Refine
Year of publication
- 2015 (80) (remove)
Document Type
- Conference Proceeding (40)
- Article (reviewed) (12)
- Article (unreviewed) (8)
- Bachelor Thesis (5)
- Part of a Book (5)
- Patent (4)
- Book (3)
- Master's Thesis (3)
Conference Type
- Konferenzartikel (30)
- Konferenz-Abstract (6)
- Konferenzband (2)
- Sonstiges (2)
Keywords
- Applikation (5)
- Abtragung (3)
- Eingebettetes System (3)
- Herz (3)
- Kommunikation (3)
- Physik (3)
- Raman-Spektroskopie (3)
- Datensicherung (2)
- Funktechnik (2)
- Herzrhythmusstörung (2)
Institute
- Fakultät Elektrotechnik und Informationstechnik (E+I) (bis 03/2019) (80) (remove)
Open Access
- Closed Access (36)
- Open Access (28)
- Bronze (8)
The demand of wireless solutions in industrial applications increases since the early nineties. This trend is not only ongoing, it is further pushed by developments in the area of software stacks like the latest Bluetooth Low Energy Stack. It is also pushed by new chip-designs and powerful and highly integrated electronic hardware. The acceptance of wireless technologies as a possible solution for industrial applications, has overcome the entry barrier [1]. The first step to see wireless as standard for many industrial applications is almost accomplished. Nevertheless there is nearly none acceptance of wireless technology for Safety applications. One highly challenging and demanding requirement is still unsolved: The aspect safety and robustness. Those topics have been addressed in many cases but always in a similar manner. WirelessHART as an example addresses this topic with redundant so called multiple propagation paths and frequency hopping to handle with interferences and loss of network participants. So far the pure peer to peer link is rarely investigated and there are less safety solutions available. One product called LoRa™ can be seen as one possible solution to address this lack of safety within wireless links. This paper focuses on the safety performance evaluation of a modem-chip-design. The use of diverse and redundant wireless technologies like LoRa can lead to an increase acceptance of wireless in safety applications. Many measurements in real industrial application have been carried out to be able to benchmark the new chip in terms of the safety aspects. The content of this research results can help to raise the level of confidence in wireless. In this paper, the term “safety” is used for data transmission reliability.
The Raman spectra from the chemical compounds toluene and cyclohexane obtained using a Fourier Transform (FT)-Raman spectrometer prototype have been contrasted with the Raman spectra of these same materials collected with two different commercial FT-Raman devices. The FT-Raman spectrometer consist of a Michelson interferometer, a self-designed photon counter and a reference photo-detector. The evaluation methodology of the spectral information, contrary to the commercial devices that commonly use the zero-crossing method, is carried out by re-sampling the Raman scattering and by accurately extracting the optical path information of the Michelson interferometer. The FTRaman arrangement has been built using conventional parts without disregarding the spectral frequency precision that usually such a FTRaman instruments deliver. No additional complex hardware components or costly software modules have been included in this FT-Raman device. The main Raman lines from the spectra obtained with the three FT-Raman devices have been compared with the Raman lines from the standard Raman spectra of these two materials. The values obtained using the FT-Raman spectrometer prototype have shown a frequency accuracy comparable to that obtained with the commercial devices without facing the need for a large investment. Although the proposed FT-Raman prototype cannot be directly compared to the last generation of FT-Raman spectrometers from the commercial manufacturers, such a device could give an opportunity to users that require high frequency precision in their spectral analysis and are provided with rather scarce resources.
6LoWPAN (IPv6 over Low Power Wireless Personal Area Networks) is gaining more and more attraction for the seamless connectivity of embedded devices for the Internet of Things. It can be observed that most of the available solutions are following an open source approach, which significantly leads to a fast development of technologies and of markets. Although the currently available implementations are in a pretty good shape, all of them come with some significant drawbacks. It was therefore decided to start the development of an own implementation, which takes the advantages from the existing solutions, but tries to avoid the drawbacks. This paper discussed the reasoning behind this decision, describes the implementation and its characteristics, as well as the testing results. The given implementation is available as open-source project under [15].
We propose secure multi-party computation techniques for the distributed computation of the average using a privacy-preserving extension of gossip algorithms. While recently there has been mainly research on the side of gossip algorithms (GA) for data aggregation itself, to the best of our knowledge, the aforementioned research line does not take into consideration the privacy of the entities involved. More concretely, it is our objective to not reveal a node's private input value to any other node in the network, while still computing the average in a fully-decentralized fashion. Not revealing in our setting means that an attacker gains only minor advantage when guessing a node's private input value. We precisely quantify an attacker's advantage when guessing - as a mean for the level of data privacy leakage of a node's contribution. Our results show that by perturbing the input values of each participating node with pseudo-random noise with appropriate statistical properties (i) only a minor and configurable leakage of private information is revealed, by at the same time (ii) providing a good average approximation at each node. Our approach can be applied to a decentralized prosumer market, in which participants act as energy consumers or producers or both, referred to as prosumers.
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.
Über die letzten Jahre entstanden unterschiedlichste Gerätschaften, besonders im mobilen Bereich und der Industrie 4.0, die große Datenmengen generieren. Diese müssen in entsprechenden Netzwerken entgegengenommen, verarbeitet und ggf. analysiert werden um einen Mehrwert zu erzielen. Ein Vertreter für die Umsetzung von Echtzeit-Datenverarbeitung ist Apache Spark, ein Open Source Framework, welches für die Analyse von Informationsströmen und Datenbeständen eingesetzt werden kann. Im Rahmen dieser Masterarbeit wird die Apache Spark Plattform von Grund auf erläutert und auf ihre Einsatzfähigkeit im Bereich der verteilten Datenverarbeitung untersucht. Durch die theoretische Einleitung in die Themen Big Data, Streaming Data, Data Mining und Real-Time Analytics wird ein grundlegendes Verständnis für die Aufgaben und Herausforderungen dieses Sachgebiets vermittelt. Es wird die Entwicklung von der Batch- zur Streamingverarbeitung vorgestellt und die Anforderungen, sowie Voraussetzungen für die Umsetzung von Echtzeitsystemen aufgezeigt.
Nachdem diese Grundlagen vermittelt wurden, folgt eine Vorstellung des Projektumfangs der Apache Software Foundation, in welchen sich auch das Spark Projekt einordnen lässt. Die Arbeit erläutert die Grundkonzepte von Apache Spark, wie die Entwicklung, Architektur und der Clusterbetrieb der Plattform. Dabei stützen sich die Untersuchungen auf praktische Beispiele, um die Arbeitsweise von Apache Spark näher aufzuzeigen. Die vorgestellten Themen fallen in die Bereiche der parallelen Datenverarbeitung mit Spark und beschäftigen sich mit den Voraussetzungen für das Erstellen von Anwendungen, die den verteilten Aufbau und die horizontale Skalierbarkeit von Spark ausnutzen. Spark bringt über eigene Bibliotheken auch Funktionalitäten für die Datenverarbeitung in speziellen Aufgabengebieten mit sich. In dieser Arbeit werden ebenfalls die beiden Bibliotheken MLlib, welche im Bereich des maschinellen Lernens Einsatz findet, und Spark Streaming, die Bibliothek für Verarbeitung von Datenflüssen, vorgestellt und deren Funktionsumfang untersucht. Das Kernthema dieser Arbeit bildet die Modellierung von Lösungsmöglichkeiten zur Analyse von Streaming Data. Es wird hierdurch die Funktionsweise von Spark und dessen Streaming Bibliothek anhand von kompletten Applikationen zur Ausreißererkennung in Datenströmen im Detail aufgezeigt.
Die Arbeit zeigt auf, dass Spark durchaus für den Einsatz zur verteilten Datenverarbeitung geeignet ist. Auch der Umgang mit Streaming Data wird durch den Bau der Prototypen nachgewiesen. In dem abschließenden Fazit werden die Erkenntnisse der Arbeit zusammengefasst und die Einsetzbarkeit von Spark diskutiert.
Cardiac resynchronization therapy with atrioventricular and interventricular delay optimized biventricular pacing is an established therapy for symptomatic heart failure patients with prolongation of QRS duration, left bundle branch block and reduced left ventricular ejection fraction. The aim of the investigation was to evaluate right atrial, right ventricular and left ventricular electrical signals of implantable electronic cardiac devices with and without signal averaging technique with novel LabVIEW software. Electrical interatrial conduction delay and inter-ventricular conduction delay may be useful parameters to evaluate electrical atrial and ventricular desynchronization in heart failure patients.