use of theWi-Fi interface or the employed method to encode and forward the data thatare collected from the sensors.

  5. On the capability of smartphones to perform as communication gateways in medical wireless personal area networks.

    Science.gov (United States)

    Morón, María José; Luque, Rafael; Casilari, Eduardo

    2014-01-02

    This paper evaluates and characterizes the technical performance of medical wireless personal area networks (WPANs) that are based on smartphones. For this purpose,a prototype of a health telemonitoring system is presented. The prototype incorporates a commercial Android smartphone, which acts as a relay point, or "gateway", between a set of wireless medical sensors and a data server. Additionally, the paper investigates if the conventional capabilities of current commercial smartphones can be affected by their use as gateways or "Holters" in health monitoring applications. Specifically, the profiling has focused on the CPU and power consumption of the mobile devices. These metrics have been measured under several test conditions modifying the smartphone model, the type of sensors connected to the WPAN, the employed Bluetooth profile (SPP (serial port profile) orHDP (health device profile)), the use of other peripherals, such as a GPS receiver, the impact of the use of the Wi-Fi interface or the employed method to encode and forward the data that are collected from the sensors.

  6. Building dynamic capabilities in large global advertising agency networks: managing the shift from mass communication to digital interactivity

    DEFF Research Database (Denmark)

    Suheimat, Wisam; Prætorius, Thim; Brambini-Pedersen, Jan Vang

    2018-01-01

    Interactive digital technologies result in significant managerial challenges for the largest global advertising agency networks. This paper, based on original data from in-depth case research in three of the largest global advertising networks, investigates how advertising agency networks manage...

  7. Connectivity of communication networks

    CERN Document Server

    Mao, Guoqiang

    2017-01-01

    This book introduces a number of recent developments on connectivity of communication networks, ranging from connectivity of large static networks and connectivity of highly dynamic networks to connectivity of small to medium sized networks. This book also introduces some applications of connectivity studies in network optimization, in network localization, and in estimating distances between nodes. The book starts with an overview of the fundamental concepts, models, tools, and methodologies used for connectivity studies. The rest of the chapters are divided into four parts: connectivity of large static networks, connectivity of highly dynamic networks, connectivity of small to medium sized networks, and applications of connectivity studies.

  8. Computer-communication networks

    CERN Document Server

    Meditch, James S

    1983-01-01

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

  9. Designing for Networked Communications

    DEFF Research Database (Denmark)

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

  10. Designing for Networked Communications

    DEFF Research Database (Denmark)

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

  11. Communications for unattended sensor networks

    Science.gov (United States)

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

    2004-07-01

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

  12. Decomposition of Network Communication Games

    NARCIS (Netherlands)

    Dietzenbacher, Bas; Borm, Peter; Hendrickx, Ruud

    2015-01-01

    Using network control structures this paper introduces network communication games as a generalization of vertex games and edge games corresponding to communication situations and studies their decomposition into unanimity games. We obtain a relation between the dividends of the network

  13. Hyperswitch Communication Network Computer

    Science.gov (United States)

    Peterson, John C.; Chow, Edward T.; Priel, Moshe; Upchurch, Edwin T.

    1993-01-01

    Hyperswitch Communications Network (HCN) computer is prototype multiple-processor computer being developed. Incorporates improved version of hyperswitch communication network described in "Hyperswitch Network For Hypercube Computer" (NPO-16905). Designed to support high-level software and expansion of itself. HCN computer is message-passing, multiple-instruction/multiple-data computer offering significant advantages over older single-processor and bus-based multiple-processor computers, with respect to price/performance ratio, reliability, availability, and manufacturing. Design of HCN operating-system software provides flexible computing environment accommodating both parallel and distributed processing. Also achieves balance among following competing factors; performance in processing and communications, ease of use, and tolerance of (and recovery from) faults.

  14. Specifying Orchestrating Capability in Network Organization and Interfirm Innovation Networks

    DEFF Research Database (Denmark)

    Hu, Yimei; Sørensen, Olav Jull

    implements its blue ocean strategy through purposively build multi-level networks, i.e. an intra network organization and interfirm innovation networks. In order to get more innovation output from external and internal networks, orchestration capability is needed and should be applied both externally...

  15. SOCIAL NETWORKS AND INTERPERSONAL COMMUNICATION

    National Research Council Canada - National Science Library

    Veronica GHEORGHIȚĂ; Alexandrina PĂDUREȚU

    2014-01-01

    .... On the other hand, social networks adversely affects communication by decreasing the interaction face to face, by imposing superficial communications experiences, grammatical and spelling erosion of the language...

  16. Delta capability for launch of communications satellites

    Science.gov (United States)

    Grimes, D. W.; Russell, W. A., Jr.; Kraft, J. D.

    1982-01-01

    The evolution of capabilities and the current performance levels of the Delta launch vehicle are outlined. The first payload was the Echo I passive communications satellite, weighing 179 lb, and placed in GEO in 1960. Emphasis since then has been to use off-the-shelf hardware where feasible. The latest version in the 3924 first stage, 3920 second stage, and Pam D apogee kick motor third stage. The Delta is presently equipped to place 2800 lb in GEO, as was proven with the 2717 lb Anik-D1 satellite. The GEO payload placement performance matches the Shuttle's, and work is therefore under way to enhance the Delta performance to handle more massive payloads. Installation of the Castor-IV solid motor separation system, thereby saving mass by utilizing compressed nitrogen, rather than mechanical thrusters to remove the strap-on boosters, is indicated, together with use of a higher performance propellant and a wider nose fairing.

  17. Social network analysis and dual rover communications

    Science.gov (United States)

    Litaker, Harry L.; Howard, Robert L.

    2013-10-01

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

  18. Understanding the Relationship Between Organizational Networking and Network Capability

    Directory of Open Access Journals (Sweden)

    Hutu Raul Alexandru

    2015-07-01

    Full Text Available Organizational networking refers to firms‘ behaviours as activities, routines, practices which enable an organization to make sense of and capitalize on their networks of direct and indirect business relationships. The relationships are more important today when the business environment is more competitive. The firms can develop their organizational networking strategies by developing their network capability which refers to its ability to build, handle and exploit relationships. These capabilities are included in a complex configuration with other capabilities and competencies. The aim of this paper is to explore how network capabilities are structured and we tried to understand how they could be improved in order to obtain higher performance. Achieving a good network position that allows firms to make use of business opportunities is a main strategic aim of firms

  19. Secure Network-Centric Aviation Communication (SNAC)

    Science.gov (United States)

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

    2017-01-01

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

  20. Deep Space Network Capabilities for Receiving Weak Probe Signals

    Science.gov (United States)

    Asmar, Sami; Johnston, Doug; Preston, Robert

    2005-01-01

    Planetary probes can encounter mission scenarios where communication is not favorable during critical maneuvers or emergencies. Launch, initial acquisition, landing, trajectory corrections, safing. Communication challenges due to sub-optimum antenna pointing or transmitted power, amplitude/frequency dynamics, etc. Prevent lock-up on signal and extraction of telemetry. Examples: loss of Mars Observer, nutation of Ulysses, Galileo antenna, Mars Pathfinder and Mars Exploration Rovers Entry, Descent, and Landing, and the Cassini Saturn Orbit Insertion. A Deep Space Network capability to handle such cases has been used successfully to receive signals to characterize the scenario. This paper will describe the capability and highlight the cases of the critical communications for the Mars rovers and Saturn Orbit Insertion and preparation radio tracking of the Huygens probe at (non-DSN) radio telescopes.

  1. Communication in Animal Social Networks

    NARCIS (Netherlands)

    Snijders, Lysanne; Naguib, Marc

    2017-01-01

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

  2. Decomposition of network communication games

    NARCIS (Netherlands)

    Dietzenbacher, Bas; Borm, Peter; Hendrickx, Ruud

    Using network control structures, this paper introduces a general class of network communication games and studies their decomposition into unanimity games. We obtain a relation between the dividends in any network communication game and its underlying transferable utility game, which depends on the

  3. SOCIAL NETWORKS AND INTERPERSONAL COMMUNICATION

    OpenAIRE

    Veronica GHEORGHIȚĂ; Alexandrina PĂDUREȚU

    2014-01-01

    Social networks visible influence people's ability to interact and communicate. Extending social circles by establishing virtual links involves a number of positive aspects such as: instant access to options for interaction, sharing of information to large communities of people, intensification of acts of communication, high levels of feedback and trust with people with whom we communicate. On the other hand, social networks adversely affects communication by decreasing the interaction face t...

  4. Heterogeneous delivering capability promotes traffic efficiency in complex networks

    Science.gov (United States)

    Zhu, Yan-Bo; Guan, Xiang-Min; Zhang, Xue-Jun

    2015-12-01

    Traffic is one of the most fundamental dynamical processes in networked systems. With the homogeneous delivery capability of nodes, the global dynamic routing strategy proposed by Ling et al. [Phys. Rev. E81, 016113 (2010)] adequately uses the dynamic information during the process and thus it can reach a quite high network capacity. In this paper, based on the global dynamic routing strategy, we proposed a heterogeneous delivery allocation strategy of nodes on scale-free networks with consideration of nodes degree. It is found that the network capacity as well as some other indexes reflecting transportation efficiency are further improved. Our work may be useful for the design of more efficient routing strategies in communication or transportation systems.

  5. SOCIAL NETWORKS AND INTERPERSONAL COMMUNICATION

    Directory of Open Access Journals (Sweden)

    Veronica GHEORGHIȚĂ

    2014-11-01

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

  6. Enhanced sensing and communication via quantum networks

    Science.gov (United States)

    Smith, James F.

    2017-05-01

    A network based on quantum information has been developed to improve sensing and communications capabilities. Quantum teleportation offers features for communicating information not found in classical procedures. It is fundamental to the quantum network approach. A version of quantum teleportation based on hyper-entanglement is used to bring about these improvements. Recently invented methods of improving sensing and communication via quantum information based on hyper-entanglement are discussed. These techniques offer huge improvements in the SNR, signal to interference ratio, and time-on-target of various sensors including RADAR and LADAR. Hyper-entanglement refers to quantum entanglement in more than one degree of freedom, e.g. polarization, energy-time, orbital angular momentum (OAM), etc. The quantum network makes use of quantum memory located in each node of the network, thus the network forms a quantum repeater. The quantum repeater facilitates the use of quantum teleportation, and superdense coding. Superdense coding refers to the ability to incorporate more than one classical bit into each transmitted qubit. The network of sensors and/or communication devices has an enhanced resistance to interference sources. The repeater has the potential for greatly reducing loss in communications and sensor systems related to the effect of the atmosphere on fragile quantum states. Measures of effectiveness (MOEs) are discussed that show the utility of the network for improving sensing and communications in the presence of loss and noise. The quantum repeater will reduce overall size, weight, power and cost (SWAPC) of fielded components of systems.

  7. Intelligent Communication Module for Wireless Biosensor Networks

    OpenAIRE

    Naik, R.; Singh, J.; Le, H. P.

    2010-01-01

    This chapter presented a new paradigm of biosensors which have processing capability with an intelligent and adaptive wireless communication module. The adaptive communication module efficiently reconfigures its hardware components according to the changes in operating environment in order to reduce system power consumption and optimally utilise resources. The chapter presented several significant applications of wireless biosensor networks which hold enormous potential to benefit the communi...

  8. Computational capabilities of graph neural networks.

    Science.gov (United States)

    Scarselli, Franco; Gori, Marco; Tsoi, Ah Chung; Hagenbuchner, Markus; Monfardini, Gabriele

    2009-01-01

    In this paper, we will consider the approximation properties of a recently introduced neural network model called graph neural network (GNN), which can be used to process-structured data inputs, e.g., acyclic graphs, cyclic graphs, and directed or undirected graphs. This class of neural networks implements a function tau(G,n) is an element of IR(m) that maps a graph G and one of its nodes n onto an m-dimensional Euclidean space. We characterize the functions that can be approximated by GNNs, in probability, up to any prescribed degree of precision. This set contains the maps that satisfy a property called preservation of the unfolding equivalence, and includes most of the practically useful functions on graphs; the only known exception is when the input graph contains particular patterns of symmetries when unfolding equivalence may not be preserved. The result can be considered an extension of the universal approximation property established for the classic feedforward neural networks (FNNs). Some experimental examples are used to show the computational capabilities of the proposed model.

  9. Complex Dynamics in Communication Networks

    CERN Document Server

    Kocarev, Ljupco

    2005-01-01

    Computer and communication networks are among society's most important infrastructures. The internet, in particular, is a giant global network of networks without central control or administration. It is a paradigm of a complex system, where complexity may arise from different sources: topological structure, network evolution, connection and node diversity, or dynamical evolution. The present volume is the first book entirely devoted to the new and emerging field of nonlinear dynamics of TCP/IP networks. It addresses both scientists and engineers working in the general field of communication networks.

  10. Securing underwater wireless communication networks

    OpenAIRE

    Domingo Aladrén, Mari Carmen

    2011-01-01

    Underwater wireless communication networks are particularly vulnerable to malicious attacks due to the high bit error rates, large and variable propagation delays, and low bandwidth of acoustic channels. The unique characteristics of the underwater acoustic communication channel, and the differences between underwater sensor networks and their ground-based counterparts require the development of efficient and reliable security mechanisms. In this article, a compl...

  11. Topological Rankings in Communication Networks

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  12. Dynamic Pathloss Model for Future Mobile Communication Networks

    DEFF Research Database (Denmark)

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

    2016-01-01

    — Future mobile communication networks (MCNs) are expected to be more intelligent and proactive based on new capabilities that increase agility and performance. However, for any successful mobile network service, the dexterity in network deployment is a key factor. The efficiency of the network...

  13. MIMO Communication for Cellular Networks

    CERN Document Server

    Huang, Howard; Venkatesan, Sivarama

    2012-01-01

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

  14. Advancing Unmanned Aircraft Sensor Collection and Communication Capabilities with Optical Communications

    Science.gov (United States)

    Lukaczyk, T.

    2015-12-01

    Unmanned aircraft systems (UAS) are now being used for monitoring climate change over both land and seas. Their uses include monitoring of cloud conditions and atmospheric composition of chemicals and aerosols due to pollution, dust storms, fires, volcanic activity and air-sea fluxes. Additional studies of carbon flux are important for various ecosystem studies of both marine and terrestrial environments specifically, and can be related to climate change dynamics. Many measurements are becoming more complex as additional sensors become small enough to operate on more widely available small UAS. These include interferometric radars as well as scanning and fan-beam lidar systems which produce data streams even greater than those of high resolution video. These can be used to precisely map surfaces of the earth, ocean or ice features that are important for a variety of earth system studies. As these additional sensor capabilities are added to UAS the ability to transmit data back to ground or ship monitoring sites is limited by traditional wireless communication protocols. We describe results of tests of optical communication systems that provide significantly greater communication bandwidths for UAS, and discuss both the bandwidth and effective range of these systems, as well as their power and weight requirements both for systems on UAS, as well as those of ground-based receiver stations. We justify our additional use of Delay and Disruption Tolerant Networking (DTN) communication protocols with optical communication methods to ensure security and continuity of command and control operations. Finally, we discuss the implications for receiving, geo-referencing, archiving and displaying data streams from sensors communicated via optical communication to better enable real-time anomaly detection and adaptive sampling capabilities using multiple UAS or other unmanned or manned systems.

  15. Emerging trends in communication networks

    CERN Document Server

    Hasan, Syed Faraz

    2014-01-01

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

  16. EPA Library Network Communication Strategies

    Science.gov (United States)

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

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

    Science.gov (United States)

    McNeal, McKenzie, III.

    2012-01-01

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

  18. Fourth international conference on Networks & Communications

    CERN Document Server

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

    2013-01-01

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

  19. Communicating embedded systems networks applications

    CERN Document Server

    Krief, Francine

    2013-01-01

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

  20. Challenges of Integrating NASAs Space Communication Networks

    Science.gov (United States)

    Reinert, Jessica M.; Barnes, Patrick

    2013-01-01

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

  1. Challenges of Integrating NASA's Space Communications Networks

    Science.gov (United States)

    Reinert, Jessica; Barnes, Patrick

    2013-01-01

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

  2. Overview of covert communications through networks

    Science.gov (United States)

    Caloyannides, Michael A.

    2002-08-01

    Covert communications through digital networks are a small subset of covert channel communications through all other networks such as human contacts, postal, telephone, ham radio and other networks. The repertoire of options available to anyone for covert communications through digital networks is limited only by imagination; covert communications are therefore inherently uncontrollable.

  3. Flexible Next Generation Communication Networks

    Directory of Open Access Journals (Sweden)

    Konstantinos Demestichas

    2013-12-01

    Full Text Available The increasing bandwidth demand of the end-users makes the need for efficient resource management more compelling in next generation communication networks. Nowadays, the mobile communications scenery is characterized by the continuous growth of new services, the provision of which poses the need for higher data rates to guarantee satisfactory quality of experience for the end-users. The advent of evolved mobile communication networks (such as LTE - Long Term Evolution promises to encounter this demand by offering increased capacity, high data rates, seamless mobility and low latency. Nonetheless, during this evolutionary process, the backhaul part of mobile networks has received less attention. This paper discusses on ways for further evolution of mobile networks by rendering backhaul connectivity more flexible, robust and self-aware.

  4. RELATIONSHIPS AND COMMUNICATION NETWORKS

    OpenAIRE

    Stefan VLADUTESCU

    2012-01-01

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

  5. A vision of network-centric military communications

    Science.gov (United States)

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

    2005-05-01

    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.

  6. Epidermal electronics with advanced capabilities in near-field communication.

    Science.gov (United States)

    Kim, Jeonghyun; Banks, Anthony; Cheng, Huanyu; Xie, Zhaoqian; Xu, Sheng; Jang, Kyung-In; Lee, Jung Woo; Liu, Zhuangjian; Gutruf, Philipp; Huang, Xian; Wei, Pinghung; Liu, Fei; Li, Kan; Dalal, Mitul; Ghaffari, Roozbeh; Feng, Xue; Huang, Yonggang; Gupta, Sanjay; Paik, Ungyu; Rogers, John A

    2015-02-25

    Epidermal electronics with advanced capabilities in near field communications (NFC) are presented. The systems include stretchable coils and thinned NFC chips on thin, low modulus stretchable adhesives, to allow seamless, conformal contact with the skin and simultaneous capabilities for wireless interfaces to any standard, NFC-enabled smartphone, even under extreme deformation and after/during normal daily activities. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Beliefs dynamics in communication networks

    NARCIS (Netherlands)

    Azomahou, T.T.; Opolot, D.

    2014-01-01

    We study the dynamics of individual beliefs and information aggregation when agents communicate via a social network. We provide a general framework of social learning that captures the interactive effects of three main factors on the structure of individual beliefs resulting from such a dynamic

  8. Fifth International Conference on Networks & Communications

    CERN Document Server

    Nagamalai, Dhinaharan; Rajasekaran, Sanguthevar

    2014-01-01

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

  9. Using networking and communications software in business

    CERN Document Server

    McBride, PK

    2014-01-01

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

  10. Communication Policies in Knowledge Networks

    Science.gov (United States)

    Ioannidis, Evangelos; Varsakelis, Nikos; Antoniou, Ioannis

    2018-02-01

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

  11. A network for development communication.

    Science.gov (United States)

    Bessette, G

    1996-01-01

    With the goal to promote a type of development that requires its beneficiaries to assume responsibility for it, the International Development Research Center (IDRC) set up a program in West Africa focusing on communication as a development tool within communities. The program is specifically designed for nongovernmental organizations (NGOs) in nine countries in the region. The NGOs defined five basic elements for improving communication to promote better development in their area which include training, basic education, conditions favoring success, traditional communication, and increasing recognition of the African woman. The program, which will be implemented in early 1996, is aimed at creating a network in participatory development communication. This program enables NGOs to undertake numerous research activities related to the program, bring their activities to the attention of communities, and learn better ways of helping the communities to take part in their own development.

  12. Rattlesnake: a network for real-time Multimedia Communication

    NARCIS (Netherlands)

    Smit, Gerardus Johannes Maria; Havinga, Paul J.M.; Smit, Michel J.P.; Smit, M.J.P.

    1992-01-01

    In this extended abstract we describe the design of a local area network suitable for distributed multimedia communications. Multimedia applications require a communication infrastructure with capabilities beyond the current state of the art : real-time stream traffic, small end-to-end latency with

  13. Rattlesnake: A Network for Real-Time Multimedia Communications

    NARCIS (Netherlands)

    Smit, Gerardus Johannes Maria; Havinga, Paul J.M.; Smit, M.J.P.; Smit, Michel J.P.

    In this extended abstract we describe the design of a local area network suitable for distributed multimedia communications. Multimedia applications require a communication infrastructure with capabilities beyond the current state of the art : real-time stream traffic, small end-to-end latency with

  14. Applied data communications and networks

    CERN Document Server

    Buchanan, W

    1996-01-01

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

  15. Communications in interference limited networks

    CERN Document Server

    2016-01-01

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

  16. Information communication on complex networks

    Science.gov (United States)

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

    2013-02-01

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

  17. COMMUNICATION MANAGEMENT CRISIS IN SOCIAL NETWORKS

    Directory of Open Access Journals (Sweden)

    Ana Mª Enrique Jiménez

    2013-04-01

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

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

    Science.gov (United States)

    Buttles, John W

    2013-04-23

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

  19. A Novel Frequency Communication Technology in Power Distribution Communication Network

    OpenAIRE

    Li Ying-Jun

    2017-01-01

    With the expansion of the power terminal access network scale, the main road corridor resources, branch line cable Laying difficulties has become an important factor restricting the construction of the network. In this paper, we focus on the frequency communication technology in power distribution communication network, and design a novel technology in communication mode, error correcting coding and data transfer frame format. We also discuss the influence of voltage phase difference on power...

  20. TCP Performance over Gigabit-Capable Passive Optical Networks

    Science.gov (United States)

    Orozco, Julio; Ros, David

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

  1. Building capability through networking with investors and researchers

    DEFF Research Database (Denmark)

    Wang, Daojuan; Schøtt, Thomas

    A startup requires financing, typically, and the startup is based on innovation, often. Capabilities for innovation and financing may be built simultaneously and created jointly at inception. Co-creation of capabilities for financing and innovation is accounted for in this study. Co...... of startups at inception, by 9,161 entrepreneurs, surveyed in Global Entrepreneurship Monitor in 49 countries. Co-creation is found to be reduced by the entrepreneur’s networking in the private sphere of family and friends, but to be benefiting from networking in the public sphere, especially by networking...... with investors and researchers simultaneously. The findings contribute to understanding capability building as embedded in networks around the startup....

  2. PIPELINES AS COMMUNICATION NETWORK LINKS

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-03-14

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

  3. GAS MAIN SENSOR AND COMMUNICATIONS NETWORK SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Hagen Schempf

    2004-09-30

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

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

    African Journals Online (AJOL)

    Despite the rapid growth in the use of modern communication media to improve access to agricultural information, local information networks remain an important means of communication among rural folk. This study examined informal communication networks of rural farmers in the Ahafo Ano south district of Ghana to ...

  5. Evaluation of maritime emergency rescue capability based on network analysis

    Science.gov (United States)

    Haixiang, Pang; Yijia, Ma; Tianyu, Mao; Shengjing, Liu; Yajie, Zhang

    2017-12-01

    Maritime emergency rescue operations are complex and random, it leads to the complexity of the evaluation of maritime emergency rescue capability. In this paper, we considered the relationship between the evaluation indexes of maritime emergency rescue capability, used Analytic Network Process to determine the weight of each index, took into account the feedback relationship between indicators to determine the index weight, improved the scientific and reliability of the model, and combined with fuzzy comprehensive evaluation to evaluate the rescue capability. According to the evaluation results which combined with the index weight, maritime sector can propose a targeted improvement measures to effectively improve maritime emergency rescue capability.

  6. Digital associative memory neural network with optical learning capability

    Science.gov (United States)

    Watanabe, Minoru; Ohtsubo, Junji

    1994-12-01

    A digital associative memory neural network system with optical learning and recalling capabilities is proposed by using liquid crystal television spatial light modulators and an Optic RAM detector. In spite of the drawback of the limited memory capacity compared with optical analogue associative memory neural network, the proposed optical digital neural network has the advantage of all optical learning and recalling capabilities, thus an all optics network system is easily realized. Some experimental results of the learning and the recalling for character recognitions are presented. This new optical architecture offers compactness of the system and the fast learning and recalling properties. Based on the results, the practical system for the implementation of a faster optical digital associative memory neural network system with ferro-electric liquid crystal SLMs is also proposed.

  7. Explore the Capability of ESPAR Antennas for Low Cost Communication

    DEFF Research Database (Denmark)

    Han, Bo; Kalis, A; Papadias, C.

    . However, for higher modulation schemes like 16-QAM, more radiation patterns are needed which require a wider control range on the parasitic antenna load. In order to explore the capability of ESPAR antennas, negative resistance was proposed, but their values cannot be easily controlled both on the real...... and imaginary part. So a matching network is required to control the load value. This paper presents an idea of adjusting the parasitic ESPAR antenna loads with controllable passive elements. According to simulation, the control circuit consumes less than 1mW power on 64 patterns selection, which explores...

  8. Data Farming Process and Initial Network Analysis Capabilities

    Directory of Open Access Journals (Sweden)

    Gary Horne

    2016-01-01

    Full Text Available Data Farming, network applications and approaches to integrate network analysis and processes to the data farming paradigm are presented as approaches to address complex system questions. Data Farming is a quantified approach that examines questions in large possibility spaces using modeling and simulation. It evaluates whole landscapes of outcomes to draw insights from outcome distributions and outliers. Social network analysis and graph theory are widely used techniques for the evaluation of social systems. Incorporation of these techniques into the data farming process provides analysts examining complex systems with a powerful new suite of tools for more fully exploring and understanding the effect of interactions in complex systems. The integration of network analysis with data farming techniques provides modelers with the capability to gain insight into the effect of network attributes, whether the network is explicitly defined or emergent, on the breadth of the model outcome space and the effect of model inputs on the resultant network statistics.

  9. Building capability through networking with investors and researchers

    DEFF Research Database (Denmark)

    Wang, Daojuan; Schøtt, Thomas

    -creation is embedded in the network around the starting entrepreneur, we expect. Co-creation benefits from networking with potential investors and with researchers and inventors, we hypothesize, and especially by networking with both investors and researchers concurrently. Co-creation is analyzed in a sample...... of startups at inception, by 9,161 entrepreneurs, surveyed in Global Entrepreneurship Monitor in 49 countries. Co-creation is found to be reduced by the entrepreneur’s networking in the private sphere of family and friends, but to be benefiting from networking in the public sphere, especially by networking...... with investors and researchers simultaneously. The findings contribute to understanding capability building as embedded in networks around the startup....

  10. Terminal-oriented computer-communication networks.

    Science.gov (United States)

    Schwartz, M.; Boorstyn, R. R.; Pickholtz, R. L.

    1972-01-01

    Four examples of currently operating computer-communication networks are described in this tutorial paper. They include the TYMNET network, the GE Information Services network, the NASDAQ over-the-counter stock-quotation system, and the Computer Sciences Infonet. These networks all use programmable concentrators for combining a multiplicity of terminals. Included in the discussion for each network is a description of the overall network structure, the handling and transmission of messages, communication requirements, routing and reliability consideration where applicable, operating data and design specifications where available, and unique design features in the area of computer communications.

  11. Ad-hoc networking towards seamless communications

    CERN Document Server

    Gavrilovska, Liljana

    2006-01-01

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

  12. Maritime wideband communication networks video transmission scheduling

    CERN Document Server

    Yang, Tingting

    2014-01-01

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

  13. Wireless communications networks for the smart grid

    CERN Document Server

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

    2014-01-01

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

  14. Social networks: communication and change

    Directory of Open Access Journals (Sweden)

    Gustavo Cardoso

    2011-01-01

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

  15. Interference suppression capabilities of smart cognitive-femto networks (SCFN)

    KAUST Repository

    Shakir, Muhammad

    2013-01-01

    Cognitive Radios are considered a standard part of future heterogeneous mobile network architectures. In this chapter, a two tier heterogeneous network with multiple Radio Access Technologies (RATs) is considered, namely (1) the secondary network, which comprises of Cognitive-Femto BS (CFBS), and (2) the macrocell network, which is considered a primary network. By exploiting the cooperation among the CFBS, the multiple CFBS can be considered a single base station with multiple geographically dispersed antennas, which can reduce the interference levels by directing the main beam toward the desired femtocell mobile user. The resultant network is referred to as Smart Cognitive-Femto Network (SCFN). In order to determine the effectiveness of the proposed smart network, the interference rejection capabilities of the SCFN is studied. It has been shown that the smart network offers significant performance improvements in interference suppression and Signal to Interference Ratio (SIR) and may be considered a promising solution to the interference management problems in future heterogeneous networks. © 2013, IGI Global.

  16. Effects of Network Capabilities on Firm Performance across Cultures

    Directory of Open Access Journals (Sweden)

    Papastamatelou Julie

    2016-03-01

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

  17. Advanced Communication and Networking Technologies for Mars Exploration

    Science.gov (United States)

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

    2001-01-01

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

  18. Intercultural Communication in Online Social Networking Discourse

    Science.gov (United States)

    Chen, Hsin-I

    2017-01-01

    This article presents a case study that examines how an online social networking community is constituted through intercultural discourse on the part of one learner sojourning in the US. Using Byram's model of intercultural communicative competence, this study examines the learner's naturalistic communication in a social networking site (SNS). The…

  19. Real-Time Communication Networks Onboard Ships

    DEFF Research Database (Denmark)

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

    1995-01-01

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

  20. Future networks and technologies supporting innovative communications

    DEFF Research Database (Denmark)

    Prasad, Ramjee

    2012-01-01

    and applications. This paper focuses on the technological aspects of ubiquitous networking and communication technologies, including challenges related to green communications, and security, privacy and trust. The paper proposes a novel concept for a Wireless Innovative System for Dynamically Operating Mega......-communications (WISDOM) that combines the aspects of personal- and cognitive radio- networks to let seamlessly bridge the virtual and physical worlds offering a constant level of all-senses, context-based, rich communication experience over fixed and wireless networks for the end users while realizing a new generation...

  1. Effective Protocols for Mobile Communications and Networking

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-12-01

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

  2. Communication and Networking in Smart Grids

    CERN Document Server

    Xiao, Yang

    2012-01-01

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

  3. Optimal configuration of digital communication network

    Science.gov (United States)

    Hwang, Yong G.

    1990-12-01

    As the costs for maintaining computer communication networks are rapidly rising, it is particularly important to design the network efficiently. The objective of this thesis is to model the minimum cost design of digital communications networks and propose a heuristical solution approach to the formulated model. The minimum cost design has been modeled as a zero-one integer programming problem. The Lagrangian relaxation method and subgradient optimization procedure have been used to find reasonably good feasible solutions. Although the reliability for computer communication networks is as important as the cost factor, only the cost factor is considered in the context of this thesis.

  4. A Simplified Mobile Ad Hoc Network Structure for Helicopter Communication

    Directory of Open Access Journals (Sweden)

    Abdeldime Mohamed Salih Abdelgader

    2016-01-01

    Full Text Available There are a number of volunteer and statutory organizations who are capable of conducting an emergency response using helicopters. Rescue operations require a rapidly deployable high bandwidth network to coordinate necessary relief efforts between rescue teams on the ground and helicopters. Due to massive destruction and loss of services, ordinary communication infrastructures may collapse in these situations. Consequently, information exchange becomes one of the major challenges in these circumstances. Helicopters can be also employed for providing many services in rugged environments, military applications, and aerial photography. Ad hoc network can be used to provide alternative communication link between a set of helicopters, particularly in case of significant amount of data required to be shared. This paper addresses the ability of using ad hoc networks to support the communication between a set of helicopters. A simplified network structure model is presented and extensively discussed. Furthermore, a streamlined routing algorithm is proposed. Comprehensive simulations are conducted to evaluate the proposed routing algorithm.

  5. On collaborative anonymous communications in lossy networks

    OpenAIRE

    Rebollo-Monedero, David; Forné Muñoz, Jorge; Pallarès Segarra, Esteve; Parra-Arnau, Javier; Tripp Barba, Carolina; Urquiza Aguiar, Luis; Aguilar Igartua, Mónica

    2013-01-01

    Message encryption does not prevent eavesdroppers from unveiling who is communicating with whom, when, or how frequently, a privacy risk wireless networks are particularly vulnerable to. The Crowds protocol, a well-established anonymous communication system, capitalizes on user collaboration to enforce sender anonymity. This work formulates a mathematical model of a Crowd-like protocol for anonymous communication in a lossy network, establishes quantifiable metrics of anonymity and quality of...

  6. Gas Main Sensor and Communications Network System

    Energy Technology Data Exchange (ETDEWEB)

    Hagen Schempf

    2006-05-31

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

  7. Corporate Communication in the Network Economy

    DEFF Research Database (Denmark)

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

    This paper draws on ideas in economics and game theory to develop a new theory of marketing and corporate communication in the emerging network economy. We argue that in a network economy, firms and consumers will confront `coordination problems.' With the emerging network economy all this become...... a simple game theoretic model to explain this, and discuss marketing applications and possible strategies.Key wordsCoordination problems, common knowledge, corporate communication...

  8. Global operations networks in motion: Managing configurations and capabilities

    DEFF Research Database (Denmark)

    Slepniov, Dmitrij; Wæhrens, Brian Vejrum; Jørgensen, Claus

    2010-01-01

    In the past, the ‘Made in the World’ label, although capturing what may lie ahead, seemed awkward and futuristic. Today, it has become a reality. An ample array of global products are built up of numerous components and modules manufactured by global networks of differentiated partners rather than...... within the boundaries of one national entity. The purpose of this paper is to contribute to bridging the empirical gap in the area of global operations networks and provide insights into how they change over time. The paper is based on the cases of three Danish companies and their global operations...... networks. It finds a number of common patterns highlighting organizational effects and managerial challenges faced by the companies regarding rapid changes in their networks configurations and capabilities. The paper details the variables determining these changes and suggests how the on-going interplay...

  9. Modeling data throughput on communication networks

    Energy Technology Data Exchange (ETDEWEB)

    Eldridge, J.M.

    1993-11-01

    New challenges in high performance computing and communications are driving the need for fast, geographically distributed networks. Applications such as modeling physical phenomena, interactive visualization, large data set transfers, and distributed supercomputing require high performance networking [St89][Ra92][Ca92]. One measure of a communication network`s performance is the time it takes to complete a task -- such as transferring a data file or displaying a graphics image on a remote monitor. Throughput, defined as the ratio of the number of useful data bits transmitted per the time required to transmit those bits, is a useful gauge of how well a communication system meets this performance measure. This paper develops and describes an analytical model of throughput. The model is a tool network designers can use to predict network throughput. It also provides insight into those parts of the network that act as a performance bottleneck.

  10. Neural network modeling of a dolphin's sonar discrimination capabilities

    DEFF Research Database (Denmark)

    Andersen, Lars Nonboe; René Rasmussen, A; Au, WWL

    1994-01-01

    The capability of an echo-locating dolphin to discriminate differences in the wall thickness of cylinders was previously modeled by a counterpropagation neural network using only spectral information of the echoes [W. W. L. Au, J. Acoust. Soc. Am. 95, 2728–2735 (1994)]. In this study, both time...... and frequency information were used to model the dolphin discrimination capabilities. Echoes from the same cylinders were digitized using a broadband simulated dolphin sonar signal with the transducer mounted on the dolphin's pen. The echoes were filtered by a bank of continuous constant-Q digital filters...

  11. Communication on the structure of biological networks

    Indian Academy of Sciences (India)

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

  12. Communication-Free Distributed Coverage for Networked Systems

    KAUST Repository

    Yazicioglu, A. Yasin

    2016-01-15

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

  13. The National Biomedical Communications Network as a Developing Structure *

    Science.gov (United States)

    Davis, Ruth M.

    1971-01-01

    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. PMID:5542912

  14. The handbook of optical communication networks

    CERN Document Server

    Ilyas, Mohammad

    2003-01-01

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

  15. Evaluation of communication in wireless underground sensor networks

    Science.gov (United States)

    Yu, X. Q.; Zhang, Z. L.; Han, W. T.

    2017-06-01

    Wireless underground sensor networks (WUSN) are an emerging area of research that promises to provide communication capabilities to buried sensors. In this paper, experimental measurements have been conducted with commodity sensor motes at the frequency of 2.4GHz and 433 MHz, respectively. Experiments are run to examine the received signal strength of correctly received packets and the packet error rate for a communication link. The tests show the potential feasibility of the WUSN with the use of powerful RF transceivers at 433MHz frequency. Moreover, we also illustrate a classification for wireless underground sensor network communication. Finally, we conclude that the effects of burial depth, inter-node distance and volumetric water content of the soil on the signal strength and packet error rate in communication of WUSN.

  16. Location of terminals in a communications network

    DEFF Research Database (Denmark)

    2015-01-01

    A method (400, 500) of identifying nodes in a communications network is disclosed, the nodes being for use in locating wireless terminals within the network based upon reports from the wireless terminals of transmissions received from the nodes. The method (400, 500) comprises prioritising......, a reference node. Also disclosed is a method (100, 200) for locating a plurality of wireless terminals in a communications network, the network comprising a plurality of network nodes at known locations, wherein the nodes emit wireless transmissions in an unsynchronised manner, such that a time difference...... exists between the emission time of corresponding transmissions from different nodes. The method comprises receiving reports from a plurality of wireless terminals of transmissions received from the network nodes (110, 210), selecting a subset of network nodes (120, 220) and identifying a plurality...

  17. Stochastic modelling and control of communication networks

    NARCIS (Netherlands)

    Zuraniewski, P.W.

    2011-01-01

    The unprecedented growth of the Information Technologies sector observed within the past years creates an excellent opportunity to conduct new, exciting and interdisciplinary research. Increasing complexity of the communication networks calls for incorporating rigorously developed and reliable

  18. Message transfer in a communication network

    Indian Academy of Sciences (India)

    We study message transfer in a 2-d communication network of regular nodes and randomly distributed hubs. ... The substrate model on which message communication takes place is shown in figure 1a. This is a regular ..... and run time of 4Dst when various decongestion strategies are applied. In. (a) the waiting time ...

  19. Information and Communication Network Among Natural Scientists ...

    African Journals Online (AJOL)

    This study tries to find out the extent of information and communication networks among natural scientists in Ahmadu Bello University, Zaria. Their ways of information sharing, and the extent of their participation in information networking were investigated. Using two (2) research questions, data was collected from 299 pure ...

  20. Evolutionary dynamics of complex communications networks

    CERN Document Server

    Karyotis, Vasileios; Papavassiliou, Symeon

    2013-01-01

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

  1. Voice communication capability of selected inflight headgear devices

    Science.gov (United States)

    McKinley, R. L.; Nixon, C. W.; Moore, T. J.

    1981-06-01

    The voice communication effectiveness (MRT word intelligibility) of selected Air Force communications terminal equipment was evaluated in simulated operational noise environments. Analyses of the resulting data indicate: standard AF communications headsets H-133, HGU-26/P and H-157 performed in a manner consistent with their purposes with the H-133 providing the best communication, the HGU-26/P second and the H-157 third; percent correct intelligibility in the 115 dB noise condition was reduced as much as 15% for the H-133 and 50% for the H-157 over the ambient noise condition; communication performance varied over 5 to 10 percent when used with the AIC vs the AIC and RF radio; and the UK chemical defense hood provided a slightly better talking environment than the MBU-5/P and a worse listening environment than the HGU-26/P.

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

    Directory of Open Access Journals (Sweden)

    Zhang Hongliang

    2018-01-01

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

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

    African Journals Online (AJOL)

    The massive growth of electronic commerce represent a new set of vulnerabilities aimed at the distortion, disruption, and destruction of the global and national information infrastructures, and are indeed significant threats to the integrity of networked systems. This paper investigates the perception of communication network ...

  4. Reusable Social Networking Capabilities for an Earth Science Collaboratory

    Science.gov (United States)

    Lynnes, C.; Da Silva, D.; Leptoukh, G. G.; Ramachandran, R.

    2011-12-01

    A vast untapped resource of data, tools, information and knowledge lies within the Earth science community. This is due to the fact that it is difficult to share the full spectrum of these entities, particularly their full context. As a result, most knowledge exchange is through person-to-person contact at meetings, email and journal articles, each of which can support only a limited level of detail. We propose the creation of an Earth Science Collaboratory (ESC): a framework that would enable sharing of data, tools, workflows, results and the contextual knowledge about these information entities. The Drupal platform is well positioned to provide the key social networking capabilities to the ESC. As a proof of concept of a rich collaboration mechanism, we have developed a Drupal-based mechanism for graphically annotating and commenting on results images from analysis workflows in the online Giovanni analysis system for remote sensing data. The annotations can be tagged and shared with others in the community. These capabilities are further supplemented by a Research Notebook capability reused from another online analysis system named Talkoot. The goal is a reusable set of modules that can integrate with variety of other applications either within Drupal web frameworks or at a machine level.

  5. Capability-based Access Control Delegation Model on the Federated IoT Network

    DEFF Research Database (Denmark)

    Anggorojati, Bayu; Mahalle, Parikshit N.; Prasad, Neeli R.

    2012-01-01

    Flexibility is an important property for general access control system and especially in the Internet of Things (IoT), which can be achieved by access or authority delegation. Delegation mechanisms in access control that have been studied until now have been intended mainly for a system that has...... no resource constraint, such as a web-based system, which is not very suitable for a highly pervasive system such as IoT. To this end, this paper presents an access delegation method with security considerations based on Capability-based Context Aware Access Control (CCAAC) model intended for federated...... machine-to-machine communication or IoT networks. The main idea of our proposed model is that the access delegation is realized by means of a capability propagation mechanism, and incorporating the context information as well as secure capability propagation under federated IoT environments. By using...

  6. Antecedents of network capability and their effects on innovation performance: an empirical test of hi-tech firms in China

    NARCIS (Netherlands)

    Fang, Gang; Ma, Xiang Yuan; Brouwers-Ren, Liqin; Zhou, Qing

    2014-01-01

    A firm’s competitive advantage can come not only from internal resources but also from inter-firm innovation networks. This paper shows that network capabilities (i.e., network visioning capability, network constructing capability, network operating capability and network centring capability) are

  7. On the interference suppression capabilities of cognitive enabled femto cellular networks

    KAUST Repository

    Shakir, Muhammad

    2012-06-01

    Cognitive Radios are considered as a standard part of future Heterogeneous mobile network architecture. In this paper, we consider a two tier Heterogeneous network with multiple radio access technologies (RATS) namely; (i) the secondary network which comprises of cognitive enabled femto base stations which are referred to as cognitive-femto BS (CFBS) such that each of the BS are equipped with a single antenna and (ii) the macrocell network which is considered as a primary network. The effectiveness of the cognitive transmission is based on the efficient spectrum sensing algorithms which determine the availability of the spectrum holes. However, it is equally important for the cognitive network to minimize the cross-tier interference particularly during (i) the spectrum sensing and (ii) the cognitive transmission if spectrum is available. By exploiting the cooperation among the CFBS, the multiple CFBS can be considered as a single base station with multiple geographically dispersed antennas. In this context, we proposed a smart network where CFBS collaborates to reduce the cross-tier interference level by directing the main beam toward the desired femtocell mobile user and creating toward the cross-tier interference. The resultant network is referred to as Smart cognitive-femto network (SCFN) which requires the CFBS to be self-aware such that the CFBS are aware of their surroundings and adapt accordingly to maintain a reliable and efficient communication link. In order to determine the effectiveness of the proposed smart network, we study the interference rejection (or suppression) capabilities of the SCFN. It has been shown that the proposed smart network offers significant performance improvements in interference suppression and signal to interference ratio (SIR) and may be considered as a promising solution to the interference management problems in Heterogeneous network. © 2012 IEEE.

  8. Secure and Authenticated Data Communication in Wireless Sensor Networks.

    Science.gov (United States)

    Alfandi, Omar; Bochem, Arne; Kellner, Ansgar; Göge, Christian; Hogrefe, Dieter

    2015-08-10

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

  9. Communication networks for the tactical edge

    Science.gov (United States)

    Evans, Joseph B.; Pennington, Steven G.; Ewy, Benjamin J.

    2017-04-01

    Information at the tactical level is increasingly critical in today's conflicts. The proliferation of commercial tablets and smart phones has created the ability for extensive information sharing at the tactical edge, beyond the traditional tactical voice communications and location information. This is particularly the case in Gray Zone conflicts, in which tactical decision making and actions are intertwined with information sharing and exploitation. Networking of tactical devices is the key to this information sharing. In this work, we detail and analyze two network models at different parts of the Gray Zone spectrum, and explore a number of networking options including Named Data Networking. We also compare networking approaches in a variety of realistic operating environments. Our results show that Named Data Networking is a good match for the disrupted networking environments found in many tactical situations

  10. Noise-enhanced classical and quantum capacities in communication networks.

    Science.gov (United States)

    Caruso, Filippo; Huelga, Susana F; Plenio, Martin B

    2010-11-05

    The unavoidable presence of noise is thought to be one of the major problems to solve in order to pave the way for implementing quantum information technologies in realistic physical platforms. However, here we show a clear example in which noise, in terms of dephasing, may enhance the capability of transmitting not only classical but also quantum information, encoded in quantum systems, through communication networks. In particular, we find analytically and numerically the quantum and classical capacities for a large family of quantum channels and show that these information transmission rates can be strongly enhanced by introducing dephasing noise in the complex network dynamics.

  11. How Chinese Semantics Capability Improves Interpretation in Visual Communication

    Science.gov (United States)

    Cheng, Chu-Yu; Ou, Yang-Kun; Kin, Ching-Lung

    2017-01-01

    A visual representation involves delivering messages through visually communicated images. The study assumed that semantic recognition can affect visual interpretation ability, and the result showed that students graduating from a general high school achieve satisfactory results in semantic recognition and image interpretation tasks than students…

  12. Intracity Quantum Communication via Thermal Microwave Networks

    Science.gov (United States)

    Xiang, Ze-Liang; Zhang, Mengzhen; Jiang, Liang; Rabl, Peter

    2017-01-01

    Communication over proven-secure quantum channels is potentially one of the most wide-ranging applications of currently developed quantum technologies. It is generally envisioned that in future quantum networks, separated nodes containing stationary solid-state or atomic qubits are connected via the exchange of optical photons over large distances. In this work, we explore an intriguing alternative for quantum communication via all-microwave networks. To make this possible, we describe a general protocol for sending quantum states through thermal channels, even when the number of thermal photons in the channel is much larger than 1. The protocol can be implemented with state-of-the-art superconducting circuits and enables the transfer of quantum states over distances of about 100 m via microwave transmission lines cooled to only T =4 K . This opens up new possibilities for quantum communication within and across buildings and, consequently, for the implementation of intracity quantum networks based on microwave technology only.

  13. Case studies of attacks on communication networks

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-06-15

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

  14. Green networking and communications ICT for sustainability

    CERN Document Server

    Khan, Shafiullah

    2013-01-01

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

  15. Professional networking using computer-mediated communication.

    Science.gov (United States)

    Washer, Peter

    Traditionally, professionals have networked with others in their field through attending conferences, professional organizations, direct mailing, and via the workplace. Recently, there have been new possibilities to network with other professionals using the internet. This article looks at the possibilities that the internet offers for professional networking, particularly e-mailing lists, newsgroups and membership databases, and compares them against more traditional methods of professional networking. The different types of computer-mediated communication are discussed and their relative merits and disadvantages are examined. The benefits and potential pitfalls of internet professional networking, as it relates to the nursing profession, are examined. Practical advice is offered on how the internet can be used as a means to foster professional networks of academic, clinical or research interests.

  16. A Capability Maturity Framework for Sustainable Information and Communication Technology

    OpenAIRE

    Donnellan, Brian; Sheridan, Charles; Curry, Edward

    2011-01-01

    Researchers estimate that information and communication technology (ICT) is responsible for at least 2 percent of global greenhouse gas (GHG) emissions. Furthermore, in any individual business, ICT is responsible for a much higher percentage of that business's GHG footprint. Yet researchers also estimate that ICT can provide business solutions to reduce its GHG footprint fivefold. However, because the field is new and evolving, few guidelines and best practices are available. To address this ...

  17. Integrating Cellular Handset Capabilities with Military Wireless Communications

    Science.gov (United States)

    2010-06-01

    open source OpenBTS software on a Linux computer with attached SDR ( USRP v1). The OpenBTS software provided the BTS capability, when concurrently...change (PBX) requirement. GNURadio was installed and initiated as the signal processing package ( USRP initiator). A VoIP client was installed to...initiate voice calls from the com- puter. The most relevant hardware difference between our tactical radios and the USRP configuration appears to be the

  18. Content Delivery in Future Mobile Communication Networks

    Science.gov (United States)

    Jonas, Karl; Raber, Sergey

    2003-07-01

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

  19. Social networks: communication and change

    OpenAIRE

    Cardoso, Gustavo; Lamy, Cláudia

    2011-01-01

    Virtual social networks have brought about the possibility for open and plural debate, where all those with the necessary literacy skills and means are able to participate in the creation and dissemination of information. By pressing political agents and determining the “agenda” of a lot of the media, users demonstrate that we stand at an ideal platform for creating both real social movements and more or less fleeting events, as manifestos or virtual campaigns. Nonetheless, in order to under...

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

    CERN Document Server

    Ma, Maode

    2012-01-01

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

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

    African Journals Online (AJOL)

    AJRH Managing Editor

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

  2. Communication network for telemedicine | Debretsion | Zede Journal

    African Journals Online (AJOL)

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

  3. Message transfer in a communication network

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 70; Issue 6. Message transfer in a communication network. Satyam Mukherjee ... a rapid drop in the average travel time as a function of hub density. This power-law tail arises as a consequence of the log-normal distribution of travel times seen at high hub densities.

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

    African Journals Online (AJOL)

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

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

    African Journals Online (AJOL)

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

  6. Protocol for Communication Networking for Formation Flying

    Science.gov (United States)

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

    2009-01-01

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

  7. Military Communications and Networks (Communications et reseaux militaires)

    Science.gov (United States)

    2010-09-01

    déroulé conjointement avec la Conférence sur l’information et la Communication Militaires (CCM), conférence reconnue qui réunit la plupart des experts...over the air measurements. Fisher offered a system approach to analysing the necessary waveforms, no results or recommendations were offered. The...problem in MANETs using IPv6 and presented results for a physically deployed network at DGA France. The penultimate paper 20 analysed the

  8. Experimental integration of quantum key distribution and gigabit-capable passive optical network

    Science.gov (United States)

    Sun, Wei; Wang, Liu-Jun; Sun, Xiang-Xiang; Mao, Yingqiu; Yin, Hua-Lei; Wang, Bi-Xiao; Chen, Teng-Yun; Pan, Jian-Wei

    2018-01-01

    Quantum key distribution (QKD) ensures information-theoretic security for the distribution of random bits between two remote parties. To extend QKD applications to fiber-to-the-home optical communications, such as gigabit-capable passive optical networks (GPONs), an effective method is the use of wavelength-division multiplexing. However, the Raman scattering noise from intensive classical traffic and the huge loss introduced by the beam splitter in a GPON severely limits the performance of QKD. Here, we demonstrate the integration of QKD and a commercial GPON system with fiber lengths up to 14 km, in which the maximum splitting ratio of the beam splitter reaches 1:64. By placing the QKD transmitter on the optical line terminal side, we reduce the Raman noise collected at the QKD receiver. Using a bypass structure, the loss of the beam splitter is circumvented effectively. Our results pave the way to extending the applications of QKD to last-mile communications.

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

    Science.gov (United States)

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

    2016-01-01

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

  10. Energy, Entropy and Exergy in Communication Networks

    Directory of Open Access Journals (Sweden)

    Slavisa Aleksic

    2013-10-01

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

  11. Performance Analysis of 3G Communication Network

    Directory of Open Access Journals (Sweden)

    Toni Anwar

    2013-09-01

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

  12. Communication through resonance in spiking neuronal networks.

    Science.gov (United States)

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

    2014-08-01

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

  13. The Complementary Effects of Empathy and Nonverbal Communication Training on Persuasion Capabilities

    Science.gov (United States)

    Peterson, Robin T.; Leonhardt, James M.

    2015-01-01

    This paper investigates the possible complementary effects that training in empathy and nonverbal communication may have on persuasion capabilities. The narrative considers implications from the literature and describes an exploratory study in which students, in a managerial setting, were trained in empathy and nonverbal communication. Subsequent…

  14. Anonymous communication networks protecting privacy on the web

    CERN Document Server

    Peng, Kun

    2014-01-01

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

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

    Science.gov (United States)

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

    1999-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-11-01

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

  17. Capacity analysis of vehicular communication networks

    CERN Document Server

    Lu, Ning

    2013-01-01

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

  18. Position estimation of transceivers in communication networks

    Science.gov (United States)

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

    2008-06-03

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

  19. Satellite communications network design and analysis

    CERN Document Server

    Jo, Kenneth Y

    2011-01-01

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

  20. An FPGA-based torus communication network

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-02-15

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

  1. Cognitive Radio for Tactical Wireless Communication Networks

    Science.gov (United States)

    2011-10-09

    12:10:41 6 Michael B. Pursley, Thomas C. Royster. Adaptive-rate nonbinary LDPC coding for frequency-hop communications, MILCOM 2008 - 2008 IEEE...interference in a frequency-hop (FH) packet radio network. Performance results are given in [PuR08] for irregular low-density parity-check ( LDPC ) codes in...FH spread-spectrum systems with nonbinary orthogonal modulation. Two adaptive LDPC coding protocols are devised and evaluated. Each employs

  2. Stochastic modelling and control of communication networks

    OpenAIRE

    Zuraniewski, P.W.

    2011-01-01

    The unprecedented growth of the Information Technologies sector observed within the past years creates an excellent opportunity to conduct new, exciting and interdisciplinary research. Increasing complexity of the communication networks calls for incorporating rigorously developed and reliable methods for traffic control and management. Mathematics may offer extremely valuable tools to achieve these goals but transforming an engineering problem into the mathematical one requires a good unders...

  3. Discovery Monday - Behind the plug: communication networks

    CERN Multimedia

    2004-01-01

    Ever wondered what happens to your email when you click "send"? And when you make a phone call, how does your voice travel down the wire? Find out more about communication networks and their applications. Do not miss the next Discovery Monday in Microcosm on 1st March (see Bulletin 9/2004)! Monday 1st March from 7.30pm to 9.00pm, in Microcosm. Entrance Free.

  4. Intracity Quantum Communication via Thermal Microwave Networks

    Directory of Open Access Journals (Sweden)

    Ze-Liang Xiang

    2017-03-01

    Full Text Available Communication over proven-secure quantum channels is potentially one of the most wide-ranging applications of currently developed quantum technologies. It is generally envisioned that in future quantum networks, separated nodes containing stationary solid-state or atomic qubits are connected via the exchange of optical photons over large distances. In this work, we explore an intriguing alternative for quantum communication via all-microwave networks. To make this possible, we describe a general protocol for sending quantum states through thermal channels, even when the number of thermal photons in the channel is much larger than 1. The protocol can be implemented with state-of-the-art superconducting circuits and enables the transfer of quantum states over distances of about 100 m via microwave transmission lines cooled to only T=4  K. This opens up new possibilities for quantum communication within and across buildings and, consequently, for the implementation of intracity quantum networks based on microwave technology only.

  5. Local area network terminal management in support of stock point logistics integrated communications environment (SPLICE)

    OpenAIRE

    Barnes, Jerry D.

    1982-01-01

    Approved for public release; distribution is unlimited This thesis examines the questions of user requirements, design considerations, and network environment for a local area network Terminal Management function in support of the Naval Supply Systems Command's Stock Point Logistics Integrated Communications Environment (SPLICE). Criteria are developed from this examination. They include process-process communication, virtual terminal, and user defined screen capabilities as well as a ne...

  6. Network Capabilities in Project-Based Organizations ; A Case Study of Avantor AS

    OpenAIRE

    Hussain, Tahiya; Reinemo, Ine

    2016-01-01

    Masteroppgave(MSc) in Master of Science in Business, Strategy - Handelshøyskolen BI, 2016 The objectives of this thesis are to highlight the important elements and factors for creating and sustaining network capabilities in project-based organizations. A network capability is a firm’s ability to handle the relationships they are embedded in. The purpose is to provide new insight to the existing theory in an attempt to develop theory on network capabilities within the establishe...

  7. Critical size of ego communication networks

    Science.gov (United States)

    Wang, Qing; Gao, Jian; Zhou, Tao; Hu, Zheng; Tian, Hui

    2016-06-01

    With the help of information and communication technologies, studies on the overall social networks have been extensively reported recently. However, investigations on the directed Ego Communication Networks (ECNs) remain insufficient, where an ECN stands for a sub network composed of a centralized individual and his/her direct contacts. In this paper, the directed ECNs are built on the Call Detail Records (CDRs), which cover more than 7 million people of a provincial capital city in China for half a year. Results show that there is a critical size for ECN at about 150, above which the average emotional closeness between ego and alters drops, the balanced relationship between ego and network collapses, and the proportion of strong ties decreases. This paper not only demonstrate the significance of ECN size in affecting its properties, but also shows accordance with the “Dunbar's Number”. These results can be viewed as a cross-culture supportive evidence to the well-known Social Brain Hypothesis (SBH).

  8. Community detection based on network communicability

    Science.gov (United States)

    Estrada, Ernesto

    2011-03-01

    We propose a new method for detecting communities based on the concept of communicability between nodes in a complex network. This method, designated as N-ComBa K-means, uses a normalized version of the adjacency matrix to build the communicability matrix and then applies K-means clustering to find the communities in a graph. We analyze how this method performs for some pathological cases found in the analysis of the detection limit of communities and propose some possible solutions on the basis of the analysis of the ratio of local to global densities in graphs. We use four different quality criteria for detecting the best clustering and compare the new approach with the Girvan-Newman algorithm for the analysis of two "classical" networks: karate club and bottlenose dolphins. Finally, we analyze the more challenging case of homogeneous networks with community structure, for which the Girvan-Newman completely fails in detecting any clustering. The N-ComBa K-means approach performs very well in these situations and we applied it to detect the community structure in an international trade network of miscellaneous manufactures of metal having these characteristics. Some final remarks about the general philosophy of community detection are also discussed.

  9. Community detection based on network communicability.

    Science.gov (United States)

    Estrada, Ernesto

    2011-03-01

    We propose a new method for detecting communities based on the concept of communicability between nodes in a complex network. This method, designated as N-ComBa K-means, uses a normalized version of the adjacency matrix to build the communicability matrix and then applies K-means clustering to find the communities in a graph. We analyze how this method performs for some pathological cases found in the analysis of the detection limit of communities and propose some possible solutions on the basis of the analysis of the ratio of local to global densities in graphs. We use four different quality criteria for detecting the best clustering and compare the new approach with the Girvan-Newman algorithm for the analysis of two "classical" networks: karate club and bottlenose dolphins. Finally, we analyze the more challenging case of homogeneous networks with community structure, for which the Girvan-Newman completely fails in detecting any clustering. The N-ComBa K-means approach performs very well in these situations and we applied it to detect the community structure in an international trade network of miscellaneous manufactures of metal having these characteristics. Some final remarks about the general philosophy of community detection are also discussed.

  10. Resource Management in Broadband Communication Networks

    DEFF Research Database (Denmark)

    Hansen, Mads Stenhuus

    2003-01-01

    This thesis - Resource Management in Broadband Communication Networks - deals with different ways of optimizing the available resources of data- or telecommunication networks. Especially topics like optimal routing, load balancing and fast recovery of routes in case of link failures are covered....... The first part gives a brief description of some of the existing protocols for routing and controlling resources, such as RSVP, OSPF, BGP, PNNI, etc. The remaining part concerns the following two fundamentally different approaches to resource management etc.: - Software agents - Simulated ants...... at developing a demonstration platform, where software agents handled virtually all aspects of controlling an ATM-based network. In the beginning of the part about simulated ants it is explained how scientists believe ants in nature find their way through the environment between their nest and food sources...

  11. Collaboration and communication in a networked economy

    Directory of Open Access Journals (Sweden)

    Hans-Christian Pfohl

    2015-06-01

    Full Text Available Background: The networked economy is a result of the increasing specialization and productivity. The blurring of company boundaries enables potential for new competitive advantages. However, along with the growing networked economy, the complexity also increases. Methods: With their current study the German logistics association sheds a light on the most important trends of the networked and complex economy and the strategies of logistics and supply chain management (SCM coping with them. Results and conclusions: This paper focuses on the collaboration of actors in logistics and supply chain management and the communication required for being successful. Furthermore, going beyond the study, the role of collaboration for innovation in logistics and SCM is considered, that has been neglected in literature so far. Finally, the paper concludes with a discussion reflecting the current state of collaboration in the context of its potential.

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

    Science.gov (United States)

    Bhasin, Kul B.; Hayden, Jeffrey L.

    2008-01-01

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

  13. Queue-length synchronization in communication networks.

    Science.gov (United States)

    Mukherjee, Satyam; Gupte, Neelima

    2009-05-01

    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.

  14. Secure and Authenticated Data Communication in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Omar Alfandi

    2015-08-01

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

  15. Secure and Authenticated Data Communication in Wireless Sensor Networks

    Science.gov (United States)

    Alfandi, Omar; Bochem, Arne; Kellner, Ansgar; Göge, Christian; Hogrefe, Dieter

    2015-01-01

    Securing communications in wireless sensor networks is increasingly important as the diversity of applications increases. However, even today, it is equally important for the measures employed to be energy efficient. For this reason, this publication analyzes the suitability of various cryptographic primitives for use in WSNs according to various criteria and, finally, describes a modular, PKI-based framework for confidential, authenticated, secure communications in which most suitable primitives can be employed. Due to the limited capabilities of common WSN motes, criteria for the selection of primitives are security, power efficiency and memory requirements. The implementation of the framework and the singular components have been tested and benchmarked in our testbed of IRISmotes. PMID:26266413

  16. Marketing communications model for innovation networks

    Directory of Open Access Journals (Sweden)

    Tiago João Freitas Correia

    2015-10-01

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

  17. Enhancing optical communication with deep neural networks

    Science.gov (United States)

    Lohani, Sanjaya; Knutson, Erin; Tkach, Sam; Huver, Sean; Glasser, Ryan; Tulane University Collaboration; Deep Science AI Collaboration

    The spatial profile of optical modes may be altered such that they contain nonzero orbital angular momentum (OAM). Laguerre-Gauss (LG) states of light have a helical wavefront and well-defined OAM, and have recently been shown to allow for larger information transfer rates in optical communications as compared to using only Gaussian modes. A primary difficulty, however, is the accurate classification of different OAM optical states, which contain different values of OAM, in the detection stage. The difficulty in this differentiation increases as larger degrees of OAM are used. Here we show the performance of deep neural networks in the simultaneous classification of numerically generated, noisy, Laguerre-Gauss states with OAM value up to 100 can reach near 100% accuracy. This method relies only on the intensity profile of the detected OAM states, avoiding bulky and difficult-to-implement methods that are required to measure the phase profile of the modes in the receiver of the communication platform. This allows for a simplification in the network design and an increase in performance when using states with large degrees of OAM. We anticipate that this approach will allow for significant advances in the development of optical communication technologies. We acknowledge funding from the Louisiana State Board of Regents and Northrop Grumman - NG NEXT.

  18. Joint preprocesser-based detector for cooperative networks with limited hardware processing capability

    KAUST Repository

    Abuzaid, Abdulrahman I.

    2015-02-01

    In this letter, a joint detector for cooperative communication networks is proposed when the destination has limited hardware processing capability. The transmitter sends its symbols with the help of L relays. As the destination has limited hardware, only U out of L signals are processed and the energy of the remaining relays is lost. To solve this problem, a joint preprocessing based detector is proposed. This joint preprocessor based detector operate on the principles of minimizing the symbol error rate (SER). For a realistic assessment, pilot symbol aided channel estimation is incorporated for this proposed detector. From our simulations, it can be observed that our proposed detector achieves the same SER performance as that of the maximum likelihood (ML) detector with all participating relays. Additionally, our detector outperforms selection combining (SC), channel shortening (CS) scheme and reduced-rank techniques when using the same U. Our proposed scheme has low computational complexity.

  19. Opportunistic spectrum utilization in vehicular communication networks

    CERN Document Server

    Cheng, Nan

    2016-01-01

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

  20. Networked Adaptive Interactive Hybrid Systems (NAIHS) for multiplatform engagement capability

    NARCIS (Netherlands)

    Kester, L.J.H.M.

    2008-01-01

    Advances in network technologies enable distributed systems, operating in complex physical environments, to coordinate their activities over larger areas within shorter time intervals. Some envisioned application domains for such systems are defence, crisis management, traffic management and public

  1. Trends in Area of Safety Communications within Industrial Networks

    Directory of Open Access Journals (Sweden)

    Maria Franekova

    2005-01-01

    Full Text Available The paper deals with the problems of safety communication in industrial networks for purpose of assurance of functional safety. It is intents on analysis of treats on industry networks and there is described recommended safety protections and their location into layer communication protocol applicable in fieldbus network, which they are used within safety critical processes control.

  2. Wi-Fi Network Communication Technology Design | Onibere ...

    African Journals Online (AJOL)

    This paper is concerned with chronicling the design issues of Wi -Fi network communication technology taking into consideration constraints and challenges addressed in the evolution of other communications networks, such as wired public switched telephone network (PSTN) for internet connectivity. These constraints ...

  3. Dynamic Resource Allocation and QoS Control Capabilities of the Japanese Academic Backbone Network

    Directory of Open Access Journals (Sweden)

    Michihiro Aoki

    2010-08-01

    Full Text Available Dynamic resource control capabilities have become increasingly important for academic networks that must support big scientific research projects at the same time as less data intensive research and educational activities. This paper describes the dynamic resource allocation and QoS control capabilities of the Japanese academic backbone network, called SINET3, which supports a variety of academic applications with a wide range of network services. The article describes the network architecture, networking technologies, resource allocation, QoS control, and layer-1 bandwidth on-demand services. It also details typical services developed for scientific research, including the user interface, resource control, and management functions, and includes performance evaluations.

  4. Establishing seismic network capabilities in Haïti

    Science.gov (United States)

    Clouard, Valerie; Saurel, Jean-Marie; Prepetit, Claude; McNamara, Daniel; Hough, Susan; Saint-Louis, Mildor; Altidor, Jean-Robert

    2014-05-01

    The January 12, 2010 earthquake ruptured a poorly instrumented region that is located on a complex, wide, deformed zone on the boundary between the Caribbean Plate and the North American Plate. This event evidenced the need for a permanent seismic network in Haiti. Immediately after the 2010 earthquake, a strong motion network was deployed by USGS and 3 broadband seismometers were installed by the NRCAN. All this instrumentation is still working, however, it is mainly located around Port-au-Prince. In 2011, the UTS (Technical Unit of Seismology) was created by the BME (Mining and Energy Bureau) to take in charge the seismic monitoring of the national territory and a Memorandum of Understanding was signed with IPGP that would help through its Antilles Volcano and Seismic Observatories. After a 2-month training in Martinique of Haitian operators, Earthworm and Seiscomp3 were installed on the UTS server and neighboring country stations were include to the detection network. To enlarge the seismic networks to the whole territory, 10 broadband seismometers and 6 accelerometers were acquired. With these new stations, which will be installed in 2014 in secured places equipped with internet or VSAT antenna and with network code AY, the seismic performance standards for the detection and analysis of earthquakes change: 1) Earthquake detection from 30 seconds to 10, 2) Minimum magnitude threshold from M3.8 to M2.8, and 3) Initial hypocenter error from 5km to less than 2 km. The remaining efforts should focus on permanent and qualified human resources to maintain these networks.

  5. 76 FR 60870 - In the Matter of Certain Electronic Devices With Communication Capabilities, Components Thereof...

    Science.gov (United States)

    2011-09-30

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION In the Matter of Certain Electronic Devices With Communication Capabilities, Components Thereof... 19 U.S.C. 1337 AGENCY: U.S. International Trade Commission. ACTION: Notice. SUMMARY: Notice is hereby...

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

    DEFF Research Database (Denmark)

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

    2018-01-01

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

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

    CERN Document Server

    Antoniou, Josephina

    2012-01-01

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

  8. HoloNetwork: communicating science through holography

    Science.gov (United States)

    Pombo, Pedro; Santos, Emanuel; Magalhães, Carolina

    2017-03-01

    Since 1997 a program dedicated to holography has been developed and implemented in Portugal. This program started with focus on schools and science education. The HoloNetwork was created and it has been spread at a National level, involving a group of thirty schools and hundreds of students and teachers. In 2009 this network started to work to achieve a new target, the general public. With this goal, a larger program was developed with focus on science and society and on science communication through holography. For the implementation of this new program, special holography outreach activities were built, dedicated to informal learning and seven Science Centers around Portugal were add into the HoloNetwork. During last years, we have been working on holography, based on two main branches, one dedicated to schools and with the aimed to promote physics teaching and to teach how to make holograms, and another dedicated to society and with the aimed to promote holography and to increase scientific literacy. This paper would analyze the educational program, all holography outreach activities, exhibitions or events, all equipments, materials and setups used and it would present the holographic techniques explored with students or with the public. Finally, the results obtained in this work would be present and explored, with focus on students impact and outcomes, taking into account the public engagement on holography and its effect into scientific culture and analyzing the quality of holograms made by students and by the general public. subject.

  9. Discovery Monday - Behind the plug: communication networks

    CERN Multimedia

    2004-01-01

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

  10. Cooperative UAV-Based Communications Backbone for Sensor Networks

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, R S

    2001-10-07

    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.

  11. Earthquake detection capability of the Swiss Seismic Network

    Science.gov (United States)

    Nanjo, K. Z.; Schorlemmer, D.; Woessner, J.; Wiemer, S.; Giardini, D.

    2010-06-01

    A reliable estimate of completeness magnitudes is vital for many seismicity- and hazard-related studies. Here we adopted and further developed the Probability-based Magnitude of Completeness (PMC) method. This method determines network detection completeness (MP) using only empirical data: earthquake catalogue, phase picks and station information. To evaluate the applicability to low- or moderate-seismicity regions, we performed a case study in Switzerland. The Swiss Seismic Network (SSN) at present is recording seismicity with one of the densest networks of broad-band sensors in Europe. Based on data from 1983 January 1 to 2008 March 31, we found strong spatio-temporal variability of network completeness: the highest value of MP in Switzerland at present is 2.5 in the far southwest, close to the national boundary, whereas MP is lower than 1.6 in high-seismicity areas. Thus, events of magnitude 2.5 can be detected in all of Switzerland. We evaluated the temporal evolution of MP for the last 20 yr, showing the successful improvement of the SSN. We next introduced the calculation of uncertainties to the probabilistic method using a bootstrap approach. The results show that the uncertainties in completeness magnitudes are generally less than 0.1 magnitude units, implying that the method generates stable estimates of completeness magnitudes. We explored the possible use of PMC: (1) as a tool to estimate the number of missing earthquakes in moderate-seismicity regions and (2) as a network planning tool with simulation computations of installations of one or more virtual stations to assess the completeness and identify appropriate locations for new station installations. We compared our results with an existing study of the completeness based on detecting the point of deviation from a power law in the earthquake-size distribution. In general, the new approach provides higher estimates of the completeness magnitude than the traditional one. We associate this observation

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

    NARCIS (Netherlands)

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Joaquín Goñi

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

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

    Science.gov (United States)

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

    2013-01-01

    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.

  15. Motivation and requirements for determining a Network Warfare Capability

    CSIR Research Space (South Africa)

    Veerasamy, N

    2010-06-01

    Full Text Available technology for their day-to-day operation (Panda, Giordano 1999). A report by the Defense Science Board in the United States of America (USA) explains that challenges in the present age include information assurance, and that this requires new...", International Journal of Information Security, vol. 1, no. 1, pp. 3-13. Munro, N. 1996, "Sketching a national Information Warfare defense plan", Communications of the ACM, vol. 39, no. 11, pp. 15-17. Panda, B. & Giordano, J. 1999, "Defensive Information...

  16. Research on key technology of space laser communication network

    Science.gov (United States)

    Chang, Chengwu; Huang, Huiming; Liu, Hongyang; Gao, Shenghua; Cheng, Liyu

    2016-10-01

    Since the 21st century, Spatial laser communication has made a breakthrough development. Europe, the United States, Japan and other space powers have carried out the test of spatial laser communication technology on-orbit, and put forward a series of plans. In 2011, China made the first technology demonstration of satellite-ground laser communication carried by HY-2 satellite. Nowadays, in order to improve the transmission rate of spatial network, the topic of spatial laser communication network is becoming a research hotspot at home and abroad. This thesis, from the basic problem of spatial laser communication network to solve, analyzes the main difference between spatial network and ground network, which draws forth the key technology of spatial laser communication backbone network, and systematically introduces our research on aggregation, addressing, architecture of spatial network. From the perspective of technology development status and trends, the thesis proposes the development route of spatial laser communication network in stages. So as to provide reference about the development of spatial laser communication network in China.

  17. Detection capability of the Italian network for teleseismic events

    Directory of Open Access Journals (Sweden)

    A. Marchetti

    1994-06-01

    Full Text Available The future GSE experiment is based on a global seismic monitoring system, that should be designed for monitoring compliance with a nuclear test ban treaty. Every country participating in the test will transmit data to the International Data Center. Because of the high quality of data required, we decided to conduct this study in order to determine the set of stations to be used in the experiment. The Italian telemetered seismological network can detect all events of at least magnitude 2.5 whose epicenters are inside the network itself. For external events the situation is different: the capabilíty of detection is conditioned not only by the noise condition of the station, but also by the relative position of epicenter and station. The ING bulletin (January 1991-June 1992 was the data set for the present work. Comparing these data with the National Earthquake Information Center (NEIC bulletin, we established which stations are most reliable in detecting teleseismic events and, moreover, how distance and back-azimuth can influence event detection. Furthermore, we investigated the reliability of the automatic acquisition system in relation to teleseismic event detection.

  18. Control and estimation methods over communication networks

    CERN Document Server

    Mahmoud, Magdi S

    2014-01-01

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

  19. Communication networks beyond the capacity crunch.

    Science.gov (United States)

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

    2016-03-06

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

  20. Consensus in networks of mobile communicating agents.

    Science.gov (United States)

    Baronchelli, Andrea; Díaz-Guilera, Albert

    2012-01-01

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

  1. Identifying Social Communities in Complex Communications for Network Efficiency

    Science.gov (United States)

    Hui, Pan; Yoneki, Eiko; Crowcroft, Jon; Chan, Shu-Yan

    Complex communication networks, more particular Mobile Ad Hoc Networks (MANET) and Pocket Switched Networks (PSN), rely on short range radio and device mobility to transfer data across the network. These kind of mobile networks contain duality in nature: they are radio networks at the same time also human networks, and hence knowledge from social networks can be also applicable here. In this paper, we demonstrate how identifying social communities can significantly improve the forwarding efficiencies in term of delivery ratio and delivery cost. We verify our hypothesis using data from five human mobility experiments and test on two application scenarios, asynchronous messaging and publish/subscribe service.

  2. Information hiding in communication networks fundamentals, mechanisms, applications, and countermeasures

    CERN Document Server

    Mazurczyk, Wojciech; Zander, Sebastian; Houmansadr, Amir; Szczypiorski, Krzysztof

    2016-01-01

    Describes Information Hiding in communication networks, and highlights their important issues, challenges, trends, and applications. This book provides the fundamental concepts, terminology, and classifications of information hiding in communication networks along with its historical background. Information Hiding In Communication Networks: Fundamentals, Mechanisms, Applications, and Countermeasures begins with introducing data concealment methods and their evolution. Chapter two discusses the existing terminology and describes the model for hidden communication and related communication scenarios. Chapters three to five present the main classes of information hiding in communication networks accompanied by a discussion of their robustness and undetectability. The book concludes with a discussion of potential countermeasures against information hiding techniques, which includes different types of mechanisms for the detection, limitation and prevention of covert co munication channels.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    assigned, licensed spectrum; thus, it is under full control of the cellular network. D2D communication creates a market potential for new services, new approaches to efficient spectrum use, and security concepts. This is especially true if D2D communication is extended to larger communication groups...... organized in meshed clusters. In this article, we discuss the potential and shortcomings of D2D communication as proposed today, advocating for the use of network coding as an enabling technology for enhanced security and communication efficiency using the PlayNCool and CORE protocols as key examples...

  4. Building a Data Science capability for USGS water research and communication

    Science.gov (United States)

    Appling, A.; Read, E. K.

    2015-12-01

    Interpreting and communicating water issues in an era of exponentially increasing information requires a blend of domain expertise, computational proficiency, and communication skills. The USGS Office of Water Information has established a Data Science team to meet these needs, providing challenging careers for diverse domain scientists and innovators in the fields of information technology and data visualization. Here, we detail the experience of building a Data Science capability as a bridging element between traditional water resources analyses and modern computing tools and data management techniques. This approach includes four major components: 1) building reusable research tools, 2) documenting data-intensive research approaches in peer reviewed journals, 3) communicating complex water resources issues with interactive web visualizations, and 4) offering training programs for our peers in scientific computing. These components collectively improve the efficiency, transparency, and reproducibility of USGS data analyses and scientific workflows.

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

    Directory of Open Access Journals (Sweden)

    S. C. Dutta

    2013-06-01

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

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

    OpenAIRE

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

    2013-01-01

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

  7. Validation of Bosch' Mobile Communication NetworkArchitecture with SPIN

    NARCIS (Netherlands)

    Ruys, T.C.; Langerak, Romanus

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

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  9. Large deviations for Gaussian queues modelling communication networks

    CERN Document Server

    Mandjes, Michel

    2007-01-01

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

  10. Low power radio communication platform for wireless sensor network

    NARCIS (Netherlands)

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

    2009-01-01

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

  11. NASA Near Earth Network (NEN), Deep Space Network (DSN) and Space Network (SN) Support of CubeSat Communications

    Science.gov (United States)

    Schaire, Scott H.; Altunc, Serhat; Bussey, George; Shaw, Harry; Horne, Bill; Schier, Jim

    2015-01-01

    There has been a historical trend to increase capability and drive down the Size, Weight and Power (SWAP) of satellites and that trend continues today. Small satellites, including systems conforming to the CubeSat specification, because of their low launch and development costs, are enabling new concepts and capabilities for science investigations across multiple fields of interest to NASA. NASA scientists and engineers across many of NASAs Mission Directorates and Centers are developing exciting CubeSat concepts and welcome potential partnerships for CubeSat endeavors. From a communications and tracking point of view, small satellites including CubeSats are a challenge to coordinate because of existing small spacecraft constraints, such as limited SWAP and attitude control, low power, and the potential for high numbers of operational spacecraft. The NASA Space Communications and Navigation (SCaN) Programs Near Earth Network (NEN), Deep Space Network (DSN) and the Space Network (SN) are customer driven organizations that provide comprehensive communications services for space assets including data transport between a missions orbiting satellite and its Mission Operations Center (MOC). The NASA NEN consists of multiple ground antennas. The SN consists of a constellation of geosynchronous (Earth orbiting) relay satellites, named the Tracking and Data Relay Satellite System (TDRSS). The DSN currently makes available 13 antennas at its three tracking stations located around the world for interplanetary communication. The presentation will analyze how well these space communication networks are positioned to support the emerging small satellite and CubeSat market. Recognizing the potential support, the presentation will review the basic capabilities of the NEN, DSN and SN in the context of small satellites and will present information about NEN, DSN and SN-compatible flight radios and antenna development activities at the Goddard Space Flight Center (GSFC) and across

  12. Anomaly Detection Approaches for Communication Networks

    Science.gov (United States)

    Thottan, Marina; Liu, Guanglei; Ji, Chuanyi

    In recent years, network anomaly detection has become an important area for both commercial interests as well as academic research. Applications of anomaly detection typically stem from the perspectives of network monitoring and network security. In network monitoring, a service provider is often interested in capturing such network characteristics as heavy flows, flow size distributions, and the number of distinct flows. In network security, the interest lies in characterizing known or unknown anomalous patterns of an attack or a virus.

  13. Time-Predictable Communication on a Time-Division Multiplexing Network-on-Chip Multicore

    DEFF Research Database (Denmark)

    Sørensen, Rasmus Bo

    This thesis presents time-predictable inter-core communication on a multicore platform with a time-division multiplexing (TDM) network-on-chip (NoC) for hard real-time systems. The thesis is structured as a collection of papers that contribute within the areas of: reconfigurable TDM NoCs, static...... of the Argo NoC network interface (NI) that supports instantaneous reconfiguration, a TDM traffic scheduler that generates virtual circuit (VC) configurations for the Argo NoC, and software functions for two types of intercore communication. The new generation of the Argo NoC adds the capability...

  14. Near Earth Network (NEN) CubeSat Communications

    Science.gov (United States)

    Schaire, Scott

    2017-01-01

    developers who are developing radios that offer lower cost and, in some cases, more capabilities with fewer constraints. The NEN is ready to begin supporting CubeSat missions. The NEN is considering network upgrades to broaden the types of CubeSat missions that can be supported and is supporting both the CubeSat community and radio developers to ensure future CubeSat missions have multiple options when choosing a network for their communications support.

  15. Investigating communication networks contextually: Qualitative network analysis as cross-media research

    Directory of Open Access Journals (Sweden)

    Andreas Hepp

    2016-06-01

    Full Text Available This article introduces the approach of contextualised communication network analysis as a qualitative procedure for researching communicative relationships realised through the media. It combines qualitative interviews on media appropriation, egocentric network maps, and media diaries. Through the triangulation of these methods of data collection, it is possible to gain a differentiated insight into the specific meanings, structures and processes of communication networks across a variety of media. The approach is illustrated using a recent study dealing with the mediatisation of community building among young people. In this context, the qualitative communication network analysis has been applied to distinguish “localists” from “centrists”, “multilocalists”, and “pluralists”. These different “horizons of mediatised communitisation” are connected to distinct communication networks. Since this involves today a variety of different media, the contextual analysis of communication networks necessarily has to imply a cross-media perspective.

  16. Behavioral modeling approach for optical communication network design

    Science.gov (United States)

    Vuorinen, Kimmo; Jacquemod, Gilles; Gaffiot, Frederic; Seassal, Christian

    1997-12-01

    An optical communication networks can be divided in two levels: communication level, which defines the protocols, the control and the management of the networks and physical level formed by photonic and electronic components in order to transmit and receive the data between different nodes of the network. Traditionally, these two levels are considered separately in the optical communication network design process. This can lead to an erroneous or non-ideal networks implementation, due to the fact that the communication and physical levels are not independent. For example, in WDM communication network the maximum achievable data rate is limited not only by the networks protocol, but depends also on the implementation of the physical level: tuning delay of the optical multiplexers. Also the lack of the possibilities for co-verification of the communication and the physical levels together could lead to misinterpretations between the designers of the different levels and thus induce design faults. Since the prototyping is extremely expensive and time consuming, an integrated simulation of both communication and physical levels is necessary, at least in some extend. In this paper, a behavioral modeling approach that allows a co- simulation of the communication and the physical levels is presented. It is based on the use of a VHDL-AMS-like hardware description language, dedicated to electronic system modeling, but also suitable for modeling and simulation of non- electronic and mixed-domain systems. The behavioral models for photonic and electronic components, as well as the software are integrated in a unique simulator in order to co-simulate the communication (control) and the physical level (data path) of a WDM optical communication network.

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

    Directory of Open Access Journals (Sweden)

    Lipi Chhaya

    2017-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Mohamed A. Ahmed

    2016-03-01

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

  19. Initial Characterization of Optical Communications with Disruption-Tolerant Network Protocols

    Science.gov (United States)

    Schoolcraft, Joshua; Wilson, Keith

    2011-01-01

    Disruption-tolerant networks (DTNs) are groups of network assets connected with a suite of communication protocol technologies designed to mitigate the effects of link delay and disruption. Application of DTN protocols to diverse groups of network resources in multiple sub-networks results in an overlay network-of-networks with autonomous data routing capability. In space environments where delay or disruption is expected, performance of this type of architecture (such as an interplanetary internet) can increase with the inclusion of new communications mediums and techniques. Space-based optical communication links are therefore an excellent building block of space DTN architectures. When compared to traditional radio frequency (RF) communications, optical systems can provide extremely power-efficient and high bandwidth links bridging sub-networks. Because optical links are more susceptible to link disruption and experience the same light-speed delays as RF, optical-enabled DTN architectures can lessen potential drawbacks and maintain the benefits of autonomous optical communications over deep space distances. These environment-driven expectations - link delay and interruption, along with asymmetric data rates - are the purpose of the proof-of-concept experiment outlined herein. In recognizing the potential of these two technologies, we report an initial experiment and characterization of the performance of a DTN-enabled space optical link. The experiment design employs a point-to-point free-space optical link configured to have asymmetric bandwidth. This link connects two networked systems running a DTN protocol implementation designed and written at JPL for use on spacecraft, and further configured for higher bandwidth performance. Comparing baseline data transmission metrics with and without periodic optical link interruptions, the experiment confirmed the DTN protocols' ability to handle real-world unexpected link outages while maintaining capability of

  20. 5th International Conference on Electronics, Communications and Networks

    CERN Document Server

    2016-01-01

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

  1. Communication networks and spatial ecology in nightingales

    NARCIS (Netherlands)

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

    2011-01-01

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

  2. Extending the Capabilities of Closed-loop Distributed Engine Control Simulations Using LAN Communication

    Science.gov (United States)

    Aretskin-Hariton, Eliot D.; Zinnecker, Alicia Mae; Culley, Dennis E.

    2014-01-01

    Distributed Engine Control (DEC) is an enabling technology that has the potential to advance the state-of-the-art in gas turbine engine control. To analyze the capabilities that DEC offers, a Hardware-In-the-Loop (HIL) test bed is being developed at NASA Glenn Research Center. This test bed will support a systems-level analysis of control capabilities in closed-loop engine simulations. The structure of the HIL emulates a virtual test cell by implementing the operator functions, control system, and engine on three separate computers. This implementation increases the flexibility and extensibility of the HIL. Here, a method is discussed for implementing these interfaces by connecting the three platforms over a dedicated Local Area Network (LAN). This approach is verified using the Commercial Modular Aero-Propulsion System Simulation 40k (C-MAPSS40k), which is typically implemented on one computer. There are marginal differences between the results from simulation of the typical and the three-computer implementation. Additional analysis of the LAN network, including characterization of network load, packet drop, and latency, is presented. The three-computer setup supports the incorporation of complex control models and proprietary engine models into the HIL framework.

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

    Science.gov (United States)

    Brown, Dot; Oetzel, John; Henderson, Alison

    2016-11-01

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

  4. 2014 International Conference on Wireless Communications, Networking and Applications

    CERN Document Server

    2016-01-01

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

  5. ADAPTIVE NETWORK CODING IN WIRELESS COMMUNICATIONS

    DEFF Research Database (Denmark)

    2017-01-01

    A first network node (eNB) is configured to receive (404), from a second network node (UE), channel performance indicator values regarding a serving cell, and estimate (404) a number of network-coded packets based on the received channel performance indicator values, such that the estimated numbe...

  6. Communication on the structure of biological networks

    Indian Academy of Sciences (India)

    Among all biological networks studied here, the undirected structure of neuronal networks not only possesses the small-world property but the same is also expressed remarkably to a higher degree compared to any randomly generated network which possesses the same degree sequence. A relatively high percentage of ...

  7. Advanced communication and network requirements in Europe

    DEFF Research Database (Denmark)

    Falch, Morten; Enemark, Rasmus

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

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

    Science.gov (United States)

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

    2016-08-01

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

  9. Mesh Network Architecture for Enabling Inter-Spacecraft Communication

    Science.gov (United States)

    Becker, Christopher; Merrill, Garrick

    2017-01-01

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

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

    CERN Document Server

    2017-01-01

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

  11. Army Social Media: Harnessing the Power of Networked Communications

    Science.gov (United States)

    2011-09-01

    9/1/2011 Army Social Media : harnessing the power of networked communications Report Documentation Page Form ApprovedOMB No. 0704-0188 Public...4. TITLE AND SUBTITLE Army Social Media : harnessing the power of networked communications 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM...the Chief of Public Affairs,Online and Social Media Division,1500 Pentagon,Washington,DC,20301 8. PERFORMING ORGANIZATION REPORT NUMBER 9

  12. A time reference distribution concept for a time division communication network

    Science.gov (United States)

    Stover, H. A.

    1973-01-01

    Starting with an assumed ideal network having perfect clocks at every node and known fixed transmission delays between nodes, the effects of adding tolerances to both transmission delays and nodal clocks is described. The advantages of controlling tolerances on time rather than frequency are discussed. Then a concept is presented for maintaining these tolerances on time throughout the network. This concept, called time reference distribution, is a systematic technique for distributing time reference to all nodes of the network. It is reliable, survivable and possesses many other desirable characteristics. Some of its features such as an excellent self monitoring capability will be pointed out. Some preliminary estimates of the accuracy that might be expected are developed and there is a brief discussion of the impact upon communication system costs. Time reference distribution is a concept that appears very attractive. It has not had experimental evaluation and has not yet been endorsed for use in any communication network.

  13. Cross-cultural communication capabilities of U.S. military trainers: host nation perspective.

    Science.gov (United States)

    Mahmood, Maysaa; Alameri, Ali; Jawad, Shakir; Alani, Yasir; Zuerlein, Scott; Nakano, Gregg; Anderson, Warner; Beadling, Charles

    2013-06-01

    A survey was conducted to assess trainee perception of the cross-cultural communication competency of U.S. military trainers and their satisfaction with the training they received. Findings from the survey show that U.S. military trainers rely significantly on local interpreters. This indicates variability in the ability of the trainers to communicate effectively with host nation partners, the variability being dependent on the capabilities of the individual interpreter. The findings illustrate the importance of providing military health personnel with training on how to work effectively with interpreters. The use of supplementary resources such as electronic translation devises when the interpreter is not capable of conveying health-related training information with the desired level of accuracy is recommended. Expanding the availability of general cultural training, which provides baseline information on local values, traditions, and customs in addition to health-specific cultural orientation, is also recommended to help military health trainers customize their training content and methods to fit the local environment. Reprint & Copyright © 2013 Association of Military Surgeons of the U.S.

  14. True Nature of Supply Network Communication Structure

    Directory of Open Access Journals (Sweden)

    Lokhman Hakim bin Osman

    2016-04-01

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

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

    Science.gov (United States)

    Owari, Masaki; Kato, Go; Hayashi, Masahito

    2018-01-01

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

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

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

    Communication for Influence : Building ICTD Networks in Central, East and West Africa. This project seeks to help achieve universal affordable access to broadband information and communication technology (ICT) infrastructure in a number of countries on ... Bénin : lí oí¹ il faut 3, 4, même 5 cartes SIM pour faire un appel.

  17. Technology Developments Integrating a Space Network Communications Testbed

    Science.gov (United States)

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

    2006-01-01

    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.

  18. Synchrophasor Sensor Networks for Grid Communication and Protection.

    Science.gov (United States)

    Gharavi, Hamid; Hu, Bin

    2017-07-01

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

  19. A Comparative Analysis of Fortress (ES520) and Mesh Dynamics’ (4000 Series) Networking Capabilities During Coasts 2007 Field Experiments

    Science.gov (United States)

    2008-03-01

    features such as security, remote management , networking protocol, mobility, transportability, quality of service, and ruggedness. These features...specifications, which include radio layout, network remote management capability, mobility capability, multicast capability, security implementations, and...implementations. In comparing the two products Mesh Dynamics has the advantage in the categories of quality of service, remote management , and mobility. But

  20. Compliance and Functional Testing of IEEE 1451.1 for NCAP-to-NCAP Communications in a Sensor Network

    Science.gov (United States)

    Figueroa, Jorge; Gurkan, Deniz; Yuan, X.; Benhaddou, D.; Liu, H.; Singla, A.; Franzl, R.; Ma, H.; Bhatt, S.; Morris, J.; hide

    2008-01-01

    Distributed control in a networked environment is an irreplaceable feature in systems with remote sensors and actuators. Although distributed control was not originally designed to be networked, usage of off-the-shelf networking technologies has become so prevalent that control systems are desired to have access mechanisms similar to computer networks. However, proprietary transducer interfaces for network communications and distributed control overwhelmingly dominate this industry. Unless the lack of compatibility and interoperability among transducers is resolved, the mature level of access (that computer networking can deliver) will not be achieved in such networked distributed control systems. Standardization of networked transducer interfaces will enable devices from different manufacturers to talk to each other and ensure their plug-and-play capability. One such standard is the suite of IEEE 1451 for sensor network communication and transducer interfaces. The suite not only provides a standard interface for smart transducers, but also outlines the connection of an NCAP (network capable application processor) and transducers (through a transducer interface module TIM). This paper presents the design of the compliance testing of IEEE 1451.1 (referred to as Dot1) compatible NCAP-to-NCAP communications on a link-layer independent medium. The paper also represents the first demonstration of NCAP-to-NCAP communications with Dot1 compatibility: a tester NCAP and an NCAP under test (NUT).

  1. Distributed Optimization of Multi Beam Directional Communication Networks

    Science.gov (United States)

    2017-06-30

    spatial processing strategies for multi-beam transmission with a simple MAC layer in a simulation study. Full-duplex communications ease the burden on...Distributed Optimization of Multi-Beam Directional Communication Networks Theodoros Tsiligkaridis MIT Lincoln Laboratory Lexington, MA 02141, USA...based routing. I. INTRODUCTION Missions where multiple communication goals are of in- terest are becoming more prevalent in military applications

  2. Communication to within a fidelity criterion over unknown networks by reduction to reliable communication problems over unknown networks

    CERN Document Server

    Agarwal, Mukul

    2010-01-01

    Consider a scenerio where various users want to communicate with each other over an unknown network to within a fidelity criterion. Thus, there are various users. Each user has a source that it wants to send to another user to within some distortion level. We abstract this problem as that of universal communication of random sources over networks to within a distortion criterion. We compute ta universally reliably achievable region for a set of networks where networks in the set are defined in terms of end to end distortion that they achieve for transmission of independent signals between various nodes assuming that there is common randomness between sender and corresponding receiver. Using this, we provide results for when communication of independent signals to within particular fidelity criteria is possible in terms of when reliable communication is possible. Using this, we show that when the sources at the various nodes are independent of each other, it is sufficient to consider separation architectures: ...

  3. Reliable Communication in Wireless Meshed Networks using Network Coding

    DEFF Research Database (Denmark)

    Pahlevani, Peyman; Paramanathan, Achuthan; Hundebøll, Martin

    2012-01-01

    The advantages of network coding have been extensively studied in the field of wireless networks. Integrating network coding with existing IEEE 802.11 MAC layer is a challenging problem. The IEEE 802.11 MAC does not provide any reliability mechanisms for overheard packets. This paper addresses th...... introduce some signaling overhead, the results show that the performance is yet improved....

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

    DEFF Research Database (Denmark)

    Sindbæk, Søren Michael

    2015-01-01

    Long-distance communication has emerged as a particular focus for archaeologicalexploration using network theory, analysis, and modelling. The promise is apparentlyobvious: communication in the past doubtlessly had properties of complex, dynamicnetworks, and archaeological datasets almost certainly...... preserve patterns of thisinteraction. Formal network analysis and modelling holds the potential to identify anddemonstrate such patterns, where traditional methods often prove inadequate. Thearchaeological study of communication networks in the past, however, calls for radically different analytical......,and use patterns. This point is demonstrated with reference to a study of Viking-period communication in the North Sea region...

  5. Interpreting physical flows in networks as a communication system

    Indian Academy of Sciences (India)

    communication systems and multiple-channel commu- nication systems. Moreover, we are able to interpret directly the information transmission capacity of the network with the network invariants, such as the node degree. 2. Methods and model. The starting point in our approach is to define and to analytically solve the ...

  6. Green Networking for Major Components of Information Communication Technology Systems

    Directory of Open Access Journals (Sweden)

    Zeadally Sherali

    2009-01-01

    Full Text Available Abstract Green Networking can be the way to help reduce carbon emissions by the Information and Communications Technology (ICT Industry. This paper presents some of the major components of Green Networking and discusses how the carbon footprint of these components can be reduced.

  7. The National Biomedical Communications Network as a Developing Structure.

    Science.gov (United States)

    Davis, Ruth M.

    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…

  8. Close communication and 2-clubs in corporate networks: Europe 2010

    NARCIS (Netherlands)

    Mokken, R.J.; Heemskerk, E.M.; Laan, S.

    2016-01-01

    Corporate networks, as induced by interlocking directorates between corporations, provide structures of personal communication between their boards. This paper studies such networks using the framework of a previous paper by Laan et al. (Soc Netw Anal Min, 2016. doi:10.1007/s13278-016-0326-0) where

  9. fraud detection in mobile communications networks using user

    African Journals Online (AJOL)

    DEPT OF AGRICULTURAL ENGINEERING

    Keywords: Call data, fraud detection, neural networks, probabilistic models, user profiling ... Intrusion detection approach can be divided into two classes of .... Raw call data. Call data simulator. SOM Neural. Network. Probabilistic. System. Monitoring. Database. Database. Fig. 3: Mobile communication detection tools.

  10. Real-Time Communication in Wireless Home Networks

    NARCIS (Netherlands)

    Scholten, Johan; Jansen, P.G.

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

  11. Seamless integrated network system for wireless communication systems

    NARCIS (Netherlands)

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

    2006-01-01

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

  12. Seamless integrated network system for wireless communication systems

    NARCIS (Netherlands)

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

    2002-01-01

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

  13. The facilitation of groups and networks: capabilities to shape creative cooperation

    DEFF Research Database (Denmark)

    Rasmussen, Lauge Baungaard

    2003-01-01

    The facilitator, defined as a process guide of creative cooperation, is becoming more and more in focus to assist groups,teams and networks to meet these challenges. The author defines and exemplifies different levels of creative coorperation. Core capabilities of facilitation are defined...

  14. Efficient Optimization Methods for Communication Network Planning and Assessment

    OpenAIRE

    Kiese, Moritz

    2010-01-01

    In this work, we develop efficient mathematical planning methods to design communication networks. First, we examine future technologies for optical backbone networks. As new, more intelligent nodes cause higher dynamics in the transport networks, fast planning methods are required. To this end, we develop a heuristic planning algorithm. The evaluation of the cost-efficiency of new, adapative transmission techniques comprises the second topic of this section. In the second part of this work, ...

  15. Wireless Network Communications Overview for Space Mission Operations

    Science.gov (United States)

    Fink, Patrick W.

    2009-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  17. Communicability reveals a transition to coordinated behavior in multiplex networks

    Science.gov (United States)

    Estrada, Ernesto; Gómez-Gardeñes, Jesús

    2014-04-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Michael D Conover

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

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

    Science.gov (United States)

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

    2013-01-01

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

  20. 2007 Information and Communication Network Among Natural ...

    African Journals Online (AJOL)

    ezra

    Introduction. Generally, scientist need information about current research and developmental activities and their socioeconomic implications in their fields of ... network in science. The establishment of sustainable information network opens up the horizon of information sharing wider. Garvey (1980) observed that a.

  1. Network Coding Protocols for Smart Grid Communications

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  2. Emergence of communication in socio-biological networks

    CERN Document Server

    Berea, Anamaria

    2018-01-01

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

  3. 2nd International Conference on Green Communications and Networks 2012

    CERN Document Server

    Ma, Maode; GCN 2012

    2013-01-01

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

  4. Proceedings of International Conference on Communication and Networks

    CERN Document Server

    Verma, Pramode; Trivedi, Bhushan

    2017-01-01

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

  5. Evolving Small-Cell Communications towards Mobile-over-FTTx Networks

    OpenAIRE

    Zhang, Jian A.; Collings, Iain B.; Chen, Chung Shue; Laurent, Roullet; Luo, Lin; Siu-Wai, Ho; Yuan, Jinhong

    2013-01-01

    International audience; Small cell techniques are recognized as the best way to deliver high capacity for broadband cellular communications. Femtocell and distributed antenna systems (DAS) are important components in the overall small cell story, but are not the complete solution. They have major disadvantages of very limited cooperation capability and expensive deployment cost, respectively. In this article, we propose a novel mobile-over-FTTx (MoF) network architecture, where a fiber-to-the...

  6. Visible light communications in heterogeneous networks: pave the way for user-centric design

    OpenAIRE

    Zhang, Rong; Wang, Jiaheng; Wang, Zhaocheng; Xu, Zhengyuan; Zhao, Chunming; Hanzo, Lajos

    2015-01-01

    At the time of writing, there is substantial research interest in the subject of Visible Light Communications (VLC) owing to its capability of offering significant traffic offloading potential in highly crowded Radio Frequency (RF) scenarios. We introduce the user-centric design of VLC for Heterogeneous Networks (HetNet), where three key aspects are identified and elaborated on, namely 1) signal coverage quality, 2) system control and 3) service provision aspects. More explicitly, the concept...

  7. Promoting scientific collaboration and research through integrated social networking capabilities within the OpenTopography Portal

    Science.gov (United States)

    Nandigam, V.; Crosby, C. J.; Baru, C.

    2009-04-01

    LiDAR (Light Distance And Ranging) topography data offer earth scientists the opportunity to study the earth's surface at very high resolutions. As a result, the popularity of these data is growing dramatically. However, the management, distribution, and analysis of community LiDAR data sets is a challenge due to their massive size (multi-billion point, mutli-terabyte). We have also found that many earth science users of these data sets lack the computing resources and expertise required to process these data. We have developed the OpenTopography Portal to democratize access to these large and computationally challenging data sets. The OpenTopography Portal uses cyberinfrastructure technology developed by the GEON project to provide access to LiDAR data in a variety of formats. LiDAR data products available range from simple Google Earth visualizations of LiDAR-derived hillshades to 1 km2 tiles of standard digital elevation model (DEM) products as well as LiDAR point cloud data and user generated custom-DEMs. We have found that the wide spectrum of LiDAR users have variable scientific applications, computing resources and technical experience and thus require a data system with multiple distribution mechanisms and platforms to serve a broader range of user communities. Because the volume of LiDAR topography data available is rapidly expanding, and data analysis techniques are evolving, there is a need for the user community to be able to communicate and interact to share knowledge and experiences. To address this need, the OpenTopography Portal enables social networking capabilities through a variety of collaboration tools, web 2.0 technologies and customized usage pattern tracking. Fundamentally, these tools offer users the ability to communicate, to access and share documents, participate in discussions, and to keep up to date on upcoming events and emerging technologies. The OpenTopography portal achieves the social networking capabilities by integrating various

  8. Training resonant communicators. From raining resonant communicators. From neural networks to network society

    Directory of Open Access Journals (Sweden)

    Gotzon Toral Madariaga

    2013-02-01

    Full Text Available 0 0 1 121 669 USAL 5 1 789 14.0 Normal 0 21 false false false ES JA X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:Calibri; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-ansi-language:ES; mso-fareast-language:EN-US;} Media control is no longer exclusively in the hands of professional broadcasters. New educational projects must empower users so that they can exercise their digital citizenship. As well as acquiring essential technical skills to move in an interconnected world, emotional literacy is also indispensable for people to desire to take part effectively in this augmented community. So, besides teaching audiovisual technology, this project seeks to re-program the relationship that students develop with a situation that is typically stressful. We propose an expanded practice that enables students to recognize and voluntarily activate their communication biology. This way, users can become actors in new communication networks, and global communication flow will be more plural and richer.

  9. Overlapping coalition formation games in wireless communication networks

    CERN Document Server

    Wang, Tianyu; Saad, Walid; Han, Zhu

    2017-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Miguel Ángel Nicolás

    2014-11-01

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

  11. Ninth International Conference on Wireless Communication and Sensor Networks

    CERN Document Server

    Tiwari, Murlidhar; Arora, Anish

    2014-01-01

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

  12. Job-related social networks and communication technology.

    Science.gov (United States)

    Nelson Bryen, Diane; Potts, Blyden B; Carey, Allison C

    2006-03-01

    In order to examine the social networks of individuals who rely on AAC, 38 adults who used AAC provided information about how they developed and maintained job-related social networks and how communication technologies helped them to do so. The respondents met new people who might become part of their job-related networks during social events with family or friends, as well as at meetings, conferences, and workshops. They also frequently used generic communication technologies such as the phone, email, computer, and the Internet to maintain contact with people in their social networks. Findings suggest that land-line telephones, email, and the Internet were used by the largest percentage of respondents, with email and the Internet used most frequently to contact the largest number of people. Qualitative data provided information about the use of technology for enhancing participants' job-related networks and suggestions for new or improved technologies.

  13. Signaling communication events in a computer network

    Science.gov (United States)

    Bender, Carl A.; DiNicola, Paul D.; Gildea, Kevin J.; Govindaraju, Rama K.; Kim, Chulho; Mirza, Jamshed H.; Shah, Gautam H.; Nieplocha, Jaroslaw

    2000-01-01

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

  14. The Vital Network: An Algorithmic Milieu of Communication and Control

    Directory of Open Access Journals (Sweden)

    Sandra Robinson

    2016-09-01

    Full Text Available The biological turn in computing has influenced the development of algorithmic control and what I call the vital network: a dynamic, relational, and generative assemblage that is self-organizing in response to the heterogeneity of contemporary network processes, connections, and communication. I discuss this biological turn in computation and control for communication alongside historically significant developments in cybernetics that set out the foundation for the development of self-regulating computer systems. Control is shifting away from models that historically relied on the human-animal model of cognition to govern communication and control, as in early cybernetics and computer science, to a decentred, nonhuman model of control by algorithm for communication and networks. To illustrate the rise of contemporary algorithmic control, I outline a particular example, that of the biologically-inspired routing algorithm known as a ‘quorum sensing’ algorithm. The increasing expansion of algorithms as a sense-making apparatus is important in the context of social media, but also in the subsystems that coordinate networked flows of information. In that domain, algorithms are not inferring categories of identity, sociality, and practice associated with Internet consumers, rather, these algorithms are designed to act on information flows as they are transmitted along the network. The development of autonomous control realized through the power of the algorithm to monitor, sort, organize, determine, and transmit communication is the form of control emerging as a postscript to Gilles Deleuze’s ‘postscript on societies of control.’

  15. The Device Centric Communication System for 5G Networks

    Science.gov (United States)

    Biswash, S. K.; Jayakody, D. N. K.

    2017-01-01

    The Fifth Generation Communication (5G) networks have several functional features such as: Massive Multiple Input and Multiple Output (MIMO), Device centric data and voice support, Smarter-device communications, etc. The objective for 5G networks is to gain the 1000x more throughput, 10x spectral efficiency, 100 x more energy efficiency than existing technologies. The 5G system will provide the balance between the Quality of Experience (QoE) and the Quality of Service (QoS), without compromising the user benefit. The data rate has been the key metric for wireless QoS; QoE deals with the delay and throughput. In order to realize a balance between the QoS and QoE, we propose a cellular Device centric communication methodology for the overlapping network coverage area in the 5G communication system. The multiple beacon signals mobile tower refers to an overlapping network area, and a user must be forwarded to the next location area. To resolve this issue, we suggest the user centric methodology (without Base Station interface) to handover the device in the next area, until the users finalize the communication. The proposed method will reduce the signalling cost and overheads for the communication.

  16. Communicating the sum of sources over a network

    CERN Document Server

    Ramamoorthy, Aditya

    2010-01-01

    We consider the network communication scenario, over directed acyclic networks with unit capacity edges in which a number of sources $s_i$ each holding independent unit-entropy information $X_i$ wish to communicate the sum $\\sum{X_i}$ to a set of terminals $t_j$. We show that in the case in which there are only two sources or only two terminals, communication is possible if and only if each source terminal pair $s_i/t_j$ is connected by at least a single path. For the more general communication problem in which there are three sources and three terminals, we prove that a single path connecting the source terminal pairs does not suffice to communicate $\\sum{X_i}$. We then present an efficient encoding scheme which enables the communication of $\\sum{X_i}$ for the three sources, three terminals case, given that each source terminal pair is connected by two edge disjoint paths. Our encoding scheme includes a structural decomposition of the network at hand which may be found useful for other network coding problem...

  17. Hierarchical Communication Network Architectures for Offshore Wind Power Farms

    Directory of Open Access Journals (Sweden)

    Mohamed A. Ahmed

    2014-05-01

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

  18. CNMO: Towards the Construction of a Communication Network Modelling Ontology

    Science.gov (United States)

    Rahman, Muhammad Azizur; Pakstas, Algirdas; Wang, Frank Zhigang

    Ontologies that explicitly identify objects, properties, and relationships in specific domains are essential for collaboration that involves sharing of data, knowledge or resources. A communications network modelling ontology (CNMO) has been designed to represent a network model as well as aspects related to its development and actual network operation. Network nodes/sites, link, traffic sources, protocols as well as aspects of the modeling/simulation scenario and operational aspects are defined with their formal representation. A CNMO may be beneficial for various network design/simulation/research communities due to the uniform representation of network models. This ontology is designed using terminology and concepts from various network modeling, simulation and topology generation tools.

  19. Mutual Interference Models for CDMA Mobile Communication Networks

    Directory of Open Access Journals (Sweden)

    K. Hrudkay

    2002-12-01

    Full Text Available Nowadays we are witnesses of a huge development one of the mostprogressive communication technology - mobile networks. The mainproblem in these networks is an elimination of the mutual interference,which, mainly in non-orthogonal CDMA networks, is the principalobstacle for reaching high transmission rates The aim of thiscontribution is to give simplified view to mutual interference modelsfor orthogonal and non-orthogonal CDMA networks. The contribution isintended mainly for PhD. students to help them to obtain an orientationin such a complicated areas, as the interference models for CDMAnetworks are.

  20. VIRTUAL NETWORK COMMUNICATION AND ITS IMPACT ON INTERPERSONAL RELATIONS

    Directory of Open Access Journals (Sweden)

    Сергей Николаевич Хуторной

    2013-08-01

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

  1. Secure Communication in Vehicular Networks - PRESERVE Demo

    NARCIS (Netherlands)

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

    2012-01-01

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

  2. Impact of distance on the network management capability of the home base firm

    DEFF Research Database (Denmark)

    Mykhaylenko, Alona; Wæhrens, Brian Vejrum; Slepniov, Dmitrij

    For many globally dispersed organizations the home base (HB) is historically the locus of integrative, coordinating and innovating efforts, important for the overall performance. The growing concerns about the offshoring strategies posing threats to the capabilities of the HB draw attention to how...... a HB can continuously sustain its centrality. The well-known challenges of distance in the distributed working arrangements may be regarded as a major threat to the network management capabilities (NMCs) of the HB. Therefore, this paper investigates what role does distance between the HB and its...

  3. A method for secure communications over a public fiber-optical network.

    Science.gov (United States)

    Wu, Bernard B; Narimanov, Evgenii E

    2006-05-01

    We develop a spread-spectrum based approach to secure communications over existing fiber-optical networks. Secure transmission for a dedicated user is achieved by overlaying a covert channel onto a host channel in the existing active fiber link. The covert channel is optically encoded and temporally spread, and has average power below the noise floor in the fiber, making it hidden for a direct detection thus allowing for cryptographic and steganographic security capabilities. The presence for the host channel in the network provides an ad hoc security expansion and increases the difficulty for an eavesdropper to intercept and decode the secure signal.

  4. Stream Traffic Communication in Packet Switched Networks,

    Science.gov (United States)

    1977-08-01

    Currently, the interconnection of surh networks [ McKe 74a] and the standardization of protocols [Pouz 75), (Hove 76) are each of considerable interest in the...clear that failures do occur in practice. Long term monitoring of the ARPANET [ McKe 74) shows a mean time between failures (MTBF) of 431 hours for Lines...D. C.) [ McKe 74) McKenzie, A. A. Letter to S. D. Crocker. 16 Janu- ary 1974. [ McKe 74a] McKenzie, A. M. "Some Computer Network Intercon- nection

  5. Network Coding Protocols for Smart Grid Communications

    DEFF Research Database (Denmark)

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

    2014-01-01

    We propose a robust network coding protocol for enhancing the reliability and speed of data gathering in smart grids. At the heart of our protocol lies the idea of tunable sparse network coding, which adopts the transmission of sparsely coded packets at the beginning of the transmission process...... but then switches to a denser coding structure towards the end. Our systematic mechanism maintains the sparse structure during the recombination of packets at the intermediate nodes. The performance of our protocol is compared by means of simulations of IEEE reference grids against standard master-slave protocols...

  6. Securing Communication in Ambient Networks for Speech Therapy Systems

    Directory of Open Access Journals (Sweden)

    ZAHARIA, M. H.

    2007-11-01

    Full Text Available One of the most present issues of computer wireless networks is the security. Comparing with their wired counterpart, the wireless networks not only accentuate some of the well-known security vulnerabilities but they are subject of new and specific ones. Among the existing wireless networks the ad hoc ones are the most exposed to attacks and collusions due to the absence of any centralized control. The most efficient way to ensure the communication secrecy, inclusively for ad hoc wireless networks, is the cryptography. From many reasons, following from specific operating conditions, the employment of asymmetric key techniques and Public Key Infrastructure is not a realistic choice. In the networks with a large number of nodes, as wireless sensor networks, a large number of secret keys are involved in order to ensure the communication secrecy. While dynamicity is one of the essential features of mobile wireless networks, when nodes may leave or join the network and in the absence of a centralized control entity, the management of secret keys is crucial. The paper presents the main aspects of mobile wireless networks security and focuses on the key management issue in ad-hoc wireless networks.In this paper the problem of securing mobile devices used in ambient networks for speech therapy is presented. The main target consists in making various mobile devices involved in speech therapy to maintain both the confidentiality of personal data of the patient and also to avoid interference when simultaneous communicate with the control center. Due to non-technical type of user all password management will be made automatic by the control system. As result the mobile device will have a user transparent security layer added. The problem of people from isolated community treatment is also solved by this approach.

  7. Future cooperative communication systems driven by social mobile networks

    DEFF Research Database (Denmark)

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

    2011-01-01

    In this work we are underlining the importance of social mobile networks for upcoming cooperative communication systems. The assumption of this work is that future mobile communication systems will incorporate user cooperation, i.e. a combination of cellular access in parallel with ongoing short...... range links to the neighboring devices. It has been shown that user cooperation enables higher data rates, better spectral efficiencies, and reduces the energy consumption of the mobile unit. In this work the social mobile networks are identified to be a fertile ground to facilitate the cooperative use...... cases. By the example of the Gedda-Headz gaming community, possible links between cooperative mobile communication and social mobile networks are shown....

  8. Topological networks for quantum communication between distant qubits

    Science.gov (United States)

    Lang, Nicolai; Büchler, Hans Peter

    2017-11-01

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

  9. Communications and Information: Network Management. Volume 1

    Science.gov (United States)

    1999-07-02

    local units to reduce the risks of remote management . When approved, the global or regional NM element provides guidance on accommodating this...Management X Setting parameters X X Changing network configuration X X Moves, adds, changes X X X Remote management X X Router management X Load

  10. Position Estimation of Transceivers in Communication Networks

    Energy Technology Data Exchange (ETDEWEB)

    Dowla, F; Kent, C

    2004-01-20

    With rapid developments in wireless sensor networks, there is a growing need for transceiver position estimation independent of GPS, which may not be available in indoor networks. Our approach is to use range estimates from time-of-flight (TOF) measurements, a technique well suited to large bandwidth physical links, such as in ultra-wideband (UWB) systems. In our UWB systems, pulse duration less than 200 psecs can easily be resolved to less than a foot. Assuming an encoded UWB physical layer, we first test positioning accuracy using simulations. We are interested in sensitivity to range errors and the required number of ranging nodes, and we show that in a high-precision environment, such as UWB, the optimal number of transmitters is four. Four transmitters with {+-}20ft. range error can locate a receiver to within one or two feet. We then implement these algorithms on an 802.11 wireless network and demonstrate the ability to locate a network access point to approximately 20 feet.

  11. Cognitive Radio Networks for Tactical Wireless Communications

    Science.gov (United States)

    2014-12-01

    communications. DRDC-RDDC-2014-R185 i Résumé …….. Le champ de bataille moderne est un environnement exigeant pour les réseaux de...et la réduction de l’encombrement du spectre, une résilience accrue des communications dans des environnements hétérogènes dynamiques, en plus de...without compromising security. –––––––––––––––––––––––––––––––––––––––––––––––––––––––- Le champ de bataille moderne est un environnement exigeant

  12. First-Use Analysis of Communication in a Social Network

    Science.gov (United States)

    Itaya, Satoko; Yoshinaga, Naoki; Davis, Peter; Tanaka, Rie; Konishi, Taku; Doi, Shinich; Yamada, Keiji

    The study of communication activity in social networks is aimed at understanding and promoting communications in groups, organizations and communities. In this paper, we propose a method for the analysis of communication records to extract content-based network activity, with a focus on first-use. Links between people in a social network are defined based on content and temporal relation of messages sent and received. We introduce the notion of first-use, first-use paths, and classes of users based on first-usage. First-use is defined with respect to a specific time period and specific communication content. It refers to the sending of messages containing the specified contents for the first time before being receiving them from any other user in the specified time period. First-use paths are defined as sequences of first-use events in communication networks, and m-ary classes of users are defined recursively as users who receive for the first time from (m-1)-ary users. We present an example of application of the analysis to the email records of a large company.

  13. A Secure Communication Suite for Underwater Acoustic Sensor Networks

    Directory of Open Access Journals (Sweden)

    Angelica Lo Duca

    2012-11-01

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

  14. A secure communication suite for underwater acoustic sensor networks.

    Science.gov (United States)

    Dini, Gianluca; Lo Duca, Angelica

    2012-11-07

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

  15. A Secure Communication Suite for Underwater Acoustic Sensor Networks

    Science.gov (United States)

    Dini, Gianluca; Duca, Angelica Lo

    2012-01-01

    In this paper we describe a security suite for Underwater Acoustic Sensor Networks comprising both fixed and mobile nodes. The security suite is composed of a secure routing protocol and a set of cryptographic primitives aimed at protecting the confidentiality and the integrity of underwater communication while taking into account the unique characteristics and constraints of the acoustic channel. By means of experiments and simulations based on real data, we show that the suite is suitable for an underwater networking environment as it introduces limited, and sometimes negligible, communication and power consumption overhead. PMID:23202204

  16. Non-line-of-sight underwater optical wireless communication network.

    Science.gov (United States)

    Arnon, Shlomi; Kedar, Debbie

    2009-03-01

    The growing need for ocean observation systems has stimulated considerable interest within the research community in advancing the enabling technologies of underwater wireless communication and underwater sensor networks. Sensors and ad hoc sensor networks are the emerging tools for performing extensive data-gathering operations on land, and solutions in the subsea setting are being sought. Efficient communication from the sensors and within the network is critical, but the underwater environment is extremely challenging. Addressing the special features of underwater wireless communication in sensor networks, we propose a novel non-line-of-sight network concept in which the link is implemented by means of back-reflection of the propagating optic signal at the ocean-air interface and derive a mathematical model of the channel. Point-to-multipoint links can be achieved in an energy efficient manner and broadcast broadband communications, such as video transmissions, can be executed. We show achievable bit error rates as a function of sensor node separation and demonstrate the feasibility of this concept using state-of-the-art silicon photomultiplier detectors.

  17. Distributed fusion estimation for sensor networks with communication constraints

    CERN Document Server

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

    2016-01-01

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

  18. Seamless and secure communications over heterogeneous wireless networks

    CERN Document Server

    Cao, Jiannong

    2014-01-01

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

  19. Advanced Communication for Wireless Sensor Networks

    Science.gov (United States)

    2016-08-22

    interest has been identified. To verify the performance of the new ASP architecture , we used our ASP to perform vehicle classification while the digital...years. Figure 38 illustrates the architecture of our ASP as well as the projected power savings. Figure 38. Left: block diagram of our analog...estimation produced by an object or subject using sensory data collected by a distributed sensor network was a challenging problem. While the problem was

  20. A study on the multiple dynamic wavelength distribution for gigabit capable passive optical networks

    Directory of Open Access Journals (Sweden)

    Gustavo Adolfo Puerto Leguizamón

    2014-04-01

    Full Text Available This paper presents a data traffic based study aiming at evaluating the impact of dynamic wavelength allocation on a Gigabit capable Passive Optical Network (GPON. In Passive Optical Networks (PON, an Optical Line Terminal (OLT feeds different PONs in such a way that a given wavelength channel is evenly distributed between the Optical Network Units (ONU at each PON. However, PONs do not specify any kind of dynamic behavior on the way the wavelengths are allocated in the network, a completely static distribution is implemented instead. In thispaper we evaluate the network performance in terms of packet losses and throughput for a number of ONUs being out-of-profile while featuring a given percentage of traffic in excess for a fixed wavelength distribution and for multiple dynamic wavelength allocation. Results show that for a multichannel operation with four wavelengths, the network throughput increases up to a rough value of 19% while the packet losses drop from 22 % to 1.8 % as compared with a static wavelength distribution.

  1. Networks on the Edge of Forever: Examining the Feasibility of using Meteor Burst (MB) Communication Networks on Mars

    Science.gov (United States)

    Charania, A.

    2002-01-01

    The envisioned future may include continuous operating outposts and networks on other worlds supporting human and robotic exploration. Given this possibility, a feasibility analysis is performed of a communications architecture based upon reflection of ion trails from meteors in planetary atmospheres. Meteor Burst (MB) communication systems use meteoritic impacts on planetary atmospheres as two-way, short burst communication nodes. MB systems consist of semi-continuous, low bandwidth networks. These systems possess both long distance capability (hundred of kilometers) and have lower susceptibility to atmospheric perturbations. Every day millions of meteors come into Earth's upper atmosphere with enough energy to ionize gas molecules suitably to reflect radio waves and facilitate communications beyond line of site. The ionized trail occurs at altitudes of 100 km with lengths reaching 30 km. The trial sustains itself long enough to support typical network distances of 1800 km. The initial step to use meteors in this fashion includes detection of a usable ionic trail. A probe signal is sent from one station to another in the network. If there is a meteor trail present, the probe signal is reflected to a receiving station. When another station receives the probe signal, it sends an acknowledgement to the originating station to proceed with transfer on that trail in a high-speed digital data burst. This probe-main signal handshaking occurs each time a burst of data is sent and can occur several times over the course of just one useable meteor trail. Given the need for non-data sending probe signals and error correcting bits; typical transmission data rates vary from a few kilobits per second to over 100 kilobits per second. On Earth, MB links open up hundreds of time per hour depending upon daily and seasonal variations. Meteor bursts were first noticed in detail in the 1930s. With the capabilities of modern computer processing, MB systems have become both technically

  2. Interoperable Communications for Hierarchical Heterogeneous Wireless Networks

    Science.gov (United States)

    2016-04-01

    policy or decision, unless so designated by other documentation . 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS (ES) U.S. Army Research Office...P.O. Box 12211 Research Triangle Park, NC 27709-2211 Cognitive radio; Wireless Networks REPORT DOCUMENTATION PAGE 11. SPONSOR/MONITOR’S REPORT...secondary user node to monitor the activity of the primary user.” cnmpAvgLinkCongestionInd(11) “The value of the average link con- gestion metric for one or

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

    Science.gov (United States)

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

    2013-01-01

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

  4. Building oceanographic and atmospheric observation networks by composition: unmanned vehicles, communication networks, and planning and execution control frameworks

    Science.gov (United States)

    Sousa, J. T.; Pinto, J.; Martins, R.; Costa, M.; Ferreira, F.; Gomes, R.

    2014-12-01

    The problem of developing mobile oceanographic and atmospheric observation networks (MOAO) with coordinated air and ocean vehicles is discussed in the framework of the communications and control software tool chain developed at Underwater Systems and Technologies Laboratory (LSTS) from Porto University. This is done with reference to field experiments to illustrate key capabilities and to assess future MOAO operations. First, the motivation for building MOAO by "composition" of air and ocean vehicles, communication networks, and planning and execution control frameworks is discussed - in networked vehicle systems information and commands are exchanged among multiple vehicles and operators, and the roles, relative positions, and dependencies of these vehicles and operators change during operations. Second, the planning and execution control framework developed at LSTS for multi-vehicle systems is discussed with reference to key concepts such as autonomy, mixed-initiative interactions, and layered organization. Third, the LSTS tool software tool chain is presented to show how to develop MOAO by composition. The tool chain comprises the Neptus command and control framework for mixed initiative interactions, the underlying IMC messaging protocol, and the DUNE on-board software. Fourth, selected LSTS operational deployments illustrate MOAO capability building. In 2012 we demonstrated the use of UAS to "ferry" data from UUVs located beyond line of sight (BLOS). In 2013 we demonstrated coordinated observations of coastal fronts with small UAS and UUVs, "bent" BLOS through the use of UAS as communication relays, and UAS tracking of juvenile hammer-head sharks. In 2014 we demonstrated UUV adaptive sampling with the closed loop controller of the UUV residing on a UAS; this was done with the help of a Wave Glider ASV with a communications gateway. The results from these experiments provide a background for assessing potential future UAS operations in a compositional MOAO.

  5. Role of Communication Networks in Behavioral Systems Analysis

    Science.gov (United States)

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

    2009-01-01

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

  6. Knowledge work and communication challenges in networked enterprises

    NARCIS (Netherlands)

    Barjis, J.; Gupta, A.; Sharda, R.

    2010-01-01

    A modern enterprise is a heavily wired and networked socio-technical system where multiple components play in symphony to yield a competitive position in the ear of digital economy. While the underling communication and interaction systems facilitate knowledge workers to carry out the enterprise

  7. Communicating, Networking: Interacting: The International Year of Global Understanding - IYGU

    National Research Council Canada - National Science Library

    Margaret E. Robertson

    2016-01-01

    ... for the world’s people, and the health of the planet, is an ongoing project.IYGU recognises the integral roles of networking and communication systems, as well as interactions between people, near and far, as fundamental for building better futures...

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

    Science.gov (United States)

    Riley, Carroll L.; Manson, Joni L.

    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…

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

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

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

  10. Large Deviations for Gaussian Queues (Modelling Communication Networks)

    NARCIS (Netherlands)

    Mandjes, M.R.H.

    2007-01-01

    In recent years the significance of Gaussian processes to communication networks has grown considerably. The inherent flexibility of the Gaussian traffic model enables the analysis, in a single mathematical framework, of systems with both long-range and short-range dependent input streams. Large

  11. Large Deviations for Gaussian Queues: Modelling Communication Networks

    NARCIS (Netherlands)

    M.R.H. Mandjes (Michel)

    2007-01-01

    htmlabstractIn recent years the significance of Gaussian processes to communication networks has grown considerably. The inherent flexibility of the Gaussian traffic model enables the analysis, in a single mathematical framework, of systems with both long-range and short-range dependent input

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

    NARCIS (Netherlands)

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

    2013-01-01

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

  13. Communication, Social Networks, and Influence in Citizen Participation.

    Science.gov (United States)

    Gaunt, Thomas P.

    1998-01-01

    Interviews and surveys of participants in five community projects investigated whether the communication process for citizen participation is a factor in increasing or decreasing citizen influence in decision making for a project. Findings demonstrate the importance of social-network analysis in assessing the effectiveness of participation…

  14. Video Communication for Networked Communities: Challenges and Opportunities

    NARCIS (Netherlands)

    T. Stevens; P.S. Cesar Garcia (Pablo Santiago); I. Kegel; N. Farber; D. Williams; M. Ursu; P. Stenton; P. Torres; M. Falekakis; R. Kaiser

    2012-01-01

    htmlabstractWhile advances in commercial video conferencing and social networking are driving more people to communicate using video, it is still difficult to achieve a sense of co-presence - that is to make the technology transparent to its users - when mediating ad hoc interactions between groups

  15. Multi-platform laser communication networking optical antenna system design

    Science.gov (United States)

    Zhang, Tao

    2016-10-01

    In this paper, a new conclusion based on rotating parabolic model and a different scheme of laser communication networking antenna system has been put forward in the paper. Based on rotating parabolic antenna, a new theory of the optical properties have been deduced, which can realize larger dynamic, duplex, networking communications among multiple platforms in 360° azimuth and pitch range. Meanwhile, depending on the operation mode of the system, multiple mathematical optimization models have been established. Tracking communication range, emission energy efficiency and receiving energy efficiency have been analyzed and optimized. Relationship among opening up and low apertures, the lens unit aperture, focal length of lens unit as well as rotating parabolic focal length have been analyzed. Tracking pitching range and emission energy utilization has carried on the theoretical derivation and optimization and networking platform link between energy receiver and transmitter has been analyzed. Taking some parameters of this new system into calculation, optimized results can be utilized with MATLAB software for its application and system of communication engineering. The rotating parabolic internal can form a hollow structure, which is utilized for miniaturization, light-weighted design and realize duplex communication in a wide range and distance. Circular orbit guidance is the modern way used in dynamic tracking system. The new theory and optical antenna system has widespread applications value as well.

  16. Consensus of Multiagent Systems With Distance-Dependent Communication Networks.

    Science.gov (United States)

    Jing, Gangshan; Zheng, Yuanshi; Wang, Long

    In this paper, we study the consensus problem of discrete-time and continuous-time multiagent systems with distance-dependent communication networks, respectively. The communication weight between any two agents is assumed to be a nonincreasing function of their distance. First, we consider the networks with fixed connectivity. In this case, the interaction between adjacent agents always exists but the influence could possibly become negligible if the distance is long enough. We show that consensus can be reached under arbitrary initial states if the decay rate of the communication weight is less than a given bound. Second, we study the networks with distance-dependent connectivity. It is assumed that any two agents interact with each other if and only if their distance does not exceed a fixed range. With the validity of some conditions related to the property of the initial communication graph, we prove that consensus can be achieved asymptotically. Third, we present some applications of the main results to opinion consensus problems and formation control problems. Finally, several simulation examples are presented to illustrate the effectiveness of the theoretical findings.In this paper, we study the consensus problem of discrete-time and continuous-time multiagent systems with distance-dependent communication networks, respectively. The communication weight between any two agents is assumed to be a nonincreasing function of their distance. First, we consider the networks with fixed connectivity. In this case, the interaction between adjacent agents always exists but the influence could possibly become negligible if the distance is long enough. We show that consensus can be reached under arbitrary initial states if the decay rate of the communication weight is less than a given bound. Second, we study the networks with distance-dependent connectivity. It is assumed that any two agents interact with each other if and only if their distance does not exceed a fixed

  17. Test experience on an ultrareliable computer communication network

    Science.gov (United States)

    Abbott, L. W.

    1984-01-01

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

  18. Optimal Planning of Communication System of CPS for Distribution Network

    Directory of Open Access Journals (Sweden)

    Ting Yang

    2017-01-01

    Full Text Available IoT is the technical basis to realize the CPS (Cyber Physical System for distribution networks, with which the complex system becomes more intelligent and controllable. Because of the multihop and self-organization characteristics, the large-scale heterogeneous CPS network becomes more difficult to plan. Using topological potential theory, one of typical big data analysis technologies, this paper proposed a novel optimal CPS planning model. Topological potential equalization is considered as the optimization objective function in heterogeneous CPS network with the constraints of communication requirements, physical infrastructures, and network reliability. An improved binary particle swarm optimization algorithm is proposed to solve this complex optimal problem. Two IEEE classic examples are adopted in the simulation, and the results show that, compared with benchmark algorithms, our proposed method can provide an effective topology optimization scheme to improve the network reliability and transmitting performance.

  19. Energy-Efficient Communication in Multi-interface Wireless Networks

    Science.gov (United States)

    Athanassopoulos, Stavros; Caragiannis, Ioannis; Kaklamanis, Christos; Papaioannou, Evi

    We study communication problems in wireless networks supporting multiple interfaces. In such networks, two nodes can communicate if they are close and share a common interface. The activation of each interface has a cost reflecting the energy consumed when a node uses this interface. We distinguish between the symmetric and non-symmetric case, depending on whether all nodes have the same activation cost for each interface or not. For the symmetric case, we present a (3/2 + ɛ)-approximation algorithm for the problem of achieving connectivity with minimum activation cost, improving a previous bound of 2. For the non-symmetric case, we show that the connectivity problem is not approximable within a sublogarithmic factor in the number of nodes and present a logarithmic approximation algorithm for a more general problem that models group communication.

  20. Reliability Improved Cooperative Communication over Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Zhuangbin Chen

    2017-10-01

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

  1. QoS-Aware Chain-based Data Aggregation in Cooperating Vehicular Communication Networks and Wireless Sensor Networks

    NARCIS (Netherlands)

    Taghikhaki, Zahra; Zhang, Y.; Meratnia, Nirvana; Havinga, Paul J.M.

    2012-01-01

    Vehicular Communication Networks (VCNs) and Wireless Sensor Networks (WSNs) are emerging types of networks, which have individually been extensively explored. However, their cooperation and exploring advantages offered by their integration are unexplored topics. Such integration help better

  2. Exploiting the In-Network Capabilities of Multicast to Discover Proximate IPTV Channels

    Directory of Open Access Journals (Sweden)

    William Donnelly

    2010-09-01

    Full Text Available IPTV has become the next generation of television due, in part, to its ability to support features that have been lacking in conventional broadcasting—for example, end-user interactivity, personalisation and localisation. Providers are also searching for the most efficient delivery methods to provide the greatest amount of contents at the lowest cost. At present IPTV uses IP multicast to deliver live TV channels in an over-provisioned walled-garden network due to issues of deploying multicast and QoS challenges in the public Internet. However, IPTV is likely to shift into some parts of the public Internet in the future as a managed service. Multicast routing is performed on a per-session destination-address basis so each router maintains a table of all of the multicast addresses to which the content is being forwarded. We exploit this information to discover and join the in-progress channels of geographically proximate users and to create a new incentivised premium service in future IPTV networks called ProxyTV. This approach is expected to minimise network bandwidth requirements as it enables ISPs to optimise bandwidth on their edge networks. This becomes increasingly significant as TV content consumes more and more bandwidth, especially with the onset of HD and 3D capabilities. In this paper, we have presented in detail the concept with the results of a survey and an analysis of network traffic to justify the proposed approach.

  3. Radar network communication through sensing of frequency hopping

    Science.gov (United States)

    Dowla, Farid; Nekoogar, Faranak

    2013-05-28

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

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

    Science.gov (United States)

    Montain, J.; Byrne, J. M.

    2010-12-01

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

  5. Influence and Dissemination Of Sentiments in Social Network Communication Patterns

    DEFF Research Database (Denmark)

    Hillmann, Robert; Trier, Matthias

    2013-01-01

    of sentiments in a quantitative analysis that is based on retrieved textual messages of communication patterns in over 12000 online social networks. Our empirical results suggest a general influence of sentiments on node communication patterns that is evidenced by increased occurrences of subsequent messages......Previous research suggests the existence of sentiments in online social networks. In comparison to real life human interaction, in which sentiments have been shown to have an influence on human behaviour, it is not yet completely understood which mechanisms explain how sentiments influence users...... in online environments. We develop a theoretical framework that tries to bridge the gap between social influence theories that focus on offline interactions on one hand and online interaction in social networks on the other hand. We then test our hypothesis about the influence and dissemination...

  6. PROACTIVE APPROACH TO THE INCIDENT AND PROBLEM MANAGEMENT IN COMMUNICATION NETWORKS

    Directory of Open Access Journals (Sweden)

    Vjeran Strahonja

    2007-06-01

    Full Text Available Proactive approach to communication network maintenance has the capability of enhancing the integrity and reliability of communication networks, as well as of reducing maintenance costs and overall number of incidents. This paper presents approaches to problem and incident prevention with the help of root-cause analysis, aligning that with the goal to foresee software performance. Implementation of proactive approach requires recognition of enterprise's current level of maintenance better insights into available approaches and tools, as well as their comparison, interoperability, integration and further development. The approach we are proposing and elaborating in this paper lies on the construction of a metamodel of the problem management of information technology, particularly the proactive problem management. The metamodel is derived from the original ITIL specification and presented in an object-oriented fashion by using structure (class diagrams conform to UML notation. Based on current research, appropriate metrics based on the concept of Key Performance Indicators is suggested.

  7. Creating Communications, Computing, and Networking Technology Development Road Maps for Future NASA Human and Robotic Missions

    Science.gov (United States)

    Bhasin, Kul; Hayden, Jeffrey L.

    2005-01-01

    For human and robotic exploration missions in the Vision for Exploration, roadmaps are needed for capability development and investments based on advanced technology developments. A roadmap development process was undertaken for the needed communications, and networking capabilities and technologies for the future human and robotics missions. The underlying processes are derived from work carried out during development of the future space communications architecture, an d NASA's Space Architect Office (SAO) defined formats and structures for accumulating data. Interrelationships were established among emerging requirements, the capability analysis and technology status, and performance data. After developing an architectural communications and networking framework structured around the assumed needs for human and robotic exploration, in the vicinity of Earth, Moon, along the path to Mars, and in the vicinity of Mars, information was gathered from expert participants. This information was used to identify the capabilities expected from the new infrastructure and the technological gaps in the way of obtaining them. We define realistic, long-term space communication architectures based on emerging needs and translate the needs into interfaces, functions, and computer processing that will be required. In developing our roadmapping process, we defined requirements for achieving end-to-end activities that will be carried out by future NASA human and robotic missions. This paper describes: 10 the architectural framework developed for analysis; 2) our approach to gathering and analyzing data from NASA, industry, and academia; 3) an outline of the technology research to be done, including milestones for technology research and demonstrations with timelines; and 4) the technology roadmaps themselves.

  8. Simulated apoptosis/neurogenesis regulates learning and memory capabilities of adaptive neural networks.

    Science.gov (United States)

    Chambers, R Andrew; Potenza, Marc N; Hoffman, Ralph E; Miranker, Willard

    2004-04-01

    Characterization of neuronal death and neurogenesis in the adult brain of birds, humans, and other mammals raises the possibility that neuronal turnover represents a special form of neuroplasticity associated with stress responses, cognition, and the pathophysiology and treatment of psychiatric disorders. Multilayer neural network models capable of learning alphabetic character representations via incremental synaptic connection strength changes were used to assess additional learning and memory effects incurred by simulation of coordinated apoptotic and neurogenic events in the middle layer. Using a consistent incremental learning capability across all neurons and experimental conditions, increasing the number of middle layer neurons undergoing turnover increased network learning capacity for new information, and increased forgetting of old information. Simulations also showed that specific patterns of neural turnover based on individual neuronal connection characteristics, or the temporal-spatial pattern of neurons chosen for turnover during new learning impacts new learning performance. These simulations predict that apoptotic and neurogenic events could act together to produce specific learning and memory effects beyond those provided by ongoing mechanisms of connection plasticity in neuronal populations. Regulation of rates as well as patterns of neuronal turnover may serve an important function in tuning the informatic properties of plastic networks according to novel informational demands. Analogous regulation in the hippocampus may provide for adaptive cognitive and emotional responses to novel and stressful contexts, or operate suboptimally as a basis for psychiatric disorders. The implications of these elementary simulations for future biological and neural modeling research on apoptosis and neurogenesis are discussed.

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

    Directory of Open Access Journals (Sweden)

    V. Ondryhal

    2011-06-01

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

  10. A Cooperative Communication Model Tailored for Energy Balance in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Camila F. Rêgo

    2017-08-01

    Full Text Available Wireless Sensor Networks (WSN are characterized by their capacity of monitoring the environment, gathering and sharing information. Nodes in a WSN usually cooperate in the task of forwarding the sensed data to a sink node for later retrieval and analysis. The success of this task depends on the availability of efficient routes that meet the application requirements. As topology may change overtime, alternatives to improve and maintain network connectivity are highly desired. In this context, Cooperative Communication (CC emerged as an alternative to improve network connectivity. Despite its benefits, CC-links are known to have higher energy demands as compared to traditional, direct, links. In particular, CC-links require the source node to expend more power than others nodes, shortening their life span. The main contribution of this paper is to propose a new Cooperative Communication model, capable of increasing the energy balance of the CC-links while improving network connectivity. Simulation results show that, compared to other CC schemes, the source node of a Cooperative Communication reduces the amount of expended energy by 68% in the evaluated settings.

  11. Structures and Infrastructures of International R&D Networks: A Capability Maturity Perspective

    DEFF Research Database (Denmark)

    Niang, Mohamed; Wæhrens, Brian Vejrum

    to dispersed development. Design/Methodology/Approach: This is a qualitative study of the process of distributing R&D. By comparing selected firms, the researchers identify a pattern of dispersion of R&D activities in three Danish firms. Findings and Discussion: Drawing from the case studies, the researchers...... present a capability maturity model. Furthermore, understanding the interaction between new structures and infrastructures of the dispersed networks is viewed as a key requirement for developing organizational capabilities and formulating adequate strategies that leverage dispersed R&D. Organizational...... and strategic implications of the model emphasize increased interrelations and a need for coordination resulting in rising coordination costs. Decentralized control is viewed a mean to combine the advantages of centralization and decentralization. Originality/Value: While the offshoring of production has widely...

  12. Case study of the development of a SANDF tactical data link network enabling capability [Journal article

    CSIR Research Space (South Africa)

    Smith

    2011-11-01

    Full Text Available stream_source_info Smith_2011_ABSTARCT ONLY.pdf.txt stream_content_type text/plain stream_size 5823 Content-Encoding ISO-8859-1 stream_name Smith_2011_ABSTARCT ONLY.pdf.txt Content-Type text/plain; charset=ISO-8859... SANDF TACTICAL DATA LINK NETWORK ENABLING CAPABILITY Corn? J. Smith and Jacobus P. Venter * Abstract. In the scope of Tactical Data Links (TDL), the South African National Defence Force (SANDF) started the journey to establish a national TDL...

  13. Effect of signal noise on the learning capability of an artificial neural network

    Science.gov (United States)

    Vega, J. J.; Reynoso, R.; Calvet, H. Carrillo

    2009-07-01

    Digital Pulse Shape Analysis (DPSA) by artificial neural networks (ANN) is becoming an important tool to extract relevant information from digitized signals in different areas. In this paper, we present a systematic evidence of how the concomitant noise that distorts the signals or patterns to be identified by an ANN set limits to its learning capability. Also, we present evidence that explains overtraining as a competition between the relevant pattern features, on the one side, against the signal noise, on the other side, as the main cause defining the shape of the error surface in weight space and, consequently, determining the steepest descent path that controls the ANN adaptation process.

  14. Effect of signal noise on the learning capability of an artificial neural network

    Energy Technology Data Exchange (ETDEWEB)

    Vega, J.J. [Departamento del Acelerador, Gerencia de Ciencias Ambientales, Instituto Nacional de Investigaciones Nucleares, Apartado Postal 18-1027, Mexico D.F. 11801 (Mexico)], E-mail: jjvc@nuclear.inin.mx; Reynoso, R. [Departamento del Acelerador, Gerencia de Ciencias Ambientales, Instituto Nacional de Investigaciones Nucleares, Apartado Postal 18-1027, Mexico D.F. 11801 (Mexico); Calvet, H. Carrillo [Laboratorio de Dinamica no Lineal, Facultad de Ciencias, Universidad Nacional Autonoma de Mexico, Mexico D.F. 04510 (Mexico)

    2009-07-21

    Digital Pulse Shape Analysis (DPSA) by artificial neural networks (ANN) is becoming an important tool to extract relevant information from digitized signals in different areas. In this paper, we present a systematic evidence of how the concomitant noise that distorts the signals or patterns to be identified by an ANN set limits to its learning capability. Also, we present evidence that explains overtraining as a competition between the relevant pattern features, on the one side, against the signal noise, on the other side, as the main cause defining the shape of the error surface in weight space and, consequently, determining the steepest descent path that controls the ANN adaptation process.

  15. Comparison of High Performance Network Options: EDR InfiniBand vs.100Gb RDMA Capable Ethernet

    Energy Technology Data Exchange (ETDEWEB)

    Kachelmeier, Luke Anthony [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Univ. of New Mexico, Albuquerque, NM (United States); Van Wig, Faith Virginia [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Missouri Univ. of Science and Technology, Rolla, MO (United States); Erickson, Kari Natania [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); New Mexico Inst. of Mining and Technology, Socorro, NM (United States)

    2016-08-08

    These are the slides for a presentation at the HPC Mini Showcase. This is a comparison of two different high performance network options: EDR InfiniBand and 100Gb RDMA capable ethernet. The conclusion of this comparison is the following: there is good potential, as shown with the direct results; 100Gb technology is too new and not standardized, thus deployment effort is complex for both options; different companies are not necessarily compatible; if you want 100Gb/s, you must get it all from one place.

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2014-10-01

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

  18. Research on optic antenna of space laser communication networking

    Science.gov (United States)

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

    2013-08-01

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

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

    Directory of Open Access Journals (Sweden)

    Simeone O

    2007-01-01

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

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

    NARCIS (Netherlands)

    de Vries, Sjoerd A.; Isaias, P.

    2002-01-01

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

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

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  2. High-Throughput Network Communication with NetIO

    CERN Document Server

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

    2016-01-01

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

  3. Asymmetrical Modulation for Uplink Communication in Cooperative Networks

    DEFF Research Database (Denmark)

    Zhang, Qi; Fitzek, Frank H.P.; Iversen, Villy Bæk

    2008-01-01

    In this paper a spectrum efficient uplink communication method for cooperative wireless networks is presented. In cellular controlled peer to peer (CCP2P) cooperative wireless networks the mobile device is logically connected over cellular links with the base station and simultaneously over short...... is generating signals that are conveyed towards the base station and the neighboring devices in the same frequency and even at the same time. The signal is composed in such a way that it has different meanings for the neighboring devices than the base station. While the base station is getting the coarse...

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

    CERN Document Server

    Neely, Michael

    2010-01-01

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

  5. ECS: Efficient Communication Scheduling for Underwater Sensor Networks

    Directory of Open Access Journals (Sweden)

    Lu Hong

    2011-03-01

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

  6. ECS: efficient communication scheduling for underwater sensor networks.

    Science.gov (United States)

    Hong, Lu; Hong, Feng; Guo, Zhongwen; Li, Zhengbao

    2011-01-01

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

  7. Radio propagation and adaptive antennas for wireless communication networks

    CERN Document Server

    Blaunstein, Nathan

    2014-01-01

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

  8. Practical issues in picture archiving and communication system and networking

    Science.gov (United States)

    Kalyanpur, Arjun; Singh, Jasbir; Bedi, Ricky

    2010-01-01

    Picture Archiving and Communication System (PACS) is a key workflow tool in the functioning of radiology departments worldwide, today, and its utilization is rapidly growing in India. The key challenges in PACS implementation are related to vendor and feature selection, integration with the existing HIS, user training, maintenance and scalability to meet increasing demands. Additionally, the networking requirements that PACS imposes on hospital networks are not insignificant. This article attempts to review these issues from the standpoint of what a prospective or new user needs to know. PMID:20351983

  9. Practical issues in picture archiving and communication system and networking

    Directory of Open Access Journals (Sweden)

    Kalyanpur Arjun

    2010-01-01

    Full Text Available Picture Archiving and Communication System (PACS is a key workflow tool in the functioning of radiology departments worldwide, today, and its utilization is rapidly growing in India. The key challenges in PACS implementation are related to vendor and feature selection, integration with the existing HIS, user training, maintenance and scalability to meet increasing demands. Additionally, the networking requirements that PACS imposes on hospital networks are not insignificant. This article attempts to review these issues from the standpoint of what a prospective or new user needs to know.

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

    NARCIS (Netherlands)

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

    2013-01-01

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

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

    Science.gov (United States)

    Hoder, Douglas; Bergamo, Marcos

    1996-01-01

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

  12. Improvements to Optical Communication Capabilities Achieved through the Optical Injection of Semiconductor Lasers

    Science.gov (United States)

    2012-03-22

    electromagnetic radiation . Never the less, guided optical communication does not dominate the entire communications industry since copper wires still...sequenced spread-spectrum (CSSS) communication symbols (compliant with IEEE 802.11a or WiFi ) on a widely tunable microwave frequency exclusively... radiation (photons) with random direction, random phase, and energy equal to the band-gap as, described by Equation (6). 27 Figure 2.6: Driving

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

    Science.gov (United States)

    1973-01-01

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

  14. Successive lag synchronization on dynamical networks with communication delay

    Science.gov (United States)

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

    2016-03-01

    In this paper, successive lag synchronization (SLS) on a dynamical network with communication delay is investigated. In order to achieve SLS on the dynamical network with communication delay, we design linear feedback control and adaptive control, respectively. By using the Lyapunov function method, we obtain some sufficient conditions for global stability of SLS. To verify these results, some numerical examples are further presented. This work may find potential applications in consensus of multi-agent systems. Project supported by the National Natural Science Foundation of China (Grant No. 61004101), the Natural Science Foundation Program of Guangxi Province, China (Grant No. 2015GXNSFBB139002), the Graduate Innovation Project of Guilin University of Electronic Technology, China (Grant No. GDYCSZ201472), and the Guangxi Colleges and Universities Key Laboratory of Data Analysis and Computation, Guilin University of Electronic Technology, China.

  15. Asymmetries in commitment in an avian communication network

    Science.gov (United States)

    Randler, Christoph; Vollmer, Christian

    2013-02-01

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

  16. Modeling and Analysis of Mobility Management in Mobile Communication Networks

    Directory of Open Access Journals (Sweden)

    Woon Min Baek

    2014-01-01

    Full Text Available 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.

  17. Analyzing the Dynamics of Communication in Online Social Networks

    Science.gov (United States)

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

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

  18. Networked Airbourne Communications Using Adaptive Multi Beam Directional Links

    Science.gov (United States)

    2016-03-05

    January 8, 2009. works introduce more sophisticated channel models, and route selection by a method called percolation [7], [8]. For these examples ...Networked Airborne Communications Using Adaptive Multi-Beam Directional Links R. Bruce MacLeod Member, IEEE, and Adam Margetts Member, IEEE MIT...provide new techniques for increasing throughput in airborne adaptive directional net- works. By adaptive directional linking, we mean systems that can

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

    Science.gov (United States)

    2017-09-01

    experiment using Intel Arduino 101 to control the Iridium 9602 Modem, also known as the RockBlock MK2, to test the possibility of sending a text file from...the next-generation NPSFS. 14. SUBJECT TERMS space, Femto satellite, NPSFS, network, communication, Arduino , RockBlock, Iridium Modem 15. NUMBER...using System Tool Kit with QualNet (STK/QualNet) software. For the next generation of NPSFS, we conducted an experiment using Intel Arduino 101 to

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

    Energy Technology Data Exchange (ETDEWEB)

    1990-05-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Anna Notaro

    2014-12-01

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

  3. Detection and localization capability of an urban seismic sinkhole monitoring network

    Science.gov (United States)

    Becker, Dirk; Dahm, Torsten; Schneider, Fabian

    2017-04-01

    Microseismic events linked to underground processes in sinkhole areas might serve as precursors to larger mass dislocation or rupture events which can cause felt ground shaking or even structural damage. To identify these weak and shallow events, a sensitive local seismic monitoring network is needed. In case of an urban environment the performance of local monitoring networks is severely compromised by the high anthropogenic noise level. We study the detection and localization capability of such a network, which is already partly installed in the urban area of the city of Hamburg, Germany, within the joint project SIMULTAN (http://www.gfz-potsdam.de/en/section/near-surface-geophysics/projects/simultan/). SIMULTAN aims to monitor a known sinkhole structure and gain a better understanding of the underlying processes. The current network consists of six surface stations installed in the basement of private houses and underground structures of a research facility (DESY - Deutsches Elektronen Synchrotron). During the started monitoring campaign since 2015, no microseismic events could be unambiguously attributed to the sinkholes. To estimate the detection and location capability of the network, we calculate synthetic waveforms based on the location and mechanism of former events in the area. These waveforms are combined with the recorded urban seismic noise at the station sites. As detection algorithms a simple STA/LTA trigger and a more sophisticated phase detector are used. While the STA/LTA detector delivers stable results and is able to detect events with a moment magnitude as low as 0.35 at a distance of 1.3km from the source even under the present high noise conditions the phase detector is more sensitive but also less stable. It should be stressed that due to the local near surface conditions of the wave propagation the detections are generally performed on S- or surface waves and not on P-waves, which have a significantly lower amplitude. Due to the often

  4. Augmenting communication, emotion expression and interaction capabilities of individuals with cerebral palsy

    OpenAIRE

    Scherer, Reinhold; Wagner, Johanna; Billinger, Martin; Müller-Putz, Gernot; Raya, Rafael; Rocon de Lima, Eduardo; Mohamad, Yehya; Tassilo Hettich, Dirk; Bolinger, Elaina; Iosa, Marco; Cincotti, Febo; Londral, Ana Rita; Mesquita, Joana; Lloria Garcia, Mariano; Belda, Juanma

    2014-01-01

    Providing individuals with cerebral palsy (CP) tools to communicate and interact with the environment independently and reliably since childhood would allow for a more active participation in education and social life. We outline first steps towards the development of such a hybrid brain-computer interface-based (BCI) communication tool.

  5. Practical Quantum Communication and Cryptography for WDM Optical Networks

    Science.gov (United States)

    Kumar, Prem

    2004-11-01

    Keeping in mind the ubiquitous standard optical fiber for long-distance transmission and the widespread availability of efficient active and passive fiber devices, we have been developing telecom-band resources for practical quantum communication and cryptography in wave-division-multiplexed (WDM) optical networks. In this talk I present our recent results on two fronts: i) telecom-band in-fiber entanglement generation, storage, and long-distance distribution and ii) quantum-noise protected high-speed data encryption through an optically-amplified WDM line. Along the first front, with our in-fiber entanglement source all four Bell states can be readily produced and we have demonstrated violation of Bell's inequalities by up to 10 standard deviations of measurement uncertainty. With such a source we have demonstrated storage of entanglement for up to 1/8 of a millisecond. Furthermore, when each photon of the entangled pair is propagated in separate 25km-long standard fibers, high visibility quantum interference is still observed, demonstrating that this system is capable of long-distance (> 50 km) entanglement distribution. Along the second front, we have implemented a new quantum cryptographic scheme, based on Yuen's KCQ protocol, in which the inherent quantum noise of coherent states of light is used to perform the cryptographic service of data encryption. In this scheme a legitimate receiver, with use of a short, shared, secret-key, executes a simple binary decision rule on every transmitted bit. An eavesdropper, on the other hand, who does not possess the secret-key, is subjected to an irreducible quantum uncertainty in each measurement, even with the use of ideal detectors. We have implemented this scheme to demonstrate quantum-noise-protected data encryption at 650 Mbps through a 200 km, in-line amplified, WDM line. The line simultaneously carried two 10 Gbps standard data channels, 100 GHz on either side of the encrypted channel, which shows that this scheme

  6. A programmable analog VLSI neural network processor for communication receivers.

    Science.gov (United States)

    Choi, J; Bang, S H; Sheu, B J

    1993-01-01

    An analog VLSI neural network processor was designed and fabricated for communication receiver applications. It does not require prior estimation of the channel characteristics. A powerful channel equalizer was implemented with this processor chip configured as a four-layered perceptron network. The compact synapse cell is realized with an enhanced wide-range Gilbert multiplier circuit. The output neuron consists of a linear current-to-voltage converter and a sigmoid function generator with a controllable voltage gain. Network training is performed by the modified Kalman neuro-filtering algorithm to speed up the convergence process for intersymbol interference and white Gaussian noise communication channels. The learning process is done in the companion DSP board which also keeps the synapse weight for later use of the chip. The VLSI neural network processor chip occupies a silicon area of 4.6 mmx6.8 mm and was fabricated in a 2-mum double-polysilicon CMOS technology. System analysis and experimental results are presented.

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

    Science.gov (United States)

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

    2015-01-01

    Appropriate network design is very significant for Underwater Wireless Sensor Networks (UWSNs). Application-oriented UWSNs are planned to achieve certain objectives. Therefore, there is always a demand for efficient data routing schemes, which can fulfill certain requirements of application-oriented UWSNs. These networks can be of any shape, i.e., rectangular, cylindrical or square. In this paper, we propose chain-based routing schemes for application-oriented cylindrical networks and also formulate mathematical models to find a global optimum path for data transmission. In the first scheme, we devise four interconnected chains of sensor nodes to perform data communication. In the second scheme, we propose routing scheme in which two chains of sensor nodes are interconnected, whereas in third scheme single-chain based routing is done in cylindrical networks. After finding local optimum paths in separate chains, we find global optimum paths through their interconnection. Moreover, we develop a computational model for the analysis of end-to-end delay. We compare the performance of the above three proposed schemes with that of Power Efficient Gathering System in Sensor Information Systems (PEGASIS) and Congestion adjusted PEGASIS (C-PEGASIS). Simulation results show that our proposed 4-chain based scheme performs better than the other selected schemes in terms of network lifetime, end-to-end delay, path loss, transmission loss, and packet sending rate. PMID:25658394

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

    Directory of Open Access Journals (Sweden)

    Nadeem Javaid

    2015-02-01

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

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

    Science.gov (United States)

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

    2015-02-04

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

  10. Communication network for decentralized remote tele-science during the Spacelab mission IML-2

    Science.gov (United States)

    Christ, Uwe; Schulz, Klaus-Juergen; Incollingo, Marco

    1994-01-01

    The ESA communication network for decentralized remote telescience during the Spacelab mission IML-2, called Interconnection Ground Subnetwork (IGS), provided data, voice conferencing, video distribution/conferencing and high rate data services to 5 remote user centers in Europe. The combination of services allowed the experimenters to interact with their experiments as they would normally do from the Payload Operations Control Center (POCC) at MSFC. In addition, to enhance their science results, they were able to make use of reference facilities and computing resources in their home laboratory, which typically are not available in the POCC. Characteristics of the IML-2 communications implementation were the adaptation to the different user needs based on modular service capabilities of IGS and the cost optimization for the connectivity. This was achieved by using a combination of traditional leased lines, satellite based VSAT connectivity and N-ISDN according to the simulation and mission schedule for each remote site. The central management system of IGS allows minimization of staffing and the involvement of communications personnel at the remote sites. The successful operation of IGS for IML-2 as a precursor network for the Columbus Orbital Facility (COF) has proven the concept for communications to support the operation of the COF decentralized scenario.

  11. Altered network communication following a neuroprotective drug treatment.

    Directory of Open Access Journals (Sweden)

    Kathleen Vincent

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

  12. Accepting Hybrid Networks of Evolutionary Processors with Special Topologies and Small Communication

    Directory of Open Access Journals (Sweden)

    Jürgen Dassow

    2010-08-01

    Full Text Available Starting from the fact that complete Accepting Hybrid Networks of Evolutionary Processors allow much communication between the nodes and are far from network structures used in practice, we propose in this paper three network topologies that restrict the communication: star networks, ring networks, and grid networks. We show that ring-AHNEPs can simulate 2-tag systems, thus we deduce the existence of a universal ring-AHNEP. For star networks or grid networks, we show a more general result; that is, each recursively enumerable language can be accepted efficiently by a star- or grid-AHNEP. We also present bounds for the size of these star and grid networks. As a consequence we get that each recursively enumerable can be accepted by networks with at most 13 communication channels and by networks where each node communicates with at most three other nodes.

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

    KAUST Repository

    AlAmmouri, Ahmad

    2016-04-01

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

  14. Network security with openSSL cryptography for secure communications

    CERN Document Server

    Viega, John; Chandra, Pravir

    2002-01-01

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

  15. Strategies for Power Line Communications Smart Metering Network Deployment

    Directory of Open Access Journals (Sweden)

    Alberto Sendin

    2014-04-01

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

  16. Wireless Communications and Networking Technologies for Smart Grid: Paradigms and Challenges

    OpenAIRE

    Fang, Xi; Yang, Dejun; Xue, Guoliang

    2011-01-01

    Smart grid, regarded as the next generation power grid, uses two-way flows of electricity and information to create a widely distributed automated energy delivery network. In this work we present our vision on smart grid from the perspective of wireless communications and networking technologies. We present wireless communication and networking paradigms for four typical scenarios in the future smart grid and also point out the research challenges of the wireless communication and networking ...

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

    Science.gov (United States)

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

    2010-01-01

    Plants can defend themselves to pathogen and herbivore attack by responding to chemical signals that are emitted by attacked plants. It is well established that such signals can be transferred through the air. In theory, plants can also communicate with each other through underground common mycorrhizal networks (CMNs) that interconnect roots of multiple plants. However, until now research focused on plant-to-plant carbon nutrient movement and there is no evidence that defense signals can be exchanged through such mycorrhizal hyphal networks. Here, we show that CMNs mediate plant-plant communication between healthy plants and pathogen-infected tomato plants (Lycopersicon esculentum Mill.). After establishment of CMNs with the arbuscular mycorrhizal fungus Glomus mosseae between tomato plants, inoculation of ‘donor’ plants with the pathogen Alternaria solani led to increases in disease resistance and activities of the putative defensive enzymes, peroxidase, polyphenol oxidase, chitinase, β-1,3-glucanase, phenylalanine ammonia-lyase and lipoxygenase in healthy neighbouring ‘receiver’ plants. The uninfected ‘receiver’ plants also activated six defence-related genes when CMNs connected ‘donor’ plants challenged with A. solani. This finding indicates that CMNs may function as a plant-plant underground communication conduit whereby disease resistance and induced defence signals can be transferred between the healthy and pathogen-infected neighbouring plants, suggesting that plants can ‘eavesdrop’ on defence signals from the pathogen-challenged neighbours through CMNs to activate defences before being attacked themselves. PMID:20967206

  18. Tuneable drug-loading capability of chitosan hydrogels with varied network architectures

    CERN Document Server

    Tronci, Giuseppe; Russell, Stephen J; Wood, David J; Akashi, Mitsuru

    2013-01-01

    Advanced bioactive systems with defined macroscopic properties and spatio-temporal sequestration of extracellular biomacromolecules are highly desirable for next generation therapeutics. Here, chitosan hydrogels were prepared with neutral or negatively-charged crosslinkers in order to promote selective electrostatic complexation with charged drugs. Chitosan (CT) was functionalised with varied dicarboxylic acids, such as tartaric acid (TA), poly(ethylene glycol) bis(carboxymethyl) ether (PEG), 1.4-Phenylenediacetic acid (4Ph) and 5-Sulfoisophthalic acid monosodium salt (PhS), whereby PhS was hypothesised to act as a simple mimetic of heparin. ATR FT-IR showed the presence of C=O amide I, N-H amide II and C=O ester bands, providing evidence of covalent network formation. The crosslinker content was reversely quantified by 1H-NMR on partially-degraded network oligomers, so that 18 mol% PhS was exemplarily determined. Swellability, compressability, material morphology, and drug-loading capability were successfull...

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

    Directory of Open Access Journals (Sweden)

    Francisco Porcel-Rodríguez

    2016-08-01

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

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

    Science.gov (United States)

    Porcel-Rodríguez, Francisco; Valenzuela-Valdés, Juan; Padilla, Pablo; Luna-Valero, Francisco; Luque-Baena, Rafael; López-Gordo, Miguel Ángel

    2016-08-20

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

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

    Directory of Open Access Journals (Sweden)

    Ligang Wu

    2017-02-01

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

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

    Science.gov (United States)

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

    2017-06-01

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

  3. Space Communications and Navigation (SCaN) Integrated Network Architecture Definition Document (ADD). Volume 1; Executive Summary; Revision 1

    Science.gov (United States)

    Younes, Badri A.; Schier, James S.

    2010-01-01

    The SCaN Program has defined an integrated network architecture that fully meets the Administrator s mandate to the Program, and will result in a NASA infrastructure capable of providing the needed and enabling communications services to future space missions. The integrated network architecture will increase SCaN operational efficiency and interoperability through standardization, commonality and technology infusion. It will enable NASA missions requiring advanced communication and tracking capabilities such as: a. Optical communication b. Antenna arraying c. Lunar and Mars Relays d. Integrated network management (service management and network control) and integrated service execution e. Enhanced tracking for navigation f. Space internetworking with DTN and IP g. End-to-end security h. Enhanced security services Moreover, the SCaN Program has created an Integrated Network Roadmap that depicts an orchestrated and coherent evolution path toward the target architecture, encompassing all aspects that concern network assets (i.e., operations and maintenance, sustaining engineering, upgrade efforts, and major development). This roadmap identifies major NASA ADPs, and shows dependencies and drivers among the various planned undertakings and timelines. The roadmap is scalable to accommodate timely adjustments in response to Agency needs, goals, objectives and funding. Future challenges to implementing this architecture include balancing user mission needs, technology development, and the availability of funding within NASA s priorities. Strategies for addressing these challenges are to: define a flexible architecture, update the architecture periodically, use ADPs to evaluate options and determine when to make decisions, and to engage the stakeholders in these evaluations. In addition, the SCaN Program will evaluate and respond to mission need dates for technical and operational capabilities to be provided by the SCaN integrated network. In that regard, the architecture

  4. Network-Capable Application Process and Wireless Intelligent Sensors for ISHM

    Science.gov (United States)

    Figueroa, Fernando; Morris, Jon; Turowski, Mark; Wang, Ray

    2011-01-01

    Intelligent sensor technology and systems are increasingly becoming attractive means to serve as frameworks for intelligent rocket test facilities with embedded intelligent sensor elements, distributed data acquisition elements, and onboard data acquisition elements. Networked intelligent processors enable users and systems integrators to automatically configure their measurement automation systems for analog sensors. NASA and leading sensor vendors are working together to apply the IEEE 1451 standard for adding plug-and-play capabilities for wireless analog transducers through the use of a Transducer Electronic Data Sheet (TEDS) in order to simplify sensor setup, use, and maintenance, to automatically obtain calibration data, and to eliminate manual data entry and error. A TEDS contains the critical information needed by an instrument or measurement system to identify, characterize, interface, and properly use the signal from an analog sensor. A TEDS is deployed for a sensor in one of two ways. First, the TEDS can reside in embedded, nonvolatile memory (typically flash memory) within the intelligent processor. Second, a virtual TEDS can exist as a separate file, downloadable from the Internet. This concept of virtual TEDS extends the benefits of the standardized TEDS to legacy sensors and applications where the embedded memory is not available. An HTML-based user interface provides a visual tool to interface with those distributed sensors that a TEDS is associated with, to automate the sensor management process. Implementing and deploying the IEEE 1451.1-based Network-Capable Application Process (NCAP) can achieve support for intelligent process in Integrated Systems Health Management (ISHM) for the purpose of monitoring, detection of anomalies, diagnosis of causes of anomalies, prediction of future anomalies, mitigation to maintain operability, and integrated awareness of system health by the operator. It can also support local data collection and storage. This

  5. Performance Modeling of Communication Networks with Markov Chains

    CERN Document Server

    Mo, Jeonghoon

    2010-01-01

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

  6. Future mobile communications LTE optimization and mobile network virtualization

    CERN Document Server

    Zaki, Yasir

    2012-01-01

    The key to a successful future mobile communication system lies in the design of its radio scheduler. One of the key challenges of the radio scheduler is how to provide the right balance between Quality of Service (QoS) guarantees and the overall system performance. Yasir Zaki proposes innovative solutions for the design of the Long Term Evolution (LTE) radio scheduler and presents several LTE radio scheduler analytical models that can be used as efficient tools for radio dimensioning. The author also introduces a novel wireless network virtualization framework and highlights the potential gai

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

    Science.gov (United States)

    Qiu, Yun-Liang; Peng, Ming-Qi

    2013-12-01

    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.

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

    Science.gov (United States)

    Inukai, T.; Campanella, S. J.

    1984-01-01

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

  9. SPECIFICITY OF COMMUNICATION DOCTOR – PATIENT, ONLINE, THROUGH SOCIAL NETWORKS

    Directory of Open Access Journals (Sweden)

    Florin-Alexandru LUCA

    2014-12-01

    Full Text Available A survey in 2013 of Division Market Research Group Rentrop Straton Romanian-German - "state services and private clinics. Comparative Analysis ", highlights the fact that into urban population in Romania, the internet is the most popular source of information on health services. According to the survey, 81.9% of respondents use the Internet to find out about the best doctors available to them. Preferences of respondents to the online environment as the main source of information translates into ease of access and the possibility of interaction, but also trust recommendations based on personal experiences, recommendations can be found through discussion forums, mostly or comments left on pages on social networking sites. In the present study we try to emphasize the specificity of communication physician - patient online through social networks.

  10. 10 CFR 73.54 - Protection of digital computer and communication systems and networks.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Protection of digital computer and communication systems... computer and communication systems and networks. By November 23, 2009 each licensee currently licensed to... provide high assurance that digital computer and communication systems and networks are adequately...

  11. Multicore fiber beamforming network for broadband satellite communications

    Science.gov (United States)

    Zainullin, Airat; Vidal, Borja; Macho, Andres; Llorente, Roberto

    2017-02-01

    Multi-core fiber (MCF) has been one of the main innovations in fiber optics in the last decade. Reported work on MCF has been focused on increasing the transmission capacity of optical communication links by exploiting space-division multiplexing. Additionally, MCF presents a strong potential in optical beamforming networks. The use of MCF can increase the compactness of the broadband antenna array controller. This is of utmost importance in platforms where size and weight are critical parameters such as communications satellites and airplanes. Here, an optical beamforming architecture that exploits the space-division capacity of MCF to implement compact optical beamforming networks is proposed, being a new application field for MCF. The experimental demonstration of this system using a 4-core MCF that controls a four-element antenna array is reported. An analysis of the impact of MCF on the performance of antenna arrays is presented. The analysis indicates that the main limitation comes from the relatively high insertion loss in the MCF fan-in and fan-out devices, which leads to angle dependent losses which can be mitigated by using fixed optical attenuators or a photonic lantern to reduce MCF insertion loss. The crosstalk requirements are also experimentally evaluated for the proposed MCF-based architecture. The potential signal impairment in the beamforming network is analytically evaluated, being of special importance when MCF with a large number of cores is considered. Finally, the optimization of the proposed MCF-based beamforming network is addressed targeting the scalability to large arrays.

  12. Strategic Communication Science and Technology Plan: Current Activities, Capability Gaps and Areas for Further Investment

    Science.gov (United States)

    2009-04-01

    Office/ Booz - Allen C SC Training Providing COCOM planners and DoD representatives to U.S. country teams with appropriate training in SC, public...populations. Major components are social networking; capturing knowledge of cheap , sustainable emergency response gadgets; reshaping policy in

  13. An Optimum Space-to-Ground Communication Concept for CubeSat Platform Utilizing NASA Space Network and Near Earth Network

    Science.gov (United States)

    Wong, Yen F.; Kegege, Obadiah; Schaire, Scott H.; Bussey, George; Altunc, Serhat; Zhang, Yuwen; Patel, Chitra

    2016-01-01

    National Aeronautics and Space Administration (NASA) CubeSat missions are expected to grow rapidly in the next decade. Higher data rate CubeSats are transitioning away from Amateur Radio bands to higher frequency bands. A high-level communication architecture for future space-to-ground CubeSat communication was proposed within NASA Goddard Space Flight Center. This architecture addresses CubeSat direct-to-ground communication, CubeSat to Tracking Data Relay Satellite System (TDRSS) communication, CubeSat constellation with Mothership direct-to-ground communication, and CubeSat Constellation with Mothership communication through K-Band Single Access (KSA).A Study has been performed to explore this communication architecture, through simulations, analyses, and identifying technologies, to develop the optimum communication concepts for CubeSat communications. This paper will present details of the simulation and analysis that include CubeSat swarm, daughter shipmother ship constellation, Near Earth Network (NEN) S and X-band direct to ground link, TDRS Multiple Access (MA) array vs Single Access mode, notional transceiverantenna configurations, ground asset configurations and Code Division Multiple Access (CDMA) signal trades for daughter mother CubeSat constellation inter-satellite crosslink. Results of Space Science X-band 10 MHz maximum achievable data rate study will be summarized. Assessment of Technology Readiness Level (TRL) of current CubeSat communication technologies capabilities will be presented. Compatibility test of the CubeSat transceiver through NEN and Space Network (SN) will be discussed. Based on the analyses, signal trade studies and technology assessments, the functional design and performance requirements as well as operation concepts for future CubeSat end-to-end communications will be derived.

  14. Artificial Neural Network Application for Power Transfer Capability and Voltage Calculations in Multi-Area Power System

    Directory of Open Access Journals (Sweden)

    Palukuru NAGENDRA

    2010-12-01

    Full Text Available In this study, the use of artificial neural network (ANN based model, multi-layer perceptron (MLP network, to compute the transfer capabilities in a multi-area power system was explored. The input for the ANN is load status and the outputs are the transfer capability among the system areas, voltage magnitudes and voltage angles at concerned buses of the areas under consideration. The repeated power flow (RPF method is used in this paper for calculating the power transfer capability, voltage magnitudes and voltage angles necessary for the generation of input-output patterns for training the proposed MLP neural network. Preliminary investigations on a three area 30-bus system reveal that the proposed model is computationally faster than the conventional method.

  15. Responsibility, capability, and Active SETI: Policy, law, ethics, and communication with extraterrestrial intelligence

    Science.gov (United States)

    Vakoch, Douglas A.

    2011-02-01

    With recently growing interest in the Active Search for Extraterrestrial Intelligence (SETI), in which humankind would send intentional signals to extraterrestrial civilizations, there have been increased concerns about appropriate policy, as well as the role of space law and ethics in guiding such activities. Implicit in these discussions are notions of responsibility and capability that affect judgments about whether humans or other civilizations should initiate transmissions. Existing protocols that guide SETI research address transmissions from Earth, but there is debate over whether these guidelines should inform de novo transmissions as well. Relevant responsibilities to address include (1) looking out for the interests of humankind as a whole, (2) being truthful in interstellar messages, and (3) benefiting extraterrestrial civilizations. Our capabilities as a species and a civilization affect how well we can fulfill responsibilities, as seen when we consider whether we will be able to reach consensus about message contents (and whether that would be desirable), and whether we have the capacity to decode messages from beings that rely on different sensory modalities. The interplay of these responsibilities and capabilities suggests that humankind should place increased emphasis on Active SETI.

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

    Science.gov (United States)

    2010-05-11

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

  17. Particle Swarm Optimization for Adaptive Resource Allocation in Communication Networks

    Directory of Open Access Journals (Sweden)

    Gheitanchi Shahin

    2010-01-01

    Full Text Available A generalized model of particle swarm optimization (PSO technique is proposed as a low complexity method for adaptive centralized and distributed resource allocation in communication networks. The proposed model is applied to adaptive multicarrier cooperative communications (MCCC technique which utilizes the subcarriers in deep fade using a relay node in order to improve the bandwidth efficiency. Centralized PSO, based on virtual particles (VPs, is introduced for single layer and cross-layer subcarrier allocation to improve the bit error rate performance in multipath frequency selective fading channels. In the single layer strategy, the subcarriers are allocated based on the channel gains. In the cross-layer strategy, the subcarriers are allocated based on a joint measure of channel gains and distance provided by the physical layer and network layer to mitigate the effect of path loss. The concept of training particles in distributed PSO is proposed and then is applied for relay node selection. The computational complexity and traffic of the proposed techniques are investigated, and it is shown that using PSO for subcarrier allocation has a lower complexity than the techniques in the literature. Significant reduction in the traffic overhead of PSO is demonstrated when using trained particles in distributed optimizations.

  18. TAM AIRLINES ON TWITTER: COMMUNICATION CHANNEL OR SOCIAL NETWORK?

    Directory of Open Access Journals (Sweden)

    Cynthia Harumy Watanabe Corrêa

    2010-12-01

    Full Text Available The research emphasizes the social appropriation of Information and Communication Technologies by the Brazilian aviation industry, through a case study of communication strategies of TAM on the social networking site Twitter. TAM is a leader in the Brazilian domestic market and gradually conquering its space in Mercosul. This is an exploratory research, based on content analysis of messages sent to the company profile on Twitter, in order to check whether indeed the consolidation of a social network between TAM and its followers. We analyzed all messages posted since July 3, 2009, the date of the first post in the company profile, until the day January 31, 2010. Among the subjects discussed, there was the predominance of information and promotions. The study concludes that, under Twitter, TAM has yet reached a high degree of social interaction with his followers, because the major number of messages is directed to promotional marketing.

  19. Communication Network Architectures for Smart-Wind Power Farms

    Directory of Open Access Journals (Sweden)

    Mohamed A. Ahmed

    2014-06-01

    Full Text Available Developments in the wind power industry have enabled a new generation of wind turbines with longer blades, taller towers, higher efficiency, and lower maintenance costs due to the maturity of related technologies. Nevertheless, wind turbines are still blind machines because the control center is responsible for managing and controlling individual wind turbines that are turned on or off according to demand for electricity. In this paper, we propose a communication network architecture for smart-wind power farms (Smart-WPFs. The proposed architecture is designed for wind turbines to communicate directly and share sensing data in order to maximize power generation, WPF availability, and turbine efficiency. We also designed a sensor data frame structure to carry sensing data from different wind turbine parts such as the rotor, transformer, nacelle, etc. The data frame includes a logical node ID (LNID, sensor node ID (SNID, sensor type (ST, and sensor data based on the International Electrotechnical Commission (IEC 61400-25 standard. We present an analytical model that describes upstream traffic between the wind turbines and the control center. Using a queueing theory approach, the upstream traffic is evaluated in view of bandwidth utilization and average queuing delay. The performance of the proposed network architectures are evaluated by using analytical and simulation models.

  20. Alternative Path Communication in Wide-Scale Cluster-Tree Wireless Sensor Networks Using Inactive Periods.

    Science.gov (United States)

    Leão, Erico; Montez, Carlos; Moraes, Ricardo; Portugal, Paulo; Vasques, Francisco

    2017-05-06

    The IEEE 802.15.4/ZigBee cluster-tree topology is a suitable technology to deploy wide-scale Wireless Sensor Networks (WSNs). These networks are usually designed to support convergecast traffic, where all communication paths go through the PAN (Personal Area Network) coordinator. Nevertheless, peer-to-peer communication relationships may be also required for different types of WSN applications. That is the typical case of sensor and actuator networks, where local control loops must be closed using a reduced number of communication hops. The use of communication schemes optimised just for the support of convergecast traffic may result in higher network congestion and in a potentially higher number of communication hops. Within this context, this paper proposes an Alternative-Route Definition (ARounD) communication scheme for WSNs. The underlying idea of ARounD is to setup alternative communication paths between specific source and destination nodes, avoiding congested cluster-tree paths. These alternative paths consider shorter inter-cluster paths, using a set of intermediate nodes to relay messages during their inactive periods in the cluster-tree network. Simulation results show that the ARounD communication scheme can significantly decrease the end-to-end communication delay, when compared to the use of standard cluster-tree communication schemes. Moreover, the ARounD communication scheme is able to reduce the network congestion around the PAN coordinator, enabling the reduction of the number of message drops due to queue overflows in the cluster-tree network.

  1. Managing Supply Chain Networks: A Framework for Achieving Superior Performance through Leadership Capabilities Development in Supply Chain Node

    OpenAIRE

    Cooper, Sharp; Watson, Derek; Worrall, Rob

    2016-01-01

    Leadership capability is acknowledged as a major challenge for organizations and a pre-requisite for sustaining high levels of organizational performance and supply chain competitiveness. Recent research highlights how globalisation has led to the extension of domestic supply chains, particularly SME ones, to include both suppliers and customers globally. This paper examines the role capabilities development in managers and leaders as nexus of their supply chain networks have to play in achie...

  2. Organizational structure and communication networks in a university environment.

    Science.gov (United States)

    Mathiesen, Joachim; Jamtveit, Bjørn; Sneppen, Kim

    2010-07-01

    The "six degrees of separation" between any two individuals on Earth has become emblematic of the "small world" theme, even though the information conveyed via a chain of human encounters decays very rapidly with increasing chain length, and diffusion of information via this process may be very inefficient in large human organizations. The information flow on a communication network in a large organization, the University of Oslo, has been studied by analyzing email records. The records allow for quantification of communication intensity across organizational levels and between organizational units (referred to as "modules"). We find that the number of email messages within modules scales with module size to the power of 1.29±.06 , and the frequency of communication between individuals decays exponentially with the number of links required upward in the organizational hierarchy before they are connected. Our data also indicates that the number of messages sent by administrative units is proportional to the number of individuals at lower levels in the administrative hierarchy, and the "divergence of information" within modules is associated with this linear relationship. The observed scaling is consistent with a hierarchical system in which individuals far apart in the organization interact little with each other and receive a disproportionate number of messages from higher levels in the administrative hierarchy.

  3. Lightweight Integrated Solar Array and Transceiver. [Improving Electrical Power and Communication Capabilities in Small Spacecraft

    Science.gov (United States)

    Carr, John; Martinez, Andres; Petro, Andrew

    2015-01-01

    The Lightweight Integrated Solar Array and Transceiver (LISA-T) project will leverage several existing and on-going efforts at Marshall Space Flight Center (MSFC) for the design, development, fabrication, and test of a launch stowed, orbit deployed structure on which thin-film photovoltaics for power generation and antenna elements for communication, are embedded. Photovoltaics is a method for converting solar energy into electricity using semiconductor materials. The system will provide higher power generation with a lower mass, smaller stowage volume, and lower cost than the state of the art solar arrays, while simultaneously enabling deployable antenna concepts.

  4. The Deep Space Network: A Radio Communications Instrument for Deep Space Exploration

    Science.gov (United States)

    Renzetti, N. A.; Stelzried, C. T.; Noreen, G. K.; Slobin, S. D.; Petty, S. M.; Trowbridge, D. L.; Donnelly, H.; Kinman, P. W.; Armstrong, J. W.; Burow, N. A.

    1983-01-01

    The primary purpose of the Deep Space Network (DSN) is to serve as a communications instrument for deep space exploration, providing communications between the spacecraft and the ground facilities. The uplink communications channel provides instructions or commands to the spacecraft. The downlink communications channel provides command verification and spacecraft engineering and science instrument payload data.

  5. SOCIAL NETWORKS USED BY TEENS AND PARENTAL CONTROL OF THEIR ONLINE COMMUNICATION

    National Research Council Canada - National Science Library

    Marsela Shehu; Ylli Zhurda

    2017-01-01

    .... It allows teens to develop their own interests, to identify with others. The aim of the study is to present concrete evidence regarding to the communication through social networks and parental care in the management of online communication...

  6. Social Networks Used by Teens and Parental Control of Their Online Communication

    National Research Council Canada - National Science Library

    M. Shehu; Y. Zhurda

    2017-01-01

    .... It allows teens to develop their own interests, to identify with others. The aim of the study is to present concrete evidence regarding to the communication through social networks and parental care in the management of online communication...

  7. Implications of conspecific background noise for features of blue tit, Cyanistes caeruleus , communication networks at dawn

    DEFF Research Database (Denmark)

    Poesel, Angelika; Dabelsteen, Torben; Pedersen, Simon Boel

    2007-01-01

    Abstract  Communication among animals often comprises several signallers and receivers within the signal's transmission range. In such communication networks, individuals can extract information about differences in relative performance of conspecifics by eavesdropping on their signalling interac...

  8. 76 FR 23812 - Reliability and Continuity of Communications Networks, Including Broadband Technologies; Effects...

    Science.gov (United States)

    2011-04-28

    ... they begin to deploy Smart Grid. Hospitals and healthcare providers can leverage broadband technologies... COMMISSION Reliability and Continuity of Communications Networks, Including Broadband Technologies; Effects... broadband technologies. 4. Today's increasingly interconnected world is one in which communications services...

  9. A cross-layer communication framework for wireless networked control systems

    NARCIS (Netherlands)

    Israr, N.; Scanlon, W.G.; Irwin, G.W.

    2009-01-01

    This paper presents a robust, dynamic cross-layer wireless communication architecture for wireless networked control systems. Each layer in the proposed protocol architecture contributes to the overall goal of reliable, energy efficient communication. The protocol stack also features a

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    In our recent study, we introduced the PlayNCool protocol that increases the throughput of the wireless networks by enabling a helper node to strengthen the communication link between two neighboring nodes and using random linear network coding. This paper focuses on design and implementation...... using Aalborg University's Raspberry Pi test-bed. Our results show that selecting the best policy to activate the helper node is a key to guarantee the performance of PlayNCool protocol. We also study the effect of neighbor nodes in the performance of PlayNCool. Using a helper in presence of active...... neighbors is useful even if the channel from helper to destination is not better than the channel between sender and destination. PlayNCool increases the gain of end-to-end communication by two-fold or more while maintaining compatibility to standard wireless ad-hoc routing protocols....

  11. Directedness of information flow in mobile phone communication networks

    CERN Document Server

    Peruani, Fernando; 10.1371/journal.pone.0028860

    2013-01-01

    Without having direct access to the information that is being exchanged, traces of information flow can be obtained by looking at temporal sequences of user interactions. These sequences can be represented as causality trees whose statistics result from a complex interplay between the topology of the underlying (social) network and the time correlations among the communications. Here, we study causality trees in mobile-phone data, which can be represented as a dynamical directed network. This representation of the data reveals the existence of super-spreaders and super-receivers. We show that the tree statistics, respectively the information spreading process, are extremely sensitive to the in-out degree correlation exhibited by the users. We also learn that a given information, e.g., a rumor, would require users to retransmit it for more than 30 hours in order to cover a macroscopic fraction of the system. Our analysis indicates that topological node-node correlations of the underlying social network, while ...

  12. Cross-Layer Design for Energy-Efficient Secure Multicast Communications in Ad Hoc Networks

    National Research Council Canada - National Science Library

    Lazos, Loukas; Poovendran, Radha

    2004-01-01

    .... They present an analytical formulation of the energy expenditure associated with the communication overhead of key management, and highlight its dependence on network topology and key distribution method...

  13. The usage of Internet social networking as a tool of linguist students' intercultural communication competence growth

    Directory of Open Access Journals (Sweden)

    Сергей Владимирович Сороколетов

    2009-06-01

    Full Text Available In work concepts «the intercultural communicative competence», «a social network», possibilities of use social the Internet of network FaceBook in training of students-linguists are described.

  14. A coalitional graph game framework for network coding-aided D2D communication

    National Research Council Canada - National Science Library

    Zhao, Yulei; Li, Yong; Ding, Zhiguo; Ge, Ning; Poor, H Vincent

    2016-01-01

    .... In this paper, a coalitional graph game framework is proposed to jointly accomplish resource allocation and relay selection, two challenging problems in network coding-aided D2D communication networks...

  15. Direct-Sequence Spread-Spectrum Modulation for Utility Packet Transmission in Underwater Acoustic Communication Networks

    National Research Council Canada - National Science Library

    Duke, Peter

    2002-01-01

    ...) modulation for utility-packet transmission in Seaweb underwater wireless acoustic communications networks, Seaweb networks require robust channel-tolerant utility packets having a low probability of detection (LPD...

  16. MmWave Vehicle-to-Infrastructure Communication :Analysis of Urban Microcellular Networks

    Science.gov (United States)

    2017-05-01

    Vehicle-to-infrastructure (V2I) communication may provide high data rates to vehicles via millimeterwave (mmWave) microcellular networks. This report uses stochastic geometry to analyze the coverage of urban mmWave microcellular networks. Prior work ...

  17. Capability of local operations and classical communication to distinguish bipartite unitary operations

    Science.gov (United States)

    Li, Lvzhou; Zheng, Shenggen; Situ, Haozhen; Qiu, Daowen

    2017-11-01

    The problem studied in this paper is, if the number of queries to unitary operations is fixed, say k , then when do local operations and classical communication (LOCC) suffice for optimally distinguishing bipartite unitary operations? We consider the above problem for two-qubit unitary operations in the case of k =1 , showing that for two two-qubit entangling unitary operations without local parties, LOCC achieves the same distinguishability as the global operations. Specifically, we obtain the following: (i) if such two unitary operations are perfectly distinguishable by global operations, then they are perfectly distinguishable by LOCC also, and (ii) if they are not perfectly distinguishable by global operations, then LOCC can achieve the same optimal discrimination probability as the global operations.

  18. Expanded serial communication capability for the transport systems research vehicle laptop computers

    Science.gov (United States)

    Easley, Wesley C.

    1991-01-01

    A recent upgrade of the Transport Systems Research Vehicle (TSRV) operated by the Advanced Transport Operating Systems Program Office at the NASA Langley Research Center included installation of a number of Grid 1500 series laptop computers. Each unit is a 80386-based IBM PC clone. RS-232 data busses are needed for TSRV flight research programs, and it has been advantageous to extend the application of the Grids in this area. Use was made of the expansion features of the Grid internal bus to add a user programmable serial communication channel. Software to allow use of the Grid bus expansion has been written and placed in a Turbo C library for incorporation into applications programs in a transparent manner via function calls. Port setup; interrupt-driven, two-way data transfer; and software flow control are built into the library functions.

  19. Designing Networks that are Capable of Self-Healing and Adapting

    Science.gov (United States)

    2017-04-01

    Time, Evolution, Networks , and Function’ (program manager : C. Macedonia). Part of this program focuses on robustness of networks , which compliments...8725 John J. Kingman Road, MS 6201 Fort Belvoir, VA 22060-6201 T E C H N IC A L R E P O R T DTRA-TR-15-78 Designing Networks that are...from statistical mechanics, combinatorics, boolean networks , and numerical simulations, and inspired by design principles from biological networks , we

  20. On Study of Construction of New Generation Intelligent Communication Network for Distribution System

    Science.gov (United States)

    Wu, Dan; Zhang, Xueyan

    2017-09-01

    many new technological means are integrated in the new network of smart electricity distribution including electric power technology, control technology and information technology, and in this area, people carry out profound research to the construction of communication network and power distribution network. This paper analyzes specific structures of the communication network for distribution system, discusses the development trend of it, explores its technical system in depth, and finally proposes some concrete constructive strategies, hoping to be a valuable reference for related research persons.

  1. Interfacing Space Communications and Navigation Network Simulation with Distributed System Integration Laboratories (DSIL)

    Science.gov (United States)

    Jennings, Esther H.; Nguyen, Sam P.; Wang, Shin-Ywan; Woo, Simon S.

    2008-01-01

    NASA's planned Lunar missions will involve multiple NASA centers where each participating center has a specific role and specialization. In this vision, the Constellation program (CxP)'s Distributed System Integration Laboratories (DSIL) architecture consist of multiple System Integration Labs (SILs), with simulators, emulators, testlabs and control centers interacting with each other over a broadband network to perform test and verification for mission scenarios. To support the end-to-end simulation and emulation effort of NASA' exploration initiatives, different NASA centers are interconnected to participate in distributed simulations. Currently, DSIL has interconnections among the following NASA centers: Johnson Space Center (JSC), Kennedy Space Center (KSC), Marshall Space Flight Center (MSFC) and Jet Propulsion Laboratory (JPL). Through interconnections and interactions among different NASA centers, critical resources and data can be shared, while independent simulations can be performed simultaneously at different NASA locations, to effectively utilize the simulation and emulation capabilities at each center. Furthermore, the development of DSIL can maximally leverage the existing project simulation and testing plans. In this work, we describe the specific role and development activities at JPL for Space Communications and Navigation Network (SCaN) simulator using the Multi-mission Advanced Communications Hybrid Environment for Test and Evaluation (MACHETE) tool to simulate communications effects among mission assets. Using MACHETE, different space network configurations among spacecrafts and ground systems of various parameter sets can be simulated. Data that is necessary for tracking, navigation, and guidance of spacecrafts such as Crew Exploration Vehicle (CEV), Crew Launch Vehicle (CLV), and Lunar Relay Satellite (LRS) and orbit calculation data are disseminated to different NASA centers and updated periodically using the High Level Architecture (HLA). In

  2. Blocking probabilities in mobile communications networks with time-varying rates ad redialing subscribers

    NARCIS (Netherlands)

    Abdalla, Nadra; Boucherie, Richardus J.

    Call-blocking probabilities are among the key performance measures in mobile communications networks. For their analysis, mobile networks can be modelled as networks of Erlang loss queues with common capacity restrictions dictated by the allocation of frequencies to the cells of the network.

  3. Network Coded Cooperative Communication in a Real-Time Wireless Hospital Sensor Network.

    Science.gov (United States)

    Prakash, R; Balaji Ganesh, A; Sivabalan, Somu

    2017-05-01

    The paper presents a network coded cooperative communication (NC-CC) enabled wireless hospital sensor network architecture for monitoring health as well as postural activities of a patient. A wearable device, referred as a smartband is interfaced with pulse rate, body temperature sensors and an accelerometer along with wireless protocol services, such as Bluetooth and Radio-Frequency transceiver and Wi-Fi. The energy efficiency of wearable device is improved by embedding a linear acceleration based transmission duty cycling algorithm (NC-DRDC). The real-time demonstration is carried-out in a hospital environment to evaluate the performance characteristics, such as power spectral density, energy consumption, signal to noise ratio, packet delivery ratio and transmission offset. The resource sharing and energy efficiency features of network coding technique are improved by proposing an algorithm referred as network coding based dynamic retransmit/rebroadcast decision control (LA-TDC). From the experimental results, it is observed that the proposed LA-TDC algorithm reduces network traffic and end-to-end delay by an average of 27.8% and 21.6%, respectively than traditional network coded wireless transmission. The wireless architecture is deployed in a hospital environment and results are then successfully validated.

  4. A Study of the Classification Capabilities of Neural Networks Using Unsupervised Learning: A Comparison with K-Means Clustering.

    Science.gov (United States)

    Balakrishnan, P. V. (Sunder); And Others

    1994-01-01

    A simulation study compares nonhierarchical clustering capabilities of a class of neural networks using Kohonen learning with a K-means clustering procedure. The focus is on the ability of the procedures to recover correctly the known cluster structure in the data. Advantages and disadvantages of the procedures are reviewed. (SLD)

  5. Innovation and communicative action: health management networks and technologies.

    Science.gov (United States)

    Rivera, Francisco Javier Uribe; Artmann, Elizabeth

    2016-11-03

    This article discusses elements of a theory of innovation from the perspective of innovation networks and social construction of technology, based on Habermas' Theory of Communicative Action and authors from the Sociology of Innovation. Based on the theoretical framework of the communicative production of scientific facts, we focus on innovation management as a basic dimension that must meet some organizational and methodological requirements in order to power its results. We present and discuss instruments such as Situational Planning, Prospective Analysis, Strategic Portfolio Management, and Networks Management that can help deal with the challenge of innovation and exploration of the future. We conclude that network organizational formats centered on reflexivity of interdisciplinary groups and planning approaches that encourage innovation criteria in assessing the attractiveness of activities and that help anticipate forms of innovation through systematic prospective analysis can potentiate the process of generating innovation as a product of networks. Resumo: No artigo são discutidos elementos de uma teoria da inovação numa perspectiva de redes de inovação e de construção social da tecnologia, a partir da Teoria do Agir Comunicativo de Habermas e de autores da Sociologia da Inovação. Com base no marco teórico da produção comunicativa de fatos científicos, focamos a gestão da inovação como uma dimensão fundamental que deve contemplar alguns requisitos, tanto de natureza organizacional quanto metodológica, para potencializar seus resultados. Apresentamos e discutimos instrumentos como o Planejamento Situacional, a Análise Prospectiva, a Gestão Estratégica de Portfólios e a Gestão de Redes que podem contribuir para o desafio da inovação e exploração do futuro. Conclui-se que formas organizativas em rede, centradas na reflexividade de grupos interdisciplinares, e enfoques de planejamento que estimulem o uso de critérios de inovação na

  6. Enhanced TCP for maritime communications over satellite network

    Science.gov (United States)

    Zong, Liang; Du, Wencai; Bai, Yong

    2014-10-01

    For maritime communications over satellite network, TCP performance is essential for data transmissions. TCP ADaLR is congestion control algorithm that the sender judgments the relevant window change and measures roundtrip time to control congestion window. It can adapt to the characteristics of the satellite link and improve the performance of TCP than conventional TCP. However, it does not take into account distinction of random packet loss and congestion loss like TCP Veno. In this paper, we propose further enhancement of TCP ADaLR, called TCP ADaLR+, that can distinguish between random packet loss and congestion loss. The improved performance of proposed TCP ADaLR+ is demonstrated by simulations.

  7. Development of compositional and contextual communicable congruence in robots by using dynamic neural network models.

    Science.gov (United States)

    Park, Gibeom; Tani, Jun

    2015-12-01

    The current study presents neurorobotics experiments on acquisition of skills for "communicable congruence" with human via learning. A dynamic neural network model which is characterized by its multiple timescale dynamics property was utilized as a neuromorphic model for controlling a humanoid robot. In the experimental task, the humanoid robot was trained to generate specific sequential movement patterns as responding to various sequences of imperative gesture patterns demonstrated by the human subjects by following predefined compositional semantic rules. The experimental results showed that (1) the adopted MTRNN can achieve generalization by learning in the lower feature perception level by using a limited set of tutoring patterns, (2) the MTRNN can learn to extract compositional semantic rules with generalization in its higher level characterized by slow timescale dynamics, (3) the MTRNN can develop another type of cognitive capability for controlling the internal contextual processes as situated to on-going task sequences without being provided with cues for explicitly indicating task segmentation points. The analysis on the dynamic property developed in the MTRNN via learning indicated that the aforementioned cognitive mechanisms were achieved by self-organization of adequate functional hierarchy by utilizing the constraint of the multiple timescale property and the topological connectivity imposed on the network configuration. These results of the current research could contribute to developments of socially intelligent robots endowed with cognitive communicative competency similar to that of human. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Digital commuting transit system to communication networks of electric sector. Sistema de conmutacion digital de transito para las redes de comunicacion del sector electrico

    Energy Technology Data Exchange (ETDEWEB)

    Conde Sanchez, C. (Iberdrola (Spain)); Samitier Otero, C. (Dimat S.A. (Spain))

    The need to optimize the quality of the services offered by power utility companies entails making available those communication system capable of offering modern voice and data facilities. The use of such communication networks results in the better management of power distribution. The development of a system which satisfies this need has been carried out within the Electrotechnical research Programme PIE and coordinated by Iberdrola. (Author)

  9. Socioeconomic correlations and stratification in social-communication networks.

    Science.gov (United States)

    Leo, Yannick; Fleury, Eric; Alvarez-Hamelin, J Ignacio; Sarraute, Carlos; Karsai, Márton

    2016-12-01

    The uneven distribution of wealth and individual economic capacities are among the main forces, which shape modern societies and arguably bias the emerging social structures. However, the study of correlations between the social network and economic status of individuals is difficult due to the lack of large-scale multimodal data disclosing both the social ties and economic indicators of the same population. Here, we close this gap through the analysis of coupled datasets recording the mobile phone communications and bank transaction history of one million anonymized individuals living in a Latin American country. We show that wealth and debt are unevenly distributed among people in agreement with the Pareto principle; the observed social structure is strongly stratified, with people being better connected to others of their own socioeconomic class rather than to others of different classes; the social network appears to have assortative socioeconomic correlations and tightly connected 'rich clubs'; and that individuals from the same class live closer to each other but commute further if they are wealthier. These results are based on a representative, society-large population, and empirically demonstrate some long-lasting hypotheses on socioeconomic correlations, which potentially lay behind social segregation, and induce differences in human mobility. © 2016 The Author(s).

  10. Communicating Earth Observation (EO)-based landslide mapping capabilities to practitioners

    Science.gov (United States)

    Albrecht, Florian; Hölbling, Daniel; Eisank, Clemens; Weinke, Elisabeth; Vecchiotti, Filippo; Kociu, Arben

    2016-04-01

    with potential users from the Geological Survey of Austria (GBA), various geological services of provinces of Austria, Germany and Italy, the Austrian Service for Torrent and Avalanche Control (WLV), the Austrian Federal Forestry Office (ÖBf), the Austrian Mountaineering Club (ÖAV) and infrastructure owners like the Austrian Road Maintenance Agency (ASFINAG). The results will show how EO-based landslide information products can be made accessible to responsible authorities in an innovative and easy manner and how new analysis methods can be promoted among a broad audience. Thus, the communication and knowledge exchange between researchers, the public, stakeholders and practitioners can be improved.

  11. Adaptive Communication as a Means toward better Performance : Can fit for purpose communication capability building activities help organizations in communicating to deliver strategy and to improve performance?

    NARCIS (Netherlands)

    M. Schipper (Mariska)

    2010-01-01

    textabstractExecutive Summary The focus on the success factors for excellent performance has been growing in the last decades. One of the factors that is generally believed to have a positive relationship with organizational performance, is the internal communication process. Even though many

  12. Security Shift in Future Network Architectures

    NARCIS (Netherlands)

    Hartog, T.; Schotanus, H.A.; Verkoelen, C.A.A.

    2010-01-01

    In current practice military communication infrastructures are deployed as stand-alone networked information systems. Network-Enabled Capabilities (NEC) and combined military operations lead to new requirements which current communication architectures cannot deliver. This paper informs IT

  13. 77 FR 36305 - Stream Communications Network & Media, Inc.; Order of Suspension of Trading

    Science.gov (United States)

    2012-06-18

    ... From the Federal Register Online via the Government Publishing Office SECURITIES AND EXCHANGE COMMISSION Stream Communications Network & Media, Inc.; Order of Suspension of Trading June 14, 2012. It... concerning the securities of Stream Communications Network & Media, Inc. because it has not filed any...

  14. The Effectiveness of Using Social Communications Networks in Mathematics Teachers' Professional Development

    Science.gov (United States)

    Hussein, Hisham Barakat

    2013-01-01

    The study aims to determine the effectiveness of using social communications networks in mathematics teachers' professional development. The main research questions was: what is the effectiveness of using social communications networks in mathematics teachers' professional development. The sub questions were: (1) what are the standards of…

  15. Teaching Students How to Integrate and Assess Social Networking Tools in Marketing Communications

    Science.gov (United States)

    Schlee, Regina Pefanis; Harich, Katrin R.

    2013-01-01

    This research is based on two studies that focus on teaching students how to integrate and assess social networking tools in marketing communications. Study 1 examines how students in marketing classes utilize social networking tools and explores their attitudes regarding the use of such tools for marketing communications. Study 2 focuses on an…

  16. Intention processing in communication: a common brain network for language and gestures.

    Science.gov (United States)

    Enrici, Ivan; Adenzato, Mauro; Cappa, Stefano; Bara, Bruno G; Tettamanti, Marco

    2011-09-01

    Human communicative competence is based on the ability to process a specific class of mental states, namely, communicative intention. The present fMRI study aims to analyze whether intention processing in communication is affected by the expressive means through which a communicative intention is conveyed, that is, the linguistic or extralinguistic gestural means. Combined factorial and conjunction analyses were used to test two sets of predictions: first, that a common brain network is recruited for the comprehension of communicative intentions independently of the modality through which they are conveyed; second, that additional brain areas are specifically recruited depending on the communicative modality used, reflecting distinct sensorimotor gateways. Our results clearly showed that a common neural network is engaged in communicative intention processing independently of the modality used. This network includes the precuneus, the left and right posterior STS and TPJ, and the medial pFC. Additional brain areas outside those involved in intention processing are specifically engaged by the particular communicative modality, that is, a peri-sylvian language network for the linguistic modality and a sensorimotor network for the extralinguistic modality. Thus, common representation of communicative intention may be accessed by modality-specific gateways, which are distinct for linguistic versus extralinguistic expressive means. Taken together, our results indicate that the information acquired by different communicative modalities is equivalent from a mental processing standpoint, in particular, at the point at which the actor's communicative intention has to be reconstructed.

  17. Location capability of a sparse regional network (RSTN) using a multi-phase earthquake location algorithm (REGLOC)

    Energy Technology Data Exchange (ETDEWEB)

    Hutchings, L.

    1994-01-01

    The Regional Seismic Test Network (RSTN) was deployed by the US Department of Energy (DOE) to determine whether data recorded by a regional network could be used to detect and accurately locate seismic events that might be clandestine nuclear tests. The purpose of this paper is to evaluate the location capability of the RSTN. A major part of this project was the development of the location algorithm REGLOC and application of Basian a prior statistics for determining the accuracy of the location estimates. REGLOC utilizes all identifiable phases, including backazimuth, in the location. Ninty-four events, distributed throughout the network area, detected by both the RSTN and located by local networks were used in the study. The location capability of the RSTN was evaluated by estimating the location accuracy, error ellipse accuracy, and the percentage of events that could be located, as a function of magnitude. The location accuracy was verified by comparing the RSTN results for the 94 events with published locations based on data from the local networks. The error ellipse accuracy was evaluated by determining whether the error ellipse includes the actual location. The percentage of events located was assessed by combining detection capability with location capability to determine the percentage of events that could be located within the study area. Events were located with both an average crustal model for the entire region, and with regional velocity models along with station corrections obtained from master events. Most events with a magnitude <3.0 can only be located with arrivals from one station. Their average location errors are 453 and 414 km for the average- and regional-velocity model locations, respectively. Single station locations are very unreliable because they depend on accurate backazimuth estimates, and backazimuth proved to be a very unreliable computation.

  18. Decentralized Control of Unmanned Aerial Robots for Wireless Airborne Communication Networks

    Directory of Open Access Journals (Sweden)

    Deok-Jin Lee

    2010-09-01

    Full Text Available This paper presents a cooperative control strategy for a team of aerial robotic vehicles to establish wireless airborne communication networks between distributed heterogeneous vehicles. Each aerial robot serves as a flying mobile sensor performing a reconfigurable communication relay node which enabls communication networks with static or slow-moving nodes on gorund or ocean. For distributed optimal deployment of the aerial vehicles for communication networks, an adaptive hill-climbing type decentralized control algorithm is developed to seek out local extremum for optimal localization of the vehicles. The sensor networks estabilished by the decentralized cooperative control approach can adopt its configuraiton in response to signal strength as the function of the relative distance between the autonomous aerial robots and distributed sensor nodes in the sensed environment. Simulation studies are conducted to evaluate the effectiveness of the proposed decentralized cooperative control technique for robust communication networks.

  19. A distributed data base management capability for the deep space network

    Science.gov (United States)

    Bryan, A. I.

    1976-01-01

    The Configuration Control and Audit Assembly (CCA) is reported that has been designed to provide a distributed data base management capability for the DSN. The CCA utilizes capabilities provided by the DSN standard minicomputer and the DSN standard nonreal time high level management oriented programming language, MBASIC. The characteristics of the CCA for the first phase of implementation are described.

  20. Research on social communication network evolution based on topology potential distribution

    Science.gov (United States)

    Zhao, Dongjie; Jiang, Jian; Li, Deyi; Zhang, Haisu; Chen, Guisheng

    2011-12-01

    Aiming at the problem of social communication network evolution, first, topology potential is introduced to measure the local influence among nodes in networks. Second, from the perspective of topology potential distribution the method of network evolution description based on topology potential distribution is presented, which takes the artificial intelligence with uncertainty as basic theory and local influence among nodes as essentiality. Then, a social communication network is constructed by enron email dataset, the method presented is used to analyze the characteristic of the social communication network evolution and some useful conclusions are got, implying that the method is effective, which shows that topology potential distribution can effectively describe the characteristic of sociology and detect the local changes in social communication network.

  1. Max-Flow Min-Cut Theorems for Communication Networks Based on Equational Logic

    CERN Document Server

    Gadouleau, Maximilien

    2010-01-01

    Traditionally, communication networks are modeled and analyzed in terms of information flows in graphs. In this paper, we introduce a new symbolic approach to communication networks, where the topology of the underlying network is contained in a set of formal terms. To any choice of coding functions we associate a measure of performance, referred to as the dispersion. We thus show that many communication problems can be recast as dispersion problems in this setup. We state and prove variants of a theorem concerning dispersion of information in communication networks which generalizes the network coding theorem. The dispersion theorem resembles the max-flow min-cut theorem for commodity networks and states that the minimal cut value can be asymptotically achieved by the use of coding functions based on a routing scheme that uses dynamic headers. We then prove that linear coding functions are insufficient in general. More specifically, there exist terms which have an arbitrarily large dispersion for non-linear ...

  2. Unified Approach to Modeling and Simulation of Space Communication Networks and Systems

    Science.gov (United States)

    Barritt, Brian; Bhasin, Kul; Eddy, Wesley; Matthews, Seth

    2010-01-01

    Network simulator software tools are often used to model the behaviors and interactions of applications, protocols, packets, and data links in terrestrial communication networks. Other software tools that model the physics, orbital dynamics, and RF characteristics of space systems have matured to allow for rapid, detailed analysis of space communication links. However, the absence of a unified toolset that integrates the two modeling approaches has encumbered the systems engineers tasked with the design, architecture, and analysis of complex space communication networks and systems. This paper presents the unified approach and describes the motivation, challenges, and our solution - the customization of the network simulator to integrate with astronautical analysis software tools for high-fidelity end-to-end simulation. Keywords space; communication; systems; networking; simulation; modeling; QualNet; STK; integration; space networks

  3. CMIP: a software package capable of reconstructing genome-wide regulatory networks using gene expression data.

    Science.gov (United States)

    Zheng, Guangyong; Xu, Yaochen; Zhang, Xiujun; Liu, Zhi-Ping; Wang, Zhuo; Chen, Luonan; Zhu, Xin-Guang

    2016-12-23

    A gene regulatory network (GRN) represents interactions of genes inside a cell or tissue, in which vertexes and edges stand for genes and their regulatory interactions respectively. Reconstruction of gene regulatory networks, in particular, genome-scale networks, is essential for comparative exploration of different species and mechanistic investigation of biological processes. Currently, most of network inference methods are computationally intensive, which are usually effective for small-scale tasks (e.g., networks with a few hundred genes), but are difficult to construct GRNs at genome-scale. Here, we present a software package for gene regulatory network reconstruction at a genomic level, in which gene interaction is measured by the conditional mutual information measurement using a parallel computing framework (so the package is named CMIP). The package is a greatly improved implementation of our previous PCA-CMI algorithm. In CMIP, we provide not only an automatic threshold determination method but also an effective parallel computing framework for network inference. Performance tests on benchmark datasets show that the accuracy of CMIP is comparable to most current network inference methods. Moreover, running tests on synthetic datasets demonstrate that CMIP can handle large datasets especially genome-wide datasets within an acceptable time period. In addition, successful application on a real genomic dataset confirms its practical applicability of the package. This new software package provides a powerful tool for genomic network reconstruction to biological community. The software can be accessed at http://www.picb.ac.cn/CMIP/ .

  4. On Tradeoffs between Trust Accuracy and Resource Consumption in Communications and Social Networks

    Science.gov (United States)

    2016-04-11

    sociological effects is a very complex problem. Elements of trust relationship dynamics in the communication network context can be adapted to...On Tradeoffs between Trust Accuracy and Resource Consumption in Communications and Social Networks Jin-Hee Cho, Kevin Chan, Ananthram Swami, Brian...effectively is critical in tactical networks in order to facilitate cooperation and decision making tasks as well as to meet system goals such as

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

    Science.gov (United States)

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

    2014-01-01

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

  6. Evaluation of the Impact of Furniture on Communications Performance for Ubiquitous Deployment of Wireless Sensor Networks in Smart Homes

    Directory of Open Access Journals (Sweden)

    Antonio F. Gómez Skarmeta

    2012-05-01

    Full Text Available The extensions of the environment with the integration of sensing systems in any space, in conjunction with ubiquitous computing are enabling the so-called Smart Space Sensor Networks. This new generation of networks are offering full connectivity with any object, through the Internet of Things (IoT and/or the Web, i.e., the Web of Things. These connectivity capabilities are making it feasible to sense the behaviours of people at home and act accordingly. These sensing systems must be integrated within typical elements found at home such as furniture. For that reason, this work considers furniture as an interesting element for the transparent location of sensors. Furniture is a ubiquitous object, i.e., it can be found everywhere at home or the office, and it can integrate and hide the sensors of a network. This work addresses the lack of an exhaustive study of the effect of furniture on signal losses. In addition an easy-to-use tool for estimating the robustness of the communication channel among the sensor nodes and gateways is proposed. Specifically, the losses in a sensor network signal due to the materials found within the communication link are evaluated. Then, this work proposes a software tool that gathers the obtained results and is capable of evaluating the impact of a given set of materials on the communications. This tool also provides a mechanism to optimize the sensor network deployments during the definition of smart spaces. Specifically, it provides information such as: maximum distances between sensor nodes, most suitable type of furniture to integrate sensors, or battery life of sensor nodes. This tool has been validated empirically in the lab, and it is currently being used by several enterprise partners of the Technological Centre of Furniture and Wood in the southeast of Spain.

  7. Evaluation of the impact of furniture on communications performance for ubiquitous deployment of Wireless Sensor Networks in smart homes.

    Science.gov (United States)

    Bleda, Andrés L; Jara, Antonio J; Maestre, Rafael; Santa, Guadalupe; Gómez Skarmeta, Antonio F

    2012-01-01

    The extensions of the environment with the integration of sensing systems in any space, in conjunction with ubiquitous computing are enabling the so-called Smart Space Sensor Networks. This new generation of networks are offering full connectivity with any object, through the Internet of Things (IoT) and/or the Web, i.e., the Web of Things. These connectivity capabilities are making it feasible to sense the behaviours of people at home and act accordingly. These sensing systems must be integrated within typical elements found at home such as furniture. For that reason, this work considers furniture as an interesting element for the transparent location of sensors. Furniture is a ubiquitous object, i.e., it can be found everywhere at home or the office, and it can integrate and hide the sensors of a network. This work addresses the lack of an exhaustive study of the effect of furniture on signal losses. In addition an easy-to-use tool for estimating the robustness of the communication channel among the sensor nodes and gateways is proposed. Specifically, the losses in a sensor network signal due to the materials found within the communication link are evaluated. Then, this work proposes a software tool that gathers the obtained results and is capable of evaluating the impact of a given set of materials on the communications. This tool also provides a mechanism to optimize the sensor network deployments during the definition of smart spaces. Specifically, it provides information such as: maximum distances between sensor nodes, most suitable type of furniture to integrate sensors, or battery life of sensor nodes. This tool has been validated empirically in the lab, and it is currently being used by several enterprise partners of the Technological Centre of Furniture and Wood in the southeast of Spain.

  8. Evaluation of the Impact of Furniture on Communications Performance for Ubiquitous Deployment of Wireless Sensor Networks in Smart Homes

    Science.gov (United States)

    Bleda, Andrés L.; Jara, Antonio J.; Maestre, Rafael; Santa, Guadalupe; Gómez Skarmeta, Antonio F.

    2012-01-01

    The extensions of the environment with the integration of sensing systems in any space, in conjunction with ubiquitous computing are enabling the so-called Smart Space Sensor Networks. This new generation of networks are offering full connectivity with any object, through the Internet of Things (IoT) and/or the Web, i.e., the Web of Things. These connectivity capabilities are making it feasible to sense the behaviours of people at home and act accordingly. These sensing systems must be integrated within typical elements found at home such as furniture. For that reason, this work considers furniture as an interesting element for the transparent location of sensors. Furniture is a ubiquitous object, i.e., it can be found everywhere at home or the office, and it can integrate and hide the sensors of a network. This work addresses the lack of an exhaustive study of the effect of furniture on signal losses. In addition an easy-to-use tool for estimating the robustness of the communication channel among the sensor nodes and gateways is proposed. Specifically, the losses in a sensor network signal due to the materials found within the communication link are evaluated. Then, this work proposes a software tool that gathers the obtained results and is capable of evaluating the impact of a given set of materials on the communications. This tool also provides a mechanism to optimize the sensor network deployments during the definition of smart spaces. Specifically, it provides information such as: maximum distances between sensor nodes, most suitable type of furniture to integrate sensors, or battery life of sensor nodes. This tool has been validated empirically in the lab, and it is currently being used by several enterprise partners of the Technological Centre of Furniture and Wood in the southeast of Spain. PMID:22778653

  9. Evaluation and Simulation of Common Video Conference Traffics in Communication Networks

    Directory of Open Access Journals (Sweden)

    Farhad faghani

    2014-01-01

    Full Text Available Multimedia traffics are the basic traffics in data communication networks. Especially Video conferences are the most desirable traffics in huge networks(wired, wireless, …. Traffic modeling can help us to evaluate the real networks. So, in order to have good services in data communication networks which provide multimedia services, QoS will be very important .In this research we tried to have an exact traffic model design and simulation to overcome QoS challenges. Also, we predict bandwidth by Kalman filter in Ethernet networks.

  10. Stochastic Characterization of Communication Network Latency for Wide Area Grid Control Applications.

    Energy Technology Data Exchange (ETDEWEB)

    Ameme, Dan Selorm Kwami [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Guttromson, Ross [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-10-01

    This report characterizes communications network latency under various network topologies and qualities of service (QoS). The characterizations are probabilistic in nature, allowing deeper analysis of stability for Internet Protocol (IP) based feedback control systems used in grid applications. The work involves the use of Raspberry Pi computers as a proxy for a controlled resource, and an ns-3 network simulator on a Linux server to create an experimental platform (testbed) that can be used to model wide-area grid control network communications in smart grid. Modbus protocol is used for information transport, and Routing Information Protocol is used for dynamic route selection within the simulated network.

  11. A social network approach to understanding science communication among fire professionals

    Science.gov (United States)

    Vita Wright

    2012-01-01

    Studies of science communication and use in the fire management community suggest manager's access research via informal information networks and that these networks vary by both agency and position. We used a phone survey followed by traditional statistical analyses to understand the informal social networks of fire professionals in two western regions of the...

  12. A social network approach to understanding science communication among fire professionals (Abstract)

    Science.gov (United States)

    Vita Wright; Andrea Thode; Anne Mottek-Lucas; Jacklynn Fallon; Megan Matonis

    2012-01-01

    Studies of science communication and use in the fire management community suggest manager's access research via informal information networks and that these networks vary by both agency and position. We used a phone survey followed by traditional statistical analyses to understand the informal social networks of fire professionals in two western regions of the...

  13. Improving Fault Ride-Through Capability of Variable Speed Wind Turbines in Distribution Networks

    DEFF Research Database (Denmark)

    Mokryani, Geev; Siano, P.; Piccolo, Antonio

    2013-01-01

    In this paper, a fuzzy controller for improving the fault ride-through (FRT) capability of variable speed wind turbines (WTs) equipped with a doubly fed induction generator (DFIG) is presented. DFIGs can be used as reactive power sources to control the voltage at the point of common coupling (PCC...... on a real 37-bus weak distribution system confirmed that the proposed controller can enhance the FRT capability....

  14. Social Networking: Changing the way we communicate and do business.

    OpenAIRE

    Jones, Kevin

    2009-01-01

    This paper reviews the value of social networking and the impact it can have on small and large businesses. The paper also reviews the Social Networking Business Plan and the power of recommender networks. Examples are given of inbound and outbound marketing techniques. Social Networking is an integral part of inbound marketing. A synopsis of the evolving demographic of social networkers is presented to add clarity and show potential for social networking websites and tools.

  15. Adaptive autonomous Communications Routing Optimizer for Network Efficiency Management Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Maximizing network efficiency for NASA's Space Networking resources is a large, complex, distributed problem, requiring substantial collaboration. We propose the...

  16. Computation and Communication Evaluation of an Authentication Mechanism for Time-Triggered Networked Control Systems

    Directory of Open Access Journals (Sweden)

    Goncalo Martins

    2016-07-01

    Full Text Available In modern networked control applications, confidentiality and integrity are important features to address in order to prevent against attacks. Moreover, network control systems are a fundamental part of the communication components of current cyber-physical systems (e.g., automotive communications. Many networked control systems employ Time-Triggered (TT architectures that provide mechanisms enabling the exchange of precise and synchronous messages. TT systems have computation and communication constraints, and with the aim to enable secure communications in the network, it is important to evaluate the computational and communication overhead of implementing secure communication mechanisms. This paper presents a comprehensive analysis and evaluation of the effects of adding a Hash-based Message Authentication (HMAC to TT networked control systems. The contributions of the paper include (1 the analysis and experimental validation of the communication overhead, as well as a scalability analysis that utilizes the experimental result for both wired and wireless platforms and (2 an experimental evaluation of the computational overhead of HMAC based on a kernel-level Linux implementation. An automotive application is used as an example, and the results show that it is feasible to implement a secure communication mechanism without interfering with the existing automotive controller execution times. The methods and results of the paper can be used for evaluating the performance impact of security mechanisms and, thus, for the design of secure wired and wireless TT networked control systems.

  17. Computation and Communication Evaluation of an Authentication Mechanism for Time-Triggered Networked Control Systems.

    Science.gov (United States)

    Martins, Goncalo; Moondra, Arul; Dubey, Abhishek; Bhattacharjee, Anirban; Koutsoukos, Xenofon D

    2016-07-25

    In modern networked control applications, confidentiality and integrity are important features to address in order to prevent against attacks. Moreover, network control systems are a fundamental part of the communication components of current cyber-physical systems (e.g., automotive communications). Many networked control systems employ Time-Triggered (TT) architectures that provide mechanisms enabling the exchange of precise and synchronous messages. TT systems have computation and communication constraints, and with the aim to enable secure communications in the network, it is important to evaluate the computational and communication overhead of implementing secure communication mechanisms. This paper presents a comprehensive analysis and evaluation of the effects of adding a Hash-based Message Authentication (HMAC) to TT networked control systems. The contributions of the paper include (1) the analysis and experimental validation of the communication overhead, as well as a scalability analysis that utilizes the experimental result for both wired and wireless platforms and (2) an experimental evaluation of the computational overhead of HMAC based on a kernel-level Linux implementation. An automotive application is used as an example, and the results show that it is feasible to implement a secure communication mechanism without interfering with the existing automotive controller execution times. The methods and results of the paper can be used for evaluating the performance impact of security mechanisms and, thus, for the design of secure wired and wireless TT networked control systems.

  18. Educational network comparative analysis of small groups: Short- and long-term communications

    Science.gov (United States)

    Berg, D. B.; Zvereva, O. M.; Nazarova, Yu. Yu.; Chepurov, E. G.; Kokovin, A. V.; Ranyuk, S. V.

    2017-11-01

    The present study is devoted to the discussion of small group communication network structures. These communications were observed in student groups, where actors were united with a regular educational activity. The comparative analysis was carried out for networks of short-term (1 hour) and long-term (4 weeks) communications, it was based on seven structural parameters, and consisted of two stages. At the first stage, differences between the network graphs were examined, and the random corresponding Bernoulli graphs were built. At the second stage, revealed differences were compared. Calculations were performed using UCINET software framework. It was found out that networks of long-term and short-term communications are quite different: the structure of a short-term communication network is close to a random one, whereas the most of long-term communication network parameters differ from the corresponding random ones by more than 30%. This difference can be explained by strong "noisiness" of a short-term communication network, and the lack of social in it.

  19. Designing Networks that are Capable of Self-Healing and Adapting

    Science.gov (United States)

    2017-04-01

    Undergrad. Res. Fellowship, visiting from Caltech. Undergraduate Eugene Park Math Duke Models of self-healing networks (undergrad. senior thesis...Graduate student Anastasia Deckard Math Duke 3rd/4th year PhD. Wrote software for simulation. Undergraduate Nick Day Math LIMS Summer project at...have been accepted by, or have been submitted to, peer-reviewed journals . Easily repairable networks R Farr, J Harer, T Fink Phys. Rev. Lett., 113, 13

  20. Acquisition in a World of Joint Capabilities: Methods for Understanding Cross-Organizational Network Performance

    Science.gov (United States)

    2016-04-30

    UNL Robert Flowe, Office of Acquisition Resources & Analysis, OUSD (AT&L) Brendan Fernes , Student, The Cooper Union An Optimization-Based Approach... diversity of network partners based upon the rank abundance curve. The β3 is the percent of network partners that are considered joint programs. The β4...program element. The second was a diversity measure. Diversity was measured by the slope of the rank abundance curve. The percent of the partners that

  1. Communication between office-based primary care providers and nurses working within patients' homes: an analysis of process data from CAPABLE.

    Science.gov (United States)

    Smith, Patrick D; Boyd, Cynthia; Bellantoni, Julia; Roth, Jill; Becker, Kathleen L; Savage, Jessica; Nkimbeng, Manka; Szanton, Sarah L

    2016-02-01

    To examine themes of communication between office-based primary care providers and nurses working in private residences; to assess which methods of communication elicit fruitful responses to nurses' concerns. Lack of effective communication between home health care nurses and primary care providers contributes to clinical errors, inefficient care delivery and decreased patient safety. Few studies have described best practices related to frequency, methods and reasons for communication between community-based nurses and primary care providers. Secondary analysis of process data from 'Community Aging in Place: Advancing Better Living for Elders (CAPABLE)'. Independent reviewers analysed nurse documentation of communication (phone calls, letters and client coaching) initiated for 70 patients and analysed 45 letters to primary care providers to identify common concerns and recommendations raised by CAPABLE nurses. Primary care providers responded to 86% of phone calls, 56% of letters and 50% of client coaching efforts. Primary care providers addressed 86% of concerns communicated by phone, 34% of concerns communicated by letter and 41% of client-raised concerns. Nurses' letters addressed five key concerns: medication safety, pain, change in activities of daily living, fall safety and mental health. In letters, CAPABLE nurses recommended 58 interventions: medication change; referral to a specialist; patient education; and further diagnostic evaluation. Effective communication between home-based nurses and primary care providers enhances care coordination and improves outcomes for home-dwelling elders. Various methods of contact show promise for addressing specific communication needs. Nurses practicing within patients' homes can improve care coordination by using phone calls to address minor matters and written letters for detailed communication. Future research should explore implementation of Situation, Background, Assessment and Recommendation in home care to promote

  2. ISS Efforts to Fully Utilize its Target Acquisition Capability Serves as an Analog for Future Laser Pointing Communications Systems

    Science.gov (United States)

    Jackson, Dan

    2017-01-01

    The ISS is an outstanding platform for developing, testing and refining laser communications systems for future exploration. A recent ISS project which improved ISS communications satellite acquisition performance proves the platform’s utility as a laser communications systems testbed.

  3. Using satellite communications for a mobile computer network

    Science.gov (United States)

    Wyman, Douglas J.

    1993-01-01

    The topics discussed include the following: patrol car automation, mobile computer network, network requirements, network design overview, MCN mobile network software, MCN hub operation, mobile satellite software, hub satellite software, the benefits of patrol car automation, the benefits of satellite mobile computing, and national law enforcement satellite.

  4. Estimating the Theoretical Value for LAN Network Throughput Based Power Line Communications Technology Under the Homeplug 1.0 Standard

    Directory of Open Access Journals (Sweden)

    Martha Fabiola Contreras Higuera

    2013-06-01

    Full Text Available Power Line Communications (PLC refers to a group of technologies that allow to establish communication processes under the use of the grid as a physical means of transmission. The use of the grid as a physical means of transmission of information is not a new idea. Until a few years ago, the use of PLC had been limited to the implementation of solutions of control, automation and monitoring of sensors; which did not require a high bandwidth for its operation.During the late 1990s due to the new technological developments and the need to implement new alternatives for transfer of information, it was possible to reach speeds on the order of the Mbps, establishing the possibility of making use of the electricity network as a network of access. The current state of technology PLC allows to reach speeds of up to 200Mbps, which has enabled the transformation of the grid in a true network of band wide, capable of supporting data, voice and video provided by a telecommunications operator. The use of PLC-based network adapters allow easily design LANs and broadband communications through the electrical network, making any outlet in a point of connection for the user, without the need for wiring additional to existing ones.  The electrical network is a structure which so far has been exclusively used for the transport of electrical energy. However, it is possible to make use of this network in processes of communication and transmission of information such as: voice, data and video; Bearing in mind that grid had not been designed for this purpose. The performance is without doubt one of the aspects of greatest interest in the global analysis in networks LAN, due to the effect it produces on the end user. Basically, the most common parameters for evaluating the performance of a network are: Throughput, use of the canal and various measures of retardation. In this article is presented a simple analysis of the HomePlug 1.0 standard applied to the

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

    Science.gov (United States)

    Kim, Jeong-Nam

    2018-01-01

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

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

    CERN Document Server

    Pathan, Al-Sakib Khan; Khan, Shafiullah

    2014-01-01

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

  7. A Robust Optimization Based Energy-Aware Virtual Network Function Placement Proposal for Small Cell 5G Networks with Mobile Edge Computing Capabilities

    Directory of Open Access Journals (Sweden)

    Bego Blanco

    2017-01-01

    Full Text Available In the context of cloud-enabled 5G radio access networks with network function virtualization capabilities, we focus on the virtual network function placement problem for a multitenant cluster of small cells that provide mobile edge computing services. Under an emerging distributed network architecture and hardware infrastructure, we employ cloud-enabled small cells that integrate microservers for virtualization execution, equipped with additional hardware appliances. We develop an energy-aware placement solution using a robust optimization approach based on service demand uncertainty in order to minimize the power consumption in the system constrained by network service latency requirements and infrastructure terms. Then, we discuss the results of the proposed placement mechanism in 5G scenarios that combine several service flavours and robust protection values. Once the impact of the service flavour and robust protection on the global power consumption of the system is analyzed, numerical results indicate that our proposal succeeds in efficiently placing the virtual network functions that compose the network services in the available hardware infrastructure while fulfilling service constraints.

  8. Cooperative device-to-device communication in cognitive radio cellular networks

    CERN Document Server

    Li, Peng

    2014-01-01

    This brief examines current research on cooperative device-to-device (D2D) communication as an enhanced offloading technology to improve the performance of cognitive radio cellular networks. By providing an extensive review of recent advances in D2D communication, the authors demonstrate that the quality of D2D links significantly affects offloading performance in cellular networks, which motivates the design of cooperative D2D communication. After presenting the architecture of cooperative D2D communication, the challenges of capacity maximization and energy efficiency are addressed by optimi

  9. Case study: development of a SANDF tactical data link network enabling capability

    CSIR Research Space (South Africa)

    Smith, CJ

    2011-11-01

    Full Text Available appropriately named Link-ZA. This paper expands on the implementation evolution and challenges of the standard over the last 10 years and provides a generic TDL Capability Model with a strategy for establishing interoperability between different implementations...

  10. A Novel Dual Separate Paths (DSP) Algorithm Providing Fault-Tolerant Communication for Wireless Sensor Networks.

    Science.gov (United States)

    Tien, Nguyen Xuan; Kim, Semog; Rhee, Jong Myung; Park, Sang Yoon

    2017-07-25

    Fault tolerance has long been a major concern for sensor communications in fault-tolerant cyber physical systems (CPSs). Network failure problems often occur in wireless sensor networks (WSNs) due to various factors such as the insufficient power of sensor nodes, the dislocation of sensor nodes, the unstable state of wireless links, and unpredictable environmental interference. Fault tolerance is thus one of the key requirements for data communications in WSN applications. This paper proposes a novel path redundancy-based algorithm, called dual separate paths (DSP), that provides fault-tolerant communication with the improvement of the network traffic performance for WSN applications, such as fault-tolerant CPSs. The proposed DSP algorithm establishes two separate paths between a source and a destination in a network based on the network topology information. These paths are node-disjoint paths and have optimal path distances. Unicast frames are delivered from the source to the destination in the network through the dual paths, providing fault-tolerant communication and reducing redundant unicast traffic for the network. The DSP algorithm can be applied to wired and wireless networks, such as WSNs, to provide seamless fault-tolerant communication for mission-critical and life-critical applications such as fault-tolerant CPSs. The analyzed and simulated results show that the DSP-based approach not only provides fault-tolerant communication, but also improves network traffic performance. For the case study in this paper, when the DSP algorithm was applied to high-availability seamless redundancy (HSR) networks, the proposed DSP-based approach reduced the network traffic by 80% to 88% compared with the standard HSR protocol, thus improving network traffic performance.

  11. Statistically validated mobile communication networks: the evolution of motifs in European and Chinese data

    Science.gov (United States)

    Li, Ming-Xia; Palchykov, Vasyl; Jiang, Zhi-Qiang; Kaski, Kimmo; Kertész, János; Miccichè, Salvatore; Tumminello, Michele; Zhou, Wei-Xing; Mantegna, Rosario N.

    2014-08-01

    Big data open up unprecedented opportunities for investigating complex systems, including society. In particular, communication data serve as major sources for computational social sciences, but they have to be cleaned and filtered as they may contain spurious information due to recording errors as well as interactions, like commercial and marketing activities, not directly related to the social network. The network constructed from communication data can only be considered as a proxy for the network of social relationships. Here we apply a systematic method, based on multiple-hypothesis testing, to statistically validate the links and then construct the corresponding Bonferroni network, generalized to the directed case. We study two large datasets of mobile phone records, one from Europe and the other from China. For both datasets we compare the raw data networks with the corresponding Bonferroni networks and point out significant differences in the structures and in the basic network measures. We show evidence that the Bonferroni network provides a better proxy for the network of social interactions than the original one. Using the filtered networks, we investigated the statistics and temporal evolution of small directed 3-motifs and concluded that closed communication triads have a formation time scale, which is quite fast and typically intraday. We also find that open communication triads preferentially evolve into other open triads with a higher fraction of reciprocated calls. These stylized facts were observed for both datasets.

  12. Second language social networks and communication-related acculturative stress: The role of interconnectedness

    Directory of Open Access Journals (Sweden)

    Marina M Doucerain

    2015-08-01

    Full Text Available Although a substantial amount of cross-cultural psychology research has investigated acculturative stress in general, little attention has been devoted specifically to communication-related acculturative stress. In line with the view that cross-cultural adaptation and second language (L2 learning are social and interpersonal phenomena, the present study examines the hypothesis that migrants' L2 social network size and interconnectedness predict communication-related acculturative stress. The main idea underlying this hypothesis is that L2 social networks play an important role in fostering social and cultural aspects of communicative competence. Specifically, higher interconnectedness may reflect greater access to unmodified natural cultural representations and L2 communication practices, thus fostering communicative competence through observational learning. As such, structural aspects of migrants' L2 social networks may be protective against acculturative stress arising from chronic communication difficulties. Results from a study of first generation migrant students (N=100 support this idea by showing that both inclusiveness and density of the participants' L2 network account for unique variance in communication-related acculturative stress but not in general acculturative stress. These results support the idea that research on cross-cultural adaptation would benefit from disentangling the various facets of acculturative stress and that the structure of migrants' L2 network matters for language related outcomes. Finally, this study contributes to an emerging body of work that attempts to integrate cultural/cross-cultural research on acculturation and research on intercultural communication and second language learning.

  13. Consensus algorithm in smart grid and communication networks

    Science.gov (United States)

    Alfagee, Husain Abdulaziz

    On a daily basis, consensus theory attracts more and more researches from different areas of interest, to apply its techniques to solve technical problems in a way that is faster, more reliable, and even more precise than ever before. A power system network is one of those fields that consensus theory employs extensively. The use of the consensus algorithm to solve the Economic Dispatch and Load Restoration Problems is a good example. Instead of a conventional central controller, some researchers have explored an algorithm to solve the above mentioned problems, in a distribution manner, using the consensus algorithm, which is based on calculation methods, i.e., non estimation methods, for updating the information consensus matrix. Starting from this point of solving these types of problems mentioned, specifically, in a distribution fashion, using the consensus algorithm, we have implemented a new advanced consensus algorithm. It is based on the adaptive estimation techniques, such as the Gradient Algorithm and the Recursive Least Square Algorithm, to solve the same problems. This advanced work was tested on different case studies that had formerly been explored, as seen in references 5, 7, and 18. Three and five generators, or agents, with different topologies, correspond to the Economic Dispatch Problem and the IEEE 16-Bus power system corresponds to the Load Restoration Problem. In all the cases we have studied, the results met our expectations with extreme accuracy, and completely matched the results of the previous researchers. There is little question that this research proves the capability and dependability of using the consensus algorithm, based on the estimation methods as the Gradient Algorithm and the Recursive Least Square Algorithm to solve such power problems.

  14. Research on the Architecture of a Basic Reconfigurable Information Communication Network

    Directory of Open Access Journals (Sweden)

    Ruimin Wang

    2013-01-01

    Full Text Available The current information network cannot fundamentally meet some urgent requirements, such as providing ubiquitous information services and various types of heterogeneous network, supporting diverse and comprehensive network services, possessing high quality communication effects, ensuring the security and credibility of information interaction, and implementing effective supervisory control. This paper provides the theory system for the basic reconfigurable information communication network based on the analysis of present problems on the Internet and summarizes the root of these problems. It also provides an in-depth discussion about the related technologies and the prime components of the architecture.

  15. Coping with the Upcoming Heterogeneity in 5G Communications and Storage Using Fulcrum Network Codes

    DEFF Research Database (Denmark)

    Roetter, Daniel Enrique Lucani; Pedersen, Morten Videbæk; Heide, Janus

    2014-01-01

    In this paper, Fulcrum network codes are introduced as a viable solution to cope with the heterogeneity of 5G communication and storage systems. Fulcrum network codes are an enhancement of random linear network codes (RLNC) offering high throughput performance at low overhead. This contrasts...... with state of the art solutions that only offer a trade-off between performance and overhead. Additionally, Fulcrum network codes allow any communication or storage node to choose its decoding parameters, e.g., field size, based on their individual computational power or available energy. This means...

  16. Proceedings of the Workshop on Advanced Network and Technology Concepts for Mobile, Micro, and Personal Communications

    Science.gov (United States)

    Paul, Lori (Editor)

    1991-01-01

    The Workshop on Advanced Network and Technology Concepts for Mobile, Micro, and Personal Communications was held at NASA's JPL Laboratory on 30-31 May 1991. It provided a forum for reviewing the development of advanced network and technology concepts for turn-of-the-century telecommunications. The workshop was organized into three main categories: (1) Satellite-Based Networks (L-band, C-band, Ku-band, and Ka-band); (2) Terrestrial-Based Networks (cellular, CT2, PCN, GSM, and other networks); and (3) Hybrid Satellite/Terrestrial Networks. The proceedings contain presentation papers from each of the above categories.

  17. An integrated PHY-MAC analytical model for IEEE 802.15.7 VLC network with MPR capability

    Science.gov (United States)

    Yu, Hai-feng; Chi, Xue-fen; Liu, Jian

    2014-09-01

    Considering that the collision caused by hidden terminal is particularly serious due to the narrow beams of optical devices, the multi-packet reception (MPR) is introduced to mitigate the collisions for IEEE 802.15.7 visible light communication (VLC) system. To explore the impact of MPR on system performance and investigate the interaction between physical (PHY) layer and media access control (MAC) layer, a three dimensional (3D) integrated PHY-MAC analytical model of carrier sense multiple access/collision avoidance (CSMA/CA) is established based on Markov chain theory for VLC system, in which MPR is implemented through the use of orthogonal code sequence. Throughput is derived to evaluate the performance of VLC system with MPR capability under imperfect optical channel. The results can be used for the performance optimization of a VLC system with MPR capability.

  18. Comparison of the Performance and Capabilities of Femtocell versus Wi-Fi Networks

    Science.gov (United States)

    2012-09-01

    of Electrical and Electronics Engineers IKEV2 Internet Key Exchange Version 2 INTSERV Integrated Services IP Internet Protocol IPSEC ...correctly identify valid femtocells within the network. Another means of ensuring security is the use of Internet Protocol Security ( IPsec ). IPsec is a...gateway uses Internet Protocol Security ( IPSec ) and Internet Key Exchange (IKEv2) Internet security protocols for encryption support and for the

  19. Applying the concept of network enabled capabilities to incident management in the Netherlands

    NARCIS (Netherlands)

    Immers, L.H.; Huisken, G.

    2008-01-01

    The application of Incident Management to the Dutch road network suffers from serious problems in terms of availability of accurate and up-to-date information. In this paper we present an approach aimed at diminishing the occurrence of misunderstandings. This approach is based on the concept of

  20. Inferring Social Relations from Online and Communication Networks

    OpenAIRE

    Nasim, Mehwish

    2016-01-01

    In this work analyzed the interplay between social relations in the form of friendship ties, attributes and interaction in online social networks. In this context we analyzed composition of social circles in online social networks and showed that social circles are homophilious with respect to at least one node attribute. We showed that using the right combination of network and interaction features, links can be inferred in online covert networks. We also analyzed longitudinal dyadic interac...

  1. A network society communicative model for optimizing the Refugee Status Determination (RSD) procedures

    National Research Council Canada - National Science Library

    Andrea Pacheco Pacífico

    2013-01-01

      This article recommends a new way to improve Refugee Status Determination (RSD) procedures by proposing a network society communicative model based on active involvement and dialogue among all implementing partners...

  2. Potentials and Limitations of CDMA Networks for Combined Inter-Satellite Communication and Relative Navigation

    NARCIS (Netherlands)

    Sun, R.; Guo, J.; Gill, E.K.A.; Maessen, D.C.

    2012-01-01

    Precision formation flying missions require formation acquisition and maintenance through the interactions among spacecraft by the inter-satellite communication and relative navigation. This paper analyses the dedicated system constraints of the network architecture for precision formation flying

  3. Asynchronous Free-Space Optical CDMA Communications System for Last-mile Access Network

    DEFF Research Database (Denmark)

    Jurado-Navas, Antonio; Raddo, Thiago R.; Sanches, Anderson L.

    2016-01-01

    We propose a new hybrid asynchronous OCDMA-FSO communications system for access network solutions. New ABER expressions are derived under gamma-gamma scintillation channels, where all users can surprisingly achieve error-free transmissions when FEC is employed....

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

    Science.gov (United States)

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

    2013-12-01

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

  5. FY 1999 Blue Book: Computing, Information, and Communications: Networked Computing for the 21st Century

    Data.gov (United States)

    Networking and Information Technology Research and Development, Executive Office of the President — U.S.research and development R and D in computing, communications, and information technologies has enabled unprecedented scientific and engineering advances,...

  6. In-House Communication Support System Based on the Information Propagation Model Utilizes Social Network

    Science.gov (United States)

    Takeuchi, Susumu; Teranishi, Yuuichi; Harumoto, Kaname; Shimojo, Shinji

    Almost all companies are now utilizing computer networks to support speedier and more effective in-house information-sharing and communication. However, existing systems are designed to support communications only within the same department. Therefore, in our research, we propose an in-house communication support system which is based on the “Information Propagation Model (IPM).” The IPM is proposed to realize word-of-mouth communication in a social network, and to support information-sharing on the network. By applying the system in a real company, we found that information could be exchanged between different and unrelated departments, and such exchanges of information could help to build new relationships between the users who are apart on the social network.

  7. A Wireless Communications Laboratory on Cellular Network Planning

    Science.gov (United States)

    Dawy, Z.; Husseini, A.; Yaacoub, E.; Al-Kanj, L.

    2010-01-01

    The field of radio network planning and optimization (RNPO) is central for wireless cellular network design, deployment, and enhancement. Wireless cellular operators invest huge sums of capital on deploying, launching, and maintaining their networks in order to ensure competitive performance and high user satisfaction. This work presents a lab…

  8. [Communication management of collaborative networks of science, technology and innovation in health].

    Science.gov (United States)

    Martins, Wagner de Jesus; Artmann, Elizabeth; Rivera, Francisco Javier Uribe

    2012-12-01

    The objective of the article was to propose a model of communication management of networks for the Health Innovation System in Brazil. The health production complex and its relationship with the nation's development are addressed and some suggestions for operationalization of the proposed model are also presented. The discussion is based on Habermas' theory and similar cases from other countries. Communication strategies and approaches to commitment dialogue for concerted actions and consensus-building based on critical reasoning may help strengthen democratic networks.

  9. Mapping Ad Hoc Communications Network of a Large Number Fixed-Wing UAV Swarm

    Science.gov (United States)

    2017-03-01

    NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS MAPPING AD HOC COMMUNICATIONS NETWORK OF A LARGE NUMBER FIXED-WING UAV SWARM by Alexis...SUBTITLE MAPPING AD HOC COMMUNICATIONS NETWORK OF A LARGE NUMBER FIXED-WING UAV SWARM 5. FUNDING NUMBERS 6. AUTHOR(S) Alexis Pospischil 7. PERFORMING... UAVs ) simultaneously as a self-organizing swarm. These vehicles were able to execute behaviors based on message notification from a single ground

  10. Ablation as targeted perturbation to rewire communication network of persistent atrial fibrillation.

    Science.gov (United States)

    Tao, Susumu; Way, Samuel F; Garland, Joshua; Chrispin, Jonathan; Ciuffo, Luisa A; Balouch, Muhammad A; Nazarian, Saman; Spragg, David D; Marine, Joseph E; Berger, Ronald D; Calkins, Hugh; Ashikaga, Hiroshi

    2017-01-01

    Persistent atrial fibrillation (AF) can be viewed as disintegrated patterns of information transmission by action potential across the communication network consisting of nodes linked by functional connectivity. To test the hypothesis that ablation of persistent AF is associated with improvement in both local and global connectivity within the communication networks, we analyzed multi-electrode basket catheter electrograms of 22 consecutive patients (63.5 ± 9.7 years, 78% male) during persistent AF before and after the focal impulse and rotor modulation-guided ablation. Eight patients (36%) developed recurrence within 6 months after ablation. We defined communication networks of AF by nodes (cardiac tissue adjacent to each electrode) and edges (mutual information between pairs of nodes). To evaluate patient-specific parameters of communication, thresholds of mutual information were applied to preserve 10% to 30% of the strongest edges. There was no significant difference in network parameters between both atria at baseline. Ablation effectively rewired the communication network of persistent AF to improve the overall connectivity. In addition, successful ablation improved local connectivity by increasing the average clustering coefficient, and also improved global connectivity by decreasing the characteristic path length. As a result, successful ablation improved the efficiency and robustness of the communication network by increasing the small-world index. These changes were not observed in patients with AF recurrence. Furthermore, a significant increase in the small-world index after ablation was associated with synchronization of the rhythm by acute AF termination. In conclusion, successful ablation rewires communication networks during persistent AF, making it more robust, efficient, and easier to synchronize. Quantitative analysis of communication networks provides not only a mechanistic insight that AF may be sustained by spatially localized sources and

  11. Communications Training Courses Across the Leopold Leadership Network

    Science.gov (United States)

    Hayden, T.; Gerber, L. R.; Silver, W. L.

    2012-12-01

    For nearly fifteen years, the Leopold Leadership Program has provided science communication training and support to mid-career academic environmental researchers from across North America. There has been an emphasis throughout on effective communication to non-scientific audiences. Increasingly, Leopold fellows have been developing communications courses for their own students, responding to the need for future scientists to be able to communicate well with the public, the media, policy makers and other audiences. At a June 2012 reunion meeting, a group of past fellows and communications trainers conducted a curriculum exchange, sharing experiences and ideas for successful inclusion of communications training in environmental science curricula. This presentation will present case studies from several institutions, including the use of podcasting, web columns, social media, in-person presentation and other presentation styles for connecting general audiences. We will share best practices, challenges and recommendations for curriculum development and institutional acceptance.

  12. Inter-domain networking innovation on steroids: empowering ixps with SDN capabilities

    KAUST Repository

    Chiesa, Marco

    2016-10-14

    While innovation in inter-domain routing has remained stagnant for over a decade, Internet exchange points (IXPs) are consolidating their role as economically advantageous interconnection points for reducing path latencies and exchanging ever increasing amounts of traffic. As such, IXPs appear as a natural place to foster network innovation and assess the benefits of SDN, a recent technological trend that has already boosted innovation within data center networks. In this article, we give a comprehensive overview of use cases for SDN at IXPs, which leverage the superior vantage point of an IXP to introduce advanced features like load balancing and DDoS mitigation. We discuss the benefits of SDN solutions by analyzing real-world data from one of the largest IXPs. We also leverage insights into IXP operations to shape benefits not only for members but also for operators.

  13. Managerial capabilities of the home base in an intra-organisational global network

    DEFF Research Database (Denmark)

    Mykhaylenko, Alona

    ENGLISH SUMMARY The challenges and opportunities of globalisation tempt firms to reconfigure their operations and relocate (or offshore) various activities to the most advantageous destinations. Such offshore operations tend to gradually become complex and intertwined, leading to the transition....... This investigation was conducted through a retrospective longitudinal case study of one Danish original equipment manufacturer and its three subsidiaries in China, Slovakia, and the US. The findings, first of all, support, extend, and modify the revised Uppsala globalisation model with regard to the types...... of experiential knowledge enabling the intra-organisational network evolution process, its drivers, and relationships between the parts of the model. The findings also suggest the existence of distinguishable evolutionary stages. Additionally, the resu lts indicate that changes in particular network configuration...

  14. WHY ENTREPRENEUR OVERCONFIDENCE AFFECT ITS PROJECT FINANCIAL CAPABILITY: EVIDENCE FROM TUNISIA USING THE BAYESIAN NETWORK METHOD

    OpenAIRE

    Salima TAKTAK; AZOUZI Mohamed Ali; Triki, Mohamed

    2013-01-01

    This article discusses the effect of the entrepreneur’s profile on financing his creative project. It analyzes the impact of overconfidence on improving perceptions financing capacity of the project. To analyze this relationship we used networks as Bayesian data analysis method. Our sample is composed of 200 entrepreneurs. Our results show a high level of entrepreneur’s overconfidence positively affects the evaluation of financing capacity of the project.

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

    Science.gov (United States)

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

    1996-05-01

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

  16. Evaluating the Capability of High-Altitude Infrasound Platforms to Cover Gaps in Existing Networks.

    Energy Technology Data Exchange (ETDEWEB)

    Bowman, Daniel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-09-01

    A variety of Earth surface and atmospheric sources generate low frequency sound waves that can travel great distances. Despite a rich history of ground-based sensor studies, very few experiments have investigated the prospects of free floating microphone arrays at high altitudes. However, recent initiatives have shown that such networks have very low background noise and may sample an acoustic wave field that is fundamentally different than that at the Earth's surface. The experiments have been limited to at most two stations at altitude, limiting their utility in acoustic event detection and localization. We describe the deployment of five drifting microphone stations at altitudes between 21 and 24 km above sea level. The stations detected one of two regional ground-based explosions as well as the ocean microbarom while traveling almost 500 km across the American Southwest. The explosion signal consisted of multiple arrivals; signal amplitudes did not correlate with sensor elevation or source range. A sparse network method that employed curved wave front corrections was able to determine the backazimuth from the free flying network to the acoustic source. Episodic broad band signals similar to those seen on previous flights in the same region were noted as well, but their source remains unclear. Background noise levels were commensurate with those on infrasound stations in the International Monitoring System (IMS) below 2 seconds, but sensor self noise appears to dominate at higher frequencies.

  17. A Mobility and Traffic Generation Framework for Modeling and Simulating Ad Hoc Communication Networks

    Directory of Open Access Journals (Sweden)

    Chris Barrett

    2004-01-01

    Full Text Available We present a generic mobility and traffic generation framework that can be incorporated into a tool for modeling and simulating large scale ad~hoc networks. Three components of this framework, namely a mobility data generator (MDG, a graph structure generator (GSG and an occlusion modification tool (OMT allow a variety of mobility models to be incorporated into the tool. The MDG module generates positions of transceivers at specified time instants. The GSG module constructs the graph corresponding to the ad hoc network from the mobility data provided by MDG. The OMT module modifies the connectivity of the graph produced by GSG to allow for occlusion effects. With two other modules, namely an activity data generator (ADG which generates packet transmission activities for transceivers and a packet activity simulator (PAS which simulates the movement and interaction of packets among the transceivers, the framework allows the modeling and simulation of ad hoc communication networks. The design of the framework allows a user to incorporate various realistic parameters crucial in the simulation. We illustrate the utility of our framework through a comparative study of three mobility models. Two of these are synthetic models (random waypoint and exponentially correlated mobility proposed in the literature. The third model is based on an urban population mobility modeling tool (TRANSIMS developed at the Los Alamos National Laboratory. This tool is capable of providing comprehensive information about the demographics, mobility and interactions of members of a large urban population. A comparison of these models is carried out by computing a variety of parameters associated with the graph structures generated by the models. There has recently been interest in the structural properties of graphs that arise in real world systems. We examine two aspects of this for the graphs created by the mobility models: change associated with power control (range of

  18. Including 10-Gigabit-capable Passive Optical Network under End-to-End Generalized Multi-Protocol Label Switching Provisioned Quality of Service

    DEFF Research Database (Denmark)

    Brewka, Lukasz Jerzy; Gavler, Anders; Wessing, Henrik

    2012-01-01

    End-to-end quality of service provisioning is still a challenging task despite many years of research and development in this area. Considering a generalized multi-protocol label switching based core/metro network and resource reservation protocol capable home gateways, it is the access part...... of the network where quality of service signaling is bridged. This article proposes strategies for generalized multi-protocol label switching control over next emerging passive optical network standard, i.e., the 10-gigabit-capable passive optical network. Node management and resource allocation approaches...... are discussed, and possible issues are raised. The analysis shows that consideration of a 10-gigabit-capable passive optical network as a generalized multi-protocol label switching controlled domain is valid and may advance end-to-end quality of service provisioning for passive optical network based customers....

  19. Intracellular organelle networks: Understanding their organization and communication through systems-level modeling and analysis

    Institute of Scientific and Technical Information of China (English)

    Qinle Ba; Ge Yang

    2017-01-01

    BACKGROUND:Membrane-bound intracellular organelles are biochemically distinct compartments used by eukaryotic cells for serving specialized physiological functions and organizing their internal environment.Recent studies revealed surprisingly extensive communication between these organelles and highlighted the network nature of their organization and communication.Since organization and communication of the organelles are carried out at the systems level through their networks,systems-level studies are essential for understanding the underlying mechanisms.METHODS:We reviewed recent studies that used systems-level quantitative modeling and analysis to understand organization and communication of intracellular organelle networks.RESULTS:We first review modeling and analysis studies on how fusion/fission and degradation/biogenesis,two essential and closely related classes of activities of individual organelles,collectively mediate the dynamic organization of their networks.We then tum to another important aspect of the dynamic organization of the organelle networks,namely how organelles are physically connected within their networks,a property referred to as the topology of the networks in mathematics,and summarize some of their distinct properties.Lastly,we briefly review modeling and analysis studies that aim to understand communication between different organelle networks,focusing on cellular calcium homeostasis as an example.We conclude with a brief discussion of future directions for research in this area.CONCLUSIONS:Together,the reviewed studies provide critical insights into how diverse activities of individual organelles collectively mediate the organization and communication of their networks.They demonstrate the essential role of systemslevel modeling and analysis in understanding complex behavior of such networks.

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

    CERN Document Server

    Chang, Gee-Kung; Ellinas, Georgios

    2017-01-01

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

  1. The Relationship among Communication Network Roles, Job Stress, and Burnout in Educational Organizations.

    Science.gov (United States)

    Ray, Eileen Berlin

    1991-01-01

    Expands the definition of supportive communication ties and examines the relationship of communication network roles to job stress and burnout in public elementary schools. Finds that isolates report significantly less stress than linkers, group members, and dyads and significantly less burnout than linkers and dyads. (SR)

  2. Signal Quality Outage Analysis for Ultra-Reliable Communications in Cellular Networks

    DEFF Research Database (Denmark)

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

    2015-01-01

    Ultra-reliable communications over wireless will open the possibility for a wide range of novel use cases and applications. In cellular networks, achieving reliable communication is challenging due to many factors, particularly the fading of the desired signal and the interference. In this regard...

  3. ENTREPRENEURIAL CAPABILITIES

    DEFF Research Database (Denmark)

    Rasmussen, Lauge Baungaard; Nielsen, Thorkild

    2003-01-01

    The aim of this article is to analyse entrepreneurship from an action research perspective. What is entrepreneurship about? Which are the fundamental capabilities and processes of entrepreneurship? To answer these questions the article includes a case study of a Danish entrepreneur and his networks...

  4. Transformation of Traditional Marketing Communications in to Paradigms of Social Media Networking

    OpenAIRE

    Nair, T. R. Gopalakrishnan; Subramaniam, Kumarashvari

    2012-01-01

    Effective Communication for marketing is a vital field in business organizations, which is used to convey the details about their products and services to the market segments and subsequently to build long lasting customer relationships. This paper focuses on an emerging component of the integrated marketing communication, ie. social media networking, as it is increasingly becoming the trend. In 21st century, the marketing communication platforms show a tendency to shift towards innovative te...

  5. Verifying cell loss requirements in high-speed communication networks

    Directory of Open Access Journals (Sweden)

    Kerry W. Fendick

    1998-01-01

    Full Text Available In high-speed communication networks it is common to have requirements of very small cell loss probabilities due to buffer overflow. Losses are measured to verify that the cell loss requirements are being met, but it is not clear how to interpret such measurements. We propose methods for determining whether or not cell loss requirements are being met. A key idea is to look at the stream of losses as successive clusters of losses. Often clusters of losses, rather than individual losses, should be regarded as the important “loss events”. Thus we propose modeling the cell loss process by a batch Poisson stochastic process. Successive clusters of losses are assumed to arrive according to a Poisson process. Within each cluster, cell losses do not occur at a single time, but the distance between losses within a cluster should be negligible compared to the distance between clusters. Thus, for the purpose of estimating the cell loss probability, we ignore the spaces between successive cell losses in a cluster of losses. Asymptotic theory suggests that the counting process of losses initiating clusters often should be approximately a Poisson process even though the cell arrival process is not nearly Poisson. The batch Poisson model is relatively easy to test statistically and fit; e.g., the batch-size distribution and the batch arrival rate can readily be estimated from cell loss data. Since batch (cluster sizes may be highly variable, it may be useful to focus on the number of batches instead of the number of cells in a measurement interval. We also propose a method for approximately determining the parameters of a special batch Poisson cell loss with geometric batch-size distribution from a queueing model of the buffer content. For this step, we use a reflected Brownian motion (RBM approximation of a G/D/1/C queueing model. We also use the RBM model to estimate the input burstiness given the cell loss rate. In addition, we use the RBM model to

  6. On the Capability of Artificial Neural Networks to Compensate Nonlinearities in Wavelength Sensing

    Science.gov (United States)

    Hafiane, Mohamed Lamine; Dibi, Zohir; Manck, Otto

    2009-01-01

    An intelligent sensor for light wavelength readout, suitable for visible range optical applications, has been developed. Using buried triple photo-junction as basic pixel sensing element in combination with artificial neural network (ANN), the wavelength readout with a full-scale error of less than 1.5% over the range of 400 to 780 nm can be achieved. Through this work, the applicability of the ANN approach in optical sensing is investigated and compared with conventional methods, and a good compromise between accuracy and the possibility for on-chip implementation was thus found. Indeed, this technique can serve different purposes and may replace conventional methods. PMID:22574051

  7. The Use of Social Networks as a Communication Tool between Teachers and Students: A Literature Review

    Science.gov (United States)

    Froment, Facundo; García González, Alfonso Javier; Bohórquez, M. Rocío

    2017-01-01

    Social networks have drastically changed communication between people, constituting a means of everyday use by which information is created and shared in a simple, instantaneous way with the rest of the world. Although social networks were not initially created for academic purposes, they are gradually being used as a means of communication…

  8. Scholarly Communication in the Network Environment: Issues of Principle, Policy and Practice.

    Science.gov (United States)

    Kahin, Brian

    1992-01-01

    Discussion of legal and ethical issues raised by the growth of research networking focuses on two general areas: (1) communication, prepublication, and publication; and (2) the network as a distribution environment. Issues considered include joint authorship, rights in computer conferencing, derivative works, control of dissemination, site…

  9. Social Network Sites and Student-Lecturer Communication: An Academic Voice

    Science.gov (United States)

    Jones, Joanna; Gaffney-Rhys, Ruth; Jones, Edward

    2011-01-01

    This article presents a synthesis of existing ideas relating to the use of social network sites by faculty within higher education institutions (HEIs) to communicate with the student body. As previous research has been from a student-centric perspective, importantly this study explores the use of social networks for student-faculty communication…

  10. Success Factors and Challenges of an Information Communication Technology Network in Rural Schools

    Science.gov (United States)

    Mihai, Maryke A.

    2017-01-01

    In April 2008, an interactive information communication technology (ICT) network was established in Mpumalanga, South Africa. the network involved the implementation of SMART board interactive whiteboards (IWBs) and collaboration between a leading school and several disadvantaged schools. the main purpose of the Mpumalanga IWB project was to reach…

  11. Communication method for high density wireless networks, terminal, cluster master device, central node, and system therefor

    NARCIS (Netherlands)

    Havinga, Paul J.M.; van Hoesel, L.F.W.; Bijwaard, D.

    2009-01-01

    Large-scale wireless sensor and actuator networks(LWSANs) are networks that consist of many sensor and/or actuator devices (i.e. >1,000 devices). These sensor and/or actuator devices (also called nodes) communicate wirelessly to deliver their sensor readings to one or more gateway devices in the

  12. Multiscale Analysis of Spreading in a Large Communication Network

    OpenAIRE

    Kivelä, Mikko; Pan, Raj Kumar; Kaski, Kimmo; Kertész, János; Saramäki, Jari; Karsai, Márton

    2011-01-01

    In temporal networks, both the topology of the underlying network and the timings of interaction events can be crucial in determining how some dynamic process mediated by the network unfolds. We have explored the limiting case of the speed of spreading in the SI model, set up such that an event between an infectious and susceptible individual always transmits the infection. The speed of this process sets an upper bound for the speed of any dynamic process that is mediated through the interact...

  13. Optimal Power Allocation of Relay Sensor Node Capable of Energy Harvesting in Cooperative Cognitive Radio Network.

    Science.gov (United States)

    Son, Pham Ngoc; Har, Dongsoo; Cho, Nam Ik; Kong, Hyung Yun

    2017-03-21

    A cooperative cognitive radio scheme exploiting primary signals for energy harvesting is proposed. The relay sensor node denoted as the secondary transmitter (ST) harvests energy from the primary signal transmitted from the primary transmitter, and then uses it to transmit power superposed codes of the secrecy signal of the secondary network (SN) and of the primary signal of the primary network (PN). The harvested energy is split into two parts according to a power splitting ratio, one for decoding the primary signal and the other for charging the battery. In power superposition coding, the amount of fractional power allocated to the primary signal is determined by another power allocation parameter (e.g., the power sharing coefficient). Our main concern is to investigate the impact of the two power parameters on the performances of the PN and the SN. Analytical or mathematical expressions of the outage probabilities of the PN and the SN are derived in terms of the power parameters, location of the ST, channel gain, and other system related parameters. A jointly optimal power splitting ratio and power sharing coefficient for achieving target outage probabilities of the PN and the SN, are found using these expressions and validated by simulations.

  14. Line-plane broadcasting in a data communications network of a parallel computer

    Science.gov (United States)

    Archer, Charles J.; Berg, Jeremy E.; Blocksome, Michael A.; Smith, Brian E.

    2010-06-08

    Methods, apparatus, and products are disclosed for line-plane broadcasting in a data communications network of a parallel computer, the parallel computer comprising a plurality of compute nodes connected together through the network, the network optimized for point to point data communications and characterized by at least a first dimension, a second dimension, and a third dimension, that include: initiating, by a broadcasting compute node, a broadcast operation, including sending a message to all of the compute nodes along an axis of the first dimension for the network; sending, by each compute node along the axis of the first dimension, the message to all of the compute nodes along an axis of the second dimension for the network; and sending, by each compute node along the axis of the second dimension, the message to all of the compute nodes along an axis of the third dimension for the network.

  15. Cognitive Networking With Regards to NASA's Space Communication and Navigation Program

    Science.gov (United States)

    Ivancic, William D.; Paulsen, Phillip E.; Vaden, Karl R.; Ponchak, Denise S.

    2013-01-01

    This report describes cognitive networking (CN) and its application to NASA's Space Communication and Networking (SCaN) Program. This report clarifies the terminology and framework of CN and provides some examples of cognitive systems. It then provides a methodology for developing and deploying CN techniques and technologies. Finally, the report attempts to answer specific questions regarding how CN could benefit SCaN. It also describes SCaN's current and target networks and proposes places where cognition could be deployed.

  16. Intrusion detection for IP-based multimedia communications over wireless networks

    CERN Document Server

    Tang, Jin

    2013-01-01

    IP-based multimedia communications have become increasingly popular in recent years. With the increasing coverage of the IEEE 802:11™ based wireless networks, IP-based multimedia communications over wireless networks are also drawing extensive attention in both academia and industry. Due to the openness and distributed nature of the protocols involved, such as the session initiation protocol (SIP) and the IEEE 802:11™ standard, it becomes easy for malicious users in the network to achieve their own gain or disrupt the service by deviating from the normal protocol behaviors. This SpringerBrief

  17. Throughput, Energy and Overhead of Multicast Device-to-Device Communications with Network Coded Cooperation

    DEFF Research Database (Denmark)

    Hernandez Marcano, Nestor Javier; Heide, Janus; Lucani Rötter, Daniel Enrique

    2016-01-01

    Cooperation strategies in mobile networks typically rely in short range technologies, like LTE-A Device to Device (D2D) communications, for data exchange between devices forming mobile clouds. These communications provide a better device experience since the clouds offload the network. Nevertheless......, this assumes that the throughput gains and energy savings in multicasting are much larger between devices than the base station to the receivers. However, current mobile networks suffer from many different issues varying the performance in data rates, which calls into question these assumptions. Therefore...

  18. A Literature Study on Dynamic Bandwidth Allocation Mechanisms for Tandem Communication Networks

    Directory of Open Access Journals (Sweden)

    CH.V. RAGHAVENDRAN

    2014-10-01

    Full Text Available Modeling and performance prediction are becoming increasingly important issues in the design and operation of computer communications systems. In this paper a review is carried out on how Tandem queuing models with Dynamic Bandwidth Allocation have been applied so far into the performance evaluation of Communication Networks. Queuing network models with finite/infinite capacity buffers and blocking have been applied as more realistic models of systems with finite capacity resources. First we review basic properties of exponential queuing systems, and then give an overview of recent progress made in the areas of dynamic bandwidth allocation for tandem queuing network models and performance measures.

  19. Second language social networks and communication-related acculturative stress: the role of interconnectedness

    Science.gov (United States)

    Doucerain, Marina M.; Varnaamkhaasti, Raheleh S.; Segalowitz, Norman; Ryder, Andrew G.

    2015-01-01

    Although a substantial amount of cross-cultural psychology research has investigated acculturative stress in general, little attention has been devoted specifically to communication-related acculturative stress (CRAS). In line with the view that cross-cultural adaptation and second language (L2) learning are social and interpersonal phenomena, the present study examines the hypothesis that migrants’ L2 social network size and interconnectedness predict CRAS. The main idea underlying this hypothesis is that L2 social networks play an important role in fostering social and cultural aspects of communicative competence. Specifically, higher interconnectedness may reflect greater access to unmodified natural cultural representations and L2 communication practices, thus fostering communicative competence through observational learning. As such, structural aspects of migrants’ L2 social networks may be protective against acculturative stress arising from chronic communication difficulties. Results from a study of first generation migrant students (N = 100) support this idea by showing that both inclusiveness and density of the participants’ L2 network account for unique variance in CRAS but not in general acculturative stress. These results support the idea that research on cross-cultural adaptation would benefit from disentangling the various facets of acculturative stress and that the structure of migrants’ L2 network matters for language related outcomes. Finally, this study contributes to an emerging body of work that attempts to integrate cultural/cross-cultural research on acculturation and research on intercultural communication and second language learning. PMID:26300809

  20. Second language social networks and communication-related acculturative stress: the role of interconnectedness.

    Science.gov (United States)

    Doucerain, Marina M; Varnaamkhaasti, Raheleh S; Segalowitz, Norman; Ryder, Andrew G

    2015-01-01

    Although a substantial amount of cross-cultural psychology research has investigated acculturative stress in general, little attention has been devoted specifically to communication-related acculturative stress (CRAS). In line with the view that cross-cultural adaptation and second language (L2) learning are social and interpersonal phenomena, the present study examines the hypothesis that migrants' L2 social network size and interconnectedness predict CRAS. The main idea underlying this hypothesis is that L2 social networks play an important role in fostering social and cultural aspects of communicative competence. Specifically, higher interconnectedness may reflect greater access to unmodified natural cultural representations and L2 communication practices, thus fostering communicative competence through observational learning. As such, structural aspects of migrants' L2 social networks may be protective against acculturative stress arising from chronic communication difficulties. Results from a study of first generation migrant students (N = 100) support this idea by showing that both inclusiveness and density of the participants' L2 network account for unique variance in CRAS but not in general acculturative stress. These results support the idea that research on cross-cultural adaptation would benefit from disentangling the various facets of acculturative stress and that the structure of migrants' L2 network matters for language related outcomes. Finally, this study contributes to an emerging body of work that attempts to integrate cultural/cross-cultural research on acculturation and research on intercultural communication and second language learning.