• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1406-1407
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• 2006

본 논문에서는 기존의 250V급 트렌치 전극형 파워 MOSFET을 구조적으로 개선하여, 600V 이상의 순방향 항복 전압을 갖는 파워 MOSFET을 설계 하였다. 본 논문에서 제안한 구조로 기존의 250V급 트렌치 전극형 파워 MOSFET에 비하여 더욱 높은 순방향 항복 전압을 얻었다. 또한, 기존의 LDMOS 구조로 500V 이상의 항복 전압을 얻기 위해서 $100{\mu}m$ 이상의 크기를 필요로 했던 반면에, 본 논문에서 제안한 소자의 크기(vertical 크기)는 $50{\mu}m$로서, 소자의 소형화 및 고효율화 측면에서 더욱 우수한 특성을 얻었다. 본 논문은 2-D 공정시뮬레이터 및 소자 시뮬레이터를 바탕으로, 트렌치 옥사이드의 두께 및 폭, 에피층의 두께 변화 등의 설계변수와 이온주입 도즈 및 열처리 시간에 따른 공정변수에 대한 시뮬레이션을 수행하여, 본 논문에서 제안한 구조가 타당함을 입증하였다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.5
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• pp.287-300
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• 2022

The introduction of Connected and Automated(CAD) technology has a growing interests especially in areas with low demand for transport, where often the local transport services do not connect to peripheral areas for more efficient and convenient mobility services. However, there are few researches on CAD-based mobility services in areas with low demand for transport. Because current researches are mainly focuses on introduction of CAD-based mobility services in area with high demand for transport such as urban and highway. These two areas have different road environments and these differences require different driving technology especially related to Operational Design Domain(ODD). ODD is important factors for introduction of CAD-based mobility services. Therefore, we compare the road environments of areas with low demand for transport and areas with high demand for transport in terms of ODD. In addition, this paper proposes suggest guidance for the introduction of CAD-based mobility services in areas with low demand for transport such as rural and suburban areas.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.2
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• pp.26-32
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• 2002

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.6
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• pp.34-42
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• 2014

This study is a fundamental research to determine the emergency evacuation roads considering road network function and connectivity. First of all, the functional aspects of the road networks are analyzed in the target area, Sejong city, by using degree centrality(DC) and closeness centrality(CC) from GIS based database. Secondly, how network connectivity makes a change in user's travel pattern and travel time and how it affects the whole network are analyzed using TransCAD simulation program. Finally, after performing cluster analysis of index, first and second emergency evacuation roads are determined by judging the characteristics of clusters. The results of this research will be helpful for making a decision to diminish secondary damages when confronting unexpected disasters.

• International Journal of CAD/CAM
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• v.2 no.1
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• pp.69-75
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• 2002

This paper presents the development of an Intelligent Cavity Layout Design System (ICLDS) for multiple cavity injection moulds. The system is intended to assist mould designers in cavity layout design at concept design stage. The complexities and principles of cavity layout design as well as various dependencies in injection mould design are introduced. The knowledge in cavity layout design is summarized and classified. The functionality, the overall structure and general process of ICLDS are explained. The paper also discusses such issues as knowledge representation and case-based reasoning used in the development of the system. The functionality of the system is illustrated with an example of cavity layout design problem.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2006.06a
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• pp.381-384
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• 2006

인터넷과 IT 인프라의 증가는 인터넷 기반의 전자상거래 시스템의 성장을 주도하였고, 이와 관련된 새로운 형태의 서비스가 나타나는 계기가 되었다. 그러나, 현재 전자상거래 서비스는 구매자가 웹에 접속하여 인터넷 쇼핑몰에 보이는 상품을 선택하여 결제 및 상품을 수신하는 방식으로 이루어진다. 또한 구매 판단을 결정할 때 최저가격 외에 신속한 배송, 부가 서비스 등의 다양한 의사결정 요소가 있음에도 불구하고, 인터넷 쇼핑몰에서 제시한 최저가의 판단요소에 의존함으로 구매자가 수동적인 입장이 된다. 따라서, 본 논문에서는 이러한 문제점을 해결하기 위해 상호간에 의견교환 및 사용자가 정한 우선순위에 따른 판단을 효과적으로 할 수 있는 서비스인 게임이론 기반의 지능모델을 제시한다 게임이론은 전통적으로 경제문제 협상과 정치문제 협상, 워 게임 등에 적용되었다. 본 연구에서는 이 점에 착안하여 게임이론 알고리듬을 이용하여 e-Commerce를 위한 지능모델에 적용하여, 기존의 수동적이고 사용자의 취향에 따라 다양한 의사결정 요소를 선택 할 수 없었던 문제를 해결한다.

• Journal of Mechanical Science and Technology
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• v.14 no.6
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• pp.655-665
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• 2000

We propose an efficient algorithm for the purpose of satisfying a wide range of design constraints represented with equality and inequality equations as well as production rules. The algorithm employs simulated-annealing and a production rule inference engine and works on design constraints represented with networks. The algorithm fulfills equality constraints through constraint satisfaction processes like variable elimination while taking into account inequality constraints and inferring production rules. It can also reduce the load of the optimization procedure if necessary. We demonstrate the implementation of the algorithm with the result on machine tool design.

• IE interfaces
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• v.6 no.2
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• pp.3-17
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• 1993

Traditionally, programs for NC machine tools have been created using either a maunual method or a computer-assisted method. However, both methods are known to be complex, time-consuming and error-prone. This paper presents an intelligent system, called "INPPC" which is interfaced with a CAD system to generate APT NC part program automatically. The INPPC is developed by using VP-Expert rule-based expert system development tool, and obtains the information about the part shape by searching the CAD database, about the process by asking the related questions to the user, and about the machine tooling by searching the tool database. The INPPC is implemented on an IBM compatible PC/AT under MS-DOS, and its performance is demonstrated by consulting a simple example problem.

• International Journal of CAD/CAM
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• v.9 no.1
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• pp.37-46
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• 2010

Existing methods for the registration of blurred images are efficient for the artificially blurred images or a planar registration, but not suitable for the naturally blurred images existing in the real image mosaic process. In this paper, we attempt to resolve this problem and propose a method for a distortion-free stitching of naturally blurred images for image mosaic. It adopts a multi-resolution and robust feature based inter-layer mosaic together. In each layer, Harris corner detector is chosen to effectively detect features and RANSAC is used to find reliable matches for further calibration as well as an initial homography as the initial motion of next layer. Simplex and subspace trust region methods are used consequently to estimate the stable focal length and rotation matrix through the transformation property of feature matches. In order to stitch multiple images together, an iterative registration strategy is also adopted to estimate the focal length of each image. Experimental results demonstrate the performance of the proposed method.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.7
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• pp.15-24
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• 2021

In this paper, to analyze the types of surface morphology error according to factors that cause machining error, the experiments were conducted in the ultra-precision diamond machine using a diamond tool. The factors causing machining error were classified into the pressure variation of compressed air, external shock, tool errors, machining conditions (rotational speed and feed rate), tool wear, and vibration. The pressure variation of compressed air causes a form accuracy error with waviness. An external shock causes a ring-shaped surface defect. The installed diamond tool for machining often has height error, feed-direction position error, and radius size error. The types of form accuracy error according to the tool's errors were analyzed by CAD simulation. The surface roughness is dependent on the tool radius, rotational speed, and feed rate. It was confirmed that the surface roughness was significantly affected by tool wear and vibration, and the surface roughness of Rz 0.0105 ㎛ was achieved.