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Partizipatives Parasitieren
(2016)
Dieses Lehr- und Übungsbuch ermöglicht dem Anfänger in der 3D-Modellierung einen schnellen Einstieg in die Arbeit mit dem neuen CAD-System Onshape. Als cloudbasierte Freeware bietet Onshape einen kostenlosen und einfachen Zugang zu CAD über das Internet. In diesem Buch wird als praktisches Übungsbeispiel ein Miniaturauto mit Ballonantrieb modelliert. Dabei werden die besonderen Anforderungen an eine 3D-Druck-gerechte Gestaltung erläutert und umgesetzt. Schwerpunkte bilden die grundlegenden Funktionen zur Modellierung von Einzelteilen und Baugruppen sowie die Erstellung von einfachen technischen Zeichnungen. Somit ist das Ergebnis dieser „Schritt für Schritt“-Anleitung die vollständige Modellierung eines Miniaturautos, das am 3D-Drucker in ein reales Modell umgesetzt und einfach zusammengebaut werden kann. Das didaktische Konzept ist so ausgelegt, dass alle Schritte für ein Selbststudium geeignet sind.
Vom Studenten zum Chef
(2016)
Langzeit-EKG-Scripte
(2016)
Journalist
(2016)
This work describes a non-parametric camera-based method for the calibration of Optical See-Through Glasses (OSTG). Existing works model the optical system through perspective projection and parametric functions. In the border areas of the displays such models are often inadequate. Moreover, rigid calibration patterns, that produce only a small amount of non-equidistant point correspondences, are used. In order to overcome these disadvantages every single display pixel is calibrated individually. The error prone user interaction is avoided by using cameras placed behind the displays of the OSTG. The displays show a shifting pattern that is used to calculate the pixels' locations. A camera mounted rigidly on the OSTG is used to find the relations between the system components. The obtained results show better accuracies than in previous works and prove that a second calibration step for user adaptation is necessary for high accuracy applications.
Gamification implies the application of methods and design patterns from gaming to non-gaming areas like learning or working. We applied an existing gamification design to production processes in an organization which provides sheltered employment for impaired persons. In contrast to existing work, we investigated not only a short period but a complete workday to measure the effects on the work performance. The study indicates that gamification has (1) a negative effect on workers with considerable cognitive impairments, (2) no significant effect on workers with medium cognitive impairments and (3) a positive effect on workers with mild cognitive impairments.
In this work, we investigate how gamification can be integrated into work processes in the automotive industry. The contribution contains five parts: (1) An introduction showing how gamification has become increasingly common, especially in education, health and the service industry. (2) An analysis on the state of the art of gamified applications, discussing several best practices. (3) An analysis of the special requirements for gamification in production, regarding both external norms and the mindset of workers in this domain. (4) An overview of first approaches towards a gamification of production, focusing on solutions for impaired workers in sheltered work organizations. (5) A study with a focus group of instructors at two large car manufacturers. Based on the presentation of three potential designs for the gamification of production, the study investigates the general acceptance of gamification in modern production and determines which design is best suited for future implementations.
The paper recommends an approach to estimate effectively the probability of buffer overflow in high-speed communication networks, capable of carrying diverse traffic, including self-similar teletraffic, and supporting diverse levels of quality of service. Simulations with stochastic, long-range dependent self-similar traffic source models are conducted. A new efficient algorithm, based on a variant of the RESTART/LRE method, is developed and applied to accelerate the buffer overflow simulation in a finite buffer single server model under long-range dependent self-similar traffic load with different buffer sizes. Numerical examples and simulation results are shown
Die Vielfalt der Protokolle, die praktisch auf allen Ebenen der Netzwerkkommunikation zu berücksichtigen ist, stellt eine der großen Herausforderungen bei der fortschreitenden Automatisierung des intelligenten Hauses dar. Unter dem Überbegriff Internet der Dinge (Internet of Things) entstehen gegenwärtig zahlreiche neue Entwicklungen, Standards, Allianzen und so genannte Ökosysteme. Diese haben die Absicht einer horizontalen Integration gewerkeübergreifender Anwendungen und verfolgen fast alle das Ziel, die Situation zu vereinfachen, die Entwicklungen zu beschleunigen und Markterfolge zu erreichen. Leider macht diese Vielfalt momentan die Welt aber eher noch komplexer und bringt damit das Risiko mit sich, genau das Gegenteil der ursprünglichen Absichten zu erreichen. Dieser Beitrag versucht, die Entwicklungen möglichst systematisch zu kategorisieren und mögliche Lösungsansätze zu beschreiben.
In the age data digitalization, important applications of optics and photonics based sensors and technology lie in the field of biometrics and image processing. Protecting user data in a safe and secure way is an essential task in this area. However, traditional cryptographic protocols rely heavily on computer aided computation. Secure protocols which rely only on human interactions are usually simpler to understand. In many scenarios development of such protocols are also important for ease of implementation and deployment. Visual cryptography (VC) is an encryption technique on images (or text) in which decryption is done by human visual system. In this technique, an image is encrypted into number of pieces (known as shares). When the printed shares are physically superimposed together, the image can be decrypted with human vision. Modern digital watermarking technologies can be combined with VC for image copyright protection where the shares can be watermarks (small identification) embedded in the image. Similarly, VC can be used for improving security of biometric authentication. This paper presents about design and implementation of a practical laboratory experiment based on the concept of VC for a course in media engineering. Specifically, our contribution deals with integration of VC in different schemes for applications like digital watermarking and biometric authentication in the field of optics and photonics. We describe theoretical concepts and propose our infrastructure for the experiment. Finally, we will evaluate the learning outcome of the experiment, performed by the students. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
High mobility, electrolyte-gated transistors (EGTs) show high DC performance at low voltages (< 2 V). To model those EGTs, we have used different models for the below and the above threshold regime with appropriate interpolation to ensure continuity and smoothness over all regimes. This empirical model matches very well with our measured results obtained by the electrical characterization of EGTs.
In a recent paper it has been shown that the effective nonlinear constant which is used in a P-Matrix approach to describe third-order intermodulation (IMD3) in surface acoustic wave (SAW) devices can be obtained from finite element (FEM) calculations of a periodic cell using nonlinear tensor data [1]. In this paper we extend this FEM calculation and show that the IMD3 of an infinite periodic array of electrodes on a piezoelectric substrate can be directly simulated in the sagittal plane. This direct approach opens the way for a FEM based simulation of nonlinearities for finite and generalized structures avoiding the simplifications of phenomenological approaches.
Physics-based Modeling of the Electric Arc furnace Process using Object-Oriented Language Modelica
(2016)
Electric arc furnaces (EAF) are complex industrial plants whose actual behavior depends upon numerous factors. Due to its energy intensive operation, the EAF process has always been subject to optimization efforts. For these reasons, several models have been proposed in literature to analyze and predict different modes of operation. Most of these models focused on the processes inside the vessel itself. The present paper introduces a dynamic, physics-based model of a complete EAF plant which consists of the four subsystems vessel, electric system, electrode regulation, and off-gas system. Furthermore the solid phase is not treated to be homogenous but a simple spatial discretization is employed. Hence it is possible to simulate the energy input by electric arcs and fossil fuel burners depending on the state of the melting progress. The model is implemented in object-oriented, equation-based language Modelica. The simulation results are compared to literature data.
The effect of fluctuating maskers on speech understanding of high-performing cochlear implant users
(2016)
Objective: The present study evaluated whether the poorer baseline performance of cochlear implant (CI) users or the technical and/or physiological properties of CI stimulation are responsible for the absence of masking release. Design: This study measured speech reception thresholds (SRTs) in continuous and modulated noise as a function of signal to noise ratio (SNR). Study sample: A total of 24 subjects participated: 12 normal-hearing (NH) listeners and 12 subjects provided with recent MED-EL CI systems. Results: The mean SRT of CI users in continuous noise was −3.0 ± 1.5 dB SNR (mean ± SEM), while the normal-hearing group reached −5.9 ± 0.8 dB SNR. In modulated noise, the difference across groups increased considerably. For CI users, the mean SRT worsened to −1.4 ± 2.3 dB SNR, while it improved for normal-hearing listeners to −18.9 ± 3.8 dB SNR. Conclusions: The detrimental effect of fluctuating maskers on SRTs in CI users shown by prior studies was confirmed by the current study. Concluding, the absence of masking release is mainly caused by the technical and/or physiological properties of CI stimulation, not just the poorer baseline performance of many CI users compared to normal-hearing subjects. Speech understanding in modulated noise was more robust in CI users who had a relatively large electrical dynamic range.
In diesem Beitrag wird die Anwendbarkeit von bereits in der Literatur beschriebenen und in der Praxis bewährten Entlastungsgeometrien für Wellenabsätze auf Zahnwellen mit freiem Auslauf mit der Methode der Finiten Elemente FEM untersucht. Dabei zeigte sich, dass eine direkte Verwendung der bestehenden Vorschläge nicht immer möglich war. Deshalb wurden diese Entlastungsnuten und -übergänge für eine beanspruchungsgerechte Anwendung im Bereich der Zahnwellen modifiziert und optimiert. Basierend auf den dabei erzielten Ergebnissen wurden neue konstruktive Möglichkeiten zur günstigsten Ausprägung der freien Auslaufgestaltung entwickelt und erforscht. Der beobachtete merkliche Abfall der Kerbspannung infolge von Entlastungsmöglichkeiten soll dem Konstrukteur einen Anlass geben, diese häufiger anzuwenden. Die Industrie, insbesondere kleinere Betriebe, können mithilfe der in diesem Aufsatz vorliegenden Erkenntnisse durch optimierte Dimensionierung der Profiwellen Kosten und Bauteilgewicht sparen.
Empirische Untersuchungen zum visuellen Wahrnehmen beim Lesen und Verstehen technischer Zeichnungen
(2016)
Es wurden 49 Einzelpersonen aus dem Studiengang „Maschinenbau“ der Hochschule Offenburg bei der Lösungssuche für eine zeichnerische Aufgabe mit Hilfe der Eyetracking-Technik beobachtet. Aus den Experimenten ergeben sich Aufschlüsse über das tatsächliche Vorgehen von Studierenden beim Lesen technischer Zeichnungen. Die Analyse der empirischen Untersuchungen legt die Vermutung nahe, dass die zunehmende Digitalisierung der Gesellschaft und der zunehmende Umgang mit elektronischen Kleinstgeräten verstärkt zu einem punktuellen und schnellen Wahrnehmungsverhalten führen. Ruhe und Gelassenheit im Umgang mit Informationen gehen verloren, ebenso das Denken im Kontext. Somit muss es Aufgabe der Lehre sein, wieder verstärkt ein ruhiges, strukturiertes und auf Zusammenhänge ausgerichtetes Vorgehen zu vermitteln und zu üben.
Today the methods of numerical simulation of sheet metal forming offer a great diversity of possibilities for optimization in product development and in process design. However, the results from simulation are only available as virtual models. Because there are any forming tools available during the early stages of product development, physical models that could serve to represent the virtual results are therefore lacking. Physical 3D-models can be created using 3D-printing and serve as an illustration and present a better understanding of the simulation results. In this way, the results from the simulation can be made more “comprehensible” within a development team. This paper presents the possibilities of 3D-colour printing with particular consideration of the requirements regarding the implementation of sheet metal forming simulation. Using concrete examples of sheet metal forming, the manufacturing of 3D colour models will be expounded upon on the basis of simulation results.
There is increasing evidence of central hyperexcitability in chronic whiplash-associated disorders (cWAD). However, little is known about how an apparently simple cervical spine injury can induce changes in cerebral processes. The present study was designed (1) to validate previous results showing alterations of regional cerebral blood flow (rCBF) in cWAD, (2) to test if central hyperexcitability reflects changes in rCBF upon non-painful stimulation of the neck, and (3) to verify our hypothesis that the missing link in understanding the underlying pathophysiology could be the close interaction between the neck and midbrain structures. For this purpose, alterations of rCBF were explored in a case-control study using H215O positron emission tomography, where each group was exposed to four different conditions, including rest and different levels of non-painful electrical stimulation of the neck. rCBF was found to be elevated in patients with cWAD in the posterior cingulate and precuneus, and decreased in the superior temporal, parahippocampal, and inferior frontal gyri, the thalamus and the insular cortex when compared with rCBF in healthy controls. No differences in rCBF were observed between different levels of electrical stimulation. The alterations in regions directly involved with pain perception and interoceptive processing indicate that cWAD symptoms might be the consequence of a mismatch during the integration of information in brain regions involved in pain processing.
There is a growing trend for the use of thermo-active building systems (TABS) for the heating and cooling of buildings, because these systems are known to be very economical and efficient. However, their control is complicated due to the large thermal inertia, and their parameterization is time-consuming. With conventional TABS-control strategies, the required thermal comfort in buildings can often not be maintained, particularly if the internal heat sources are suddenly changed. This paper shows measurement results and evaluations of the operation of a novel adaptive and predictive calculation method, based on a multiple linear regression (AMLR) for the control of TABS. The measurement results are compared with the standard TABS strategy. The results show that the electrical pump energy could be reduced by more than 86%. Including the weather adjustment, it could be demonstrated that thermal energy savings of over 41% could be reached. In addition, the thermal comfort could be improved due to the possibility to specify mean room set-point temperatures. With the AMLR, comfort category I of the comfort norms ISO 7730 and DIN EN 15251 are observed in about 95% of occasions. With the standard TABS strategy, only about 24% are within category I.
Adaptive predictive control of thermo-active building systems (TABS) based on a multiple regression algorithm: First practical test. Available from: https://www.researchgate.net/publication/305903009_Adaptive_predictive_control_of_thermo-active_building_systems_TABS_based_on_a_multiple_regression_algorithm_First_practical_test [accessed Jul 7, 2017].
All you need is sleep
(2016)
In 21st century, the century when the humanity hopes to embark on interplanetary travel, we are yet to fully reach an understanding of our very own idiosyncratic terra incognita – the human sleep. Sleep is a highly conserved evolutionary process that constitutes approximately one third of our life, and the lack or inadequate sleep may lead to impairment across multiple cognitive domains (Tononi and Cirelli, 2014; Lim and Dinges, 2010). Sleep deprivation also leads to aberrant brain functioning, immunological and metabolic collapse, and if it is sufficiently prolonged it will ultimately lead to death (Tononi and Cirelli, 2014).
Nickel cobalt aluminum oxide (NCA) based lithium-ion battery electrodes exhibit a distinct asymmetry in discharge/charge behavior towards high bulk stoichiometry (low state of charge). We show that basic electrochemical relationships, that is, the Nernst equation and the Butler-Volmer equation, are able to reproduce this behavior when a two-step reaction mechanism is assumed. The two-step mechanism consists of (1) lithium-ion adsorption from the electrolyte onto the active material particle surface under electron transfer, and (2) intercalation of surface-adsorbed lithium atoms into the bulk material. The asymmetry of experimental half-cell data of an NCA electrode cycled at 0.1 C-rate can be quantitatively reproduced with this simple model. The model parameters show two alternative solutions, predicting either a saturated (highly-covered) or a depleted surface for high bulk lithiation.
We present a novel scheme for Slotted ALOHA random access systems that combines physical-layer network coding (PLNC) with multiuser detection (MUD). The PLNC and MUD are applied jointly at the physical layer to be able to extract any linear combination of messages experiencing a collision within a slot. The set of combinations extracted from a whole frame is then processed by the receiver to recover the original packets. A simple precoding stage at the transmitting terminals allows the receiver to further decrease the packet loss rate. We present results for the decoding at the physical layer as well as several performance measures at frame level, namely, throughput, packet loss rate, and energy efficiency. The results we present are promising and suggest that a cross-layer approach leveraging on the joint use of PLNC and MUD can significantly improve the performance of random access systems in the presence of slow fading.
Wireless sensor networks have found their way into a wide range of applications among which environmental monitoring systems have attracted increasing interests of researchers. The main challenges for the applications are scalability of the network size and energy efficiency of the spatially distributed motes. These devices are mostly battery-powered and spend most of their energy budget on the radio transceiver module. A so-called Wake-On-Radio (WOR) technology can be used to achieve a reasonable balance among power consumption, range, complexity and response time. In this paper, a novel design for integration of WOR into IEEE802.1.5.4 is presented, which flexibly allows trade-offs in energy consumption between sender and receiver station, between real-time capability and energy consumption. For identical behavior, the proposed scheme is significantly more efficient than other schemes, which were proposed in recent publications, while preserving backward compatibility with standard IEEE802.15.4 transceivers.
Ultra wide band (UWB) signals are well suited both for short-range wireless communication and for high-precision localization applications. Channel impulse response (CIR) analysis in UWB systems is a major element in localization estimation. In this paper, practical aspects of CIR are presented. I.e. a technique for the construction of the accumulated echo-gram of a multipath delayed signal is proposed. Decawave hardware was used to demonstrate the technique of analysis of fine structure of signals with a sub-nanosecond resolution. Temporal stability, reliability and two-way characteristics of such echo-grams are discussed as well. The results of using two EVK1000 radio modules as a radar installation to detect a target in indoor environments prove that a low cost UWB intrusion detection and through-the-wall-vision systems might be developed using the proposed technique.
In the work at hand, we combine a Private Information Retrieval (PIR) protocol with Somewhat Homomorphic Encryption (SHE) and use Searchable Encryption (SE) with the objective to provide security and confidentiality features for a third party cloud security audit. During the auditing process, a third party auditor will act on behalf of a cloud service user to validate the security requirements performed by a cloud service provider. Our concrete contribution consists of developing a PIR protocol which is proceeding directly on a log database of encrypted data and allowing to retrieve a sum or a product of multiple encrypted elements. Subsequently, we concretely apply our new form of PIR protocol to a cloud audit use case where searchable encryption is employed to allow additional confidentiality requirements to the privacy of the user. Exemplarily we are considering and evaluating an audit of client accesses to a controlled resource provided by a cloud service provider.
Agile Business Intelligence als Beispiel für ein domänenspezifisch angepasstes Vorgehensmodell
(2016)
Business-Intelligence-Systeme stellen durch ihre Unterstützung bei der Entscheidungsfindung für Unternehmen eine wichtige Rolle dar. Mit einer stetig dynamischeren Unternehmensumwelt geht daher die Anforderung nach der agilen Entwicklung dieser Systeme einher, so dass in der BI-Domäne zunehmend erfolgreich agile Methoden und Vorgehensmodelle eingesetzt werden. Die Weiterentwicklung und Anpassung von BI-Systemen ist dahingehend besonders, dass diese in der Regel langjährig gewachsenen Systemen und Strukturen betreffen, die strengen regulatorischen Rahmenbedingungen unterliegen, was eine Herausforderung für agile Vorgehensweisen darstellt. Wurden die Werte und Prinzipien des agilen Manifests [AM01] und die daraus abgeleiteten Methoden zu Beginn meist eins zu eins auf den Bereich BI übertragen, so hat sich das Verständnis von BI- Agilität als ganzheitliche Eigenschaft der BI im deutschsprachigen Raum etabliert, und agile Me- thoden wurden auf die Besonderheiten der BI-Domäne adaptiert. In diesem Beitrag werden BI-Agilität und Agile BI erläutert, ein Ordnungsrahmen für Maßnahmen zur Steigerung der BI-Agilität eingeführt sowie Herausforderungen bei Agile BI erläutert.
Institute of Reliable Embedded Systems and Communication Electronics, Offenburg University of Applied Sciences, Germany has developed an automated testing environment, Automated Physical TestBeds (APTB), for analyzing the performance of wireless systems and its supporting protocols. Wireless physical networking nodes can connect to this APTB and the antenna output of this attaches with the RF waveguides. To model the RF environment this RF waveguides then establish wired connection among RF elements like splitters, attenuators and switches. In such kind of set up it’s well possible to vary the path characteristics by altering the attenuators and switches. The major advantage of using APTB is the possibility of isolated, well controlled, repeatable test environment in various conditions to run statistical analysis and even to execute regression tests. This paper provides an overview of the design and implementation of APTB, demonstrates its ability to automate test cases, and its efficiency.
Due to a controversial enrollment policy in most engineering programs at German Universities of Applied Sciences (UAS), many freshmen show very low school grades in key subjects like Math and Physics. Nevertheless they expect to be entertained in the lectures and get demotivated easily. Despite initial reservations, a cheer-and-challenge approach was developed for teaching Mechanics to freshmen having very diverse school grades. When tested, it showed astonishing results.
The Paper presents the design and development of a blended learning concept for an engineering course in the field of color representation and display technologies. A suitable learning environment is crucial for the success of the teaching scenario. A mixture of theoretical lectures and hands-on activities with practical applications and experiments, combined with the advantages of modern digital media is the main topic of the paper. Blended learning describes the didactical change of attendance periods and online periods. The e-learning environment for the online period is designed toward an easy access and interaction. Present digital media extends the established teaching scenarios and enables the presentation of videos, animations and augmented reality (AR). Visualizations are effective tools to impart learning contents with lasting effect. The preparation and evaluation of the theoretical lectures and the hands-on activities are stimulated and affects positively the attendance periods. The tasks and experiments require the students to work independently and to develop individual solution strategies. This engages and motivates the students, deepens the knowledge. The authors will present their experience with the implemented blended learning scenario in this field of optics and photonics. All aspects of the learning environment will be introduced.
IPv6 over LoRaWAN™
(2016)
Although short-range wireless communication explicitly targets local and regional applications, range continues to be a highly important issue. The range directly depends on the so-called link budget, which can be increased by the choice of modulation and coding schemes. The recent transceiver generation in particular comes with extensive and flexible support for software-defined radio (SDR). The SX127× family from Semtech Corp. is a member of this device class and promises significant benefits for range, robust performance, and battery lifetime compared to competing technologies. This contribution gives a short overview of the technologies to support Long Range (LoRa™) and the corresponding Layer 2 protocol (LoRaWAN™). It particularly describes the possibility to combine the Internet Protocol, i.e. IPv6, into LoRaWAN™, so that it can be directly integrated into a full-fledged Internet of Things (IoT). The proposed solution, which we name 6LoRaWAN, has been implemented and tested; results of the experiments are also shown in this paper.
Battery degradation is a complex physicochemical process that strongly depends on operating conditions and environment. We present a model-based analysis of lithium-ion battery degradation in smart microgrids, in particular, a single-family house and an office tract with photovoltaics generator. We use a multi-scale multi-physics model of a graphite/lithium iron phosphate (LiFePO4, LFP) cell including SEI formation as ageing mechanism. The cell-level model is dynamically coupled to a system-level model consisting of photovoltaics, inverter, power consumption profiles, grid interaction, and energy management system, fed with historic weather data. The behavior of the cell in terms of degradation propensity, performance, state of charge and other internal states is predicted over an annual operation cycle. As result, we have identified a peak in degradation rate during the battery charging process, caused by charging overpotentials. Ageing strongly depends on the load situation, where the predicted annual capacity fade is 1.9 % for the single-family house and only 1.3 % for the office tract.
Wireless communication systems more and more become part of our daily live. Especially with the Internet of Things (IoT) the overall connectivity increases rapidly since everyday objects become part of the global network. For this purpose several new wireless protocols have arisen, whereas 6LoWPAN (IPv6 over Low power Wireless Personal Area Networks) can be seen as one of the most important protocols within this sector. Originally designed on top of the IEEE802.15.4 standard it is a subject to various adaptions that will allow to use 6LoWPAN over different technologies; e.g. DECT Ultra Low Energy (ULE). Although this high connectivity offers a lot of new possibilities, there are several requirements and pitfalls coming along with such new systems. With an increasing number of connected devices the interoperability between different providers is one of the biggest challenges, which makes it necessary to verify the functionality and stability of the devices and the network. Therefore testing becomes one of the key components that decides on success or failure of such a system. Although there are several protocol implementations commonly available; e.g., for IoT based systems, there is still a lack of according tools and environments as well as for functional and conformance testing. This article describes the architecture and functioning of the proposed test framework based on Testing and Test Control Notation Version 3 (TTCN-3) for 6LoWPAN over ULE networks.
In the last decade, IPv6 over Low power Wireless Personal Area Networks (IEEE802.15.4), also known as 6LoWPAN, has well evolved as a primary contender for short range wireless communications and holds the promise of an Internet of Things, which is completely based on the Internet Protocol. The authors' team has developed a 6LoWPAN protocol stack in C language, the stack without the necessity to use a specific design environment or operating system. It is highly flexible, modular, and portable and can be enhanced by several interesting modules, like a Wake-On-Radio-(WOR) MAC layer or a TLS1.2 based security sublayer. The stack is made available as open source at https://github.com/hso-esk/emb6. It was extensively tested on the Automated Physical Testbed (APTB) for Wireless Systems, which is available in the authors' lab and allows a flexible setup and full control of arbitrary topologies. The results of the measurements demonstrate a very good stability and short-term with long-term performance also under dynamic conditions.
Practical exercises are a crucial part of many curricula. Even simple exercises can improve the understanding of the underlying subject. Most experimental setups require special hardware. To carry out e. g. a lens experiments the students need access to an optical bench, various lenses, light sources, apertures and a screen. In our previous publication we demonstrated the use of augmented reality visualization techniques in order to let the students prepare with a simulated experimental setup. Within the context of our intended blended learning concept we want to utilize augmented or virtual reality techniques for stationary laboratory exercises. Unlike applications running on mobile devices, stationary setups can be extended more easily with additional interfaces and thus allow for more complex interactions and simulations in virtual reality (VR) and augmented reality (AR). The most significant difference is the possibility to allow interactions beyond touching a screen. The LEAP Motion controller is a small inexpensive device that allows for the tracking of the user’s hands and fingers in three dimensions. It is conceivable to allow the user to interact with the simulation’s virtual elements by the user’s very hand position, movement and gesture. In this paper we evaluate possible applications of the LEAP Motion controller for simulated experiments in augmented and virtual reality. We pay particular attention to the devices strengths and weaknesses and want to point out useful and less useful application scenarios. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
BiCI users’ sensitivity to interaural phase differences for single- and multi-channel stimulation
(2016)
Aufgrund der zunehmenden Bedeutung von E-Prüfungen an Hochschulen und Universitäten werden Lösungen benötigt, die eine einfache, schnelle und sichere Nutzung von bestehenden Poolräumen für verschiedene Prüfungsszenarien ermöglichen. Das Projekt bwLehrpool hat in der Vergangenheit gezeigt, dass mit Hilfe von Virtualisierung eine große Anzahl an unterschiedlichen, individualisierten Lehrumgebungen flexibel und räumlich unabhängig verteilt werden kann. Im nächsten Schritt sollen nun Erweiterungen entwickelt werden, die diese Flexibilität auch für elektronische Prüfungen nutzbar macht. Dabei gilt es vor allem, die Vorteile, wie z.B. die Nutzung von Softwareunterstützung für realitätsnahe Aufgabenstellungen, mit der Notwendigkeit nach größtmöglicher Sicherheit und schneller Umrüstzeit der Infrastruktur in Einklang zu bringen. Um den aktuellen Entwicklungsstand zu testen, wurde im Wintersemester 2015/2016 an der Hochschule Offenburg eine E-Prüfung unter bwLehrpool durch über 140 Studierende durchgeführt. Die Ergebnisse zeigen, dass die Anforderungen bisher erfolgreich umgesetzt werden konnten, allerdings noch mehr manueller Aufwand nötig ist, als gewünscht. Der Ablauf soll in Zukunft weiter vereinfacht und verstetigt werden.
With our society moving towards Industry 4.0, an increasing number of tasks and procedures in manual workplaces are augmented with a digital component. While the research area of Internet-of-Things focuses on combining physical objects with their digital counterpart, the question arises how the interface to human workers should be designed in such Industry 4.0 environments. The project motionEAP focuses on using Augmented Reality for creating an interface between workers and digital products in interactive workplace scenarios. In this paper, we summarize the work that has been done in the motionEAP project over the run-time of 4 years. Further, we provide guidelines for creating interactive workplaces using Augmented Reality, based on the experience we gained.
The uncertain and time-variant nature of renewable energy results in the need to deal with peaks in the production of energy. One approach is to achieve a load shift and thereby help balancing the grid by using thermally Activated Building Systems (TABS). Control systems currently in place do not exploit the full potential of TABS. This paper reviews how Model Predictive Control can possibly reduce the fluctuations of the demand and supply of (renewable) energy as it enables the TABS to react to the dynamics of weather and its impact on the grid at any time.
Die Verwendung von Kameras als Messmittel für medizinische Anwendungen setzt deren präzise Kalibrierung voraus. Gängige Verfahren modellieren die Abbildungseigenschaften einer Kamera mittels perspektivischer Projektion und parametrisierter Funktionen zur Beschreibung von Linsenverzerrung. In den Randbereichen des Kamerabildes sind diese Modelle oft unzureichend. Außerdem bedingt die Verwendung starrer Kalibriermuster eine in der Regel kleine Anzahl an nicht gleichmäßig verteilten Punktkorrespondenzen zur Bestimmung der Modellparameter. In der vorliegenden Arbeit wird ein vollkommen neues und nicht auf Modellen basierendes Kalibrierverfahren vorgestellt, bei dem jedes Kamerapixel unabhängig von jedem anderen kalibriert wird.
Virtuelle Modell "begreifbar" Machen - Darstellung von Simulationsergebnissen mittels 3D-Farbdruck
(2016)
Einsatz von Additive Manufacturing zur Darstellung von Simulationsergebnissen in der Blechumformung
(2016)
Die Namen Cormack und Hounsfield sind für den Radiologen zu einem wichtigen Synonym für die Computertomographie (CT) geworden. Der mathematische Wegbereiter für die CT, Johann Radon, kommt in der radiologischen Diskussion und den historischen Rückblicken hingegen oft zu Unrecht zu kurz. Die folgende Kurzübersicht möchte daher dem interessierten Leser die wichtigsten historischen Eckdaten zu dem in vielerlei Hinsicht bewegenden Leben und Wirken dieses großen Mathematikers näherbringen.
This is a commentary note on the situation of functional neuroimaging in psychiatry. With this we would like to encourage psychiatrists and the journal editors of psychiatric and related journals to at least rethink the role of functional neuroimaging in this discipline and use these imaging techniques in their various aspects of clinical diagnosis and therapy regimens,respectively.
eLetter zum Artikel "How hair can reveal a history" von Hanae Armitage & Nala Rogers, veröffentlicht in Science, Vol. 351, Issue 6278, Seite 1134 (doi.org/10.1126/science.351.6278.1134)
Die vorliegende Arbeit setzt sich mit dem Thema YouTube als Teil der Jugendkultur auseinander. Dabei wird der Frage nachgegangen, inwiefern sich die Nutzung der Videoplattform auf das Verhalten der Jugendlichen auswirkt. Im Zuge dessen sollen zudem Einblicke darüber gewonnen werden, welchen Einfluss YouTube auf die Lebenswelt der Jugendlichen nimmt. Diese Fragestellungen werden auf Basis aktu- eller Fachliteratur und vor dem Hintergrund der Erkenntnisse aus quantitativer und qualitativer Befragung diskutiert. So können mengenmäßig erhobene Daten durch die Einbindung subjektiver Meinungen unterstützt werden.
Die starke Nachfrage für wirtschaftliche und technische Lösungen zur Umsetzung der Energiewende wirkt sich auch auf Projektinitiativen der Forschungsgruppen am Institut für Energiesystemtechnik (INES) der Hochschule Offenburg aus. Am Campus Nord entsteht seit 2012 ein intelligentes Energienetz als Reallabor, das als Teil eines Smart Grid betrieben werden kann.
Forschung im Fokus 2016
(2016)
Energy and environment continue to be major issues of human mankind. This holds true on the regional, the national, and the global level. And it is one of the problems, where engineers and scientists in conjunction with political will and people's awareness, can find new approaches and solutions to save the natural resources and to make their use more efficient.
Campus Winter 2016/2017
(2016)
Campus Sommer 2016
(2016)
MPC-Workshop Februar 2016
(2016)
Die vorliegende Bachelor-Thesis befasst sich mit dem Potential von Onlinevideos sowohl für Privatpersonen, als auch für Unternehmen sowie mit den dazugehörigen Erfolgsfaktoren am Beispiel der Videoplattform YouTube. Die sogenannten YouTuber sind angemeldete Nutzer, die selbst Videocontent produzieren. Mittels eines Monetarisierungssystems seitens YouTube können die entsprechenden Kanalbetreiber Einnahmen generieren. Unternehmen hingegen können das Portal nutzen, um zielgerichtet ihre Werbung zu platzieren. Diese Abschlussarbeit deckt die erfolgversprechenden Hintergründe sowie die Umsetzungsstrategien auf, um dadurch eine der effektivsten Werbemöglichkeiten optimal einsetzen zu können.
We herein present a topology design method based on local optimality criteria which has been implemented in an open source Navier-Stokes solver for turbulent flows. Our method aims for the fast generation of geometry proposals in the early conceptual phase. To the best of our knowledge, this is the first local criteria approach utilizing a wall function turbulence model in order to consider turbulent flows. In order to allow for the growth as well as the shrinkage, or even the formation or disappearance of structural features, a topological approach is chosen. By introducing a volume fraction parameter, we distinguish between fluid and solid properties in each control volume. The fluid-solid interface is represented by an immersed boundary method using a piecewise linear surface reconstruction.
Die neueste Generation von programmierbaren Logikbausteinen verfügt neben den konfigurierbaren Logikzellen über einen oder mehrere leistungsfähige Mikroprozessoren. In dieser Arbeit wird gezeigt, wie ein bestehendes Zwei-Chip-System auf einen Xilinx Zynq 7000 mit zwei ARM A9-Cores migriert wird. Bei dem System handelt es sich um das „GPS-gestützte Kreisel-system ADMA“ des Unternehmens GeneSys. Die neue Lösung verbessert den Datenaustausch zwischen dem ersten Mikroprozessor zur digitalen Signalverarbeitung und dem zweiten Prozessor zur Ablaufsteuerung durch ein Shared Memory. Für die schnelle und echtzeitfähige Datenübertragung werden zahlreiche hochbitratige Schnittstellengenutzt.
This paper describes the new Sweaty II humanoid adult size robot trying to qualify for the RoboCup 2016 adult size humanoid competition. Based on experiences during RoboCup 2014, the Sweaty robot has been completely redesigned to a new robot Sweaty II. A major change is the use of linear actuators for the legs. Another characteristic is its indirect actuation by means of rods. This allows a variable transmission ratio depending on the angle of a joint.
The humanoid Sweaty was the finalist in this year’s robocup soccer championship(adult size). For the optimization of the gait and the stability, data concerning forces and torques in the ankle joints would be helpful. In the following paper the development of a six-axis force and torque sensor for the humanoid robot Sweaty is described. Since commercial sensors do not meet the demands for the sensors in Sweatys ankle joints, a new sensor was developed. As a measuring devices we used strain gauges and custom electronics based on an acam PS09. The geometry was analyzed with the FEM program ANSYS to get optimal dimensions for the measuring beams. In addition ANSYS was used to optimize the position for the strain gauges on the beam.
The Metering Bus, also known as M-Bus, is a European standard EN13757-3 for reading out metering devices, like electricity, water, gas, or heat meters. Although real-life M-Bus networks can reach a significant size and complexity, only very simple protocol analyzers are available to observe and maintain such networks. In order to provide developers and installers with the ability to analyze the real bus signals easily, a web-based monitoring tool for the M-Bus has been designed and implemented. Combined with a physical bus interface it allows for measuring and recording the bus signals. For this at first a circuit has been developed, which transforms the voltage and current-modulated M-Bus signals to a voltage signal that can be read by a standard ADC and processed by an MCU. The bus signals and packets are displayed using a web server, which analyzes and classifies the frame fragments. As an additional feature an oscilloscope functionality is included in order to visualize the physical signal on the bus. This paper describes the development of the read-out circuit for the Wired M-Bus and the data recovery.
Towards a gamification of industrial production: a comparative study in sheltered work environments
(2015)
Using video game elements to improve user experience and user engagement in non-game applications is called "gamification". This method of enriching human-computer interaction has been applied successfully in education, health and general business processes. However, it has not been established in industrial production so far.
After discussing the requirements specific for the production domain we present two workplaces augmented with gamification. Both implementations are based on a common framework for context-aware assistive systems but exemplify different approaches: the visualization of work performance is complex in System 1 and simple in System 2.
Based on two studies in sheltered work environments with impaired workers, we analyze and compare the systems' effects on work and on workers. We show that gamification leads to a speed-accuracy-tradeoff if no quality-related feedback is provided. Another finding is that there is a highly significant raise in acceptance if a straightforward visualization approach for gamification is used.
Design approaches for the gamification of production environments: a study focusing on acceptance
(2015)
Gamification is an ever more popular method to increase motivation and user experience in real-world settings. It is widely used in the areas of marketing, health and education. However, in production environments, it is a new concept. To be accepted in the industrial domain, it has to be seamlessly integrated in the regular work processes.
In this work we make the following contributions to the field of gamification in production: (1) we analyze the state of the art and introduce domain-specific requirements; (2) we present two implementations gamifying production based on alternative design approaches; (3) these are evaluated in a sheltered work organization. The comparative study focuses acceptance, motivation and perceived happiness.
The results reveal that a pyramid design showing each work process as a step on the way towards a cup at the top is strongly preferred to a more abstract approach where the processes are represented by a single circle and two bars.
A wet-chemical treatment system for electrochemically coating flat substrates with coating material, has having a basin for receiving an electrolyte, a transporting means, by means of which the flat substrates can be transported through the electrolyte horizontally, and at least one contact element which comprises a shaft having an axis of rotation and a cylindrical circumferential surface suitable for rolling on the substrate, wherein the circumferential surface comprises at least one electrically insulated segment and at least one electrically conductive segment which can be connected to a current source in such a way that the polarity can be reversed, wherein the axis of rotation of the contact element is positioned above the surface of the electrolyte, and wherein the contact element is designed as a consumable electrode.
With projectors and depth cameras getting cheaper, assistive systems in industrial manufacturing are becoming increasingly ubiquitous. As these systems are able to continuously provide feedback using in-situ projection, they are perfectly suited for supporting impaired workers in assembling products. However, so far little research has been conducted to understand the effects of projected instructions on impaired workers. In this paper, we identify common visualizations used by assistive systems for impaired workers and introduce a simple contour visualization. Through a user study with 64 impaired participants we compare the different visualizations to a control group using no visual feedback in a real world assembly scenario, i.e. assembling a clamp. Furthermore, we introduce a simplified version of the NASA-TLX questionnaire designed for impaired participants. The results reveal that the contour visualization is significantly better in perceived mental load and perceived performance of the participants. Further, participants made fewer errors and were able to assemble the clamp faster using the contour visualization compared to a video visualization, a pictorial visualization and a control group using no visual feedback.
The invention concerns a method for spectrum monitoring a given frequency band, in which the spectral power density (S(f)) within the given frequency band is determined for all noise and signal components in the frequency band and, in order to detect the presence of one or more signals within the given frequency band, it is evaluated whether the spectral power density (S(f)) exceeds a threshold value (&lgr;). According to the invention, the threshold value (&lgr;) is calculated in accordance with an estimation of a distribution density (hR(S)) for the noise component of the spectral power density (S(f)) within the given frequency band and in accordance with a predefined value for the false-alarm probability (Pfa).
In this work we provide an overview of gamification, i.e. the application of methods from game design to enrich non-gaming processes. The contribution is divided into five subsections: an introduction focusing on the progression of gamification through the hype cycle in the recent years (1), a brief introduction to gamification mechanics (1) and an overview of the state of the art in established areas (3). The focus is a discussion of more recent attempts of gamification in service and production (4). We also discuss the ethical implications (5) and the future perspectives (6) of gamified business processes. Gamification has been successfully applied in the domains education (serious games) and health (exergames) and is spreading to other areas. In recent years there have been various attempts to “gamify” business processes. While the first efforts date back as far as the collection of miles in frequent flyer programs, we will portray some of the more recent and comprehensive software-based approaches in the service industry, e.g. the gamification of processes in sales and marketing. We discuss their accomplishments as well as their social and ethical implicatio. Finally a very recent approach is presented: the application of gamification in the domain of industrial production. We discuss the special requirements in this domain and the effects on the business level and on the users. We conclude with a prognosis on the future development of gamification.
It is the purpose of this paper to address ethical issues concerning the development and application of Assistive Technology at Workplaces (ATW). We shall give a concrete technical concept how such technology might be constructed and propose eight technical functions it should adopt in order to serve its purpose. Then, we discuss the normative questions why one should use ATW, and by what means. We argue that ATW is good to the extent that it ensures social inclusion and consider four normative domains in which its worth might consists in. In addition, we insist that ATW must satisfy two requirements of good workplaces, which we specify as (a) an exploitation restraint and (b) a duty of care.
The Effect of Gamification on Emotions - The Potential of Facial Recognition in Work Environmentsns
(2015)
Gamification means using video game elements to improve user experience and user engagement in non-game services and applications. This article describes the effects when gamification is used in work contexts. Here we focus on industrial production. We describe how facial recognition can be employed to measure and quantify the effect of gamification on the users’ emotions.
The quantitative results show that gamification significantly reduces both task completion time and error rate. However, the results concerning the effect on emotions are surprising. Without gamification there are not only more unhappy expressions (as to expect) but surprisingly also more happy expressions. Both findings are statistically highly significant.
We think that in redundant production work there are generally more (negative) emotions involved. When there is no gamification happy and unhappy balance each other. In contrast gamification seems to shift the spectrum of moods towards “relaxed”. Especially for work environments such a calm attitude is a desirable effect on the users. Thus our findings support the use of gamification.
Video game developers continuously increase the degree of details and realism in games to create more human-like characters. But increasing the human-likeness becomes a problem in regard to the Uncanny Valley phenomenon that predicts negative feelings of people towards artificial entities. We developed an avatar creation system to examine preferences towards parametrized faces and explore in regard to the Uncanny Valley phenomenon how people design faces that they like or reject. Based on the 3D model of the Caucasian average face, 420 participants generate 1341 faces of positively and negatively associated concepts of both gender. The results show that some characteristics associated with the Uncanny Valley are used to create villains or repulsive faces. Heroic faces get attractive features but are rarely and little stylized. A voluntarily designed face is very similar to the heroine. This indicates that there is a tendency of users to design feminine and attractive but still credible faces.
Energietechnik
(2015)
Kurz und prägant werden die Energieumwandlungsprozesse dargestellt. Die Schwerpunkte reichen von der kompletten Beschreibung der nachhaltigen, erneuerbaren Energietechniken, über Gas- und Dampfturbinen-Kraftwerke sowie Kraft-Wärme-Kälte-Kopplungsanlagen bis hin zur Energieverteilung und zum Kyoto-Protokoll. Zu allen Kapiteln gibt es Aufgaben mit vollständigen Lösungen im Anhang. In der aktuellen Auflage wurden in den Kapiteln 3 und 15 die Zahlenwerte aktualisiert. Kapitel 9 wurde entsprechend der neuen Anbieterstruktur überarbeitet und Kapitel 10 um die Adsorptionstechniken ergänzt. Die Kapitel 17-20 wurden vollständig überarbeitet und stellen den aktuellen Stand der globalen politischen Aspekte dar.
Recent advances in motion recognition allow the development of Context-Aware Assistive Systems (CAAS) for industrial workplaces that go far beyond the state of the art: they can capture a user's movement in real-time and provide adequate feedback. Thus, CAAS can address important questions, like Which part is assembled next? Where do I fasten it? Did an error occur? Did I process the part in time? These new CAAS can also make use of projectors to display the feedback within the corresponding area on the workspace (in-situ). Furthermore, the real-time analysis of work processes allows the implementation of motivating elements (gamification) into the repetitive work routines that are common in manual production. In this chapter, the authors first describe the relevant backgrounds from industry, computer science, and psychology. They then briefly introduce a precedent implementation of CAAS and its inherent problems. The authors then provide a generic model of CAAS and finally present a revised and improved implementation.
Zeitungsverlage haben jahrzehntelang in einem sehr stabilen Marktumfeld agiert, sodass die Kunst darin bestand, das Umfeld möglichst weiterhin konstant zu halten und die bestehenden Märkte und Produkte zu optimieren. Die neuen Medien- und Produktformen, die in dieser Zeit im Publikums- und Werbemarkt aufkamen, wurden bei den lokalen und regionalen Verlagen in das eigene Angebotsspektrum integriert, sodass am Ende im Regelfall ein oftmals kleiner, aber hochprofitabler Medienkonzern ins Internetzeitalter eintrat. Hier kommen nun zunehmend Anforderungen an digitale Geschäftsmodelle auf, die neue Geschäftsmodelle erfordern, die skalierbar sind.
With major intellectual properties there is a long tradition of cross-media value chains -- usually starting with books and comics, then transgressing to film and TV and finally reaching interactive media like video games. In recent years the situation has changed: (1) smaller productions start to establish cross media value chains; (2) there is a trend from sequential towards parallel content production. In this work we describe how the production of a historic documentary takes a cross media approach right from the start. We analyze how this impacts the content creation pipelines with respect to story, audience and realization. The focus of the case study is the impact on the production of a documentary game. In a second step we reflect on the experiences gained so far and derive recommendations for future small-scale cross media productions.
Verfahren zur Bestimmung von Eigenschaften einer Rohrleitung, insbesondere der Position eines Abzweigs einer Abwasserrohrleitung, (a) bei dem ein Schallwellensendesignal (S, S') an einem vorgegebenen Einspeisepunkt in die Rohrleitung (1) eingespeist wird und sich in axialer Richtung der Rohrleitung (1) ausbreitet, (b) wobei das Frequenzspektrum des Schallwellensendesignals (S, S') eine Frequenzkomponente oder einen Spektralbereich aufweist, dessen maximale Frequenz kleiner ist als die untere Grenzfrequenz (fc) für die erste Obermode, (c) bei dem innerhalb der Rohrleitung (1) reflektierte Anteile (Sr1, Sr2, Sr3, S'r1, S'r2, S'r3) des Schallwellensendesignals (S, S') als Schallwellenempfangssignal (E, E') detektiert werden, und (d) bei dem die Rohrleitung (1) durch eine Auswertung des Schallwellenempfangssignal (E, E') in Bezug auf das Schallwellensendesignal (S, S') hinsichtlich des Vorhandenseins von Schallwellenreflexionen (Sr1, Sr2, Sr3, S'r1, S'r2, S'r3) verursachenden Reflexionsorten entlang der Rohrleitung (1) untersucht wird, (e) wobei mittels der Auswertung des Schallwellenempfangssignals (E, E') zumindest jeweils der Abstand (I) eines Reflexionsortes von dem Einspeisepunkt bestimmt wird.