Trends In Software Development Research Articles

Sampled-dataH2 optimal output feedback control for civil structures

An optimal control method involving sampled data is considered for use in earthquake and wind engineering applications. The structure is modelled as a continuous system attached to a discrete-time controller using zero-order sample-and-hold devices. Examples of two buildings with active base isolators and a 163 m tall planar frame with an active mass damper are considered. The buildings with the base isolators are subjected to excitation input using the 1940 El Centro earthquake (NS component) as an example, while the planar frame is subjected to assumed sinusoidal gusts with a period close to that of the frame. The controlled responses (with and without time delays) are studied. To further analyze the features of the control designs, the building examples with base isolators are subjected to five other different earthquake excitation records. Trends in control performance and effectiveness are presented and discussed. The results suggest that such systems are potentially suited for implementation in the vibration control of civil infrastructures; such potentiality becomes more realistic with the current trends in software development and the increased use of digital computers. Copyright © 1999 John Wiley & Sons, Ltd.

Control systems engineering education

This comprehensive article deals with the important field of control systems engineering education. Efforts have been made to present some historical perspectives, major concepts and thoughts on a practical curriculum when this field is viewed as a discipline. Also discussed are curricular issues including typical laboratory systems with emphasis on the role of simulation, logic and sequencing, and real-time simulation. An elaborate section is devoted to CACE software, its role in teaching and learning, potential shortfalls, and trends in software development and use. Views from industry are sought in terms of desirable skills in the practicing engineer and continuing education needs. A survey of a few academic programs and a complete list of textbooks in control over the past three decades appear in the appendices.

CDROM USER INTERFACE EVALUATION: THE APPROPRIATENESS OF GUIS

Following a general trend in software development, CDROM applications are increasingly implementing Graphical User Interfaces (GUIs). The general assumption is that GUIs offer advantages in terms of ease of learning and use, especially for non‐expert users. Moreover, the adoption of GUIs for CDROMs has been suggested as a means of providing a de facto standard interface. This study assesses the appropriateness of GUIs, more specifically Windows‐based interfaces for CDROM. An evaluation model was devised to carry out an expert evaluation of the interfaces of seven CDROM products. The model identified two levels of interaction, the dialogue level and task level, and focused on general interface features, search and retrieval tasks, and output and processing options as well as the help facilities. The results are discussed in the light of HCI Usability Criteria and design guidelines (including general interface design guidelines, specific Windows design guidelines and The CDROM Consistent Interface Guidelines) to assess to what extent the applications comply and appropriate recommendations are made.

An interconnection language for reuse at the template/module level

Reuse is becoming a potent trend in software development and a major way to boost software productivity. To put reusable software units together, one has to be able to find them with minimal effort in the first place. The effort needed to access, understand, and customize the code must be less than the effort required to create new code. A simple library of components cannot provide sufficient methods to facilitate the selection and interconnection of the reusable modules. The context of this work is the ROPCO (reuse of persistent code and object code) environment and the primary candidates for reuse are the modules and templates. The objective of this article is to present the design of an interconnection language which can be incorporated with other ROPCO components to facilitate the selection, customization, and interconnection of reusable modules in the ROPCO software development environment. This language helps to define the interface specifications of the components and find the best module(s)/template(s) meeting the desired specification. The detailed algorithms of the operations that are necessary at the user level to support the reuse of available components are given and described in detail with a view toward verification.

Authoring systems: An introduction and assessment

THIS ARTICLE summarizes information about authoring system technology resulting from a recent review of eighty products. Alternative authoring approaches, such as programming languages, authoring languages, and authoring systems are described. Assumptions underlying authoring system development and use concerning productivity, course quality, and course development are examined. Selection procedures and criteria are suggested that are sensitive to the varied authoring needs of different contexts. Finally, trends in software development, evaluation, marketing, and use are presented.

The development of GRAMSKIL: A call grammar program for learners of English as a Second Language

To improve the grammatical skills of university-level students in an English as a Second Language (ESL) environment, the authors created a prototype software called GRAMSKIL. GRAM- SKIL differs from the current trend of software development in computer assisted language learning in two ways. Firstly, our program aims to develop grammatical competence instead of communicative competence in ESL learners. Secondly, it adopts the not-so-common approach of using a general purpose software tool—dBase III—to produce the program. GRAMSKIL uses the programming facility of dBase III to design menu-driven tasks which are user-friendly, and so computer novices can run the program without having to learn to run the database package. Moreover, GRAMSKIL allows teachers with little knowledge of database management systems to create their own database or modify the data to tailor them to the needs of their learners.

Closing the Generation Gap

Power system engineers have been using computers ever since the first generation computers (so named much later) came into existence. Automatic power system computations have been reported as early as 1947 [1]. According to recent statistics, the power industry is the third largest user of computers in the U.S.A. The explosive developments during the last decade have required the power engineer to be much more computer-literate and the power engineering curriculum has undergone drastic revisions to accommodate this requirement. Recent software concepts recommend a move towards using fourth generation languages for large application program development. Utilizing a fourth generation language can result in applications built in a fraction of the time with a fraction of the expenditure as compared to using third generation languages. The present day power student is going to face challenges of much greater magnitudes when he joins the power industry and the time is ripe for the introduction of fourth generation languages (4GL) and 'closing' the generation gap. Many salient features of 4GLs that make them useful as effective tools for presenting power system problems to the students are first described. The beneficial aspects of getting exposed to these new trends in software development are illustrated through a distribution analysis program being developed at the Tennessee Technological University. Specific examples of database application, line impedance calculation and very flexible load modeling are included.

A new direction in personal computer software

The personalization of computers is made possible by three major factors--advances in microelectronics, the availability of inexpensive software for a spectrum of applications, and the increased user-friendliness of computer systems. This paper examines the trends in software development, and presents estimates of the escalating costs involved in such development. Major studies by AT & T and by others stress that the true need is for more sophisticated and effective communication tools rather than for more computing power. Effective communication often pivots around the impact of diverse types of information--numeric, textual, and pictorial. Current endeavors are towards refining and integrating several existing technologies to implement software that enables programmers and non-programmers alike to readily manipulate images comprised of different types of information. This paper examines the emerging field of presentation graphics software and presents details of a new product in this nascent field. The conclusion emphasizes the impact of graphic computing in enlarging the spectrum of personal computer applications.