Grobe, Lars Oliver
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Grobe, L. O.
L. O. Grobe
Grobe, Lars Oliver.
L. O. Grobe
Grobe, Lars Oliver.
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Main Affiliation
02.02. Department of Architecture
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Current Staff
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Sustainable Development Goals
1NO POVERTY
0
Research Products
2ZERO HUNGER
0
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3GOOD HEALTH AND WELL-BEING
0
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4QUALITY EDUCATION
1
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5GENDER EQUALITY
0
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6CLEAN WATER AND SANITATION
0
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7AFFORDABLE AND CLEAN ENERGY
1
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8DECENT WORK AND ECONOMIC GROWTH
1
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9INDUSTRY, INNOVATION AND INFRASTRUCTURE
5
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10REDUCED INEQUALITIES
0
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11SUSTAINABLE CITIES AND COMMUNITIES
0
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12RESPONSIBLE CONSUMPTION AND PRODUCTION
1
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13CLIMATE ACTION
1
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14LIFE BELOW WATER
0
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15LIFE ON LAND
0
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16PEACE, JUSTICE AND STRONG INSTITUTIONS
0
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17PARTNERSHIPS FOR THE GOALS
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This researcher does not have a WoS ID.
Scholarly Output
10
Articles
7
Views / Downloads
8490/5299
Supervised MSc Theses
0
Supervised PhD Theses
1
WoS Citation Count
95
Scopus Citation Count
120
Patents
0
Projects
0
WoS Citations per Publication
9.50
Scopus Citations per Publication
12.00
Open Access Source
10
Supervised Theses
1
| Journal | Count |
|---|---|
| Energy and Buildings | 2 |
| Buildings | 1 |
| International Conference CISBAT 2015 Future Buildings and Districts Sustainability from Nano to Urban Scale | 1 |
| Journal of Building Performance Simulation | 1 |
| Journal of Facade Design and Engineering | 1 |
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10 results
Scholarly Output Search Results
Now showing 1 - 10 of 10
Article Citation - WoS: 7Citation - Scopus: 8Computational Combination of the Optical Properties of Fenestration Layers at High Directional Resolution(MDPI Multidisciplinary Digital Publishing Institute, 2017) Grobe, Lars OliverComplex fenestration systems typically comprise co-planar, clear and scattering layers. As there are many ways to combine layers in fenestration systems, a common approach in building simulation is to store optical properties separate for each layer. System properties are then computed employing a fast matrix formalism, often based on a directional basis devised by JHKlems comprising 145 incident and 145 outgoing directions. While this low directional resolution is found sufficient to predict illuminance and solar gains, it is too coarse to replicate the effects of directionality in the generation of imagery. For increased accuracy, a modification of the matrix formalism is proposed. The tensor-tree format of RADIANCE, employing an algorithm subdividing the hemisphere at variable resolutions, replaces the directional basis. The utilization of the tensor-tree with interfaces to simulation software allows sharing and re-use of data. The light scattering properties of two exemplary fenestration systems as computed employing the matrix formalism at variable resolution show good accordance with the results of ray-tracing. Computation times are reduced to 0.4% to 2.5% compared to ray-tracing through co-planar layers. Imagery computed employing the method illustrates the effect of directional resolution. The method is supposed to foster research in the field of daylighting, as well as applications in planning and design.Doctoral Thesis Data-Driven Modelling of Daylight Redirecting Fenestration at Variable Directional Resolution(Izmir Institute of Technology, 2019) Grobe, Lars Oliver; Kazanasmaz, Tuğçe; Wittkopf, StephenDaylight Redirecting Fenestration (DRF) aims at the optimal utilisation of daylight in buildings striving for high visual comfort standards. Daylight simulation allows to assess whether this objective is met in architectural context, and guides decisions in building design as well as the development of DRF. The daylight simulation suite Radiance allows to employ data-driven models of variable resolution to accurately replicate the irregular light scattering by DRF. In this context, this research provides methods to improve DRFs’ integration in daylight assessments. The thesis consolidates a series of publications that address particular problems in the generation and application of data-driven models, with a focus on accurate image synthesis for visual comfort assessments. First, the parametrisation of model generation from gonio-photometric measurements is tested. Second, a novel extension of the instrumentation allows to characterise and subsequently model retro-reflection by an innovative coating. Applied in DRF, the coating controls solar gains and glare, while maintaining a view to the outside. Third, to assemble accurate data-driven models of fenestration layers into descriptions of the entire DRF, an approach employing matrix calculations is adapted and tested. Finally, the Photon Map implementation in Radiance is modified for efficient image synthesis with data-driven models, and employed in a simplified but accurate approach to Climate-Based Daylight Modelling that demonstrates the potential of retro-reflection to efficiently control glare and maintain view with static DRF. The research contributes to the applicability of data-driven models, and confirms the potential of DRF to reconcile diverging daylight performance targets such as glare control and view.Article Citation - Scopus: 8High-Resolution Data-Driven Models of Daylight Redirection Components(TU Delft Open, 2017) Grobe, Lars Oliver; Wittkopf, Stephen; Kazanasmaz, Zehra TuğçeDaylight 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.Conference Object Comparison of Measured and Computed Bsdf of a Daylight Redirecting Component(EPFL Scientific Publications, 2015) Grobe, Lars Oliver; Noback, A.; Wittkopf, Stephen; Kazanasmaz, Zehra TuğçeThe Bidirectional Scatter Distribution Function (BSDF) of a selected Daylight Redirecting Component (DRC) is computed by a virtual goniophotometer using the enhanced photon map extension in Radiance, and compared to measured BSDF data. The DRC comprises a stack of tilted aluminum louvers with configurable inclination angle. The profile of the louvers is designed to control transmission depending on sun altitude, and to redirect light up towards the ceiling. The measured BSDF of the DRC is obtained from a scanning goniophotometer. For a sparse set of three source directions, the distribution is recorded at ≃ 250,000 receiver directions. The asymmetric angular resolution allows detailed observation of characteristic features in the distribution, which are assumed to persist over a range of source directions. For each pair of source and receiver directions in the measurement, the computed BSDF is generated from a model of the DRC, replicating the measurement with a virtual goniophotometer. The simulation relies only on the enhanced photon map extension for Radiance. The BSDF from measurement and simulation are compared qualitatively and quantitatively to discuss the degree of accordance. The presence of characteristic features and their topology is evaluated by comparing polar surface plots of the distributions and profiles of the scatter plane. The direct-hemispherical transmission is compared for each measurement and simulation. The RMSE of each computed distribution against the corresponding measurements is calculated to quantify the directionally resolved deviation. A high degree of qualitative accordance between the computed and the measured BSDF is achieved. Prominent features in the BSDF are represented by the model. A deviation of −6% to +15% is observed in a quantitative comparison of direct-hemispherical transmission by integration of computed and measured BSDF. The RMSE indicates higher deviations for lower source altitudes, where a direct transmission peak in the distribution is underestimated by the model. The method is proposed as a means to validate the capability of the enhanced photon map to predict transmission through DRC.Conference Object Citation - WoS: 3Citation - Scopus: 4Photon Mapping To Accelerate Daylight Simulation With High-Resolution, Data-Driven Fenestration Models(IOP Publishing Ltd., 2019) Grobe, Lars OliverData-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: 14Citation - Scopus: 14Photon-Mapping in Climate-Based Daylight Modelling With High-Resolution Bsdfs(Elsevier Ltd., 2019) Grobe, Lars OliverVisual comfort assessments employing luminance-based metrics rely on efficient CBDM techniques for image synthesis. Data-driven BSDF models allow to isolate internal light paths in optically CFS from CBDM. Bidirectional photon mapping is proposed for the efficient sampling of such models in the calculation of the direct solar component in CBDM. The method allows accurate image synthesis for visual comfort assessments with only two calculation steps, achieving comparable accuracy as the established but complex 5PM. The validity of the approach is confirmed by comparison with backward ray-tracing. Its exemplary application to compare two CFS in terms of glare control demonstrates the importance to achieve reconcilability of conflicting targets such as view and glare control in daylighting. (C) 2019 Elsevier B.V. All rights reserved.Article Citation - WoS: 40Citation - Scopus: 51Three 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, StephenThis 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.Article Citation - WoS: 14Citation - Scopus: 15Photon Mapping in Image-Based Visual Comfort Assessments With Bsdf Models of High Resolution(Taylor and Francis Ltd., 2019) Grobe, Lars OliverData-driven models replicate the irregular Bidirectional Scattering Distribution Functions (BSDFs) of optically Complex Fenestration Systems in daylight simulation. RADIANCE employs the tensor tree to store the BSDF at high directional resolution. Its application in backward ray-tracing is however challenging, since the density of stochastic samples must match the model resolution. BSDF proxy and peak extraction address this problem, but are limited to cases when either the fenestration geometry, or the shape and direction of the transmission peak are known. Photon Mapping is proposed to efficiently sample arbitrary BSDFs from the known sun direction. The existing implementation in RADIANCE is extended to account for light sources and their reflections in the field of view, that are of particular importance for visual comfort assessments. The method achieves a high degree of accordance with ray-tracing, and reduces simulation times by approximate to 95% with data-driven models of high resolution.Article Citation - WoS: 12Citation - Scopus: 15Characterization and Data-Driven Modeling of a Retro-Reflective Coating in Radiance(Elsevier Ltd., 2018) Grobe, Lars OliverRetro-reflective coatings applied to blinds of reduced geometric complexity promise to provide view to the outside while effectively controlling solar gains and glare. To characterize the reflection characteristics of such coatings over the entire solar spectrum, a novel extension to a scanning gonio-photometer is developed. The extended instrument is tested and applied to measure a coating's Bidirectional Reflection Distribution Function including the region of the retro-reflected peak. The measured datasets are compiled into a data-driven reflection model for the daylight simulation software RADIANCE. This model is applied to illustrate the coating's effect in a comparison to purely diffuse and specular surface finishes on geometrically identical, flat blinds. Daylight supply, the probability of glare, and solar gains are assessed for an exemplary, South-oriented office under sunny sky conditions. The results indicate the potential of the coating to effectively shade direct sunlight even if applied on blinds with minimalistic geometries. The modeling technique is shown to be a general means to replicate the irregular optical properties of the coating, which cannot be represented by the standard models in daylight simulation software.Article Citation - WoS: 5Citation - Scopus: 5Scale-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 TuğçeDaylight 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.