• Title/Summary/Keyword: communication networks

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Adaptive Query Flooding using Neighbor Information for Routing Performance Enhancement in Ad Hoc Networks (Ad Hoc Network에서 라우팅 성능 향상을 위한 이웃 노드 정보를 이용한 적응성 경로 구성 전송 방식)

  • Lee Hakhu;Kang Sangwook;An Sunshin
    • Journal of KIISE:Information Networking
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    • v.31 no.6
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    • pp.673-684
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    • 2004
  • As the wireless mobile communication is being widespread, mobile technologies will have important roles in the communication with the explosive growth of demanding for wireless portable devices. Among the mobile technologies, a great deal of interest has been taken in mobile ad hoc network (MANET), which is a collection of wireless mobile nodes forming a temporary network without the aid of stationary infrastructure in recent. Furthermore, considering characteristic of ad hoc networks, the design of efficient routing protocols is an important issue. In recent years, on-demand protocols among routing protocols have noticed because of the low routing overhead. However, on-demand protocols suffer from production of the enormous query Packets by broadcasting in order to setup routes, that is, a flooding scheme. The flooding scheme is very costly and results in serious problem, which we refer as the broadcast storm problem. In this paper, we propose a Dynamic Adaptation Query flooding Using Neighbor Topology (NT-DAQ) scheme, in order to resolve the broadcast storm Problem. When a route discovery is in progress, each mobile node decides on the basis of neighbor topology information whether discovery process participates or not. Therefore, our proposed scheme enables to improve network performance in which minimize the number of query rackets. We evaluate the efficiency of our proposed scheme through simulation.

Suggestion of an Fiber Channel-Embedded IPTV STB for Optical Fiber-based IPTV Networks (광섬유 기반 IPTV 네트워크를 위한 FC 내장형 IPTV STB 제안)

  • Chung, Sung-Wook
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.10 no.3
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    • pp.213-219
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    • 2017
  • Recently, the Internet Protocol Television (IPTV) services have become very common, enabling various Internet-based services as well as watching TV. In the IPTV system, a Set-Top box (STB) plays a key role as a network terminal device that transmits and receives realtime multimedia contents. In addition, the IPTV networks are usually supported by broadband optical fiber-base network such as fiber-to-the-home (FTTH), However, a general IPTV STB is regarded as one of the local area network (LAN)-attached devices while sharing the bandwidth of the LAN (e.g., Ethernet). In order to overcome the limited bandwidth utilization by fully facilitating the broadband bandwidth (e.g., 1 Gbps) of the optical fiber-based network, we propose a new FC (Fiber Channel)-embedded IPTV STB which can be directly attached to the optical fiber network. Then, we verify that the impacts of the proposed FC-embedded IPTV STB by organizing the the FC-AL (Fiber Channel-Arbitration Loop) network equipped with the FC-embedded IPTV We measures the average Start-up Delay, Average Reject Ratio and the Number of Concurrent Users through extensive simulations to investigate the performances of the suggested FC-AL-based IPTV network. Surprisingly, the IPTV network architecture with the proposed FC-embedded IPTV STBs has an excellent average start-up delay of less than 10 msec, an acceptable average reject ratio of less than 3 % as well as a linear increase of the number of concurrent users when extending the architecture. This reveals that the proposed FC embedded STB has a superior impacts on the performance of the entire IPTV network by effectively utilizing the broadband bandwidth of the fiber optic-based network.

Feature Extraction using Discrete Wavelet Transform and Dynamic Time-Warped Algorithms in Wireless Sensor Networks for Barbed Wire Entanglements Surveillance (철조망 감시를 위한 무선 센서 네트워크에서 이산 웨이블릿 변환과 동적 시간 정합 알고리즘을 이용한 특징 추출)

  • Lee, Tae-Young;Cha, Dae-Hyun;Hong, Jin-Keun;Han, Kun-Hui;Hwang, Chan-Sik
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.4
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    • pp.1342-1347
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    • 2010
  • Various researches have been studied on WSN(wireless sensor network) for barbed wire entanglements surveillance applications such as industry facilities, security area, prison, military area, airport, etc. Currently, barbed wire entanglements surveillance is formed wire sensor network environment. Traditional wire sensor network guarantee high data transmission rate. Therefore, wire sensor network use fast fourier transform of data of high transmission rate for extraction of feature parameter. However, wireless sensor network in comparison with wire sensor network has very low data transmission rate. Therefore, wireless sensor network doesn't use fast fourier transform of wire sensor network for extraction of feature parameter. In this paper, proposed method use 1 level approximation coefficient of DTW(dynamic time-warped) algorithms based on DWT(discrete wavelet transform) for extraction of detection feature parameter and classification feature parameter for barbed wire entanglements surveillance. l level approximation coefficient have time information and frequency information of signal. Therefore, Dynamic time-warped algorithms based on discrete wavelet transform improve detection and classification of target rather than using energy of signal.

A Route Stability-based Direction Guided Routing Protocol in Mobile Ad-hoc Wireless Networks (모바일 Ad-hoc 무선 네트워크에서 경로 안정성 기반 방향성 안내 라우팅 프로토콜)

  • Ha, Suehyung;Le, The Dung;An, Beongku
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.12 no.6
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    • pp.257-264
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    • 2012
  • In this paper, we propose a Route Stability-based Direction Guided Routing protocol(RSDGR) in mobile ad-hoc wireless networks. The main features and contributions of the proposed routing protocol are as follows. First, it can calculate link stability between two nodes as well as route stability of multi hop quantitatively by using nodes' mobility. And this protocol can establish the most stable path between a source node and a destination node. Second, according to the route stability between a source node and a destination node, it can control and optimize the direction guided region dynamically for route setup. Third, we suggest theoretical model for quantitative calculation of link stability between two nodes and route stability of multi hop path. The performance evaluation of the proposed routing protocol is performed by simulation using OPNET(Optimized Network Engineering Tool) and theoretical analysis. The results of performance evaluation show that the patterns of PDR are similar in simulation and analysis according to route stability. The faster mobile nodes' velocity and the smaller source node's direct guided reigion, the lower route stability and PDR and the higher delay and control overhead related to this.

An Integrated Processing Method for Image and Sensing Data Based on Location in Mobile Sensor Networks (이동 센서 네트워크에서 위치 기반의 동영상 및 센싱 데이터 통합 처리 방안)

  • Ko, Minjung;Jung, Juyoung;Boo, Junpil;Kim, Dohyun
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.8 no.5
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    • pp.65-71
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    • 2008
  • Recently, the research is progressing on the SWE(Sensor Web Enablement) platform of OGC(Open Geospatial Consortium) to provide the sensing data and moving pictures collected in a sensor network through the Internet Web. However, existed research does not deal with moving objects like cars, trains, ships, and person. Therefore, we present a method to deal with integrated sensing data collected by GPS device, sensor network, and image devices. Also, this paper proposes an integrated processing method for image and sensing data based on location in mobile sensor networks. Additionally, according to proposed methods, we design and implement the combine adapter. This combine adapter receives a contexts data, and provides the common interface included parsing, queueing, creating unified message function. We verity the proposed method which deal with the integrated sensing data based on combine adapter efficiently. Therefore, the research is expected to help the development of a various context information service based on location in future.

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Cluster Coordinator Node Based Inter-Cell Interference Management Methods in Heterogeneous Networks (이기종 네트워크에서 클러스터 코디네이터 노드 기반의 셀간 간섭 관리 방법)

  • Yang, Mochan;Wu, Shanai;Shin, Oh-Soon;Shin, Yoan
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38A no.3
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    • pp.277-288
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    • 2013
  • 3GPP LTE-Advanced (Third Generation Partnership Project Long Term Evolution-Advanced) as a next generation mobile communication standard introduced small base stations such as femto cells or pico cells, and D2D (Device-to-Device) communications between mobiles in the proximity in order to satisfy the needs of rapidly growing wireless data traffic. A diverse range of topics has been studied to solve various interference situations which may occur within a single cell. In particular, an introduction of a small base station along with D2D communication raises important issues of how to increase the channel capacity and frequency efficiency in HetNets (Heterogeneous Networks). To this end, we propose in this paper methods to manage the interference between the macro cell and other small cells in the HetNet to improve the frequency efficiency. The proposed CCN (Cluster Coordinator Node)-assisted ICI (Inter-Cell Interference) avoidance methods exploit the CCN to control the interference in HetNet comprising of an MeNB (Macro enhanced Node-B) and a large number of small cells. A CCN which is located at the center of a number of small cells serves to avoid the interference between macro cell and small cells. We propose methods of resource allocation to avoid ICI for user equipments within the CCN coverage, and evaluate their performance through system-level computer simulations.

Naming Scheme and Its Implementation for the Network Management of Content Centric Networking Integrated with SNMP (SNMP를 연동한 콘텐츠 중심 네트워킹 망관리를 위한 이름 구조 및 이의 구현)

  • Kim, Kwangsoo;Roh, Byeong-hee
    • KIPS Transactions on Computer and Communication Systems
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    • v.7 no.5
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    • pp.119-126
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    • 2018
  • Content-centric networking (CCN) is a future Internet technology to reorganize the paradigm of end-to-end communication of the current IP-based Internet architecture into a content-based paradigm. In managing such new networks, the network management is one of the most important functions. The standard for typical network management in existing IP networks is Simple Network Management Protocol (SNMP). Though there have been several works to implement network management functions on CCN, they have their own limitations to apply them to pure CCN operational environments. The basic reason of the limitation is that existing methods operate in an IP-overlay structure, or do not support push-type information exchange. In this paper, we propose a new naming structure that can accommodate both pull and push-type SNMP methods for CCN network management with SNMP. Then, methods to support GET and TRAP methods as well as a SET method of SNMP in the pure CCN environment using the proposed naming structure are proposed. We implement the proposed method using CCNx, and construct a CCN network testbed to validate the effectiveness of the proposed method by monitoring appropriate exchange of SNMP messages over the testbed.

Animation and Machines: designing expressive robot-human interactions (애니메이션과 기계: 감정 표현 로봇과 인간과의 상호작용 연구)

  • Schlittler, Joao Paulo Amaral
    • Cartoon and Animation Studies
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    • s.49
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    • pp.677-696
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    • 2017
  • Cartoons and consequently animation are an effective way of visualizing futuristic scenarios. Here we look at how animation is becoming ubiquitous and an integral part of this future today: the cybernetic and mediated society that we are being transformed into. Animation therefore becomes a form of speech between humans and this networked reality, either as an interface or as representation that gives temporal form to objects. Animation or specifically animated films usually are associated with character based short and feature films, fiction or nonfiction. However animation is not constricted to traditional cinematic formats and language, the same way that design and communication have become treated as separate fields, however according to $Vil{\acute{e}}m$ Flusser they aren't. The same premise can be applied to animation in a networked culture: Animation has become an intrinsic to design processes and products - as in motion graphics, interface design and three-dimensional visualization. Video-games, virtual reality, map based apps and social networks constitute layers of an expanded universe that embodies our network based culture. They are products of design and media disciplines that are increasingly relying on animation as a universal language suited to multi-cultural interactions carried in digital ambients. In this sense animation becomes a discourse, the same way as Roland Barthes describes myth as a type of speech. With the objective of exploring the role of animation as a design tool, the proposed research intends to develop transmedia creative visual strategies using animation both as narrative and as an user interface.

A study on traffic signal control at signalized intersections in VANETs (VANETs 환경에서 단일 교차로의 교통신호 제어방법에 관한 연구)

  • Chang, Hyeong-Jun;Park, Gwi-Tae
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.10 no.6
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    • pp.108-117
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    • 2011
  • Seoul metropolitan government has been operating traffic signal control system with the name of COSMOS since 2001. COSMOS uses the degrees of saturation and congestion which are calculated by installing loop detectors. At present, inductive loop detector is generally used for detecting vehicles but it is inconvenient and costly for maintenance since it is buried on the road. In addition, the estimated queue length might be influenced in case of error occurred in measuring speed, because it only uses the speed of vehicles passing by the detector. A traffic signal control algorithm which enables smooth traffic flow at intersection is proposed. The proposed algorithm assigns vehicles to the group of each lane and calculates traffic volume and congestion degree using traffic information of each group using VANETs(Vehicular Ad-hoc Networks) inter-vehicle communication. It does not demand additional devices installation such as cameras, sensors or image processing units. In this paper, the algorithm we suggest is verified for AJWT(Average Junction Waiting Time) and TQL(Total Queue Length) under single intersection model based on GLD(Green Light District) Simulator. And the result is better than Random control method and Best first control method. In case real-time control method with VANETs is generalized, this research that suggests the technology of traffic control in signalized intersections using wireless communication will be highly useful.

Design and evaluation of a VPRS-based misbehavior detection scheme for VANETs (차량애드혹망을 위한 가변정밀도 러프집합 기반 부정행위 탐지 방법의 설계 및 평가)

  • Kim, Chil-Hwa;Bae, Ihn-Han
    • Journal of the Korean Data and Information Science Society
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    • v.22 no.6
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    • pp.1153-1166
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    • 2011
  • Detecting misbehavior in vehicular ad-hoc networks is very important problem with wide range of implications including safety related and congestion avoidance applications. Most misbehavior detection schemes are concerned with detection of malicious nodes. In most situations, vehicles would send wrong information because of selfish reasons of their owners. Because of rational behavior, it is more important to detect false information than to identify misbehaving nodes. In this paper, we propose the variable precision rough sets based misbehavior detection scheme which detects false alert message and misbehaving nodes by observing their action after sending out the alert messages. In the proposed scheme, the alert information system, alert profile is constructed from valid actions of moving nodes in vehicular ad-hoc networks. Once a moving vehicle receives an alert message from another vehicle, it finds out the alert type from the alert message. When the vehicle later receives a beacon from alert raised vehicle after an elapse of time, then it computes the relative classification error by using variable precision rough sets from the alert information system. If the relative classification error is lager than the maximum allowable relative classification error of the alert type, the vehicle decides the message as false alert message. Th performance of the proposed scheme is evaluated as two metrics: correct ratio and incorrect ratio through a simulation.