.Net+SQL Server图像存取的研究与实现

图像是管理信息系统中必不可少的数据,这类大容量数据的存取方式和普通数据有很大的区别。本文主要研究图像在SQL Server数据库中的存取方法。通过存取方法的研究,减少代码、简化算法、降低磁盘读写频率,提高执行效率。     

还原卡的防穿透程序设计

机器狗病毒是通过获取磁盘矢量偏移量以及对虚拟磁盘读写映射到真实磁盘,将请求下发到底层设备,达到绕过还原卡的磁盘过滤,实现系统攻击的。在还原卡加载的驱动中加入代码使还原系统能截获病毒的Irp请求,分析它所要访问的底层磁盘设备的对象信息,修改Windows内核中磁盘相关设备对象的信息,隐藏真实的磁盘设备对象指针,可以使机器狗病毒所发出的磁盘读写请求仍经过还原卡的磁盘过滤动从而达到防穿透的目的。     

基于异步并发的高性能iSCSI系统研究

在大数据时代,虚拟机技术的使用对于存储系统的易管理性、高并发性能提出了新的挑战。在虚拟机环境中,上层应用程序对于底层存储系统的IO特征呈现随机化、碎片化。为了解决这一问题,对FileIO读写模式提出了新的软件架构,结合磁盘条带化思想,使用文件模拟磁盘文件,并使用Linux原生的device-mapper映射机制进行实现。实验结果显示,在高并发环境下,改进后的FileIO模式在读写带宽和iops上都有明显提高。     

基于XOR算法从磁盘崩溃中恢复数据之策略

对服务器数据的保护目前绝大多数采用备份盘技术,数据盘数量与备份盘数量相等.采用冗余盘技术,冗余盘数量小于数据盘数量,这主要得益于逻辑异或XOR算法.无论是单磁盘崩溃或者两个磁盘同时崩溃,利用冗余盘数据与未损数据盘数据进行XOR运算,均能时磁盘崩溃后的数据进行有效恢复.     

教学中实时磁盘调度策略研究

多媒体服务器需要一个实时磁盘调度算法来为实时流提供同步数据.传统的磁盘调度算法没有考虑磁盘请求的实时性,因此需要对传统的磁盘调度算法SCAN进行改进以使其能够应用于多媒体服务器的磁盘请求.本文提出一个新的实时磁盘调度DBA-SCAN(Dynamic-Bandwidth-Assignment-SCAN)算法,DBA-SCAN算法将实时流分为保证任务和可选任务.只有当一个流中的保证任务被满足时,接纳控制才会接纳这个流.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SCAN算法进行对比,实验结果显示,DBA-SCAN明显为实时流提供了更好的质量,同时也大大缩短了非实时任务的响应时间.     

Openstack云环境中虚拟机性能评测

介绍Openstack的特点,运用实验和对比的方法,对基于Openstack云环境中虚拟机的启动时间、虚拟机之间的文件传输速度、虚拟机之间的通信时长、以及虚拟机磁盘读写速度等性能进行了测试,测试结果将为各计算节点项目的部署提供一定的参考。     

基于AES算法的文件加密

介绍AES算法的基本理论,并应用到具体软件实现中。在AES算法实现中,预先存储正反S盒查找表,提高算法执行的运行速度;使用密文挪用技术,解决待处理数据长度不是分组长度整数倍的问题;提出优化文件读写方案,使用多线程和缓存技术,提高系统加密解密的吞吐量。测试加密软件的基本功能,并对软件性能作量级测试。     

存储寄存算法及其应用

传统的“双机热备式”服务计算模型具有难以克服的缺陷,很难满足日益流行的服务计算环境中的数据一致性、数据完整性和数据高可用性的要求,本文提出的存储寄存算法摒弃了旧的计算模型中的共享存储,通过在对端节点中寄存自己的一份完整数据拷贝,从而可以更低的价格实现具有更高数据安全性和可用性以及更快切换效率、更高读写性能的服务计算环境。     

基于多媒体的PC机磁盘调度器

针对目前PC机调度算法存在寻找时问和忽略请求数据在磁盘中位置的缺点，提出了细条磁盘调度结构，细条磁盘调度框架使用了两级调度结构，它由一个与应用类无关的调度器和一组与应用类相关的调度器组成，当各类请求到来时，进入各自的挂起队列中，然后通过类相关调度器移到调度队列中，根据先来先服务的原则从调度队列中分配给服务，这样就大大减少寻找时间，充分利用了请求在磁盘中的位置，从而解决了目前调度算法效率低下的问题。     

数据库并行查询方案研究

传统的连接并行执行算法的执行过程中,易造成算法的网络传输量大,磁盘I/O量大,磁盘占用空间大,直接影响了连接操作的执行效率。而基于合格标记的连接并行执行算法通过关联模式来记录连接结果,避免了大量描述信息从磁盘读出和写入以及在网络上的传送,同时减少了磁盘占用空间,很大程度地提高了连接操作并行执行的效率。     

改进的基于旋转位置磁盘调度算法

1IntroductionIn the past ,for disk-scheduling problems , peopleused disk-scheduling algorithms[1]based on disk armposition. Disk rotation was ignored and only the mov-ing distance of disk heads into was takeninto account .Thus ,the problemof seekti me was turnedinto one ofseek distance and further to absolute sumof the differ-ence between cylinders .Suppose that the head beginsat cylinderC0and the schedule order isC1,C2,…,Cn.The total number of cylinders the heads traversehas the following …     

随书光盘的管理与利用

为了提高图书馆随书光盘的利用率，可通过以下措施对随书光盘进行管理：书盘分离，随书光盘保存在电子阅览室供读者使用；建立随书光盘数据库，充分利用校园网对随书光盘进行网上发布；注重对随书光盘的二次开发。     

基于批判性阅读的专业英语阅读教学实验研究

近年来,批判性阅读模式倍受关注,它主要强调在阅读过程中,学习者不仅要理解文章内容,分析全文的结构,总结主题思想,更要注重判断、分析和评价作者的观点、论证过程、写作目的和语气,以此来形成自己对某个问题的看法。实验研究结果表明：批判性阅读策略培训可以提高学生应用策略的频率和意识;批判性阅读可以提高学生的阅读能力和议论文的写作能力,显著程度大于常规教学方式;学生对批判性阅读教学的满意度较高。     

Component processes of early reading, spelling, and narrative writing skills in Turkish: a longitudinal study

The study examined: (a) the role of phonological, grammatical, and rapid automatized naming (RAN) skills in reading and spelling development; and (b) the component processes of early narrative writing skills. Fifty-seven Turkish-speaking children were followed from Grade 1 to Grade 2. RAN was the most powerful longitudinal predictor of reading speed and its effect was evident even when previous reading skills were taken into account. Broadly, the phonological and grammatical skills made reliable contributions to spelling performance but their effects were completely mediated by previous spelling skills. Different aspects of the narrative writing skills were related to different processing skills. While handwriting speed predicted writing fluency, spelling accuracy predicted spelling error rate. Vocabulary and working memory were the only reliable longitudinal predictors of the quality of composition content. The overall model, however, failed to explain any reliable variance in the structural quality of the compositions.     

Discrepant SAT Critical Reading and Writing Scores: Implications for College Performance

Despite the similarities that researchers note between the cognitive processes and knowledge involved in reading and writing, there are students who are much stronger readers than writers and those who are much stronger writers than readers. The addition of the writing section to the SAT provides an opportunity to examine whether certain groups of students are more likely to exhibit stronger performance in reading versus writing and the academic consequences of this discrepant performance. Results of this study, based on hierarchical linear models of student performance, showed that even after controlling for relevant student characteristics and prior academic performance, an SAT critical reading–writing discrepancy had a small effect on 1st-year grade point average as well as English course grades in college. Specifically, students who had relatively higher writing scores as compared to their critical reading scores earned higher grades in their 1st year of college as well as in their 1st-year English course(s).     

On the basis of source: Impacts of individual differences on multiple-document integrated reading and writing tasks

Few studies have explored how general skills in both reading and writing influence performance on integrated, source-based writing. The goal of the present study was to consider the relative contributions of reading and writing ability on multiple-document integrative reading and writing tasks. Students in the U.S. (n = 94) completed two tasks in which they read text sets about a socioscientific issue, generated constructed responses while reading, and then composed integrated essays. They also completed individual difference measures (general knowledge, reading skill, reading strategy use) and wrote independent essays to assess their writing ability. Mixed effect models revealed that general knowledge and reading skills contributed to integrated essay performance, but that once general writing ability was entered into the model, it became the strongest predictor of integrated writing scores. These results suggest the need for deeper consideration of the role of writing skills in integrated reading and writing tasks.     

Exploring the relationship of creative thinking to reading and writing

This study explores if extensive practice in reading or writing is related to high creative performance. In total, 196 university students participated in the study by filling out a questionnaire and completing a creativity test. The questionnaire inquires the total courses taken in the school year, total hours spent on reading, total hours on writing, and background information. The results indicated that students who spent more time on reading/writing performed significantly better on the creativity test. This study concludes that creativity scores, especially scores of elaboration, are significantly correlated with attitudes toward reading/writing, and the amount of time spent on reading/writing.     

Reading and writing self-efficacy of incarcerated adults

This paper is the first to examine the Reading and Writing Self-Efficacy Scale among incarcerated adults. The aim was to examine whether performance of reading and spelling tests (Reading Speed, Nonsense Words and Spelling) explained individual differences in the participants' efficacy beliefs in reading and writing. Six hundred subjects rated their efficacy beliefs in reading and writing, and 92 of them were also sampled for a reading and spelling test. Factor analysis yielded a two-factor solution dividing the reading items and writing items into separate factors and hierarchical regression analysis revealed that education level and test performance accounted for 36.9% and 34.9% of the statistical variance in reading self-efficacy and writing self-efficacy, respectively. The results suggest that assessment of self-efficacy in reading and writing should be included in a screening procedure of reading and spelling difficulties.     

When Is Reading Also Writing: Sources of Individual Differences on the New Reading Performance Assessments

This research examined component processes that contribute to performance on one of the new, standards-based reading tests that have become a staple in many states. Participants were 60 Grade 4 students randomly sampled from 7 classrooms in a rural school district. The particular test we studied employed a mixture of traditional (multiple-choice) and performance assessment approaches (constructed-response items that required written responses). Our findings indicated that multiple-choice and constructed-response items enlisted different cognitive skills. Writing ability emerged as an important source of individual differences in explaining overall reading ability, but its influence was limited to performance on constructed-response items. After controlling for word identification and listening, writing ability accounted for no variance in multiple-choice reading scores. By contrast, writing ability accounted for unique variance in reading ability, even after controlling for word identification and listening skill, and explained more variance in constructed-response reading scores than did either word identification or listening skill. In addition, performance on the multiple-choice reading measure along with writing ability accounted for nearly all of the reliable variance in performance on the constructed-response reading measure.     

对安全使用计算机闪存的思考

从计算机闪存的接口、闪存驱动、闪存读写、闪存安全使用、闪存加密、以及闪存病毒六个方面探讨如何正确使用计算机闪存问题,并提出相应的对策,非常必要。