Steps toward building mathematical and computer models from cognitive task analyses

Typically, detailed quantitative and computer models of human operators performing real world tasks cannot easily be developed. We propose a technique that more easily allows for that development. We propose that when a cognitive task analysis has been carried out, a computer simulation model useful for approximations of task completion time is often within reach. The first step is to construct an activity network or order-of-processing diagram from the task analysis. Second, activity durations are found in the literature or approximated through multidimensional scaling. Finally, equations are written for calculating task completion time, or a program is written for simulations to estimate this time. Resulting models can be useful for optimizing system design. The approach is illustrated with an activity network by W. D. Gray, B. E. John, and M. E. Atwood (1993) for a telephone operator task. Simulations demonstrate the feasibility of using multidimensional scaling to obtain approximate activity durations. The approach is also illustrated with an order-of-processing diagram representing drivers reading roadside message displays. We point out that if a more detailed picture of unobservable mental processes in a task is needed, techniques have been developed for this through analysis of response times. Actual or potential applications of this research include system design, human-computer interaction, message comprehension, and simulation of information-processing tasks.     

A computer program for analyses of vital statistics-based occupational mortality data

Routinely collected vital statistics mortality data (death certificate data) on occupation and industry are useful for (1) generating hypotheses about potential occupational hazards and (2) identifying occupational mortality differentials possibly associated with socioeconomic and life-style factors. This paper presents a Fortran program that analyzes occupational mortality using vital statistics and census data. The user can form any desired grouping of age, race, occupation (or industry), and cause of death codes for analysis. The program also allows stratification on social class or other user-defined correlates of occupation such as smoking behavior. Furthermore, program output can be used for Poisson regression analysis of mortality rates.     

WAALSURF: Molecular graphics on a personal computer

The advent of increasingly powerful graphics boards for personal computers will soon allow quite advanced molecular graphics applications on inexpensive personal computer configurations. This paper describes an interactive molecular data display program, called WAALSURF, implemented on two different personal computers, IBM's PC-AT equipped with a Professional Graphics Adapter and Commodore's Amiga. These programs allow the inspection of data bases containing data of molecules with some thousand atoms each. The molecular data can be used to generate a range of representations from skeleton, ball-and-stick to space filled Van der Waals surfaces. To foster 3D perception coloring, perspective and lighting depth cues are included, with stereo images as an option. A versatile user interface is provided, allowing the operator to manipulate objects as well as display parameters. Under interactive control the user may rotate molecules in static or animation mode, label sections, strip outer layers and dock molecules while changing the color and the number of atoms displayed. A logging facility is provided to resume a new session where the previous one left off.     

Molecular interaction networks in the analyses of sequence variation and proteomics data

Protein–protein interaction networks are typically generated in standard cell lines or model organisms as it is prohibitively difficult to record large interaction datasets from specific tissues or disease models at a reasonable pace. Although the interaction data are of high confidence, they thus do not reflect in vivo relationships as such. A wealth of physiologically relevant protein information, obtained under different conditions and from different systems, is available including information on genetic variation, protein levels, and PTMs. However, these data are difficult to assess comprehensively because the relationships between the entities remain elusive from the measurements. Here, we exemplarily highlight recent studies that gained deeper insight from genetic variation, protein, and PTM measurements using interaction information pointing toward the importance and potential of interaction networks for the interpretation of sequencing and proteomics data.     

Molecular dynamics simulation using the cray-1 vector processing computer

Algorithms are presented which enable molecular dynamics simulations of liquids to be performed most efficiently on the Cray-1 vector processing computer. For 256 atoms interacting via the Lennard-Jones potential the CPU time per step of the simulation is 22 ms.     

Molecular dynamics of a model polymer on a hypercube parallel computer

In this paper, we discuss the implementation and solution of molecular dynamics polymer models on the Intel iPSC Hypercube parallel computer. We first describe a model problem whose inherent parallelism can be exploited effectively and which is therefore amenable to parallel solution. We next discuss the salient features of the hypercube programs that were used to solve the model problem. Finally, we present results which demonstrate that the efficiencies of the solutions approach 100% as the number of atoms in the polymer and the number of hypercube processors are increased for the problem in question. The results demonstrate that parallel solutions of polymer problems using a hypercube architecture offer potentially significant savings over sequential solutions.     

Molecular solutions of the RSA public-key cryptosystem on a DNA-based computer

The RSA public-key cryptosystem is an algorithm that converts a plain-text to its corresponding cipher-text, and then converts the cipher-text back into its corresponding plain-text. In this article, we propose five DNA-based algorithms??parallel adder, parallel subtractor, parallel multiplier, parallel comparator, and parallel modular arithmetic??that construct molecular solutions for any (plain-text, cipher-text) pair for the RSA public-key cryptosystem. Furthermore, we demonstrate that an eavesdropper can decode an encrypted message overheard with the linear steps in the size of the encrypted message overheard.     

Audio-enhanced computer assisted learning and computer controlled audio-instruction

A computer controlled language laboratory cassette recorder has been used as a computer peripheral to enhance computer assisted learning by the addition of an audio channel of communication. To facilitate the production of audio-enhanced CAL material a simple author code system has been devised. The same cassette recorder has also been used under the control of an “on-board” micro-computer to increase the flexibility of audio-instruction by allowing branching amongst sections of audio material in response to answers to questions.     

Aggression,competition and computer games: computer and human opponents

Violence and aggression in computer games has been a concern of social commentators and an interest of media researchers for more than 10 years. Violent content has been at the top of the agenda even though aggression and hostility have been identified as a part of competitive gaming situations. The role of the opponent in this process has been largely overlooked. We examined the difference in frustration and aggression in game play after users encountered the computer as opponent and a proximate person as opponent using the same CD-ROM version of Monopoly. We found that users experienced higher levels of aggressive feelings after playing the computer than after playing a stranger face-to-face. It appears that aggression related to computer gaming may be reduced through the humanization of computer opponents.     

高校微机室计算机主机硬件故障分析与修复

为了快速高效地判断并排除计算机主机硬件故障,更好地完成高校微机室的计算机硬件维护工作,基于多年实践工作经验,对计算机主机的常见故障作了详细的归纳总结.通过分析故障现象,运用听看结合、交叉判断、逐一排除等技巧查找到故障点,最终采用快捷、经济的实用方法排除故障,从而,确保高校教学活动的正常进行.     

Intuition and computer models

Models of pattern-generating cellular sheets were devised to gain insight into the origin of patterns in embryogenesis. Students, many of whom had no previous experience with computers, worked with these models to test the effect of various assumptions. A number of discoveries of possible biological importance were made, but an unexpected discovery was the usefulness of human intuition. When the computer and its program made user interaction easy, the user “played” the model as one might play an arcade game. The model's capabilities and limits were grasped intuitively. Later, analysis led us to new assumptions and new models. Thus the work progressed quite effectively with alternating intuition and cerebration. Microcomputers are particularly effective in this method of research.     

Interactive computer aided design using computer graphics

The development of a software system for general network design using interactive computer graphics poses many problems, which must be solved in a way consistent with the principles of man-machine communication as applied to network design, so as to obtain a system suited both to networks of any nature and also to any type of network design technique.This paper states the principles influencing the development of such a system and presents the design decisions made and the one implementation.     

Teaching computer music in a computer setting

Using a computer to produce sound in the classroom is not new and has been used for ear training and drill-and-practice for some time. Computer music can also provide computer students with an alternative means to explore traditional computer concepts: modular design, functional decomposition, and iterative development. Combining these uses for computer music would produce a course where both computer students and music students could gain an insight to the use of system development techniques. Such a course is described in this paper along with notes on how this course was implemented.     

Promoting healthy computer use: timing-informed computer health animations for prolonged sitting computer users

Accompanying the increase in computer and Internet use worldwide, physical inactivity has become prevalent in most developed and developing countries. Extended computer use may contribute to symptoms such as visual impairment and musculoskeletal disorders. To reduce the risk of physical inactivity and promote healthier computer use, this study tries to develop a timed broadcast of health-related animations for users sitting at computers for prolonged periods. In addition, we examine the effects that the program has on the computer-related health beliefs and behaviour of participants. Before-and-after survey questionnaires were used for data collection. The results show that the animation program indeed had a positive effect when reminding participants to take a break and stretch their bodies. The program influenced the beliefs and behaviours of participants with regard to their health. The development and examination were documented and discussed within the context of health agencies planning the next steps in an effort to promote, develop and evaluate healthy computer use.     

浅谈学校计算机网络机房的管理和维护

公共机房的管理与维护是保证学校正常教学活动的基础工作.科学的管理,会使机房维护工作事半功倍.本文根据笔者在中学公共机房十多年来的工作经验,通过对公共机房的软件、硬件设备的管理,系统的维护等方面详尽的阐述,并对在机房管理与维护中经常遇到的问题及解决方法总结出几点建议,可有效提高计算机机房的管理效率.     

A computer attitude scale for computer science freshmen and its educational implications

Abstract The successful integration of computers in educational environments depends, to a great extent, on students' attitudes towards them. Widely used computer attitude scales (CASs) focus on the beliefs of typical computer users and do not reveal the more refined attitudes of groups that use computers extensively and develop unique relations with them. This study presents the development and validation of a CAS especially designed for computer science freshmen (CASF). The scale consists of five factors, namely, self-confidence in previous knowledge, hardware usage anxiety, computer engagement, fears of long-lasting negative consequences of computer use and evaluation of positive consequences of computers in personal and social life. Using an analytic computer experience construct, the scale's components were related to multiple aspects of students' computer experience. CASF responses can inform a variety of instructional decisions and classroom management strategies for the first phase of the students' studies.