• 한국경영과학회지
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• 제13권2호
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• pp.59-65
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• 1988

This paper discusses the problem of coordinating aggregate planning and production schedules, minimizing the combined set-up inventory and capacity costs. In this study, by using the relation of fixed production quantity and the number of set-up we develop a heuristirc procedure of solving the discrete demand, fixed production quantity, variable capacity problem. First, we obtain the trade-off between set-up cost and capacity cost, then search the point minimizing the combined inventory and capacity costs.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2004년도 추계학술대회 및 정기총회
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• pp.371-374
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• 2004

The ultimate purpose of Supply Chain Management (SCM) is maximizing the profits of the overall Supply Chain (SC) through increasing customer satisfaction and decreasing operating cost. It can be successfully accomplished only when SC system balances demands with supply activities coordinated by aggregate planning, mid-term level of Supply Chain Planning(SCP). However, the existing measures to mainly estimate the specific function of SCM are not enough to evaluate the state of SC with respect to the balance between supply and demand in operating. To solve this problem, we develop a new SC performance measure, Balancing Point, using momentum concept. a fundamental knowledge of physics. Momentum concept can explain the relation among objects so that it can consider the balance between supply and demand in SC operating. The developed measure can not only consider the current state of the SC system but also take planned but not executed supply activities and upcoming demands into account. Therefore, using Balancing point, we can be aware of the unbalanced state of SC in advance.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2001년도 추계학술대회 논문집
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• pp.139-142
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• 2001

This study suggests an approach for determining fleet size for container road transportation with dynamic demand in Korea. With the forecasted monthly container transportation data a year, a heuristic algorithm is developed to determine the number of company-owned trucks, mandated trucks, and rented trucks in order to minimize the expected annual operating cost, which is based on the solution technologies used in the aggregate production planning and the pickup-and-delivery problem. Finally the algorithm is tested for the problem how the trucking company determines the fleet size for transporting containers.

• Management Science and Financial Engineering
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• 제8권2호
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• pp.33-45
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• 2002

This study suggests an approach for determining fleet size for LTL (less -than-truckload) transportation with dynamic demand for on-time supply of the parts between the assembly line in an automobile company and its part suppliers in Korea. The vehicles operated by the transportation trucking companies in Korea in general can be classified into three types depending on the ways how their expenses occur; company -owned truck, mandated truck which is owned by outsider who entrusts the company with its operation, and rented truck (outsourcing) . With the forecasted monthly production data a year, a heuristic algorithm is developed to determine the number of company-owned trucks, mandated trucks, and rented trucks in order to minimize the expected annual operating cost, which is based on the solution technologies used in the aggregate production planning and vehicle routing problem. Finally the algorithm is tested for the problem how the trucking company transports parts for the automobile company.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제16권4호
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• pp.225-237
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• 2016

In conventional transportation problem (TP), all the parameters are always certain. But, many of the real life situations in industry or organization, the parameters (supply, demand and cost) of the TP are not precise which are imprecise in nature in different factors like the market condition, variations in rates of diesel, traffic jams, weather in hilly areas, capacity of men and machine, long power cut, labourer's over time work, unexpected failures in machine, seasonal changes and many more. To counter these problems, depending on the nature of the parameters, the TP is classified into two categories namely type-2 and type-4 fuzzy transportation problems (FTPs) under uncertain environment and formulates the problem and utilizes the trapezoidal fuzzy number (TrFN) to solve the TP. The existing ranking procedure of Liou and Wang (1992) is used to transform the type-2 and type-4 FTPs into a crisp one so that the conventional method may be applied to solve the TP. Moreover, the solution procedure differs from TP to type-2 and type-4 FTPs in allocation step only. Therefore a simple and efficient method denoted by PSK (P. Senthil Kumar) method is proposed to obtain an optimal solution in terms of TrFNs. From this fuzzy solution, the decision maker (DM) can decide the level of acceptance for the transportation cost or profit. Thus, the major applications of fuzzy set theory are widely used in areas such as inventory control, communication network, aggregate planning, employment scheduling, and personnel assignment and so on.

• 자원환경지질
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• 제57권2호
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• pp.129-141
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• 2024

본 연구는 지역산업연관표를 이용하여 생산-생산 승수를 도출하고 비금속광물 부문과 콘크리트 제품 부문을 통해 골재의 유발효과를 추정하였다. 유발효과를 파악할 수 있도록 지역산업연관표를 활용하여 분석을 진행하였다. 골재의 유발효과를 도출함에 있어 지역산업연관표를 이용하는 것은 부문분류 문제로 인해 어려움이 있는데, 본 연구는 골재를 포함한 비금속광물 부문을 골재로 간주한 분석과 골재생산의 대부분을 수요하는 콘크리트 제품 부문을 분석함으로써 부문분류 제약으로 인한 난점을 완화하고자 하였다. 산업연관효과를 추정하는 과정에서 골재의 생산감소 상황을 전제해 진행하였으며, 콘크리트 제품 부문을 분석하는 과정에서는 골재 생산감소로 인한 콘크리트 제품 생산감소의 효과, 즉 골재 1단위 생산감소는 콘크리트 제품 부문 0.8511단위의 생산감소를 전제로 분석하였다. 지역산업연관표가 구분하고 있는 17개 광역시도에 대해 자기지역 내 및 지역간 유발효과를 산출하였다. 골재 생산감소로 인해 자기지역에서 발생하는 생산감소 효과는 지역별 평균 1.28의 유발효과를 보였으며, 타지역의 골재 생산감소로 인한 생산감소 효과는 지역별 평균 0.10의 유발효과를 보였다. 취업효과도 산출하였는데, 지역별 골재 및 콘크리트 제품 부문의 규모에 따른 차이를 나타낼 수 있도록 10% 생산감소 상황을 전제하여 취업효과를 산출하였다.

• 대한공간정보학회지
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• 제3권1호
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• pp.91-104
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• 1995

교통 및 기타 공간계획 과정에 있어서 분석을 위한 공간분할은 필수적이다. 공간 분할에 있어서 두 가지의 중요한 변수는 scale과 aggregation이라고 할 수 있는바 이들 2가지의 조합에 따라서 분할된 공간상의 계획결과물은 실로 엄청난 차이를 보일 때도 있다. 본고에서는 이들 공간 zone 분항 및 재구성 체계의 과정 및 결정기법을 살펴 보는데 우선 목적이 있고, 또한 vector형 GIS의 위상관계자료를 이용한 교통 zone체계의 재설정 방법을 제시해 봄으로써 경직된 교통계획상의 zone체계 구성에의 변화를 창출해 보았다. 시범연구로서는 남한을 132개의 세부 zone으로 구분한 뒤 사회경제적 지표에 의한 동질적인 zone체계를 구축하여 교통계획에 응용하였으나 애초에 macro된 세부 zone체계를 사용한 나머지 aggregate된 zone이 concave한 문제점 또한 발견되었다.

• Journal of Electrical Engineering and Technology
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• 제13권5호
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• pp.1769-1777
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• 2018

This paper proposes a method for optimal placement of Phasor Measurement Units (PMUs) considering system configuration and its attributes during the planning phase of PMU deployment. Each bus of the system is assessed on four diverse attributes; namely, redundancy of measurements, rotor angle and frequency monitoring of generator buses, reactive power deficiency, and maximum loading limit under transmission line outage contingency, and a consolidated 'degree of criticality' is determined using Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). The major contribution of the proposed work is the development of modified objective function which incorporates values of the degree of criticality of buses. The problem is formulated as maximization of the aggregate degree of criticality of the system. The resultant PMU configuration extends complete observability of the system and majority of the PMUs are located on critical buses. As budgetary restrictions on utilities may not allow installation PMUs even at optimal locations in a single phase, multi-horizon deployment of PMUs is also addressed. The proposed approach is tested on IEEE 14-bus, IEEE 30-bus, New England (NE) 39-bus, IEEE 57-bus and IEEE 118-bus systems and compared with some existing methods.

• 한국지역사회생활과학회지
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• 제21권1호
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• pp.105-115
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• 2010

This study explores the gender differences in the relationship between social support, social networks and drinking behavior and illustrates gender differences in drinking behavior in order to provide evidence in planning a community health promotion program. Data was collected from 444 surveys (Male=190, Female=244) from a total of 1,899 adult residents in 738 households in the "Y" Apartment Complex in the Gangnam area of Seoul, Korea. Results show significantly higher rates of drinking frequency and alcohol consumption volume in males. Women with high-risk drinking behavior have fewer social relationships than women with normal drinking behavior. Within social networks, friends were significantly associated with drinking behavior and alchol abuse. Drinkers had more friends than non-drinkers in both genders. However, in association with alchol abuse, while male abusers had less friends than normal male drinkers, women abusers had more friends, indicating women who have drinking problems have a stronger social network. This pattern suggests gender differences in the association between social networks and alchol abuse. Therefore in approaching drinking issues, social support and social networks act as a key factor. For men, alcohol prevention programs should be aimed at achieving healthy drinking behavior at the aggregate level including people in his social support and social network groups. For women, the priority is alchol abuse. More attention is required in revealing the context between female social networks and alchol abuse and in developing coping strategies other than drinking.

• 한국지리정보학회지
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• 제17권1호
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• pp.50-60
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• 2014

본 연구는 재해로부터 안전한 도시조성을 위하여 현재 시행중인 기후변화 재해취약성분석 제도의 조기정착을 위한 방안마련의 일환으로, 현행 재해취약성분석 제도의 특징과 개선방안 검토를 목적으로 한다. 이를 위해 부산 해운대구를 대상으로 재해유형 중 해수면 상승 재해에 대하여 실증분석을 수행하였다. 분석은 집계구와 동을 분석단위로 설정하여 각각 재해취약성을 분석하였으며, 분석과정과 분석결과의 비교 검토를 통하여 개선방안을 검토하였다. 분석결과 공간단위에 따라 결과가 다르게 도출되는 공간단위수정가능성의 문제가 발생하였다. 개선방안 검토는 분석진행 과정별로 도출하였으며, 분석의 기반이 되는 공간단위의 설정단계에서는 분석단위 조정, 점수산정방식 조정, 재해유형별 명확한 분석방안마련 등이 필요한 것으로 나타났다. 분석실행 단계에서는 변수에 따른 가중치 설정, 변수의 다양화, 주관적 분석선정방안 배제 등이 필요한 것으로 나타났다. 정확한 도시종합 재해취약성분석 결과는 미래 기후변화에 효율적으로 대응 가능한 도시방재력 향상의 밑거름이 될 것으로 기대된다.