• Korean Management Science Review
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• v.32 no.4
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• pp.19-28
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• 2015

This study presents a mathematical programming model to develop production planning in the manufacturing processes for photovoltaic silicon ingots and wafers. The model is formulated as a linear programming model that maximizes total growth margin, which is composed of production cost, inventory cost, shortage cost, and sales profit while considering the constraints associated with the production environments of photovoltaic materials. In order to demonstrate the utility of the model for production planning, we run operations for a planning horizon of a year for a case study. When the primary results of this mathematical programming are compared with the historical records, the model could have resulted in the considerable increase of the total growth margin by effectively reducing inventory cost if a decision maker had employed the model as a decision support system with perfect information for sales demand.

• Architectural research
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• v.8 no.2
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• pp.43-48
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• 2006

The appropriate fleet estimation of the excavation equipment is a major factor in the determination of the cost and time requirements of a project. But the decision of what kind of equipment selected is often based on heuristic methods or trial and error in Korea. Thus, this study proposes a prototype model that uses genetic algorithms to select fleet estimation of loaders (backhoe) and trucks used in excavation work. To verify the applicability of this model, the case study was performed. And the result of the genetic model was compared with that of the trial & error method. The use of the genetic model suggested this study required 44days, 2 units of backhoes, 7 units of trucks, and a total cost of 171,839,756 won. With the estimated fleet number of equipment, the minimum cost of excavation work can be calculated, taking account of the time-cost trade-off. By utilizing this prototype model, the efficiency of excavation work can be improved.

• Proceedings of the KIEE Conference
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• 2002.11b
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• pp.375-377
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• 2002

In many parts of the world. the electricity industry is undergoing unprecedented changes. Hence, in order to reform the electricity industry readily and efficiently and minimize the confusion by these restructuring, it is required the systematic studies related to transmission pricing and transmission cost allocation issues. However, even now the basis of transmission cost allocation rate is not equipped so that the regulation body has determined the allocating rate under the common practice. In this paper it is demonstrated that the decision of transmission cost allocation rate is the regulation body's own right. For the analysis, game theory is applied to the procedure determining this rate and the competition to determine this rate between generators and distributors is modeled as the arbitration game.

• The Journal of Fisheries Business Administration
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• v.49 no.4
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• pp.19-36
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• 2018

Overstock in aquaculture is a matter of concern in aquaculture management. To sort fish based on fingerling size in case of overstocking is an important problem in aquaculture farm. This study aims to determine the amount of fry overstock and sorting time in aquaculture farm. This study builds a mathematical model that finds the value of decision variables to optimize objective function summing up the fingerling purchasing cost, aquaculture farm operating cost and feeding cost under mortality and farming period constraints. The proposed mathematical model involves following biological and economical variables and coefficients: (1) number of fingerlings, (2) sorting time, (3) fish growth rate and variation, (4) mortality, (5) price of a fry (6) feeding cost, and (7) possible sorting periods. Numerical simulation is presented herein. The objective of numerical simulation is to provide decision makers to analyse and comprehend the proposed model. When extensive biological data about growth function of fry becomes available, the proposed model can be widely applicable to real aquaculture farms.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.22 no.3
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• pp.107-117
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• 2016

In order to reduce packaging and logistics costs for any business, it is important to identify opportunities for improvement throughout an entire logistics system including measurement of the performance and cost of packaging. Although the importance of packaging in a supply chain has been recognized by many scholars and experts, the total cost and value of packaging have not been successfully estimated. This paper reviews the recent researches and articles that tried to quantify the value of packaging focusing on the business decision between reusable and expendable shipping container systems. Three key factors such as cost, ownership, and standardization are identified and discussed in terms of impact on supply chain costs and performances. It is important to understand that the decision of a package system can change a logistics activities and even entire logistical system. Hence, the total cost and value of transport packaging should be calculated with understanding of interactions with logistical activities throughout supply chain. Identifying the opportunities and constraints of packaging changes on total logistics cost and activities must be carefully examined before implementation of a packaging system.

• Journal of Preventive Medicine and Public Health
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• v.23 no.1 s.29
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• pp.65-76
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• 1990

Hospitals are experiencing an increasing amount of financial difficulty due to government control of hospital rates since national health insurance has been implemented. The decision support system (DSS) was developed to provide cost and revenue information for the services rendered by each department in an effort to reduce costs. This information may be used to identify the causes of financial loss if cost exceeds revenue and to conduct variance analysis or portfolio analysis to improve financial situation of hospitals. The DSS was developed using a micro-mainframe interface approach where the mainframe computer collects and summarizes daily cost and revenue data and the micro computer computes the cost for each department. The significances of this paper are to determine the cost allocation basis and methods which are suitable to Korean situation and to apply DSS technology to the cost analysis.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.6
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• pp.1-8
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• 2019

Modern weapon systems are multifunctional, with capabilities for executing complex missions. However, they are required to be highly reliable, which increases their total cost of ownership. Because it is necessary to produce the best results within a limited budget, there is an increasing interest in development, acquisition, and maintenance costs. Consequently, there is a need for tools that calculate the lifecycle costs of weapons systems development to facilitate decision making. In this study, we propose a cost calculation function based on the Markov process simulator-a reliability, availability, and maintainability analysis tool developed by applying the Markov-Monte Carlo method-as an alternative to these requirements to facilitate decision-making in systems development.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10c
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• pp.223-225
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• 2002

Decision tree는 목표 데이터에 대한 계층적 관점을 보여준다는 의미에서 데이터를 보다 잘 이해하는데 많은 도움이 되나 탐욕법(greedy algorithm)에 의한 트리 생성법의 한계로 인해 최적의 예측자라고는 할 수가 없다. 이와 같은 약점을 보완하기 위하여 일반적 방법으로 생성한 decision tree에 대하여 다차원 연관규칙 알고리즘을 적용함으로써 짱은 길이의 최적 부분 규칙집합을 구하는 방법을 제시하였고 실험을 통해 그와 같은 사실을 확인하였다.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.6
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• pp.165-173
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• 2004

H.264 is the newest international video coding standard that provides high coding efficiency. A macroblock in H.264 has 7 different motion-compensation block sizes in the Inter mode, and several different prediction directions in the Intra mode. In order to achieve as highest coding efficiency as possible, H.264 reference model employs complex mode decision technique based on rate-distortion (RD) optimization which requires high computational complexity. In this paper, we propose two techniques -'early SKIP mode decision' and 'selective intra mode decision' - which can further reduce the computational complexity. Simulation results show that without considerable performance degradation, the proposed methods reduce encoding time by 30% on average and save the number of computing rate-distortion cost by 72%.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1090-1097
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• 2008

This study conducted the decision method of lateral flow in abutment structures founded on the soft soils and the reliability analysis on the foundation pile for abutment. On the basis of the results, this study proposed the reliability design model. Reliability analysis was conducted by applying second moment method, point estimation method, and expected total cost minimization to lateral movement index, lateral movement decision index, modified lateral movement decision index, and circular failure safety factor for the decision criteria of lateral flow. The reliability index by analysis method had a similar tendency each other. Point estimation method was found as a practical method in the aspect of convenience because it could conduct the analysis only by mean and standard deviation as well as the partial derivative on random variables was not necessary. Optimum reliability index and optimum safety according to increasing in failure factors and load ratio were analyzed and loads and resistance factors of the design criteria of optimum reliability were estimated. It presented rational design model which can consider construction level and stability and economical efficiency overall.