• 제목/요약/키워드: Network Connectivity

검색결과 765건 처리시간 0.027초

ZigBee/IEEE802.15.4 표준을 사용하는 Ad Hoc 네트워크 상의 전력 통제 (Power control in Ad Hoc network using ZigBee/IEEE802.15.4 Standard)

  • ;이재광
    • 한국정보보호학회:학술대회논문집
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    • 한국정보보호학회 2006년도 하계학술대회
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    • pp.219-222
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    • 2006
  • In this paper an intrusion detection system technique of wireless Ad Hoc network is explained and the advantage of making them work in IEEE 802.15.4/ZigBee wireless standard is also discussed. The methodology that is mentioned here is intrusion detection architecture based on a local intrusion database [1]. An ad hoc network is a collection of nodes that is connected through a wireless medium forming rapidly changing topologies. Due to increased connectivity (especially on the Internet), and the vast spectrum of financial possibilities that are opening up, more and more systems are subject to attack by intruders. An ideal IDS should able to detect an anomaly caused by the intruders quickly so that the misbehaving node/nodes can be identified and appropriate actions (e.g. punish or avoid misbehaving nodes) can be taken so that further damage to the network is minimized

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FTTH-PON 가입자망 설계에서 Splitter Location-Allocation 문제 (A Splitter Location-Allocation Problem in Designing FTTH-PON Access Networks)

  • 박찬우;이영호;한정희
    • 한국경영과학회지
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    • 제36권2호
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    • pp.1-14
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    • 2011
  • In this paper, we deal with an access network design problem of fiber-to-the-home passive optical network (FTTH-PON). The FTTH-PON network design problem seeks to minimize the total cost of optical splitters and cables that provide optical connectivity between central office and subscribers. We develop a flow-based mixed integer programming (MIP) model with nonlinear link cost. By developing valid inequalities and preprocessing rules, we enhance the strength of the proposed MIP model in generating tight lower bounds for the problem. We develop an effective Tabu Search (TS) heuristic algorithm that provides good quality feasible solutions to the problem. Computational results demonstrate that the valid inequalities and preprocessing rules are effective for improving the LP-relaxation lower bound and TS algorithm finds good quality solutions within reasonable time bounds.

효율적인 원거리 데이터 전송을 위한 Zigbee 노드들의 그룹화 알고리즘 (Grouping Algorithms of Zigbee Nodes for Efficient Data Transmission to Long Range)

  • 우성제;신복덕
    • 전기학회논문지
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    • 제61권4호
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    • pp.632-638
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    • 2012
  • ZigBee network, based on PHY, MAC layer provides a specification for a suite of high level communication protocols using small, low-power digital radio based on an IEEE 802.15.4 standard. Meshing is a type of daisy chaining from one device to another. This technique allows the short range of an individual node to be expanded and multiplied, covering a much larger area. Each wireless technology that makes it to market serves a special purpose or function. Zigbee provides short-range connectivity in what is called a personal-area network (PAN). Within ZigBee PAN coordinator as manages an entire ZigBee network, the short range of frequency band was only selected because the technology allows typically less than 100 kbp or ZigBee troubles in retransmission processing and delaying data tranmission works to create unproductive condition of work. This research was proposed the method, based on short range frequency of zigBee nodes enable to long range of remote data transmission with specific algorithm tools.

사회네트워크에서 사용자 행위정보를 활용한 퍼지 기반의 신뢰관계망 추론 모형 (A Fuzzy-based Inference Model for Web of Trust Using User Behavior Information in Social Network)

  • 송희석
    • Journal of Information Technology Applications and Management
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    • 제17권4호
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    • pp.39-56
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    • 2010
  • We are sometimes interacting with people who we know nothing and facing with the difficult task of making decisions involving risk in social network. To reduce risk, the topic of building Web of trust is receiving considerable attention in social network. The easiest approach to build Web of trust will be to ask users to represent level of trust explicitly toward another users. However, there exists sparsity issue in Web of trust which is represented explicitly by users as well as it is difficult to urge users to express their level of trustworthiness. We propose a fuzzy-based inference model for Web of trust using user behavior information in social network. According to the experiment result which is applied in Epinions.com, the proposed model show improved connectivity in resulting Web of trust as well as reduced prediction error of trustworthiness compared to existing computational model.

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속성정보를 이용한 최적의 자율망 경로탐색 기법에 관한 연구 (A study on Ad hoc network path of optimized by using context awareness)

  • 지삼현;이강환
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2008년도 하계종합학술대회
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    • pp.765-766
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    • 2008
  • In this paper, It has been emphasized of important path access during transmit of node when each node transmit broadcast service which one's of new MANET (Mobile Ad hoc Networks) of autonomy and mobility network structures. It has proposed analysis methods are hierarchical path structure of transmit which experience context aware through confidence to network connectivity alone as issue which can be reduce duplicate of beam forming on networks and maintenance one's of method got to optimized of transmission network that status information of context awareness using ad hoc ODDMRP(Ontology Doppler effect Dynamic Multicast Routing Protocol) path method.

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Cooperative Coordination Method of Neural Network Controller Module for Autonomous Mobile Robot Navigation

  • Joo, Han-Seong;Young, Oh-Se
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.178.3-178
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    • 2001
  • This paper is concerned with designing a neural network based navigator that is optimized in a user-defined sense for a mobile robot using ultrasonic sensors to travel to a goal position safely and efficiently without any prior map of the environment. The neural network has a dynamically reconfigurable structure that not only can optimize the weights but also the input sensory connectivity in order to meet any user-defined objective. Therefore, in this research, we can select an optimal subset of sensory inputs that results in the best performance related to both navigation and structural complexity. Further, this research uses the manually trained initial population and the modular neural network to alleviate ...

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BL-CAST:Beacon-Less Broadcast Protocol for Vehicular Ad Hoc Networks

  • Khan, Ajmal;Cho, You-Ze
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제8권4호
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    • pp.1223-1236
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    • 2014
  • With the extension of wireless technology, vehicular ad hoc networks provide important services for the dissemination of general data and emergency warnings. However, since, the vehicle topology frequently changes from a dense to a sparse network depending on the speed of the moving vehicles and the time of day, vehicular ad hoc networks require a protocol that can facilitate the efficient and reliable dissemination of emergency messages in a highly mobile environment under dense or intermittent vehicular connectivity. Therefore, this paper proposes a new vehicular broadcast protocol, called BL-CAST, that can operate effectively in both dense and sparse network scenarios. As a low overhead multi-hop broadcast protocol, BL-CAST does not rely on the periodic exchange of beacons for updating location information. Instead, the location information of a vehicle is included in a broadcast message to identify the last rebroadcasting vehicle in an intermittently connected network. Simulation results show that BL-CAST outperforms the DV-CAST protocol in terms of the end-to-end delay, message delivery ratio and network overhead.

DTMNs를 위한 신뢰성 있는 데이터 전송 지원 방법 (A Reliable Transport Supporting Method for a DTMNs)

  • 서두옥;이동호
    • 디지털산업정보학회논문지
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    • 제5권4호
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    • pp.151-160
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    • 2009
  • While portable and wireless devices are pouring, a new network technology is needed as a breakthrough. The new network technology features large delays, intermittent connectivity, and absence of an end-to-end path from sources to destinations. A network which has one of those characteristics is called DTNs(Delay Tolerant Networks). The main 4 routing methods have been researched so far in extream environment. In this paper, we look into the reliability of DTMNs(Delay Tolerant Mobile Networks) in several different situations, and propose an algorithm that selects a positive routine by sending the only information of its position when making a connection to a detected node. We simulate the proposed algorithm here in DTN using ONE simulator. As a result, it shows that the algorithm reduces the number of message transmission each node.

A Genetic Algorithm Approach for the Design of Minimum Cost Survivable Networks with Bounded Rings

  • B. Ombuki;M. Nakamura;Na, Z.kao;K.Onage
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 ITC-CSCC -1
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    • pp.493-496
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    • 2000
  • We study the problem of designing at minimum cost a two-connected network topology such that the shortest cycle to which each edge belongs does not exceed a given maximum number of hops. This problem is considered as part of network planning and arises in the design of backbone networks. We propose a genetic algorithm approach that uses a solution representation, in which the connectivity and ring constraints can be easily encoded. We also propose a crossover operator that ensures a generated solution is feasible. By doing so, the checking of constraints is avoided and no repair mechanism is required. We carry out experimental evaluations to investigate the solution representation issues and GA operators for the network design problem.

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Adaptive Zone Routing Technique for Wireless Ad hoc Network

  • Thongpook, Tawan;Thumthawatworn, Thanachai
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2002년도 ITC-CSCC -3
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    • pp.1839-1842
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    • 2002
  • Ad hoc networks are characterized by multi- hop wireless connectivity, frequently changing network topology and the need for efficient dynamic routing protocols. In this paper, we proposed a new technique to adjust the zone radius by concentrating the changes of network traffic in a particular direction, which we refer to as AZRP. We demonstrate that even though ZRP and AZRP share a similar hybrid routing behavior, the differences in the protocol mechanics can lead to significant performance differentials. We discuss the algorithm and report on the performance of AZRP scheme, and compare it to the ZRP routing protocol. Our results indicate clearly that AZRP outperforms ZRP by reducing significantly the number of route query messages. And thereby increases the efficiency of the network load.

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