Design and development of planar reconfigurable motion generators

This article presents the concept of a new class of mechanical devices for multi-phase motion generation tasks. Reconfigurable Motion Generators are a new class of mechanical devices that are designed for a specific part family and their associated motion generation tasks. The research endeavors to realize a novel concept for Reconfigurable Motion Generators (RMGs) for multi-phase planar motion generation. Reconfigurable Motion Generators are capable of configuration changes according to variations in the motion generation requirements. Thus, Reconfigurable Motion Generators bridge the gap between the relative high flexibility and high cost of totally flexible devices (e.g., industrial robots) and the low flexibility and low cost of fully dedicated devices (e.g., cams and linkages). This paper introduces the concept of Reconfigurable Motion Generators that may be deployed in various automated manufacturing environments involving multi-phase motion generation tasks. The development, manufacturing, and testing of a prototype and the control system for a planar Reconfigurable Motion Generator based on a five-bar mechanism are discussed.     

An algebraic multigrid-based algorithm for circuit clustering

Digital circuits have grown exponentially in their sizes over the past decades. To be able to automate the design of these circuits, efficient algorithms are needed. One of the challenging stages of circuit design is the physical design where the physical locations of the components of a circuit are determined. Coarsening or clustering algorithms have become popular with physical designers due to their ability to reduce circuit sizes in the intermediate design steps such that the design can be performed faster and with higher quality. In this paper, a new clustering algorithm based on the algebraic multigrid (AMG) technique is presented. In the proposed algorithm, AMG is used to assign weights to connections between cells of a circuit and find cells that are best suited to become the initial cells for clusters, seed cells. The seed cells and the weights between them and the other cells are then used to cluster the cells of a circuit. The analysis of the proposed algorithm proves linear-time complexity, O(N), where N is the number of pins in a circuit. The numerical experiments demonstrate that AMG-based clustering can achieve high quality clusters and improve circuit placement designs with low computational cost.     

主链含邻位取代单元及吡啶环聚酰亚胺的合成与性能

以o-羟基苯乙酮、对氯硝基苯和苯甲醛为原料,通过亲核取代反应、改进的Chichibabin反应以及水合肼催化还原合成了一种新型含邻位取代单元及吡啶环的芳香二胺4-苯基-2,6-双[3-(4-氨基苯氧基)苯基]吡啶(o,p-PAPP).以N,N-二甲基甲酰胺(DMF)为溶剂,将o,p-PAPP分别与3,3',4,4'-二苯醚四羧酸二酐(ODPA)、2,2-双[4-(3,4-二羧基苯氧基)苯基]丙烷二酐(BPADA)、3,3',4,4'-二苯酮四甲酸二酐(BTDA)及均苯四甲酸二酐(PMDA)通过常规的两步法,合成了4种聚酰亚胺.用FTIR、DSC、TGA、XRD、溶解性测试、UV-Vis和荧光光谱对聚合物的结构和性能进行了表征.FTIR结果表明,所得的聚合物在1780,1720和1380cm-1左右出现了聚酰亚胺的特征吸收峰.实验所得的PI能很好地溶解于常见有机溶剂(如DMF,DMAC,DMSO,NMP,THF,CHCl3),在氮气氛中,PI的10%失重温度(T10)为444.2～467.5℃,800℃时的残余质量(Rw)为49.6%～58.3%.同时PI分子主链中的吡啶环结构使其具有良好的紫外光吸收性能,经HCl质子化后,在460 nm附近出现非常强的荧光发射峰.     

超声提取党参总皂苷的工艺

优选党参总皂苷的最佳超声波提取工艺条件。采用正交试验设计优化党参总皂苷提取工艺的影响因素,通过比色法测定总皂苷含量,并与传统提取法进行比较。超声波强化提取总皂苷的提取工艺为甲醇提取,料液比1:20(g/mL),超声时间为30min,超声次数3次。方法操作简便、条件稳定,提高了药材的利用率,可用于党参总皂苷的提取。     

Capacitated Network Design using Bin-Packing

In this paper, we consider the Capacitated Network Design (CND) problem. We investigate the relationship between CND and the Bin-Packing problem. This is exploited for identifying new classes of valid inequalities for the CND problem and developing a branch-and-cut algorithm to solve it efficiently.     

数学方法论在数学教学中的应用

本文介绍了运用数学方法论的观点指导数学教学的一种崭新的数学教育方式,即应用数学的发展规律、数学的思想方法和数学中的发现、发明与创新的观点设计数学教学．     

基于EDA技术的高职教学实践

实验教学是高职教学中的重要环节之一,而传统的实验教学方式已不能适应当前高校的发展步伐。EDA技术的出现,很好地解决了这一问题。本文对电子设计自动化（Electronic Design Automation）技术进行了介绍,说明了高职院校开展EDA教学的重要性;以具体实例对基于EDA技术的实践教学系统的可行性进行了探讨。     

谈自动搓背机的设计

针对个人洗澡时,特别是老年人,后背难于搓到、搓净,洗澡比较吃力这一现实,设计了自动搓背机。本产品采用了丝杠、螺母副实现上下运动以适应不同人体高度;采用曲柄滑块机构实现左右运行完成搓背;采用凸轮顶杆机构完成按摩。在参加＂第五届全国大学生机械创新设计大赛＂时,荣获了陕西赛区二等奖。本文主要介绍了自动搓背机的设计过程,可为新产品的开发提供参考。     

基于VB.NET的WEB数据库应用

以网络实验信息管理系统为研究背景,应用VB.NET将数据库信息发布到Internet上,很好地实现了WEB数据库建立、绑定、查询、编辑等操作,功能齐全,便于扩展。     

民用飞机研制中的定费用设计研究

据统计,飞机全寿命周期成本的85%在设计阶段已经确定,因此在设计阶段控制成本、开展定费用设计,对全机最终成本的控制有巨大作用。本文分析了定费用设计在民机研制中的意义,阐述了在民机研制过程中运用定费用设计进行成本控制的流程与方法。