基于监测技术的注塑工艺参数研究

模腔温度对塑料制品的表面质量具有很大的影响。借助奇石乐模腔温度测量传感器,直接测量注塑成型过程中,塑料模具型腔中的温度最大值,然后采用正交实验的方法,分析工艺参数对模腔温度最大值的影响次序,根据效应关系图详细分析工艺参数对模腔温度最大值的影响规律。     

注塑机前模板的有限元分析

模板是注塑机的重要零件之一,模板结构设计影响机器的性能和制造成本,因此精确计算工作时模板的受力状况较为重要。运用有限元理论和方法对特定型号注塑机的前模板进行计算分析,为模板结构优化设计提供有用数据。     

An outcome-based assessment process for accrediting computing programmes

The calls for accountability in higher education have made outcome-based assessment a key accreditation component. Accreditation remains a well-regarded seal of approval on college quality, and requires the programme to set clear, appropriate, and measurable goals and courses to attain them. Furthermore, programmes must demonstrate that responsibilities associated with the goals are being carried out. Assessment leaders face various challenges including process design and implementation, faculty buy-in, and resources availability. This paper presents an outcome-based assessment approach that facilitates faculty participation while simplifying the assessment and reporting processes through effective and meaningful visualisation. The proposed approach has been implemented and used for the successful ABET accreditation of a computer science programme, and can be easily adapted to any higher education programme.     

Multi-objective process parameter optimization for energy saving in injection molding process

This paper deals with a multi-objective parameter optimization framework for energy saving in injection molding process. It combines an experimental design by Taguchi’s method, a process analysis by analysis of variance (ANOVA), a process modeling algorithm by artificial neural network (ANN), and a multi-objective parameter optimization algorithm by genetic algorithm (GA)-based lexicographic method. Local and global Pareto analyses show the trade-off between product quality and energy consumption. The implementation of the proposed framework can reduce the energy consumption significantly in laboratory scale tests, and at the same time, the product quality can meet the pre-determined requirements.     

基于云计算的数据中心虚拟机管理平台的设计

随着数字化校园和绿色校园的深入开展,校园网各项业务逐渐自动化和集成化。大连理工大学基于VMware虚拟化技术构建了安全高效的数据中心,并对校内各部门提供虚拟机服务。然而在虚拟机申请和管理维护过程中涉及大量人工操作,这构成了数据中心管理瓶颈。基于云计算思想设计了虚拟机管理平台,并以Web服务虚拟机申请为例介绍了该平台的功能。该管理平台对提高虚拟机管理效率有重要意义。     

含水弱化的软岩变参数蠕变损伤模型研究

为准确描述软岩受水弱化作用影响的蠕变特性,基于西原模型,引入与含水率有关的损伤变量Dω以及与时间相关的损伤变量Dt,建立了考虑软岩含水劣化效应的变参数蠕变本构模型,并采用参数反演的方法对模型的合理性和正确性进行了验证。研究表明:水的存在导致软岩蠕变量增加,到达稳定蠕变的时间延长;改进的蠕变损伤模型在不同含水状态和不同应力等级下的拟合曲线与试验曲线都十分吻合;该模型可以较好地描述蠕变全过程尤其是加速蠕变阶段。开展含水弱化软岩蠕变损伤本构关系的研究,将为进一步认识软岩的流变特性提供一定的理论依据。     

基于GPU的多项式矩阵特征值并行计算

以多项式矩阵特征值求解问题为背景,推导任意项式特征值计算方法,阐述了基于图形处理单元(GPU)的并行计算机理并建立Matlab快速并行计算平台。以二次特征值计算为例,分别测试基于GPU的单精度类型计算与双精度类型计算的效率与误差,同时验证公式的正确性。数值计算表明,单精度计算与双精度计算能够大幅度降低计算时间,提高计算效率,误差对比分析也表明GPU的计算结果能够满足一定的工程计算要求。     

基于工作过程系统化的数控机床及其应用教学设计

根据专业培养目标以及主要就业岗位对职业能力和知识结构的要求,以"数控机床和零件"为载体,以数控机床编程与操作能力培养为中心,设计了"认识数控机床、观察分析数控车床、观察分析数控铣床、观察分析加工中心、阶梯轴的编程与加工、带螺纹轴的编程与加工、手轮槽的编程与加工、凸模板的编程与加工、基座的编程与加工"等9个项目,25个学习情境,67个工作任务,并对其中的"凸模板的编程与加工"学习情境进行了教学单元设计.     

计算机仿真技术在自动化专业教学过程中的应用研究

为充分发挥计算机仿真技术的优越性,研究将计算机仿真技术与工科大学自动化专业的教学过程相结合的教学改革方法。研究内容包括计算机仿真技术在课堂授课、课程实验、课程设计和毕业设计等多个教学环节中的应用,以及半实物仿真等先进仿真技术与自动化专业教学过程的结合。将计算机仿真与自动化专业教学相结合,可丰富和完善现有的教学手段和模式,有利于培养学生的创新能力。     

Application of multi-criteria decision making methods for selection of micro-EDM process parameters

Ti-6A1-4V super alloy is an important engi- neering material with good strength to weight ratio and a wide range of applications in a number of engineering fields because of its excellent physical and mechanical properties. This work determines optimum process parameters such as pulse on time, peak current, gap voltage and flushing pressure, which influence the micro-electro discharge machining （EDM） process during machining of Ti-6AI-4V using combined methods of response surface methodology （RSM） and fuzzy-technique for order pref- erence by similarity to ideal solution （TOPSIS）. Central composite design （CCD） is used in the experimental investigation. A decision making model is developed to identify the optimum process parameters in the micro- EDM process, which influences several machining criteri- ons such as material removal rate （MRR）, tool wear rate （TWR）, overcut （OC） and taper. Triangular fuzzy numbers are used to determine the weighting factor for each process criterion. Further a fuzzy-TOPSIS method is used to select the most desirable factor level combinations. The proposed technique can be used to select optimal process parameters from various sets of combinations of process parameters in a micro-EDM process.     

基于数字信号处理的注塑模参数优化实验设计

将实验设计与数据处理、数字信号处理、塑料成型工艺与模具设计等实验课程有机结合,采用正交试验法设计注塑模参数优化实验方案,由Matlab进行极差、方差分析确定影响成型质量的工艺因素显著性,通过回归分析建立工艺优化模型,通过遗传算法对模型寻优,获得最佳工艺参数。拓宽了实验的广度与深度,提高了综合实验质量,激发了学生的学习兴趣和创新意识,提升了科研能力。     

以评促学:构建基于写作任务的作文自动评阅系统

近年来,作文自动评阅(Automated Writing Evaluation,AWE)系统开始广泛应用于英语写作教学,为学生提供及时、反复、丰富的反馈,同时也减轻了写作教师的工作压力,但在写作教学中如何有效利用AWE系统的研究还不多见。文章针对我国英语教学的现状,在促学评价理论的基础上,结合写作教学经验,构建了一个基于写作任务的作文自动评阅系统。该系统旨在充分利用AWE系统培养学生自己修改作文的能力,帮助学生成为一个独立自主的写作者,并提高写作反馈的质量和英语写作教学的效率。     

A review of Computer Science resources for learning and teaching with K-12 computing curricula: an Australian case study

To support teachers to implement Computer Science curricula into classrooms from the very first year of school, teachers, schools and organisations seek quality curriculum resources to support implementation and teacher professional development. Until now, many Computer Science resources and outreach initiatives have targeted K-12 school-age children, with the intention to engage children and increase interest, rather than to formally teach concepts and skills. What is the educational quality of existing Computer Science resources and to what extent are they suitable for classroom learning and teaching? In this paper, an assessment framework is presented to evaluate the quality of online Computer Science resources. Further, a semi-systematic review of available online Computer Science resources was conducted to evaluate resources available for classroom learning and teaching and to identify gaps in resource availability, using the Australian curriculum as a case study analysis. The findings reveal a predominance of quality resources, however, a number of critical gaps were identified. This paper provides recommendations and guidance for the development of new and supplementary resources and future research.     

基于响应面法座椅撑板拉延成型工艺参数优化

针对拉延成型过程易出现的潜在缺陷,选取凸凹模间隙、拉延筋作用力和压边力3个重要工艺参数作为影响因素,采用Box-Benhnken法设计响应曲面试验,建立工艺参数与最大减薄率和最大变厚率之间的响应面模型;通过响应面模型得到最优参数组合,即凸凹模间隙为1mm,拉延筋作用力因子为0.36,压边力为350kN。采用优化参数组合进行试模,试模结果与仿真结果的误差均小于3%,吻合较好,表明基于响应面法对工艺参数进行优化的方案切实可行,为板料拉延成型的优化提供1种方法。     

Learning to support learning together: an experience with the soft systems methodology

An action research approach called soft systems methodology (SSM) was used to foster organisational learning in a school regarding the role of the learning support department within the school and its relation with the normal teaching‐learning activities. From an initial situation of lack of coordination as well as mutual misunderstanding and distrust among some of the actors in the situation, eight months of work yielded as a result a better working environment among the participants, the creation of a volunteer discussion group functioning on a permanent basis, and a clarification and modification of some of the learning support activities. This change can also be described as learning by learning support staff, school teachers and administrators on how to work together, as well as on how to support children's learning in a better way. Nevertheless, another event that occurred after the intervention shows the importance of considering a wider system than that limited by the participants in the intervention.     

读码器手柄注射模设计

分析了读码器外壳塑件的工艺性，详细介绍了读码器手柄的注射模具设计方案，重点阐述了如何解决模具结构设计中的侧向分型抽芯与开模方向的型芯的干涉问题，并总结了该模具的结构特点与使用效果。     

An in-plane low-noise accelerometer fabricated with an improved process flow

We present a bulk micromachined in-plane capacitive accelerometer fabricated with an improved process flow, by etching only one-fifth of the wafer thickness at the back of the silicon while forming the bar-structure electrode for the sensing capacitor. The improved flow greatly lowers the footing effect during deep reactive ion etching （DRIE）, and increases the proof mass by 54% compared to the traditional way, resulting in both improved device quality and a higher yield rate. Acceleration in the X direction is sensed capacitively by varying the overlapped area of a differential capacitor pair, which eliminates the nonlinear behavior by fixing the parallel-plate gap. The damping coefficient of the sensing motion is low due to the slide-film damping. A large proof mass is made using DRIE, which also ensures that dimensions of the spring beams in the Y and Z directions can be made large to lower cross axis coupling and increase the pull-in voltage. The theoretical Brownian noise floor is 0.47 μg/Hz^1/2 at room temperature and atmospheric pressure. The tested frequency response of a prototype complies with the low damping design scheme. Output data for input acceleration from -1 g to 1 g are recorded by a digital multimeter and show very good linearity. The tested random bias of the prototype is 130 μg at an averaging time of around 6 s.     

带同类恶化工件机器排序的多用户模型

We consider a scheduling problem involving a single processor utilized by two customers with constant deteriorating jobs,i.e.,jobs whose processing times are an increasing function of their starting times.Traditionally,such scenarios are modeled by assuming that each customer has the same criterion.In practice,this assumption may not hold.Instead of using a single criterion,we examine the implications of minimizing an aggregate scheduling objective function in which jobs belonging to different customers are evaluated with their individual criteria.We examine three basic scheduling criteria:minimizing makespan,minimizing maximum lateness,and minimizing total weighted completion time.We demonstrate all the scheduling problems considered are polynomially solvable.     

外部注入八字形腔实现带宽增强的随机信号输出

利用分布反馈式半导体激光器（DFBSL）注入八字形光纤环实现了带宽增加的光随机信号输出.在实验中,DFBSL工作在阈值附近,由于其自发辐射而产生的随机信号经放大后注入到八字形光纤环.实验结果表明：经八字形光纤环输出地随机信号带宽增加,并且当八字形环左环无光隔离器时输出信号的随机性要优于有隔离器时的情况.