非等变角对数螺旋线在扭曲叶片绘型中的应用

扭曲叶片的绘型常采用的单锥面展开法 ,因是基于局部相似 ,所以 ,存在误差 ,无法分析 ,难以编程。笔者在有关水泵问题研究中 ,对扭曲叶片绘型的单锥面展开法进行了改进 ,给出利用非等变角对数螺旋线进行叶片绘型的新方法。这种方法能够很好地控制β角的变化规律 ,并能对误差进行分析和修正 ,便于编程计算 ,易于操作 ,在水泵设计中有广泛的实用价值。     

管理信息系统中在线帮助子系统设计

在线帮助是数据库管理系统的重要组成部分。本文以 Foxpro2.0为基础讨论了面向应用的在线帮助子系统的几种设计方法。     

大新站开行万吨列车的实践与创新

大秦铁路大新站通过改造站场及运输设备、优化运输组织结构、修改和完善铁路运输规章制度，成功开行万t重载列车。为适应大秦线全面开行2万t列车的新形势，大新站仍需继续改造既有设施，改进运输组织方式，大幅提高装车组织效率。     

保护输电线路安全法律问题分析

近年来,我国电力行业的发展与进步是举世瞩目的,同时,我国也逐年加强了电力基础设施建设与完善的步伐,基本实现了全功输电工作的顺利开展和进行。电力是国家重要能源与基础产业,关系国计民生,随着经济发展和社会进步,人们对电力能源的依赖和需求也越来越高。     

劳动密集型企业一线员工流失的原因与对策

近几年来,人力资源的供给与需求之间的矛盾日益突出,特别是劳动密集型企业一线员工稳定性差,流动性大,且员工队伍参差不齐,低学历比重大,直接影响企业生产经营活动的正常进行,劳动密集型企业有必要构建员工与企业共享发展成果机制,强化对一线员工的培训与学历提升,建立转岗轮岗制度,实现工作丰富化,提供具有竞争性的工资福利待遇以增加对一线员工的吸引力,从而实现企业的可持续发展。     

早餐工程货物配送路线优化分析

近几年城市早餐工程给广大市民带来了极大的方便,文章介绍了如何选取早餐工程物流配送路线,旨在找到各条货物配送路线中最短的一条;本文把所有早餐工程点及连接各个早餐摊位点的所有道路、路口归为一个无向网络图。通过优化方法得出完成早餐货物配送任务的最短路线。     

洪江青山洞金矿深部钻探工艺探讨

液动锤在钻探施工中具有能提高硬岩钻进速度、减小孔斜和提高岩心采取率等优点,技术成熟,应用领域正在拓宽。文章结合工程实际,介绍了绳索取心液动锤钻探技术在洪江青山洞金矿区的使用情况,并对应用效果进行了分析探讨。     

Using Simulation and Data Envelopment Analysis to Compare Assembly Line Balancing Solutions

This paper presents a technique for comparing the results of different assembly line balancing strategies by using Data Envelopment Analysis (DEA). Initially, several heuristics--which can be thought of as assembly line balancing strategies--were used to solve seven line-balancing problems. The resulting line balance solutions provided two pieces of information that were of particular interest: the number of workers needed and the amount of equipment needed. These two items were considered inputs for DEA. The different line balance solutions were then used as layouts for simulated production runs. From the simulation experiments, several output performance measures were obtained which were of particular interest and were used as outputs for DEA. The analysis shows that DEA is effective in suggesting which line balancing heuristics are most promising.     

Optimization of postal express line network under mixed driving pattern of trucks

Details about the movement of trucks on postal express lines are investigated to improve the performances of mail distribution. A mixed driving pattern of trucks is introduced to minimize the transportation cost of a postal express line network with a service level requirement. We formulate this problem as a mixed p meeting depots location with shipment scheduling problem and build a MINLP model. A two-level tabu search procedure based on shipment grouping method is developed. Through a series of computational experiments and sensitivity analysis on different instances, some managerial insights of the network under mixed driving pattern are revealed.     

基于电力线载波通信的家电控制系统

电力线载波通信是用电力线路作为通信媒介进行数据传输。介绍了在低压配电线上用电力线载波专用芯片ST7536实现数据的传输,采用电力线载波形式,设计出了一个家电网络控制系统,对家电网络进行远程集中控制,可以对多路家用电器的运行情况进行实时监测和控制,并分析了电力线通信的通道特性及其干扰,结合电力通信的特点提出了解决办法。