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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 en-countered 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 photo-graphs 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 in-creased, 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 stackons 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. [ABSTRACT FROM AUTHOR]

Earthquakes cause time-dependent displacement motion due to dynamic effect on structures. Response of structures to these effects is based on the subgrade soil properties. Investigations after 17 August 1999 Marmara Earthquake revealed that structural damage is less than expected level on many buildings despite of their worse subgrade soil properties. In this study, the effects of soil properties on dynamic behaviors of reinforced concrete buildings under influence of earthquakes are investigated. Thus, the structure models with 3, 6, 10 stories which have the same plan and rigidity are formed. Behaviors of these models are examined for two different soils, namely soft and hard soils under the effect of three different earthquakes. Dynamic analysis is performed by using time history analyses of SAP 2000 computer program. Results from different models were compared in terms of displacements, internal forces and period responses. [ABSTRACT FROM AUTHOR]

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