在线考试系统数据库安全分析与对策

在线考试系统作为一种考试方式,在实际教学中得到了广泛的应用,但是很多在线考试系统存一定的安全问题,本文着重在线考试系统的数据库问题解决方案与实现途径。     

在线考试系统的研究与设计

介绍在线考试系统涉及到的体系结构以及Web数据库技术,并分析在线考试系统的功能需求,在此基础上设计了在线考试系统的三大功能模块,以实现方便考试管理及防止作弊的功能．     

基于J2EE在线考试系统的设计与实现

在线考试系统可以利用网络,随时随地对学生进行考试,是传统考场的延伸,课题是在分析在线考试系统现状的基础上,结合软件工程的思想,详细分析了在线考试系统的总体结构。在线考试系统是在结合先进的教学管理方法和现代网络技术基础上,采用JSP、JavaBean等技术构建,实现题库管理、试卷的手动/自动生成、考试管理、考试控制、考试结果的公布与查询等功能。     

在线考试系统的设计与实现

考察了现有考试系统存在的缺陷,分析了在线考试系统的结构,并提出了一种利用Internet进行考试的在线考试系统的设计思路和实现方法。     

基于JSP的在线考试系统的设计

在线考试系统能够为学校提供一个简化传统考试的方案,是现代考试方法改革的必然要求,也是深化教育教学改革的需要.基于JSP的在线考试系统正是结合了JSP、MySQL数据库等技术开发出的一种在线考试系统,从在线考试系统的功能需求分析入手,得出其应包含管理员模块、学生考试模块、教师维护模块、系统退出模块,并详细介绍各个模块的功能设计.     

高校在线考试系统的设计实现

在线考试系统由于具有减轻教师负担,节约成本,提高考试公平性的特点,已经开始被应用到各种考试中。高等院校由于考试科目繁多,学生数量庞大,对在线考试系统的需求更为强烈。本文针对高校考试的特点,对在线考试系统进行了分析和基础设计。     

基于Web的在线考试系统

提出了基于web的在线考试系统的解决方案，介绍了在线考试系统的功能、系统设计以及人机交互的实现，讨论了在线考试系统的实现策略、对系统文件及数据库的保护、系统的安全性等。     

基于MVC和Ajax技术的在线考试系统的设计与实现

文章首先分析了在线考试系统的开发背景和意义,探讨了在线考试系统的开发模式和实现技术;然后介绍了以J2EE体系结构为基础的MVC开发模式和Ajax技术,并以此基础上实现了在线考试系统。     

高职院校网络在线考试系统的应用现状分析

针对高职院校网络在线考试系统的建设问题进行了探讨和分析,指出,随着网络技术在教学中的不断应用和普及,改变传统的考试模式,探索网络在线考试系统的应用,是一种趋势。对在线考试系统可实现的功能指标和创新之处作了具体阐述,并提出了完善系统的措施。     

基于.NET的发卷交卷系统设计

随着计算机技术的不断普及,高校的普通期末考试,很多科目都是在机房利用计算机进行考试,一方面基于B/S模式的在线考试系统虽然在客观题方面有着比较大的优势,然而对于主观题并无优势可言,有些主观题甚至不适合采用基于B/S模式的在线考试系统来进行考试;另一方面这种基于B/S模式的在线考试系统通用性不强,一个考试系统只适合一门课程的考试;针对基于B/S模式的在线考试系统的局限性,提出了用.NET开发通用性很强的适合多种课程考试的发卷交卷系统。     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

英文诗歌中的喻类修辞

为了有助于提高英文爱好者的个人情操、文化素养和学习兴趣,以及专业人员对英语学习和研究进行多途径的探索,本文通过一些精选诗歌的引证和分析,着重论述了喻类修辞法在英文诗歌中的运用其及效果。     

Man Is Unable to Change the Miserable Life——Analysis of the Arrangement of Four Characters in The Glass Menagerie

Tennessee Williams is considered as one of the most important American playwrights since World War II.The Glass Menagerie is his first successful drama,which describes a tragic situation of family and means to say that Man is unable to change the miserable life,no matter whatever means he try,This essay focuses on the analysis of the arrangement of the four main characters:Laura.Amanda,Jim and Tom to reveal the theme.Laura is fragile.Amanda is brave.Jim is vital.Tom is sensible.And all of them develop and try the different means to struggle against life,but fail tragically.With the evidence,the paper comes to conclusion naturally that Man is unable to change the miserable life,and he dooms to fail.     

Characterization of root-nodulating bacteria on Retama raetam in arid Tunisian soils

The aim of this study is to investigate the diversity of Retama raetam root-nodule bacteria isolated from arid regions of Tunisia. Twelve isolates, chosen as representative for different 16S rRNA gene patterns, were characterized by 16S rRNA gene sequencing and phenotypic analysis. Isolates were assigned to Sinorhizobium, Rhizobium and Agrobacterium. Symbiotic properties of Sinorhizobium and Rhizobium isolates showed a large diversity in their capacity to infect their host plant and fix atmospheric nitrogen. Strain RK 22 identified as Rhizobium was the most effective isolate.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。