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排序方式: 共有10000条查询结果,搜索用时 421 毫秒
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.
使用遗传算法的自适应Kalman滤波器 总被引:5,自引:0,他引:5
基于Magill的Kalman撼波器池结构,设计了使用遗传算法的自适应Kalman滤波器,给出了离线和在线两种实现方案.离线方案以辨识滤波参数为主要目的,进而可以对状态进行较准确的事后估计;在线方案以实时地对状态进行估计为目的.对滤波参数寻优使用具有良好性能的浮点数编码遗传算法,该算法与二进制编码遗传算法相比收敛速度更快、搜索全局最优的能力更强.仿真结果验证了所提出的自适应Kalman滤波器的有效性. 相似文献
993.
994.
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
995.
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
996.
本文研究了厩肥区、秸杆区、化肥区和无肥对照区四种不同培肥管理措施对土壤微生物生态特征的影响,结果表明,施入厩肥、化肥或秸杆还田均能明显增加土壤微生物生物量及呼吸量;土壤微生物生物质量、土壤呼吸及代谢商等微生物指标均与土壤有机质的变化呈相同的变化趋势;BIOLOG生态盘测试亦揭示了培肥管理措施能明显影响土壤微生物的群落结构。 相似文献
997.
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
998.
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
999.
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
1000.