具有学习效果的两机流水车间调度启发式算法研究

以最小化时间表长为目标函数,对具有学习效果的两机流水车间调度问题进行研究.由于工序加工时间引入了学习效果,传统的Johnson法则和NEH启发式算法不再适用.针对该问题的NP-hard特性,提出了JNEH和MNEH两种求解问题的多项式启发式算法.计算机数据实验证明了新的启发式算法求解问题的可行性和有效性;表明了JNEH启发式算法和MNEH启发式算法对小规模问题求解的精度更高、稳定性更好;同时证明MNEH启发式算法对求解大规模问题具有比传统算法更好的寻优性能和鲁棒性.     

带时间窗车辆调度问题的蚁群算法

为求解带时间窗约束的配送中心车辆调度问题, 运用蚁群算法把时间窗约束转化为惩罚函数形式, 将其并入目标函数后, 建立了满足客户配送时间要求条件下的运输费用最低的车辆调度模型, 提出了模型的求解程序, 并以某算例进行了仿真分析。分析结果表明: 该模型通过参数的不同标定, 可以转化成旅行商模型、硬时间窗或软时间窗的车辆调度模型; 仿真算例中, 配送路线最优行驶距离为794 km, 车辆最长行驶时间为8.2 h, 该算法能有效求解配送中心车辆调度问题。     

求解带硬时间窗车辆路径问题的改进UMDA 算法

针对带硬时间窗的车辆路径问题(VRPHTW)求解,提出了一种混合单变量边 缘分布算法(hybrid UDMA,hUDMA),改进了基本UMDA的概率模型.统计节点按路径分 布的概率,使其能够在解空间上找到节点-路径的分布关系,提高了UMDA的全局搜索 能力.采用两阶段插入法进行最佳节点搜索和路径分配完成UMDA采样操作,通过种群 进化来获取最优解.计算Solomon 100 客户的6 类问题56 个算例的实验结果表明：在最优 解的取得方面,C类算例能够全部取得最优解,R、RC类算例能以50%左右概率取得最优 解;在平均误差方面,C类算例计算结果与已知最优解一致,R、RC类算例计算误差率与 已知最优解比较接近,平均误差率为1.03%.     

Imprecise reliability assessment for heavy numerical control machine tools against small sample size problem

Small sample size problem is one of the main problems that heavy numerical control (NC) machine tools encounter in their reliability assessment. In order to deal with the small sample size problem, many indirect reliability data such as reliability data of similar products, expert opinion, and engineers’ experience are used in reliability assessment. However, the existing mathematical theories cannot simultaneously process the above reliability data of multiple types, and thus imprecise probability theory is introduced. Imprecise probability theory can simultaneously process multiple reliability data by quantifying multiple uncertainties (stochastic uncertainty, fuzzy uncertainty, epistemic uncertainty, etc.) together. Although imprecise probability theory has so many advantages, the existing natural extension models are complex and the computation result is imprecise. Therefore, they need some improvement for the better application of reliability engineering. This paper proposes an improved imprecise reliability assessment method by introducing empirical probability distributions to natural extension model, and the improved natural extension model is applied to the reliability assessment of heavy NC machine tool spindle to illustrate its effectiveness.     

浅谈ATS故障下的行车调度方法

目前广州地铁一、二、四号线都采用西门子的ATS列车自动控制信号系统,该系统主要由COM机工作站、SICAS联锁工作站及MMI、LOW人机接口工作站组成整个信号系统。在中央ATS监控系统发生故障时,作为调度控制中心的行车调度员,无法对全线列车进行有效监控与指挥,在该信号故障下,行车调度员在自动监控系统部分功能缺失的情况时,实行人工控制模式,降低ATS故障下通讯缺陷、信号降级运行下对行车的影响,为乘客提供优质的服务,减少该故障对营运服务的影响。     

Opportunistic preventive maintenance optimization for multi-unit series systems with combing multi-preventive maintenance techniques

This paper proposes a dynamic opportunistic preventive maintenance (PM) optimization policy for multi-unit series systems by integrating multi PM techniques. Two PM techniques, periodic PM and sequential PM, are considered. Whenever one of the units reaches its reliability threshold, a PM action has to be performed on that unit. At that time the whole system has to be stopped and PM opportunities arise for the other units of the system. An optimal PM practice is determined by maximizing the short-term cumulative opportunistic maintenance (OM) cost savings for the whole system. Numerical examples are given to show how this approach works. Finally, a comparison between the proposed PM policy and the other policies is given.     

沥青路面推移拥包形成的原因及防治措施

沥青路面属柔性路面，它具有一定的行车舒适性、振动小和噪音低等优点，在我国的公路路面中占绝对的比例。但就已建公路而言，有相当部分没有完成预期的使用功能，存在使用期达不到设计使用年限的问题。有的路面第一年建成，当年或第二年就出现部分推移和拥包，严重影响了车辆行驶的安全性、舒适性，在社会和经济上造成了不可弥补的损失和影响。     

沥青混凝土路面早期破坏原因及防治措施

路面早期破坏即道路在使用初期就产生裂缝．沉陷、变形等现象。沥青混凝土路面的破损形式主要有裂缝(包括横、纵．龟、网裂)及变形(包括车辙、推移．波浪、沉陷、松散、剥落、坑槽)．它们对路面的破坏主要是雨、雪水通过面层缝隙进入各结构层．导致各结构层松散、强度散失，从而形成更大面积的破坏。破坏的原因是多方面的，主要包括设计、施工、养护、行车荷载、自然环境．其中施工是主要因素。     

用变点分析方法评价城市公共汽车预防维修效果

维修保养的效果影响车辆的运行可靠性和维修费用.基于现场数据,采用变点分析方法,分析汽车二级保养和三级保养前、后失效发生率的变化,并由此评价车辆不同级保养的效果.该方法可为企业维修质量的改进提供依据.     

Evolutionary algorithms for solving unconstrained multilevel lot-sizing problem with series structure

This paper presents a comparative study of evolutionary algorithms which are considered to be effective in solving the multilevel lot-sizing problem in material requirement planning (MRP) systems. Three evolutionary algorithms (simulated annealing (SA), particle swarm optimization (PSO) and genetic algorithm (GA)) are provided. For evaluating the performances of algorithms, the distribution of total cost (objective function) and the average computational time are compared. As a result, both GA and PSO have better cost performances with lower average total costs and smaller standard deviations. When the scale of the multilevel lot-sizing problem becomes larger, PSO is of a shorter computational time.     

Online sequential extreme learning machine based multilayer perception with output self feedback for time series prediction

This study presents a time series prediction model with output self feedback which is implemented based on online sequential extreme learning machine. The output variables derived from multilayer perception can feedback to the network input layer to create a temporal relation between the current node inputs and the lagged node outputs while overcoming the limitation of memory which is a vital part for any time-series prediction application. The model can overcome the static prediction problem with most time series prediction models and can effectively cope with the dynamic properties of time series data. A linear and a nonlinear forecasting algorithms based on online extreme learning machine are proposed to implement the output feedback forecasting model. They are both recursive estimator and have two distinct phases: Predict and Update. The proposed model was tested against different kinds of time series data and the results indicate that the model outperforms the original static model without feedback.     

TL2000路面强化剂在重庆鹅公岩大桥桥面预防性养护中的应用

介绍了TL2000路面强化剂主要特点和施工方法,以及在重庆鹅公岩大桥桥面工程中的成功应用.实测数据表明,TL2000路面强化剂可以有效地提高桥面的防渗水性能,适用于钢箱梁桥桥面的预防性养护.     

一类非线性边值问题Ambrosetti-Prodi型条件下的参数无解性

笔者在文中利用严格上下解及等度连续等概念研究在Ambrosetti Prodi型条件下带参数的非线性边值问题的无解性,并给出带参数非线性边值问题无解的参数取值范围.     

寒冷地区滑模摊铺水泥混凝土路面应用研究

随着滑模摊铺水泥混凝土施工工艺推广应用 ,社会和建设单位对滑模摊铺水泥混凝土路面提出了更高的要求 ,详细介绍了寒冷地区滑模摊铺水泥混凝土路面施工工艺及质量控制措施。     

多目标决策问题的模糊数学解法

针对多目标决策问题，在已知目标权重范围的前提下，应用模糊数学理论提出了一种求解多目标决策问题的客观赋权的模糊算法，把多目标决策问题转化为单目标规划问题进行求解，并通过实例说明了此方法的具体应用．最后进行了理论分析，论证了该算法的先进性与有效性。     

沥青混凝土路面铣刨刀具失效分析与改进措施

通过沥青混凝土路面铣刨刀具材料性能、刀具结构及工作形式的研究,分析了沥青混凝土路面铣刨刀具的失效机理,研究了提高沥青混凝土路面铣刨刀具使用寿命的具体措施。研究内容对推广路面铣刨机在公路养护中的应用,提高我国公路养护机械化作业水平具有重要意义。     

一类非线性边值问题Ambrosetti-Prodi型条件下多解的存在性

利用严格上下解和迭合度论证了Ambrosetti Prodi型条件下带参数的非线性边值问题多解的存在性,给出了两个主要结果.     

远洋船舶垃圾处理技术的研究

船舶垃圾污染海洋环境是目前国际、国内亟待解决的问题．分析了远洋船舶在停泊港口时和航行时处理船舶垃圾的几种典型方式．对焚烧处理方式中燃烧不完全、燃烧不稳定、能量利用不高问题进行了研究,提出船用焚烧炉采用具有不确定性保性能鲁棒控制系统和富氧燃烧．建议利用船舶垃圾燃烧过程中所释放热量,为其他装置提供能量,从而达到节能减排效果,对船舶垃圾处理技术发展具有一定的指导意义．