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11.
Relationships between characteristics of motorcycles and hydrocarbon emissions in Taiwan: A note 总被引:1,自引:0,他引:1
C.W. Lin Y.R. Chen S.J. Lu S.W. Cho K.S. Lin Y.C. Chiu X.Y. Tang 《Transportation Research Part D: Transport and Environment》2008,13(5):351-354
Taiwan’s inspection and maintenance (I/M) programs identifies high-emission motorcycles but, although these help reduce air pollution, they have been criticized for being cost-ineffective. This study examines the relationship between characteristics of motorcycles and hydrocarbon emissions in the Central Air Quality Basin of Taiwan. It is shown that engine size and type, age and manufacturer of a motorcycle significantly affect HC emissions. Larger-size engines emit smaller amounts of HCs; whereas older motorcycles emitted greater amounts. In addition, two-stroke-engine machines produced significantly higher HC emission levels than four-strokes. Variations in HC emissions testing are a result of various I/M testing locations and efficiency may be improved by modifying these. 相似文献
12.
Forng-Chen Chiu Wen-Chuan Tiao Jenhwa Guo 《Journal of Marine Science and Technology》2009,14(2):228-239
The present study focuses on the nonlinear behavior of pressure on the hull surface of a high-speed vessel in irregular waves,
particularly the pressure responses of alternately wet and dry areas near the waterline and on the bow zone. The vessel has
high deadrise angles that may be subject to slight impact and water pile-up effects. A series of experiments in regular and
irregular head waves were conducted, and the validity of applying Volterra modeling was investigated. In a previous article
using experimental data in regular waves, it was confirmed that the approximate third-order Volterra model adequately simulated
the variation of pressure responses in regular waves of different steepness up to a wave amplitude with a wavelength ratio
of 0.01, even for the highly nonlinear pressures acting on the abovementioned areas of the hull surface. In this article,
further validation for the second part of the study was obtained using experimental data in irregular waves. The frequency
response functions obtained from the previous study’s experimental data in regular waves were applied to the third-order Volterra
model by combining the input of irregular waves to simulate the responses in irregular waves of sea state five. Then, the
spectra and statistics were analyzed. For the motions, accelerations, and pressure responses in irregular waves (as well as
for the simulated time histories) variance spectra and statistics such as cumulative distributions of peak values and probability
density functions were compared with the experimental results. It was confirmed that even for highly nonlinear and non-Gaussian
pressures on the abovementioned areas of the hull surface, the approximate third-order Volterra model simulates the pressure
responses in irregular head waves up to a sea state of five with adequate accuracy on deterministic and statistical bases. 相似文献