New Model for VDT Associated Visual Comfort in Office Spaces

In office rooms a significant aspect of visual discomfort is related to visual quality of computer screens and it\u27s necessary to consider this visual quality as an important subject in quality of design. In this study a new method was developed to predict the visual quality of computer screen which is based on contrast reduction due to reflection. The new developed contrast model which is the basis of the new developed evaluation method is named the model of minimum required contrast

Engineering data compendium. Human perception and performance. User's guide

The concept underlying the Engineering Data Compendium was the product of a research and development program (Integrated Perceptual Information for Designers project) aimed at facilitating the application of basic research findings in human performance to the design and military crew systems. The principal objective was to develop a workable strategy for: (1) identifying and distilling information of potential value to system design from the existing research literature, and (2) presenting this technical information in a way that would aid its accessibility, interpretability, and applicability by systems designers. The present four volumes of the Engineering Data Compendium represent the first implementation of this strategy. This is the first volume, the User's Guide, containing a description of the program and instructions for its use

Understanding, Modeling, and Simulating the Discrepancy Between Intended and Perceived Image Appearance on Optical See-Through Augmented Reality Displays

Augmented reality (AR) displays are transitioning from being primarily used in research and development settings, to being used by the general public. With this transition, these displays will be used by more people, in many different environments, and in many different contexts. Like other displays, the user\u27s perception of virtual imagery is influenced by the characteristics of the user\u27s environment, creating a discrepancy between the intended appearance and the perceived appearance of virtual imagery shown on the display. However, this problem is much more apparent for optical see-through AR displays, such as the HoloLens. For these displays, imagery is superimposed onto the user\u27s view of their environment, which can cause the imagery to become transparent and washed out in appearance from the user\u27s perspective. Any change in the user\u27s environment conditions or in the user\u27s position introduces changes to the perceived appearance of the AR imagery, and current AR displays do not adapt to maintain a consistent perceived appearance of the imagery being displayed. Because of this, in many environments the user may misinterpret or fail to notice information shown on the display. In this dissertation, I investigate the factors that influence user perception of AR imagery and demonstrate examples of how the user\u27s perception is affected for applications involving user interfaces, attention cues, and virtual humans. I establish a mathematical model that relates the user, their environment, their AR display, and AR imagery in terms of luminance or illuminance contrast. I demonstrate how this model can be used to classify the user\u27s viewing conditions and identify problems the user is prone to experience when in these conditions. I demonstrate how the model can be used to simulate changes in the user\u27s viewing conditions and to identify methods to maintain the perceived appearance of the AR imagery in changing conditions

Modeling of VDT Workstation System Risk Factors.

The objectives of this research were to determine the most important risk factors in VDT workstations associated with physical symptoms and to investigate the interrelationship among these risk factors. A conceptual model was first developed to describe the interrelationship among the basic components in a VDT workstation system and their possible health effects. A research model was then proposed to describe the hypothesized relationships among the following categories of variables: demographic, task, workstation design, work environment, psychosocial factors, work posture, psychological stress, musculoskeletal symptoms, visual symptoms, and general physical symptoms. A method which consisted of a questionnaire, measurement and posture analysis was then developed. A field study was conducted among daily computer users in a local industry. Ninety three VDT operators participated in the study. Factor analysis was applied to the physical symptoms to help identify the underlying factors. Multiple regression was used to determine the most important factors related to the physical symptoms and the effect of interactions among the risk factors. The four factors identified among physical symptoms are: ocular discomfort, general musculoskeletal symptoms, upper extremity symptoms, and other physical symptoms. Ocular discomfort is significantly related to screen glare; both general musculoskeletal symptoms and other physical symptoms are related to fatigue; and upper extremity symptoms are related to awkward upper body posture. Many interactions between the risk factors and their effects are identified, such as, psychosocial factors and demographic, and workstation factors and working posture. Psychosocial factors are found to interact with other variables and contribute to psychological stress. The implication of this research is that both physical and social environment need to be evaluated and the interactions among the components of a VDT workstation system need to be understood in order to determine physical symptom risk factors

Legibility of visual display units

Call number: LD2668 .R4 IE 1988 P73Master of ScienceIndustrial and Manufacturing Systems Engineerin

Lighting Retrofitting: improving energy efficiency and lighting quality

In order to minimize energy consumption for lighting and increasing lighting quality in existing offices, old lighting systems can be retrofitted with more efficient luminaires. Installing LED luminaires with inbuilt lighting controls can lead to high energy savings with low installation time. A case study has been analysed to define energy savings potentials of this technology. The conducted analysis can be used as a monitoring guideline for the evaluation of lighting retrofitting result

On the typography of flight-deck documentation

Many types of paper documentation are employed on the flight-deck. They range from a simple checklist card to a bulky Aircraft Flight Manual (AFM). Some of these documentations have typographical and graphical deficiencies; yet, many cockpit tasks such as conducting checklists, way-point entry, limitations and performance calculations, and many more, require the use of these documents. Moreover, during emergency and abnormal situations, the flight crews' effectiveness in combating the situation is highly dependent on such documentation; accessing and reading procedures has a significant impact on flight safety. Although flight-deck documentation are an important (and sometimes critical) form of display in the modern cockpit, there is a dearth of information on how to effectively design these displays. The object of this report is to provide a summary of the available literature regarding the design and typographical aspects of printed matter. The report attempts 'to bridge' the gap between basic research about typography, and the kind of information needed by designers of flight-deck documentation. The report focuses on typographical factors such as type-faces, character height, use of lower- and upper-case characters, line length, and spacing. Some graphical aspects such as layout, color coding, fonts, and character contrast are also discussed. In addition, several aspects of cockpit reading conditions such as glare, angular alignment, and paper quality are addressed. Finally, a list of recommendations for the graphical design of flight-deck documentation is provided

VDT workplace design and effects on muscle disorders and eye strain among students at an educational institute

The advancement of information technology encouraged schools, universities and other educational institutions to use visual display terminal (VDT) in conducting lectures rendering services and developing various systems. The use of personal computer (PC) and laptops are common among students. Classrooms are equipped with liquid crystal display (LCD) screens for lecturers to display their lectures for students. Many cases have not been reported because of lack of awareness and understanding on ergonomic. However, Poor ergonomics of the physical environment of VDT can cause musculoskeletal disorders (MSDs); the inappropriateness of school design may influence student achievement negatively. The viewing distance and position of the screens have been found as the main factors causing MSDs. The students’ satisfactions on VDT used in the education institute were determined. The effects of VDT workplace design parameters on muscle disorder and eye strain among students were determined. Ergonomically positions of VDT for safer and comfortable use among students were proposed. Data obtained from 215 LCD projector users and 103 desktop monitor users were analyzed using frequency tables, one sample t-test and Spearman’s rank order correlation coefficient. The frequency analysis for the level of satisfaction among LCD projector users showed that most of the users (88.4%) were satisfied with the viewing distance, and were least satisfied with the lighting(51.6%). For the monitor user, the users were highly satisfied with user/ screen position (80.6%) and least satisfied with the viewing distance (61.2%). Most of the LCD projector users (36.7%), experienced eye pain while performing study tasks on the projector screen, and the least pain were for head pain (22.8%). Most of the desktop monitor users (54.9%) were experienced head pain while performing study tasks on the monitors, and only (32%) experienced back pain. The relationship between the level of satisfaction for physical environment and MSDs was determined using Spearman’s rank order correlation coefficient. Results showed that, there were a significant and negative relationship between satisfaction of lighting and the level of back pain (rs = - 0.213, p < 0.001), head pain (rs = - 0.266, p < 0.001), neck pain (rs = - 0.119, p < 0.034) and eye pain (rs = - 0.292, p < 0.001) levels. Significant relationships were found between the level of distance satisfaction and the level of back pain (rs = - 0.148, p < 0.01) and eye pain (rs = - 0.151, p < 0.04). The results of association between satisfaction of position and MSDs pain indicated that only the relationship between satisfaction of position and the eye pain (rs = - 0.151, p < 0.005) was significant and negative. The results implied that the eye is the part of the body which is affected by all the other variables (lighting, distance, and position), but particularly more affected by problems with lighting in the study hall. In conclusion, this study has demonstrated that there is a lack of satisfaction with respect to some items within the physical environment, and there were MSDs disorders associated with VDT use, especially the lighting. These all likely to play a significant role in affecting the user’s health, and subsequently their performance. Thus providing enough lighting sources above the students and nearby the ( monitor/ p- screen), added to the windows in the classrooms and libraries. Also, ensure the proper distance like an arm's length for monitor users and (2 to 10 ) meters for the presentation screen users added to the students position directly in front of the monitor or p- screen with considering the study hall design ( sloped or flat) to provide viewing angle ( 0° to -20°), which allow the students to read the text at or slightly below eyes level, all of those are suggested to reduce the MSDs among UPM students