Windows NT与Windows 2000的磁盘特性

本文分别介绍了在Windows NT和Windows 2000系统下的磁盘分类，着重阐述了各类磁盘在Windows NT和Windows 2000系统下的特性、相同点和区别，详细说明了各类磁盘在Windows NT和Windows 2000系统下的使用方法和应该注意的问题一     

优化你的磁盘

优化你的磁盘仲蔚（黑龙江省双鸭山矿务局信息中心，１５５１０３）在实际应用中，经常删除、拷贝文件会造成磁盘空间的杂乱，容易产生交叉链簇，使文件存放不连续，降低磁盘的读写速度，破坏磁盘中的数据。如果能对磁盘及时进行整理，就可以避免上述现象，使磁盘工作在最...     

一个基于动态带宽分配有效实时磁盘调度算法

多媒体服务器需要一个实时磁盘调度算法为具有软实时要求的连续多媒体流服务。传统的磁盘调度算法不适应实时多媒体流。提出一个新的实时磁盘调度DBA-SCAN（Dynamic-Band-width-Assignment-SCAN）算法。DBA-SCAN算法通过带宽预留和接纳控制机制为处于服务中多媒体流提供质量保证。对于非实时任务也预留了带宽以保证非实时任务具有合理的响应时间。DBA-SCAN采用一种积极策略在运行时动态回收未用的带宽。被回收的带宽被用于为可选任务或者更多的非实时任务服务。通过模拟实验对DBA-SCAN算法和WRR-SCAN算法进行对比,实验结果显示,DBA-SCAN为实时多媒体流提供了更好的质量。     

磁盘存储技术的进展

采用垂直记录已使面密度达到３Ｍｂ／ｍｍ＾２，可望超高磁记录面密度达到１００Ｍｂ／ｍｍ＾２。现在磁盘存储技术发展很快。本文概述了磁盘存储技术的进展，展望了高密度磁记录的前景。     

操作系统提高磁盘系统的性能分析与探讨

磁盘驱动调度对磁盘的效率有重要影响。磁盘驱动调度算法的好坏直接影响辅助存储器的效率,从而影响计算机系统的整体效率。本文针对四种不同的调度算法进行分析,通过具体的参数进行探讨。了解了磁盘调度不同算法的优劣。     

磁盘文件的备份方式与备份策略

<正> 为了避免计算机磁盘出错或无意中覆盖或删除数据而造成损失,及时地做磁盘文件的备份是用户一项很重要的工作。但因备份命令的使用方式较多,若使用不当会使备份费时、费力。因此,用户掌握备份方式及其策略与技巧是很重要的。 一、磁盘文件的备份方式 磁盘操作系统DOS中的BACKUP命令提供了三种文件备份的方式,即完全备份,增量备份和差异备份。 1.完全备份 完全备份是指对用户所选择的所有文件进行备份。它包括:(1)全部备份——备份磁盘上所有的文件;(2)部位备份——只备份磁盘上某种类型的文件、或某一驱动器下的所有文件或一个或多个目录下的文件。例如:<1>BACKUP C:\ A:/S 把C盘上所有的文件及子目录备份至A盘;<2>BACKUP C:\POXPRO\*.DBF A:     

智能网络磁盘存储系统通信协议分析

智能网络磁盘存储系统的出现,极大地提高了数据存储的效率和效果,在其实际运行中,存储系统的通信协议具有重要的作用,能够确保智能网络磁盘存储系统的正常、高效运行。因此,应当对这一问题进行细致的分析,从而推动存储技术的不断提高。     

SOLARIS磁盘研究

本文对SOLARIS磁盘从分区、命名进行了简单介绍，然后用命令对SOLARIS中磁盘进行操作，并进行了分析。     

The dynamic digital disk

The DVD (digital versatile disk) standard was the first format to truly unite the computer and consumer electronics environments-but it also launched an unprecedented debate about copy protection. The DVD is much more than just a new and improved version of the CD. Advances in optical storage, signal processing, and disc manufacturing technology have emerged in the 15 years or so since the CD's birth, and the new disc includes or builds on many of them. But DVD has also been a wake-up call for the motion picture and music industries, rousing them to ready their intellectual property for the new age of digital distribution of content. Four main specifications apply to the physical media itself: one each for the DVD-ROM, DVD-RAM, DVD-R, and DVD-RW. Next, at the logical layer, a common file system specification supports all applications. Named the Universal Disc Format (UDF), it was developed by the Optical Storage Trade Association, Santa Barbara, Calif. Together, the logical and physical layers support an overlying set of applications defined by the DVD-Video, DVD-Audio, and (as yet developmental) DVD-Professional specifications     

Analysis of the microstrip disk antenna element

The circular microstrip antenna element is formed by a radiating disk closely spaced above a ground plane. It is modeled as a cylindrical cavity with magnetic walls which can be resonant in the transverse magnetic (TM) modes. The far fields and the radiation conductances for different mode structures have been calculated assuming a magnetic line current flowing along the perimeter of the disk. The directivity of a disk antenna excited in the dominant mode is between 4.8 dB and 9.9 dB, depending on the size. Losses, due to imperfect supporting dielectrics and to the finite conductivity of the conductors, have been derived by means of a perturbation technique. Graphs are given for design purposes showing the input impedance, theQfactor, and the radiation efficiency at resonance for different modes and thicknesses. The air-filled microstrip antenna has the highest efficiency and the broadest bandwidth at a given resonant frequency.     

The scaling of CVD rotating disk reactors to large sizes and comparison with theory

An important advantage of the rotating disk reactor (RDR) geometry for chemical vapor deposition is the one-dimensional nature of the transport process over a wide range of operating conditions. Due to geometric complexity, models for most chemical vapor depositon (CVD) reactors have been used to fit existing data and are not very useful as predictors of performance for changed dimensions, particularly larger ones. Previous RDR modeling results have shown good agreement with experiment for smaller sizes (typically single wafer) and have also resulted in a set of scaling “laws” for scaling to larger sizes. In this work, we report the use of these scaling laws to design larger RDRs and to determine optimal process conditions. We then compare the experimental results to those predicted by the model. Previously, our largest RDR utilized an 180 mm diameter disk, which holds 6 × 50 mm or 3 × 76 mm wafers. The new systems have disks of 300 and 420 mm diameter, holding 17 and 38, 50 mm wafers, respectively. In general, excellent agreement was obtained when the new systems were run at conditions predicted by the scaling laws. As the disk diameter increases, the model calls for a reduced rotational rate, a lower operating pressure and a main carrier gas flow that increases sublinearly with the disk area. Experimental growths were made with the III-V materials AlGaAs and InGaAlP, on GaAs substrates of 50, 76, and 100 mm diameters. Uniformities and electrical and optical properties similar to those obtained in smaller RDR systems were obtained under conditions predicted by the model. We also discuss the trade-offs involved where one parameter is fixed by process needs, necessitating that others must be adjusted accordingly. It should be stressed that these adjustments are all calculated from the model and are designed to maintain the ideal flow and thermal environments obtained with the smaller systems. We find that typical metalorganic chemical vapor deposition process parameters are easily accommodated for these disk sizes. We believe that this is the first report of a truly scalable CVD reactor geometry with both theoretical and experimental justification. Using the RDR technique therefore enables the grower to develop a process on a small system and transfer it to a larger system for manufacturing, without having to reinvent the process. It also enables the CVD system manufacturer to design and build new systems that will perform in a predictable manner, or to adapt new process conditions to an existing system, without requiring extensive re-engineering efforts.     

全硬盘自动播出系统浅析

随着数字化技术的发展,在广播电视领域,非线性记录媒体一磁盘记录设备,具有线性媒体不可能有的一些特点,尤其是对目前有些电视台采用24小时不间断循环播出模式特别适合。目前国内对于重复性大的广告用硬盘播出的比较多,但对于整个播出系统用硬盘播出的还不多。但是国外许多厂家已经推出了一些全硬盘播出的产品,像TEK的Pmfle,Avid的硬盘播出系统,Drm公司的硬盘播出系统等。这些全硬盘播出系统,虽然价格比较贵,但可能是一个发展的方向。对于这些全硬盘播出系统,节目信号是怎样的一个流程,各部分是如何工作的,与传统的切换台方…     

Analysis and performance of some basic space-time architectures

In this paper, we discuss some of the most basic architectural superstructures for wireless links with multiple antennas: M at the transmit site and N at the receive site. Toward leveraging the gains of the last half century of coding theory, we emphasize those structures that can be composed using spatially one dimensional coders and decoders. These structures are investigated primarily under a probability of outage constraint. The random matrix channel is assumed to hold steady for such a large number of M-dimensional vector symbol transmission times, that an infinite time horizon Shannon analysis provides useful insights. The resulting extraordinary capacities are contrasted for architectures that differ in the way that they manage self-interference in the presence of additive receiver noise. A universally optimal architecture with a diagonal space-time layering is treated, as is an architecture with horizontal space-time layering and an architecture with a single outer code. Some capacity asymptotes for large numbers of antennas are also included. Some results for frequency selective channels are presented: It is only necessary to feedback M rates, one per transmit antenna, to attain capacity. Also, capacity of an (M,N) link is, in a certain sense, invariant with respect to signaling format.     

利用动态链接库实现C++与VB的混合编程

C+ +与Visual Basic是目前使用最广的两种通用语言,两种语言各有优点,首先阐述了混合编程的目的和优势,探讨了为什么要混合编程,然后介绍了利用动态链接库实现这两种语言的具体方法,最后举了三个混合编程的例子,这些例子应用了文中介绍的混合编程的方法,也展示了混合编程的优势.     

分类算法的分析与比较

在全面综述通用机器学习归纳分类算法的基础上,采用算法分类机制分析的方法,从预测精度、学习效率、健壮性等方面对决策树和规则归纳分类算法进行深入的分析和比较研究,为在不同的应用领域选择最优分类算法奠定了基础。由于RIPPER分类算法采用了重复增量裁减机制,所以在计算复杂性、分类精度、噪音数据适应性等方面都优于其它分类算法,更适用于入侵检测建模使用。     

热容模式下片状激光介质瞬态温度及热应力分析

为了研究激光介质热畸变对固体热容激光器的影响,数值计算了高功率激光二极管阵列抽运片状激光介质的瞬态温度场和热应力分布。结果表明,在相同的抽运功率密度下,激光介质中的温度分布和热应力分布不仅与激光介质几何构型及抽运光空间分布有关,还与抽运光斑在介质表面的填充因子密切相关。当抽运光斑未充满激光介质时,介质的表面靠近边缘处会出现大的拉应力集中,并且介质表面的最大轴向位移和最大拉应力随光斑填充因子增大而增大;而当抽运光充满介质时,表面是压应力,较小的拉应力存在于介质内部。     

Analysis of blocking dynamic circuits

In order for dynamic circuits to operate correctly, their inputs must be monotonically rising during evaluation. Blocking dynamic circuits satisfy this constraint by delaying evaluation until all inputs have been properly setup relative to the evaluation clock. By viewing dynamic gates as latches, we demonstrate that the optimal delay of a blocking dynamic gate may occur when the setup time is negative. With blocking dynamic circuits, cascading low-skew dynamic gates allows each dynamic gate to tolerate a degraded input level. The larger noise margin provides greater flexibility with the delay versus noise margin tradeoff (i.e., the circuit robustness versus speed tradeoff). This paper generalizes blocking dynamic circuits and provides a systematic approach for assigning clock phases, given delay and noise margin constraints. Using this framework, one can analyze any logic network consisting of blocking dynamic circuits.     

Static and dynamic properties of InGaAsP-InP distributed feedbacklasers-a detailed comparison between experiment and theory

We have investigated the static and dynamic characteristics of phase shifted InGaAsP-InP DFB lasers mainly focusing on a comprehensive comparison between experimental results and numerical simulations. Experimental data of InGaAsP-InP mushroom type DFB lasers have been recorded, such as optical spectra, variations of the mode wavelengths with continuous and pulsed injection current, side mode suppression ratio, relative intensity noise, small signal amplitude modulation, and the transient response to 10 and 15 Gb/s large signal modulation. The theoretical model calculations in this paper are based on the transfer matrix method in combination with a rate equation analysis and take into account longitudinal mode spatial hole burning which is modified by the inhomogeneous current injection resulting from the axially varying Fermi voltage in both the static and the dynamic case. A good agreement between the experimental data and the theoretical simulations has been obtained extracting a set of parameters which consistently describes the measurements of our devices