Filtern
Erscheinungsjahr
Dokumenttyp
- Wissenschaftlicher Artikel (213)
- Konferenzveröffentlichung (210)
- Teil eines Buches (Kapitel) (31)
- Sonstiges (29)
- Video (14)
- Buch (Monographie) (13)
- Preprint (9)
- Dissertation (4)
- Arbeitspapier (4)
- Bericht (3)
Sprache
- Englisch (535) (entfernen)
Schlagworte
- Robotik (8)
- Flugkörper (7)
- UAV (7)
- Rettungsrobotik (5)
- Polymer-Elektrolytmembran-Brennstoffzelle (4)
- adhesion (4)
- Bionik (3)
- Erweiterte Realität <Informatik> (3)
- Gespenstschrecken (3)
- Haftorgan (3)
- OCSR (3)
- stick insects (3)
- Augmented Reality (2)
- CDK (2)
- Competency-Oriented Exams (2)
- Deep learning (2)
- Dissipative Particle Dynamics (2)
- Field measurement (2)
- Human-Robot Interaction (2)
- Solar modules (2)
- Twitter <Softwareplattform> (2)
- biomimicry (2)
- hydraulic compression (2)
- modular stack design (2)
- open quantum systems (2)
- social innovation (2)
- carbon nanofibers, platinum electrodeposition, ele ctrochemical surface area (1)
- 360 degree Feedback (1)
- 360° Panorama (1)
- AI (1)
- API 1130 (1)
- Aerosol (1)
- Aggregation-prone (1)
- Air handling unit (1)
- Alternative Geschäftsmodelle (1)
- Amylase, Enzymcharakterisierung (1)
- Anorganische Analyse (1)
- Artificial Intelligence (1)
- Assessment Center (1)
- Assisted living technologies (1)
- Assistive robotics (1)
- Augmented Three-Phase AC-Railgun (1)
- Autonomous Agents (1)
- Bildverarbeitung (1)
- Biomechanics (1)
- Biomedical monitoring, Hospitals, Electrocardiography, Wireless communication, Patient monitoring, Wireless sensor networks (1)
- Biomimetics (1)
- Bone morphogenetic protein 2 (1)
- Brand theory (1)
- COIL (1)
- CPM (1)
- Carboxylate (1)
- Case-Study (1)
- Cell-free implant (1)
- Chemical image depiction (1)
- Chemical space (1)
- Chemical structure depictions (1)
- Cheminformatics (1)
- Chemistry Development Kit (1)
- Chemistry Development Kit, CDK, Molecule fragmentation, In silico fragmentation, Scaffolds, Functional groups, Glycosidic moieties, Rich client, Graphical user interface, GUI (1)
- Chief Executive Officer (1)
- Climate change (1)
- Clustering (1)
- Codegenerierung (1)
- Communication management (1)
- Constructive Alignment (1)
- Continuous Assessment (1)
- Continuous Queries (1)
- Cookie <Internet> (1)
- Cr(VI) and Zn(II) cations (1)
- Crowdfunding (1)
- Data Collection (1)
- Data Journalism (1)
- Datalog (1)
- Datenjournalismus (1)
- Datensatz (1)
- Datenschutz (1)
- Deductive Databases (1)
- Deep Learning (1)
- Depiction generator image augmentation (1)
- Deutschland / Technische Regeln für brennbare Flüssigkeiten (1)
- Dissipative particle dynamics, DPD, Surfactant, Bilayer, Lamellar, Simulation, Mesoscopic (1)
- Distributed Software Development (1)
- E. coli SHuffle® T7 (1)
- Elastizitätsmodul (1)
- Elektrodenvorbereitung (1)
- Enterprise JavaBeans (1)
- Erneuerbare Energien (1)
- Europe (1)
- Evidence-based Management (1)
- Exams with Third-Party Applications (1)
- Fehlererkennung (1)
- Fehlerortung (1)
- Flipped Classroom (1)
- Flügelform (1)
- Formative Assessment (1)
- Fragmentation (1)
- Future capacity needs (1)
- Greek dept crisis (1)
- Hand-drawn images (1)
- Hands-free Interaction (1)
- Homogene Kühlung (1)
- Human-centered computing (1)
- Hydraulic cell compression (1)
- Hydraulic compression, Carbon Nano Fibers, PEM Fuel Cells, Catalyst utilization (1)
- Hydrogen evolution reaction (1)
- Hydrophilicity enhanced hBMP2 variant (1)
- ICP-Massenspektrometrie (1)
- Implantat (1)
- In-silico-design (1)
- Incremental Evaluation (1)
- Indigo (1)
- Interactive Voting Systems (1)
- Intercultural Collaboration (1)
- Journalismus (1)
- Juristenausbildung (1)
- Kalman filter (1)
- Kernspintomografie (1)
- Kohlenstoff (1)
- Kohlenstoff-Nanoröhre (1)
- Laser Synthesis Electrocatalytic Water Splitting (1)
- Leadership Competencies (1)
- Leak detection (1)
- Leckerkennung (1)
- Leckortung (1)
- Lecksuchgerät (1)
- Lecküberwachung (1)
- Lüftungsanlage (1)
- MITRE (1)
- Machine Learning (1)
- Mapping (1)
- Maus (1)
- Media Brands (1)
- Media brand characteristics (1)
- Media positioning (1)
- Methodology (1)
- Middle-range Theory (1)
- Mikrofotografie (1)
- Mixed Reality (1)
- Molecule images (1)
- Multi-Agent System (1)
- Multiphase Rail Launcher (1)
- Mund-Nasen-Schutz (1)
- N,N,O Ligands (1)
- N,N′ Ligands (1)
- Nanofaser (1)
- Natural products (1)
- Naturstoff (1)
- NeRF (1)
- New Public Governance (1)
- New Public Management (1)
- New Work, Information and Communication Industry, Innovation, Organizational Goals, Survey (1)
- Normalisierung (1)
- OSINT (1)
- Object Recognition (1)
- Object-relational Mapping (1)
- Objektverfolgung (1)
- Ohrwurm (1)
- Online Programming Exams (1)
- Online Supervision (1)
- Online-Werbung (1)
- Optical Chemical Structure Recognition (1)
- Ortsbestimmung (1)
- PEM Electrolysis, Hydrogen, Hydraulic Compression, High Pressure (1)
- PEM electrolysis (1)
- PEM fuel cell (1)
- PEM fuel cell electrocatalysts, Carbon nanofibers, Oxygen plasma activation, Pulsed electroplating. (1)
- PEM fuel cells (1)
- PEM water electrolysis (1)
- PEM-Brennstoffzelle (1)
- Peer Assessment (1)
- Peer Instruction (1)
- People with disabilities (1)
- Performance prediction (1)
- Persistenz <Informatik> (1)
- Politische Berichterstattung (1)
- Polymere (1)
- Privatsphäre (1)
- Project-based Learning (1)
- PtCoMn (1)
- RDKit (1)
- RIS (1)
- Regeln der Technik (1)
- Rescue Robotics (1)
- Robot assistive drinking (1)
- Robot assistive eating (1)
- Rwanda (1)
- SARS-CoV-2 (1)
- Sauerstoffplasmaaktivierung (1)
- Scaffold (1)
- Scaffold network (1)
- Scaffold tree (1)
- Segmentation; Correlation; Diseases; Convolutional Neural Networks (1)
- Small UAVs (1)
- Smart Grid (1)
- Social Innovation (1)
- Social Learning (1)
- Social Media (1)
- Spondylodese (1)
- Stack <Brennstoffzelle> (1)
- Stellite 6; HVOF-spraying; Laser remelting; Cavitation erosion; Coatings (1)
- Student Activation (1)
- TRFL (1)
- Temperature coefficients (1)
- Ternary alloy catalyst preparation (1)
- Tetraplegie (1)
- Thermal Performance (1)
- Titanium; Al2O3–TiO2 coatings; Nanoindentation (1)
- Tracking (1)
- Transformative Teaching (1)
- Twitter (1)
- Update Propagation (1)
- Upscaling laboratory models (1)
- Urban heat island (1)
- Visual Monocular SLAM (1)
- Young´s modulus (1)
- Zinc (1)
- Zustandsmaschine (1)
- academic and job-related self-control demands (1)
- activated sludge (1)
- advanced persistent threats (1)
- aerosol (1)
- air hygiene (1)
- airborne infection (1)
- antecedents (1)
- artificial intelligence (1)
- assistive robotics (1)
- augmented reality (1)
- bacterial toxicity (1)
- balance (1)
- barrel cortex, cell types, multielectrode recordings, perception, psychophysics (1)
- bio-inspired functional surface (1)
- bioinspired (1)
- biomimetic (1)
- biomimetic materials (1)
- biomimetics; functional morphology; plant biomechanics; plant motion; strain analysis; structure–function relationship; 3D digital image correlation (3D-DIC); Hakea sericea; Hakea salicifolia (1)
- blockchain (1)
- bloxberg (1)
- carbon nano fibres (1)
- carbon nanofibers, platinum electrodeposition, electrocatalysts (1)
- cartilage defect (1)
- cartilage regeneration (1)
- chlorinated phenols (1)
- cluster (1)
- cobot (1)
- collaborative online international learning (COIL) (1)
- compassionate love (1)
- composition (1)
- conical intersection (1)
- consent banner (1)
- cookie banner (1)
- cookies (1)
- critical review (1)
- cyber kill chain (1)
- demagnetization cooling (1)
- design process (1)
- distributed software development (1)
- diversity (1)
- dlt (1)
- dynamic capabilities (1)
- efficiency of exciton transfer (1)
- electrode preparation (1)
- empowerment (1)
- entrepreneurial diversity (1)
- entrepreneurship (1)
- ethereum (1)
- ethics (1)
- excitation energy transfer (1)
- expert interviews (1)
- face mask (1)
- farming (1)
- gender stereotypes (1)
- gender-sensitive design (1)
- gender-specific design (1)
- human robot interaction (1)
- human-centered design (1)
- human-robot collaboration (1)
- hybrid sensor system (1)
- ingots (1)
- innovation (1)
- intercultural collaboration (1)
- interdisciplinary students project (1)
- international comparative study (1)
- intersectionality (1)
- irritation (1)
- leak locating (1)
- leak monitoring (1)
- long-term toxicity (1)
- luminescent bacteria (1)
- machine learning (1)
- managerial vs. non-managerial actors (1)
- measurement study (1)
- media accountability (1)
- microfoundations (1)
- multi-level model of competence (1)
- narcissism (1)
- neutrality (1)
- nonadiabatic dynamics (1)
- noncommuting fluctuations (1)
- nonequilibrium quantum transport (1)
- normalisation (1)
- open science (1)
- optical chemical structure recognition (1)
- oxygen plasma activation (1)
- pH-shift elution (1)
- participatory design (1)
- phishing (1)
- photovoltaic power systems (1)
- poa (1)
- poe (1)
- policymakers (1)
- political journalism (1)
- privacy (1)
- product development (1)
- project-based learning (1)
- projection (1)
- public policy (1)
- quality standards (1)
- quantum dissipation (1)
- reconnaissance (1)
- relevance (1)
- respiration inhibition (1)
- risk management (1)
- role identity (1)
- sensor fusion (1)
- servant leadership (1)
- shared user control (1)
- silicon (1)
- solar cells (1)
- solution finding (1)
- spatial policy (1)
- state machine (1)
- study and working time per week (1)
- sustainable development (1)
- television news coverage (1)
- theorising (1)
- trait self-control (1)
- transport (1)
- tree frog (1)
- user acceptance (1)
- ventilation (1)
- vibronic coupling (1)
- virtual reality (1)
- visual cues (1)
- visualization techniques (1)
- watchblogs (1)
- web measurement (1)
- Änderung (1)
Institut
- Westfälisches Institut für Gesundheit (115)
- Institut für Internetsicherheit (56)
- Informatik und Kommunikation (51)
- Elektrotechnik und angewandte Naturwissenschaften (50)
- Wirtschaft und Informationstechnik Bocholt (46)
- Westfälisches Energieinstitut (45)
- Institut für biologische und chemische Informatik (37)
- Maschinenbau Bocholt (37)
- Institut Arbeit und Technik (15)
- Wirtschaftsingenieurwesen (15)
- Institut für Innovationsforschung und -management (11)
- Fachbereiche (9)
- Wirtschaftsrecht (9)
- Maschinenbau und Facilities Management (3)
- Strategische Projekte (2)
- Institute (1)
This study investigates differences between treatment plans generated by Ray Tracing (RT) and Monte Carlo (MC) calculation algorithms in homogeneous and heterogeneous body regions. Particularly, we focus on the head and on the thorax, respectively, for robotic stereotactic radiotherapy and radiosurgery with Cyberknife. Radiation plans for tumors located in the head and in the thorax region have been calculated and compared to each other in 47 cases and several tumor types.
CIP is an open-source high-level function library for (non-linear) curve fitting and data smoothing (with cubic splines), clustering (k-medoids, ART-2a) and machine learning (multiple linear/polynomial regression, feed-forward perceptron-type shallow and deep neural networks and support vector machines). In addition it provides several heuristics for the selection of training and test data or methods to estimate the relevance of data input components. CIP is built on top of the computing platform Mathematica to exploit its algorithmic and graphical capabilities.
CIP is an open-source high-level function library for (non-linear) curve fitting and data smoothing (with cubic splines), clustering (k-medoids, ART-2a) and machine learning (multiple linear/polynomial regression, feed-forward perceptron-type shallow and deep neural networks and support vector machines). In addition it provides several heuristics for the selection of training and test data or methods to estimate the relevance of data input components. CIP is built on top of the computing platform Mathematica to exploit its algorithmic and graphical capabilities.
Background: By reviewing image quality and diagnostic perception, the suitability of a statistical model-based iterative reconstruction algorithm in conjunction with low-dose computed tomography for lung cancer screening is investigated.
Methods: Artificial lung nodules shaped as spheres and spiculated spheres made from material with calibrated Hounsfield units were attached on marked positions in the lung structure of anthropomorphic phantoms. The phantoms were scanned using standard high contrast, and two low-dose computed tomography protocols: low-dose and ultra-low-dose. For the reconstruction, the filtered back projection and the iterative reconstruction algorithm ADMIRE at different strength levels (S1–S5) and the kernels Bl57, Br32, Br69 were used. Expert radiologists assessed image quality by performing 4-field-ranking tests and reading all image series to examine the aptitude for the detectability of lung nodules. Signal-to-noise ratio was investigated as objective image quality parameter.
Results: In ranking tests for lung foci detection expert radiologists prefer medium to high iterative reconstruction strength levels. For the standard clinical kernel Bl57 and varying phantom diameter, a noticeable preference for S4 was detected. Experienced radiologists graded filtered back projection reconstructed images with the highest perceptibility. Less experienced readers assessed filtered back projection and iterative reconstruction equally with the highest grades for the Bl57 kernel. Independently of the dose protocol, the signal-to-noise ratio increases with the iterative reconstruction strength level, specifically for Br69 and Bl57.
Conclusions: Subjective image perception does not significantly correlate with the experience of the radiologist, which presumably mirrors reader’s training and accustomed reading adjustments. Regarding signal-to-noise ratio, iterative reconstruction outperforms filtered back projection for spheres and spiculated spheres. Iterative reconstruction matters. It promises to be an alternative to filtered back projection allowing for lung-cancer screening at markedly decreased radiation exposure but comparable or even improved image quality.
This introduction to a special issue about concepts and facets of entrepreneurial diversity serves as a starting point for further discussion and research in this field. For this purpose, we provide information about the roots of the study of diversity and current trends in entrepreneurship research and present a frame for (researching) entrepreneurial diversity. Additionally, we briefly summarize the three papers selected for inclusion in this special issue. Together, they offer insights into the intersections of different diversity dimensions, personality as a deep dimension of team composition, and a general critical reflection on the conceptualization of entrepreneurial diversity. Taken together, the papers in this special issue present new findings and contribute to further advancing the long overdue research on and discussion about diversity in the field of entrepreneurship.
Gaining customer loyalty is an important goal of marketing, and loyalty programs are intended to help in reaching it. Research on loyalty programs suggests that customers differentiate between loyalty to a company and loyalty to a loyalty program, yet little is known about the consequences of these two types of loyalty. Therefore, our study intends to make two main contributions: (1) improving our understanding of the constructs “program loyalty” and “company loyalty”, (2) investigating the relative impact of the two types of loyalty on preference, intention, and purchase behavior for the case of a multi-firm loyalty program. Results indicate that company loyalty influences a customer’s choice to visit a particular provider and to prefer it over competitors, but it is not a strong predictor of purchase behavior. Conversely, program loyalty is a far more important driver of purchase behavior. This implies that company loyalty primarily attracts customers to a particular provider and program loyalty ensures that once inside the store, more money is spent.
The wireless data logger system “Cor/log® BAN BT” (CL) allows seamless 24/7 monitoring of relevant vital sign parameters. CL covers the entire period of acute point of care inside the hospital and the recovery period, when first mobility is achieved and when the patient is released into an ambulatory or homecare environment. The CL records the relevant vital signs such as ECG, respiration, pulse oximetry with plethysmogram and movement. The vital data collected with the CL data logger is saved on a memory card for further analysis and is simultaneously transmitted in real-time to a telemedicine server via a smartphone or tablet. The smartphone also provides GPS location information. In addition Cor/log View, an Android Application for viewing recorded vital sign data originating from the CL, was developed. CL has also a connector to the generic MedM health cloud. MedM is a generic patient data management system (PDMS) consisting of a cloud portal and a mobile health app. The app runs on Android, iOS and Windows. The app can connects wirelessly to the CL physiologic monitor and stores the vital signs in the cloud.
Corporate Social Responsibility and Diversity Management. Theoretical Approaches and Best Practices
(2017)
Creating chemo- & bioinformatics workflows, further developments within the CDK-Taverna Project
(2008)
We study the dynamics of a quantum two-state system driven through an avoided crossing under the influence of a super-Ohmic environment. We determine the Landau–Zener probability employing the numerical exact quasi-adiabatic path integral and a Markovian weak coupling approach. Increasing the driving time in the numerical protocol, we find converged results which shows that super-Ohmic environments only influence the Landau Zener probability within a finite crossing time window. This crossing time is qualitatively determined by the environmental cut-off energy. At weak coupling, we show that the Markovian weak coupling approach provides an accurate description. Since pure dephasing of a super-Ohmic bath is non-Markovian, this highlights that pure dephasing hardly influences the Landau–Zener probability. The finite crossing time window, thus, results from the suppression of relaxation once the energy splitting exceeds the environmental cut-off energy.
Radiotherapy (RT) treatment planning is based on computed tomography (CT) images and traditionally uses the conventional Hounsfield unit (CHU) range. This HU range is suited for human tissue but inappropriate for metallic materials. To guarantee safety of patient carrying implants precise HU quantification is beneficial for accurate dose calculations in planning software. Some modern CT systems offer an extended HU range (EHU). This study focuses the suitability of these two HU ranges for the quantification of metallic components of active implantable medical devices (AIMD). CT acquisitions of various metallic and non-metallic materials aligned in a water phantom were investigated. From our acquisitions we calculated that materials with mass-density ρ > 3.0 g/cm3 cannot be represented in the CHU range. For these materials the EHU range could be used for accurate HU quantification. Since the EHU range does not effect the HU values for materials ρ < 3.0 g/cm3, it can be used as a standard for RT treatment planning for patient with and without implants.
Innovationen fördern nachweislich die Wettbewerbsfähigkeit von Unternehmen. Dafür müssen innovative Ideen generiert und in marktfähige Produkte und Dienstleistungen umgesetzt werden. »Innovationen im Unternehmen kultivieren« dokumentiert praxisnah, wie Firmen ihre Innovationskultur durch gezielte Führungsmaßnahmen entwickeln und weiter voranbringen. Die erste Fallstudie beschreibt die unternehmensweite Henkel-Initiative, die 2006 die Beschäftigten noch stärker mobilisieren und ein größeres Gefühl von »ownership« schaffen sollte, und vergleicht sie mit herkömmlichen Systemen des betrieblichen Vorschlagswesens. Die Fallstudie des Pharmaunternehmens Novartis befasst sich mit der Umstellung auf eine werteorientierte Unternehmensführung für High Performance und Innovationsführerschaft. Die Fallstudie »B. Braun Melsungen Sharing Expertise« zeigt anhand eines Produktentwicklungsprozesses, wie sich externe Innovationsimpulse erschließen lassen.
The translation of images of chemical structures into machine-readable representations of the depicted molecules is known as optical chemical structure recognition (OCSR). There has been a lot of progress over the last three decades in this field, but the development of systems for the recognition of complex hand-drawn structure depictions is still at the beginning. Currently, there is no data for the systematic evaluation of OCSR methods on hand-drawn structures available. Here we present DECIMER - Hand-drawn molecule images, a standardised, openly available benchmark dataset of 5088 hand-drawn depictions of diversely picked chemical structures. Every structure depiction in the dataset is mapped to a machine-readable representation of the underlying molecule. The dataset is openly available and published under the CC-BY 4.0 licence which applies very few limitations. We hope that it will contribute to the further development of the field.
The number of publications describing chemical structures has increased steadily over the last decades. However, the majority of published chemical information is currently not available in machine-readable form in public databases. It remains a challenge to automate the process of information extraction in a way that requires less manual intervention - especially the mining of chemical structure depictions. As an open-source platform that leverages recent advancements in deep learning, computer vision, and natural language processing, DECIMER.ai (Deep lEarning for Chemical IMagE Recognition) strives to automatically segment, classify, and translate chemical structure depictions from the printed literature. The segmentation and classification tools are the only openly available packages of their kind, and the optical chemical structure recognition (OCSR) core application yields outstanding performance on all benchmark datasets. The source code, the trained models and the datasets developed in this work have been published under permissive licences. An instance of the DECIMER web application is available at https://decimer.ai.
The translation of images of chemical structures into machine-readable representations of the depicted molecules is known as optical chemical structure recognition (OCSR). There has been a lot of progress over the last three decades in this field, but the development of systems for the recognition of complex hand-drawn structure depictions is still at the beginning. Currently, there is no data for the systematic evaluation of OCSR methods on hand-drawn structures available. Here we present DECIMER — Hand-drawn molecule images, a standardised, openly available benchmark dataset of 5088 hand-drawn depictions of diversely picked chemical structures. Every structure depiction in the dataset is mapped to a machine-readable representation of the underlying molecule. The dataset is openly available and published under the CC-BY 4.0 licence which applies very few limitations. We hope that it will contribute to the further development of the field.
Dephasing in quantum systems is typically the result of their interaction with environmental degrees of freedom. We investigate within a spin-boson model the influence of a super-Ohmic environment on the dynamics of a quantum two-state system. A super-Ohmic environment thereby models typical bulk phonons which are a common disturbance for solid state quantum systems as, for example, nitrogen-vacancy centers. By applying the numerically exact quasiadiabatic path-integral approach we show that for strong system-bath coupling, pseudocoherent dynamics emerges, i.e., oscillatory dynamics at short times due to slaving of the quantum system to the bath dynamics. We extend the phase diagram known for sub-Ohmic and Ohmic environments into the super-Ohmic regime and observe a pronounced nonmonotonous behavior. Super-Ohmic purely dephasing fluctuations strongly suppress the amplitude of coherent dynamics at very short times with no subsequent further decay at later times. Nevertheless, they render the dynamics overdamped. The corresponding phase separation line shows also a nonmonotonous behavior, very similar to the pseudocoherent dynamics.
We study a quantum two-level system under the influence of two independent baths, i.e., a sub-Ohmic pure dephasing bath and an Ohmic or sub-Ohmic relaxational bath. We show that cooling such a system invariably polarizes one of the two baths. A polarized relaxational bath creates an effective asymmetry. This asymmetry can be suppressed by additional dephasing noise. This being less effective, the more dominant low frequencies are in the dephasing noise. A polarized dephasing bath generates a large shift in the coherent oscillation frequency of the two-level system. This frequency shift is little affected by additional relaxational noise nor by the frequency distribution of the dephasing noise itself. As our model reflects a typical situation for superconducting phase qubits, our findings can help optimize cooling protocols for future quantum electronic devices.
This technical report is about the mission and the experience gained during the reconnaissance of an industrial hall with hazardous substances after a major fire in Berlin. During this operation, only UAVs and cameras were used to obtain information about the site and the building. First, a geo-referenced 3D model of the building was created in order to plan the entry into the hall. Subsequently, the UAVs were used to fly in the heavily damaged interior and take pictures from inside of the hall. A 360° camera mounted under the UAV was used to collect images of the surrounding area especially from sections that were difficult to fly into. Since the collected data set contained similar images as well as blurred images, it was cleaned from non-optimal images using visual SLAM, bundle adjustment and blur detection so that a 3D model and overviews could be calculated. It was shown that the emergency services were not able to extract the necessary information from the 3D model. Therefore, an interactive panorama viewer with links to other 360° images was implemented where the links to the other images depends on the semi dense point cloud and located camera positions of the visual SLAM algorithm so that the emergency forces could view the surroundings.
Description and Analysis of Glycosidic Residues in the Largest Open Natural Products Database
(2021)
Design and Development of a Bioreactor System for Mechanical Stimulation of Musculoskeletal Tissue
(2023)
We report on the development of a bioreactor system for mechanical stimulation of musculoskeletal tissues. The ultimate object is to improve the quality of medical treatment following injuries of the enthesis tissue. To this end, the tissue formation process through the effect of mechanical stimulation is investigated. A six-well system was designed, 3D printed and tested. An integrated actuator creates strain by applying a force. A contactless position sensor monitors the travels. An electronic circuit controls the bioreactor using a microcontroller. An IoT platform connects the microcontroller to a smartphone, enabling the user to alter variables, trigger actions and monitor the system. The system was stabilised by implementing two PID controllers and safety measures. The results show that the bioreactor design is suited to execute mechanical stimulation and to investigate the tissue formation and regeneration process …
In this research computer tomography (CT) iterative reconstruction (IR) algorithms are investigated, specifically the impact of their statistical and model-based strength on image quality in low-dose lung screening CT protocols in comparison to filtered back projection (FBP). It has been probed whether statistical, model-based IR in conjunction with low-dose, and ultra-low-dose protocols are suitable for lungcancer screening. To this end, artificial lung nodules shaped as spheres and spicules made from material with calibrated Hounsfield units (HU) were attached on marked positions in the lung structure of an anthropomorphic phantom. Nodule positions were selected by distinguished radiologists. The phantom with nodules was scanned on a CT Scanner using standard high contrast (SHC), low-dose (LD) and ultra low-dose (ULD) protocol. For reconstruction FBP and the IR algorithm ADMIRE at three different …
Three-dimensional magnetic resonance medical images may contain scanner- and patient-induced geometric distortion. For qualitative diagnosis, geometric errors of a few millimeters are often tolerated. However, quantitative applications such as image-guided neurosurgery and radiotherapy can require an accuracy of a millimeter or better. We have developed a method to accurately measure scanner-induced geometric distortion and to correct the MR images for this type of distortion. The method involves a number of steps. First, a specially designed phantom is scanned that contains a large number of reference structures on positions with a manufacturing error of less than 0.05 mm. Next, the positions of the reference structures are automatically detected in the scanned images and a higher-order polynomial distortion-correction transformation is estimated. Then the patient is scanned and the transformation is applied to correct the patient images for the detected distortion. The distortion-correction method is explained in detail in this paper. The accuracy of the method has been measured with synthetically generated phantom scans that contain an exactly-known amount and type of distortion. The reproducibility of the method has been measured by applying it to a series of consecutive phantom scans. Validation results are briefly described in this paper, a more-detailed description is given in another submission to SPIE Medical Imaging 2001.
As a rule, an experiment carried out at school or in undergraduate study
courses is rather simple and not very informative. However, when the experiments
are to be performed using modern methods, they are often abstract and
difficult to understand. Here, we describe a quick and simple experiment,
namely the enzymatic characterization of ptyalin (human salivary amylase)
using a starch degradation assay. With the experimental setup presented here,
enzyme parameters, such as pH optimum, temperature optimum, chloride
dependence, and sensitivity to certain chemicals can be easily determined. This
experiment can serve as a good model for enzyme characterization in general,
as modern methods usually follow the same principle: determination of the
activity of the enzyme under different conditions. As different alleles occur in
humans, a random selection of test subjects will be quite different with regard
to ptyalin activities. Therefore, when the students measure their own ptyalin
activity, significant differences will emerge, and this will give them an idea of
the genetic diversity in human populations. The evaluation has shown that the
pupils have gained a solid understanding of the topic through this experiment.
Carbon Nanofibers (CNF) are considered to be a promising catalyst support material due to their unique characteristics, excellent mechanical, electrical and structural properties, high surface area and nevertheless, good interaction with metallic catalyst particles. The possibility of preparing CNF decorated with platinum by an electrochemical method was tested, using a hexachloroplatinic bath solution. The experiments were carried out with the aid of a Potentiostat/Galvanostat Ivium Technologies Vertex, in a three – electrode cell. The aim of the present work was to determine the electrochemical surface area (ECSA) of the CNF-Pt catalysts in relation to the functionalization treatment of fibers, using an electrochemical method. ECSA for different functionalized CNF-Pt catalysts was determined by cyclic voltammetry in 0.5 M H2SO4 solution. The highest active surface of platinum was obtained for the samples with CNF functionalized by plasma treatment using 80 W for 1800 s. The obtained results correlate very well with the particles size and distribution of platinum, revealed by scanning electron microscopy (SEM) and the quantity of deposited platinum determined by thermo gravimetrical analysis (TGA) respectively. Cyclic voltammetry (CV) has been proven to be a suitable method for estimation of the ECSA of the electrocatalysts.
Platinum is one of the most effective electro catalysts for PEMFCs (proton exchange membrane fuel cells), but because of its prohibitive price, the use of this metal in industrial purposes is limited. As a consequence, during last years, several materials have been investigated, in order to obtain an efficient catalyst for both ORR (oxygen reduction reaction) and HOR (hydrogen oxidation reaction), which can replace the expensive platinum but preserving the same properties: high electrical conductivity, structural stability and good corrosion resistance. Moreover, one of the most important parameters for catalyst materials is the electrochemical surface area (real surface area), which has a strong influence on the reaction rate and also on the current density.
CNFs (carbon nanofibers) are considered to be a promising catalyst support material due to their unique characteristics, excellent mechanical, electrical and structural properties, high surface area and nevertheless, good interaction with platinum particles.
The possibility of preparing CNFs decorated with platinum by electrochemical methods was tested, using a hexachloroplatinic solution bath. The experiments were carried out with the aid of a Potentiostat/Galvanostat MMate 510, in a three – electrode cell.
The aim of the present work was to determine the electrochemical surface area of the CNFs – Pt catalysts, using an electrochemical method. The obtained results correlate very well with the particles size and distribution of platinum, analyzed by SEM (scanning electron microscopy) respectively with the quantity of deposited platinum determined by TG (thermo gravimetrical analyses). Cyclic voltammetry is a suitable method for estimation of the real surface area for catalyst particles.
Adhesive organs like arolia of insects allow these animals to climb on different substrates by creating high adhesion forces. According to the Dahlquist criterion, arolia must be very soft exhibiting an effective Young's modulus of below 100 kPa to adhere well to different substrates. In previous studies the effective Young´s moduli of adhesive organs were determined using indentation tests yielding their structure to be very soft indeed. However, arolia show a layered structure, thus the values measured by indentation tests comprise the effective Young´s moduli of the whole organs. In this study, a new approach is illustrated to measure the Young´s modulus of the outermost layer of the arolium, i.e. of the epicuticle, of the stick insect Carausius morosus by tensile testing. Due to the inner fibrous structure of the arolium tensile tests allow the characterisation of the overlying epicuticle.
For this experimental work gas diffusion electrodes (GDE) with low platinum loading are prepared for the application as anodes in polymer electrolyte membrane fuel cells. As catalyst support material, carbon nano fibres (CNF) are investigated due to high specific surface area as well as high graphitisation degree. Optimisation is achieved by an economic and environmental friendly pre-treatment process in oxygen plasma. For electrode preparation an ink is used containing oxygen plasma activated CNFs as well as hydrophilic polymer. After spray coating of this CNF ink on a graphitic substrate, platinum is deposited by pulse plating method. Preliminary results established that the plasma activation improves considerably CNF dispersibility as well as the amount, respectively, the morphology of the deposited platinum. Morphology and microstructure are observed by electron microscopy. Platinum loading is determined by thermogravimetric analysis to be in the range of 0.010 to 0.016 mg cm-2. Furthermore, MEAs are prepared from these GDEs and testing is performed in a novel modular test stack based on hydraulic compression. Technical information about the test stack design and functions are given in this work. In this test environment maximum specific power output of 182 mW cm-2 has been obtained under robust operation conditions.
The membrane electrode assemblies (MEA) for polymer electrolyte membrane fuel cells (PEMFC) developed at the Westphalian Energy Institute are based on oxygen plasma activated carbon nanotubes (CNT) doped with platinum particles. For electrode preparation an ink is used containing the activated CNTs as well as hydrophobic and hydrophilic material in solved form. After this ink is sprayed onto a graphitic substrate platinum particles are deposited by pulse plating method, where the plasma activation enhances CNT dispersibility as well as platinum deposition. This materials mixture is structured in nanoscale with the aim to increase the catalyst particles’ specific surface. For low reactance at operation, homogeneous compression of the MEA’s layers is necessary within a PEMFC. A novel stack architecture for electrochemical cells, especially PEMFC as well as PEM electrolysers, has been developed in order to achieve ideal cell operation conditions. Single cells of such a stack are inserted into flexible slots that are surrounded by a hydraulic medium which is pressurised during operation in order to achieve an even compression and cooling of the stack’s cells. With this stack design it has been possible to construct a test facility for simultaneous characterisation of several MEA samples. As compression and temperature conditions of every single sample are the same, the effects of e.g. different electrode configurations can be investigated with the novel test system.
This paper describes a new concept and experiences of a distributed interdisciplinary learning programme for students across continents. The aim is to provide students with a truly Global Intercultural Project Experience (GIPE) by working together with peers from around the world, and solving real-life client’s problems. We have received seed-funding for four annual projects to engage students from Germany (Europe), Namibia (Africa), Indonesia (Asia), and Peru (Latin-America). In 2020, 30 students from four continents engaged in a one-semester distributed software development project for a Namibian client. Despite Covid-19 they successfully completed the project expressing deep appreciation for the learning opportunities overcoming challenges of working across wide-spread time zones, cultures, changing requirements, and various technical challenges. Considering the vast learning benefits, we suggest to incorporate such projects in all tertiary education curricula across the globe.
Diversity Management - an approach to use people of different ages as a resource in enterprises
(2003)
Problem
- How to effectively use aerial robots to support rescue forces?
- How to achieve good flight characteristics and long flight times?
- How to enable simple and intuitive control?
- How to efficiently record image data of the environment?
- How to generate flight and image data for rescue forces?
Implementation:
The flying robot was designed in Autodesk Fusion360. In order to achieve high stability as well as low weight, the frame was milled from carbon. Mounts such as for GPS and 360° camera were 3D printed. A special feature is that the flying robot is not visible in the panoramic view of the 360° camera. The flight controller of the robot was set up using Ardupilot. The communication with the robot is done via MAVLink (UDP).To support different platforms, a software was realized as a web application. The front end was created using HTML, CSS and Javascript.
The back end is based on Flask-Socket-IO (Python). For the intelligent recognition of motor vehicles a micro controller with an integrated camera is used. For the post-processing of flight and video data a pipeline was implemented for automation.
This paper develops a framework for understanding the relationships between approaches to learning adopted by students in the context of higher education and the culture of the country they were brought up in. The paper, after examining the more widely used Kolb's learning styles, opts for another categorisation, namely the so called learning approaches developed by Entwistle and others (for example, Entwistle and Ramsden, 1983; Biggs, 1987; Entwistle, 1992; Tait, Entwistle and McCune, 1998; Biggs, Kember and Leung, 2001). Each of the main categories of learning approaches identified by his school, namely, deep, surface apathetic, and strategic are related to Hofstede's cultural dimensions, namely, power distance, individualism vs. collectivism, uncertainty avoidance, long vs. short time orientation and masculinity vs. femininity and a series of hypotheses developed that could be tested in cross cultural samples. This study would give practical hints on students moving out to study in different cultures (e.g. for higher education) and for teachers dealing with students from multiple cultures.
(PDF) Does culture influence learning styles in higher education?. Available from: https://www.researchgate.net/publication/254836756_Does_culture_influence_learning_styles_in_higher_education [accessed Jul 09 2018].
Competency-oriented exams offer a wide range of advantages, especially where the use and mastery of third-party applications and tools play an important role. Therefore, we developed a competency-oriented setup for both our programming classes and exams ensuring their constructive alignment.
Exams were moved to the computer lab and designed to test both conceptional skills as well as the use of state-of-the-art programming tools. At the peak of the COVID-19 pandemic, when exams had to be moved from lab to online, we needed to design an online setup for our practical programming exams preserving the competency-oriented approach and its constructive alignment as well as the validity, reliability and fairness of the exams. The key was to use the same online tools that have been introduced
for running lectures and practical classes offering almost the same learning experience as before the pandemic. However, to ensure the validity and fairness of the exams, some kind of online supervision needed to be implemented as technical solutions were found to be either unusable or not working
properly in our case. This paper discusses the driving factors, the resulting technical and organizational setup as well as students’ feedback and lessons learned for further improvements. Therefore, COVID-19 has not been able to ruin our competency-oriented programming exams.
When an open quantum system is driven by an external time-dependent force, the coupling of the driving to the central system is usually included, whereas the impact of the driving field on the bath is neglected. We investigate the effect of a quantum bath of linearly driven harmonic oscillators on the relaxation dynamics of a quantum two-level system which is not directly driven. In particular, we calculate the frequency-dependent response of the system when the bath is subject to Dirac and Gaussian driving pulses. We show that a time-retarded effective force on the system is induced by the driven bath which depends on the full history of the perturbation and the spectral characteristics of the underlying bath. In particular, when a structured Ohmic bath with a pronounced Lorentzian peak is considered, the dynamical response of the system to a driven bath is qualitatively different than that of the undriven bath. Specifically, additional resonances appear which can be directly associated with a Jaynes-Cummings-like effective energy spectrum.
A qualitative work‐flow analysis of a neurosurgical procedure indicates that the resolution of the image used to plan the intervention is the major source of inaccuracy. Quantitative experimental measurements confirm this observation. They fail, however, to explain the relationship between the accuracy of the frame components involved in a stereotactic procedure and the overall application accuracy. This investigation shows that the novel Gaussian approach is a flexible framework for the calculation of the application accuracy of frame systems. Therefore, the Gaussian approach provides a detailed understanding of the interplay between the various factors affecting accuracy. The basic ideas and limitations of the Gaussian approach are briefly explained. The effect of fiducial marker distribution and registration is investigated and shown to introduce a spatial dependence to the accuracy. The results of the Gaussian approach are compared with experimental data for three stereotactic frame devices: Leksell G, Cosman–Roberts–Wells, and Brown–Roberts–Wells. Although the Gaussian approach is an approximation, it reproduces the accuracy measured in the experiment within the statistical error of that experiment. Comp Aid Surg 4:77–86 (1999). © 1999 Wiley‐Liss, Inc.
In the polymer electrolyte membrane fuel cells (PEMFC) state of the art, rare and expensive platinum group metals (PGM) or PGM alloys are used as catalyst material. Reduction of PGMs in PEMFC electrodes is strongly required to reach cost targets for this technology. An optimal catalyst utilization is achieved in case of nano-structured particles supported on carbon material with a large specific surface area. In this study, graphitic material, in form of carbon nanofibers (CNF), is decorated with Pt particles, serving as catalyst material for PEMFC electrodes with low Pt loading. As a novelty, the effect of oxygen plasma treatment of CNFs previously to platinum particle deposition has been studied. Electrodes are investigated in respect of the optimal morphology, microstructure as well as electrochemical properties. Therefore, samples are characterized by means of scanning electron microscopy combined with energy dispersive X-ray analysis, transmission electron microscopy, thermogravimetry, X-ray diffraction as well as X-ray fluorescence analysis. In order to determine the electrochemical active surface area of catalyst particles, cyclic voltammetry has been performed in 0.5 M sulphuric acid. Selected samples have been investigated in a PEMFC test bench according to their polarization behavior.
In state of the art polymer electrolyte membrane fuel cells (PEMFC) rare and expensive platinum group metals (PGM) are used as catalyst material. Reduction of PGM in PEMFC electrodes is strongly required to reach cost targets for this technology. An optimal catalyst utilisation is achieved in the case of nano-structured particles supported on carbon material with a large specific surface area. In this study, graphitic material in form of carbon nanofibres (CNFs) is decorated with platinum (Pt) particles serving as catalyst material for PEMFC electrodes with low Pt loading. For electrode preparation CNFs have been previously activated by means of radio frequency induced oxygen plasma. This kind of treatment results in formation of functional groups on the CNF’s surface which directly influences the characteristics of subsequent Pt particle deposition. Different plasma parameters (plasma power, gas flow or exposure time) have to be set in order to achieve formation of oxygen containing functional groups (hydroxylic, carboxylic or carbonylic) on the CNF’s surface. In the frame of this experimental work, electrodes are investigated in respect of optimal morphology, microstructure as well as electrochemical properties. Therefore, samples were characterised by means of scanning electron microscopy combined with energy dispersive X-ray analysis, transmission electron microscopy, thermogravimetry, X-ray diffraction, X-ray fluorescence as well as polarisation measurements.
Efficient tool to calculate two-dimensional optical spectra for photoactive molecular complexes
(2015)
Flying insects employ elegant optical-flow-based strategies to solve complex tasks such as landing or obstacle avoidance. Roboticists have mimicked these strategies on flying robots with only limited success, because optical flow (1) cannot disentangle distance from velocity and (2) is less informative in the highly important flight direction. Here, we propose a solution to these fundamental shortcomings by having robots learn to estimate distances to objects by their visual appearance. The learning process obtains supervised targets from a stability-based distance estimation approach. We have successfully implemented the process on a small flying robot. For the task of landing, it results in faster, smooth landings. For the task of obstacle avoidance, it results in higher success rates at higher flight speeds. Our results yield improved robotic visual navigation capabilities and lead to a novel hypothesis on insect intelligence: behaviours that were described as optical-flow-based and hardwired actually benefit from learning processes.
Environmental Protection
(2018)
Environmental rocking ratchet: Environmental rectification by a harmonically driven avoided crossing
(2017)
We propose a rocking ratchet designed as a symmetric quantum two-state system driven by a single periodic harmonic force and influenced symmetrically by thermal fluctuations. We show that the necessary broken symmetry can dynamically be achieved by a thermal environment that couples to the energy difference between the two states and the tunnel coupling between them. The quantum two-state system is driven by the harmonic periodic drive through its avoided crossing. The correspondingly driven dissipative quantum dynamics results on average in a finite population difference between both states. This then causes directed particle transport.
The algorithm for automated functional groups detection and extraction of organic molecules developed by Peter Ertl is implemented on the basis of the Chemistry Development Kit (CDK).
Folder Basic contains the basic ErtlFunctionalGroupsFinder code and test code for integration in Java projects.
Folder CDK contains CDK library jar file cdk-2.2.jar that ErtlFunctionalGroupsFinder works with.
Folder Evaluation contains sample code for evaluation of functional groups with ErtlFunctionalGroupsFinder.
Folder JUnit 4 contains library jar files for unit testing.
Folder Performance contains a jar library for performance tests.
ErtlFunctionalGroupsFinder is described in the scientific literature
We argue that effective leadership development should be evidence-based, i.e. that it combines the best available scientific evidence with
research in the specific organizational context. To illustrate our proposition, we report findings from a case study in a multinational organization. The goal was to examine which rater source in the company’s 360 degree feedback would provide the most valid information about leadership competencies. Therefore, we explored relationships between 360 degree ratings and assessment center (AC) ratings of the same leadership competencies (N=151). It was predicted that AC ratings show higher overlap with 360 degree ratings for behaviors that specific rating
sources can more easily observe in the ratees’ work life. Results showed that peers were the most accurate observers of leadership competencies in 360 degree assessments, compared to managers and subordinates. This corroborates our argument for an evidence-based instead of an
intuitive handling of 360 degree feedback results. Practical implications and avenues for future research are discussed.
The purpose of this work was to develop and investigate a radiofrequency (RF) coil to perform image studies on small animals using the 7T magnetic resonance imaging (MRI) system, installed in the imaging platform in the autopsy room (Portuguese acronym PISA), at the University of Sao Paulo, Brazil, which is the unique 7T MRI scanner installed in South America. Due to a high demand to create new specific coils for this 7T system, it is necessary to carefully assess the distribution of electromagnetic (EM) fields generated by the coils and evaluate the patient/object safety during MRI procedures. To achieve this goal 3D numerical methods were used to design and analyse a 8-rungs transmit/receive linearly driven birdcage coil for small animals. Calculated magnetic field (B 1) distributions generated by the coil were crosschecked with measured results, indicating good confidence in the simulated results.