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991.
李明哲 《哈尔滨理工大学学报》2003,8(5):13-15
根据图的直径大小,通过对图H联系数集的分析,证明了顶点数u≤7的A(H)=3图是惟一的,即肯定了满足A(H)=3最小图的惟一性. 相似文献
992.
Optimum selection of cutting conditions importantly contribute to the increase of productivity and the reduction of costs, therefore utmost attention is paid to this problem in this contribution. In this paper, a neural network-based approach to complex optimization of cutting parameters is proposed. It describes the multi-objective technique of optimization of cutting conditions by means of the neural networks taking into consideration the technological, economic and organizational limitations. To reach higher precision of the predicted results, a neural optimization algorithm is developed and presented to ensure simple, fast and efficient optimization of all important turning parameters. The approach is suitable for fast determination of optimum cutting parameters during machining, where there is not enough time for deep analysis. To demonstrate the procedure and performance of the neural network approach, an illustrative example is discussed in detail. 相似文献
993.
Erwei BAI 《控制理论与应用(英文版)》2003,1(1):17-27
The least trimmed squares estimator (LTS) is a well known robust estimator in terms of protecting the estimate from the outliers. Its high computational complexity is however a problem in practice. We show that the LTS estimate can be obtained by a simple algorithm with the complexity O( N In N) for large N, where N is the number of measurements. We also show that though the LTS is robust in terms of the outliers, it is sensitive to the inliers. The concept of the inliers is introduced. Moreover, the Generalized Least Trimmed Squares estimator (GLTS) together with its solution are presented that reduces the effect of both the outliers and the inliers. 相似文献
994.
In this paper, the problem of robust matrix root‐clustering is addressed. The studied matrices are subject to both polytopic and unstructured uncertainties. An original point is the large choice of clustering regions enabled by the proposed approach since these regions can be unions of possibly disjoint and non‐symmetric subregions of the complex plane. The precise purpose is, considering a specified polytope, to determine the greatest robustness bound on the unstructured uncertainty such that robust matrix root‐clustering is ensured. To reduce conservatism in the derivation of the bound, the reasoning relies on a framework based upon parameter‐dependent Lyapunov functions. The bound value is computed by solving an ?? ?? ? problem. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
995.
L Jarlan P MazzegaE Mougin F LavenuG Marty P.L FrisonP Hiernaux 《Remote sensing of environment》2003,87(1):72-84
The West African Sahel rainfall regime is known for its spatio-temporal variability at different scales which has a strong impact on vegetation development. This study presents results of the combined use of a simple water balance model, a radiative transfer model and ERS scatterometer data to produce map of vegetation biomass and thus vegetation cover at a spatial resolution of 25 km. The backscattering coefficient measured by spaceborne wind scatterometers over Sahel shows a marked seasonality linked to the drastic changes of both soil and vegetation dielectric properties associated to the alternating dry and wet seasons. For lack of a direct observation, METEOSAT rainfall estimates are used to calculate temporal series of soil moisture with the help of a water balance model. This a priori information is used as input of the radiative transfer model that simulates the interaction between the radar wave and the surface components (soil and vegetation). Then, an inversion algorithm is applied to retrieve vegetation aerial mass from the ERS scatterometer data. Because of the nonlinear feature of the inverse problem to be solved, the inversion is performed using a global stochastic nonlinear inversion method. A good agreement is obtained between the inverse solutions and independent field measurements with mean and standard deviation of −54 and 130 kg of dry matter by hectare (kg DM/ha), respectively. The algorithm is then applied to a 350,000 km2 area including the Malian Gourma and Seno region and a Sahelian part of Burkina Faso during two contrasted seasons (1999 and 2000). At the considered resolution, the obtained herbaceous mass maps show a global qualitative consistency (r2=0.71) with NDVI images acquired by the VEGETATION instrument. 相似文献
996.
997.
研究了一类分布参数系统在有限维输出反馈下的指数能稳性,用构造有限维观测输出反馈控制器的方法,得到这一类系统反馈指数能稳的充分条件. 相似文献
998.
基于WEB的远程可视化并行计算化学系统 总被引:2,自引:3,他引:2
以PC Linux并行计算系统为支撑,研制了基于Web方式的可视远程计算化学系统RVCCS。此系统使用Web技术替代传统Telnet方式的远程计算模式,在Web界面中实现了作业提交、作业后台运行、作业状态实时查看、计算结果图示化、分子结构三维化等功能,提供了一种简单易用的远程可视计算方式。使用此系统建立的Web方式远程计算化学站点GHPCC(http://www.ghpcc.gzu.edu.cn)自1998年为国内用户提供计算服务以来,接受了各高校和科研单位化学工作者提交的上万次远程计算,为化学工作者提供了一个分子模拟和化学计算的有力工具。 相似文献
999.
计量单位是一种国际性的通用语言。本文列举了化工计算中常用的计量单位,针对化工计算中不同制度间计量单位换算的需求,利用Borland C Builder5.0开发了计量单位换算软件-UltraConverter。软件具有操作简,便、界面友好、功能强大等优点。实践证明,可以广泛应用于各领域。 相似文献
1000.
This paper presents a homotopy-based algorithm for the recovery of depth cues in the spatial domain. The algorithm specifically deals with defocus blur and spatial shifts, that is 2D motion, stereo disparities and/or zooming disparities. These cues are estimated from two images of the same scene acquired by a camera evolving in time and/or space. We show that they can be simultaneously computed by resolving a system of equations using a homotopy method. The proposed algorithm is tested using synthetic and real images. The results confirm that the use of a homotopy method leads to a dense and accurate estimation of depth cues. This approach has been integrated into an application for relief estimation from remotely sensed images. 相似文献