The Electric Traveling Salesman Problem with Time Windows

To minimize greenhouse gas emissions, the logistic field has seen an increasing usage of electric vehicles. The resulting distribution planning problems present new computational challenges.We address a problem, called Electric Traveling Salesman Problem with Time Windows. We propose a mixed integer linear formulation that can solve 20-customer instances in short computing times and a Three-Phase Heuristic algorithm based on General Variable Neighborhood Search and Dynamic Programming.Computational results show that the heuristic algorithm can find the optimal solution in most small-size instances within a tenth of a second and achieves goods solutions in instances with up to 200 customers.     

如何运用动态规划分配供货时间

动态规划理论经常用于资源分配问题的研究,但分配资源时没有考虑时间先后的问题,有很大局限性,不符合实际情况。本文在动态规划理论应用的基础上,针对实际情况做了一定处理,解决了这一问题。     

Instrumentality: A note on the Aesthetics of Programming

In this paper I want to describe a way to explain the beauty of instrumental action. Instrumental action is, in this paper, any action whose goal lies outside the action itself. Most of our everyday actions could be included in this category: driving to work, taking the buss, writing memos, letters and e-mails, designing cars, managing organisations, etc. We do not do these things for their own sake, we do them in order to attain some other goal. I do not intend to get any deeper into the concept of instrumental action so I will use an example instead of talking in a general manner. I have chosen to lead the argument from the example of programming, but this paper is not primarily about technology. The Dutch painter Piet Mondrian (1872-1944) had already been a relatively well known painter for a few years before he became (in)famous for his revolutionary ideas about aesthetics. His ideas are better transmitted through his paintings but he also wrote about them, which makes it easier for anyone who wishes to use them as references. In this case, all references to him are extracted from the collection The New Art-The New Life (Mondrian 1993, Da Capo Press, New York). I shall try to give an account of the aesthetics of instrumental action with the help of Mondrian's writings. I would like to explain the beauty of instrumental action using the concept of "relationships", as Mondrian did for his paintings.     

“C语言程序设计”双语教学改革研究

现代教育体制人才培养目标是塑造复合型人才,程序设计和外语是复合型人才必须具备的两项基本能力。"C语言程序设计"课程已成为理工类专业程序设计的必修课程,课程中开展双语教学改革可以很大程度上推进人才培养战略的步伐。     

基于AHP-整数规划法的油料配送中心选址模型

油料配送中心选址对油料的保障效率有着重要的影响。影响油料配送中心选址的因素众多,文中首先选用层次分析法(AHP)法对这些影响因素进行处理,得到各个候选地址的权值。然后针对AHP方法无法解决条件约束问题,将AHP与整数规划方法相结合,提出了一种基于AHP-整数规划的油料配送中心选址模型。最后通过实例说明该模型能够有效解决油料配送中心选址问题。     

《Java程序设计》双语教学研究

文章首先明确了开展《Java程序设计》课程双语教学的必要性。根据教学实际的需要,本文从教材选取、教学方法和手段、课程实践和课程考核等方面,探讨了该课程双语教学的实施方法。教学实践证明了教学方法的有效性。     

基于Winsock的TCP/IP网络通信

西方通过单地址的点－－点通信和广播地址的广播通信程序的设计，较深入地探讨了基于Ｗｉｎｓｏｃｋ的ＴＣＰ／ＩＰ网络通信编程技术。     

基于柔性理念的新产品研发资金投入与时间控制研究

在产品生命周期的基础上,对一个产品的创意酝酿到最终退出市场进行全面分析,建立了非线性规划模型,从而对其整个生命过程的资金投入与时间进行有效控制。然后,建立了基于柔性理念的多目标规划模型,并用人-机会话及滚动式方法对其求解。结果旨在为企业寻找最优决策方案,进而最大限度地实现研发价值。     

微机网数据与VAX机的传递转换及用户信息Oracle的编程实现

本文探讨了微机ＮＯＶＥＬＬ网与ＶＡＸ机的数据传送，Ｆｏｘｐｒｏ数据库与Ｏｒａｃｌｅ库的转换及用户信息Ｏｒａｃｌｅ的编程实现。     

长江流域海铁联运模式下港口集疏运物流网络研究

为加快构建长江流域综合立体交通走廊,提出以海铁联运模式为主的港口集疏运物流网络。根据复杂网络的中心性理论选取度中心度、中间中心度、接近中心度和特征向量中心度构建城市物流连通性评价指标,结合收敛相关算法对城市进行分类,筛选出长江流域海铁联运物流网络的枢纽城市;建立以物流成本最小化为目标,考虑枢纽城市铁路运输规模效益的整数规划模型,以模拟退火算法求解该模型,构建以南京、武汉、重庆、株洲、鹰潭为枢纽的海铁联运物流网络。研究发现,铁路运输的单位成本随运输规模和运输距离的提升而降低;与各城市不经枢纽的单一运输模式相比,货物由海铁联运物流网络运输可获得更大的运输规模效益,使其产生的运输成本更低,可节省约20.5%的物流成本。