Effects of temperature on the tribological behavior of Al0.25CoCrFeNi high-entropy alloy

The tribological behavior of Al_0.25CoCrFeNi high-entropy alloy (HEA) sliding against Si₃N₄ ball was investigated from room temperature to 600 ℃. The microstructure of the alloys was characterized by simple FCC phase with 260 HV. Below 300 ℃, with increasing temperature, the wear rate increased due to high temperature softening. The wear rate remained stabilized above 300 ℃ due to the anti-wear effect of the oxidation film on the contact interface. The dominant wear mechanism of HEA changed from abrasive wear at room temperature to delamination wear at 200 ℃, then delamination wear and oxidative wear at 300 ℃ and became oxidative above 300 ℃. Moreover, the adhesive wear existed concomitantly below 300 ℃.     

UPE: Utah prototyping environment for robot manipulators

Developing an environment that enables optimal and flexible design of robot manipulators using reconfigurable links, joints, actuators, and sensors is an essential step for efficient robot design and prototyping. Such an environment should have the right mix of software and hardware components for designing the physical parts and the controllers, and for the algorithmic control of the robot modules (kinematics, inverse kinematics, dynamics, trajectory planning, analog control and digital computer control). Specifying object-based communications and catalog mechanisms between the software modules, controllers, physical parts, CAD designs, and actuator and sensor components is a necessary step in the prototyping activities.In this paper, we propose a flexible prototyping environment for robot manipulators with the required subsystems and interfaces between the different components of this environment. This environment provides a close tie between the design parameters of the robot manipulator by the different subsystems involved in the design process. The design and implementation of this environment along with the implementation of some of the subsystems are presented, and some examples that demonstrate the functionality of the environment are discussed. This work was supported in part by DARPA grant N00014-91-J-4123, NSF grant CDA 9024721, and a University of Utah Research Committee grant. All opinions, findings, conclusions or recommendations expressed in this document are those of the author and do not necessarily reflect the views of the sponsoring agencies.     

An empirical investigation of architectural prototyping

Architectural prototyping is the process of using executable code to investigate stakeholders’ software architecture concerns with respect to a system under development. Previous work has established this as a useful and cost-effective way of exploration and learning of the design space of a system and in addressing issues regarding quality attributes, architectural risks, and the problem of knowledge transfer and conformance. However, the actual industrial use of architectural prototyping has not been thoroughly researched so far. In this article, we report from three studies of architectural prototyping in practice. First, we report findings from an ethnographic study of practicing software architects. Secondly, we report from a focus group on architectural prototyping involving architects from four companies. And, thirdly, we report from a survey study of 20 practicing software architects and software developers. Our findings indicate that architectural prototyping plays an important and frequent role in resolving problems experimentally, but less so in exploring alternative solutions. Furthermore, architectural prototypes include end-user or business related functionality rather than purely architectural functionality. Based on these observations we provide recommendations for effective industrial architectural prototyping.     

Evaluation of customer impressions using virtual prototypes in the internet environment

This study aims to investigate a cost effective and efficient way of analyzing customer impressions on design alternatives by incorporating the benefits of virtual prototyping into the Internet-based experimental environment. It is hypothesized that the results of the Internet-based experiment using the images of virtual prototypes are comparable to those of the virtual reality-based environment using virtual prototypes. Two experiments were conducted. In the virtual reality environment, participants were employed to evaluate virtual prototypes while in the Internet environment participants evaluated images of the same virtual prototypes from their own places. For each experiment, 16 male participants were employed to evaluate 32 different virtual prototypes generated from the combination of 17 design elements of automobile interior. The results of the experiments indicated that there were no significant differences between the two experimental methods while the Internet environment-based method could save considerable time and efforts for experimentation. This study concludes that the Internet-based evaluation method using the images of virtual prototypes could be a cost effective and efficient way of analyzing customer impressions on design alternatives.

Relevance to Industry

This study showed that the results of the Internet-based evaluation method using the images of virtual prototypes are comparable to those of the virtual reality-based method using real virtual prototypes. The Internet-based evaluation method could be used as a cost effective and efficient way of collecting and analyzing various customers’ impressions on design alternatives at the early stage of product development process.     

基于GIS的土地信息系统的设计与实现

土地信息系统是面向土地管理的地理信息系统,是由土地相关信息组成的数据库以及收集、描述、处理和分配这些数据的技术方法组成.文中介绍了一个土地信息系统的组成,并着重讨论了系统的技术要点及实现方法.     

专家系统软件开发生存期模型分析

文章根据专家系统类软件的特点,在分析已有软件开发生存期模型优缺点基础上,提出了一种适用于专家系统的开发模型,它以瀑布模型为基本框架,在不同开发阶段引入了快速原型开发模型和面向对象技术以克服瀑布模型的缺点。实践表明这种开发模型是可行的。     

激光变长线快速成型系统中的图形分区算法

在建立激光变长线快速成型系统加工过程的数学模型的基础上,提出了一种可对任意平面图形进行分区处理的分区算法,该算法的使用不仅使所得分区图形能满足激光变长线扫描的要求,还可以使平面图形的分区数最少,有利于成型机激光器使用寿命和加工效率的提高。     

大型MIS系统的复合开发方法

本文介绍了软件开发的生命周期法和快速原型法的基本思想及其局限性,并将两种开发方法相结合,提出了一种大型MIS系统的复合开发方法,以实现快速有效地开发MIS系统。     

基于快速成型技术的警用小型电子产品工业设计方法研究

本文介绍了一种基于快速成型技术的警用小型电子产品的工业设计方法。与传统设计方法相比较,该方法在创新设计理念、缩短产品研制周期、保证产品质量等方面都有了重大突破。同时,本文以电子护照读写机具设计为例,详细阐述了应用这种方法进行警用小型电子产品设计的方法和流程,并将该方法与传统设计方法进行了详细的分析和比较。     

A PC-Based Simulator/Controller/Monitor Software for a Generic 6-DOF Manipulator

General form application is a very important issue in industrial design. Prototyping a design helps in determining system parameters, ranges and in structuring better systems. Robotics is one of the industrial design fields in which prototyping is crucial for improved functionality. Developing an environment that enables optimal and flexible design using reconfigurable links, joints, actuators and sensors is essential for using robots in the education and industrial fields. We propose a PC-based software package to control, monitor, and simulate a generic 6-DOF (six degrees of freedom) robot including a spherical wrist. This package may be used as a black box for the design implementations or as a white (detailed) box for learning about the basics of robotics and simulation technology.