《机械基础》试题库系统的建设与组卷

《机械基础》课程是高职机类和近机类的专业基础课,为了提高教学管理水平,以高职机械基础教学中大量的试题为基础,结合教学的实际需求,进行了机械基础系列课程试题库软件的需求分析,提出具有控制整个试卷中各种难度试题的分布的解决方案,并在试题库软件中进行实现组卷、修改和答案生成。该软件具有智能性、独立性和开放性的特点。     

基于OpenXml的《液压与气动》试题库系统的建设与组卷

本文通过研究目前试题库的应用技术和发展现状,并根据《液压与气动》课程的特点,进行了机械基础系列课程试题库软件的需求分析,建立了软件模型,提出具有控制整个试卷中各种难度试题的分布的解决方案。同时,使用OpenXml技术实现试题的预览,并在试题库软件中进行实现组卷、修改和答案生成。该课题以高职液压与气动教学中大量的试题为基础,结合教学的实际需求,利用OpenXml技术完成了《液压与气动》课程试题库软件系统的开发。该软件具有智能性、独立性和开放性的特点。     

机械原理试题库管理系统设计

在Visual Basic6.0环境下设计了“机械原理试题库管理系统”，采用RichTextBox控件实现同一试题字段中的图形与文本组合，使试郑编排更灵活。设计的试题库系统包含试题录入、编辑、查询、试卷生成、打印输出等功能。     

高职《机械基础》试题库中确定试题难度的方法研究

建设高质量试题库的一个难点就是如何确定试题库中每道试题的难度值,解决好这一问题是保证抽卷系统组出的试卷难度合适,不出现试卷难度偏高或偏低情况的关键。本文结合高职《机械基础》试题库的实际情况分析研究了确定试题难度的四种方法,最后得出结论采用模糊综合评价法确定的试题难度具有较高的可靠性,但是计算较为复杂,因此在试题库建设中应将四种方法相结合来共同确定试题的难度。     

CAD／M类软件课程的随机试卷生成系统开发

为了推进 CAD/M 类课程的标准化考试和教考分离,研究操作类的 CAD/M 试题库构成模式,开发随机试卷生成系统是实现标准化考试和教考分离的一个重要途径.分析试题构成的特点和试题问相关性的不同,提出以直选和组选两种方式进行随机抽题,试题间无关联的组卷采用直选方式,相关性试题的组卷采用组选方式,实现了将生成的随机试卷转换成 Word 格式.运行结果表明,系统输出的试卷能满足实际教学的需要.     

基于VB的机械制图试卷自动生成系统开发与研究

根据机械制图试题的特点,以VB 6.0为软件开发平台,采用Access数据库,开发了机械制图试卷自动生成系统.该系统采用将题目按知识点、题型、难度分别存储,分类检索,用户可根据需要按知识点分布、题目类型、难易程度等不同条件,从试题库中自动查找试题并组卷.在排版方面该系统采用了AutoCAD试题文件嵌入到Word文件的混和排版形式.该系统的完成使“画法几何及机械制图”、 “工程制图”、“工程制图基础”等课程的组卷更科学、更规范.     

智能在线考试系统中遗传算法组卷的设计和实现

计算机考试系统研究主要是用来实现学生上机考试,传统的组卷方法采取完全随机的方式来抽题对试卷在能力和层次上的差异性、覆盖面宽窄等现象难以有效解决.本文阐述了遗传算法组卷在计算机考试系统中的设计和实现,从试题的数量及试题库结构两个方面分析、解决上述问题.     

试题库成卷版面设计技术

根据现有试题库软件在生成试卷时版面布局不完善的问题,提出了一种成卷版面设计技术。它使用的核心技术是VBA,通过编程实现自动排版和输出功能。该技术同样适用于期刊、网上购物订单等的版面设计。     

基于网络的智能化通用考试系统的设计与实现

介绍了基于Internet的智能化通用考试系统的设计理论和实现技术,建立了基于题库结构、试题结构和控制参数的“智能组卷功能”的实现算法,给出了“选题”的随机线性规则算法。基于ASP技术,实现了数据库设计、网络系统结构设计等。     

画法几何及机械制图试题库系统的开发

分析《画法几何与机械制图》试卷的特点,提出了这门课程试题库与普及性试题库的差异性及特殊性,在此基础上开发了适用于这门课程的专用试卷生成系统。     

制造业企业的数据采集系统分析与设计

针对某启动器生产厂数据采集需求,设计并实现了基于工业以太网的数据采集系统。该系统分为自动采集和手工采集两部分,对制造过程中的关键实时数据实现自动采集,而无法通过仪表获取的数据通过客户端手工录入：针对手工录入、统计表格种类繁多、形式多样和不同表格间数据重复的问题,本文提炼出几个表格模板,并减少数据冗余,实现了PC客户端录入统一格式。     

A new branch and bound algorithm for loading problems in flexible manufacturing systems

Loading problems in flexible manufacturing systems involve assigning operations for selected part types and their associated tools to machines or machine groups. One of the objectives might be to maximize the expected production rate (throughput) of the system. Because of the difficulty in dealing with this objective directly, a commonly used surrogate objective is the closeness of the actual workload allocation to the continuous workload allocation that maximizes throughput. We test several measures of closeness and discuss correlations between these measures and throughput. Using the best measure, we show how to modify an existing branch and bound algorithm which was developed for the case of equal target workloads for all machine groups to accommodate unequal target workloads. We also develop a new branch and bound algorithm which can be used for both types of problems. The efficiency of the algorithm in finding optimal solutions is achieved through the application of better branching rules and improved dominance results. Computational results on randomly generated test problems indicate that the new algorithm performs well.     

商业银行风险及其防范对策

针对我国商业银行在经营风险中存在的问题,结合商业银行的具体特点,将风险主要分为信用风险、利率风险、流动性风险和操作风险.并对商业银行风险的产生原因、危害以及防范措施提出了看法.     

A novel optimal working process in the design of parametric progressive dies

The objective of this study was to establish a genetic algorithm to solve the problems of ranking the working steps in progressive dies. The working area of punch in working station of progressive die was regarded as the basic reference for gene coding. The moment generated from punch to mold center is defined as fitness function. A common method, remainder stochastic sampling with replacement (RSSR), was adopted to carry out gene reproduction process calculation. We combined the fixed crossover rate and mutation rate to be the crossover and mutation process calculation basis and then obtained the optimum process in which the total moment relative to the mold center was at a minimum. Finally, we developed a “dimension-driven” Windows graphical program written in Visual C++ as an interface for parametric input and communicated with the ACAD software through a DXF file. This system is expected to be a helpful tool for designers facing demands for higher quality, lower cost and shorter delivery time for sheet metal products.     

Experimental Study on the Friction Characteristics of Lasertex Steel Sheets During Metal Forming Process

The surface of steel sheets used in the metal-forming process discussed in this article was textured by a laser-ablation technique. Differently shaped craters are formed in a patterned structure on the steel surface by controlling the pulsed-laser power density, pulse-repetition rate, and pulse duration. Lasertex sheets formed by this process have unique friction characteristics because of the uniform surface roughness and valley-biased topography. The friction of lasertex sheets was studied using a metal-forming bench test rig. Influencing factors, including surface roughness and sliding velocity, were studied under lubricated conditions. The friction of lasertex sheets was compared with that of shot-blasted sheets. The results showed that the coefficient of friction of the lasertex sheet under dry friction decreases with an increase in surface roughness and changes little with varying sliding velocity. With lubrication, the coefficient of friction of the lasertex sheet rises with an increase in surface roughness and decreases with an increase in sliding velocity. Lasertex sheets were found to have lower friction coefficients than shot-blasted sheets over the rage of surface roughness and sliding velocity investigated.     

复合快速成形中板材移送机构及运动仿真研究

研究开发了在复合快速成形中根据板材移送命令,把指定的板材从板材存放处自动找出,并移送到工作台进行叠加作业的板材移送机构及运动仿真系统;采用OpenGL和GLUT图形库进行了机构的造型和可视化;利用VC++(MFC)中的SetTimer定时功能实现了机构的运动仿真;该系统可适用于5种板材的自由选取,运行可靠稳定.     

Selectable light‐sheet uniformity using tuned axial scanning

Light‐sheet fluorescence microscopy (LSFM) is an optical sectioning technique capable of rapid three‐dimensional (3D) imaging of a wide range of specimens with reduced phototoxicity and superior background rejection. However, traditional light‐sheet generation approaches based on elliptical or circular Gaussian beams suffer an inherent trade‐off between light‐sheet thickness and area over which this thickness is preserved. Recently, an increase in light‐sheet uniformity was demonstrated using rapid biaxial Gaussian beam scanning along the lateral and beam propagation directions. Here we apply a similar scanning concept to an elliptical beam generated by a cylindrical lens. In this case, only z‐scanning of the elliptical beam is required and hence experimental implementation of the setup can be simplified. We introduce a simple dimensionless uniformity statistic to better characterize scanned light‐sheets and experimentally demonstrate custom tailored uniformities up to a factor of 5 higher than those of unscanned elliptical beams. This technique offers a straightforward way to generate and characterize a custom illumination profile that provides enhanced utilization of the detector dynamic range and field of view, opening the door to faster and more efficient 2D and 3D imaging.     

The effect of anisotropy in fracture toughness and yield strength in the tearing of ductile sheet materials

The dependence with orientation of the yield strength and tearing fracture toughness of cold-rolled 64/36 -bass and acetate sheets was determined. Parallel strips were cut into larger sheets of the same materials, rolled up on a slotted key, and converged to form pointed tongues which became detached from the larger sheets. The tongue length: width aspect ratio varied with direction in the plane of the sheet. A rigid-plastic fracture mechanics model of sheet tearing, which explained tear path convergence on the basis of minimum work rate [1] is extended to include ‘lift-off’ of the sheet under the slotted roller and gives agreement between the measured aspect ratios and the variation with direction of the independent determinations of yield strength and toughness.     

Tribological properties of few-layer graphene oxide sheets as oil-based lubricant additives

The performance of a lubricant largely depends on the additives it involves. However, currently used additives cause severe pollution if they are burned and exhausted. Therefore, it is necessary to develop a new generation of green additives. Graphene oxide (GO) consists of only C, H and O and thus is considered to be environmentally friendly. So the tribological properties of the few-layer GO sheet as an additive in hydrocarbon base oil are investigated systematically. It is found that, with the addition of GO sheets, both the coefficient of friction (COF) and wear are decreased and the working temperature range of the lubricant is expanded in the positive direction. Moreover, GO sheets has better performance under higher sliding speed and the optimized concentration of GO sheets is determined to be 0.5wt%. After rubbing, GO is detected on the wear scars through Raman spectroscopy. And it is believed that, during the rubbing, GO sheets adhere to the sliding surfaces, behaving like protective films and preventing the sliding surfaces from contacting with each other directly. This paper proves that the GO sheet is an effective lubricant additive, illuminates the lubrication mechanism, and provides some critical parameters for the practical application of GO sheets in lubrication.     

基于ASP.NET的商业银行数据批量处理业务流程管理系统设计

针对现有大型银行数据中心日常数据批量处理业务中的自动化程度低、数据交接错误和操作流程变更频繁等问题。论文分析并设计了一种基于ASP．NET的大型商业银行数据批量处理业务流程管理系统。该系统主要用于大型商业银行的操作和管理人员对于商业银行数据批量处理时数据交接．操作流程变更和操作流程管理。