• 한국소음진동공학회논문집
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• 제17권5호
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• pp.398-404
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• 2007

In this study, the sensitivity of annoyance was investigated by the subjective jury test for the variations of the frequency components along with various sound pressure levels of sixteen environmental noise sources. Annoyance was, also, evaluated for the road traffic noises. Sound pressure levels were $54{\sim}84\;dB$ which individually divided frequency components with eight bands of equally three bark bands. The results show that vehicle traffic noise is recognized as the most serious environment noise source. The sensitivity of human perception of annoyance in frequency bands is quite different from A-weighting curve. The annoyance found out to be more sensitive in high frequency region and reached its maximum in 3.4 kHz.

• International Journal of Automotive Technology
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• 제6권2호
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• pp.141-148
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• 2005

In order to reduce the time and costs of improving the performance of vehicle suspensions, the techniques for optimizing damping and air spring characteristic were proposed. A full vehicle model for a bus is constructed with a car body, front and rear suspension linkages, air springs, dampers, tires, and a steering system. An air spring and a damper are modeled with nonlinear characteristics using experimental data and a curve fitting technique. The objective function for ride quality is WRMS (Weighted RMS) of the power spectral density of the vertical acceleration at the driver's seat, middle seat and rear seat. The objective function for handling performance is the RMS (Root Mean Squares) of the roll angle, roll rate, yaw rate, and lateral acceleration at the center of gravity of a body during a lane change. The design variables are determined by damping coefficients, damping exponents and curve fitting parameters of air spring characteristic curves. The Taguchi method is used in order to investigate sensitivity of design variables. Since ride and handling performances are mutually conflicting characteristics, the validity of the developed optimum design procedure is demonstrated by comparing the trends of ride and handling performance indices with respect to the ratio of weighting factors. The global criterion method is proposed to obtain the solution of multi-objective optimization problem.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 B
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• pp.574-577
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• 1995

The proposed method is described for scheduling their output of thermal power units so as to comply with total emission constraint, area emission constraint and the both of those constraints. Also, by using a trade-off curve, representing all dispatch alternatives and conflict between the emission and the fuel cost, the sensitivity analysis of the emission and the fuel cost is applied to this algorithm. By the way, this proposed method is analyzed how dispatch changes as a function of the total environmental cost, and as a function of the relative weighting of individual environmental insults, e.g, NOx and $SO_{2}$. By applying the proposed method to the system, the usefulness of this method is verified.

• 한국철도학회논문집
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• 제6권2호
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• pp.114-121
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• 2003

In this paper, a new evaluation system was developed for ride comfort test and vibration level test on railway vehicles. These tests are carried out by applying different equipments and test procedures before now. But this developed system is capable of ride comfort test and vibration test by a single integrated system. Also, the evaluation algorithm for the ride comfort was compared and verified by simulation results with VAMPIRE software. With this developed system, the comfort in a passenger coach and the vibration in a freight car were verified by the results in field test.

• 에너지공학
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• 제6권2호
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• pp.129-136
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• 1997

본 연구는 전력계통의 화력발전소로부터 배출되는 NOx및 SO$_2$같은 대기환경오염물질을 고려한 새로운 경제부하배분법을 제시한다. 제안된 방법은 총배출량 제약, 지역별 배출랑 제약 그리고 이들의 동시제약을 만족하면서 화력발전기의 출력을 계획하는 것에 대해 설명되어진다. 또한, 모든 부하배분의 대체안이며 배출량과 총연료비 사이의 상호상충관계를 나타내는 Trade-Off곡선에 의해 배출량과 총연료비 사이의 감도해석이 이 알고리즘에 적용된다. 한편, 이 제안된 방법은 개별적 환경피해(NOx, SO$_2$등)의 상대적 가중치와 총환경비용의 함수로써 경제부하배분이 이것에 의해 어떻게 변화되는지를 해석한다. 본 연구에서 제안된 방법을 시험계통에 적용하여 그 유용성을 검증하였다.