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Mobile devices are nowadays used almost ubiquitously by a large number of users. 2013 was the first year in which the number of sold mobile devices (tablet computers and mobile phones) outperformed the number of PCs’ sold. And this trend seems to be continuing in the coming years. Additionally, the scenarios in which these kinds of devices are used, grow almost day by day. Another trend in modern landscapes is the idea of Cloud Computing, that basically allows for a very flexible provision of computational services to customers. Yet, these two trends are not well connected. Of course there exists already quite a large amount of mobile applications (apps) that utilize Cloud Computing based services. The other way round, that mobile devices provide one of the building blocks for the provision of Cloud Computing based services is not well established yet. Therefore, this paper concentrates on an extension of a technology that allows to provide standardized Web Services, as one of the building blocks for Cloud Computing, on mobile devices. The extension hereby consists of a new approach that now also allows to provide asynchronous Web Services on mobile devices, in contrast to synchronous ones. Additionally, this paper also illustrates how the described technology was already used in an app provided by a business partner.
This paper describes the design and development stages of a web-based framework, aiming to support the creation of mobile applications within the context of mobile learning. The suggested approach offers the opportunity to deploy and execute these applications on mobile devices. This web-based solution additionally offers the possibility to visualize the data collected by the mobile applications in a web-browser. Despite previous research efforts carried out in this domain, few of the projects have addressed these processes from a purely web-based perspective. Currently, a prototype of an authoring tool for creating mobile data collection applications is already implemented. In order to integrate and validate this solution in everyday educational settings, we are collaborating with a network of high schools. On the basis of workshops with teachers we will carry out, refinements and requirements for further enhancements will be collected and will be used to guide our coming efforts.
Recommender systems have become an important application domain related to the development of personalized mobile services. Thus, various recommender mechanisms have been developed for filtering and delivering relevant information to mobile users. This paper presents a rich context model to provide the relevant content of news to the current context of mobile users. The proposed rich context model allows not only providing relevant news with respect to the user’s current context but, at the same time, also determines a convenient representation format of news suitable for mobile devices.
In recent years, teachers have started to conduct pedagogical activities to promote different kinds of learning interactions supported by rich media. The deployment of such activities is rapidly increasing, as teachers and students own technological means that allow supporting them along such interactions. These activities can be carried out in traditional classroom settings while using regular computers. Additionally, they can also be conducted from anywhere at any time while using smartphones and tablets. In this paper, we describe a pedagogical activity requiring students to author and later peer- assess learning interactions
incorporated to videos in YouTube. We describe EDU.Tube, an environment that enables them to create, share and consume such rich media learning activities across a variety of devices. We then detail a plan for the implementation of an activity that took place in 3 different classes dealing with diverse materials addressing computer science related topics. Finally, we also
provide an evaluation presenting students' insights and feedbacks resulting from the experienced activity. We discuss and analyze these outcomes in order to elaborate on them as concerns that could be applied for the further deployment of the EDU.Tube environment.
This paper presents a web-based framework that allows the creation and deployment of mobile learning activities. We present an authoring tool that allows not-technically skilled persons to design mobile learning tasks and deploy them as a web-based mobile application. Since the presented approach is based exclusively on web-technologies, the deployed mobile application can be executed via a mobile browser and therefore is platform independent. Despite previous research efforts carried out in this domain, few of the projects have addressed this course of actions from a purely web-based perspective. Through the latest development of web technologies, mobile applications have access to internal sensors like camera, microphone and GPS and therefore allow data collection within web-applications. In order to validate whether the proposed framework can be applied in educational settings, we conducted a pilot study with experienced teachers and present the results of these efforts in this paper.
With the introduction of Apple’s iPhone, gesture control became pop-
ular and was perceived as an intuitive means of interaction. Contact-
less gestures received broad attention with the X-Box Kinect.
Current technology is limited to a small number of uses, mainly
in entertainment systems. The target of this project is to increase the
range of possible applications, e.g. to the field of automotive,
industrial applications (manufacturing plants), assisted living in con-
texts ranging from private households to hospitals (interaction for
people with disabilities) and many more.
With a rapidly ageing population, it is increasingly important to de-
velop devices for elderly and disabled people that can support and aid
them in their daily lives, helping them to live at home as long as pos-
sible. The goal of this project is to implement a human-machine inter-
action and assistance system that can offer personalised health sup-
port for elderly people, or for those who have special needs in the
home environment.
As smart homes are being more and more popular, the needs of finding assisting systems which interface between users and home environments are growing. Furthermore, for elderly and disabled people living in such homes it is totally important to develop devices, which can support and aid them in their ordinary daily life. This demands means and tools that extend independent living and promote improved health. In this work we reviewed the state of the art in the assistant systems in home environments. A case study of medical assisting system for elderly and people with disabilities is discussed deeply. A smart nfc-based person-specific assistant system for services in home environment is proposed. The role of this system is the assisting by controlling of home activities and adaption of home-human interface towards the needs of the considered person. For the special case of medical assisting the system has the ability of providing for elderly or disabled people person-specific medical assistance. The system has the ability of identifying its interaction partner using some biometric features. According to the recognized ID the system, first, adopts towards the needs of recognized person. Second the system represents person-specific list of medicaments either visually, on screen, or acoustic, speaker. And third the system gives an alarm in the case of taking medicament either later or earlier as normal taking time.
In the context of existing approaches to cluster computing we present a newly developed modular framework `SimpleHydra' for rapid deployment and management of Beowulf clusters. Instead of focusing only the pure computation tasks on homogeneous clusters (i.e. clusters with identically set up nodes), this framework aims to ease the configuration of heterogeneous clusters and to provide a low-level / high-level object-oriented API for low-latency distributed computing. Our framework does not make any restrictions regarding the hardware and minimizes the use of external libraries to the case of special modules. In addition to that our framework enables the user to develop highly dynamic cluster topologies. We describe the framework's general structure as well as time critical elements, give application examples in the `Big-Data' context during a research project and briefly discuss additional features. Furthermore we give a thorough theoretical time/space complexity analysis of our implemented methods and general approaches.
In this paper, we describe an efficient method for a fast people re-identification based on models of human clothes. An initial model is estimated during people detection and tracking, which will be refined during the re-identification. This stepwise extraction, combination and comparing of features speeds up the whole re-identification. For the refining, several saliency maps are used to extract individual features. These individual features are located separately for any human body part. The body parts are located with an optimized GPU-based HOG detector. Furthermore, we introduce a meanshift-based fusion concept which utilizes multiple detectors in order to increase the detection reliability.
Currently in home environments, robot assisting systems with emotion understanding ability are generally achieved in two several manners. The first is the implementing of such systems in such a way that they offer general services for all considered persons without considering privacy, special needs of their interaction partners. The second way is the targetting of such systems for merely one person. In this work we present a robot assisting system, which has both the abilities of assisting several persons at the same time and sustaining their privacy and security issues. The robot can interact with it's interaction partner emotionally by analyzing the emotions of her expressed either visually, facial expression, or auditive, speech prosody. The role of this system is the providing of person-specific support in home environment. In order to identify its interaction partner the system uses diverse biometric traits. According to the recognized ID the system, first, adopts towards the needs of recognized person. Second the system loads the corresponding emotional profile of the detected interaction partner in order to practice a person-specific emotional human-robot interaction, which has an advantage over the person independent interaction.
Bipolar electrosurgical systems are used for the treatment of benign prostatic hyperplasia (BPH) in urology. In order to analyse electrothermal processes during surgery the power loss density distribution around a bipolar resectoscope is calculated out of the measured potential distribution in isotonic saline solution ex situ. During further analysis power loss density values act as input for the Penne's bioheat equation. To achieve results, which are as realistic as possible, a method to obtain power loss density values, depending on the observed tissue or medium in the operating field, is presented. Applying this method, the power loss density distribution in isotonic saline solution at 25 °C is compared to the distribution calculated for the average conductivity of biological tissue in the region of interest.
Influencing Parameters on Measuring the Cross-Section Area of Hot Rolled Rods in Steel Industries
(2014)
Die transurethrale Resektion der Prostata (TURP) ist ein Verfahren der Elektrochirurgie innerhalb der Urologie. Thema der Arbeit ist die Entwicklung einer Methodik für realitätsnahe vergleichende Untersuchungen der elektrothermischen Vorgänge um Resektoskope zur bipolaren TURP. Die Relevanz dieses Themas liegt in der aktuellen Diskussion, ob elektrothermische Verletzungen eine mögliche Ursache urethraler Komplikationen darstellen. In diesem Kontext sind nicht die Vorgänge an der Resektionselektrode sondern in nicht behandelten Arealen des Operationsgebiets von Interesse. Bisher durchgeführte Untersuchungen konzentrieren sich auf monopolare Systeme. Untersuchte bipolare Elektrodenanordnungen unterscheiden sich allerdings von heutigen bipolaren Resektoskopen. Die vorhandenen Erkenntnisse sind deshalb nur äußerst eingeschränkt anwendbar. Informationen zu thermischen Vorgängen bezüglich Spätkomplikationen liegen nicht vor.
Der gewählte Ansatz aus messtechnischer Bestimmung der 3D Potentialverteilung ex situ sowie modellbasierter und numerischer Analyse der sich daraus ergebenden 3D Verlustleistungsdichteverteilung und der darauf beruhenden Temperaturberechnung im operationsnahen Gewebe ermöglicht ein auf die Realität übertragbares Ergebnis. Die berechnete Temperatur dient des Weiteren als Grundlage einer medizinischen Einschätzung hinsichtlich des Potentials elektrothermischer Verletzungen. Ergebnis der Arbeit ist, dass vergleichende Untersuchungen bipolarer Resektoskope mit der entwickelten Methodik durchführbar sind. Für die untersuchte bipolare Elektrodenanordnung erscheinen elektrothermische Verletzungen als Ursache urethraler Strikturen bei konservativer Betrachtung und unter durchschnittlichen Operationsbedingungen ohne intraoperative Komplikationen unwahrscheinlich.
Optimization of Encircling Eddy Current Sensors for Online Monitoring of Hot Rolled Round Steel Bars
(2014)
Modern manufacturing industries are continually working on quality enhancements for the hot rolling process of round products. One method for improving the finalisation of the rods is the implementation of an automatic size control system. As a result of these trends over the last few years, there has been an increasing demand for more accurate online measurements. Thus the reason for the research performed for this thesis. A particular challenge throughout this research was dealing with the temperature changes (up to 1200°C) from the in- and output of the fervent rolling stocks, and the effect this temperature changes had on the sensors. Furthermore, there is also high demand for developing fast and practical electronic measuring equipment, capable of measuring during high transport velocities (up to 120 m/s). The eddy current principle is just one of the very few methods available which can with-stand such harsh industrial environments. In fact, eddy current sensors are already being integrated into online monitoring tasks for hot rolling processes. The measurement uncertainty, however, is still considerably large for process control purposes. One reason for this lies within the ability for eddy current detectors to receive signals influenced by outward forces, i.e. forces dependent on its location, its geometry, the outside temperature and the material properties of a particular target. Thus the current accuracy for a cross-sectional area measurement, for example, is no higher than 1%. As a result, this thesis investigates the magnitude of all individual influential factors on the eddy current detectors, using model-based analysis techniques. The analytical model provides a solution for all rotationally symmetrical targets and the FEA model covers all of the other influencing parameters in a more time consuming manner. This thesis then provides different methods which are developed to separate the cross-sectional area measurement of a rod from all of the other influencing parameters. In addition, a material tracking approach for round products is developed. Two different kinds of prototypes, capable of measuring approximately 466 Tons of red-hot steel rods during the production process, are finally introduced in this thesis. The usefulness of the eddy current principle is validated by the provided field test results. The count accuracy for the identification of 2876 bars was found to be 99.93%, and the average measurement accuracy for the cross-sectional area experiments was reduced to ± 0.29 % when including all of the findings.
Efficient photoluminescence (PL) spectra from GaN and InGaN layers at temperatures up to 1100 K are observed with low noise floor and high dynamic resolution. A number of detailed spectral features in the PL can be directly linked to physical properties of the epitaxial grown layer. The method is suggested as an in situ monitoring tool during epitaxy of nitride LED and laser structures. Layer properties like thickness, band gap or film temperature distribution are feasible.
Electro-magnetic acoustic transducers (EMATs) are intended as non-contact and non-destructive ultrasound transducers for metallic material. The transmitted intensities from EMATS are modest, particularly at notable lift off distances. Some time ago a concept for a “coil only EMAT” was presented, without static magnetic field. In this contribution, such compact “coil only EMATs” with effective areas of 1–5 cm2 were driven to excessive power levels at MHz frequencies, using pulsed power technologies. RF induction currents of 10 kA and tens of Megawatts are applied. With increasing power the electroacoustic conversion efficiency also increases. The total effect is of second order or quadratic, therefore non-linear and progressive, and yields strong ultrasound signals up to kW/cm2 at MHz frequencies in the metal. Even at considerable lift off distances (cm) the ultrasound can be readily detected. Test materials are aluminum, ferromagnetic steel and stainless steel (non-ferromagnetic). Thereby, most metal types are represented. The technique is compared experimentally with other non-contact methods: laser pulse induced ultrasound and spark induced ultrasound, both damaging to the test object’s surface. At small lift off distances, the intensity from this EMAT concept clearly outperforms the laser pulses or heavy spark impacts.
To analyze the electric field around bipolar resectoscopes, used in urology, in terms of reasons for late complications after a surgical treatment a flexible multielectrode system was developed to measure the 3-D potential distribution. A high spatial resolution is achieved with the least possible individual measurements under the conditions of a quasi-static electric field. A flexible arrangement and positioning of the measuring points in the vertical direction of the experimental environment enable an adjustable spatial resolution and the selection of the region of interest. The existing influence of the multielectrode system on the measuring results is described and a correction method is presented to achieve significant results. Thus, the multielectrode system is usable for a comparative study of bipolar resectoscopes varying in the arrangement of resection and return electrode.
LEDs gelten als umweltfreundliche Beleuchtungstechnik. Für die Massenanwendung arbeiten die LED-Hersteller an einer Senkung der Kosten bzw. einer Erhöhung der Ausbeute, insbesondere bei der aufwendigen LED-Kristallbeschichtung auf den Wafern. Während der Beschichtung (MOCVD) werden optische In-situ-Messgeräte zur Überwachung des Prozesses genutzt. Die hier vorgestellte Untersuchung beschäftigt sich mit dem Einfluss von Super-Photolumineszenz-Effekten bei einer möglichen In-situ-Prozesskontrolle in der MOCVD.
Wirbelstromsensoren sind in der industriellen Messtechnik stark verbreitet. Insbesondere bei der Herstellung warmgewalzter Halbzeuge können sie durch ihre Robustheit gegenüber Wasserdampf und hohen Walzguttemperaturen überzeugen. Ein noch offenes Feld ist die In-Situ‐Detektion von Rissen im Draht während des Walzprozesses bei Walzgeschwindigkeiten bis zu 100 m/s und Materialtemperaturen bis zu 1200 ℃. Im Folgenden soll mittels der Finiten-Elemente-Analyse untersucht werden, wie sich Längsrisse im Draht auf Oberflächenströme und damit auf deren magnetische Flussdichte auswirken. Ziel ist es, Aussagen über den Einfluss verschiedener Rissbreiten und Risstiefen auf die magnetische Flussdichte zu machen und so einen möglichen Effekt auf einen Wirbelstromsensor untersuchen zu können.
MeHRWert Ausgabe 5 Juni 2014
(2014)