Fuzzy赋范空间上算子的微分

本文给出了Fuzzy赋范空间上算子的Fuzzy Frechet微分、Fuzzy Gateaux微分的定义,讨论了它们的一些性质。     

钢筋混凝土细长构件截面几何关系探讨

本文运用 Hellinger-Reissner 变分原理,给出了从基本平衡方程导出钢筋混凝土构件截面上应变分布情况的一般方法。所给出的方法适用于受压区混凝土应变分布的任何规定形式。计算表明.若认为受压区混凝土在变彤过程中具有线性应变分布,则受拉钢筋应变与该分布一起满足平截面假定。     

From linear to nonlinear control means: a practical progression

With the rapid advance of digital control hardware, it is time to take the simple but effective proportional-integral-derivative (PID) control technology to the next level of performance and robustness. For this purpose, a nonlinear PID and active disturbance rejection framework are introduced in this paper. It complements the existing theory in that (1) it actively and systematically explores the use of nonlinear control mechanisms for better performance, even for linear plants; (2) it represents a control strategy that is rather independent of mathematical models of the plants, thus achieving inherent robustness and reducing design complexity. Stability analysis, as well as software/hardware test results, are presented. It is evident that the proposed framework lends itself well in seeking innovative solutions to practical problems while maintaining the simplicity and the intuitiveness of the existing technology.     

Probabilistic ensemble simplified fuzzy ARTMAP for sonar target differentiation

This study investigates the processing of sonar signals with ensemble neural networks for robust recognition of simple objects such as plane, corner and trapezium surface. The ensemble neural networks can differentiate the target objects with high accuracy. The simplified fuzzy ARTMAP (SFAM) and probabilistic ensemble simplified fuzzy ARTMAP (PESFAM) are compared in terms of classification accuracy. The PESFAM implements an accurate and effective probabilistic plurality voting method to combine outputs from multiple SFAM classifiers. Five benchmark data sets have been used to evaluate the applicability of the proposed ensemble SFAM network. The PESFAM achieves good accuracy based on the twofold cross-validation results. In addition, the effectiveness of the proposed ensemble SFAM is delineated in sonar target differentiation. The experiments demonstrate the potential of PESFAM classifiers in offering an optimal solution to the data-ordering problem of SFAM implementation and also as an intelligent classification tool in mobile robot application.     

从商品住宅售价状况看天津居住空间分异现象

通过分析天津市市内六区商品住宅售价分布的情况，发现天津市居住空间分异现象已经初见端倪，就此对其特征及产生原因进行了综合研究，探讨居住空间分异的机制，并且寻求解决途径与方法，展望天津市居住空间的演化趋势。     

在暂态过程中电力系统频率的估算

提出了一种在暂态过程下测量电力系统频率的快速准确算法。该算法考虑了RL电路中的暂态电流，假设暂态电流含有一个按正弦规律变化的周期分量和一个按指数规律变化的非周期分量。通过数字微分，非周期分量的参数如时间常数以及整个非周期分量可以用采样序列准确计算，进而利用计算出的量和采样序列来估算出暂态过程中电力系统的频率。整个估算过程仅需一个周波的时间，测量的精确度高于99．99％，而且测量精度不受周期分量和非周期分量参数变化的影响，更不受采样频率的影响，因此非常适应于电力系统的实时测量和控制。     

“To be recorded” analysis in reverse-mode automatic differentiation

The automatic generation of adjoints of mathematical models that are implemented as computer programs is receiving increased attention in the scientific and engineering communities. Reverse-mode automatic differentiation is of particular interest for large-scale optimization problems. It allows the computation of gradients at a small constant multiple of the cost for evaluating the objective function itself, independent of the number of input parameters. Source-to-source transformation tools apply simple differentiation rules to generate adjoint codes based on the adjoint version of every statement. In order to guarantee correctness, certain values that are computed and overwritten in the original program must be made available in the adjoint program. For their determination we introduce a static data-flow analysis called “to be recorded” analysis. Possible overestimation of this set must be kept minimal to get efficient adjoint codes. This efficiency is essential for the applicability of source-to-source transformation tools to real-world applications.     

Multiclass P2P networks: Static resource allocation for service differentiation and bandwidth diversity

We propose a multiclass fluid model for BitTorrent-like content-distribution systems. The new model can model heterogeneous peers, in which peers have different access bandwidths. The model can also model BitTorrent-like systems which provide differential service (for example, first class and second class service) to the participating peers. The fluid model leads to a non-linear system of differential equations with special structure. For the service differentiation problem, we prove that the system of differential equations admits a unique stable equilibrium, that we compute in closed-form. We also provide the average download times for both classes. For the bandwidth diversity problem, we show that the system of differential equations has a stable state that may depend on the initial conditions. We compute the average download time of both classes for each reachable steady-state.     

<Emphasis Type="Italic">M/G</Emphasis>/1 System with Adjustment at the Beginning of Its Busy Period

M/G/1 queuing system is considered in which the first incoming request initializes system adjustment. After adjustment, the system services the first and then the next incoming requests. Ergodic probabilities are computed based on the theory of regenerative processes and on the busy period and time of staying in different states. Recurrence is analyzed which corresponds to the mathematical expectation of the time of staying in different states.The study was sponsored by the Hungarian National Fund for Scientific research (Grants OTKA T034110 and T034280/2000) and by the Fund of the Research Group on Number Theory of the Hungarian Academy of Sciences.__________Translated from Kibernetika i Sistemnyi Analiz, No. 1, pp. 117–123, January–February 2005.