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See detail§ 36. Die Pädagogik
Oelkers, Jürgen; Tröhler, Daniel UL

in Holzhey, Helmut; Mudroch, Vilem (Eds.) Die Philosophie des 18. Jahrhunderts 5/1+2: Heiliges Römische Reich Deutscher Nation. Schweiz. Nord- und Osteuropa (2014)

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See detail3D Beamforming for Spectral Coexistence of Satellite and Terrestrial Networks
Sharma, Shree Krishna UL; Chatzinotas, Symeon UL; Grotz, Joel et al

in IEEE Vehicular Technology Conference 2015 (2015, September)

Satellite communication (SatCom) is facing a spectrum scarcity problem due to the limited available exclusive spectrum and the high demand of the broadband satellite services. In this context, there has ... [more ▼]

Satellite communication (SatCom) is facing a spectrum scarcity problem due to the limited available exclusive spectrum and the high demand of the broadband satellite services. In this context, there has been an increasing interest in the satellite community to exploit the non-exclusive Ka-band spectrum in order to enhance the spectral efficiency of future broadband satellite systems. Herein, we propose a novel concept of enabling the spectral coexistence of satellite and terrestrial networks using three dimensional (3D) beamforming, which exploits the elevation dimension in addition to the commonly used azimuth dimension. The proposed beamforming solution is employed in a Multiple-Input Low Noise Block Downconverter (MLNB) based Feed Array Reflector (FAR) in contrast to the widely used Uniform Linear Array (ULA) structure. Within the employed antenna structure, the performance of the proposed beamforming solution is evaluated considering different feed arrangements. Finally, a database-assisted approach and two blind approaches are suggested for the effective implementation of the proposed solutions. [less ▲]

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See detail3D Crack Detection Using an XFEM Variant and Global Optimization Algorithms
Agathos, Konstantinos UL; Chatzi, Eleni; Bordas, Stéphane UL

Scientific Conference (2016, May)

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See detail3D Cultures of Parkinson's Disease‐Specific Dopaminergic Neurons for High Content Phenotyping and Drug Testing
Bolognin, Silvia UL; Fossépré, Marie; Qing, Xiaobing et al

in Advanced Science (2018)

Parkinson's disease (PD)‐specific neurons, grown in standard 2D cultures, typically only display weak endophenotypes. The cultivation of PD patient‐specific neurons, derived from induced pluripotent stem ... [more ▼]

Parkinson's disease (PD)‐specific neurons, grown in standard 2D cultures, typically only display weak endophenotypes. The cultivation of PD patient‐specific neurons, derived from induced pluripotent stem cells carrying the LRRK2‐G2019S mutation, is optimized in 3D microfluidics. The automated image analysis algorithms are implemented to enable pharmacophenomics in disease‐relevant conditions. In contrast to 2D cultures, this 3D approach reveals robust endophenotypes. High‐content imaging data show decreased dopaminergic differentiation and branching complexity, altered mitochondrial morphology, and increased cell death in LRRK2‐G2019S neurons compared to isogenic lines without using stressor agents. Treatment with the LRRK2 inhibitor 2 (Inh2) rescues LRRK2‐G2019S‐dependent dopaminergic phenotypes. Strikingly, a holistic analysis of all studied features shows that the genetic background of the PD patients, and not the LRRK2‐G2019S mutation, constitutes the strongest contribution to the phenotypes. These data support the use of advanced in vitro models for future patient stratification and personalized drug development. [less ▲]

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See detail3D DEM – FEM Coupling to Analyse the Tractive Performance of Different Tire Treads in Soil
Michael, Mark UL; Peters, Bernhard UL

in Idelsohn, S; Papadrakakis, M; Schrefler, B (Eds.) Computational Methods for Coupled Problems in Science and Engineering V (2013, June)

This contribution investigates the tractive performance of different tire treads on granular terrain by an efficient combination of the Discrete Element Method (DEM) and the Finite Element Method (FEM ... [more ▼]

This contribution investigates the tractive performance of different tire treads on granular terrain by an efficient combination of the Discrete Element Method (DEM) and the Finite Element Method (FEM). The proposed coupling method has been shown to be a sufficient technique when resolving the different length scales involved in engineering problems dealing with granular assemblies in contact with deformable bodies [1][2]. Herein, the extended discrete element method (XDEM) is used to describe the dynamics of the granular assembly. Thereby the discrete approach accounts for the motion and forces of each grain individually. On the other hand, the finite element method accurately predicts the deformations and stresses acting within the tire tread. Hence, the simulation domain occupied by the tire is efficiently described as a continuous entity. The coupling of both method is based on the interface shared by the two spatially separated domains. The interface coupling enables to apply a contact model fitting the particular contact behaviour between the grains and the tread surface. Thus, contact forces develop at the interface and propagate into each domain. The coupling method enables to capture both responses simultaneously. Each grain in contact with the tread surface generates a contact force which it reacts on repulsively. The contact forces sum up over the surface and cause the tire tread to deform. The resultant stresses are then again recognised by the granular assembly. The coupling method compensates quite naturally the shortages of both numerical methods. It further employs a fast contact detection algorithm to spare valuable computation time [1]. The proposed DEM-FEM Coupling technique was employed to study the tractive performance of four different tire treads on a soil layer of the material sand. The simulations were conducted in accordance to the experimental measurements undertaken by Shinone et al. [3]. The contact forces at the surface of smooth, lug, rib and block tread patterns are captured by 3D simulations of different slip values of each tire tread. The simulation results are used to analyse the gross tractive effort, running resistance and drawbar pull of the different tread patterns in sand. [less ▲]

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See detail3D fatigue fracture modeling by isogeometric boundary element methods
Peng, Xuan; Atroshchenko, Elena; Kerfriden, Pierre et al

Scientific Conference (2016, April 01)

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See detail3D meso-scale modelling of foamed concrete based on X-ray Computed Tomography
Nguyen, Tuan; Ghazlan, Abdallah; Kashani, Alireza et al

in Construction and Building Materials (2018), 188

Foamed concrete has been widely used in infrastructure construction and poses new challenges to design and modelling. This paper investigates the behaviour of foamed concrete with the help of X-ray ... [more ▼]

Foamed concrete has been widely used in infrastructure construction and poses new challenges to design and modelling. This paper investigates the behaviour of foamed concrete with the help of X-ray Computed Tomography (XCT), which is capable of characterising the microstructure of foamed concrete. An in situ compressive test-XCT scan is carried out to observe the failure mechanism of foamed concrete by XCT when subjected to compression load. A meso-scale simulation based on XCT images is conducted to simulate the behaviour of foamed concrete. An algorithm that directly reconstructs the meso-scale model from XCT images is developed. The experimental and numerical results show that foamed concrete exhibits a significant change in mechanical behaviour; it is less brittle compared to the response of dense samples. However, the reduction in the level of brittleness is accompanied by a significant decrease in compressive strength. Failure development inside samples is successfully captured by the XCT scan and the meso-scale modelling. The topology of foamed structures, in particular the chain of interconnected pores, influences the failure mechanism of foamed concrete. The combination of XCT scan and meso-scale modelling provides a comprehensive framework to understand the mechanical behaviour of foamed concrete. [less ▲]

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See detail3D Mixed Invariant and its Application on Object Classification
Feng, Shuo; Aouada, Djamila UL; Krim, Hamid et al

in IEEE International Conference on Acoustics, Speech and Signal Processing, 2007. ICASSP 2007 (2007, April)

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See detail3D Modellierung von Festbettreaktoren mit Hilfe der XDEM
Hoffmann, Florian UL

Presentation (2013, July 05)

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See detail3D Modelling of bored tunnels
Van Baars, Stefan UL

in Brinkgreve (Ed.) Proc. Int. Symposium Beyond 2000 in Computational Geotechnics (1999)

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See detail3D object following based on visual information for Unmanned Aerial Vehicles
Mondragón, I. F.; Campoy, P.; Olivares Mendez, Miguel Angel UL et al

in Robotics Symposium, 2011 IEEE IX Latin American and IEEE Colombian Conference on Automatic Control and Industry Applications (LARC) (2011)

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See detail3D Object Recognition Using Fully Intrinsic Skeletal Graphs
Aouada, Djamila UL; Krim, Hamid

in International Conference on Computational Imaging, 2008 (2008, February)

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See detail3D organotypic cultures of human HepaRG cells: a tool for in vitro toxicity studies.
Gunness, Patrina; Mueller, Daniel; Shevchenko, Valery et al

in Toxicological sciences : an official journal of the Society of Toxicology (2013), 133(1), 67-78

Drug-induced human hepatotoxicity is difficult to predict using the current in vitro systems. In this study, long-term 3D organotypic cultures of the human hepatoma HepaRG cell line were prepared using a ... [more ▼]

Drug-induced human hepatotoxicity is difficult to predict using the current in vitro systems. In this study, long-term 3D organotypic cultures of the human hepatoma HepaRG cell line were prepared using a high-throughput hanging drop method. The organotypic cultures were maintained for 3 weeks and assessed for (1) liver specific functions, including phase I enzyme and transporter activities, (2) expression of liver-specific proteins, and (3) responses to three drugs (acetaminophen, troglitazone, and rosiglitazone). Our results show that the organotypic cultures maintain high liver-specific functionality during 3 weeks of culture. The immunohistochemistry analyses illustrate that the organotypic cultures express liver-specific markers such as albumin, CYP3A4, CYP2E1, and MRP-2 throughout the cultivation period. Accordingly, the production rates of albumin and glucose, as well as CYP2E1 activity, were significantly higher in the 3D versus the 2D cultures. Toxicity studies show that the organotypic cultures are more sensitive to acetaminophen- and rosiglitazone-induced toxicity but less sensitive to troglitazone-induced toxicity than the 2D cultures. Furthermore, the EC50 value (2.7mM) for acetaminophen on the 3D cultures was similar to in vivo toxicity. In summary, the results from our study suggest that the 3D organotypic HepaRG culture is a promising in vitro tool for more accurate assessment of acute and also possibly for chronic drug-induced hepatotoxicity. [less ▲]

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See detail3D organotypic HepaRG cultures as in vitro model for acute and repeated dose toxicity studies.
Mueller, Daniel; Kramer, Lisa; Hoffmann, Esther et al

in Toxicology in vitro : an international journal published in association with BIBRA (2014), 28(1), 104-12

Predictive in vitro models alternative to in vivo animal will have a significant impact in toxicology. Conventional 2D models do not reflect the complexity of a 3D organ resulting in discrepancies between ... [more ▼]

Predictive in vitro models alternative to in vivo animal will have a significant impact in toxicology. Conventional 2D models do not reflect the complexity of a 3D organ resulting in discrepancies between experimental in vitro and in vivo data. Using 3D HepaRG organotypic cultures we tested four drugs (aflatoxin B1, amiodarone, valproic acid and chlorpromazine) for toxic effects and compared the results with 2D HepaRG and HepG2 cultures. We show that 3D HepaRG cultures are more sensitive than the other tested cultures to aflatoxin B1 which is only toxic upon metabolic activation in the liver. We observed that CYP3A4 activity is higher in the 3D HepaRG cultures compared to the 2D HepaRG cultures. Furthermore, we investigated repeated dose toxicity of chlorpromazine and assessed its effects on glucose and lactate metabolism. Sub-toxic concentrations of chlorpromazine induced significant metabolic changes in both 2D and 3D HepaRG cultures upon acute and repeated dose (3 doses) exposure. In summary, our data support the hypothesis that 3D cell culture models better mimic the in vivo tissue and improve cellular functionality. The 3D HepaRG organotypic cultures represent a high throughput system for drug toxicity screening. This system is therefore a promising tool in preclinical testing of human relevance which can allow reducing and/or replacing animal testing for drug adverse effects. [less ▲]

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See detail3D pose estimation based on planar object tracking for UAVs control
Mondragon, Ivan F.; Campoy, Pascual; Martinez, Carol et al

in Proccedings of IEEE International Conference on Robotics and Automation (ICRA) (2010)

This article presents a real time Unmanned Aerial Vehicles UAVs 3D pose estimation method using planar object tracking, in order to be used on the control system of a UAV. The method explodes the rich ... [more ▼]

This article presents a real time Unmanned Aerial Vehicles UAVs 3D pose estimation method using planar object tracking, in order to be used on the control system of a UAV. The method explodes the rich information obtained by a projective transformation of planar objects on a calibrated camera. The algorithm obtains the metric and projective components of a reference object (landmark or helipad) with respect to the UAV camera coordinate system, using a robust real time object tracking based on homographies. The algorithm is validated on real flights that compare the estimated data against that obtained by the inertial measurement unit IMU, showing that the proposed method robustly estimates the helicopter's 3D position with respect to a reference landmark, with a high quality on the position and orientation estimation when the aircraft is flying at low altitudes, a situation in which the GPS information is often inaccurate. The obtained results indicate that the proposed algorithm is suitable for complex control tasks, such as autonomous landing, accurate low altitude positioning and dropping of payloads. [less ▲]

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See detail3D Printing: The Next 5 years by Claude Wolf – Into the Future engineered by the Zs
Wolf, Claude UL

E-print/Working paper (2017)

3D Printing: The Next 5 years by Claude Wolf – Into the Future engineered by the Zs The future of 3D Printing or Additive Manufacturing [AM] will be driven by the next generation of engineers who are just ... [more ▼]

3D Printing: The Next 5 years by Claude Wolf – Into the Future engineered by the Zs The future of 3D Printing or Additive Manufacturing [AM] will be driven by the next generation of engineers who are just about to qualify, the Z generation (1994-2010). Do we, educators, know this Z generation? Do we know what motivates them? The Z generation is a generation of digital natives interacting with PCs, iPads, smartphones and the internet since birth, a pragmatic and short term orientated generation. Our prejudice brands them as unprepared and unmotivated, with their 10 second attention spans, but in reality, they have already proven they are creative, determined and hardworking as well as team oriented, when they are given the opportunity. They have understood that 3D printing offers them this opportunity. [less ▲]

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See detailA 3D shear material damping model for man-made vibrations of the ground
Macijauskas, Darius UL; Van Baars, Stefan UL

in 13th Baltic Sea Region Geotechnical Conference (2016, September)

Man-made vibrations from different types of sources are usually measured on the surface of the ground or building. The measured signal is always the superposition of all travelling basic waves. For a ... [more ▼]

Man-made vibrations from different types of sources are usually measured on the surface of the ground or building. The measured signal is always the superposition of all travelling basic waves. For a homogeneous half space there are three basic waves – the Compressional (P-wave), Shear (S-wave) and Rayleigh wave (R-wave). Depending on the measuring equipment, only the accelerations or velocities in time of the superposed wave can be measured, but not the distribution of the individual basic waves. Additional problems are that each of the basic waves has its own velocity, besides the body and surface waves have different attenuation laws. By using the rules of superposition of harmonic waves and also the propagation laws of the P-, S- and R-waves, it should be theoretically possible to split the measured superposed signal into the basic waves, because mathematically a system of equations can be assembled which describes the displacements at multiple measuring points in time. In this paper this problem has been solved for a homogenous, elastic and isotropic soil, which is disturbed by a harmonically oscillating disc on the surface. A numerical simulation was performed using a finite element method. The displacements in time were recorded in 10 points on the surface and a system of superposed equations was assembled and solved. The findings prove that each of the three basic waves has its own phase shift with the source, something which was not known before. [less ▲]

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