阿里安5运载器的发射与操作设备

阿里安５支载器有一套新的发射操作程序。法国库鲁圭亚那航天中心为发射阿里安５运载器构筑了阿里安第３发射场。该发射场的主要设施有：运载火箭组装厂房、最后组装厂房、发射控制中心、发射区及活动发射平台等。     

多裂缝防治措施研究

在对某些复杂地层进行水力压裂施工时,常会遇到异常高压及脱砂现象,有时导致施工失败,而多裂缝的产生是这些现象的本质原因。通过大量的调研分析,系统总结了多裂缝的防治措施。主要包括对地层的准确认识、合理的完井措施、合理的施工参数及流体参数、多级支撑剂段塞技术、前置液量的选择、小型测试压裂辅助补孔等措施。     

常规潜艇总体任务可靠性的建模与仿真

针对当前常规潜艇总体任务可靠性建模和计算中存在的问题,以鱼雷攻击任务为例,通过任务剖面和任务与系统关系分析,建立常规潜艇总体任务可靠性双层模型,并根据多阶段任务系统理论和蒙特卡罗方法进行任务可靠性仿真,得到常规潜艇总体任务可靠度.为常规潜艇及其它大型复杂武器系统总体任务可靠性的预计、分配和评估提供一种新方法.     

Identification of stable operating ranges of a counter-current multistage fluidized bed reactor with downcomer

This paper describes the stable operating range for a multistage gas–solid fluidized bed reactor and the influence of downcomer and aspect ratio on stable and uniform gas–solid fluidization. A three-stage counter-current fluidized bed reactor was designed, fabricated and operated and range of stable operation for lime and sand particles has been determined. In addition to that a comprehensive discussion on dynamics of downcomer has been made to ensure smooth transfer of solids from one stage to another. A theoretical model has been developed to predict the solid height in downcomer and tested for experimental conditions. The influence of aspect ratio on distributor to bed ratio (P_p/P_b) was investigated for the reactor for uniform fluidization.     

一类动态规划问题的解法与算法

本文给出了终止段未知的离散动态规划问题的解法和算法，并且结合经济问题的实际应用以及解法。     

Bifurcation and chaos in power systems

A detailed example of a power system model with load dynamics is studied by investigating qualitative changes or bifurcations in its behaviour as a reactive power demand at one load bus is increased. In addition to the saddle-node bifurcation often associated with voltage collapse, we find other bifurcation phenomena which include Hopf bifurcation, cyclic fold bifurcation, period doubling bifurcation, and the emergence of chaos. The presence of these dynamic bifurcations motivates a re-examination of the role of saddle-node bifurcations in the voltage collapse phenomenon. In fact, simulation results suggest that voltage collapse may take place before the reactive power demand is increased to the system steady-state operating limit where a saddle-node bifurcation is detected. We also consider the role that the algebraic constraints imposed by some load models may play in the global analysis of the attractors of the system. Implications for power system operations are drawn.     

A survey on multistage/multiphase statistical modeling methods for batch processes

In industrial manufacturing, most batch processes are inherently multistage/multiphase in nature. To ensure both quality consistency of the manufactured products and safe operation of this kind of batch process, different multivariate statistical process control (MSPC) methods have been proposed in recent years. This paper gives an overview of multistage/multiphase statistical process control methods used for process analysis, monitoring, quality prediction and online quality improvement. Different types of phase divisions and modeling strategies are introduced and the method properties are discussed. For comparisons, a selection guide to these methods for different application purposes is provided. Finally, some promising research directions are suggested based on existing works.     

Feedback stabilization of bifurcations in multivariable nonlinear systems—Part II: Hopf bifurcations

In this paper we derive necessary and sufficient conditions of stabilizability for multi‐input nonlinear systems possessing a Hopf bifurcation with the critical mode being linearly uncontrollable, under the non‐degeneracy assumption that stability can be determined by the third order term in the normal form of the dynamics on the centre manifold. Stabilizability is defined as the existence of a sufficiently smooth state feedback such that the Hopf bifurcation of the closed‐loop system is supercritical, which is equivalent to local asymptotic stability of the system at the bifurcation point. We prove that under the non‐degeneracy conditions, stabilizability is equivalent to the existence of solutions to a third order algebraic inequality of the feedback gains. Explicit conditions for the existence of solutions to the algebraic inequality are derived, and the stabilizing feedback laws are constructed. Part of the sufficient conditions are equivalent to the rank conditions of an augmented matrix which is a generalization of the Popov–Belevitch–Hautus (PBH) rank test of controllability for linear time invariant (LTI) systems. We also apply our theory to feedback control of rotating stall in axial compression systems using bleed valve as actuators. Copyright © 2006 John Wiley & Sons, Ltd.     

Attractor Spaces as Modules: A Semi-Eliminative Reduction of Symbolic AI to Dynamic Systems Theory

I propose a semi-eliminative reduction of Fodors concept of module to the concept of attractor basin which is used in Cognitive Dynamic Systems Theory (DST). I show how attractor basins perform the same explanatory function as modules in several DST based research program. Attractor basins in some organic dynamic systems have even been able to perform cognitive functions which are equivalent to the If/Then/Else loop in the computer language LISP. I suggest directions for future research programs which could find similar equivalencies between organic dynamic systems and other cognitive functions. This type of research could help us discover how (and/or if) it is possible to use Dynamic Systems Theory to more accurately model the cognitive functions that are now being modeled by subroutines in Symbolic AI computer models. If such a reduction of subroutines to basins of attraction is possible, it could free AI from the limitations that prompted Fodor to say that it was impossible to model certain higher level cognitive functions.     

Heuristic solution approaches to the pharmaceutical R&D pipeline management problem

The paper presents two heuristic approaches, a shrinking horizon multiple two-stage stochastic programming (MTSSP) decomposition algorithm and a knapsack decomposition algorithm (KDA), for solving multistage stochastic programmes (MSSPs) with endogenous uncertainty, specifically focusing on pharmaceutical research and development (R&D) pipeline management problem. The MTSSP decomposition algorithm decomposes the problem into a series of two-stage stochastic programmes, which are solved as resources become available. The KDA decomposes the MSSP into a series of knapsack problems, which are created and solved at key decision points on a rolling horizon fashion. Based on the results of the six case studies, both the MTSSP decomposition algorithm and the KDA generate implementable solutions that are within three percent of the rigorous MSSP solution obtained by CPLEX 12.51. Both methods showed several orders of magnitude decrease in the CPU times compared to ones that were required to solve the rigorous MSSP.