• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1006-1011
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• 2003

In this study, a novel systematic design procedure by Genetic Algorithm of a two stage relief valve is proposed. First of all, a mathematical model describing the dynamics of a balanced piston type relief valve has been derived. Governing equations such as dynamic equations for the main spool and the pilot spool and flow equations for each orifice are established. The mathematical model is verified by comparing the results of simulation with that of experiments. Furthermore, influences of the parameters on the dynamic characteristics of a relief valve have been investigated by simulation of the proposed model. Major design parameters on the valve response are determined, which affect the system response significantly. And then, using the determined parameters, the optimization of the two stage relief valve by Genetic Algorithm, which is a random search algorithm can find the global optimum without converging local optimum, is performed. The optimal design process of a two stage relief valve is presented to determine the major design parameters. Fitness function reflects the changing pressure according to parameters. It is shown that the genetic algorithms satisfactorily optimized the major design parameters of the two stage relief valve.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.501-506
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• 2002

In this study, a novel systematic design procedure by Genetic Algorithm of a two stage relief valve is proposed. First of all. a mathematical model describing the dynamics of a balanced piston type relief valve has been derived. Governing equations such as dynamic equations for the main spool and the pilot spool and flow equations for each orifice are established. The mathematical model is verified by comparing the results of simulation with that of experiments. Furthermore, influences of the parameters on the dynamic characteristics of a relief valve have been investigated by simulation of the proposed model. Major design parameters on the valve response are determined, which affect the system response significantly. And then, using the determined parameters, the optimization of the two stage relief valve by Genetic Algorithm, which is a random search algorithm can find the global optimum without converging local optimum, is performed. The optimal design process of a two stage relief valve is presented to determine the major design parameters. Fitness function reflects the changing pressure according to parameters. It is shown that the genetic algorithms satisfactorily optimized the major design parameters of the two stage relief valve.

• IE interfaces
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• v.20 no.4
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• pp.469-478
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• 2007

Rail transportation terminals play an important role in inland transportation systems, because the operation productivity in the terminals significantly influences the efficiency of the whole transportation systems. This paper addresses a design method of a real rail terminal that satisfies a pre-specified throughput capacity. In order to construct high performance rail terminal, it is shown how design parameters can be estimated systematically. Examples of the design parameters are the number of transshipment tracks, the number of rail cranes, and the number of internal trucks. These design parameters are estimated by using simple equations and the validity of the values of these parameters are tested by using simulation. Furthermore, some iterative correction procedure, which uses the simulation technique and the equations alternately, are proposed.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.911-920
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• 2010

A closed-type erosion control dam were suggested as an effective method to protect from debris flow damages caused by seasonal rainstorm, typhoon, and local heavy rain. However, design method on a closed-type erosion control dam currently practiced in the engineering is not well established with respect to type of the dam, design parameters, maintenance and so forth. In this study, design parameters for closed-type erosion control dam were evaluated and the comparison of design parameters used in Korea and Japan was performed. Based on the results of this study, modification of design method for closed-type erosion control dam are recommended.

• Proceedings of the IEEK Conference
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• 2000.06a
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• pp.65-68
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• 2000

In this paper, design parameters are investigated and design procedure is established for PCS mobile station, especially for receiver RF block. And simulation environment to analyze parameters of the receiver RF block to determine whether it satisfies the receiver standard, IS-98C, is calculated. Design parameters are simulated and optimized. With simulated results, PCS mobile station is implemented and tested. Measured results show good agreement with simulation Design procedure can be used to get optimum characteristics for each of receiver block. By using optimum characteristics, mobile station can be designed more efficiently.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.8
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• pp.805-812
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• 1990

In this paper, a design on the superconducting monolith for superconducting pulse magnet is described. Both stability and AC loss parameters are used in the design process, which restricted various design parameters. Determined design parameters satisfy both stability and AC loss restrictions. Finally superconducting monolith is flattened, fitting for magnet and acquiring transposition effect.

• Journal of the Korea Convergence Society
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• v.12 no.9
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• pp.1-10
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• 2021

In the past, designers relied primarily on past experience and reference to industry standard thresholds to design spaces. Such design often results in spaces that do not meet the needs of users. The purpose of this paper is to investigate the process and way of generating design parameters by constructing a BP neural network algorithm for spatial design. From the perspective. This paper adopts an experimental research method to take a kindergarten with a large number of complex needs in space as the object of study, and through the BP neural network algorithm in machine learning, the correlation between environmental behavior parameters and spatial design parameters is imprinted. The way of generating spatial design parameters is studied. In the future, the corresponding spatial design parameters can be derived by replacing specific environmental behavior influence factors, which can be applied to a wider range of scenarios and improve the efficiency of designers.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.6
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• pp.799-806
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• 2004

This paper presents a scheme for finding an optimal combination of design parameters affecting on the handling performance of a large truck using design of experiments. The average of the sum of peak-to-peak roll angles at the first and second part of the double lane is used as an objective function for design of experiments. Six design parameters are selected from all possible parameters affecting on the handling performance. The table of orthogonal arrays is made by 27 times simulations. A computational model of a large truck is developed by MSC/NASTRAN and MSC/ADAMS, and verified the reliability of it with the results of vehicle tests performed in a double lane change course. It is used for the simulations. Analyses of variance and factor effect of the table of orthogonal arrays are performed. This paper proposes an optimal combination of those six design parameters for improving the handling performance of the large truck.

• Earthquakes and Structures
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• v.19 no.5
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• pp.395-409
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• 2020

With verifications through many relevant researches in the past few decades, adopting the equivalent lateral force procedure for designing seismically isolated structures as a preliminary or even final design approach has become considerably mature and publicly acceptable, especially for seismic isolation systems that mechanically exhibit bilinear hysteretic behavior. During the design procedure, in addition to a given seismic demand, structural designers still need to previously determine three parameters, such as mechanical properties of seismic isolation systems or design parameters and performance indices of seismically isolated structures. However, an arbitrary or improper selection of given parameters might cause diverse or even unacceptable design results, thus troubling structural designers very much. In this study, first, based on the criterion that at least either two design parameters or two performance indices of seismically isolated structures are decided previously, the rationality and applicability of design results obtained from different conditions are examined. Moreover, to consider variations of design parameters of seismically isolated structures attributed to uncertainties of mechanical properties of seismic isolation systems, one of the conditions is adopted to perform bounding analysis for seismic isolation design. The analysis results indicate that with a reasonable equivalent damping ratio designed, considering a specific variation for two design parameters (the effective stiffness and equivalent damping ratio) could present more conservative bounding design results (in terms of isolation displacement and acceleration transmissibility) than considering the same variation but for two mechanical properties (the characteristic strength and post-yield stiffness).

• Structural Engineering and Mechanics
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• v.50 no.5
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• pp.697-708
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• 2014

The intentional buckling design of micro-films has various potential applications in engineering. The buckling amplitude and critical strain of micro-films are the crucial parameters for the buckling design. In the reported studies, the film parameters were regarded as deterministic. However, the geometrical and physical parameters uncertainty of micro-films due to manufacturing becomes prominent and needs to be considered. In the present paper, the probabilistic nonlinear buckling analysis of micro-films with uncertain parameters is proposed for design accuracy and reliability. The nonlinear differential equation and its asymptotic solution for the buckling micro-film with nominal parameters are firstly established. The mean values, standard deviations and variation coefficients of the buckling amplitude and critical strain are calculated by using the probability densities of uncertain parameters such as the film span length, thickness, elastic modulus and compressive force, to reveal the effects of the film parameter uncertainty on the buckling deformation. The results obtained illustrate the probabilistic relation between buckling deformation and uncertain parameters, and are useful for accurate and reliable buckling design in terms of probability.