Lean production system design for fishing net manufacturing using lean principles and simulation optimization

Value stream mapping (VSM) is a useful tool for describing the manufacturing state, especially for distinguishing between those activities that add value and those that do not. It can help in eliminating non-value activities and reducing the work in process (WIP) and thereby increase the service level. This research follows the guidelines for designing future state VSM. These guidelines consist of five factors which can be changed simply, without any investment. These five factors are (1) production unit; (2) pacemaker process; (3) number of batches; (4) production sequence; and (5) supermarket size. The five factors are applied to a fishing net manufacturing system. Using experimental design and a simulation optimizing tool, the five factors are optimized. The results show that the future state maps can increase service level and reduce WIP by at least 29.41% and 33.92% respectively. For the present study, the lean principles are innovatively adopted in solving a fishing net manufacturing system which is not a well-addressed problem in literature. In light of the promising empirical results, the proposed methodologies are also readily applicable to similar industries.     

Lean philosophy: implementation in a forging company

This research addresses the implementation of lean philosophy in a forging company with a focus on radial forging production flow lines. Here, the prime motive is to evolve and test several strategies to eliminate waste on the shop floor. In this research, a systematic approach is suggested for the implementation of lean principles. This paper describes an application of value stream mapping (VSM). Consequently, the present and future states of value stream maps are constructed to improve the production process by identifying waste and its sources. Furthermore, Taguchi’s method of design of experiments is pursued here to minimize the forging defects produced due to imperfect operating conditions. A noticeable reduction in set-up time and work-in-process (WIP) inventory level is substantiated. Finally, we conclude with a discussion of managerial implications and the future scope of research.     

汛期采金船的缆绳牵拉

本文介绍了采金船渡汛时的停泊方向及采金船在洪水中可能产生拖曳力的估算方法，为了防止采金船汛期发生溜船事故，建议采用缆绳牵拉固船的措施，以保障采金船的汛期安全。     

基于Lotus Notes软件平台创建江铜办公自动化系统

本文介绍利用LotusNotes软件平台的电子邮件、复合文档数据库、工作流和完全的Client/Server技术 ,建立一个以开放、先进的Intranet/web及消息传递和工作流管理技术为核心的新一代全方位网络办公自动化系统。     

关于Delphi7的Zlib压缩库的应用

在数据库应用过程中,往往要对一些文件进行保存,如果直接保存,会浪费很多数据库空间,势必造成对数据库处理速度的影响。介绍利用Delphi7提供的Zlib压缩库在数据库存取文件时可以直接进行压缩和解压缩处理,使得在数据库中存取文件变得越来越方便。     

聚合物冷拉过程的流函数分析

用流函数法分析了聚合物拉伸成形时，颈缩的发生和扩展过程，文中论证了采用流函数法的优越性和适用性，并将流函数法计算结果和有限元法计算结果作了对比。     

Optimal Conditions for Preparing Ultra-Fine CeO2 Powders in A Submerged Circulative Impinging Stream Reactor

Cerium carbonate powders were produced in a submerged circulation impinging stream reactor (SCISR) from Ce(NO3)3·6H2O. NH4HCO3 was used as a precipitant in the reaction. Cerium carbonate powders were roasted to produce ultra-fine cerium dioxide (CeO2) powders. The optimal conditions of such production process were obtained by orthogonal and one-factor experiments. The results showed that ultra-fine and narrowly distributed cerium carbonate powders were produced under the optimal flowing conditions. The concentrations of Ce(NO3)3 and NH4HCO3 solutions were 0.25 and 0.3 mol·L-1, respectively. The concentration of PEG4000 added in these two solutions was 4 g·L-1. The stirring ratio, reaction temperature, feeding time, solution pH, reaction time and digestion time were 900 r·min-1, 80 ℃, 20 min, 5～6, 5 min and 1 h, respectively. The final product, CeO2 powders, was obtained by roasting the produced cerium carbonate in air for 3 h at 500 ℃. The finally produced CeO2 powders were torispherical particles with a narrow size distribution of 0.8～2.5 μm. The crystal structure of CeO2 powders belonged to cubic crystal system and its space point group was O5H-FM3M. Under optimal conditions, powders produced by SCISR were finer and more narrowly distributed than that by Stirred Tank Reactor (STR).     

曝光数据流优化问题的蒙特卡罗算法

集成工艺中控制图形发生器产生掩模图形的数据流文件的数据排列顺序优化,是一个其结点数可达数千个之多的大规模旅行商问题(从镜头架的位置,即每个矩形的矩心为结点),常规算法早已不适用。本文采用多阶段蒙特卡罗算法并加以改进,补充了“分层优化模式”,邻接结点的预合并和在各个阶段末提取共同子路径并删去相关结点等一系列逐步缩小问题规模的措施,形成了一个实用的优化算法。相应的软件已成功地应用于薄膜磁头的数据流文件的优化。     

新型技术用于乳状液膜法脱酚的进一步研究

本文对模拟的含酚废水,采用新型技术对乳状液膜法脱酚进行了进一步的探讨。对所采用的制乳设备———撞击流-旋转填料床对制乳率、提取设备———旋转填料床对脱酚率、破乳设备———无机微孔膜法破乳的重要参数(如透过压方式、膜孔径等对膜通量和破乳率的影响)进行了研究。并且讨论了破乳后的油相回用情况。实验结果表明:撞击流-旋转填料床的制乳效率可达99.90 %以上,脱酚率可达99%左右,且瞬间完成;膜孔径越小,破乳率越高,膜通量越小;外压内抽方式的破乳效果优于单外压方式的破乳效果。对于粒径为5～2 5 μm乳液,用膜孔径为2 .0 μm的SiC微孔膜,在外压为6 0kPa、内负压为30kPa的外压内抽破乳方式下破乳,破乳率可达96 .4 % ,膜通量可达90 0L·(m2 ·h) -1。     

PLC上位机监控软件的开发

为提高硫化机控制水平，采用电阻式触摸平板电脑为上位机与PLC相结合。系统设计主要包括各监控画面的设计和上位机与PLC之间的通信设计，监控主画面设计成包含所有操作员需要了解的数据。实时曲线画面为圆盘型和直线型两种，上位机与PLC之间的通信采用VB6.0编程，实际运行证明状态良好。