• 한국주거학회논문집
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• 제17권4호
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• pp.83-91
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• 2006

Although the large supply of multi-family housings played a very important role in forming the urban structure and allocation of functions, and also enhanced the whole level of housing environment, it caused several problems relating to physical form such as isolation of housing estate, inhumanity of the exterior space, and mismatch with the urban structure. To handle these problems, the purpose of this study is to analyse design elements which have a direct impact on physical forms, thereby understand the characteristics of planning. Therefore design elements are reformed into respective analyzing indices. This study analyzes design elements based on analysing indices. Thus, several important results were found from the Factor Analysis and after classifying housing estates into several types, the study found the characteristics of planning within each type of housing estates.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2001년도 학술대회 논문집
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• pp.84-88
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• 2001

The optimum cross-sectional area Profile of gas-cooled high-temperature superconductor (HTS) current lead is analyzed to have minimum helium boil-off rate. The conventional constant area HTS lead has much higher helium consumption than the optimum HTS lead considered in this study. The optimum HTS lead has variable cross-sectional area to have constant safety factor. An analytical formula of optimum shape of lead and temperature profile are obtained. For multi-step HTS current leads, the optimum tape lengths and minimum heat dissipation rate are also formulated. The developed formulations are applied to the Bi-2223 material, and the differences between constant area, constant safety-factor, and multi-step current leads are discussed.

• 한국통신학회논문지
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• 제26권11B호
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• pp.1540-1545
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• 2001

This paper is concerned with the reverse link performance of multi-code CDMA systems in multipath fading environments. The degree of orthogonality loss among multiple spreading code channels is characterized as the orthogonality factor. It depends on various system parameters including multipath power profiles of propagation channels and the number of Paths resolved at a Rake receiver. The effect of the parameters on the system performance is then investigated in terms of bit error rate and required signal quality. The results show that multipath delay power profiles dominantly affect mutual interference among multi-code channels and multipath combining gain by bandwidth expansion is not so great due to the increase of the mutual interference. Moreover, the orthogonality factor is derived as the value of between (1/m) and 1.

• International Journal of Control, Automation, and Systems
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• 제4권5호
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• pp.615-623
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• 2006

The gyroscope free strap-down INS is composed only of accelerometers. Any gyroscope free INS navigation error is deeply affected by the accuracy of the sensor bias, scale factor, orientation and location error. However these parameters can be found by calibration. There is an important research issue about a multi-position calibration method in this paper. It provides a novel method to find the error parameters for the six-accelerometer INS. A superior simulation is shown that the multi-position calibration can find the specifications of a six-accelerometer INS in laboratory. From these parameters the six-accelerometer INS could apply in realistic navigation.

• 한국안전학회지
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• 제29권1호
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• pp.59-63
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• 2014

Smoke is one of the most critical factor when escaping from the fire since it reduces visibility and interrupts finding emergency exit lights. Therefore, it is recommended that an evacuation simulation program should incorporate the smoke factor. In addition, it is suggested that the program should include not only the unilateral damage by the smoke but also the detour evacuation by risk communication. In this study, MAS (Multi Agent System)-based simulation program which incorporates the reduced walking speed by smoke and adopts the dispersion evacuation logic during escaping from the fire. To make comparison, a commercial evacuation program, Pathfinder was used. It was found that the simulation results of MAS (Multi Agent System)-based program is better than Pathfinder in terms of safe evacuation. It means that evacuation simulation need a additional evaluation categories that include not only quick evacuation time but also safe evacuee number.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.443-448
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• 2005

This study aimed to evaluate the room acoustical performances of multi-purpose halls, analyzing the architectural features by survey and the acoustical characteristics by measurements. Moreover, vocabularies appropriate for the evaluation of the room acoustical performance were determined through questionnaire and subjective responses. From the correlation analysis and factor analysis to the physical values through measurements and the subjective evaluation using vocabularies, useful vocabularies for the evaluation of multi-purpose halls' acoustical performances were determined and physical parameters corresponding to the vocabulary were identified.

• Communications for Statistical Applications and Methods
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• 제28권6호
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• pp.611-626
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• 2021

Marital status has been identified as an important risk factor affecting adult mortality. Many studies have found that marriage has positive effects on mortality and increases life expectancy. Since most pension contracts providing retirement income are provided to married couples, mortality assumption for actuarial valuation based on the entire population is likely to overestimate the actual mortality of the group of beneficiaries specified in the contracts. This study considered the differences in mortality according to marital status to analyze the length and value of the payments of a typical pension contract for a married couple. The study quantified the effect on actuarial measurements of considering marital status in mortality assumptions with a multi-state model framework using Korean experience mortality data organized by marital status. The results of analysis indicate that considering marital status in mortality assumptions improves mortality risk management.

• 한국환경과학회지
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• 제12권6호
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• pp.605-613
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• 2003

In order to make use of the protection effect against wind by the vegetation, it examined whether it should make what vegetation form and arrangement using the 2-dimensional non-hydrostatic model. When the foliage shielding factor increases, it becomes hard to take in protection effect against wind in a residential section. When it makes height of vegetation high, it becomes hard to take in protection effect against wind with height. In the comparison in the case where vegetation high is gradually made low toward wind-stream from a vegetation, and the case of making it low gradually, although former tends to receive the protection effect against wind by the vegetation, attenuation of wind velicity becomes large. In the comparison in the case where foliage shielding factor and distribution of density of leaf are gathered gradually toward wind-stream from a vegetation. It has been understood to evaluate to height the influence that the vegetation multi-layer model by which the heat revenue and expenditure in the direction of the vegetation height is considered is used, and to characterize the vegetation group by the parameter setting.

• 한국진공학회지
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• 제16권6호
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• pp.405-413
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• 2007

진공시스템 최적화 설계를 위한 시스템 성능에 대한 설계인자 영향이 전산모사로 연구되었다. 본 연구로 상업화 전산모사기인 $VacSim^{Multi}$에 의한 진공시스템 모델링기구가 제시되었으며 진공시스템의 진공생성기구인 펌핑계 설계인자의 영향을 평가하여 향후 여러 설계인자들의 전산모사 연구 가능성이 확인되었다. $VacSim^{Multi}$의 저진공펌프 모델 전산모사 결과와 펌프사양에 의한 배기거동이 오차범위로 일치하였으며 부스터펌프의 사용이 중진공영역 응용에 효과적인 것으로 확인되었다. 또한 자체 배기능력이 없는 유확산펌프와 터보분자펌프 배기계의 최적화보조펌프 조합이 제시되었으며, 유확산 및 터보분자펌프 배기계의 시스템 공정응용특성도 확인되었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권1호
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• pp.511-535
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• 2017

Internet banking is one of many services provided by financial institutions that have become very popular with an increasing trend. Due to the increased amount of usage of the service, Internet banking has become a target from adversaries. One of the points that are at risk of an attack is the login process. Therefore, it is necessary to have a security mechanism that can reduce this risk. This research designs and develops a multi-factor authentication protocol, starting from a registration system, which generates authentication factors, to an actual authentication mechanism. These factors can be categorised into two groups: short term and long term. For the authentication protocol, only three messages need to be exchanged between a client and a financial institution's server. Many cryptographic processes are incorporated into the protocol, such as symmetric and asymmetric cryptography, a symmetric key generation process, a method for generating and verifying digital signatures. All of the authentication messages have been proved and analysed by the logic of GNY and the criteria of OWASP-AT-009. Even though there are additional factors of authentication, users do not really feel any extra load on their part, as shown by the satisfactory survey.