Interactive Computer Graphics Applied to Chemistry: Experiences and New Developments

This paper is essentially a progress report on three years of effort in computer graphics applied to chemistry. The major technical and human problems encountered when running our facility and integrating it into a chemistry department are described. Then progress of our research project, which is developing application programs in several areas of computer graphics applied to chemical education and research, is reviewed. Recent developments in the field of the representation of dynamic processes in molecules and illustrating some basic concepts of reaction mechanisms in organic chemistry are presented, and the important role of graphics in depicting adequately 3D reaction paths is stressed. Finally, some technical problems arising when using the calligraphic system as an audio-visual tool for teaching chemistry are discussed and some possible solutions are presented.     

The next generation of language labs: Can mobiles help? A case study

One major challenge regarding the use of today's language labs relates to teachers' and students' awareness and computer skills. Most teachers and students may not have the requisite computer skills and might soon become overwhelmed by the sophisticated functionality of today's digital lab systems. Thus, they should be provided with the appropriate training and technical support to reduce the apprehension that is usually associated with new technology. Recurrent technical problems are another shortcoming. Failure to operate the lab equipment efficiently due to hardware or software problems will inevitably cause delays and frustration for both students and instructors.To overcome such problems in existing language labs, this paper presents a novel cross-platform mobile lab system for language learning, called Mlab. The target users of MLab are language teachers and students, and the system offers them the freedom to move around and use their own devices at any time and in any place. Therefore, this research paper presents Mlab development and evaluation through three approaches: a holistic test case scenario, think aloud and interview sessions. The results showed high usability rates and generally positive attitudes toward using the mobile lab system.     

Not a mellifluous march to maturity [computer market]

The maturity of the computer market is discussed. There are three distinct types of maturity - technical, market, and organizational - and they neither relate to one another in a straightforward way nor do they relate to restructuring. That obscures a second and deeper problem. Restructuring can lead to bitter losses for employees.     

A system for WYSIWYG colour communication

Despite the development of more powerful and cheaper colour imaging devices, computer users often spend considerable effort creating colours on the screen only to find that when printed out later they appear to be a completely different shade. This is a problem which computer-aided design and colour management systems are only just beginning to address properly. More generally, if high colour fidelity is desired, there is cause for concern whenever attempts are made to reproduce the same colour across any different media. In the past, such problems have tended to be overcome by elaborate, tedious, iterative and usually manual matching processes. With rapid response times becoming increasingly important, the ability to communicate colour both quickly and accurately is highly desirable. This paper follows on from an earlier one in this journal which described a prototype system which was used successfully to demonstrate the feasibility of accurate colour fidelity and communication. The system, Colour-Talk, has since been further refined and the most recent developments are discussed here. This system illustrates a new way of communicating colour using the techniques of device independency and colour appearance modelling, both of which are essential to achieving WYSIWYG colour.     

Strategies for extending the useful lifetime of DES

Since 1977, private-sector users have been attracted to cryptography as a way to preserve the security of computer traffic in transit or files because of the availability of the U.S. Data Encryption Standard (DES). However, technical advances such as supercomputers and fifth-generation software threaten the security of DES. The National Security Agency have announced that they will not certify DES after 1988. Nevertheless, selection of secure modes of operation, use of DES chips as part of a multikey cipher system, or modification of the DES algorithm in software can produce cipher systems strong enough to protect most data for another decade at least.     

Control of spam: a comparative approach with special reference to India

Spam and other related online threats are a real concern to all Internet users as they can lead to online fraud involving counterfeit websites, the theft of personal data such as credit card information, personal information through illicit access to computer systems and false or misleading representations in the market place. These are not imaginary threats but are supported by empirical evidence. This wastes time to users opening spam with misleading subject lines, wastes Internet resources trying to block it, consumes storage and bandwidth, and costs money in fighting it. E-commerce cannot flourish in an uncertain environment where security of personal data is not guaranteed. With the aim of boosting confidence in online commerce and protecting the interests of consumers, governments have introduced anti-spam legislation to protect consumers and businesses. This legislation has introduced different parameters. However, legislation alone cannot prevent spam. It is to be combined with technological measures. There is no separate legislation in India to deal with this problem. This paper analyses technological solutions and legal measures in the light of trans-national developments to provide background for any judicial decision making or legislative policy in India.     

Key Developments in Computer Technology: A Survey

Genesis of survey. During the past six months, a cross section of computer professionals, including most of the chairmen of the Computer Society's technical committees and several other society members, was interviewed with the objective of summarizing their assessment of the major developments in computer technology. (The names of those consulted are listed on p. 75.) Attention was concentrated on the principal recent developments in the computer field and on the major problems that stand in the way of future progress.     

When the chips are down: Social and technical aspects of computer failure and repair

This paper explores computer failure as a social event by examining recorded interactions between computer users and help-desk consultants (technicians). It was found, first, that the nature of a failure was negotiated between participants rather than being simply technically evident. Failure was defined from users' perspectives, in relation to what they were trying to achieve, rather than according to technical parameters. Secondly, negotiations of failure had social consequences for both users and help-desk consultants. Both avoided being seen as incompetent and actively defended their social standing. Thirdly, such social issues sometimes took precedence over technical and practical ones. The implications for HCI theorists and practitioners are twofold: firstly, failure should be accepted as a regular part of computer use in which human–computer interaction continues even though the interface may be non-functional. Secondly, the management of failure could be better addressed if technicians were trained in social as well as technical intervention skills.     

Formality Considered Harmful: Experiences, Emerging Themes, and Directions on the Use of Formal Representations in Interactive Systems

This paper reflects on experiences designing, developing, and working with users of a variety of interactive computer systems. The authors propose, based on these experiences, that the cause of a number of unexpected difficulties in human-computer interaction lies in users' unwillingness or inability to make structure, content, or procedures explicit. Besides recounting experiences with system use, this paper discusses why users reject or circumvent formalisms which require such explicit expression, and suggests how system designers can anticipate and compensate for problems users have in making implicit aspects of their tasks explicit. The authors propose computational approaches that address this problem, including incremental and system-assisted formalization mechanisms and methods for recognizing and using undeclared structure; they also propose non-computational solutions that involve designers and users reaching a shared understanding of the task situation and the methods that motivate the formalisms. This paper poses that, while it is impossible to remove all formalisms from computing systems, system designers need to match the level of formal expression entailed with the goals and situation of the users -- a design criteria not commonly mentioned in current interface design.     

Information flows amongst executives: their implications for systems development

Senior managers have tended to resist the incursion into their personal domain of computer systems meant for their use. Their main criticism is that technical solutions are being imposed on them without an adequate analysis of the problems at hand. This suggests that the way in which executives obtain and exchange information may not be adequately understood. With the help of a framework designed to identify top executives' networks of information flows, the study reported in this paper analysed the information practices of 16 executives from four organizations. The findings of the research indicated that executives use a combination of communication flows and information flows in a proportion which varies depending upon the context of their different activities. It also revealed that executives initiated information and communication flows of a different nature depending upon the role they play and the level of those with whom they deal within the organization. The results of the study suggest that very specific approaches are needed when identifying executives' needs in terms of developing systems aimed at supporting top managers' strategic activities.     

A genetic algorithm for solving the two-dimensional assortment problem

Assortment problems arise in various industries such as the steel, paper, textiles and transportation industries. Two-dimensional assortment problems involve finding the best way of placing a set of rectangles within another rectangle whose area is minimized. Such problems are nonlinear and combinatorial. Current mixed integer programming models give optimal solutions, but the computation times are unacceptable. This study proposes a genetic algorithm that incorporates a novel random packing process and an encoding scheme for solving the assortment problem. Numerical examples indicate that the proposed genetic algorithm is considerably more efficient and effective than a fast integer programming model. Errors with respect to the optimal solutions are low such that numerous practical industrial cutting problems can be solved efficiently using the proposed method.     

Information technology: Effect on local government and dp in the next 5 years: (Group discussion report)

DP/MIS has just begun to scratch the surface in making data available to users. There will be a tremendous emerging market resulting from users' needs for help in dealing with data and applying technology to their jobs. If DP does not respond there will be many private organizations who will step in, although for the sake of continuity, many of these services can and probably should come from inside the organization.For the past 15 years “experts” have been predicting that programmers would soon disappear and there would be an exponential growth in demand for those who could interface the organization's vast information resources. Although the technology is exploding, particularly in the hardware area, the promises of fourth and fifth generation languages and applications developers have yet to be realized in the workplace. Although a lot of processing is being distributed to users, there still is no solution to the need to bring it together, coordinate the efforts and control the process for decision making.In the next 5 years it seemed unlikely to most participants that the job of DP would be modified so much that their primary role would be assisting users. DP/MIS executives, at least in the mid-sized and larger organizations, will still have large technical staff's working on complicated technical problems. There will be a need for new and more innovative ways for DP/MIS and users to work together for the benefit of the entire organization. Many of these ways have not yet been imagined but should be emerging by the time ALGIS meets again in 18 months.One thing was clear to the Workshop participants. Information processing functions will no longer continue to be automated without first a careful analysis of what is being automated, why and how it will benefit the organization. There will also be an increasing demand for networking solutions and integration of diverse hardware and software.As users become more computer literate, DP will have to be more savvy about dealing with organization politics. More and more local council members, for example, are becoming computer literate. Many come from the private sector where they are using computers daily. The demand in the U.K., for example, has become so great that 68 local authorities have bought PC's to give their council members to take home. The effect of these developments on organizations and on local government computing was recommended for consideration at the next ALGIS workshop in Belgium.     

Expressive rendering: a review of nonphotorealistic techniques

The success of graphics systems that render photorealistic output has obscured parallel developments in nonphotorealistic rendering. A review of these “expressive” systems suggests a framework for further development. One of the authors, Simon Schofield, has developed a prototype system that gives users a wide variety of automatic rendering styles-from the almost photorealistic, through the styles resembling artists' sketches or paintings, to abstract renderings of entirely new forms. The significant problems associated with NPR are primarily aesthetic and only secondarily technical. The culturally oriented theoretical problems surrounding the field are many and, at their most difficult, broach central issues of perception and representation. We therefore begin by discussing the limitations of photorealism as a representational style. However, the technical problems of implementing an NPR system are not trivial. As far as we know, the literature defines no general framework for an NPR system, although it does include an array of more focused solutions. We survey more than 15 of these solutions. On the basis of this survey, we then define a framework for NPR systems that distinguishes them from systems focused on photorealism. We also identify the characteristics of NPR systems that go beyond the tendency to simulate traditional media, functioning instead as 3D renderers. In this context, we briefly describe Schofield's system, called Piranesi, which operates this way     

DW-RBAC: A formal security model of delegation and revocation in workflow systems

One reason workflow systems have been criticized as being inflexible is that they lack support for delegation. This paper shows how delegation can be introduced in a workflow system by extending the role-based access control (RBAC) model. The current RBAC model is a security mechanism to implement access control in organizations by allowing users to be assigned to roles and privileges to be associated with the roles. Thus, users can perform tasks based on the privileges possessed by their own role or roles they inherit by virtue of their organizational position. However, there is no easy way to handle delegations within this model. This paper tries to treat the issues surrounding delegation in workflow systems in a comprehensive way. We show how delegations can be incorporated into the RBAC model in a simple and straightforward manner. The new extended model is called RBAC with delegation in a workflow context (DW-RBAC). It allows for delegations to be specified from a user to another user, and later revoked when the delegation is no longer required. The implications of such specifications and their subsequent revocations are examined. Several formal definitions for assertion, acceptance, execution and revocation are provided, and proofs are given for the important properties of our delegation framework.     

New Developments in Computer Assisted Creative Problem Solving

A new kind of computer assisted creative problem solving method is examined in which visual images are provided to support the process. Until now, much attention has been given to developing programmes which help to structure problems and ideas so that they become more meaningful to the people who are concerned with them. Emphasis has been placed almost entirely on the written word as form of expression. It is argued that a combination of pictorial imagery and written words may be more effective in helping users to gain insights into problems and to come up with ideas or solutions to problems.     

User-driven modelling: Visualisation and systematic interaction for end-user programming

This research enables computer literate engineers to model problems in software by minimising code they need to write. Software development is difficult for many engineers as they may have no time, experience, or access to software development tools necessary to model their problems. Using a combination of modelling via use of formulae (equations) and visualisation of the way these formulae interact, it is possible to construct modelling software without requiring code. This technique of user-driven modelling/programming (UDM/P) could be applied to any problem that requires linked equations to be represented and tracked, and results from these calculated. End-user programming could be tackled by many researchers co-operating to create specific solutions to different kinds of end-user programming problems. A stepped ontology based translation process assists with progress towards a generic solution, this is first applied to engineering modelling.     

Developing a navigation aid for the frail and visually impaired

This paper describes the development of a new navigational aid for the frail, elderly, and visually impaired person. The users were involved both in the user requirements study and in the evaluation of different prototypes. The results show that the users were able to provide information on their current aid, the use situation, and their preference regarding different solutions, but they had difficulties to provide the detailed answers on technical solutions required by the technical development team. Further, prototype evaluations with users enabled the technical team to understand the users and their use situation.     

Authorized workflow schemas: deciding realizability through \mathsf{LTL }(\mathsf{F }) model checking

Many business processes are modeled as workflows, which often need to comply with business rules, legal requirements, and authorization policies. Workflow satisfiability is the problem of determining whether there exists a workflow instance that realizes the workflow specification while simultaneously complying with such constraints. This problem has already been studied by the computer security community, with the development of algorithms and the study of their worst-case complexity. These solutions are often tailored to a particular workflow model and are, therefore, of little or no use in analyzing different models; their worst-case complexities are likely to be an unreliable judge of their feasibility; and they lack support for other forms of analysis such as the determination of the smallest number of users required to satisfy a workflow specification. We propose model checking of an NP-complete fragment $\mathsf{LTL }(\mathsf{F })$ of propositional linear-time temporal logic as an alternative solution. We report encodings in LTL(F) that can compute a set of solutions (thus deciding satisfiability), compute minimal user bases and a safe bound on the resiliency of satisfiability under the removal of users. These theoretical contributions are validated through detailed experiments whose results attest to the viability of our proposed approach.