436 research outputs found

    Aerospace medicine and biology: A continuing bibliography with indexes (supplement 407)

    Get PDF
    This bibliography lists 289 reports, articles and other documents announced in the NASA Scientific and Technical Information System during Nov. 1995. Subject coverage includes: aerospace medicine and physiology, life support systems and man/system technology, protective clothing, exobiology and extraterrestrial life, planetary biology, and flight crew behavior and performance

    Langley aerospace test highlights, 1990

    Get PDF
    The role of NASA-Langley is to perform basic and applied research necessary for the advancement of aeronautics and spaceflight, to generate new and advanced concepts for the accomplishment of related national goals, and to provide research advice, technological support, and assistance to other NASA installations, other government agencies, and industry. Some of the significant tests are highlighted which were performed during 1990 in the NASA-Langley test facilities, a number of which are unique in the world. Both the broad range of the research and technology activities at NASA-Langley and the contributions of this work toward maintaining U.S. leadership in aeronautics and space research are illustrated. Other highlights of Langley research and technology for 1990 are described in Research and Technology 1990 Langley Research Center

    A Perceptual Color-Matching Method for Examining Color Blending in Augmented Reality Head-Up Display Graphics

    Get PDF
    Augmented reality (AR) offers new ways to visualize information on-the-go. As noted in related work, AR graphics presented via optical see-through AR displays are particularly prone to color blending, whereby intended graphic colors may be perceptually altered by real-world backgrounds, ultimately degrading usability. This work adds to this body of knowledge by presenting a methodology for assessing AR interface color robustness, as quantitatively measured via shifts in the CIE color space, and qualitatively assessed in terms of users’ perceived color name. We conducted a human factors study where twelve participants examined eight AR colors atop three real-world backgrounds as viewed through an in-vehicle AR head-up display (HUD); a type of optical see-through display used to project driving-related information atop the forward-looking road scene. Participants completed visual search tasks, matched the perceived AR HUD color against the WCS color palette, and verbally named the perceived color. We present analysis that suggests blue, green, and yellow AR colors are relatively robust, while red and brown are not, and discuss the impact of chromaticity shift and dispersion on outdoor AR interface design. While this work presents a case study in transportation, the methodology is applicable to a wide range of AR displays in many application domains and settings

    Evaluation of the color image and video processing chain and visual quality management for consumer systems

    Get PDF
    With the advent of novel digital display technologies, color processing is increasingly becoming a key aspect in consumer video applications. Today’s state-of-the-art displays require sophisticated color and image reproduction techniques in order to achieve larger screen size, higher luminance and higher resolution than ever before. However, from color science perspective, there are clearly opportunities for improvement in the color reproduction capabilities of various emerging and conventional display technologies. This research seeks to identify potential areas for improvement in color processing in a video processing chain. As part of this research, various processes involved in a typical video processing chain in consumer video applications were reviewed. Several published color and contrast enhancement algorithms were evaluated, and a novel algorithm was developed to enhance color and contrast in images and videos in an effective and coordinated manner. Further, a psychophysical technique was developed and implemented for performing visual evaluation of color image and consumer video quality. Based on the performance analysis and visual experiments involving various algorithms, guidelines were proposed for the development of an effective color and contrast enhancement method for images and video applications. It is hoped that the knowledge gained from this research will help build a better understanding of color processing and color quality management methods in consumer video

    Perspectives on Nuclear Medicine for Molecular Diagnosis and Integrated Therapy

    Get PDF
    nuclear medicine; diagnostic radiolog

    Technology 2004, Vol. 2

    Get PDF
    Proceedings from symposia of the Technology 2004 Conference, November 8-10, 1994, Washington, DC. Volume 2 features papers on computers and software, virtual reality simulation, environmental technology, video and imaging, medical technology and life sciences, robotics and artificial intelligence, and electronics

    Airframe assembly, systems integration and flight testing of a long endurance electric UAV

    Get PDF
    The need to adopt new techniques and practices in the Aerospace Industry branch is a consequence of technological development. The present work aims to study the use of solar power as a main energy source in the aviation, in this case for a flight of long endurance of an unmanned air vehicle. This master thesis follows on previous works of the LEEUAV, where it was done the design and construction of a long endurance unmanned aerial system. Thus, the main objective of this work is the systems integration, flight testing and concepts validation. LEEUAV, a prototype of 4.5 meters’ wingspan and ultralight structure partially covered by solar cells was designed to fulfil a continuous flight mission of at least 8 hours on the equinox. The 5.42Kg remotely piloted aircraft was successfully tested showing the agreement with theoretical calculations already made. The longest flight achieved lasted more than 8.5 hours’ resulting in a total distance travelled of more than 75 km. In order to validate the airworthiness concept of the LEEUAV several flight tests were performed and their respective data (static and total pressure, air temperature, ground speed and pitch angle) was collected for further analysis, using a flight controller with multiple sensors on board. The results obtained allowed to study the general performance of the aircraft, the main defects, agreement with the theoretical results as well as determine the real values of aerodynamic coefficients (????, ????), through a reading and processing flight data algorithm in Software MATLAB. Finally, some future expectations for upcoming work are suggested in order to make the LEEUAV an Unmanned Aerial Vehicle of reference.A necessidade de adoção de novas técnicas e práticas no ramo da Indústria Aeronáutica é uma consequência do desenvolvimento tecnológico. O presente trabalho aborda o uso de energia solar como principal fonte de energia na aviação, com enfoque num voo de grande autonomia de uma aeronave não tripulada. Esta tese de mestrado surge na sequência de trabalhos anteriores relativos ao LEEUAV, nos quais se efetuou o projeto e construção de uma aeronave não tripulada de grande autonomia. Assim, o principal objetivo deste trabalho é a integração de sistemas, testes de voo e validação de conceitos. O UAV Solar LEEUAV é um protótipo de 4.5 metros de envergadura e de estrutura ultraleve parcialmente coberto de células fotovoltaicas sendo projetado para cumprir uma missão de voo contínuo de pelo menos 8h no equinócio. O avião de 5.42kg foi testado com sucesso mostrando a concordância com os cálculos teóricos já elaborados. O voo mais longo conseguido foi de 3.13 horas correspondendo a uma distância total percorrida de 96.265 km. De modo a validar o conceito de aeronavegabilidade do LEEUAV foram efetuados vários voos de teste e recolhidos dados de voo (pressão estática e dinâmica, temperatura do ar, velocidade no solo e ângulo de arfagem) para posterior análise, utilizando um controlador de voo com múltiplos sensores a bordo. A análise dos resultados obtidos permitiu precisar o desempenho geral da aeronave, os principais defeitos, concordância com os resultados teóricos assim como determinar os valores reais dos coeficientes aerodinâmicos (???? , ????) através de um algoritmo de leitura e processamento de dados de voo, em Software MATLAB. Por fim, são referidas algumas sugestões para o desenvolvimento de novos trabalhos com o objetivo de tornar O LEEUAV num veículo aéreo não tripulado de referência

    In situ sensors for measurements in the global trosposphere

    Get PDF
    Current techniques available for the in situ measurement of ambient trace gas species, particulate composition, and particulate size distribution are reviewed. The operational specifications of the various techniques are described. Most of the techniques described are those that have been used in airborne applications or show promise of being adaptable to airborne applications. Some of the instruments described are specialty items that are not commercially-available. In situ measurement techniques for several meteorological parameters important in the study of the distribution and transport of ambient air pollutants are discussed. Some remote measurement techniques for meteorological parameters are also discussed. State-of-the-art measurement capabilities are compared with a list of capabilities and specifications desired by NASA for ambient measurements in the global troposphere
    • …
    corecore