• Journal of Korean Society of Industrial and Systems Engineering
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• v.28 no.4
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• pp.85-93
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• 2005

This paper is designed a VSI ${\overline{X}}$-CRL synthetic control chart in aspect of economy. We found the optimal sampling interval and various control limit factors under various cost parameters using cost function, proposed Lorenzen and Vance. Optimal design parameters include the sample size, control limit width, sampling interval, CRL/S chart control limit; L. Comparison and analysis of cost parameters are applied between synthetic VSI ${\overline{X}}$-CRL chart and FSI ${\overline{X}}$-CRL chart. The result of this paper shows that VSI ${\overline{X}}$-CRL chart brings cost-cutting effect of 3.04% control expense less than FSI control chart. It may not be difficult to establish the optimal economic control parameters to apply the practical cost parameters in the field.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.10a
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• pp.150-153
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• 2001

The present work concerns optimal design for the injection molding process of a deflection yoke (coil separator). The optimal design for the injection molding process is developed using design of experiments and finite element analysis. Two design of experiments approaches are applied such as: the design of experiment for mold design and the design the experiments for determination of process parameters. Finite element analyses have been carried out as a design of experiments for mold design: runner system and cooling channel. In order to determine optimal process experiments have been performed for various process conditions with the design of experiments scheduling.

• Smart Structures and Systems
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• v.13 no.3
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• pp.473-500
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• 2014

Tuned mass dampers (TMDs) have been installed in many high-rise buildings, to improve their resiliency under dynamic loads. However, high-rise buildings may experience natural frequency changes under ambient temperature fluctuations, extreme wind loads and relative humidity variations. This makes the design of a TMD challenging and may lead to a detuned scenario, which can reduce significantly the performance. To alleviate this problem, the current paper presents a proposed approach for the design of a robust and efficient TMD. The approach accounts for the uncertain natural frequency, the optimization objective and the input excitation. The study shows that robust design parameters can be different from the optimal parameters. Nevertheless, predetermined optimal parameters are useful to attain design robustness. A case study of a high-rise building is executed. The TMD designed with the proposed approach showed its robustness and effectiveness in reducing the responses of high-rise buildings under multidirectional wind. The case study represents an engineered design that is instructive. The results show that shear buildings may be controlled with less effort than cantilever buildings. Structural control performance in high-rise buildings may depend on the shape of the building, hence the flow patterns, as well as the wind direction angle. To further increase the performance of the robust TMD in one lateral direction, active control using LQG and fuzzy logic controllers was carried out. The performance of the controllers is remarkable in enhancing the response reduction. In addition, the fuzzy logic controller may be more robust than the LQG controller.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2001.06a
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• pp.257-262
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• 2001

A numerical analysis is undertaken to show tile influence of bearing design parameters on tile load capacity of air lubricated spiral grooved thrust bearing. The governing equation derived from the mass balance is solved by the finite difference method. Optimal values for various design parameters are obtained to maximize the load capacity. The design parameters are the groove angle, the groove width ratio, the groove height ratio, arid the seal ratio.

• The Journal of the Acoustical Society of Korea
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• v.20 no.2E
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• pp.51-58
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• 2001

Equations of motion of an engine mount system including foundation flexibility are derived. Forced vibration analysis is carried out for the given engine mount system excited with the unbalanced force and moment. A new optimal design method for the engine mount system is proposed, in which vibration characteristics of the chassis frame structure are considered as design parameters.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.46.4-46
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• 2002

This study was motivated how it might be possible to validate structured sampling with orthogonal array for optimal design of a pin. The Taguchi method by orthogonal array, one of the structured sampling methods, has much advantage that is row cost and time saving for experiments. But this method has been applied in limited areas especially for mechanical problems. In this study, we experimented whether the structured sampling is useful for applying optimal design of mechanical elements. For the experiment, we first set up a mechanical problem which was related to determining optimal parameters associated a pin's crack occurred inside a hole. We, then, calculated combination of...

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.7
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• pp.369-373
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• 2006

In this paper, an optimal method for determining design parameters of a Switched Reluctance Motor is researched. The dominant design parameters are stator and rotor pole arc and switching on and off angle. The parameters affecting performance are examined and selected using evolutionary computations and commercial CAD program. The simulated design method is compared with conventional procedure.

• Computational Structural Engineering
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• v.10 no.2
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• pp.233-242
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• 1997

The main purpose of this paper is to investigate the dynamic optimal design of continuous beams. The computer-aided optimization technique is used to obtain the near-optimal parameters of continuous beam. The computer program is developed to obtain the natural frequency parameters and the forced vibration responses to a transit point load for the continuous beam with variable support spacing, mass and stiffness. The model test data is in good agreement with the computer calculation, which serves to validate the mathematical analysis. The optimization function to describe the design efficiency is defined as a linear combination of four dimensionless span characteristics; the maximum dynamic stress; the stress difference between span segments; the rms deflection under the transit point load; and the total span mass. Studies of three span beams show that the beam with near-optimal parameters can improve design efficiency when compared to a uniform beam with even spacing of the same total span length.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1508-1511
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• 1997

In this paper, design parameters of Rapid Thermal Processing(RrW) to minimize the wafer tempera ture uniformity errors are proposed. 1,anip ling positions and the wafer height are important parameters for waf er temperature uniformity in R'I'P. We propose the method to seek lamp ling positions and the wafer height for optimal temperature uniformity. l'he ~~roposed method is applied to seek optimal lamp ling positions and the waf er height of 8 inch wafer. 'I'o seek the optimal lamp ling positions and the wafer height, we var\ulcorner. lamp ling 110s itions and the wafer height and then formulate the wafer temperature uniformity problem to the linear programmi ng problem. Finally, it is shown that the wafer temperature uniformity in RI'I' designed by optimal prarneters is improved to comparing with Ii'l'P designed by the other method.

• International Journal of Korean Welding Society
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• v.3 no.2
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• pp.15-23
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• 2003

A genetic algorithm was applied to an arc welding process to determine near optimal settings of welding process parameters which produce good weld quality. This method searches for optimal settings of welding parameters through systematic experiments without a model between input and output variables. It has an advantage of being able to find optimal conditions with a fewer number of experiments than conventional full factorial design. A genetic algorithm was applied to optimization of weld bead geometry. In the optimization problem, the input variables were wire feed rate, welding voltage, and welding speed, root opening and the output variables were bead height, bead width, penetration and back bead width. The number of level for each input variable is 8, 16, 8 and 3, respectively. Therefore, according to the conventional full factorial design, in order to find the optimal welding conditions, 3,072 experiments must be performed. The genetic algorithm, however, found the near optimal welding conditions from less than 48 experiments.