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101.
Evaluation of rainfall networks using entropy: II. Application 总被引:2,自引:0,他引:2
This paper, the second in the series, applies the entropy approach to space and time evaluation of rainfall networks in Louisiana. The evaluation is made for five sampling intervals: daily, 2-day, weekly, monthly, and yearly, and for two separate seasons. In each case, the best combination of raingages is suggested and the lines of equal information (isoinformation contours) are constructed showing the areas of greater or less information transfer. The isoinformation lines are especially suitable in decisions concerning the expansion of the existing network or deleting the unnecessary raingages. 相似文献
102.
Modeling molecular interactions in signalling networks is important from various perspectives such as predicting side effects
of drugs, explaining unusual cellular behavior and drug and therapy design. Various formal languages have been proposed for
representing and reasoning about molecular interactions. The interactions are modeled as triggered events in most of the approaches.
The triggering of events is assumed to be immediate: once an interaction is triggered, it should occur immediately. Although
working well for engineering systems, this assumption poses a serious problem in modeling biological systems. Our knowledge
about biological systems is inherently incomplete, thus molecular interactions are constantly elaborated and refined at different
granularity of abstraction. The model of immediate triggers can not consistently deal with this refinement. In this paper
we propose an action language to address this problem. We show that the language allows for refinements of biological knowledge,
although at a higher cost in terms of complexity.
相似文献
103.
以江苏省南通市为研究区,利用采样点实测数据,借助GRNN神经网络模型并结合3S技术对农田土壤重金属的空间动态分布进行了深入研究。结果表明,GRNN神经网络模型能够智能地学习各个采样点的空间位置与该点各重金属含量之间的映射关系,并能够稳健地对各个空间插值点处的土壤重金属含量进行预测;结果显示南通市农田土壤重金属污染总体较轻,但也存在局部地区的严重污染。在运用GRNN神经网络模型进行空间插值了解重金属空间动态分布的基础上,可以根据污染的状况确定农产品的生产布局和规划。 相似文献
104.
No authorship indicated 《Canadian Metallurgical Quarterly》2006,61(8):757
Presents the citation to Marcia K. Johnson, who received the Award for Distinguished Scientific Contributions "for raising and illuminating fundamental questions about the cognitive and neural processes that constitute the subjective experience of mental life." A brief profile and a selected bibliography, as well as Johnson's award address, entitled Memory and Reality (see record 2006-21079-028), accompany the citation. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
105.
The area covered by a mobile ad hoc network consists of obstacles that inhibit transmission and areas where communications
can take place. Physical structures, such as buildings, that block transmission, or lakes, where forwarding nodes cannot be
located, are permanent obstacles. Temporary obstacles are created as mobile nodes enter or leave an area. Our hypothesis is
that the spaces between nearby obstacles are bottlenecks that inhibit the flows in the network. We partition the network into
areas that are encompassed by obstacles and bottlenecks. All of the nodes in an area are treated as a single super node, and
the bottlenecks between areas are the links between the super nodes. As individual nodes move, the flows and paths in the
model change more slowly than the paths and flows between the individual nodes. We apply flow control algorithms to the model
and perform admission control within a super node based on the flows that are assigned by the flow control algorithm. We apply
the model to the Columbia University campus, and use max–min, fair bottleneck flow control to assign the flows. Our hypothesis
is verified for this example. 相似文献
106.
Joel 《Journal of Parallel and Distributed Computing》2005,65(12):1601-1606
Lee and Batcher have designed networks that efficiently merge k separately provided sorted sequences of known lengths totalling n. We show that the design is still possible, and in fact easier to describe, if we do not make use of the lengths, or even the directions of monotonicity, of the individual sequences—the sequences can be provided in a single undelimited concatenation of length n. The depth of the simplest resulting network to sort sequences that are “k-tonic” and of length n is , generalizing Batcher's 1968 results for the extreme values of k (k=2 corresponding to merging, and k=n/2 corresponding to general sorting).The exposition is self-contained and can serve even as an introduction to sorting networks and Batcher's results. 相似文献
107.
正则模糊神经网络对一类连续模糊值函数的普遍近似性 总被引:5,自引:0,他引:5
本文讨论了正则模糊神经网络于对定义于区间[0,T0]上连续可减模糊值函数的普遍近似性,在此基础上,证明了[0,T0]上取值为三角形模糊连续递增函数可用正则模糊神经网络逼近到任意精度。 相似文献
108.
本文对[5]的4位人工神经网络A/D变换器进行了研究.指出按其方法推广实现多位A/D时存在突触电阻大小以至无法实现且抗干扰能力也不好的问题并给出了解决办法.同时对如何改善神经元转移特性的硬限幅曲线作了简单讨论. 相似文献
109.
Jonas Sjberg Qinghua Zhang Lennart Ljung Albert Benveniste Bernard Delyon Pierre-Yves Glorennec Hkan Hjalmarsson Anatoli Juditsky 《Automatica》1995,31(12):1691-1724
A nonlinear black-box structure for a dynamical system is a model structure that is prepared to describe virtually any nonlinear dynamics. There has been considerable recent interest in this area, with structures based on neural networks, radial basis networks, wavelet networks and hinging hyperplanes, as well as wavelet-transform-based methods and models based on fuzzy sets and fuzzy rules. This paper describes all these approaches in a common framework, from a user's perspective. It focuses on what are the common features in the different approaches, the choices that have to be made and what considerations are relevant for a successful system-identification application of these techniques. It is pointed out that the nonlinear structures can be seen as a concatenation of a mapping form observed data to a regression vector and a nonlinear mapping from the regressor space to the output space. These mappings are discussed separately. The latter mapping is usually formed as a basis function expansion. The basis functions are typically formed from one simple scalar function, which is modified in terms of scale and location. The expansion from the scalar argument to the regressor space is achieved by a radial- or a ridge-type approach. Basic techniques for estimating the parameters in the structures are criterion minimization, as well as two-step procedures, where first the relevant basis functions are determined, using data, and then a linear least-squares step to determine the coordinates of the function approximation. A particular problem is to deal with the large number of potentially necessary parameters. This is handled by making the number of ‘used’ parameters considerably less than the number of ‘offered’ parameters, by regularization, shrinking, pruning or regressor selection. 相似文献
110.
神经网络在电路诊断中的应用 总被引:6,自引:1,他引:5
目的:阐述了目前电路基于数据库技术和人工智能专家系统及神经网络原理的故障诊断系统。方法:将所记录的模糊症状输入到系统中,通过模糊运算后,运用神经网络学习算法来寻找故障类型。结果:介绍了人工神经网络技术在电路诊断中的应用,并给出系统故障诊断软件的设计,结论:所用专家系统和神经网络相结合的方法改进电子电路故障诊断是可行的。 相似文献