弧形轨道电站门机大车运行机构的设计

针对水电站拱形大坝上使用的门式起重机大车行走机构车轮组必须被设计成能够自如转向结构这一问题,经过反复研究和现场试验,设计了新型的自由转向机构,解决了该问题。     

汽车转向传动轴相位角的设计

转向力是评价汽车操纵稳定性的重要指标,转向时转向力会出现时轻时重的波动现象。文章阐明了传动轴相位角与转向力的关系,对某转向力波动过大的重型卡车进行了相位角改进设计。     

高地隙液压四轮驱动喷雾机转向防滑控制系统

本文主要建立了高低隙四轮驱动喷雾机转向过程中的线性自由度模型，并且以前轮转向作为例子计算出了实际的转向角，设计了一种可以以实际速比与理论转速比差值为控制对象的转向防滑控制系统。     

基于遗传算法的企业配送路径问题研究

为提高企业竞争力,加快企业发展,企业已将优化重点转向物流配送环节,文中通过遗传算法设计并求解企业配送路径问题,设计合理的配送路线,提高配送效率,降低物流成本。     

浅析体外预应力加固设计

对体外预应力加固中体外预应力索、锚固系统、转向装置三个方面在设计时应注意的一些问题进行了分析,并阐述作为主动加固的体外预应力加固技术的特点。     

管柱助力式中间轴万向节叉内花键的设计与优化

文章针对C-EPS相比于HPS的中间轴在转向过程中,需要承受更大的扭矩,对转向中间轴连接用的万向节组件的配合及其本身强度提出了更高的设计要求,通过分析某车型的C-EPS的具体设计实例,描述了C-EPS中间轴与转向机连接内花键的设计与计算,利用ABAQUS软件分析夹紧结构的应力集中区域,在该区域增设应力孔以降低最大应力,优化后的方案试验表明应力分布更为均匀。     

多轴挂车转向机构优化设计

本文对组合式多轴挂车的转向机构进行了分析,建立了挂车转向系统机构的优化设计模型.应用优化软件对设计模型进行了优化求解,给出了针对任意一轴线上转向机构的MATLAB优化程序.使用该优化程序对某专用车辆厂生产的多轴挂车转向机构进行了优化设计,计算结果表明本方法是正确的、实用的.     

四轮电动车方向机机构的结构分析与设计

四轮电动车方向机机构,是电动车重要的机构之一,它包括方向机、转向节、拉杆,它的做功方式是在方向机的转动作用下,带动拉杆,拉杆拉动转向节,转向节转动带动轮子而实现转向。设计构思是在原有的电动车方向机机构的基础上,增加一个杠杆机构,方向机前移,使方向机机构的转向在杠杆的作用下,增加了转向力量,进而使电动车转向更加便捷、可靠。该设计克服了原有方向机机构结构的不足,使电动车行走在条件恶劣的路段时,方向机机构转向受控、灵活,方便控制;以及利于电动车扩大车型时满足电动车的转向需要,避免了原有方向机机构的缺陷,使操作人员驾驶更加方便、可靠。     

BIM技术在临时工程规划设计中的应用

BIM技术的出现改变了建筑领域的设计流程,改善了信息传递丢失这一状况,实现了项目从单纯几何表达转向全信息模型的集成、从各专业孤立完成某一项目转向各专业协同完成项目、从离散的分部设计转向基于同一模型的全过程整体设计。基于BIM技术的三维设计不仅能够精确表达建筑的几何特征,还能对模型赋予各类信息,不存在表达障碍。将BIM技术应用到临时工程规划设计中能够对设计方案进行直观而全面的比选,提高临时占地及空间利用率,使规划更合理。基于BIM技术的模块化的设计能大大提高临时工程规划设计效率。本文对箱梁场等临时工程的设计方式、方法和流程进行了研究,利用BIM技术对临时工程做快速可视化设计,合理调整场地布局,提升了企业临时工程规划设计水平。     

采用线控转向系统提高叉车工作效率及安全性

一般来说，采用液压转向系统的传统叉车需要使用泵和软管，通过液体将液压输送到用于控制车辆转向的电机。这种方法通常会产生大量损耗，例如，在不使用转向系统时，仍需要提供使液压泵运转的能量。常规的液压转向系统还需要将软管经转向管柱布置到车轮，以输送液压用液体。软管占据了很大空间，也增加了成本，并降低了设计的灵活性。此外，传统液压转向系统的局限性还体现在，为改善和提高转向系统的安全性和工作效率而进行的设计比较困难，并且费用较高（如稳定性控制）。     

小型水力发电厂管理模式初探

简要分析当前小型水力发电厂的生产管理现状,结合实际提出＂大公司、小电厂,区域化、中心站＂生产管理模式,介绍在此模式下的机构设置及人员配置。     

Instability and concentration in the distribution of wealth

We consider a setup in which infinitely lived households face idiosyncratic investment risk and show that in this case the equilibrium distribution of wealth becomes increasingly right-skewed over time until wealth concentrates entirely at the top. The households in our setup are identical in terms of their patience and their abilities, and we assume that there are no redistributive mechanisms—neither explicit in the form of government tax or fiscal policies, nor implicit in the form of limited intergenerational transfers. Our results demonstrate that the presence of such redistributive mechanisms alone ensures the stability of the distribution of wealth over time.     

Employee rights and capital mobility

In this article I analyze the impact that capital mobility has on employee rights in the workplace by studying the effects of the relocation of General Motor’s Corvette plant from St. Louis to Bowling Green, Kentucky. This relocation not only afforded GM an opportunity to increase its control over its hourly work force, but it also set in motion a process in which the rights’ claims of management and workers were redefined. Through a number of planned and unplanned mechanisms, management invaded spaces created by workers, and, as a result, workers’ ability to pursue their interests was diminished. In the concluding section, I discuss the implications of this for research on employee rights and for combining the concern for rights with labor process theory.     

航空运输企业发展现代物流的战略方法

文中介绍了企业经营战略的定义,战略五大要素以及战略的制定过程。同时分别为选择个性化物流服务为目标的物流发展模式、集成物流发展模式、融入供应链的物流发展模式的航空运输企业制定了相应的物流发展战略,即服务品牌战略、加强与第三方物流合作的战略和供应链管理战略。     

Production lot sizing for deterministic rolling schedules

In this article, we study production planning for a rolling horizon in which demands are known with certainty for a given number of periods in the future (the forecast window M). The rolling horizon approach implements only the earliest production decision before the model is rerun. The next production plan will again be based on M periods of future demand information, and its first lot-sizing decision will be implemented.Six separate lot-sizing methods were evaluated for use in a rolling schedule. These include the Wagner-Whitin algorithm, the Silver-Meal heuristic, Maximum Part-Period Gain of Karni, Heuristics 1 and 2 of Bookbinder and Tan, and Modification 1 to the Silver-Meal heuristic by Silver and Miltenburg.The performance of each lot-sizing rule was studied for demands simulated from the following distributions: normal, uniform (each with four different standard deviations); bimodal uniform (two types); and trend seasonal (both increasing and decreasing trends). We considered four values of the setup cost (leading to natural ordering cycles in an EOQ model of three, four, five, and six periods) and forecast windows in the range 2 M 20.Eight 300-period replications were performed for each combination of demand pattern, setup cost, and lot-sizing method. The analysis thus required consideration of 2304 300-period replications (6 lot-sizing methods × 12 demand patterns × 4 values of setup cost × 8 realizations), each of which was solved for nineteen different values of the forecast window M. The performance of the lot-sizing methods was evaluated on the basis of their average cost increase over the optimal solution to each 300-period problem, as though all these demands were known initially.For smaller forecast windows, say 4 M 8, the most effective lot-sizing rules were Heuristic 2 of Bookbinder and Tan and the modified Silver-Meal heuristic. Rolling schedules from each were generally 1% to 5% in total cost above that of the optimal 300-period solution. For larger forecast windows, M 10 or so, the most effective lot-sizing method was the Wagner-Whitin algorithm. In agreement with other research on this problem, we found that the value of M at which the Wagner-Whitin algorithm first becomes the most effective lot-sizing rule is a decreasing function of the standard deviation of the demand distribution.     

Explaining variance in the accuracy of prediction markets

Thus far, the focus in prediction market research has been on establishing its forecast accuracy relative to those of other prediction methods, or on the investigation of a few single sources of forecast error. This article is the first attempt to overcome the narrow focus of the literature by combining observational and experimental analyses of prediction market errors. It investigates the prediction error of a real money prediction market uusing a logarithmic market scoring rule for 65 direct democratic votes in Switzerland. The article distinguishes between prediction market error due to the setup of the market, features of the event to be predicted, and the participants involved, and finds that the prediction market accuracy varies primarily according to the setup of the market, with the features of the event and especially the composition of the participant sample hardly mattering.     

双机牵引接力吊

文章以广州市内环路广花放射线高架桥钢横梁的架设施工为例，介绍一种利用起重机吊装施工的新方法——双机牵引接力吊。这种吊装方法由双机抬吊发展而来，扩展了起重机吊装跨越障碍物能力，充分展现了起重机吊装的简便、快捷、安全等多方面优势。     

双机牵引接力吊

文章以广州市内环路广花放射线高架桥钢横梁的架设施工为例,介绍一种利用起重机吊装施工的新方法——双机牵引接力吊。这种吊装方法由双机抬吊发展而来,扩展了起重机吊装跨越障碍物能力,充分展现了起重机吊装的简便、快捷、安全等多方面优势。     

地方城乡规划管理制度的渐进改革和完善:以温州为案例的研究

以温州市为例,从实施管理的角度和层面讨论地方城乡规划制度渐进改革与完善的途径.在对温州市规划管理机构设置、职能权限、管理体制调查研究的基础上,对其现行的规划管理制度从6个方面给出了总体分析和评价,指出了存在的7个问题及其原因.最后结合我国城市规划管理制度的改革要求,提出了温州市规划管理制度改进和完善的若干对策和建议.     

On estimating the reliability after sequentially estimating the mean: The exponential case

Sequential estimation problems for the mean parameter of an exponential distribution has received much attention over the years. Purely sequential and accelerated sequential estimators and their asymptotic second-order characteristics have been laid out in the existing literature, both for minimum risk point as well as bounded length confidence interval estimation of the mean parameter. Having obtained a data set from such sequentially designed experiments, the paper investigates estimation problems for the associatedreliability function. Second-order approximations are provided for the bias and mean squared error of the proposed estimator of the reliability function, first under a general setup. An ad hoc bias-corrected version is also introduced. Then, the proposed estimator is investigated further under some specific sequential sampling strategies, already available in the literature. In the end, simulation results are presented for comparing the proposed estimators of the reliability function for moderate sample sizes and various sequential sampling strategies.