TY - JOUR ED - Professur Theorie und Geschichte der modernen Architektur, T1 - Das Bauhaus Dessau wird Zentrum für Gestaltung : Festveranstaltung des Ministerrates der DDR am 6. Dezember 1986 N2 - Wissenschaftliches Kolloquium vom 24. bis 26. Juni 1986 in Weimar an der Hochschule für Architektur und Bauwesen zum Thema: 'Der wissenschaftlich-technische Fortschritt und die sozial-kulturellen Funktionen von Architektur und industrieller Formgestaltung in unserer Epoche' T3 - Wissenschaftliche Zeitschrift / Hochschule für Architektur und Bauwesen - 33.1987,4-6/339 KW - Dessau / Bauhaus KW - Bauhaus-Kolloquium KW - Weimar KW - 1986 Y1 - 1987 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-9959 ER - TY - JOUR ED - Professur Theorie und Geschichte der modernen Architektur, T1 - Gegen Neofaschismus und Krieg, für Frieden und Völkerverständigung N2 - Wissenschaftliches Kolloquium vom 27. bis 30. Juni 1989 in Weimar an der Hochschule für Architektur und Bauwesen zum Thema: ‚Produktivkraftentwicklung und Umweltgestaltung. Sozialer und wissenschaftlich-technischer Fortschritt in ihren Auswirkungen auf Architektur und industrielle Formgestaltung in unserer Zeit. Zum 100. Geburtstag von Hannes Meyer' T3 - Wissenschaftliche Zeitschrift / Hochschule für Architektur und Bauwesen - 36.1990,1-3/3-6 KW - Bauhaus KW - Kongress KW - Bauhaus-Kolloquium KW - Weimar KW - 1989 Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-10937 ER - TY - JOUR ED - Professur Theorie und Geschichte der modernen Architektur, T1 - Bauhaus medial - zur Rezeption des Bauhauses zwischen 1919 und 1991 N2 - Wissenschaftliches Kolloquium vom 18. bis 21. Juni 1992 in Weimar an der Hochschule für Architektur und Bauwesen zum Thema: ‚Architektur und Macht' T3 - Wissenschaftliche Zeitschrift / Hochschule für Architektur und Bauwesen - 38.1992,5-6/273-276 KW - Bauhaus KW - Rezeption KW - Bauhaus-Kolloquium KW - Weimar KW - 1992 Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-11154 ER - TY - JOUR ED - Professur Theorie und Geschichte der modernen Architektur, T1 - Friedensinitiative des 4. Internationalen Bauhauskolloquiums - Umweltgestaltung erfordert Friedenskampf N2 - Wissenschaftliches Kolloquium vom 24. bis 26. Juni 1986 in Weimar an der Hochschule für Architektur und Bauwesen zum Thema: 'Der wissenschaftlich-technische Fortschritt und die sozial-kulturellen Funktionen von Architektur und industrieller Formgestaltung in unserer Epoche' T3 - Wissenschaftliche Zeitschrift / Hochschule für Architektur und Bauwesen - 33.1987,4-6/188-189 KW - Bauhaus KW - Kongress KW - Bauhaus-Kolloquium KW - Weimar KW - 1986 Y1 - 1987 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-10420 ER - TY - JOUR ED - Professur Theorie und Geschichte der modernen Architektur, T1 - Konrad Püschel - Schülerarbeiten am Bauhaus Dessau : Kabinettausstellung im Juni 1979 in Weimar N2 - Wissenschaftliches Kolloquium vom 27. bis 29. Juni 1979 in Weimar an der Hochschule für Architektur und Bauwesen zum Thema: '60 Jahre Gründung Bauhaus' T3 - Wissenschaftliche Zeitschrift / Hochschule für Architektur und Bauwesen - 26.1979,4-5/454 KW - Püschel KW - Konrad KW - Dessau / Bauhaus KW - Bauentwurf KW - Bauhaus-Kolloquium KW - Weimar KW - 1979 Y1 - 1979 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-8971 ER - TY - JOUR A1 - Abbaspour-Gilandeh, Yousef A1 - Molaee, Amir A1 - Sabzi, Sajad A1 - Nabipour, Narjes A1 - Shamshirband, Shahaboddin A1 - Mosavi, Amir T1 - A Combined Method of Image Processing and Artificial Neural Network for the Identification of 13 Iranian Rice Cultivars JF - agronomy N2 - Due to the importance of identifying crop cultivars, the advancement of accurate assessment of cultivars is considered essential. The existing methods for identifying rice cultivars are mainly time-consuming, costly, and destructive. Therefore, the development of novel methods is highly beneficial. The aim of the present research is to classify common rice cultivars in Iran based on color, morphologic, and texture properties using artificial intelligence (AI) methods. In doing so, digital images of 13 rice cultivars in Iran in three forms of paddy, brown, and white are analyzed through pre-processing and segmentation of using MATLAB. Ninety-two specificities, including 60 color, 14 morphologic, and 18 texture properties, were identified for each rice cultivar. In the next step, the normal distribution of data was evaluated, and the possibility of observing a significant difference between all specificities of cultivars was studied using variance analysis. In addition, the least significant difference (LSD) test was performed to obtain a more accurate comparison between cultivars. To reduce data dimensions and focus on the most effective components, principal component analysis (PCA) was employed. Accordingly, the accuracy of rice cultivar separations was calculated for paddy, brown rice, and white rice using discriminant analysis (DA), which was 89.2%, 87.7%, and 83.1%, respectively. To identify and classify the desired cultivars, a multilayered perceptron neural network was implemented based on the most effective components. The results showed 100% accuracy of the network in identifying and classifying all mentioned rice cultivars. Hence, it is concluded that the integrated method of image processing and pattern recognition methods, such as statistical classification and artificial neural networks, can be used for identifying and classification of rice cultivars. KW - Maschinelles Lernen KW - Machine learning KW - food informatics KW - big data KW - artificial neural networks KW - artificial intelligence KW - image processing KW - rice Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20200123-40695 UR - https://www.mdpi.com/2073-4395/10/1/117 VL - 2020 IS - Volume 10, Issue 1, 117 PB - MDPI ER - TY - JOUR A1 - Abdalla, Jamal T1 - Elements of an Agent-based Mediative Communication Protocol for Design Objects N2 - Integrated structural engineering system usually consists of large number of design objects that may be distributed across different platforms. These design objects need to communicate data and information among each other. For efficient communication among design objects a common communication protocol need to be defined. This paper presents the elements of a communication protocol that uses a mediator agent to facilitate communication among design objects. This protocol is termed the Mediative Communication Protocol (MCP). The protocol uses certain design communication performatives and the semantics of an Agent Communication language (ACL) mainly the Knowledge and Query Manipulation Language (KQML) to implement its steps. Details of a Mediator Agent, that will facilitate the communication among design objects, is presented. The Unified Modeling Language (UML) is used to present the Meditative protocol and show how the mediator agent can be use to execute the steps of the meditative communication protocol. An example from structural engineering application is presented to demonstrate and validate the protocol. It is concluded that the meditative protocol is a viable protocol to facilitate object-to-object communication and also has potential to facilitate communication among the different project participants at the higher level of integrated structural engineering systems. KW - Mehragentensystem KW - Lernendes System KW - Kommunikationsprotokoll Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2207 ER - TY - JOUR A1 - Abdelnour, Mena A1 - Zabel, Volkmar T1 - Modal identification of structures with a dynamic behaviour characterised by global and local modes at close frequencies JF - Acta Mechanica N2 - Identification of modal parameters of a space frame structure is a complex assignment due to a large number of degrees of freedom, close natural frequencies, and different vibrating mechanisms. Research has been carried out on the modal identification of rather simple truss structures. So far, less attention has been given to complex three-dimensional truss structures. This work develops a vibration-based methodology for determining modal information of three-dimensional space truss structures. The method uses a relatively complex space truss structure for its verification. Numerical modelling of the system gives modal information about the expected vibration behaviour. The identification process involves closely spaced modes that are characterised by local and global vibration mechanisms. To distinguish between local and global vibrations of the system, modal strain energies are used as an indicator. The experimental validation, which incorporated a modal analysis employing the stochastic subspace identification method, has confirmed that considering relatively high model orders is required to identify specific mode shapes. Especially in the case of the determination of local deformation modes of space truss members, higher model orders have to be taken into account than in the modal identification of most other types of structures. KW - Fachwerkbau KW - Holzkonstruktion KW - Schwingung KW - three-dimensional truss structures KW - vibration-based methodology KW - numerical modelling Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20230525-63822 UR - https://link.springer.com/article/10.1007/s00707-023-03598-z VL - 2023 SP - 1 EP - 21 PB - Springer CY - Wien ER - TY - JOUR A1 - Abrahamczyk, Lars A1 - Uzair, Aanis T1 - On the use of climate models for estimating the non-stationary characteristic values of climatic actions in civil engineering practice JF - Frontiers in Built Environment N2 - The characteristic values of climatic actions in current structural design codes are based on a specified probability of exceedance during the design working life of a structure. These values are traditionally determined from the past observation data under a stationary climate assumption. However, this assumption becomes invalid in the context of climate change, where the frequency and intensity of climatic extremes varies with respect to time. This paper presents a methodology to calculate the non-stationary characteristic values using state of the art climate model projections. The non-stationary characteristic values are calculated in compliance with the requirements of structural design codes by forming quasi-stationary windows of the entire bias-corrected climate model data. Three approaches for the calculation of non-stationary characteristic values considering the design working life of a structure are compared and their consequences on exceedance probability are discussed. KW - Klimaänderung KW - Bauwerk KW - climate change KW - climate models KW - extreme value analysis KW - characteristic value KW - OA-Publikationsfonds2023 Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20230524-63751 UR - https://www.frontiersin.org/articles/10.3389/fbuil.2023.1108328/full VL - 2023 IS - volume 9, article 1108328 SP - 1 EP - 9 PB - Frontier Media CY - Lausanne ER - TY - JOUR A1 - Achenbach, Marcus A1 - Lahmer, Tom A1 - Morgenthal, Guido T1 - Global Sensitivity Analysis of Reinforced Concrete Walls Subjected to Standard Fire - A Comparison of Methods JF - 14th International Probabilistic Workshop N2 - Global Sensitivity Analysis of Reinforced Concrete Walls Subjected to Standard Fire—A Comparison of Methods KW - Angewandte Mathematik KW - Stochastik KW - Strukturmechanik Y1 - 2017 SP - 97 EP - 106 ER - TY - JOUR A1 - Achenbach, Marcus A1 - Lahmer, Tom A1 - Morgenthal, Guido T1 - Identification of the thermal properties of concrete for the temperature calculation of concrete slabs and columns subjected to a standard fire—Methodology and proposal for simplified formulations JF - Fire Safety Journal 87 N2 - The fire resistance of concrete members is controlled by the temperature distribution of the considered cross section. The thermal analysis can be performed with the advanced temperature dependent physical properties provided by 5EN6 1992-1-2. But the recalculation of laboratory tests on columns from 5TU6 Braunschweig shows, that there are deviations between the calculated and measured temperatures. Therefore it can be assumed, that the mathematical formulation of these thermal properties could be improved. A sensitivity analysis is performed to identify the governing parameters of the temperature calculation and a nonlinear optimization method is used to enhance the formulation of the thermal properties. The proposed simplified properties are partly validated by the recalculation of measured temperatures of concrete columns. These first results show, that the scatter of the differences from the calculated to the measured temperatures can be reduced by the proposed simple model for the thermal analysis of concrete. KW - Sensitivitätsanalyse KW - Thermodynamische Eigenschaft KW - Fire resistance; Parameter optimization; Sensitivity analysis; Thermal properties Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170331-30929 UR - http://www.sciencedirect.com/science/article/pii/S0379711216301965 SP - 80 EP - 86 ER - TY - JOUR A1 - Adamatzky, Andrew A1 - Schubert, Theresa T1 - Slime mold microfluidic logical gates JF - Materials Today N2 - We demonstrate how logical operations can be implemented in ensembles of protoplasmic tubes of acellular slime mold Physarum polycephalum. The tactile response of the protoplasmic tubes is used to actuate analogs of two- and four-input logical gates and memory devices. The slime mold tube logical gates display results of logical operations by blocking flow in mechanically stimulated tube fragments and redirecting the flow to output tube fragments. We demonstrate how XOR and NOR gates are constructed. We also exemplify circuits of hybrid gates and a memory device. The slime mold based gates are non-electronic, simple and inexpensive, and several gates can be realized simultaneously at sites where protoplasmic tubes merge. KW - Physarum polycephalum KW - protoplasmic tubes, Nucleolus-Organisator-Region Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170413-31168 SP - 86 EP - 91 ER - TY - JOUR A1 - Adlerová, Alena T1 - Krásná jizba und Bauhaus : zur Produktgestaltung in der CSR 1928-1938 N2 - Wissenschaftliches Kolloquium vom 27. bis 29. Juni 1979 in Weimar an der Hochschule für Architektur und Bauwesen zum Thema: '60 Jahre Gründung Bauhaus' T3 - Wissenschaftliche Zeitschrift / Hochschule für Architektur und Bauwesen - 26.1979,4-5/425-429 KW - Tschechoslowakei KW - Produktgestaltung KW - Bauhaus-Kolloquium KW - Weimar KW - 1979 Y1 - 1979 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-9071 ER - TY - JOUR A1 - Aguinaga, José Guillermo De T1 - Error in prediction due to data type availability in a coupled hydro-mechanical model JF - Electronic Journal of Geotechnical Engineering N2 - Different types of data provide different type of information. The present research analyzes the error on prediction obtained under different data type availability for calibration. The contribution of different measurement types to model calibration and prognosis are evaluated. A coupled 2D hydro-mechanical model of a water retaining dam is taken as an example. Here, the mean effective stress in the porous skeleton is reduced due to an increase in pore water pressure under drawdown conditions. Relevant model parameters are identified by scaled sensitivities. Then, Particle Swarm Optimization is applied to determine the optimal parameter values and finally, the error in prognosis is determined. We compare the predictions of the optimized models with results from a forward run of the reference model to obtain the actual prediction errors. The analyses presented here were performed calibrating the hydro-mechanical model to 31 data sets of 100 observations of varying data types. The prognosis results improve when using diversified information for calibration. However, when using several types of information, the number of observations has to be increased to be able to cover a representative part of the model domain. For an analysis with constant number of observations, a compromise between data type availability and domain coverage proves to be the best solution. Which type of calibration information contributes to the best prognoses could not be determined in advance. The error in model prognosis does not depend on the error in calibration, but on the parameter error, which unfortunately cannot be determined in inverse problems since we do not know its real value. The best prognoses were obtained independent of calibration fit. However, excellent calibration fits led to an increase in prognosis error variation. In the case of excellent fits; parameters' values came near the limits of reasonable physical values more often. To improve the prognoses reliability, the expected value of the parameters should be considered as prior information on the optimization algorithm. KW - Sensitivitätsanalyse KW - Damm KW - Embankment, sensitivity analysis, parameter identification, Particle Swarm Optimization KW - Fehlerabschätzung Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170413-31170 UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-84868020397&partnerID=40&md5=72c87bb112839303c1ef9a4afa8c6421 SP - 2459 EP - 2471 ER - TY - JOUR A1 - Ahmadi, Mohammad Hossein A1 - Baghban, Alireza A1 - Sadeghzadeh, Milad A1 - Zamen, Mohammad A1 - Mosavi, Amir A1 - Shamshirband, Shahaboddin A1 - Kumar, Ravinder A1 - Mohammadi-Khanaposhtani, Mohammad T1 - Evaluation of electrical efficiency of photovoltaic thermal solar collector JF - Engineering Applications of Computational Fluid Mechanics N2 - In this study, machine learning methods of artificial neural networks (ANNs), least squares support vector machines (LSSVM), and neuro-fuzzy are used for advancing prediction models for thermal performance of a photovoltaic-thermal solar collector (PV/T). In the proposed models, the inlet temperature, flow rate, heat, solar radiation, and the sun heat have been considered as the input variables. Data set has been extracted through experimental measurements from a novel solar collector system. Different analyses are performed to examine the credibility of the introduced models and evaluate their performances. The proposed LSSVM model outperformed the ANFIS and ANNs models. LSSVM model is reported suitable when the laboratory measurements are costly and time-consuming, or achieving such values requires sophisticated interpretations. KW - Fotovoltaik KW - Erneuerbare Energien KW - Solar KW - Deep learning KW - Machine learning KW - Renewable energy KW - neural networks (NNs) KW - adaptive neuro-fuzzy inference system (ANFIS) KW - least square support vector machine (LSSVM) KW - photovoltaic-thermal (PV/T) KW - hybrid machine learning model KW - OA-Publikationsfonds2020 Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20200304-41049 UR - https://www.tandfonline.com/doi/full/10.1080/19942060.2020.1734094 VL - 2020 IS - volume 14, issue 1 SP - 545 EP - 565 PB - Taylor & Francis ER - TY - JOUR A1 - Aicher, Andreas A1 - Börmel, Melanie A1 - Londong, Jörg A1 - Beier, Silvio T1 - Vertical green system for gray water treatment: Analysis of the VertiKKA-module in a field test JF - Frontiers in Environmental Science N2 - This work presents a modular Vertical Green System (VGS) for gray water treatment, developed at the Bauhaus-Universität Weimar. The concept was transformed into a field study with four modules built and tested with synthetic gray water. Each module set contains a small and larger module with the same treatment substrate and was fed hourly. A combination of lightweight structural material and biochar of agricultural residues and wood chips was used as the treatment substrate. In this article, we present the first 18 weeks of operation. Regarding the treatment efficiency, the parameters chemical oxygen demand (COD), total phosphorous (TP), ortho-phosphate (ortho-P), total bound nitrogen (TNb), ammonium nitrogen (NH4-N), and nitrate nitrogen (NO3-N) were analyzed and are presented in this work. The results of the modules with agricultural residues are promising. Up to 92% COD reduction is stated in the data. The phosphate and nitrogen fractions are reduced significantly in these modules. By contrast, the modules with wood chips reduce only 67% of the incoming COD and respectively less regarding phosphates and the nitrogen fraction. KW - Grauwasser KW - Abwassertechnologie KW - vertical green system KW - grey water treatment KW - urban heat island effect KW - OA-Publikationsfonds2022 Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20230124-48840 UR - https://www.frontiersin.org/articles/10.3389/fenvs.2022.976005/full VL - 2022 IS - Volume 10 (2022), article 976005 SP - 1 EP - 7 PB - Frontiers Media CY - Lausanne ER - TY - JOUR A1 - Akis, Tonguç T1 - Haptic in Architectural Design Education : New Possibilities in the Information Age N2 - Wissenschaftliches Kolloquium vom 19. bis 22. April 2007 in Weimar an der Bauhaus-Universität zum Thema: ‚Die Realität des Imaginären. Architektur und das digitale Bild' T3 - Schriften der Bauhaus-Universität Weimar - 120/36 KW - Architektur KW - Design KW - Raum KW - Bild KW - Digitalisierung KW - Bauhaus-Kolloquium KW - Weimar KW - 2007 Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20080728-13702 ER - TY - JOUR A1 - Al-Yasiri, Zainab Riyadh Shaker A1 - Mutashar, Hayder Majid A1 - Gürlebeck, Klaus A1 - Lahmer, Tom ED - Shafiullah, GM T1 - Damage Sensitive Signals for the Assessment of the Conditions of Wind Turbine Rotor Blades Using Electromagnetic Waves JF - Infrastructures N2 - One of the most important renewable energy technologies used nowadays are wind power turbines. In this paper, we are interested in identifying the operating status of wind turbines, especially rotor blades, by means of multiphysical models. It is a state-of-the-art technology to test mechanical structures with ultrasonic-based methods. However, due to the density and the required high resolution, the testing is performed with high-frequency waves, which cannot penetrate the structure in depth. Therefore, there is a need to adopt techniques in the fields of multiphysical model-based inversion schemes or data-driven structural health monitoring. Before investing effort in the development of such approaches, further insights and approaches are necessary to make the techniques applicable to structures such as wind power plants (blades). Among the expected developments, further accelerations of the so-called “forward codes” for a more efficient implementation of the wave equation could be envisaged. Here, we employ electromagnetic waves for the early detection of cracks. Because in many practical situations, it is not possible to apply techniques from tomography (characterized by multiple sources and sensor pairs), we focus here on the question of whether the existence of cracks can be determined by using only one source for the sent waves. KW - Windkraftwerk KW - Rotorblatt KW - Elektrostatische Welle KW - MATLAB KW - wind turbine rotor blades KW - electromagnetic waves KW - crack detection KW - Empire XPU 8.01 KW - Matlab KW - OA-Publikationsfonds2022 Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20220831-47093 UR - https://www.mdpi.com/2412-3811/7/8/104 VL - 2022 IS - Volume 7, Issue 8 (August 2022), article 104 PB - MDPI CY - Basel ER - TY - JOUR A1 - Alalade, Muyiwa A1 - Nguyen-Tuan, Long A1 - Wuttke, Frank A1 - Lahmer, Tom T1 - Damage identification in gravity dams using dynamic coupled hydro-mechanical XFEM JF - International Journal of Mechanics and Materials in Design N2 - Damage identification in gravity dams using dynamic coupled hydro-mechanical XFEM. KW - Angewandte Mathematik KW - Stochastik KW - Strukturmechanik Y1 - 2017 U6 - http://dx.doi.org/10.25643/bauhaus-universitaet.3596 SP - 1 EP - 19 ER - TY - JOUR A1 - Alalade, Muyiwa A1 - Reichert, Ina A1 - Köhn, Daniel A1 - Wuttke, Frank A1 - Lahmer, Tom ED - Qu, Chunxu ED - Gao, Chunxu ED - Zhang, Rui ED - Jia, Ziguang ED - Li, Jiaxiang T1 - A Cyclic Multi-Stage Implementation of the Full-Waveform Inversion for the Identification of Anomalies in Dams JF - Infrastructures N2 - For the safe and efficient operation of dams, frequent monitoring and maintenance are required. These are usually expensive, time consuming, and cumbersome. To alleviate these issues, we propose applying a wave-based scheme for the location and quantification of damages in dams. To obtain high-resolution “interpretable” images of the damaged regions, we drew inspiration from non-linear full-multigrid methods for inverse problems and applied a new cyclic multi-stage full-waveform inversion (FWI) scheme. Our approach is less susceptible to the stability issues faced by the standard FWI scheme when dealing with ill-posed problems. In this paper, we first selected an optimal acquisition setup and then applied synthetic data to demonstrate the capability of our approach in identifying a series of anomalies in dams by a mixture of reflection and transmission tomography. The results had sufficient robustness, showing the prospects of application in the field of non-destructive testing of dams. KW - Damm KW - Defekt KW - inverse analysis KW - damage identification KW - full-waveform inversion KW - dams KW - wave propagation KW - OA-Publikationsfonds2022 Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20221201-48396 UR - https://www.mdpi.com/2412-3811/7/12/161 VL - 2022 IS - Volume 7, issue 12, article 161 PB - MDPI CY - Basel ER - TY - JOUR A1 - Albert, Andrej A1 - Freischlad, Mark A1 - Pullmann, Torben T1 - Acquisition of Conceptual Design Knowledge in Structural Engineering N2 - Expert systems integrating fuzzy reasoning techniques represent a powerful tool to support practicing engineers during the early stages of structural design. In this context fuzzy models have proved themselves to be very suitable for the representation of complex design knowledge. However their definition is a laborious task. This paper introduces an approach for the design and the optimization of fuzzy systems based upon Genetic Programming. To keep the emerging fuzzy systems transparent a new framework for the definition of linguistic variables is also introduced. KW - Mehragentensystem KW - Lernendes System KW - Wissensverarbeitung Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2154 ER - TY - JOUR A1 - Alemu, Yohannes L. A1 - Habte, Bedilu A1 - Lahmer, Tom A1 - Urgessa, Girum T1 - Topologically preoptimized ground structure (TPOGS) for the optimization of 3D RC buildings JF - Asian Journal of Civil Engineering N2 - As an optimization that starts from a randomly selected structure generally does not guarantee reasonable optimality, the use of a systemic approach, named the ground structure, is widely accepted in steel-made truss and frame structural design. However, in the case of reinforced concrete (RC) structural optimization, because of the orthogonal orientation of structural members, randomly chosen or architect-sketched framing is used. Such a one-time fixed layout trend, in addition to its lack of a systemic approach, does not necessarily guarantee optimality. In this study, an approach for generating a candidate ground structure to be used for cost or weight minimization of 3D RC building structures with included slabs is developed. A multiobjective function at the floor optimization stage and a single objective function at the frame optimization stage are considered. A particle swarm optimization (PSO) method is employed for selecting the optimal ground structure. This method enables generating a simple, yet potential, real-world representation of topologically preoptimized ground structure while both structural and main architectural requirements are considered. This is supported by a case study for different floor domain sizes. KW - Bodenmechanik KW - Strukturanalyse KW - Optimierung KW - Stahlbetonkonstruktion KW - Dreidimensionales Modell KW - ground structure KW - TPOGS KW - topology optimization KW - 3D reinforced concrete buildings Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20230517-63677 UR - https://link.springer.com/article/10.1007/s42107-023-00640-2 VL - 2023 SP - 1 EP - 11 PB - Springer International Publishing CY - Cham ER - TY - JOUR A1 - Alkam, Feras A1 - Lahmer, Tom T1 - A robust method of the status monitoring of catenary poles installed along high-speed electrified train tracks JF - Results in Engineering N2 - Electric trains are considered one of the most eco-friendly and safest means of transportation. Catenary poles are used worldwide to support overhead power lines for electric trains. The performance of the catenary poles has an extensive influence on the integrity of the train systems and, consequently, the connected human services. It became a must nowadays to develop SHM systems that provide the instantaneous status of catenary poles in- service, making the decision-making processes to keep or repair the damaged poles more feasible. This study develops a data-driven, model-free approach for status monitoring of cantilever structures, focusing on pre-stressed, spun-cast ultrahigh-strength concrete catenary poles installed along high-speed train tracks. The pro-posed approach evaluates multiple damage features in an unfied damage index, which leads to straightforward interpretation and comparison of the output. Besides, it distinguishes between multiple damage scenarios of the poles, either the ones caused by material degradation of the concrete or by the cracks that can be propagated during the life span of the given structure. Moreover, using a logistic function to classify the integrity of structure avoids the expensive learning step in the existing damage detection approaches, namely, using the modern machine and deep learning methods. The findings of this study look very promising when applied to other types of cantilever structures, such as the poles that support the power transmission lines, antenna masts, chimneys, and wind turbines. KW - Fahrleitung KW - Catenary poles KW - SHM KW - Model-free status monitoring KW - Sigmoid function KW - High-speed electric train KW - Schaden KW - OA-Publikationsfonds2021 Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20211011-45212 UR - https://www.sciencedirect.com/science/article/pii/S2590123021000906?via%3Dihub VL - 2021 IS - volume 12, article 100289 SP - 1 EP - 8 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Alkam, Feras A1 - Lahmer, Tom T1 - Eigenfrequency-Based Bayesian Approach for Damage Identification in Catenary Poles JF - Infrastructures N2 - This study proposes an efficient Bayesian, frequency-based damage identification approach to identify damages in cantilever structures with an acceptable error rate, even at high noise levels. The catenary poles of electric high-speed train systems were selected as a realistic case study to cover the objectives of this study. Compared to other frequency-based damage detection approaches described in the literature, the proposed approach is efficiently able to detect damages in cantilever structures to higher levels of damage detection, namely identifying both the damage location and severity using a low-cost structural health monitoring (SHM) system with a limited number of sensors; for example, accelerometers. The integration of Bayesian inference, as a stochastic framework, in the proposed approach, makes it possible to utilize the benefit of data fusion in merging the informative data from multiple damage features, which increases the quality and accuracy of the results. The findings provide the decision-maker with the information required to manage the maintenance, repair, or replacement procedures. KW - Fahrleitung KW - Schaden KW - Fahrleitungsmast KW - Schadenserkennung KW - vibration-based damage identification KW - Bayesian inference Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210510-44256 UR - https://www.mdpi.com/2412-3811/6/4/57 VL - 2021 IS - Volume 6, issue 4, article 57 SP - 1 EP - 19 PB - MDPI CY - Basel ER - TY - JOUR A1 - Allen, Stan T1 - After mechanical reproduction N2 - Wissenschaftliches Kolloquium vom 27. bis 30. Juni 1996 in Weimar an der Bauhaus-Universität zum Thema: ‚Techno-Fiction. Zur Kritik der technologischen Utopien' T3 - Thesis // Bauhaus-Universität - 43.1997,1-2/61-64 KW - Architektur KW - Technologie KW - Fiktion KW - Bauhaus-Kolloquium KW - Weimar KW - 1996 Y1 - 1997 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-11686 ER - TY - JOUR A1 - Alsaad, Hayder A1 - Hartmann, Maria A1 - Hilbel, Rebecca A1 - Völker, Conrad T1 - ENVI-met validation data accompanied with simulation data of the impact of facade greening on the urban microclimate JF - Data in Brief N2 - This dataset consists mainly of two subsets. The first subset includes measurements and simulation data conducted to validate the simulation tool ENVI-met. The measurements were conducted at the campus of the Bauhaus-University Weimar in Weimar, Germany and consisted of recording exterior air temperature, globe temperature, relative humidity, and wind velocity at 1.5 m at four points on four different days. After the measurements, the geometry of the campus was modelled and meshed; the simulations were conducted using the weather data of the measurements days with the aim of investigating the accuracy of the model. The second data subset consists of ENVI-met simulation data of the potential of facade greening in improving the outdoor environment and the indoor air temperature during heatwaves in Central European cities. The data consist of the boundary conditions and the simulation output of two simulation models: with and without facade greening. The geometry of the models corresponded to a residential buildings district in Stuttgart, Germany. The simulation output consisted of exterior air temperature, mean radiant temperature, relative humidity, and wind velocity at 12 different probe points in the model in addition to the indoor air temperature of an exemplary building. The dataset presents both vertical profiles of the probed parameters as well as the time series output of the five-day simulation duration. Both data subsets correspond to the investigations presented in the co-submitted article [1]. KW - Messung KW - Measurements KW - Simulations KW - ENVI-met KW - Living wall KW - Green facade KW - Simulation KW - OA-Publikationsfonds2022 Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20220511-46455 UR - https://www.sciencedirect.com/science/article/pii/S2352340922004048#! VL - 2022 IS - Volume 42, article 108200 SP - 1 EP - 13 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Alsaad, Hayder A1 - Hartmann, Maria A1 - Voelker, Conrad T1 - The effect of a living wall system designated for greywater treatment on the hygrothermal performance of the facade JF - Energy and Buildings N2 - Besides their multiple known benefits regarding urban microclimate, living walls can be used as decentralized stand-alone systems to treat greywater locally at the buildings. While this offers numerous environmental advantages, it can have a considerable impact on the hygrothermal performance of the facade as such systems involve bringing large quantities of water onto the facade. As it is difficult to represent complex entities such as plants in the typical simulation tools used for heat and moisture transport, this study suggests a new approach to tackle this challenge by coupling two tools: ENVI-Met and Delphin. ENVI-Met was used to simulate the impact of the plants to determine the local environmental parameters at the living wall. Delphin, on the other hand, was used to conduct the hygrothermal simulations using the local parameters calculated by ENVI-Met. Four wall constructions were investigated in this study: an uninsulated brick wall, a precast concrete plate, a sandy limestone wall, and a double-shell wall. The results showed that the living wall improved the U-value, the exterior surface temperature, and the heat flux through the wall. Moreover, the living wall did not increase the risk of moisture in the wall during winter and eliminated the risk of condensation. KW - Feuchteleitung KW - Diffusionswärme KW - Heat transport KW - Moisture transport KW - Living wall KW - Delphin KW - ENVI-Met Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20240116-65299 UR - https://www.sciencedirect.com/science/article/pii/S0378778821009956 VL - 2022 IS - volume 255, article 111711 ER - TY - JOUR A1 - Alsaad, Hayder A1 - Hartmann, Maria A1 - Völker, Conrad T1 - Hygrothermal simulation data of a living wall system for decentralized greywater treatment JF - Data in Brief N2 - This dataset presents the numerical analysis of the heat and moisture transport through a facade equipped with a living wall system designated for greywater treatment. While such greening systems provide many environmental benefits, they involve pumping large quantities of water onto the wall assembly, which can increase the risk of moisture in the wall as well as impaired energetic performance due to increased thermal conductivity with increased moisture content in the building materials. This dataset was acquired through numerical simulation using the coupling of two simulation tools, namely Envi-Met and Delphin. This coupling was used to include the complex role the plants play in shaping the near-wall environmental parameters in the hygrothermal simulations. Four different wall assemblies were investigated, each assembly was assessed twice: with and without the living wall. The presented data include the input and output parameters of the simulations, which were presented in the co-submitted article [1]. KW - Kupplung KW - Feuchteleitung KW - Heat transport KW - Moisture transport KW - Living wall KW - Wärmeübertragung KW - coupling KW - ENVI-Met KW - Delphin KW - OA-Publikationsfonds2022 Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20220106-45483 UR - https://www.sciencedirect.com/science/article/pii/S2352340921010167?via%3Dihub VL - 2022 IS - volume 40, article 107741 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Alsaad, Hayder A1 - Schälte, Gereon A1 - Schneeweiß, Mario A1 - Becher, Lia A1 - Pollack, Moritz A1 - Gena, Amayu Wakoya A1 - Schweiker, Marcel A1 - Hartmann, Maria A1 - Voelker, Conrad A1 - Rossaint, Rolf A1 - Irrgang, Matthias T1 - The Spread of Exhaled Air and Aerosols during Physical Exercise JF - Journal of Clinical Medicine N2 - Physical exercise demonstrates a special case of aerosol emission due to its associated elevated breathing rate. This can lead to a faster spread of airborne viruses and respiratory diseases. Therefore, this study investigates cross-infection risk during training. Twelve human subjects exercised on a cycle ergometer under three mask scenarios: no mask, surgical mask, and FFP2 mask. The emitted aerosols were measured in a grey room with a measurement setup equipped with an optical particle sensor. The spread of expired air was qualitatively and quantitatively assessed using schlieren imaging. Moreover, user satisfaction surveys were conducted to evaluate the comfort of wearing face masks during training. The results indicated that both surgical and FFP2 masks significantly reduced particles emission with a reduction efficiency of 87.1% and 91.3% of all particle sizes, respectively. However, compared to surgical masks, FFP2 masks provided a nearly tenfold greater reduction of the particle size range with long residence time in the air (0.3–0.5 μm). Furthermore, the investigated masks reduced exhalation spreading distances to less than 0.15 m and 0.1 m in the case of the surgical mask and FFP2 mask, respectively. User satisfaction solely differed with respect to perceived dyspnea between no mask and FFP2 mask conditions. KW - Sport KW - Training KW - Fahrradergometer KW - sport KW - training KW - cycle ergometer KW - schlieren imaging KW - particles concentration KW - OA-Publikationsfonds2023 Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20230208-49262 UR - https://www.mdpi.com/2077-0383/12/4/1300 VL - 2023 IS - Volume 12, issue 4, article 1300 PB - Basel CY - MDPI ER - TY - JOUR A1 - Alsaad, Hayder A1 - Völker, Conrad T1 - Performance assessment of a ductless personalized ventilation system using a validated CFD model JF - Journal of Building Performance Simulation N2 - The aim of this study is twofold: to validate a computational fluid dynamics (CFD) model, and then to use the validated model to evaluate the performance of a ductless personalized ventilation (DPV) system. To validate the numerical model, a series of measurements was conducted in a climate chamber equipped with a thermal manikin. Various turbulence models, settings, and options were tested; simulation results were compared to the measured data to determine the turbulence model and solver settings that achieve the best agreement between the measured and simulated values. Subsequently, the validated CFD model was then used to evaluate the thermal environment and indoor air quality in a room equipped with a DPV system combined with displacement ventilation. Results from the numerical model were then used to quantify thermal sensation and comfort using the UC Berkeley thermal comfort model. KW - Ventilation KW - Validierung KW - Strömungsmechanik KW - Raumklima KW - personalized ventilation KW - validation KW - computational fluid dynamics KW - thermal comfort KW - indoor air quality Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20190218-38500 UR - https://www.tandfonline.com/doi/full/10.1080/19401493.2018.1431806 N1 - Copyright 2018 Taylor & Francis Group and the International Building Performance Simulation Association (IBPSA). This article may be downloaded for personal use only. Any other use requires prior permission of the authors and Taylor & Francis Group. This is an Accepted Manuscript of an article published by Taylor & Francis in the Journal of Building Performance Simulation 11 (6), 689–704 (2018) and may be found at https://doi.org/10.1080/19401493.2018.1431806 VL - 2018 IS - 11, Heft 6 SP - 689 EP - 704 ER - TY - JOUR A1 - Alsaad, Hayder A1 - Völker, Conrad T1 - Qualitative evaluation of the flow supplied by personalized ventilation using schlieren imaging and thermography JF - Building and Environment N2 - Personalized ventilation (PV) is a mean of delivering conditioned outdoor air into the breathing zone of the occupants. This study aims to qualitatively investigate the personalized flows using two methods of visualization: (1) schlieren imaging using a large schlieren mirror and (2) thermography using an infrared camera. While the schlieren imaging was used to render the velocity and mass transport of the supplied flow, thermography was implemented to visualize the air temperature distribution induced by the PV. Both studies were conducted using a thermal manikin to simulate an occupant facing a PV outlet. As a reference, the flow supplied by an axial fan and a cased axial fan was visualized with the schlieren system as well and compared to the flow supplied by PV. Schlieren visualization results indicate that the steady, low-turbulence flow supplied by PV was able to penetrate the thermal convective boundary layer encasing the manikin's body, providing clean air for inhalation. Contrarily, the axial fan diffused the supplied air over a large target area with high turbulence intensity; it only disturbed the convective boundary layer rather than destroying it. The cased fan supplied a flow with a reduced target area which allowed supplying more air into the breathing zone compared to the fan. The results of thermography visualization showed that the supplied cool air from PV penetrated the corona-shaped thermal boundary layer. Furthermore, the supplied air cooled the surface temperature of the face, which indicates the large impact of PV on local thermal sensation and comfort. KW - Bildverarbeitung KW - Photothermische Methode KW - Visualisierung KW - Belüftung KW - Lüftungsanlage KW - Schlieren imaging KW - Thermography KW - Visualization KW - Personalized ventilation KW - Axial fan Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20211008-45117 UR - https://www.sciencedirect.com/science/article/abs/pii/S0360132319306602?via%3Dihub N1 - This is the accepted manuscript of the article published by Elsevier in Building and Environment 167 (2020) 106450, which can be found at https://doi.org/10.1016/j.buildenv.2019.106450. VL - 2020 IS - Volume 167, article 106450 PB - Elsevier CY - New York ER - TY - JOUR A1 - Alsaad, Hayder A1 - Völker, Conrad T1 - Der Kühlungseffekt der personalisierten Lüftung T1 - The cooling effect of personalized ventilation systems JF - Bauphysik N2 - Personalisierte Lüftung (PL) kann die thermische Behaglichkeit sowie die Qualität der eingeatmeten Atemluft verbessern, in dem jedem Arbeitsplatz Frischluft separat zugeführt wird. In diesem Beitrag wird die Wirkung der PL auf die thermische Behaglichkeit der Nutzer unter sommerlichen Randbedingungen untersucht. Hierfür wurden zwei Ansätze zur Bewertung des Kühlungseffekts der PL untersucht: basierend auf (1) der äquivalenten Temperatur und (2) dem thermischen Empfinden. Grundlage der Auswertung sind in einer Klimakammer gemessene sowie numerisch simulierte Daten. Vor der Durchführung der Simulationen wurde das numerische Modell zunächst anhand der gemessenen Daten validiert. Die Ergebnisse zeigen, dass der Ansatz basierend auf dem thermischen Empfinden zur Evaluierung des Kühlungseffekts der PL sinnvoller sein kann, da bei diesem die komplexen physiologischen Faktoren besser berücksichtigt werden. N2 - Personalized ventilation (PV) can improve thermal comfort and inhaled air quality by supplying air to each workstation separately. This study investigates the impact of PV on the thermal state of the users under summer boundary conditions. Two approaches to evaluating the cooling effect of PV were investigated, based on equivalent temperature and based on thermal sensation. Both approaches implemented measured and simulated values of the cooling effect of PV. Before conducting the simulations, the numerical model was first validated against measured data collected in a climate chamber equipped with a thermal manikin. Results indicated that the thermal sensation approach can be more suitable for evaluating the cooling effect of PV due to the complex physiological factors it considers. KW - Lüftung KW - Strömung KW - Raumklima KW - Temperatur KW - personalized ventilation KW - computational fluid dynamics KW - Simulation KW - personalisierte Lüftung KW - äquivalente Temperatur KW - thermisches Empfinden Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20201020-42723 UR - https://onlinelibrary.wiley.com/doi/abs/10.1002/bapi.202000018 N1 - © 2020 Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Berlin. Dieser Artikel kann für den persönlichen Gebrauch heruntergeladen werden. Andere Verwendungen bedürfen der vorherigen Zustimmung der Autoren und des Verlags Ernst & Sohn. Der folgende Artikel erschien in der Bauphysik 42 (2020), Heft 5, 218-225, DOI: 10.1002/bapi.202000018 VL - 2020 IS - volume 42, issue 5 SP - 218 EP - 225 PB - Ernst & Sohn bei John Wiley & Sons CY - Hoboken ER - TY - JOUR A1 - Alsaad, Hayder A1 - Völker, Conrad T1 - Performance evaluation of ductless personalized ventilation in comparison with desk fans using numerical simulations JF - Indoor Air N2 - The performance of ductless personalized ventilation (DPV) was compared to the performance of a typical desk fan since they are both stand-alone systems that allow the users to personalize their indoor environment. The two systems were evaluated using a validated computational fluid dynamics (CFD) model of an office room occupied by two users. To investigate the impact of DPV and the fan on the inhaled air quality, two types of contamination sources were modelled in the domain: an active source and a passive source. Additionally, the influence of the compared systems on thermal comfort was assessed using the coupling of CFD with the comfort model developed by the University of California, Berkeley (UCB model). Results indicated that DPV performed generally better than the desk fan. It provided better thermal comfort and showed a superior performance in removing the exhaled contaminants. However, the desk fan performed better in removing the contaminants emitted from a passive source near the floor level. This indicates that the performance of DPV and desk fans depends highly on the location of the contamination source. Moreover, the simulations showed that both systems increased the spread of exhaled contamination when used by the source occupant. KW - Behaglichkeit KW - Raumklima KW - Strömungsmechanik KW - Fluid KW - computational fluid dynamics KW - desk fan KW - ductless personalized ventilation KW - IAQ KW - thermal comfort Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20200422-41407 UR - https://onlinelibrary.wiley.com/doi/full/10.1111/ina.12672 VL - 2020 PB - John Wiley & Sons Ltd ER - TY - JOUR A1 - Alsaad, Hayder A1 - Völker, Conrad T1 - Could the ductless personalized ventilation be an alternative to the regular ducted personalized ventilation? JF - Indoor Air N2 - This study investigates the performance of two systems: personalized ventilation (PV) and ductless personalized ventilation (DPV). Even though the literature indicates a compelling performance of PV, it is not often used in practice due to its impracticality. Therefore, the present study assesses the possibility of replacing the inflexible PV with DPV in office rooms equipped with displacement ventilation (DV) in the summer season. Numerical simulations were utilized to evaluate the inhaled concentration of pollutants when PV and DPV are used. The systems were compared in a simulated office with two occupants: a susceptible occupant and a source occupant. Three types of pollution were simulated: exhaled infectious air, dermally emitted contamination, and room contamination from a passive source. Results indicated that PV improved the inhaled air quality regardless of the location of the pollution source; a higher PV supply flow rate positively impacted the inhaled air quality. Contrarily, the performance of DPV was highly sensitive to the source location and the personalized flow rate. A higher DPV flow rate tends to decrease the inhaled air quality due to increased mixing of pollutants in the room. Moreover, both systems achieved better results when the personalized system of the source occupant was switched off. KW - Strömungsmechanik KW - Kontamination KW - Belüftung KW - Luftqualität KW - computational fluid dynamics KW - cross-contamination KW - ductless personalized ventilation KW - indoor air quality KW - tracer gas Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20200805-42072 UR - https://onlinelibrary.wiley.com/doi/full/10.1111/ina.12720 VL - 2020 PB - John Wiley & Sons Ltd ER - TY - JOUR A1 - Amani, Jafar A1 - Bagherzadeh, Amir Saboor A1 - Rabczuk, Timon T1 - Error estimate and adaptive refinement in Mixed Discrete Least Squares Meshless method JF - Mathematical Problems in Engineering N2 - Error estimate and adaptive refinement in Mixed Discrete Least Squares Meshless method KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 ER - TY - JOUR A1 - Amani, Jafar A1 - Saboor Bagherzadeh, Amir A1 - Rabczuk, Timon T1 - Error estimate and adaptive refinement in mixed discrete least squares meshless method JF - Mathematical Problems in Engineering N2 - The node moving and multistage node enrichment adaptive refinement procedures are extended in mixed discrete least squares meshless (MDLSM) method for efficient analysis of elasticity problems. In the formulation of MDLSM method, mixed formulation is accepted to avoid second-order differentiation of shape functions and to obtain displacements and stresses simultaneously. In the refinement procedures, a robust error estimator based on the value of the least square residuals functional of the governing differential equations and its boundaries at nodal points is used which is inherently available from the MDLSM formulation and can efficiently identify the zones with higher numerical errors. The results are compared with the refinement procedures in the irreducible formulation of discrete least squares meshless (DLSM) method and show the accuracy and efficiency of the proposed procedures. Also, the comparison of the error norms and convergence rate show the fidelity of the proposed adaptive refinement procedures in the MDLSM method. KW - Elastizität KW - Fehlerabschätzung KW - MDLSM method Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170413-31181 ER - TY - JOUR A1 - Amiri, Fatemeh A1 - Millán, D. A1 - Shen, Y. A1 - Rabczuk, Timon A1 - Arroyo, M. T1 - Phase-field modeling of fracture in linear thin shells JF - Theoretical and Applied Fracture Mechanics N2 - Phase-field modeling of fracture in linear thin shells KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 SP - 102 EP - 109 ER - TY - JOUR A1 - Amirinasab, Mehdi A1 - Shamshirband, Shahaboddin A1 - Chronopoulos, Anthony Theodore A1 - Mosavi, Amir A1 - Nabipour, Narjes T1 - Energy‐Efficient Method for Wireless Sensor Networks Low‐Power Radio Operation in Internet of Things JF - electronics N2 - The radio operation in wireless sensor networks (WSN) in Internet of Things (IoT)applications is the most common source for power consumption. Consequently, recognizing and controlling the factors affecting radio operation can be valuable for managing the node power consumption. Among essential factors affecting radio operation, the time spent for checking the radio is of utmost importance for monitoring power consumption. It can lead to false WakeUp or idle listening in radio duty cycles and ContikiMAC. ContikiMAC is a low‐power radio duty‐cycle protocol in Contiki OS used in WakeUp mode, as a clear channel assessment (CCA) for checking radio status periodically. This paper presents a detailed analysis of radio WakeUp time factors of ContikiMAC. Furthermore, we propose a lightweight CCA (LW‐CCA) as an extension to ContikiMAC to reduce the Radio Duty‐Cycles in false WakeUps and idle listening though using dynamic received signal strength indicator (RSSI) status check time. The simulation results in the Cooja simulator show that LW‐CCA reduces about 8% energy consumption in nodes while maintaining up to 99% of the packet delivery rate (PDR). KW - Internet der Dinge KW - Internet of things KW - wireless sensor networks KW - ContikiMAC KW - energy efficiency KW - duty-cycles KW - clear channel assessments KW - fog computing KW - smart sensors KW - signal processing KW - received signal strength indicator KW - OA-Publikationsfonds2020 KW - RSSI Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20200213-40954 UR - https://www.mdpi.com/2079-9292/9/2/320 VL - 2020 IS - volume 9, issue 2, 320 PB - MDPI ER - TY - JOUR A1 - Anders, Frauke A1 - König, Reinhard T1 - Analyse und Generierung von Straßennetzwerken mittels graphenbasierter Methoden N2 - Der vorliegende Beitrag ist in zwei thematische Teilebereiche gegliedert. Der erste Teil beschäftigt sich mit der Analyse von Graphen, insbesondere von Graphen, die Straßennetzwerke repräsentieren. Hierzu werden Methoden aus der Graphentheorie angewendet und Kenngrößen aus der Space Syntax Methode ausgewertet. Ein Framework, welches basierend auf der Graphentheorie in Architektur und Stadtplanung Einzug gehalten hat, ist die Space Syntax Methode. Sie umfasst die Ableitung unterschiedlicher Kenngrößen eines Graphen bzw. Netzwerkes, wodurch eine Analyse für architektonische und stadtplanerische Zwecke ermöglicht wird. Der zweite Teil dieses Berichts beschäftigt sich mit der Generierung von Graphen, insbe-sondere der von Straßennetzwerkgraphen. Die generativen Methoden basieren zum Teil auf den gewonnenen Erkenntnissen der Analyse von Straßennetzwerken. Es werden unterschiedliche Ansätze untersucht, um verschiedene Parameterwerte zur Generierung von Straßengraphen festzulegen. Als Ergebnis der Arbeiten ist ein Softwaretool entstanden, welches es erlaubt, auf Grundlage einer Voronoi-Tesselierung realistische Straßennetzwerkgraphen zu erzeugen. T3 - Arbeitspapiere Informatik in der Architektur - Nr. 7 KW - Graph KW - Straßennetzwerk analyse, graph-basierte generative Methoden Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20120509-16514 UR - http://infar.architektur.uni-weimar.de/service/drupal-infar/Arbeitspapiere ER - TY - JOUR A1 - Anic, Filip A1 - Penava, Davorin A1 - Sarhosis, Vasilis A1 - Abrahamczyk, Lars T1 - Development and Calibration of a 3D Micromodel for Evaluation of Masonry Infilled RC Frame Structural Vulnerability to Earthquakes JF - Geosciences N2 - Within the scope of literature, the influence of openings within the infill walls that are bounded by a reinforced concrete frame and excited by seismic drift forces in both in- and out-of-plane direction is still uncharted. Therefore, a 3D micromodel was developed and calibrated thereafter, to gain more insight in the topic. The micromodels were calibrated against their equivalent physical test specimens of in-plane, out-of-plane drift driven tests on frames with and without infill walls and openings, as well as out-of-plane bend test of masonry walls. Micromodels were rectified based on their behavior and damage states. As a result of the calibration process, it was found that micromodels were sensitive and insensitive to various parameters, regarding the model’s behavior and computational stability. It was found that, even within the same material model, some parameters had more effects when attributed to concrete rather than on masonry. Generally, the in-plane behavior of infilled frames was found to be largely governed by the interface material model. The out-of-plane masonry wall simulations were governed by the tensile strength of both the interface and masonry material model. Yet, the out-of-plane drift driven test was governed by the concrete material properties. KW - Verwundbarkeit KW - Ausfachung KW - Stahlbeton KW - RC frames KW - unreinforced masonry infill walls KW - openings KW - structural vulnerability KW - out-of-plane seismic load KW - OA-Publikationsfonds2021 Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20211202-45370 UR - https://www.mdpi.com/2076-3263/11/11/468 VL - 2021 IS - Voume 11, issue 11, article 468 PB - MDPI CY - Basel ER - TY - JOUR A1 - Anitescu, Cosmin A1 - Jia, Yue A1 - Zhang, Yongjie A1 - Rabczuk, Timon T1 - An isogeometric collocation method using superconvergent points JF - Computer Methods in Applied Mechanics and Engineer-ing N2 - An isogeometric collocation method using superconvergent points KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2015 SP - 1073 EP - 1097 ER - TY - JOUR A1 - Ansari, Meisam A1 - Tartaglione, Fabiola A1 - Könke, Carsten T1 - Experimental Validation of Dynamic Response of Small-Scale Metaconcrete Beams at Resonance Vibration JF - materials N2 - Structures and their components experience substantially large vibration amplitudes at resonance, which can cause their failure. The scope of this study is the utilization of silicone-coated steel balls in concrete as damping aggregates to suppress the resonance vibration. The heavy steel cores oscillate with a frequency close to the resonance frequency of the structure. Due to the phase difference between the vibrations of the cores and the structure, the cores counteract the vibration of the structure. The core-coating inclusions are randomly distributed in concrete similar to standard aggregates. This mixture is referred to as metaconcrete. The main goal of this work is to validate the ability of the inclusions to suppress mechanical vibration through laboratory experiments. For this purpose, two small-scale metaconcrete beams were cast and tested. In a free vibration test, the metaconcrete beams exhibited a larger damping ratio compared to a similar beam cast from conventional concrete. The vibration amplitudes of the metaconcrete beams at resonance were measured with a frequency sweep test. In comparison with the conventional concrete beam, both metaconcrete beams demonstrated smaller vibration amplitudes. Both experiments verified an improvement in the dynamic response of the metaconcrete beams at resonance vibration. KW - Beton KW - metaconcrete KW - Schwingungsdämpfung KW - damping aggregate KW - vibration absorber KW - free vibration test KW - frequency sweep test Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20230818-64154 UR - https://www.mdpi.com/1996-1944/16/14/5029 VL - 2023 IS - volume 16, issue 14, article 5029 SP - 1 EP - 17 PB - MDPI CY - Basel ER - TY - JOUR A1 - Ansari, Meisam A1 - Zacharias, Christin A1 - Könke, Carsten T1 - Metaconcrete: An Experimental Study on the Impact of the Core-Coating Inclusions on Mechanical Vibration JF - materials N2 - Resonance vibration of structures is an unpleasant incident that can be conventionally avoided by using a Tuned Mass Damper (TMD). The scope of this paper contains the utilization of engineered inclusions in concrete as damping aggregates to suppress resonance vibration similar to a TMD. The inclusions are composed of a stainless-steel core with a spherical shape coated with silicone. This configuration has been the subject of several studies and it is best known as Metaconcrete. This paper presents the procedure of a free vibration test conducted with two small-scaled concrete beams. The beams exhibited a higher damping ratio after the core-coating element was secured to them. Subsequently, two meso-models of small-scaled beams were created: one representing conventional concrete and the other representing concrete with the core-coating inclusions. The frequency response curves of the models were obtained. The change in the response peak verified the ability of the inclusions to suppress the resonance vibration. This study concludes that the core-coating inclusions can be utilized in concrete as damping aggregates. KW - Beton KW - Schwingungsdämpfung KW - metaconcrete KW - damping aggregate KW - vibration absorber Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20230315-49370 UR - https://www.mdpi.com/1996-1944/16/5/1836 VL - 2023 IS - Volume 16, Issue 5, article 1836 SP - 1 EP - 18 PB - MDPI CY - Basel ER - TY - JOUR A1 - Arash, Behrouz A1 - Rabczuk, Timon A1 - Jiang, Jin-Wu T1 - Nanoresonators and their applications: a state of the art review JF - Applied Physics Reviews N2 - Nanoresonators and their applications: a state of the art review KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2015 ER - TY - JOUR A1 - Areias, Pedro A1 - Pinto da Costa, A. A1 - Rabczuk, Timon A1 - Queiros de Melo, F. J. M. A1 - Dias-da-Costa, D. T1 - An alternative formulation for quasi-static frictional and cohesive contact problems JF - Computational Mechanics N2 - An alternative formulation for quasi-static frictional and cohesive contact problems KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 SP - 807 EP - 824 ER - TY - JOUR A1 - Areias, Pedro A1 - Rabczuk, Timon T1 - Finite strain fracture of plates and shells with configurational forces and edge rotation JF - International Journal for Numerical Methods in Engineering N2 - Finite strain fracture of plates and shells with configurational forces and edge rotation KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2013 ER - TY - JOUR A1 - Areias, Pedro A1 - Rabczuk, Timon A1 - Barbosa, J.I. T1 - The extended unsymmetric frontal solution for multiple-point constraints JF - Engineering Computations N2 - The extended unsymmetric frontal solution for multiple-point constraints KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 ER - TY - JOUR A1 - Areias, Pedro A1 - Rabczuk, Timon A1 - Camanho, P.P. T1 - Finite strain fracture of 2D problems with injected anisotropic softening elements JF - Theoretical and Applied Fracture Mechanics N2 - Finite strain fracture of 2D problems with injected anisotropic softening elements KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 ER - TY - JOUR A1 - Areias, Pedro A1 - Rabczuk, Timon A1 - Cesar de Sa, J.M. A1 - Garcao, J.E. T1 - Finite strain quadrilateral shell using least-squares _t of relative Lagrangian in-plane strains JF - Finite Elements in Analysis and Design N2 - Finite strain quadrilateral shell using least-squares _t of relative Lagrangian in-plane strains KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2015 SP - 26 EP - 40 ER - TY - JOUR A1 - Areias, Pedro A1 - Rabczuk, Timon A1 - Cesar de Sa, J.M. A1 - Jorge, R.N. T1 - A semi-implicit _nite strain shell algorithm using in-plane strains based on least-squares JF - Computational Mechanics N2 - A semi-implicit _nite strain shell algorithm using in-plane strains based on least-squares KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2015 ER -