第100个是正版的，第101个为什么就是盗版的？

IT人员小李购买了100份Windows XP操作系统的正版授权许可．并为技术部门安装了100台电脑。由于业务需要．他又多装了几台电脑．他想．我买的是正版．多装几台应该没问题吧？后来．小李通过与微软销售代表的沟通．发现自己买100个正版授权．在安装第101台电脑时．就已经构成了盗版行为。     

雷达之间干扰协调计算方法和干扰准则

针对雷达与雷达之间的电磁干扰问题．提出了干扰计算方法．干扰准则和射频过载的方法．建立了发射机模型、分析了接收机．发射机耦合特性．并给出了相应的计算实例。     

2011年第二季度全球互联网域名城长超过500万

根据VeriSign在其最新域名行业简报中发布的数据,2011年第二季度域名总数达到2．15亿,与第一季度相比,第二季度互联网域名数量增长了520万,增幅为2．5％。88％的．com和．net域名指向有效的网站。注册的．com和．net域名超过1．1亿,占注册域名总量的大头。第二季度．com和．net域名环比第一季度增长了1．8％,同比增长了8．3％。     

传统媒体和新媒体融合发展

互联网、宽带和移动快速发展 目前网民已经达到了6．3个亿．手机网民达到了5．27个亿．占整个网民的比例达到了83．4％。手机的不同应用增长迅速,手机网络视频增长率达到了19．1％,手机网络游戏增长了16.9％．更快的是手机网络购物（42．0％）、手机网上支付（63．4％）、手机网上银行（56．4％）、手机旅行预订（65．4％）,等等。     

浪漫之约 情动初夏

不久前的春季,尼康发布了COOLPIX系列8款新产品．以高倍率变焦为主要特色．集台了轻薄．触摸屏．缤纷色彩等众多时尚元素．同时保持了尼康产品传统的优秀拍摄性能。     

浅谈数字版权管理

数字版权管理的需求所在随着高新技术特别是数字技术、信息技术、网络技术的迅猛发展．给广播电视行业带来革命性的变化．不仅节目制作的质量大大提高了．而且拓展了多种信息传输．接入的方式．提高了节目资源的利用率．为满足大众日益增长的个性化需求提供了可能。     

更简单，更安全——SCape防护面罩

虽然外形还是原来的样子．但是这次S2IS带给我们的改进还是相当多的．首先是像素升级到了500万．变焦能力到了12倍．等效焦距达到了36mm～432mm。其次．相机的视频动画录制功能进一步加强了．图像处理引擎也升级为更快速的DIGIC Ⅱ。有了这样一门“小钢炮”．夏天出去拍摄真的可以做得“指哪儿打哪儿”了。     

半电波暗室的场均匀性校准及相关问题的思考

本文介绍了IEC61000．4．3（2006）中．在进行辐射抗扰度实验时对场地的场均匀性校准方法．阐述了场均匀性的重要性．并分析了校准过程中的校准步骤．校准方法和数据处理方式．并对校准过程中容易出现的问题进行了相应的解答。     

电磁环境影响的防护──ITU－T SG5 1994年会议专题技术报告

本文主要介绍了ＩＴＵ－Ｔ第５研究组１９９３～１９９６年研究期第二次会议情况。这次会议讨论了各课题的研究进展情况，原则通过了新建议草案Ｋ．Ｅ和“关于人身安全的建议”及现有建议Ｋ．１２、Ｋ．１５、Ｋ．２２的修订草案，其中Ｋ．１２建议中包括有中国提交文稿的内容。这些新建议草案和建议修订草案将进一步完善后，提交至１９９５年１月第５研究组第三次会议，按ＷＴＳＣ的第１号决议规定程序进行正式批准。会议讨论和修改了新草案Ｋ．ｃｌａ、Ｋ．Ｉ、Ｋ．ｓｅｌ、Ｋ．Ｒ、Ｋ．Ｏ、Ｋ．Ｌ及Ｋ．Ｃ的最新文本；还讨论了关于修改Ｋ．１０、Ｋ．２０、Ｋ．２１、Ｋ．２５、Ｋ．２７、及Ｋ．３１等现有建议的提议。会议还确定了下一步工作的计划。     

＂四部曲＂替换路由器电源

一、病入膏肓 在上网兴趣正浓时，突然上不去了，pingDNS．不通．又ping网关．还是不通。赶紧查找故障．发现交换机没有问题．但路由器的风扇没有动静不转了，再看路由器的电源指示灯也不亮了．     

部分空间相干光经准均匀介质的散射

基于一阶波恩近似,研究了部分空间相干平面光经准均匀介质的散射特性,得到了远场散射光谱强度和光谱相干度的解析表达式。讨论了入射光的空间相干性和介质特性对散射场光谱强度和光谱相干度的影响。比较了入射光是完全相干光和部分相干光时,散射场光谱强度和相干度的区别。研究结果表明:入射光的空间相干性对散射场光谱强度的分布有重要影响;随着入射光空间相干长度的增大,光谱宽度减小;光谱相干度随着入射光束腰宽度或介质有效半径的增大而减小。当准均匀介质的有效半径和相干长度、入射光的空间相干长度满足一定条件时,散射光是完全相干光。     

基于不同业务模型的TCP性能分析

TCP稳定性对网络应用性能有直接的影响。本文根据TCP所承载的不同业务类型，即分别加载FTP业务和具有自相似特性的业务，分别从拥塞窗口的变化特征、TCP连接的同步现象，以及RED参数调节对TCP性能的影响等三个方面分析了TCP性能。实验数据表明，带宽的增加只是影响TCP工作稳定性的一个原因，TCP所承载的业务类型特征的差异对TCP的稳定性有直接的影响。而采用RED和TD这两种不同的缓存管理机制对TCP的工作稳定性的影响基本没有差异。实验还进一步研究了业务特征与TCP同步现象的联系。结果表明，同步现象除了跟TCP连接数与链路的带宽之比有关外，与TCP承载的业务类型也有关系。通过调整RED的两个主要参数和，实验结果表明，它们对TCP性能的影响不显著。     

Forced nonlinear precession of the magnetization vector under the conditions of an orientation transition

Forced nonlinear precession of the magnetization vector in a normally magnetized magnetic plate under the conditions of an orientation transition is considered. It is shown that, in the field lower than the form demagnetization field, the variable circularly polarized field causes precession of the equilibrium position of the magnetization vector. It is demonstrated based on a vector model in which the precession period of the equilibrium position is inversely proportional to the squared amplitude of the variable field and the sine of the angle of deviation of the equilibrium position of magnetization from the constant field. It is shown that the critical parameters necessary for excitation of precession of the equilibrium position are the amplitude and frequency of the variable field. Diagrams determining domains of existence of precession of the equilibrium position for different saturation magnetization of a magnetic plate are constructed in terms of the coordinates variable field amplitude-frequency. The role of dissipation of magnetization oscillations in the determination of the critical parameters is elucidated. The features of precession in the presence of asymmetric excitation and in the presence of anisotropy in the plane of the plate are noted.     

基于FPGA的数字图像匹配

FPGA在通信、数字图像的相关处理、网络、仪器、工业控制、军事和航空航天等众多领域得到了广泛应用。FPGA已经成为现代电子系统中非常重要的一员。FPGA作为一种专门的半定制电路而出现的,既解决了定制电路的不足,又克服了原有可编程器件门电路数有限的缺点。因而其在数字图像方面的应用的优势也越来越凸显出来,利用FPGA来实现数字图像的匹配已经是现代科技发展的趋势。本文通过采用FPGA技术来实现对数字图像的处理,将一般的RGB图像经过FPGA的处理运算单元转换成灰度图,且保证生成的灰度图像的灰度值是采用一个8位二进制数表示。然后设计并行处理的加法器来实现对灰度图像的每个像素点的灰度值的比较。对每次加法器的运算结果要进行保存,然后将所有的加法器所得的运算结果进行叠加处理,将叠加处理的值再进行存储。对每一幅图像都进行上述相应的处理,最后通过分析比较就可以得出最后的处理结果,最小的两幅图就是最匹配的图像。     

Mixing of Two Renewal Processes and Its Applications to Reliability Theory

The probabilistic behavior of repairable two-state systems is studied. It is assumed that the reliability of the system can be measured by the amount of time the system has been operative. The operating and repair states are a pair of renewal processes, a particular mixture of which describes the statistical behavior of the system. The object of this contribution is to extend the results of Muth who has earlier obtained the average value of the downtime and its variance, when one of the constituent renewal processes has its interval lengths distributed exponentially. This paper, by the repeated use of the method of regeneration points, obtains the mean and mean-square values of the uptime distribution. In addition the correlation of the uptime for different times has been derived and a proof of Takacs' theorem is provided. Since the criteria for the reliability of the system include the associated cost, it is worthwhile investigating the operating cost over any period of time for arbitrary distribution of the two states. In particular a demonstration of the calculation of the first two moments of the total cost is given.     

Wavelet analysis for brain-function imaging

The authors present a new algorithmic procedure for the analysis of brain images. This procedure is specifically designed to image the activity and functional organization of the brain. The authors' results are tested on data collected and previously analyzed with the technique known as in vivo optical imaging of intrinsic signals. The authors' procedure enhances the applicability of this technique and facilitates the extension of the underlying ideas to other imaging problems (e.g., functional MRI). The authors' thrust is two fold. First, they give a systematic method to control the blood vessel artifacts which typically reduce the dynamic range of the image. They propose a mathematical model for the vibrations in time of the veins and arteries and they design a new method for cleaning the images of the vessels with the highest time variations. This procedure is based on the analysis of the singularities of the images. The use of wavelet transform is of crucial importance in characterizing the singularities and reconstructing appropriate versions of the original images. The second important component of the authors' work is the analysis of the time evolution of the fine structure of the images. They show that, once the images have been cleaned of the blood vessel vibrations/variations, the principal component of the time evolutions of the signals is due to the functional activity following the stimuli. The part of the brain where this function takes place can be localized and delineated with precision.     

基于微流控的人卵母细胞特性检测

人的卵母细胞特性的研究对于临床医学具有重要意义,可以通过卵母细胞的大小对其活性进行研究。采用微流控平台与MATLAB算法相结合的方法,利用微流控器件的沟道对卵母细胞进行挤压,由于卵母细胞的活性不同对于挤压的反应也不同,活性越好的卵母细胞通过沟道时变形性越好,经检测卵母细胞有很好的活性;拍摄卵母细胞发生形变与卵母细胞通过沟道的视频,利用MATLAB程序进行图像处理得到卵母细胞的大小,测得卵母细胞的直径约为170μm。这种方法有别于传统方法,在一定程度上使用了算法识别,提高了卵母细胞分析统计的准确度,提升了工作效率。由于人的卵母细胞比较珍贵,只进行了初期实验研究,证明此方法确实可行。     

多光子Tavis-Cummings模型中运动原子与二项式光场相互作用的量子纠缠

利用全量子理论,研究了多光子Tavis-Cummings模型中运动原子与二项式光场相互作用系统的量子纠缠特性,讨论了不同初始状态下的二项式光场系数和原子运动速度对纠缠特性的影响.结果表明：二项式光场系数不影响场熵演化的周期性,但影响场熵峰值大小.随着原子跃迁光子数的增多,场熵演化的周期性和消纠缠现象逐渐消失.原子运动的速度影响场熵的演化周期,且影响场熵峰值的大小,而原子跃迁光子数的增大,会消弱原子运动速度对场熵演化的影响.当光场处于中间态,原子运动速度较低,且原子跃迁光子数较大时,光场与原子可以长久地处于量子纠缠态.     

有线电视加解密系统研究

有线电视加解密技术是有线电视付费管理的一个重要技术保障。在发射端,先将各路电视视频信号进行同步时基校准后,根据同步图案数据确定的同步图案实现每一路电视信号的同步信号的时基处理,以完成电视信号加密(加扰),随后将各路加密(加扰)电视信号连同数据的调制信号一起发送。在接收端,先根据射频信号解调出同步图案数据,并根据解调出的同步图案数据对射频信号进行群解密(解扰),从而实现了电视信号的单加群解。     

An analysis of the second moment of fluctuating electromagnetic fields part II: An application to measurement

The theory of the dyadic field spectrum (DFS) of a fluctuating electromagnetic field developed in Part I is applied to the analysis of a particular experiment. The experiment is simply the measurement of the DFS by means of a two-element interferometer. The analysis includes the effect of the polarization and receiving pattern of the interferometer on the measurement and applies to the DFS of a partially polarized, partially coherent radiation field of arbitrary spectral width radiated by an incoherent source. The approach used in this calculation is that described in Section III-C of Part I. It is based on the application of the dyadic Green's function of the electric type for the interferometer. The power at the receiving terminals of the interferometer is expressed in terms of the DFS of the source and the antenna pattern of the interferometer. A method for measuring the distribution of polarization over the source is described.