Reusing single-user applications to create collaborative multi-member applications

In contrast to single-user applications, most collaborative multi-member applications have been developed as vehicles for investigating various research issues, and even existing commercial collaborative multi-member applications have not widely accepted by end-users. The paper will describe an innovative approach and relative techniques that can be used to convert existing single-user applications into collaborative applications, without modifying the source code and knowledge of the API of the original single-user applications. The main idea is that user events occurring through the interactions with the application can be caught, distributed, and reconstructed. This approach and supporting techniques were tested in the process of transparently converting a single-user AutoCAD application into a real-time collaborative AutoCAD application called CoAutoCAD, which not only retains the original function and user interface of the single-user AutoCAD application, but supports group collaboration capabilities as well.     

Inferential control applications

In high-order, long-dead-time processes, inferential control systems will generally outperform conventional feedback control systems. To implement inferential control the user must know how to

• •—tune the inferential controller on line,
• •—avoid control degradation due to saturation of the control effort,
• •—smooth manual-automatic switching,
• •—design a cascade control system.

In addition, the user should be able to determine whether the benefits of inferential control justify its selection over a PID control system. This report presents ways to meet these requirements and applies the methods to an industrial autoclave plant and to a laboratory heat exchange system.     

Texture modelling applications

The paper describes a technique by which realistic textures can be constructed from a statistical model. It further tells us, in principle, how to map the texture onto a surface of any shape, maintaining consistency and scaling, without producing repeating patterns. It describes how a method designed earlier for grey scales alone can be extended to the colour case. The generalization of the former work to macroscopic textures is also presented. An application of this method to the Design is finally shown.     

Supporting cooperative applications

Cooperative applications which have started to emerge from CSCW research place new demands on the computer technology used to support them. These demands raise a number of fundamental questions about the way in which computing systems provide application support. This paper examines a number of issues surrounding the support of cooperative applications and how they impact both CSCW and computer science research. In particular, the relationship between cooperative applications and the supporting techniques of distributed systems and database technology are investigated. Cooperative applications question many of the design assumptions embodied within these techniques, and ask far reaching questions of the technology. Traditionally, support systems have been unaware of cooperative activities and have hidden the actions of others from each user. This paper examines the implications of this choice and the need to consider alternative approaches to the provision of systems support. The paper concludes by highlighting a number of issues which need to be addressed both by computer science and CSCW reseachers.     

Testing web applications

Traditional testing techniques are not adequate for web-based applications, since they miss their additional features such as their multi-tier nature, hyperlink-based structure, and event-driven feature. Limited work has been done on testing web applications. In this paper, we propose new techniques for white box testing of web applications developed in the .NET environment with emphasis on their event-driven feature. We extend recent work on modeling of web applications by enhancing previous dependence graphs and proposing an event-based dependence graph model. We apply data flow testing techniques to these dependence graphs and propose an event flow testing technique. Also, we present a few coverage testing approaches for web applications. Further, we propose mutation testing operators for evaluating the adequacy of web application tests.     

Business visualization applications

Three-dimensional computer graphics can be extremely expressive. With the correct approach to a layout's visual design, people can quickly and easily comprehend large amounts of information. You can convey far more information in 3D than with 2D bar charts, or rows and columns of numbers. This article provides examples of information visualization applications in several industries, including the capital markets, retail banking, manufacturing, and consumer product goods. These examples help show what it means to put abstract information in 3D and what benefits result     

Securing e-commerce applications

Although smart cards are now beginning to make a significant impact in the traditional financial, identity and transit markets, many industry insiders report that the e-commerce market is still disappointingly slow. In fact, some people have told CTT “each year people say this is the year for smart cards to really take off in e-commerce, and each year the reality fails to live up to expectations.” Part of the problem is a classic ‘chicken and egg’ situation: Without chip technology, there is little point in implementing a chip acceptance device. Likewise, without a critical mass of chip readers in operation, what is the point of implementing a chip card?     

移动应用修炼之道

IT界的移动领域,如今暗潮涌动。3G、AppStore、Android、iPhone,甚至是山寨,一个个接踵而来的名词不断地回响在我们的耳边,经过这个移动终端、网络、应用、平台和内容各大运营商争夺用户的"乱世"之后,新一代移动平台及其生态系统即将诞生了。而最能反映整个移动生态链变化的,便是基于移动应用的诸多产品。从它们的创意产生,直至捞到第一桶金,每一个环节都与整个生态链息息相关。而且,"得应用者得天下"一句并不为过。拥有一个好的移动应用产品,不仅能够使厂商广为获利,更重要的是同时能够虏获千万用户的心。本期特别策划,就将围绕移动应用产品的生命周期,将移动产品最有特点的生产环节进行拆分、组合,为读者讲述移动应用产品的修炼之道,同时反映出新一代移动平台的生态状况,在更高的层次上关注移动产品,关注移动领域。     

Robust control applications

This paper (first presented as a plenary lecture at the Fifth IFAC Symposium on Robust Control Design, Toulouse, July 2006) demonstrates the practical importance of robust control theory by describing its application to two non-trivial practical control problems. Part 1 considers helicopter control and Part 2 addresses saturation problems in high-performance head-positioning servo systems in high-density hard-disk drives.In Part 1, we present the design and flight test of a new batch of H_∞ controllers for the Bell 205 helicopter. At the heart of each controller is an H_∞ loop-shaping controller, augmented with a hand-tuned reference filter to improve tracking performance and to reduce a perceived phase lag which pilots had complained of previously. Flight testing revealed that, with such an architecture, it was relatively easy to get Level 1 handling qualities ratings in low aggression manoeuvres. Further fine tuning resulted in Level 1 qualities for high aggression manoeuvres and one controller performed to Level 1 standard in all manoeuvres tested.In Part 2, we consider how robust control techniques can be used to design anti-windup compensators to counter performance and stability problems associated with saturating actuators in state-of-the-art hard-disk drive servo systems. A promising two-stage approach is given and illustrated with experimental results.     

Computer applications in mechanics

This paper reviews the various ways in which the computer can be used within the mechanics section of a typical beginning physics course. While the authors are concerned primarily with the introductory college level course, many of the details would also be applicable to high school physics courses.