• 전기의세계
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• 제40권5호
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• pp.27-35
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• 1991

전원개발계획은 단독으로 결정되는 것이 아니라 국가경제운용정책 및 에너지 정책과 더불어 전력회사의 요금정책, 부하관리, 재무계획, 전원입지, 송전계통계획 등과 연계되어 결정되어야 한다. 기존의 전원개발계획은 주어진 수요예측안을 이용하여 수요를 기준신뢰도 범위내에서 최소비용으로 만족시킬 수 있도록 전원설비투자를 결정하는 것이었으나 향후로는 부하관리정책을 포함한 수급계획(supply-demand planning)의 수립기법, 미래 수용와 연료 가격등 경제요인의 불확실성 및 환경규제 등의 요인을 감안한 전략계획기법(strategic planning) 그리고 재무계획 등 관련계획 업무를 포함하는 종합계획 모형(corporate planning model)의 구축에 대한 방안을 강구해야 할 것이다.

• Korean Journal of Construction Engineering and Management
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• 제20권6호
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• pp.23-33
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• 2019

The purpose of this study is to analyze the housing price variation within the redevelopment project district, affected by the characteristics of project and implementation stage. This study implemented the hedonic price model employing the actual transaction price with 24 dependent variables from 2006 to 2016 inside 19 redevelopment districts in Seoul. Research finding indicates that the larger ratio of the number of tenants and general distribution, the smaller ratio of rented households and the more positive effect of housing price. It is noteworthy that this study demonstrated the actual transaction price of houses located within the project districts by implementation stage. This study is expected to help the policy makers, the developers and the investors make more reliable decisions on the feasibility study related to the redevelopment project.

• Journal of Intelligence and Information Systems
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• 제29권2호
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• pp.129-148
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• 2023

Bitcoin is a blockchain technology-based digital currency that has been recognized as a representative cryptocurrency and a financial investment asset. Due to its highly volatile nature, Bitcoin has gained a lot of attention from investors and the public. Based on this popularity, numerous studies have been conducted on price and trend prediction using machine learning and deep learning. This study employed LSTM (Long Short Term Memory) and CNN (Convolutional Neural Networks), which have shown potential for predictive performance in the finance domain, to enhance the classification accuracy in Bitcoin price trend prediction. XAI(eXplainable Artificial Intelligence) techniques were applied to the predictive model to enhance its explainability and interpretability by providing a comprehensive explanation of the model. In the empirical experiment, CNN was applied to technical indicators and Google trend data to build a Bitcoin price trend prediction model, and the CNN model using both technical indicators and Google trend data clearly outperformed the other models using neural networks, SVM, and LSTM. Then SHAP(Shapley Additive exPlanations) was applied to the predictive model to obtain explanations about the output values. Important prediction drivers in input variables were extracted through global interpretation, and the interpretation of the predictive model's decision process for each instance was suggested through local interpretation. The results show that our proposed research framework demonstrates both improved classification accuracy and explainability by using CNN, Google trend data, and SHAP.

• Journal of the Korean Geographical Society
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• 제39권6호
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• pp.907-921
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• 2004

Lots of characteristics such as dwelling, neighborhood, and accessibility characteristics affect to the housevalue. Many researches have been done to identify values of each characteristic using hedonic technique. However, there is a limit to identify interaction of each characteristic and variation of each characteristic among the accessibility context. This paper has implemented the Expansion Method research paradigm to model the housevalue determination process in the city of Seoul. The findings of this paper have revealed the presence of contextual variations in the housevalue determination process. The initial model for housevalue reveals that as $F_1$ increases (i.e., larger the number of rooms/bathrooms, larger parking space) and/or $F_2$ increases (i.e., higher owner occupied housing units, higher apartment housing units) and/or $F_3$ increases, (i.e., higher the ratio of higher than college graduated households, 8 school zone, older housing units) the estimated housevalue increases. However, the above relationships drift across their respective contexts. The houses which have negative $F_1$ value, the housevalue does not fluctuate according to the distance to the city center or subcenters. However, the houses which have positive $F_1$ value, the closer to the subcenters or shorter to the river, the higher the estimated housevalues. On the other hand, in areas far from the subcenters, the estimated housevalues does not fluctuate much according to the corresponding $F_2$ level. In areas close to the subcenters, the estimated housevalues vary tremendously according to the $F_2$ value. In the residual analysis, it is revealed that large apartment which are located in Kangnam, IchongDong, MokDong are underestimated. This paper has contributed to our understanding of the housevalue determination process by providing an alternative conceptualization to the traditional approach.

• Proceedings of the Korea Water Resources Association Conference
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• 한국수자원학회 2021년도 학술발표회
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• pp.305-305
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• 2021

XP-SWMM은 EAP-SWMM의 Runoff 기능을 보완하고 2D 해석 기능을 새롭게 추가하여 만든 외산(XP Solutions) 프로그램으로 도시유역 유출량 산정, 우수관거 추적 등과 같은 모의가 가능한 종합 모형이다. 그 중 2차원 분석 기능(2D XP-SWMM)은 연산 결과를 Tu-Flow 모형에 대입한 도시침수 해석모형으로 실무에서 주로 사용되고 있다. 그러나 XP-SWMM은 수량 부분 외에도 수질 부분의 다양한 모형이 통합되어 있어 라이센스 가격이 상당히 높고, 국내 환경에 적합한 모형 수정 등 기술지원을 받기 어렵다는 단점을 갖고 있다. 또한, 실무 활용성이 높은 2차원 분석기능의 경우 모의에 소요되는 시간이 크다는 한계점을 갖고 있다. 2D XP-SWMM 연산의 소요시간이 큰 주요 원인은 계산 시간간격마다 큰 셀수의 행렬 계산을 반복하기 때문이며, 격자를 촘촘하게 설정할수록(행렬의 수가 증가할수록) 수치해석에 소요되는 시간은 기하급수적으로 늘어나게 된다. 2D XP-SWMM 연산은 편미분방정식을 계산하는 모형으로 반복법을 채택하고 있기 때문에 짧은 시간내에 침수해석을 진행해야하는 웹기반 초단기 홍수예경보 시스템 등에 활용하기에는 적합하지 않다. 본 연구에서는 2D XP-SWMM 보다 연산속도를 향상시킨 2차원 도시침수 모형을 개발하였다. 기존 XP-SWMM 중심의 실무 적용성을 유지하고자 XP-SWMM과 동일하게 EPA-SWMM 엔진을 활용하였고 DEM 기반의 지표수 흐름방향 결정 알고리즘을 결합하였다. 본 연구에서 개발한 도시침수 모형 결과를 울산광역시, 청주시 등 도심지에서 발생한 과거 침수피해의 양상과 비교하여 그 타당성을 검증하였다.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 한국경영과학회 2005년도 추계학술대회 및 정기총회
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• pp.221-226
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• 2005

Gifford(1992, 1993, 1997, 1998)는 제한적 주의력(limited attention)의 관점에서 벤처경영자, R&D 관리자, 혁신자, 벤처 캐피탈의 의사결정을 연구하였다. 창업경영자 (entrepreneurs)는 기술 개발, 제품디자인 개발, 원자재 확보, 제품 생산, 유통채널 확보, 가격정책 결정, 판매촉진 및 마케팅정책 결정 등의 다양한 경영활동을 수행하고 끊임없이 창업기회(entrepreneurial opportunities)를 추구하는 사람이다. Gifford 는 벤처 경영자를 창업기회와 다양한 경영활동의 포트폴리오(portfolio)를 수행하고 관리하는 대리인으로 간주한 '마술사 모형(Juggler model)' 을 제시하고 이익극대화의 관점에서 대리인의 의사결정을 분석하였다. 그녀는 모형을 통하여 특정시점을 지난 기존 메뉴를 포기 하고 새로운 창업기회를 평가하는 '포기정책(discard policy)' 과 아울러 기존 메뉴를 관리한 이후 새로운 창업기회를 평가하는 '연령검사(age inspection)' 를 동시에 사용한다는 결과를 도출하였다. 본 논문은 Gifford의 마술사 모형(Juggler model)을 수정, 발전시켜 창업경영자의 의사결정을 분석하였다. Gifford의 모형은 성장하지 않는 창업기회의 포트폴리오 결정에 대한 모형이기 때문에 창업기회의 성장성이 벤처경영자의 의사결정에 어떤 영향을 미치는가에 대한 논의가 전혀 없었다. 본 논문에서는 창업경영자를 기업가적 활동을 수행하는 사람으로 정의하고 벤처경영자의 의사결정을 분석하였다. 성장률이 큰 기업에서 기업가적 활동을 수행할 때 창업경영자가 창출하는 기업의 현재가치는 크게 증가하게 되는 반면 성장률이 떨어지는 기업에서 기업가적 활동을 수행할때 창업경영자가 창출하는 기업의 현재가치는 크게 감소하게 된다. 또, 창업경영자는 성장률이 큰기업을 선택하면 관리횟수가 줄어들게 되고 이익의 감소 없이 빠르게 수확할 수가 있다. 국가의 정책과 제도가 창업경영자를 보다 성 장률이 높은 기업에서 기업가활동을 하게 한다면 국가경제의 성장속도는 빨라지게 될 것이다.

• Journal of the Korea Convergence Society
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• 제10권3호
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• pp.193-201
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• 2019

The public's interest regarding multi-household houses, one of the small-scale housings used as profit earning property, has been increasing. Previous studies regarding price, such as the rent and sales price of multi-household houses', however, were difficult to find. Thus, this study set forth to find out what characteristics influence the sales price of multi-household houses so as to provide further suggestions to investors' decision makings and developers' strategy establishments. The data was retrieved from multi-household sales transacted in Changwon City. Through empirical analysis, this paper found that prices were high in Euichang-gu and Seongsan-gu, and meaningful variables in terms of locations were distance from major trade areas(-), distance from main streets(-), and Corner site(+). Meaningful variables related to household characteristics were total floor area(+), Studio type(+), Southern exposure(+), Building age(-), and Full-furnished(+).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 한국정보통신학회 2013년도 춘계학술대회
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• pp.474-477
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• 2013

As the market-based spectrum policy is introduced, an interest in the economic value of the frequency is increasing. Research and practical applications concerning the methodology for the estimation of the economic value of the frequency and its determinants are actively engaged, which are used for setting a reserve price and bid price of spectrum auction and a spectrum clearance cost. In this study, by the analysis of the spectrum valuation methodology, we derive the changes in the factors affecting the valuation and propose to apply improved. In the model frequency value is consist of technical value, commercial value and strategic value, we find the dynamics of fluctuation factors and suggest how to apply them to spectrum policy.

• Environmental and Resource Economics Review
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• 제19권1호
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• pp.3-21
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• 2010

By the significant structural change in 1999, a partial privatization has occurred in Korean fossil-fuel power generation sector. Under the current price scheme wholesale electricity price is dependent on output size, and hence, may not satisfy the assumption of price-taking producers. The purpose of our study is constructing the productivity change measurements of Korean power generation sector taking into account possibly imperfect competition and variable returns to scale. Our approach based on Harrison (1994) and Levinsohn (1993) derives the plant-level productivity measurements of the period between 2001 and 2007, as well as the measurements of mark-ups and returns to scale. It is shown that the mark-up size is dependent on the plants' fuel type and is decreasing over time. Allowing for imperfect competition and variable returns to scale adjusts the productivity measurements substantially.

• The Journal of the Korea Contents Association
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• 제19권4호
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• pp.79-90
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• 2019

As an increasing number of cloud service providers begin to provide cloud computing services, they form a competitive market to compete for users. Due to different resource configurations and service workloads, users may observe different response times for their service requests and experience different levels of service quality. To compete for cloud users, it is crucial for each cloud service provider to determine an optimal price that best corresponds to their service qualities while also guaranteeing maximum profit. To achieve this goal, the underlying rationale and characteristics in this competitive market must be clarified. In this paper, we analyze price competition in the multimedia cloud service market with two service providers. We characterize the nature of non-cooperative games in a duopoly multimedia cloud service market with the goal of capturing how each cloud service provider determines its optimal price to compete with the other and maximize its own profit. To do this, we introduce a queueing model to characterize the service process in a multimedia cloud data center. Based on performance measures of the proposed queueing model, we suggest a price competition problem in a duopoly multimedia cloud service market. By solving this problem, we can obtain the optimal equilibrium prices.