@article{DokhanchiArnoldVogeletal.2020,
  author    = {Dokhanchi, Najmeh Sadat and Arnold, J{\"o}rg and Vogel, Albert and V{\"o}lker, Conrad},
  title     = {Measurement of indoor air temperature distribution using acoustic travel-time tomography: Optimization of transducers location and sound-ray coverage of the room},
  series = {Measurement},
  volume    = {2020},
  journal   = {Measurement},
  number    = {Volume 164, article 107934},
  publisher = {Elsevier},
  address   = {Amsterdam},
  doi       = {10.1016/j.measurement.2020.107934},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220524-46473},
  year      = {2020},
  abstract  = {Acoustic travel-time TOMography (ATOM) allows the measurement and reconstruction of air temperature distributions. Due to limiting factors, such as the challenge of travel-time estimation of the early reflections in the room impulse response, which heavily depends on the position of transducers inside the measurement area, ATOM is applied mainly outdoors. To apply ATOM in buildings, this paper presents a numerical solution to optimize the positions of transducers. This optimization avoids reflection overlaps, leading to distinguishable travel-times in the impulse response reflectogram. To increase the accuracy of the measured temperature within tomographic voxels, an additional function is employed to the proposed numerical method to minimize the number of sound-path-free voxels, ensuring the best sound-ray coverage of the room. Subsequently, an experimental set-up has been performed to verify the proposed numerical method. The results indicate the positive impact of the optimal positions of transducers on the distribution of ATOM-temperatures.},
  subject      = {Bauphysik},
  language  = {en}
}
@inproceedings{DokhanchiArnoldVogeletal.,
  author    = {Dokhanchi, Najmeh Sadat and Arnold, J{\"o}rg and Vogel, Albert and V{\"o}lker, Conrad},
  title     = {Acoustic Travel-Time Tomography: Optimal Positioning of Transceiver and Maximal Sound-Ray Coverage of the Room},
  series = {Fortschritte der Akustik - DAGA 2019},
  booktitle = {Fortschritte der Akustik - DAGA 2019},
  doi       = {10.25643/bauhaus-universitaet.3877},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190408-38778},
  pages     = {4},
  abstract  = {Acoustic travel-time tomography (ATOM) determines the distribution of the temperature in a propagation medium by measuring the travel-time of acoustic signals between transmitters and receivers. To employ ATOM for indoor climate measurements, the impulse responses have been measured in the climate chamber lab of the Bauhaus-University Weimar and compared with the theoretical results of its image source model (ISM). A challenging task is distinguishing the reflections of interest in the reflectogram when the sound rays have similar travel-times. This paper presents a numerical method to address this problem by finding optimal positions of transmitter and receiver, since they have a direct impact on the distribution of travel times. These optimal positions have the minimum number of simultaneous arrival time within a threshold level. Moreover, for the tomographic reconstruction, when some of the voxels remain empty of sound-rays, it leads to inaccurate determination of the air temperature within those voxels. Based on the presented numerical method, the number of empty tomographic voxels are minimized to ensure the best sound-ray coverage of the room. Subsequently, a spatial temperature distribution is estimated by simultaneous iterative reconstruction technique (SIRT). The experimental set-up in the climate chamber verifies the simulation results.},
  subject      = {Bauphysik},
  language  = {en}
}
@techreport{VogelVoelkerArnoldetal.,
  author    = {Vogel, Albert and V{\"o}lker, Conrad and Arnold, J{\"o}rg and Schmidt, Jens and Thurow, Torsten and Braunes, J{\"o}rg and Tonn, Christian and Bode, Kay-Andr{\´e} and Baldy, Franziska and Erfurt, Wolfgang and Tatarin, Ren{\´e}},
  title     = {Methoden und Baustoffe zur nutzerorientierten Bausanierung. Schlussbericht zum InnoProfile Forschungsvorhaben},
  organization    = {Bauhaus-Universit{\"a}t Weimar},
  isbn      = {978-3-86068-501-3 (Printausg.)},
  doi       = {10.25643/bauhaus-universitaet.2022},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20130830-20229},
  pages     = {106},
  abstract  = {Nutzerorientierte Bausanierung bedeutet eine gegen{\"u}ber dem konventionellen Vorgehen deutlich verst{\"a}rkte Ausrichtung des Planungs- und Sanierungsprozesses auf die Anforderungen und Bed{\"u}rfnisse des zuk{\"u}nftigen Nutzers eines Geb{\"a}udes. Dies hat einerseits ein hochwertigeres Produkt zum Ergebnis, erfordert andererseits aber auch den Einsatz neuer Methoden und Baustoffe sowie ein vernetztes Zusammenarbeiten aller am Bauprozess Beteiligten. Der Fokus der Publikation liegt dabei auf den Bereichen, die eine hohe Relevanz f{\"u}r die nutzerorientierte Bausanierung aufweisen. Dabei handelt es sich insbesondere um: Computergest{\"u}tztes Bauaufmaß und digitale Bauwerksmodellierung (BIM), bauphysikalische Methoden zur Optimierung von Energieeffizienz und Behaglichkeit bei der Sanierung von Bestandsgeb{\"a}uden, zerst{\"o}rungsfreie Untersuchungsmethoden im Rahmen einer substanzschonenden Bauzustandsanalyse und Entwicklung von Erg{\"a}nzungsbaustoffen. Das Projekt nuBau ist eine Kooperation zwischen den Fakult{\"a}ten Bauingenieurwesen und Architektur der Bauhaus-Universit{\"a}t Weimar. Die beteiligten Professuren sind: Bauphysik, Informatik in der Architektur, Polymere Werkstoffe und Werkstoffe des Bauens.},
  subject      = {Nutzerorientierte Bausanierung},
  language  = {de}
}