• 한국항행학회논문지
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• 제15권5호
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• pp.906-912
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• 2011

본 논문에서는 건물에 산재되어 있는 비상등을 효과적으로 관리하기 위하여 별도의 통신선을 포설하지 않고 지능형 클러스터 감시망을 구성한다. 또한, 비상등의 위치에 구애받음 없이 감시장치를 설치할 수 있고, 감시망을 구성함에 있어 게이트웨이로 지정된 감시장치가 고장나더라도 사각지대 없이 비상등의 상태를 감시 및 관리가 가능하며, 비상등을 항시 점검 및 관리할 수 있는 비상등감시장치와 비상등관리시스템을 구현하였다. 실험결과, 구현 시스템은 설계 규격대로 동작하였고, 감시망 구성, 상태정보 측정 및 초기화가 안정적으로 구성됨을 확인하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권4호
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• pp.1535-1554
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• 2016

This paper proposes a novel channel assignment scheme called multi-cluster based dynamic channel assignment (MC-DCA) to improve system performance for the downlink of dense femtocell networks (DFNs) based on orthogonal frequency division multiple access (OFDMA) and frequency division duplexing (FDD). In order to dynamically assign channels for femtocell access points (FAPs), the MC-DCA scheme uses a heuristic method that consists of two steps: one is a multiple cluster assignment step to group FAPs using graph coloring algorithm with some extensions, while the other is a dynamic subchannel assignment step to allocate subchannels for maximizing the system capacity. Through simulations, we first find optimum parameters of the multiple FAP clustering to maximize the system capacity and then evaluate system performance in terms of the mean FAP capacity, unsatisfied femtocell user equipment (FUE) probability, and mean FAP power consumption for data transmission based on a given FUE traffic load. As a result, the MC-DCA scheme outperforms other schemes in two different DFN environments for commercial and office buildings.

• Tribology and Lubricants
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• 제12권4호
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• pp.52-59
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• 1996

The results of the electrical contact conductivity of multi-contact spots accounting the surface roughness and the non-conductive films of different origins such as air, water, cutting oil, and machining oil are presented. The array of metal spheres compressed between two flat plates has been used for simulation of the contact behavior of multiple contact of solids, under normal loading. Measurement of electrical contact resistance has been made using the equipment providing the adequate accuracy in the range of micro Ohms. The data on electrical contact resistance have been compared with theoretical predictions using the multiple contact model of constriction resistance. The effect of single spot number and array on conductivity of contact has been evaluated. The results of the experiments show that the contact resistance are closely related to the number of loading cycles, form of surface roughness, and presence of non-conductive films that reduce the size of the real electrical contact spots.

• 지능정보연구
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• 제6권1호
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• pp.97-112
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• 2000

The basic idea of case-based reasoning is to solve a new problem using the previous problem-solving experiences. In this research we develop a case-based reasoning system for equipment malfunction diagnosis. We first divide the case base into clusters using the case-based clustering technique. Then we develop an appropriate case-based diagnostic system for each cluster. In other words for individual cluster a different case-based diagnostic system which uses different weights for attributes is developed. As a result multiple case-based reasoning system are operating to solve a diagnostic problem. In comparison to the performance of the single case-based reasoning system our system reduces the computation time by 50% and increases the accuracy by 5% point.

• 기술경영경제학회:학술대회논문집
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• 기술경영경제학회 2002년도 제21회 하계학술발표회 논문집
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• pp.238-256
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• 2002

Competitiveness of a nation can be explained by the concept of national innovation systems(NIS). As components of NIS, industry clusters become the issue in analysing innovative activity of an economy. Innovative clusters can be identified by the innovation survey or other economic activity data. Input-output Table was used widely as a tool for quantitative analysis, This paper classifies seven clusters in Korean industry based on inter-industries trade of intermediary goods and services, Maximizing procedure method is used in analysing input-output table. Identified clusters are Textiles/chemicals, Construction/Material, Instrument/Equipment, Automobile, Services, Energy, and Agriculture/Food cluster, Among these clusters, some different characteristics in R&D portfolios are detected. R&D investment characteristics of each cluster give us significant implications in understanding innovative dynamics of Korean industry.

• 대한기계학회논문집A
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• 제30권3호
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• pp.231-240
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• 2006

Immersive virtual reality (VR) for the manufacturing planning helps to shorten the planning times as well as to improve the quality of planning results. However, VR equipment is expensive, both in terms of development efforts and device. Engineers also spend time to manually repair erroneous 3-D shape because of imperfect translation between 3-D engineering CAD model and VR system format. In this paper a method is proposed to link 3-D engineering CAD model to a multichannel visualization system with PC clusters. The multichannel visualization module enables distributed computing for PC clusters, which can reduce the cost of VR experience while offering high performance. Each PC in a cluster renders a particular viewpoint of a scene. Scenes are synchronized by reading parameters from the master scene control module and passing them to client scenes.

• 대한기계학회논문집
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• 제18권11호
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• pp.2967-2972
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• 1994

The multiple character of the contact interaction and the collective behavior of elementary microcontacts play a significant role in all the processes occurring in the surface layers, including the failure due to friction and wear. The array of metal spheres compressed between flat plates has been used for simulation of the contact behavior of multiple contact of solids under normal loading. An experimental design has been made providing regular array of the spheres at the same size with different spatial order. Measurement of electrial contact resistance has been made using the equipment providing the adequate accuracy in the range of micro Ohms. The data on electrical contact resistance have been compared with theoretical predictions using the multiple contact model of constriction resistance. The effect of single spots number and array on conductivity of contact has been evaluated.

• 한국산학기술학회논문지
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• 제19권2호
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• pp.370-379
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• 2018

우리나라는 중이온 가속기 건설을 중심으로 과학지식이 사업화로 연결될 수 있도록 하는 지리적 공간으로서의 국제과학비즈니스벨트에 관한 계획을 2009년에 확정하였다. 과학기반 클러스터의 형성 단계에서 국제과학비즈니스벨트의 각 클러스터의 우선 유치업종의 선택은 클러스터의 성격과 발전에 많은 영향을 미칠 수 있다는 점에서 매우 중요하다. 본 연구는 정부에서 제시한 국제과학비즈니스벨트의 과학기반 혁신클러스터의 조성을 위해 유치해야 할 핵심 업종들을 제시하고자 한다. 산업별로 클러스터 형성과정이 상이할 뿐만 아니라, 산업 내 특정 업종이 클러스터의 성장과정에 미치는 영향력이 다르기 때문에 혁신생태계 조성을 위한 앵커 섹터를 파악하는 것이 매우 중요하다. 국제과학비즈니스벨트 내 4개 클러스터의 형성 및 성장을 위한 기업을 분석하기 위해 본 연구는 Swann & Prevezer의 산업 클러스터링(industrial clustering) 모델을 활용하여 분석하였다. 본 연구에서는 기업 관련 자료의 경우 2014년의 제조업 및 서비스업 대상 한국기업혁신조사(ICT 클러스터), 2014년 국내 바이오산업 실태조사(바이오헬스케어 클러스터), 2015 국내 나노융합산업 실태조사(첨단산업 클러스터)에 관한 최신자료를 이용하였다. ICT, 바이오헬스케어, 나노 등 3개 산업군에 대한 클러스터링 분석을 수행한 결과 각 산업군에는 다른 여러 섹터에 속하는 기업들의 지역 내 진입을 유발하는 중심적 역할을 하는 섹터들이 있는 것으로 나타났는데, ICT 산업의 경우 정보통신서비스 섹터, 바이오헬스케어 산업의 경우 바이오공정/기기 섹터, 나노 산업군의 경우 나노전자 섹터가 각각 중심적 역할을 하는 것으로 분석되었다. 분석 결과를 바탕으로 본 연구는 국제과학비즈니스벨트 클러스터를 육성하기 위한 기업 유치 전략과 정책에 대한 시사점을 제시하였다.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1996년도 춘계공동학술대회논문집; 공군사관학교, 청주; 26-27 Apr. 1996
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• pp.655-657
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• 1996

In this study, the methods and equipment that can be used to detail the anthropomorphic data were developed. This new method that utilizes the Moire' interferometry and image processing technique is less expensive than the conventional methods. We took 36 subjects (18 years to 28 years old). The face area was calculated based on contour information. The cluster analysis about those data enables us to classify our subjects into four groups.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2001년도 춘계학술대회 발표논문집
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• pp.79-81
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• 2001

저압 기상 영역에서 Anhydrous HF 가스와 Methanol vapor를 사용하는 산화막 식각공정을 수행하기 위하여 (1) 반응기 부피의 최소화, (B) 공정압력의 최소화, (3) 고순도 알루미나 Reactor 적용, (4) Cluster화의 개념을 적용한 VPC 장치를 제작하였다. Wafer의 온도, HF의 분압 및 Working Pressure 등의 공정변수에 따른 Oxide Wafer의 식각특성의 변화를 확인하였다. 또한 Etch Uniformity를 향상시키기 위하여 Shower Head 구조를 변경시켜서 실험하였으며, CFD Simulation을 이용하여 Reactor내에서의 HF gas 및 Methanol vapor의 분율을 예측하였다.