• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.565-568
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• 2007

The high pressure hydrogen gas refueling system is required for fuel cell vehicle. In this paper, a commercial computational fluid dynamics (CFD) code, FLUENT is adopted to investigate the gas flow characteristics inside the check valve for various refueling and tank pressures. The results showed that the choking phenomena can occur for certain refueling pressures, therefore refueling processes should be divided by multiple stages. And a design method to prevent the seal departure problem which reported in CNG usages is required.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.407.3-408
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• 2002

A portable near infrared (NIR) system which was newly integrated by our lab has been used to develop a non-invasive blood glucose monitoring. The portable NIR system includes a tungsten halogen lamp, a photo diode array type-InGaAs detector, and specialized reflectance fiber optic probes. The shape of probes is composed of two parts. one for illumination into sample and the other for receiving the radiation from sample. Three kinds of probes with different distance between illumination and receiving part. such as 0.03. 0.1. and 0.5mm, were investigated for optimization. (omitted)

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2005.03a
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• pp.521-528
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• 2005

In our previous study, we have developed a preliminary design procedure of MR dampers for controlling seismic response of building structures. In this paper, the effectiveness the proposed method is verified through the numerical analysis of the structures with various period and story number, and twenty earthquake loads are used for statistical assessment. The comparison between the proposed method and simplified sequential search algorithm indicates that the capacity, number and the placement of the MR damper which can achieve the given performance objective are reasonably determined using the proposed design procedure.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.30A no.9
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• pp.38-45
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• 1993

In this study, the degradation characteristics of drain output resis-tance was described due to hot electron effects. An semi-empirical model for the degraded drain output resistance was derived from the measured device characteristics. The suggested model was verified from the measured data and the device parameter dependence was also analyzed. The degradation of drain output resistance was increased with stress time and had linear relationship with the degradation of drain current. The device lifetime which was defined by failure criteria of drain output resistance (such as $\Delta$ro/roo=5%) was equivalent to that of failure criteria of drain current (such as $\Delta$ID/ID=5%)

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.81-82
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• 2015

Recently, fault detection and diagnosis techniques have been significantly considered to reduce possible economic loss due to faulty in photovoltaic power systems. This paper presents a new fault location diagnosis method for photovoltaic power systems. The proposed algorithm compares the output voltage generated from a photovoltaic array to the outputs of its neighboring arrays. This concept is realized by obtaining error voltages among all arrays, which are simply defined by deviation between its neighboring arrays. We accomplish a real-time experiment to demonstrate reliability of the proposed fault location diagnosis by using a 60W photovoltaic power system test-bed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.165-168
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• 2012

In this paper, to remind ourselves that exist in the world what kind of security system is also difficult to defend a system with computerized access system representative of infringement that, Computerized personnel act of infringement cases, and thus the extent of the damage and the severity Revisited, Furthermore, technical measures beyond the limits of the technical security measures in line computerized rights management representative and for infringement prevention measures in Human Resource Management through its own alternative to find.

• The KIPS Transactions:PartA
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• v.15A no.1
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• pp.27-34
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• 2008

In this paper, We propose a new parallel computer topology, called the Postorder Fibonacci Circulants and analyze its properties. It is compared with Fibonacci cubes, when its number of nodes is kept the same of comparable one. Its diameter is improved from n-2 to $[\frac{n}{3}]$ and its topology is changed from asymmetric to symmetric. It includes Fibonacci cube as a spanning graph.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.421-422
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• 2006

Using the still image through the camera reports which the moving object tracking system. Moving object direction detected to compare the two difference images. And base block set at moving object. Matching area set current difference image. The edge image of prior frame and current frame implement the moving object tracking system to block matching.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.750-753
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• 2010

본 논문에서는 텐셔닝 에어빔 시스템(Tensioning Air Beam System: 이하 TABS)의 휨실험 및 수치해석를 통하여 TABS의 성능을 고찰하고자 한다. TABS는 스위스의 엠파(EMPA)에서 Tensairity라는 이름으로 처음 제안되어져, 다수의 연구결과가 발표되었으나 설계에 있어 중요한 변수인 압력, 케이블 장력과 시스템 구조성능의 상관관계가 명확치 않으므로 실제 구조물의 적용에는 정성적, 정량적인 자료가 불충분하다고 할 수 있다. 따라서 텐셔닝 에어빔의 구조성능 파악을 목적으로, 다양한 압력조건과 케이블의 초기장력에 대한 구조실험을 실시하였고, 유한요소법을 이용한 해석결과와 실험값을 비교하여 제안모델의 유효성을 검토하였다.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.584-587
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• 2010

본 논문에서는 고유치문제에 근거한 텐세그러티 구조물의 형상탐색에 대하여 제시하고자 한다. 하지만 자기평형 응력을 구하기 위해서 정방형 행렬이 아닌 장방형 행렬을 풀어야 하는 난제가 발생하므로 선행 연구자들은 이를 해결하기 위해 내력밀도법과 일반역행렬을 이용한 방법 등을 제시하였다. 본 연구에서는 새롭게 형상을 탐색하는 방법을 제시하여 텐세그러티 구조물 및 케이블 돔 구조물의 자기평형 응력을 얻었다. 제시한 방법은 기존의 방법을 기본으로 한 모든 절점의 평형 방정식을 고유치문제로 정식화하였다. 이를 증명하기 위해 몇 가지 예제에 대하여 수치해석을 수행하였고 타당성을 검증하기 위하여 기존의 방법과 비교하였다. 제시된 방법은 기존의 방법과 같은 결과가 나왔으며 해답을 얻는 과정이 훨씬 간단하였다.