Refine
Year of publication
- 2021 (127) (remove)
Document Type
- Article (63)
- Conference Proceeding (46)
- Part of a Book (12)
- Book (2)
- Doctoral Thesis (2)
- Other (1)
- Preprint (1)
Language
- English (127) (remove)
Has Fulltext
- no (127) (remove)
Keywords
- Hydrogen (2)
- NOx emissions (2)
- Out-of-plane load (2)
- Principal component analysis (2)
- autonomous driving (2)
- building information modelling (2)
- capacitive field-effect sensor (2)
- constructive alignment (2)
- earthquakes (2)
- electro mobility (2)
- examination (2)
- harmonic radar (2)
- hydrogen (2)
- industrial facilities (2)
- installations (2)
- long-term retention (2)
- multimodal (2)
- piping (2)
- practical learning (2)
- robotic process automation (2)
- seismic loading (2)
- 3D object detection (1)
- 3D printing (1)
- 3D-printing (1)
- Adaptive Systems (1)
- AlterG (1)
- Augmented Reality (1)
- Authenticity (1)
- BIM (1)
- Bacillus sp (1)
- Biosolubilization (1)
- Bloom’s Taxonomy (1)
- Bootstrap (1)
- CellDrum (1)
- Central receiver power plant (1)
- Coefficient of ocular rigidity (1)
- Competence Developing Games (1)
- Computational modeling (1)
- Concentrated systems (1)
- Concentrating solar power (1)
- Corneo-scleral shell (1)
- Cross-platform (1)
- DLR-ESTEC GOSSAMER roadmap for solar sailing (1)
- Deep learning (1)
- Deuterated solvents (1)
- Deuterium NMR (1)
- Differential tonometry (1)
- Drinfeld modules (1)
- EEG (1)
- Earthquake (1)
- Earthquake Engineering (1)
- Emissions (1)
- Empirical process (1)
- Enterprise Architecture (1)
- Error Recovery (1)
- Evaluation (1)
- Eyeball (1)
- Flame residence time (1)
- Flame temperature (1)
- Frame structure (1)
- Frequency Doubler (1)
- Frequency mixing magnetic detection (1)
- Freshmen (1)
- Fresnel power plant (1)
- Fuel-flexibility (1)
- Functional Delta Method (1)
- GOSSAMER-1 (1)
- GPU (1)
- Game-based learning (1)
- Gamification (1)
- Gas turbine (1)
- Gas turbine combustion (1)
- Glaucoma (1)
- HVAC (1)
- Hadamard differentiability (1)
- Harmonic Radar (1)
- Heparin (1)
- Heuristic algorithms (1)
- Hilbert Room (1)
- Hyperdifferentials (1)
- IR (1)
- IR spectroscopy (1)
- IT security education (1)
- Impedance Spectroscopy (1)
- Implementation Case (1)
- In- plane damage (1)
- Keyword analysis (1)
- LPS (1)
- Langevin theory (1)
- LiDAR (1)
- Lightning protection system (1)
- Linear discriminant analysis (1)
- MUT measurement; scanner (1)
- Machine learning (1)
- Magnetic nanoparticles (1)
- Manufacturer (1)
- Masonry infill (1)
- Micromagnetic simulation (1)
- Micromix (1)
- Mixed-integer nonlinear programming (1)
- Mobile web (1)
- Modelica (1)
- Multi-storey (1)
- Muscle Fascicle (1)
- Muscle Force (1)
- NOx (1)
- Natural language processing (1)
- Nonequilibrium dynamics (1)
- Ocular blood flow (1)
- Operators (1)
- Optimization (1)
- Out-of-plane failure (1)
- Out-of-plane strength (1)
- PWA (1)
- Paired sample (1)
- Piping (1)
- Postulates (1)
- Powertrain (1)
- Pressure-volume relationship (1)
- Process model (1)
- Progressive Web App (1)
- Quantenmechanik (1)
- RVA (1)
- Radar (1)
- Rescue System (1)
- Resilience (1)
- Robotic Process Automation (1)
- Robotic process automation (1)
- SFCW (1)
- Schrödingers cat (1)
- Seismic loading (1)
- Septic cardiomyopathy (1)
- Sharing mobility (1)
- Simulation (1)
- Sleep EEG (1)
- Small spacecraft (1)
- Smart Building Engineering (1)
- Soft independent modeling of class analogy (1)
- Solar sail (1)
- Standardization (1)
- Stiffness (1)
- TMV adsorption (1)
- Tag (1)
- Tank (1)
- Ta₂O₅ gate (1)
- Tendon Rupture (1)
- Three-dimensional displays (1)
- Transcendence (1)
- Transponder (1)
- Unreinforced masonry walls (1)
- Validation (1)
- Vascular response (1)
- Visual field asymmetry (1)
- Water distribution system (1)
- actin cytoskeleton (1)
- actuator-sensor system (1)
- additive manufactureing (1)
- applications (1)
- artificial intelligence (1)
- biopotential electrodes (1)
- building energy modelling (1)
- building energy simulation (1)
- business models (1)
- business process automation (1)
- capacitive EIS sensor (1)
- cardiomyocyte biomechanics (1)
- colorization (1)
- combustor (1)
- combustor development (1)
- commercial offthe- shelf solutions (1)
- construction (1)
- control gate (1)
- crop yield (1)
- culpability (1)
- cyber physical production system (1)
- cyber-physical production systems (1)
- detection of charged macromolecules (1)
- digital factory (1)
- digital shadow (1)
- digitalization (1)
- dissemination (1)
- do-it-yourself (1)
- down-conductor (1)
- drop jump (1)
- early warning and response system (1)
- education (1)
- electrically driven compressors (1)
- embedded hardware (1)
- emote practical training (1)
- energy transition (1)
- engine demonstration (1)
- enzyme kinetics (1)
- equivalent circuit (1)
- event-based simulation (1)
- field-effect sensor (1)
- food production (1)
- fragility curves (1)
- frequency mixing magnetic detection (1)
- fuel cell (1)
- fuels (1)
- gait (1)
- gas turbine (1)
- genetic algorithm (1)
- glass (1)
- global optimization (1)
- gold nanoparticles (1)
- harmonic radar tags (1)
- heat demand (1)
- heat transfer coefficient (1)
- humic acid (1)
- hyper-gravity (1)
- hypo-gravity (1)
- industrial agents (1)
- industrial gas turbine (1)
- information systems (1)
- integration SHM in BIM (1)
- interconnected sensor systems (1)
- internal combustion engine (1)
- internet of production (1)
- intraclass correlation coefficient (1)
- laser based powder fusion (1)
- liability (1)
- light-addressable electrode (1)
- light-addressable potentiometric sensor (1)
- lignite (1)
- lockdown conditions (1)
- locomotion (1)
- low-rank coal (1)
- magnetic nanoparticles (1)
- management (1)
- masonry structures (1)
- metal façade (1)
- microfluidics (1)
- microwave measurements (1)
- mobility behaviour (1)
- model-predictive control (1)
- multi-agent systems (1)
- multianalyte detection (1)
- multiplex detection (1)
- muscle fascicle behavior (1)
- muscle mechanics (1)
- nonlinear VNA measurements (1)
- nonlinear radar (1)
- on-chip integrated addressable EISCAP sensors (1)
- open educational resources (1)
- parabolic flight (1)
- plant virus detection (1)
- polystyrene sulfonate (1)
- prefabrication (1)
- qNMR (1)
- rehabilitation (1)
- remote teamwork (1)
- renewable energies (1)
- research framework (1)
- roleplay (1)
- running (1)
- sarcomere operating length (1)
- seismic risk (1)
- seismic structural damage detection via SHM (1)
- seismic vulnerability (1)
- sensor networks (1)
- sensors (1)
- series elastic element behavior (1)
- shoulder (1)
- small and medium scaled companies (1)
- smart building engineering (1)
- smart engineering (1)
- software evaluation (1)
- software selection (1)
- soil amendment (1)
- soil health (1)
- soil remediation (1)
- sprint start (1)
- standard error of measurement (1)
- steel columns (1)
- stochastic optimization (1)
- storage dispatch (1)
- storage optimisation (1)
- stretch reflex (1)
- sustainability (1)
- t-modules (1)
- technology (1)
- test-retest reliability (1)
- thermal storage (1)
- tobacco mosaic virus (TMV) (1)
- touch voltage (1)
- transponder (1)
- ultrasonography (1)
- ultrasound imaging (1)
- unloading (1)
- urban farming (1)
- user & usage (1)
- virtual reality (1)
- walking (1)
Institute
- Fachbereich Medizintechnik und Technomathematik (42)
- IfB - Institut für Bioengineering (31)
- Fachbereich Elektrotechnik und Informationstechnik (24)
- Fachbereich Luft- und Raumfahrttechnik (18)
- Fachbereich Energietechnik (15)
- INB - Institut für Nano- und Biotechnologien (10)
- Fachbereich Chemie und Biotechnologie (8)
- Solar-Institut Jülich (8)
- Fachbereich Bauingenieurwesen (7)
- ECSM European Center for Sustainable Mobility (6)
- MASKOR Institut für Mobile Autonome Systeme und Kognitive Robotik (6)
- Fachbereich Maschinenbau und Mechatronik (3)
- Fachbereich Wirtschaftswissenschaften (3)
- IMP - Institut für Mikrowellen- und Plasmatechnik (2)
- Nowum-Energy (2)
- ZHQ - Bereich Hochschuldidaktik und Evaluation (2)
- Arbeitsstelle fuer Hochschuldidaktik und Studienberatung (1)
- Digitalisierung in Studium & Lehre (1)
- Freshman Institute (1)
- IaAM - Institut für angewandte Automation und Mechatronik (1)
Geochemical characterisation of hypersaline waters is difficult as high concentrations of salts hinder the analysis of constituents at low concentrations, such as trace metals, and the collection of samples for trace metal analysis in natural waters can be easily contaminated. This is particularly the case if samples are collected by non-conventional techniques such as those required for aquatic subglacial environments. In this paper we present the first analysis of a subglacial brine from Taylor Valley, (~ 78°S), Antarctica for the trace metals: Ba, Co, Mo, Rb, Sr, V, and U. Samples were collected englacially using an electrothermal melting probe called the IceMole. This probe uses differential heating of a copper head as well as the probe’s sidewalls and an ice screw at the melting head to move through glacier ice. Detailed blanks, meltwater, and subglacial brine samples were collected to evaluate the impact of the IceMole and the borehole pump, the melting and collection process, filtration, and storage on the geochemistry of the samples collected by this device. Comparisons between melt water profiles through the glacier ice and blank analysis, with published studies on ice geochemistry, suggest the potential for minor contributions of some species Rb, As, Co, Mn, Ni, NH4+, and NO2−+NO3− from the IceMole. The ability to conduct detailed chemical analyses of subglacial fluids collected with melting probes is critical for the future exploration of the hundreds of deep subglacial lakes in Antarctica.
Component failures within water supply systems can lead to significant performance losses. One way to address these losses is the explicit anticipation of failures within the design process. We consider a water supply system for high-rise buildings, where pump failures are the most likely failure scenarios. We explicitly consider these failures within an early design stage which leads to a more resilient system, i.e., a system which is able to operate under a predefined number of arbitrary pump failures. We use a mathematical optimization approach to compute such a resilient design. This is based on a multi-stage model for topology optimization, which can be described by a system of nonlinear inequalities and integrality constraints. Such a model has to be both computationally tractable and to represent the real-world system accurately. We therefore validate the algorithmic solutions using experiments on a scaled test rig for high-rise buildings. The test rig allows for an arbitrary connection of pumps to reproduce scaled versions of booster station designs for high-rise buildings. We experimentally verify the applicability of the presented optimization model and that the proposed resilience properties are also fulfilled in real systems.
Most drugs are no longer produced in their own countries by the pharmaceutical companies, but by contract manufacturers or at manufacturing sites in countries that can produce more cheaply. This not only makes it difficult to trace them back but also leaves room for criminal organizations to fake them unnoticed. For these reasons, it is becoming increasingly difficult to determine the exact origin of drugs. The goal of this work was to investigate how exactly this is possible by using different spectroscopic methods like nuclear magnetic resonance and near- and mid-infrared spectroscopy in combination with multivariate data analysis. As an example, 56 out of 64 different paracetamol preparations, collected from 19 countries around the world, were chosen to investigate whether it is possible to determine the pharmaceutical company, manufacturing site, or country of origin. By means of suitable pre-processing of the spectra and the different information contained in each method, principal component analysis was able to evaluate manufacturing relationships between individual companies and to differentiate between production sites or formulations. Linear discriminant analysis showed different results depending on the spectral method and purpose. For all spectroscopic methods, it was found that the classification of the preparations to their manufacturer achieves better results than the classification to their pharmaceutical company. The best results were obtained with nuclear magnetic resonance and near-infrared data, with 94.6%/99.6% and 98.7/100% of the spectra of the preparations correctly assigned to their pharmaceutical company or manufacturer.
Through a mirror darkly – On the obscurity of teaching goals in game-based learning in IT security
(2021)
Teachers and instructors use very specific language communicating teaching goals. The most widely used frameworks of common reference are the Bloom’s Taxonomy and the Revised Bloom’s Taxonomy. The latter provides distinction of 209 different teaching goals which are connected to methods. In Competence Developing Games (CDGs - serious games to convey knowledge) and in IT security education, a two- or three level typology exists, reducing possible learning outcomes to awareness, training, and education. This study explores whether this much simpler framework succeeds in achieving the same range of learning outcomes. Method wise a keyword analysis was conducted. The results were threefold: 1. The words used to describe teaching goals in CDGs on IT security education do not reflect the whole range of learning outcomes. 2. The word choice is nevertheless different from common language, indicating an intentional use of language. 3. IT security CDGs use different sets of terms to describe learning outcomes, depending on whether they are awareness, training, or education games. The interpretation of the findings is that the reduction to just three types of CDGs reduces the capacity to communicate and think about learning outcomes and consequently reduces the outcomes that are intentionally achieved.
For typical cases of non-isolated lightning
protection systems (LPS) the impulse currents are investigated which may flow through a human body directly touching a structural part of the LPS. Based on a basic LPS model with conventional down-conductors especially the cases of external and internal steel columns and metal façades are considered and compared. Numerical simulations of the line quantities voltages and currents in the time domain are performed with an equivalent circuit of the entire LPS.
As a result it can be stated that by increasing the number of conventional down-conductors and external steel columns the threat for a human being can indeed be reduced, but not down to an acceptable limit. In case of internal steel columns used as natural down-conductors the threat can be reduced sufficiently, depending on the low-resistive connection of the steel columns to the lightning equipotential bonding or the earth termination system, resp. If a metal façade is used the threat for human beings touching is usually very low, if the façade is sufficiently interconnected and multiply connected to the lightning equipotential bonding or the earth termination system, resp.
Stretch-shortening type actions are characterized by lengthening of the pre-activated muscle-tendon unit (MTU) in the eccentric phase immediately followed by muscle shortening. Under 1 g, pre-activity before and muscle activity after ground contact, scale muscle stiffness, which is crucial for the recoil properties of the MTU in the subsequent push-off. This study aimed to examine the neuro-mechanical coupling of the stretch-shortening cycle in response to gravity levels ranging from 0.1 to 2 g. During parabolic flights, 17 subjects performed drop jumps while electromyography (EMG) of the lower limb muscles was combined with ultrasound images of the gastrocnemius medialis, 2D kinematics and kinetics to depict changes in energy management and performance. Neuro-mechanical coupling in 1 g was characterized by high magnitudes of pre-activity and eccentric muscle activity allowing an isometric muscle behavior during ground contact. EMG during pre-activity and the concentric phase systematically increased from 0.1 to 1 g. Below 1 g the EMG in the eccentric phase was diminished, leading to muscle lengthening and reduced MTU stretches. Kinetic energy at take-off and performance were decreased compared to 1 g. Above 1 g, reduced EMG in the eccentric phase was accompanied by large MTU and muscle stretch, increased joint flexion amplitudes, energy loss and reduced performance. The energy outcome function established by linear mixed model reveals that the central nervous system regulates the extensor muscles phase- and load-specifically. In conclusion, neuro-mechanical coupling appears to be optimized in 1 g. Below 1 g, the energy outcome is compromised by reduced muscle stiffness. Above 1 g, loading progressively induces muscle lengthening, thus facilitating energy dissipation.
Test-retest reliability of the internal shoulder rotator muscles' stretch reflex in healthy men
(2021)
Until now the reproducibility of the short latency stretch reflex of the internal rotator muscles of the glenohumeral joint has not been identified. Twenty-three healthy male participants performed three sets of external shoulder rotation stretches with various pre-activation levels on two different dates of measurement to assess test-retest reliability. All stretches were applied with a dynamometer acceleration of 104°/s2 and a velocity of 150°/s. Electromyographical response was measured via surface EMG. Reflex latencies showed a pre-activation effect (ƞ2 = 0,355). ICC ranged from 0,735 to 0,909 indicating an overall “good” relative reliability. SRD 95% lay between ±7,0 to ±12,3 ms.. The reflex gain showed overall poor test-retest reproducibility. The chosen methodological approach presented a suitable test protocol for shoulder muscles stretch reflex latency evaluation. A proof-of-concept study to validate the presented methodical approach in shoulder involvement including subjects with clinically relevant conditions is recommended.
In the context of the Solvency II directive, the operation of an internal risk model is a possible way for risk assessment and for the determination of the solvency capital requirement of an insurance company in the European Union. A Monte Carlo procedure is customary to generate a model output. To be compliant with the directive, validation of the internal risk model is conducted on the basis of the model output. For this purpose, we suggest a new test for checking whether there is a significant change in the modeled solvency capital requirement. Asymptotic properties of the test statistic are investigated and a bootstrap approximation is justified. A simulation study investigates the performance of the test in the finite sample case and confirms the theoretical results. The internal risk model and the application of the test is illustrated in a simplified example. The method has more general usage for inference of a broad class of law-invariant and coherent risk measures on the basis of a paired sample.
The transition within transportation towards battery electric vehicles can lead to a more sustainable future. To account for the development goal ‘climate action’ stated by the United Nations, it is mandatory, within the conceptual design phase, to derive energy-efficient system designs. One barrier is the uncertainty of the driving behaviour within the usage phase. This uncertainty is often addressed by using a stochastic synthesis process to derive representative driving cycles and by using cycle-based optimization. To deal with this uncertainty, a new approach based on a stochastic optimization program is presented. This leads to an optimization model that is solved with an exact solver. It is compared to a system design approach based on driving cycles and a genetic algorithm solver. Both approaches are applied to find efficient electric powertrains with fixed-speed and multi-speed transmissions. Hence, the similarities, differences and respective advantages of each optimization procedure are discussed.
The course Physics for Electrical Engineering is part of the curriculum of the
bachelor program Electrical Engineering at University of Applied Science Aachen.
Before covid-19 the course was conducted in a rather traditional way with all parts
(lecture, exercise and lab) face-to-face. This teaching approach changed
fundamentally within a week when the covid-19 limitations forced all courses to
distance learning. All parts of the course were transformed to pure distance learning
including synchronous and asynchronous parts for the lecture, live online-sessions
for the exercises and self-paced labs at home. Using these methods, the course was
able to impart the required knowledge and competencies. Taking the teacher’s
observations of the student’s learning behaviour and engagement, the formal and
informal feedback of the students and the results of the exams into account, the new
methods are evaluated with respect to effectiveness, sustainability and suitability for
competence transfer. Based on this analysis strong and weak points of the concept
and countermeasures to solve the weak points were identified. The analysis further
leads to a sustainable teaching approach combining synchronous and asynchronous
parts with self-paced learning times that can be used in a very flexible manner for
different learning scenarios, pure online, hybrid (mixture of online and presence
times) and pure presence teaching.
This chapter describes three general strategies to master uncertainty in technical systems: robustness, flexibility and resilience. It builds on the previous chapters about methods to analyse and identify uncertainty and may rely on the availability of technologies for particular systems, such as active components. Robustness aims for the design of technical systems that are insensitive to anticipated uncertainties. Flexibility increases the ability of a system to work under different situations. Resilience extends this characteristic by requiring a given minimal functional performance, even after disturbances or failure of system components, and it may incorporate recovery. The three strategies are described and discussed in turn. Moreover, they are demonstrated on specific technical systems.
The progress in natural language processing (NLP) research over the last years, offers novel business opportunities for companies, as automated user interaction or improved data analysis. Building sophisticated NLP applications requires dealing with modern machine learning (ML) technologies, which impedes enterprises from establishing successful NLP projects. Our experience in applied NLP research projects shows that the continuous integration of research prototypes in production-like environments with quality assurance builds trust in the software and shows convenience and usefulness regarding the business goal. We introduce STAMP 4 NLP as an iterative and incremental process model for developing NLP applications. With STAMP 4 NLP, we merge software engineering principles with best practices from data science. Instantiating our process model allows efficiently creating prototypes by utilizing templates, conventions, and implementations, enabling developers and data scientists to focus on the business goals. Due to our iterative-incremental approach, businesses can deploy an enhanced version of the prototype to their software environment after every iteration, maximizing potential business value and trust early and avoiding the cost of successful yet never deployed experiments.
In positron emission tomography improving time, energy and spatial detector resolutions and using Compton kinematics introduces the possibility to reconstruct a radioactivity distribution image from scatter coincidences, thereby enhancing image quality. The number of single scattered coincidences alone is in the same order of magnitude as true coincidences. In this work, a compact Compton camera module based on monolithic scintillation material is investigated as a detector ring module. The detector interactions are simulated with Monte Carlo package GATE. The scattering angle inside the tissue is derived from the energy of the scattered photon, which results in a set of possible scattering trajectories or broken line of response. The Compton kinematics collimation reduces the number of solutions. Additionally, the time of flight information helps localize the position of the annihilation. One of the questions of this investigation is related to how the energy, spatial and temporal resolutions help confine the possible annihilation volume. A comparison of currently technically feasible detector resolutions (under laboratory conditions) demonstrates the influence on this annihilation volume and shows that energy and coincidence time resolution have a significant impact. An enhancement of the latter from 400 ps to 100 ps leads to a smaller annihilation volume of around 50%, while a change of the energy resolution in the absorber layer from 12% to 4.5% results in a reduction of 60%. The inclusion of single tissue-scattered data has the potential to increase the sensitivity of a scanner by a factor of 2 to 3 times. The concept can be further optimized and extended for multiple scatter coincidences and subsequently validated by a reconstruction algorithm.
In this study, a recently proposed NMR standardization approach by 2H integral of deuterated solvent for quantitative multicomponent analysis of complex mixtures is presented. As a proof of principle, the existing NMR routine for the analysis of Aloe vera products was modified. Instead of using absolute integrals of targeted compounds and internal standard (nicotinamide) from 1H-NMR spectra, quantification was performed based on the ratio of a particular 1H-NMR compound integral and 2H-NMR signal of deuterated solvent D2O. Validation characteristics (linearity, repeatability, accuracy) were evaluated and the results showed that the method has the same precision as internal standardization in case of multicomponent screening. Moreover, a dehydration process by freeze drying is not necessary for the new routine. Now, our NMR profiling of A. vera products needs only limited sample preparation and data processing. The new standardization methodology provides an appealing alternative for multicomponent NMR screening. In general, this novel approach, using standardization by 2H integral, benefits from reduced sample preparation steps and uncertainties, and is recommended in different application areas (purity determination, forensics, pharmaceutical analysis, etc.).