自适应形式的计算机等级考试的应用研究

目前,计算机等级考试采用的还是基于计算机的考试形式,计算机在整个考试中所起的作用仅局限于题目的呈现和成绩的统计,起到考试"执行者"的作用。由于考试并没有因材施测,考试不能很好地考察学生的真实水平,考生抽取试题时存在"运气",考试的合理性和公平性受到很大质疑。自适应形式的计算机等级考试可以解决传统计算机等级考试固有的弊病,可以实现"因材施测",并且考试的实施和组织更加经济。对自适应形式的计算机等级考试中所涉及的几个关键技术问题进行研究,探索大规模实施自适应形式的计算机等级考试的可行性,并进行模拟研究和实证研究。     

区分度与测验进程相匹配的CAT选题策略

选题策略是计算机化自适应测验(CAT)的核心.该文提出了一种新的选题策略,是一种相对严格的“升a”方法,它选择区分度参数的百分等级尽可能接近测验进程的项目,而且还可以通过调整控制参数的取值来满足不同测验场景的需求.Monte Carlo实验结果表明:该方法在测验精度、项目曝光率控制和题库利用率等方面均表现良好.     

计算机等级考试组卷策略分析与研究

试卷的质量是影响考试达到既定目标的关键因素。在自动化考试系统中,自动组卷是考试系统自动化操作的核心目标之一,而自动组卷的效率与质量由所采用的组卷策略来决定。对计算机等级考试中的模拟系统进行重复组卷研究,结果表明,现行的计算机等级考试系统中采用的组卷策略存在弊端,有需要进一步改进的地方,并针对相关问题提出了解决方案。     

项目反应理论下计算机自适应考试系统的设计与实现

项目反应理论下的计算机自适应考试能够根据应试者的实际能力水平选择相应难度的试题,做到因人施测,实现更快、更准地对应试者能力进行估计。对计算机自适应考试施测过程进行了描述,对模型的选择、选题策略、参数估计等关键技术进行研究并提出相应的解决方法,实现了系统的设计与开发。     

基于计算机自适应的大学生社会责任感测验

构建基于计算机自适应的大学生社会责任感测验的题库,并基于真实数据模拟CAT过程,检测CAT的测验效率并探讨用CAT测量社会责任感的可行性.使用探索性因素分析对测验进行单维性检验,根据项目反应理论选择高质量的项目,构建基于计算机自适应的大学生社会责任感测验(CAT-SRS).然后,基于纸笔测验的实测数据进行CAT模拟,验证CAT-SRS的有效性.研究结果表明:CAT-SRS符合项目反应理论等级反应模型的假设,各个参数比较理想,测量结果与5个原量表纸笔测验结果的相关性较高.CAT-SRS可在测验长度较短时实现对大学生社会责任感的准确测量.     

基于平均数形式的选题策略比较

在3PLM模型下,将改进的最大优先级指标(MMPI)方法和各类平均数形式相结合得到的4种新选题策略在提高测验精度、控制项目曝光均匀性、降低平均违规次数、提高题库利用率等方面均表现更好.经定长测验和不定长测验的蒙特卡洛模拟,MMPI下算术平方根平均数形式的选题策略表现最优.     

基于项目反应理论的自适应考试系统设计

针对传统考试的缺点和不足,介绍了项目反应理论基本概念,在此基础上结合计算机网络技术的发展提出了计算机自适应考试系统的设计。并进一步阐述了系统的体系结构,各功能模块的设计,重点改进了按区分度的选题策略,有效地控制试题曝光率。能够根据不同能力被测试者随机选择试题项目,减少了测试长度,与传统在线考试系统相比提高了考试效率。     

从计算机等级考试看上机操作的重要性

时下人们常把电脑与外语称作“打开21世纪大门的钥匙”,因此信息技术也就成了人们关注的焦点.与此相适应,我国出现了许多形式的计算机考试,其中,影响较大的有水平考试和等级考试两大类.水平考试即“中国计算机应用软件人员水平考试”,主要面向计算机专业人员,在本文中暂不讨论;等级考试则主要面向非计算机专业人员,分为由原国家教委考试中心组织的面向社会的全国计算机等     

计算机等级考试与计算机基础教学改革

计算机等级考试在一定程度上促进了高校计算机基础教学的发展，同时也有一些不利因素，给教学提出了更高的要求。在新形势下，必须转变观念，有针对性地对计算机基础课程的教学进行全面改革，使等级考试与学生实际虚册能力的培养相结合，以培养出更多高素质的实用人才。     

基于项目反应理论的《计算机与信息技术基础》课程的自适应考试系统设计与实现

由于传统的计算机考试都基于经典测量理论,存在诸多缺点和不足.针对现状,结合国内外已有的研究以及实践经验,在现有的新疆计算机一级等级考试题库建设的基础上,尝试实现了基于项目反应理论的《计算机与信息技术基础》课程的小规模自适应考试系统,与之前系统不同的是,它能根据考生的能力水平抽取匹配的题目.结果表明,该系统能更精确地测查...     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

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。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

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.     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to