• Title/Summary/Keyword: 대규모 망 성능 평가

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Design and Implementation of a Simulator for the Performance Simulation of a Large-Scale Network Using OPNET (OPNET을 이용한 대규모 망 성능 모의실험을 위한 시뮬레이터 설계 및 구현)

  • Park, Jeong-Sook;Jeon, Yong-Hee
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.3B
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    • pp.274-287
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    • 2009
  • In the Internet environment in which best-effort services are provided, we need to guarantee end-to-end performance rather than hop performance to provide services with a variety of QoS(Quality of Service) requirements. The end-to-end performance is affected by many factors along the path of traffic flow. Most existing simulation studies are concentrated on a single node or a few nodes. We need much different approach considering the simulation execution time to simulate a large-scale network. In this paper, we derive requirements and present methodologies for the implementation of the simulator to simulate it. Then, we design and implement our simulator using OPNET. Performance evaluation is carried out using the simulator for large-scale KII (National Information Infrastructure in Korea). We use a self-similar traffic model and present some results on the end-to-end performance metric for the networks.

Performance Evaluation of the routing protocols in a Large Scale Circuit Switched Telecommunication Network Composed of Mobile and Fixed Subscribers (${\cdot}$ 무선 가입자로 구성된 대규모 회선 교환망에서 라우팅프로토콜에 대한 성능평가)

  • Ko, Jong-Ha;Shin, Ho-Gan;Lee, Jong-Kyu
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.36S no.7
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    • pp.1-8
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    • 1999
  • In this paper, we have proposed and evaluated the performance of the routiong protocols servicing the mobile and fixed subscribers in a large e scale circuit switched telecommunication network, connected by gateways. The large scale network consists of several subnetworks, and a subnetwork is composed of $M{\times}N$ nodes in grid topology. When a call for mobile subscriber occurs, the current routing protocols search the whole large scale network to find a mobile subscriber. Therefore, it causes many redundant packets and long call setup delay. So, we have proposed a new routing protocol, in which the destination subscriber is first searched at the subnetwork where the call is proposed protocol is better than that of the current protocol.

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Constructing Korean Lexical Concept Network for Encyclopedia Question-Answering System (백과사전 질의응답 시스템을 위한 어휘개념망 구축)

  • Choi, Mi-Ran;Oh, Hyo-Jung;Jang, Myung-Gil
    • Annual Conference on Human and Language Technology
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    • 2004.10d
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    • pp.99-105
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    • 2004
  • 백과사전 질의응답 시스템은 사용자의 자연어 질문과 검색 대상 문서인 백과사전 내용의 의미를 파악하기 위한 고정밀 자연어 처리 기술이 요구된다. 이러한 고정밀 자연어 처리 기술을 위한 중요한 언어자원을 제공하기 위하여 한국어 명사와 동사로 구성되는 대규모 어휘개념망을 구축하였다. 한국어 어휘개념망은 명사와 동사의 상하위 관계를 주요 계층구조로 하여 다양한 한국어 어휘 기초 자료를 바탕으로 구축되었다. 구축된 규모는 일반명사 약 6만 어휘와 동사 약 2만 어휘를 포함한다. 이 논문에서는 어휘개념망을 구축하기 위한 방법과 과정을 소개하고 지금까지 구축된 어휘개념망의 특성에 대해 기술하며, 백과사전 질의응답 시스템에서 어떻게 활용되는지 시스템 구성요소의 예를 들어서 설명한다. 또한 현재 구축된 어휘개념망의 성능 평가를 위해 일반 코퍼스에 대한 커버리지 측정 결과를 기술한다.

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Chinese Unsupervised Word Sense Disambiguation using WordNet (어휘의미망을 이용한 중국어 비감독 어의 중의성 해소)

  • Lian, Guang-Zhe;Kim, Minho;Kwon, Hyuk-Chul
    • Proceedings of the Korea Information Processing Society Conference
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    • 2012.04a
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    • pp.365-368
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    • 2012
  • 어의 중의성 해소는 자연어처리에서 중요한 역할을 한다. 감독 중의성 해소 방법은 비감독 중의성 해소 방법보다 높은 성능을 나타내지만, 구축비용이 큰 대규모 의미부착 말뭉치가 필요하다. 본 논문에서는 중국어 어휘의미망(HowNet)과 의미 미부착 말뭉치를 이용한 중국어 비감독 어의 중의성 해소 방법을 제안한다. 의미 미부착 말뭉치에서 통계정보를 추출하고, 중국어 어휘 의미망에서 중의성 어휘의 의미별 형제어를 추출하여 중의성 어휘의 주변 문맥에 나타나는 어휘와 카이제곱검정(${\chi}^2$-test)에 의한 독립성 검정을 통해 어휘 간 연관성을 판단하고 중의성 해소를 한다. 본 논문에서 제안한 중의성 해소방법의 성능을 SemEval-2007 평가데이터에서 측정한 결과 명사와 동사에서 각각 64.7%, 49.4%를 나타냈다. 이는 SemEval-2007 중국어 비감독 중의성 해소에서 가장 높은 성능을 나타낸 시스템보다 13.1%, 13.9% 높은 성능이다.

Opportunistic Multipath Routing Scheme for Guaranteeing End-to-End Reliability in Large-Scale Wireless Sensor Networks (대규모 무선 센서 망에서 종단 간 신뢰성 보장을 위한 기회적 다중경로 라우팅 방안)

  • Kim, Cheonyong;Jung, Kwansoo;Kim, Sang-Ha
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.10
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    • pp.2026-2034
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    • 2015
  • Wireless sensor networks (WSNs) consist of a lot of sensor nodes having limited transmission range. So multi-hop transmission is used for communication among nodes but the multi-hop transmission degrade the end-to-end reliability. Multipath routing and opportunistic routing are typical approaches for guaranteeing end-to-end reliability in WSNs. The existing protocols improve the reliability effectively in small networks but they suffer from rapid performance degradation in large networks. In this paper, we propose the opportunistic multipath routing protocol for guaranteeing end-to-end reliability in large WSNs. Applying multipath routing and opportunistic routing simultaneously is very hard because their conflicting routing features. The proposed protocol applies these approaches simultaneously by section-based routing thereby enhancing end-to-end reliability. Additionally, the proposed protocol guarantees required reliability by the concept of section reliability. The section reliability over a certain level might satisfy required end-to-end reliability. Our simulation results show that the proposed protocol is more suitable for guaranteeing reliability than existing protocols in large-scale WSNs.

A study on the Interpretation Technique of Fall-Of-Potential Curve for Grounding Performance Evaluation of a Large Grounding Electrode Network (대규모 접지전극 망의 접지성능 평가를 위한 겉보기저항곡선의 해석에 관한 연구)

  • Choi, Jong-Kee;Ryu, Hee-Young;Lee, Dongil;Jung, Gil-Jo;Kim, Kyung-Chul
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.19 no.2
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    • pp.49-54
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    • 2005
  • Measuring ground resistance is a typical way of performance evaluation of a grounding electrode. Among various ground resistance measurement methods, FOP (Fall-Of-Potential) method has been widely used, especially in case of a relatively large grounding electrode such as a substation grounding mesh grid Since FOP measurement line has to be increased as the size of grounding electrode increases, however, it is often that securing long enough FOP-line is practically impossible. In this paper, a sophisticated interpretation method of FOP measurement ma which is applicable to large grounding electrode networks, is presented.

Two-phase Multicast in Wormhole-switched Bidirectional Banyan Networks (웜홀 스위칭하는 양방향 베니언 망에서의 두 단계 멀티캐스트)

  • Kwon, Wi-Nam;Kwon, Bo-Seob;Park, Jae-Hyung;Yun, Hyeon-Su
    • Journal of KIISE:Computer Systems and Theory
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    • v.27 no.3
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    • pp.255-263
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    • 2000
  • A multistage interconnection network is a suitable class of interconnection architecture for constructing large-scale multicomputers. Broadcast and multicast communication are fundamental in supporting collective communication operations such as reduction and barrier synchronization. In this paper, we propose a new multicast technique in wormhole-switched bidirectional multistage banyan networks for constructing large-scale multicomputers. To efficiently support broadcast and multicast with simple additional hardware without deadlock, we propose a two-phase multicast algorithm which takes only two transmissions to perform a broadcast and a multicast to an arbitrary number of desired destinations. We encode a header as a cube and adopt the most upper input link first scheme with periodic priority rotation as arbitration mechanism on contented output links. We coalesce the desired destination addresses into multiple number of cubes. And then, we evaluate the performance of the proposed algorithm by simulation. The proposed two-phase multicast algorithm makes a significant improvement in terms of latency. It is noticeable that the two-phase algorithm keeps broadcast latency as efficient as the multicast latency of fanout 2^m where m is the minimum integer satisfying $2^m{\geq} {\sqrt{N}}$ ( N is a network size).

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A Fault-tolerant MIN with Distributed Multiple Paths (분산 다중경로를 갖는 오류허용 다단계 상호연결망)

  • Lee, Myung-Suk;Son, Yoo-Ek
    • Proceedings of the Korea Information Processing Society Conference
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    • 2003.05a
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    • pp.113-116
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    • 2003
  • 다단계 상호연결망(MIN)은 대규모 병렬처리 능력을 가지는 대표적 연결망 구조이다. 그러나 MIN은 입출력 사이의 단일경로와 블록킹 네트워크를 가지는 특성으로 인해 시스템 성능저하를 가져올 수 있다. 이러한 문제를 개선하기 위해 버퍼를 이용하거나 적은 하드웨어 추가와 스위치 대역폭 확장이 가능한 링크를 N배만큼 확장시키는 방법을 사용한다. 본 논문에서는 기존에 오류를 허용하기 위해 제안된 구조들보다 좀더 많은 오류를 허용하기 위한 방법으로 입력버퍼와 확장경로를 사용하여 HOL 블록킹을 방지하고 오류허용 기능을 향상시키는데 그 목적이 있다. 이에 따라 네트워크에 다중 오류가 발생하더라도 부하분산을 통해 이를 허용할 수 있는 구조를 제안하고 시뮬레이션을 통해 그 성능을 평가한다.

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Design and Implementation of Network Defense Simulator (네트워크 방어 시뮬레이터 설계 및 구현)

  • 이철원;윤주범;임을규
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.4C
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    • pp.441-447
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    • 2004
  • Information security simulator is required for the study on the cyber intrusion and defense as information security has been increasingly popular Until now, the main purposes of information security simulation are security estimation of small network as well as performance analysis of information protection systems. However, network simulators that can simulate attacks in a huge network are in needs since large scale internet attacks are very common in these days. In this paper we proposed a simulator design and its implementation details. Our simulator is implemented by expanding the SSFNet program to the client-sewer architecture. A cyber attack scenario used in our simulator is composed by the advanced attack tree model. We analyzed the simulation results to show the correctness of our network defense simulator.

A Flexibility Assessment Method Based on Actual Output Performance to Address the Variability of Renewable Energy (재생에너지 변동성 대응을 위한 실제 출력 성능에 기반한 유연성 평가 방법)

  • Seung-Heon Song;Wook-Ryun Lee;Joo-Hee Woo
    • Journal of IKEEE
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    • v.28 no.3
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    • pp.419-425
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    • 2024
  • As the variability of renewable energy output increases, there is a growing emphasis on flexible resources that facilitate effective output control to maintain the stability of the power grid. In the absence of such flexible resources, grid instability, including large-scale blackouts, may occur. Therefore, methods for assessing flexibility are essential for the effective utilization of flexible resources that mitigate variability. This study proposes a performance-based assessment method to accurately evaluate the effectiveness of flexible resources, considering both grid stability and efficiency. The validity of this method was verified through a case study that accounted for potential errors during actual operations.