Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

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  • Conference Object
    Citation - WoS: 3
    Citation - Scopus: 4
    Photon Mapping To Accelerate Daylight Simulation With High-Resolution, Data-Driven Fenestration Models
    (IOP Publishing Ltd., 2019) Grobe, Lars Oliver
    Data-driven modelling provides a general means to represent optically complex fenestration in daylight simulation by its Bidirectional Scattering Distribution Function (BSDF). Radiance employs the tensor tree as a compact data structure to store the BSDF at high directional resolution. The application of such models under sunny sky conditions is, however, computationally demanding, since the density of stochastic backward samples must match the BSDF resolution. The bidirectional Photon Map is proposed to rapidly forward-sample the BSDF, starting from the known sun direction. Its exemplary application shows a potential speed-up of ≥ 98% when compared to backward ray-tracing.
  • Article
    Citation - WoS: 5
    Citation - Scopus: 5
    Scale-Model and Simulation-Based Assessments for Design Alternatives of Daylight Redirecting Systems for Side-Lighting in an Educational Design Room
    (Middle East Technical University, 2017) Grobe, Lars Oliver; Hancı Geçit, Burcu; Sevinç, Zeynep; Altınkaya, Gülce; Aksakarya, Gizem; Ergin, Meltem; Öztürk, Yasemin; Kazanasmaz, Zehra Tuğçe
    Daylight has been proven to have positive effects on well-being, comfort and performance of occupants in buildings; it specifically increases learning performance in educational buildings. Side-lighting from one direction leads to unbalanced and insufficient illuminance, especially in large and deep spaces. A design studio at the Izmir Institute of Technology (IZTECH) in Urla, Turkey, has been chosen as an example of a space in such a context. Its geometrical attributes has taken to be the baseline. First, four daylight redirecting systems are applied on its 1/15 scale model to understand and compare their redirection behavior visually. Second, measurements on the scale model are taken to compare the daylight illuminance distributions. Third, to assess the overall performance in the sunny climate, illuminance and luminance maps for photorealistic visualization are calculated in monthly steps over one year. For efficient calculation of the time-steps to be considered, the daylight coefficient method has been applied. Though light ducts are found to be effective for high sun angles, in summer and equinoxes; very low illuminance in entire space make them fail in winter. Light shelves are determined to be the most convenient ones for this space, since they provided sufficient, uniform and high illuminance in equinoxes and winter.
  • Article
    Citation - Scopus: 8
    High-Resolution Data-Driven Models of Daylight Redirection Components
    (TU Delft Open, 2017) Grobe, Lars Oliver; Wittkopf, Stephen; Kazanasmaz, Zehra Tuğçe
    Daylight Redirecting Components (DRCs) guide daylight to zones with insufficient daylight exposure. They reduce energy demand for lighting, heating and cooling, and improve visual and thermal comfort. The data-driven model in Radiance is a means to model DRCs in daylight simulation. Rather than internal optical mechanisms, their resulting Bidirectional Scattering Distribution Function (BSDF) is replicated. We present models of two DRCs that are generated from measurements. The impact of the following three necessary steps in the generation of data-driven models from measured BSDF shall be evaluated: 1) interpolation between measurements at sparse sets of incident directions; 2) extrapolation for directions that cannot be measured; 3) application of a directional basis of given directional resolution. It is shown that data-driven models can provide a realistic representation of both DRCs. The sensitivity to effects from interpolation differs for the two DRCs due to the varying complexity of their BSDFs. Due to the irregularity of the measured BSDFs, extrapolation is not reliable and fails for both tested DRCs. Different measurement and modeling protocols should be applied to different class systems, rather than aiming at a common low-resolution discretization.
  • Article
    Citation - WoS: 40
    Citation - Scopus: 51
    Three Approaches To Optimize Optical Properties and Size of a South-Facing Window for Spatial Daylight Autonomy
    (Elsevier Ltd., 2016) Kazanasmaz, Zehra Tuğçe; Grobe, Lars Oliver; Bauer, Carsten; Krehel, Marek; Wittkopf, Stephen
    This study presents optimization approaches by a recent Climate-Based-Daylight-Modeling tool, EvalDRC, to figure out the necessary area for a daylight redirecting micro-prism film (MPF) while minimizing the glazing area. The performance of a window in terms of spatial Daylight Autonomy (sDA) is optimized by its geometry and optical properties. Data implemented in simulation model are gathered through on-site measurements and Bidirectional-Scattering Distribution Function (BSDF) gonio-measurements. EvalDRC based on Radiance with a data driven model of the films' BSDF evaluates the window configurations in the whole year. The case to achieve an sDA of at least 75% is a South-facing window of a classroom in Switzerland. A window zone from 0.90 m to 1.80 m height provides view to the outside. The upper zone from 1.80 m to 3.60 m is divided into six areas of 0.30 m height in three optimization approaches including the operation of sunshades as well. First, the size of the clear glazing is incrementally reduced to find the smallest acceptable window-to-wall ratio (WWR). Second, micro-prism films are applied to an incrementally varying fraction the initial glazed area to determine the minimum film-to-window ratio (FWR). Finally, both approaches are combined for a minimum FWR and WWR. With clear glazing and WWR of 75%, the sDA of 70.2% fails to meet the requirements. An sDA of 86.4% and 80.8% can be achieved with WWR 75%, FWR 1/9 and WWR 50%, FWR 1/2 respectively. The results demonstrate the films' potential to improve the performance of windows with reduced WWR.