Recent investigations into infants' intersensory perception suggest a specific developmental pattern for infants' attention to visible and auditory attributes of dynamic human faces. This work has proposed that infants' perception seems to progress along a sensory continuum: beginning with multimodal sensory cues (e.g., auditory and visual), then visual-cues alone, and finally auditory-cues alone. Additionally, research has proposed that amodal or invariant sensory information directs infants' attention to specific redundant aspects in the surrounding environment (e.g., temporal synchronicity). The current research attempted to clarify the potential methodological confounds contained in previous investigations into infant intersensory development by contrasting infant behavior within fixed trial and infant-controlled habituation procedures. Moreover, the current research examined infants' attention to auditory manipulations within multimodal displays when redundant sensory information (synchronicity) was or was not available. In Experiment 1, 4-month-old infants were habituated to complex audiovisual displays of a male or female face within an infant controlled habituation procedure, and then tested for response recovery to a change in voice. For half the infants, the change in voice maintained synchronicity with the face, and for the other half, it did not. The results showed significant response recovery (i.e., dishabituation) to the change in voice regardless of the synchronicity condition. In Experiment 2, 4-month-old infants received the same face+voice test recordings used in Experiment 1, but now within a fixed trial habituation procedure. Again, synchronicity was manipulated across groups of infants. In contrast to Experiment 1, the infants in the fixed-trial experiment failed to show evidence of voice discrimination. These results suggest that infant controlled procedures may be more sensitive to infant attention, especially in terms of complex social displays. In addition, synchronicity appeared to be unnecessary in terms of infants' ability to detect vocal differences across multimodal displays. In sum, these results highlight the importance of research methodology (e.g., infant control) and overall stimulus complexity (e.g., discrete vs. complex) involving studies of infants' intersensory development. / Ph. D.

The objective of this study was to determine which size symbols should be used by the U.S. Army for an operator control unit to indicate the status of unmanned ground vehicles (UGVs). Three sizes of symbols were studied. The symbols subtended 20, 40, and 69 minutes of arc corresponding to 0.116, 0.233, and 0.400 inches high when viewed at a distance of 20 inches from a touch screen. Twelve participants were asked to watch the symbols on a map display and touch one of four UGV symbols when it stopped moving. Different numbers (0, 8 and 12) of distracter symbols with the same height as the UGV symbols appeared during the experimental trials. The time to notice that a UGV symbol had stopped (recognition time) and to touch the screen (response time) were measured. Participants were asked for Subjective Workload Assessment Technique (SWAT) ratings for each combination of symbol size and number of distracter symbols. Errors committed while attempting to touch the correct symbol were counted. Participants made very few errors attempting to touch the wrong symbol. Results for the time and error measures were as expected for changes in symbol size. As symbol size increased, recognition time, response time, and extra touches decreased. Significant differences were seen in these measures between the subtending 20 and 40 minutes of arc and between symbols subtending 20 and 69 minutes of arc. Also, as expected, subjective mental workload increased as symbol size decreased with differences seen between all symbol size levels. No significant differences were observed for workload manipulation (number of distracter symbols) as measured by time and error. However, SWAT scores did show a significant difference as a result of number of distracters. The differences between 0 and 8 distracters and between 0 and 12 distracters were significant. There was no significant interaction between symbol size and number of distracters for any of the measures. Overall results suggest that symbols smaller than those recommended for keypads may be sufficient for interactive map displays. For static platforms with barehanded operators, symbols that subtend 40 minutes of arc may be sufficiently large to ensure adequate touch screen performance under low to moderate workload conditions. / Master of Science

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Os dispositivos emissores de luz orgânicos OLEDs têm despertado um enorme interesse tanto da comunidade científica quanto das empresas presentes no mercado mundial de displays. As características de elevado ângulo de visão, alta eficiência energética, possibilidade de confecção de displays flexíveis que não necessitam retroiluminação, baixo peso, fácil processabilidade, dentre outras, fazem com que os displays fabricados com materiais orgânicos apresentem um enorme potencial para as mais diversas aplicações. O presente trabalho teve como objetivo contribuir para a construção e caracterização de displays monocromáticos à base de polímeros luminescentes depositados pela técnica Ink Jet. Para tanto foram preparados os padrões de linhas x colunas, formadores dos pontos luminosos (pixels) de matrizes passivas e desenvolvidos processos para deposição dos filmes finos de polímeros semicondutores. A utilização da deposição por Ink Jet aparece como uma técnica chave para a produção de dispositivos poliméricos. Nesta pesquisa, como material luminescente foi utilizado um polímero da família do polifluoreno, de fácil processamento e elevada eficiência luminosa, enquanto que como eletrodos foram utilizados o óxido de estanho e índio (ITO) e Alumínio. O ITO foi utilizado por possuir baixa resistividade elétrica, elevada função de trabalho e elevada transmitância na região do visível. O processo de encapsulamento do display se deu por meio do acondicionamento destes dispositivos em ambiente isento de oxigênio e umidade, evitando-se os efeitos já conhecidos da foto-oxidação das camadas poliméricas. Os dispositivos, uma vez preparados, foram caracterizados por meio de medidas ópticas (fotoluminescência), elétricas (eletroluminescência, condutividade) e de desempenho (eficiência luminosa e luminância). / Organic Light Emitters Diodes OLEDs is a promising field of study and a huge market opportunity to semiconductor players. Thanks to its potential characteristics to replace the main todays display technologies like lightweight, low voltage, wide viewing angle, high resolution, fast switching, broad color range and the possibility to fabricate flexible devices, makes the organic semiconductors a potential candidate to develop, in a near future, devices and systems that even could not be imagined before. This work aims to contribute to the manufacturing process field and to the characterization of displays made by ink jet deposition technique. To achieve this objective, line x column patterns were produced, in which the pixels are generated at the crossing of lines and columns. The ink jet printing of materials is playing an important role in industry because it provides a low-cost manufacture environment potential. In this work, we studied the morphology of the ink jet deposition of polyfluorene over Indium Tin Oxide (ITO) substrates treated by different procedures. Those materials where used because the polyfluorene polymer presents high light emission efficiency and easiness of processing. The electrodes were prepared with ITO (due its low resistivity, high work function and high transmittance in the visible spectrum) and aluminum. The processed displays were sealed inside an inert ambient with positive pressure to avoid the photo-oxidation of the semiconductor luminescent polymer layers. The devices were characterized by optical (photoluminescence), electrical (electroluminescence) and performance (brightness, luminous efficiency) measurements.

Os dispositivos emissores de luz orgânicos OLEDs têm despertado um enorme interesse tanto da comunidade científica quanto das empresas presentes no mercado mundial de displays. As características de elevado ângulo de visão, alta eficiência energética, possibilidade de confecção de displays flexíveis que não necessitam retroiluminação, baixo peso, fácil processabilidade, dentre outras, fazem com que os displays fabricados com materiais orgânicos apresentem um enorme potencial para as mais diversas aplicações. O presente trabalho teve como objetivo contribuir para a construção e caracterização de displays monocromáticos à base de polímeros luminescentes depositados pela técnica Ink Jet. Para tanto foram preparados os padrões de linhas x colunas, formadores dos pontos luminosos (pixels) de matrizes passivas e desenvolvidos processos para deposição dos filmes finos de polímeros semicondutores. A utilização da deposição por Ink Jet aparece como uma técnica chave para a produção de dispositivos poliméricos. Nesta pesquisa, como material luminescente foi utilizado um polímero da família do polifluoreno, de fácil processamento e elevada eficiência luminosa, enquanto que como eletrodos foram utilizados o óxido de estanho e índio (ITO) e Alumínio. O ITO foi utilizado por possuir baixa resistividade elétrica, elevada função de trabalho e elevada transmitância na região do visível. O processo de encapsulamento do display se deu por meio do acondicionamento destes dispositivos em ambiente isento de oxigênio e umidade, evitando-se os efeitos já conhecidos da foto-oxidação das camadas poliméricas. Os dispositivos, uma vez preparados, foram caracterizados por meio de medidas ópticas (fotoluminescência), elétricas (eletroluminescência, condutividade) e de desempenho (eficiência luminosa e luminância). / Organic Light Emitters Diodes OLEDs is a promising field of study and a huge market opportunity to semiconductor players. Thanks to its potential characteristics to replace the main todays display technologies like lightweight, low voltage, wide viewing angle, high resolution, fast switching, broad color range and the possibility to fabricate flexible devices, makes the organic semiconductors a potential candidate to develop, in a near future, devices and systems that even could not be imagined before. This work aims to contribute to the manufacturing process field and to the characterization of displays made by ink jet deposition technique. To achieve this objective, line x column patterns were produced, in which the pixels are generated at the crossing of lines and columns. The ink jet printing of materials is playing an important role in industry because it provides a low-cost manufacture environment potential. In this work, we studied the morphology of the ink jet deposition of polyfluorene over Indium Tin Oxide (ITO) substrates treated by different procedures. Those materials where used because the polyfluorene polymer presents high light emission efficiency and easiness of processing. The electrodes were prepared with ITO (due its low resistivity, high work function and high transmittance in the visible spectrum) and aluminum. The processed displays were sealed inside an inert ambient with positive pressure to avoid the photo-oxidation of the semiconductor luminescent polymer layers. The devices were characterized by optical (photoluminescence), electrical (electroluminescence) and performance (brightness, luminous efficiency) measurements.

Prescriptions for effective display of quantitative information involving more than two variables are not available. To explore the effectiveness of retinal variables in facilitating the interpretation of information and decision making when used in conjunction, a study with 135 participants was conducted. The study involved the use of color shape, color value, and value shape as retinal variables in interactive displays that required participants to answer nine questions in three levels of complexity (identification of data points, analyses of local comparisons and global trends). Time-on-task scores and performance scores were measured. In addition, a View Clamp eye tracker system was used and 12 out of the 135 participants completed the task of answering questions while their eye movements were recorded. Repeated measures analysis followed by multiple comparisons of means showed that participants in the color and shape group performed significantly better and faster than color/value and shape/value groups only for questions that involved studying global trends and decision making (level 3). The shape and value group was significantly faster than color and shape group in answering level 1. Color and value as retinal variables produced results that indicated that the two variables when used in conjunction could be suitable for display of data that involved comparison. This needs to be explored further. Eye movements provided further evidence to the feature integration theory (Treisman, 1982) and showed feature search occurred right away as participants entered the display. 78% of those who reported mental strategies indicated that they identified the features used in the display first.

Head mounted projection display (HMPD) technology, as an alternative to conventional head mounted displays (HMD), offers a potential of designing wide field-of-view (FOV), low distortion optical see-through HMDs (OST-HMDs). Existing HMPD designs, however, suffer from problems of low luminance and low image resolution, which limits the applications of such information displays for the scenarios which require high luminance and high image fidelity. The design of a polarized head mounted projection display (p-HMPD) was recently proposed to overcome the challenge of low luminous efficiency in existing HMPD designs. Polarization management was employed to reduce the light loss caused by beamsplitting in an HMPD.The work in this dissertation focuses on the development and evaluation of an SXGA resolution, high efficiency p-HMPD system. The main contributions are as follows. First, the key elements in the polarization management scheme of a p-HMPD were selected and their polarization performances were characterized by measuring their Mueller matrices, based on which the overall display performance of a p-HMPD was analyzed.Second, based on a pair of ferroelectric liquid-crystal-on-silicon (FLCoS) microdisplays, a compact illumination unit and a light-weight projection system were designed, from which a p-HMPD prototype was built. Following the prototype implementation, a series of calibrations were performed to obtain correct color presentation, desired focusing setting, and optical system characteristics necessary for achieving accurate registration between virtual objects and their counterparts in the real world.Third, the imaging properties of a retroreflective screen which is an essential part of a p-HMPD or HMPD were studied and its effects on the image resolution of an HMPD system were further characterized.Finally, the performance of the system was evaluated through two objective user experiments, including a visual acuity assessment and a depth perception accuracy assessment.

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