• Proceedings of the Korea Inteligent Information System Society Conference
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• 2001.06a
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• pp.393-398
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• 2001

특정 영역에 대해 사용자에게 관련 정보를 제공해 주는 서비스를 하는 정보 에이전트를 개발 중이다. 정보 에이전트는 사용자 질의 처리를 달은 Agent Manager와 지식베이스를 관리하는 KB Manager, 그리고 Web으로부터 해당 영역의 관련 문서를 끌어오는 Web Manager로 구성되어 있다. Web Manager는 방문할 URL을 수집하고, 이들 문서에 대한 관련 평가와 Indexing을 수행한다. Web Manager는 검색 엔진을 이용하거나, 방문한 문서의 link를 이용하여 URL을 수집하는데 이러한 URL수집기법은 많은 관련 문서를 놓치는 문제점이 있다. 이 문제점을 해결하기 위해서 해당 영역과 관련된 Site들을 대상으로 Link를 이용해 문서들을 모아와, 문서들을 TAG들의 패턴으로 얻어낸 문서 형식을 이용해 Clustering하며 관련 문서들의 Group을 찾아내는 적극적 문서 수집 기법을 제안한다. 실험 결과, Link와 Clustering을 이용할 경우 기존보다 효과적으로 관련 문서를 많이 수집할 수 있음을 알 수 있다.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.04a
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• pp.149-154
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• 2000

시스템이 복잡해짐에 따라 현재 사용되고 있는 무작위적 테스트나 시뮬레이션은 프로토콜의 정확성을 확인하기에 충분하지 못하므로 보다 효율적이고 믿을 만한 검증 방법이 필요하다. 본 논문은 ETRI에서 개발한 디렉토리 기반 CC-NUMA시스템의 CCA(Cache Coherent Agent)보드 내부 버스인 I-Link(Inside Link) 버스의 중재 프로토콜을 정형 검증에 쓰이는 도구 중의 하나인 VIS(Verification Interacting with Synthesis)를 이용하여 검증한다. VIS는 Verilog 입력을 받는 도구이므로 개발 단계에서 만들어진 소스를 그대로 이용하여 검증하는 기법을 사용하였고 이를 통해 보다 정확한 명세와 검증을 할 수 있었다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.579-581
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• 2019

In this paper, dispersion-managed optimal link configuration with the growth/decay distribution of accumlative dispersion as the fiber span is increased, in which optical phase conjugator placed at midway, is proposed. It is confirmed that if net residual dispersion set to be -15 ps/nm or 15 ps/nm in the proposed optical link configuration, the best compensation of the distorted wavelength division multiplexed channels will be obtained.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.3
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• pp.816-839
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• 2023

In a random vector functional link (RVFL) network, shortcomings such as local optimal stagnation and decreased convergence performance cause a reduction in the accuracy of illumination correction by only inputting the weights and biases of hidden neurons. In this study, we proposed an improved regularized random vector functional link (RRVFL) network algorithm with an optimized grey wolf optimizer (GWO). Herein, we first proposed the moth-flame optimization (MFO) algorithm to provide a set of excellent initial populations to improve the convergence rate of GWO. Thereafter, the MFO-GWO algorithm simultaneously optimized the input feature, input weight, hidden node and bias of RRVFL, thereby avoiding local optimal stagnation. Finally, the MFO-GWO-RRVFL algorithm was applied to ameliorate the performance of illumination correction of various test images. The experimental results revealed that the MFO-GWO-RRVFL algorithm was stable, compatible, and exhibited a fast convergence rate.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.309-311
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• 1996

In this paper, we propose two types of novel discrete time current control methods of modified fixed band hysteresis control and optimal control for Parallel Resonant DC Link Inverters(PRDCLI). Because zero bus voltage intervals are generated on the DC link of PRDCLI, we can obtain the information of counter electromotive force(emf) by a simple estimation strategy. The proposed current controllers predict the currents of the next resonant cycle using the obstained information of counter emf and the average values of DC link voltages. The computer simulation results for a simple equivalent circuit of induction motor show that the proposed control methods are more effective than conventional methods.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.1
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• pp.84-91
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• 2011

The Systems Interoperability Test and Evaluation System(SITES) is an T&E support tool for both information system and weapon system. The SITES was developed by reference to the Level of Information Systems Interoperability(LISI) in US. We use the tool via MND Broad convergence Network(BCN) in order to assess information system's interoperability. Nowadays, there are many ongoing researches on expanding assessment capability into weapon systems. As part of those research topics, this paper analyze the characteristics of tactical data-link messages which is the way to exchange the information among the weapon systems, and reflect that characteristics in interoperability level assessment.

• Journal of Korea Multimedia Society
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• v.16 no.9
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• pp.1067-1076
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• 2013

Known as an important criterion that evaluates performance of future high-speed backbone networks, burst data loss ratio is well-studied in Optical Burst Switching networks. Current literatures mostly focus on reduce burst loss ratio without considering the system stability and link utilization after reducing. In this paper, we propose a novel framework which comes from feedback theoretic to dynamically control burst loss ratio in OBS. The proposed scheme tries to track the pre-set values of burst loss ratio and increases the stability and link utilization degree. The simulation results show that measured burst loss ratio always tracks setup reference with small errors, wavelength channel utilization is increased up to 2% and the system stability is also improved.

• 재활복지
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• v.17 no.4
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• pp.291-309
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• 2013

Web usability is utilized as a standard for constructing and managing website to be useful by people of all abilities and disabilities. Link integrity is one of main criteria for web usability evaluation. Links that are found to be broken or pointing to irrelevant information lead gradual degradation of link integrity over time. This study has conducted investigation for link integrity of Korean public institution website. Among 49 website that are accessible by an automatic link checker software, 91.8% of the website has more than one broken links. Also average number of broken links is 50.5 that is 0.33% of the number of links. 29 websites consist of internal broken links. And 22 website do not provide any information on the missing page. Broken links enlower website confidence by reducing web usability as well as they prohibit web search engine not to provide information on the website. Therefore, web developers and managers need to be aware of importance of link integrity and prohibit web usability degradation by performing link validation as a web management task or periodically.

• Journal of Electrical Engineering and Technology
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• v.9 no.6
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• pp.1944-1953
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• 2014

This paper shows the design and control methods of the bidirectional DC-DC converter to generate the proper DC-link voltage of a PMSM drive. Conventionally, because the controllable power of the PWM based voltage source inverter is limited by its DC-link voltage, the DC-DC converter is used for boosted DC-link voltage if the inverter source cannot generate enough operating voltage for the PMSM drive. In this paper, to obtain more utilization of this DC-DC converter, optimal DC-link voltage control for PMSM drive will be explained. First, the process and current path of the DC-DC converter will be illustrated, and a control method of this converter for variable DC-link voltage will then be explained. Finally, an improvement analysis of the optimal DC-link voltage control method, especially on the deadtime effect, will be explained. The DC-DC converter of the proposed control method is verified by the experiments by comparing with the conventional constant voltage control method.

• Journal of Korean Society of Transportation
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• v.23 no.6 s.84
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• pp.19-30
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• 2005

The objective of this research is to keep track of path travel time using methods of collecting traffic data. Users of traffic information are looking for extensive information on path travel time, which is referred to as the time taken for traveling from the origin to the destination. However, all the information available is the average path travel times, which is a simple sum of the average link travel times. The average path travel time services are not up to the expectation of traffic information consumers. To improve provide more accurate path travel time services, this research makes a number of different estimates of various path travel times on one path, assuming it will be under the same condition, and provides a range of estimates with their probabilities to the consumers, who are looking for detailed information. To estimate the distribution of the path travel times as a combination of link travel times. this research analyzes the relation between the link travel time and path travel time. Based on the result of the estimation. this research develops the algorithm that combines the distribution of link travel time and estimates the path travel time based on the link travel times. This algorithm was tested and proven to be highly reliable for estimating the path traffic time.