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- Fakultät Architektur und Gestaltung (41)
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Die Hochschule Konstanz Technik Wirtschaft und Gestaltung (HTWG) leistet sich einen technologischen Think-Tank: Das Open Innovation Lab. Es ist ein Labor, welches über Hierarchien und Fakultätsgrenzen hinweg für die Hochschulangehörigen geöffnet ist. Es leistet seinen Beitrag zu Lehre, Forschung und Transfer. Bezogen auf das Lernen ermöglicht das Labor, für den allgegenwärtigen Prozess der Digitalisierung soziale Verantwortung zu übernehmen und Kreativität im Umfeld technologischer Möglichkeiten zu entwickeln. Drei Ebenen wirken hier zusammen: das Individuum, das Miteinander und die übergreifende Organisationsstruktur.
Optical surface inspection
(2016)
Optical surface inspection: A novelty detection approach based on CNN-encoded texture features
(2018)
In inspection systems for textured surfaces, a reference texture is typically known before novel examples are inspected. Mostly, the reference is only available in a digital format. As a consequence, there is no dataset of defective examples available that could be used to train a classifier. We propose a texture model approach to novelty detection. The texture model uses features encoded by a convolutional neural network (CNN) trained on natural image data. The CNN activations represent the specific characteristics of the digital reference texture which are learned by a one-class classifier. We evaluate our novelty detector in a digital print inspection scenario. The inspection unit is based on a camera array and a flashing light illumination which allows for inline capturing of multichannel images at a high rate. In order to compare our results to manual inspection, we integrated our inspection unit into an industrial single-pass printing system.
Diese Bachelorarbeit behandelt die Prozessoptimierung des Bemusterungsprozesses mithilfe Lean und agilen Methoden. Die Arbeit orientiert sich dabei an dem Unternehmen Ed. Züblin AG und deren vorhandenen Möglichkeiten. Das Konzept lässt sich jedoch mindestens zu teilen mit den nötigen Anpassungen auf andere Unternehmen und Projekte übertragen. Mithilfe einer Wertstromanalyse und Interviews wurde der Ist-Prozess aufgezeigt. Dabei kamen verschiedene Durchführungen der Bemusterungen im Unternehmen mit unterschiedlichen Problemen zum Vorschein. Unter anderem gab es durch fehlende oder falsche Planung ständige Anforderungsänderungen, Lücken in der Durchführung und Einschränkungen in der Kommunikation. Eine Umstrukturierung des Prozessablaufes, Anpassungen in der Planung mithilfe von Sprints und Überlegungen zur Organisation und den Mitarbeitern sollen die Probleme in den Griff bekommen. Dieser Beitrag soll somit eine Aufklärung zur Bemusterung sein und Anreize und Ideen zur Verbesserung liefern.
Projekte aus dem Hochbau, wie z.B. Schulgebäude sind eine klassische Aufgabe der Tragwerksplanung. Dabei steht eine Vielzahl an unterschiedlichen Bauweisen zur Verfügung. Vor dem Hintergrund der Klimakrise und den damit verbundenen Klimaschutzzielen von Paris besteht akuter Handlungsbedarf in allen Bereichen des Lebens, besonders aber im Bausektor, welcher maßgeblich zu den gesamten Treibhausgasemissionen beiträgt. Deshalb wird momentan vermehrt auf Lösungen in Holzbauweise zurückgegriffen. Neben der Gründung nehmen die Geschossdecken den größten Anteil an den Umweltwirkungen ein. Dieser Anteil steigt mit zunehmender Deckenfläche an. Dadurch besteht ein großes Potenzial bei der Verringerung der Treibhausgasemissionen durch geeignete Auswahl des Deckensystems und Optimierung der Tragstruktur.
In Diskussionen über den Klimawandel wird oft eine nachhaltige Entwicklung thematisiert. Für den Vergleich wurde eine Optimierung durchgeführt zur Beurteilung des CO2-Einsparpotenziales. Um alle Aspekte der Nachhaltigkeit zu erfüllen, wurden die gefundenen Varianten auf Basis gängiger Zertifizierungssysteme für Nachhaltigkeit bewertet. Jede Variante erfüllt dabei die Anforderungen an maximale Spannungen und Verformungen. Durch die Optimierung und den folgenden Vergleich wurde das Optimierungspotenzial verdeutlicht. Gleichzeitig entstehen teilweise nutzungsbedingte Konflikte aus der Optimierung und Anforderungen aus dem Schallschutz.
Optimierungsansätze zur Verbesserung der Leistungsbeschreibungen bei öffentlichen Bauvorhaben
(2021)
Elbphilharmonie, BER, Bischofsresistenz Limburg, Stuttgart 21, Alter Elbtunnel Hamburg. Alles bekannte deutsche Bauprojekte der letzten 20 Jahre. Alle mit einer Gemeinsamkeit: Exorbitante Kostenexplosionen und Bauzeitenverzögerungen.
In dieser Arbeit wird aufgezeigt, weshalb solche Kostenexplosionen auch aufgrund von Unklarheiten bzw. Fehlern in Leistungsbeschreibungen entstehen und welches enorme Potential klare und erschöpfende Leistungsbeschreibungen haben, um bereits im Vorfeld eines Bauvorhabens die Weichen für einen reibungslosen und erfolgreichen Projektverlauf zu stellen.
According to the World Food Organization, nearly half of all root and tuber crops worldwide are not consumed, but are lost due to inappropriate storage and post-harvest losses. In developing countries such as Ethiopia, potatoes have not been dried, but are traditionally stored in potato clamps. So far, dried potatoes have not been converted into usable foods.
The aim of the present work is to convert potatoes - perishable rootlets and tubers - into stable products by hot air drying. Hot air dryers are economical to operate in industrialized countries. In Africa, this is reserved for larger industrial companies only. In regions with a tropical climate, however, the use of solar tunnel dryers is worthwhile. These are a good choice for farming and small industries and wherever electrical energy is difficult or impossible to obtain.
In a first part of the work, the drying process of potatoes was investigated, in particular with regard to the change of thermal, mechanical and chemical quality parameters. In an evaluation of the literature it was found that potatoes are not subject to quality changes if the water activityis below a value of 0.2. In order to determine the water content associated with this value at storage temperature, the known equations for the sorption equilibrium were evaluated and verified with own experimental investigations. This determined the end point of the drying process.
The following experimental investigations showed a process-dependent change of the quality criteria such as color, shrinkage, and mechanical properties as well as the content of valuedetermining substances such as vitamin C and starch. The differences in the course and magnitude of the quality changes were attributed to the glass transition that takes place during the drying process. For the determination of the glass transition temperature a new, simple method based on the measurement of mechanical properties could be developed. The knowledge of the glass transition temperature allowed optimizing the drying process. The drying process could be carried out in the rubbery or glassy region, depending on the expected quality changes. Thus, all information was available to produce high quality dried potatoes in an industrial process.
Since the production of potato products in less industrialized regions without sufficient supply of electrical energy should be included, potatoes were dried with a solar tunnel dryer. Examination of the quality properties mentioned above confirmed the process-dependent quality changes.
Finally, the dried product was ground and with the flour thus produced, wheat flour was replaced for baking bread. An evaluation of the finished bread by a panel showed that the acceptance of the bread according to the new recipe was high, also with regard to baking volume, taste, texture and color.
This work shows that by drying potatoes can be transformed a well accepted, storable and easily transportable product. The risk of losses or degradation is minimized. It can be produced on an industrial as well as on farm level. If the influence of the glass transition is taken into account, it is possible to optimize the quality of the product.
The intentions of the so-called "More Electrical Aircraft" (MEA) are higher efficiency and lower weight. A main topic here is the application of electrical instead of hydraulical, pneumatical and mechanical systems. The necessary power electronic devices have intermediate DC-links, which are typically supplied by a three-phase system with active B6 and passive B12 rectifiers. A possible alternative is the B6 diode bridge in combination with an active power filter (APF). Due to the parallel arrangement, the APF offers a higher power density and is able to compensate for harmonics from several devices. The use of the diode bridge rectifier alone is not permitted due to the highly distorted phase current. The following investigations are dealing with the development of an active power filter for a three-phase supply with variable frequency from 360 to 800 Hz. All relevant components such as inductors, EMC-filters, power modules and DC-link capacitor are designed. A particular focus is put on the customized power module with SiC-MOSFETs and SiC-diodes, which is characterized electrically and thermally. The maximum supply frequency slope has a value of 50 Hz/ms, which requires a high dynamic and robustness on the control algorithm. Furthermore, the content of 5th and 7th harmonics must be reduced to less than 2 %, which demands a high accuracy. To cope with both requirements, a two-stage filter algorithm is developed and implemented in two independent signal processors. Simulations and laboratory experiments confirm the performance and robustness of the control algorithm. This work comprehensively presents the design of aerospace rectifiers. The results were published in conferences and patents.
Organisation und Sprache
(2004)
Der radikale Wandel im Unternehmensumfeld bringt Unsicherheit und Komplexität mit sich. Daher ist ein Paradigmenwechsel im Management gefordert, denn scheinbar bewährte Rezepte funktionieren nicht mehr. Dieses Kapitel zeigt dazu, wie Führung 4.0 oder Digital Leadership die notwendigen dynamischen Fähigkeiten in der Organisation implementiert. Darüber hinaus wird dargestellt, wie eine Kernherausforderung der digitalen Transformation für etablierte Unternehmen gelingen kann – Ambidextrie (Beidhändigkeit) umzusetzen. Anhand zahlreicher Praxisbeispiele wird beschrieben, wie diese Beidhändigkeit – gleichzeitig das Kerngeschäft effizient zu optimieren und durch strategische Innovation in neue Geschäfte zu wachsen – strategische Erneuerung und digitale Transformation ermöglicht. Es wird aufgezeigt, wie die notwendige Unternehmerorientierung (Entrepreneur Orientation) gestärkt und Corporate Entrepreneurship erfolgreich umgesetzt werden kann. Als konkrete Option der Implementierung werden dazu unternehmerische, agile Teams – sogenannte eingebettete Unternehmerteams oder Corporate Start-ups – beschrieben. Auf Basis unserer Befragung von ca. 2000 Tech-Unternehmen und der Auswertung von mehr als 5000 Interviewminuten mit Geschäftsführern und Innovationsverantwortlichen in über 40 Unternehmen werden Empfehlungen zu Aufbau und Führung dieser Teams sowie kritische Erfolgsfaktoren erläutert.
Im Mittelpunkt des Forschungsprojekts steht die Intention, dem Management von Unternehmen (in Deutschland meist Vorstand oder Geschäftsführer) Empfehlungen zu geben, mit welchen unternehmerischen Maßnahmen sie die Erfüllung der an sie gestellten Organisations- und Aufsichtspflichten angemessen erfüllen können. Dabei wird der Fokus auf solche Maßnahmen gelegt, die im Rahmen eines umfassenden Compliance Management Systems implementiert werden, die dazu dienen, Fehlverhalten der Mitglieder eines Unternehmens zu verhindern und eine redliche und regelgetreue Führung der Geschäfte zu ermöglichen und sicherzustellen (sog. Business Conduct Compliance).
Organizational leadership
(2015)
To assess the quality of a person’s sleep, it is essential to examine the sleep behaviour by identifying the several sleep stages, their durations and sleep cycles. The established and gold standard procedure for sleep stage scoring is overnight polysomnography (PSG) with the Rechtschaffen and Kales (R-K) method. Unfortunately, the conduct of PSG is timeconsuming and unfamiliar for the subjects and might have an impact of the recorded data. To avoid the disadvantages with PSG, it is important to make further investigations in low-cost home diagnostic systems. For this intention it is necessary to find suitable bio vital parameters for classifying sleep stages without any physical impairments at the same time.
Due to the promising results in several publications we want to analyse existing methods for sleep stage classification based on the parameters body movement,
heartbeat and respiration. Our aim was to find different behaviour patterns in the several sleep stages. Therefore, the average values of 15 wholenight PSG recordings -obtained from the ‘DREAMS Subjects Database’- where analysed in the light of heartbeat, body movement and respiration with 10 different methods.
This Chapter introduces parameterized, or parametric, Model Order Reduction (pMOR). The Sections are offered in a prefered order for reading, but can be read independently. Section 5.1, written by Jorge Fernández Villena, L. Miguel Silveira, Wil H.A. Schilders, Gabriela Ciuprina, Daniel Ioan and Sebastian Kula, overviews the basic principles for pMOR. Due to higher integration and increasing frequency-based effects, large, full Electromagnetic Models (EM) are needed for accurate prediction of the real behavior of integrated passives and interconnects. Furthermore, these structures are subject to parametric effects due to small variations of the geometric and physical properties of the inherent materials and manufacturing process. Accuracy requirements lead to huge models, which are expensive to simulate and this cost is increased when parameters and their effects are taken into account. This Section introduces the framework of pMOR, which aims at generating reduced models for systems depending on a set of parameters.
Purpose The purpose of this paper is to find out tourism movement patterns via the tracking of tourists with the help of positioning systems like GPS in the rural area of the Lake Constance destination in Germany. In doing so past, present and future of tourist tracking is illustrated. Design/methodology/approach The tracking is realized via common smartphones extended by an app, with dedicated sensors like position loggers and a survey. The three different approaches are applied in order to compare and cross-check results (triangulation of data and methods). Findings Movement patterns turned out to be diverse and individualistic within the rural destination of Lake Constance and following an ants trail in sub-destinations like the city of Constance. Repeat visitors and first-time visitors alike always visit the bigger cities and main day-trip destinations of the Lake. A possible prediction tool enables new avenues of governing tourism movement patterns. Research limitations/implications The tracking techniques can be developed further into the direction of “quantified self” using gamification in order to make the tracking app even more attractive. Practical implications An algorithm-based prediction tool would offer new perspectives to the management of tourism movements. Social implications Further research is needed to overcome the feeling of invasiveness of the app to allow tracking with that approach. Originality/value This study is original and innovative because of the first-time use of a smartphone app in tourist tracking, the application on a rural destination and the conceptual description of a prediction tool.
Path planning and collision avoidance for safe autonomous vessel navigation in dynamic environments
(2017)
Stress and physical activities are important aspects of life of people. Body reactions on stress and on physical activities can be very similar but long-term stress leads to diseases and damages the body. Currently there is no method to differentiate easily and clearly between these two aspects in a time slot. We have confronted this problem while developing a mobile system for detection and analysis of stress. This paper presents an approach, which uses a long-term monitor with ECG/EKG capabilities and analysis of the heart rate data that is extracted from the device. The focus of the work is to find characteristics that are useful for differentiation between physical activity and stress.
Monitoring heart rate and breathing is essential in understanding the physiological processes for sleep analysis. Polysomnography (PSG) system have traditionally been used for sleep monitoring, but alternative methods can help to make sleep monitoring more portable in someone's home. This study conducted a series of experiments to investigate the use of pressure sensors placed under the bed as an alternative to PSG for monitoring heart rate and breathing during sleep. The following sets of experiments involved the addition of small rubber domes - transparent and black - that were glued to the pressure sensor. The resulting data were compared with the PSG system to determine the accuracy of the pressure sensor readings. The study found that the pressure sensor provided reliable data for extracting heart rate and respiration rate, with mean absolute errors (MAE) of 2.32 and 3.24 for respiration and heart rate, respectively. However, the addition of small rubber hemispheres did not significantly improve the accuracy of the readings, with MAEs of 2.3 bpm and 7.56 breaths per minute for respiration rate and heart rate, respectively. The findings of this study suggest that pressure sensors placed under the bed may serve as a viable alternative to traditional PSG systems for monitoring heart rate and breathing during sleep. These sensors provide a more comfortable and non-invasive method of sleep monitoring. However, the addition of small rubber domes did not significantly enhance the accuracy of the readings, indicating that it may not be a worthwhile addition to the pressure sensor system.
Sleep is an important aspect in life of every human being. The average sleep duration for an adult is approximately 7 h per day. Sleep is necessary to regenerate physical and psychological state of a human. A bad sleep quality has a major impact on the health status and can lead to different diseases. In this paper an approach will be presented, which uses a long-term monitoring of vital data gathered by a body sensor during the day and the night supported by mobile application connected to an analyzing system, to estimate sleep quality of its user as well as give recommendations to improve it in real-time. Actimetry and historical data will be used to improve the individual recommendations, based on common techniques used in the area of machine learning and big data analysis.
Assistive environments are entering our homes faster than ever. However, there are still various barriers to be broken. One of the crucial points is a personalization of offered services and integration of assistive technologies in common objects and therefore in a regular daily routine. Recognition of sleep patterns for the preliminary sleep study is one of the health services that could be performed in an undisturbing way. This article proposes the hardware system for the measurement of bio-vital signals necessary for initial sleep study in a non-obtrusive way. The first results confirm the potential of measurement of breathing and movement signals with the proposed system.
Personalmarketing
(2011)
Aufgrund der Corona-Pandemie kam es 2020 zu einer verstärkten Nutzung von Homeoffice und Teleworking. Sowohl bzgl. der Wahl des Arbeitsortes als auch der genutzen Kommunikationstechnologien existieren Pfadabhängigkeiten. Der Beitrag thematisiert diese Pfadabhängigkeiten systematisch, insbesondere ihre Ursachen und Folgen sowie die Möglichkeiten zur Pfadbrechung.
Die jüngeren Entscheidungen des EuGH sowie des BAG zur Arbeitszeiterfassung haben trotz ihrer eigentlich klaren Aussagen in der betrieblichen Praxis zu teils erheblichen Verunsicherungen geführt: Müssen nun wirklich die Arbeitszeiten der Beschäftigten erfasst werden und wie wirkt sich das auf die in vielen Unternehmen gelebte „Vertrauensarbeitszeit“ aus?
The multichannel Wiener filter (MWF) is a well-established noise reduction technique for speech processing. Most commonly, the speech component in a selected reference microphone is estimated. The choice of this reference microphone influences the broadband output signal-to-noise ratio (SNR) as well as the speech distortion. Recently, a generalized formulation for the MWF (G-MWF) was proposed that uses a weighted sum of the individual transfer functions from the speaker to the microphones to form a better speech reference resulting in an improved broadband output SNR. For the MWF, the influence of the phase reference is often neglected, because it has no impact on the narrow-band output SNR. The G-MWF allows an arbitrary choice of the phase reference especially in the context of spatially distributed microphones.
In this work, we demonstrate that the phase reference determines the overall transfer function and hence has an impact on both the speech distortion and the broadband output SNR. We propose two speech references that achieve a better signal-to-reverberation ratio (SRR) and an improvement in the broadband output SNR. Both proposed references are based on the phase of a delay-and-sum beamformer. Hence, the time-difference-of-arrival (TDOA) of the speech source is required to align the signals. The different techniques are compared in terms of SRR and SNR performance.
Philosophie & Rhetorik
(2020)
Photovoltaik
(2010)
Physik Methoden
(2023)
The Burrows–Wheeler transformation (BWT) is a reversible block sorting transform that is an integral part of many data compression algorithms. This work proposes a memory-efficient pipelined decoder for the BWT. In particular, the authors consider the limited context order BWT that has low memory requirements and enable fast encoding. However, the decoding of the limited context order BWT is typically much slower than the encoding. The proposed decoder pipeline provides a fast inverse BWT by splitting the decoding into several processing stages which are executed in parallel.
Pitting susceptibility of metastable austenitic stainless steels as a function of surface conditions
(2019)
The influence of surface roughness and local defects on pitting susceptibility of type 304 (UNS S30400) and type 301 (UNS S30100) in chloride solution were investigated. Because the mechanical properties can be regarded as decisive for the achieved surface quality, different properties of the base material were obtained by cold rolling the metastable austenites. This was done before the surfaces were finished. Therefor the surfaces were treated by different grinding parameters to generate different surface conditions and different defects. As a reference, different standardised surface finishes were used.
By using and comparing different methods for the characterization of surface roughness and surface texture, it is possible to find a relationship between the quantity and characteristics of local defects on the one hand and pitting susceptibility on the other hand. For the machining parameters used, a ranking of the influencing factors on the corrosion resistance achieved could be determined.
The automated application of software-based solutions for estimating the pitting susceptibility of machined surfaces and components will be discussed using concrete examples.
Pitting susceptibility of metastable austenitic stainless steels as a function of surface conditions
(2019)
Fachvortrag auf der 10th International European Stainless Steel Conference and 6th European Duplex Stainless Steel Conference (ESSC & DUPLEX 2019), 30.09. – 02.10.2019, Vienna, Austria
The detection of differences between images of a printed reference and a reprinted wood decor often requires an initial image registration step. Depending on the digitalization method, the reprint will be displaced and rotated with respect to the reference. The aim of registration is to match the images as precisely as possible. In our approach, images are first matched globally by extracting feature points from both images and finding corresponding point pairs using the RANSAC algorithm. From these correspondences, we compute a global projective transformation between both images. In order to get a pixel-wise registration, we train a learning machine on the point correspondences found by RANSAC. The learning algorithm (in our case Gaussian process regression) is used to nonlinearly interpolate between the feature points which results in a high precision image registration method on wood decors.
Der Einsatz von Plagiatssoftware sollte auf die Zielgruppe abgestimmt sein. Da die Beurteilung des digitalen Prüfberichts Expertenwissen voraussetzt, erscheint ein unbegleiteter Zugriff nicht sinnvoll. Da meist nicht mit Betrugsabsicht, sondern aus Regelunkenntnis plagiiert wird, ist eine Beschränkung auf eine flächendeckende Detektion keine Lösung. Umfassendes Regelwissen, ein Verständnis für die grundlegende Bedeutung intertextueller Bezüge sowie selbstverantwortliches Handeln sind Vermittlungsziele der HTWG-Schreibberatung. Zu diesem Zweck macht das HTWG-Modell den Schreibkursbesuch zur Zulassungsvoraussetzung für die freiwillige Plagiatskontrolle und behält sich die Deutungshoheit über den Prüfbericht vor.
Planspiel KLIMA 10.X
(1992)
Pop-up Workshopreihe
(2020)