• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2006년도 춘계공동학술대회 논문집
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• pp.187-192
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• 2006

In the absence of a clear command and control structure, a key challenge in supply chain management is the coordination and alignment of the supply chain members who pursue divergent and often conflicting goals. The newsvendor model is typically used as a framework to quantify the cost of misalignment and to assess the impact of coordination initiatives. This paper considers a fuzzy approach for the newsvendor problem which includes a single manufacturer and a single retailer. We use several fuzzy parameters in the model such as the demand, the wholesale price, and the market sales price. We apply a coordination policy, referred to as buyback, to solve the fuzzy newsvendor problem. Based on the buyback policy, the optimal order quantity of the retailer can be computed, and the possible profits of the members in the supply chain can be calculated with minimum sharing of private information. Focusing on the fuzzy model with buyback policy for the newsvendor problem, we illustrate exemplary fuzzy models. We also illustrate an integration model, which extends a single-manufacturer-single-retailer model to the single-manufacturer-multiple-retailer setting. In the extended model, we consider three coordination policies including quantity discount, profit sharing, and buyback, as well as non-coordination case.

• 한국수자원학회논문집
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• 제42권9호
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• pp.759-771
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• 2009

장거리 용수공급 시스템에서 전력비용은 전체 운영비용의 큰 부분을 차지한다. 본 연구는 시간단위의 펌프와 배수지 시스템의 최적 운영계획을 평가하기 위해 동적계획기법에 기초한 방법론을 제시하고 있다. 해석방법은 운영비용 최소화 관점에서 펌프용량 확대를 전제로 현재 가용 펌프의 효율적 운전과 전력요금체계, 시간별 용수수요 추이 그리고 배수지 특성과 송수관로의 제약조건 등을 고려하였다. 이를 위해 적용 가능한 시스템 운영목적과 제약조건이 제시되었고 개발된 방법은 수도권 광역상수도 양주계통의 2개 가압장과 5개 배수지를 대상으로 적용하였다. 적용결과는 펌프 확장의 경우 상당한 수준의 운전비용을 절감할 수 있는 것으로 나타났으며, 이와 같은 방법은 기존 시스템의 최적운영은 물론 생애주기 비용 최소화 측면에서 신규 용수공급 체계의 설계 등에 적절히 활용될 수 있다.

• 한국실천공학교육학회논문지
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• 제3권1호
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• pp.127-135
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• 2011

기존의 과부족인원 중심의 정량적 분석을 위주로 하는 직업훈련 수요연구에서는 직무능력의 질적 불일치에 대한 문제점이 존재한다. 이에 대한 보완적 연구로써 특정한 산업과 관련한 직종 내 직무기술에 대한 정성적 분석을 통해 직업훈련 프로그램에 대한 개선논의가 필요하다. 본 연구는 디스플레이 산업을 대상으로 직종별 직무기술요소의 상대적 중요도와 격차를 이용한 시급성 분석결과를 제시하고, 이를 기반으로 정성적 상향식 훈련 프로그램의 설계 가능성을 논의하고자 한다. 연구 수행방법으로는 디스플레이 산업에 특화된 직무기술요소 수요조사를 수행하였으며, 직종과 직무, 그리고 각 직무기술요소의 정성적 수요를 분석하여 8개의 직종과 29개 세부직무별 직무기술요소들에 대해서 인력수준별로 제시하였다. 또한 기업의 직무기술의 확보방법을 분석하고 지역의 대표적 교육과정과 연계를 예시함으로써 직업훈련 프로그램의 적정한 공급 방안을 찾고자 하였다.

• 산업경영시스템학회지
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• 제21권48호
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• pp.37-52
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• 1998

In many distribution systems important cost reductions and/or service improvements may be achieved by adopting an efficient inventory policy and proper selection of facilities. These efficiency improvements and service enhancements clearly require an integrated approach towards various logistical planning functions. The areas of inventory control and transportation planning need to be closely coordinated. The purpose of this paper is to construct an integrated model that can minimize the total cost of the transportation and inventory systems between multiple origin and destination points, where in origin point i has the supply of commodities and in destination point j requires the commodities. In this case, demands of the destination points are assumed random variables which have a known probability distribution. Using the lot-size reorder-point policy and the safety stock level that minimize total cost we find optimal distribution centers which transport the commodities to the destination points and suggest an optimal inventory policy to the selected distribution center. We also show if a demand greater than one unit will occur at a particular time, we describe the approximate optional replenishment policy from computational results of this lot-size reorder-point policy. This model is formulated as a 0-1 nonlinear integer programming problem. To solve the problem, this paper proposes heuristic computational procedures and a computer program with UNIX C language. In the usefulness review, we show the meaning and validity of the proposed model and exhibit the results of a comparison between our approach and the traditional approach, respectively.

• 농업과학연구
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• 제45권4호
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• pp.859-870
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• 2018

Dried red peppers are a staple agricultural product used in Korean cuisine and as such, are an important aspect of agricultural producers' income. Correctly forecasting both their supply and demand situations and price is very important in terms of the producers' income and consumer price stability. The primary objective of this study was to compare the performance of time series forecasting models for dried red peppers in Korea. In this study, three models (an autoregressive model with exogenous variables [ARX], AR-exponential generalized autoregressive conditional heteroscedasticity [EGARCH], and ARX-EGARCH) are presented for forecasting the wholesale price of dried red peppers. As a result of the analysis, it was shown that the ARX model and ARX-EGARCH model, each of which adopt both the rolling window and the adding approach and use the agricultural cooperatives price as the exogenous variable, showed a better forecasting performance compared to the autoregressive model (AR)-EGARCH model. Based on the estimation methods and results, there was no significant difference in the accuracy of the estimation between the rolling window and adding approach. In the case of dried red peppers, there is limitation in building the price forecasting models with a market-structured approach. In this regard, estimating a forecasting model using only price data and identifying the forecast performance can be expected to complement the current pricing forecast model which relies on market shipments.

• 한국수자원학회논문집
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• 제50권7호
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• pp.503-511
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• 2017

수자원 계획 및 운영을 위한 수요량을 추정하는데 있어, 실제 이용 추세를 반영한 생활용수나 공업용수와 달리 농업용수는 용수공급시설의 규모를 결정하기 위한 방법론이 주로 적용되어 왔다. 이는 불가피하게 농업용수의 과다추정으로 이어질 수 있으며, 전체 수자원 계획의 관점에서 각 용도별 용수 수급계획의 불균형을 초래할 수 있다. 본 연구에서는 기존 방법론과 비교하여 순물소모량 개념의 접근방법의 차이에 대해 고찰하였으며, 이를 제주도 전역에 적용하여 농업용수 수요량 특성을 분석하였다. 수요량 산정에 핵심적인 인자인 증발산량의 정확한 추정을 위하여 SWAT 모형을 적용하고, 제주도 지역의 지형 및 기상, 유출, 물이용 특성을 반영한 유역 모델링을 수행하였으며, 기존 물수지 결과와 비교하여 모델링 자료의 신뢰성을 평가하였다. 과거기간(1992~2013년)에 대해 제주도 전체의 수요량은 연간 427 mm로 분석되었으며, 동부와 서부 해안지역을 중심으로 상대적으로 높은 수요량을 나타내었다. 유역면적 $30km^2$ 이상인 10개 하천유역에 대해서도 연평균 수요량 및 계절별 변화 특성을 분석하였다. 또한, 장래 2020년 지역별 작물재배면적을 적용하여 10년 빈도 가뭄에 대응한 수요량을 산정한 결과 기존 제시된 수요량 대비 54% 수준으로 나타났다. 이는 수요량 산정목적에 따른 접근방법의 차이로 인해서 나타난 결과로서, 수자원 관리 및 운영의 관점에서 보면 순물소모량만큼의 추가적인 수요가 예상되지만, 실제 공급의 관점에서는 기존 수요량만큼의 시설계획이 필요하다고 판단할 수 있다. 본 연구에서 적용된 방법론 및 결과의 실무 활용을 위해서는 공학적인 검증은 물론이고 정책적 제도적인 측면에서의 합리적인 논의가 필요할 것이다.

• STI Policy Review
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• 제5권1호
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• pp.75-97
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• 2014

Entrepreneurial financing, such as publicly initiated venture capital or grant schemes, serves as an important policy instrument that aims to bridge the financing gap facing young, innovative businesses, a gap that is mainly due to higher risk and growing uncertainty, and to strategically promote the creation of new ventures through the revitalization of their venture capital industries. This study examines public venture capital initiatives in Australia, Canada, and Sweden, and discovered that all three countries actively foster their venture capital industry through the formation of funds or the provision of tax incentives. It is notable that the majority of financing initiatives heavily depend on supply-side measures rather than demand-driven policies that focus on stimulating private investment in technological innovations and discoveries. This paper discusses in-depth the policy impact of public financing initiatives and their subsequent side-effects raised in the process such as overlapping in funding structure across the country, lack of monitoring and evaluation for feedback, fragmentation across the government ministries and agencies, and competition with the private sector, which may cause inefficiency as a result of public intervention. Financial constraints may arise for many reasons, partly resulting from the lack of investment readiness of young entrepreneurs. This signals a policy shift towards the creation of market-driven demand away from the traditional supply-push approach, and is a grand challenge to policymakers in entrepreneurial financing. Attention is leaning towards the efficiency and effectiveness of these public-financing initiatives in terms of their policy roles. It is worth noting that policy should focus on generating synergy so available resources can be channeled into the early, risky stage of new ventures, working as facilitator to the achievement of an intended policy goal.

• 에너지공학
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• 제25권3호
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• pp.136-148
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• 2016

본 논문은 최근 공표된 Post-2020 신기후체제의 국가적 대응에 따른 발전부문의 역할들을 시나리오로 설정하여 경제적 파급효과를 비교 분석 하였다. 이를 위해 제7차 전력수급기본계획에서 제시한 2030년 발전원별 추정 발전량에 IAEA에서 발표한 온실가스 배출계수를 적용하여 온실가스 배출량을 예측하여 발전부문에서 발생시키는 초과 배출량을 산정하였다. 초과 배출량 감축을 위해 세 가지 시나리오를 기반으로 하였으며, 이들은 원자력발전소로 대체, 신재생발전설비 확대, CCS 도입 등이다. 분석 결과 원자력 발전소 대체 시나리오가 배출량 감소 및 경제적인 측면에서 가장 긍정적인 결과를 보였다.

• 한국정보시스템학회지:정보시스템연구
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• 제29권2호
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• pp.221-242
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• 2020

Purpose This study collects data of the recently activated online black market and analyzes it to present a specific method for preparing for a hacking attack. This study aims to make safe from the cyber attacks, including hacking, from the perspective of individuals and businesses by closely analyzing hacking methods and tools in a situation where they are easily shared. Design/methodology/approach To prepare for the hacking attack through the online black market, this study uses the routine activity theory to identify the opportunity factors of the hacking attack. Based on this, text mining and social network techniques are applied to reveal the most dangerous areas of security. It finds out suitable targets in routine activity theory through text mining techniques and motivated offenders through social network analysis. Lastly, the absence of guardians and the parts required by guardians are extracted using both analysis techniques simultaneously. Findings As a result of text mining, there was a large supply of hacking gift cards, and the demand to attack sites such as Amazon and Netflix was very high. In addition, interest in accounts and combos was in high demand and supply. As a result of social network analysis, users who actively share hacking information and tools can be identified. When these two analyzes were synthesized, it was found that specialized managers are required in the areas of proxy, maker and many managers are required for the buyer network, and skilled managers are required for the seller network.

• 한국수소및신에너지학회논문집
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• 제33권5호
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• pp.470-498
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• 2022

Recently, the world has been considering hydrogen energy as the primary energy transition means to achieve carbon neutrality by 2050. In order to achieve the goal of reducing greenhouse gas emissions, Korea is also promoting a clean hydrogen economy. However, it is necessary to introduce various clean hydrogen from overseas so that the projected demand can not meet the domestically produced. For this study, we conducted the policy comparison approach between countries other than the generally considered technical and economic approaches. The finding proposes the direction of bilateral cooperation for a strategy of securing overseas clean hydrogen from a geopolitical perspective. Germany was a target country for the policy comparison since it has a high proportion of manufacturing, like Korea, and is taking the lead in the renewable-based energy transition policy. According to the survey and analysis of the policy establishment status and new projects of the two countries, Germany is promoting bilateral international cooperation in the hydrogen area with about 33 countries based on 7 types of activities. In comparison, Korea is involved in bilateral cooperation with about 12 countries on relatively few activities. Among the types of bilateral cooperation, R&D cooperation with advanced countries for hydrogen technology was a common activity type. Germany preemptively promotes cooperation for demonstration and commercialization, considering geopolitical means and strengthening manpower training and assistance on policy and regulation to preoccupy the market for the future. Therefore, it is necessary to consider establishing a network of an entire life cycle of supply and demand network that links the future market with securing clean hydrogen considering the geopolitical distribution. To this end, Korea also needs to expand bilateral cooperation countries by activity type, and it seems necessary to seek various geopolitical-based bilateral cooperation and support measures for developing countries to diversify the supply sources of hydrogen.