• 한국콘텐츠학회논문지
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• 제18권5호
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• pp.357-366
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• 2018

본 연구는 2015년 중국 극장에서 개봉된 200편 영화를 대상으로 영화 흥행 수익에 영향을 미치는 요인들에 대해 분석하였다. 회귀분석결과 중국 극장 개봉영화 흥행에 유의미하게 영향을 미치는 요인들은 주연배우인기지수, 온라인평점, 제작사 파워, 중국제작영화여부 였으며, 배급사 파워, 영화의 장르, IP활용여부, 제작사/배급사 결합여부는 유의하지 않은 것으로 나타났다. 이는 영화의 장르가 주요한 영향을 미쳤던 기존 연구결과와는 차이가 있으며, 인터넷으로 평가되는 주연 배우 인기지수, 온라인 평점 등이 흥행수익에 영향을 미치는 가장 중요한 요소로 나타나 중국 극장에서 상영되는 영화 흥행에 온라인 마케팅 요소가 영향을 미치는 주요한 요인으로 부각되고 있음을 알 수 있다.

• Journal of Information Processing Systems
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• 제15권2호
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• pp.331-343
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• 2019

Dynamic thermal rating of the overhead transmission lines is affected by many uncertain factors. The ambient temperature, wind speed and wind direction are the main sources of uncertainty. Measurement uncertainty is an important parameter to evaluate the reliability of measurement results. This paper presents the uncertainty analysis based on Monte Carlo. On the basis of establishing the mathematical model and setting the probability density function of the input parameter value, the probability density function of the output value is determined by probability distribution random sampling. Through the calculation and analysis of the transient thermal balance equation and the steady- state thermal balance equation, the steady-state current carrying capacity, the transient current carrying capacity, the standard uncertainty and the probability distribution of the minimum and maximum values of the conductor under 95% confidence interval are obtained. The simulation results indicate that Monte Carlo method can decrease the computational complexity, speed up the calculation, and increase the validity and reliability of the uncertainty evaluation.

• Smart Structures and Systems
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• 제15권3호
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• pp.751-767
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• 2015

A new procedure is proposed for assessing probabilistic condition of structures considering effect of measured data uncertainty. In this procedure, multiple Finite Element (FE) models are identified by using weighting vectors that represent the uncertainty conditions of measured data. The distribution of structural parameters is analysed using a Principal Component Analysis (PCA) in relation to uncertainty conditions, and the identified models are classified into groups according to their similarity by using a K-means method. The condition of a structure is then assessed probabilistically using FE models in the classified groups, each of which represents specific uncertainty condition of measured data. Yeondae bridge, a steel-box girder expressway bridge in Korea, is used as an illustrative example. Probabilistic condition of the bridge is evaluated by the distribution of load rating factors obtained using multiple FE models. The numerical example shows that the proposed method can quantify uncertainty of measured data and subsequently evaluate efficiently the probabilistic condition of bridges.

• 한국콘텐츠학회논문지
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• 제15권8호
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• pp.544-555
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• 2015

본 연구는 농경유역 중소하천의 주요 지점에서 실측된 현장자료를 사용하여 유량과 총유사량 관계곡선과 이들 간의 관계식을 유도한다. 실측치 총유사량 자료는 수심평균농도와 하상에서 각각의 부유사와 소류사 채취기(DH-48, D-74 및 BLH-84, BL-84)에 의해 채집된 시료를 건조 또는 여과법, 체분석에 의한 입도분포곡선을 통해 얻은 부유사량에 소류사량을 합하여 얻었다. 이들 현장자료는 농경유역 논산수계 내 4개 대상하천의 국가-지방하천 수로구간 7개 측점에서 2012년 8월부터 2014년 9월까지 측정되었다. 그 결과, 유량과 총유사량에 대한 관계곡선과 관계식은 현장측정 자료군의 분포특성을 분석함으로써 멱함수형으로 유도하였으며, 이들 관계식은 수공 유사공학의 이론적 연구뿐만 아니라 실무적 응용에 있어 세굴, 퇴적 및 이송을 해석하는데 유용한 도구로 사용될 수 있을 것이다.

• 대한전기학회논문지:전력기술부문A
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• 제52권7호
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• pp.414-420
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• 2003

The domestic needs for larger capability of power sources are increasing to cope with the expanding power load which results from the industrial developments & the progressed life style. In summer, the peak load is mainly due to the non-industrial reasons such as air-conditioners and other cooling equipments. To cover the concentrated peak load in stable, the power transmission lines should be more constructed and efficiently operated. The ampacity design of the underground cable system is generally following international standards such as IEC287, IEC60853 and JCS168 which regards the shape of 100% daily full power loads. It is not so efficient to neglect the real shapes of load curves generally below 60~70% of full load. The dynamic (real time) rating system tends to be used with the measured thermal parameters which make it possible to calculate the maximum ampacity within required periods. In this paper, the CTM(Conductor Temperature Monitoring) which is the base of dynamic rating systems for tunnel environment is proposed by a design of lumped thermal network ($\pi$-type thermal model) and distribution temperature sensor attached configuration, including the estimation results of its performances by load cycle test on 345kV single phase XLPE cable.

• Journal of the Korean Data and Information Science Society
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• 제20권2호
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• pp.261-272
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• 2009

신용평가모형에서 두 집단의 판별력 검정방법 중의 하나로 두 분포함수의 동일성 검정을 위한 비모수적인 Kolmogorov-Smirnov (K-S) 검정방법이 대표적으로 적용되고 있다. 본 연구에서는 신용평가모형에서 두 분포함수의 동일성 검정을 위하여 K-S 검정 방법 외에 Cramer-Von Mises, Anderson-Darling, Watson 검정방법들을 소개하고 Joseph (2005)의 기준에 대응하는 판단기준을 제안한다. 또한 신용평가 자료와 유사한 상황 하에서의 모의실험을 통해서 불량률, 표본크기 그리고 제II종 오류율을 고려한 대안적인 판단기준을 제시하고 그 적용방법에 대해서 살펴본다.

• 한국구조물진단유지관리공학회 논문집
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• 제5권3호
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• pp.115-122
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• 2001

Bridge load rating calculations provide a basis for determining the load carrying capacity of bridges. Load rating requires engineering judgement in determining a rating value that is applicable to maintaining the safe use of the bridge and arriving at posting and permit decisions. Load testing is an effective means in calculating the rating value of bridge. In Korea, load carrying capacity of bridge is modified by response modification factor that is determined from comparisons of measured values and analysis results. This paper presents the development of a method for determining the response the modification factor, using traffic loads. The proposed method is based on the results of computer simulations of traffic action effects. The simulation program generates random traffic actions for defined traffic conditions and determines the frequency distribution of maximum traffic action effects. A comparison between the proposed method and the present method shows good agreement in estimating the modified load carrying capacity of bridges.

• The Journal of Asian Finance, Economics and Business
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• 제8권8호
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• pp.443-451
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• 2021

The classification standards for hotels in Vietnam are different from many other hotel classification standards in the world. This study aims to analyze customer reviews on the TripAdvisor website to develop a new algorithm for hotel rating that is independent of Vietnam's hotel classification standards. This method can be applied to individual hotels, or hotels of a region or the whole country, while online booking sites only rate individual hotels. Data was crawled from TripAdvisor with 22,287 reviews of 5 cities in Vietnam. This study used a statistical model to analyze the review dataset and build an algorithm to rate hotels according to aspects or hotel overall. The results have less rating deviation when compared to the TripAdvisor system. This study also supports hotel managers to regularly update the status of their hotels using data from customer reviews, from which, managers can strategize long-term solutions to improve the quality of the hotel in all aspects and attract more travelers to Vietnam. Moreover, this method can be developed into an automatic system to rate hotels and update the status of service quality more quickly, thus, saving time and costs.

• The Journal of Asian Finance, Economics and Business
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• 제9권7호
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• pp.185-196
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• 2022

The purpose of this study is to examine the effects of split ratings on earnings management through cost adjustments based on asymmetric cost behaviors. Using a sample of 2,027 Korean firm-year observations over the 2002-2019 period, we analyze whether a firm deliberately reduces discretionary costs, such as selling, general, and administrative (SG&A) expenses, to improve profits when it receives multiple ratings from credit rating agencies (CRAs). While examining earnings management incentives in the presence of split ratings, we also investigate the moderating effects of Chaebols, Korea's unique corporate governance structure. We find that split-rating firms show less stickiness in SG&A costs compared to non-split-rating firms when sales decrease. This result implies the deliberate reduction of discretionary costs to improve earnings in the presence of split ratings, which are more likely to change in future credit assessments. We also find that the incentives for earnings management of split-rating firms are limited in Chaebol firms, which have high levels of socio-economic surveillance and support affiliated firms through the internal market of corporate groups. This study contributes to existing research by identifying new determinants of cost behavior by using the framework of asymmetric cost behavior in relation to earnings management incentives.

• 전력전자학회논문지
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• 제7권4호
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• pp.359-365
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• 2002

최근 상업용 빌딩, 주거용 빌딩 및 공장등의 저전압 3상 4선식 배전계통에서 PC, UPS, 정류기기, 조명장치 및 사무용기기등 비선형 부하의 사용이 증가하고 있으며, 이로 인한 과도한 중성선 전류는 중성선의 고장, 변압기의 과열 및 중성선과 접지사이의 전압강하등 심각한 문제를 야기시키고 있다. 본 논문에서는 3상 4선식 배전계통에서 중성선 전류 제거를 위한 새로운 저감된 용량의 능동전력필터를 제안한다. 제안한 방식은 제어가 간단하고 불평형에 기인하는 기본파 전류만이 인버터 스위치로 흐를 수 있기 때문에 인버터의 VA 정격이 작아진다. 제안한 시스템은 실험에 의하여 그 타당성을 입증한다.