WorldWideScience

Sample records for network issue number

  1. Making Connections: Using Social Network Analysis for Program Evaluation. Issue Brief. Number 1

    Science.gov (United States)

    Honeycutt, Todd

    2009-01-01

    Social network analysis (SNA) is a methodological approach to measuring and mapping relationships. It can be used to study whole networks, all of the ties within a defined group, or connections that individuals have in their personal communities. The resulting graph-based structures illustrate the composition and effectiveness of networks on a…

  2. Issue Professionals in Transnational Networks

    DEFF Research Database (Denmark)

    Henriksen, Lasse Folke; Seabrooke, Leonard

    Professionals and organizations both seek to exploit and cooperate with each other. Professionals seek alliances in their own peer networks while organizations do the same. These networks carry not only information that inform incentives but norms about appropriate forms of governance and practices...... that guide how they actually work. In this paper we outline how professionals and organizations operate in two-level networks through a focus on issue control over issues of transnational governance. As such, this interdisciplinary paper brings together insights from Organization Studies and International...... Relations to discuss how professionals and organizations battle over issue control through the designation of tasks and the creation of overlapping networks. We outline the emergence of ‘issue professionals’ and how they attempt network management. We do so via a case on transnational sustainability...

  3. Special issue on network coding

    Science.gov (United States)

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

    2017-12-01

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

  4. The Issue Network as a Deliberative Space

    DEFF Research Database (Denmark)

    Ørmen, Jacob

    2012-01-01

    Through an analysis of the Danish asylum issue network on the Internet, this article discusses the possibilities of the online sphere as a deliberative space, where politics is happening. By assessing the hyperlink structure of the issue network and a subsequent content analysis of the claims...... and deliberative activity is not as definitive as it is often assumed in network analysis...

  5. Security Issues in Networks with Internet Access

    National Research Council Canada - National Science Library

    Landwehr, Carl E; Goldschlag, David M

    1997-01-01

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

  6. Engineering Issues for an Adaptive Defense Network

    National Research Council Canada - National Science Library

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

    2001-01-01

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

  7. Biased trapping issue on weighted hierarchical networks

    Indian Academy of Sciences (India)

    In this paper, we present trapping issues of weight-dependent walks on weighted hierarchical networks which are based on the classic scale-free hierarchical networks. Assuming that edge's weight is used as local information by a random walker, we introduce a biased walk. The biased walk is that a walker, at each step, ...

  8. Availability Issues in Wireless Visual Sensor Networks

    Science.gov (United States)

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

    2014-01-01

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

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

    NARCIS (Netherlands)

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

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

  10. On quality issues in networked value constellations

    NARCIS (Netherlands)

    Zarvic, N.; Wieringa, Roelf J.; van Eck, Pascal; Camarinha-Matos, L.M.; Picard, W.

    2008-01-01

    One of the main purposes of collaborative networks is to satisfy specific consumer needs, which one company cannot satisfy alone. With the opening of the internet in the 1990s the number of companies that collaborate by means of computer networks increased rapidly. As far as one of our main foci is

  11. Multiplex congruence network of natural numbers

    Science.gov (United States)

    Yan, Xiao-Yong; Wang, Wen-Xu; Chen, Guan-Rong; Shi, Ding-Hua

    2016-03-01

    Congruence theory has many applications in physical, social, biological and technological systems. Congruence arithmetic has been a fundamental tool for data security and computer algebra. However, much less attention was devoted to the topological features of congruence relations among natural numbers. Here, we explore the congruence relations in the setting of a multiplex network and unveil some unique and outstanding properties of the multiplex congruence network. Analytical results show that every layer therein is a sparse and heterogeneous subnetwork with a scale-free topology. Counterintuitively, every layer has an extremely strong controllability in spite of its scale-free structure that is usually difficult to control. Another amazing feature is that the controllability is robust against targeted attacks to critical nodes but vulnerable to random failures, which also differs from ordinary scale-free networks. The multi-chain structure with a small number of chain roots arising from each layer accounts for the strong controllability and the abnormal feature. The multiplex congruence network offers a graphical solution to the simultaneous congruences problem, which may have implication in cryptography based on simultaneous congruences. Our work also gains insight into the design of networks integrating advantages of both heterogeneous and homogeneous networks without inheriting their limitations.

  12. Ethical Issues in Network System Design

    Directory of Open Access Journals (Sweden)

    Duncan Langford

    1997-05-01

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

  13. Embedded generation and network management issues

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

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

  14. Management issues in multilayered network architectures

    Science.gov (United States)

    Piergigli, Mauro; Vercelli, Roberto; Zucchinali, A.

    1996-12-01

    The importance of managing networks and services is finally being accepted by both operators/service providers and HW/SW manufacturers. Standards are thus coming for managing solutions based on any new emerging technology. However standards and commercial solutions have different level of completeness and performance depending on the related managed technology. Thus, being real systems often composed of a mix of different technologies, the quality of their overall management is limited by the less mature and effective single technology management system. Today broadband networks can be seen as a layered structure including ATM, SDH and WDM optical layers. While the management of SDH is quite mature and significant results are reached for ATM management, the management of the WDM optical layer is still in its infancy. Therefore the WDM layer management is a critical factor in the development of the overall broadband network management. The paper, after few considerations on general public network management issues, presents some solutions currently under study for the WDM optical layer management. Although the improvement of the weaker single technology management system surely improves the quality of the overall layered network management, this is just one step along the path for optimizing it. The objective is in fact the integration of the single layer management systems into a global one, avoiding duplications and improving efficiency and effectiveness. The paper presents at the end some considerations about this topic that is rapidly getting hot because of the potential economical benefits such as integration can offer.

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

    Science.gov (United States)

    Cain, Jeff

    2008-02-15

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

  16. Artificial neural networks with an infinite number of nodes

    Science.gov (United States)

    Blekas, K.; Lagaris, I. E.

    2017-10-01

    A new class of Artificial Neural Networks is described incorporating a node density function and functional weights. This network containing an infinite number of nodes, excels in generalizing and possesses a superior extrapolation capability.

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

    Science.gov (United States)

    Henriksen, Lasse Folke; Seabrooke, Leonard

    2016-09-01

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

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

    Science.gov (United States)

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

    2001-01-01

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

  19. Identifying network representation issues with the network trip.

    Science.gov (United States)

    2012-04-23

    The purpose of this study was to evaluate the effects of road-network representation on the application of the Network Robustness Index (NRI), using the Chittenden County Regional Transportation Model. The results are expected to improve the requirem...

  20. Network protocols. Special issue; Netwerkprotocollen. Themanummer

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-11-15

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

  1. Coverage and Connectivity Issue in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Rachit Trivedi

    2013-04-01

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

  2. Challenges and research issues from the Italian Hearing Voices Network.

    OpenAIRE

    Cardano, Mario; Fornace, Gino; Macario, Marcello; Pezzano, Roberto; Piona, Glenda; Poobello, Raffaella; Santoni, Alessandra

    2014-01-01

    The Association "Rete Italiana Noi e le Voci" (Italian Hearing Voices Network, IHVN) is characterized by the active collaboration between voice hearers, mental health professionals and researchers. Goal of this presentation is to share two network challenges and research issues: (1) Psychiatric drugs: Based on the insights gained from Robert Whitaker's meta-analysis on the development of psychiatric drugs use and its effects, the study on this issue has become a priority in our research agend...

  3. Effect of mean network coordination number on dispersivity characteristics

    NARCIS (Netherlands)

    Vasilyev, L.; Raoof, A.; Nordbotten, J.M.

    2012-01-01

    In this study, we investigate the role of topology on the macroscopic (centimeter scale) dispersion characteristics derived from pore-network models.We consider 3D random porous networks extracted from a regular cubic lattice with coordination number distributed in accordance with real porous

  4. Learning as Issue Framing in Agricultural Innovation Networks

    Science.gov (United States)

    Tisenkopfs, Talis; Kunda, Ilona; Šumane, Sandra

    2014-01-01

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

  5. Authentication Issues in Multi-Service Residential Access Networks

    OpenAIRE

    Rossebo, Judith; Ronan, John; Walsh, Kristian

    2003-01-01

    Multi-service residential access networks allow residential customers to choose amongst a variety of service offerings, over a range of Core Networks and subject to user requirements such as QoS, mobility, cost and availability. These issues place requirements on authentication for network access, with a need for mutual authentication of the residential gateway (RG) to the local access point (LAP). The EU-IST project TORRENT is building a testbed providing for multi-service residential access...

  6. Issues related to social network advertising

    Directory of Open Access Journals (Sweden)

    Tecău, A. S.

    2012-01-01

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

  7. Young Viewers/Film Review Supplement. Issue Number One.

    Science.gov (United States)

    Gaffney, Maureen, Ed.

    1979-01-01

    Designed for media specialists and educators, this issue reviews 16 short films for children under the age of 14. Films included in the review range from 2 to 29 minutes in length and include song, puppet, verbal, nonverbal, and live-action animation. Topics cover fantasy and fairy tales, handicapped children, advertising techniques, inner city…

  8. Guest Editorial: Special Issue on Cognitive, Cellular and Mobile Networks

    Directory of Open Access Journals (Sweden)

    Shiwen Mao

    2016-01-01

    Full Text Available This special issue consists of a collection of papers on the latest advances in cognitive, cellular, and mobile networks. It consists of the top papers selected and extended from The Cognitive, Cellular, and Mobile Networks (CCM Track of 24th International Conference on Computer Communications and Networks (ICCCN 2015, held in Las Vegas, Nevada, USA. August 3 – August 6, 2015, as well as open call submissions. We hope that this SI will serve as good references for engineers, scientists, researchers, and academics in the field of Cognitive, Cellular, and Mobile Networks.

  9. Key management issue in SCADA networks: A review

    Directory of Open Access Journals (Sweden)

    Abdalhossein Rezai

    2017-02-01

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

  10. Wireless networks and security issues, challenges and research trends

    CERN Document Server

    Pathan, Al-Sakib

    2013-01-01

     “Wireless Networks and Security” provides a broad coverage of wireless security issues including cryptographic coprocessors, encryption, authentication, key management, attacks and countermeasures, secure routing, secure medium access control, intrusion detection, epidemics, security performance analysis, security issues in applications. The contributions identify various vulnerabilities in the physical layer, MAC layer, network layer, transport layer, and application layer, and focus on ways of strengthening security mechanisms and services throughout the layers. This carefully edited monograph is targeting  for researchers, post-graduate students in universities, academics, and industry practitioners or professionals.  

  11. Interamerican networks for physics education: some issues and comments

    Science.gov (United States)

    Halpern, Teodoro

    1988-10-01

    This paper provides comments about some critical and fundamental issues relevant to the creation of successful interamerican Networks for Physics Education, stressing the need for: Establishing the underlying educational goals for the proposed projects. Clear communication of these goals to interested constituencies and the public at large. Forceful image development to obtain wide-based funding. The interdependence of individuals and institutions in the networks. Closing the developed-vs.-underdeveloped schism. Sucess in this endeavour will eliminate one of the main reasons for failure of a ``cooperative'' project. This paper also provides examples of succesful interamerican Networks and some of the underlying for their successes.

  12. Library Network Statistics and Performance Measures: Approaches and Issues

    Directory of Open Access Journals (Sweden)

    John Carlo Bertot

    2001-07-01

    Full Text Available Library networked statistics and performance measures are important indicators of the use, uses, and users of networked services that libraries offer their patrons. This article focuses on three efforts to develop and standardize library network statistics and performance measures. In particular, the article discusses, compares, and contrasts selected aspects of the International Standards Organization (ISO, U.S. public library network statistics, and Association of Research Library (ARL efforts. The three approaches attempt to capture, describe, and present library networked activities in similar ways through similar approaches – yet they differ in key areas. It is important to note that there are a number of national and international efforts underway that continue to research the library network statistics and performance measure environment.

  13. Data management issues in mobile ad hoc networks.

    Science.gov (United States)

    Hara, Takahiro

    2017-01-01

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

  14. Data management issues in mobile ad hoc networks

    Science.gov (United States)

    HARA, Takahiro

    2017-01-01

    Research on mobile ad hoc networks (MANETs) has become a hot research topic since the middle 1990’s. Over the first decade, most research focused on networking techniques, ignoring data management issues. We, however, realized early the importance of data management in MANETs, and have been conducting studies in this area for 15 years. In this review, we summarize some key technical issues related to data management in MANETs, and the studies we have done in addressing these issues, which include placement of data replicas, update management, and query processing with security management. The techniques proposed in our studies have been designed with deep considerations of MANET features including network partitioning, node participation/disappearance, limited network bandwidth, and energy efficiency. Our studies published in early 2000’s have developed a new research field as data management in MANETs. Also, our recent studies are expected to be significant guidelines of new research directions. We conclude the review by discussing some future directions for research. PMID:28496052

  15. Introduction to Focus Issue: Quantitative Approaches to Genetic Networks

    Science.gov (United States)

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

    2013-06-01

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

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

    Science.gov (United States)

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

    2017-03-01

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

  17. 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

  18. 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.

  19. A large number of stepping motor network construction by PLC

    Science.gov (United States)

    Mei, Lin; Zhang, Kai; Hongqiang, Guo

    2017-11-01

    In the flexible automatic line, the equipment is complex, the control mode is flexible, how to realize the large number of step and servo motor information interaction, the orderly control become a difficult control. Based on the existing flexible production line, this paper makes a comparative study of its network strategy. After research, an Ethernet + PROFIBUSE communication configuration based on PROFINET IO and profibus was proposed, which can effectively improve the data interaction efficiency of the equipment and stable data interaction information.

  20. Estimation of the number of extreme pathways for metabolic networks

    Directory of Open Access Journals (Sweden)

    Thiele Ines

    2007-09-01

    Full Text Available Abstract Background The set of extreme pathways (ExPa, {pi}, defines the convex basis vectors used for the mathematical characterization of the null space of the stoichiometric matrix for biochemical reaction networks. ExPa analysis has been used for a number of studies to determine properties of metabolic networks as well as to obtain insight into their physiological and functional states in silico. However, the number of ExPas, p = |{pi}|, grows with the size and complexity of the network being studied, and this poses a computational challenge. For this study, we investigated the relationship between the number of extreme pathways and simple network properties. Results We established an estimating function for the number of ExPas using these easily obtainable network measurements. In particular, it was found that log [p] had an exponential relationship with log⁡[∑i=1Rd−id+ici] MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaacyGGSbaBcqGGVbWBcqGGNbWzdaWadaqaamaaqadabaGaemizaq2aaSbaaSqaaiabgkHiTmaaBaaameaacqWGPbqAaeqaaaWcbeaakiabdsgaKnaaBaaaleaacqGHRaWkdaWgaaadbaGaemyAaKgabeaaaSqabaGccqWGJbWydaWgaaWcbaGaemyAaKgabeaaaeaacqWGPbqAcqGH9aqpcqaIXaqmaeaacqWGsbGua0GaeyyeIuoaaOGaay5waiaaw2faaaaa@4414@, where R = |Reff| is the number of active reactions in a network, d−i MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaacqWGKbazdaWgaaWcbaGaeyOeI0YaaSbaaWqaaiabdMgaPbqabaaaleqaaaaa@30A9@ and d+i MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb

  1. On the Issues and Challenges of Fiber-Wireless (Fi-Wi Networks

    Directory of Open Access Journals (Sweden)

    Harry Tin Win

    2013-01-01

    Full Text Available The objective of this article is to present various aspects of Fiber-Wireless (Fi-Wi networks, which is a technology of current interest of the researchers. Fiber-wireless technology, known in short as “Fi-Wi,” is a combination of optical-fiber-based network and wireless network. Fi-Wi has recently come forward as one of the emerging future network technologies yet the term is often mixed up with wireless-fidelity (Wi-Fi technology. In fact, Wi-Fi network could be included in a Fi-Wi architecture. Due to the unfamiliarity with the term, “Fi-Wi” and similar sounding commonly known “Wi-Fi,” many students, even academics and practitioners sometimes may not be able to differentiate between these. In the recent years, a good number of works on various issues of Fi-Wi have come out, but an overall survey with the latest advancements in the area is yet to be found. Hence, in this work, we analyze various issues and challenges of implementing Fi-Wi networks in practical scenarios to allow researchers to find future directions of research and general readers to understand the issues better.

  2. Sampling and measurement issues in establishing a climate reference upper air network

    Science.gov (United States)

    Gardiner, T.; Madonna, F.; Wang, J.; Whiteman, D. N.; Dykema, J.; Fassò, A.; Thorne, P. W.; Bodeker, G.

    2013-09-01

    The GCOS Reference Upper Air Network (GRUAN) is an international reference observing network, designed to meet climate requirements and to fill a major void in the current global observing system. Upper air observations within the GRUAN network will provide long-term high-quality climate records, will be used to constrain and validate data from space based remote sensors, and will provide accurate data for the study of atmospheric processes. The network covers measurements of a range of key climate variables including temperature. Implementation of the network has started, and as part of this process a number of scientific questions need to be addressed in order to establish a viable climate reference upper air network, in addition to meeting the other objectives for the network measurements. These include quantifying collocation issues for different measurement techniques including the impact on the overall uncertainty of combined measurements; change management requirements when switching between sensors; assessing the benefit of complementary measurements of the same variable using different measurement techniques; and establishing the appropriate sampling strategy to determine long-term trends. This paper reviews the work that is currently underway to address these issues.

  3. Network Architecture, Security Issues, and Hardware Implementation of a Home Area Network for Smart Grid

    OpenAIRE

    Saponara, Sergio; Bacchillone, Tony

    2012-01-01

    This paper discusses aims, architecture, and security issues of Smart Grid, taking care of the lesson learned at University of Pisa in research projects on smart energy and grid. A key element of Smart Grid is the energy home area network (HAN), for which an implementation is proposed, dealing with its security aspects and showing some solutions for realizing a wireless network based on ZigBee. Possible hardware-software architectures and implementations using COTS (Commercial Off The Shelf) ...

  4. Insights Into Collaborative Networks Of Nonprofit, Private, And Public Organizations That Address Complex Health Issues.

    Science.gov (United States)

    Hogg, Rachel A; Varda, Danielle

    2016-11-01

    Community networks that include nonprofit, public, and private organizations have formed around many health issues, such as chronic disease management and healthy living and eating. Despite the increases in the numbers of and funding for cross-sector networks, and the growing literature about them, there are limited data and methods that can be used to assess their effectiveness and analyze their designs. We addressed this gap in knowledge by analyzing the characteristics of 260 cross-sector community health networks that collectively consisted of 7,816 organizations during the period 2008-15. We found that nonprofit organizations were more prevalent than private firms or government agencies in these networks. Traditional types of partners in community health networks such as hospitals, community health centers, and public health agencies were the most trusted and valued by other members of their networks. However, nontraditional partners, such as employer or business groups and colleges or universities, reported contributing relatively high numbers of resources to their networks. Further evidence is needed to inform collaborative management processes and policies as a mechanism for building what the Robert Wood Johnson Foundation describes as a culture of health. Project HOPE—The People-to-People Health Foundation, Inc.

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

    Directory of Open Access Journals (Sweden)

    Muhammad Khalid

    2017-01-01

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

  6. Safety in numbers? Tackling domestic abuse in couples and network therapies.

    Science.gov (United States)

    Galvani, Sarah A

    2007-03-01

    Family, network or couples-based therapies have been helping to support people with substance problems for decades. Their value in supporting a person to change their alcohol or drug use is clear. However, as links between substance use and domestic abuse are increasingly recognised, these approaches need to reflect on the potential safety risks they present to people taking part. The prevalence of domestic abuse among people receiving drug and alcohol services is considerably higher than general population estimates, yet this does not appear to have been adequately addressed in network therapies. This article suggests that this needs to change and that safety of service users needs to be at least as important as the intervention itself. It offers for debate a number of potential safety issues raised by network therapies where there is evidence of domestic abuse; it provides examples of three approaches used to marshal social and network support in substance interventions; and offers a number of suggestions for how network therapies can ensure their use remains safe and supportive where there is domestic abuse.

  7. Neural Networks and Fault Probability Evaluation for Diagnosis Issues

    Science.gov (United States)

    Lefebvre, Dimitri; Guersi, Noureddine

    2014-01-01

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

  8. Neural Networks and Fault Probability Evaluation for Diagnosis Issues

    Directory of Open Access Journals (Sweden)

    Yahia Kourd

    2014-01-01

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

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

    African Journals Online (AJOL)

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

  10. Engineering applications of fpgas chaotic systems, artificial neural networks, random number generators, and secure communication systems

    CERN Document Server

    Tlelo-Cuautle, Esteban; de la Fraga, Luis Gerardo

    2016-01-01

    This book offers readers a clear guide to implementing engineering applications with FPGAs, from the mathematical description to the hardware synthesis, including discussion of VHDL programming and co-simulation issues. Coverage includes FPGA realizations such as: chaos generators that are described from their mathematical models; artificial neural networks (ANNs) to predict chaotic time series, for which a discussion of different ANN topologies is included, with different learning techniques and activation functions; random number generators (RNGs) that are realized using different chaos generators, and discussions of their maximum Lyapunov exponent values and entropies. Finally, optimized chaotic oscillators are synchronized and realized to implement a secure communication system that processes black and white and grey-scale images. In each application, readers will find VHDL programming guidelines and computer arithmetic issues, along with co-simulation examples with Active-HDL and Simulink. Readers will b...

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

    African Journals Online (AJOL)

    Network gateway redundancy technology makes it possible for computer devices to have access to multiple exit and entry points in the network, thus, eliminates the problem of a single point failure in both Ethernet and Internet networking systems. For effective implementation of network gateway redundancy, however, ideal ...

  12. Network Architecture, Security Issues, and Hardware Implementation of a Home Area Network for Smart Grid

    Directory of Open Access Journals (Sweden)

    Sergio Saponara

    2012-01-01

    Full Text Available This paper discusses aims, architecture, and security issues of Smart Grid, taking care of the lesson learned at University of Pisa in research projects on smart energy and grid. A key element of Smart Grid is the energy home area network (HAN, for which an implementation is proposed, dealing with its security aspects and showing some solutions for realizing a wireless network based on ZigBee. Possible hardware-software architectures and implementations using COTS (Commercial Off The Shelf components are presented for key building blocks of the energy HAN such as smart power meters and plugs and a home smart information box providing energy management policy and supporting user's energy awareness.

  13. 71 Network Gateway Technology: The Issue of Redundancy towards ...

    African Journals Online (AJOL)

    User

    2012-01-24

    Jan 24, 2012 ... is an open source standard. The major network devices used in network gateway redundancy configuration are the routers and multilayer switches. They are used as active and backup devices depending on the type of network topology. Whenever the active gateway fails, in the event of hardware failure,.

  14. Privacy Issues of a National Research and Education Network.

    Science.gov (United States)

    Katz, James E.; Graveman, Richard F.

    1991-01-01

    Discussion of the right to privacy of communications focuses on privacy expectations within a National Research and Education Network (NREN). Highlights include privacy needs in scientific and education communications; academic and research networks; network security and privacy concerns; protection strategies; and consequences of privacy…

  15. Survey on Security Issues in Vehicular Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Bassem Mokhtar

    2015-12-01

    Full Text Available Vehicular Ad hoc NETworks are special case of ad hoc networks that, besides lacking infrastructure, communicating entities move with various accelerations. Accordingly, this impedes establishing reliable end-to-end communication paths and having efficient data transfer. Thus, VANETs have different network concerns and security challenges to get the availability of ubiquitous connectivity, secure communications, and reputation management systems which affect the trust in cooperation and negotiation between mobile networking entities. In this survey, we discuss the security features, challenges, and attacks of VANETs, and we classify the security attacks of VANETs due to the different network layers.

  16. Dynamic traffic grooming for port number optimization in WDM optical mesh networks

    Science.gov (United States)

    Huang, Jun; Zeng, Qingji; Liu, Jimin; Xiao, Pengcheng; Liu, Hua; Xiao, Shilin

    2004-04-01

    In this paper, the objective was optimizing the port number with dynamic traffic grooming of SDH/SONET WDM mesh networks to give useful referenced data to networks design and the cost control of networks. The performances of different path select routing algorithms were evaluated in WDM grooming networks by considering traffic of different bandwidth requests. Finally, the results were presented and compared with in distributed-controlled WDM mesh networks.

  17. Expected Number of Fixed Points in Boolean Networks with Arbitrary Topology

    Science.gov (United States)

    Mori, Fumito; Mochizuki, Atsushi

    2017-07-01

    Boolean network models describe genetic, neural, and social dynamics in complex networks, where the dynamics depend generally on network topology. Fixed points in a genetic regulatory network are typically considered to correspond to cell types in an organism. We prove that the expected number of fixed points in a Boolean network, with Boolean functions drawn from probability distributions that are not required to be uniform or identical, is one, and is independent of network topology if only a feedback arc set satisfies a stochastic neutrality condition. We also demonstrate that the expected number is increased by the predominance of positive feedback in a cycle.

  18. 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…

  19. A Review on Sensor Network Issues and Robotics

    Directory of Open Access Journals (Sweden)

    Ji Hyoung Ryu

    2015-01-01

    Full Text Available The interaction of distributed robotics and wireless sensor networks has led to the creation of mobile sensor networks. There has been an increasing interest in building mobile sensor networks and they are the favored class of WSNs in which mobility plays a key role in the execution of an application. More and more researches focus on development of mobile wireless sensor networks (MWSNs due to its favorable advantages and applications. In WSNs robotics can play a crucial role, and integrating static nodes with mobile robots enhances the capabilities of both types of devices and enables new applications. In this paper we present an overview on mobile sensor networks in robotics and vice versa and robotic sensor network applications.

  20. Government information collections in the networked environment new issues and models

    CERN Document Server

    Cheverie, Joan F

    2013-01-01

    This insightful book explores the challenging issues related to effective access to government information.Amidst all the chaos of today's dynamic information transition period, the only constants related to government information are change and inconsistency, yet with Government Information Collections in the Networked Environment: New Issues and Models, you will defeat the challenging issues and take advantage of the opportunities that networked government information collections have to offer. This valuable book gives you a fresh opportunity to rethink collecting activities and to

  1. Virtualized cloud data center networks issues in resource management

    CERN Document Server

    Tsai, Linjiun

    2016-01-01

    This book discusses the characteristics of virtualized cloud networking, identifies the requirements of cloud network management, and illustrates the challenges in deploying virtual clusters in multi-tenant cloud data centers. The book also introduces network partitioning techniques to provide contention-free allocation, topology-invariant reallocation, and highly efficient resource utilization, based on the Fat-tree network structure. Managing cloud data center resources without considering resource contentions among different cloud services and dynamic resource demands adversely affects the performance of cloud services and reduces the resource utilization of cloud data centers. These challenges are mainly due to strict cluster topology requirements, resource contentions between uncooperative cloud services, and spatial/temporal data center resource fragmentation. Cloud data center network resource allocation/reallocation which cope well with such challenges will allow cloud services to be provisioned with ...

  2. Issues in the use of neural networks in information retrieval

    CERN Document Server

    Iatan, Iuliana F

    2017-01-01

    This book highlights the ability of neural networks (NNs) to be excellent pattern matchers and their importance in information retrieval (IR), which is based on index term matching. The book defines a new NN-based method for learning image similarity and describes how to use fuzzy Gaussian neural networks to predict personality. It introduces the fuzzy Clifford Gaussian network, and two concurrent neural models: (1) concurrent fuzzy nonlinear perceptron modules, and (2) concurrent fuzzy Gaussian neural network modules. Furthermore, it explains the design of a new model of fuzzy nonlinear perceptron based on alpha level sets and describes a recurrent fuzzy neural network model with a learning algorithm based on the improved particle swarm optimization method.

  3. ARL: A Bimonthly Report on Research Library Issues and Actions from ARL, CNI, and SPARC. Number 251

    Science.gov (United States)

    Association of Research Libraries, 2007

    2007-01-01

    ARL is the bimonthly report on research library issues and actions from ARL (Association of Research Libraries), CNI (Coalition of Networked Information), and SPARC (Scholarly Publishing and Academic Resources Coalition). ARL reports on current issues of interest to academic and research library administrators, staff, and users; higher education…

  4. ARL: A Bimonthly Report on Research Library Issues and Actions from ARL, CNI, and SPARC. Number 244

    Science.gov (United States)

    Barrett, G. Jaia, Ed.

    2006-01-01

    ARL is the bimonthly report on research library issues and actions from ARL (Association of Research Libraries), CNI (Coalition of Networked Information), and SPARC (Scholarly Publishing and Academic Resources Coalition). ARL reports on current issues of interest to academic and research library administrators, staff, and users; higher education…

  5. ARL: A Bimonthly Report on Research Library Issues and Actions from ARL, CNI, and SPARC. Number 255

    Science.gov (United States)

    Barrett, G. Jaia, Ed.

    2007-01-01

    ARL is the bimonthly report on research library issues and actions from ARL (Association of Research Libraries), CNI (Coalition of Networked Information), and SPARC (Scholarly Publishing and Academic Resources Coalition). ARL reports on current issues of interest to academic and research library administrators, staff, and users; higher education…

  6. ARL: A Bimonthly Report on Research Library Issues and Actions from ARL, CNI, and SPARC. Number 254

    Science.gov (United States)

    Barrett, G. Jaia, Ed.

    2007-01-01

    ARL is the bimonthly report on research library issues and actions from ARL (Association of Research Libraries), CNI (Coalition of Networked Information), and SPARC (Scholarly Publishing and Academic Resources Coalition). ARL reports on current issues of interest to academic and research library administrators, staff, and users; higher education…

  7. Advances in neural networks computational and theoretical issues

    CERN Document Server

    Esposito, Anna; Morabito, Francesco

    2015-01-01

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

  8. 71 Network Gateway Technology: The Issue of Redundancy towards ...

    African Journals Online (AJOL)

    User

    2012-01-24

    . Network gateway ... Two important components are the transmission media, that carry the computers signals, typically on ... devices such as personal computers or servers can function as a gateway. However, a computer ...

  9. Analysing Membership Profile Privacy Issues in Online Social Networks

    OpenAIRE

    Abdulhamid, Shafii Muhammad; Abdulazeez, Hassan; Abraham, Ochoche; Mohammed, Umar

    2014-01-01

    A social networking site is an on-line service that attracts a society of subscribers and provides such users with a multiplicity of tools for distribution personal data and creating subscribers generated content directed to a given users interest and personal life. Operators of online social networks are gradually giving out potentially sensitive information about users and their relationships with advertisers, application developers, and data-mining researchers. Some criminals too uses info...

  10. Genetic Algorithms in Wireless Networking: Techniques, Applications, and Issues

    OpenAIRE

    Mehboob, Usama; Qadir, Junaid; Ali, Salman; Vasilakos, Athanasios

    2014-01-01

    In recent times, wireless access technology is becoming increasingly commonplace due to the ease of operation and installation of untethered wireless media. The design of wireless networking is challenging due to the highly dynamic environmental condition that makes parameter optimization a complex task. Due to the dynamic, and often unknown, operating conditions, modern wireless networking standards increasingly rely on machine learning and artificial intelligence algorithms. Genetic algorit...

  11. Framing of Ethical Issues in the Network Society

    DEFF Research Database (Denmark)

    Etter, Michael; Vestergaard Jørgensen, Anne

    Purpose: This study investigates the moral framing of an ethical issue by various actors and looks at the agenda setting effects between news media and the active online public as represented in social media. Design: We coded 4114 sentences manually and conducted an analysis of conditional...... probability of co-occurrence between actors and issues to identify associative frames. An ARIMA model and time series are applied to detect the interplay between the active online public and news media over a period of three months. Findings: The analysis reveals different framings of the ethical issue...

  12. Modeling users' activity on twitter networks: validation of Dunbar's number.

    Directory of Open Access Journals (Sweden)

    Bruno Gonçalves

    Full Text Available Microblogging and mobile devices appear to augment human social capabilities, which raises the question whether they remove cognitive or biological constraints on human communication. In this paper we analyze a dataset of Twitter conversations collected across six months involving 1.7 million individuals and test the theoretical cognitive limit on the number of stable social relationships known as Dunbar's number. We find that the data are in agreement with Dunbar's result; users can entertain a maximum of 100-200 stable relationships. Thus, the 'economy of attention' is limited in the online world by cognitive and biological constraints as predicted by Dunbar's theory. We propose a simple model for users' behavior that includes finite priority queuing and time resources that reproduces the observed social behavior.

  13. Modeling users' activity on Twitter networks: validation of Dunbar's number

    Science.gov (United States)

    Goncalves, Bruno; Perra, Nicola; Vespignani, Alessandro

    2012-02-01

    Microblogging and mobile devices appear to augment human social capabilities, which raises the question whether they remove cognitive or biological constraints on human communication. In this paper we analyze a dataset of Twitter conversations collected across six months involving 1.7 million individuals and test the theoretical cognitive limit on the number of stable social relationships known as Dunbar's number. We find that the data are in agreement with Dunbar's result; users can entertain a maximum of 100-200 stable relationships. Thus, the ``economy of attention'' is limited in the online world by cognitive and biological constraints as predicted by Dunbar's theory. We propose a simple model for users' behavior that includes finite priority queuing and time resources that reproduces the observed social behavior.

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

    Science.gov (United States)

    Willebrand, Heinz A.

    2003-04-01

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

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

    Science.gov (United States)

    Wihbey, Jean A.

    2010-01-01

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

  16. Early detection network design and search strategy issues

    Science.gov (United States)

    We conducted a series of field and related modeling studies (2005-2012) to evaluate search strategies for Great Lakes coastal ecosystems that are at risk of invasion by non-native aquatic species. In developing a network, we should design to achieve an acceptable limit of detect...

  17. 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

  18. GPP Webinar: Solar Utilization in Higher Education Networking & Information Sharing Group: Financing Issues Discussion

    Science.gov (United States)

    This presentation from a Solar Utilization in Higher Education Networking and Information webinar covers financing and project economics issues related to solar project development in the higher education sector.

  19. Reducing the Density and Number of Tobacco Retailers: Policy Solutions and Legal Issues.

    Science.gov (United States)

    Ackerman, Amy; Etow, Alexis; Bartel, Sara; Ribisl, Kurt M

    2017-02-01

    Because higher density of tobacco retailers is associated with greater tobacco use, U.S. communities seek ways to reduce the density and number of tobacco retailers. This approach can reduce the concentration of tobacco retailers in poorer communities, limit youth exposure to tobacco advertising, and prevent misleading associations between tobacco and health messaging. Communities can reduce the density and number of tobacco retailers by imposing minimum distance requirements between existing retailers, capping the number of retailers in a given geographic area, establishing a maximum number of retailers proportional to population size, and prohibiting sales at certain types of establishments, such as pharmacies, or within a certain distance of locations serving youth. Local governments use direct regulation, licensing, or zoning laws to enact these changes. We analyze each approach under U.S. constitutional law to assist communities in selecting and implementing one or more of these methods. There are few published legal opinions that address these strategies in the context of tobacco control. But potential constitutional challenges include violations of the Takings Clause of the Fifth Amendment, which protects property owners from onerous government regulations, and under the Fourteenth Amendment's Equal Protection and Due Process Clauses, which protect business owners from arbitrary or unreasonable regulations that do not further a legitimate government interest. Because there is an evidentiary basis linking the density of tobacco retailers to smoking rates in a community, courts are likely to reject constitutional challenges to carefully crafted laws that reduce the number of tobacco retailers. Our review of the relevant constitutional issues confirms that local governments have the authority to utilize laws and policies to reduce the density and number of tobacco retailers in their communities, given existing public health data. The analysis guides policy

  20. Explaining How Political Actors Gain Strategic Positions: Predictors of Centrality in State Reading Policy Issue Networks

    Science.gov (United States)

    Young, Tamara V.; Wang, Yuling; Lewis, Wayne D.

    2016-01-01

    Using data from interviews with 111 reading policy actors from California, Connecticut, Michigan, and Utah, this study explains how individuals acquire central positions in issue networks. Regression analyses showed that the greater a policy actor's reputed influence was and the more similar their preferences were to other members in the network,…

  1. Adjustment of issue positions based on network strategies in a nelection campaign: A two-mode network autoregression model with cross-nested random effects

    NARCIS (Netherlands)

    Kleinnijenhuis, J.; de Nooy, W.

    2013-01-01

    During election campaigns, political parties deliver statements on salient issues in the news media, which are called issue positions. This article conceptualizes issue positions as a valued and longitudinal two-mode network of parties by issues. The network is valued because parties pronounce pro

  2. Adjustment of issue positions based on network strategies in an election campaign: a two-mode network autoregression model with cross-nested random effects

    NARCIS (Netherlands)

    Kleinnijenhuis, J.; de Nooy, W.

    2013-01-01

    During election campaigns, political parties deliver statements on salient issues in the news media, which are called issue positions. This article conceptualizes issue positions as a valued and longitudinal two-mode network of parties by issues. The network is valued because parties pronounce pro

  3. Using Active Networking to Detect and Troubleshoot Issues in Tactical Data Networks

    Science.gov (United States)

    2014-06-01

    team SDN software defined networking SIPRnet Secret Internet Protocol Router Network SSH secure shell xiv SVG Scalable Vector Graphics SNMP Simple...networking ( SDN ) paradigm, which has gained popularity in recent years, has its roots in the idea of programmable networks [6]. By extending the...addressed by SDN [6]. While there are simi- larities between SDN and active networking, SDN is primarily concerned with the idea of separating the control

  4. Awareness of LGBT aging issues among aging services network providers.

    Science.gov (United States)

    Hughes, Anne K; Harold, Rena D; Boyer, Janet M

    2011-10-01

    Very little research exists examining the interactions between community-based aging service providers and lesbian, gay, bisexual, and transgender (LGBT) older adults. It is unclear whether mainstream aging services acknowledge the needs of this community. We asked direct care providers and administrators in the Michigan aging services network to describe their work with LGBT older adults. We found there are very few services specific to the needs of older LGBT adults and very little outreach to this community. At the agency level, resistance to providing services was found.

  5. Issue Obtrusiveness and the Agenda-Setting Effects of National Network News.

    Science.gov (United States)

    Demers, David Pearce; And Others

    1989-01-01

    Examines effects of issue obtrusiveness on network news agenda-setting. Tests two competing models: (1) obtrusive contingency (agenda-setting effects decrease as personal experience with issues increase); and (2) cognitive-priming contingency (agenda-setting effects increase as obtrusiveness increases). Finds no support for obtrusive contingency…

  6. The optimization issues in an agile all-photonic backbone network

    Science.gov (United States)

    Zhang, Yiming; Yang, Oliver W.; Zhai, Yihua

    2005-02-01

    The Agile All-photonic Backbone Network (AAPN) architecture has been proposed by the telecommunication industry as a potential candidate for the ultra high speed Next Generation Optical Network (NGON) architecture. AAPN network structure is composed of adaptive optical core switches and edge routers in an overlaid star physical topology. In this paper, we examine various optimization issues for AAPN architectures. The optimization procedure is based on a Lagrangean relaxation and subgradient method. Based on the optimization methodology provided in the previous research, we propose a modified algorithm to optimize AAPN networks, with respect to the assumptions used in AAPN. The results for different network configurations are studied and the influence of network resources is also studied. Our algorithm is shown to be very computational effective on the AAPN networks, and the bounds generated are mostly within 1% of the final objective value.

  7. Personal support networks, social capital, and risk of relapse among individuals treated for substance use issues.

    Science.gov (United States)

    Panebianco, Daria; Gallupe, Owen; Carrington, Peter J; Colozzi, Ivo

    2016-01-01

    The success of treatment for substance use issues varies with personal and social factors, including the composition and structure of the individual's personal support network. This paper describes the personal support networks and social capital of a sample of Italian adults after long-term residential therapeutic treatment for substance use issues, and analyses network correlates of post-treatment substance use (relapse). Using a social network analysis approach, data were obtained from structured interviews (90-120 min long) with 80 former clients of a large non-governmental therapeutic treatment agency in Italy providing voluntary residential treatments and rehabilitation services for substance use issues. Participants had concluded the program at least six months prior. Data were collected on socio-demographic variables, addiction history, current drug use status (drug-free or relapsed), and the composition and structure of personal support networks. Factors related to risk of relapse were assessed using bivariate and multivariate logistic regression models. A main goal of this study was to identify differences between the support network profiles of drug free and relapsed participants. Drug free participants had larger, less dense, more heterogeneous and reciprocal support networks, and more brokerage social capital than relapsed participants. Additionally, a lower risk of relapse was associated with higher socio-economic status, being married/cohabiting, and having network members with higher socio-economic status, who have greater occupational heterogeneity, and reciprocate support. Post-treatment relapse was found to be negatively associated with the socioeconomic status and occupational heterogeneity of ego's support network, reciprocity in the ties between ego and network members, and a support network in which the members are relatively loosely connected with one another (i.e., ego possesses "brokerage social capital"). These findings suggest the

  8. FCJ Issue 20 Editorial Essay : Networked Utopias and Speculative Futures.

    Directory of Open Access Journals (Sweden)

    Su Ballard

    2012-07-01

    Full Text Available The future began somewhere. The impulse behind this issue of The Fibreculture Journal was a crisis of imagination with regards to how the future might look and behave. Our starting point was the notion of post-millennial tension – the idea that in the decades following the year 2000 we find ourselves living in an era that was meant to be the future, but where many of our futuristic hopes and fantasies remain unfulfilled. Worse, our historical visions of hyper-technological futures seem to have propelled us into a perilous position where humankind may not have any kind of future at all. In the space between ever-hopeful techno-futurism and the realities of a world forever changed by the pursuit of the resources required to fuel it, we asked if the age-old concept of utopia still has the strength to generate galvanising visions of the future....

  9. Coauthorship networks: A directed network approach considering the order and number of coauthors

    CERN Document Server

    Kim, Jinseok

    2015-01-01

    In many scientific fields, the order of coauthors on a paper conveys information about each individual's contribution to a piece of joint work. We argue that in prior network analyses of coauthorship networks, the information on ordering has been insufficiently considered because ties between authors are typically symmetrized. This is basically the same as assuming that each co-author has contributed equally to a paper. We introduce a solution to this problem by adopting a coauthorship credit allocation model proposed by Kim and Diesner (2014), which in its core conceptualizes co-authoring as a directed, weighted, and self-looped network. We test and validate our application of the adopted framework based on a sample data of 861 authors who have published in the journal Psychometrika. Results suggest that this novel sociometric approach can complement traditional measures based on undirected networks and expand insights into coauthoring patterns such as the hierarchy of collaboration among scholars. As anothe...

  10. Integrated Bayesian network framework for modeling complex ecological issues.

    Science.gov (United States)

    Johnson, Sandra; Mengersen, Kerrie

    2012-07-01

    The management of environmental problems is multifaceted, requiring varied and sometimes conflicting objectives and perspectives to be considered. Bayesian network (BN) modeling facilitates the integration of information from diverse sources and is well suited to tackling the management challenges of complex environmental problems. However, combining several perspectives in one model can lead to large, unwieldy BNs that are difficult to maintain and understand. Conversely, an oversimplified model may lead to an unrealistic representation of the environmental problem. Environmental managers require the current research and available knowledge about an environmental problem of interest to be consolidated in a meaningful way, thereby enabling the assessment of potential impacts and different courses of action. Previous investigations of the environmental problem of interest may have already resulted in the construction of several disparate ecological models. On the other hand, the opportunity may exist to initiate this modeling. In the first instance, the challenge is to integrate existing models and to merge the information and perspectives from these models. In the second instance, the challenge is to include different aspects of the environmental problem incorporating both the scientific and management requirements. Although the paths leading to the combined model may differ for these 2 situations, the common objective is to design an integrated model that captures the available information and research, yet is simple to maintain, expand, and refine. BN modeling is typically an iterative process, and we describe a heuristic method, the iterative Bayesian network development cycle (IBNDC), for the development of integrated BN models that are suitable for both situations outlined above. The IBNDC approach facilitates object-oriented BN (OOBN) modeling, arguably viewed as the next logical step in adaptive management modeling, and that embraces iterative development

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

    Science.gov (United States)

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

    2017-04-23

    Spectrum sensing (SS) enables the coexistence of non-coordinated heterogeneous wireless systems operating in the same band. Due to its computational simplicity, energy detection (ED) technique has been widespread employed in SS applications; nonetheless, the conventional ED may be unreliable under environmental impairments, justifying the use of ED-based variants. Assessing ED algorithms from theoretical and simulation viewpoints relies on several assumptions and simplifications which, eventually, lead to conclusions that do not necessarily meet the requirements imposed by real propagation environments. This work addresses those problems by dealing with practical implementation issues of adaptive least mean square (LMS)-based ED algorithms. The paper proposes a new adaptive ED algorithm that uses a variable step-size guaranteeing the LMS convergence in time-varying environments. Several implementation guidelines are provided and, additionally, an empirical assessment and validation with a software defined radio-based hardware is carried out. Experimental results show good performance in terms of probabilities of detection ( P d > 0 . 9 ) and false alarm ( P f ∼ 0 . 05 ) in a range of low signal-to-noise ratios around [ - 4 , 1 ] dB, in both single-node and cooperative modes. The proposed sensing methodology enables a seamless monitoring of the radio electromagnetic spectrum in order to provide band occupancy information for an efficient usage among several wireless communications systems.

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

    Directory of Open Access Journals (Sweden)

    Iker Sobron

    2017-04-01

    Full Text Available Spectrum sensing (SS enables the coexistence of non-coordinated heterogeneous wireless systems operating in the same band. Due to its computational simplicity, energy detection (ED technique has been widespread employed in SS applications; nonetheless, the conventional ED may be unreliable under environmental impairments, justifying the use of ED-based variants. Assessing ED algorithms from theoretical and simulation viewpoints relies on several assumptions and simplifications which, eventually, lead to conclusions that do not necessarily meet the requirements imposed by real propagation environments. This work addresses those problems by dealing with practical implementation issues of adaptive least mean square (LMS-based ED algorithms. The paper proposes a new adaptive ED algorithm that uses a variable step-size guaranteeing the LMS convergence in time-varying environments. Several implementation guidelines are provided and, additionally, an empirical assessment and validation with a software defined radio-based hardware is carried out. Experimental results show good performance in terms of probabilities of detection ( P d > 0 . 9 and false alarm ( P f ∼ 0 . 05 in a range of low signal-to-noise ratios around [ - 4 , 1 ] dB, in both single-node and cooperative modes. The proposed sensing methodology enables a seamless monitoring of the radio electromagnetic spectrum in order to provide band occupancy information for an efficient usage among several wireless communications systems.

  13. Special issue on searching and mining the web and social networks

    OpenAIRE

    Litvak, Nelli; Vigna, Sebastiano

    2014-01-01

    The past few decades have seen the rise of online social networks as a worldwide phenomenon with a high impact on our society. Beyond the obvious exposure phenomena, with obvious implications on security and privacy, people have started to become acquainted—even married!—in online social networks. In parallel, we have seen an enormous growth in terms of the number of published articles in computer science, mathematics and physics that study the organization of such networks. The availability ...

  14. Stimulus number, duration and intensity encoding in randomly connected attractor networks with synaptic depression

    Directory of Open Access Journals (Sweden)

    Paul eMiller

    2013-05-01

    Full Text Available Randomly connected recurrent networks of excitatory groups of neurons can possess a multitude of attractor states. When the internal excitatory synapses of these networks are depressing, the attractor states can be destabilized with increasing input. This leads to an itinerancy, where with either repeated transient stimuli, or increasing duration of a single stimulus, the network activity advances through sequences of attractor states. We find that the resulting network state, which persists beyond stimulus offset, can encode the number of stimuli presented via a distributed representation of neural activity with non-monotonic tuning curves for most neurons. Increased duration of a single stimulus is encoded via different distributed representations, so unlike an integrator, the network distinguishes separate successive presentations of a short stimulus from a single presentation of a longer stimulus with equal total duration. Moreover, different amplitudes of stimulus cause new, distinct activity patterns, such that changes in stimulus number, duration and amplitude can be distinguished from each other. These properties of the network depend on dynamic depressing synapses, as they disappear if synapses are static. Thus short-term synaptic depression allows a network to store separately the different dynamic properties of a spatially constant stimulus.

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

    Directory of Open Access Journals (Sweden)

    S. Bakici

    2017-11-01

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

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

    Science.gov (United States)

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

    2017-11-01

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

  17. Retrieving infinite numbers of patterns in a spin-glass model of immune networks

    Science.gov (United States)

    Agliari, E.; Annibale, A.; Barra, A.; Coolen, A. C. C.; Tantari, D.

    2017-01-01

    The similarity between neural and (adaptive) immune networks has been known for decades, but so far we did not understand the mechanism that allows the immune system, unlike associative neural networks, to recall and execute a large number of memorized defense strategies in parallel. The explanation turns out to lie in the network topology. Neurons interact typically with a large number of other neurons, whereas interactions among lymphocytes in immune networks are very specific, and described by graphs with finite connectivity. In this paper we use replica techniques to solve a statistical mechanical immune network model with “coordinator branches” (T-cells) and “effector branches” (B-cells), and show how the finite connectivity enables the coordinators to manage an extensive number of effectors simultaneously, even above the percolation threshold (where clonal cross-talk is not negligible). A consequence of its underlying topological sparsity is that the adaptive immune system exhibits only weak ergodicity breaking, so that also spontaneous switch-like effects as bi-stabilities are present: the latter may play a significant role in the maintenance of immune homeostasis.

  18. Some Issues of the Paradigm of Multi-learning Machine - Modular Neural Networks

    DEFF Research Database (Denmark)

    Wang, Pan; Feng, Shuai; Fan, Zhun

    2009-01-01

    This paper addresses some issues on the weighted linear integration of modular neural networks (MNN: a paradigm of hybrid multi-learning machines). First, from the general meaning of variable weights and variable elements synthesis, three basic kinds of integrated models are discussed that are in......This paper addresses some issues on the weighted linear integration of modular neural networks (MNN: a paradigm of hybrid multi-learning machines). First, from the general meaning of variable weights and variable elements synthesis, three basic kinds of integrated models are discussed...... that are intrinsic-factors-determined, extrinsic-factors-determined, and hybrid-factors-determined. The authors point out: integrations dominated by both of the internal and external elements are highly correlative with not only the historical quality of the sub-networks, but also with the environment in which...

  19. Defense AR Journal. Volume 16, Number 2, Issue 51, July 2009

    Science.gov (United States)

    2009-07-01

    the Research and Development Branch of the eLearning Technology Center at DAU. We wrap up this issue with a Letter to the Editor called “Show Me the...total annual operating hours accumulated by all rounds in service and is dependent on quantity per platform , platform density, monthly OPTEMPO of the... platform , and munitions expenditure rate. Figure 5 illustrates the impact of reducing the platform OPTEMPO by 5 hr/mo increments. The analysis assumed

  20. Defense Acquisition Research Journal. Volume 19, Number 1, Issue 61, January 2012

    Science.gov (United States)

    2012-01-01

    January 2012 Vol. 19 No. 1 ISSUE 61 p. 121 The Defense Acquisition Professional Reading List Wired for War: The Robotics Revolution and Conflict...rise of robotics surely marks the most far-reaching paradigm shift of 21st century defense acquisition. PRESENTED ON BEHALF OF DAU BY: THE DEFENSE...different export control lists. Nonetheless, U.S. space firms are expected to navigate through this maze of bureaucracy and comply with regulations. Failure

  1. Education by the Numbers: The Fiscal Effect of School Choice Programs, 1990-2006. School Choice Issues in Depth

    Science.gov (United States)

    Aud, Susan L.

    2007-01-01

    School choice programs, which allow students to attend the public or private school of their choice using public funds, have taken root in the U.S. and are growing rapidly both in number and size. Their fiscal impact has become an important political issue. Proponents say school choice saves money because private schooling is more efficient,…

  2. Introduction to Focus Issue: Complex Dynamics in Networks, Multilayered Structures and Systems

    Science.gov (United States)

    Boccaletti, Stefano; Criado, Regino; Romance, Miguel; Torres, Joaquín J.

    2016-06-01

    In the last years, network scientists have directed their interest to the multi-layer character of real-world systems, and explicitly considered the structural and dynamical organization of graphs made of diverse layers between its constituents. Most complex systems include multiple subsystems and layers of connectivity and, in many cases, the interdependent components of systems interact through many different channels. Such a new perspective is indeed found to be the adequate representation for a wealth of features exhibited by networked systems in the real world. The contributions presented in this Focus Issue cover, from different points of view, the many achievements and still open questions in the field of multi-layer networks, such as: new frameworks and structures to represent and analyze heterogeneous complex systems, different aspects related to synchronization and centrality of complex networks, interplay between layers, and applications to logistic, biological, social, and technological fields.

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

    Science.gov (United States)

    Kumar, Pardeep; Lee, Hoon-Jae

    2012-01-01

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

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

    Science.gov (United States)

    Kumar, Pardeep; Lee, Hoon-Jae

    2012-01-01

    Healthcare applications are considered as promising fields for wireless sensor networks, where patients can be monitored using wireless medical sensor networks (WMSNs). Current WMSN healthcare research trends focus on patient reliable communication, patient mobility, and energy-efficient routing, as a few examples. However, deploying new technologies in healthcare applications without considering security makes patient privacy vulnerable. Moreover, the physiological data of an individual are highly sensitive. Therefore, security is a paramount requirement of healthcare applications, especially in the case of patient privacy, if the patient has an embarrassing disease. This paper discusses the security and privacy issues in healthcare application using WMSNs. We highlight some popular healthcare projects using wireless medical sensor networks, and discuss their security. Our aim is to instigate discussion on these critical issues since the success of healthcare application depends directly on patient security and privacy, for ethic as well as legal reasons. In addition, we discuss the issues with existing security mechanisms, and sketch out the important security requirements for such applications. In addition, the paper reviews existing schemes that have been recently proposed to provide security solutions in wireless healthcare scenarios. Finally, the paper ends up with a summary of open security research issues that need to be explored for future healthcare applications using WMSNs. PMID:22368458

  5. The issue of cavitation number value in studies of water treatment by hydrodynamic cavitation.

    Science.gov (United States)

    Šarc, Andrej; Stepišnik-Perdih, Tadej; Petkovšek, Martin; Dular, Matevž

    2017-01-01

    Within the last years there has been a substantial increase in reports of utilization of hydrodynamic cavitation in various applications. It has came to our attention that many times the results are poorly repeatable with the main reason being that the researchers put significant emphasis on the value of the cavitation number when describing the conditions at which their device operates. In the present paper we firstly point to the fact that the cavitation number cannot be used as a single parameter that gives the cavitation condition and that large inconsistencies in the reports exist. Then we show experiments where the influences of the geometry, the flow velocity, the medium temperature and quality on the size, dynamics and aggressiveness of cavitation were assessed. Finally we show that there are significant inconsistencies in the definition of the cavitation number itself. In conclusions we propose a number of parameters, which should accompany any report on the utilization of hydrodynamic cavitation, to make it repeatable and to enable faster progress of science and technology development. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Defense AR Journal. Volume 17, Number 3, Issue 55, July 2010. Managing the Unknown

    Science.gov (United States)

    2010-07-01

    1965) states that the number of components on a digital chip doubles every 18 months, which means digital products become practical that weren’t...a Ferrari costs a lot because of its features—a V-12/8400 rpm engine, aerodynamic body, high-performance suspension, and leather interior. The fact

  7. Defense Acquisition Research Journal. Volume 18, Number 2, Issue 58, April 2011

    Science.gov (United States)

    2011-04-01

    workforce. Managers need to understand the concept of commitment and which behaviors are displayed by employees committed to the organization ( Coetzee ...Lawrence Erlbaum Associates. Cattell, R. B. (1966). The scree test for the number of factors. Multivariate Behavioral Research, 1(2), 245–276. Coetzee

  8. Small numbers, disclosure risk, security, and reliability issues in Web-based data query systems.

    Science.gov (United States)

    Rudolph, Barbara A; Shah, Gulzar H; Love, Denise

    2006-01-01

    This article describes the process for developing consensus guidelines and tools for releasing public health data via the Web and highlights approaches leading agencies have taken to balance disclosure risk with public dissemination of reliable health statistics. An agency's choice of statistical methods for improving the reliability of released data for Web-based query systems is based upon a number of factors, including query system design (dynamic analysis vs preaggregated data and tables), population size, cell size, data use, and how data will be supplied to users. The article also describes those efforts that are necessary to reduce the risk of disclosure of an individual's protected health information.

  9. Transnational issue-specific expert networking: A pathway to local policy change.

    Science.gov (United States)

    O'Brien, Cheryl

    2015-12-01

    This article reports on key findings from a study of subnational governments in Mexico and Nigeria (O'Brien, 2013). With empirical richness of the case study method and small-n statistical analysis across the subnational units for each country, this study asks: How can we push the needle toward more progressive policy change on violence against women in developing and democratizing contexts? This study finds that issue-specific expert networking is a civic pathway to subnational policy responsiveness in Mexico and Nigeria. The dynamics of this pathway illuminate local-global political connections, and this study shows how issue-specific expert networking is important for the diffusion of an international norm and policies on violence against women. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Incremental Optimization of Hub and Spoke Network for the Spokes’ Numbers and Flow

    Directory of Open Access Journals (Sweden)

    Yanfeng Wang

    2015-01-01

    Full Text Available Hub and spoke network problem is solved as part of a strategic decision making process which may have a profound effect on the future of enterprises. In view of the existing network structure, as time goes on, the number of spokes and the flow change because of different sources of uncertainty. Hence, the incremental optimization of hub and spoke network problem is considered in this paper, and the policy makers should adopt a series of strategies to cope with the change, such as setting up new hubs, adjusting the capacity level of original hubs, or closing some original hubs. The objective is to minimize the total cost, which includes the setup costs for the new hubs, the closure costs, and the adjustment costs for the original hubs as well as the flow routing costs. Two mixed-integer linear programming formulations are proposed and analyzed for this problem. China Deppon Logistics as an example is performed to present computational analysis, and we analyze the changes in the solutions driven by the number of spokes and the flow. The tests also allow an analysis to consider the effect of variation in parameters on network.

  11. News Framing of Population and Family Planning Issues via Syntactic Network Analysis

    Science.gov (United States)

    Legara, Erika; Monterola, Christopher; David, Clarissa; Mae Atun, Jenna

    Contentious political debates regarding the issues on population and family planning have been perennial over the past four decades especially in developing countries. While its prominence in the public agenda varies depending on other national issues vying for public attention, its presence in policy and political agendas is constant. Here, a computational approach to framing analysis is developed that examines the pattern of media coverage on the population issue in the Philippines. The content of 146 articles sampled from 1988 to 2007 in Manila Bulletin (one of the leading newspapers in the Philippines) is analyzed by creating a syntactic network of concept co-occurrences. The topological properties of the network indicates that the discussion of an article revolves around few central ideas. Moreover, cluster analysis of the network suggests three well-defined frame themes, namely: (1) Development Frame; (2) Maternal Health Frame; and (3) Framing by the Catholic Church. Our results support the thesis that the inability to fruitfully discuss points of contention to reach agreement about suitable population policies in the Philippines is due to the mismatched frames within which it is discussed.

  12. Presentation of our Issue 6, number 11 “Language and power relations”

    Directory of Open Access Journals (Sweden)

    Rolando Blas Sánchez

    2018-01-01

    Full Text Available It is estimated that there are around 7,000 languages in the world.  Only some of them have the status of being official languages and others are international languages. Many times, their status is linked to economic or political factors. In other cases, it is due to the colonizing inheritance. Those languages that do not enjoy a high status end up having limited spaces for their use or perishing if they cease to be transmitted to subsequent generations of speakers. This phenomenon occurs in all latitudes of the world. In the particular case of Our America, we can find this problematic with the indigenous languages and, although less visible, but with the same importance, with the Creole languages. For the readers of our magazine, in number 11 of this publication, we present a varied discussion about some practices of languages and their interactions with others. There are historical studies on the subversive power and resistance of indigenous languages, pedagogical proposals to maintain and revitalize them, strategic approaches to decolonization of thought and knowledge, analyses of the relationship between language, power and identity, and reflections on the situation of other languages that coexist in multilingual areas such as Creole and the difficulties and prejudices they face because they do not have a high status.

  13. Network modeling of the transcriptional effects of copy number aberrations in glioblastoma

    Science.gov (United States)

    Jörnsten, Rebecka; Abenius, Tobias; Kling, Teresia; Schmidt, Linnéa; Johansson, Erik; Nordling, Torbjörn E M; Nordlander, Bodil; Sander, Chris; Gennemark, Peter; Funa, Keiko; Nilsson, Björn; Lindahl, Linda; Nelander, Sven

    2011-01-01

    DNA copy number aberrations (CNAs) are a hallmark of cancer genomes. However, little is known about how such changes affect global gene expression. We develop a modeling framework, EPoC (Endogenous Perturbation analysis of Cancer), to (1) detect disease-driving CNAs and their effect on target mRNA expression, and to (2) stratify cancer patients into long- and short-term survivors. Our method constructs causal network models of gene expression by combining genome-wide DNA- and RNA-level data. Prognostic scores are obtained from a singular value decomposition of the networks. By applying EPoC to glioblastoma data from The Cancer Genome Atlas consortium, we demonstrate that the resulting network models contain known disease-relevant hub genes, reveal interesting candidate hubs, and uncover predictors of patient survival. Targeted validations in four glioblastoma cell lines support selected predictions, and implicate the p53-interacting protein Necdin in suppressing glioblastoma cell growth. We conclude that large-scale network modeling of the effects of CNAs on gene expression may provide insights into the biology of human cancer. Free software in MATLAB and R is provided. PMID:21525872

  14. The optimal number, type and location of devices in automation of electrical distribution networks

    Directory of Open Access Journals (Sweden)

    Popović Željko N.

    2015-01-01

    Full Text Available This paper presents the mixed integer linear programming based model for determining optimal number, type and location of remotely controlled and supervised devices in distribution networks in the presence of distributed generators. The proposed model takes into consideration a number of different devices simultaneously (remotely controlled circuit breakers/reclosers, sectionalizing switches, remotely supervised and local fault passage indicators along with the following: expected outage cost to consumers and producers due to momentary and long-term interruptions, automated device expenses (capital investment, installation, and annual operation and maintenance costs, number and expenses of crews involved in the isolation and restoration process. Furthermore, the other possible benefits of each of automated device are also taken into account (e.g., benefits due to decreasing the cost of switching operations in normal conditions. The obtained numerical results emphasize the importance of consideration of different types of automation devices simultaneously. They also show that the proposed approach have a potential to improve the process of determining of the best automation strategy in real life distribution networks.

  15. Estimating marine aerosol particle volume and number from Maritime Aerosol Network data

    Directory of Open Access Journals (Sweden)

    A. M. Sayer

    2012-09-01

    Full Text Available As well as spectral aerosol optical depth (AOD, aerosol composition and concentration (number, volume, or mass are of interest for a variety of applications. However, remote sensing of these quantities is more difficult than for AOD, as it is more sensitive to assumptions relating to aerosol composition. This study uses spectral AOD measured on Maritime Aerosol Network (MAN cruises, with the additional constraint of a microphysical model for unpolluted maritime aerosol based on analysis of Aerosol Robotic Network (AERONET inversions, to estimate these quantities over open ocean. When the MAN data are subset to those likely to be comprised of maritime aerosol, number and volume concentrations obtained are physically reasonable. Attempts to estimate surface concentration from columnar abundance, however, are shown to be limited by uncertainties in vertical distribution. Columnar AOD at 550 nm and aerosol number for unpolluted maritime cases are also compared with Moderate Resolution Imaging Spectroradiometer (MODIS data, for both the present Collection 5.1 and forthcoming Collection 6. MODIS provides a best-fitting retrieval solution, as well as the average for several different solutions, with different aerosol microphysical models. The "average solution" MODIS dataset agrees more closely with MAN than the "best solution" dataset. Terra tends to retrieve lower aerosol number than MAN, and Aqua higher, linked with differences in the aerosol models commonly chosen. Collection 6 AOD is likely to agree more closely with MAN over open ocean than Collection 5.1. In situations where spectral AOD is measured accurately, and aerosol microphysical properties are reasonably well-constrained, estimates of aerosol number and volume using MAN or similar data would provide for a greater variety of potential comparisons with aerosol properties derived from satellite or chemistry transport model data. However, without accurate AOD data and prior knowledge of

  16. Fundamental Lifetime Mechanisms in Routing Protocols for Wireless Sensor Networks: A Survey and Open Issues

    Science.gov (United States)

    Eslaminejad, Mohammadreza; Razak, Shukor Abd

    2012-01-01

    Wireless sensor networks basically consist of low cost sensor nodes which collect data from environment and relay them to a sink, where they will be subsequently processed. Since wireless nodes are severely power-constrained, the major concern is how to conserve the nodes' energy so that network lifetime can be extended significantly. Employing one static sink can rapidly exhaust the energy of sink neighbors. Furthermore, using a non-optimal single path together with a maximum transmission power level may quickly deplete the energy of individual nodes on the route. This all results in unbalanced energy consumption through the sensor field, and hence a negative effect on the network lifetime. In this paper, we present a comprehensive taxonomy of the various mechanisms applied for increasing the network lifetime. These techniques, whether in the routing or cross-layer area, fall within the following types: multi-sink, mobile sink, multi-path, power control and bio-inspired algorithms, depending on the protocol operation. In this taxonomy, special attention has been devoted to the multi-sink, power control and bio-inspired algorithms, which have not yet received much consideration in the literature. Moreover, each class covers a variety of the state-of-the-art protocols, which should provide ideas for potential future works. Finally, we compare these mechanisms and discuss open research issues. PMID:23202008

  17. Fundamental Lifetime Mechanisms in Routing Protocols for Wireless Sensor Networks: A Survey and Open Issues

    Directory of Open Access Journals (Sweden)

    Shukor Abd Razak

    2012-10-01

    Full Text Available Wireless sensor networks basically consist of low cost sensor nodes which collect data from environment and relay them to a sink, where they will be subsequently processed. Since wireless nodes are severely power-constrained, the major concern is how to conserve the nodes’ energy so that network lifetime can be extended significantly. Employing one static sink can rapidly exhaust the energy of sink neighbors. Furthermore, using a non-optimal single path together with a maximum transmission power level may quickly deplete the energy of individual nodes on the route. This all results in unbalanced energy consumption through the sensor field, and hence a negative effect on the network lifetime. In this paper, we present a comprehensive taxonomy of the various mechanisms applied for increasing the network lifetime. These techniques, whether in the routing or cross-layer area, fall within the following types: multi-sink, mobile sink, multi-path, power control and bio-inspired algorithms, depending on the protocol operation. In this taxonomy, special attention has been devoted to the multi-sink, power control and bio-inspired algorithms, which have not yet received much consideration in the literature. Moreover, each class covers a variety of the state-of-the-art protocols, which should provide ideas for potential future works. Finally, we compare these mechanisms and discuss open research issues.

  18. Routing in Wireless Multimedia Sensor Networks: A Survey of Existing Protocols and Open Research Issues

    Directory of Open Access Journals (Sweden)

    Vikas Bhandary

    2016-01-01

    Full Text Available With the advancement of wireless sensor networks (WSNs and technology, applicability of WSNs as a system is touching new heights. The development of multimedia nodes has led to the creation of another intelligent distributed system, which can transfer real-time multimedia traffic, ubiquitously. Wireless multimedia sensor networks (WMSNs are applicable in a wide range of areas including area monitoring and video surveillance. But due to unreliable error-prone communication medium and application specific quality of service (QoS requirements, routing of real-time multimedia traffic in WMSNs poses a serious problem. The paper discusses various existing routing strategies in WMSNs, with their properties and limitations which lead to open research issues. Further, detailed classification and analytical comparison of discussed protocols are also presented.

  19. GPP Webinar: Solar Utilization in Higher Education Networking & Information Sharing Group: RFP, Contract, and Administrative Issues Discussion

    Science.gov (United States)

    This presentation from a Solar Utilization in Higher Education Networking and Information webinar covers contracts, Request for Proposals (RFPs), and administrative issues related to solar project development in the higher education sector.

  20. Introduction to focus issue: Synchronization in large networks and continuous media-data, models, and supermodels.

    Science.gov (United States)

    Duane, Gregory S; Grabow, Carsten; Selten, Frank; Ghil, Michael

    2017-12-01

    The synchronization of loosely coupled chaotic systems has increasingly found applications to large networks of differential equations and to models of continuous media. These applications are at the core of the present Focus Issue. Synchronization between a system and its model, based on limited observations, gives a new perspective on data assimilation. Synchronization among different models of the same system defines a supermodel that can achieve partial consensus among models that otherwise disagree in several respects. Finally, novel methods of time series analysis permit a better description of synchronization in a system that is only observed partially and for a relatively short time. This Focus Issue discusses synchronization in extended systems or in components thereof, with particular attention to data assimilation, supermodeling, and their applications to various areas, from climate modeling to macroeconomics.

  1. Introduction to focus issue: Synchronization in large networks and continuous media—data, models, and supermodels

    Science.gov (United States)

    Duane, Gregory S.; Grabow, Carsten; Selten, Frank; Ghil, Michael

    2017-12-01

    The synchronization of loosely coupled chaotic systems has increasingly found applications to large networks of differential equations and to models of continuous media. These applications are at the core of the present Focus Issue. Synchronization between a system and its model, based on limited observations, gives a new perspective on data assimilation. Synchronization among different models of the same system defines a supermodel that can achieve partial consensus among models that otherwise disagree in several respects. Finally, novel methods of time series analysis permit a better description of synchronization in a system that is only observed partially and for a relatively short time. This Focus Issue discusses synchronization in extended systems or in components thereof, with particular attention to data assimilation, supermodeling, and their applications to various areas, from climate modeling to macroeconomics.

  2. Artificial neural networks used for the prediction of the cetane number of biodiesel

    Energy Technology Data Exchange (ETDEWEB)

    Ramadhas, A.S.; Jayaraj, S.; Muraleedharan, C. [Department of Mechanical Engineering, National Institute of Technology Calicut, Calicut-673 601 (India); Padmakumari, K. [Department of Electrical Engineering, National Institute of Technology Calicut, Calicut-673 601 (India)

    2006-12-15

    Cetane number (CN) is one of the most significant properties to specify the ignition quality of any fuel for internal combustion engines. The CN of biodiesel varies widely in the range of 48-67 depending upon various parameters including the oil processing technology and climatic conditions where the feedstock (vegetable oil) is collected. Determination of the CN of a fuel by an experimental procedure is a tedious job for the upcoming biodiesel production industry. The fatty acid composition of base oil predominantly affects the CN of the biodiesel produced from it. This paper discusses the currently available CN estimation techniques and the necessity of accurate prediction of CN of biodiesel. Artificial Neural Network (ANN) models are developed to predict the CN of any biodiesel. The present paper deals with the application of multi-layer feed forward, radial base, generalized regression and recurrent network models for the prediction of CN. The fatty acid compositions of biodiesel and the experimental CNs are used to train the networks. The parameters that affect the development of the model are also discussed. ANN predicted CNs are found to be in agreement with the experimental CNs. Hence, the ANN models developed can be used reliably for the prediction of CN of biodiesel. (author)

  3. Optimizing the Number of Cooperating Terminals for Energy Aware Task Computing in Wireless Networks

    DEFF Research Database (Denmark)

    Olsen, Anders Brødløs; Fitzek, Frank H. P.; Koch, Peter

    2005-01-01

    It is generally accepted that energy consumption is a significant design constraint for mobile handheld systems, therefore motivations for methods optimizing the energy consumption making better use of the restricted battery resources are evident. A novel concept of distributed task computing...... is previously proposed (D2VS), where the overall idea of selective distribution of tasks among terminals is made. In this paper the optimal number of terminals for cooperative task computing in a wireless network will be investigated. The paper presents an energy model for the proposed scheme. Energy...... consumption of the terminals with respect to their workload and the overhead of distributing tasks among terminals are taken into account. The paper shows, that the number of cooperating terminals is in general limited to a few, though alternating with respect to the various system parameters....

  4. Gender Variations in the Effects of Number of Organizational Memberships, Number of Social Networking Sites, and Grade-Point Average on Global Social Responsibility in Filipino University Students

    OpenAIRE

    Lee, Romeo B.; Baring, Rito V.; Sta. Maria, Madelene A.

    2016-01-01

    The study seeks to estimate gender variations in the direct effects of (a) number of organizational memberships, (b) number of social networking sites (SNS), and (c) grade-point average (GPA) on global social responsibility (GSR); and in the indirect effects of (a) and of (b) through (c) on GSR. Cross-sectional survey data were drawn from questionnaire interviews involving 3,173 Filipino university students. Based on a path model, the three factors were tested to determine their inter-relatio...

  5. Minimum Number of Observation Points for LEO Satellite Orbit Estimation by OWL Network

    Directory of Open Access Journals (Sweden)

    Maru Park

    2015-12-01

    Full Text Available By using the Optical Wide-field Patrol (OWL network developed by the Korea Astronomy and Space Science Institute (KASI we generated the right ascension and declination angle data from optical observation of Low Earth Orbit (LEO satellites. We performed an analysis to verify the optimum number of observations needed per arc for successful estimation of orbit. The currently functioning OWL observatories are located in Daejeon (South Korea, Songino (Mongolia, and Oukaïmeden (Morocco. The Daejeon Observatory is functioning as a test bed. In this study, the observed targets were Gravity Probe B, COSMOS 1455, COSMOS 1726, COSMOS 2428, SEASAT 1, ATV-5, and CryoSat-2 (all in LEO. These satellites were observed from the test bed and the Songino Observatory of the OWL network during 21 nights in 2014 and 2015. After we estimated the orbit from systematically selected sets of observation points (20, 50, 100, and 150 for each pass, we compared the difference between the orbit estimates for each case, and the Two Line Element set (TLE from the Joint Space Operation Center (JSpOC. Then, we determined the average of the difference and selected the optimal observation points by comparing the average values.

  6. The Worldviews Network: Digital Planetariums for Engaging Public Audiences in Global Change Issues

    Science.gov (United States)

    Wyatt, R. J.; Koontz, K.; Yu, K.; Gardiner, N.; Connolly, R.; Mcconville, D.

    2013-12-01

    Utilizing the capabilities of digital planetariums, the Denver Museum of Nature & Science, the California Academy of Sciences, NOVA/WGBH, The Elumenati, and affiliates of the National Oceanic & Atmospheric Administration formed the Worldviews Network. The network's mission is to place Earth in its cosmic context to encourage participants to explore connections between social & ecological issues in their backyards. Worldviews launched with informal science institution partners: the American Museum of Natural History, the Perot Museum of Nature & Science, the Journey Museum, the Bell Museum of Natural History, the University of Michigan Natural History Museum, and the National Environmental Modeling & Analysis Center. Worldviews uses immersive visualization technology to engage public audiences on issues of global environmental change at a bioregional level. An immersive planetarium show and dialogue deepens public engagement and awareness of complex human-natural system interactions. People have altered the global climate system. Our communities are increasingly vulnerable to extreme weather events. Land use decisions that people make every day put both human lives and biodiversity at risk through direct and indirect effects. The Worldviews programs demonstrate the complex linkages between Earth's physical and biological systems and their relationship to human health, agriculture, infrastructure, water resources, and energy. We have focused on critical thresholds, such as freshwater use, biodiversity loss, land use change, and anthropogenic changes to the nitrogen and phosphorus cycles. We have been guided by environmental literacy principles to help our audiences understand that humans drive current trends in coupled human-natural systems--and that humans could choose to play an important role in reversing these trends. Museum and planetarium staff members join the Worldviews Network team and external advisers to produce programs that span cosmic, global, and

  7. Security and privacy issues in wireless sensor networks for healthcare applications.

    Science.gov (United States)

    Al Ameen, Moshaddique; Liu, Jingwei; Kwak, Kyungsup

    2012-02-01

    The use of wireless sensor networks (WSN) in healthcare applications is growing in a fast pace. Numerous applications such as heart rate monitor, blood pressure monitor and endoscopic capsule are already in use. To address the growing use of sensor technology in this area, a new field known as wireless body area networks (WBAN or simply BAN) has emerged. As most devices and their applications are wireless in nature, security and privacy concerns are among major areas of concern. Due to direct involvement of humans also increases the sensitivity. Whether the data gathered from patients or individuals are obtained with the consent of the person or without it due to the need by the system, misuse or privacy concerns may restrict people from taking advantage of the full benefits from the system. People may not see these devices safe for daily use. There may also possibility of serious social unrest due to the fear that such devices may be used for monitoring and tracking individuals by government agencies or other private organizations. In this paper we discuss these issues and analyze in detail the problems and their possible measures.

  8. Generation of a superposition of odd photon number states for quantum information networks

    DEFF Research Database (Denmark)

    Neergaard-Nielsen, Jonas Schou; Nielsen, B.; Hettich, C.

    2006-01-01

    Quantum information networks, quantum memories, quantum repeaters, linear optics quantum computers Udgivelsesdato: 25 August......Quantum information networks, quantum memories, quantum repeaters, linear optics quantum computers Udgivelsesdato: 25 August...

  9. Towards full network virtualization in horizontal IaaS federation: security issues

    National Research Council Canada - National Science Library

    Nimkar, Anant V; Ghosh, Soumya K

    2013-01-01

    .... virtual machines, virtual switches, and virtual routers) and virtual links. Today’s datacenters for cloud computing do not supply full network virtualization in terms of user-level network management and user-agreed network topology...

  10. Module number of default mode network: inter-subject variability and effects of sleep deprivation.

    Science.gov (United States)

    Wang, Yulin; Liu, Huan; Hitchman, Glenn; Lei, Xu

    2015-01-30

    Sleep deprivation have shown its great influence on the default mode network (DMN). The DMN is a core system in resting state brain activity. Recent studies have focused on its subsystems and multiple functions. However, the individual specific organization of the DMN is rarely investigated. As the effects of sleep deprivation (SD) on mood are well documented, a more interesting question is whether changes in the processing of emotional information due to sleep deprivation are related to any specific topological properties of the DMN. In this study, we proposed an index, module number of DMN (mnDMN), to measure the specific modular structure of the DMN for each individual. Our results showed that the DMN was generally split into two modules after SD, and the decreased functional connectivity between the two modules was related to a worsening of the participants׳ self-reported emotional state. Furthermore, the mnDMN was correlated with participants' rating scores of high valence pictures in the SD session, indicating that the mnDMN might reflect mood valuation in the human brain. Overall, our research reveals the diversity of the DMN, and may contribute towards a better understanding of the properties and functions of the DMN. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Tobacco industry issues management organizations: Creating a global corporate network to undermine public health

    Directory of Open Access Journals (Sweden)

    Malone Ruth E

    2008-01-01

    Full Text Available Abstract Background The global tobacco epidemic claims 5 million lives each year, facilitated by the ability of transnational tobacco companies to delay or thwart meaningful tobacco control worldwide. A series of cross-company tobacco industry "issues management organizations" has played an important role in coordinating and implementing common strategies to defeat tobacco control efforts at international, national, and regional levels. This study examines the development and enumerates the activities of these organizations and explores the implications of continuing industry cooperation for global public health. Methods Using a snowball sampling strategy, we collected documentary data from tobacco industry documents archives and assembled them into a chronologically organized case study. Results The International Committee on Smoking Issues (ICOSI was formed in 1977 by seven tobacco company chief executives to create common anti-tobacco control strategies and build a global network of regional and national manufacturing associations. The organization's name subsequently changed to INFOTAB. The multinational companies built the organization rapidly: by 1984, it had 69 members operating in 57 countries. INFOTAB material, including position papers and "action kits" helped members challenge local tobacco control measures and maintain tobacco-friendly environments. In 1992 INFOTAB was replaced by two smaller organizations. The Tobacco Documentation Centre, which continues to operate, distributes smoking-related information and industry argumentation to members, some produced by cross-company committees. Agro-Tobacco Services, and now Hallmark Marketing Services, assists the INFOTAB-backed and industry supported International Tobacco Growers Association in advancing claims regarding the economic importance of tobacco in developing nations. Conclusion The massive scale and scope of this industry effort illustrate how corporate interests, when

  12. Tobacco industry issues management organizations: creating a global corporate network to undermine public health.

    Science.gov (United States)

    McDaniel, Patricia A; Intinarelli, Gina; Malone, Ruth E

    2008-01-17

    The global tobacco epidemic claims 5 million lives each year, facilitated by the ability of transnational tobacco companies to delay or thwart meaningful tobacco control worldwide. A series of cross-company tobacco industry "issues management organizations" has played an important role in coordinating and implementing common strategies to defeat tobacco control efforts at international, national, and regional levels. This study examines the development and enumerates the activities of these organizations and explores the implications of continuing industry cooperation for global public health. Using a snowball sampling strategy, we collected documentary data from tobacco industry documents archives and assembled them into a chronologically organized case study. The International Committee on Smoking Issues (ICOSI) was formed in 1977 by seven tobacco company chief executives to create common anti-tobacco control strategies and build a global network of regional and national manufacturing associations. The organization's name subsequently changed to INFOTAB. The multinational companies built the organization rapidly: by 1984, it had 69 members operating in 57 countries. INFOTAB material, including position papers and "action kits" helped members challenge local tobacco control measures and maintain tobacco-friendly environments. In 1992 INFOTAB was replaced by two smaller organizations. The Tobacco Documentation Centre, which continues to operate, distributes smoking-related information and industry argumentation to members, some produced by cross-company committees. Agro-Tobacco Services, and now Hallmark Marketing Services, assists the INFOTAB-backed and industry supported International Tobacco Growers Association in advancing claims regarding the economic importance of tobacco in developing nations. The massive scale and scope of this industry effort illustrate how corporate interests, when threatened by the globalization of public health, sidestep competitive

  13. Tobacco industry issues management organizations: Creating a global corporate network to undermine public health

    Science.gov (United States)

    McDaniel, Patricia A; Intinarelli, Gina; Malone, Ruth E

    2008-01-01

    Background The global tobacco epidemic claims 5 million lives each year, facilitated by the ability of transnational tobacco companies to delay or thwart meaningful tobacco control worldwide. A series of cross-company tobacco industry "issues management organizations" has played an important role in coordinating and implementing common strategies to defeat tobacco control efforts at international, national, and regional levels. This study examines the development and enumerates the activities of these organizations and explores the implications of continuing industry cooperation for global public health. Methods Using a snowball sampling strategy, we collected documentary data from tobacco industry documents archives and assembled them into a chronologically organized case study. Results The International Committee on Smoking Issues (ICOSI) was formed in 1977 by seven tobacco company chief executives to create common anti-tobacco control strategies and build a global network of regional and national manufacturing associations. The organization's name subsequently changed to INFOTAB. The multinational companies built the organization rapidly: by 1984, it had 69 members operating in 57 countries. INFOTAB material, including position papers and "action kits" helped members challenge local tobacco control measures and maintain tobacco-friendly environments. In 1992 INFOTAB was replaced by two smaller organizations. The Tobacco Documentation Centre, which continues to operate, distributes smoking-related information and industry argumentation to members, some produced by cross-company committees. Agro-Tobacco Services, and now Hallmark Marketing Services, assists the INFOTAB-backed and industry supported International Tobacco Growers Association in advancing claims regarding the economic importance of tobacco in developing nations. Conclusion The massive scale and scope of this industry effort illustrate how corporate interests, when threatened by the globalization of

  14. Exotic Plant Infestation Is Associated with Decreased Modularity and Increased Numbers of Connectors in Mixed-Grass Prairie Pollination Networks.

    Directory of Open Access Journals (Sweden)

    Diane L Larson

    Full Text Available The majority of pollinating insects are generalists whose lifetimes overlap flowering periods of many potentially suitable plant species. Such generality is instrumental in allowing exotic plant species to invade pollination networks. The particulars of how existing networks change in response to an invasive plant over the course of its phenology are not well characterized, but may shed light on the probability of long-term effects on plant-pollinator interactions and the stability of network structure. Here we describe changes in network topology and modular structure of infested and non-infested networks during the flowering season of the generalist non-native flowering plant, Cirsium arvense in mixed-grass prairie at Badlands National Park, South Dakota, USA. Objectives were to compare network-level effects of infestation as they propagate over the season in infested and non-infested (with respect to C. arvense networks. We characterized plant-pollinator networks on 5 non-infested and 7 infested 1-ha plots during 4 sample periods that collectively covered the length of C. arvense flowering period. Two other abundantly-flowering invasive plants were present during this time: Melilotus officinalis had highly variable floral abundance in both C. arvense-infested and non-infested plots and Convolvulus arvensis, which occurred almost exclusively in infested plots and peaked early in the season. Modularity, including roles of individual species, and network topology were assessed for each sample period as well as in pooled infested and non-infested networks. Differences in modularity and network metrics between infested and non-infested networks were limited to the third and fourth sample periods, during flower senescence of C. arvense and the other invasive species; generality of pollinators rose concurrently, suggesting rewiring of the network and a lag effect of earlier floral abundance. Modularity was lower and number of connectors higher in

  15. Exotic Plant Infestation Is Associated with Decreased Modularity and Increased Numbers of Connectors in Mixed-Grass Prairie Pollination Networks.

    Science.gov (United States)

    Larson, Diane L; Rabie, Paul A; Droege, Sam; Larson, Jennifer L; Haar, Milton

    2016-01-01

    The majority of pollinating insects are generalists whose lifetimes overlap flowering periods of many potentially suitable plant species. Such generality is instrumental in allowing exotic plant species to invade pollination networks. The particulars of how existing networks change in response to an invasive plant over the course of its phenology are not well characterized, but may shed light on the probability of long-term effects on plant-pollinator interactions and the stability of network structure. Here we describe changes in network topology and modular structure of infested and non-infested networks during the flowering season of the generalist non-native flowering plant, Cirsium arvense in mixed-grass prairie at Badlands National Park, South Dakota, USA. Objectives were to compare network-level effects of infestation as they propagate over the season in infested and non-infested (with respect to C. arvense) networks. We characterized plant-pollinator networks on 5 non-infested and 7 infested 1-ha plots during 4 sample periods that collectively covered the length of C. arvense flowering period. Two other abundantly-flowering invasive plants were present during this time: Melilotus officinalis had highly variable floral abundance in both C. arvense-infested and non-infested plots and Convolvulus arvensis, which occurred almost exclusively in infested plots and peaked early in the season. Modularity, including roles of individual species, and network topology were assessed for each sample period as well as in pooled infested and non-infested networks. Differences in modularity and network metrics between infested and non-infested networks were limited to the third and fourth sample periods, during flower senescence of C. arvense and the other invasive species; generality of pollinators rose concurrently, suggesting rewiring of the network and a lag effect of earlier floral abundance. Modularity was lower and number of connectors higher in infested networks

  16. Exotic plant infestation is associated with decreased modularity and increased numbers of connectors in mixed-grass prairie pollination networks

    Science.gov (United States)

    Larson, Diane L.; Rabie, Paul A.; Droege, Sam; Larson, Jennifer L.; Haar, Milton

    2016-01-01

    The majority of pollinating insects are generalists whose lifetimes overlap flowering periods of many potentially suitable plant species. Such generality is instrumental in allowing exotic plant species to invade pollination networks. The particulars of how existing networks change in response to an invasive plant over the course of its phenology are not well characterized, but may shed light on the probability of long-term effects on plant-pollinator interactions and the stability of network structure. Here we describe changes in network topology and modular structure of infested and non-infested networks during the flowering season of the generalist non-native flowering plant, Cirsium arvense in mixed-grass prairie at Badlands National Park, South Dakota, USA. Objectives were to compare network-level effects of infestation as they propagate over the season in infested and non-infested (with respect to C. arvense) networks. We characterized plant-pollinator networks on 5 non-infested and 7 infested 1-ha plots during 4 sample periods that collectively covered the length of C. arvense flowering period. Two other abundantly-flowering invasive plants were present during this time: Melilotus officinalis had highly variable floral abundance in both C. arvense-infested and non-infested plots andConvolvulus arvensis, which occurred almost exclusively in infested plots and peaked early in the season. Modularity, including roles of individual species, and network topology were assessed for each sample period as well as in pooled infested and non-infested networks. Differences in modularity and network metrics between infested and non-infested networks were limited to the third and fourth sample periods, during flower senescence of C. arvenseand the other invasive species; generality of pollinators rose concurrently, suggesting rewiring of the network and a lag effect of earlier floral abundance. Modularity was lower and number of connectors higher in infested

  17. Cross-Cultural Collisions in Cyberspace: Case Studies of International Legal Issues for Educators Working in Globally Networked Learning Environments

    Science.gov (United States)

    Rife, Martine Courant

    2010-01-01

    This article explores some of the legal and law-related challenges educators face in designing, implementing, and sustaining globally networked learning environments (GNLEs) in the context of conflicting international laws on intellectual property and censorship/free speech. By discussing cases and areas involving such legal issues, the article…

  18. Secure Military Social Networking and Rapid Sensemaking in Domain Specific Concept Systems: Research Issues and Future Solutions

    Directory of Open Access Journals (Sweden)

    Richard Picking

    2012-03-01

    Full Text Available This paper identifies the need for a secure military social networking site and the underlying research issues linked to the successful development of such sites. The paper further proposes a solution to the most basic issues by identifying and tackling known potential security threats to military personnel and their families. The paper further defines the base platform for this development to facilitate rapid sensemaking to inform critical communications and rapid decision making processes during abrupt governance and eco-system change, and how the plethora of information (termed as Big Data on social networking sites can be analysed and harnessed. Underlying architectural issues, efficiency and complexity are explored and their future development is considered.

  19. Dynamic mobility applications policy analysis : policy and institutional issues for intelligent network flow optimization (INFLO).

    Science.gov (United States)

    2014-12-01

    The report documents policy considerations for the Intelligent Network Flow Optimization (INFLO) connected vehicle applications : bundle. INFLO aims to optimize network flow on freeways and arterials by informing motorists of existing and impen...

  20. History, current issues and future of the brazilian network for attending and studying Trypanosoma cruzi/HIV coinfection.

    Science.gov (United States)

    Ramos Júnior, Alberto Novaes; Correia, Dalmo; Almeida, Eros Antônio; Shikanai-Yasuda, Maria Aparecida

    2010-11-24

    In countries with endemic Chagas disease, coinfection involving Trypanosoma cruzi and HIV is expected to become more frequent. There is a clear need to structure a comprehensive care network aimed at dealing with this situation, with mobilization going from primary care to care at the highest level of technological complexity. The objective of this study was to describe the Brazilian response to the challenges of Chagas disease: the history, current issues, and future of the Brazilian Network for attending and studying T. cruzi/HIV coinfection. This descriptive study reviewed technical documents relating to the basis and structuring process of the Brazilian network for attending and studying T. cruzi/HIV coinfection. The process of setting up the network was marked by technical and political debates in technical-scientific meetings going back to the 1990s. This process made it possible to expand and focus on different aspects of comprehensive care for Chagas disease in Brazil, regardless of the associated immunosuppressive conditions. These meetings produced a structure of national technical guidelines and standards, health care and research protocols and research priorities, along with mobilization and awareness-raising among HIV/AIDS reference centers regarding occurrences of coinfection. The creation of the Brazilian network was a milestone for the country in terms of integration of control programs, with the reference point of quality of care and comprehensiveness. The possibility of extending this network to form a Latin American network is seen as a strategy for dealing more effectively with this condition.

  1. Quality of Service Issues for Reinforcement Learning Based Routing Algorithm for Ad-Hoc Networks

    OpenAIRE

    Kulkarni, Shrirang Ambaji; Rao, G. Raghavendra

    2012-01-01

    Mobile ad-hoc networks are dynamic networks which are decentralized and autonomous in nature. Many routing algorithms have been proposed for these dynamic networks. It is an important problem to model Quality of Service requirements on these types of algorithms which traditionally have certain limitations. To model this scenario we have considered a reinforcement learning algorithm SAMPLE. SAMPLE promises to deal effectively with congestion and under high traffic load. As it is natural for ad...

  2. Network theory: key issues for the analysis of the "brain drain"

    Directory of Open Access Journals (Sweden)

    Diana Carolina Henao

    2012-12-01

    Full Text Available This paper offers an analysis of the brain drain from the perspective of the network theory. Some definitions and key concepts of the network theory have been discussed in relation to criteria and reasons that are taken into account by people with broad educational capital from developing countries who are involved in the research in different areas of knowledge and who seek to adapt to other scientific collaboration networks in the developed countries.

  3. Design Issues for Traffic Management for the ATM UBR + Service for TCP Over Satellite Networks

    Science.gov (United States)

    Jain, Raj

    1999-01-01

    This project was a comprehensive research program for developing techniques for improving the performance of Internet protocols over Asynchronous Transfer Mode (ATM) based satellite networks. Among the service categories provided by ATM networks, the most commonly used category for data traffic is the unspecified bit rate (UBR) service. UBR allows sources to send data into the network without any feedback control. The project resulted in the numerous ATM Forum contributions and papers.

  4. Blending Hydrogen into Natural Gas Pipeline Networks. A Review of Key Issues

    Energy Technology Data Exchange (ETDEWEB)

    Melaina, M. W. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Antonia, O. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Penev, M. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2013-03-01

    This study assesses the potential to deliver hydrogen through the existing natural gas pipeline network as a hydrogen and natural gas mixture to defray the cost of building dedicated hydrogen pipelines. Blending hydrogen into the existing natural gas pipeline network has also been proposed as a means of increasing the output of renewable energy systems such as large wind farms.

  5. A Novel Network for Mentoring Family Physicians on Mental Health Issues Using E-Mail

    Science.gov (United States)

    Hunter, Jon J.; Rockman, Patricia; Gingrich, Nadine; Silveira, Jose; Salach, Lena

    2008-01-01

    Objective: Family practitioners are significant providers of mental health care and routinely report difficulty acquiring timely support in this area. The Collaborative Mental Health Care Network assembled groups of family practitioners and provided them with mental health practitioner mentors. This article addresses communication in the Network,…

  6. Applying social network analysis in economic geography: framing some key analytic issues

    NARCIS (Netherlands)

    Wal, A.L.J. ter; Boschma, R.A.

    2007-01-01

    Social network analysis attracts increasing attention in economic geography. We claim social network analysis is a promising tool for empirically investigating the structure and evolution of inter-organizational interaction and knowledge flows within and across regions. However, the potential of

  7. Special issue on searching and mining the web and social networks

    NARCIS (Netherlands)

    Litvak, Nelli; Vigna, Sebastiano

    2014-01-01

    The past few decades have seen the rise of online social networks as a worldwide phenomenon with a high impact on our society. Beyond the obvious exposure phenomena, with obvious implications on security and privacy, people have started to become acquainted—even married!—in online social networks.

  8. The evolutionary and ecological consequences of animal social networks: emerging issues.

    Science.gov (United States)

    Kurvers, Ralf H J M; Krause, Jens; Croft, Darren P; Wilson, Alexander D M; Wolf, Max

    2014-06-01

    The first generation of research on animal social networks was primarily aimed at introducing the concept of social networks to the fields of animal behaviour and behavioural ecology. More recently, a diverse body of evidence has shown that social fine structure matters on a broader scale than initially expected, affecting many key ecological and evolutionary processes. Here, we review this development. We discuss the effects of social network structure on evolutionary dynamics (genetic drift, fixation probabilities, and frequency-dependent selection) and social evolution (cooperation and between-individual behavioural differences). We discuss how social network structure can affect important coevolutionary processes (host-pathogen interactions and mutualisms) and population stability. We also discuss the potentially important, but poorly studied, role of social network structure on dispersal and invasion. Throughout, we highlight important areas for future research. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. KEY ISSUES OF CONCEPTS' FORMATION OF THE NETWORK OF RESOURCE CENTER OF DISTANCE EDUCATION OF GENERAL EDUCATION INSTITUTIONS

    Directory of Open Access Journals (Sweden)

    Yuriy M. Bogachkov

    2013-06-01

    Full Text Available In the article the problem of constructing a network of resource centers for Distance Education to meet the needs of general secondary schools is presented. Modern educational trends in the use of Internet services in education are viewed.  Main contradictions, solution of which helps to create a network of resource centers, are identified. The definition of key terms related to the range of issues are given. The basic categories of participants, who  implementation of e-learning and networking are oriented on. There are considered the basic tasks of  distance education resource centers' functioning and types of supporting: personnel, regulatory, informative, systematic and  technical etc. The review of possible models of implementation of  students' distance education is reviewed . Three options for business models of resource centers, depending on funding  sources are offered.

  10. Networks of VTA Neurons Encode Real-Time Information about Uncertain Numbers of Actions Executed to Earn a Reward

    Directory of Open Access Journals (Sweden)

    Jesse Wood

    2017-08-01

    Full Text Available Multiple and unpredictable numbers of actions are often required to achieve a goal. In order to organize behavior and allocate effort so that optimal behavioral policies can be selected, it is necessary to continually monitor ongoing actions. Real-time processing of information related to actions and outcomes is typically assigned to the prefrontal cortex and basal ganglia, but also depends on midbrain regions, especially the ventral tegmental area (VTA. We were interested in how individual VTA neurons, as well as networks within the VTA, encode salient events when an unpredictable number of serial actions are required to obtain a reward. We recorded from ensembles of putative dopamine and non-dopamine neurons in the VTA as animals performed multiple cued trials in a recording session where, in each trial, serial actions were randomly rewarded. While averaging population activity did not reveal a response pattern, we observed that different neurons were selectively tuned to low, medium, or high numbered actions in a trial. This preferential tuning of putative dopamine and non-dopamine VTA neurons to different subsets of actions in a trial allowed information about binned action number to be decoded from the ensemble activity. At the network level, tuning curve similarity was positively associated with action-evoked noise correlations, suggesting that action number selectivity reflects functional connectivity within these networks. Analysis of phasic responses to cue and reward revealed that the requirement to execute multiple and uncertain numbers of actions weakens both cue-evoked responses and cue-reward response correlation. The functional connectivity and ensemble coding scheme that we observe here may allow VTA neurons to cooperatively provide a real-time account of ongoing behavior. These computations may be critical to cognitive and motivational functions that have long been associated with VTA dopamine neurons.

  11. Multistability of phase-locking and topological winding numbers in locally coupled Kuramoto models on single-loop networks

    Science.gov (United States)

    Delabays, Robin; Coletta, Tommaso; Jacquod, Philippe

    2016-03-01

    Determining the number of stable phase-locked solutions for locally coupled Kuramoto models is a long-standing mathematical problem with important implications in biology, condensed matter physics, and electrical engineering among others. We investigate Kuramoto models on networks with various topologies and show that different phase-locked solutions are related to one another by loop currents. The latter take only discrete values, as they are characterized by topological winding numbers. This result is generically valid for any network and also applies beyond the Kuramoto model, as long as the coupling between oscillators is antisymmetric in the oscillators' coordinates. Motivated by these results, we further investigate loop currents in Kuramoto-like models. We consider loop currents in nonoriented n-node cycle networks with nearest-neighbor coupling. Amplifying on earlier works, we give an algebraic upper bound N ≤ 2 Int [ n / 4 ] + 1 for the number N of different, linearly stable phase-locked solutions. We show that the number of different stable solutions monotonically decreases as the coupling strength is decreased. Furthermore stable solutions with a single angle difference exceeding π/2 emerge as the coupling constant K is reduced, as smooth continuations of solutions with all angle differences smaller than π/2 at higher K. In a cycle network with nearest-neighbor coupling, we further show that phase-locked solutions with two or more angle differences larger than π/2 are all linearly unstable. We point out similarities between loop currents and vortices in superfluids and superconductors as well as persistent currents in superconducting rings and two-dimensional Josephson junction arrays.

  12. Recognition physical activities with optimal number of wearable sensors using data mining algorithms and deep belief network.

    Science.gov (United States)

    Al-Fatlawi, Ali H; Fatlawi, Hayder K; Sai Ho Ling

    2017-07-01

    Daily physical activities monitoring is benefiting the health care field in several ways, in particular with the development of the wearable sensors. This paper adopts effective ways to calculate the optimal number of the necessary sensors and to build a reliable and a high accuracy monitoring system. Three data mining algorithms, namely Decision Tree, Random Forest and PART Algorithm, have been applied for the sensors selection process. Furthermore, the deep belief network (DBN) has been investigated to recognise 33 physical activities effectively. The results indicated that the proposed method is reliable with an overall accuracy of 96.52% and the number of sensors is minimised from nine to six sensors.

  13. Gender Variations in the Effects of Number of Organizational Memberships, Number of Social Networking Sites, and Grade-Point Average on Global Social Responsibility in Filipino University Students.

    Science.gov (United States)

    Lee, Romeo B; Baring, Rito V; Sta Maria, Madelene A

    2016-02-01

    The study seeks to estimate gender variations in the direct effects of (a) number of organizational memberships, (b) number of social networking sites (SNS), and (c) grade-point average (GPA) on global social responsibility (GSR); and in the indirect effects of (a) and of (b) through (c) on GSR. Cross-sectional survey data were drawn from questionnaire interviews involving 3,173 Filipino university students. Based on a path model, the three factors were tested to determine their inter-relationships and their relationships with GSR. The direct and total effects of the exogenous factors on the dependent variable are statistically significantly robust. The indirect effects of organizational memberships on GSR through GPA are also statistically significant, but the indirect effects of SNS on GSR through GPA are marginal. Men and women significantly differ only in terms of the total effects of their organizational memberships on GSR. The lack of broad gender variations in the effects of SNS, organizational memberships and GPA on GSR may be linked to the relatively homogenous characteristics and experiences of the university students interviewed. There is a need for more path models to better understand the predictors of GSR in local students.

  14. Gender Variations in the Effects of Number of Organizational Memberships, Number of Social Networking Sites, and Grade-Point Average on Global Social Responsibility in Filipino University Students

    Science.gov (United States)

    Lee, Romeo B.; Baring, Rito V.; Sta. Maria, Madelene A.

    2016-01-01

    The study seeks to estimate gender variations in the direct effects of (a) number of organizational memberships, (b) number of social networking sites (SNS), and (c) grade-point average (GPA) on global social responsibility (GSR); and in the indirect effects of (a) and of (b) through (c) on GSR. Cross-sectional survey data were drawn from questionnaire interviews involving 3,173 Filipino university students. Based on a path model, the three factors were tested to determine their inter-relationships and their relationships with GSR. The direct and total effects of the exogenous factors on the dependent variable are statistically significantly robust. The indirect effects of organizational memberships on GSR through GPA are also statistically significant, but the indirect effects of SNS on GSR through GPA are marginal. Men and women significantly differ only in terms of the total effects of their organizational memberships on GSR. The lack of broad gender variations in the effects of SNS, organizational memberships and GPA on GSR may be linked to the relatively homogenous characteristics and experiences of the university students interviewed. There is a need for more path models to better understand the predictors of GSR in local students. PMID:27247700

  15. How to Generate Personal Networks: Issues and Tools for a Sociological Perspective

    OpenAIRE

    Bidart, Claire; Charbonneau, Johanne

    2012-01-01

    Document de travail, à paraître dans la revue "Field Methods" en Août 2011; Each name generator produces its own type of personal network and has its own assumptions and boundaries. Following a quick review of these tools and their distinctive characteristics, we propose a new name generator to study the link between sociability and socialization. The sociological point of view leads to building large networks rooted in the social contexts of everyday life rather than networks focused on spec...

  16. Numerical Investigation of Nanofluid Mixed Convection in an Inclined Channel and Predicting Nusselt Number with Artificial Neural Networks

    Directory of Open Access Journals (Sweden)

    Hamid Teimouri

    2015-09-01

    Full Text Available Artificial Neural Networks (ANNs are used as a new approach in determination of Nusselt number of copper water nanofluid in an inclined channel with three heat sources. For training the ANNs, the simulation results are obtained by Finite Volume Method (FVM. The effects of independent parameters, including the Reynolds number, Rayleigh number, inclination angle, and the solid volume fraction of nanoparticles, on the streamlines, isotherm lines, and the average Nusselt number have been studied. Artificial neural networks (ANN used to find a relation involve independent parameters for estimating the Nusselt number. The back propagation-learning algorithm with the tangent sigmoid transfer function is used to sequence the ANN. Finally, analytical relations for the nanofluid mixed convection in a channel are derived from the available ANN. It is shown that the coefficient of multiple determination (R 2 between the FVM and ANN predicted values is equal to 0.99866, maximum relative error is less than 5.9128% and mean square error is 1.13×10 -3 . Results show that the obtained formulation is obviously within acceptable limits.

  17. Theoretical framework on selected core issues on conditions for productive learning in networked learning environments

    DEFF Research Database (Denmark)

    Dirckinck-Holmfeld, Lone; Svendsen, Brian Møller; Ponti, Marisa

    The report documents and summarises the elements and dimensions that have been identified to describe and analyse the case studies collected in the Kaleidoscope Jointly Executed Integrating Research Project (JEIRP) on Conditions for productive learning in network learning environments....

  18. Language and Letters of the Bluestocking Network : Sociolinguistic Issues in Eighteenth Century Epistolary English

    OpenAIRE

    Sairio, Anni

    2009-01-01

    This study deals with language change and variation in the correspondence of the eighteenth-century Bluestocking circle, a social network which provided learned men and women with an informal environment for the pursuit of scholarly entertainment. Elizabeth Montagu (1718 1800), a notable social hostess and a Shakespearean scholar, was one of their key figures. The study presents the reconstruction of Elizabeth Montagu s social networks from her youth to her later years with a special focus on...

  19. Calculating the Number of Cluster Heads Based on the Rate-Distortion Function in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Mingxin Yang

    2014-01-01

    Full Text Available Due to limited resources in wireless sensor nodes, energy efficiency is considered as one of the primary constraints in the design of the topology of wireless sensor networks (WSNs. Since data that are collected by wireless sensor nodes exhibit the characteristics of temporal association, data fusion has also become a very important means of reducing network traffic as well as eliminating data redundancy as far as data transmission is concerned. Another reason for data fusion is that, in many applications, only some of the data that are collected can meet the requirements of the sink node. In this paper, we propose a method to calculate the number of cluster heads or data aggregators during data fusion based on the rate-distortion function. In our discussion, we will first establish an energy consumption model and then describe a method for calculating the number of cluster heads from the point of view of reducing energy consumption. We will also show through theoretical analysis and experimentation that the network topology design based on the rate-distortion function is indeed more energy-efficient.

  20. Using neural networks with new morphological variables to recognize the number of jets in $e^{+} e^{-}$ reactions

    CERN Document Server

    Mjahed, M

    1999-01-01

    In this work, we aim to construct a new set of variables, to recognize the number of jets produced in the e/sup +/ e/sup -/ events. These so-called morphological variables usually used in image processing and recognition problems, are comparable to the classical sphericity, aplanarity etc.. The amelioration of the recognition efficiency is obtained thanks to the use of a back-propagation neural network. The survey first done on the generated Lund Monte Carlo events could be reinforced thereafter by taking into account the simulation of the ALEPH detector. The neural network performed on this later kind of events, successfully identifies the 4 classes of events (event with 2, 3, 4 jets or with an isotropic distribution (0 jets)). (33 refs).

  1. Blind identification of the number of sub-carriers for orthogonal frequency division multiplexing-based elastic optical networking

    Science.gov (United States)

    Zhao, Lei; Xu, Hengying; Bai, Chenglin

    2018-03-01

    In orthogonal frequency division multiplexing (OFDM)-based elastic optical networking (EON), it is imperative to identify unknown parameters of OFDM-based EON signals quickly, intelligently and robustly. Because the number of sub-carriers determines the size of the sub-carriers spacing and then affects the symbol period of the OFDM and the anti-dispersion capability of the system, the identification of the number of sub-carriers has a profound effect on the identification of other key parameters of the system. In this paper, we proposed a method of number identification for sub-carriers of OFDM-based EON signals with help of high-order cyclic cumulant. The specific fourth-order cyclic cumulant exists only at the location of its sub-carriers frequencies. So the identification of the number of sub-carriers can be implemented by detecting the cyclic-frequencies. The proposed scheme in our study can be divided into three sub-stages, i.e. estimating the spectral range, calculating the high-order cyclic cumulant and identifying the number of sub-carriers. When the optical signal-to-noise ratios (OSNR) varied from 16dB to 22dB, the number of sub-carriers (64-512) was successfully identified in the experiment, and from the statistical point of view, the average identification absolute accuracy (IAAs) exceeded 94%.

  2. Blending Hydrogen into Natural Gas Pipeline Networks: A Review of Key Issues

    Energy Technology Data Exchange (ETDEWEB)

    Melaina, M. W.; Antonia, O.; Penev, M.

    2013-03-01

    The United States has 11 distinct natural gas pipeline corridors: five originate in the Southwest, four deliver natural gas from Canada, and two extend from the Rocky Mountain region. This study assesses the potential to deliver hydrogen through the existing natural gas pipeline network as a hydrogen and natural gas mixture to defray the cost of building dedicated hydrogen pipelines.

  3. Being "Dumped" from Facebook: Negotiating Issues of Boundaries and Identity in an Online Social Networking Space

    Science.gov (United States)

    Best, Gill; Hajzler, Darko; Pancini, Geri; Tout, Dan

    2011-01-01

    While Facebook, the world's most popular Social Networking Site (SNS), has been warmly welcomed by many commentators and practitioners within the educational community, its effects, impacts and implications arguably remain insufficiently understood. Through the provision of an anecdotal and experiential account of the authors' attempt to introduce…

  4. Social networking profiles and professionalism issues in residency applicants: an original study-cohort study.

    Science.gov (United States)

    Ponce, Brent A; Determann, Jason R; Boohaker, Hikel A; Sheppard, Evan; McGwin, Gerald; Theiss, Steven

    2013-01-01

    To determine the frequency of social networking, the degree of information publicly disclosed, and whether unprofessional content was identified in applicants from the 2010 Residency Match. Medical professionalism is an essential competency for physicians to learn, and information found on social networking sites may be hazardous to the doctor-patient relationship and an institution's public perception. No study has analyzed the social network content of applicants applying for residency. Online review of social networking Facebook profiles of graduating medical students applying for a residency in orthopedic surgery. Evidence of unprofessional content was based upon Accreditation Council for Graduate Medical Education guidelines. Additional recorded applicant data included as follows: age, United States Medical Licensing Examination part I score, and residency composite score. Relationship between professionalism score and recorded data points was evaluated using an analysis of variance. Nearly half of all applicants, 46% (200/431), had a Facebook profile. The majority of profiles (85%) did not restrict online access to their profile. Unprofessional content was identified in 16% of resident applicant profiles. Variables associated with lower professionalism scores included unmarried relationship status and lower residency composite scores. It is critical for healthcare professionals to recognize both the benefits and risks present with electronic communication and to vigorously protect the content of material allowed to be publically accessed through the Internet. Copyright © 2013 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  5. Genetic basis for developmental homeostasis of germline stem cell niche number: a network of Tramtrack-Group nuclear BTB factors.

    Directory of Open Access Journals (Sweden)

    Mathieu Bartoletti

    Full Text Available The potential to produce new cells during adult life depends on the number of stem cell niches and the capacity of stem cells to divide, and is therefore under the control of programs ensuring developmental homeostasis. However, it remains generally unknown how the number of stem cell niches is controlled. In the insect ovary, each germline stem cell (GSC niche is embedded in a functional unit called an ovariole. The number of ovarioles, and thus the number of GSC niches, varies widely among species. In Drosophila, morphogenesis of ovarioles starts in larvae with the formation of terminal filaments (TFs, each made of 8-10 cells that pile up and sort in stacks. TFs constitute organizers of individual germline stem cell niches during larval and early pupal development. In the Drosophila melanogaster subgroup, the number of ovarioles varies interspecifically from 8 to 20. Here we show that pipsqueak, Trithorax-like, batman and the bric-à-brac (bab locus, all encoding nuclear BTB/POZ factors of the Tramtrack Group, are involved in limiting the number of ovarioles in D. melanogaster. At least two different processes are differentially perturbed by reducing the function of these genes. We found that when the bab dose is reduced, sorting of TF cells into TFs was affected such that each TF contains fewer cells and more TFs are formed. In contrast, psq mutants exhibited a greater number of TF cells per ovary, with a normal number of cells per TF, thereby leading to formation of more TFs per ovary than in the wild type. Our results indicate that two parallel genetic pathways under the control of a network of nuclear BTB factors are combined in order to negatively control the number of germline stem cell niches.

  6. Genetic basis for developmental homeostasis of germline stem cell niche number: a network of Tramtrack-Group nuclear BTB factors.

    Science.gov (United States)

    Bartoletti, Mathieu; Rubin, Thomas; Chalvet, Fabienne; Netter, Sophie; Dos Santos, Nicolas; Poisot, Emilie; Paces-Fessy, Mélanie; Cumenal, Delphine; Peronnet, Frédérique; Pret, Anne-Marie; Théodore, Laurent

    2012-01-01

    The potential to produce new cells during adult life depends on the number of stem cell niches and the capacity of stem cells to divide, and is therefore under the control of programs ensuring developmental homeostasis. However, it remains generally unknown how the number of stem cell niches is controlled. In the insect ovary, each germline stem cell (GSC) niche is embedded in a functional unit called an ovariole. The number of ovarioles, and thus the number of GSC niches, varies widely among species. In Drosophila, morphogenesis of ovarioles starts in larvae with the formation of terminal filaments (TFs), each made of 8-10 cells that pile up and sort in stacks. TFs constitute organizers of individual germline stem cell niches during larval and early pupal development. In the Drosophila melanogaster subgroup, the number of ovarioles varies interspecifically from 8 to 20. Here we show that pipsqueak, Trithorax-like, batman and the bric-à-brac (bab) locus, all encoding nuclear BTB/POZ factors of the Tramtrack Group, are involved in limiting the number of ovarioles in D. melanogaster. At least two different processes are differentially perturbed by reducing the function of these genes. We found that when the bab dose is reduced, sorting of TF cells into TFs was affected such that each TF contains fewer cells and more TFs are formed. In contrast, psq mutants exhibited a greater number of TF cells per ovary, with a normal number of cells per TF, thereby leading to formation of more TFs per ovary than in the wild type. Our results indicate that two parallel genetic pathways under the control of a network of nuclear BTB factors are combined in order to negatively control the number of germline stem cell niches.

  7. Critical hydraulic gradient for nonlinear flow through rock fracture networks: The roles of aperture, surface roughness, and number of intersections

    Science.gov (United States)

    Liu, Richeng; Li, Bo; Jiang, Yujing

    2016-02-01

    Transition of fluid flow from the linear to the nonlinear regime has been confirmed in single rock fractures when the Reynolds number (Re) exceeds some critical values, yet the criterion for such a transition in discrete fracture networks (DFNs) has received little attention. This study conducted flow tests on crossed fracture models with a single intersection and performed numerical simulations on fluid flow through DFNs of various geometric characteristics. The roles of aperture, surface roughness, and number of intersections of fractures on the variation of the critical hydraulic gradient (Jc) for the onset of nonlinear flow through DFNs were systematically investigated. The results showed that the relationship between hydraulic gradient (J) and flow rate can be well quantified by Forchheimer's law; when J drops below Jc, it reduces to the widely used cubic law, by diminishing the nonlinear term. Larger apertures, rougher fracture surfaces, and a greater number of intersections in a DFN would result in the onset of nonlinear flow at a lower Jc. Mathematical expressions of Jc and the coefficients involved in Forchheimer's law were developed based on multi-variable regressions of simulation results, which can help to choose proper governing equations when solving problems associated with fluid flow in fracture networks.

  8. Assessing Argumentative Representation with Bayesian Network Models in Debatable Social Issues

    Science.gov (United States)

    Zhang, Zhidong; Lu, Jingyan

    2014-01-01

    This study seeks to obtain argumentation models, which represent argumentative processes and an assessment structure in secondary school debatable issues in the social sciences. The argumentation model was developed based on mixed methods, a combination of both theory-driven and data-driven methods. The coding system provided a combing point by…

  9. Prediction of Currency Volume Issued in Taiwan Using a Hybrid Artificial Neural Network and Multiple Regression Approach

    Directory of Open Access Journals (Sweden)

    Yuehjen E. Shao

    2013-01-01

    Full Text Available Because the volume of currency issued by a country always affects its interest rate, price index, income levels, and many other important macroeconomic variables, the prediction of currency volume issued has attracted considerable attention in recent years. In contrast to the typical single-stage forecast model, this study proposes a hybrid forecasting approach to predict the volume of currency issued in Taiwan. The proposed hybrid models consist of artificial neural network (ANN and multiple regression (MR components. The MR component of the hybrid models is established for a selection of fewer explanatory variables, wherein the selected variables are of higher importance. The ANN component is then designed to generate forecasts based on those important explanatory variables. Subsequently, the model is used to analyze a real dataset of Taiwan's currency from 1996 to 2011 and twenty associated explanatory variables. The prediction results reveal that the proposed hybrid scheme exhibits superior forecasting performance for predicting the volume of currency issued in Taiwan.

  10. Passing Corrupt Data Across Network Layers: An Overview of Recent Developments and Issues

    Directory of Open Access Journals (Sweden)

    Michael Welzl

    2005-02-01

    Full Text Available Recent Internet developments seem to make a point for passing corrupt data from the link to the network layer and above instead of ensuring data integrity with a checksum and ARQ. We give an overview of these efforts (the UDP Lite and DCCP protocols and explain which circumstances would justify delivery of erroneous data; clearly, the missing piece in the puzzle is efficient and meaningful interlayer communication.

  11. PUFKEY: A High-Security and High-Throughput Hardware True Random Number Generator for Sensor Networks

    Directory of Open Access Journals (Sweden)

    Dongfang Li

    2015-10-01

    Full Text Available Random number generators (RNG play an important role in many sensor network systems and applications, such as those requiring secure and robust communications. In this paper, we develop a high-security and high-throughput hardware true random number generator, called PUFKEY, which consists of two kinds of physical unclonable function (PUF elements. Combined with a conditioning algorithm, true random seeds are extracted from the noise on the start-up pattern of SRAM memories. These true random seeds contain full entropy. Then, the true random seeds are used as the input for a non-deterministic hardware RNG to generate a stream of true random bits with a throughput as high as 803 Mbps. The experimental results show that the bitstream generated by the proposed PUFKEY can pass all standard national institute of standards and technology (NIST randomness tests and is resilient to a wide range of security attacks.

  12. PUFKEY: a high-security and high-throughput hardware true random number generator for sensor networks.

    Science.gov (United States)

    Li, Dongfang; Lu, Zhaojun; Zou, Xuecheng; Liu, Zhenglin

    2015-10-16

    Random number generators (RNG) play an important role in many sensor network systems and applications, such as those requiring secure and robust communications. In this paper, we develop a high-security and high-throughput hardware true random number generator, called PUFKEY, which consists of two kinds of physical unclonable function (PUF) elements. Combined with a conditioning algorithm, true random seeds are extracted from the noise on the start-up pattern of SRAM memories. These true random seeds contain full entropy. Then, the true random seeds are used as the input for a non-deterministic hardware RNG to generate a stream of true random bits with a throughput as high as 803 Mbps. The experimental results show that the bitstream generated by the proposed PUFKEY can pass all standard national institute of standards and technology (NIST) randomness tests and is resilient to a wide range of security attacks.

  13. Management of Power Quality Issues in Low Voltage Networks using Electric Vehicles: Experimental Validation

    DEFF Research Database (Denmark)

    Martinenas, Sergejus; Knezovic, Katarina; Marinelli, Mattia

    2017-01-01

    the existing and future power quality problems. One of the main aspects of the power quality relates to voltage quality. The aim of this work is to experimentally analyse whether series-produced EVs, adhering to contemporary standard and without relying on any V2G capability, can mitigate line voltage drops...... in improving the power quality of a highly unbalanced grid......As Electric Vehicles (EVs) are becoming more wide spread, their high power consumption presents challenges for the residential low voltage networks, especially when connected to long feeders with unevenly distributed loads. However, if intelligently integrated, EVs can also partially solve...

  14. Dynamic spectrum access in wireless ad hoc networks: issues and possible solutions

    Science.gov (United States)

    Zhang, Zhensheng; Soni, Tarun

    2010-04-01

    In this paper, we present a brief overview on the recent development of the dynamical spectrum access (DSA) techniques, focusing on the following areas: characteristics of the available bandwidth of the primary users, sensing technologies and sensing intervals to detect white spaces, spectrum allocation and management, reliability of the secondary user, tradeoff between spectrum/performance gain versus additional overhead used in implementing DSA, and cross layer optimization in spectrum sharing. Some of tradeoff studies are presented in terms of price of anarchy, which is defined as the price that a decentralized system should pay for not being coordinated. We will also discuss some of the open issues in deploying DSA.

  15. Using network screening methods to determine locations with specific safety issues: A design consistency case study.

    Science.gov (United States)

    Butsick, Andrew J; Wood, Jonathan S; Jovanis, Paul P

    2017-09-01

    The Highway Safety Manual provides multiple methods that can be used to identify sites with promise (SWiPs) for safety improvement. However, most of these methods cannot be used to identify sites with specific problems. Furthermore, given that infrastructure funding is often specified for use related to specific problems/programs, a method for identifying SWiPs related to those programs would be very useful. This research establishes a method for Identifying SWiPs with specific issues. This is accomplished using two safety performance functions (SPFs). This method is applied to identifying SWiPs with geometric design consistency issues. Mixed effects negative binomial regression was used to develop two SPFs using 5 years of crash data and over 8754km of two-lane rural roadway. The first SPF contained typical roadway elements while the second contained additional geometric design consistency parameters. After empirical Bayes adjustments, sites with promise (SWiPs) were identified. The disparity between SWiPs identified by the two SPFs was evident; 40 unique sites were identified by each model out of the top 220 segments. By comparing sites across the two models, candidate road segments can be identified where a lack design consistency may be contributing to an increase in expected crashes. Practitioners can use this method to more effectively identify roadway segments suffering from reduced safety performance due to geometric design inconsistency, with detailed engineering studies of identified sites required to confirm the initial assessment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Some issues related to simulation of the tracking and communications computer network

    Science.gov (United States)

    Lacovara, Robert C.

    1989-01-01

    The Communications Performance and Integration branch of the Tracking and Communications Division has an ongoing involvement in the simulation of its flight hardware for Space Station Freedom. Specifically, the communication process between central processor(s) and orbital replaceable units (ORU's) is simulated with varying degrees of fidelity. The results of investigations into three aspects of this simulation effort are given. The most general area involves the use of computer assisted software engineering (CASE) tools for this particular simulation. The second area of interest is simulation methods for systems of mixed hardware and software. The final area investigated is the application of simulation methods to one of the proposed computer network protocols for space station, specifically IEEE 802.4.

  17. CULTURAL ISSUES OF SOCIAL NETWORKS, THEIR PRINCIPLES AND VALUES IN SOCIAL INCLUSION

    Directory of Open Access Journals (Sweden)

    Alessandro Marco Rosini

    2015-09-01

    Full Text Available This article aims to show the importance of a samba school for the local community (in relation to social inclusion and redemption of human values, reflect on the application of this learning created at community to a (organization and discuss the role of people in organizational and cultural strengthening in a social networking environment. It also shows how the use of information technology and communication (ITC can contribute to the evolution of educational scenario of those communities. The scientific method for this is case study, using Delphi technique, where the main community stakeholders are interviewed. Care, respect and consideration for the people who are part of the community are important factors in these social communities. The learning generated by the community and their leaders’ effort are determining for them. ITC can help this learning.

  18. Insights and issues with simulating terrestrial DOC loading of Arctic river networks

    Science.gov (United States)

    Kicklighter, David W.; Hayes, Daniel J.; McClelland, James W.; Peterson, Bruce J.; McGuire, A. David; Melillo, Jerry M.

    2013-01-01

    Terrestrial carbon dynamics influence the contribution of dissolved organic carbon (DOC) to river networks in addition to hydrology. In this study, we use a biogeochemical process model to simulate the lateral transfer of DOC from land to the Arctic Ocean via riverine transport. We estimate that, over the 20th century, the pan-Arctic watershed has contributed, on average, 32 Tg C/yr of DOC to river networks emptying into the Arctic Ocean with most of the DOC coming from the extensive area of boreal deciduous needle-leaved forests and forested wetlands in Eurasian watersheds. We also estimate that the rate of terrestrial DOC loading has been increasing by 0.037 Tg C/yr2 over the 20th century primarily as a result of climate-induced increases in water yield. These increases have been offset by decreases in terrestrial DOC loading caused by wildfires. Other environmental factors (CO2 fertilization, ozone pollution, atmospheric nitrogen deposition, timber harvest, agriculture) are estimated to have relatively small effects on terrestrial DOC loading to Arctic rivers. The effects of the various environmental factors on terrestrial carbon dynamics have both offset and enhanced concurrent effects on hydrology to influence terrestrial DOC loading and may be changing the relative importance of terrestrial carbon dynamics on this carbon flux. Improvements in simulating terrestrial DOC loading to pan-Arctic rivers in the future will require better information on the production and consumption of DOC within the soil profile, the transfer of DOC from land to headwater streams, the spatial distribution of precipitation and its temporal trends, carbon dynamics of larch-dominated ecosystems in eastern Siberia, and the role of industrial organic effluents on carbon budgets of rivers in western Russia.

  19. Normal impingement loads due to small air jets issuing from a base plate and reflecting off a platform for various jet Mach numbers, separation distances, and ambient pressures

    Science.gov (United States)

    Hoffman, S.

    1972-01-01

    An investigation was conducted in a 12.5-meter-diameter vacuum sphere to determine the impingement loads due to air jets issuing from and perpendicular to a circular base and reflecting off a square platform, that is, a simulation of rendezvous maneuvering, docking, launch, impact dampers etc. The nozzles had exit Mach numbers of 1, 3, 5, and 7. The ambient pressures were 0.0006, 5, 225, and 760 torr. Under near-field separation distances and at 0.0006 torr, reflections were significant; and ratios of the impingement force to thrust on both plates in the biplane arrangement varied from about 750 for exit Mach number 1 to 120 for exit Mach number 7. The far-field force ratios were near unity for the platform and zero for the base and indicated few, if any, reflections. Some reversals and rapid changes in loads were obtained at transition distances between the near and far fields. In general, increasing the exit Mach number or ambient pressure reduced the impingement loads.

  20. Advancements of Data Anomaly Detection Research in Wireless Sensor Networks: A Survey and Open Issues

    Science.gov (United States)

    Rassam, Murad A.; Zainal, Anazida; Maarof, Mohd Aizaini

    2013-01-01

    Wireless Sensor Networks (WSNs) are important and necessary platforms for the future as the concept “Internet of Things” has emerged lately. They are used for monitoring, tracking, or controlling of many applications in industry, health care, habitat, and military. However, the quality of data collected by sensor nodes is affected by anomalies that occur due to various reasons, such as node failures, reading errors, unusual events, and malicious attacks. Therefore, anomaly detection is a necessary process to ensure the quality of sensor data before it is utilized for making decisions. In this review, we present the challenges of anomaly detection in WSNs and state the requirements to design efficient and effective anomaly detection models. We then review the latest advancements of data anomaly detection research in WSNs and classify current detection approaches in five main classes based on the detection methods used to design these approaches. Varieties of the state-of-the-art models for each class are covered and their limitations are highlighted to provide ideas for potential future works. Furthermore, the reviewed approaches are compared and evaluated based on how well they meet the stated requirements. Finally, the general limitations of current approaches are mentioned and further research opportunities are suggested and discussed. PMID:23966182

  1. Advancements of Data Anomaly Detection Research in Wireless Sensor Networks: A Survey and Open Issues

    Directory of Open Access Journals (Sweden)

    Mohd Aizaini Maarof

    2013-08-01

    Full Text Available Wireless Sensor Networks (WSNs are important and necessary platforms for the future as the concept “Internet of Things” has emerged lately. They are used for monitoring, tracking, or controlling of many applications in industry, health care, habitat, and military. However, the quality of data collected by sensor nodes is affected by anomalies that occur due to various reasons, such as node failures, reading errors, unusual events, and malicious attacks. Therefore, anomaly detection is a necessary process to ensure the quality of sensor data before it is utilized for making decisions. In this review, we present the challenges of anomaly detection in WSNs and state the requirements to design efficient and effective anomaly detection models. We then review the latest advancements of data anomaly detection research in WSNs and classify current detection approaches in five main classes based on the detection methods used to design these approaches. Varieties of the state-of-the-art models for each class are covered and their limitations are highlighted to provide ideas for potential future works. Furthermore, the reviewed approaches are compared and evaluated based on how well they meet the stated requirements. Finally, the general limitations of current approaches are mentioned and further research opportunities are suggested and discussed.

  2. Advancements of data anomaly detection research in wireless sensor networks: a survey and open issues.

    Science.gov (United States)

    Rassam, Murad A; Zainal, Anazida; Maarof, Mohd Aizaini

    2013-08-07

    Wireless Sensor Networks (WSNs) are important and necessary platforms for the future as the concept "Internet of Things" has emerged lately. They are used for monitoring, tracking, or controlling of many applications in industry, health care, habitat, and military. However, the quality of data collected by sensor nodes is affected by anomalies that occur due to various reasons, such as node failures, reading errors, unusual events, and malicious attacks. Therefore, anomaly detection is a necessary process to ensure the quality of sensor data before it is utilized for making decisions. In this review, we present the challenges of anomaly detection in WSNs and state the requirements to design efficient and effective anomaly detection models. We then review the latest advancements of data anomaly detection research in WSNs and classify current detection approaches in five main classes based on the detection methods used to design these approaches. Varieties of the state-of-the-art models for each class are covered and their limitations are highlighted to provide ideas for potential future works. Furthermore, the reviewed approaches are compared and evaluated based on how well they meet the stated requirements. Finally, the general limitations of current approaches are mentioned and further research opportunities are suggested and discussed.

  3. Methodological issues in the design and analyses of neonatal research studies: Experience of the NICHD Neonatal Research Network.

    Science.gov (United States)

    Das, Abhik; Tyson, Jon; Pedroza, Claudia; Schmidt, Barbara; Gantz, Marie; Wallace, Dennis; Truog, William E; Higgins, Rosemary D

    2016-10-01

    Impressive advances in neonatology have occurred over the 30 years of life of The Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network (NRN). However, substantial room for improvement remains in investigating and further developing the evidence base for improving outcomes among the extremely premature. We discuss some of the specific methodological challenges in the statistical design and analysis of randomized trials and observational studies in this population. Challenges faced by the NRN include designing trials for unusual or rare outcomes, accounting for and explaining center variations, identifying other subgroup differences, and balancing safety and efficacy concerns between short-term hospital outcomes and longer-term neurodevelopmental outcomes. In conclusion, the constellation of unique patient characteristics in neonates calls for broad understanding and careful consideration of the issues identified in this article for conducting rigorous studies in this population. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. The Issue of the Number of Priests in the USA and the UK in the Second Half of the 20th Century

    Directory of Open Access Journals (Sweden)

    Emelyanov Nikolai, archpriest

    2016-05-01

    Full Text Available The author analyzes different approaches towards evaluating the number of Roman Catholic and Protestant priests in the USA and in the Church of England. He considers the three narratives in the framework of which the problem under investigation has been posed: the “demography of the priesthood”, the “priest labor market” and the “territorial distribution of the clergy”. Schoenherr’s model (1993 is built upon the “organizational demography” approaches as well as upon the theory of rational choice and asks the question about what is going to happen to the population of the Catholic priests in the US in the nearest twenty years. Demographic tendencies for a long time prevalent lead to substantial changes in the overall structure of the population. The singling out of such tendencies and the determining factors behind them is extremely important for organizational planning. American Protestant denominations have toward the end of the 20th century found themselves in the situation of redundancy of priests. The research authored by Carroll (1980 is based upon the logic of the labor market and considers the interrelation between three values: number of the members of a Church; number of priests; number of churches. These values reflect the offer and demand dynamics in the priest labor market. The researcher calculates the number of payments necessary to ensure the receiving of constant salary by a priest. He analyzes the factors determining the offer and demand interrelation in the labor market. The research poses the question about the functions exercised by a priest. Still another tendency in the research on the number of priests exists in the Church of England; this tendency is connected with the issue of optimum territorial distribution of priests. The key research work here is the so-called “Paul report” (1964 which establishes the dependence of involvement in religious practices on the three following factors: number of

  5. Artificial Neural Network to Modeling Zero-inflated Count Data: Application to Predicting Number of Return to Blood Donation.

    Science.gov (United States)

    Haghani, Shima; Sedehi, Morteza; Kheiri, Soleiman

    2017-09-02

    Traditional statistical models often are based on certain presuppositions and limitations that may not presence in actual data and lead to turbulence in estimation or prediction. In these situations, artificial neural networks (ANNs) could be suitable alternative rather than classical statistical methods.  A prospective cohort study. The study was conducted in Shahrekord Blood Transfusion Center, Shahrekord, central Iran, on blood donors from 2008-2009. The accuracy of the proposed model to prediction of number of return to blood donations was compared with classical statistical models. A number of 864 donors who had a first-time successful donation were followed for five years. Number of return for blood donation was considered as response variable. Poisson regression (PR), negative binomial regression (NBR), zero-inflated Poisson regression (ZIPR) and zero-inflated negative binomial regression (ZINBR) as well as ANN model were fitted to data. MSE criterion was used to compare models. To fitting the models, STATISTICA 10 and, R 3.2.2 was used RESULTS: The MSE of PR, NBR, ZIPR, ZINBR and ANN models was obtained 2.71, 1.01, 1.54, 0.094 and 0.056 for the training and 4.05, 9.89, 3.99, 2.53 and 0.27 for the test data, respectively. The ANN model had the least MSE in both training, and test data set and has a better performance than classic models. ANN could be a suitable alternative for modeling such data because of fewer restrictions.

  6. Comparing large number of metaheuristics for artificial neural networks training to predict water temperature in a natural river

    Science.gov (United States)

    Piotrowski, Adam P.; Osuch, Marzena; Napiorkowski, Maciej J.; Rowinski, Pawel M.; Napiorkowski, Jaroslaw J.

    2014-03-01

    Nature-inspired metaheuristics found various applications in different fields of science, including the problem of artificial neural networks (ANN) training. However, very versatile opinions regarding the performance of metaheuristics applied to ANN training may be found in the literature. Both nature-inspired metaheuristics and ANNs are widely applied to various geophysical and environmental problems. Among them the water temperature forecasting in a natural river, especially in colder climate zones where the seasonality plays important role, is of great importance, as water temperature has strong impact on aquatic life and chemistry. As the impact of possible future climate change on water temperature is not trivial, models are needed to allow projection of streamwater temperature based on simple hydro-meteorological variables. In this paper the detailed comparison of the performance of nature-inspired optimization methods and Levenberg-Marquardt (LM) algorithm in ANNs training is performed, based on the case study of water temperature forecasting in a natural stream, namely Biala Tarnowska river in southern Poland. Over 50 variants of 22 various metaheuristics, including a large number of Differential Evolution, as well as some Particle Swarm Optimization, Evolution Strategies, multialgorithms and Direct Search methods are compared with LM algorithm on ANN training for the described case study. The impact of population size and some control parameters of particular metaheuristics on the ANN training performance are verified. It is found that despite widely claimed large improvement in nature-inspired methods during last years, the vast majority of them are still outperformed by LM algorithm on the selected problem. The only methods that, based on this case study, seem competitive to LM algorithm in terms of the final performance (but not speed) are Differential Evolution algorithms that benefit from the concept of Global and Local neighborhood-based mutation

  7. A prototype implementation of a network-level intrusion detection system. Technical report number CS91-11

    Energy Technology Data Exchange (ETDEWEB)

    Heady, R.; Luger, G.F.; Maccabe, A.B.; Servilla, M.; Sturtevant, J. [New Mexico Univ., Albuquerque, NM (United States). Dept. of Computer Science

    1991-05-15

    This paper presents the implementation of a prototype network level intrusion detection system. The prototype system monitors base level information in network packets (source, destination, packet size, time, and network protocol), learning the normal patterns and announcing anomalies as they occur. The goal of this research is to determine the applicability of current intrusion detection technology to the detection of network level intrusions. In particular, the authors are investigating the possibility of using this technology to detect and react to worm programs.

  8. Genome-wide copy number variation study associates metabotropic glutamate receptor gene networks with attention deficit hyperactivity disorder

    Science.gov (United States)

    Elia, Josephine; Glessner, Joseph T; Wang, Kai; Takahashi, Nagahide; Shtir, Corina J; Hadley, Dexter; Sleiman, Patrick M A; Zhang, Haitao; Kim, Cecilia E; Robison, Reid; Lyon, Gholson J; Flory, James H; Bradfield, Jonathan P; Imielinski, Marcin; Hou, Cuiping; Frackelton, Edward C; Chiavacci, Rosetta M; Sakurai, Takeshi; Rabin, Cara; Middleton, Frank A; Thomas, Kelly A; Garris, Maria; Mentch, Frank; Freitag, Christine M; Steinhausen, Hans-Christoph; Todorov, Alexandre A; Reif, Andreas; Rothenberger, Aribert; Franke, Barbara; Mick, Eric O; Roeyers, Herbert; Buitelaar, Jan; Lesch, Klaus-Peter; Banaschewski, Tobias; Ebstein, Richard P; Mulas, Fernando; Oades, Robert D; Sergeant, Joseph; Sonuga-Barke, Edmund; Renner, Tobias J; Romanos, Marcel; Romanos, Jasmin; Warnke, Andreas; Walitza, Susanne; Meyer, Jobst; Pálmason, Haukur; Seitz, Christiane; Loo, Sandra K; Smalley, Susan L; Biederman, Joseph; Kent, Lindsey; Asherson, Philip; Anney, Richard J L; Gaynor, J William; Shaw, Philip; Devoto, Marcella; White, Peter S; Grant, Struan F A; Buxbaum, Joseph D; Rapoport, Judith L; Williams, Nigel M; Nelson, Stanley F; Faraone, Stephen V; Hakonarson, Hakon

    2014-01-01

    Attention deficit hyperactivity disorder (ADHD) is a common, heritable neuropsychiatric disorder of unknown etiology. We performed a whole-genome copy number variation (CNV) study on 1,013 cases with ADHD and 4,105 healthy children of European ancestry using 550,000 SNPs. We evaluated statistically significant findings in multiple independent cohorts, with a total of 2,493 cases with ADHD and 9,222 controls of European ancestry, using matched platforms. CNVs affecting metabotropic glutamate receptor genes were enriched across all cohorts (P = 2.1 × 10−9). We saw GRM5 (encoding glutamate receptor, metabotropic 5) deletions in ten cases and one control (P = 1.36 × 10−6). We saw GRM7 deletions in six cases, and we saw GRM8 deletions in eight cases and no controls. GRM1 was duplicated in eight cases. We experimentally validated the observed variants using quantitative RT-PCR. A gene network analysis showed that genes interacting with the genes in the GRM family are enriched for CNVs in ~10% of the cases (P = 4.38 × 10−10) after correction for occurrence in the controls. We identified rare recurrent CNVs affecting glutamatergic neurotransmission genes that were overrepresented in multiple ADHD cohorts. PMID:22138692

  9. Analysis of the Network of Protected Areas in China Based on a Geographic Perspective: Current Status, Issues and Integration

    Directory of Open Access Journals (Sweden)

    Mengtian Cao

    2015-11-01

    Full Text Available With the continued growth of protected areas (PAs in China in terms of the number, coverage and varieties of protected objects, how to efficiently manage the protected areas to ensure both resource protection and environmental protection has become a crucial research question. By applying a geographic perspective in an analysis of the development and evolution of protected areas in China, this paper presents the results of an analysis focused on the status and the types of current approaches to the management of natural protected areas to reveal the problems that exist in their management and to further explore an integration strategy for the protected area network. It proposes that the future management of protected areas should prioritize their legal status, the sustainable livelihood of individuals living in close proximity to them, and the establishment of a unified database to achieve grid and information management of the protected areas.

  10. Analysis of the impact of connecting a larger number of small hydroelectric power plants to the short-circuit currents values and relay protection system of distribution network

    Directory of Open Access Journals (Sweden)

    Sučević Nikola

    2017-01-01

    Full Text Available In this paper the influence of a large number of small hydro power plants on the short-circuit currents is analysed, as well as the operation of the relay protection system within the real distribution network in Serbia. The necessary modification of the existing protection functions, as well as the implementation of the new proposed protection functions, are presented and discussed. Network modeling and analysis are performed using the program tool DIgSILENT PowerFactory.

  11. Body Area Networks

    Directory of Open Access Journals (Sweden)

    G. Prabhakara Reddy

    2013-01-01

    Full Text Available Recent technological advances in integrated circuits, wireless networks, and physiological sensing have enabled miniature, lightweight, low power, intelligent monitoring devices to be integrated into a Body Area Network (BAN. This new type of technology hold much promise for future patient health monitoring. BANs promise inexpensive, unobtrusive, and unsupervised ambulatory monitoring during normal daily activities for long periods of time. However, in order for BANs to become ubiquitous and affordable, a number of challenging issues must be resolved, such as integration, standardisation, system design, customisation, security and privacy, and social issues. This paper presents an overview of many of these issues and indeed the background and rationale of body area networks.

  12. High Lithium Transference Number Electrolytes via Creation of 3-Dimensional, Charged, Nanoporous Networks from Dense Functionalized Nanoparticle Composites

    KAUST Repository

    Schaefer, Jennifer L.

    2013-03-26

    High lithium transference number, tLi+, electrolytes are desired for use in both lithium-ion and lithium metal rechargeable battery technologies. Historically, low tLi+ electrolytes have hindered device performance by allowing ion concentration gradients within the cell, leading to high internal resistances that ultimately limit cell lifetime, charging rates, and energy density. Herein, we report on the synthesis and electrochemical features of electrolytes based on nanoparticle salts designed to provide high tLi+. The salts are created by cofunctionalization of metal oxide nanoparticles with neutral organic ligands and tethered lithium salts. When dispersed in a conducting fluid such as tetraglyme, they spontaneously form a charged, nanoporous network of particles at moderate nanoparticle loadings. Modification of the tethered anion chemistry from -SO3 - to -SO3BF3 - is shown to enhance ionic conductivity of the electrolytes by facilitating ion pair dissociation. At a particle volume fraction of 0.15, the electrolyte exists as a self-supported, nanoporous gel with an optimum ionic conductivity of 10 -4 S/cm at room temperature. Galvanostatic polarization measurements on symmetric lithium metal cells containing the electrolyte show that the cell short circuit time, tSC, is inversely proportional to the square of the applied current density tSC ∼ J-2, consistent with previously predicted results for traditional polymer-in-salt electrolytes with low tLi+. Our findings suggest that electrolytes with tLi+ ≈ 1 and good ion-pair dissociation delay lithium dendrite nucleation and may lead to improved lithium plating in rechargeable batteries with metallic lithium anodes. © 2013 American Chemical Society.

  13. Means to facilitate Smart Grid. Issue paper - working group 2; Denmark. Smart Grid Network; Virkemidler til fremme af Smart Grid. Issue paper, arbejdsgruppe 2

    Energy Technology Data Exchange (ETDEWEB)

    Hjortkjaer, A.-G. (DONG Energy, Fredericia (Denmark)); Madsen, Claus (ABB A/S, Skovlunde (Denmark)); Tang, J. (Dansk Fjernvarme, Kolding (Denmark)) (and others)

    2011-07-01

    The Smart Grid Network was established in 2010 by the Danish climate and energy minister tasked with developing recommendations for future actions and initiatives that make it possible to handle up to 50% electricity from wind energy in the power system in 2020. The task of working group 2 of the Smart Grid Network is stated as: ''The group will, building on existing surveys and analyses propose what new tools are needed in the years to 2020 to ensure intelligence in both transmission and distribution systems for the power grid in Denmark. Moreover, how public and private investments can be effectively brought into play. Among the measures envisaged are e.g. tariffs and charges''. The working group 2 identifies four areas that will promote the development of a smart grid. The proposed tools and means are related to: 1) Price signals to customers that reflect the value of consumption flexibility; 2) New economic regulation of network utilities' smart grid activities; 3) Taxes that support an effective electrification; 4) Effective activation of distributed storage and production. (LN)

  14. The Technical Issues Of Traffic Analysis

    Directory of Open Access Journals (Sweden)

    Pavel Vladimirovich Yegorov

    2016-03-01

    Full Text Available The main problem in the analysis of Internet traffic associated with a large number of network applications, complex patterns of communication and a significant amounts of information. The definition of the category of traffic using the analysis of the number of port is irrelevant for P2P applications, streaming data and many other types of network applications. The article describes some of technical issues related to the analysis of Internet traffic.

  15. Articulation points in complex networks

    Science.gov (United States)

    Tian, Liang; Bashan, Amir; Shi, Da-Ning; Liu, Yang-Yu

    2017-01-01

    An articulation point in a network is a node whose removal disconnects the network. Those nodes play key roles in ensuring connectivity of many real-world networks, from infrastructure networks to protein interaction networks and terrorist communication networks. Despite their fundamental importance, a general framework of studying articulation points in complex networks is lacking. Here we develop analytical tools to study key issues pertinent to articulation points, such as the expected number of them and the network vulnerability against their removal, in an arbitrary complex network. We find that a greedy articulation point removal process provides us a different perspective on the organizational principles of complex networks. Moreover, this process results in a rich phase diagram with two fundamentally different types of percolation transitions. Our results shed light on the design of more resilient infrastructure networks and the effective destruction of terrorist communication networks.

  16. Operations of electric taxis to serve advance reservations by trip chaining: Sensitivity analysis on network size, customer demand and number of charging stations

    Directory of Open Access Journals (Sweden)

    Hao Wang

    2016-10-01

    Full Text Available This research investigated the performance of an Electric Taxi (ET fleet that catered solely for customers with advance reservations. In a previously related research, a customized Paired Pickup and Delivery Problem with Time Window and Charging Station (PPDPTWCS had been formulated to solve for the minimum number of taxis that would serve a fixed set of customer demand. The concept behind this fleet optimization was to chain multiple customer trips and trips to Charging Stations (CSs to form a route and assigned to a taxi driver. In this paper the sensitivity of the ET fleet’s operations with respect to network sizes, customer demand densities and number of CSs have been investigated. It also analyzed the market shares of the CSs and the occupancy of a CS over time. The results showed that, (1 the expansion of network size or the increase in customer demand density led to increase in fleet size, number of trips to the CSs and maximum occupancies at the CSs but these performance measures grew at different rates; (2 when the network size and number of CSs were fixed, an increase in customer demand density led to a better utilization of taxis in terms of more customers served per taxi and higher average revenue per taxi; (3 given the same network size and demand density, the ET fleet’s performance was relatively insensitive to the number of CSs; and (4 the usage of individual CS was affected by the number of CS and their locations; and (5 when all the ETs were fully charged at the beginning of the same shift hour, they visited the CSs in bunches when their batteries were about to run out. These findings contribute to a better understanding of the operations of the ET fleet and the CSs. They could be used for making better decisions in the planning of ET operations.

  17. Ground wave emergency network environmental assessment for northwestern Colorado relay node site number RN 8C924CO

    Science.gov (United States)

    1993-02-01

    The Ground Wave Emergency Network (GWEN) is a radio communication system designed to relay emergency messages between strategic military areas in the continental United States. The system is immune to the effects of high-altitude electromagnetic pulse (HEMP) energy surges caused by nuclear bursts in the ionosphere that would disrupt conventional communications equipment such as telephones and shortwave radios. A failure of such equipment would prevent timely communications among top military and civilian leaders and strategic Air Force locations and prevent U.S. assessment and retaliation during an attack. GWEN is an essential part of a defense modernization program to upgrade and improve our nation's communications system, thereby strengthening deterrence. The GWEN system consists of a network of relay nodes, receive-only stations, and input/output stations. Each relay node, such as the one proposed in southern Nevada consists of a guyed radio tower facility similar to those used by commercial AM broadcast transmitters.

  18. Research, development and demonstration. Issue paper - working group 3; Denmark. Smart Grid Network; Forskning, udvikling og demonstration. Issue paper, arbejdsgruppe 3

    Energy Technology Data Exchange (ETDEWEB)

    Balasiu, A. (Siemens A/S, Ballerup (Denmark)); Troi, A. (Danmarks Tekniske Univ.. Risoe Nationallaboratoriet for Baeredygtig Energi, Roskilde (Denmark)); Andersen, Casper (DI Energibranchen, Copenhagen (Denmark)) (and others)

    2011-07-01

    The Smart Grid Network was established in 2010 by the Danish climate and energy minister tasked with developing recommendations for future actions and initiatives that make it possible to handle up to 50% electricity from wind energy in the power system in 2020. The task of working group 3 was defined as: - An overview of the Danish research and development of smart grids and related areas; - Conducting an analysis of the research and development needs required for the introduction of a smart grid in Denmark. Based on this analysis, provide suggestions for new large research and development projects; - Provide recommendations on how the activities are best carried out taking into account innovation, economic growth and jobs. In the analysis it is explained that Denmark so far has a strong position in several elements of RD and D activities. This position will soon be threatened as several European countries have launched ambitious initiatives to strengthen the national position. The working group recommends that Denmark gives priority to Smart Grids as a national action in order to solve the challenge of technically and economically efficient integration of renewable energy. Smart Grid is a catalyst that strengthens a new green growth industry (cleantech) in Denmark. Research and development has an important role to play in this development. A common vision and roadmap must be established for research institutions, energy companies and industries related to research, development and demonstration of Smart Grid, which can maintain and expand Denmark's global leadership position. As part of this, there is a need to strengthen and market research infrastructures, which can turn Denmark into a global hub for smart grid development. There is a current need to strengthen the advanced technical and scientific research in the complexities of the power system, research on market design, user behavior and smart grid interoperability. (LN)

  19. On Delay and Security in Network Coding

    Science.gov (United States)

    Dikaliotis, Theodoros K.

    2013-01-01

    In this thesis, delay and security issues in network coding are considered. First, we study the delay incurred in the transmission of a fixed number of packets through acyclic networks comprised of erasure links. The two transmission schemes studied are routing with hop-by-hop retransmissions, where every node in the network simply stores and…

  20. Chiropractic Health Care: A National Study of Cost of Education, Service Utilization, Number of Practicing Doctors of Chiropractic, and Other Key Policy Issues. Volumes I-II.

    Science.gov (United States)

    von Kuster, Thomas, Jr.

    Results from the first federally sponsored study of the chiropractic health care profession are presented, and a broad range of facts and issues of concern to policy-makers, the profession, and the public are described. The two-year project included three national surveys of: service providers (doctors of chiropractic in practice more than two…

  1. A comparison of strategies for estimation of ultrafine particle number concentrations in urban air pollution monitoring networks.

    Science.gov (United States)

    Reggente, Matteo; Peters, Jan; Theunis, Jan; Van Poppel, Martine; Rademaker, Michael; De Baets, Bernard; Kumar, Prashant

    2015-04-01

    We propose three estimation strategies (local, remote and mixed) for ultrafine particles (UFP) at three sites in an urban air pollution monitoring network. Estimates are obtained through Gaussian process regression based on concentrations of gaseous pollutants (NOx, O3, CO) and UFP. As local strategy, we use local measurements of gaseous pollutants (local covariates) to estimate UFP at the same site. As remote strategy, we use measurements of gaseous pollutants and UFP from two independent sites (remote covariates) to estimate UFP at a third site. As mixed strategy, we use local and remote covariates to estimate UFP. The results suggest: UFP can be estimated with good accuracy based on NOx measurements at the same location; it is possible to estimate UFP at one location based on measurements of NOx or UFP at two remote locations; the addition of remote UFP to local NOx, O3 or CO measurements improves models' performance. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Special Issue on ActorNetwork Theory, Value CoCreation and Design in Open Innovation Environments

    DEFF Research Database (Denmark)

    Tanev, Stoyan; Storni, Cristiano; Stuedahl, Dagny

    2015-01-01

    The present special issue focuses on the application of ANT to the articulation of a cocreative perspective on design in open innovation environments. The Editors invited submissions by authors using ANT to explore and discuss the link between value co-creation, design and innovation and especially...

  3. KALEIDOSCOPE - THE LOOK OF PHYSICAL EDUCATION TEACHERS OF PORTO ALEGRE’S EDUCATION NETWORK FOR ETHNIC RACIAL ISSUES

    Directory of Open Access Journals (Sweden)

    Gabriela Nobre Bins

    2016-09-01

    Full Text Available This article presents the analysis of the responses of  Porto Alegre’s municipal physical education teachers to a questionnaire about racial ethnic issues. Through quantitative and qualitative analysis it presents a profile of what teachers think about this subject.

  4. Product Platform Development in Industrial Networks

    DEFF Research Database (Denmark)

    Karlsson, Christer; Skold, Martin

    2011-01-01

    The article examines the strategic issues involved in the deployment of product platform development in an industrial network. The move entails identifying the types and characteristics of generically different product platform strategies and clarifying strategic motives and differences. Number...

  5. Hyle, The International Journal for the Philosophy of Chemistry, Special Issue on Modeling, Volume 5, Number 1, and Volume 6 (edited by Joachim Schummer)

    Science.gov (United States)

    Earley, Joseph E., Sr.

    2001-04-01

    Many kinds of activity pass through similar developmental phases: a chaotic initial stage, a period of quick increase, then mature consolidation, and ultimate gradual decline. Philosophy of chemistry appears to be in its exciting phase of rapid growth. Conventions and expectations have not yet fully congealed. In this field, at this time (as Ivan prophesied), all is permitted. One take-home message that chemical educators can gather from perusing these issues of Hyle is that both chemists and philosophers can contribute to progress in the emerging field of philosophy of chemistry, if each is willing to do the homework in the other field. Another notable point is that this rapidly developing area deals with interesting and important research problems, many of which are directly related to what gets taught in chemistry courses at all levels.

  6. Tough New Issues Refocus Health Education

    Science.gov (United States)

    Dessoff, Alan

    2011-01-01

    From dating violence to sexting and social networking, districts are struggling to address a number of sensitive and relatively new health education issues that are aggravated by students' increasing access to computers, cell phones and other digital devices. Through new or revised curricula, administrators are attempting to deal with these and…

  7. Rare copy number variants observed in hereditary breast cancer cases disrupt genes in estrogen signaling and TP53 tumor suppression network.

    Directory of Open Access Journals (Sweden)

    Katri Pylkäs

    Full Text Available Breast cancer is the most common cancer in women in developed countries, and the contribution of genetic susceptibility to breast cancer development has been well-recognized. However, a great proportion of these hereditary predisposing factors still remain unidentified. To examine the contribution of rare copy number variants (CNVs in breast cancer predisposition, high-resolution genome-wide scans were performed on genomic DNA of 103 BRCA1, BRCA2, and PALB2 mutation negative familial breast cancer cases and 128 geographically matched healthy female controls; for replication an independent cohort of 75 similarly mutation negative young breast cancer patients was used. All observed rare variants were confirmed by independent methods. The studied breast cancer cases showed a consistent increase in the frequency of rare CNVs when compared to controls. Furthermore, the biological networks of the disrupted genes differed between the two groups. In familial cases the observed mutations disrupted genes, which were significantly overrepresented in cellular functions related to maintenance of genomic integrity, including DNA double-strand break repair (P = 0.0211. Biological network analysis in the two independent breast cancer cohorts showed that the disrupted genes were closely related to estrogen signaling and TP53 centered tumor suppressor network. These results suggest that rare CNVs represent an alternative source of genetic variation influencing hereditary risk for breast cancer.

  8. Rare copy number variants observed in hereditary breast cancer cases disrupt genes in estrogen signaling and TP53 tumor suppression network.

    Science.gov (United States)

    Pylkäs, Katri; Vuorela, Mikko; Otsukka, Meeri; Kallioniemi, Anne; Jukkola-Vuorinen, Arja; Winqvist, Robert

    2012-01-01

    Breast cancer is the most common cancer in women in developed countries, and the contribution of genetic susceptibility to breast cancer development has been well-recognized. However, a great proportion of these hereditary predisposing factors still remain unidentified. To examine the contribution of rare copy number variants (CNVs) in breast cancer predisposition, high-resolution genome-wide scans were performed on genomic DNA of 103 BRCA1, BRCA2, and PALB2 mutation negative familial breast cancer cases and 128 geographically matched healthy female controls; for replication an independent cohort of 75 similarly mutation negative young breast cancer patients was used. All observed rare variants were confirmed by independent methods. The studied breast cancer cases showed a consistent increase in the frequency of rare CNVs when compared to controls. Furthermore, the biological networks of the disrupted genes differed between the two groups. In familial cases the observed mutations disrupted genes, which were significantly overrepresented in cellular functions related to maintenance of genomic integrity, including DNA double-strand break repair (P = 0.0211). Biological network analysis in the two independent breast cancer cohorts showed that the disrupted genes were closely related to estrogen signaling and TP53 centered tumor suppressor network. These results suggest that rare CNVs represent an alternative source of genetic variation influencing hereditary risk for breast cancer.

  9. Security evaluation of Unix networks

    OpenAIRE

    Brown, Thomas L.

    1993-01-01

    Approved for public release, distribution is unlimited. In recent years, computer networks have significantly increased in both complexity and number, and these networks are attractive targets for attack and intrusion. Unix networks being managed by the government and providing access to unclassified sensitive information are particularly vulnerable to attack. Ensuring the security of sensitive information will be one of the single most important management issues in computer/information s...

  10. Establishing a communications-intensive network to resolve artificial intelligence issues within NASA's Space Station Freedom research centers community

    Science.gov (United States)

    Howard, E. Davis, III

    1990-01-01

    MITRE Corporation's, A Review of Space Station Freedom Program Capabilities for the Development and Application of Advanced Automation, cites as a critical issue the following situation, extant at the NASA facilities visited in the course of preparing the review: The major issues noted with regard to design and research facilities deal with cooperative problem solving, technology transfer, and communication between these facilities. While the authors were visiting lab and test beds to collect information, personnel at many of these facilities were interested in any information they could collect on activities at other facilities. A formal means of gathering this information could not be identified by these personnel. While communication between some facilities was taking place or was planned, for technology transfer or coordination of schedules (e.g., for SADP demonstrations), poor communication between these facilities could lead to a lack of technical standards, duplication of effort, poorly defined interfaces, scheduling problems, and increased cost. Formal mechanisms by which effective communication and cooperative problem solving can take place, and information can be disseminated, must be defined. A solution is proposed for the communications aspects of the issues addressed above; and offered at the same time a solution which can prove effective in dealing with some of the problems being encountered with expertise being lost via retirement or defection to the private sector. The proffered recommendations are recognizably cost-effective and tap the rising sector of expert knowledge being produced by the American academic community.

  11. Sensor networks or smart artifacts?:An exploration of organizational issues of an industrial health and safety monitoring system

    OpenAIRE

    Kortuem, Gerd; Alford, David; Ball, Linden; Busby, Jerry; Davies, Nigel; Efstratiou, Christos; Finney, Joe; Iszatt-White, Marian; Kinder, Katharina

    2007-01-01

    Industrial health and safety is an important yet largely unexplored application area of ubiquitous computing. In this paper we investigate the relationship between technology and organization in the context of a concrete industrial health and safety system. The system is designed to reduce the number of incidents of "�vibration white finger"� (VWF) at construction sites and uses wireless sensor nodes for monitoring workers'� exposure to vibrations and testing of compliance with legal health a...

  12. Network security vulnerabilities and personal privacy issues in Healthcare Information Systems: a case study in a private hospital in Turkey.

    Science.gov (United States)

    Namoğlu, Nihan; Ulgen, Yekta

    2013-01-01

    Healthcare industry has become widely dependent on information technology and internet as it moves from paper to electronic records. Healthcare Information System has to provide a high quality service to patients and a productive knowledge share between healthcare staff by means of patient data. With the internet being commonly used across hospitals, healthcare industry got its own share from cyber threats like other industries in the world. The challenge is allowing knowledge transfer to hospital staff while still ensuring compliance with security mandates. Working in collaboration with a private hospital in Turkey; this study aims to reveal the essential elements of a 21st century business continuity plan for hospitals while presenting the security vulnerabilities in the current hospital information systems and personal privacy auditing standards proposed by regulations and laws. We will survey the accreditation criteria in Turkey and counterparts in US and EU. We will also interview with medical staff in the hospital to understand the needs for personal privacy and the technical staff to perceive the technical requirements in terms of network security configuration and deployment. As hospitals are adopting electronic transactions, it should be considered a must to protect these electronic health records in terms of personal privacy aspects.

  13. Making Knowledge from Numbers : The Shale Network as an Honest Broker for Evaluating and Educating about the Impacts of Hydraulic Fracturing in the Marcellus Shale Region

    Science.gov (United States)

    Pollak, J.; Brantley, S.; Williams, J.; Dykhoff, S.; Brazil, L. I.

    2015-12-01

    The Marcellus Shale Network is an NSF-funded project that investigates the impacts of hydraulic fracturing for shale gas development on water resources in and around the state of Pennsylvania. It is a collaborative effort that aims to be an honest broker in the shale gas conversation by involving multiple entities (including universities, government agencies, industry groups, nonprofits, etc.) to collect, analyze, and disseminate data that describe the past and current conditions of water in the Marcellus shale region. A critical component of this project has been to engage multiple types of stakeholders - academia, government agencies, industry, and citizen science groups - in annual workshops to present and discuss how to ensure the integrity of water resources in light of the challenges that natural gas extraction can present. Each workshop has included a hands-on activity that allows participants to access water quality data using the tools provided by the CUAHSI Water Data Center. One of these tools is HydroDesktop, which is an open source GIS application that can be used in formal and informal education settings as a geoscience research tool. In addition to being a GIS, HydroDesktop accesses CUAHSI's large catalog of water data thus enabling students, professional researchers, and citizen scientists to discover data that can expand the understanding of water quality issues in one's local environment and beyond. This presentation will highlight the goals of the Shale Network project and the stakeholders involved in addition to how cyberinfrastructure is being used to create a democratic, data-driven conversation about the relationship between energy production from shale gas and our water resources.

  14. A Novel Design of an Automatic Lighting Control System for a Wireless Sensor Network with Increased Sensor Lifetime and Reduced Sensor Numbers

    Science.gov (United States)

    Mohamaddoust, Reza; Haghighat, Abolfazl Toroghi; Sharif, Mohamad Javad Motahari; Capanni, Niccolo

    2011-01-01

    Wireless sensor networks (WSN) are currently being applied to energy conservation applications such as light control. We propose a design for such a system called a Lighting Automatic Control System (LACS). The LACS system contains a centralized or distributed architecture determined by application requirements and space usage. The system optimizes the calculations and communications for lighting intensity, incorporates user illumination requirements according to their activities and performs adjustments based on external lighting effects in external sensor and external sensor-less architectures. Methods are proposed for reducing the number of sensors required and increasing the lifetime of those used, for considerably reduced energy consumption. Additionally we suggest methods for improving uniformity of illuminance distribution on a workplane’s surface, which improves user satisfaction. Finally simulation results are presented to verify the effectiveness of our design. PMID:22164114

  15. Data linkage capabilities in Australia: practical issues identified by a Population Health Research Network 'Proof of Concept project'.

    Science.gov (United States)

    Mitchell, Rebecca J; Cameron, Cate M; McClure, Rod J; Williamson, Ann M

    2015-08-01

    To describe the practical issues that need to be overcome to conduct national data linkage projects in Australia and propose recommendations to improve efficiency. Review of the processes, documentation and applications required to conduct national data linkage in Australia. The establishment of state and national data linkage centres in Australia has placed Australia at the forefront of research linking health-related administrative data collections. However, improvements are needed to reduce the clerical burden on researchers, simplify the process of obtaining ethics approval, improve data accessibility, and thus improve the efficiency of data linkage research. While a sound state and national data linkage infrastructure is in place, the current complexity, duplication and lack of cohesion undermines any attempts to conduct research involving national record linkage in a timely manner. Data linkage applications and Human Research Ethics Committee approval processes need to be streamlined and duplication removed, in order to reduce the administrative and financial burden on researchers if national data linkage research is to be viable. © 2015 Public Health Association of Australia.

  16. A Continuous 3D-Graphene Network to Overcome Threshold Issues and Contact Resistance in Thermally Conductive Graphene Nanocomposites

    Directory of Open Access Journals (Sweden)

    Federico Conrado

    2017-01-01

    Full Text Available In order to overcome thermal resistance issues in polymeric matrix composites, self-standing graphene aerogels were synthetized and infiltrated with an epoxy resin, in order to create conductive preferential pathways through which heat can be easily transported. These continuous highly thermally conductive 3D-structures show, due to the high interconnection degree of graphene flakes, enhanced transport properties. Two kinds of aerogels were investigated, obtained by hydrothermal synthesis (HS and ice-templated direct freeze synthesis (DFS. Following HS method an isotropic structure is obtained, and following DFS method instead an anisotropic arrangement of graphene flakes results. The density of the structure can be tuned leading to a different amount of graphene inside the final composite. The residual oxygen, known to be detrimental to thermal properties, was removed by thermal treatment before the infiltration process. With 1,25 wt.% of graphene, using HS method, the thermal conductivity of the polymeric resin was increased by 80%, suggesting that this technique is a valid route to improve the thermal performance of graphene-based composites. When preferential orientation of the filler was present (DFS case, thermal conductivity was increased more than 25% with a graphene content of only 0,27 wt.%, demonstrating that oriented structures can further improve the thermal transport efficiency.

  17. The Platte River - High Plains Aquifer (PR-HPA) Long Term Agroecosystem Research (LTAR) Network - Data and Technological Resources to Address Current and Emerging Issues in Agroecosystems.

    Science.gov (United States)

    Okalebo, J. A.; Wienhold, B.; Suyker, A.; Erickson, G.; Hayes, M. J.; Awada, T.

    2015-12-01

    The Platte River - High Plains Aquifer (PR-HPA) is one of 18 established Long Term Agroecosystem Research (LTAR) networks across the US. PR-HPA is a partnership between the Institute of Agriculture and Natural Resources at the University of Nebraska-Lincoln (UNL), the USDA-ARS Agroecosystem Management Research Unit (AMRU) in Lincoln, and the USDA-ARS Environmental Management Research Unit (EMRU) in Clay Center, NE. The PR-HPA network encompasses 27,750 ha of research sites with data going back to the early 1900s. A partial list of on-going research projects include those encompassing long-term manuring and continuous corn (Est. 1912), dryland tillage plots (Est. 1970), soil nutrients and tillage (Est. 1983), biofuel feedstock studies (Est. 2001), and carbon sequestration study (Est. 2000). Affiliated partners include the National Drought Mitigation Center (NDMC) that develops measures to improve preparedness and adaptation to climate variability and drought; the High Plains Regional Climate Center (HPRCC) that coordinates data acquisition from over 170 automated weather stations and around 50 automated soil moisture network across NE and beyond; the AMERIFLUX and NEBFLUX networks that coordinate the water vapor and carbon dioxide flux measurements across NE with emphasis on rainfed and irrigated crop lands; the ARS Greenhouse gas Reduction through Agricultural Carbon Enhancement network (GRACEnet) and the Resilient Economic Agricultural Practices (REAP) project; and the Center for Advanced Land Management Information Technologies (CALMIT) that assists with the use of geospatial technologies for agriculture and natural resource applications. Current emphases are on addressing present-day and emerging issues related to profitability and sustainability of agroecosystems. The poster will highlight some of the ongoing and planned efforts in research pertaining to climate variability and change, water sustainability, and ecological and agronomic challenges associated

  18. A declarative approach to multi-layer path finding based on semantic network descriptions

    NARCIS (Netherlands)

    Xu, L.; Dijkstra, F.; Marchal, D.; Taal, A.; Grosso, P.; de Laat, C.

    2009-01-01

    With the increasing demand for dynamic network connections between multiple research networks, a number of issues on multi-layer hybrid networks need to be addressed, such as network representation, path finding, and path provisioning. This paper focuses on solving the multi-layer path finding

  19. The International Haemovigilance Network Database for the Surveillance of Adverse Reactions and Events in Donors and Recipients of Blood Components: technical issues and results.

    Science.gov (United States)

    Politis, C; Wiersum, J C; Richardson, C; Robillard, P; Jorgensen, J; Renaudier, P; Faber, J-C; Wood, E M

    2016-11-01

    The International Haemovigilance Network's ISTARE is an online database for surveillance of all adverse reactions (ARs) and adverse events (AEs) associated with donation of blood and transfusion of blood components, irrespective of severity or the harm caused. ISTARE aims to unify the collection and sharing of information with a view to harmonizing best practices for haemovigilance systems around the world. Adverse reactionss and adverse events are recorded by blood component, type of reaction, severity and imputability to transfusion, using internationally agreed standard definitions. From 2006 to 2012, 125 national sets of annual aggregated data were received from 25 countries, covering 132.8 million blood components issued. The incidence of all ARs was 77.5 per 100 000 components issued, of which 25% were severe (19.1 per 100 000). Of 349 deaths (0.26 per 100 000), 58% were due to the three ARs related to the respiratory system: transfusion-associated circulatory overload (TACO, 27%), transfusion-associated acute lung injury (TRALI, 19%) and transfusion-associated dyspnoea (TAD, 12%). Cumulatively, 594 477 donor complications were reported (rate 660 per 100 000), of which 2.9% were severe. ISTARE is a well-established surveillance tool offering important contributions to international efforts to maximize transfusion safety. © 2016 International Society of Blood Transfusion.

  20. Scanning number and brightness yields absolute protein concentrations in live cells: a crucial parameter controlling functional bio-molecular interaction networks.

    Science.gov (United States)

    Papini, Christina; Royer, Catherine A

    2018-02-01

    Biological function results from properly timed bio-molecular interactions that transduce external or internal signals, resulting in any number of cellular fates, including triggering of cell-state transitions (division, differentiation, transformation, apoptosis), metabolic homeostasis and adjustment to changing physical or nutritional environments, amongst many more. These bio-molecular interactions can be modulated by chemical modifications of proteins, nucleic acids, lipids and other small molecules. They can result in bio-molecular transport from one cellular compartment to the other and often trigger specific enzyme activities involved in bio-molecular synthesis, modification or degradation. Clearly, a mechanistic understanding of any given high level biological function requires a quantitative characterization of the principal bio-molecular interactions involved and how these may change dynamically. Such information can be obtained using fluctation analysis, in particular scanning number and brightness, and used to build and test mechanistic models of the functional network to define which characteristics are the most important for its regulation.

  1. Energy, transport network and financial issues: PR perspectives for economic development in time of Euro-Med area change

    Directory of Open Access Journals (Sweden)

    Amanda Jane Succi

    2012-02-01

    At first this will involve the policy makers at the central level, like the Ministry of Education and Sciences and the main research actors in the public and in the private sector. The criteria of the geographical and the subjects coverage has been also used in order to be able to present a public institutions of the higher education and research but even the enterprises that act in the research area are mainly focusing to the integration of these two systems which have been working separately for a long period of time and that must become efficient in order to adapt to the conditions of a country that has limited financial resources. This article is intended to provide a comprehensive overview of the scientific research in Albania, focusing in defining the priority areas for the research in social sciences. The information about the higher education and the potential problems that it faces, is based on a big number of research institutions, selected based on their involvement in scientific research in social sciences. This article brings into evidence the fact that in order to establish a stable and effective infrastructure in scientific research in Albania, is important to work in different directions. A successful way to increase the efficasity through the elements of the “innovative system” is by working with organizations that work in specific sectors of the economy, aiming for a possible cooperation in scientific search, for an important social contribution.

  2. Optical Access Networks

    Science.gov (United States)

    Zheng, Jun; Ansari, Nirwan

    2005-06-01

    Call for Papers: Optical Access Networks With the wide deployment of fiber-optic technology over the past two decades, we have witnessed a tremendous growth of bandwidth capacity in the backbone networks of today's telecommunications infrastructure. However, access networks, which cover the "last-mile" areas and serve numerous residential and small business users, have not been scaled up commensurately. The local subscriber lines for telephone and cable television are still using twisted pairs and coaxial cables. Most residential connections to the Internet are still through dial-up modems operating at a low speed on twisted pairs. As the demand for access bandwidth increases with emerging high-bandwidth applications, such as distance learning, high-definition television (HDTV), and video on demand (VoD), the last-mile access networks have become a bandwidth bottleneck in today's telecommunications infrastructure. To ease this bottleneck, it is imperative to provide sufficient bandwidth capacity in the access networks to open the bottleneck and thus present more opportunities for the provisioning of multiservices. Optical access solutions promise huge bandwidth to service providers and low-cost high-bandwidth services to end users and are therefore widely considered the technology of choice for next-generation access networks. To realize the vision of optical access networks, however, many key issues still need to be addressed, such as network architectures, signaling protocols, and implementation standards. The major challenges lie in the fact that an optical solution must be not only robust, scalable, and flexible, but also implemented at a low cost comparable to that of existing access solutions in order to increase the economic viability of many potential high-bandwidth applications. In recent years, optical access networks have been receiving tremendous attention from both academia and industry. A large number of research activities have been carried out or

  3. The Class Number Problem

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 3; Issue 7. The Class Number Problem - An Introduction to Algebraic Number Theory. Rajat Tandon. General Article Volume 3 Issue 7 July 1998 pp 28-37. Fulltext. Click here to view fulltext PDF. Permanent link:

  4. An artificial neural network to safely reduce the number of ambulance ECGs transmitted for physician assessment in a system with prehospital detection of ST elevation myocardial infarction

    Directory of Open Access Journals (Sweden)

    Forberg Jakob L

    2012-02-01

    Full Text Available Abstract Background Pre-hospital electrocardiogram (ECG transmission to an expert for interpretation and triage reduces time to acute percutaneous coronary intervention (PCI in patients with ST elevation Myocardial Infarction (STEMI. In order to detect all STEMI patients, the ECG should be transmitted in all cases of suspected acute cardiac ischemia. The aim of this study was to examine the ability of an artificial neural network (ANN to safely reduce the number of ECGs transmitted by identifying patients without STEMI and patients not needing acute PCI. Methods Five hundred and sixty ambulance ECGs transmitted to the coronary care unit (CCU in routine care were prospectively collected. The ECG interpretation by the ANN was compared with the diagnosis (STEMI or not and the need for an acute PCI (or not as determined from the Swedish coronary angiography and angioplasty register. The CCU physician's real time ECG interpretation (STEMI or not and triage decision (acute PCI or not were registered for comparison. Results The ANN sensitivity, specificity, positive and negative predictive values for STEMI was 95%, 68%, 18% and 99%, respectively, and for a need of acute PCI it was 97%, 68%, 17% and 100%. The area under the ANN's receiver operating characteristics curve for STEMI detection was 0.93 (95% CI 0.89-0.96 and for predicting the need of acute PCI 0.94 (95% CI 0.90-0.97. If ECGs where the ANN did not identify a STEMI or a need of acute PCI were theoretically to be withheld from transmission, the number of ECGs sent to the CCU could have been reduced by 64% without missing any case with STEMI or a need of immediate PCI. Conclusions Our ANN had an excellent ability to predict STEMI and the need of acute PCI in ambulance ECGs, and has a potential to safely reduce the number of ECG transmitted to the CCU by almost two thirds.

  5. Seven Issues Revisited

    DEFF Research Database (Denmark)

    Grønbæk, Kaj; Whitehead, Jim; De Bra, Paul

    2002-01-01

    It has been 15 years since the original presentation by Frank Halasz at Hypertext'87 on seven issues for the next generation of hypertext systems. These issues are: Search and Query Composites Virtual Structures Computation in/over hypertext network Versioning Collaborative Work Extensibility...

  6. MPK-1/ERK regulatory network controls the number of sperm by regulating timing of sperm-oocyte switch in C. elegans germline.

    Science.gov (United States)

    Yoon, Dong Suk; Alfhili, Mohammad A; Friend, Kyle; Lee, Myon-Hee

    2017-09-30

    The precise regulation of germline sexual fate is crucial for animal fertility. In C. elegans, the production of either type of gamete, sperm or oocyte, becomes mutually exclusive beyond the larval stage. Hermaphrodites initially produce sperm and then switch to produce oocytes. This change of fate during germline development is tightly controlled by several regulators. In C. elegans hermaphrodites, FBF-1 and FBF-2 (>95% identical, members of the Pumilio RNA-binding protein family) proteins function redundantly to promote the sperm-oocyte switch. Here, we demonstrate that loss of LIP-1 (dual specificity phosphatase) in fbf-1(ok91) single mutants leads to excess sperm production due to a delayed sperm-oocyte switch. This phenotype was dramatically rescued by depletion of MPK-1 (an ERK homolog). In contrast, loss of LIP-1 in fbf-2(q738) single mutants leads to a premature sperm-oocyte switch and loss of sperm. Notably, fbf-1 fbf-2; lip-1 triple mutants produce excess sperm. These results suggest that the MPK-1/ERK regulatory network, including FBF-1, FBF-2, and LIP-1, controls the number of sperm by regulating the timing of the sperm-oocyte switch in C. elegans. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Using networked technologies to support conferences

    OpenAIRE

    Kelly, B.; Tonkin, E.; Shabajee, P

    2005-01-01

    The increasing availability of WiFi networks in conference venues is an opportunity to provide additional services for conference delegates and to enhance and enrich the learning experience. This paper reviews experiences of use of networked applications in a conference environment and outlines a number of potentially useful technologies. The paper addresses potential concerns over use of networked technologies including dangers of disruption and distraction, legal and copyright issues as wel...

  8. Neutron spectrometry and dosimetry with neural networks and Bonner spheres: a study to reduce the spheres number; Espectrometria y dosimetria neutronica con redes neuronales y esferas Bonner: un estudio para reducir el numero de esferas

    Energy Technology Data Exchange (ETDEWEB)

    Espinoza G, J. G.; Martinez B, M. R.; Leon P, A. A.; Hernandez P, C. F.; Castaneda M, V. H.; Solis S, L. O.; Castaneda M, R.; Ortiz R, J. M.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Av. Ramon Lopez Velarde 801, Col. Centro, 98000 Zacatecas, Zac. (Mexico); Mendez, R. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Laboratorio de Patrones Neutronicos, Av. Complutense 22, 28040 Madrid (Spain); Gallego, E. [Universidad Politecnica de Madrid, Departamento de Ingenieria Nuclear, C. Jose Gutierrez Abascal 2, 28006 Madrid (Spain); De Sousa L, M. A. [Centro de Desenvolvimento da Tecnologia Nuclear / CNEN, Av. Pte. Antonio Carlos 6627, Pampulha, 31270-901 Belo Horizonte, MG (Brazil)

    2016-10-15

    For neutron spectrometry and neutron dosimetry, the Bonner spheres spectrometric system has been the most widely used system, however, the number, size and weight of the spheres composing the system, as well as the need to use a reconstruction code and the long periods of time used to carry out the measurements are some of the disadvantages of this system. For the reconstruction of the spectra, different techniques such as artificial neural networks of reverse propagation have been used. The objective of this work was to reduce the number of Bonner spheres and to use counting speeds in a reverse propagation neural network, optimized by means of the robust design methodology, to reconstruct the neutron spectra. For the design of the neural network we used the neutron spectra of the IAEA and the response matrix of the Bonner spheres with {sup 6}LiI(Eu) detector. The performance of the network was compared; using 7 Bonner spheres against other cases where only 2 and one sphere are used. The network topologies were trained 36 times for each case keeping constant the objective error (1E(-3)), the training algorithm was trains cg and the robust design methodology to determine the best network architectures. With these, the best and worst results were compared. The results obtained using 7 spheres were similar to those with the 5-in sphere, however is still in an information analysis stage. (Author)

  9. Dirac's Large Numbers Hypothesis

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 8; Issue 8. Dirac's Large Numbers Hypothesis. Biman Nath. Article-in-a-Box Volume 8 Issue 8 August 2003 pp 7-7. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/008/08/0007-0007. Author Affiliations.

  10. Littlewood and Number Theory

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 18; Issue 9. Littlewood and Number Theory. M Ram Murty. General Article Volume 18 Issue 9 September 2013 pp 789-798. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/018/09/0789-0798. Keywords.

  11. Optical Access Networks

    Science.gov (United States)

    Zheng, Jun; Ansari, Nirwan

    2005-01-01

    networks have been receiving tremendous attention from both academia and industry. A large number of research activities have been carried out or are now underway this hot area. The purpose of this feature issue is to expose the networking community to the latest research breakthroughs and progresses in the area of optical access networks. h2>Scope of Contributionsh2> This feature issue aims to present a collection of papers that focus on the state-of-the-art research in various networking aspects of optical access networks. Original papers are solicited from all researchers involved in area of optical access networks. Topics of interest include but not limited to: Optical access network architectures and protocols Passive optical networks (BPON, EPON, GPON, etc.) Active optical networks Multiple access control Multiservices and QoS provisioning Network survivability Field trials and standards Performance modeling and analysis h2>Manuscript Submissionh2> To submit to this special issue, follow the normal procedure for submission to JON, indicating ``Optical Access Networks feature' in the ``Comments' field of the online submission form. For all other questions relating to this feature issue, please send an e-mail to jon@osa.org, subject line ``Optical Access Networks' Additional information can be found on the JON website: http://www.osa-jon.org/submission/. Submission Deadline: 1 June 2005

  12. Thin Coating of Microporous Organic Network Makes a Big Difference: Sustainability Issue of Ni Electrodes on the PET Textile for Flexible Lithium-Ion Batteries.

    Science.gov (United States)

    Kang, Chang Wan; Choi, Jaewon; Ko, Yoon-Joo; Lee, Sang Moon; Kim, Hae Jin; Kim, Jong Pil; Son, Seung Uk

    2017-10-25

    Poly(ethylene terephthalate) fibers (PET-Fs) were coated with microporous organic networks (MONs) by the Sonogashira coupling of tetra(4-ethynylphenyl)methane with 1,4-diiodobenzene. Ni was deposited on the PET-F@MON via electroless deposition. Interestingly, although Ni on the PET-F showed a sharp decrease in conductivity in repeated bending tests, the PET-F@MON@Ni showed excellent retention of conductivity. We suggest that thin MON layers play roles of an efficient binder for Ni attachment to fibers and a structural buffer for the relaxation of bending strain. The positive effect of MON was supported by scanning electron microscopy studies of the PET-F@Ni or PET-F@MON@Ni retrieved after 2000 bending numbers. Although Ni on the PET-F showed severe detachment after bending tests, PET-F@MON@Ni retained the original morphologies. The pouch cells of lithium-ion batteries fabricated using PET-F@MON@Ni as the current collectors showed excellent performance against bending.

  13. Smart network expansion - (no) an issue for urban network operators. With hot spot analysis to smart grid; Smarter Netzausbau - (k)ein Thema fuer staedtische Netzbetreiber. Mit Hotspotanalyse zum Smart Grid

    Energy Technology Data Exchange (ETDEWEB)

    Safirov, Janko; Guarente, Andreas; Haas, Hans-Juergen [Stadtwerke Solingen Netz GmbH, Solingen (Germany); Ladermann, Alexander; Seeger, Nick; Fritz, Wolfgang [Consentec GmbH, Aachen (Germany)

    2013-04-29

    The ongoing construction of production facilities based on renewable energy sources in distribution networks has led to measures to reinforce power distribution systems with many network operators, or this occurs in the near future. Many areal network operators with extended network structures and often lower load in comparison to the installed generation capacity are in the focus of these developments. In contrast, it is frequently assumed for urban distribution networks that these are affected at most sporadic by measures to reinforce power distribution systems. However, basically also for urban network operators the question concerning the development of the supply task rises.

  14. Statistical Network Analysis for Functional MRI: Mean Networks and Group Comparisons.

    Directory of Open Access Journals (Sweden)

    Cedric E Ginestet

    2014-05-01

    Full Text Available Comparing networks in neuroscience is hard, because the topological properties of a given network are necessarily dependent on the number of edges of that network. This problem arises in the analysis of both weighted and unweighted networks. The term density is often used in this context, in order to refer to the mean edge weight of a weighted network, or to the number of edges in an unweighted one. Comparing families of networks is therefore statistically difficult because differences in topology are necessarily associated with differences in density. In this review paper, we consider this problem from two different perspectives, which include (i the construction of summary networks, such as how to compute and visualize the mean network from a sample of network-valued data points; and (ii how to test for topological differences, when two families of networks also exhibit significant differences in density. In the first instance, we show that the issue of summarizing a family of networks can be conducted by either adopting a mass-univariate approach, which produces a statistical parametric network (SPN, or by directly computing the mean network, provided that a metric has been specified on the space of all networks with a given number of nodes. In the second part of this review, we then highlight the inherent problems associated with the comparison of topological functions of families of networks that differ in density. In particular, we show that a wide range of topological summaries, such as global efficiency and network modularity are highly sensitive to differences in density. Moreover, these problems are not restricted to unweighted metrics, as we demonstrate that the same issues remain present when considering the weighted versions of these metrics. We conclude by encouraging caution, when reporting such statistical comparisons, and by emphasizing the importance of constructing summary networks.

  15. Neural Network Model for Thermal Inactivation of Salmonella Typhimurium to Elimination in Ground Chicken: Acquisition of Data by Whole Sample Enrichment, Miniature Most-Probable-Number Method.

    Science.gov (United States)

    Oscar, T P

    2017-01-01

    Predictive models are valuable tools for assessing food safety. Existing thermal inactivation models for Salmonella and ground chicken do not provide predictions above 71°C, which is below the recommended final cooked temperature of 73.9°C for chicken. They also do not predict when all Salmonella are eliminated without extrapolating beyond the data used to develop them. Thus, a study was undertaken to develop a model for thermal inactivation of Salmonella to elimination in ground chicken at temperatures above those of existing models. Ground chicken thigh portions (0.76 cm(3)) in microcentrifuge tubes were inoculated with 4.45 ± 0.25 log most probable number (MPN) of a single strain of Salmonella Typhimurium (chicken isolate). They were cooked at 50 to 100°C in 2 or 2.5°C increments in a heating block that simulated two-sided pan frying. A whole sample enrichment, miniature MPN (WSE-mMPN) method was used for enumeration. The lower limit of detection was one Salmonella cell per portion. MPN data were used to develop a multiple-layer feedforward neural network model. Model performance was evaluated using the acceptable prediction zone (APZ) method. The proportion of residuals in an APZ (pAPZ) from -1 log (fail-safe) to 0.5 log (fail-dangerous) was 0.911 (379 of 416) for dependent data and 0.910 (162 of 178) for independent data for interpolation. A pAPZ ≥0.7 indicated that model predictions had acceptable bias and accuracy. There were no local prediction problems because pAPZ for individual thermal inactivation curves ranged from 0.813 to 1.000. Independent data for interpolation satisfied the test data criteria of the APZ method. Thus, the model was successfully validated. Predicted times for a 1-log reduction ranged from 9.6 min at 56°C to 0.71 min at 100°C. Predicted times for elimination ranged from 8.6 min at 60°C to 1.4 min at 100°C. The model will be a valuable new tool for predicting and managing this important risk to public health.

  16. Dental problems and Familismo: social network discussion of oral health issues among adults of Mexican origin living in the Midwest United States.

    Science.gov (United States)

    Maupome, G; McConnell, W R; Perry, B L

    2016-12-01

    To examine the influence of collectivist orientation (often called familismo when applied to the Latino sub-group in the United States) in oral health discussion networks. Through respondent-driven sampling and face-to-face interviews, we identified respondents' (egos) personal social network members (alters). Egos stated whom they talked with about oral health, and how often they discussed dental problems in the preceding 12 months. An urban community of adult Mexican-American immigrants in the Midwest United States. We interviewed 332 egos (90% born in Mexico); egos named an average of 3.9 alters in their networks, 1,299 in total. We applied egocentric network methods to examine the ego, alter, and network variables that characterize health discussion networks. Kin were most often leveraged when dental problems arose; egos relied on individuals whom they perceive to have better knowledge about dental matters. However, reliance on knowledgeable alters decreased among egos with greater behavioral acculturation. This paper developed a network-based conceptualization of familismo. We describe the structure of oral health networks, including kin, fictive kin, peers, and health professionals, and examine how networks and acculturation help shape oral health among these Mexican-Americans.

  17. Report number codes

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, R.N. (ed.)

    1985-05-01

    This publication lists all report number codes processed by the Office of Scientific and Technical Information. The report codes are substantially based on the American National Standards Institute, Standard Technical Report Number (STRN)-Format and Creation Z39.23-1983. The Standard Technical Report Number (STRN) provides one of the primary methods of identifying a specific technical report. The STRN consists of two parts: The report code and the sequential number. The report code identifies the issuing organization, a specific program, or a type of document. The sequential number, which is assigned in sequence by each report issuing entity, is not included in this publication. Part I of this compilation is alphabetized by report codes followed by issuing installations. Part II lists the issuing organization followed by the assigned report code(s). In both Parts I and II, the names of issuing organizations appear for the most part in the form used at the time the reports were issued. However, for some of the more prolific installations which have had name changes, all entries have been merged under the current name.

  18. Optimization of the architecture of a neural network in neutron spectrometry to reduce the number of Bonner spheres; Optimizacion de la arquitectura de una red neuronal en espectrometria de neutrones para reducer el numero de esferas Bonner

    Energy Technology Data Exchange (ETDEWEB)

    Leon P, A. A.; Martinez B, M. R.; Hernandez P, C. F.; Espinoza G, J. G.; Castaneda M, V. H.; Solis S, L. O.; Castaneda M, R.; Ortiz R, J. M.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Av. Ramon Lopez Velarde 801, Col. Centro, 98000 Zacatecas, Zac. (Mexico); Mendez V, R. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Laboratorio de Patrones Neutronicos, Av. Complutense 22, 28040 Madrid (Spain); Gallego, E. [Universidad Politecnica de Madrid, Departamento de Ingenieria Nuclear, ETSI Industriales, Jose Gutierrez Abascal 2, 28006 Madrid (Spain); De Sousa L, M. A. [Centro de Desenvolvimento da Tecnologia Nuclear / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901 Pampulha, Belo Horizonte, Minas Gerais (Brazil)

    2016-10-15

    The neutron spectrometry is an experimental process for determining the energy distribution called the Spectrum. Among the methods available for neutron spectrometry, one can mention the Bonner Sphere Spectrometric System as one of the most used, consisting of a detector placed in the center of a set of polyethylene spheres whose diameters range from 2 to 18 inches, however has some disadvantages such as the long periods of time to perform the measurements, the weight and the spheres number that vary according to the system. From this, alternative methods such as artificial neural networks are proposed. For this project neural networks of reverse propagation were used with the methodology of robust design of artificial neural networks, with the aid of a computational tool that maximizes the performance, making the time used for the training s of the network is the smallest possible and thus gets the orthogonal fixes quickly to determine the best network topology. The counting rates of a spectrometric system with 7 spheres, 2 spheres and one sphere of 5 and 8 inches were used. This methodology seeks to reduce the work used as in the spectrometric system formed by a greater number of spheres, since to enter less data in the counting rates to obtain the spectra with 60 energy levels saves time and space, because at having a smaller number of spheres its portability is easier to move from one place to another, for this we performed several experiments with different errors until we reached the optimal error so that the topology of the network was appropriate and find the best design parameters. A statistical software JMP was also used to obtain the best topologies and thus to retrain obtaining its best and worst spectra, in order to determine if the reduction is possible. (Author)

  19. Innovation Networks to Stimulate Public and Private Sector Collaboration for Advisory Services Innovation and Coordination: The Case of Pasture Performance Issues in the New Zealand Dairy Industry

    Science.gov (United States)

    Rijswijk, K.; Brazendale, R.

    2017-01-01

    Purpose: An innovation network, called the Pasture Improvement Leadership Group (PILG), was formed to improve the quality and consistency of advice provided to dairy farmers in New Zealand, after they expressed dissatisfaction with their pastures. The aim of this paper is to better understand the challenges of forming and maintaining networks to…

  20. Number names and number understanding

    DEFF Research Database (Denmark)

    Ejersbo, Lisser Rye; Misfeldt, Morten

    2014-01-01

    through using mathematical names for the numbers such as one-ten-one for 11 and five-ten-six for 56. The project combines the renaming of numbers with supporting the teaching with the new number names. Our hypothesis is that Danish children have more difficulties learning and working with numbers, because...

  1. Identifying Clusters of Complex Urban–Rural Issues as Part of Policy Making Process Using a Network Analysis Approach: A Case Study in Bahía de Los Ángeles, Mexico

    Directory of Open Access Journals (Sweden)

    Javier Sandoval

    2017-06-01

    Full Text Available Improving human settlements diagnosis is a key factor in effective urban planning and the design of efficient policy making. In this paper, we illustrate how network theory concepts can be applied to reveal the topological structure of functional relationships in a network of heterogeneous urban–rural issues. This mapping is done using clustering algorithms and centrality value techniques. By analyzing emergent groups of urban–rural related issues, our methodology was applied to a rural community, considering in this exercise environmental matters and real estate interests as a way to better understand the structure of salient issues in the context of its urban development program design. Results show clusters that arrange themselves not by an obvious similarity in their constituent components, but by relations observed in urban–rural settings that hint on the issues that the urban development program must focus. Due to its complex nature, the classification of these emerging clusters and how they must be treated in traditional planning instruments is a new challenge that this novel methodology reveals.

  2. Proth Numbers

    Directory of Open Access Journals (Sweden)

    Schwarzweller Christoph

    2015-02-01

    Full Text Available In this article we introduce Proth numbers and prove two theorems on such numbers being prime [3]. We also give revised versions of Pocklington’s theorem and of the Legendre symbol. Finally, we prove Pepin’s theorem and that the fifth Fermat number is not prime.

  3. Fibonacci numbers

    CERN Document Server

    Vorob'ev, Nikolai Nikolaevich

    2011-01-01

    Fibonacci numbers date back to an 800-year-old problem concerning the number of offspring born in a single year to a pair of rabbits. This book offers the solution and explores the occurrence of Fibonacci numbers in number theory, continued fractions, and geometry. A discussion of the ""golden section"" rectangle, in which the lengths of the sides can be expressed as a ration of two successive Fibonacci numbers, draws upon attempts by ancient and medieval thinkers to base aesthetic and philosophical principles on the beauty of these figures. Recreational readers as well as students and teacher

  4. Sagan numbers

    OpenAIRE

    Mendonça, J. Ricardo G.

    2012-01-01

    We define a new class of numbers based on the first occurrence of certain patterns of zeros and ones in the expansion of irracional numbers in a given basis and call them Sagan numbers, since they were first mentioned, in a special case, by the North-american astronomer Carl E. Sagan in his science-fiction novel "Contact." Sagan numbers hold connections with a wealth of mathematical ideas. We describe some properties of the newly defined numbers and indicate directions for further amusement.

  5. Algebraic Numbers

    Directory of Open Access Journals (Sweden)

    Watase Yasushige

    2016-12-01

    Full Text Available This article provides definitions and examples upon an integral element of unital commutative rings. An algebraic number is also treated as consequence of a concept of “integral”. Definitions for an integral closure, an algebraic integer and a transcendental numbers [14], [1], [10] and [7] are included as well. As an application of an algebraic number, this article includes a formal proof of a ring extension of rational number field ℚ induced by substitution of an algebraic number to the polynomial ring of ℚ[x] turns to be a field.

  6. Ground wave emergency network final operational capability: Environmental assessment for northwestern Nebraska relay node, site number RN 8C930NE

    Science.gov (United States)

    1993-02-01

    The Ground Wave Emergency Network (GWEN) is a radio communication system designed to relay emergency messages between strategic military areas in the continental United States. The system is immune to the effects of high-altitude electromagnetic pulse (HEMP) energy surges caused by nuclear bursts in the ionosphere that would disrupt conventional communications equipment such as telephones and shortwave radios. A failure of such equipment would prevent timely communications among top military and civilian leaders and strategic Air Force locations and prevent U.S. assessment and retaliation during an attack. GWEN is an essential part of a defense modernization program to upgrade and improve our nation's communications system, thereby strengthening deterrence. The GWEN system consists of a network of relay nodes, receive-only stations, and input/output stations. Each relay node, such as the one proposed in northwestern Nebraska, consists of a guyed radio tower facility similar to those used by commercial AM broadcast transmitters.

  7. Ground wave emergency network final operational capability: Environmental assessment for southern Nevada relay node site number RN 8W918NV

    Science.gov (United States)

    1993-03-01

    The Ground Wave Emergency Network (GWEN) is a radio communication system designed to relay emergency messages between strategic military areas in the continental United States. The system is immune to the effects of high-altitude electromagnetic pulse (HEMP) energy surges caused by nuclear bursts in the ionosphere that would disrupt conventional communications equipment such as telephones and shortwave radios. A failure of such equipment would prevent timely communications among top military and civilian leaders and strategic Air Force locations and prevent U.S. assessment and retaliation during an attack. GWEN is an essential part of a defense modernization program to upgrade and improve our nation's communications system, thereby strengthening deterrence. The GWEN system consists of a network of relay nodes, receive-only stations, and input/output stations. Each relay node, such as the one proposed in southern Nevada consists of a guyed radio tower facility similar to those used by commercial AM broadcast transmitters.

  8. Automated conflict resolution issues

    Science.gov (United States)

    Wike, Jeffrey S.

    1991-01-01

    A discussion is presented of how conflicts for Space Network resources should be resolved in the ATDRSS era. The following topics are presented: a description of how resource conflicts are currently resolved; a description of issues associated with automated conflict resolution; present conflict resolution strategies; and topics for further discussion.

  9. Colombia: Issues for Congress

    National Research Council Canada - National Science Library

    Veillette, Connie

    2005-01-01

    .... The Congress has expressed concern with respect to a number of Colombia-related issues including human rights, the aerial eradication of illicit drug crops, interdiction programs, the situation of U.S...

  10. Intelligent future wireless networks for energy efficiency: overall analysis and standardization activities

    CSIR Research Space (South Africa)

    Kliks, A

    2013-10-01

    Full Text Available This chapter addresses a number of issues related to standardization and regulatory policies aiming at promoting energy-efficient communications and networking, highlighting the need of synergic approach. It encompasses the analysis of various...

  11. Eulerian numbers

    CERN Document Server

    Petersen, T Kyle

    2015-01-01

    This text presents the Eulerian numbers in the context of modern enumerative, algebraic, and geometric combinatorics. The book first studies Eulerian numbers from a purely combinatorial point of view, then embarks on a tour of how these numbers arise in the study of hyperplane arrangements, polytopes, and simplicial complexes. Some topics include a thorough discussion of gamma-nonnegativity and real-rootedness for Eulerian polynomials, as well as the weak order and the shard intersection order of the symmetric group. The book also includes a parallel story of Catalan combinatorics, wherein the Eulerian numbers are replaced with Narayana numbers. Again there is a progression from combinatorics to geometry, including discussion of the associahedron and the lattice of noncrossing partitions. The final chapters discuss how both the Eulerian and Narayana numbers have analogues in any finite Coxeter group, with many of the same enumerative and geometric properties. There are four supplemental chapters throughout, ...

  12. Network Coding

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 15; Issue 7. Network Coding. K V Rashmi Nihar B Shah P Vijay Kumar. General Article Volume 15 Issue 7 July 2010 pp 604-621. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/015/07/0604-0621. Keywords.

  13. [Doctors and the benefits and dangers of social networks].

    Science.gov (United States)

    Tisseron, Serge

    2015-05-13

    Social networks have many different uses. Most young people use them for experimentation and innovation. Social networks help young people get familiar with the digital world, and develop themselves in interrelation with their peers. But social networks can also be used to avoid relationships in the real world, or to practice different forms of harassment. A specific danger lies in forgetting that a great number of people can have access to personal information posted online. Doctors should be particularly aware of this issue.

  14. Inter-organizational network studies – a literature review

    DEFF Research Database (Denmark)

    Bergenholtz, Carsten; Waldstrøm, Christian

    2011-01-01

    network analysis. However, this has not been without serious theoretical and ethodological issues. Most notably, a number of the concepts, methods and theories used within the field of inter-organizational networks originate from research in interpersonal and intra-organizational networks where some...... of the methodological issues (e.g. unit of analysis and boundary specification) are more easily addressed. In order to map the different methodological approaches in the field of inter-organizational networks, this paper presents a large-scale systematic literature review of the last 12 years’ research on inter......-organizational networks, with a focus on the methodological features. Some of the main variables relate to the unit of analysis, whether social network analysis is applied and what concept of a network is involved. The main findings of this paper are that few of the previous studies have used the full methodological (and...

  15. First Time Rapid and Accurate Detection of Massive Number of Metal Absorption Lines in the Early Universe Using Deep Neural Network

    Science.gov (United States)

    Zhao, Yinan; Ge, Jian; Yuan, Xiaoyong; Li, Xiaolin; Zhao, Tiffany; Wang, Cindy

    2018-01-01

    Metal absorption line systems in the distant quasar spectra have been used as one of the most powerful tools to probe gas content in the early Universe. The MgII λλ 2796, 2803 doublet is one of the most popular metal absorption lines and has been used to trace gas and global star formation at redshifts between ~0.5 to 2.5. In the past, machine learning algorithms have been used to detect absorption lines systems in the large sky survey, such as Principle Component Analysis, Gaussian Process and decision tree, but the overall detection process is not only complicated, but also time consuming. It usually takes a few months to go through the entire quasar spectral dataset from each of the Sloan Digital Sky Survey (SDSS) data release. In this work, we applied the deep neural network, or “ deep learning” algorithms, in the most recently SDSS DR14 quasar spectra and were able to randomly search 20000 quasar spectra and detect 2887 strong Mg II absorption features in just 9 seconds. Our detection algorithms were verified with previously released DR12 and DR7 data and published Mg II catalog and the detection accuracy is 90%. This is the first time that deep neural network has demonstrated its promising power in both speed and accuracy in replacing tedious, repetitive human work in searching for narrow absorption patterns in a big dataset. We will present our detection algorithms and also statistical results of the newly detected Mg II absorption lines.

  16. Number theory

    CERN Document Server

    Andrews, George E

    1994-01-01

    Although mathematics majors are usually conversant with number theory by the time they have completed a course in abstract algebra, other undergraduates, especially those in education and the liberal arts, often need a more basic introduction to the topic.In this book the author solves the problem of maintaining the interest of students at both levels by offering a combinatorial approach to elementary number theory. In studying number theory from such a perspective, mathematics majors are spared repetition and provided with new insights, while other students benefit from the consequent simpl

  17. Properties of healthcare teaming networks as a function of network construction algorithms.

    Science.gov (United States)

    Zand, Martin S; Trayhan, Melissa; Farooq, Samir A; Fucile, Christopher; Ghoshal, Gourab; White, Robert J; Quill, Caroline M; Rosenberg, Alexander; Barbosa, Hugo Serrano; Bush, Kristen; Chafi, Hassan; Boudreau, Timothy

    2017-01-01

    Network models of healthcare systems can be used to examine how providers collaborate, communicate, refer patients to each other, and to map how patients traverse the network of providers. Most healthcare service network models have been constructed from patient claims data, using billing claims to link a patient with a specific provider in time. The data sets can be quite large (106-108 individual claims per year), making standard methods for network construction computationally challenging and thus requiring the use of alternate construction algorithms. While these alternate methods have seen increasing use in generating healthcare networks, there is little to no literature comparing the differences in the structural properties of the generated networks, which as we demonstrate, can be dramatically different. To address this issue, we compared the properties of healthcare networks constructed using different algorithms from 2013 Medicare Part B outpatient claims data. Three different algorithms were compared: binning, sliding frame, and trace-route. Unipartite networks linking either providers or healthcare organizations by shared patients were built using each method. We find that each algorithm produced networks with substantially different topological properties, as reflected by numbers of edges, network density, assortativity, clustering coefficients and other structural measures. Provider networks adhered to a power law, while organization networks were best fit by a power law with exponential cutoff. Censoring networks to exclude edges with less than 11 shared patients, a common de-identification practice for healthcare network data, markedly reduced edge numbers and network density, and greatly altered measures of vertex prominence such as the betweenness centrality. Data analysis identified patterns in the distance patients travel between network providers, and a striking set of teaming relationships between providers in the Northeast United States and

  18. Nice numbers

    CERN Document Server

    Barnes, John

    2016-01-01

    In this intriguing book, John Barnes takes us on a journey through aspects of numbers much as he took us on a geometrical journey in Gems of Geometry. Similarly originating from a series of lectures for adult students at Reading and Oxford University, this book touches a variety of amusing and fascinating topics regarding numbers and their uses both ancient and modern. The author intrigues and challenges his audience with both fundamental number topics such as prime numbers and cryptography, and themes of daily needs and pleasures such as counting one's assets, keeping track of time, and enjoying music. Puzzles and exercises at the end of each lecture offer additional inspiration, and numerous illustrations accompany the reader. Furthermore, a number of appendices provides in-depth insights into diverse topics such as Pascal’s triangle, the Rubik cube, Mersenne’s curious keyboards, and many others. A theme running through is the thought of what is our favourite number. Written in an engaging and witty sty...

  19. Deploying temporary networks for upscaling of sparse network stations

    Science.gov (United States)

    Coopersmith, Evan J.; Cosh, Michael H.; Bell, Jesse E.; Kelly, Victoria; Hall, Mark; Palecki, Michael A.; Temimi, Marouane

    2016-10-01

    Soil observations networks at the national scale play an integral role in hydrologic modeling, drought assessment, agricultural decision support, and our ability to understand climate change. Understanding soil moisture variability is necessary to apply these measurements to model calibration, business and consumer applications, or even human health issues. The installation of soil moisture sensors as sparse, national networks is necessitated by limited financial resources. However, this results in the incomplete sampling of the local heterogeneity of soil type, vegetation cover, topography, and the fine spatial distribution of precipitation events. To this end, temporary networks can be installed in the areas surrounding a permanent installation within a sparse network. The temporary networks deployed in this study provide a more representative average at the 3 km and 9 km scales, localized about the permanent gauge. The value of such temporary networks is demonstrated at test sites in Millbrook, New York and Crossville, Tennessee. The capacity of a single U.S. Climate Reference Network (USCRN) sensor set to approximate the average of a temporary network at the 3 km and 9 km scales using a simple linear scaling function is tested. The capacity of a temporary network to provide reliable estimates with diminishing numbers of sensors, the temporal stability of those networks, and ultimately, the relationship of the variability of those networks to soil moisture conditions at the permanent sensor are investigated. In this manner, this work demonstrates the single-season installation of a temporary network as a mechanism to characterize the soil moisture variability at a permanent gauge within a sparse network.

  20. Funny Numbers

    Directory of Open Access Journals (Sweden)

    Theodore M. Porter

    2012-12-01

    Full Text Available The struggle over cure rate measures in nineteenth-century asylums provides an exemplary instance of how, when used for official assessments of institutions, these numbers become sites of contestation. The evasion of goals and corruption of measures tends to make these numbers “funny” in the sense of becoming dis-honest, while the mismatch between boring, technical appearances and cunning backstage manipulations supplies dark humor. The dangers are evident in recent efforts to decentralize the functions of governments and corporations using incen-tives based on quantified targets.

  1. Networking for big data

    CERN Document Server

    Yu, Shui; Misic, Jelena; Shen, Xuemin (Sherman)

    2015-01-01

    Networking for Big Data supplies an unprecedented look at cutting-edge research on the networking and communication aspects of Big Data. Starting with a comprehensive introduction to Big Data and its networking issues, it offers deep technical coverage of both theory and applications.The book is divided into four sections: introduction to Big Data, networking theory and design for Big Data, networking security for Big Data, and platforms and systems for Big Data applications. Focusing on key networking issues in Big Data, the book explains network design and implementation for Big Data. It exa

  2. Transfinite Numbers

    Indian Academy of Sciences (India)

    How many points are there on a line? Which is more in number- points on a line or lines in a plane? These are some natural questions that have occurred to us sometime or the other. It is interesting to note the difference between the two questions. Do we have to know how many points and lines there are to answer.

  3. Triangular Numbers

    Indian Academy of Sciences (India)

    Admin

    Left: Anuradha S Garge completed her PhD from. Pune University in 2008 under the supervision of Prof. S A Katre. Her research interests include K-theory and number theory. Besides mathematics, she is interested in (singing) indian classical music and yoga. Right: Shailesh Shirali is. Director of Sahyadri School.

  4. Intelligence in the power grid and services to the consumers. Issue paper - working group 4; Denmark. Smart Grid Network; Intelligens i el-nettet og serviceydelser til forbrugerne. Issue paper, arbejdsgruppe 4

    Energy Technology Data Exchange (ETDEWEB)

    Jonsen, B.O. (Solar Danmark A/S, Vejen (Denmark)); Hauge, B. (IT-Branchen, Copenhagen (Denmark)); Strunge, C. (Energinet.dk, Fredericia (Denmark)) (and others)

    2011-07-01

    The Smart Grid Network was established in 2010 by the Danish climate and energy minister tasked with developing recommendations for future actions and initiatives that make it possible to handle up to 50% electricity from wind energy in the power system in 2020. The task of working group 4 was to investigate what it takes to involve consumers in smart grid and how to create good conditions for new services related to smart grid. Against this background, the working group agreed the following recommendations: 1) Enhance consumer engagement. A prerequisite for electricity customers becoming involved in smart grid is that they have awareness and knowledge about the smart grid and their own possibilities for action in relation thereto. Therefore it is important that concepts such as smart grid and flexible electricity consumption gradually become popular among electric customers; 2) Minimize the risk. In order to promote electric customers' and other stakeholders' participation in the smart grid, the risk of this participation must be minimized. It is therefore recommended to enhance the skills of the professionals and to establish a common framework for security; 3) Make it easier to create new services. Part of the potential of smart grid can be realized through new services such as delivery of flexible electricity consumption for electric cars and heat pumps and the resale of local power generation at the customer. To facilitate the conditions for these services, the working group recommends that better access to relevant data is created, that the interoperability of smart grid solutions is strengthened, that requirements for buildings are made, that it is made easier to be an aggregator, and that test and inspiration laboratories for small and medium enterprises in the smart grid area are established. (LN)

  5. A Distributed Network Mobility Management Scheme for Hierarchical Mobile IPv6 Networks

    Science.gov (United States)

    Kawano, Keita; Kinoshita, Kazuhiko; Yamai, Nariyoshi

    Route optimization for network mobility is a key technique for providing a node in a mobile network (Mobile Network Node or MNN) with high quality broadband communications. Many schemes adding route optimization function to Network Mobility (NEMO) Basic Support protocol, the standardized network mobility management protocol from the IETF nemo working group, have already been proposed in recent years. One such scheme, a scheme using Hierarchical Mobile IPv6 (HMIPv6) aims to overcome micromobility management issues as well by applying a mechanism based on HMIPv6. The traditional scheme, however, suffers from a significant number of signaling messages as the number of MNNs and/or the number of their Correspondent Nodes (CNs) increase, because many messages notifying the MNNs' Home Agents (HAMNNs) and the CNs of the mobile network's movement are generated simultaneously each time the mobile network moves to the domain of another micromobility management router (Mobility Anchor Point or MAP). This paper proposes a scheme to overcome this problem. Our scheme reduces the number of signaling messages generated at the same time by managing the mobility of MNNs using multiple MAPs distributed within a network for load sharing. The results of simulation experiments show that our scheme works efficiently compared to the traditional scheme when a mobile network has many MNNs and/or these MNNs communicate with many CNs.

  6. Pragmatic Numbers

    DEFF Research Database (Denmark)

    Seabrooke, Leonard

    2012-01-01

    Sector Assessment Programme (FSAP). While the IMF is typically viewed as an institution that enforces global standards for economic governance through the imposition of quantitative targets (‘numbers’ for this special issue), I suggest that its use of benchmarking in the generation of financial data can...... market actors. This article suggests that we cannot simply view the IMF staff as hostage to their commanders. Rather, the IMF's use of ‘pragmatic numbers’ within FSAPs demonstrates one method by which an institution seeks to foster learning under constraint.......Do international organisations generate benchmarks as tools for policy enforcement or policy learning? This article suggests that the latter is possible even in unlikely scenarios. It does this through a case study on the ‘power of numbers’ in the International Monetary Fund's (IMF) Financial...

  7. Production, Innovation and Service Networks

    DEFF Research Database (Denmark)

    Slepniov, Dmitrij; Wæhrens, Brian Vejrum; Johansen, John

    2012-01-01

    Production, innovation and service networks of companies all over the world become increasingly decentralised, specialised and interdependent. These three characteristics combined inevitably lead to the formation of complex configurations of resources, crossing both national and organisational...... borders. The existing studies do not adequately address the complex interplay between co-evolving production, innovation and service networks. The widening geographical and cognitive gaps between these networks mean that coordinating them and managing their interfaces in a global operations context...... are becoming strategically important. The purpose of this paper is to address this issue and to develop a number of propositions about the development and organisation of these networks. The paper highlights the critical importance of engineering operations in this process. The propositions are developed...

  8. Network exploitation using WAMI tracks

    Science.gov (United States)

    Rimey, Ray; Record, Jim; Keefe, Dan; Kennedy, Levi; Cramer, Chris

    2011-06-01

    Creating and exploiting network models from wide area motion imagery (WAMI) is an important task for intelligence analysis. Tracks of entities observed moving in the WAMI sensor data are extracted, then large numbers of tracks are studied over long time intervals to determine specific locations that are visited (e.g., buildings in an urban environment), what locations are related to other locations, and the function of each location. This paper describes several parts of the network detection/exploitation problem, and summarizes a solution technique for each: (a) Detecting nodes; (b) Detecting links between known nodes; (c) Node attributes to characterize a node; (d) Link attributes to characterize each link; (e) Link structure inferred from node attributes and vice versa; and (f) Decomposing a detected network into smaller networks. Experimental results are presented for each solution technique, and those are used to discuss issues for each problem part and its solution technique.

  9. Number names and number understanding

    DEFF Research Database (Denmark)

    Ejersbo, Lisser Rye; Misfeldt, Morten

    2014-01-01

    This paper concerns the results from the first year of a three-year research project involving the relationship between Danish number names and their corresponding digits in the canonical base 10 system. The project aims to develop a system to help the students’ understanding of the base 10 syste...

  10. Topological analysis of telecommunications networks

    Directory of Open Access Journals (Sweden)

    Milojko V. Jevtović

    2011-01-01

    Full Text Available A topological analysis of the structure of telecommunications networks is a very interesting topic in the network research, but also a key issue in their design and planning. Satisfying multiple criteria in terms of locations of switching nodes as well as their connectivity with respect to the requests for capacity, transmission speed, reliability, availability and cost are the main research objectives. There are three ways of presenting the topology of telecommunications networks: table, matrix or graph method. The table method is suitable for a network of a relatively small number of nodes in relation to the number of links. The matrix method involves the formation of a connection matrix in which its columns present source traffic nodes and its rows are the switching systems that belong to the destination. The method of the topology graph means that the network nodes are connected via directional or unidirectional links. We can thus easily analyze the structural parameters of telecommunications networks. This paper presents the mathematical analysis of the star-, ring-, fully connected loop- and grid (matrix-shaped topology as well as the topology based on the shortest path tree. For each of these topologies, the expressions for determining the number of branches, the middle level of reliability, the medium length and the average length of the link are given in tables. For the fully connected loop network with five nodes the values of all topological parameters are calculated. Based on the topological parameters, the relationships that represent integral and distributed indicators of reliability are given in this work as well as the values of the particular network. The main objectives of the topology optimization of telecommunications networks are: achieving the minimum complexity, maximum capacity, the shortest path message transfer, the maximum speed of communication and maximum economy. The performance of telecommunications networks is

  11. A network approach for provisional assay recognition of a Hendra virus antibody ELISA: test validation with low sample numbers from infected horses.

    Science.gov (United States)

    Colling, Axel; Lunt, Ross; Bergfeld, Jemma; McNabb, Leanne; Halpin, Kim; Juzva, Susan; Newberry, Kim; Morrissy, Chris; Loomes, Cameron; Warner, Simone; Diallo, Ibrahim; Kirkland, Peter; Broder, Christopher C; Carlile, Gemma; Loh, Mai Hlaing; Waugh, Caryll; Wright, Lynda; Watson, James; Eagles, Debbie; Zuelke, Kurt; McCullough, Sam; Daniels, Peter

    2018-02-01

    Obtaining statistically sound numbers of sera from Hendra virus (HeV)-infected horses is problematic because affected individuals usually die or are euthanized before developing a serum antibody response. As a consequence, test validation becomes a challenge. Our approach is an extension of OIE principles for provisional recognition and included 7 validation panels tested across multiple laboratories that provided estimates for test performance characteristics. At a 0.4 S/P cutoff, 16 of 19 sera from HeV-infected horses gave positive results in the HeV soluble G, indirect ELISA (HeVsG iELISA; DSe 84.2% [95% CI: 60.4-96.6%]); 463 of 477 non-infected horse sera tested negative (DSp 97.1% [95% CI: 95.1-98.4%]). The HeVsG iELISA eliminated almost all false-positive results from the previously used HeV iELISA, with marginally decreased relative sensitivity. Assay robustness was evaluated in inter-laboratory and proficiency testing panels. The HeVsG iELISA is considered to be fit for purpose for serosurveillance and international movement of horses when virus neutralization is used for follow-up testing of positive or inconclusive serum samples.

  12. Implementation of DRAMA in Macrocell Network

    Directory of Open Access Journals (Sweden)

    AHMED Afaz Uddin

    2015-05-01

    Full Text Available In this paper, Modified-Dynamic Resource Allocation Management Algorithm is implemented in macrocell network. Previously, the algorithm was developed for heterogeneous network with both smallcell and macrocell network. The increasing number of network nodes in wireless cellular communication has increased the demand of proper resource allocation in heterogeneous network. Inter-cell interference is still considered as one of the most challenging issues in vast deployment of mobile base stations in urban and sub-urban areas. In LTE and LTE-A network, spectrum sharing and leasing mandated by huge number of base stations (indoor and outdoor deployed, has an adverse effect on systems throughput and quality of service. Advances in resource management strategies has improved the interference scenarios in vast scale. A modified dynamic resource allocation management algorithm for macrocell network is proposed here to counter the intercell interference. Simulation environment is developed to study the performance of M-DRAMA for the marcoell network. The performance analysis shows that higher number of users get quality coverage at high node density.

  13. IJIMAI Editors Note - Vol. 4 Issue 1

    Directory of Open Access Journals (Sweden)

    Mohamed Bahaj

    2016-09-01

    Full Text Available The research works presented in this issue are based on various topics of interest, among which are included: Pattern Recognition, Multimedia Information Retrieval, Knowledge extraction and knowledge mining, Data mining, Intelligent Systems and Artificial Intelligence, Wireless Technology, Network Telecommunication, Security and Network Management, Advanced Network Technologies.

  14. Effect of a small number of training cases on the performance of massive training artificial neural network (MTANN) for reduction of false positives in computerized detection of lung nodules in low-dose CT

    Science.gov (United States)

    Suzuki, Kenji; Armato, Samuel G., III; Li, Feng; Sone, Shusuke; Doi, Kunio

    2003-05-01

    In this study, we investigated a pattern-classification technique which can be trained with a small number of cases with a massive training artificial neural network (MTANN) for reduction of false positives in computerized detection of lung nodules in low-dose CT (LDCT). The MTANN consists of a modified multilayer artificial neural network (ANN), which is capable of operating on image data directly. The MTANN is trained by use of a large number of sub-regions extracted from input images together with the teacher images containing the distribution for the "likelihood of being a nodule." The output image is obtained by scanning of an input image with the MTANN. In the MTANN, the distinction between nodules and non-nodules is treated as an image-processing task, in other words, as a highly nonlinear filter that performs both nodule enhancement and non-nodule suppression. This allows us to train the MTANN not on a case basis, but on a sub-region basis. Therefore, the MTANN can be trained with a very small number of cases. Our database consisted of 101 LDCT scans acquired from 71 patients in a lung cancer screening program. The scans consisted of 2,822 sections, and contained 121 nodules including 104 nodules representing confirmed primary cancers. With our current CAD scheme, a sensitivity of 81.0% (98/121 nodules) with 0.99 false positives per section (2,804/2,822) was achieved. By use of the MTANN trained with a small number of training cases (n=10), i.e., five pairs of nodules and non-nodules, we were able to remove 55.8% of false positives without a reduction in the number of true positives, i.e., a classification sensitivity of 100%. Thus, the false-positive rate of our current CAD scheme was reduced from 0.99 to 0.44 false positive per section, while the current sensitivity (81.0%) was maintained.

  15. Five years of interdisciplinary research on ageing and technology: Outcomes of the Lower Saxony Research Network Design of Environments for Ageing (GAL)--an introduction to this Special Issue on Ageing and Technology.

    Science.gov (United States)

    Haux, Reinhold; Hein, Andreas; Kolb, Gerald; Künemund, Harald; Eichelberg, Marco

    2014-01-01

    This Special Issue of Informatics for Health and Social Care is presenting outcomes of the Lower Saxony Research Network Design of Environments for Ageing (abbreviated as GAL), probably one of the largest inter- and multidisciplinary research projects on aging and technology. In order to investigate and provide answers on whether new information and communication technologies can contribute to keeping, or even improving quality of life, health and self-sufficiency in ageing societies through new ways of living and new forms of care, GAL had been established as a five-year research project, running from 2008 to 2013. Ambient-assisted living technologies in personal and home environments were especially important. During the five years of research in GAL, more than seventy researchers from computer science, economics, engineering, geriatrics, gerontology, informatics, medicine, nursing science and rehabilitation pedagogy intensively collaborated in finding answers.

  16. High-fat meal effect on LDL, HDL, and VLDL particle size and number in the Genetics of Lipid-Lowering drugs and diet network (GOLDN): an interventional study

    Science.gov (United States)

    2011-01-01

    Background Postprandial lipemia (PPL) is likely a risk factor for cardiovascular disease but these changes have not been well described and characterized in a large cohort. We assessed acute changes in the size and concentration of total and subclasses of LDL, HDL, and VLDL particles in response to a high-fat meal. Participants (n = 1048) from the Genetics of Lipid-Lowering Drugs and Diet Network (GOLDN) Study who ingested a high-fat meal were included in this analysis. Lipids were measured at 0 hr (fasting), 3.5 hr, and 6 hr after a standardized fat meal. Particle size distributions were determined using nuclear magnetic resonance spectroscopy. Analyses were stratified by baseline triglycerides (normal vs. elevated) and gender. The effect of PPL on changes in lipoprotein subclasses was assessed using repeated measures ANOVA. Results Postprandially, LDL-C, HDL-C, VLDL-C, and triglycerides increased regardless of baseline triglyceride status, with the largest increases in VLDL-C and TG; however, those with elevated triglycerides demonstrated larger magnitude of response. Total LDL particle number decreased over the 6-hour time interval, mostly from a decrease in the number of small LDL particles. Similarly, total VLDL particle number decreased due to reductions in medium and small VLDL particles. Large VLDL particles and chylomicrons demonstrated the largest increase in concentration. HDL particles demonstrated minimal overall changes in total particle number. Conclusions We have characterized the changes in LDL and VLDL particle number, and their subclass patterns following a high-fat meal. PMID:22008512

  17. High-fat meal effect on LDL, HDL, and VLDL particle size and number in the Genetics of Lipid-Lowering drugs and diet network (GOLDN: an interventional study

    Directory of Open Access Journals (Sweden)

    Straka Robert J

    2011-10-01

    Full Text Available Abstract Background Postprandial lipemia (PPL is likely a risk factor for cardiovascular disease but these changes have not been well described and characterized in a large cohort. We assessed acute changes in the size and concentration of total and subclasses of LDL, HDL, and VLDL particles in response to a high-fat meal. Participants (n = 1048 from the Genetics of Lipid-Lowering Drugs and Diet Network (GOLDN Study who ingested a high-fat meal were included in this analysis. Lipids were measured at 0 hr (fasting, 3.5 hr, and 6 hr after a standardized fat meal. Particle size distributions were determined using nuclear magnetic resonance spectroscopy. Analyses were stratified by baseline triglycerides (normal vs. elevated and gender. The effect of PPL on changes in lipoprotein subclasses was assessed using repeated measures ANOVA. Results Postprandially, LDL-C, HDL-C, VLDL-C, and triglycerides increased regardless of baseline triglyceride status, with the largest increases in VLDL-C and TG; however, those with elevated triglycerides demonstrated larger magnitude of response. Total LDL particle number decreased over the 6-hour time interval, mostly from a decrease in the number of small LDL particles. Similarly, total VLDL particle number decreased due to reductions in medium and small VLDL particles. Large VLDL particles and chylomicrons demonstrated the largest increase in concentration. HDL particles demonstrated minimal overall changes in total particle number. Conclusions We have characterized the changes in LDL and VLDL particle number, and their subclass patterns following a high-fat meal.

  18. Research Article Special Issue

    African Journals Online (AJOL)

    pc

    2017-10-17

    Oct 17, 2017 ... number of 222 students from primary and secondary schools around Kuala Lumpur are obese. [8]. It is also ... and secondary schools in Malaysia explained the issue of NPFStests implementation is due to the irregular ... increase in the flexibility component among secondary school students [10]. Through ...

  19. Theoretical Issues

    Energy Technology Data Exchange (ETDEWEB)

    Marc Vanderhaeghen

    2007-04-01

    The theoretical issues in the interpretation of the precision measurements of the nucleon-to-Delta transition by means of electromagnetic probes are highlighted. The results of these measurements are confronted with the state-of-the-art calculations based on chiral effective-field theories (EFT), lattice QCD, large-Nc relations, perturbative QCD, and QCD-inspired models. The link of the nucleon-to-Delta form factors to generalized parton distributions (GPDs) is also discussed.

  20. Increase in the number of distributed power generation installations in electricity distribution grids - Simulation in a 16 kV medium-voltage network; Zunahme der dezentralen Energieerzeugungsanlagen in elektrischen Verteilnetzen: Simulationen im 16 kV Mittelspannungsnetz des AEW

    Energy Technology Data Exchange (ETDEWEB)

    Hoeckel, M.; Luechinger, P.

    2003-07-01

    This is the seventh part of a ten-part final report for the Swiss Federal Office of Energy (SFOE) on a project that looked into potential problems relating to the Swiss electricity distribution grid with respect to the increasing number of distributed power generation facilities being put into service. The identification of special conditions for the grid's operation and future development that take increasing decentralised power production into account are discussed. The results of the project activities encompass the analysis and evaluation of various problem areas associated with planning and management of the grid during normal operation and periods of malfunction, as well as required modifications to safety systems and grid configurations. This sixth appendix to the main report presents and discusses the results of simulations made on the basis of the real-life 16 kV medium-voltage distribution network operated by the Aargovian electricity utility AEW. This appendix describes the simulation methods used and the basic characteristics of medium-voltage networks and distributed generation facilities. Different types of load profiles, including domestic and industrial loads, are discussed. The results of the simulations are presented in graphical form and provide profiles of voltage and current, active and reactive power and further mains characteristics for varying load conditions. Also, daily profiles for situations with and without distributed generation are presented and short-circuit simulations and grid dynamics are discussed.

  1. Increase in the number of distributed power generation installations in electricity distribution grids - Simulation in a 400 V low-voltage network; Zunahme der dezentralen Energieerzeugungsanlagen in elektrischen Verteilnetzen: Simulationen im 400 V Niederspannungsnetz des ewz

    Energy Technology Data Exchange (ETDEWEB)

    Hoeckel, M.; Luechinger, P.

    2003-07-01

    This is the sixth part of a ten-part final report for the Swiss Federal Office of Energy (SFOE) on a project that looked into potential problems relating to the Swiss electricity distribution grid with respect to the increasing number of distributed power generation facilities being put into service. The identification of special conditions for the grid's operation and future development that take increasing decentralised power production into account are discussed. The results of the project activities encompass the analysis and evaluation of various problem areas associated with planning and management of the grid during normal operation and periods of malfunction, as well as required modifications to safety systems and grid configurations. This fifth appendix to the main report presents and discusses the results of simulations made on the basis of the real-life 400 V low-voltage distribution network operated by the public utilities of the City of Zurich, Switzerland. This comprehensive appendix describes the simulation methods used and the basic characteristics of low-voltage networks and distributed generation facilities. The 6 simulation variants used are also described. The results of the simulations are presented in graphical form and provide profiles of voltage and current, active and reactive power and further mains characteristics for varying load conditions. Also, short-circuit simulations and harmonics analysis are discussed.

  2. THE RELATIONSHIP BETWEEN NUMBER NAMES AND NUMBER CONCEPTS

    DEFF Research Database (Denmark)

    Ejersbo, Lisser Rye; Misfeldt, Morten

    2016-01-01

    the regularity or irregularity of number naming affects children’s formation of number concepts and arithmetic performance. We investigate this issue by reviewing relevant literature and undertaking a design research project addressing the specific irregularities of the Danish number names. In this project......, a second, regular set of number names is introduced in primary school. The study’s findings suggest that the regularity of number names influences the development of number concepts and creates a positive impact on the understanding of the base-10 system....

  3. Airborne Network Camera Standard

    Science.gov (United States)

    2015-06-01

    Optical Systems Group Document 466-15 AIRBORNE NETWORK CAMERA STANDARD DISTRIBUTION A: APPROVED FOR PUBLIC RELEASE...Airborne Network Camera Standard 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER...without the focus of standardization for interoperable command and control, storage, and data streaming has been the airborne network camera systems used

  4. Issues and challenges with integrating patient-reported outcomes in clinical trials supported by the National Cancer Institute-sponsored clinical trials networks.

    Science.gov (United States)

    Bruner, Deborah Watkins; Bryan, Charlene J; Aaronson, Neil; Blackmore, C Craig; Brundage, Michael; Cella, David; Ganz, Patricia A; Gotay, Carolyn; Hinds, Pamela S; Kornblith, Alice B; Movsas, Benjamin; Sloan, Jeff; Wenzel, Lari; Whalen, Giles

    2007-11-10

    The objective of this report is to provide a historical overview of and the issues and challenges inherent in the incorporation of patient-reported outcomes (PROs) into multinational cancer clinical trials in the cancer cooperative groups. An online survey of 12 cancer cooperative groups from the United States, Canada, and Europe was conducted between June and August of 2006. Each of the cooperative groups designated one respondent, who was a member of one of the PRO committees within the cooperative group. There was a 100% response rate, and all of the cancer clinical trial cooperative groups reported conducting PRO research. PRO research has been conducted in the cancer cooperative groups for an average of 15 years (range, 6 to 30 years), and all groups had multidisciplinary committees focused on the design of PRO end points and the choice of appropriate PRO measures for cancer clinical trials. The cooperative groups reported that 5% to 50% of cancer treatment trials and an estimated 50% to 75% of cancer control trials contained PRO primary and secondary end points. There was considerable heterogeneity among the cooperative groups with respect to the formal and informal policies and procedures or cooperative group culture towards PROs, investigator training/mentorship, and resource availability for the measurement and conduct of PRO research within the individual cooperatives. The challenges faced by the cooperative groups to the incorporation of PROs into cancer clinical trials are varied. Some common opportunities for improvement include the adoption of standardized training/mentorship mechanisms for investigators for the conduct of PRO assessments and data collection and the development of minimal criteria for PRO measure acceptability. A positive cultural shift has occurred in most of the cooperative groups related to the incorporation of PROs in clinical trials; however, financial and other resource barriers remain and need to be addressed.

  5. Issues and Challenges With Integrating Patient-Reported Outcomes in Clinical Trials Supported by the National Cancer Institute–Sponsored Clinical Trials Networks

    Science.gov (United States)

    Bruner, Deborah Watkins; Bryan, Charlene J.; Aaronson, Neil; Blackmore, C. Craig; Brundage, Michael; Cella, David; Ganz, Patricia A.; Gotay, Carolyn; Hinds, Pamela S.; Kornblith, Alice B.; Movsas, Benjamin; Sloan, Jeff; Wenzel, Lari; Whalen, Giles

    2016-01-01

    Purpose The objective of this report is to provide a historical overview of and the issues and challenges inherent in the incorporation of patient-reported outcomes (PROs) into multinational cancer clinical trials in the cancer cooperative groups. Methods An online survey of 12 cancer cooperative groups from the United States, Canada, and Europe was conducted between June and August of 2006. Each of the cooperative groups designated one respondent, who was a member of one of the PRO committees within the cooperative group. Results There was a 100% response rate, and all of the cancer clinical trial cooperative groups reported conducting PRO research. PRO research has been conducted in the cancer cooperative groups for an average of 15 years (range, 6 to 30 years), and all groups had multidisciplinary committees focused on the design of PRO end points and the choice of appropriate PRO measures for cancer clinical trials. The cooperative groups reported that 5% to 50% of cancer treatment trials and an estimated 50% to 75% of cancer control trials contained PRO primary and secondary end points. There was considerable heterogeneity among the cooperative groups with respect to the formal and informal policies and procedures or cooperative group culture towards PROs, investigator training/mentorship, and resource availability for the measurement and conduct of PRO research within the individual cooperatives. Conclusion The challenges faced by the cooperative groups to the incorporation of PROs into cancer clinical trials are varied. Some common opportunities for improvement include the adoption of standardized training/mentorship mechanisms for investigators for the conduct of PRO assessments and data collection and the development of minimal criteria for PRO measure acceptability. A positive cultural shift has occurred in most of the cooperative groups related to the incorporation of PROs in clinical trials; however, financial and other resource barriers remain and need

  6. 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.

  7. Security for multihop wireless networks

    CERN Document Server

    Khan, Shafiullah

    2014-01-01

    Security for Multihop Wireless Networks provides broad coverage of the security issues facing multihop wireless networks. Presenting the work of a different group of expert contributors in each chapter, it explores security in mobile ad hoc networks, wireless sensor networks, wireless mesh networks, and personal area networks.Detailing technologies and processes that can help you secure your wireless networks, the book covers cryptographic coprocessors, encryption, authentication, key management, attacks and countermeasures, secure routing, secure medium access control, intrusion detection, ep

  8. Seeded Bayesian Networks: Constructing genetic networks from microarray data

    Directory of Open Access Journals (Sweden)

    Quackenbush John

    2008-07-01

    Full Text Available Abstract Background DNA microarrays and other genomics-inspired technologies provide large datasets that often include hidden patterns of correlation between genes reflecting the complex processes that underlie cellular metabolism and physiology. The challenge in analyzing large-scale expression data has been to extract biologically meaningful inferences regarding these processes – often represented as networks – in an environment where the datasets are often imperfect and biological noise can obscure the actual signal. Although many techniques have been developed in an attempt to address these issues, to date their ability to extract meaningful and predictive network relationships has been limited. Here we describe a method that draws on prior information about gene-gene interactions to infer biologically relevant pathways from microarray data. Our approach consists of using preliminary networks derived from the literature and/or protein-protein interaction data as seeds for a Bayesian network analysis of microarray results. Results Through a bootstrap analysis of gene expression data derived from a number of leukemia studies, we demonstrate that seeded Bayesian Networks have the ability to identify high-confidence gene-gene interactions which can then be validated by comparison to other sources of pathway data. Conclusion The use of network seeds greatly improves the ability of Bayesian Network analysis to learn gene interaction networks from gene expression data. We demonstrate that the use of seeds derived from the biomedical literature or high-throughput protein-protein interaction data, or the combination, provides improvement over a standard Bayesian Network analysis, allowing networks involving dynamic processes to be deduced from the static snapshots of biological systems that represent the most common source of microarray data. Software implementing these methods has been included in the widely used TM4 microarray analysis package.

  9. High Performance Network Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Jesse E [Los Alamos National Laboratory

    2012-08-10

    Network Monitoring requires a substantial use of data and error analysis to overcome issues with clusters. Zenoss and Splunk help to monitor system log messages that are reporting issues about the clusters to monitoring services. Infiniband infrastructure on a number of clusters upgraded to ibmon2. ibmon2 requires different filters to report errors to system administrators. Focus for this summer is to: (1) Implement ibmon2 filters on monitoring boxes to report system errors to system administrators using Zenoss and Splunk; (2) Modify and improve scripts for monitoring and administrative usage; (3) Learn more about networks including services and maintenance for high performance computing systems; and (4) Gain a life experience working with professionals under real world situations. Filters were created to account for clusters running ibmon2 v1.0.0-1 10 Filters currently implemented for ibmon2 using Python. Filters look for threshold of port counters. Over certain counts, filters report errors to on-call system administrators and modifies grid to show local host with issue.

  10. Percolation in clustered networks

    OpenAIRE

    Miller, Joel C

    2009-01-01

    The social networks that infectious diseases spread along are typically clustered. Because of the close relation between percolation and epidemic spread, the behavior of percolation in such networks gives insight into infectious disease dynamics. A number of authors have studied clustered networks, but the networks often contain preferential mixing between high degree nodes. We introduce a class of random clustered networks and another class of random unclustered networks with the same prefer...

  11. The Brothel Phone Number

    DEFF Research Database (Denmark)

    Korsby, Trine Mygind

    2017-01-01

    -infrastructure in its own right, providing an entry point into the wider infrastructure of transnational pimping. The pimps’ embodied certainty of how to operate successfully in their neighbourhood in Romania is produced in resonance with the local, urban materiality. This interplay generates body techniques, which...... in turn cultivate and maximize uncertainty about themselves in others. When making the move to go abroad into unknown terrains, accessing the infrastructure generated by the phone number can provide certainty and consolidate one’s position within criminal networks abroad. However, at the same time...

  12. Energy Efficient Digital Networks

    Energy Technology Data Exchange (ETDEWEB)

    Lanzisera, Steven [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Brown, Richard [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2013-01-01

    Digital networks are the foundation of the information services, and play an expanding and indispensable role in our lives, via the Internet, email, mobile phones, etc. However, these networks consume energy, both through the direct energy use of the network interfaces and equipment that comprise the network, and in the effect they have on the operating patterns of devices connected to the network. The purpose of this research was to investigate a variety of technology and policy issues related to the energy use caused by digital networks, and to further develop several energy-efficiency technologies targeted at networks.

  13. Modeling the citation network by network cosmology.

    Science.gov (United States)

    Xie, Zheng; Ouyang, Zhenzheng; Zhang, Pengyuan; Yi, Dongyun; Kong, Dexing

    2015-01-01

    Citation between papers can be treated as a causal relationship. In addition, some citation networks have a number of similarities to the causal networks in network cosmology, e.g., the similar in-and out-degree distributions. Hence, it is possible to model the citation network using network cosmology. The casual network models built on homogenous spacetimes have some restrictions when describing some phenomena in citation networks, e.g., the hot papers receive more citations than other simultaneously published papers. We propose an inhomogenous causal network model to model the citation network, the connection mechanism of which well expresses some features of citation. The node growth trend and degree distributions of the generated networks also fit those of some citation networks well.

  14. Modeling the citation network by network cosmology.

    Directory of Open Access Journals (Sweden)

    Zheng Xie

    Full Text Available Citation between papers can be treated as a causal relationship. In addition, some citation networks have a number of similarities to the causal networks in network cosmology, e.g., the similar in-and out-degree distributions. Hence, it is possible to model the citation network using network cosmology. The casual network models built on homogenous spacetimes have some restrictions when describing some phenomena in citation networks, e.g., the hot papers receive more citations than other simultaneously published papers. We propose an inhomogenous causal network model to model the citation network, the connection mechanism of which well expresses some features of citation. The node growth trend and degree distributions of the generated networks also fit those of some citation networks well.

  15. Organizational Issues, Structure, and Processes of Care in 257 ICUs in Latin America: A Study From the Latin America Intensive Care Network.

    Science.gov (United States)

    Estenssoro, Elisa; Alegría, Leyla; Murias, Gastón; Friedman, Gilberto; Castro, Ricardo; Nin Vaeza, Nicolas; Loudet, Cecilia; Bruhn, Alejandro; Jibaja, Manuel; Ospina-Tascon, Gustavo; Ríos, Fernando; Machado, Flavia R; Biasi Cavalcanti, Alexandre; Dubin, Arnaldo; Hurtado, F Javier; Briva, Arturo; Romero, Carlos; Bugedo, Guillermo; Bakker, Jan; Cecconi, Maurizio; Azevedo, Luciano; Hernandez, Glenn

    2017-08-01

    Latin America bears an important burden of critical care disease, yet the information about it is scarce. Our objective was to describe structure, organization, processes of care, and research activities in Latin-American ICUs. Web-based survey submitted to ICU directors. ICUs located in nine Latin-American countries. Individual ICUs. None. Two hundred fifty-seven of 498 (52%) of submitted surveys responded: 51% from Brazil, 17% Chile, 13% Argentina, 6% Ecuador, 5% Uruguay, 3% Colombia, and 5% between Mexico, Peru, and Paraguay. Seventy-nine percent of participating hospitals had less than 500 beds; most were public (59%) and academic (66%). ICUs were mainly medical-surgical (75%); number of beds was evenly distributed in the entire cohort; 77% had 24/7 intensivists; 46% had a physician-to-patient ratio between 1:4 and 7; and 69% had a nurse-to-patient ratio of 1 ≥ 2.1. The 24/7 presence of other specialists was deficient. Protocols in use averaged 9 ± 3. Brazil (vs the rest) had larger hospitals and ICUs and more quality, surveillance, and prevention committees, but fewer 24/7 intensivists and poorer nurse-to-patient ratio. Although standard monitoring, laboratory, and imaging practices were almost universal, more complex measurements and treatments and portable equipment were scarce after standard working hours, and in public hospitals. Mortality was 17.8%, without differences between countries. This multinational study shows major concerns in the delivery of critical care across Latin America, particularly in human resources. Technology was suboptimal, especially in public hospitals. A 24/7 availability of supporting specialists and of key procedures was inadequate. Mortality was high in comparison to high-income countries.

  16. Synergistic effects in threshold models on networks

    Science.gov (United States)

    Juul, Jonas S.; Porter, Mason A.

    2018-01-01

    Network structure can have a significant impact on the propagation of diseases, memes, and information on social networks. Different types of spreading processes (and other dynamical processes) are affected by network architecture in different ways, and it is important to develop tractable models of spreading processes on networks to explore such issues. In this paper, we incorporate the idea of synergy into a two-state ("active" or "passive") threshold model of social influence on networks. Our model's update rule is deterministic, and the influence of each meme-carrying (i.e., active) neighbor can—depending on a parameter—either be enhanced or inhibited by an amount that depends on the number of active neighbors of a node. Such a synergistic system models social behavior in which the willingness to adopt either accelerates or saturates in a way that depends on the number of neighbors who have adopted that behavior. We illustrate that our model's synergy parameter has a crucial effect on system dynamics, as it determines whether degree-k nodes are possible or impossible to activate. We simulate synergistic meme spreading on both random-graph models and networks constructed from empirical data. Using a heterogeneous mean-field approximation, which we derive under the assumption that a network is locally tree-like, we are able to determine which synergy-parameter values allow degree-k nodes to be activated for many networks and for a broad family of synergistic models.

  17. Security Attacks and its Countermeasures in Wireless Sensor Networks

    OpenAIRE

    Rajkumar; Vani B. A

    2014-01-01

    Wireless Sensor Networks have come to the forefront of the scientific community recently. Present WSNs typically communicate directly with a centralized controller or satellite. Going on the other hand, a smart WSN consists of a number of sensors spread across a geographical area; each sensor has wireless communication ability and sufficient intelligence for signal processing and networking of the data. This paper surveyed the different types of attacks, security related issue...

  18. Key Issue

    Directory of Open Access Journals (Sweden)

    Oya Y Rieger

    2012-03-01

    Full Text Available A few months ago, while I was participating in a conference about open access infrastructures, a delegate from a governmental agency asked, “Why does each library need to maintain a repository for their own scientists?” He was rightfully wondering if a broad collaboration in building a network of archives will provide a durable and extensible technology and service framework for ever-increasing digital scholarly content. The ensuing discussion did not offer a plausible response but accentuated that we do not have in place a plan for building an expandable infrastructure to facilitate communication and exchange of information among rapidly proliferating distinct instances of institutional and subject repositories.

  19. Laws of Network Value

    Directory of Open Access Journals (Sweden)

    Juan M.C. Larrosa

    2016-12-01

    Full Text Available The valuation of a social network is an issue that has been addressed based on simplifying approaches. Various value laws have been stipulated, which are largely atheoretical but have been effectively used to estimate the potential economic value of social network-based firms. This review highlights the various contributions used in the recent literature on networks valuation laws.

  20. A natural orbital analysis of the long range behavior of chemical bonding and van der Waals interaction in singlet H2: the issue of zero natural orbital occupation numbers.

    Science.gov (United States)

    Sheng, X W; Mentel, Ł M; Gritsenko, O V; Baerends, E J

    2013-04-28

    This paper gives a natural orbital (NO) based analysis of the van der Waals interaction in (singlet) H2 at long distance. The van der Waals interaction, even if not leading to a distinct van der Waals well, affects the shape of the interaction potential in the van der Waals distance range of 5-9 bohrs and can be clearly distinguished from chemical bonding effects. In the NO basis the van der Waals interaction can be quantitatively covered with, apart from the ground state configurations (1σ(g))(2) and (1σ(u))(2), just the 4 configurations (2σ(g))(2) and (2σ(u))(2), and (1π(u))(2) and (1π(g))(2). The physics of the dispersion interaction requires and explains the peculiar relatively large positive CI coefficients of the doubly excited electron configurations (2σ(u))(2) and (1π(g))(2) (the occupancy amplitudes of the 2σ(u) and 1π(gx, y) NOs) in the distance range 5-9 bohrs, which have been observed before by Cioslowski and Pernal [Chem. Phys. Lett. 430, 188 (2006)]. We show that such positive occupancy amplitudes do not necessarily lead to the existence of zero occupation numbers at some H-H distances.

  1. Two-scale cost efficiency optimization of 5G wireless backhaul networks

    OpenAIRE

    Ge, Xiaohu; Tu, Song; Mao, Guoqiang; Lau, Vincent K. N.; Pan, Linghui

    2016-01-01

    To cater for the demands of future fifth generation (5G) ultra-dense small cell networks, the wireless backhaul network is an attractive solution for the urban deployment of 5G wireless networks. Optimization of 5G wireless backhaul networks is a key issue. In this paper we propose a two-scale optimization solution to maximize the cost efficiency of 5G wireless backhaul networks. Specifically, the number and positions of gateways are optimized in the long time scale of 5G wireless backhaul ne...

  2. computer networks

    Directory of Open Access Journals (Sweden)

    N. U. Ahmed

    2002-01-01

    Full Text Available In this paper, we construct a new dynamic model for the Token Bucket (TB algorithm used in computer networks and use systems approach for its analysis. This model is then augmented by adding a dynamic model for a multiplexor at an access node where the TB exercises a policing function. In the model, traffic policing, multiplexing and network utilization are formally defined. Based on the model, we study such issues as (quality of service QoS, traffic sizing and network dimensioning. Also we propose an algorithm using feedback control to improve QoS and network utilization. Applying MPEG video traces as the input traffic to the model, we verify the usefulness and effectiveness of our model.

  3. Preface JFDE Special Issue Glass

    Directory of Open Access Journals (Sweden)

    Ulrich Knaack

    2015-05-01

    Full Text Available Facade Design and Engineering is a multidisciplinary field that touches many other scientific disciplines. Glass is one of the key materials for building envelopes, and a strong scientific community has developed over the last decade. Designers love glass for its transparency. It is strong but brittle and very demanding in terms of engineering. We continuously see new innovative developments in terms of its climatic performance, structural possibilities, construction design and new applications. Reason enough to dedicate this special issue to the topic. The issue would not have been possible without the contribution of our special editors Jan Belis and Christian Louter, who contributed through their outstanding editorial work and network. Most of the papers in this issue were carefully selected from of a number of invited submissions and conference papers of the COST Action TU0905 Mid-Term Conference, April 17+18 2013, Porec, (CRC Press/Balkema, Leiden and subsequently subjected to the regular blind review process of the journal. Glass as a building material demonstrates the nature of the architectural discipline, where science and building practice are closely linked. Buildings are the live testing bed for scientific research and, at the same time, building practice formulates new research questions. We found that many articles sent to us deal with this relation. Therefore we decided to introduce the new category ’Applied Practice’ for certain journal paper contributions, which from now on can be found at the end of each issue. Although they do not need to be purely scientific, ’Applied Practice’ papers will always discuss new developments, will have a clear structure and are subjected to the strict JFDE review process. Façade Design and Engineering is a peer reviewed, open access journal, funded by The Netherlands Organisation for Scientific Research NWO (www.nwo.nl. We see ’open access’ as the future publishing model. But it

  4. Mathematical model of highways network optimization

    Science.gov (United States)

    Sakhapov, R. L.; Nikolaeva, R. V.; Gatiyatullin, M. H.; Makhmutov, M. M.

    2017-12-01

    The article deals with the issue of highways network design. Studies show that the main requirement from road transport for the road network is to ensure the realization of all the transport links served by it, with the least possible cost. The goal of optimizing the network of highways is to increase the efficiency of transport. It is necessary to take into account a large number of factors that make it difficult to quantify and qualify their impact on the road network. In this paper, we propose building an optimal variant for locating the road network on the basis of a mathematical model. The article defines the criteria for optimality and objective functions that reflect the requirements for the road network. The most fully satisfying condition for optimality is the minimization of road and transport costs. We adopted this indicator as a criterion of optimality in the economic-mathematical model of a network of highways. Studies have shown that each offset point in the optimal binding road network is associated with all other corresponding points in the directions providing the least financial costs necessary to move passengers and cargo from this point to the other corresponding points. The article presents general principles for constructing an optimal network of roads.

  5. Transformation of legacy network management system to service oriented architecture

    Science.gov (United States)

    Sathyan, Jithesh; Shenoy, Krishnananda

    2007-09-01

    Service providers today are facing the challenge of operating and maintaining multiple networks, based on multiple technologies. Network Management System (NMS) solutions are being used to manage these networks. However the NMS is tightly coupled with Element or the Core network components. Hence there are multiple NMS solutions for heterogeneous networks. Current network management solutions are targeted at a variety of independent networks. The wide spread popularity of IP Multimedia Subsystem (IMS) is a clear indication that all of these independent networks will be integrated into a single IP-based infrastructure referred to as Next Generation Networks (NGN) in the near future. The services, network architectures and traffic pattern in NGN will dramatically differ from the current networks. The heterogeneity and complexity in NGN including concepts like Fixed Mobile Convergence will bring a number of challenges to network management. The high degree of complexity accompanying the network element technology necessitates network management systems (NMS) which can utilize this technology to provide more service interfaces while hiding the inherent complexity. As operators begin to add new networks and expand existing networks to support new technologies and products, the necessity of scalable, flexible and functionally rich NMS systems arises. Another important factor influencing NMS architecture is mergers and acquisitions among the key vendors. Ease of integration is a key impediment in the traditional hierarchical NMS architecture. These requirements trigger the need for an architectural framework that will address the NGNM (Next Generation Network Management) issues seamlessly. This paper presents a unique perspective of bringing service orientated architecture (SOA) to legacy network management systems (NMS). It advocates a staged approach in transforming a legacy NMS to SOA. The architecture at each stage is detailed along with the technical advantages and

  6. Telematics Simulation: Recent Developments & Issues.

    Science.gov (United States)

    Sutherland, Janet; Ekker, Knut; Morgan, Konrad; Crookall, David; Carbonell, Amparo Garcia

    Recent developments in Internet technologies have enabled new, more flexible forms of telematic simulation and have raised issues that were not considered in the early days of networked learning. Ultimately, these questions revolve around: (1) the learning cost-effectiveness of telematic simulation (quality and quantity of learning as opposed to…

  7. A Constructive Neural-Network Approach to Modeling Psychological Development

    Science.gov (United States)

    Shultz, Thomas R.

    2012-01-01

    This article reviews a particular computational modeling approach to the study of psychological development--that of constructive neural networks. This approach is applied to a variety of developmental domains and issues, including Piagetian tasks, shift learning, language acquisition, number comparison, habituation of visual attention, concept…

  8. Give-and-take based peer-to-peer content distribution networks

    Indian Academy of Sciences (India)

    Content Distribution Networks (CDNs) are widely used to distribute data to large number of users. Traditionally, content is being replicated among a number of surrogate servers, leading to high operational costs. In this context, Peer-to-Peer (P2P) CDNs have emerged as a viable alternative. An issue of concern in P2P ...

  9. Give-and-take based peer-to-peer content distribution networks

    Indian Academy of Sciences (India)

    Abstract. Content Distribution Networks (CDNs) are widely used to distribute data to large number of users. Traditionally, content is being replicated among a number of surrogate servers, leading to high operational costs. In this context, Peer-to-Peer (P2P). CDNs have emerged as a viable alternative. An issue of concern in ...

  10. In This Issue

    Science.gov (United States)

    Warner, Brian D.

    2018-01-01

    This list gives those asteroids in this issue for which physical observations (excluding astrometric only) were made. This includes lightcurves, color index, and H-G determinations, etc. In some cases, no specific results are reported due to a lack of or poor quality data. The page number is for the first page of the paper mentioning the asteroid. EP is the "go to page" value in the electronic version.

  11. This Issue

    Directory of Open Access Journals (Sweden)

    Editors / Herausgeber

    2015-12-01

    Full Text Available Whereas the last issue of DIEGESIS (4.1 was dedicated to “Narrative and Lies”, the current volume’s focus shifts to “Narrative and Truth”. Is there a correlation between a narrative’s truth claim and its form? Does the form of narrative allow for the possibility of certain types of truth-oriented discourses in the first place? Or does it, on the contrary, prove an impediment to authentic truthful speech?Johannes Stephan distinguishes two kinds of travelogues: those reproducing received knowledge and those attempting to present the traveller’s experiences. One example of the latter type is the Arabic ‘Travel Book’ (1764 by the Syrian author Ḥanna Dyāb, in which focalization is used not only to witness but also to visualise the experiences of the traveller.Evelyn Chew and Alex Mitchell discuss a similar problem with application to contemporary texts. They investigate the construction of truth claims in three interactive nonfiction life stories in different genres. In the three case studies, of an autobiography, a biographical docugame and a video-based web documentary respectively, subjective and objective legitimation strategies are investigated.Against a backdrop of philosophical discussions of the epistemic value of narration and with specific reference to Aristotle’s Poetics, Malte Dreyer distinguishes three forms of generating coherence in narrative texts: the causal, the teleological and the holistic. He goes on to apply these concepts to social contract theories and to discuss the validity claims of the different types of narrative explanation.In this issue’s “My Narratology” section, James Phelan responds to our questions about his personal ideas of narratology. He describes his own approach as “theorypractice” and argues in favour of conceptualising narrative as “rhetorical action”.We wish you an interesting read!

  12. From networked publics to issue publics

    DEFF Research Database (Denmark)

    Birkbak, Andreas

    2013-01-01

    that the complex connectivity of the web puts user privacy at risk and enables the enclosure of public debate in virtual echo chambers. Our first argument is that these concerns are united by a set assumptions coming from liberal political philosophy that are rarely made explicit. As a second contribution...

  13. Security Issues in Networks with Internet Access

    Science.gov (United States)

    1997-01-01

    implements SSL [ FKK 96] or SHTTP [ReSc 97] protocols [IETF]) can be used, and orders can be restricted to those originating from Web clients that...93, pages 1962-1979, ISBN 0- 8493-2909-4. [FIRST] Forum of Incident Response and Security Teams. http://www.first.org/ [ FKK 96] Freier, A.O., P

  14. Biased trapping issue on weighted hierarchical networks

    Indian Academy of Sciences (India)

    edge's weight is used as local information by a random walker, we introduce a biased walk. The biased walk is that a ... because of its role in real situations such as transport in disordered media, neuron fir- ing, spread of .... consisting of the hub node of Gg and the local hub set, Hn(1 ≤ n

  15. Virtual Networking Performance in OpenStack Platform for Network Function Virtualization

    Directory of Open Access Journals (Sweden)

    Franco Callegati

    2016-01-01

    Full Text Available The emerging Network Function Virtualization (NFV paradigm, coupled with the highly flexible and programmatic control of network devices offered by Software Defined Networking solutions, enables unprecedented levels of network virtualization that will definitely change the shape of future network architectures, where legacy telco central offices will be replaced by cloud data centers located at the edge. On the one hand, this software-centric evolution of telecommunications will allow network operators to take advantage of the increased flexibility and reduced deployment costs typical of cloud computing. On the other hand, it will pose a number of challenges in terms of virtual network performance and customer isolation. This paper intends to provide some insights on how an open-source cloud computing platform such as OpenStack implements multitenant network virtualization and how it can be used to deploy NFV, focusing in particular on packet forwarding performance issues. To this purpose, a set of experiments is presented that refer to a number of scenarios inspired by the cloud computing and NFV paradigms, considering both single tenant and multitenant scenarios. From the results of the evaluation it is possible to highlight potentials and limitations of running NFV on OpenStack.

  16. Cognitive Dynamic Optical Networks

    DEFF Research Database (Denmark)

    de Miguel, Ignacio; Duran, Ramon J.; Lorenzo, Ruben M.

    2013-01-01

    Cognitive networks are a promising solution for the control of heterogeneous optical networks. We review their fundamentals as well as a number of applications developed in the framework of the EU FP7 CHRON project.......Cognitive networks are a promising solution for the control of heterogeneous optical networks. We review their fundamentals as well as a number of applications developed in the framework of the EU FP7 CHRON project....

  17. Trans: Issue 18 Editorial

    Directory of Open Access Journals (Sweden)

    Andrew Murphie, Adrian Mackenzie, Mitchell Whitelaw

    2011-10-01

    Full Text Available It is now perhaps a commonplace that digital, networked and informational media are extremely transient. They diversify in form and function at a dizzying rate. At the same time, they transit and fuse “social” and “natural” differences in a manner which reconfigures all the worlds involved. It is also perhaps a commonplace to suggest that some established powers have found it difficult to come to grips with this (although this is perhaps beginning to change. For many, from seriously challenged newspaper proprietors to established media disciplines, it might be time to pause for breath, if only for a moment—to regroup and adapt established practices and ideas, to count the survivors from among the old media worlds of just a few years ago.While occasionally sympathetic, this issue of the Fibreculture Journal questions this approach. If we pause for breath, it is to take in the new air. This issue draws on the accelerated evolutions of media forms and processes, the microrevolutions in the social (and even the natural sciences that dynamic media foster, even the way in which “new” media lead us to reconsider the diversity of “old” media species. Summed up simply here under the sign/event of the “trans,” this issue catalyzes new concepts, accounts of and suggestions for new practices for working with all these processes.

  18. Network Vulnerability and Risk Assessment

    National Research Council Canada - National Science Library

    Alward, Randy G; Carley, Kathleen M; Madsen, Fredrik; Taylor, Vincent K; Vandenberghe, Grant

    2006-01-01

    To help understand a network and its ability to continue operating when under attack, the break out group discussed issues that need to be considered when presenting network vulnerability information...

  19. Simulating Autonomous Telecommunication Networks for Space Exploration

    Science.gov (United States)

    Segui, John S.; Jennings, Esther H.

    2008-01-01

    Currently, most interplanetary telecommunication systems require human intervention for command and control. However, considering the range from near Earth to deep space missions, combined with the increase in the number of nodes and advancements in processing capabilities, the benefits from communication autonomy will be immense. Likewise, greater mission science autonomy brings the need for unscheduled, unpredictable communication and network routing. While the terrestrial Internet protocols are highly developed their suitability for space exploration has been questioned. JPL has developed the Multi-mission Advanced Communications Hybrid Environment for Test and Evaluation (MACHETE) tool to help characterize network designs and protocols. The results will allow future mission planners to better understand the trade offs of communication protocols. This paper discusses various issues with interplanetary network and simulation results of interplanetary networking protocols.

  20. Defense Acquisition Research Journal. Volume 21, Number 1, Issue 68

    Science.gov (United States)

    2014-01-01

    21 No. 1: 486–504 Principles from microeconomic theory and operations research can provide insight into acquisition decisions to produce military...Contractors and the Defense Department Edmund Conrow (1995) developed an excellent microeconomic framework to investigate the incentives of buyers and

  1. Defense AR Journal. Volume 18, Number 1, Issue 57

    Science.gov (United States)

    2011-01-01

    included senior leaders within RDE- COM (n = 5), the deputy assistant secretaries of the Army for Defense Exports and Controls (n = 2), and the...ANTICIPATED OVERSEAS R&D EXPENDITURE OVER NEXT 3 YEARS Note. Adapted from Scattering the Seeds of Invention: The Globalisation of Research and Development...Acquisition Support Center. Economist Intelligence Unit. (2004, September). Scattering the seeds of invention: The globalisation of research and

  2. Leading Edge. Volume 7, Issue Number 4, 2012

    Science.gov (United States)

    2012-01-01

    Katyusha artillery rockets and 5 artillery shells . Dr. Stoudt is the Distinguished Engineer for Directed Energy (ST) and the NAVSEA Technical Warrant for...facility at the Pumpkin Neck Explosive Test Range to serve as a laser back- stop and measurement facility, as well as an explo- sive-test staging area...shot down 28 Katyusha artillery rockets and 5 artillery shells . On 4 November 2002, THEL shot down an incom- ing artillery shell and a mobile version

  3. Defense Acquisition Review Journal. Volume 17, Number 1, Issue 53

    Science.gov (United States)

    2010-01-01

    and fixed as needed, on the fly and from a remote location. SW Documentation CM Processes Garbage Collection 64 Bit Backup Processes Hardware...the server architecture Elections ATEC C&L Report* OPER Assess 3 ID Scaling ID CPOF “Low Hanging Fruit ” DARPA SW Delivery CPOF 3.0 TRADOC Prioritized...continuous media. Journal of Software. Queensland , Australia: School of Computing and Information Technology, Griffith University. Software Engineering

  4. Contentions over a Number of Hot Issues in Educational Economics

    Science.gov (United States)

    Xibin, Jin

    2006-01-01

    The Chinese Communist Party's Fifteenth Congress established Deng Xiaoping Theory as the guiding school of thought and propelled China's construction of socialist modernization into the 21st century. Comrade Deng Xiaoping's breakthroughs in the theory of economic construction have pushed research on the relationship between education and economic…

  5. Defense Acquisition Research Journal. Volume 24, Number 1, Issue 80

    Science.gov (United States)

    2017-01-01

    organisations . In A. Gunasekaran (Ed.), Agile Manufacturing: The 21st. Century Competitive Strategy (pp. 193–202). New York, NY: Elsevier. General...Increases  = Decreases Technical Performance  = Keeps or Improves = Reduces B al an ci ng R eq ui re m en ts  Drive consensus  Rushing to meet...Operating Environments Services’ Changing Requirements Driving Consensus Forces Concessions Increased Weight Joint Programs More Expensive Meeting Each

  6. Defense Acquisition Research Journal. Volume 22, Number 1, Issue 72.

    Science.gov (United States)

    2015-01-01

    growth in new acquisition programs by associ- ating these programs with previous ones. This technique reduces cost estimate error in the earliest...perhaps best described in a three-sentence essay about Socrates writ - ten by a fourth-grader: “Socrates was a philos- opher,” she wrote. “He went...of doing things. Once better ideas are identified, they are captured as standard work and spelled out in procedures, training, checklists, and

  7. Defense Acquisition Review Journal. Volume 16, Number 3, Issue 52

    Science.gov (United States)

    2009-10-01

    Defense Acquisition University www.dau.mil and using Federal Express, United Parcel Service, or DHL International as a source for parts delivery. As...SYSTEM *Surface Deployment and Distribution Command 3 1 6 | A Publication of the Defense Acquisition University www.dau.mil UPS, or DHL might bring...learners to gain an understanding of their strengths and weaknesses in order to provide them with the information they need to self-monitor their

  8. Erratum Special issue Journal of Biosciences Volume 32, Number 1 ...

    Indian Academy of Sciences (India)

    Administrator

    bone structure in terms of protein blocks from sequence; J. Biosci. 32 51–70. 5. ... Pal A, Chakrabarti P, Bahadur R, Rodier F and Janin J 2007 Peptide segments in protein-protein interfaces; J. Biosci. 32. 101–111 ... Rangamani P and Iyengar R 2007 Modelling spatio-temporal interactions within the cell; J. Biosci. 32 157– ...

  9. Defense Acquisition Research Journal. Volume 22, Number 2, Issue 73

    Science.gov (United States)

    2015-04-01

    Memorandum ( IDM ) Acceptable procurement progress and output—Acceptable acquisition strategy Unacceptable Quality Risk Report due to technology maturity...MMMMB 210 Note. ADM = Acquisition Decision Memorandum; GM = General Management; IDM = Investment Decision Memorandum; IGCE = Independent Government

  10. Number 1, July Special issue on Raychaudhuri equation at the ...

    Indian Academy of Sciences (India)

    A R M Yusoff, M N Syahrul and K Henkel. 285. Brief Reports. Theoretical approach to the magnetic properties of Mn(II), Cr(III), and Cu(II) complexes in the newly ..... G Mavromanolakis. 1063. Understanding the performance of CMS calorimeter . . . . . . . . .Seema Sharma. 1069. Evolution of the dual-readout calorimeter .

  11. Defense Acquisition Review Journal. Volume 17, Number 2, Issue 54

    Science.gov (United States)

    2010-04-01

    today, DoD needs a similar active strategy for determining who is best served by T&E ( Barnett , 2004). This article examines the fundamental...George.axiotis@osd.mil) 2 8 2 | A Publication of the Defense Acquisition University www.dau.mil REFERENCES Barnett , T. P. (2004). The Pentagon’s new... Dental Squadrons. (E-mail address: Alvis.Headen@langley.af.mil) 3 0 0 | A Publication of the Defense Acquisition University www.dau.mil REFERENCES

  12. Defense Acquisition Research Journal. Volume 21, Number 3, Issue 70

    Science.gov (United States)

    2014-07-01

    powdered or liquid raw materials layer by layer into a final piece. Additionally, additive manufacturing allows the elimination of welding , brackets...3D printers, computer-assisted milling machines, and laser, plasma , and water cutters, along with common tools like saws and welding gear (Hill...Wi de spr ead Po ten tia l Hu ma nit ari an Cr ise s, Go ver na nce Cr ise s Arc tic Te rrit ori al Dis pu tes R uss ia- Ge org ia Ten sio ns EU

  13. Defense Acquisition Research Journal. Volume 21, Number 2, Issue 69

    Science.gov (United States)

    2014-04-01

    literature is replete with relevant research studies in this regard ( Baltes , Briggs, Wright, & Neuman, 1999; Hamermesh, 1999; Bailey & Kurland, 2002...Findings, new directions and lessons for the study of modern work. Journal of Organizational Behavior, 23(4), 383–400. Baltes , B., Briggs, T., Wright, J

  14. Asygnosis and asygnotic networks

    Directory of Open Access Journals (Sweden)

    Edward M. Roche

    2016-05-01

    Full Text Available The purpose of this paper is to create a dialogue between disparate academic disciplines around the topics of decision making, human communication networks, and information exchange. The emergence of modern telecommunications, including social media, gaming platforms, and instant messaging has enabled the emergence of massive online global communities numbering into the tens and hundreds of millions of persons regardless of culture and language capable of exchanging ideas, images, and impressions in real time. The unprecedented scope and scale of these networks challenges contemporary theories in management and decision making, political organization and governance of institutions, sociology, and communications. Our argument is that these theories are outdated and must be rethought. We propose a simple model, "asygnosis", in which decisions and strategies are the product of the continuous (non-discrete flows of information, ideas and impressions (“memes” along ever-changing communication pathways between individuals and/or machines. These networks reflect the undirected emergence, exchange and demise of knowledge that forms around a specific idea or activity. They challenge traditional assumptions about rationality, causality, and the use of organizational structures as control mechanisms which form the basis of most social, economic and political theories. After developing the concept in detail of asyngnosis and asyngnotic networks, we apply it to current issues including unpredictable events that takes place without direct control such as the rise of spontaneous terrorism, and other social and political phenomenon such as the Arab Spring and Occupy Wall Street. Finally, the paper suggests areas of future research in a number of disciplines that might help develop the concept further, test assumptions, and lead to new insights into this emerging phenomenon.

  15. The Coverage Problem in Video-Based Wireless Sensor Networks: A Survey

    Directory of Open Access Journals (Sweden)

    Luiz Affonso Guedes

    2010-09-01

    Full Text Available Wireless sensor networks typically consist of a great number of tiny low-cost electronic devices with limited sensing and computing capabilities which cooperatively communicate to collect some kind of information from an area of interest. When wireless nodes of such networks are equipped with a low-power camera, visual data can be retrieved, facilitating a new set of novel applications. The nature of video-based wireless sensor networks demands new algorithms and solutions, since traditional wireless sensor networks approaches are not feasible or even efficient for that specialized communication scenario. The coverage problem is a crucial issue of wireless sensor networks, requiring specific solutions when video-based sensors are employed. In this paper, it is surveyed the state of the art of this particular issue, regarding strategies, algorithms and general computational solutions. Open research areas are also discussed, envisaging promising investigation considering coverage in video-based wireless sensor networks.

  16. The coverage problem in video-based wireless sensor networks: a survey.

    Science.gov (United States)

    Costa, Daniel G; Guedes, Luiz Affonso

    2010-01-01

    Wireless sensor networks typically consist of a great number of tiny low-cost electronic devices with limited sensing and computing capabilities which cooperatively communicate to collect some kind of information from an area of interest. When wireless nodes of such networks are equipped with a low-power camera, visual data can be retrieved, facilitating a new set of novel applications. The nature of video-based wireless sensor networks demands new algorithms and solutions, since traditional wireless sensor networks approaches are not feasible or even efficient for that specialized communication scenario. The coverage problem is a crucial issue of wireless sensor networks, requiring specific solutions when video-based sensors are employed. In this paper, it is surveyed the state of the art of this particular issue, regarding strategies, algorithms and general computational solutions. Open research areas are also discussed, envisaging promising investigation considering coverage in video-based wireless sensor networks.

  17. Data Storage for Social Networks A Socially Aware Approach

    CERN Document Server

    Tran, Duc A

    2012-01-01

    Evidenced by the success of Facebook, Twitter, and LinkedIn, online social networks (OSNs) have become ubiquitous, offering novel ways for people to access information and communicate with each other. As the increasing popularity of social networking is undeniable, scalability is an important issue for any OSN that wants to serve a large number of users. Storing user data for the entire network on a single server can quickly lead to a bottleneck, and, consequently, more servers are needed to expand storage capacity and lower data request traffic per server. Adding more servers is just one step

  18. Network Coding Opportunities for Wireless Grids Formed by Mobile Devices

    DEFF Research Database (Denmark)

    Nielsen, Karsten Fyhn; Madsen, Tatiana Kozlova; Fitzek, Frank

    2008-01-01

    Wireless grids have potential in sharing communication, computational and storage resources making these networks more powerful, more robust, and less cost intensive. However, to enjoy the benefits of cooperative resource sharing, a number of issues should be addressed and the cost of the wireless...... link should be taken into account. We focus on the question how nodes can efficiently communicate and distribute data in a wireless grid. We show the potential of a network coding approach when nodes have the possibility to combine packets thus increasing the amount of information per transmission. Our...... implementation demonstrates the feasibility of network coding for wireless grids formed by mobile devices....

  19. Underwater sensor nodes and networks

    National Research Council Canada - National Science Library

    Lloret, Jaime

    2013-01-01

    .... This special issue is focused on collecting recent advances on underwater sensors and underwater sensor networks in order to measure, monitor, surveillance of and control of underwater environments...

  20. Properties of healthcare teaming networks as a function of network construction algorithms

    Science.gov (United States)

    Trayhan, Melissa; Farooq, Samir A.; Fucile, Christopher; Ghoshal, Gourab; White, Robert J.; Quill, Caroline M.; Rosenberg, Alexander; Barbosa, Hugo Serrano; Bush, Kristen; Chafi, Hassan; Boudreau, Timothy

    2017-01-01

    Network models of healthcare systems can be used to examine how providers collaborate, communicate, refer patients to each other, and to map how patients traverse the network of providers. Most healthcare service network models have been constructed from patient claims data, using billing claims to link a patient with a specific provider in time. The data sets can be quite large (106–108 individual claims per year), making standard methods for network construction computationally challenging and thus requiring the use of alternate construction algorithms. While these alternate methods have seen increasing use in generating healthcare networks, there is little to no literature comparing the differences in the structural properties of the generated networks, which as we demonstrate, can be dramatically different. To address this issue, we compared the properties of healthcare networks constructed using different algorithms from 2013 Medicare Part B outpatient claims data. Three different algorithms were compared: binning, sliding frame, and trace-route. Unipartite networks linking either providers or healthcare organizations by shared patients were built using each method. We find that each algorithm produced networks with substantially different topological properties, as reflected by numbers of edges, network density, assortativity, clustering coefficients and other structural measures. Provider networks adhered to a power law, while organization networks were best fit by a power law with exponential cutoff. Censoring networks to exclude edges with less than 11 shared patients, a common de-identification practice for healthcare network data, markedly reduced edge numbers and network density, and greatly altered measures of vertex prominence such as the betweenness centrality. Data analysis identified patterns in the distance patients travel between network providers, and a striking set of teaming relationships between providers in the Northeast United States and

  1. IJIMAI Editor's Note - Vol. 3 Issue 1

    OpenAIRE

    Ruben Gonzalez Crespo

    2014-01-01

    The research works presented in this issue are based on various topics of interest, among which are included: bayesian networks, evolutionary algorithms, virtual reality, web advertising, 3D technologies, traffic expression, Smart Cities, computational sustainability, computer vision, image recognition, deep neural networks, graphical models, mobile devices, human/complex system interactions, multi-agent systems, Physics inspired behaviours, etc.

  2. IJIMAI Editor's Note - Vol. 3 Issue 7

    OpenAIRE

    Oscar Sanjuan-Martinez

    2016-01-01

    The research works presented in this issue are based on various topics of interest, among which are included: SVM and ANN Based Classification, Security in Android, Semantic Data, Planning and Software Agents, Mission Planning, Clustering in Text Mining, Mobile Networks, Weather Radars, Human Activity Recognition, LIF Neurons and DDF, Theft Prevention, Constraint Programming, Measuring Meditations Effects, Neural Networks and Deep Learning.

  3. IJIMAI Editor's Note - Vol. 3 Issue 7

    Directory of Open Access Journals (Sweden)

    Oscar Sanjuan-Martinez

    2016-06-01

    Full Text Available The research works presented in this issue are based on various topics of interest, among which are included: SVM and ANN Based Classification, Security in Android, Semantic Data, Planning and Software Agents, Mission Planning, Clustering in Text Mining, Mobile Networks, Weather Radars, Human Activity Recognition, LIF Neurons and DDF, Theft Prevention, Constraint Programming, Measuring Meditations Effects, Neural Networks and Deep Learning.

  4. Prevent P.A.D.: Know Your Numbers

    Science.gov (United States)

    ... Home Current Issue Past Issues Special Section Prevent P.A.D.: Know Your Numbers Past Issues / Summer ... By Mary Best "Timely detection and treatment of P.A.D. are critical," says Dr. Patrice Desvigne- ...

  5. PREFACE: CEWQO Topical Issue CEWQO Topical Issue

    Science.gov (United States)

    Bozic, Mirjana; Man'ko, Margarita

    2009-09-01

    by Adam et al. In the paper by V Man'ko et al the diagonal representation of the density operator (usually called P-function of Glauber-Sudarshan) is related to the star-product quantization method and to the tomographic-probability representation of quantum states. Laskowski et al suggest an elegant geometrical criterion for the separability, which is based on the local correlation measurements readily available in the laboratory. Mizrahi describes a method to derive the Pauli-Schrödinger equation starting from a simple model of a qubit carried by a massive particle. By analyzing unavoidable quantum losses as they appear in neutron phase-echo and spin rotation experiments, Rauch concludes that basic quantum irreversibility exists in neutron interferometry. Rauch also shows how entanglement effects in a single particle system demonstrate quantum contextuality, and then argues that a quantum system carries much more information than is usually extracted. Kupczynski advocates various statistical tests which could be used to search for a fine structure in experimental data in order to answer the question: is quantum theory predictably complete? For an ion confined within a Paul trap, Mihalcea constructs an invariant operator based on the Lews and Riesenfeld approach and determines the spectrum of the quasienergy operator. Popov et al construct pair-coherent states of the Barut-Girardello kind for two noninteracting subsystems of pseudoharmonic oscillators and examine their statistical properties in different regions of parameters. The property of entanglement, considered to be the most intriguing property of composite quantum systems, has been an important research subject in recent years. It is considered to be a possible resource for quantum computation and communication. Therefore, a substantial number of papers in this topical issue is devoted to entanglement. Leon et al write that two-photon emission from two atoms initially excited in a common electromagnetic

  6. A Network Traffic Control Enhancement Approach over Bluetooth Networks

    DEFF Research Database (Denmark)

    Son, L.T.; Schiøler, Henrik; Madsen, Ole Brun

    2003-01-01

    This paper analyzes network traffic control issues in Bluetooth data networks as convex optimization problem. We formulate the problem of maximizing of total network flows and minimizing the costs of flows. An adaptive distributed network traffic control scheme is proposed as an approximated...... solution of the stated optimization problem that satisfies quality of service requirements and topologically induced constraints in Bluetooth networks, such as link capacity and node resource limitations. The proposed scheme is decentralized and complies with frequent changes of topology as well...... as capacity limitations and flow requirements in the network. Simulation shows that the performance of Bluetooth networks could be improved by applying the adaptive distributed network traffic control scheme...

  7. Prostate Cancer Pathology Resource Network

    Science.gov (United States)

    2015-12-01

    AD_________________ Award Number: W81XWH-10-2-0056 TITLE: Prostate Cancer Pathology Resource Network PRINCIPAL INVESTIGATOR: Bruce J. Trock, Ph.D... Pathology Resource Network 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-10-2-0056 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Bruce J. Trock, Ph.D. Betty...The Prostate Cancer Pathology Resource Network (which has since been renamed the Prostate Cancer Biorepository Network or PCBN) is a collaboration

  8. Production, Innovation and Service Networks

    DEFF Research Database (Denmark)

    Slepniov, Dmitrij; Wæhrens, Brian Vejrum; Johansen, John

    2011-01-01

    Production, innovation and service networks of companies all over the world become increasingly decentralized, specialized and interdependent. The three characteristics combined inevitably lead to the formation of complex configurations of assets and capabilities crossing both national and organi......Production, innovation and service networks of companies all over the world become increasingly decentralized, specialized and interdependent. The three characteristics combined inevitably lead to the formation of complex configurations of assets and capabilities crossing both national...... and organisational borders. The existing studies do not adequately address the complex interplay between co-evolving production, innovation and service networks. The widening geographical and cognitive gap between these networks means that coordinating them and managing their interfaces in global operations context...... is becoming strategically important. The purpose of this paper is to address this issue and to develop a number of propositions about how companies can organize these networks and coordinate between them effectively. The propositions are developed by employing the design science approach based on a literature...

  9. Rich-cores in networks

    CERN Document Server

    Ma, Athen

    2014-01-01

    A core is said to be a group of central and densely connected nodes which governs the overall behavior of a network. Profiling this meso--scale structure currently relies on a limited number of methods which are often complex, and have scalability issues when dealing with very large networks. As a result, we are yet to fully understand its impact on network properties and dynamics. Here we introduce a simple method to profile this structure by combining the concepts of core/periphery and rich-club. The key challenge in addressing such association of the two concepts is to establish a way to define the membership of the core. The notion of a "rich-club" describes nodes which are essentially the hub of a network, as they play a dominating role in structural and functional properties. Interestingly, the definition of a rich-club naturally emphasizes high degree nodes and divides a network into two subgroups. Our approach theoretically couples the underlying principle of a rich-club with the escape time of a rand...

  10. Boundary issues

    Science.gov (United States)

    Townsend, Alan R.; Porder, Stephen

    2011-03-01

    What is our point of no return? Caesar proclaimed 'the die is cast' while crossing the Rubicon, but rarely does modern society find so visible a threshold in our continued degradation of ecosystems and the services they provide. Humans have always used their surroundings to make a living— sometimes successfully, sometimes not (Diamond 2005)—and we intuitively know that there are boundaries to our exploitation. But defining these boundaries has been a challenge since Malthus first prophesied that nature would limit the human population (Malthus 1798). In 2009, Rockström and colleagues tried to quantify what the 6.8 billion (and counting) of us could continue to get away with, and what we couldn't (Rockström et al 2009). In selecting ten 'planetary boundaries', the authors contend that a sustainable human enterprise requires treating a number of environmental thresholds as points of no return. They suggest we breach these Rubicons at our own peril, and that we've already crossed three: biodiversity loss, atmospheric CO2, and disruption of the global nitrogen (N) cycle. As they clearly hoped, the very act of setting targets has provoked scientific inquiry about their accuracy, and about the value of hard targets in the first place (Schlesinger 2009). Such debate is a good thing. Despite recent emphasis on the science of human-ecosystem interactions, understanding of our planetary boundaries is still in its infancy, and controversy can speed scientific progress (Engelhardt and Caplan 1987). A few weeks ago in this journal, Carpenter and Bennett (2011) took aim at one of the more controversial boundaries in the Rockström analysis: that for human alteration of the global phosphorus (P) cycle. Rockström's group chose riverine P export as the key indicator, suggesting that humans should not exceed a value that could trigger widespread marine anoxic events—and asserting that we have not yet crossed this threshold. There are defensible reasons for a marine

  11. 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.

  12. Security of Mobile ad-hoc Wireless Networks. A Brief Survey

    Directory of Open Access Journals (Sweden)

    TILIUTE, D. E.

    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.

  13. Global Energy Issues

    Energy Technology Data Exchange (ETDEWEB)

    Suto, M.

    2007-07-01

    The e8 is a Non-Government Organization of nine power companies from the G8 countries. It was established in 1992 to play an active role in global electricity issues and to promote sustainable energy development. The e8 is governed by the Chairmen of the member companies, who exchange their views on common themes of the year at their annual Summit meetings. At the Evian Summit in May 2006, the Chairmen discussed 'Global Energy Issues' and established a common statement of e8 commitments and recommendations as follows: (1) Optimum mix of energy supply, (2) Investment for infrastructure and demand growth, (3) Promoting sustainable energy development by sharing expertise, (4) Cooperation among electricity companies, (5) Integration and modernisation of transmission networks, (6) Inclusion of large scale-technologies under the Flexible Mechanisms, (7) International financial institutions, (8) Developments of long-term contracts in the electricity sector, (9) International Institutions - Producer and Consumer Countries, (10) Public acceptance. Guided by this statement, e8 will stride ahead toward achieving 3A's (Accessibility, Availability, Acceptability) globally. (auth)

  14. Identity Management issues in Cloud Computing

    OpenAIRE

    Saini, Smita; Mann, Deep

    2014-01-01

    Cloud computing is providing a low cost on demand services to the users, omnipresent network,large storage capacity due to these features of cloud computing web applications are moving towards the cloud and due to this migration of the web application,cloud computing platform is raised many issues like privacy, security etc. Privacy issue are major concern for the cloud computing. Privacy is to preserve the sensitive information of the cloud consumer and the major issues to the privacy are un...

  15. Wireless mesh networks

    CERN Document Server

    Held, Gilbert

    2005-01-01

    Wireless mesh networking is a new technology that has the potential to revolutionize how we access the Internet and communicate with co-workers and friends. Wireless Mesh Networks examines the concept and explores its advantages over existing technologies. This book explores existing and future applications, and examines how some of the networking protocols operate.The text offers a detailed analysis of the significant problems affecting wireless mesh networking, including network scale issues, security, and radio frequency interference, and suggests actual and potential solutions for each pro

  16. Recent developments in Lambda networking

    Science.gov (United States)

    de Laat, C.; Grosso, P.

    About 6 years ago the first baby-steps were made on opening up dark fiber and DWDM infrastructure for direct use by ISP's after the transformation of the old style Telecom sector into a market driven business. Since then Lambda workshops, community groups like GLIF and a number of experiments have led to many implementations of hybrid national research and education networks and lightpath-based circuit exchanges as pioneered by SURFnet in GigaPort and NetherLight in collaboration with StarLight in Chicago and Canarie in Canada. This article looks back on those developments, describes some current open issues and research developments and proposes a concept of terabit networking.

  17. Optimal Fragile Financial Networks

    NARCIS (Netherlands)

    Castiglionesi, F.; Navarro, N.

    2007-01-01

    We study a financial network characterized by the presence of depositors, banks and their shareholders. Belonging to a financial network is beneficial for both the depositors and banks' shareholders since the return to investment increases with the number of banks connected. However, the network is

  18. Multilevel method for modeling large-scale networks.

    Energy Technology Data Exchange (ETDEWEB)

    Safro, I. M. (Mathematics and Computer Science)

    2012-02-24

    Understanding the behavior of real complex networks is of great theoretical and practical significance. It includes developing accurate artificial models whose topological properties are similar to the real networks, generating the artificial networks at different scales under special conditions, investigating a network dynamics, reconstructing missing data, predicting network response, detecting anomalies and other tasks. Network generation, reconstruction, and prediction of its future topology are central issues of this field. In this project, we address the questions related to the understanding of the network modeling, investigating its structure and properties, and generating artificial networks. Most of the modern network generation methods are based either on various random graph models (reinforced by a set of properties such as power law distribution of node degrees, graph diameter, and number of triangles) or on the principle of replicating an existing model with elements of randomization such as R-MAT generator and Kronecker product modeling. Hierarchical models operate at different levels of network hierarchy but with the same finest elements of the network. However, in many cases the methods that include randomization and replication elements on the finest relationships between network nodes and modeling that addresses the problem of preserving a set of simplified properties do not fit accurately enough the real networks. Among the unsatisfactory features are numerically inadequate results, non-stability of algorithms on real (artificial) data, that have been tested on artificial (real) data, and incorrect behavior at different scales. One reason is that randomization and replication of existing structures can create conflicts between fine and coarse scales of the real network geometry. Moreover, the randomization and satisfying of some attribute at the same time can abolish those topological attributes that have been undefined or hidden from

  19. Neural Network Processing of Natural Language: II. Towards a Unified Model of Corticostriatal Function in Learning Sentence Comprehension and Non-Linguistic Sequencing

    Science.gov (United States)

    Dominey, Peter Ford; Inui, Toshio; Hoen, Michel

    2009-01-01

    A central issue in cognitive neuroscience today concerns how distributed neural networks in the brain that are used in language learning and processing can be involved in non-linguistic cognitive sequence learning. This issue is informed by a wealth of functional neurophysiology studies of sentence comprehension, along with a number of recent…

  20. Identifying gaps in grid middleware on fast networks with the advanced networking initiative

    Energy Technology Data Exchange (ETDEWEB)

    Dykstra, Dave [Fermilab; Garzoglio, Gabriele [Fermilab; Kim, Hyunwoo [Fermilab; Mhashilkar, Parag [Fermilab

    2012-01-01

    As of 2012, a number of US Department of Energy (DOE) National Laboratories have access to a 100 Gb/s wide-area network backbone. The ESnet Advanced Networking Initiative (ANI) project is intended to develop a prototype network, based on emerging 100 Gb/s Ethernet technology. The ANI network will support DOE's science research programs. A 100 Gb/s network test bed is a key component of the ANI project. The test bed offers the opportunity for early evaluation of 100Gb/s network infrastructure for supporting the high impact data movement typical of science collaborations and experiments. In order to make effective use of this advanced infrastructure, the applications and middleware currently used by the distributed computing systems of large-scale science need to be adapted and tested within the new environment, with gaps in functionality identified and corrected. As a user of the ANI test bed, Fermilab aims to study the issues related to end-to-end integration and use of 100 Gb/s networks for the event simulation and analysis applications of physics experiments. In this paper we discuss our findings from evaluating existing HEP Physics middleware and application components, including GridFTP, Globus Online, etc. in the high-speed environment. These will include possible recommendations to the system administrators, application and middleware developers on changes that would make production use of the 100 Gb/s networks, including data storage, caching and wide area access.

  1. Geographies of an Online Social Network.

    Science.gov (United States)

    Lengyel, Balázs; Varga, Attila; Ságvári, Bence; Jakobi, Ákos; Kertész, János

    2015-01-01

    How is online social media activity structured in the geographical space? Recent studies have shown that in spite of earlier visions about the "death of distance", physical proximity is still a major factor in social tie formation and maintenance in virtual social networks. Yet, it is unclear, what are the characteristics of the distance dependence in online social networks. In order to explore this issue the complete network of the former major Hungarian online social network is analyzed. We find that the distance dependence is weaker for the online social network ties than what was found earlier for phone communication networks. For a further analysis we introduced a coarser granularity: We identified the settlements with the nodes of a network and assigned two kinds of weights to the links between them. When the weights are proportional to the number of contacts we observed weakly formed, but spatially based modules resemble to the borders of macro-regions, the highest level of regional administration in the country. If the weights are defined relative to an uncorrelated null model, the next level of administrative regions, counties are reflected.

  2. Geographies of an Online Social Network

    Science.gov (United States)

    Lengyel, Balázs; Varga, Attila; Ságvári, Bence; Jakobi, Ákos; Kertész, János

    2015-01-01

    How is online social media activity structured in the geographical space? Recent studies have shown that in spite of earlier visions about the “death of distance”, physical proximity is still a major factor in social tie formation and maintenance in virtual social networks. Yet, it is unclear, what are the characteristics of the distance dependence in online social networks. In order to explore this issue the complete network of the former major Hungarian online social network is analyzed. We find that the distance dependence is weaker for the online social network ties than what was found earlier for phone communication networks. For a further analysis we introduced a coarser granularity: We identified the settlements with the nodes of a network and assigned two kinds of weights to the links between them. When the weights are proportional to the number of contacts we observed weakly formed, but spatially based modules resemble to the borders of macro-regions, the highest level of regional administration in the country. If the weights are defined relative to an uncorrelated null model, the next level of administrative regions, counties are reflected. PMID:26359668

  3. Z-Score-Based Modularity for Community Detection in Networks.

    Science.gov (United States)

    Miyauchi, Atsushi; Kawase, Yasushi

    2016-01-01

    Identifying community structure in networks is an issue of particular interest in network science. The modularity introduced by Newman and Girvan is the most popular quality function for community detection in networks. In this study, we identify a problem in the concept of modularity and suggest a solution to overcome this problem. Specifically, we obtain a new quality function for community detection. We refer to the function as Z-modularity because it measures the Z-score of a given partition with respect to the fraction of the number of edges within communities. Our theoretical analysis shows that Z-modularity mitigates the resolution limit of the original modularity in certain cases. Computational experiments using both artificial networks and well-known real-world networks demonstrate the validity and reliability of the proposed quality function.

  4. Low Cost Wireless Sensor Network for Continuous Bridge monitoring

    DEFF Research Database (Denmark)

    Han, Bo; Kalis, A; Tragas, P

    2012-01-01

    , since they need to propagate large amounts of data over regular time intervals towards a single destination in the network. Propagation of information is done through multiple hops, suffering from collisions, retransmis-sions and therefore high energy consumption. Moreover, since there is a bottleneck...... effect around the network sink, all routing layer algorithms will always deplete the power of the last tier before the fusion center. Fi-nally, theory shows that in such networks scalability could become an issue since transport capacity per node is severely affected as the number of nodes within...... the network increases. Therefore, in order for WSNs to be considered as an efficient tool to monitor the health state of large structures, their energy consumption should be reduced to a bare minimum. In this work we consider a couple of novel techniques for increasing the life-time of the sensor network...

  5. Systemic risk analysis in reconstructed economic and financial networks

    CERN Document Server

    Cimini, Giulio; Gabrielli, Andrea; Garlaschelli, Diego

    2014-01-01

    The assessment of fundamental properties for economic and financial systems, such as systemic risk, is systematically hindered by privacy issues$-$that put severe limitations on the available information. Here we introduce a novel method to reconstruct partially-accessible networked systems of this kind. The method is based on the knowledge of the fitnesses, $i.e.$, intrinsic node-specific properties, and of the number of connections of only a limited subset of nodes. Such information is used to calibrate a directed configuration model which can generate ensembles of networks intended to represent the real system, so that the real network properties can be estimated within the generated ensemble in terms of mean values of the observables. Here we focus on estimating those properties that are commonly used to measure the network resilience to shock and crashes. Tests on both artificial and empirical networks shows that the method is remarkably robust with respect to the limitedness of the information available...

  6. Wireless networked music performance

    CERN Document Server

    Gabrielli, Leonardo

    2016-01-01

    This book presents a comprehensive overview of the state of the art in Networked Music Performance (NMP) and a historical survey of computer music networking. It introduces current technical trends in NMP and technical issues yet to be addressed. It also lists wireless communication protocols and compares these to the requirements of NMP. Practical use cases and advancements are also discussed.

  7. Telecommunications network modelling, planning and design

    CERN Document Server

    Evans, Sharon

    2003-01-01

    Telecommunication Network Modelling, Planning and Design addresses sophisticated modelling techniques from the perspective of the communications industry and covers some of the major issues facing telecommunications network engineers and managers today. Topics covered include network planning for transmission systems, modelling of SDH transport network structures and telecommunications network design and performance modelling, as well as network costs and ROI modelling and QoS in 3G networks.

  8. Research on 6R Military Logistics Network

    Science.gov (United States)

    Jie, Wan; Wen, Wang

    The building of military logistics network is an important issue for the construction of new forces. This paper has thrown out a concept model of 6R military logistics network model based on JIT. Then we conceive of axis spoke y logistics centers network, flexible 6R organizational network, lean 6R military information network based grid. And then the strategy and proposal for the construction of the three sub networks of 6Rmilitary logistics network are given.

  9. Module identification in bipartite and directed networks

    OpenAIRE

    Guimera, R.; Sales-Pardo, M.; Amaral, L. A. N.

    2007-01-01

    Modularity is one of the most prominent properties of real-world complex networks. Here, we address the issue of module identification in two important classes of networks: bipartite networks and directed unipartite networks. Nodes in bipartite networks are divided into two non-overlapping sets, and the links must have one end node from each set. Directed unipartite networks only have one type of nodes, but links have an origin and an end. We show that directed unipartite networks can be conv...

  10. Intelligent networked teleoperation control

    CERN Document Server

    Li, Zhijun; Su, Chun-Yi

    2015-01-01

    This book describes a unified framework for networked teleoperation systems involving multiple research fields: networked control systems for linear and nonlinear forms, bilateral teleoperation, trilateral teleoperation, multilateral teleoperation and cooperative teleoperation. It closely examines networked control as a field at the intersection of systems & control and robotics and presents a number of experimental case studies on testbeds for robotic systems, including networked haptic devices, robotic network systems and sensor network systems. The concepts and results outlined are easy to understand, even for readers fairly new to the subject. As such, the book offers a valuable reference work for researchers and engineers in the fields of systems & control and robotics.

  11. Dynamics of social networks

    OpenAIRE

    Ebel, Holger; Davidsen, Joern; Bornholdt, Stefan

    2003-01-01

    Complex networks as the World Wide Web, the web of human sexual contacts or criminal networks often do not have an engineered architecture but instead are self-organized by the actions of a large number of individuals. From these local interactions non-trivial global phenomena can emerge as small-world properties or scale-free degree distributions. A simple model for the evolution of acquaintance networks highlights the essential dynamical ingredients necessary to obtain such complex network ...

  12. Networking Resource Centre

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 9. Networking Resource Centre. Information and Announcements Volume 14 Issue 9 September 2009 pp 930-930. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/014/09/0930-0930. Resonance ...

  13. Variety identification of wheat using mass spectrometry with neural networks and the influence of mass spectra processing prior to neural network analysis

    DEFF Research Database (Denmark)

    Sørensen, Helle Aagaard; Sperotto, Maria Maddalena; Petersen, M.

    2002-01-01

    The performance of matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry with neural networks in wheat variety classification is further evaluated.(1) Two principal issues were studied: (a) the number of varieties that could be classified correctly; and (b) various means...

  14. PROVISIONING RESTORABLE VIRTUAL PRIVATE NETWORKS USING BARABASI AND WAXMAN TOPOLOGY GENERATION MODEL

    Directory of Open Access Journals (Sweden)

    R. Ravi

    2010-12-01

    Full Text Available As internet usage grows exponentially, network security issues become increasingly important. Network security measures are needed to protect data during transmission. Various security controls are used to prevent the access of hackers in networks. They are firewall, virtual private networks and encryption algorithms. Out of these, the virtual private network plays a vital role in preventing hackers from accessing the networks. A Virtual Private Network (VPN provides end users with a way to privately access information on their network over a public network infrastructure such as the internet. Using a technique called “Tunneling”, data packets are transmitted across a public routed network, such as the internet that simulates a point-to-point connection. Virtual private networks provide customers with a secure and low-cost communication environment. The basic structure of the virtual circuit is to create a logical path from the source port to the destination port. This path may incorporate many hops between routers for the formation of the circuit. The final, logical path or virtual circuit acts in the same way as a direct connection between the two ports. Our proposed Provisioning Restorable Virtual Private Networks Algorithm (PRA is used to combine the provisioning and restoration algorithms to achieve better results than the ones obtained by independent restoration and provisioning. In order to ensure service quality and availability in Virtual Private Networks, seamless recovery from failures is essential. The quality of service of the Virtual Private Networks is also improved due to the combination of provisioning and restoration. The bandwidth sharing concept is also applied in link to improve the quality of service in the Virtual Private Network. The performance analysis of the proposed algorithm is carried out in terms of cost, the number of nodes, the number of VPN nodes, delay, asymmetric ratio and delay with constraints with

  15. Energy scaling and reduction in controlling complex networks

    Science.gov (United States)

    Chen, Yu-Zhong; Wang, Le-Zhi; Wang, Wen-Xu; Lai, Ying-Cheng

    2016-01-01

    Recent works revealed that the energy required to control a complex network depends on the number of driving signals and the energy distribution follows an algebraic scaling law. If one implements control using a small number of drivers, e.g. as determined by the structural controllability theory, there is a high probability that the energy will diverge. We develop a physical theory to explain the scaling behaviour through identification of the fundamental structural elements, the longest control chains (LCCs), that dominate the control energy. Based on the LCCs, we articulate a strategy to drastically reduce the control energy (e.g. in a large number of real-world networks). Owing to their structural nature, the LCCs may shed light on energy issues associated with control of nonlinear dynamical networks. PMID:27152220

  16. Unique Identification Project Issues and Challenges Unique ...

    Indian Academy of Sciences (India)

    Unique Identification Project Issues and Challenges Unique Identification Authority of India (UIDAI) · Agenda · UIDAI will issue numbers, not cards · UIDAI will authenticate IDs online · Verifying ID is a common challenge · ID is the only focus of UIDAI · Who gets UID number? Inclusive potential of UID · UID ecosystem – A ...

  17. Focus Issue on surface plasmon photonics introduction

    DEFF Research Database (Denmark)

    Levy, Uriel; Berini, Pierre; Maier, Stefan A.

    2015-01-01

    . This Focus Issue collects 23 papers related to research presented at SPP7. While this number is small compared to the total number of papers presented at the conference, the issue is representative and provides a good overview of the field at this point in time. (C) 2015 Optical Society of America...

  18. 75 FR 18572 - Facility Control Numbers

    Science.gov (United States)

    2010-04-12

    ... Internal Revenue Service Facility Control Numbers AGENCY: Internal Revenue Service (IRS), Treasury. ACTION: Notice of planned use of Facility Control Numbers. SUMMARY: The IRS has developed and is publishing in this issue of the Federal Register, Facility Control Numbers to communicate to the motor fuel industry...

  19. Designing value-creating supply chain networks

    CERN Document Server

    Martel, Alain

    2016-01-01

    Focusing on the design of robust value-creating supply chain networks (SCN) and key strategic issues related to the number; location, capacity and mission of supply chain facilities (plants, distribution centers) – as well as the network structure required to provide flexibility and resilience in an uncertain world – this book presents an innovative methodology for SCN reengineering that can be used to significantly improve the bottom line of supply chain dependent businesses. Providing readers with the tools needed to analyze and model value creation activities, Designing Value-Creating Supply Chain Networks examines the risks faced by modern supply chains, and shows how to develop plausible future scenarios to evaluate potential SCN designs. The design methods proposed are based on a visual representation formalism that facilitates the analysis and modeling of SCN design problems, book chapters incorporate several example problems and exercises which can be solved with Excel tools (Analysis tools and So...

  20. The Econometrics of Social Networks

    OpenAIRE

    Yann Bramoullé; Bernard Fortin

    2009-01-01

    In a social network, agents have their own reference group that may influence their behavior. In turn, the agents' attributes and their behavior affect the formation and the structure of the social network. We survey the econometric literature on both aspects of social networks and discuss the identification and estimation issues they raise.

  1. Number Worlds: Visual and Experimental Access to Elementary Number Theory Concepts

    Science.gov (United States)

    Sinclair, Nathalie; Zazkis, Rina; Liljedahl, Peter

    2004-01-01

    Recent research demonstrates that many issues related to the structure of natural numbers and the relationship among numbers are not well grasped by students. In this article, we describe a computer-based learning environment called "Number Worlds" that was designed to support the exploration of elementary number theory concepts by…

  2. Issue 18: Editorial

    Directory of Open Access Journals (Sweden)

    Jon Kenny

    2005-09-01

    Full Text Available This issue of Internet Archaeology begins with a paper from Dawson and Levy at the University of Calgary in Canada. They combine archaeology and anthropology with 3 dimensional computer reconstructions to view semi-subterranean winter houses from the arctic during the 12th and 13th centuries. The archaeological tradition for the peoples behind these buildings is known as Thule. The Thule have used whale bone extensively in the construction of their houses. Dawson and Levy use reconstructions and ethnographic observation to suggest the ritual and symbolism of the Thule architecture. The rest of the edition is a special issue dedicated to the ARENA (Archaeological Records of Europe: Networked Access project. ARENA was a three year project supported by the European Union through the Culture 2000 programme. It began in late 2000 and finished in December 2001 and was completed in November 2004. The object of the project was to promote preservation and access to digital data in European archaeology and to investigate and demonstrate the possibility of creating a European information infrastructure for archaeology. Three years of work has covered many areas of interest for the cultural heritage management community and archaeology as a discipline. The set of seven papers presented here can be read in their own right, each taking a separate and vital topic, or they can be seen as a collection. As a collection of papers, it highlights the many difficulties that face us as we seek to find pathways across national boundaries, but they also show us the routes that these pathways can take towards sharing archaeological data across Europe and beyond.

  3. Feminist issues in development.

    Science.gov (United States)

    Antrobus, P

    1987-01-01

    The United Nations Decade for the Advancement of Women, from 1975 to 1985, leaves a legacy of a deeper understanding of the issues, and the emergence of new networks with the experience and commitment to work for further changes. However, the role and status of women did not improve. There is a new commitment to struggle for the ending of all oppression, injustice and violence of all kinds at all levels. Feminism is a consciousness of all forms of women's oppression and a commitment to work against them. Feminist critiques illuminate the larger structures that oppress both women and men. New development theories embracing feminism are necessary to understand how patriarchy and economic systems propogate oppression. The production-oriented approach to rural development is flawed n failing to address women's lack of access to land, credit, training and new technologies. Overwhelming household tasks, cultural norms, and traditional attitudes limit women's involvement in training programs and other development activities. The basic needs approach to rural development provides access to vital services to meet a family's basic needs for nutrition, housing and clothing, and allows people's participation in decision making. However, women have little actual role in decision making so their needs, concerns and perspectives are not taken into account. Women are treated as instruments to achieve goals without appreciating their perspective. Project-based approached emphasize short term goals rather than laying the foundation for longterm changes. Few projects address structural issues or empower women. Projects must include education to increase personal growth and self reliance. Development planning can be enormously enhanced by taking gender differences into account and recognizing that people, specially poor women, can promote their own devleopment. Longterm strategies that challenge existing structures, address the existing economic order, and, most of all, recognize

  4. Children, everyday numbers and school numbers

    Directory of Open Access Journals (Sweden)

    Clélia Maria Ignatius Nogueira

    2008-08-01

    Full Text Available Relationship made by school children between “daily” numbers, or rather, numbers deployed outside the school, and numbers worked out in school under various circumstances, or rather, orally and in writing, is investigated. Analysis has been undertaken with ten six-year-old children by means of a clinical and critical method. Research results show that children interact with the environment and recognized the figures, name them, conjecture on their written mode and give coherent meaning to the figures. Analysis also demonstrates that children use numbers outside the school. They understand and exemplify the number’s different meanings in an out-class context. Since the children do not give a weighty meaning to “school” numbers, pedagogical activity with numbers fails to put into practice the recommendations of the official policy.

  5. Learning Networks, Networked Learning

    NARCIS (Netherlands)

    Sloep, Peter; Berlanga, Adriana

    2010-01-01

    Sloep, P. B., & Berlanga, A. J. (2011). Learning Networks, Networked Learning [Redes de Aprendizaje, Aprendizaje en Red]. Comunicar, XIX(37), 55-63. Retrieved from http://dx.doi.org/10.3916/C37-2011-02-05

  6. SDN controllers security issues

    OpenAIRE

    Imran, Ayesha

    2017-01-01

    Software-Defined Networking (SDN) is essentially varying the way we design and manage networks, which makes a communication network programmable. In SDN, a logically centralized controller has straight control over the packet-handling functions of the network switches, using a standard, open API (Application Programming Interface) such as OpenFlow. OpenFlow is a broadly used protocol for software-defined networks (SDNs) that presents a new model in which the control plane is inattentive from ...

  7. Network migration for printers

    CERN Multimedia

    2016-01-01

    Further to the recent General Purpose (office) Network reorganisation (as announced in the Bulletin - see here), please note that the majority of print devices will be automatically migrated to the new network IP address range on Tuesday 27 September.   This change should be transparent for these devices and therefore end-users, provided you have installed the printers from the Print Service website. A small number of devices will require manual intervention from the Printer Support team in order to migrate correctly. These devices will not change their IP address until the manual intervention, which will be carried out before Monday 3rd October. However, if you have mistakenly connected directly to the printer’s IP address, then your printing will be affected – please uninstall the printer (for help, see: KB3785), and re-install it from the Print Service website (or follow instructions for visitor machines). Please do this as soon as possible in order to avoid printing issues, t...

  8. To the Issue of Historical Prerequisites and the Significance of the Construction of the Railway Network in the Caucasus (the late 19th and early 20th Century era

    Directory of Open Access Journals (Sweden)

    Vladimir B. Karataev

    2015-12-01

    Full Text Available The article discusses the historical prerequisites of the construction of the railway network in the Caucasus in the late 19th and early 20th century era. The attention is paid to the interest of the foreign capital to the Russian railways. This article utilizes the records of Georgian national archive. A great part of materials is introduced into scientific circulation for the first time. The authors come to the conclusion that to the development of railway network in the Caucasus was paid the great attention. In the period of 1905 to 1913 years the railway network in the Caucasus has increased by 50 %. Almost the entire network was built by the funds from private entrepreneurs, and in the construction of the third road took part the local Caucasian population.

  9. 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.

  10. Increasing Scalability of Researcher Network Extraction from the Web

    Science.gov (United States)

    Asada, Yohei; Matsuo, Yutaka; Ishizuka, Mitsuru

    Social networks, which describe relations among people or organizations as a network, have recently attracted attention. With the help of a social network, we can analyze the structure of a community and thereby promote efficient communications within it. We investigate the problem of extracting a network of researchers from the Web, to assist efficient cooperation among researchers. Our method uses a search engine to get the cooccurences of names of two researchers and calculates the streangth of the relation between them. Then we label the relation by analyzing the Web pages in which these two names cooccur. Research on social network extraction using search engines as ours, is attracting attention in Japan as well as abroad. However, the former approaches issue too many queries to search engines to extract a large-scale network. In this paper, we propose a method to filter superfluous queries and facilitates the extraction of large-scale networks. By this method we are able to extract a network of around 3000-nodes. Our experimental results show that the proposed method reduces the number of queries significantly while preserving the quality of the network as compared to former methods.

  11. Introduction to the Special Issue.

    Science.gov (United States)

    Petrosino, Anthony

    2003-01-01

    Introduces the articles of this special issue focusing on randomized field trials in criminology. In spite of the overall lack of randomized field trials in criminology, some agencies and individuals are able to mount an impressive number of field trials, and these articles focus on their experiences. (SLD)

  12. Sexual Harassment: A Hidden Issue.

    Science.gov (United States)

    Association of American Colleges, Washington, DC. Project on the Status and Education of Women.

    A discussion of sexual harassment on college and university campuses addresses a number of questions and issues: myths of sexual harassment; what is sexual harassment, how widespread is it, and why are women reluctant to talk about it?; sexual harassment and the law; is harassment a violation of Title VII of the Civil Rights Act (for employees) or…

  13. Current Issues in Maritime Health

    DEFF Research Database (Denmark)

    Wagtmann, Maria Anne

    2008-01-01

     In the early part of 2008, Maria Anne Wagtmann had the opportunity to interview the former president of the International Maritime Health Association, Dr. Tim Carter, in London about a number of current maritime health issues. In this interview, Dr. Tim Carter, who is cur­rently employed...

  14. Bernoulli Numbers and the Riemann Zeta Function

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 8; Issue 7. Bernoulli Numbers and the Riemann Zeta Function. B Sury. General Article Volume 8 Issue 7 July 2003 pp 54-62. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/008/07/0054-0062. Keywords.

  15. IEEE Standard for Floating Point Numbers

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 21; Issue 1. IEEE Standard for Floating Point Numbers. V Rajaraman. General Article Volume 21 Issue 1 January 2016 pp 11-30. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/021/01/0011-0030. Keywords.

  16. A Course in Number Theory and Cryptology

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 6. A Course in Number Theory and Cryptology. Rajat Tandon. Book Review Volume 6 Issue 6 June 2001 pp 91-94. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/006/06/0091-0094 ...

  17. Transfinite Numbers-What is Infinity?

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 3. Transfinite Numbers - What is Infinity? S M Srivastava. General Article Volume 2 Issue 3 March 1997 pp 58-68. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/002/03/0058-0068. Author Affiliations.

  18. Mobile ad hoc networking

    CERN Document Server

    John Wiley & Sons

    2004-01-01

    "Assimilating the most up-to-date information on research and development activities in this rapidly growing area, Mobile Ad Hoc Networking covers physical, data link, network, and transport layers, as well as application, security, simulation, and power management issues in sensor, local area, personal, and mobile ad hoc networks. Each of the book's sixteen chapters has been written by a top expert and discusses in-depth the most important topics in the field. Mobile Ad Hoc Networking is an excellent reference and guide for professionals seeking an in-depth examination of topics that also provides a comprehensive overview of the current state-of-the-art."--Jacket.

  19. Mobile Virtual Private Networking

    Science.gov (United States)

    Pulkkis, Göran; Grahn, Kaj; Mårtens, Mathias; Mattsson, Jonny

    Mobile Virtual Private Networking (VPN) solutions based on the Internet Security Protocol (IPSec), Transport Layer Security/Secure Socket Layer (SSL/TLS), Secure Shell (SSH), 3G/GPRS cellular networks, Mobile IP, and the presently experimental Host Identity Protocol (HIP) are described, compared and evaluated. Mobile VPN solutions based on HIP are recommended for future networking because of superior processing efficiency and network capacity demand features. Mobile VPN implementation issues associated with the IP protocol versions IPv4 and IPv6 are also evaluated. Mobile VPN implementation experiences are presented and discussed.

  20. Exploring complex networks.

    Science.gov (United States)

    Strogatz, S H

    2001-03-08

    The study of networks pervades all of science, from neurobiology to statistical physics. The most basic issues are structural: how does one characterize the wiring diagram of a food web or the Internet or the metabolic network of the bacterium Escherichia coli? Are there any unifying principles underlying their topology? From the perspective of nonlinear dynamics, we would also like to understand how an enormous network of interacting dynamical systems-be they neurons, power stations or lasers-will behave collectively, given their individual dynamics and coupling architecture. Researchers are only now beginning to unravel the structure and dynamics of complex networks.

  1. Numbers Defy the Law of Large Numbers

    Science.gov (United States)

    Falk, Ruma; Lann, Avital Lavie

    2015-01-01

    As the number of independent tosses of a fair coin grows, the rates of heads and tails tend to equality. This is misinterpreted by many students as being true also for the absolute numbers of the two outcomes, which, conversely, depart unboundedly from each other in the process. Eradicating that misconception, as by coin-tossing experiments,…

  2. A network of networks.

    Science.gov (United States)

    Iedema, Rick; Verma, Raj; Wutzke, Sonia; Lyons, Nigel; McCaughan, Brian

    2017-04-10

    Purpose To further our insight into the role of networks in health system reform, the purpose of this paper is to investigate how one agency, the NSW Agency for Clinical Innovation (ACI), and the multiple networks and enabling resources that it encompasses, govern, manage and extend the potential of networks for healthcare practice improvement. Design/methodology/approach This is a case study investigation which took place over ten months through the first author's participation in network activities and discussions with the agency's staff about their main objectives, challenges and achievements, and with selected services around the state of New South Wales to understand the agency's implementation and large system transformation activities. Findings The paper demonstrates that ACI accommodates multiple networks whose oversight structures, self-organisation and systems change approaches combined in dynamic ways, effectively yield a diversity of network governances. Further, ACI bears out a paradox of "centralised decentralisation", co-locating agents of innovation with networks of implementation and evaluation expertise. This arrangement strengthens and legitimates the role of the strategic hybrid - the healthcare professional in pursuit of change and improvement, and enhances their influence and impact on the wider system. Research limitations/implications While focussing the case study on one agency only, this study is unique as it highlights inter-network connections. Contributing to the literature on network governance, this paper identifies ACI as a "network of networks" through which resources, expectations and stakeholder dynamics are dynamically and flexibly mediated and enhanced. Practical implications The co-location of and dynamic interaction among clinical networks may create synergies among networks, nurture "strategic hybrids", and enhance the impact of network activities on health system reform. Social implications Network governance requires more

  3. Improved Vehicular Information Network Architecture Using Fuzzy Based Named Data NetworkingNDN

    Directory of Open Access Journals (Sweden)

    Kanwalpreet Kaur

    2015-08-01

    Full Text Available Vehicular Ad-hoc System VANETs is really a component with smart transport systems. It has ability to prevent accidents and the road congestion issues on highways but it suffers from the accomplishment and scalability issues. To handle these difficulties from the Inter Vehicular Communication IVC we apply Name Data Networking NDN. All though in NDN the users are only concerned about necessary data and give no attention on the number of locations from where the data is coming. The NDN layout is usually much more worthy for IVC circumstance getting the ordered material labeling design as well as amp64258exible material retrieval. In this report we propose vehicular network dependent on fuzzy membership function which offers the fundamental NDN style to improve support location dependent forwarding content aggregation and distributed mobility management. This paper finally winds up the several boundaries regarding earlier approaches.

  4. Recognition of the smart card iconic numbers

    Directory of Open Access Journals (Sweden)

    Xin Xue Shi

    2016-01-01

    Full Text Available Manual way of recognizing and inputting the smart card iconic numbers leads to much time consuming, high resources consuming and low accuracy. This paper presents a new automatic method based on the technology of computer vision, including Harr operator for face detection, Fast operator for number location, image binarization, character segmentation and BP neural network for number recognition. Experimental results on 100 ID cards show that by adjusting the parameters of the BP neural network properly, the recognition accuracy is more than 99%, and the recognition time for each ID card is within 0.05 seconds.

  5. Class network routing

    Science.gov (United States)

    Bhanot, Gyan [Princeton, NJ; Blumrich, Matthias A [Ridgefield, CT; Chen, Dong [Croton On Hudson, NY; Coteus, Paul W [Yorktown Heights, NY; Gara, Alan G [Mount Kisco, NY; Giampapa, Mark E [Irvington, NY; Heidelberger, Philip [Cortlandt Manor, NY; Steinmacher-Burow, Burkhard D [Mount Kisco, NY; Takken, Todd E [Mount Kisco, NY; Vranas, Pavlos M [Bedford Hills, NY

    2009-09-08

    Class network routing is implemented in a network such as a computer network comprising a plurality of parallel compute processors at nodes thereof. Class network routing allows a compute processor to broadcast a message to a range (one or more) of other compute processors in the computer network, such as processors in a column or a row. Normally this type of operation requires a separate message to be sent to each processor. With class network routing pursuant to the invention, a single message is sufficient, which generally reduces the total number of messages in the network as well as the latency to do a broadcast. Class network routing is also applied to dense matrix inversion algorithms on distributed memory parallel supercomputers with hardware class function (multicast) capability. This is achieved by exploiting the fact that the communication patterns of dense matrix inversion can be served by hardware class functions, which results in faster execution times.

  6. Number words and number symbols a cultural history of numbers

    CERN Document Server

    Menninger, Karl

    1992-01-01

    Classic study discusses number sequence and language and explores written numerals and computations in many cultures. "The historian of mathematics will find much to interest him here both in the contents and viewpoint, while the casual reader is likely to be intrigued by the author's superior narrative ability.

  7. Scalable Virtual Network Mapping Algorithm for Internet-Scale Networks

    Science.gov (United States)

    Yang, Qiang; Wu, Chunming; Zhang, Min

    The proper allocation of network resources from a common physical substrate to a set of virtual networks (VNs) is one of the key technical challenges of network virtualization. While a variety of state-of-the-art algorithms have been proposed in an attempt to address this issue from different facets, the challenge still remains in the context of large-scale networks as the existing solutions mainly perform in a centralized manner which requires maintaining the overall and up-to-date information of the underlying substrate network. This implies the restricted scalability and computational efficiency when the network scale becomes large. This paper tackles the virtual network mapping problem and proposes a novel hierarchical algorithm in conjunction with a substrate network decomposition approach. By appropriately transforming the underlying substrate network into a collection of sub-networks, the hierarchical virtual network mapping algorithm can be carried out through a global virtual network mapping algorithm (GVNMA) and a local virtual network mapping algorithm (LVNMA) operated in the network central server and within individual sub-networks respectively with their cooperation and coordination as necessary. The proposed algorithm is assessed against the centralized approaches through a set of numerical simulation experiments for a range of network scenarios. The results show that the proposed hierarchical approach can be about 5-20 times faster for VN mapping tasks than conventional centralized approaches with acceptable communication overhead between GVNCA and LVNCA for all examined networks, whilst performs almost as well as the centralized solutions.

  8. Mechanics issues in intelligent structures

    Science.gov (United States)

    Sirkis, J. S.; Dasgupta, A.

    This paper describes many of the fundamental mechanics issues currently inhibiting the realization of the 'intelligent structures' concept. We view what is commonly referred to as 'intelligent structures' more as sensory and adaptive materials and structures that use distributed networks of structurally integrated actuator and sensor devices to achieve self-monitoring and self-adapting capabilities. Each embedded micro-device has a very localized response on the microscale to an input stimulus, which combines with the localized response of the other micro-devices in the network to produce a metered response in the macroscale structure. All length-scales posses inherent geometric, material, and time dependent non-linearities which must be successfully addressed. The goal of the mechanics research in 'intelligent structures' should be to model the inherent linear and nonlinear interaction mechanics so that accumulating modification to structural response can be predicted and then either accounted for or actively changed in some way.

  9. Complex networks an algorithmic perspective

    CERN Document Server

    Erciyes, Kayhan

    2014-01-01

    Network science is a rapidly emerging field of study that encompasses mathematics, computer science, physics, and engineering. A key issue in the study of complex networks is to understand the collective behavior of the various elements of these networks.Although the results from graph theory have proven to be powerful in investigating the structures of complex networks, few books focus on the algorithmic aspects of complex network analysis. Filling this need, Complex Networks: An Algorithmic Perspective supplies the basic theoretical algorithmic and graph theoretic knowledge needed by every r

  10. Editorial Anthrovision issue 1.1

    OpenAIRE

    Engelbrecht, Beate

    2013-01-01

    Dear reader, We welcome you to the first issue of the new online journal Anthrovision published by the Visual Anthropology Network of the European Association of Social Anthropologists (VANEASA). The title of our journal stands in certain ways for our programme and this first issue reflects some important points: Visual Anthropology is the focal point of the journal, but academic discussions are becoming more interdisciplinary and more complex, so the journal wants to publish quite diverse co...

  11. Bio-mimic optimization strategies in wireless sensor networks: a survey.

    Science.gov (United States)

    Adnan, Md Akhtaruzzaman; Abdur Razzaque, Mohammd; Ahmed, Ishtiaque; Isnin, Ismail Fauzi

    2013-12-24

    For the past 20 years, many authors have focused their investigations on wireless sensor networks. Various issues related to wireless sensor networks such as energy minimization (optimization), compression schemes, self-organizing network algorithms, routing protocols, quality of service management, security, energy harvesting, etc., have been extensively explored. The three most important issues among these are energy efficiency, quality of service and security management. To get the best possible results in one or more of these issues in wireless sensor networks optimization is necessary. Furthermore, in number of applications (e.g., body area sensor networks, vehicular ad hoc networks) these issues might conflict and require a trade-off amongst them. Due to the high energy consumption and data processing requirements, the use of classical algorithms has historically been disregarded. In this context contemporary researchers started using bio-mimetic strategy-based optimization techniques in the field of wireless sensor networks. These techniques are diverse and involve many different optimization algorithms. As far as we know, most existing works tend to focus only on optimization of one specific issue of the three mentioned above. It is high time that these individual efforts are put into perspective and a more holistic view is taken. In this paper we take a step in that direction by presenting a survey of the literature in the area of wireless sensor network optimization concentrating especially on the three most widely used bio-mimetic algorithms, namely, particle swarm optimization, ant colony optimization and genetic algorithm. In addition, to stimulate new research and development interests in this field, open research issues, challenges and future research directions are highlighted.

  12. Bio-Mimic Optimization Strategies in Wireless Sensor Networks: A Survey

    Science.gov (United States)

    Adnan, Md. Akhtaruzzaman; Razzaque, Mohammd Abdur; Ahmed, Ishtiaque; Isnin, Ismail Fauzi

    2014-01-01

    For the past 20 years, many authors have focused their investigations on wireless sensor networks. Various issues related to wireless sensor networks such as energy minimization (optimization), compression schemes, self-organizing network algorithms, routing protocols, quality of service management, security, energy harvesting, etc., have been extensively explored. The three most important issues among these are energy efficiency, quality of service and security management. To get the best possible results in one or more of these issues in wireless sensor networks optimization is necessary. Furthermore, in number of applications (e.g., body area sensor networks, vehicular ad hoc networks) these issues might conflict and require a trade-off amongst them. Due to the high energy consumption and data processing requirements, the use of classical algorithms has historically been disregarded. In this context contemporary researchers started using bio-mimetic strategy-based optimization techniques in the field of wireless sensor networks. These techniques are diverse and involve many different optimization algorithms. As far as we know, most existing works tend to focus only on optimization of one specific issue of the three mentioned above. It is high time that these individual efforts are put into perspective and a more holistic view is taken. In this paper we take a step in that direction by presenting a survey of the literature in the area of wireless sensor network optimization concentrating especially on the three most widely used bio-mimetic algorithms, namely, particle swarm optimization, ant colony optimization and genetic algorithm. In addition, to stimulate new research and development interests in this field, open research issues, challenges and future research directions are highlighted. PMID:24368702

  13. Security And Privacy Issues in Health Monitoring Systems: eCare@Home Case Study

    DEFF Research Database (Denmark)

    Wearing, Thomas; Dragoni, Nicola

    2016-01-01

    Automated systems for monitoring elderly people in their home are becoming more and more common. Indeed, an increasing number of home sensor networks for healthcare can be found in the recent literature, indicating a clear research direction in smart homes for health-care. Although the huge amount...... of sensitive data these systems deal with and expose to the external world, security and privacy issues are surpris-ingly not taken into consideration. The aim of this paper is to raise some key security and privacy issues that home health monitor systems should face with. The analysis is based on a real world...... monitoring sensor network for healthcare built in the context of the eCare@Home project....

  14. Establishing And Managing Development Networks In Africa ...

    African Journals Online (AJOL)

    Establishing And Managing Development Networks In Africa: Perspectives On The African Virtual Library And Information Network (Avlin) ... In times like this when libraries are facing problems with access and acquisition of materials, networking becomes very important. This paper discusses issues relating to networking in ...

  15. Power quality issues current harmonics

    CERN Document Server

    Mikkili, Suresh

    2015-01-01

    Power Quality Issues: Current Harmonics provides solutions for the mitigation of power quality problems related to harmonics. Focusing on active power filters (APFs) due to their excellent harmonic and reactive power compensation in two-wire (single phase), three-wire (three-phase without neutral), and four-wire (three-phase with neutral) AC power networks with nonlinear loads, the text:Introduces the APF technology, describing various APF configurations and offering guidelines for the selection of APFs for specific application considerationsCompares shunt active filter (SHAF) control strategi

  16. Phylodynamic analysis of a viral infection network

    Directory of Open Access Journals (Sweden)

    Teiichiro eShiino

    2012-07-01

    Full Text Available Viral infections by sexual and droplet transmission routes typically spread through a complex host-to-host contact network. Clarifying the transmission network and epidemiological parameters affecting the variations and dynamics of a specific pathogen is a major issue in the control of infectious diseases. However, conventional methods such as interview and/or classical phylogenetic analysis of viral gene sequences have inherent limitations and often fail to detect infectious clusters and transmission connections. Recent improvements in computational environments now permit the analysis of large datasets. In addition, novel analytical methods have been developed that serve to infer the evolutionary dynamics of virus genetic diversity using sample date information and sequence data. This type of framework, termed phylodynamics, helps connect some of the missing links on viral transmission networks, which are often hard to detect by conventional methods of epidemiology. With sufficient number of sequences available, one can use this new inference method to estimate theoretical epidemiological parameters such as temporal distributions of the primary infection, fluctuation of the pathogen population size, basic reproductive number, and the mean time span of disease infectiousness. Transmission networks estimated by this framework often have the properties of a scale-free network, which are characteristic of infectious and social communication processes. Network analysis based on phylodynamics has alluded to various suggestions concerning the infection dynamics associated with a given community and/or risk behavior. In this review, I will summarize the current methods available for identifying the transmission network using phylogeny, and present an argument on the possibilities of applying the scale-free properties to these existing frameworks.

  17. Reverse Logistics Network Structures and Design

    NARCIS (Netherlands)

    M. Fleischmann (Moritz)

    2001-01-01

    textabstractLogistics network design is commonly recognized as a strategic supply chain issue of prime importance. The location of production facilities, storage concepts, and transportation strategies are major determinants of supply chain performance. This chapter considers logistics network

  18. Data mining techniques in sensor networks summarization, interpolation and surveillance

    CERN Document Server

    Appice, Annalisa; Fumarola, Fabio; Malerba, Donato

    2013-01-01

    Sensor networks comprise of a number of sensors installed across a spatially distributed network, which gather information and periodically feed a central server with the measured data. The server monitors the data, issues possible alarms and computes fast aggregates. As data analysis requests may concern both present and past data, the server is forced to store the entire stream. But the limited storage capacity of a server may reduce the amount of data stored on the disk. One solution is to compute summaries of the data as it arrives, and to use these summaries to interpolate the real data.

  19. Applying New Network Security Technologies to SCADA Systems.

    Energy Technology Data Exchange (ETDEWEB)

    Hurd, Steven A; Stamp, Jason Edwin; Duggan, David P; Chavez, Adrian R.

    2006-11-01

    Supervisory Control and Data Acquisition (SCADA) systems for automation are very important for critical infrastructure and manufacturing operations. They have been implemented to work in a number of physical environments using a variety of hardware, software, networking protocols, and communications technologies, often before security issues became of paramount concern. To offer solutions to security shortcomings in the short/medium term, this project was to identify technologies used to secure "traditional" IT networks and systems, and then assess their efficacy with respect to SCADA systems. These proposed solutions must be relatively simple to implement, reliable, and acceptable to SCADA owners and operators. 4This page intentionally left blank.

  20. Outlook. Number 336

    Science.gov (United States)

    Council for American Private Education, 2008

    2008-01-01

    Outlook is the monthly newsletter for the Council for American Private Education (CAPE). Each issue contains information relating to private education such as: new legislation and regulations, the most recent research, court rulings, national trends, federal initiatives, private school news briefs, and more. This issue contains the following…

  1. Show me your friends and I will tell you what type of person you are: how own profile, number of friends, and type of friends influence impression formation on social network sites

    NARCIS (Netherlands)

    Utz, S.

    2010-01-01

    This experiment examines how far extraversion of the target (self-generated information), extraversion of the target's friends (friends-generated information), and number of friends (system-generated information) influence the perceived popularity, communal orientation, and social attractiveness of

  2. Research Article Special Issue

    African Journals Online (AJOL)

    2017-09-10

    Sep 10, 2017 ... Heart abnormality activity means irregular heartbeat which is known as cardiac dysrhythmia or. Arrhythmia. ... extraction is used as the input parameter for the neural network to detect the heart abnormality activity. On the ... the structure and function of RBF network has been carried out by [9]. RBF network ...

  3. Research Article Special Issue

    African Journals Online (AJOL)

    2017-09-10

    Sep 10, 2017 ... Convolutional Neural Network is known as a feed-forward artificial neural network that is originally inspired by biological process that is the form of the animal ..... Darrell T. Fully convolutional networks for semantic segmentation.In IEEE Conference on Computer Vision and Pattern Recognition, 2015, pp.

  4. Research Article Special Issue

    African Journals Online (AJOL)

    2017-09-10

    Sep 10, 2017 ... extraction is used as the input parameter for the neural network to detect the heart abnormality activity. On the other hands, Radial Basis Function network is an Artificial Neural Network. (ANN) that implements Radial Basis Functions (RBF) as activation functions. As one of the. Artificial Intelligence branches ...

  5. Combined Quarterly Technical Report Number 24. SATNET Development and Operation, Pluribus Satellite IMP Development, Remote Site Maintenance, Internet Operations and Maintenance, Mobile Access Terminal Network, TCP for the HP3000, TCP for VAX-UNIX

    Science.gov (United States)

    1982-02-01

    activities are described below. After the release of new software into the BBN gateway, we discovered that the Etam Satellite IMP could not be loaded...through the VDH circuit from the BBN gateway. Emergency software reloads required the IMP-to-IMP circuit between the Etam Satellite IMP and the SDAC...ehe second and third parts of the version number. Thus, version numbers of Satellite IMP software currently in the field are 3.4:1 for sites Etam

  6. Network coding at different layers in wireless networks

    CERN Document Server

    2016-01-01

    This book focuses on how to apply network coding at different layers in wireless networks – including MAC, routing, and TCP – with special focus on cognitive radio networks. It discusses how to select parameters in network coding (e.g., coding field, number of packets involved, and redundant information ration) in order to be suitable for the varying wireless environments. The book explores how to deploy network coding in MAC to improve network performance and examines joint network coding with opportunistic routing to improve the successful rate of routing. In regards to TCP and network coding, the text considers transport layer protocol working with network coding to overcome the transmission error rate, particularly with how to use the ACK feedback of TCP to enhance the efficiency of network coding. The book pertains to researchers and postgraduate students, especially whose interests are in opportunistic routing and TCP in cognitive radio networks.

  7. Traffic Management for Satellite-ATM Networks

    Science.gov (United States)

    Goyal, Rohit; Jain, Raj; Fahmy, Sonia; Vandalore, Bobby; Goyal, Mukul

    1998-01-01

    Various issues associated with "Traffic Management for Satellite-ATM Networks" are presented in viewgraph form. Specific topics include: 1) Traffic management issues for TCP/IP based data services over satellite-ATM networks; 2) Design issues for TCP/IP over ATM; 3) Optimization of the performance of TCP/IP over ATM for long delay networks; and 4) Evaluation of ATM service categories for TCP/IP traffic.

  8. Mobility and social network effects on extremist opinions.

    Science.gov (United States)

    Martins, André C R

    2008-09-01

    Understanding the emergence of extreme opinions and in what kind of environment they might become less extreme is a central theme in our modern globalized society. A model combining continuous opinions and observed discrete actions (CODA) capable of addressing the important issue of measuring how extreme opinions might be has been recently proposed. In this paper I show extreme opinions to arise in a ubiquitous manner in the CODA model for a multitude of social network structures. Depending on network details reducing extremism seems to be possible. However, a large number of agents with extreme opinions is always observed. A significant decrease in the number of extremists can be observed by allowing agents to change their positions in the network.

  9. Congestion control and routing over satellite networks

    Science.gov (United States)

    Cao, Jinhua

    Satellite networks and transmissions find their application in fields of computer communications, telephone communications, television broadcasting, transportation, space situational awareness systems and so on. This thesis mainly focuses on two networking issues affecting satellite networking: network congestion control and network routing optimization. Congestion, which leads to long queueing delays, packet losses or both, is a networking problem that has drawn the attention of many researchers. The goal of congestion control mechanisms is to ensure high bandwidth utilization while avoiding network congestion by regulating the rate at which traffic sources inject packets into a network. In this thesis, we propose a stable congestion controller using data-driven, safe switching control theory to improve the dynamic performance of satellite Transmission Control Protocol/Active Queue Management (TCP/AQM) networks. First, the stable region of the Proportional-Integral (PI) parameters for a nominal model is explored. Then, a PI controller, whose parameters are adaptively tuned by switching among members of a given candidate set, using observed plant data, is presented and compared with some classical AQM policy examples, such as Random Early Detection (RED) and fixed PI control. A new cost detectable switching law with an interval cost function switching algorithm, which improves the performance and also saves the computational cost, is developed and compared with a law commonly used in the switching control literature. Finite-gain stability of the system is proved. A fuzzy logic PI controller is incorporated as a special candidate to achieve good performance at all nominal points with the available set of candidate controllers. Simulations are presented to validate the theory. An effocient routing algorithm plays a key role in optimizing network resources. In this thesis, we briefly analyze Low Earth Orbit (LEO) satellite networks, review the Cross Entropy (CE

  10. Introduction to number theory

    CERN Document Server

    Vazzana, Anthony; Garth, David

    2007-01-01

    One of the oldest branches of mathematics, number theory is a vast field devoted to studying the properties of whole numbers. Offering a flexible format for a one- or two-semester course, Introduction to Number Theory uses worked examples, numerous exercises, and two popular software packages to describe a diverse array of number theory topics.

  11. Tropical Real Hurwitz numbers

    OpenAIRE

    Markwig, Hannah; Rau, Johannes

    2014-01-01

    In this paper, we define tropical analogues of real Hurwitz numbers, i.e. numbers of covers of surfaces with compatible involutions satisfying prescribed ramification properties. We prove a correspondence theorem stating the equality of the tropical numbers with their real counterparts. We apply this theorem to the case of double Hurwitz numbers (which generalizes our result from arXiv:1409.8095).

  12. Social-Driven Information Dissemination for Mobile Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Basim MAHMOOD

    2015-06-01

    Full Text Available As we move into the so-called Internet of Things (IoT, the boundary between sensor networks and social networks is likely to disappear. Moreover, previous works argue that mobility in sensor networks may become a consequence of human movement making the understanding of human mobility crucial to the design of sensor networks. When people carry sensors, they become able to use concepts from social networks in the design of sensor network infrastructures. However, to this date, the utilization of social networks in designing protocols for wireless sensor networks has not received much attention. In this paper, we focus on the concept of information dissemination in a framework where sensors are carried by people who, like most of us, are part of a social network. We propose two social-based forwarding approaches for what has been called Social Network of Sensors (SNoS. To this end, we exploit two important characteristics of ties in social networks, namely strong ties and weak ties. The former is used to achieve rapid dissemination to nearby sensors while the latter aims at dissemination to faraway sensors. We compared our results against two well-known approaches in the literature: Epidemic and PRoPHET protocols. We evaluate our approaches according to four criteria: information-dissemination distance, information-dissemination coverage area, the number of messages exchanged, and information delivery time. We believe this is the first work that investigates the issues of information-dissemination distance and information-dissemination coverage area using an approach inspired on social network concepts.

  13. The CzeCOS Network

    Science.gov (United States)

    Havránková, Kateřina; Taufarová, Klára; Šigut, Ladislav; McGloin, Ryan; Acosta, Manuel; Dušek, Jiří; Krupková, Lenka; Macálková-Mžourková, Lenka; Pavelka, Marian; Dařenová, Eva; Yadav, Shilpi; Nguyen, Vinh; Guerra, Carlos; Janous, Dalibor; Marek, Michal V.

    2017-04-01

    The Global Change Research Institute of the Czech Academy of Sciences (CzechGlobe) have established a well-equipped network of ecosystem stations, with modern instrumentation for eco-physiological, plant physiological and micrometeorological studies, and estimation of GHG emissions. The network of stations (CzeCOS) covers the main terrestrial ecosystems of the Czech Republic (young and old coniferous forest, deciduous forest, mixed floodplain forest, grassland, wetland and cropland). The ecosystem stations are equipped with eddy covariance systems, soil and stem chamber systems for CO2 efflux and instruments for making micrometeorological measurements. The network enables detailed research to be conducted on topics such as: the carbon balance of different ecosystems, energy balance closure, the impact of current climate conditions on production and ecosystem disturbances during extreme weather conditions (drought, floods, winter storms, etc.) at regional, national and international scales. As a part of global networks (Fluxnet, ANAEe, ICOS), CzeCOS participates in evaluating and predicting environmental change and helps in the proposal of mitigation measures. Another important issue studied at some of the CzeCOS sites is the use of the eddy covariance method in sloping terrain in order to improve eddy covariance data processing for sites in this kind of terrain. Here we show specific results from the sites and outline the importance of the regional/national network for improving our knowledge about the exchange of matter and energy fluxes at different ecosystems. This study was supported by the Ministry of Education, Youth and Sports of CR within the National Sustainability Program I (NPU I), grant number LO1415 and LD 15040. Computational resources were provided by the CESNET LM2015042 and the CERIT Scientific Cloud LM2015085, provided under the programme "Projects of Large Research, Development, and Innovations Infrastructures".

  14. Event localization in underwater wireless sensor networks using Monitoring Courses

    KAUST Repository

    Debont, Matthew John Robert

    2012-08-01

    We propose m-courses (Monitoring Courses), a novel solution to localize events in an underwater wireless sensor network. These networks consists of surface gateways and relay nodes. GPS can localize the position of surface gateways which can then distribute their locations through the network using acoustic modems. Relay nodes are deployed to remain static, but these untethered nodes may drift due to water currents, resulting in disruption of communication links. We develop a novel underwater alarm system using a cyclic graph model. In the event of link failure, a series of alarm packets are broadcast in the network. These alarms are then captured by the underwater m-courses, which can also be used to assure network connectivity and identify node failures. M-courses also allow the network to localize events and identify network issues locally before forwarding results upwards to a Surface Gateway node. This reduces communication overhead and allows for efficient management of nodes in a mobile network. Our results show that m-course routing reduces the number of sends required to report an event to a Surface Gateway by up to 80% when compared to a naïve routing implementation.

  15. Characterizing Sleep Issues Using Twitter.

    Science.gov (United States)

    McIver, David J; Hawkins, Jared B; Chunara, Rumi; Chatterjee, Arnaub K; Bhandari, Aman; Fitzgerald, Timothy P; Jain, Sachin H; Brownstein, John S

    2015-06-08

    Sleep issues such as insomnia affect over 50 million Americans and can lead to serious health problems, including depression and obesity, and can increase risk of injury. Social media platforms such as Twitter offer exciting potential for their use in studying and identifying both diseases and social phenomenon. Our aim was to determine whether social media can be used as a method to conduct research focusing on sleep issues. Twitter posts were collected and curated to determine whether a user exhibited signs of sleep issues based on the presence of several keywords in tweets such as insomnia, "can't sleep", Ambien, and others. Users whose tweets contain any of the keywords were designated as having self-identified sleep issues (sleep group). Users who did not have self-identified sleep issues (non-sleep group) were selected from tweets that did not contain pre-defined words or phrases used as a proxy for sleep issues. User data such as number of tweets, friends, followers, and location were collected, as well as the time and date of tweets. Additionally, the sentiment of each tweet and average sentiment of each user were determined to investigate differences between non-sleep and sleep groups. It was found that sleep group users were significantly less active on Twitter (P=.04), had fewer friends (Puser's account has been active. Sleep group users were more active during typical sleeping hours than others, which may suggest they were having difficulty sleeping. Sleep group users also had significantly lower sentiment in their tweets (P<.001), indicating a possible relationship between sleep and pyschosocial issues. We have demonstrated a novel method for studying sleep issues that allows for fast, cost-effective, and customizable data to be gathered.

  16. Contingent approach to Internet-based supply network integration

    Science.gov (United States)

    Ho, Jessica; Boughton, Nick; Kehoe, Dennis; Michaelides, Zenon

    2001-10-01

    The Internet is playing an increasingly important role in enhancing the operations of supply networks as many organizations begin to recognize the benefits of Internet- enabled supply arrangements. However, the developments and applications to-date do not extend significantly beyond the dyadic model, whereas the real advantages are to be made with the external and network models to support a coordinated and collaborative based approach. The DOMAIN research group at the University of Liverpool is currently defining new Internet- enabled approaches to enable greater collaboration across supply chains. Different e-business models and tools are focusing on different applications. Using inappropriate e- business models, tools or techniques will bring negative results instead of benefits to all the tiers in the supply network. Thus there are a number of issues to be considered before addressing Internet based supply network integration, in particular an understanding of supply chain management, the emergent business models and evaluating the effects of deploying e-business to the supply network or a particular tier. It is important to utilize a contingent approach to selecting the right e-business model to meet the specific supply chain requirements. This paper addresses the issues and provides a case study on the indirect materials supply networks.

  17. Resource Optimization Scheme for Multimedia-Enabled Wireless Mesh Networks

    Science.gov (United States)

    Ali, Amjad; Ahmed, Muhammad Ejaz; Piran, Md. Jalil; Suh, Doug Young

    2014-01-01

    Wireless mesh networking is a promising technology that can support numerous multimedia applications. Multimedia applications have stringent quality of service (QoS) requirements, i.e., bandwidth, delay, jitter, and packet loss ratio. Enabling such QoS-demanding applications over wireless mesh networks (WMNs) require QoS provisioning routing protocols that lead to the network resource underutilization problem. Moreover, random topology deployment leads to have some unused network resources. Therefore, resource optimization is one of the most critical design issues in multi-hop, multi-radio WMNs enabled with multimedia applications. Resource optimization has been studied extensively in the literature for wireless Ad Hoc and sensor networks, but existing studies have not considered resource underutilization issues caused by QoS provisioning routing and random topology deployment. Finding a QoS-provisioned path in wireless mesh networks is an NP complete problem. In this paper, we propose a novel Integer Linear Programming (ILP) optimization model to reconstruct the optimal connected mesh backbone topology with a minimum number of links and relay nodes which satisfies the given end-to-end QoS demands for multimedia traffic and identification of extra resources, while maintaining redundancy. We further propose a polynomial time heuristic algorithm called Link and Node Removal Considering Residual Capacity and Traffic Demands (LNR-RCTD). Simulation studies prove that our heuristic algorithm provides near-optimal results and saves about 20% of resources from being wasted by QoS provisioning routing and random topology deployment. PMID:25111241

  18. Resource optimization scheme for multimedia-enabled wireless mesh networks.

    Science.gov (United States)

    Ali, Amjad; Ahmed, Muhammad Ejaz; Piran, Md Jalil; Suh, Doug Young

    2014-08-08

    Wireless mesh networking is a promising technology that can support numerous multimedia applications. Multimedia applications have stringent quality of service (QoS) requirements, i.e., bandwidth, delay, jitter, and packet loss ratio. Enabling such QoS-demanding applications over wireless mesh networks (WMNs) require QoS provisioning routing protocols that lead to the network resource underutilization problem. Moreover, random topology deployment leads to have some unused network resources. Therefore, resource optimization is one of the most critical design issues in multi-hop, multi-radio WMNs enabled with multimedia applications. Resource optimization has been studied extensively in the literature for wireless Ad Hoc and sensor networks, but existing studies have not considered resource underutilization issues caused by QoS provisioning routing and random topology deployment. Finding a QoS-provisioned path in wireless mesh networks is an NP complete problem. In this paper, we propose a novel Integer Linear Programming (ILP) optimization model to reconstruct the optimal connected mesh backbone topology with a minimum number of links and relay nodes which satisfies the given end-to-end QoS demands for multimedia traffic and identification of extra resources, while maintaining redundancy. We further propose a polynomial time heuristic algorithm called Link and Node Removal Considering Residual Capacity and Traffic Demands (LNR-RCTD). Simulation studies prove that our heuristic algorithm provides near-optimal results and saves about 20% of resources from being wasted by QoS provisioning routing and random topology deployment.

  19. Security analysis of quantum key distribution on passive optical networks.

    Science.gov (United States)

    Lim, Kyongchun; Ko, Heasin; Suh, Changho; Rhee, June-Koo Kevin

    2017-05-15

    Needs for providing security to end users have brought installation of quantum key distribution (QKD) in one-to-many access networks such as passive optical networks. In the networks, a presence of optical power splitters makes issues for secure key rate more important. However, researches for QKD in access networks have mainly focused on implementation issues rather than protocol development for key rate enhancement. Since secure key rate is theoretically limited by a protocol, researches without protocol development cannot overcome the limit of secure key rate given by a protocol. This brings need of researches for protocol development. In this paper, we provide a new approach which provides secure key rate enhancement over the conventional protocol. Specifically, we propose the secure key rate formula in a passive optical network by extending the secure key rate formula based on the decoy-state BB84 protocol. For a passive optical network, we provide a way that incorporates cooperation across end users. Then, we show that the way can mitigate a photon number splitting (PNS) attack which is crucial in an well known decoy BB84 protocol. Especially, the proposed scheme enables multi-photon states to serve as secure keys unlike the conventional decoy BB84 protocol. Numerical simulations demonstrate that our proposed scheme outperforms the decoy BB84 protocol in secure key rate.

  20. Evolution of Social networks

    OpenAIRE

    Hellmann, Tim; Staudigl, Mathias

    2014-01-01

    Modeling the evolution of networks is central to our understanding of modern large communication systems, such as theWorld-Wide-Web, as well as economic and social networks. The research on social and economic networks is truly interdisciplinary and the number of modeling strategies and concepts is enormous. In this survey we present some modeling approaches, covering classical random graph models and game-theoretic models, which may be used to provide a unified framework to model an...

  1. Delay tolerant networks

    CERN Document Server

    Gao, Longxiang; Luan, Tom H

    2015-01-01

    This brief presents emerging and promising communication methods for network reliability via delay tolerant networks (DTNs). Different from traditional networks, DTNs possess unique features, such as long latency and unstable network topology. As a result, DTNs can be widely applied to critical applications, such as space communications, disaster rescue, and battlefield communications. The brief provides a complete investigation of DTNs and their current applications, from an overview to the latest development in the area. The core issue of data forward in DTNs is tackled, including the importance of social characteristics, which is an essential feature if the mobile devices are used for human communication. Security and privacy issues in DTNs are discussed, and future work is also discussed.

  2. Cybersecurity of Critical Control Networks

    Science.gov (United States)

    2015-07-14

    AFRL-OSR-VA-TR-2015-0173 CONGRESSIONAL) CYBERSECURITY OF CRITICAL CONTROL NETWORKS William Mahoney UNIVERSITY OF NEBRASKA Final Report 07/14/2015...Congressional) Cybersecurity of Critical Control Networks 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA9550-10-1-0341 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR...FA9550-10-1-0341 Cybersecurity of Critical Control Networks Report Type Final Report Primary Contact E-mail wmahoney@unomaha.edu Primary

  3. Fulcrum Network Codes

    DEFF Research Database (Denmark)

    2015-01-01

    Fulcrum network codes, which are a network coding framework, achieve three objectives: (i) to reduce the overhead per coded packet to almost 1 bit per source packet; (ii) to operate the network using only low field size operations at intermediate nodes, dramatically reducing complexity...... in the network; and (iii) to deliver an end-to-end performance that is close to that of a high field size network coding system for high-end receivers while simultaneously catering to low-end ones that can only decode in a lower field size. Sources may encode using a high field size expansion to increase...... the number of dimensions seen by the network using a linear mapping. Receivers can tradeoff computational effort with network delay, decoding in the high field size, the low field size, or a combination thereof....

  4. Network topology analysis.

    Energy Technology Data Exchange (ETDEWEB)

    Kalb, Jeffrey L.; Lee, David S.

    2008-01-01

    Emerging high-bandwidth, low-latency network technology has made network-based architectures both feasible and potentially desirable for use in satellite payload architectures. The selection of network topology is a critical component when developing these multi-node or multi-point architectures. This study examines network topologies and their effect on overall network performance. Numerous topologies were reviewed against a number of performance, reliability, and cost metrics. This document identifies a handful of good network topologies for satellite applications and the metrics used to justify them as such. Since often multiple topologies will meet the requirements of the satellite payload architecture under development, the choice of network topology is not easy, and in the end the choice of topology is influenced by both the design characteristics and requirements of the overall system and the experience of the developer.

  5. Cognitive Dynamic Optical Networks

    DEFF Research Database (Denmark)

    de Miguel, Ignacio; Duran, Ramon J.; Jimenez, Tamara

    2013-01-01

    The use of cognition is a promising element for the control of heterogeneous optical networks. Not only are cognitive networks able to sense current network conditions and act according to them, but they also take into account the knowledge acquired through past experiences; that is, they include...... learning with the aim of improving performance. In this paper, we review the fundamentals of cognitive networks and focus on their application to the optical networking area. In particular, a number of cognitive network architectures proposed so far, as well as their associated supporting technologies......, are reviewed. Moreover, several applications, mainly developed in the framework of the EU FP7 Cognitive Heterogeneous Reconfigurable Optical Network (CHRON) project, are also described....

  6. Impact of Vehicular Networks on Emergency Medical Services in Urban Areas

    OpenAIRE

    Chun-Liang Lee; Chung-Yuan Huang; Tzu-Chien Hsiao; Chun-Yen Wu; Yaw-Chung Chen; I.-Cheng Wang

    2014-01-01

    The speed with which emergency personnel can provide emergency treatment is crucial to reducing death and disability among acute and critically ill patients. Unfortunately, the rapid development of cities and increased numbers of vehicles are preventing emergency vehicles from easily reaching locations where they are needed. A significant number of researchers are experimenting with vehicular networks to address this issue, but in most studies the focus has been on communication technologies...

  7. Symmetry in Complex Networks

    Directory of Open Access Journals (Sweden)

    Angel Garrido

    2011-01-01

    Full Text Available In this paper, we analyze a few interrelated concepts about graphs, such as their degree, entropy, or their symmetry/asymmetry levels. These concepts prove useful in the study of different types of Systems, and particularly, in the analysis of Complex Networks. A System can be defined as any set of components functioning together as a whole. A systemic point of view allows us to isolate a part of the world, and so, we can focus on those aspects that interact more closely than others. Network Science analyzes the interconnections among diverse networks from different domains: physics, engineering, biology, semantics, and so on. Current developments in the quantitative analysis of Complex Networks, based on graph theory, have been rapidly translated to studies of brain network organization. The brain's systems have complex network features—such as the small-world topology, highly connected hubs and modularity. These networks are not random. The topology of many different networks shows striking similarities, such as the scale-free structure, with the degree distribution following a Power Law. How can very different systems have the same underlying topological features? Modeling and characterizing these networks, looking for their governing laws, are the current lines of research. So, we will dedicate this Special Issue paper to show measures of symmetry in Complex Networks, and highlight their close relation with measures of information and entropy.

  8. Serial Network Flow Monitor

    Science.gov (United States)

    Robinson, Julie A.; Tate-Brown, Judy M.

    2009-01-01

    Using a commercial software CD and minimal up-mass, SNFM monitors the Payload local area network (LAN) to analyze and troubleshoot LAN data traffic. Validating LAN traffic models may allow for faster and more reliable computer networks to sustain systems and science on future space missions. Research Summary: This experiment studies the function of the computer network onboard the ISS. On-orbit packet statistics are captured and used to validate ground based medium rate data link models and enhance the way that the local area network (LAN) is monitored. This information will allow monitoring and improvement in the data transfer capabilities of on-orbit computer networks. The Serial Network Flow Monitor (SNFM) experiment attempts to characterize the network equivalent of traffic jams on board ISS. The SNFM team is able to specifically target historical problem areas including the SAMS (Space Acceleration Measurement System) communication issues, data transmissions from the ISS to the ground teams, and multiple users on the network at the same time. By looking at how various users interact with each other on the network, conflicts can be identified and work can begin on solutions. SNFM is comprised of a commercial off the shelf software package that monitors packet traffic through the payload Ethernet LANs (local area networks) on board ISS.

  9. Algebraic number theory

    CERN Document Server

    Jarvis, Frazer

    2014-01-01

    The technical difficulties of algebraic number theory often make this subject appear difficult to beginners. This undergraduate textbook provides a welcome solution to these problems as it provides an approachable and thorough introduction to the topic. Algebraic Number Theory takes the reader from unique factorisation in the integers through to the modern-day number field sieve. The first few chapters consider the importance of arithmetic in fields larger than the rational numbers. Whilst some results generalise well, the unique factorisation of the integers in these more general number fields often fail. Algebraic number theory aims to overcome this problem. Most examples are taken from quadratic fields, for which calculations are easy to perform. The middle section considers more general theory and results for number fields, and the book concludes with some topics which are more likely to be suitable for advanced students, namely, the analytic class number formula and the number field sieve. This is the fi...

  10. Analysis and visualization of citation networks

    CERN Document Server

    Zhao, Dangzhi

    2015-01-01

    Citation analysis-the exploration of reference patterns in the scholarly and scientific literature-has long been applied in a number of social sciences to study research impact, knowledge flows, and knowledge networks. It has important information science applications as well, particularly in knowledge representation and in information retrieval.Recent years have seen a burgeoning interest in citation analysis to help address research, management, or information service issues such as university rankings, research evaluation, or knowledge domain visualization. This renewed and growing interest

  11. p-adic numbers

    OpenAIRE

    Grešak, Rozalija

    2015-01-01

    The field of real numbers is usually constructed using Dedekind cuts. In these thesis we focus on the construction of the field of real numbers using metric completion of rational numbers using Cauchy sequences. In a similar manner we construct the field of p-adic numbers, describe some of their basic and topological properties. We follow by a construction of complex p-adic numbers and we compare them with the ordinary complex numbers. We conclude the thesis by giving a motivation for the int...

  12. Safety-in-numbers

    DEFF Research Database (Denmark)

    Elvik, Rune; Bjørnskau, Torkel

    2017-01-01

    Highlights •26 studies of the safety-in-numbers effect are reviewed. •The existence of a safety-in-numbers effect is confirmed. •Results are consistent. •Causes of the safety-in-numbers effect are incompletely known.......Highlights •26 studies of the safety-in-numbers effect are reviewed. •The existence of a safety-in-numbers effect is confirmed. •Results are consistent. •Causes of the safety-in-numbers effect are incompletely known....

  13. Synthesis of Reliable Telecommunication Networks

    Directory of Open Access Journals (Sweden)

    Dusan Trstensky

    2005-01-01

    Full Text Available In many application, the network designer may to know to senthesise a reliable telecommunication network. Assume that a network, denoted Gm,e has the number of nodes n and the number of edges e, and the operational probability of each edge is known. The system reliability of the network is defined to be the reliability that every pair of nodes can communicate with each other. A network synthesis problem considered in this paper is to find a network G*n,e, that maximises system reliability over the class of all networks for the classes of networks Gn,n-1, Gn,m and Gn,n+1 respectively. In addition an upper bound of maximum reliability for the networks with n-node and e-edge (e>n+2 is derived in terms of node. Computational experiments for the reliability upper are also presented. the results show, that the proposed reliability upper bound is effective.

  14. China-U.S. Trade Issues

    National Research Council Canada - National Science Library

    Morrison, Wayne M

    2005-01-01

    .... With a huge population and a rapidly expanding economy, China is becoming a large market for U.S. exporters. Yet, U.S.-China commercial ties have been strained by a number of issues, including a surging...

  15. On the number of special numbers

    Indian Academy of Sciences (India)

    We now apply the theory of the Thue equation to obtain an effective bound on m. Indeed, by Lemma 3.2, we can write m2 = ba3 and m2 − 4 = cd3 with b, c cubefree. By the above, both b, c are bounded since they are cubefree and all their prime factors are less than e63727. Now we have a finite number of. Thue equations:.

  16. Management issues in automated audit analysis

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, K.A.; Hochberg, J.G.; Wilhelmy, S.K.; McClary, J.F.; Christoph, G.G.

    1994-03-01

    This paper discusses management issues associated with the design and implementation of an automated audit analysis system that we use to detect security events. It gives the viewpoint of a team directly responsible for developing and managing such a system. We use Los Alamos National Laboratory`s Network Anomaly Detection and Intrusion Reporter (NADIR) as a case in point. We examine issues encountered at Los Alamos, detail our solutions to them, and where appropriate suggest general solutions. After providing an introduction to NADIR, we explore four general management issues: cost-benefit questions, privacy considerations, legal issues, and system integrity. Our experiences are of general interest both to security professionals and to anyone who may wish to implement a similar system. While NADIR investigates security events, the methods used and the management issues are potentially applicable to a broad range of complex systems. These include those used to audit credit card transactions, medical care payments, and procurement systems.

  17. Genomic Signal Processing: The Salient Issues

    Directory of Open Access Journals (Sweden)

    Shmulevich Ilya

    2004-01-01

    Full Text Available This paper considers key issues in the emerging field of genomic signal processing and its relationship to functional genomics. It focuses on some of the biological mechanisms driving the development of genomic signal processing, in addition to their manifestation in gene-expression-based classification and genetic network modeling. Certain problems are inherent. For instance, small-sample error estimation, variable selection, and model complexity are important issues for both phenotype classification and expression prediction used in network inference. A long-term goal is to develop intervention strategies to drive network behavior, which is briefly discussed. It is hoped that this nontechnical paper demonstrates that the field of signal processing has the potential to impact and help drive genomics research.

  18. Productivity issues at organizational interfaces

    Science.gov (United States)

    Holland, A. W.

    1985-01-01

    The need for close interdependence between large numbers of diverse and specialized work groups makes the Space Program extremely vulnerable to loss of productivity at organizational interfaces. Trends within the program also suggest that the number and diversity of interfaces will grow in the near term. Continued maintenance of R&D excellence will require that interface performance issues be included in any future productivity improvement effort. The types and characteristics of organizational interfaces are briefly presented, followed by a review of factors which impact their productivity. Approaches to assessing and improving interface effectiveness are also discussed.

  19. [Neuroethics: ethical issues in neurosciences].

    Science.gov (United States)

    Crozier, Sophie

    2013-05-01

    Neuroethics is a field of bioethics on the ethical challenges of advances in neuroscience. Born in the early 2000s, neuroethics is considering a number of issues raised by the opportunities created by advances in knowledge and techniques in the field of neurology and psychiatry. In fact, what we learn about brain functions allows us to potentially influence our behavior and our actions, and questions human nature, freedom and individual responsibility, and even the place of morality in our society.

  20. Surrogacy: Ethical and Legal Issues

    Directory of Open Access Journals (Sweden)

    Pikee Saxena

    2012-01-01

    Full Text Available Surrogacy refers to a contract in which a woman carries a pregnancy "for"another couple. Number of infertile couples from all over the World approach India where commercial surrogacy is legal. Although this arrangement appears to be beneficial for all parties concerned,there are certain delicate issues which need to be addressed through carefully framed laws in order to protect the rights of the surrogate mother and the intended parents.

  1. Surrogacy: ethical and legal issues.

    Science.gov (United States)

    Saxena, Pikee; Mishra, Archana; Malik, Sonia

    2012-10-01

    Surrogacy refers to a contract in which a woman carries a pregnancy "for" another couple. Number of infertile couples from all over the World approach India where commercial surrogacy is legal. Although this arrangement appears to be beneficial for all parties concerned,there are certain delicate issues which need to be addressed through carefully framed laws in order to protect the rights of the surrogate mother and the intended parents.

  2. Brazilian Political Issues: Informed Questions

    Science.gov (United States)

    2002-01-01

    interest groups? 6. The Ministry of Labor estimates that nearly 11,000 labor unions operate in Brazil. Although unions are independent of political...parties, a number of labor leaders are 4 prominent members of political parties. Additionally, labor unions have been known to form alliances with...social movements and political parties when advocating individual issues. (Department of State, Humans Rights Report.) How influential are labor

  3. Making decisions from numbers

    Energy Technology Data Exchange (ETDEWEB)

    Somers, E.

    1987-03-01

    Regulatory agencies require numbers to provide health protection. The manner in which these numbers are derived from animal experiments and human epidemiology is considered together with the limitations and inadequacies of these numbers. Some recent examples of risk assessment in Canada are given including asbestos, drinking water, and indoor air quality. The value of these numbers in providing a measure of the hazard in a wider perspective is stressed, although they can never be the sole determinant of public policy.

  4. On maximizing the lifetime of Wireless Sensor Networks by optimally assigning energy supplies.

    Science.gov (United States)

    Asorey-Cacheda, Rafael; García-Sánchez, Antonio Javier; García-Sánchez, Felipe; García-Haro, Joan; González-Castano, Francisco Javier

    2013-08-09

    The extension of the network lifetime of Wireless Sensor Networks (WSN) is an important issue that has not been appropriately solved yet. This paper addresses this concern and proposes some techniques to plan an arbitrary WSN. To this end, we suggest a hierarchical network architecture, similar to realistic scenarios, where nodes with renewable energy sources (denoted as primary nodes) carry out most message delivery tasks, and nodes equipped with conventional chemical batteries (denoted as secondary nodes) are those with less communication demands. The key design issue of this network architecture is the development of a new optimization framework to calculate the optimal assignment of renewable energy supplies (primary node assignment) to maximize network lifetime, obtaining the minimum number of energy supplies and their node assignment. We also conduct a second optimization step to additionally minimize the number of packet hops between the source and the sink. In this work, we present an algorithm that approaches the results of the optimization framework, but with much faster execution speed, which is a good alternative for large-scale WSN networks. Finally, the network model, the optimization process and the designed algorithm are further evaluated and validated by means of computer simulation under realistic conditions. The results obtained are discussed comparatively.

  5. On Maximizing the Lifetime of Wireless Sensor Networks by Optimally Assigning Energy Supplies

    Directory of Open Access Journals (Sweden)

    Francisco Javier González-Castano

    2013-08-01

    Full Text Available The extension of the network lifetime of Wireless Sensor Networks (WSN is an important issue that has not been appropriately solved yet. This paper addresses this concern and proposes some techniques to plan an arbitrary WSN. To this end, we suggest a hierarchical network architecture, similar to realistic scenarios, where nodes with renewable energy sources (denoted as primary nodes carry out most message delivery tasks, and nodes equipped with conventional chemical batteries (denoted as secondary nodes are those with less communication demands. The key design issue of this network architecture is the development of a new optimization framework to calculate the optimal assignment of renewable energy supplies (primary node assignment to maximize network lifetime, obtaining the minimum number of energy supplies and their node assignment. We also conduct a second optimization step to additionally minimize the number of packet hops between the source and the sink. In this work, we present an algorithm that approaches the results of the optimization framework, but with much faster execution speed, which is a good alternative for large-scale WSN networks. Finally, the network model, the optimization process and the designed algorithm are further evaluated and validated by means of computer simulation under realistic conditions. The results obtained are discussed comparatively.

  6. Survey on fusible numbers

    OpenAIRE

    Xu, Junyan

    2012-01-01

    We point out that the recursive formula that appears in Erickson's presentation "Fusible Numbers" is incorrect, and pose an alternate conjecture about the structure of fusible numbers. Although we are unable to solve the conjecture, we succeed in establishing some basic properties of fusible numbers. We suggest some possible approaches to the conjecture, and list further problems in the final chapter.

  7. Discovery: Prime Numbers

    Science.gov (United States)

    de Mestre, Neville

    2008-01-01

    Prime numbers are important as the building blocks for the set of all natural numbers, because prime factorisation is an important and useful property of all natural numbers. Students can discover them by using the method known as the Sieve of Eratosthenes, named after the Greek geographer and astronomer who lived from c. 276-194 BC. Eratosthenes…

  8. Analytic number theory

    CERN Document Server

    Matsumoto, Kohji

    2002-01-01

    The book includes several survey articles on prime numbers, divisor problems, and Diophantine equations, as well as research papers on various aspects of analytic number theory such as additive problems, Diophantine approximations and the theory of zeta and L-function Audience Researchers and graduate students interested in recent development of number theory

  9. Fault-Tolerant Algorithms for Connectivity Restoration in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Yali Zeng

    2015-12-01

    Full Text Available As wireless sensor network (WSN is often deployed in a hostile environment, nodes in the networks are prone to large-scale failures, resulting in the network not working normally. In this case, an effective restoration scheme is needed to restore the faulty network timely. Most of existing restoration schemes consider more about the number of deployed nodes or fault tolerance alone, but fail to take into account the fact that network coverage and topology quality are also important to a network. To address this issue, we present two algorithms named Full 2-Connectivity Restoration Algorithm (F2CRA and Partial 3-Connectivity Restoration Algorithm (P3CRA, which restore a faulty WSN in different aspects. F2CRA constructs the fan-shaped topology structure to reduce the number of deployed nodes, while P3CRA constructs the dual-ring topology structure to improve the fault tolerance of the network. F2CRA is suitable when the restoration cost is given the priority, and P3CRA is suitable when the network quality is considered first. Compared with other algorithms, these two algorithms ensure that the network has stronger fault-tolerant function, larger coverage area and better balanced load after the restoration.

  10. Fault-Tolerant Algorithms for Connectivity Restoration in Wireless Sensor Networks.

    Science.gov (United States)

    Zeng, Yali; Xu, Li; Chen, Zhide

    2015-12-22

    As wireless sensor network (WSN) is often deployed in a hostile environment, nodes in the networks are prone to large-scale failures, resulting in the network not working normally. In this case, an effective restoration scheme is needed to restore the faulty network timely. Most of existing restoration schemes consider more about the number of deployed nodes or fault tolerance alone, but fail to take into account the fact that network coverage and topology quality are also important to a network. To address this issue, we present two algorithms named Full 2-Connectivity Restoration Algorithm (F2CRA) and Partial 3-Connectivity Restoration Algorithm (P3CRA), which restore a faulty WSN in different aspects. F2CRA constructs the fan-shaped topology structure to reduce the number of deployed nodes, while P3CRA constructs the dual-ring topology structure to improve the fault tolerance of the network. F2CRA is suitable when the restoration cost is given the priority, and P3CRA is suitable when the network quality is considered first. Compared with other algorithms, these two algorithms ensure that the network has stronger fault-tolerant function, larger coverage area and better balanced load after the restoration.

  11. Evolving production network structures

    DEFF Research Database (Denmark)

    Grunow, Martin; Gunther, H.O.; Burdenik, H.

    2007-01-01

    When deciding about future production network configurations, the current structures have to be taken into account. Further, core issues such as the maturity of the products and the capacity requirements for test runs and ramp-ups must be incorporated. Our approach is based on optimization...... modelling and assigns products and capacity expansions to production sites under the above constraints. It also considers the production complexity at the individual sites and the flexibility of the network. Our implementation results for a large manufacturing network reveal substantial possible cost...... reductions compared to the traditional manual planning results of our industrial partner....

  12. Scalable Coverage Maintenance for Dense Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Jun Lu

    2007-06-01

    Full Text Available Owing to numerous potential applications, wireless sensor networks have been attracting significant research effort recently. The critical challenge that wireless sensor networks often face is to sustain long-term operation on limited battery energy. Coverage maintenance schemes can effectively prolong network lifetime by selecting and employing a subset of sensors in the network to provide sufficient sensing coverage over a target region. We envision future wireless sensor networks composed of a vast number of miniaturized sensors in exceedingly high density. Therefore, the key issue of coverage maintenance for future sensor networks is the scalability to sensor deployment density. In this paper, we propose a novel coverage maintenance scheme, scalable coverage maintenance (SCOM, which is scalable to sensor deployment density in terms of communication overhead (i.e., number of transmitted and received beacons and computational complexity (i.e., time and space complexity. In addition, SCOM achieves high energy efficiency and load balancing over different sensors. We have validated our claims through both analysis and simulations.

  13. Applied number theory

    CERN Document Server

    Niederreiter, Harald

    2015-01-01

    This textbook effectively builds a bridge from basic number theory to recent advances in applied number theory. It presents the first unified account of the four major areas of application where number theory plays a fundamental role, namely cryptography, coding theory, quasi-Monte Carlo methods, and pseudorandom number generation, allowing the authors to delineate the manifold links and interrelations between these areas.  Number theory, which Carl-Friedrich Gauss famously dubbed the queen of mathematics, has always been considered a very beautiful field of mathematics, producing lovely results and elegant proofs. While only very few real-life applications were known in the past, today number theory can be found in everyday life: in supermarket bar code scanners, in our cars’ GPS systems, in online banking, etc.  Starting with a brief introductory course on number theory in Chapter 1, which makes the book more accessible for undergraduates, the authors describe the four main application areas in Chapters...

  14. Future-oriented power distribution grid. Handling of up to 50% fluctuating power generation in 2020. Issue paper - working group G1; Denmark. Smart Grid Network; Fremtidssikring af elnettet. Haandtering af op til 50 pct. fluktuerende elproduktion i 2020. Issue paper, arbejdsgruppe G1

    Energy Technology Data Exchange (ETDEWEB)

    Soendergren, C.; Norsk Jensen, A. (Dansk Energi, Frederiksberg (Denmark)); OEstergaard, J. (Danmarks Tekniske Univ.. DTU Elektro, Kgs. Lyngby (Denmark)) (and others)

    2011-07-01

    The Smart Grid Network was established in 2010 by the Danish climate and energy minister tasked with developing recommendations for future actions and initiatives that make it possible to handle up to 50% electricity from wind energy in the power system in 2020. The task of working group 1 of the Smart Grid Network is stated as: ''The group will, building on existing surveys and analyses of structures and constraints in the Danish electricity system 2020, define concrete ideas on the technical and system development needs for the electricity supply system when the goal of intelligent integration of 50 percent power generated by renewable energy must be met. The group should come up with concrete suggestions on how to make the power system future-oriented, such as new network and management architectures, more measuring equipment, optical sensors, and new computer and communications systems that can monitor, control and operate the power system with the aim that the new intelligence can contribute to a reliable and cost-effective power system that can handle the deployment of renewable energy''. The working group has focused on a general description of the whole overall system needs and more specifically on the power grid and its management and control. (LN)

  15. Drawing rooted phylogenetic networks.

    Science.gov (United States)

    Huson, Daniel H

    2009-01-01

    The evolutionary history of a collection of species is usually represented by a phylogenetic tree. Sometimes, phylogenetic networks are used as a means of representing reticulate evolution or of showing uncertainty and incompatibilities in evolutionary datasets. This is often done using unrooted phylogenetic networks such as split networks, due in part, to the availability of software (SplitsTree) for their computation and visualization. In this paper we discuss the problem of drawing rooted phylogenetic networks as cladograms or phylograms in a number of different views that are commonly used for rooted trees. Implementations of the algorithms are available in new releases of the Dendroscope and SplitsTree programs.

  16. Transportation network reduction

    Directory of Open Access Journals (Sweden)

    Stanislav PALÚCH

    2015-06-01

    Full Text Available Network reduction problem is formulated as follows: We are given a transportation network T, a set of important origin – destination relations R and a number q greater than 1. The goal is to find a subnetwork S of the given network T such that all shortest paths between all origin – destination pairs from R using only subnetwork S are not longer than q-multiple of the corresponding distance in original network T. A mathematical model and an exact algorithm of just mentioned task is presented.

  17. Declarative Networking

    CERN Document Server

    Loo, Boon Thau

    2012-01-01

    Declarative Networking is a programming methodology that enables developers to concisely specify network protocols and services, which are directly compiled to a dataflow framework that executes the specifications. Declarative networking proposes the use of a declarative query language for specifying and implementing network protocols, and employs a dataflow framework at runtime for communication and maintenance of network state. The primary goal of declarative networking is to greatly simplify the process of specifying, implementing, deploying and evolving a network design. In addition, decla

  18. Issues and challenges in international doctoral education in nursing.

    Science.gov (United States)

    Ketefian, Shaké; Davidson, Patricia; Daly, John; Chang, Esther; Srisuphan, Wichit

    2005-09-01

    Education is a driving force in improving the health and welfare of communities globally. Doctoral education of nurses has been identified as a critical factor for provision of leadership in practice, scholarship, research, policy and education. Since the genesis of doctoral education in nursing in the USA in the 1930s, this movement has burgeoned to over 273 doctoral programs in over 30 countries globally. The present article seeks to identify the issues and challenges in nursing doctoral education globally, and those encountered by doctoral program graduates in meeting the challenges of contemporary health care systems. Information was derived from a comprehensive literature review. Electronic databases and the Internet, using the Google search engine, were searched using the key words "doctoral education"; "nursing"; "International Network for Doctoral Education in Nursing"; "global health"; "international research collaboration". Doctoral education has been a critical force in developing nurse leaders in education, management, policy and research domains. An absence of consensus in terminology and of accurate minimum data sets precludes comparison and debate across programs. The complexity and dynamism of contemporary globalized communities render significant challenges in the conduct of doctoral programs. Addressing funding issues and faculty shortages are key issues for doctoral programs, especially those in developing countries, to achieve an identity uniquely their own. These challenges can also afford considerable opportunities for discussion, debate and the formulation of innovative and collaborative solutions to advance nursing knowledge and scholarship. In spite of discrete differences between countries and regions, the similarities in the issues facing the development of doctoral programs internationally are more striking than the differences. The harnessing of a global collective to address these issues will likely serve to not only forge the future

  19. Connected networks economy

    Energy Technology Data Exchange (ETDEWEB)

    Hamerak, K.

    1981-05-05

    Two foremost requirements for interconnected power systems are: constancy of frequency and constancy of voltage. Because there is a rigid relation between main frequency and the number of revolutions of the synchronous generators, and this leads to active load alterations in the case of frequency changes of the network, there is a need for control systems for power networks. In practice they are designed for automatic operation. For control of the number of revolutions of turbines proportional controllers are the most useful. Autocontrol also has an advantageous influence on frequency stability. Peak loads in connected networks are covered by pumping storage power plants.

  20. Tracking Transition: Issues in Asynchronous E-Mail Interviewing

    Directory of Open Access Journals (Sweden)

    Muir Houston

    2008-05-01

    Full Text Available The purpose and focus of this paper is twofold. The first concerns the methodological issues involved with tracking a mobile population, namely students graduating from university; whose patterns of residence may for some time be transitory in nature. The second is to provide some details from a small sample of graduates on the issues raised in the transition from undergraduate study. The paper will tackle the two issues in order. First, an examination of recent methods of qualitative data collection which the development of information technology, in the form of Computer Mediated Communication (CMC, has allowed is undertaken. Second, the results of using one of these techniques (asynchronous e-mail to gather information on the transition from undergraduate study are reported. In addition, advantages and disadvantages that can arise in the use of these new techniques are reported. This paper engages with the overall theme of transition in a number of ways. First, the students are in a process of transition in status; from undergraduate to graduate. Second, in many cases, they may well be in transition in terms of location; from the university location either back home, or away to a new location. Third, they are in transition in terms of activity; either seeking or into employment or engaging in further study at a higher level. Finally, they may be in transition in relation to developing new social networks. URN: urn:nbn:de:0114-fqs0802116

  1. Clustering context-specific gene regulatory networks.

    Science.gov (United States)

    Ramesh, Archana; Trevino, Robert; VON Hoff, Daniel D; Kim, Seungchan

    2010-01-01

    Gene regulatory networks (GRNs) learned from high throughput genomic data are often hard to visualize due to the large number of nodes and edges involved, rendering them difficult to appreciate. This becomes an important issue when modular structures are inherent in the inferred networks, such as in the recently proposed context-specific GRNs.(12) In this study, we investigate the application of graph clustering techniques to discern modularity in such highly complex graphs, focusing on context-specific GRNs. Identified modules are then associated with a subset of samples and the key pathways enriched in the module. Specifically, we study the use of Markov clustering and spectral clustering on cancer datasets to yield evidence on the possible association amongst different tumor types. Two sets of gene expression profiling data were analyzed to reveal context-specificity as well as modularity in genomic regulations.

  2. Micro-generation network connection (renewables)

    Energy Technology Data Exchange (ETDEWEB)

    Thornycroft, J.; Russell, T.; Curran, J.

    2003-07-01

    The drive to reduce emissions of carbon dioxide will result in an increase in the number of small generation units seeking connection to the electric power distribution network. The objectives of this study were to consider connection issues relating to micro-generation from renewables and their integration into the UK distribution network. The document is divided into two sections. The first section describes the present system which includes input from micro-generation, the technical impacts and the financial considerations. The second part discusses technical, financial and governance options for the future. A summary of preferred options and recommendations is given. The study was carried out by the Halcrow Group Ltd under contract to the DTI.

  3. From the Editor Vol: 6 number 2

    OpenAIRE

    Ugur Demiray

    2005-01-01

    From the Editor Dear TOJDES Readers Time flies. Another quarter has begun. It is a great pleasure to welcome you to the 18th issue, the Volume: 6, Number: 2 of The Turkish Online Journal of Distance Education (TOJDE), of looking forward. TOJDE has been driving and shaping by our editorial board, reviewers, authors and even unbelievable readers. In the April 2005 issue, TOJDE publishes peer-reviewed distance education articles under four umbrellas: applications, feature topics, researches, ...

  4. Modular Brain Networks.

    Science.gov (United States)

    Sporns, Olaf; Betzel, Richard F

    2016-01-01

    The development of new technologies for mapping structural and functional brain connectivity has led to the creation of comprehensive network maps of neuronal circuits and systems. The architecture of these brain networks can be examined and analyzed with a large variety of graph theory tools. Methods for detecting modules, or network communities, are of particular interest because they uncover major building blocks or subnetworks that are particularly densely connected, often corresponding to specialized functional components. A large number of methods for community detection have become available and are now widely applied in network neuroscience. This article first surveys a number of these methods, with an emphasis on their advantages and shortcomings; then it summarizes major findings on the existence of modules in both structural and functional brain networks and briefly considers their potential functional roles in brain evolution, wiring minimization, and the emergence of functional specialization and complex dynamics.

  5. A Few Large Roads or Many Small Ones? How to Accommodate Growth in Vehicle Numbers to Minimise Impacts on Wildlife

    Science.gov (United States)

    Rhodes, Jonathan R.; Lunney, Daniel; Callaghan, John; McAlpine, Clive A.

    2014-01-01

    Roads and vehicular traffic are among the most pervasive of threats to biodiversity because they fragmenting habitat, increasing mortality and opening up new areas for the exploitation of natural resources. However, the number of vehicles on roads is increasing rapidly and this is likely to continue into the future, putting increased pressure on wildlife populations. Consequently, a major challenge is the planning of road networks to accommodate increased numbers of vehicles, while minimising impacts on wildlife. Nonetheless, we currently have few principles for guiding decisions on road network planning to reduce impacts on wildlife in real landscapes. We addressed this issue by developing an approach for quantifying the impact on wildlife mortality of two alternative mechanisms for accommodating growth in vehicle numbers: (1) increasing the number of roads, and (2) increasing traffic volumes on existing roads. We applied this approach to a koala (Phascolarctos cinereus) population in eastern Australia and quantified the relative impact of each strategy on mortality. We show that, in most cases, accommodating growth in traffic through increases in volumes on existing roads has a lower impact than building new roads. An exception is where the existing road network has very low road density, but very high traffic volumes on each road. These findings have important implications for how we design road networks to reduce their impacts on biodiversity. PMID:24646891

  6. A few large roads or many small ones? How to accommodate growth in vehicle numbers to minimise impacts on wildlife.

    Directory of Open Access Journals (Sweden)

    Jonathan R Rhodes

    Full Text Available Roads and vehicular traffic are among the most pervasive of threats to biodiversity because they fragmenting habitat, increasing mortality and opening up new areas for the exploitation of natural resources. However, the number of vehicles on roads is increasing rapidly and this is likely to continue into the future, putting increased pressure on wildlife populations. Consequently, a major challenge is the planning of road networks to accommodate increased numbers of vehicles, while minimising impacts on wildlife. Nonetheless, we currently have few principles for guiding decisions on road network planning to reduce impacts on wildlife in real landscapes. We addressed this issue by developing an approach for quantifying the impact on wildlife mortality of two alternative mechanisms for accommodating growth in vehicle numbers: (1 increasing the number of roads, and (2 increasing traffic volumes on existing roads. We applied this approach to a koala (Phascolarctos cinereus population in eastern Australia and quantified the relative impact of each strategy on mortality. We show that, in most cases, accommodating growth in traffic through increases in volumes on existing roads has a lower impact than building new roads. An exception is where the existing road network has very low road density, but very high traffic volumes on each road. These findings have important implications for how we design road networks to reduce their impacts on biodiversity.

  7. Introduction [to Issue 3

    Science.gov (United States)

    Zimmerman, Christian E.; Nielsen, Jennifer L.

    2004-01-01

    Artificial propagation of aquatic organisms is increasing globally and currently accounts for approximately 32% of total world fishery production (Vannuccini, 2004). Between 1970 and 2000, aquaculture production of salmonids has grown from less than 200,000 metric tons per year to over 1.5 million metric tons (Tacon, 2003). In 1995, the number of Atlantic salmon (Salmo salar) far exceeded the carrying capacity of salmon in the wild but over 94% of all adult Atlantic salmon were in aquaculture environments (Gross, 1998).Since the 1970’s, concerns have arisen about interactions of hatchery and wild produced salmonids in native habitats. In response, research has addressed concerns about domestication and genetic impacts (Reisenbichler and McIntyre, 1977; Hindar et al., 1991; Waples, 1991; Clifford et al., 1998a; Fleming et al., 2000, 2002; Hard et al., 2000), transfer of disease and parasites (Johnsen and Jensen, 1994; Bakke and Harris, 1998), behavior of spawning adults (Fleming and Gross, 1992; Fleming et al., 1994; Økland et al., 1995; Youngston et al., 1998), differences in fitness traits and life history (Jonsson et al., 1991; Thodesen et al., 1999; McGinnity et al., 2003), and behavioral interactions between hatchery and wild juvenile salmon (Swain and Riddell, 1990; Johnsson et al., 1996; Clifford et al., 1998b). Much of this research has been driven by concerns about the impacts of escaped farmed Atlantic salmon in the North Atlantic Ocean (Hansen et al., 1991). Studies of the interactions between hatchery and wild salmonids, with few exceptions (see Myers et al., 2000), have primarily focused on interactions in freshwater environments.Interactions between hatchery and wild fishes in estuarine and marine environments have not received the same attention, but may have signifi- cant impacts on wild populations. To address this issue, we organized a symposium held at the 2003 annual meeting of the Western Division of the American Fisheries Society in San

  8. Research Article Special Issue

    African Journals Online (AJOL)

    pc

    2017-10-17

    Oct 17, 2017 ... 1. INTRODUCTION. Wireless Sensor Network technology had contributed mainly in the field of monitoring such ... Previous research stated that CDMA has the advantages to support the applications withstrict .... The wireless sensor network node deployment separated into two type of topologies such as.

  9. Research Article Special Issue

    African Journals Online (AJOL)

    2017-09-10

    Sep 10, 2017 ... The neural to aid in the decision-making the prediction of raindrop. This ity of artificial neural networks ity. Those conditions have been f raining. ... A neural network can be seen as a machine that is designed to model the way in which the ..... International Conference on Industrial Informatics, 2006, pp.

  10. Research Article Special Issue

    African Journals Online (AJOL)

    2016-05-15

    May 15, 2016 ... urban- industrial system, range of rural population motion has increased. This process increased ... Analytical Network Process method was used to achieve the effect of immigration components on the ... article entitled "The urban economy based on neural network" have addressed the urban traditional ...

  11. Research Article Special Issue

    African Journals Online (AJOL)

    2016-05-15

    May 15, 2016 ... With the growing use of the internet network, using tools that can help user to transact with the network is inevitable. One of ... methods, advantages and disadvantages will be investigated. In this paper, by taking ... heterogeneous environment such as internet and help user to take actions. There are many.

  12. Psychological issues in acquired facial trauma

    Directory of Open Access Journals (Sweden)

    De Sousa Avinash

    2010-01-01

    Full Text Available The face is a vital component of one′s personality and body image. There are a vast number of variables that influence recovery and rehabilitation from acquired facial trauma many of which are psychological in nature. The present paper presents the various psychological issues one comes across in facial trauma patients. These may range from body image issues to post-traumatic stress disorder symptoms accompanied by anxiety and depression. Issues related to facial and body image affecting social life and general quality of life are vital and the plastic surgeon should be aware of such issues and competent to deal with them in patients and families.

  13. ENERGY OPTIMIZATION IN CLUSTER BASED WIRELESS SENSOR NETWORKS

    Directory of Open Access Journals (Sweden)

    T. SHANKAR

    2014-04-01

    Full Text Available Wireless sensor networks (WSN are made up of sensor nodes which are usually battery-operated devices, and hence energy saving of sensor nodes is a major design issue. To prolong the networks lifetime, minimization of energy consumption should be implemented at all layers of the network protocol stack starting from the physical to the application layer including cross-layer optimization. Optimizing energy consumption is the main concern for designing and planning the operation of the WSN. Clustering technique is one of the methods utilized to extend lifetime of the network by applying data aggregation and balancing energy consumption among sensor nodes of the network. This paper proposed new version of Low Energy Adaptive Clustering Hierarchy (LEACH, protocols called Advanced Optimized Low Energy Adaptive Clustering Hierarchy (AOLEACH, Optimal Deterministic Low Energy Adaptive Clustering Hierarchy (ODLEACH, and Varying Probability Distance Low Energy Adaptive Clustering Hierarchy (VPDL combination with Shuffled Frog Leap Algorithm (SFLA that enables selecting best optimal adaptive cluster heads using improved threshold energy distribution compared to LEACH protocol and rotating cluster head position for uniform energy dissipation based on energy levels. The proposed algorithm optimizing the life time of the network by increasing the first node death (FND time and number of alive nodes, thereby increasing the life time of the network.

  14. REVIEW OF IRRATIONAL NUMBERS

    Directory of Open Access Journals (Sweden)

    Hafnani Hafnani

    2015-04-01

    Full Text Available Study of the set properties is simple and rarely investigated at the Department of Mathematics. This paper examines some set properties on the irrational numbers. The study is about the properties applying to the real numbers which are a complete ordered field. However, the results of this study show that those properties do not imply to the irrational numbers, but the ordered property. The prove of the irrational numberby some examples is demonstrated in this study.

  15. The simple complex numbers

    OpenAIRE

    Zalesny, Jaroslaw

    2008-01-01

    A new simple geometrical interpretation of complex numbers is presented. It differs from their usual interpretation as points in the complex plane. From the new point of view the complex numbers are rather operations on vectors than points. Moreover, in this approach the real, imaginary and complex numbers have similar interpretation. They are simply some operations on vectors. The presented interpretation is simpler, more natural, and better adjusted to possible applications in geometry and ...

  16. EW WEIGHT DEPENDENT ROUTING AND WAVELENGTH ASSIGNMENT STRATEGY FOR ALL OPTICAL NETWORKS IN ABSENCE OF WAVELENGTH CONVERTERS

    Directory of Open Access Journals (Sweden)

    Shilpa S. Patil

    2015-09-01

    Full Text Available In wavelength division multiplexed all optical networks; lightpath establishes a connection between sending and receiving nodes bypassing the electronic processing at intermediate nodes. One of the prime objectives of Routing and Wavelength Assignment (RWA problem is to maximize the number of connections efficiently by choosing the best routes. Although there are several algorithms available, improving the blocking performance in optical networks and finding optimal solutions for RWA problem has still remained a challenging issue. Wavelength conversion can be helpful in restricting the problem of wavelength continuity constraint but it increases complexity in the network. In this paper, we propose new weight dependent routing and wavelength assignment strategy for all optical networks without use of wavelength converters. Proposed weight function reduces blocking probability significantly, improving the network performance at various load conditions. Further, due to absence of wavelength converters, the cost and complexity of network reduces. Results show that the proposed strategy performs better than earlier reported methods.

  17. Time series analysis of temporal networks

    Science.gov (United States)

    Sikdar, Sandipan; Ganguly, Niloy; Mukherjee, Animesh

    2016-01-01

    A common but an important feature of all real-world networks is that they are temporal in nature, i.e., the network structure changes over time. Due to this dynamic nature, it becomes difficult to propose suitable growth models that can explain the various important characteristic properties of these networks. In fact, in many application oriented studies only knowing these properties is sufficient. For instance, if one wishes to launch a targeted attack on a network, this can be done even without the knowledge of the full network structure; rather an estimate of some of the properties is sufficient enough to launch the attack. We, in this paper show that even if the network structure at a future time point is not available one can still manage to estimate its properties. We propose a novel method to map a temporal network to a set of time series instances, analyze them and using a standard forecast model of time series, try to predict the properties of a temporal network at a later time instance. To our aim, we consider eight properties such as number of active nodes, average degree, clustering coefficient etc. and apply our prediction framework on them. We mainly focus on the temporal network of human face-to-face contacts and observe that it represents a stochastic process with memory that can be modeled as Auto-Regressive-Integrated-Moving-Average (ARIMA). We use cross validation techniques to find the percentage accuracy of our predictions. An important observation is that the frequency domain properties of the time series obtained from spectrogram analysis could be used to refine the prediction framework by identifying beforehand the cases where the error in prediction is likely to be high. This leads to an improvement of 7.96% (for error level ≤20%) in prediction accuracy on an average across all datasets. As an application we show how such prediction scheme can be used to launch targeted attacks on temporal networks. Contribution to the Topical Issue

  18. AN ENERGY EFFICIENT FITNESS BASED ROUTING PROTOCOL IN WIRELESS SENSOR NETWORKS

    Directory of Open Access Journals (Sweden)

    A. Balamurugan

    2014-03-01

    Full Text Available A wireless sensor network is a self-organized multi hop network that consists of a large number of sensor nodes. The efficiency of the sensor networks depends upon the routing protocol used. There are different routing protocols exists to extend the network lifetime by efficiently consuming the energy of the nodes. The nodes have limited energy resources and are battery powered. Therefore, designing an effective routing protocol that conserve scarce energy resources is the major critical issue in WSN. In this paper, a Fitness based Routing Protocol (FRP is proposed to optimize energy efficient data transmission. The energy consumption of nodes is reduced by selecting the nodes with minimum hop count and distance. Genetic algorithm is used as an optimization technique to find the fitted node based on its fitness value. The FRP could increase the network lifetime and throughput comparing to the other protocols. The protocol could also reduce the packet loss and end – end delay.

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

    Science.gov (United States)

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

    2017-10-01

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

  20. Numbers, sequences and series

    CERN Document Server

    Hirst, Keith

    1994-01-01

    Number and geometry are the foundations upon which mathematics has been built over some 3000 years. This book is concerned with the logical foundations of number systems from integers to complex numbers. The author has chosen to develop the ideas by illustrating the techniques used throughout mathematics rather than using a self-contained logical treatise. The idea of proof has been emphasised, as has the illustration of concepts from a graphical, numerical and algebraic point of view. Having laid the foundations of the number system, the author has then turned to the analysis of infinite proc