基于Petri网的舰载指控系统性能评价

舰载指控系统是广泛使用计算机技术的产物,分布式异步并行处理是它的突出特点。对它的分析和评价要解决的主要问题是系统结构的合理性和有效性。Petri网是描述和分析异步并发现象的一种有效的模型工具,本文以Petri网为工具,对舰载指控系统的结构性能、状态概率、任务的忙闲程度进行了定量和定性分析,从另一个角度对舰载指控系统性能进行了分析和评价,事实证明,这种方法是有效的。     

Separation of Americium from Fission Product Lanthanides Using Cyanex 301 Extraction

IntroductionThe safe management and disposal of high levelwaste (HLW) from reprocessed spentnuclearfuelis a key factor in the development of nuclearenergy.In the partitioning and transmutationnuclear fuel cycle,minor actinides Np,Am,andCm are separated from HLW and transmutated byneutrons into short- lived nuclides.In the presentprocesses forthe removal of actinides from HLW,Am and Cm are separated together with fissionproduct lanthanides(FPLns) (from La to Gd) .Table1 gives the compos…     

SSRF显微NEXAFS光束线站初步设计

设计光子能量范围为250－750eV，可覆盖C，N，O，F的K边办以及过渡金属直至Fe的L边，设计的空间分辨率为50－150nm，具备发展到30nm的能力，重点考虑了相干辐射的传输，分析了水平和垂直方向的相空间匹配问题，引入冗余照明的概念，以实现波带板的空间相干照明以及降低束线对光源不稳定性及元件振的要求，设计输出光通量可达10^9phs/(s.0.1%BW)，谱分辨率（E／ΔE）标称值3000，并可根据不同实验调整，实验站设计样品可放在真空，氦气和大气环境中工作。     

A Class of Parallel Implicit Runge-Kutta Formulas

A class of parallel implicit Runge-Kutta formulas is constructed for multiprocessor system. A family of parallel implicit two-stage fourth order Runge-Kutta formulas is given. For these formulas, the convergence is proved and the stability analysis is given. The numerical examples demonstrate that these formulas can solve an extensive class of initial value problems for the ordinary differential equations.     

A Class of Explicit Parallel Multistep Runge-Kutta Methods

In this paper, a rather general class of explicit parallel multistep Runge-Kutta methods is constructed for solving initial value problem of ordinary differential equations. Also, the corresponding convergence and stability are analysed. Several parallel computational formulae are given. The numerical experiments, including accuracy, speedup, and efficiency tests show that the methods are efficient.     

AN INFORMATION THEORETICAL APPROACH TO NEURAL NETWORKS

The purpose of this paper is to present a unified theory of several differentneural networks that have been proposed for solving various computation, pattern recog-nition, imaging, optimization, and other problems. The functioning of these networks ischaracterized by Lyapunov energy functions. The relationship between the deterministicand stochastic neural networks is examined. The simulated annealing methods for findingthe global optimum of an objective function as well as their generalization by injectingnoise into deterministic neural networks are discussed. A statistical interpretation of thedynamic evolution of the different neural networks is presented. The problem of trainingdifferent neural networks is investigated in this general framework. It is shown how thisapproach can be used not only for analyzing various neural networks, but also for the choiceof the proper neural network for solving any given problem and the design of a trainingalgorithm for the particular neural network.     

Progress in Theoretical Research on Reliability for China''''s Space Engineering

With the support of the Fundamental Reliability Theoretical Research (FRTR) Foundation of the Quality Control Bureau of Ministry of Astronautics (MOA), PRC, 9 Chinese institutes and universities have worked for years on reliability statistics problems pending to be solved in space research and development. This paper gives a brief review of our main research results, including (1) Results on Normal Distributions; (2) Results on Weibull Distributions; (3) Results on the Synthesisof System Reliability-Theoretical Method; (4) Results on the Synthesis of System Reliability-Approximation Method: Binomial Distribution, Exponential Distribution, Weibull Distribution, Parallel System, General Cases; (5) Structual Reliability; (6) Zero-Failure Reliability Estimation; (7) Storage Life and Others. All these results can be acquired from the Quality Control Bureau of the Ministry of Aero-Space Industry (MAS).     

Applying Force-Directed Placer to Wafer Scale Placement

A placement algorithm for discretionary wiring WSI system, WFDP, is proposed in this paper. WFDP employes force-directed placement algorithm. First the relative locations of macro circuit component are determined. In the phase of determining the real location of the circuit component, it avoids the problem of determining the real location of arbitrary component by employing divide-conquer strategy and removing the hierarchical division. Its computation is much more simpler than other homologous algorithm. A simple model used to estimate the quality of placement is also proposed. Although the WFDP is aimed at WSI, it can also be used in the placement of other redundancy-oriented device or system such as RVLSI, etc.     

Wind Measurement with a Wind Profiling Radar

The first troposphere wind profiling radar in China has been in operation. The paper describes the radar parameters and characteristics with some experimental results presented.     

A novel order reduction method for nonlinear dynamical system under external periodic excitations

The concept of approximate inertial manifold (AIM) is extended to develop a kind of nonlinear order reduction technique for non-autonomous nonlinear systems in second-order form in this paper. Using the modal transformation, a large nonlinear dynamical system is split into a ‘master’ subsystem, a ‘slave’ subsystem, and a ‘negligible’ subsystem. Accordingly, a novel order reduction method (Method I) is developed to construct a low order subsystem by neglecting the ‘negligible’ subsystem and slaving the ‘slav...