基于功效系数法的城市公交线网优化模型

城市公共交通线网优化是城市客运交通规划的重要部分之一。对现有公交线网进行优化,可以更有效地利用现有资源,解决城市交通问题。通过对城市公交线网优化的主要内容、优化模式、优化目标以及约束条件的分析,同时兼顾乘客出行时间、线网平均满载率、公交线网密度和公交线网的布局,对整个城市交通系统的影响提出优化目标的函数表达式及相应约束条件的数学表达式,建立公交线网优化的多目标模型。通过对模型的分析,提出可用功效系数法对模型进行寻优和评价。     

RCF-RPWM策略的功率谱分析及优化设计

在DC-AC变换器中,通过对载波频率的随机化处理,可以把输出电压的离散谱转换成连续谱,降低功率谱的峰值,达到抑制声学噪声和降低电磁干扰的目的.文中推导了采用随机载波频率RPWM策略逆变器开关函数的功率谱密度解析表达式,实验结果验证了其正确性.通过引入特征函数,提出了采用有限点载波频率进行随机时,开关频率选取的优化准则,仿真结果验证了其有效性.     

搅拌桩处理公路软弱地基施工工艺的探讨

以搅拌桩工艺处理软土地基,使其承压性能达到道路施工的必要条件。基于工程实践对其使用工艺进行技术优化,对于提高作业效率和降低工程成本是十分必要的。     

珠海电厂卸船机给料机程序分析与修改优化

为解决卸船机给料机分流挡板不到位,发生非运行侧皮带漏煤以及给煤量过大压死皮带的问题.珠海电厂煤码头对控制程序存在的缺陷漏洞进行修改优化.优化后给料机运行更为安全可靠,杜绝了事故再发生.     

Multi-objective optimization of train routing problem combined with train scheduling on a high-speed railway network

Based on train scheduling, this paper puts forward a multi-objective optimization model for train routing on high-speed railway network, which can offer an important reference for train plan to provide a better service. The model does not only consider the average travel time of trains, but also take the energy consumption and the user satisfaction into account. Based on this model, an improved GA is designed to solve the train routing problem. The simulation results demonstrate that the accurate algorithm is suitable for a small-scale network, while the improved genetic algorithm based on train control (GATC) applies to a large-scale network. Finally, a sensitivity analysis of the parameters is performed to obtain the ideal parameters; a perturbation analysis shows that the proposed method can quickly handle the train disturbance.     

数控铣床加工低碳钢零件的进给速度优化

论述了数控铣床加工低碳钢零件时进给速度的优化问题．在基于加工效率（可等效转化为加工工时）和加工成本目标函数的基础上，对这两个目标函数运用多目标函数理论进行综合，得到了多目标综合函数．通过计算，并综合表面粗糙度，进而得到进给速度的优化范围，并对不同转速下的进给速度给出了相应的优化参数，目的更接近生产实际，使技术人员不仅了解影响生产效率和成本的因素，也可在实际生产的应用中更加快捷和方便．     

Optimization of horizontal alignment geometry in road design and reconstruction

This paper presents a general formulation for optimization of horizontal road alignment, composed of tangential segments and circular curves suitably connected with transition curves (clothoids). It consists of a constrained optimization problem where the objective function is given by a line integral along the layout. The integrand is a function representing the cost of the road going through each point and, by considering different costs, a wide range of problems can be included in this formulation. To show it, we apply this methodology to three different situations. The two first cases are related with the design of a new road layout and used to solve a pair of academic examples. The third problem deals with the improvement of a road adapting the old path to current legislation, and it is solved taking as case study the reconstruction project for a regional road (NA-601) in the north of Spain.     

Optimization of transport investment and pricing policies: the role of transport pricing in network design

This paper investigates the role of transport pricing in network design and describes two facts about flow pattern in a transportation system. The first, illustrated by an example of Braess paradox, is that adding a new link to the network does not necessarily minimize the total travel time. The second is that introducing of appropriate toll pricing may reduce not only the total network time but also the travel time for each individual traveller. It follows with the investigations of different system objectives and different pricing policies (only toll pricing and distance‐based pricing are considered), and shows how they affect the system performance and flow pattern. Lastly, a systematic optimization process is proposed for integrated planning of transport network and pricing policies.     

装载机连杆机构优化设计

结合传统设计方法和现代优化方法有效地解决了原设计中装载机不能满足平移性和自动放平性的问题;在用作图法确定铰接点大致位置的基础上,建立了连杆机构参数化模型,并对模型进行了优化研究。结果表明:新机构能满足平移性和自动放平性要求。该方法对类似的机构优化问题有一定的参考价值。     

高桥墩桩基础的优化设计及因素分析

在高桥墩桩基屈曲能量法分析的基础上,提出兼顾结构稳定、强度和经济性的优化模型,并应用优化算法中非线性序列二次规划法,进行优化设计探讨,同时给出优化设计算法流程图,编制了相应的优化计算程序;为了解桥墩高度、轴向荷载、地基比例系数和混凝土弹性模量对于高桥墩桩基屈曲的影响,结合优化设计模型进行了因素分析,探讨了参数变量对目标函数最优值的影响规律和程度,比较结果说明,在进行高桥墩桩基的屈曲受力分析时,高桥墩的大变形影响不容忽视;而一般在工程设计中,可考虑将桩周土体和混凝土弹性模量的增强作用作为设计的安全储备。