排序方式： 共有140条查询结果，搜索用时 31 毫秒
31.
董晓红 《包头职业技术学院学报》2012,(1):89-91
常微分方程在自然科学和工程技术中有着广泛的应用,对于理工科院校来说,微分方程在电气工程等专业的应用尤其广泛,因此,由实际问题列出微分方程后,其解法非常关键。常微分方程的求解方法种类很多,以同一例题为例,比较常微分方程的不同解法,对比其优缺点,找出学生易于理解的方法。 相似文献
32.
梁岗 《上海海事大学学报》2000,21(4):73-79
根据实际工程中出现的一些问题 ,提出了粘弹性时变力学的分析方法 ,建立了粘弹性时变力学问题的基本方程 ;并依据此方程求得了一个时变力学问题———自重作用下矩形平面向上增长粘弹性时变力学解 相似文献
33.
本文考虑了一类具有时间相依索赔的风险模型,模型中包含了2种索赔：主索赔和由它引起的副索赔,并且副索赔可能推迟发生．利用Laplace变换方法,得到了该风险模型破产概率的计算公式,并在索赔额为指数分布的情形下,得到了破产概率所满足的微分方程,给出了破产概率的精确表达式． 相似文献
34.
讨论了一种时间分数阶扩散方程的初边值问题。首先利用分离变量法求出了方程的解,然后借助于拉普拉斯变换讨论了方程的强解、连续性和正则性等性质。 相似文献
35.
Marginal likelihood-based methods are commonly used in factor analysis for ordinal data. To obtain the maximum marginal likelihood estimator, the full information maximum likelihood (FIML) estimator uses the (adaptive) Gauss–Hermite quadrature or stochastic approximation. However, the computational burden increases rapidly as the number of factors increases, which renders FIML impractical for large factor models. Another limitation of the marginal likelihood-based approach is that it does not allow inference on the factors. In this study, we propose a hierarchical likelihood approach using the Laplace approximation that remains computationally efficient in large models. We also proposed confidence intervals for factors, which maintains the level of confidence as the sample size increases. The simulation study shows that the proposed approach generally works well. 相似文献
36.
37.
在经典完全离散风险模型的基础上研究了多险种的风险模型,推广了传统的经典模型,讨论了几个和破产时刻有关的随机变量,通过拉普拉斯变换的方法,得到了终极破产概率的递推表达式和显式表达式. 相似文献
38.
The variation of effective stress ratio of stratfied soil with semi-pervious boundaries and under cyclic loading was analyzed
on the basis of Terzagh's one-dimensional consolidation assumptions. A solution by Laplace Transform was obtained for the
case when the soil was under time-varied loading. With numerical inversion of Laplace Transform, some useful results were
obtained for several kinds of commonly encountered loadings. The results can be meaningful in engineering practice.
Project supported by the National Natural Science Foundation of China (No. 59908012) and Fok Ying Tung Education Fundation
(No. 81067), Education Ministry of China. 相似文献
39.
利用Bramble—Hilbert—Xu引理对Laplace特征值用一个非协调元作对称展开，给出该单元在研究Laplace特征值问题时的误差主项，并进一步给出外推结果，最后给出数值验证。 相似文献
40.
A new asymmetric watermarking scheme is proposed in this letter. In the proposed scheme, a secret real fractional DCT-I transform and a primitive watermark are employed to generate an asymmetric watermark. The secret watermark for embedding is derived from the primitive watermark, and is embedded in the large fractional DCT-I transformation coefficients of a cover signal. The asymmetric detection procedure is performed using a correlation test. Simulation results showed that the asymmetric detection is reliable, and that the scheme can provide minimum security. 相似文献