Eyestrain and visual display units: a review

A review is presented of current knowledge about the nature, incidence and causes of eyestrain or visual fatigue among VDU operators. It is suggested that fatigue and discomfort may result from visual, postural, environmental, work design and personal factors. However, it is concluded that all these problems can be overcome by sufficient attention to ergonomics in the design, implementation and use of VDUs.     

Musculoskeletal disorders among visual display terminal workers: individual,ergonomic, and work organizational factors

A number of individual, ergonomic, and organizational factors of presumed importance for the occurrence of musculoskeletal disorders were investigated in a group of 260 visual display terminal (VDT) workers. The cross-sectional study utilized medical and workplace investigations as well as questionnaires. The results were subjected to a multivariate analysis in order to find the major factors associated with various upper-body muscular problems. Several such factors were identified for each investigated type of musculoskeletal problem. Some were related to the individual: age, gender, woman with children at home, use of spectacles, smoking, stomach-related stress reactions, and negative affectivity. Organizational variables of importance were opportunities for flexible rest breaks, extreme peer contacts, task flexibility, and overtime. Identified ergonomic variables were static work posture, hand position, use of lower arm support, repeated work movements, and keyboard or VDT vertical position.     

Electromagnetic radiation emissions from visual display units: a review

The suggestion that workers using visual display units may be exposed to potentially hazardous electromagnetic radiations emitted by such equipment has raised the question of operational safety. In order to assess and quantify any risk a number of radiation surveys have been conducted in several countries. These surveys have followed different protocols and used a variety of field survey instruments. All have arrived at similar conclusions indicating that there are no significant levels of radiation to be found in any part of the electromagnetic spectrum emitted by such equipment.     

The impact of animated interface agents: a review of empirical research

Over the last years, the animation of interface agents has been the target of increasing interest. Largely, this increase in attention is fuelled by speculated effects on human motivation and cognition. However, empirical investigations on the effect of animated agents are still small in number and differ with regard to the measured effects. Our aim is two-fold. First, we provide a comprehensive and systematic overview of the empirical studies conducted so far in order to investigate effects of animated agents on the user's experience, behaviour and performance. Second, by discussing both implications and limitations of the existing studies, we identify some general requirements and suggestions for future studies.     

Time and information technology in teams: a review of empirical research and future research directions

Information technology (IT) is intricately bound up with time in teams. Yet a comprehensive review of what is known about time in IT-mediated teams is lacking. This paper addresses this gap. We classify time into three categories: conceptions of time, mapping activities to time, and actors relating to time. Drawing upon this framework, we review empirical information systems (IS) research on IT-mediated teams over the past three decades. Our review reveals that the research has approached time predominantly using the clock view and has examined exclusively how to map a single activity to the continuum of time. As a result, most studies operate within a simplified temporal context by conceiving time as an objective attribute that ticks away. Meanwhile, a void exists in research that recognizes time as interpretive and experienced. Our analyses also indicate that past research has been primarily interested in the differences between face-to-face and IT-mediated teams and the communication function of IT. Overall, IT remains roughly conceptualized, and research has produced fragmented insights that have small cumulative effects. To advance more substantive theory building, we propose several research directions that invite richer theorizing about how IT is related to time in teams.     

Rapid application development (RAD): an empirical review

Rapid application development (RAD) is an approach to information systems (IS) development which is much discussed in the practitioner literature. However, there is comparatively little research data on this topic. This paper forms a report of the results of a multi-disciplinary research project which has been studying this development approach for the last three years. The paper discusses seven case studies of RAD projects and compares each to issues relating to a number of RAD principles as represented in methodologies such as the recent open standard known as dynamic systems development method. We conclude with a discussion of a number of important questions relating to further research on RAD.     

Job satisfaction and visual display unit (VDU) usage: an explanatory model

Abstract

This study explores the relationship between job salisfaction and the daily usage of visual display units (VDUs). A negative correlation is found to exist between job satisfaction and utilization of the VDU. Workers who have utilized the VDU alone for data entry were more satisfied with their jobs than those workers who had used the key punch for data entry and then switched to the VDU, although they said they preferred the VDU over the key punch. The following model was found to be statistically significant:

Job satisfaction =f(-VDU Usage + Supervisor intervention+ Team membership+ job utility—performance of the task)     

Job satisfaction and visual display unit (VDU) usage: an explanatory model

This study explores the relationship between job salisfaction and the daily usage of visual display units (VDUs). A negative correlation is found to exist between job satisfaction and utilization of the VDU. Workers who have utilized the VDU alone for data entry were more satisfied with their jobs than those workers who had used the key punch for data entry and then switched to the VDU, although they said they preferred the VDU over the key punch. The following model was found to be statistically significant:

Job satisfaction =f(-VDU Usage + Supervisor intervention+ Team membership+ job utility—performance of the task)     

Effect of visual display terminal height on the trapezius muscle hardness: quantitative evaluation by a newly developed muscle hardness meter

The aim of this study was to determine trapezius muscle hardness in 9 healthy volunteers before and after word processing tasks with a video display terminal (VDT) at three different heights. When using a desktop personal computer (PC), no change was observed in muscle hardness even after a 30-min task if a subject was in the reference posture with a declination angle formed by the Reid's line directed toward the upper edge of the PC screen and the horizontal plane within 5-10 degrees. However, an increase in muscle hardness was observed after a 15-min task in a posture of looking up at the screen (angle of elevation: 15-20 degrees) and after a 30-min task in a posture of looking down at the screen (angle of declination: 15-20 degrees). When the same tasks were performed with a notebook PC, muscle hardness increased after 15 min. Fifteen minutes of relaxation exercise reduced the muscle hardness caused by VDT work.     

Effect of job demands and social support on worker stress: a study of VDT users

This study examined the effect of job demands (quantitative workload and computer-related problems) and social support (supervisor and co-worker support) on stress of VDT users. A survey questionnaire was administered to employees of three public service organizations. Two-hundred and sixty-two office workers participated in this study. Results showed that job demands (quantitative workload and computer-related problems) had a direct effect on psychological complaints of VDT users. On the other hand, co-worker support did not affect worker stress. Supervisor support was a buffer against worker stress both in the low and high job demands conditions. However, supervisor support did not have any interactive buffering effect on the relationship between job demands and worker stress.     

LED灯在虚拟显示终端中动态定位与自动寻址的研究与设计

传统LED灯集群控制系统采用列表清单实现,有诸多缺陷。采用地图和地图标记结合的视图表现手法,克服现有技术的缺点与不足,研究LED灯在虚拟显示终端中动态定位与自动寻址的地图显示方法,克服现有LED灯产品控制的地域限制、功能限制以及集群控制场合下个体识别困难等问题,结合距离定位技术,提供一种通过地图对LED灯直接定位寻址的便利功能。实验结果表明,该设计使用户可以通过地图上的标识对相应的实际地理位置上的LED灯进行精确定位控制。     

Mobile (cellular) phone use and driving: a critical review of research methodology

Studies have examined possible effects of concurrent mobile phone use on driving performance. Although interference is often apparent, determining the implications of such findings for 'real world' driving is problematic. This paper considers some relevant methodological issues including the definition of procedures and terms, operationalization of task elements, sampling of task components, and the provision of experimental controls. Suggestions are made about how methodological rigor could be improved.     

Mobile (cellular) phone use and driving: a critical review of research methodology

Studies have examined possible effects of concurrent mobile phone use on driving performance. Although interference is often apparent, determining the implications of such findings for ‘real world’ driving is problematic. This paper considers some relevant methodological issues including the definition of procedures and terms, operationalization of task elements, sampling of task components, and the provision of experimental controls. Suggestions are made about how methodological rigor could be improved.     

An alternate method for using a visual discrimination model (VDM) to optimize soft-copy display image quality

Researchers have developed visual discrimination models (VDMs) that can predict a human observer's ability to detect a target object superposed on an image. These models incorporate sophisticated knowledge of the properties of the human visual system. In the predictive approach, termed conventional VDM usage, two input images with and without a target are analyzed by an algorithm that calculates a just-noticeable-difference (JND) index, which is a taken as a measure of the detectability of the target. A new method of using the VDM is described, termed channelized VDM, which involves finding the linear combination of the VDM-generated channels (which are not used in conventional VDM analysis) that has optimal classification ability between normal and abnormal images. The classification ability can be measured using receiver operating characteristic (ROC) or two alternative forced choice (2AFC) experiments, and in special cases they can also be predicted by signal detection theory (SDT) based model-observer methods. In this study simulated background and nodule containing regions were used to validate the new method. It was found that the channelized VDM predictions were in excellent qualitative agreement with human-observer validated SDT predictions. Either VDM method (conventional or channelized) has potential applicability to soft-copy display optimization. An advantage of any VDM-based approach is that complex effects, such as visual masking, are automatically accounted for, which effects are usually not included in SDT-based methods.