Ruhr West University of Applied Sciences
Mulheim (Ruhr), Germany
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The invention relates to a method and a system for the optimized transmission of data in a wired multicarrier modulation (MCM) transmission system. The method for an optimized transmission of data in a wired multicarrier modulation (MCM) transmission system from a transmitter to one or more receivers via a transmission channel, wherein only one specified supply power is provided for the transmitter, a transmitted signal for transmitting data has a plurality of subcarriers, and the data together with redundant information is distributed to the plurality of subcarriers such that the receiver can dispense with some of the subcarriers in order to determine the data, has the following steps: determining frequency-dependent input impedances of the wired transmission channel to the transmitter, and adjusting the signal amplitude of the individual subcarriers on the basis of the measured frequency-dependent input impedances and the specified supply power.

Rueter D.,Ruhr West University of Applied Sciences
Sensors (Switzerland) | Year: 2017

This experimental study demonstrates for the first time a solid-state circuitry and design for a simple compact copper coil (without an additional bulky permanent magnet or bulky electromagnet) as a contactless electromagnetic acoustic transducer (EMAT) for pulse echo operation at MHz frequencies. A pulsed ultrasound emission into a metallic test object is electromagnetically excited by an intense MHz burst at up to 500 A through the 0.15 mm filaments of the transducer. Immediately thereafter, a smoother and quasi “DC-like” current of 100 A is applied for about 1 ms and allows an echo detection. The ultrasonic pulse echo operation for a simple, compact, non-contacting copper coil is new. Application scenarios for compact transducer techniques include very narrow and hostile environments, in which, e.g., quickly moving metal parts must be tested with only one, non-contacting ultrasound shot. The small transducer coil can be operated remotely with a cable connection, separate from the much bulkier supply circuitry. Several options for more technical and fundamental progress are discussed. © 2017 by the authors. Licensee MDPI, Basel, Switzerland.

Agency: European Commission | Branch: FP7 | Program: CP | Phase: ICT-2013.8.2 | Award Amount: 4.12M | Year: 2014

Public administrations (PA) need to cope with various challenges: new regulations, an aging workforce and the need for adopting their ICT. Technology-enhanced learning (TEL) represents thus a sensible option notably for rural local governments (RLG) that need to keep up with such changing environments, but do have limited ac-cess to training courses.From interviews of a pre-study with RLG in 5 European countries we know that obstacles are to include learning in the work process and a lack of training plans. There are deficiencies in communication and collaboration skills despite regular use of computer and mobile devices.EAGLEs main objective is to equip employees in RLG with a holistic training solution based on Open Educa-tional Resources (OER) and Open Source (OS) tools, supporting learning of critical transversal skills such as ICT literacy and professional management of change situations. EAGLE outcomes include an innovative change management model for a learning-enhanced work process, a proficiency-based cross-device OER curriculum, and contextualization tools for multilingual collaboration. These will be integrated in the novel EAGLE OER Open Learning platform that includes a new OER ontology for public administration and combines open data and learning platforms feeding into user services, argumentation technology tool and semantic search.Our solution will thus support OS business models for the benefit of technology and e-learning providers. It will be built on existing OS tools and frameworks, IEEE OER standards and the CKAN open data standards. The EAGLE consortium includes leaders in European OER, TEL, online assessment, mobile learning and e-government research as well as experts in organisational and pedagogical development, semantic web systems and services for PA.EAGLE will significantly advance the state-of-the-art in PA learning and introduce the tech-nology through our validation and associated partners in real-life RLG environments.

Bumiller G.,Ruhr West University of Applied Sciences
2012 IEEE International Symposium on Power Line Communications and Its Applications, ISPLC 2012 | Year: 2012

High speed narrow band power line communication (NB-PLC) seems to be the favored candidate for smart metering and smart grid applications on distribution lines. With more than a decade experience in this technology we have now the chance to design a new system from the scratch. This paper focus on a requirement and experience based design for the transmit signals of a NB-PLC system. After a requirement analyses proposals were done and motivated for synchronization, modulation, peak to average reduction and windowing. © 2012 IEEE.

Roemer E.,Ruhr West University of Applied Sciences
Industrial Management and Data Systems | Year: 2016

Purpose - The purpose of this paper is to provide a systematic overview with guidelines how to use partial least squares (PLS) path modeling in longitudinal studies. Practical examples from a study of the acceptance of battery electric vehicles (BEVs) in corporate fleets are used for demonstration purposes. Design/methodology/approach - In this study, data at three points in time were collected: Before the initial use of a BEV, after three and after six months of extensive usage of BEVs. Findings - Three different models are identified depending on the research objective and on the data basis. Multigroup analyses are suggested to test the difference between the path coefficients of latent variables at different points in time. Limitations for the use of repeated cross-sectional data have to be observed. Originality/value - Academics and practitioners will benefit from this paper by receiving an overview of the different PLS path models in longitudinal studies. A decision-tree enables them to make a choice regarding the most appropriate model and suggests a sequence of complementary analyses. So far, there is a lack of a tutorial type paper delivering such guidance. © 2016 Emerald Group Publishing Limited.

Hoffmann S.G.,Ruhr West University of Applied Sciences
2016 International Symposium on Power Line Communications and its Applications, ISPLC 2016 | Year: 2016

This paper describes the layer-2-security functions of two narrow-band power line communication standards, namely ITU-T G.9903 and IEEE 1901.2. We describe how access control, authentication, confidentiality and integrity for network devices are achieved in both standards. We compare the approaches by using two practice-oriented installation scenarios and by evaluating the security methods. © 2016 IEEE.

Jansen M.,Ruhr West University of Applied Sciences
CLOSER 2012 - Proceedings of the 2nd International Conference on Cloud Computing and Services Science | Year: 2012

In recent years, the number of reasonable powerful mobile devices increased. In 2011, the number of smartphone (e.g.) increased to more than 300 million units. A lot of research has already been conducted with respect of mobile devices acting as Cloud Service consumers, but still not much effort is put on mobile devices in the role of Cloud Service providers. Therefore, this paper presents an approach that allows to utilize mobile devices like smart phones or tablets as Cloud Service providers. In order to make this a reasonable approach, some of the occurring problems are discussed and it is shown how the presented architecture is able to overcome these problems. Last but not least, this paper describes some performance tests of the chosen implementation for mobile Web Services.

Gutsche K.,Ruhr West University of Applied Sciences
Procedia CIRP | Year: 2015

Approximately 80% of the costs of Product-Service-Systems (PSS) operation are labor costs. A service company's employees are their most important input factor, which therefore strongly defines the success of PSS operation, in particular this applies to PSS for the product usage life cycle phase. Consequently, it is very important to assign tasks to employees within a service project very much based on their abilities and the challenges of the tasks. This allows a sustainable use of the most important resource within PSS operation. The idea of human reliability is well established. Like for technical systems, the calculation of reliability is the basis for defining the error probability for a specific worker/group of worker within a certain process step. Within PSS operation the human reliability is not only dependent on the individual capabilities but is also very much related to the serviced product. Analyzing the relevant man-machine-systems is therefore essential when reaching for sustainability in service operation. The concept of the human reliability within a PSS defines the human probability of error by the strain of a service task. The strain is dependent on the task (its processes and (technical) tool use) and the individual capabilities of the employee. The industrial psychology has identified several factors describing the stress of a task and the human abilities. Due to research within PSS operation the general idea of the relation between strain and stress can be extended to a service-strain-stress model (SSSM) which has to be seen as a qualitative framework for a classification of service employees based on the service tasks on one hand and the different individual abilities of the employee on the other hand. The SSSM allows to assign service tasks to a worker/group of worker without exceeding a certain individual strain level and therefore to reduce the probability of error realizing a sustainable service operation. This paper outlines the idea of categorizing service operations employees according to the individual abilities, the product complexity and the time pressure within a strongly customer oriented service project. Due to the qualitative, individual characteristics of employees, the categories defined will be rather qualitative. The model can be used for a more sustainable planning of a service company's manpower or as a tool for optimizing the supply of temporary workers in the service domain. But could also work as a benchmark for service personnel management. © 2015 The Authors. Published by Elsevier B.V This is an open access article under the CC BY-NC-ND license.

Rueter D.,Ruhr West University of Applied Sciences | Morgenstern T.,Ruhr West University of Applied Sciences
Ultrasonics | Year: 2014

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. © 2014 Elsevier B.V. All rights reserved.

In a method for an optimised transmission of data in a wired multi-carrier (multi-carrier modulationMCM) transmission system from a transmitter to one or more receivers via a transmission channel, only one specified supply power is provided for the transmitter, a transmitted signal for transmitting data has a plurality of subcarriers, and the data together with redundant information is distributed to the plurality of subcarriers in such a way that the receiver can dispense with some of the subcarriers in order to determine the data. The method includes a step of determining frequency-dependent access impedances of the wired transmission channel on the transmitter, and a step of adjusting the signal amplitude of the individual subcarriers on the basis of the measured frequency-dependent access impedances sand the limited supply power.

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