PC机并行口的扩展

本文介绍一种经济实用的并行口扩展板电路。实践证明,该电路工作性能稳定,操作方便可靠,适用于PC/XT,PC/AT机的I/O扩展。     

The Economic Effect of Military Facility Contraction: A Naval Case Study

The global financial turmoil of 2008 has resulted in the curtailment of military expenditure in most western countries. At a sub-regional-level reductions in the level of activity at a major military facility can have significant economic impact. In the light of this, the paper has two objectives: to analyse the impact of the decision to terminate naval shipbuilding at the United Kingdom’s Portsmouth Naval Base; and, for illustrative purposes, to examine the possible economic consequences of further contraction at the facility. In pursuit of these aims, it is necessary to establish the output, income and employment generated by the base using a bespoke input–output model. The methodology employed can, with appropriate adjustments, be utilised in other military or civilian contexts.     

基于T-S模型的非线性系统主从控制器设计

针对同时具有输出和输入非线性的系统,通过中间虚拟控制量的设置,转化为两个非线性子系统的串联,从而简化系统结构并解决最终控制量不宜直接获取的问题。针对无人水面艇的航迹和横摇控制,设计了基于反演控制的从控制器,实现了输入非线性中虚拟控制量到舵角的映射,通过T-S模型将输出非线性系统,转化为线性时变系统,并考虑舵机的角度与角速度约束,设计了广义预测主控制器。该方法不仅简化了系统结构,同时仿真结果表明,所设计的主从控制器可以获得较好的控制效果。     

On the contribution of defense innovation to China’s economic growth

As the most knowledge-intensive industrial sectors, China’s defense industries are developing very fast. The present paper will explore the contribution of China’s defense innovation to its economic growth. Cobb–Douglas production function, integrating defense and non-defense stock in knowledge, is applied during the course. In addition, an input–output analysis of defense equipment procurement was done. Positive effect of China’s defense innovation on economic growth has been revealed by comparing the results from the two methods. And some suggestions are made to strengthen the effect.     

隔离型DC/DC变换器的嵌入式滤波设计

传统的隔离型DC/DC变换器输入端电流断续,会对电源或负载产生严重的电磁干扰,利用嵌入式滤波(Built-in Input Filter,BIF)的方法可以实现输入电流的连续。以嵌入式滤波全桥为例对嵌入式滤波的原理进行了分析,提出了隔离型DC/DC变换器嵌入式滤波拓扑、变压器以及交叉耦合电容参数的设计方法,并用该方法推导和设计了带有嵌入式滤波功能的半桥拓扑,利用PSIM软件进行了仿真分析。搭建了新型半桥拓扑的试验样机,验证了设计方法的有效性。     

输入分机核心板的改造方案

提出关于输入分机两种电路的改造方案,即绝对值和正切函数发生器电路的工程实现方法,从而解决修理中备件替换问题．经实验证明,电路具有很高的精度,且容易实现．     

Economic impact of the ministry of defence’s budget: methodological design and results for the Spanish economy

This article analyses the economic impact of the expenditure budget of the Spanish Ministry of Defence (MoD) and its Autonomous Agencies (AA), distinguishing direct, indirect and induced effects. The input–output methodology is used to find intersectoral effects on the rest of the economy. The article quantifies the economic impact in terms of production, gross value added (GVA), employed population, tax revenue, and also in terms of its contribution to the gross domestic product (GDP) of Spain in 2010. The results show that the activity of the MoD and AA generates 1.2% of the country’s GDP and 1.7% of total employment in that year.     

应用UIO的卫星姿控故障检测与仿真

为了克服未知输入对观测器的影响,防止在故障检测滤波器中出现错误的报警,以Chen和Patton提出的未知输入观测器的基本架构,设计了两个观测器.这两个观测器分别对故障敏感和不敏感,推导了两种情况下的误差方程,并且设计了残差.该残差能够与故障信号建立直接的联系,便于对故障的分析与诊断.该方法用于卫星姿控系统中,并且进行了仿真.     

ANALYSING DEFENCE DEPENDENCY: THE IMPACT OF THE ROYAL NAVY ON A SUB‐REGIONAL ECONOMY

This paper provides a methodology for estimating the economic impact of defence spending at a sub‐regional level. It does so by calculating the income and employment generated by Britain’s Royal Navy and associated defence activities in the City of Portsmouth and its surrounding area, during the financial year 2003–2004. In an era of military consolidation, the paper offers an insight into the multifaceted impact of defence‐related expenditure. Hence, it presents a generic framework that could prove useful to other researchers when seeking to measure the sub‐regional impact of naval, airforce and army facilities in other national contexts.     

基于对偶四元数的航天器六自由度相对运动输入有界控制

利用对偶四元数的理论来分析航天器六自由度的相对运动,设计了一种考虑输入有界的姿轨一体化控制器。在介绍对偶数和对偶四元数的基础上推导六自由度相对运动的姿轨耦合模型;利用双曲正切函数绝对值小于1的特性来显式地构造有界控制器,分别设计两个相互耦合的自适应调节律来动态地改变控制器的输出,并基于李雅普诺夫稳定性理论严格证明了闭环系统的全局渐近稳定性;利用数学仿真实验来验证该控制器和控制力满足给定的约束条件,能够实现航天器六自由度相对运动的精确稳定控制,并且对模型参数不确定性和外界扰动具有鲁棒性。与其他方法相比,由该控制器计算得到的控制力矩器的收敛速度更快,输出的控制力矩和控制力的最大幅值更小,且消耗的能量也更少。