基于禁忌搜索的物流配送中心选址方法研究

物流配送中心选址问题在物流网络规划中占有非常重要的地位,选址的合理与否直接关系到配送中心未来的发展。针对企业选址的一般要求,以配送中心总成本最小为目标,构造了一种物流配送中心选址模型。该模型较接近现实情况,同时,给出了求解该模型的禁忌搜索算法和简单算例。     

基于“会诊式”推理控制策略的智能型搜索引擎的研究

随着Internet和网络技术的发展,搜索引擎给人们带来的很大便利。本文分析了传统搜索引擎的缺点,探讨了"会诊式"推理控制策略的结构和特点,研究了基于"会诊式"推理控制策略的智能型搜索引擎的特征,并给出其实现技术。     

Welfare Cost of Fluctuations When Labor Market Search Interacts with Financial Frictions

We study the welfare costs of business cycles in a search and matching model with financial frictions. The model replicates the volatility on labor and financial markets. Business cycle costs are sizable. Indeed, the interactions between labor market and financial frictions magnify the impact of shocks via (i) a credit multiplier effect and (ii) an endogenous wage rigidity inherent to financial frictions. In addition, in a nonlinear framework, large welfare costs of fluctuations are explained by the high average unemployment and the low job finding rates with respect to their deterministic steady‐state values.     

Revisiting Real Wage Rigidity

In this paper, we provide empirical evidence that real wage rigidity is not a major cause of unemployment volatility. We argue that there is a disconnect between the theoretical and empirical literatures on this topic. While theoretical studies define real wage rigidity as the response of wages to changes in unemployment following productivity shocks, the empirical literature measures real wage rigidity as the estimated semi-elasticity of wages with respect to unemployment, averaged over all shocks. We show that averaging over shocks gives a biased measure of real wage rigidity, as the impact of other shocks confounds the response to productivity shocks. Our results indicate that the estimated semi-elasticity with respect to productivity shocks is twice as large as the estimated semi-elasticity averaged over all shocks. This implies that one cannot attribute unemployment volatility to real wage rigidity.     

Non-permutation flowshop scheduling in a supply chain with sequence-dependent setup times

In this paper, we consider a flowshop scheduling problem with sequence-dependent setup times and a bicriteria objective to minimize the work-in-process inventory for the producer and to maximize the customers' service level. The use of a bicriteria objective is motivated by the fact that successful companies in today's environment not only try to minimize their own cost but also try to fulfill their customers' need. Two main approaches, permutation and non-permutation schedules, are considered in finding the optimal schedule for a flowshop. In permutation schedules the sequence of jobs remains the same on all machines whereas in non-permutation schedule, jobs can have different sequence on different machines. A linear mathematical model for solving the non-permutation flowshop is developed to comply with all of the operational constraints commonly encountered in the industry, including dynamic machine availabilities, dynamic job releases, and the possibility of jobs skipping one or more machines, should their operational requirements deem that it was necessary. As the model is shown to be NP-hard, a metasearch heuristic, employing a newly developed concept known as the Tabu search with embedded progressive perturbation (TSEPP) is developed to solve, in particular, industry-size problems efficiently. The effectiveness and efficiency of the search algorithm are assessed by comparing the search algorithmic solutions with that of the optimal solutions obtained from CPLEX in solvable small problem instances.     

A decision method for supplier selection in multi-service outsourcing

Although supplier selection in multi-service outsourcing is a very important decision problem, research concerning this issue is still relatively scarce. This paper proposes a decision method for selecting a pool of suppliers for the provision of different service process/product elements. It pioneers the use of collaborative utility between partner firms for supplier selection. A multi-objective model is built to select desired suppliers. This model is proved to be NP-hard, so we develop a multi-objective algorithm based on Tabu search for solving it. We then use an example to show the applicability of the proposed model and algorithm. Extensive computational experiments are also conducted to further test the performance of the proposed algorithm.     

Modeling and optimization of a container drayage problem with resource constraints

This paper investigates the problem faced by firms that transport containers by truck in an environment with resource constraints. The considered area is export-dominant. As a result, there are three types of container movements as inbound full, outbound full, and inbound empty movements. Both the time windows at the terminal and at the customers’ places and the operation times are considered. Empty containers are also regarded as separate transportation resources besides trucks. The total operating time including waiting time of all the trucks in operation is minimized. The problem is first formulated as a directed graph and then mathematically modeled based on the graph. It falls into a multiple traveling salesman problem with time windows (m-TSPTW) with resource constraints. An algorithm based on reactive tabu search (RTS) is developed to solve the problem. A number of randomly generated examples indicate that the algorithm can be applied to the real world.     

基于Lucene的搜索引擎系统的开发与应用

随着网络信息的普及,搜索引擎的作用日益明显。回顾了搜索引擎技术的发展历程,介绍了搜索引擎的工作原理,在此基础上结合企业的实际应用阐述了搜索引擎应用系统的开发过程。     

浅论一种新的检查算法

利用平均步长的方法,查找给定值的结点位置,使用C语言描述其算法,讨论了该算法的平均检索长度,与其他算法比较,得出了该算法的优劣结论。     

TEM4短文听写对英语专业基础教学的启示

TEM4(Test for English Majors[Grade 4])测试中，考生短文听写部分失分较多是普遍现象，这是短时记忆功能紊乱的突出反映。而短时记忆容量减少，大脑工作记忆状态不佳是短时记忆功能紊乱的主要表现形式。本文通过抽样分析TEM4短文听写考生得分情况，阐述导致短时记忆功能紊乱的主要原因及其与听写技能之间的内在关联，并进一步谈及对英语专业基础阶段教学的启示。