@inproceedings{ElMoussaouiKassmiAlexopoulosetal.2021, author = {El Moussaoui, Noureddine and Kassmi, Khalil and Alexopoulos, Spiros and Schwarzer, Klemens and Chayeb, Hamid and Bachiri, Najib}, title = {Simulation studies on a new innovative design of a hybrid solar distiller MSDH alimented with a thermal and photovoltaic energy}, series = {Materialstoday: Proceedings}, volume = {45}, booktitle = {Materialstoday: Proceedings}, number = {8}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2214-7853}, doi = {10.1016/j.matpr.2021.03.115}, pages = {7653 -- 7660}, year = {2021}, abstract = {In this paper, we present the structure, the simulation the operation of a multi-stage, hybrid solar desalination system (MSDH), powered by thermal and photovoltaic (PV) (MSDH) energy. The MSDH system consists of a lower basin, eight horizontal stages, a field of four flat thermal collectors with a total area of 8.4 m2, 3 Kw PV panels and solar batteries. During the day the system is heated by thermal energy, and at night by heating resistors, powered by solar batteries. These batteries are charged by the photovoltaic panels during the day. More specifically, during the day and at night, we analyse the temperature of the stages and the production of distilled water according to the solar irradiation intensity and the electric heating power, supplied by the solar batteries. The simulations were carried out in the meteorological conditions of the winter month (February 2020), presenting intensities of irradiance and ambient temperature reaching 824 W/m2 and 23 °C respectively. The results obtained show that during the day the system is heated by the thermal collectors, the temperature of the stages and the quantity of water produced reach 80 °C and 30 Kg respectively. At night, from 6p.m. the system is heated by the electric energy stored in the batteries, the temperature of the stages and the quantity of water produced reach respectively 90 °C and 104 Kg for an electric heating power of 2 Kw. Moreover, when the electric power varies from 1 Kw to 3 Kw the quantity of water produced varies from 92 Kg to 134 Kg. The analysis of these results and their comparison with conventional solar thermal desalination systems shows a clear improvement both in the heating of the stages, by 10\%, and in the quantity of water produced by a factor of 3.}, language = {en} } @article{BialonskiCaronSchloenetal.2016, author = {Bialonski, Stephan and Caron, David A. and Schloen, Julia and Feudel, Ulrike and Kantz, Holger and Moorthi, Stefanie D.}, title = {Phytoplankton dynamics in the Southern California Bight indicate a complex mixture of transport and biology}, series = {Journal of Plankton Research}, volume = {38}, journal = {Journal of Plankton Research}, number = {4}, publisher = {Oxford University Press}, address = {Oxford}, issn = {1464-3774}, doi = {10.1093/plankt/fbv122}, pages = {1077 -- 1091}, year = {2016}, abstract = {The stimulation and dominance of potentially harmful phytoplankton taxa at a given locale and time are determined by local environmental conditions as well as by transport to or from neighboring regions. The present study investigated the occurrence of common harmful algal bloom (HAB) taxa within the Southern California Bight, using cross-correlation functions to determine potential dependencies between HAB taxa and environmental factors, and potential links to algal transport via local hydrography and currents. A simulation study, in which Lagrangian particles were released, was used to assess travel times due to advection by prevailing ocean currents in the bight. Our results indicate that transport of some taxa may be an important mechanism for the expansion of their distributions into other regions, which was supported by mean travel times derived from our simulation study and other literature on ocean currents in the Southern California Bight. In other cases, however, phytoplankton dynamics were rather linked to local environmental conditions, including coastal upwelling events. Overall, our study shows that complex current patterns in the Southern California Bight may contribute significantly to the formation and expansion of HABs in addition to local environmental factors determining the spatiotemporal dynamics of phytoplankton blooms.}, language = {en} } @incollection{BrittenBraunHesseetal.2003, author = {Britten, G. and Braun, Carsten and Hesse, M. and Ballmann, Josef}, title = {Computational aeroelasticity with reduced structural models}, series = {Flow modulation and fluid-structure interaction at airplane wings : research results of the Collaborative Research Center SFB 401 at RWTH Aachen, University of Technology, Aachen, Germany / Josef Ballmann (Ed.) Notes on numerical fluid mechanics and multidisciplinary design. Vol. 84}, booktitle = {Flow modulation and fluid-structure interaction at airplane wings : research results of the Collaborative Research Center SFB 401 at RWTH Aachen, University of Technology, Aachen, Germany / Josef Ballmann (Ed.) Notes on numerical fluid mechanics and multidisciplinary design. Vol. 84}, publisher = {Springer}, address = {Berlin}, isbn = {3-540-40209-8}, pages = {275 -- 299}, year = {2003}, language = {en} } @article{AlexopoulosBreitbachHoffschmidtetal.2008, author = {Alexopoulos, Spiros and Breitbach, Gerd and Hoffschmidt, Bernhard and Stobbe, P.}, title = {Computational fluid flow of porous resic ceramic filtering modules and optimization of the channel edge form geometry}, series = {Proceedings : April 14 - 18, 2008, Leipzig, Germany / hosted by VDI, Society for Chemical and Process Engineering . Vol 2}, journal = {Proceedings : April 14 - 18, 2008, Leipzig, Germany / hosted by VDI, Society for Chemical and Process Engineering . Vol 2}, publisher = {Filtech Exhibitions}, address = {Meerbusch}, pages = {300 -- 304}, year = {2008}, language = {en} } @article{RaffeisAdjeiKyeremehVroomenetal.2020, author = {Raffeis, Iris and Adjei-Kyeremeh, Frank and Vroomen, Uwe and Westhoff, Elmar and Bremen, Sebastian and Hohoi, Alexandru and B{\"u}hrig-Polaczek, Andreas}, title = {Qualification of a Ni-Cu alloy for the laser powder bed fusion process (LPBF): Its microstructure and mechanical properties}, series = {Applied Sciences}, volume = {10}, journal = {Applied Sciences}, number = {Art. 3401}, publisher = {MDPI}, address = {Basel}, issn = {2076-3417}, doi = {10.3390/app10103401}, pages = {1 -- 15}, year = {2020}, abstract = {As researchers continue to seek the expansion of the material base for additive manufacturing, there is a need to focus attention on the Ni-Cu group of alloys which conventionally has wide industrial applications. In this work, the G-NiCu30Nb casting alloy, a variant of the Monel family of alloys with Nb and high Si content is, for the first time, processed via the laser powder bed fusion process (LPBF). Being novel to the LPBF processes, optimum LPBF parameters were determined, and hardness and tensile tests were performed in as-built conditions and after heat treatment at 1000 °C. Microstructures of the as-cast and the as-built condition were compared. Highly dense samples (99.8\% density) were achieved after varying hatch distance (80 µm and 140 µm) with scanning speed (550 mm/s-1500 mm/s). There was no significant difference in microhardness between varied hatch distance print sets. Microhardness of the as-built condition (247 HV0.2) exceeded the as-cast microhardness (179 HV0.2.). Tensile specimens built in vertical (V) and horizontal (H) orientations revealed degrees of anisotropy and were superior to conventionally reported figures. Post heat treatment increased ductility from 20\% to 31\% (V), as well as from 16\% to 25\% (H), while ultimate tensile strength (UTS) and yield strength (YS) were considerably reduced.}, language = {en} } @inproceedings{WalterElsenMuelleretal.1999, author = {Walter, Peter and Elsen, Ingo and M{\"u}ller, Holger and Kraiss, Karl-Friedrich}, title = {3D object recognition with a specialized mixtures of experts architecture}, series = {IJCNN'99. International Joint Conference on Neural Networks. Proceedings}, booktitle = {IJCNN'99. International Joint Conference on Neural Networks. Proceedings}, publisher = {IEEE}, address = {New York}, isbn = {0-7803-5529-6}, issn = {1098-7576}, doi = {10.1109/IJCNN.1999.836243}, pages = {3563 -- 3568}, year = {1999}, abstract = {Aim of the AXON2 project (Adaptive Expert System for Object Recogniton using Neuml Networks) is the development of an object recognition system (ORS) capable of recognizing isolated 3d objects from arbitrary views. Commonly, classification is based on a single feature extracted from the original image. Here we present an architecture adapted from the Mixtures of Eaqerts algorithm which uses multiple neuml networks to integmte different features. During tmining each neural network specializes in a subset of objects or object views appropriate to the properties of the corresponding feature space. In recognition mode the system dynamically chooses the most relevant features and combines them with maximum eficiency. The remaining less relevant features arz not computed and do therefore not decelerate the-recognition process. Thus, the algorithm is well suited for ml-time applications.}, language = {en} } @article{ElsenKraiss1999, author = {Elsen, Ingo and Kraiss, Karl-Friedrich}, title = {System concept and realization of a scalable neurocomputing architecture}, series = {Systems Analysis Modelling Simulation}, volume = {35}, journal = {Systems Analysis Modelling Simulation}, number = {4}, publisher = {Gordon and Breach Science Publishers}, address = {Amsterdam}, issn = {0232-9298}, pages = {399 -- 419}, year = {1999}, abstract = {This paper describes the realization of a novel neurocomputer which is based on the concepts of a coprocessor. In contrast to existing neurocomputers the main interest was the realization of a scalable, flexible system, which is capable of computing neural networks of arbitrary topology and scale, with full independence of special hardware from the software's point of view. On the other hand, computational power should be added, whenever needed and flexibly adapted to the requirements of the application. Hardware independence is achieved by a run time system which is capable of using all available computing power, including multiple host CPUs and an arbitrary number of neural coprocessors autonomously. The realization of arbitrary neural topologies is provided through the implementation of the elementary operations which can be found in most neural topologies.}, language = {en} } @article{ElsenKraissKrumbiegeletal.1999, author = {Elsen, Ingo and Kraiss, Karl-Friedrich and Krumbiegel, Dirk and Walter, Peter and Wickel, Jochen}, title = {Visual information retrieval for 3D product identification: a midterm report}, series = {KI - K{\"u}nstliche Intelligenz}, volume = {13}, journal = {KI - K{\"u}nstliche Intelligenz}, number = {1}, publisher = {Springer}, address = {Berlin}, issn = {1610-1987}, pages = {64 -- 67}, year = {1999}, language = {en} } @inproceedings{Elsen1998, author = {Elsen, Ingo}, title = {A pixel based approach to view based object recognition with self-organizing neural networks}, series = {IECON'98. Proceedings of the 24th Annual Conference of the IEEE Industrial Electronics Society}, booktitle = {IECON'98. Proceedings of the 24th Annual Conference of the IEEE Industrial Electronics Society}, publisher = {IEEE}, address = {New York}, isbn = {0-7803-4503-7}, doi = {10.1109/IECON.1998.724032}, pages = {2040 -- 2044}, year = {1998}, abstract = {This paper addresses the pixel based classification of three dimensional objects from arbitrary views. To perform this task a coding strategy, inspired by the biological model of human vision, for pixel data is described. The coding strategy ensures that the input data is invariant against shift, scale and rotation of the object in the input domain. The image data is used as input to a class of self organizing neural networks, the Kohonen-maps or self-organizing feature maps (SOFM). To verify this approach two test sets have been generated: the first set, consisting of artificially generated images, is used to examine the classification properties of the SOFMs; the second test set examines the clustering capabilities of the SOFM when real world image data is applied to the network after it has been preprocessed to be invariant against shift, scale and rotation. It is shown that the clustering capability of the SOFM is strongly dependant on the invariance coding of the images.}, language = {en} } @inproceedings{ElsenKraissKrumbiegel1997, author = {Elsen, Ingo and Kraiss, Karl-Friedrich and Krumbiegel, Dirk}, title = {Pixel based 3D object recognition with bidirectional associative memories}, series = {International Conference on Neural Networks 1997}, booktitle = {International Conference on Neural Networks 1997}, publisher = {IEEE}, address = {New York}, isbn = {0-7803-4122-8}, pages = {1679 -- 1684}, year = {1997}, abstract = {This paper addresses the pixel based recognition of 3D objects with bidirectional associative memories. Computational power and memory requirements for this approach are identified and compared to the performance of current computer architectures by benchmarking different processors. It is shown, that the performance of special purpose hardware, like neurocomputers, is between one and two orders of magnitude higher than the performance of mainstream hardware. On the other hand, the calculation of small neural networks is performed more efficiently on mainstream processors. Based on these results a novel concept is developed, which is tailored for the efficient calculation of bidirectional associative memories. The computational efficiency is further enhanced by the application of algorithms and storage techniques which are matched to characteristics of the application at hand.}, language = {en} }