• 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.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.6
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• pp.57-63
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• 2005

According to increasing of demand for high accurate and quick measuring technology, they became to interest in industrial photogrammetry that can satisfy with this needs. This study is examined O-2A aircraft to check the application of Industrial Photogrammetry technology. To measure the aircraft alignment, the check points marked on it were used without exact aircraft design data. And to check any deformation of its external original feature, Pro-spot system has been used.

• Annual Conference on Human and Language Technology
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• 2012.10a
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• pp.117-118
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• 2012

기존의 표절 검사 소프트웨어의 경우에는 수행 시간이 지나치게 오래 걸리거나 표절의 의미가 희박한 구간들을 찾는 등의 문제가 있었다. 본 논문은 대학에서 과제물 표절 검사에 활용할 수 있는 소프트웨어인 CopyCheck을 설계 및 개발하였다. CopyCheck은 각각의 대상 문서로부터 문서 고유의 시그니처 세트를 추출 비교하여 표절이 의심되는 문서들 간의 중복 인텍스 세트를 만들어 의심 구간들을 추려낸 다음 지역 정렬 방법을 이용하여 일치 구간을 찾아내는 방법으로 많은 문서들을 대상으로도 표절 구간들을 빠르게 찾아낸다.

• Korean Journal of Computational Design and Engineering
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• v.1 no.2
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• pp.97-106
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• 1996

Existing CAD systems do not provide advanced functions for automatic checking design and drafting errors in mechanical drawings. If the knowledge of checking in mechanical ddrsfting can be implemented into computers, CAD systems could automatically check for design and drafting errors. This paper describes a method for systematic checking of dimension errors. such as deficiency and/or redundancy of dimension input-errors in dimension figures and symbols, etc. The logic for finding dimensional errors is written by using a proccedural language. A geometric model and a topological-graph model are used in this method. Checking for deficiency and redundancy of dimensions is based upon graph Theory.

• 한국정보통신설비학회:학술대회논문집
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• 2009.08a
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• pp.387-390
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• 2009

Wireless Sensor Network (WSN) can easily compromised from attackers because it has the limited resource and deployed in exposed environments. When the sensitive packets are occurred such as enemy's movement or fire alarm, attackers can selectively drop them using a compromised node. It brings the isolation between the basestation and the sensor fields. To detect selective forwarding attack, Xiao, Yu and Gao proposed checkpoint-based multi-hop acknowledgement scheme (CHEMAS). The check-point nodes are used to detect the area which generating selective forwarding attacks. However, CHEMAS has static probability of selecting check-point nodes. It cannot achieve the flexibility to coordinate between the detection ability and the energy consumption. In this paper, we propose the control method for the number fo check-point nodes. Through the control method, we can achieve the flexibility which can provide the sufficient detection ability while conserving the energy consumption.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10b
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• pp.798-803
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• 1988

This paper is concerned with a computer-aided supporting system to a systematic check of mechanical drawings. The problems treated in this paper are limited to the checking of the omissions and mis-writings of dimensioning in the mechanical drawings made by a CAD system. A drawing check system has been made up on a personal computer with Basic and Pascal. The feasibility of the proposed drawing check system is confirmed for omissions and mis-writings of dimensioning in mechanical drawings.

• Journal of Korea Multimedia Society
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• v.20 no.4
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• pp.660-670
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• 2017

In case of auditing of the information system development project applying agile methodology, it is not appropriate to carry out a comprehensive check on the establishment of information system with only the existing check on software. This study considers the characteristics of the agile methodology in terms of Information System Auditing. To improve inspection quality of development project with agile methodology by deriving detailed check items of test activities at each stage, this study proposes a strategy to improve the check on software for the test activities of the supervisory model that is suitable for agile methodology, which emphasizes repetitive work.

• Journal of Communications and Networks
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• v.17 no.4
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• pp.346-350
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• 2015

It is known that the progressive edge-growth (PEG) algorithm can be used to construct low-density parity-check (LDPC) codes at finite code lengths with large girths through the establishment of edges between variable and check nodes in an edge-by-edge manner. In [1], the authors derived a class of LDPC codes for relay communication systems by extending the full-diversity root-LDPC code. However, the submatrices of the parity-check matrix H corresponding to this code were constructed separately; thus, the girth of H was not optimized. To solve this problem, this paper proposes a modified PEG algorithm for use in the design of large girth and full-diversity LDPC codes. Simulation results indicated that the LDPC codes constructed using the modified PEG algorithm exhibited a more favorable frame error rate performance than did codes proposed in [1] over block-fading channels.

• Journal of Communications and Networks
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• v.13 no.3
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• pp.205-210
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• 2011

This paper presents an approach to the construction of multiple-rate quasi-cyclic low-density parity-check (LDPC) codes. Parity-check matrices of the proposed codes consist of $q{\times}q$ square submatrices. The block rows and block columns of the parity-check matrix correspond to the hyperplanes (${\mu}$-fiats) and points in Euclidean geometries, respectively. By decomposing the ${\mu}$-fiats, we obtain LDPC codes of different code rates and a constant code length. The code performance is investigated in term of the bit error rate and compared with those of LDPC codes given in IEEE standards. Simulation results show that our codes perform very well and have low error floors over the additive white Gaussian noise channel.

• Journal of Information Management
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• v.20 no.1
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• pp.117-138
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• 1989

In this article, the organizational structures of check- in and claim function are examined. The procedure and function of serials control system(CLASSMATE, EBSCONET, LINX, NOTIS, INNOVACQ) are analyzed, particularly in check- in and claim system. A check-in and claim system is suggested through analysis of above serials control systems.