• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.06a
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• pp.501-505
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• 1998

In this paper, an LP problem with convex polyhedral objective coefficients is treated. In the problem, the interactivities of the uncertain objective coefficients are represented by a bounded convex polyhedron (a convex polytope). We develop a computation algorithm of a maxmin achievement rate solution. To solve the problem, first, we introduce the relaxation procedure. In the algorithm, a sub-problem, a bilevel programing problem, should be solved. To solve the sub-problem, we develop a solution method based on a branch and bound method. As a result, it is shown that the problem can be solved by the repetitional use of the simplex method.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.139-142
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• 1991

The design variables of SLIM used for 3-D conveyor system are optimized by nonlinear programing. Five design variables are selected as independent ones and object function is expressed as a combination of the weight and the normal force of the motor. Maximum flux density in the teeth, primary length and starting thrust are chosen as constraint functions. Goodness factor considering of conveying characteristic is also included in the constraints. In this paper sequential unconstrained minimization technique(SUMT) and variable metric method are used to solve the nonlinear problem.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.128-133
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• 2002

The main obstacle to high track density in HDD is the structural resonances of the suspension. The most critical mode is sway mode and second torsion mode, when a data is read and written. It is common fact that the effect of two modes is smaller when a thickness is bulky. But the stiffness of suspension is smaller, the slider can follow a disk better. Because these two fact are reciprocal, a compromise is needed. So we investigated another method to improve band width without changing of the thickness of suspension but with changing of the shape. In this paper, we use two method - Sensitivity analysis and SIP using ADS. And we obtained the optimized value close to target value.

• Korean Management Science Review
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• v.14 no.1
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• pp.1-10
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• 1997

We consider a problem of estimating the economics of scale for the natural gas industries. The goal programming/constrained regression is employed for estimating the economics of scale for the natural gas industry, and the problem is formulated as a linear programing problem. Also the translog cost function is used to represent the cost structure for the natural gas industry. The Korean Gas Corporation was selected as a case study, and we demonstrate that the suggested goal programming/constrained regression approach is appropriate for estimating the economies of scale for the Korean nature gas industry.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.172-174
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• 2002

This paper proposes a new methodology for adequacy evaluation of composite power system considering an ambiguity of overload of transmission lines. Nodal arrival powers under considering an ambiguity of overload of transmission lines can be evaluated using the proposed method. Fuzzy set theory has been used in order to consider the permission level of overload of transmission lines. The problem of adequacy evaluation has been formulated using fuzzy linear programing. The effectiveness of the proposed method considering permissible overload of transmission lines has been demonstrated on the IEEE RTS.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.272-277
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• 2001

In order to evaluate variation of fatigue data of the LP steam turbine blade steel, it is important to estimate P - S - N curves to accurately define the probability distributions. In this study, new procedure is introduced to determine the expression of P - S - N curves. For this purpose, 3-parameter Weibull distribution was found to be most appropriate among assumed distributions when the probability distributions of the fatigue life were examined by the proposed analysis. Furthermore, parameter estimation for P - S - N curves was performed using various optimization to maximize the correlation coefficient. As a result of this, sequential linear programing method is used for estimation of P - S - N curves.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1993.04a
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• pp.37-44
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• 1993

There are a lot of linear dynamic analysis methods for complex structures. Each method has advantages and shortcomings. Method of dynamic analysis for complex structure is selected considering characteristics of dynamic loading, computer facility available number of degree of freedem and accuracy of results. It is a main point of view to get economical results rather then accurate ones for analysis of general complex structures, Mode superposition method and direct integration method are generally used. However, the characteristics of load is not considered in mode superpositon method, the personal computer cannot be used in direct integration methods. To over-come these shortcomings, the component mode method incorporating Ritz algorithm updated is proposed to solve economically dynamic behavior of the structures. The purpose of study is a formulation of algorithm, and computer programing suitable for dynamic analysis of the complex structure in personal computer environment.

• ETRI Journal
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• v.38 no.5
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• pp.934-940
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• 2016

In this paper, secure multicasting with the help of cooperative decode-and-forward relays is considered for the case in which a source securely sends a common message to multiple destinations in the presence of a single eavesdropper. We show that the secrecy rate maximization problem in the secure multicasting scenario under an overall power constraint can be solved using semidefinite programing with semidefinite relaxation and a bisection technique. Further, a suboptimal approach using zero-forcing beamforming and linear programming based power allocation is also proposed. Numerical results illustrate the secrecy rates achieved by the proposed schemes under secure multicasting scenarios.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.04a
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• pp.284-291
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• 1999

The reliability analysis is of great importance in their design since offshore towers are high-cost and high-risk structures. The design of platforms in the marine environment depends on results of the dynamic behavior of the structure during earthquakes and storm wave conditions. this paper presents results of an analytical study on evaluating dynamic response of steel jacket modelled by space frame elements. program $\boxDr$OFSPC$\boxUl$for the linear and nonlinear dynamic analysis of steel jacket platform has been developed using FORTRAN 90 programing language through the present study. Free vibration and dynamic behavior of steel jackets under regular and irregular wave and earthquake force are investigated using this program

• The Transactions of the Korea Information Processing Society
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• v.4 no.10
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• pp.2571-2580
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• 1997

In this paper, we deal with the resource constrain scheduling to execute behavior algorithm under resource limit. Expecially, we proposed a scheduling algorithm, called delayed scheduling, which finds the lower bound control step to assign operation under resource limit. We take in account the actual scheduling problems including multicycle operation and functional pipelining. Integer Linear Programing formulations are used to the scheduling problems in order to get optimal scheduling result. Experiment was done on the DFG model of fifth-order digital wave filter, to show it's effectiveness.