• Environmental and Resource Economics Review
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• v.9 no.2
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• pp.393-420
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• 2000

Since the transportation taxes were imposed on gasoline and diesel in 1994 for the purpose of financing the special projects, such as the construction of highways or railroads, the rates have been frequently and rapidly changed in case of need to stabilize prices or secure public fund, contrary to its own purpose. This paper presents a theoretical model for a special purpose tax based on the minimization of the dead weight los incurred by the imposition of the tax. A computable static model for the tax rate is developed and estimated for a various range of target level of total tax rebenue. The results shows that, under tax revenue of 40 trillion won, the rates for the year of 1999 are 385.2 won for one liter of gasoline and 198.4 won for one liter of diesel. The estimated gasoline rate is no more than about 59% of the current rate. However, the rate for diesel turns out to be 24% higher than the current level.

• Journal of the Korean Society of Combustion
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• v.12 no.4
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• pp.57-61
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• 2007

The aim of this study is to find out the condition that generates maximum $H_2$ through the calculation of equilibrium model with conditions of pyrolysis gases of Refuse Plastic Fuel(RPF). This study deals with the computational simulation of a RPF gasification using an equilibrium model based on minimization of the Gibbs free energy. An equilibrium analysis was carried out to determine species composition of Syngas in RPF gasification and reactions to variation of temperature, $O_2/Fuel$ ratio and Steam/Fuel ratio. Calculated results shows that hydrocarbons in pyrolyzed gas are converted to synthesis gas which is formed on hydrogen and carbon monoxide.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.1
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• pp.111-117
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• 2007

This paper presents a new approach to evaluate reliability indices of electric distribution systems using genetic Algorithm (GA). The use of reliability evaluation is an important aspect of distribution system planning and operation to adjust the reliability level of each area. In this paper, the reliability model is based on the optimal load transforming problem to minimize load generated load point outage in each sub-section. This approach is one of the most difficult procedures and become combination problems. A new approach using GA was developed for this problem. GA is a general purpose optimization technique based on principles inspired from the biological evolution using metaphors of mechanisms such as natural selection, genetic recombination and survival of the fittest. Test results for the model system with 24 nodes 29 branches are reported in the paper.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.36 no.9
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• pp.660-669
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• 1987

Routh approximation method is the most computationally attractive. But this method may cause time-response error because this method does not match the time-response directly. In this paper a new mixed method for obtaining stable reduced-order models for high-order continuous-time systems is proposed. It makes use of the advantages of the Routh approximation method and the Minimization of Integral Squared Error(MISE) criterion approach. In this mixed method the characteristic polynomial of the reduced-order model is first obtained from that of original system by using the Auxiliary Denominator Polynomial(ADP). The numerator polynomial is then determined so as to minimize the intergral squared-error of unit step responses. The advantages of the propsed method are that the reduced models are always stable if the original system are stable and the frequency domain and time domain characteristic of the original system will be preserved in the reduced models.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.48
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• pp.113-122
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• 1998

In this paper we consider the CSP requirements determination problem of new equipment(machine) system. For the newly procured equipment systems, mathematical analyses are made for the system which is constructed with the consumable parts to derive the associated CSP requirement determination model in mathematical expression. Based on these analyses, a mathematical model is derived for making an optimal CSP requirement determination subject to tile constraint of satisfying any given operational availability limitation. We assume that the failure of a part follows a Poisson process. Firstly, the operational availability concept in CSP is defined and the relation between the general system availability and the operational availability is established. Secondly, the problem is formulated as the cost minimization problem that should satisfy the operational availability limitation, and then, using the generalized Lagrange multipliers method, the optimal solution procedure is derived.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.2
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• pp.211-217
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• 2010

This paper introduces the Hull Mounted Sonar Vertical Scanning(HMS Verscan) technique to overcome the limitation of target detection in short range shadow zone. Numerical experiments were done with the HMS Verscan taking advantage of the vertical beamforming technique for two-dimension hydrospace(range-depth). For numerical experiments, ray model and high-frequency monostatic reverberation model were used. HMS Verscan increased a sound pressure level at the short range shadow zone through reflections at the sea surface and seafloor. Inclusion of the boundary scattering improved target detection due to the sound reflected into the shadow zone.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.825-827
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• 1989

A heuristic model which determines the scheduling of serial flowshops with minimization of the makespan is proposed for an idealized batch chemical plant. It generates an initial sequence by heuristic reasoning and improves it recursively until no improvement is possible. The heuristic reasoning is based on Johnson's Rule which gives the sequence with the minimum makespan for a two-unit flowshop. The evolutionary step searches the neighborhood of the current sequence for sequences with lower makespan. The robustness of this model is also examined by comparing the minimum makespan of literature examples with the theoretical one.

• Management & Information Systems Review
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• v.13
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• pp.127-140
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• 2003

Although there have been continual researches in the project scheduling problems since 1960s, the main interest has been how to improve the efficiency of a single project. The minimization problem of the project completion time given a preassigned budget might be an example. This kind of the problem is important, but estimating of the proper budget for a project may also be very important. This research deals with the budget allocation problem for the multiple project. This research is unique in that the project scheduling techniques are used for the budgeting problem. Therefore, this research may be used as a strategic decision model for the multiple large projects in public sector.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.25 no.4
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• pp.40-45
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• 2002

An AS/RS construction cost minimization model under throughput rate requirement constraint has been developed, whose objective function includes S/R machine cost, storage rack cost, and interrace conveyor cost. S/R machine cost is a function of the storage rack height, the unit load weight, and the control logic used by the system, while storage rack cost is a function of the storage rack height, the weight and the volume of the unit load. Since the model is a nonlinear integer programming problem which is very hard to solve exactly with large problem size, a solution procedure is developed to determine the height and the length of the storage rack with a fixed number of S/R machines, while increasing the number of S/R machines one by one to meet the throughput rate requirement.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.23 no.59
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• pp.53-67
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• 2000

In this paper we consider the CSP requirements determination problem of new equipment(machine) system. For the newly procured equipment systems, mathematical analyses are made for the system which is constructed with the consumable parts and the repairable parts to derive the associated CSP requirement determination model in mathematical expression. Based on these analyses, a mathematical model Is derived for making an optimal CSP requirement determination subject to the constraint of satisfying any given operational availability limitation. We assume that the failure of a part follows a Poisson process and the repair time has an exponential distribution. Firstly, the operational availability concept in CSP is defined and the relation between the general system availability and the operational availability is established. Secondly, the problem is formulated as the cost minimization problem that should satisfy the operational availability limitation, and then, using the generalized Lagrange multipliers method, the optimal solution procedure Is derived.