• 제목/요약/키워드: Kim Su-Keun

검색결과 805건 처리시간 0.024초

동일한 전달 행렬을 가지는 안정화 가능한 이종 시스템들의 출력 일치 (Output Consensus of Non-identical and Stabilizable Linear Systems Having the Same Transfer Matrix)

  • 김지수;김홍근;심형보;백주훈
    • 제어로봇시스템학회논문지
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    • 제17권9호
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    • pp.857-862
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    • 2011
  • This paper studies the output consensus problem for a class of heterogeneous linear multi-agent systems under a fixed directed communication network. The dynamics, as well as its dimension, of each agent can widely differ from the others, but all the agents are assumed to have the same transfer matrix. In addition, only the system outputs are constrained to be delivered through the network. Under these conditions, we show that the output consensus is reached by a group of identical controllers, which is designed to achieve the state consensus for the homogeneous multi-agent system obtained from the minimal realization of the transfer matrix. Finally, an example is given to demonstrate the proposed result.

An improvement of the test method to measure autogenous shrinkage in concrete at early-age

  • 무하마드 나씨르 아민;김정수;김진근
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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    • pp.569-570
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    • 2009
  • An improvement of the test method is proposed to more accurately measure early-age autogenous shrinkage in concrete particularly within first 24 hours after casting. Experiments were conducted considering existing and improved method. In improved method, hydration temperature was artificially controlled to prevent thermal deformations. Test results indicate that the autogenous shrinkage calculated by existing approach is underestimated which might be due to the wrong assumption of considering the thermal dilation coefficient to be constant (equal to 10 ${\times}$ $10^{-6}/^{\circ}C$) at early-age. We recommend that the proposed method should be adopted to better assess precise value of autogenous shrinkage or an appropriate method of determining the time-evolution of thermal dilation coefficient be considered.

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개폐식 대공간 구조물에서 지붕 맞댐부 우수차단 시스템의 수밀성 평가에 관한 연구 (Watertightness Property Evaluation of Rain-Block System)

  • 김윤호;백기열;김종수;이선규;오상근
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2010년도 춘계 학술논문 발표대회 1부
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    • pp.13-16
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    • 2010
  • This study is an Investigation on the Watertightness Properties of Rain-Block System on the Sliding-Roof Joint of Large-Span Membrane Structures. In this experimental, we test the watertightness performance of joint part of sliding door in roof of large span membrane structure(for pilot project) under environment of rain and wind. A shape of rain water blocking systems of joint part in sliding door verifies the defects and effects of water leakage prevention in precipitation with the wind conditions. For obtaining watertightness of large span membrane structures, it is necessary quality of joints and performance, and quality of membrane material of a retractable roof as well as a closed roof. Also, for obtaining quality in joints, it is essential to make a watertightness guideline for design of large-span membrane.

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충격파관 내 천음속 익형 유동의 가시화 (Visualization of Transonic Airfoil Flows in a Shock Tube)

  • 장호근;권진경;김병지;권순범;김명수
    • 한국가시화정보학회:학술대회논문집
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    • 한국가시화정보학회 2004년도 추계학술대회 논문집
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    • pp.68-71
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    • 2004
  • The experiments for NACA airfoils are conducted as the preliminary study for the aerodynamic characteristics of the transonic airfoil flow in the shock tube. The test section configurations were designed to use shock tube as simple and less costly experimental facility generating transonic flow at relatively high Reynolds numbers. Experiments at hot gas Mach numbers of 0.80, 0.82 and 0.84, Reynolds numbers of about $1.2\times10^6$ on airfoil chord length and angle of attack of $0^{\circ}\;and\;2^{\circ}$ were carried out by means of shadowgraph visualization method and static pressure measurements. Visualization results were compared with the corresponding results from the conventional transonic wind tunnel tests. The results of study showed that present shock tube facility is useful to study the proper performance characteristics in transonic Mach number range.

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Transient CFD 모사기법을 이용한 정수지 최적설계 사례연구 (Case study on Remodeling Clearwell Hydraulic Structure using Transient CFD Simulation Technique)

  • 김선진;김성수;박노석;차민환;왕창근
    • 상하수도학회지
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    • 제24권4호
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    • pp.425-432
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    • 2010
  • From the results of tracer test for the existing clearwell in Y water treatment plant, $T_{10}$ and T10/T were calculated as 150 min and 0.24, respectively. Therefore it required the modification schemes for improving hydraulic efficiency, surrogated by $T_{10}$ and $T_{10}$/T, and disinfection performance. In this study, using transient CFD(Computational Fluid Dynamics) simulation technique, tracer tests on dynamic condition for the suggested schemes were simulated. From the results of simulation, it was revealed that 8~6 baffles are necessary to guarantee the disinfection ability in the existing clearwell. Also, installing orifice baffle in the vicinity of inlet could increase plug flow fraction within clearwell.

완속여과 공정에서 표층 생물막 생성 및 제어와 원인조류 규명 (Analysis and effectiveness of biological thin Layer (Schmutzdecke) on the sand surface in slow sand filtration processes)

  • 김성수;박노석;김충환;박종근
    • 상하수도학회지
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    • 제22권3호
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    • pp.289-298
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    • 2008
  • Because of their simplicity, efficiency, and economy, slow sand filters are appropriate means of water treatment for small water systems. Biological activity within the sand bed have the strongest influence on removal efficiency of pollutants by slow sand filtration. This report investigated the microorganisms(algae) of slow sand filtration pilot plant at Y water treatment plant. Data were collected at inflow and slow sand filtration from May to October, 2007. The results indicated that the light exposure was influenced on microorganism in slow sand filtration according to the formation of algal biofilm. The relative contribution of biomass and accumulated particulates to head loss development in slow sand filters requires further study.

Basic Creep Model by Considering Autogenous Shrinkage

  • Lee, Yun;Kim, Jin-Keun;Kim, Min-Su
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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    • pp.1071-1076
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    • 2003
  • Basic creep of concrete during very early ages is an important factor on the behavior of young concrete and a great deal of research has been executed. However, in recent studies, it was revealed that the basic creep measured by sealed concrete was inaccurate, especially for high strength concrete because of autogenous shrinkage at early age. This paper presents the results from experimental study that investigate to explore the effect of autogenous shrinkage in basic creep. More specifically, four different mix proportions were casted and the primary variables were water-cement ratios. Through this research, it was found that the differences between apparent specific creep and real specific creep were remarkable in low water-cement ratio at early age. Therefore, it is recommended to modify existing creep model by considering autogenous shrinkage

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Microcystic Meningiomas: Its Immunohistochemical and Genetic Aspect

  • Koo, Sang-Keun;Han, Jin-Yeong;Kim, Su-Jin;Kim, Ki-Uk
    • Journal of Korean Neurosurgical Society
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    • 제39권2호
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    • pp.136-140
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    • 2006
  • The authors report three microcystic meningiomas with its characteristic immunohistochemical findings and chromosomal pattern. Three patients with surgically treated microcystic meningioma were studied for its radiological, histopathological findings, and chromosomal analysis was done in the one patient. Tumors were convexity meningioma in the frontal area. The tumors were enhanced homogenously in the two, and enhanced in homogenously with multiple small cysts in the other one on preoperative magenetic resonance image. Pathological examination showed marked nuclear pleomorphism, many small cysts, hyaline thickening in blood vessel wall, and mucinous background, compatable to microcystic type. EMA and vimentin were positive on the immunohistochemical stain. Chromosomal analysis showed tetrasomies of chromosome 5, 13, 17, and 20, and trisomies of chromosome 6, 7, 9, 11, 12, 16, 19, and 21, which are quite different from those of benign meningioma.

수처리 시설물에 적용되는 방수·방식재의 습윤면 부착 안정 성능평가방법에 대한 연구 (The Study on the Safety Adhesion Test of Wet Surface for Waterproofing and Anti Corrosion Materials of Water Supply Facility)

  • 최수영;김동범;박진상;박완구;김병일;오상근
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2017년도 춘계 학술논문 발표대회
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    • pp.137-138
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    • 2017
  • The Waterproofing and Anti corrosion materials applied to the water supply facility did not consider environment of water supply facility, thus defects occurred consistently on the site. In this study, it suggests safety adhesion test of wet surface and have a test for safety adhesion performance.

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친환경 자원재활용 재료와 폐자원을 이용한 고점착 자착식 방수시트재의 재료적 특성에 관한 실험적 연구 (Research on Materials Characteristics of high adhesive Self Adhesion Waterproofing Material using by the Eco-friendly Resource Recycling and Resource Waste)

  • 허능회;최은규;김수연;김진성;이종용;오상근
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2012년도 춘계 학술논문 발표대회
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    • pp.291-293
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    • 2012
  • Recently, environmental pollution and global warming and greenhouse gases are increasing, because Efforts to improve are continued throughout the world. As part of the resource recycling industry has become an important research area. In the field of waterproofing industry, focus on the resource recycling is growing, due to serious resource depletion and sharp price. Therefore, in this research on the resource recycling such as reclaimed rubber and rubber waste is enable and these eco-friendly materials are applied high adhesive flexible non-exposed type self adhesion compound waterproofing material was measured eco-friendly performance and field application was evaluated.

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