• 한국지진공학회논문집
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• 제15권2호
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• pp.11-22
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• 2011

개발된 완전 조립식 교량 하부구조에 대한 설계비교와 비선형 해석을 수행하였다. 조립식 교량 하부구조는 현행설계법과 하중저항계수설계법으로 설계하였다. 설계시에는 현 도로교설계기준에 규정된 DB-24 및 DL-24 설계활하중을 적용하였다. 이 연구는 비선형 유한요소해석을 통해서 완전 조립식 교량 하부구조의 현행 설계법인 KHBD (2005)와 AASHTO-LRFD (2007)를 평가하였다. 사용된 프로그램은 철근콘크리트 구조물의 해석을 위한 RCAHEST이다.

• Geomechanics and Engineering
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• 제32권5호
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• pp.503-512
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• 2023

In tunneling projects, a significant part of the costs is spent on segment production. By more economically producing, the cost of tunnel construction can be greatly reduced, especially in long and large-diameter tunnels. In the present study, the effect of using the Carousel method in the improvement of the production system performance compared to the conventional Static system has been studied. To carry out the research, a quantitative comparison of cost and production time was carried out for two production methods using the available documentation. The opinions of experts have been obtained using questionnaires and qualitative comparison of cost, time and production quality was done by implementation of statistical analysis. The SPSS software and the univariate t-test were used to analyze the questionnaires. According to the results of statistical analysis with SPSS, the use of the Carousel method will reduce production time and costs along with increasing manufacturing quality. According to the documentation analysis, the Carousel method reduces the cost of production by almost 30% and leads to a reduction of the production time to approximately 40% of the Static moulds system. The Carousel method has a higher production rate, efficiency, and better performance. Research into quantifying the benefits of Carousel method in the production system performance is very limited. This comparison is based on real information from the under construction Tabriz Metro project. This article can be very helpful in choosing the best production method.

• 한국산업정보학회논문지
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• 제29권2호
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• pp.119-131
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• 2024

2019년 금융위원회의 온라인 대출 중개 서비스 도입 허용에 따라 핀다와 토스같은 핀테크 대출중개 플랫폼들이 가파르게 성장하였다. 하지만 대출중개 플랫폼으로 대출을 받은 고객들은 기존의 모집법인을 통해 대출을 받은 고객들보다 채무불이행 위험도가 더 높은 것으로 보고되었다. 본 연구는 생존분석 기법을 통해 신용대출을 받기 위해 대출중개 플랫폼을 통해 대출을 받은 고객들과 모집법인을 통해 대출을 받은 고객들의 채무불이행 위험도를 비교하고 각 대출중개 플랫폼별로 고객들의 채무불이행에 영향을 주는 특성들을 비교하였다. 분석을 위해 국내 캐피털사의 고객 데이터를 활용하였으며 카플란-마이어 분석 및 AFT 모형을 활용하였다. 모집법인을 통해 대출을 받은 고객들에 비해 대출중개 플랫폼을 통해 대출을 받은 고객들은 개인사업자보다 일반 대출자의 비중이 높고 부동산을 소유하고 있을 확률이 높았으며 대출진행기간이 더 짧았다. 또한 대출진행기간 중앙값(385일)을 기준으로 채무불이행 발생 비율이 더 높았다. AFT 모형을 통해 채무불이행 발생 시기를 분석한 결과 대출중개 플랫폼은 모두 모집법인에 비해 채무불이행 발생 확률이 높은 것으로 나타났다. 또한 대출중개 플랫폼을 통해 대출을 받은 고객의 특성들이 채무불이행 발생 시기에 주는 영향은 플랫폼별로 상이하게 나타났다. 이 결과는 대출중개 플랫폼별로 고객의 리스크 차이를 고려한 맞춤형 전략이 필요함을 보여준다.

• 한국의상디자인학회지
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• 제15권3호
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• pp.1-17
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• 2013

The purpose of this study was to identify the relationships among self-esteem, physical appearance comparison, media concern, sociocultural attitude toward appearance, body attitudes, and life satisfaction. Data were collected from a convenience sample of 232 female undergraduate students. Data were analyzed using factor analysis, correlation, and multiple regression. The result showed that there was a correlation between physical appearance comparison and media concern. Self-esteem, physical appearance comparison, and media concern had an indirect influence on body attitudes through sociocultural attitude toward appearance. Self-esteem and physical appearance comparison had a direct effect on body attitude. All variables did not have an influence on life satisfaction, except self-esteem.

• 대한산업공학회지
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• 제1권1호
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• pp.87-92
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• 1975

Three approximation methods for generating outcomes on Poisson random variables are discussed. A comparison is made to determine which method requires the least computer execution time and to determine which is the most robust approximation. Results of the comparison study suggest the method to choose for the generating procedure depends on the mean value of Poisson random variable which is being generated.

• 한국소음진동공학회논문집
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• 제20권5호
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• pp.477-485
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• 2010

In this study, we suggested several approaches to evaluate the collision acceleration of a carbody under the article 16 of the Korean rolling stock safety regulations. There are various methods to evaluate the rigid body accelerations such as the displacement comparison method by double integration of filtered acceleration data, the velocity comparison method by direct integration of filtered acceleration data, and the analysis method of a velocity-time curve. We compared these methods one another using the 1D dynamic simulation model of Korean high-speed EMU composed of nonlinear springs or bars, dampers, and masses. From the simulation results, the velocity-time curve analysis method and the displacement comparison method are recommended to filter high frequency oscillations and evaluate the maximum and average accelerations of a carbody after a train collision.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.86-88
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• 2004

This paper deals with the comparison and analysis for open-circuit field of PM(permanent magnet) machines with Halbach and circumferential magnetized rotor. The governing equation is derived in terms of magnetic vector potential and 2-d polar coordinate. And then, analytical results has been verified by comparison with those obtained from FE(finite element) method. On the basis of 2-d analytical results, this paper confirms that PM machines with circumferential magnetized rotor is superior to it with Halbach magnetized rotor in terms of magnitude and sinusoidal wave-forms of flux density due to PM and required magnet volume.

• 한국대기환경학회지
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• 제14권5호
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• pp.507-518
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• 1998

A field comparison study was carried out to quantify differences among various sampling and analytical methods for volatile organic compounds (VOCs) at a site in Vlsan in June 1997. Air sampling containers (SUMMA canisters) were used by the Korea Institute of Science and Technology (KIST) and adsorption tubes (carbotrap) were used by Yeungnam University (YN Univ.) for sampling ambient air. Duplicate samples obtained by KIST were analyzed by KIST with a GC-MS system for aromatics and halogenated hydrocarbons and by Atm AA with a GC -FID system for C2∼C9 hydrocarbons, respectively. The adsorption tube samples were analyzed by YN Univ. with a GC-FID system for aromatics. VOC levels for the duplicate canister sampls analyzed by KIST and Atm AA were in good agreement. Concentrations of aromatics by the adsroption tube method were generally higher than those by the canister sampling method by factor of 1.5 to 2.0. Differences between the two sampling methods were discussed.

• 제어로봇시스템학회논문지
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• 제20권8호
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• pp.828-834
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• 2014

This paper presents a comparison among three types of approaches to an ARC (Active Roll Control) with an AARB(Active Anti-Roll Bar) for a vehicle system. Lateral acceleration and road profile are considered as disturbance. The ARC is designed with an LQ SOF (Linear Quadratic Static Output Feedback) control, $H_{\infty}$ control and SMC (Sliding Mode Control). These approaches are compared in terms of rollover prevention and ride comfort. For comparison, Bode plot analysis based on linear model and frequency response analysis based on CarSim simulation are performed.

• Asia pacific journal of information systems
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• 제16권1호
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• pp.127-144
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• 2006

The K-means algorithm is widely used at the initial stage of data analysis in data mining process, partly because of its low time complexity and the simplicity of practical implementation. Cluster validity indices are used along with the algorithm in order to determine the number of clusters as well as the clustering results of datasets. In this paper, we present a performance comparison of sixteen indices, which are selected from forty indices in literature, while considering their applicability to nonhierarchical clustering algorithms. Data sets used in the experiment are generated based on multivariate normal distribution. In particular, four error types including standardization, outlier generation, error perturbation, and noise dimension addition are considered in the comparison. Through the experiment the effects of varying number of points, attributes, and clusters on the performance are analyzed. The result of the simulation experiment shows that Calinski and Harabasz index performs the best through the all datasets and that Davis and Bouldin index becomes a strong competitor as the number of points increases in dataset.