• Journal of Electrical Engineering and Technology
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• 제8권4호
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• pp.737-743
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• 2013

The small-scaled onsite generators such as photovoltaic power, wind power, biomass and fuel cell belong to decarbonization techniques. In general, these generators tend to be connected to utility systems, and they are called distributed generations (DGs) compared with conventional centralized power plants. However, DGs may impact on stabilization of utility systems, which gets utility into trouble. In order to reduce utility's burdens (e.g., investment for facilities reinforcement) and accelerate DG introduction, the advanced operation algorithms under the existing utility systems are urgently needed. This paper presents the advanced voltage regulation method in power systems since the sending voltage of voltage regulators has been played a decisive role restricting maximum installable DG capacity (MaxC_DG). For the proposed voltage regulation method, the difference from existing voltage regulation method is explained and the detailed concept is introduced in this paper. MaxC_DG estimation through case studies based on Korean model network verifies the superiority of the proposed method.

• 문화기술의 융합
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• 제7권3호
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• pp.481-486
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• 2021

기계학습 알고리즘은 기준 함수를 채택하여 데이터를 처리하고 학습 모델을 유도한다. 군집분석에서 사용하는 기준 함수는 어떤 형태로든지 선호성을 내포하게 되고 이를 통해 유사한 데이터끼리 묶어 준 후 이를 구성하는 변수와 값들을 특정하여 군집을 정의하게 된다. 군집분석에서 사용하는 카테고리 유용도와 분할 유용도 점수가 군집분석 결과물에 어떤 영향을 주는지를 파악하고 이들이 결과에 어떤 편향성으로 이어지는지를 분석한다. 본 연구는 군집분석에 사용되는 기준 함수의 특성에 따라 결과에 미치는 영향을 파악하기 위해 여러 데이터 세트를 이용해 실험하고 결과를 평가한다.

• 한국산학기술학회논문지
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• 제21권12호
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• pp.320-330
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• 2020

화재는 높은 비정형성으로 인해 딥러닝 모델을 이용한 영상인식 분야에서도 좋은 성능을 내기가 어려운 대상 중 하나이다. 특히 지하공동구 내 화재는 딥러닝 모델의 학습을 위한 화재 데이터 확보가 어렵고 열약한 영상 조건 및 화재로 오인할 수 있는 객체가 많아 화재 검출이 어렵고 성능이 낮다. 이러한 이유로 본 연구는 딥러닝 기반의 지하공동구 내 화재 탐지 모델을 제안하고, 제안된 모델의 성능을 평가하였다. 기존 합성곱 인공신경망에 GoogleNet의 Inception block과 ResNet의 skip connection을 조합하여 어두운 환경에서 발생되는 화재 탐지를 위한 모델 구조를 제안하였으며, 제안된 모델을 효과적으로 학습시키기 위한 방법도 함께 제시하였다. 제안된 방법의 효과를 평가하기 위해 학습 후 모델을 지하공동구 및 유사환경 조건의 화재 문제와 화재로 오인할 수 있는 객체를 포함한 이미지에 적용해 결과를 분석하였다. 또한 기존 딥러닝 기반 화재 탐지 모델의 정밀도, 검출률 지표와 비교함으로써 모델의 화재 탐지 성능을 정량적으로 평가하였다. 제안된 모델의 결과는 어두운 환경에서 발생되는 화재 문제에 대해 높은 정밀도와 검출률을 나타내었으며, 유사 화재 객체에 대해 낮은 오탐 및 미탐 성능을 가지고 있음을 보여주었다.

• 유통과학연구
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• 제16권2호
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• pp.67-81
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• 2018

Purpose - Recently the importance of green consumption and corporate social responsibility has been increasing, thereby enhancing the importance of green consumption space as well. The retail space, as a representative consumption space, is now consuming more energy by introducing bigger retail space, 24-hour operation, cutting-edge equipment, and manless checkout system. Especially for retailers, who are constantly interacting with consumers, not only the economic consideration but also the consumer experience via retail service and physical retail space is crucial for their success. Therefore, this study intends to understand the main factors of motivating consumer perception about green retail space. In addition, we further investigate the mediating and moderating variables to encourage revisit intention and green retail space image. Research design, data, and methodology - In order to test our hypotheses with two models, we conducted a survey using questionnaires. In model 1, 356 respondents were surveyed to determine whether consumers' green attitudes and behaviors enhance environmentally friendly perception on retail space properties. In model 2, a questionnaire survey was conducted on 69 consumers who have experience in green retail space. Questionnaire surveys were conducted with on-line panels in Korea and analyzed using regression model and Hayes' PROCESS macro. Results - We found that consumers with green attitude put more importance on the attributes of green retail space. Also, the utility of the green retail space was found to be significant in emotional and social benefits. And, the consumers, who perceived the importance of green retail space, show higher revisit intentions. The emotional and social utilities have significant positive effects on revisit intention through green retail space image. Conclusions - This study demonstrates that a green retail space can induce positive consumer utility, thereby increasing green retail space image and revisit intention. Thus, in order to increase the image and revisit, retailers should communicate green messages with consumers, enhance green attributes of retail space, and target green consumers. To do so, we suggest that various marketing efforts such as publicity and education are needed to appeal experiential green products and retail space to consumers.

• 대한산업공학회지
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• 제42권6호
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• pp.377-385
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• 2016

The previous Adaptive Control of Thought-Rational (ACT-R) cognitive architecture model has a limitation in that it cannot accurately predict human visual search strategy, because time effect, one of important human cognitive features, is not considered. Thus, the present study proposes ACT-R cognitive modeling that contains the impact of time using a revised utility system in the ACT-R model. Then, the validation of the model is performed by comparing results of the model with eye-tracking experimental data and SEEV-T (SEEV-Time; SEEV model which considers time effect) model in "Where's Wally" game. The results demonstrate that the model data fit fairly well with the eye-tracking data ($R^2=0.91$) and SEEV-T model ($R^2=0.93$). Therefore, the modeling method which considers time effect using a revised utility system should be used in predicting the human visual search paradigm when the available time is limited.

• 한국초전도ㆍ저온공학회논문지
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• 제8권1호
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• pp.39-44
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• 2006

Before applying HTS power cable to the real utility. system analysis should be carried out by some simulation tools . Hereby the electrical power system analysis is very important for practical use of HTS devices. Nowadays PSCAD/EMTDC simulation tool is one of the most popular and useful analysis tool for the electrical power system analysis. Unfortunately the model component for HTS power cable is not provided in the PSCAD/EMTDC simulation tool In this paper. the EMTDC model component for HTS power cable has been developed considering critical current, critical temperature and recovery time constant that depend on the sorts of HTS wire. The numerical model of HTS Power cable in PSCAD/EMTDC was designed by using the real experimented data obtained from the real HTS 1G wire test. The utility application analysis of HTS power cable was also performed using the developed model component and the parameters of the real utility network in this study. The author's got good results. The developed model component for HTS power cable could be variously used when the power system includes HTS power cable, especially it will be readily analyzed by PSCAD/EMTDC in order to obtain the data for the level of fault current power flow, and power losses, and so on.

• East Asian mathematical journal
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• 제27권1호
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• pp.91-100
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• 2011

It is important to find an optimal strategy which maximize the surplus of the insurance company at the maturity time T. The purpose of this paper is to give an explicit expression for the optimal reinsurance and investment strategy, under the CEV model, which maximizes the expected exponential utility of the final value of the surplus at T. To do this optimization problem, the corresponding Hamilton-Jacobi-Bellman equation will be transformed a linear partial differential equation by applying a Legendre transform.

• 수산경영론집
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• 제27권1호
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• pp.57-65
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• 1996

This paper is concerned with the development of ameliorating inventory models. The ameliorating inventory is the inventory of goods whose utility increases over the time by ameliorating activation. The term ameliorating inventory is used in this paper at least, since the terminology is not standard well known. This study is performed according to areas; one is an economic order quantity(EOQ) model for the items whose utility is ameliorating in accordance with Weibull distribution, and the other is a partial selling quantity(PSQ) model developed for selling the surplus inventory accumulated by ameliorating activation. The proposed models cannot be solved directly in a closed form, thus we used a computer program and a graphical solution method to obtain the optimal ordering and setting quantity in this paper. Numerical examples to illustrate the effect of ameliorating rate on inventory polices are shown at the end of this paper.

• 한국조리학회지
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• 제12권2호
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• pp.137-150
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• 2006

The aim of this study was to determine the relative importance of a set of attributes which influence purchase decision of leaf mustard kimchi such as color, package, taste, availability and price, and to identify tourist product factor combinations which confer the highest utility to tourists of each age group. Conjoint model was used for this study. The findings from this study were as follows. First, it was found that all age groups regarded taste and price as the very important factor. Second, it was found that the products with different attribute levels were preferred by age groups. Third, it was found that the most preferred product in each age group was significantly different by cluster. Finally, it was found that the most preferred simulation product was different by age groups.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 1996년도 추계학술대회발표논문집; 고려대학교, 서울; 26 Oct. 1996
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• pp.53-56
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• 1996

The conventional inventory models are concerned with the items of which utilities and amount of numbers are constant over time. But in practice the items in inventory systems are increasing or decreasing. This study is concerned with the development of ameliorating inventory models. The ameliorating inventory is the inventory of goods whose utility increases over the time by ameliorating activation. The term ameliorating inventory is used in this paper at least, since the terminology is not standard well known. This study is performed according to areas; one is an economic order quantity(EOQ) model for the items whose utility is ameliorating in accordance with Weibull distribution, and the other is a partial selling quantity(PSQ) model developed for selling surplus inventory accumulated by ameliorating activation. Computer programs are developed to obtain the optimal ordering and selling quantity. Numerical examples to illustrate the effect of ameliorating rate on inventory polices are shown at the end of this paper.