• The Transactions of the Korean Institute of Electrical Engineers
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• v.32 no.2
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• pp.33-42
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• 1983

Outage cost inclusion in operational simulation is very important subject in generation planning. Conventional discretized one in probabilistic simulation has unavoidably insufficient modeling and costly computation time. Now that the analytic operational simulation is possible, the outage cost inclusion is desired. With this inclusion the objective function of operational simulation becomes convex, so that analytic manipulation is easier. The derivation of outage cost is made in this paper, and the effects is evaluated. Further marginal cost is mentioned.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.3
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• pp.299-312
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• 2016

The main objective of this paper is to develop computer simulation program for performance evaluation and cost estimation of a reverse osmosis (RO) and pressure-retarded osmosis (PRO) hybrid process to propose guidelines for its economic competitiveness use in the field. A solution-diffusion model modified with film theory and a simple cost model was applied to the simulation program. Using the simulation program, the effects of various factors, including the Operating conditions, membrane properties, and cost parameters on the RO and RO-PRO hybrid process performance and cost were examined. The simulation results showed that the RO-PRO hybrid process can be economically competitive with the RO process when electricity cost is more than 0.2 $/kWh, the PRO membrane cost is same as RO membrane cost, the power density is more than $8W/m^2$ and PRO recovery is same as 1/(1-RO recovery).

• Journal of the Korea Safety Management & Science
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• v.3 no.3
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• pp.221-230
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• 2001

The assembly tolerance design methods have applied linear or nonlinear programming methods and used simulation method and search algorithms to optimize the tolerance allocation of each part in an assembly. However, those methods are only considered to the relationship between tolerance and manufacturing cost, which do not consider a quality loss cost for each part tolerance. In this paper, the integrated simulation model used genetic algorithm and the Monte-Carlo simulation method was developed for the allocation of the optimal tolerance considering the manufacturing cost and quality loss cost.

• The Journal of Fisheries Business Administration
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• v.47 no.4
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• pp.1-13
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• 2016

Fish mortality is the most important success factor in aquaculture management. To analyze the effect of mortality considering biological and economic condition is a important problem in land-based aquaculture. This study is aimed to analyze the effect of mortality for duration of cultivation in land-based aquaculture. This study builds the mathematical model that finds the value of decision variable to minimize cost that sums up the water pool usage cost, sorting cost, fingerling cost and feeding cost under critical standing corp constraint. The proposed mathematical model involves many aspects, both biological and economical: (1) number of fingerlings (2) timing and number of batch splitting event, based on (3) fish growth rate, (4) mortality, and (5) several farming expense. Numerical simulation model presented here in. The objective of numerical simulation is to provide for decision makers to analyse and comprehend the proposed model. When extensive biological and cost data become available, the proposed model can be widely applied to yield more accurate results.

• Journal of the Korea Society for Simulation
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• v.3 no.1
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• pp.99-105
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• 1994

Most of the companies are forced to cut down the manufacturing cost to survive in the competitive environment. Among others, material distribution cost alone takes substantial portion of the total manufacturing cost. In this study, we investigate the waiting phenomenon in the toll gate and propose a new toll booth layout to reduce the waiting time, thereby reduce the total material distribution cost. SIMAN, a simulation language, is employed to evaluate the proposed layout. The experimental results show that the layout reduces the waiting time significantly. Furthermore, the result indicates that determination of the intermediate buffer space affects the performance of the proposed layout.

• Proceedings of the KIEE Conference
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• 2006.11a
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• pp.275-278
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• 2006

This paper describes a probabilistic annual congestion cost assessment of a grid at a composite power system derived from a model. This probabilistic congestion cost assessment simulation model includes capacity limitation and uncertainties of the generators and transmission lines. In this paper, the proposed probabilistic congestion cost assessment model is focused on an annualized simulation methodology for solving long-term grid expansion planning issues. It emphasizes the questions of "how should the uncertainties of system elements (generators, lines and transformers, etc.) be considered for annual congestion cost assessment from the macro economic view point"? This simulation methodology comes essentially from a probabilistic production cost simulation model of composite power systems. This type of model comes from a nodal equivalent load duration curve based on a new effective load model at load points. The characteristics and effectiveness of this new simulation model are illustrated by several case studies of a test system.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.4
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• pp.211-218
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• 2012

We analyzed the effect of inventory pooling on the system where multiple depot was used to replenish retailers and where inventories are kept only on the depots. Inventory pooling consists of inventory integration and inventory exchange. We used simulation for checking the cost saving effect of reducing the number of depot (Inventory Integration) for the case when inventories kept on every depots are commonly used for all retailers when certain depot have stock out for their retailer assigned to them (Inventory Exchange) with the constraint of service level. Simulation on wide range of parameter settings results show that cost saving effect from inventory integration diminishes when transportation cost between depot and retailers or stock out cost, or retailer number increases. The effect becomes stronger when the demands on retailers have bigger variance or average. Also the results show that the cost saving effect from inventory exchange becomes stronger on the same situation when inventory integration effect becomes stronger.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.26 no.4
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• pp.56-62
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• 2003

Recently, in order to stay at predominance in the global infinity competition, most of companies have been reducing the cost in many fields of industry First of all, the reduction of the logistics cost have been recognized greatly as the company value rises. But, the current situation of domestic logistics cost is very weak compared with Japan, U.S.A., etc. A rate of logistics cost out of GDP is still high compared with the competitors. The reduction of the transportation cost from overall logistics cost is most urgent subject. One of the methods to make a domestic transportation system efficient is the consolidation. In this paper. we try to compare the consolidated transportation model for a cost reduction with individual case. We also analyze the efficiency of consolidated transportation using simulation program with Arena of System Modeling Company.

• Korean Journal of Agricultural Science
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• v.37 no.2
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• pp.245-248
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• 2010

This study was conducted to investigate effect of changes in target fat and protein contents in milk on feed cost using a simulation modeling approach based on the 2001 dairy NRC. Two simulations were done; simulation I had a limitation (up to 20%), but simulation II had no limitation for the use of cottonseed hull in a diet. Using commonly used feed ingredients in Korea, we formulated least cost diets that meet nutrient requirement of a lactating dairy cow producing 36 kg of milk with combinations of 0.1% decrease or 0.1% increase in target milk fat or protein, respectively, from the national average milk fat (4.0%) and milk protein (3.1%). The contents of alfalfa and corn in a least-cost diet were decreased and those of tall fescue, whole cottonseed and rapeseed meal were increased with decreasing fat and/or increasing protein in milk. Scenarios that decreased target milk fat percentage from 4.0% to 3.9% reduced feed cost by 2 won per kg. Due to decrease in feed intake, daily feed cost was even more reduced (136 won per head) by decreasing target milk fat percentage. Increase in target milk protein percentage from 3.1% to 3.2% reduced feed cost by 6 won per kg. Among scenarios simulated, the least feed cost was obtained in scenario aimed for 3.9% fat and 3.2% of protein in milk. We conclude that a feeding practice for increasing milk protein percentage does not directly increase feed cost. In addition, feeding practices that increase protein content in milk is expected to improve economic life-span and reproductive performance of dairy cows.

• Journal of the Korea Society for Simulation
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• v.29 no.4
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• pp.85-94
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• 2020

In determining the feasibility of planning and launching railway transportation projects, various decision-making processes are essentially required. LCC(Life Cycle Cost) value including total construction cost and operation cost is estimated in approximation Model with rough guideline. In this study, modeling and simulation-based analysis method is proposed to support the decision making process of railroad transportation and derivation of LCC. Firstly, cost analysis model was constructed by collecting various existing rail transportation business data to enable analyze based on numerical data, and the result were analyzed by DOE(Design Of Experiments) and RSM (Response Surface Method) simulation. Professional commercial software tools were used for effective model construction and simulation. In order to verify the research results, the actual railroad transportation projects were selected, and the results of the analysis were compared.