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31.
A Bayesian approach is used to analyze the seismic events with magnitudes at least 4.7 on Taiwan. Following the idea proposed
by Ogata (1988,Journal of the American Statistical Association,83, 9–27), an epidemic model for the process of occurrence times given the observed magnitude values is considered, incorporated
with gamma prior distributions for the parameters in the model, while the hyper-parameters of the prior are essentially determined
by the seismic data in an earlier period. Bayesian inference is made on the conditional intensity function via Markov chain
Monte Carlo method. The results yield acceptable accuracies in predicting large earthquake events within short time periods. 相似文献
32.
Fan Chung 《Annals of Combinatorics》2005,9(1):1-19
We consider Laplacians for directed graphs and examine their eigenvalues. We introduce a notion of a circulation in a directed graph and its connection with the Rayleigh quotient. We then define a Cheeger constant and establish the Cheeger inequality for directed graphs. These relations can be used to deal with various problems that often arise in the study of non-reversible Markov chains including bounding the rate of convergence and deriving comparison theorems.Received September 8, 2004 相似文献
33.
Tunable microlens arrays using polymer network liquid crystal 总被引:1,自引:0,他引:1
A tunable-focus microlens array based on polymer network liquid crystal (PNLC) is demonstrated. The PNLC was prepared using an ultraviolet (UV) light exposure through a patterned photomask. The photocurable monomer in each of the UV exposed spot forms an inhomogeneous centro-symmetrical polymer network which acts as a lens when a homogeneous electric field is applied to the cell. The focal length of the microlens arrays is tunable with the applied voltage. 相似文献
34.
35.
Summary Vezetéknév 相似文献
36.
Through arylsulfonyl activation of thiourea, efficient synthesis of oligomeric guanidines can be achieved in either solution or solid-phase. Incorporation of TFA-sensitive arylsulfonyl groups, such as Pbf, during the synthesis greatly simplifies deprotection procedures for obtaining the final oligomeric guanidine products. 相似文献
37.
类锂硅离子软X射线激光研究 总被引:1,自引:0,他引:1
在激光等离子体典型参数条件下,利用碰撞-辐模型计算了类锂硅离子5f-3d和4f-3d跃的粒子数反转比率和激光增益系数。讨论了不同热带条件和不同冷却速度下,激光增益系统数的变化。计算结果表明,高功率,短脉冲激光生产的高温等离子体在快速冷却条件下能产生软X射的线激光增益。 相似文献
38.
39.
Cun Feng Fan David A. Waldman Shaw Ling Hsu 《Journal of Polymer Science.Polymer Physics》1991,29(2):235-246
Raman mechanical spectroscopy was used to examine interfacial effects on the stress distribution in model polydiacetylene fiber/epoxy composites. Epoxy release agents were coated on fiber surfaces to modify the interfacial adhesion properties. The modified fiber surfaces were then characterized by scanning electron microscopy and x-ray photoelectron spectroscopy as well as optical microscopy. No difference in the maximum stress value or stress distribution was observed for the two types of fibers, coated or uncoated, used in composites. This suggests that adhesion properties at the composite interface do not affect tensile stress transfer efficiency nor, therefore, the composite tensile modulus along the fiber axis direction in uniaxial composites. Experimental data were also compared with theoretical calculations assuming perfect bonding between fiber and matrix, and idealized frictional force transfer mechanism at the fiber–matrix interface. 相似文献
40.