Christian Braun

Mr. Christian Braun

orcid

Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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13 December 2013 in The International Journal of Life Cycle Assessment
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Journal Article
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IVIan Vázquez-Rowe
Ian Vázquez-Rowe
Antonino MarvugliaAntonino Marvuglia
Antonino Marvuglia
KFKatja Flammang
Katja Flammang
CBChristian Braun
Christian Braun
ULUlrich Leopold
Ulrich Leopold
EBEnrico Benetto
Enrico Benetto

1 September 2012
Verified
Conference Paper
Open access
CAChristian Adami
Christian Adami
CBChristian Braun
Christian Braun
PCPeter Clemens
Peter Clemens
MJMichael Joster
Michael Joster
MSMichael Suhrke
Michael Suhrke
HTHans-Joachim Taenzer
Hans-Joachim Taenzer
We report on high power microwave (HPM) susceptibility tests of vulnerable IT network components. The devices under test are five different commercial and industrial media converters, one military media converter and a shielded enclosure for commercial media converters. The report compares results of susceptibility tests in different configurations supplemented by transfer function measurements.

Verified
Journal Article
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SBSukriti Bhattacharya
Sukriti Bhattacharya
CBChristian Braun
Christian Braun
ULUlrich Leopold
Ulrich Leopold
Urbanization is leading us to a more chaotic state where healthy living becomes a prime concern. The high-rise buildings influence the urban setting with a high shadow rate on surroundings that can have no positive impact on the general neighborhood. Nevertheless, shadows are the main factor of defeatist virtual settings, they are expensive to render in real-time. This paper investigates how the amount of sunlight varies by season and how seasons can indicate the time of year to understand how shadows vary in length at different times of the day and how they change over the seasons. We propose a novel efficient (fast and scalable) algorithm to calculate a 2.5D cast-shadow map from a given LiDAR-derived Digital Surface Model (DSM). We present a proof-of-concept demonstration to examine the technical practicability of the introduced algorithm. Tensor-based techniques such as singular value decomposition, tensor unfolding are examined and deployed to represent the multidimensional data. The proposed method exploits horizon mapping ideas and extends the method to a modern graphics algorithm (Bresenham’s line drawing algorithm) to account for the DSM’s underlying surface geometry. A proof-of-concept is developed utilizing Python’s TensorFlow library, exploring data flow graphs and the tensor data structure. The heavy computer graphics algorithm used in this paper is parallelized using PySpark. Results explicate significant enhancements in overall performance while preserving accuracy at negligible variations.

23 August 2019 in The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences
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SBSukriti Bhattacharya
Sukriti Bhattacharya
CBChristian Braun
Christian Braun
ULUlrich Leopold
Ulrich Leopold
In this paper, we address the curse of dimensionality and scalability issues while managing vast volumes of multidimensional raster data in the renewable energy modeling process in an appropriate spatial and temporal context. Tensor representation provides a convenient way to capture inter-dependencies along multiple dimensions. In this direction, we propose a sophisticated way of handling large-scale multi-layered spatio-temporal data, adopted for raster-based geographic information systems (GIS). We chose Tensorflow, an open source software library developed by Google using data flow graphs, and the tensor data structure. We provide a comprehensive performance evaluation of the proposed model against r.sun in GRASS GIS. Benchmarking shows that the tensor-based approach outperforms by up to 60%, concerning overall execution time for high-resolution datasets and fine-grained time intervals for daily sums of solar irradiation [Wh.m-2.day-1].

23 August 2019 in The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences
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CBChristian Braun
Christian Braun
This paper describes results on the development of a completely FOSS-based approach assessing the electricity production potential by building façade PV. To estimate solar irradiation the hemispherical view-shed approach described by (Fu, 1999) was used. Combining it with an approach to dissect walls into regular 3D hyper-points (1-meter spacing) the sun visibility and the sky viewshed throughout the year are calculated. This results in global irradiation per hyper-point. To estimate the economic potential of each façade element an economic model was developed. This is driven by technical parameters of the installation, such as module efficiency, installation and maintenance costs, figures about payback tariffs and envisaged module lifetime. The overall result is a city-wide PV suitability and economic potential map of every building façade. The processing is based on a city model in CityGML format using the 3DCityDB database and the spatial processing functionalities of PostGIS. A set of Python scripts has been developed as a central control instance and manage parallel processing of queries against the database to achieve scalability and improved performance. We run a case study with approximately 7000 single façade elements which are processed. Since we implemented a parallel computation of the façades running on an 80-core dedicated server machine, the completion for an entire city of about 3 million hyper-points points uses a decent amount of time for the given size of the data set. The chosen approach is highly scalable, robust and can be easily implemented through standard tools and libraries.

6 August 2024 in Neural Computing and Applications
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Pierrick BruneauPierrick Bruneau
Pierrick Bruneau
DFDavid Fiorelli
David Fiorelli
CBChristian Braun
Christian Braun
DKDaniel Koster
Daniel Koster