快速CRC校验及其实现

在数据信息传输中,检错能力最佳要算循环冗余校验码(简称CRC校验)。但CRC校验最突出的问题是校验时间长,从而影响数据信息的传输速度。本文介绍的快速CRC校验法,比现有一般的CRC校验提高速度7～8倍。     

《记帐凭证录入模块》课件的设计与实现

课件能模拟会计平时工作记帐过程,充分显示动态的指令流和数据流。具有交互性,数据自动校验维护。采用模拟教学方式的记帐凭证录入模块课件的设计目的、总体设计、实现技术     

大数据访问中信息传输冗余量消除仿真

针对传统的大数据访问中信息传输冗余量消除方法存在查全率、信息传输冗余量消除效率以及速率较低等问题,提出了基于Hamming距离值的大数据访问中信息传输冗余量消除方法。利用滑动以及滚动相结合的窗口移动模式减少窗口计算量,将Rsync滚动校验算法以及MD5算法相结合,在文件任意位置开始计算滚动校验值,通过递进关系,获取连续数据块的校验值,根据不同数据块的校验值进行数据匹配。将经过匹配后的数据块利用CDC分块检测算法进行检测,根据余弦相似度计算公式以及Hamm距离值计算相似度,实现大数据访问中信息传输冗余量消除。实验结果表明,所提方法有效提高了冗余信息查全率、信息传输冗余量消除效率以及速率,能够快速、准确地消除多余的信息。     

基于B／S结构的通用学生管理系统的开发

本文叙述了通用学生成绩管理系统的整体设计思路。重点介绍了学生成绩管理系统的数据库设计、系统组成、功能设计、数据喜警计等。本系统主要功能有用户管理、学生注册、班级信息录入、学生信息录入、班级课程录入、学校专业信息录入、课程信息录入、学生成绩录入、数据统计等。     

射频仿真系统中多机通信的差错控制技术

本文介绍了在射频仿真系统中，对多机通信过程中可能出现的错误的检测和控制技术。根据本系统专用接口卡的特点，选择了方正校验和数据表决校验相结合的方法，对数据传输错误进行检测，为提高方正校验的检错能力，我们将１６位信息位平均分成了４组，分别进行校验，并利用计时和计数的方法，解决了数据丢失问题。     

用Delphi编写一个实用的DB控件

在数据库的开发中，经常会遇到这样的情况，用户在进行某个数据表的增加、删除、修改时，有些字段的值需要从其他的静态表中选取，再存入数据表。比如我们在处理企业职工信息时，需存储职工的职称，这时，我们会把已有的职称进行编码并存入职称静态表中，而在企业职工信息表中只存储该职工的职称代码，这样使数据的冗余达到最小。在录入该字段时，我们会使用Delphi的DBLookUp类控件进行录入。     

基于B/S结构的通用学生管理系统的开发

本文叙述了通用学生成绩管理系统的整体设计思路。重点介绍了学生成绩管理系统的数据库设计、系统组成、功能设计、数据库设计等。本系统主要功能有用户管理、学生注册、班级信息录入、学生信息录入、班级课程录入、学校专业信息录入、课程信息录入、学生成绩录入、数据统计等。     

一种面向RAID阵列的SSD设计优化方法

随着大数据时代的到来,固态硬盘已经逐渐在大型数据中心得到应用。作为使用最广泛的RAID技术,RAID5也开始应用于固态硬盘阵列,以保证数据的可靠性。然而,RAID5中校验信息需要频繁地更新,尤其在随机访问中,频繁地更新校验信息将会对固态硬盘阵列的性能和寿命造成很大的影响,针对此问题,提出PA SSD(Parity Aware Solid State Disk)控制器设计,从RAID5控制器得到校验信息的逻辑地址,在SSD控制器中设置一个缓存Pcache,暂存更新后的校验信息,并在SSD中将数据和校验分开布局,设置专门的区域存放校验信息。通过实验仿真测试,提出的方法能有效地减少校验信息对SSD的写操作,并且减少了SSD的擦除次数,提升了SSD阵列的性能和寿命。     

管理信息系统中通用在线辅助录入技术的实现

在线辅助录入是指录入数据的当时,立即通过按特定的键,调入必要的预录信息供选择录入,不必具体输入要录入的内容,从而达到快速录入的目的.在管理信息系统的数据录入时,往往会遇到各记录某些字段的内容是重复录入,而且这些重复的内容可以用数据库进行编码管理.然而一般的操作人员,对数据中的汉字信息录入深感速度慢,影响了应用系统的处理速度.事实上,这类汉字信息的录入问题可以利用FOXBASE的ON命令,通过按键调用中断处理,让用户实时选择在线辅助录入,使相关字段信息的录入得以很快实现,从而大大地提高录入速度.     

高考成绩数据处理系统的设计与实践

文章在文献「１」的基础上，结合高考成绩数据处理工作的特点，给出一集数据库生成，数据采集录入，数据校验等功能的一体的高考成绩数据处理系统描述与实现。     

Improving data accuracy: Selecting the best data checking technique

Data entry errors can have catastrophic effects on the results of a statistical analysis. Therefore, researchers often spend considerable effort checking their data. This paper compared the effectiveness of three data checking methods – double entry, read aloud, and visual checking – using the types of data and data entry personnel that are typically used in psychological research. To compare these techniques, we created 20 data sheets and entered them into the computer. Next, we deliberately introduced errors into this data set. Participants’ job was to locate and correct these errors.     

Preventing human error: The impact of data entry methods on data accuracy and statistical results

Human data entry can result in errors that ruin statistical results and conclusions. A single data entry error can make a moderate correlation turn to zero and a significant t-test non-significant. Therefore, researchers should design and use human computer interactions that minimize data entry errors. In this paper, 195 undergraduates were randomly assigned to three data entry methods: double entry, visual checking, and single entry. After training in their assigned method, participants entered 30 data sheets, each containing six types of data. Visual checking resulted in 2958% more errors than double entry, and was not significantly better than single entry. These data entry errors sometimes had terrible effects on coefficient alphas, correlations, and t-tests. For example, 66% of the visual checking participants produced incorrect values for coefficient alpha, which was sometimes wrong by more than .40. Moreover, these data entry errors would be hard to detect: Only 0.06% of the errors were blank or outside of the allowable range for the variables. Thus, researchers cannot rely upon histograms and frequency tables to detect data entry errors. Single entry and visual checking should be replaced with more effective data entry methods, such as double entry.     

Factors affecting accuracy in the quality control checking of fresh produce labels: A situational and laboratory‐based exploration

Manufacturing industries often rely on quality control staff to ensure mistakes are detected before products are shipped to customers. Undetected errors can result in large financial and environmental costs to packaging companies and supermarkets but the contributors to such error are underexplored. The research reported in this paper investigated human error in the quality control checking of information displayed on the labels which accompany packaged fresh produce. Initial work sought to understand the demands of label‐checking in the packhouse environment, through interviews with key quality control staff, in situ observations, and the study of historical error data held by a fresh produce packaging company. This study highlighted the dynamic and cognitively challenging environment in which label‐checking occurred, while the historical error data indicated both the scale of the packhouse's work and the infrequency of error occurring. In a separate strand of laboratory‐based research, experienced and novice label‐checkers were presented with a simulated label‐checking task and a battery of computerized and pen‐and‐paper tests. These tasks were administered to determine whether cognitive abilities could predict label‐checking accuracy in a controlled laboratory environment. Stronger abilities in two cognitive processes (information processing speed and inhibition) predicted greater overall accuracy and higher detection of labeling errors. In identifying potential contributors to human error in the quality control checking of product labels both in situ and in the laboratory, the results are relevant to manufacturing, wherever information is printed on labels, especially when labeling processes depend upon human data entry and human quality control checking.     

Secure service composition with information flow control in service clouds

Service clouds built on cloud infrastructures and service-oriented architecture provide users with a novel pattern of composing basic services to achieve complicated tasks. However, in multiple clouds environment, outsourcing data and applications pose a great challenge to information flow security for the composite services, since sensitive data may be leaked to unauthorized attackers during service composition. Although model checking has been considered as a promising approach to enforce information flow security precisely, its high complexity on modeling and the heavy cost on verification cause great burdens to the process of service composition. In this paper, we propose a distributed approach to composing services securely with information flow control. In our approach, each service component is first verified through model checking, and then a compositional verification procedure is executed to ensure the information flow security along with the composition of these services. The experimental results indicate that our approach can reduce the cost of verification compared with the global verification approach.     

光电经纬仪外引导功能室内检测技术的实现

根据光电经纬仪室内检测工作的需要,在研究数据通信原理的基础上,建立了基于TCP/IP协议的检测网络,并利用计算机软件模拟外场中各种引导设备的引导信息,将各种不同的外引导信息通过检测网络传输传送到多个经纬仪分站系统,同时接收每个分站返回的数据,进行综合分析,实现了在室内检测光电经纬仪外引导功能,为经纬仪的室内检测提供了一种新的手段.     

被动式井下考勤系统上位机模块的设计与实现

为对矿井井下人员出勤情况进行有效的统计和管理,实现矿山井下人员管理的信息化和自动化,采用RFID技术作为人员信息采集的手段,选用有源射频卡作为考勤卡,从而实现远距离、多人员、高速度被动式刷卡。通过分任务数据处理的方式设计上位机控制模块。以J2EE架构开发考勤信息处理发布系统,使井下人员信息共享。现场应用结果表明,系统设计合理、稳定,被动式刷卡避免了以往的黑工现象。     

EPA: An efficient and privacy-aware revocation mechanism for vehicular ad hoc networks

Security is vital for the reliable operation of vehicular ad hoc networks (VANETs). One of the critical security issues is the revocation of misbehaving vehicles. While essential, revocation checking can leak private information. In particular, repositories receiving the certificate status queries could infer the identity of the vehicles posing the query and the target of the query. An important loss of privacy results from this ability to tie the checking vehicle with the query’s target, due to their likely willingness to communicate. In this paper, we propose an Efficient and Privacy-Aware revocation Mechanism (EPA) based on the use of Merkle Hash Trees (MHT) and a Crowds-based anonymous protocol, which replaces the time-consuming certificate revocation lists checking process. EPA provides explicit, concise, authenticated and unforgeable information about the revocation status of each certificate while preserving the users’ privacy. Moreover, EPA reduces the security overhead for certificate status checking, and enhances the availability and usability of the revocation data. By conducting a detailed performance evaluation, EPA is demonstrated to be reliable, efficient, and scalable.     

面向去中心化存储的数据流行度去重模型

数据流行度去重方案中存在检测机构不诚实、数据存储不可靠等问题,提出一种面向去中心化存储的数据流行度去重模型。针对检测机构不诚实,模型结合区块链的不可篡改性与智能合约的不可抵赖性,将智能合约作为检测机构执行数据的重复性检测和流行度检测,保障了检测结果的真实性。针对数据存储不可靠问题,提出一种文件链存储结构,该结构满足数据流行度去重的要求,并通过添加辅助信息的方式,建立分布在不同存储节点中实现物理/逻辑上传的分片之间的逻辑关系,为流行度数据去中心化网络存储提供基础;同时,在数据块信息中添加备份标识,借助备份标识将存储网络划分为两个虚拟存储空间,分别实现数据和备份数据的检测与存储,满足了用户备份需求。安全性分析和性能分析表明,该方案具有可行性,保障了检测结果的真实性,并提高了数据存储的可靠性。     

基于知识管理的 BIM 模型建筑设计合规性自动检查系统研究

建筑设计合规性自动检查对保证建筑信息模型(BIM)符合设计规范要求,增加规范 检查自动化程度具有重要意义。结合合规性检查理论与专家系统方法,提出了以BIM 模型为检 查对象的合规性自动检查系统框架,以规则知识与推理机制分开的方式实现合规性检查过程。 以《住宅设计规范》为例,对规范中的条文进行知识分析,总结出规范知识表达式,构建规则 库和规则库访问机制;建立了逻辑策略下推理机制,将规则库中的规则信息与BIM 信息进行推 理,输出检查结果;最后构建了合规性检查系统验证平台,通过BIM 模型实例完成模型数据提 取及规则推理的过程,实现了合规性检查的功能,验证了合规性检查方法框架。该方法在一定 程度上能够指导后续的合规性检查相关研究,有效提高BIM 模型的建筑设计合规性检查效率, 保证检查质量,促进建筑工程领域信息化的发展。     

Efficient Remote Data Possession Checking in Critical Information Infrastructures

Checking data possession in networked information systems such as those related to critical infrastructures (power facilities, airports, data vaults, defense systems, etc.) is a matter of crucial importance. Remote data possession checking protocols permit to check that a remote server can access an uncorrupted file in such a way that the verifier does not need to know beforehand the entire file that is being verified. Unfortunately, current protocols only allow a limited number of successive verifications or are impractical from the computational point of view. In this paper, we present a new remote data possession checking protocol such that: 1) it allows an unlimited number of file integrity verifications; 2) its maximum running time can be chosen at set-up time and traded off against storage at the verifier.