基于单片机的脉冲电源控制系统设计

硅片的电火花线切割是一种新型的工艺方法,由于硅片的高电阻率特点,脉冲电源的参数与传统线切割设备有较大不同。通过采用MCS51系列的单片机,设计一种基于高压直流电源改进为脉冲电源的控制系统,应用到高速走丝线切割机床上来对工件进行试切,可以取得理想的切割效果。     

论公共外交与民间外交的关系

公共外交与民间外交的关系在当今国际关系中至关重要.它一方面加强了国家之间的信任和理解,另一方面树立了国家形象,增强了国际吸引力,而这些都是"软力量"建设的重要内容.因此,大力开展公共外交与民问外交是"软力量"建设的重要途径.     

印度共产党:建设"第三种替代性力量"

印度共产党是当今印度政坛仅次于印共(马)的第二大共产党组织.在80多年的历史中,虽几经分裂,但均能在调整政策纲领和生存策略的努力下生存并获得发展.在今天的印度政坛,印度共产党通过与印共(马)等左翼政治力量联合,多次在地方层面参政或执政,并成为"团结进步联盟"等主流政治力量竞相拉拢的结盟对象,在国内政治舞台上发挥着重要的影响.     

In-package P/G planes analysis and optimization based on transmission matrix method

Power integrity （PI） has become a limiting factor for the chip＇s overall performance, and how to place in-package decoupling capacitors to improve a chip＇s PI performance has become a hot issue. In this paper, we propose an improved transmission matrix method （TMM） for fast decoupling capacitance allocation. An irregular grid partition mechanism is proposed, which helps speed up the impedance computation and complies better with the irregular power/ground （P/G） plane or planes with many vias and decoupling capacitors. Furthermore, we also ameliorate the computation procedure of the impedance matrix whenever decoupling capacitors are inserted or removed at specific ports. With the fast computation of impedance change, in-package decoupling capacitor allocation is done with an efficient change based method in the frequency domain. Experimental results show that our approach can gain about 5× speedup compared with a general TMM, and is efficient in restraining the noise on the P/G plane.     

Adaptive ant-based routing in wireless sensor networks using Energy*Delay metrics

To find the optimal routing is always an important topic in wireless sensor networks （WSNs）. Considering a WSN where the nodes have limited energy, we propose a novel Energy^＊Delay model based on ant algorithms （＂E＆D ANTS＂ for short） to minimize the time delay in transferring a fixed number of data packets in an energy-constrained manner in one round. Our goal is not only to maximize the lifetime of the network but also to provide real-time data transmission services. However, because of the tradeoff of energy and delay in wireless network systems, the reinforcement learning （RL） algorithm is introduced to train the model. In this survey, the paradigm of E＆D ANTS is explicated and compared to other ant-based routing algorithms like AntNet and AntChain about the issues of routing information, routing overhead and adaptation. Simulation results show that our method performs about seven times better than AntNet and also outperforms AntChain by more than 150% in terms of energy cost and delay per round.     

明代言官的职业风险及保障机制

明代言官以言为职,在履职时面临着双重风险：一是皇帝的威胁和摧抑,二是周边各种势力的打击报复。为保证言官尽职,明代确立了一些激励和保障机制,包括鼓励直言、慎选言官、畀以重权、给予重赏、严加考察以及相应的人身保护等。这些保障机制在一定程度上激励了言官不畏风险,恪尽职守,在明中期以前发挥了较好的作用。但由于专制体制下皇权决定一切,而明代皇帝素质又普遍低下,言官保障机制不断被破坏,言官的职业风险更为突出,致使言官群体在晚明时期不断分化蜕变,从一个侧面揭示了明代士大夫的悲剧命运。     

基于MS SQL Server数据库的数据备份方法的探讨与应用

探讨并实现了三种基于MS SQL Server数据库数据备份的实际应用。三种方法各有特点,可单独应用又可相互兼顾,以达到较为安全、高效地实现MS SQL Server数据库数据备份的目的。     

两次大战之间英国"一强标准"的空军威慑战略

1923年英国政府确定了皇家空军的“一强标准”战略原则。随着国际形势的变化,英国的战略假想敌由法国转向德国,其空军发展战略也经历了从“A计划”到“M计划”的变化过程。然而,英国过分追求与德国轰炸机数量对等,实际上未能起到阻止希特勒发动战争的预期威慑作用。     

合成孔径雷达杂波功率谱的计算

在传统的杂波计算中,将地表进行"等距离-等多普勒"划分。以雷达天线的发射、接收理论和雷达的目标散射理论为基础,推导出合成孔径雷达杂波功率谱的计算公式,并对公式的闭合积分解和实时算法进行了讨论。     

利用PowerDesigner建立数据仓库多维模型的研究

本文介绍了数据仓库的多维模型,对使用PowerDesigner建立数据仓库多维模型进行研究, 并分析了其在“学生成绩分析”系统中应用。