《电子CAD》课程教学改革与实践

根据职业岗位能力分析设计<电子CAD>课程教学模式,以项目为载体实施教材改革,以工学结合和开放式课堂实施实践教学改革,旨在提高学习兴趣,学以致用,缩短课堂与企业的距离.     

一种基于MATLAB和Nastran的船体结构优化程序研究

在分析船体结构优化问题的特殊性和由此造成的困难的基础上,论证了自行开发船体结构优化程序的必要性;利用MATLAB可以调用外部程序的特点和其强大的数据处理能力,研究了如何用MATLAB集成Nastran开发船体结构优化程序;最后以甲板板架的优化为例验证了此类程序的开发可行性.     

三种沥青混合料四点弯曲疲劳试验机的对比

采用ASTME1301-95标准,对amesCox＆Sons、COOPERSD IPC沥青混合料疲劳试验机进行了对比研究。沥青混合料初始弯曲劲度模量、疲劳寿命的试验结果及疲劳寿命的回归方程结果表明,上述三种四点弯曲疲劳试验机的试验结果具有较好的一致性：同时指出了应重视沥青混合料疲劳小梁试件的制作工艺与质量对疲劳试验结果的影响。     

Biofuel refinery location and supply chain planning under traffic congestion

This research focuses on planning biofuel refinery locations where the total system cost for refinery investment, feedstock and product transportation and public travel is minimized. Shipment routing of both feedstock and product in the biofuel supply chain and the resulting traffic congestion impact are incorporated into the model to decide optimal locations of biofuel refineries. A Lagrangian relaxation based heuristic algorithm is introduced to obtain near-optimum feasible solutions efficiently. To further improve optimality, a branch-and-bound framework (with linear programming relaxation and Lagrangian relaxation bounding procedures) is developed. Numerical experiments with several testing examples demonstrate that the proposed algorithms solve the problem effectively. An empirical Illinois case study and a series of sensitivity analyses are conducted to show the effects of highway congestion on refinery location design and total system costs.     

A mixed-integer linear program for optimizing sensor locations along freeway corridors

How to optimally allocate limited freeway sensor resources is of great interest to transportation engineers. In this paper, we focus on the optimal allocation of point sensors, such as loop detectors, to minimize performance measurement errors. Although it has been shown that the minimization problem can be intuitively formulated as a nonlinear program, the formulation is so complex that only heuristic approaches can be used to solve the problem. In this paper, we transform the nonlinear program into an equivalent mixed-integer linear model. The linearized model is shown to have a graphical interpretation and can be solved using resource constrained shortest path algorithms. A customized Branch-and-Bound technique is then proposed to solve the resource constrained shortest path problem. Numerical experiments along an urban freeway corridor demonstrate that this sensor location model is successful in allocating loop detectors to improve the accuracy of travel time estimation.     

450MPa级船用钢冲击实验研究及Cowper-Symonds本构模型

应用SHPB实验技术,对450MPa级船用钢进行冲击实验研究,建立了材料的Cowper-Symonds本构模型.冲击实验发现,450MPa级船用钢的动态流动应力在变形过程中,具有二次非线性强化规律、存在强化转折点.当材料的变形小于转折点的应变时,动态流动应力随应变的增大而增大;当材料的变形大于转折点的应变时,动态流动应力随应变的增大而减小.文中还对Cowper-Symonds本构模型的适用范围进行了讨论.     

漏洞检测静态分析方法的优化策略

目前软件漏洞静态解决方案大都有针对性的检测某些方面的软件漏洞,无法做到全面、高效、准确的检测出所有漏洞。通过讨论目前已有的一些漏洞检测技术与工具,并研究这些工具与技术各自存在的优势与缺陷。在此基础上提出改进漏洞检测静态分析的优化策略。     

航路规划反舰导弹对海军合同对海攻击战术的影响

反舰导弹作为一种精确制导武器,其发展备受各国关注。随着航路规划技术应用的日益成熟,越来越多的反舰导弹开始具备航路规划功能。航路规划技术使反舰导弹具备了较强的火力机动能力,使发射平台可以通过火力机动弥补了兵力机动能力的不足,从而深刻影响了海军合同对海攻击战术。文章介绍了航路规划反舰导弹的战术特性,并对合同对海攻击战术进行定性分析,就航路规划反舰导弹对海军合同对海攻击战术产生的影响进行了分析研究。     

强夯置换法加固地基现场试验研究

为评估强夯置换施工对周边油气管道的影响,结合大亚湾石化区强夯置换加固路基工程,在试验路段(周边无油气管)布置了位移边桩、测斜管和强夯振动监测点。利用全站仪测量了地表变形情况;数字测斜仪测量了土体内部的侧向变形情况;振动测试仪记录了强夯施工时地表监测点的振动曲线。试验结果表明:深层侧向位移在2～4 m深度范围内衰减较快,5 m以下深层侧向位移基本为零;强夯置换振动的影响范围为25～30 m。对位移和振动的监测数据的分析,可知在5 000 kN.m的夯击能时:强夯置换施工的影响范围为25～30 m。     

一种发动机总成试漏机的研制

本文介绍了半自动化气密试验的构成、分类及工作原理。针对发动机泄露测试问题,提出了一种发动机总成试漏机的设计方法,并对其结构及工作流程做了简单介绍。最后,阐述了该技术对我国发动机行业发展的意义。