• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.8 s.101
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• pp.897-903
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• 2005

When driving on uniformly tining concrete pavement road, the whine noise which has high spectrum at the specific frequency related to the uniform tining space exist. In this paper, a randomization method of tining space for concrete pavements is proposed to reduce the whine noise. The proposed method is developed based on the LCG(linear congruential generator) algorithm. The design parameters used in the method are number of different tining space, ratio of each tining space, total linings of each size. sequence of actual tining under given constant drag length and texture. Monte Carlo simulations are used to validate the proposed method.

• International Journal of Highway Engineering
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• v.7 no.4 s.26
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• pp.125-140
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• 2005

This study suggests a suitable random transverse tining for reduction tire/road noise from concrete pavement. Through literature reviews, random transverse tining that can disperse the energy concentrated to the specific frequency was suggested using the LCG(linear congruential generators) algorithm. The spacing of tining from this study is applied to Daegu-Pohang express highway. For the purpose oi comparison, two other random tining sections were included that are research products from Chung-Ang university and Wisconsin DOT. In result of pass-by noise measurement by car, though designed section is superior to the others as noise reduction by reducing pitch noise, the effectiveness is not large. In case of traffic noise measurement, lower noise was observed at random transverse tining sections than uniformly transverse tining section, too. But there are seine differences between pass-by noise and traffic noise.

• Journal of KIISE
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• v.42 no.12
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• pp.1467-1473
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• 2015

In this paper, we implemented a parallel random number generation program on GPU's, which are known for high performance computing, using LCG (Linear Congruential Generator). Random numbers are important in all fields requiring the use of randomness, and LCG is one of the most widely used methods for the generation of pseudo-random numbers. We explained the parallel program using the NVIDIA CUDA model and MPI(Message Passing Interface) and showed uniform distribution and performance results. We also used a Monte Carlo algorithm to calculate pi(${\pi}$) comparing the parallel random number generator with cuRAND, which is a CUDA library function, and showed that our program is much more efficient. Finally we compared performance results using multi-GPU's with those of ideal speedups.

• Proceedings of the KIPE Conference
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• 2004.11a
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• pp.90-95
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• 2004

본 연구에서는 일반적으로 사용되고 있는 랜덤 수 발생 알고리즘인 LCG(Linear Congruential Generator)대신에 카오스 2중 텐트사상(Tent Mapping)에 의한 저 스위칭 소음 유도모터구동 시스템을 제안하였다. 2중 텐트사상에 의한 랜덤 수 발생을 위해 카오스 발생 영역인 $\lambda=0.99$에서의 2중 텐트사상의 분기도(Bifurcation Diagram)를 사용하였다. 카오스 랜덤수와 3상 기준 정현파는 80C196 마이크로 콘트롤러가 전담하고 있으며, 80C196으로부터 발생된 카오스 랜덤 수에 의하여 MAX038로부터 랜덤 주파수의 삼각파 캐리어가 발생된다. 기계적인 소음이 없는 ECB(Eddy current Brake)를 부하로 사용한 3상 유도모터 구동 장치를 제작하여 본 연구의 타당성을 입증하였다.