• Journal of Korean Society of Industrial and Systems Engineering
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• v.23 no.55
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• pp.1-11
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• 2000

Taguchi's robust design methodology has focus only a single characteristic or response, but the quality of most products is seldom defined by a characteristics, and is rather the composite of a family of characteristics which are often interrelated and nearly always measured in a variety of units. The multiple characteristics problem is how to compromise the conflicts among the selected levels of the design parameters for each individual characteristic. In this paper, Methodology using SN ratio optimized by univariate technique is proposed and a parameter design procedure to achieve the optimal compromise among several different response variables is developed. Also, We propose a decision model to incorporates the values assigned by a group of experts on different factors in weighting decision. Using this model, SN ratio of taguchi method for each of subjective factors as well as values of weights are used in this comprehensive method for weighting decision.

• Journal of Veterinary Clinics
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• v.17 no.2
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• pp.311-315
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• 2000

Recombinant interleukin-2 (IL-2) has been demonstated as an antineoplastic agent in mice and human, and the route of administration is important to IL-2-induced therapeutic responses. Therefore, the current experiment was undertaken to clarify the effect of IL-2 administration route on antitumor response against subcutaneous Meth-A tumor in mice. At the beginning of each experiment, normal BALB/c mice were injected subcutaneously with $5{\times}10^6$ Meth-A tumor cells. Beginning on day 7, experimental groups were treated with a 5-day course of IL-2 (intraperitoneal or subcutaneous injection of 30, 000 IU every 12 hours for 5 days). The result of this experiment revealed that Meth-A tumor grew progressively in control mice. Intraperitoneal IL-2 treatment decreased significantly tumor growth and prolonged survival, compared with control mice. Subcutaneous IL-2 treatment decreased significantly tumor growth until day 11 and tumor cells, grew progressively thereafter, but mice in this group survived longer than control mice.

• Journal of the Korea Society for Simulation
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• v.9 no.4
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• pp.67-75
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• 2000

Often system analysts are interested in the estimation of percentile for system performance. For instance, in PERT network system, the percentile that the project. Typically the control variate method is used to reduce the variability of mean response using the correlation between the response and the control variates with a little additional cost during the course of simulation. In the same spirit, we apply this method to estimate the percentile of project completion time in PERT system, and evaluate the efficiency of the controlled estimator for its percentile.1 Simulation results indicate that the controlled estimators are more effective in reducing the variances of estimators than the simple estimators, however those tend to a little underestimate the percentiles for some critical values. We need more simulation experiments to examine such a kind of bias problem. We expect this research presents a step forward in the area of variance reduction techniques of stochastic simulation.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10b
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• pp.1273-1278
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• 2000

Bridge load rating calculations provide a basis for determining the safe load capacity of bridge. Load rating requires engineering judgement in determining a rating value that is applicable to maintaining the safe use of the bridge and arriving at posting and permit decisions. Load testing is an effective means in calculating the rating value of bridge. In Korea, load carrying capacity of bridge is modified by stress modification factor that is determined from comparisons of measured values and analysis results The stress modification factor may be corrupted by vehicle location error that is defined as the gap of test vehicle location between load testing and analysis. In this study, the effects of vehicle location error to structural response and stress modification factor are investigated, and a new method for evaluating stress modification factor is proposed. The random data analysis shows that the proposed method is less sensitive to vehicle location error than the present method.

• Journal of the Korea Institute of Military Science and Technology
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• v.3 no.2
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• pp.121-130
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• 2000

A practical method is proposed to improve hit probability of the digital gun fire control system, when the measured rate of the tracking sensor becomes biased under some operational situation. For ground moving target it is shown that the well-known Kalman filter which uses position measurement only can be optimally used to eliminate the rate bias error. On the other hand, for 3D moving aircraft we present a new algorithm which incorporate FIR-type filter, which uses position and rate measurement at the same time, and the fixed-lag smoother using position measurement only, and show that it has the optimal performance in terms of both estimation accuracy and response time.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.723-725
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• 2000

This paper presents a parameter identification method to estimate the stator resistance. stator inductance, rotor resistance and rotor inductance of the induction motor. A step voltage is applied across the stator terminals while the machine is in the standstill condition, and the resulting stator voltage and current response are measured. Observer/Kalman Filter Identification(OKID) algorithm is used to estimate induction motor parameters. Simulation results are presented to verify the identified model.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.997-999
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• 2000

BLDC Motor has many advantages for control. This paper presents to perform constant speed against disturbance during operation. BLDC motor control used I-P algorithm to have fast response, reliable stability and robust response. In this paper I-P algorithm applied to 50W BLDC Motor According to results, I-P algorithm characteristics is confirmed.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.647-649
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• 2000

This paper presents a optimization procedure by using Response Surface Methodology(RSM) to determine design Parameters for reducing cogging torque in BLDC motor of Electric Power Steering (EPS). RSM is achieved through using the experiment design method in combination with Finite Element Method and well adapted to make analytical model for a complex problem considering a lot of interaction of these parameters. Moreover, Sequential Quadratic Problem (SQP) method is used to solve the resulting of constrained nonlinear optimization problem.

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.1143-1146
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• 1998

Static excitation systems with high gain and fast response times greatly aid transient stability. but at the same time tend to reduce small signal stability. The objective of the power system stabilizer(PSS) control is to provide a positive contribution to damping of the generator rotor angle swings, which are in a broad range of frequencies in the power system. Therefore, this paper shows the field test results for the GE's EX2000 PSS tuning on units at Seo-Incheon power plant. The test is to verify that the PSS response meets GE's design, criteria. The responses of generator terminal voltage, active power, field voltage and current were analyzed and PSS gain was tuned by 10 finally.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.792-794
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• 2000

This paper describes the design and the analysis of electromagnetic system of Magnetic Switch using 2D parametric finite element method(EM-Pulse). Magnetic Switch is electrical equipment, which is widely used for switching on/off motors in industrial field. The transient state is simulated in order to calculate the response time of Magnetic Switch. The simulation is based upon a step-by-step integration of the electric circuit equations and the core movement. The contactor uses a permanent magnet for maintaining the closed state. The presented solution takes account of non-linear magnetic material property and spring force controlled by core position. The dynamic response of Magnetic Switch predicted by the simulation agrees closely with the required condition.