Thesis (M. S.)--Literature, Communication, and Culture, Georgia Institute of Technology, 2009. / Committee Chair: Mazalek, Ali; Committee Member: Bolter, Jay David; Committee Member: Do, Ellen Yi-Luen; Committee Member: Nitsche, Michael; Committee Member: Winegarden, Claudia R.

Orientador: Aparecida Mari Igut / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-27T00:33:00Z (GMT). No. of bitstreams: 1 Estepa_AdrianaPaolaCastillo_M.pdf: 4613304 bytes, checksum: 19e87ad38d3723336006e6b5ea012417 (MD5) Previous issue date: 2014 / Resumo: Introdução: Os computadores são parte da vida moderna e seu uso deles massificado; diariamente as pessoas passam várias horas diante de uma tela pelas diversas facilidades no trabalho, no lazer, na conectividade, entre outros. Ao mesmo tempo também trazem riscos à saúde de seus usuários, sendo descritos problemas psicológicos, problemas musculoesqueléticos e problemas visuais; estes últimos apresentam uma alta prevalência (50%-70%) e os sintomas visuais e oculares, que trazem incômodos para realização de atividades com o computador, reduzem a produtividade dos trabalhadores e diminuem a qualidade de vida dos usuários de computadores. Estes efeitos à saúde visual têm sido pouco estudados pela comunidade científica. Objetivos: Levantar a frequência de casos da Síndrome da Visão do Computador em professores universitários e identificar os fatores de risco associados à presença da CVS. Metodologia: Trata-se de estudo de tipo transversal observacional e participam professores de uma universidade pública do Estado de São Paulo; foram aplicados dois questionários, um versando sobre aspectos do trabalho e do uso de computadores e outro, sobre sintomas oculares e visuais. Além disso, foram realizados exames visuais. A coleta de dados foi feita entre os meses de Fevereiro a Dezembro de 2013 no campus da universidade. Critérios de Inclusão: Professores da universidade. Critérios de Exclusão: Professores que não usem o computador. Resultados: Em uma amostra de 53 professores a Síndrome da Visão do Computador foi encontrada em 30 professores, 19 deles classificados com a forma leve da Síndrome, 10 com a moderada e 1 com a severa; os sintomas que mais incomodaram os professores foram fadiga (30 participantes), ressecamento ocular (20 participantes), irritação ocular (17 participantes). Foram encontrados problemas binoculares em 27 dos 53 professores e diminuição na produção lacrimal em 12/53. Conclusões: Os professores universitários são uma população com uma alta prevalência da Síndrome da Visão do computador, na amostra apresentou-se a síndrome em mais da metade dos participantes 30/23(56%), concordando assim com as prevalências da Síndrome encontradas nos estudos internacionais. Três variáveis foram associadas significativamente ao aparecimento da CVS nos professores universitários, a idade que minimiza as chances de ter CVS (OR: 0,91 IC: 0,83/0,97 P-value: 0,015), as horas de uso diárias no computador que aumentam as chances de apresentar CVS (OR: 1,26 IC: 1,05/1,57 P-value: 0,021), e os problemas vergenciais como insuficiência ou excesso de convergência ou divergência, os quais estão associados positivamente com o aparecimento da síndrome (OR: 3,24 IC: 1,06/10,49 P-value: 0,042). Palavras chave: Síndrome da Visão do Computador, astenopia, videoterminais, ergonomia, saúde do trabalhador / Abstract: Computers are part of modern life, their use sprayed and people spend several hours using them as they bring several facilities in work, leisure, connectivity, among others. Computers also brought risks to the health of its users, psychological problems, musculoskeletal problems and visual problems, although the latter with a high prevalence (50% -70%) and with visual and ocular symptoms that diminish the quality of life of users, bother working with the computer and reduce worker productivity, has been little studied by the scientific community. Objectives: The study aims to estimate the cases frequency of the Computer Vision Syndrome in teachers and to identify risk factors associated with the presence of CVS. Methodology: This is a cross-sectional-observational study with teachers of a public university which two questionnaires and a visual test is performed to find and evaluate the possible symptoms of Computer Vision Syndrome of as well as their associated factors. The survey is conducted between the months of February to December 2013 at the University campus. Inclusion Criteria: Teachers and researchers at university. Exclusion Criteria: Teachers and researches that do not use the computer. Results: In a sample of 53 teachers of Computer Vision Syndrome was found in 30 teachers, 19 were classified as mild form of the syndrome, 10 with moderate and 1 with severe, the symptoms that bother the teachers were fatigue (30 participants), ocular dryness (20 participants), eye irritation (17 participants). Binocular problems were found in 27 of the 53 teachers and decrease in tear production in 12/53. Conclusions: The teachers are a population with a high prevalence of the Computer Vision Syndrome, the sample presented the syndrome in more than half of the participants 30/23 (56%), thus agreeing with the prevalence of the syndrome found in international studies. Three variables were significantly associated with 5 % with the onset of CVS on university teachers , the age that minimizes the chances of having CVS (OR: 0.91 IC: 0.83/0.97 P-value: 0.015), hours daily use of the computer that increase the chances of presenting CVS (OR: 1.26 IC: 1.05/1.57 P-value: 0.021), and vergenciais problems like deficiency or excess of convergence or divergence, which are positively associated with the onset of the syndrome (OR: 3.24 IC: 1.06/10.49 P-value: 0.042). Keywords: Computer Vision Syndrome, asthenopia, video display terminals, ergonomics, occupational health / Mestrado / Epidemiologia / Mestra em Saúde Coletiva

Display/control gain is the amount of movement that occurs on a display in response to a unit amount of movement on the control. Two studies were conducted to determine the adequacy of identifying the optimum gain for an interface as a method of control-display interface optimization. The first study examined the effects of changes in both the maximum control input and the display width on target acquisition performance with a touch tablet and a trackball. The hypothesis that an interaction between the control input and the display output would determine performance was not supported for either device. There was a main effect of the control input for the touch tablet, and significant effects of the control input and the display width for the trackball. The results also indicate that, at least for the touch tablet, gain is not a sufficient specification for performance. The second study evaluated the effects of changes in the display amplitude, the display target width, and the control amplitude. There were significant interactions among these three factors for both touch tablet and trackball target acquisition performance. These results extend the findings of the first study with respect to the inability of gain to predict performance. In addition, the inadequacy of Fitts' Law as it applies to the given interfaces is discussed. / Ph. D. / incomplete_metadata

The Navy, through its Total Quality Leadership (TQL) program, has emphasized the need for objective criteria in making design decisions. There are numerous tools available to aid human factors engineers meet the Navy’s need. For example, simulation modeling provides objective design decisions without incurring the high costs associated with prototype building and testing. Unfortunately, simulation modeling of human— machine systems is limited by the lack of task completion time and variance data for various objectives. Moreover, no study has explored the use of a simulation model with a Predetermined Time System (PTS) as a valid method for making design decisions for display interactive consoles. This dissertation concerns the development and validation of a methodology to incorporate a PTS known as Modapts into a simulation modeling tool known as Micro Saint. The operator task context for the model was an interactive displays and controls console known as the AN/SLQ-32(V). In addition, the dissertation examined the incorporation of a cognitive workload metric known as the Subjective Workload Assessment Technique (SWAT) into the Micro Saint model. The dissertation was conducted in three phases. In the first phase, a task analysis was performed to identify operator task and hardware interface redesign options. In the second phase data were collected from two groups of six participants who performed an operationally realistic task on 24 different configurations of a Macintosh AN/SLQ-32(V) simulator. Configurations of the simulated AN/SLQ-32(V) were defined by combinations of two display formats, two color conditions, and two emitter symbol sets, presented under three emitter density conditions. Data from Group 1 were used to assign standard deviations, probability distributions and Modapts times to a Micro Saint model of the task. The third phase of the study consisted of (1) verifying the model-generated performance scores and workload scores by comparison against scores obtained from Group 1 using regression analyses, and (2) validation of the model by comparison against Group 2. The results indicate that the Modapts/Micro Saint methodology was a valid way to predict performance scores obtained from the 24 simulated AN/SLQ-32(V) prototypes (R² = 0.78). The workload metric used in the task network model accounted for 76 percent of the variance in Group 2 mean workload scores, but the slope of the regression was different from unity (p = 0.05). The statistical finding suggests that the model does not provide an exact prediction of workload scores. Further regression analysis of Group 1 and Group 2 workload scores indicates that the two groups were not homogenous with respect to workload ratings. / Ph. D.

The purpose of this study was to determine the extent specific ergonomic factor implementations in computer and video display terminal (VDT) installations for student use in middle school classrooms. The data interpretations using existing furniture without modification or adaptation. Of all the seating observed, 75% of the seating met standards for middle school students. Keyboards and video display screens had been placed on existing tables and were all higher than ergonomically desirable for middle school students or adults.

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

The purpose of this study was to determine the effect on selected Upward Bound students' vocabulary retention rate and attitude toward computers when using color in a computer assisted instructional (CAI) program. Past research on the use of color in the educational process does not answer questions about possible effects it may have when used in CAI programs. Specific areas addressed by this study include: (1) differences in color computer assisted instructional software and achromatic versions of the lesson, (2) differences in the short-term vocabulary retention rate for color versus achromatic versions, (3) differences in the long-term vocabulary retention rate for color versus achromatic versions, (4) differences on the affective attitude scale for color versus achromatic versions, (5) differences in short-term memory based on gender and computer experience, (6) differences in long-term memory based on gender and computer experience and (7) differences on the affective attitude scale based on gender and computer experience. Subjects in the experiment were high school students participating in Upward Bound programs at Texas Christian University and the University of North Texas. A pretestposttest design was used and data were obtained from seventy-one students. A CAI program presented students with twenty words and definitions via a drill and practice mode. The words came from Schuster's list of rare and seldom used words considered easy to learn. Two computer systems were used in this study, achromatic and color. Students completed the Computer Attitude Scale at the beginning and end of the CAI lesson. A pretest, immediate posttest and two week delayed posttest were administered to both experimental groups. Analysis of the data revealed a significant difference in long-term memory based on gender and computer experience. Girls using the color version of the lesson scored significantly higher on the delayed posttest than girls using the achromatic version.

Recent applications in three-dimensional (3-D) presentation of information has emphasized the use of field-sequential stereoscopic CRT displays. The usefulness of stereopsis to present depth information has been studied in terms of performance measures such as search time, search accuracy, and subjective image quality ratings. Few, if any, studies have been conducted to investigate the influence of stereopsis upon cognitive workload. This dissertation is a description of two experiments using 3-D images presented on a Tektronix SGS 620 field-sequential stereoscopic CRT. Comparisons were made between presentations incorporating monocular cues only (2 1/2-D) and scenes containing monocular cues plus retinal disparity (3-D). In the first experiment, 11 participants were required to make inter-elements distance judgments under conditions of varying perspective angle, scene complexity, and depth cues while performing an interval production task. Accuracy was found to be significantly enhanced by the addition of retinal disparity as well as by decreases in the complexity of the presented scene. Cognitive workload increased significantly with increases in scene complexity, but no significant difference in workload was found between the stereoscopic and non-stereoscopic presentation formats. The second experiment investigated the effects of stereopsis on target identification under varying conditions of background complexity, target coding schemes, number of elements, signal-to-noise ratio, and depth cues. Accuracy measures, response time, and workload ratings were degraded by increases in scene background complexity, signal:noise ratio, and number of elements. Target coding methods which incorporated color were found to be significantly better than those in which targets were identified by shape only. No significant difference was found between 2 1/2-D and 3-D presentation for any of the dependent measures. The results indicate that retinal disparity it most appropriate for tasks, such as determination of object location in depth, in which the additional information provided by the depth cue is directly related to the task. Retinal disparity provides the most benefit for depth judgment tasks involving highly complex scenes. In cases of very simple tasks or simple scenes, the addition of retinal disparity is contra-indicated. / Ph. D.

The purpose of this investigation was to determine the color preference of Thai and American students for text and background computer color combinations. The primary purpose of this study was to determine if there were differences between Thai and American students' computer color combination preferences.

Thesis (MScPhysio)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Aims: To assess the effect of a vertical height adjustment of the chair and visual display unit (VDU) on work related upper quadrant musculoskeletal pain (WRUQMP) and sitting comfort in computer users. The upper quadrant refers to the occiput, cervical and upper thoracic spine including the clavicles and scapulae. Methods: An N=1 study was conducted using the ABC design whereby an ergonomic workstation adjustment, of VDU and chair height, was compared to the subject’s usual workstation settings. Pain and sitting comfort were measured using visual analogue scales (VAS). The subject was assessed over the four week phases as she performed her typical VDU work. The results were compiled and tabulated. Results: Both the mean and variance in pain intensity decreased after the workstation intervention. A deterioration was noted in sitting comfort. Conclusion: The vertical height adjustment of the chair and VDU may have contributed to a decrease in WRUQMP in this subject. This safe, economical workstation intervention may be a practical management option for the computer user suffering from WRUQMP. Further research into the measurement of comfort whilst sitting at a computer workstation, is recommended. / AFRIKAANSE OPSOMMING: Doelwitte: Om die effek te bepaal van n vertikale aanpassing van die stoel en beeldskerm van rekenaargebruikers op werksverwandte boonste kwadrant muskuloskeletale pyn en sitgemak. Die boonste kwadrant verwys na die oksiput, servikale en boonste torakale werwelkolom en sluit ook die klavikel en skapula in. Methode: Die N=1 studie is onderneem met gebruik van die ABC ontwerp in terme waarvan n ergonomiese aanpassing van stoel en beeldskerm vergelyk is met die normale gebruik van die deelnemer. Pyn en sitgemak is gemeet deur die gebruik van die Visueel analoogskaal. Die interwensies is ge-evalueer oor vierweekfases tydens normale rekenaar gebruik van die deelnemer. Die resultate is saamgestel en getabuleer. Uitkoms: Beide die gemiddelde en veranderlike pynintensiteit het verminder nadat die werkstasie aangepas is. Geen verbetering in sitgemak is opgemerk nie. Gevolgtrekking: Die vertikale hoogte-aanpassing van die stoel en beeldskerm het moontlik bygedra tot die verminderde pynvlakke in hierdie deelnemer. Hierdie veilige, ekonomiese verstelling is moontlik n praktiese beheeropsie vir rekenaargebruikers wat werksverwandte boonste kwadrant muskuloskeletale pyn verduur. Verder studie in die meet en waarneming van sitgemak tydens rekenaarwerk is nodig.