• Title/Summary/Keyword: Lee Sam

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Hydraulic Characteristics of Sediment Transport in the Narrow Pass of River (하천축소부에서의 유사거동 특성에 관한 실험적 연구)

  • Choi, Ho-Kyun;Kim, Won-Il;Lee, Sam-Hee;Ahn, Won-Sik
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.203-206
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    • 2008
  • There are lots of the narrow pass on alluvial channel of Korea. Most of research about this narrow pass of channel were focused on incremental effect of water level at backwater segment. In the meantime this research showed that it is important to valuate the river-bed variation at backward and forward around narrow pass. The sediment deposit at not only the backward of narrow pass but also the forward affected incremental effect of water level. The sediment deposit at the forward of narrow pass headed by sediment that passed through the narrow passed or scoured right around it.

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A Probe Detection based on Private Cloud using BlockChain (블록체인을 적용한 사설 클라우드 기반 침입시도탐지)

  • Lee, Seyul
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.14 no.2
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    • pp.11-17
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    • 2018
  • IDS/IPS and networked computer systems are playing an increasingly important role in our society. They have been the targets of a malicious attacks that actually turn into intrusions. That is why computer security has become an important concern for network administrators. Recently, various Detection/Prevention System schemes have been proposed based on various technologies. However, the techniques, which have been applied in many systems is useful for existing intrusion patterns on standard-only systems. Therefore, probe detection of private clouds using BlockChain has become a major security protection technology to detection potential attacks. In addition, BlockChain and Probe detection need to take into account the relationship between the various factors. We should develop a new probe detection technology that uses BlockChain to fine new pattern detection probes in cloud service security in the end. In this paper, we propose a probe detection using Fuzzy Cognitive Map(FCM) and Self Adaptive Module(SAM) based on service security using BlockChain technology.

세종시대 천문시계 옥루 메커니즘에 대한 연구

  • Kim, Sang-Hyeok;Lee, Yong-Sam
    • Bulletin of the Korean Space Science Society
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    • 2010.04a
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    • pp.33.2-33.2
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    • 2010
  • 옥루(玉漏)는 1438년(세종 20)에 장영실이 제작한 자동물시계이다. 종, 북, 징을 타격하여 시간을 알려주고 태양운행 장치가 있어 절기를 알 수 있도록 하였다. 옥루에 대한 관련 문헌을 연구하여 옥루 작동구조에 대하여 분석하였다. 옥루는 물의 흐름을 이용한 수력으로 운행하는 동력장치를 두고 있다. 옥루를 이루고 있는 가산의 형태는 빈풍도를 나타낸 것으로 백성들의 농사짓는 어려움을 볼 수 있게 하였다. 옥루의 구조는 산위, 산기슭, 평지로 구분할 수 있다. 산위에는 태양운행 장치, 옥녀(玉女)와 사신(四神), 산기슭에는 사신(司辰)과 무사(武士), 평지에는 12신(神), 옥녀(玉女), 관인(官人)이 위치해 있다. 각 층별로 구성되어 있는 시간을 알려주는 인형들의 기본적인 운행 메커니즘에 대하여 분석하고 작동 개념도로 제시하였다. 또한 태양운행장치의 작동 원리에 대해서 개념도로 제시하였다.

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Geometric Corrections of Inaccessible Area Imagery by Employing a Correlative Method

  • Lee, Hong-Shik;Park, Jun-Ku;Lim, Sam-Sung
    • Journal of Korean Society for Geospatial Information Science
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    • v.10 no.5 s.23
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    • pp.67-74
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    • 2002
  • The geometriccorrection of a satellite imagery is performed by making a systematic correction with satellite ephemerides and attitude angles followed by employing the Ground Control Points (GCSs) or Digital Elevation Models (DEMs). In a remote area or an inaccessible area, however, GCPs are unavailable to be surveyed and thus they can be obtained only by reading maps, which are not accurate in reality. In this study, we performed the systematic correction process to the inaccessible area and the precise geometric correction process to the adjacent accessible area by using GCPs. Then we analyzed the correlation between the two geo-referenced Korea Multiurpose Satellite (KOMPSAT-1 EOC) images. A new geometrical correction for the inaccessible area imagery is achieved by applying the correlation to the inaccessibleimagery. By employing this new method, the accuracy of the inaccessible area imagery is significantly improved absolutely and relatively.

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The Analysis of Power Quality for the Synchro/Asynchro Generation System in Dae kwan Ryung Actual Wind Farm (대관령 풍력실증단지의 동기/유도발전기 전력품질 분석)

  • Kim, Hyun-Han;Jeong, Jong-Chan;Ki, Woo-Bong;Lee, Kue-Sam;Kim, Kwang-Ho
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.770-771
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    • 2007
  • Wind power plant is based on the wind energy so the active power is frequently changed and connected to grid according with wind condition. These characteristics are bed effect to distribution line. On this reserch, we want to analyze the quality of electric power synchro/asynchronous generation system in Dae Kwan Ryung wind farm. The contents of analysis are active/reactive power variation and total demand distortion and transiency and sag/swell phenomena. we hope this research can contribute to the power quality improvement.

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RFI Noise Reduction of the Electric Train in the Frequency Range of 9 kHz to 150 kHz (철도차량의 9 kHz~150 kHz 대역에서의 RFI 노이즈 저감연구)

  • Kang, Yong-Sam;Lee, Jongwoo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.63 no.1
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    • pp.179-183
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    • 2014
  • An electric railway is unique system that electric trains consumed huge electric power are travelled and is much interested with EMC. There were several problems exceeding the standard in the frequency range of 9 kHz to 150 kHz because the radiation noises were moved the higher frequency range according to developing the power electronic technology. It is studied the analytic simulation for reducing noise level in terms of cables of the electric train and is experimentally approved the reduction effectiveness.

Study for shielded enclosure and rod grounding electrode (쉴딩차폐와 봉상접지에 관한 연구)

  • Kim, Ju-Chan;Kim, Sung-Sam;Choi, Jong-Gyu;Lee, Chung-Sik;Koh, Hee-Seog
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2006.05a
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    • pp.414-417
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    • 2006
  • Especially, the case which the facilities have been shielded in the building. In this case there must be suitable grounding system, and this case must be considered sufficiently to the one part of the design at the design. in addition there must be an electric leakage defense system and The case to be a criterion signal ground system. Rod type grounding electrodes is applied much and we studied the relation that rod type grounding method and shielding room as newly grounding object. in this paper, shield room is the object(target) to be established newly additionally, we try to describe about the flow of a grounding technology concept change and a ground facilities.

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Service Scenarios for Green House Gas Monitoring Service over NGN

  • Choi, Sam-Gil;Kim, Dong-Il;Lee, Soong-Hee
    • Journal of information and communication convergence engineering
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    • v.9 no.4
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    • pp.401-404
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    • 2011
  • Considerations for green house gas (GHG) monitoring over next generation network (NGN) are regarded as a green convergence service for the successful reduction of GHG emission leading to resolve global warming issue in that NGN is expected to provide secure connections to fixed-and-mobile converged (FMC) features. Model-based scenario approach is an appropriate way to standardize and actualize the desired service. This paper first describes the service scenario of GHG monitoring service over NGN.

Design and Implementation of the Log-Structured File System Utilizing Nonvolatile Memory (비휘발성 메모리를 활용하는 Log-Structured File System의 설계 및 구현)

  • Kang, Yang-Wook;Choi, Jong-Moo;Lee, Dong-Hee;Noh, Sam-H.
    • Proceedings of the Korean Information Science Society Conference
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    • 2007.06b
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    • pp.310-314
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    • 2007
  • Log-Structured File system은 쓰기에 최적화한 파일 시스템으로 변경된 데이터를 최대한 모아서 순차적으로 기록하는 방식을 가지고 있다. 그러나 실제 시스템에서는 주기적인 동기화로 인해 작은 크기의 데이터들이 디스크로 쓰여지게 되면서 원래의 디자인 목표를 살리지 못하게 된다. 본 연구에서는 최근 급속도로 발전하고 있는 비휘발성 메모리(NVRAM)를 이용해서 주기적인 동기화를 없애고 작은 단위의 쓰기는 NVRAM을 통해 흡수하도록 하였다. 이를 통하여 DRAM만 있는 LFS에 비해 33% 가량 TPC-C 수행 성능이 향상되고, 더 빠르고 고른 응답 시간을 보일 수 있었다.

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SMPS for Low Standby Power Consumption (대기전력저감을 위한 SMPS)

  • Chung, Bong-Geun;Jang, Sang-Ho;Kim, Eun-Soo;Choi, Moon-Gi;Lee, Jae-Sam
    • Proceedings of the KIPE Conference
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    • 2008.10a
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    • pp.146-149
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    • 2008
  • 최근 대기전력저감기능을 갖는 PWM IC를 적용한 플라이백 컨버터는 대기전력 모드 시 Burst 스위칭 동작에 의해 소모 전력을 최소화 할 수 있지만 경 부하 및 대기전력모드 시 변압기를 통해 흐르는 큰 여자전류에 의해 여전히 낮은 효율특성을 가지는 문제점이 있었다. 본 논문에서는 경 부하 및 대기전력모드 동작 시 변압기에 흐르는 여자전류를 최소화함으로 효율을 개선한 회로를 제안하였으며 50인치 PDP TV PSU (Power Supply Unit)에 있어서 대기전력 및 보조전원으로 사용된 74W 플라이백 컨버터에 적용하여 비교 검토하여 보았다.

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