• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.03a
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• pp.103-103
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• 2011

비스코스레이온(Viscose Rayon)소재는 목재 펄프를 원료로 한 재생섬유(습식방사)로서 Drape성과 반발성은 탁월하나, 습식방사에 따른 분자구조적 불안정성으로 건 습열처리시 형태불안정(치수변화율이 큼)으로 제직(준비) 및 후공정상 여러 가지 Trouble 유발과 완제품 세탁시 수축발생으로 종종 Dry Creanning 해야 하는 문제점들이 내재되어 있다. 또한 수분흡수시 강도저하, 수축과 구김, 염색 불균염 등의 문제점과 섬유공정상 생활취급상에 많은 애로를 가지고 있으며, 구성고분자가 수소결합에 의해 강고하여 "신축문제", 수분흡수시 팽윤(Swelling)에 의한 형태불안, 즉 "수축문제"가 개선해야 할 고질적 문제로 남아있다. 따라서 본 연구에서는 레이온 소재의 형태안정화 제품을 개발하기 위하여 복합사고공 및 염색가공 기술을 개발하고자한다. 신축 및 복합기술에 의한 Rayon DTY, N/R 신축 및 복합기술에 의한 Rayon DTY, N/R 복합가공사를 개발, 제편직 요소기술과 염가공기술을 연구하므로서 형태안정성 레이온 복합소재 제품을 개발하고자 한다. Rayon 소재의 후공정 용이성과 형태안정성을 부여하기 위하여, 레이온 DTY가공사, Rayon-합섬 장(長)-장(長) 복합사를 개발하여 CoolBiz용 냉감소재 및 스포츠 웨어 소재 등으로 활용하고자 한다. 사가공기술에 의한 신도 16%, 수축률 1.6%인 형태안정 Rayon DTY 소재를 개발하였으며, 선연후가공기술에 의하여 N/R 복합가공사를 개발, 신도 18%, 수축률 1.2%인 차별화 레이온 소재를 개발하였다. 이에 기존 Rayon 후가공 및 염색공정과 상이한 개발된 선연후 가연 Rayon DTY가공사 및 T/R혼방사를 활용한 직물에 대하여 최적 전처리, 염색 후가공 공정의 최적 조건을 알아보았다.

• Journal of Korean Society of Transportation
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• v.15 no.2
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• pp.7-23
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• 1997

본 연구의 목적은 설문조사를 통해 주민들이 실정에 맞는 거주자우선주차제의 실행 요건을 결정하는데 있다. 연구의 구성은 제2장에서 거주자우선주차제의 이론적 배경을 검토 하고, 제3장에서는 실행요건의 결정을 위한 연구분석의 틀을 제시하며, 제4장에서는 설문조 사의 방법과 조사내용에 대한 분석결과를 제시한다. 마지막으로 제5장에서는 결론과 정책건 의로 맺음한다. 이론적으로 분석결과 거주자우선주차제는 주차수요관리와 주차장공급촉진이 라는 2원적인 목표를 내재하고 있는 것으로 나타났다. 그결과 허가요금, 시행시간대 등의 실 행요건을 결정하는데 있어서 다양한 외부요인들을 고려하여야 할 필요가 있으며, 외부요인 들은 거주자들의 사회경제적 특성, 주거환경적특성, 주차행태적 특성, 기타특성 들로 구성된 다. 실행요건을 결정하기 위해 주민들에 대한 설문조사를 실시하였고 그 분석결과는 다음과 같다. 1) 요금수준 결정시 차고지 공급 목적일 경우 높은 수준의 요금을 부과하되 지역적 소득수준을 감안 하여야 하며, 목적이 수요관리에 있을 때는 외부인에 대한 규제만 하면 되 기 때문에 주민들에게는 무료이거나 가능한 낮은 요금을 징수하는 것이 바람직하다. 2) 공 간적 범위는 주민들의 근거리주차 선호 때문에 블록단위 또는 세가로를 중심으로 시행하되, 집앞돌폭이 4m 미만이거나 8m 이상일 경우에는 공간적 범위를 넓게 잡는 것이 바람직 할 것이다. 3) 주차면 배정은 독점적 사용권을 부여하는 방식이 공공재의 사유화라는 부작용 및 주차면의 비효율적 사용이라는 측면이 있기 때문에 가능한 공동이용방식을 채용함이 바 람직 한 것으로 나타났다. 4) 외부인 주처허가는 전용주택가 지역에서는 허용하여도 그리 큰 문제는 없을 것이나, 외부인 주차수요가 많은 지역에서는 무조건적 허락보다는 요금지불, 주차확인증과 같은 제도적 보완을 통해 허용해야 한다. 5) 시행시간대 결정시 전용주거지역 에서는 야간만 실시하여도 문제가 없으나 그외 지역에서는 주차수요를 고려하여 주간 또는 전일로 시행할 필요가 있다. 특히 주차문제가 하루종일 발생하는 경우와 출퇴근시 주차문제 가 많은 곳에서는 하루종일 시행할 필요가 있다. 그러나 차고지 확보율이 지나치게 낮은 곳 에서는 야간시 주민반대에 부디칠 가능성이 크기 때문에 차고지 여건이 개선될 때 까지는 시행을 보류할 필요가 있을 것으로 판단된다.

• Journal of Korean Society of Transportation
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• v.22 no.2 s.73
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• pp.77-86
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• 2004

In this study, we applied the Bayesian Network for the case of the mode choice models using the Seoul metropolitan area's house trip survey Data. Sex and age were used lot the independent variables for the explanation or the mode choice, and the relationships between the mode choice and the travellers' social characteristics were identified by the Bayesian Network. Furthermore, trip and mode's characteristics such as time and fare were also used for independent variables and the mode choice models were developed. It was found that the Bayesian Network were useful tool to overcome the problems which were in the traditional mode choice models. In particular, the various transport policies could be evaluated in the very short time by the established relation-ships. It is expected that the Bayesian Network will be utilized as the important tools for the transport analysis.

• The Journal of Engineering Geology
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• v.20 no.4
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• pp.437-447
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• 2010

A probabilistic analysis of slope stability is an appropriate solution in dealing with uncertainty in problems related to engineering geology. In this study, a Monte Carlo simulation was performed to evaluate the performance function that is Barton's equation. A large number of randomly generated values were obtained for random variables, and the performance function was calculated repeatedly using randomly generated values. A previous study provided information of slope geometry and the random characteristics of random variables such as JRC and JCS. The present approach was adopted to analyze two failed slopes. The probabilities of failure were evaluated for each slope, and sensitivity analysis was performed to assess the influence of each random variable on the probability of failure. The analysis results were then compared with the results of a deterministic analysis, indicating that the probabilistic analysis yielded reliable results.

• The Journal of the Korea Contents Association
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• v.7 no.7
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• pp.11-23
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• 2007

Applications involving moving objects require index structures to handle frequent updates of objects' locations efficiently. Several methods to index the current, the past and the future positions of moving objects have been proposed for the applications. Most of them are based on R-tree like index structures. Some researches have made efforts to improve update performance of R-trees that are actually focused on query performance. Even though the update performance is improved by researchers' efforts, the overhead and immaturity of concurrency control algorithms of R-trees makes us hesitate to choose them for moving objects. In this paper, we propose an update efficient indexing method that can be applicable for indexing the past, the current and the future locations. The proposed index is based on B+-Trees and Hilbert curve. We present an advanced Hilbert curve that adjusts automatically the order of Hilbert curve in subregions according to the data distribution and the number of data objects. Through empirical studies, we show that our strategy achieves higher response time and throughput.

• Journal of Advanced Navigation Technology
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• v.21 no.2
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• pp.155-162
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• 2017

In recent years, aviation-related safety-critical systems have been developed in Korea, but these products have not satisfied the specified requirements and thus have not been commercialized or commercialized. Due to increasing complexity of the modern aviation system, traditional verification and validation techniques are not sufficient to identify and reduce latent risks in the system. To overcome this shortcoming, a new method which is called 'Independent verification and validation (IV&V)' is suggested. However, academic researches on the effectiveness of this independent verification and validation have not been conducted domestically, and it is performed very rarely even overseas. Therefore, in this paper, we investigated the application of independent verification and validation of the safety-critical aviation systems performed by advanced aviation organizations, and analyzed various positive effects on projects. As a result of the analysis, IV&V shows that early error detection rate is increased, potential risk is mitigated early, and the complex reworking probability, which appears later in the development life cycle, is reduced, greatly preventing the development schedule and costs from increasing.

• Journal of Korea Water Resources Association
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• v.38 no.9 s.158
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• pp.761-770
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• 2005

This study applied the fuzzy logic control for the construction of the reservoir operation model which can consider uncertainty of the predicted inflow in determining reservoir release during flood period. The control rule is usually constructed based on the opinion of experts which is a general technique. To improve the drawback of general technique, this study constructed the Fuzzy-Tabu search model automatically established by the fuzzy rule using Tabu search which is a global optimization technique. As the results, the peak release is decreased and the flood control efficiency is improved. The total release is also decreased and this represents the benefit in water use. Consequently, it is confirmed that the effect of flood control can be increased through the constructed model. It also shows that the available water resources after the flood is more increased. So, the proposed Fuzzy-Tabu search model could be better than the actual reservoir operation methodology in the aspect of water use.

• Journal of the Korea Institute of Building Construction
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• v.16 no.6
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• pp.487-495
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• 2016

The losses of accidents in the construction industry was significantly increased during the past decades. Therefore, the study of risk management measures in the domestic construction has become very important, and the inherent risk factors need to derive and analyze them based on the quantified method. However, most studies on the construction risk are conducted finding on the qualitative way. This study analysis the accident records from actual construction sites as a quantities study. A correlation analysis and regression analysis are adopted to identify the risk factors and develop a model. The results of this study are expected to be evolve through the accumulated effect and verification of data in the future through continuous feedback.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.3
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• pp.16-22
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• 2013

A general characterization procedure based on the extraction of a 2n-port admittance matrix corresponding to n uniform coupled lines on the multi-layered substrate using the Finite-Difference Time-Domain (FDTD) technique is presented. In this paper, the frequency-dependent normal mode parameters are obtained from the 2n-port admittance matrix to analyze multi-layered asymmetric coupled line structure, which in turn provides the frequency-dependent propagation constant, effective dielectric constant, and line-mode characteristic impedances. To illustrate the technique, several practical coupled line structures on multi-layered substrate have been simulated. Especially, embedded conductor structures have been simulated. Comparisons with Spectral Domain Method are given, and their results agree well. It is shown that the FDTD based time domain characterization procedure is an excellent broadband simulation tool for the design of multiconductor coupled lines on multilayered PCBs as well as thick or thin hybrid structures.

• Journal of KIISE
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• v.42 no.11
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• pp.1349-1360
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• 2015

In order to improve software quality, it is necessary to efficiently and effectively remove software defects in source codes. In the development field, defects are removed according to removal ratio or severity of defects. There are several studies on the removal of defects based on software quality attributes, and several other studies have been done to improve the software quality using classification of the severity of defects, when working on projects. These studies have thus far been insufficient in terms of identifying if there exists relationships between defects or whether any type of defect is more important than others. Therefore, in this study, we collected various types of software defects, standards organization, companies, and researchers. We modeled the defects types using an ANP model, and developed the weighted severities of the defects types, with respect to the general application software, using the ANP model. When general application software is developed, we will be able to use the weight for each severity of defect type, and we expect to be able to remove defects efficiently and effectively.