Offenburg University of Applied Sciences
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Evaluation of Design Considerations for Radome Heating Foils in Automotive Radars
No full textSnow and ice layers can lead to functional impairments or unavailability of radar sensors, which are of particular concern to advanced driver assistance systems (ADAS) and autonomous driving (AD). This article discusses the evaluation of heating foils which are employed for the removal of snow and ice layers on radomes of automotive radars. Heating foils are made of wire grids embedded into a dielectric foil material, which is then integrated into bumpers or design-emblems. A comprehensive study of the transmission properties of the heating foils for the frequency range of 76 to 81 GHz is presented using analytical, simulative, and experimental approaches. A transmission measurement setup based on the quasi-optical technique was implemented to assess the transmission through the heating foils. As a result of this study, recommendations are made on the wire spacing that ensures minimum attenuation to the radar signals
Impact of footwear bending stiffness and torsional stiffness on ankle biomechanics during handballspecific fake-and-cut manoeuvres
No full textIn this study, the impact of footwear bending stiffness on ankle and foot biomechanics during indoor fake-and-cut manoeuvres was investigated. Footwear, along with torsional and bending stiffness, are hypothesized to influence the risk of ankle sprain injury. In this study, a mobile, pneumatically driven cantilever rig was used to quantify these footwear characteristics. Following this, participants executed fake-and-cut movements wearing their habitual footwear, while motion capture and force plate data were recorded. Utilizing machine learning clustering algorithms, participants were grouped based on their footwear stiffness. Subsequent SPM analysis revealed lower forefoot dorsiflexion and increased forefoot inversion in the stiff group. These findings underscore the need for further research on the interaction between shoe properties and injury risk indicators
Advanced predictive maintenance and fault diagnosis strategy for enhanced HVAC efficiency in buildings
No full textVariable refrigerant flow (VRF) systems are constantly prone to failures during their lifespan, causing breakdowns, high energy bills, and indoor discomfort. In addition to correctly identifying these defects, fault detection, and diagnostic studies should be able to anticipate and predict the anomalies before they occur for efficient maintenance. Therefore, this study introduces an efficient self-learning predictive maintenance system, CACMMS (Cloud Air Conditioning Monitoring & Management System), designed to anticipate refrigerant leaks in VRF systems. Unlike previous efforts, this system leverages advanced fault detection and diagnosis strategies in a real existing building to enhance prediction accuracy. The study employed three noise filtering models (Kalman filter, moving average, S-G smoothing) in the preprocessing phase. Ten features were selected for assessment, and four machine learning models (decision tree, random forest, K-nearest neighbor, support vector machine) were compared. The accuracy, precision, sensitivity, computation time as well and confusion matrix were used as performance indicators and metrics to evaluate and choose the best performant model. Results indicated that decision tree and random forest models achieved over 95 % accuracy with execution times between 0.70 s and 3.32 s, outperforming K-nearest neighbor and support vector machine models. These findings highlight the system’s potential to reduce downtime and energy costs through effective predictive maintenance
Retail-786k: a Large-Scale Dataset for Visual Entity Matching
No full textEntity Matching (EM) defines the task of learning to group objects by transferring semantic concepts from example groups (=entities) to unseen data. Despite the general availability of image data in the context of many EM-problems, most currently available EM-algorithms solely rely on (textual) meta data.
In this paper, we introduce the first publicly available large-scale dataset for "visual entity matching'', based on a production level use case in the retail domain. Using scanned advertisement leaflets, collected over several years from different European retailers, we provide a total of
786k manually annotated, high resolution product images containing
18k different individual retail products which are grouped into
3k entities. The annotation of these product entities is based on a price comparison task, where each entity forms an equivalence class of comparable products.
Following on a first baseline evaluation, we show that the proposed "visual entity matching'' constitutes a novel learning problem which can not sufficiently be solved using standard image based classification and retrieval algorithms. Instead, novel approaches which allow to transfer example based visual equivalent classes to new data are needed to address the proposed problem. The aim of this paper is to provide a benchmark for such algorithms
Selbstorganisation und Komplexitätsreduktion als Entscheidungswerkzeuge unter dynamischen Bedingungen
No full textDie Fähigkeit, Entscheidungen unter dynamischen Bedingungen zu treffen, ist eine zentrale Management-Kompetenz. In diesem Beitrag wollen wir vom Standpunkt aktueller Herausforderungen aus einen neuen Blick auf den etablierten Begriff der Selbstorganisation von Hermann Haken werfen, der hierauf Anwendungen aufweist
Zurück zu Stift und Papier
No full textDie Bildungspolitik in Deutschland - und auch in der Schweiz - läuft den europäischen und internationalen Entwicklungen hinterher. In vielen Ländern geht es nicht mehr um Konzepte der Frühdigitalisierung oder die 1:1-Ausstattung der Schülerinnen und Schüler mit Endgeräten. Im Gegenteil! Diese Staaten ersetzen in ihren Schulen Laptops und Tablets durch gedruckte Bücher und Schreibhefte; sie verbieten private Smartphones und sperren das Internet. Was ist passiert
Dispositif de commande pour un support circulatoire extracorporel lors d'une stimulation cardiaque
No full textThe invention relates to a method for the open-loop/closed-loop control of an extracorporeal circulatory support of a patient receiving at least periodic cardiac stimulation, and corresponding devices and systems. A corresponding method is also provided for the open-loop/closed-loop control of an extracorporeal circulatory support of a patient receiving at least periodic cardiac stimulation, comprising the following steps: receiving (10) an ECG signal of a supported patient over a predefined time period; detecting 12) one or more stimulation signals (20) of the supported patient; and evaluating the ECG signal to identify (16) at least one change (22) in amplitude characterising a cardiac cycle phase and provide (18) a trigger signal for the extracorporeal circulatory support based on the identified at least one amplitude change (22). According to the invention, the detection (12) of the at least one stimulation signal (20) occurs with a scanning frequency of at least 1 kHz.Die vorliegende Erfindung betrifft Verfahren zum Steuern/Regeln einer extrakorporalen Kreislaufunterstützung eines zumindest zeitweise herzstimulierten Patienten sowie entsprechende Vorrichtungen und Systeme. Entsprechend wird ein Verfahren zum Steuern/Regeln einer extrakorporalen Kreislaufunterstützung eines zumindest zeitweise herzstimulierten Patienten vorgeschlagen, umfassend die Schritte: Empfangen (10) eines EKG-Signals eines unterstützten Patienten über einen vorgegebenen Zeitraum; Erfassen (1 2) van einem oder mehreren Stimulationssignalen (20) des unterstützten Patienten; und Auswerten des EKG-Signals zum Identifizieren (16) mindestens einer für eine Herzzyklusphase charakteristische Amplitudenänderung (22) und Bereitstellen (18) eines Triggersignals für die extrakorporale Kreislaufunterstützung basierend auf der identifizierten mindestens einen Amplitudenänderung (22). Erfindungsgemäß erfolgt das Erfassen (12) des mindestens einen Stimulationssignals (20) mit einer Abtastfrequenz von mindestens 1 kHz.L'invention concerne un procédé de commande de boucle ouverte/boucle fermée d'un support circulatoire extracorporel d'un patient recevant au moins une stimulation cardiaque périodique, ainsi que des dispositifs et des systèmes correspondants. L'invention concerne également un procédé correspondant pour la commande de boucle ouverte/boucle fermée d'un support circulatoire extracorporel d'un patient recevant au moins une stimulation cardiaque périodique, comprenant les étapes suivantes consistant à : recevoir (10) un signal ECG d'un patient pris en charge sur une période de temps prédéfinie; détecter (12) un ou plusieurs signaux de stimulation (20) du patient pris en charge; et évaluer le signal ECG pour identifier (16) au moins un changement (22) en amplitude caractérisant une phase de cycle cardiaque et fournir (18) un signal de déclenchement pour le support circulatoire extracorporel sur la base du ou des changements d'amplitude identifiés (22). Selon l'invention, la détection (12) du ou des signaux de stimulation (20) a lieu avec une fréquence de balayage d'au moins 1 kHz
Measures and Technologies for a Low-Carbon Zambian Energy System
No full textThis report delves into the essential technologies and strategies that Zambia can adopt to transition towards a sustainable, low-carbon energy future. It is the second in a series of three reports and explores the intersection of technology, policy, and investment, providing a roadmap for reducing emissions while maintaining economic growth and improving energy security. The report acknowledges the significant challenges that lie ahead. Financing remains a major barrier, with limited access to capital for large-scale renewable projects and carbon removal initiatives. Additionally, the technical capacity to implement and maintain new technologies is still developing, requiring targeted training and knowledge transfer initiatives. With the right mix of policy incentives, technological investments, and international collaboration, Zambia could potentially position itself as a leader in low-carbon development within the region, while simultaneously achieving its climate goals and improving energy security
