• 한국경영과학회지
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• 제36권1호
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• pp.39-55
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• 2011

Process monitoring has been emphasized for the monitoring of complex system such as chemical processing industries to achieve the efficiency enhancement, quality management, safety improvement. Recently, ICA (Independent Component Analysis) based MSPC (Multivariate Statistical Process Control) was widely used in process monitoring approaches. Moreover, DICA (Dynamic ICA) has been introduced to consider the system dynamics. However, the existing approaches show the limitation that their performances are strongly dependent on the statistical distributions of control variables. To improve the limitation, we propose a novel approach for process monitoring by integrating DICA and LOF (Local Outlier Factor). In this paper, we aim to improve the fault detection rate with the proposed method. LOF detects local outliers by using density of surrounding space so that its performance is regardless of data distribution. Therefore, the proposed method not only can consider the system dynamics but can also assure robust performance regardless of the statistical distributions of control variables. Comparison experiments were conducted on the widely used benchmark dataset, Tennessee Eastman process (TE process), and showed the improved performance than existing approaches.

• 한국항공우주학회지
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• 제39권12호
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• pp.1107-1114
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• 2011

본 논문에서는 레이저 피닝(Laser peening) 구조물에 대한 피로 수명을 예측하였다. 레이저 피닝에 의해 생성된 압축잔류응력(Compressive residual stress)을 계산하기 위해서 유한 요소 시뮬레이션(Finite element simulation)을 수행하였고, 피로 수명 예측 시에 압축잔류응력 효과를 고려하기 위해서 수정된 Goodman 식을 사용하였다. 또한, S-N 선도 모델 불확실성(Model uncertainty)을 고려한 피로 수명 예측을 위해 부가 적응 인자 접근법(Additive adjustment factor approach)을 적용하여 예측된 피로 수명의 신뢰 구간(Reliable bounds)을 결정하였다.

• Structural Engineering and Mechanics
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• 제84권5호
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• pp.675-684
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• 2022

The conventional single-degree-of-freedom (SDOF) system is appropriate for dynamic response analysis of paneltype structures without an opening. However, the typical building structures usually have four-sided fixed walls having an opening. Therefore, it may induce a considerable error when dynamic responses are estimated based on the conventional SDOF system, since the SDOF system cannot consider the effect of an opening during the SDOF analysis. For this reason, this study proposes a new SDOF system to consider the effect of an opening by adjusting its load-mass factor. The load-mass factor can be modified based on the assumption that the behaviors of the four-sided fixed wall with an opening is very similar to the behaviors of the same size wall without an opening, when the uniformly distributed blast loaded area is identical. In order to confirm a feasibility of the proposed SDOF system, a series of numerical simulations were carried out for the four-sided fixed reinforced concrete (RC) wall under a blast load. The dynamic responses estimated from the proposed SDOF system and the conventional SDOF system were compared with the dynamic responses evaluated from the finite element (FE) analysis. Especially, for the maximum dynamic responses except for 50% opening case, the proposed SDOF system had about 1.1% to 25.7% normalized errors while the conventional SDOF system had about 4.1% to 49.1% normalized errors.

• Journal of Information Processing Systems
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• 제7권2호
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• pp.341-354
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• 2011

Analyzing the relationships among the parameters for quantifying the quality of research published in journals is a challenging task. In this paper, we analyze the relationships between the impact factor, h-index, and g-index of a journal. To keep our analysis simple and easy to understand, we consider a generalized version of the impact factor where there is no time window. In the absence of the time window, the impact factor converges to the number of citations received per paper. This is not only justified for the impact factor, it also simplifies the analysis of the h-index and g-index as well because addition of a time window in the form of years complicates the computation of indices too. We derive the expressions for the relationships among impact factor, h index, and g-index and validate them using a given set of publication-citation data.

• 한국식품조리과학회지
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• 제30권3호
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• pp.360-367
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• 2014

This study analyzed the Importance-Performance Analysis of selective attributes of Ethnic Food Restaurant. A total of 369 questionnaires were analyzed. Five factors were obtained from factor analysis of Importance variance of selective attributes of Ethnic food restaurant: Factor 1 "Quality", Factor 2 "Service", Factor 3 "Physical environment", Factor 4 "Uniqueness", Factor 5 "Health". Also, "Quality", "Physical environment", "Uniqueness" factors influenced overall satisfaction. In addition, according to the IPA results, selective attributes with low satisfaction and high importance in the second quadrant were 'Sanitation that comfort hospitality', 'Level of service' and 'Price'. These results suggest that when customers select Ethnic food restaurant, they consider 'food price' and 'food quality'. Therefore, manager of ethnic food restaurant should take these improvement factors into consideration in order to meet consumer's expectations.

• 한국콘텐츠학회논문지
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• 제16권11호
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• pp.409-419
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• 2016

본 연구는 커피전문점 방문 동기에 따른 커피전문점의 선택속성에 있어서 차이가 있는지를 살펴보고, 커피 전문점에서 구매하는 커피의 종류에 차이가 발생하는 지를 살펴보고자 한다. 서울 경기지역 대학에 재학중인 대학생 중 커피전문점을 이용한 209명을 모집단으로 분석을 위해서 spss통계 패키지 프로그램을 이용하였다. 커피전문점을 방문하는 동기는 편리성, 사회적 만남, 심리적 요인, 경제적 요인, 정신적 요인 및 습관적 방문 등 크게 6가지로 도출하였다. 6가지 커피전문점 방문동기에 따라 응답자를 집단화하면 경제적 동기나 습관적 동기로 커피 전문점을 방문하는 집단은 다른 집단에 비해 '커피의 다양성'을 더 중요하게 고려하였고, 편리적 동기 및 습관적 동기로 방문하는 집단은 다른 집단에 비해 '종업원의 친절도'를 더 중요하게 생각했으며, 사회적 동기로 방문하는 집단은 '저렴한 커피 값'을 월등히 중요하게 생각하는 것으로 나타났다. 커피전문점 방문동기나 선택속성이 최종 선택한 커피의 종류에 유의적인 영향을 미치지 못하는 것은 특정 종류의 커피(아메리카노, 라떼)를 압도적으로 많이 선택하는 결과이기 때문이며, 이는 커피의 다양성 측면에서 전문점들이 소비자인 대학생들의 선택의 폭을 넓히는 데 충분한 노력이나 차별성을 보여주고 있지 못하는 것에도 원인이 있다 할 것이다.

• 디지털융복합연구
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• 제13권11호
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• pp.417-425
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• 2015

본 연구는 한국과 중국소비자들의 소셜커머스 이용 시 고려요인, 쇼핑가치, 구매만족 그리고 재방문의도에는 차이가 있는지 확인한 것이다. 먼저 소셜커머스를 이용할 경우 고려하는 요인을 확인한 결과 경제성, 유용성, 정보성, 편의성으로 확인되었다. 첫째, 소셜커머스 이용 시 경제성, 편의성 요인은 한국 소비자들이 더 많이 고려하는 것으로 확인되었다. 그러나 소셜커머스의 유용성은 중국소비자들이 더 많이 고려하는 것으로 확인되었다. 정보성은 한국과 중국소비자들에게는 차이가 없는 것으로 확인되었다. 둘째, 소셜커머스의 합리적 쇼핑가치와 쾌락적 쇼핑가치 모두 중국소비자들이 더 높은 것으로 확인되었다. 셋째, 소셜커머스 이용에 따른 구매만족에는 한국소비자들이 더 높은 것으로 확인되었다. 넷째, 소셜커머스 재방문의도는 중국소비자들이 더 높은 것으로 확인되었다. 이상의 연구결과는 소셜커머스 이용에 따른 한국과 중국소비자들의 차이를 확인함으로써 한국기업의 중국 진출을 위한 소셜커머스 활용에 의미 있는 자료가 될 것으로 사료 드리는 바이다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2009년도 춘계학술대회 논문집
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• pp.53-58
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• 2009

Solar photovoltaic power generation system is judging that by the most suitable new refreshing energy in real condition of our country forward continuously interest for solar photovoltaic power generation system and diffusion me enlarged. Output decline problem is item to consider necessarily and should be verified in continuous interest for solar photovoltaic power generation system are diffusion. Present plan that minimize output decline calculating module liver optimum interval that consider recitation of a poem to reduce output decline by module liver shade by incidence angle consideration and this that occupy most parts among factor because do output of solar photovoltaic power generation system well.

• 대한산업공학회지
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• 제29권2호
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• pp.145-149
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• 2003

We consider the estimation of failure rate and acceleration factor under type-I censoring without using acceleration model when testing is conducted in only one highly accelerated condition. Failure times of an item are assumed to be exponentially distributed. It is also assumed that the uncertainty about the acceleration factor, the failure time contraction ratio between accelerated condition and use condition, can be modeled by the uniform or gamma prior distribution of appropriate parameters. We respectively use Bayes and maximum likelihood approaches to estimate acceleration factor and failure rate in the use condition. An example is given to show how the method can be applied.

• Journal of the Korean Data and Information Science Society
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• 제18권4호
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• pp.1191-1203
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• 2007

In this paper, we consider the hypothesis testing for the homogeneity of the shape parameters in the gamma distributions. The noninformative priors such as Jeffreys# prior or reference prior are usually improper which yields a calibration problem that makes the Bayes factor to be defined up to a multiplicative constant. So we propose the objective Bayesian testing procedure for the homogeneity of the shape parameters based on the fractional Bayes factor and the intrinsic Bayes factor under the reference prior. Simulation study and a real data example are provided.