Laser-field synchrotron radiation

An electron with an appropriate initial velocity injected into an oncoming, ultraintense circularly polarized laser pulse can execute a circular relativistic motion at the peak of the laser pulse. The circulating electron then radiates in the same manner as that in the storage ring of a conventional synchrotron source. Owing to the extremely small orbit radius, the laser-field synchrotron radiation thus generated can be a compact source of radiation pulses at short wavelength and short duration.

Optical intrinsically fuzzy mathematical morphology for gray-scale image processing

Intrinsically fuzzy morphological erosion and dilation are extended to a total of eight operations that have been formulated in terms of a single morphological operation--biased dilation. Based on the spatial coding of a fuzzy variable, a bidirectional projection concept is proposed. Thus, fuzzy logic operations, arithmetic operations, gray-scale dilation, and erosion for the extended intrinsically fuzzy morphological operations can be included in a unified algorithm with only biased dilation and fuzzy logic operations. To execute this image algebra approach we present a cellular two-layer processing architecture that consists of a biased dilation processor and a fuzzy logic processor. (C) 1996 Optical Society of America

Effect of beta-irradiation on photoluminescence of MOCVD grown GaN

The effect of beta particles interaction on the optical properties of MOCVD grown GaN is reported. A significant change in luminescence properties of GaN is observed after exposing the material with 0.6 MeV beta particles with low dose of 10(12) cm(-2). The results obtained from photoluminescence measurements of irradiated GaN samples in low dose are found contradictory to those reported in literature for samples irradiated with heavy dose (> 10(15) cm(-2)) of electron. An increase in intensity of yellow luminescence has been observed with increasing dose of beta particles which is in disagreement to the already reported results in literature for heavily irradiated samples. A model has been proposed to sort out this inconsistency. The increase in YL intensity at low dose is attributed to the increase in concentration of VGaON complex whereas production of non-radiative VGaON clusters is assumed to justify the decrease in YL intensity at high dose.

多层企业应用的关键:J2EE应用服务器

Application server provides a platform that helps users to create,deploy,execute,integrate and maintainmulti-tier enterprise applications. This paper analyzes a variety of implementation strategies of application servers,th eh gives evaluating features for J2EE application server and compares the 4 representative products.

一种新的多智能体强化学习算法及其在多机器人协作任务中的应用

在多机器人系统中 ,评价一个机器人行为的好坏常常依赖于其它机器人的行为 ,此时必须采用组合动作以实现多机器人的协作 ,但采用组合动作的强化学习算法由于学习空间异常庞大而收敛得极慢 .本文提出的新方法通过预测各机器人执行动作的概率来降低学习空间的维数 ,并应用于多机器人协作任务之中 .实验结果表明 ,基于预测的加速强化学习算法可以比原始算法更快地获得多机器人的协作策略 .

四坐标位姿测量仪设计研究与误差分析

四坐标位姿测量仪是针对某轻型汽车底盘前悬置横梁上四孔位姿测量而设计的新型仪器·该测量仪以六自由度并联机构作为执行机构 ,能够迅速准确地到达被测孔的实际位置 ,测量头具有对非测量参数误差的自适应和自调整能力·采用比较法实现参数测量·该机构结构新颖 ,测量效率高·系统分析研究了各因素造成的测量误差 ,指出了减小测量误差的措施 ,从而为精确设计测量仪提供了可靠依据·

机器人插件作业的视觉导引方法研究

插件作业 (parts mating)是装配机器人的一项基本作业环节 .本文介绍了以双目立体视觉实现该作业的视觉导引方法 .该方法通过采用人机交互方式 ,借助于人的智慧 ,提高了图像特征提取和匹配的准确性和可靠性、可直观准确地给出插件作业的动作参数 ,克服了自动视觉计算复杂、鲁棒性差的缺点 ,适用于机器人遥操作作业 .实验表明 ,基于人机交互的机器人插件作业在立体视觉导引下是完全可行的

基于Multi-Agent的生产过程建模与仿真技术研究

某些流程行业由于采用按配方进行分组加工的模式组织生产,在排产时存在多条路径调度优化的问题,应用一般的优化算法对于现场在线调度难以给出满意结果,而基于Agent的过程仿真在解决离散、非线性系统模拟方面有显著的优势,本文采用Agent的方法对生产过程建模,然后对方案组内的备选方案进行仿真,通过对比各方案的仿真结果找到最优的方案作为执行方案,为现场的优化排产提供决策支持。

基于数字化生产模型的事件建模系统设计

文章主要对基于数字化生产模型的事件建模系统进行了介绍。首先引入了支撑事件建模系统的MES基础运行平台,介绍了平台的功能以及系统结构;接着描述了事件的相关概念,并对事件建模系统的设计方法进行了介绍,最后给出了系统的具体应用实例。

塔里木盆地历史时期的自然环境演变

Exploit Tarim Basin Historical Physical Geographic Information System by linking historical documents and Geographic Information System, reconstruct the physical environmental evolution in Tarirn Basin during historical period (the last 2 Ka), special discuss riverhead of the Yellow River and Lop Nur. Based on analyzing Chinese historical documents (antiquity maps and texts), extract physical environmental information in Xiyu during historical period from Twenty-Five History and geographic books and records past dynasties, divide it into 4 period of time. Regarding digital topographical maps as base maps and looking on water bodies, vegetation and desert as central factors, quantify historical physical geographic data in Geographic Information System in terms of dynastic combination of Xianqin-Han, Jin-Wei-Nanbeichao, Tang-Wudai and Song-Yuan-Ming-Qing, execute physical environmental maps of Xiyu through the ages, in order to image the changes of water system, oasis and desert in Xiyu during the last 2 Ka. Compare cross orientation the relation of environmental factors all historical period of time from the influence of climate to oasis and desert, deem that climate condition decided ecological structure in direct and restrict the extent of desertification, especially climate corresponded the style of oasis and the spread of desert in the period of Jin-Wei-Nanbeichao and Tang-Wudai. Compare portrait direction the physical environmental characters in Xiyu during different period of time from 5 aspects of water bodies, oasis, desert, products and climate, deem that physical environment in Xiyu changed in all aspects during historical period. The origin of Lysenkoism about the Yellow River Undercurrent is agelong, whose ascending and descending at times due to investigating the riverhead of the Yellow River time after time during historical period and researching and disputing about the geographic location of Jishishan Mountain. It could consider the faultage in northeastern Qinghai-Xizang Plateau as the channels of undercurrent according to the research of modern geoscience field in the riverhead region.