• Fire Science and Engineering
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• v.20 no.4 s.64
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• pp.42-57
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• 2006

This study suggests improvement plans : safety check system security through combination in stages, unification of fire inspection, enterprising security of prevention work, enforcement of certificate of qualification for safety, activation of civil partner-ship of fire disaster prevention through contrast prevention work of administrative service with civil mind and an in-depth analysis : dispersed and duplicated management current safety check service, improper commission collection, immorality diffusion of involved, potential irregularities causes, deficit of professionalism security.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.7C
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• pp.587-593
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• 2010

In this paper we design an irregular low-density parity-check (LDPC) code for multiple-input multiple-output (MIMO) system, using a simple extrinsic information transfer (EXIT) chart method. The MIMO systems considered are optimal maximum a posteriori probability (MAP) detector. The MIMO detector and the LDPC decoder exchange soft information and form a turbo iterative receiver. The EXIT charts are used to obtain the edge degree distribution of the irregular LDPC code which is optimized for the MIMO detector. It is shown that the performance of the designed LDPC code is better than that of conventional LDPC code which was optimized for either the Additive White Gaussian Noise (AWGN) channel or the MIMO channel.

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.5
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• pp.514-525
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• 2023

This study conducted numerical simulations with the purpose of analyzing the impact of variations in outlet pressure conditions under extreme temperature conditions on the fluid dynamics and performance of a check valve utilized in hydrogen refueling systems. Under the extreme temperature conditions, changes in outlet pressure conditions of the check valve were investigated to analyze velocity distributions, pressure distributions, and temperature distributions in the operational and connection regions. The analysis results indicated that changes in outlet pressure had a significant influence on the internal temperature variation of the check valve. Furthermore, due to density variations in the connection region caused by the cooling effect of excessively cooled hydrogen, a bias in the primary flow direction towards the lower part of the valve outlet was observed in the outlet area. Through a comparison of the results of the valve's inherent flow performance, represented by the flow coefficient, it was observed that when the pressure difference between the inlet and outlet was below 0.37 MPa, sufficient flow was not ensured.

• Journal for History of Mathematics
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• v.21 no.2
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• pp.103-118
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• 2008

Barcode technology is becoming an essential tool for every companies, and this makes help us to gain time, analysis of goods, an inventory control, a prevention of burglar and so on. In this paper, we have treated about the history of barcode, its error correcting using the check digit, and the present and future of barcode. We wish roles of mathematician on new barcode system which it bring on an economical efficiency and stability.

• 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.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.12
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• pp.88-96
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• 2015

This paper describes a new method for enhancing the accuracy of network analysis applications in energy management systems. Topology processing, state estimation, power flow analysis, and contingency analysis play a key factor in the stable and reliable operation of power systems. In this respect, the aim of topology processing is to provide the electrical buses and the electrical islands with the actual state of the power system as input data. The results of topology processing is used to input of other applications. New method, which includes the topology error analysis based on inconsistency check, coherency check, bus mismatch check, and outaged device check is proposed to enhance the accuracy of network analysis. The proposed methodology is conducted by energy management systems and the Korean power systems have been utilized for the test systems.