95 research outputs found

    Detection of the stroboscopic effect by young adults varying in sensitivity

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    The advent of LED lighting has renewed concern about the possible visual, neurobiological, and performance and cognition effects of cyclic variations in lighting system luminous flux (temporal light modulation). The stroboscopic visibility measure (SVM) characterises the temporal light modulation signal to predict the visibility of the stroboscopic effect, one of the visual perception effects of temporal light modulation. A SVM of 1 means that the average person would detect the phenomenon 50% of the time. There is little published data describing the population sensitivity to the stroboscopic effect in relation to the SVM, and none focusing on people subject to visual stress. This experiment, conducted in parallel in Canada and France, examined stroboscopic detection for horizontal and vertical moving targets when viewed under commercially available lamps varying in SVM conditions (SVM: ∼0; ∼0.4; ∼0.9; ∼1.4; ∼3.0). As expected, stroboscopic detection scores increased with increasing SVM. For the horizontal task, average scores were lower than the expected 4/8 at ∼0.90, but increased non-linearly with higher SVMs. Stroboscopic detection scores did not differ between people low and high in pattern glare sensitivity, but people in the high-pattern glare sensitivity group reported greater annoyance in the SVM ∼1.4 and ∼3.0 conditions

    Evaluating the in-situ effectiveness of indoor environment guidelines on occupant satisfaction

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    Post occupancy evaluation (POE) studies typically use a combination of occupant questionnaires and physical measurements of various aspects of the indoor environment to assess building performance. These physical measurements are often compared against published reference limits to evaluate compliance and satisfactory performance. This study investigates whether indoor environment conditions compatible with published indoor environment quality (IEQ) standards and guidelines are predictive of occupant satisfaction. Data used in this study were collected as part of two large building evaluation field studies conducted in the past eight years. Occupant questionnaire and physical measurement data from 11 office buildings across North America were used (N=194). Inputs for the analyses were demographic factors and workstation characteristics, as well as aspects of the measured physical indoor environment. Outcome variables were various measures of environmental satisfaction (i.e. lighting, acoustics/privacy, and ventilation/temperature). The results of this study suggest that occupants had higher satisfaction with lighting when measured desktop illuminance levels were within IESNA RP-1-12 (2012) recommendations. Measured sound levels and thermal conditions within reference limits did not correlate to higher occupant satisfaction in their respective categories

    Lighting Quality Evaluations using Images on a High Dynamic Range Display

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    Limited research comparing participant ratings of luminous environments to ratings of images of those environments indicates that images can be a reasonable surrogate for the real space, particularly on ratings related to aesthetics. However, the realism of such images when presented on computer screens is potentially limited by conventional display technologies that cannot reproduce the full range of luminances in real spaces. In this pilot experiment we used a new, high dynamic range (HDR) computer monitor capable of producing screen luminances and contrasts comparable to those in a real space. Fifty-four participants viewed three images of a conventional office in two display modes: HDR monitor and conventional monitor. Participants rated each image for room appearance, environmental satisfaction and realism. These ratings were also compared to similar ratings made by participants in an earlier experiment (reported in 1998) who occupied the real spaces depicted in the images. Results indicate that computer screen images are perceived in a similar way as real luminous environments. HDR images are perceived differently than images on a conventional monitor: they are rated as brighter and less attractive, as expected. Given their more authentic luminances, HDR images should be perceived as more similar to the real space, but our results neither support nor refute this

    Validation of the use of high dynamic range images and displays in lighting research

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    Bu çalışmanın amacı, Yüksek Dinamik Ölçekli (YDÖ) görüntüleme tekniğinin kullanıldığı YDÖ monitörlerin aydınlatma mühendisliği problemlerinin çözümünde kullanılabileceğini göstermektedir. Bu makalede sunulan ilk deney, YDÖ monitörde görüntülenen YDÖ fotoğrafların, LCD ekranda görüntülenen (tek pozlamadan oluşan) geleneksel fotoğraflardan daha gerçekçi olduğu hipoteziyle tasarlanmıştır. Altı adet hacmin detaylı parıltı ölçümleri noktasal ölçüm yapabilen bir parıltı ölçer ve parıltı kamerası kullanılarak yapıldıktan sonra, bu parıltı değerleri YDÖ ekrana yansıtılmıştır. Deney sonuçları YDÖ fotoğraf tekniği ile üretilen fotoğrafların YDÖ ekrandaki göruntülerinin, LCD ekranda görüntülenen tek pozlamadan oluşan fotoğraflardan daha gerçekçi algılandığını göstermiştir. Çalışmanın ikinci bölümünde, YDÖ görüntüleme tekniğinden faydalanılarak bir açık plan ofisteki aydınlatma kalitesi incelenmiştir. Bu çalışmada, görüntü karakteristikleri (ortalama parıltı, parıltı dağılımı ve doğal ışığı hacme alan pencere büyüklüğü) ile hacmin aydınlatma kalitesi arasındaki bağıntı incelenmiştir. Çalışmanın sonuçları, YDÖ ekranda sergilenen YDÖ fotoğrafların özellikle doğal ışık içeren görüntülerde aydınlatma kalitesi analizi yapmak amacıyla gerçek hacim yerine kullanılabileceğini göstermektedir. Henüz inşa edilmemiş binaların grafik simulasyonlarının, gerçek hacimde sağlanması öngörülen parıltı değerleriyle YDÖ ekranda görüntülenmesi, aydınlatma projesine ilişkin karar aşamasında faydalı olacaktır. YDÖ teknolojisi kullanılarak elde edilen sonuçlar literatürdeki çalışmalarla tutarlı olması, YDÖ teknolojisinin aydınlatma mühendisliği problemlerinin çözümünde kullanılmasına ilişkin güveni arttırmaktadır. Anahtar Kelimeler: Aydınlatma tasarımı, Yüksek Dinamik Ölçekli fotoğraflama tekniği, Yüksek Dinamik Ölçekli monitör, aydınlatma kalitesi, ofis aydınlatması.The main goal of this study is to show that a High Dynamic Range (HDR) display can be used in the study of lighting engineering problems, and as a tool in the lighting design process to enhance communications between lighting designers and their clients. Printed photographs, renderings or images displayed on conventional Cathode-Ray Tube (CRT) or Liquid-Crystal Display (LCD) monitors do not represent the spaces in realistic luminances. Calibrated HDR images contain luminance information from the real space, but current LCD monitors cannot present luminances as high as the luminances encountered in the real world. Therefore, these sources do not provide enough information to make accurate judgements of light and shade in the lighting design process. The HDR display used in this study could display luminances up to 4000 cd/m2 and overcame these problems. This research shows that the HDR method may be used as a surrogate for experiencing a real space to investigate lighting engineering problems both for research and the design process. The first experiment was designed to investigate the hypothesis that HDR images on an HDR screen would be perceived as more realistic than conventional images displayed on conventional LCD displays. Extensive luminance measurements were conducted using a spot luminance meter and a luminance camera to facilitate accurate reproduction of real space luminances of six scenes (corridor, gym, mezzanine, lobby, open-plan office, staircase) on the HDR display. Thirty-nine participants viewed six scenes in three modes: the real scenes (observing real spaces in the building), single exposure photographs of the scenes shown in conventional mode (screen resolution and luminance of HDR display adjusted to that of a conventional LCD display), and the HDR photographs shown in HDR mode (capable of luminances as high as 4000 cd/m2 and 216 distinct luminance levels). Half of the participants visited the real spaces first, and the other half saw the digital images first. For each presentation (real and digital images), participants rated what they saw on four semantic differential scales: dim - bright; non-uniform - uniform; unpleasant - pleasant; glaring - not glaring. Participants then viewed the six digital image pairs again, and recorded whether the HDR or conventional image was more realistic. This experiment demonstrated that HDR images presented on an HDR display are rated as significantly more realistic than conventional computer images. The second experiment demonstrated the use of HDR images as a research tool. The experiment focused on the relationship between scene characteristics (average luminance, luminance variability and view size) and space appearance judgements. Twenty-one scenes were created, each scene being the view from an interior cubicle across one cubicle to the exterior wall. The scenes varied in terms of the cubicle panels, window blind setting, and presence or absence of a neighbour in the adjacent cubicle. Extensive luminance measurements were conducted. Sets of bracketed images were taken for each of the 21 scenes, and then these images were combined into HDR images using the software Photosphere. The calibrated HDR images were shown on an HDR display at realistic luminances to 43 participants. The participants rated each scene on 8 scales. The average ratings for each image were plotted against the average luminance, luminance variability and relative view size for that image. The second experiment of the dissertation supported the hypothesis that as panel height in an open office gets lower, ratings for satisfaction with lighting increase, and ratings for privacy decrease. As the view size increased, ratings for satisfaction with lighting and amount of view increased. Regarding satisfaction with privacy, Hybrid (one fabric and one glass stack-on on the second panel) performed as well as Standing Privacy (two fabric stack-ons on the second panel), and regarding satisfaction with view and satisfaction with lighting, Hybrid performed better than Standing Privacy.The results imply that HDR displays may be successfully deployed in the lighting research projects. Both experiments show that people can respond to HDR images in the same way as they would respond to the real space. The results of both experiments are consistent with what is already known from studies of images and in real spaces, which adds confidence to the use of HDR display. Keywords: Lighting design, High Dynamic Range images, High Dynamic Range display, real space luminance matching, open-plan office lighting, lighting quality.

    Ten Questions Concerning Well-Being in the Built Environment

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    Well-being in the built environment is a topic that features frequently in building standards and certification schemes, in scholarly articles and in the general press. However, despite this surge in attention, there are still many questions on how to effectively design, measure, and nurture well-being in the built environment. Bringing together experts from academia and the building industry, this paper aims to demonstrate that the promotion of well-being requires a departure from conventional agendas. The ten questions and answers have been arranged to offer a range of perspectives on the principles and strategies that can better sustain the consideration of well-being in the design and operation of the built environment. Placing a specific focus on some of the key physical factors (e.g., light, temperature, sound, and air quality) of indoor environmental quality (IEQ) that strongly influence occupant perception of built spaces, attention is also given to the value of multi-sensory variability, to how to monitor and communicate well-being outcomes in support of organizational and operational strategies, and to future research needs and their translation into building practice and standards. Seen as a whole, a new framework emerges, accentuating the integration of diverse new competencies required to support the design and operation of built environments that respond to the multifaceted physical, physiological, and psychological needs of their occupants

    Inference on inspiral signals using LISA MLDC data

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    In this paper we describe a Bayesian inference framework for analysis of data obtained by LISA. We set up a model for binary inspiral signals as defined for the Mock LISA Data Challenge 1.2 (MLDC), and implemented a Markov chain Monte Carlo (MCMC) algorithm to facilitate exploration and integration of the posterior distribution over the 9-dimensional parameter space. Here we present intermediate results showing how, using this method, information about the 9 parameters can be extracted from the data.Comment: Accepted for publication in Classical and Quantum Gravity, GWDAW-11 special issu

    Study protocol: developing a decision system for inclusive housing: applying a systematic, mixed-method quasi-experimental design

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    Background Identifying the housing preferences of people with complex disabilities is a much needed, but under-developed area of practice and scholarship. Despite the recognition that housing is a social determinant of health and quality of life, there is an absence of empirical methodologies that can practically and systematically involve consumers in this complex service delivery and housing design market. A rigorous process for making effective and consistent development decisions is needed to ensure resources are used effectively and the needs of consumers with complex disability are properly met. Methods/Design This 3-year project aims to identify how the public and private housing market in Australia can better respond to the needs of people with complex disabilities whilst simultaneously achieving key corporate objectives. First, using the Customer Relationship Management framework, qualitative (Nominal Group Technique) and quantitative (Discrete Choice Experiment) methods will be used to quantify the housing preferences of consumers and their carers. A systematic mixed-method, quasi-experimental design will then be used to quantify the development priorities of other key stakeholders (e.g., architects, developers, Government housing services etc.) in relation to inclusive housing for people with complex disabilities. Stakeholders randomly assigned to Group 1 (experimental group) will participate in a series of focus groups employing Analytical Hierarchical Process (AHP) methodology. Stakeholders randomly assigned to Group 2 (control group) will participate in focus groups employing existing decision making processes to inclusive housing development (e.g., Risk, Opportunity, Cost, Benefit considerations). Using comparative stakeholder analysis, this research design will enable the AHP methodology (a proposed tool to guide inclusive housing development decisions) to be tested. Discussion It is anticipated that the findings of this study will enable stakeholders to incorporate consumer housing preferences into commercial decisions. Housing designers and developers will benefit from the creation of a parsimonious set of consumer-led housing preferences by which to make informed investments in future housing and contribute to future housing policy. The research design has not been applied in the Australian research context or elsewhere, and will provide a much needed blueprint for market investment to develop viable, consumer directed inclusive housing options for people with complex disability

    The Alzheimer's Disease Neuroimaging Initiative 3: Continued innovation for clinical trial improvement

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    INTRODUCTION: The overall goal of the Alzheimer's Disease Neuroimaging Initiative (ADNI) is to validate biomarkers for Alzheimer's disease (AD) clinical trials. ADNI-3, which began on August 1, 2016, is a 5-year renewal of the current ADNI-2 study. METHODS: ADNI-3 will follow current and additional subjects with normal cognition, mild cognitive impairment, and AD using innovative technologies such as tau imaging, magnetic resonance imaging sequences for connectivity analyses, and a highly automated immunoassay platform and mass spectroscopy approach for cerebrospinal fluid biomarker analysis. A Systems Biology/pathway approach will be used to identify genetic factors for subject selection/enrichment. Amyloid positron emission tomography scanning will be standardized using the Centiloid method. The Brain Health Registry will help recruit subjects and monitor subject cognition. RESULTS: Multimodal analyses will provide insight into AD pathophysiology and disease progression. DISCUSSION: ADNI-3 will aim to inform AD treatment trials and facilitate development of AD disease-modifying treatments

    Clinically-relevant rapamycin treatment regimens enhance CD8+ effector memory T cell function in the skin and allow their infiltration into cutaneous squamous cell carcinoma

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    Patients receiving immunosuppressive drugs to prevent organ transplant rejection exhibit a greatly increased risk of developing cutaneous squamous cell carcinoma (SCC). However, not all immunosuppressive drugs confer the same risk. Randomised, controlled trials demonstrate that switching renal transplant recipients receiving calcineurin inhibitor-based therapies to mammalian target of rapamycin (mTOR) inhibitors results in a reduced incidence of de novo SSC formation, and can even result in the regression of pre-existing premalignant lesions. However, the contribution played by residual immune function in this setting is unclear. We examined the hypotheses that mTOR inhibitors promote the enhanced differentiation and function of CD8 memory T cells in the skin. Here, we demonstrate that the long-term oral administration of rapamycin to achieve clinically-relevant whole blood drug target thresholds, creates a “low rapamycin dose” environment in the skin. While both rapamycin and the calcineurin inhibitor tacrolimus elongated the survival of OVA-expressing skin grafts, and inhibited short-term antigen-specific CD8 T cell responses, rapamycin but not tacrolimus permitted the statistically significant infiltration of CD8 effector memory T cells into UV-induced SCC lesions. Furthermore, rapamycin uniquely enhanced the number and function of CD8 effector and central memory T cells in a model of long-term contact hypersensitivity provided that rapamycin was present during the antigen sensitization phase. Thus, our findings suggest that patients switched to mTOR inhibitor regimens likely experience enhanced CD8 memory T cell function to new antigen-challenges in their skin, which could contribute to their lower risk of de novo SSC formation and regression of pre-existing premalignant lesions
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