@inproceedings{21524, abstract = {{For the measurement of process data in bioreactors, very small wireless sensors are currently under development to replace the conventional rod probes. The so-called Sens-o-Spheres measure the temperature and in future the oxygen content and the pH of fluids. In order to evaluate the distribution of the measured values within the process, it is necessary to locate the wireless sensors. Because of the small size of the sphere (diameter 8 mm), inhomogeneous ambient media and the size of the reactor (less than 2 m), an inductive locating by magnetic fields with a frequency of f = 13.56 MHz is necessary. Since the behaviour of the magnetic field is very different from that of the electromagnetic wave, new locating methods are required, which are presented in this paper.}}, author = {{Lange, Sven and Schröder, Dominik and Hedayat, Christian and Otto, Thomas and Hilleringmann, Ulrich}}, booktitle = {{2019 17th IEEE International New Circuits and Systems Conference (NEWCAS)}}, isbn = {{9781728110318}}, keywords = {{oxygen content, inhomogeneous ambient media, magnetic field, inductive locating method, miniaturized wireless sensors, inhomogeneous dielectrics, conventional rod probes, Sens-o-Spheres measure, frequency 13.56 MHz}}, location = {{Munich, Germany}}, title = {{{Inductive Locating Method to Locate Miniaturized Wireless Sensors within Inhomogeneous Dielectrics}}}, doi = {{10.1109/newcas44328.2019.8961227}}, year = {{2019}}, } @inproceedings{10780, author = {{Guettatfi, Zakarya and Hübner, Philipp and Platzner, Marco and Rinner, Bernhard}}, booktitle = {{12th International Symposium on Reconfigurable Communication-centric Systems-on-Chip (ReCoSoC)}}, keywords = {{embedded systems, image sensors, power aware computing, wireless sensor networks, Zynq-based VSN node prototype, computational self-awareness, design approach, platform levels, power consumption, visual sensor networks, visual sensor nodes, Cameras, Hardware, Middleware, Multicore processing, Operating systems, Runtime, Reconfigurable platforms, distributed embedded systems, performance-resource trade-off, self-awareness, visual sensor nodes}}, pages = {{1--8}}, title = {{{Computational self-awareness as design approach for visual sensor nodes}}}, doi = {{10.1109/ReCoSoC.2017.8016147}}, year = {{2017}}, } @article{11886, abstract = {{Today, we are often surrounded by devices with one or more microphones, such as smartphones, laptops, and wireless microphones. If they are part of an acoustic sensor network, their distribution in the environment can be beneficially exploited for various speech processing tasks. However, applications like speaker localization, speaker tracking, and speech enhancement by beamforming avail themselves of the geometrical configuration of the sensors. Therefore, acoustic microphone geometry calibration has recently become a very active field of research. This article provides an application-oriented, comprehensive survey of existing methods for microphone position self-calibration, which will be categorized by the measurements they use and the scenarios they can calibrate. Selected methods will be evaluated comparatively with real-world recordings.}}, author = {{Plinge, Axel and Jacob, Florian and Haeb-Umbach, Reinhold and Fink, Gernot A.}}, issn = {{1053-5888}}, journal = {{IEEE Signal Processing Magazine}}, keywords = {{Acoustic sensors, Microphones, Portable computers, Smart phones, Wireless communication, Wireless sensor networks}}, number = {{4}}, pages = {{14--29}}, title = {{{Acoustic Microphone Geometry Calibration: An overview and experimental evaluation of state-of-the-art algorithms}}}, doi = {{10.1109/MSP.2016.2555198}}, volume = {{33}}, year = {{2016}}, } @inproceedings{11818, abstract = {{In this paper we present a system for indoor navigation based on received signal strength index information of Wireless-LAN access points and relative position estimates. The relative position information is gathered from inertial smartphone sensors using a step detection and an orientation estimate. Our map data is hosted on a server employing a map renderer and a SQL database. The database includes a complete multilevel office building, within which the user can navigate. During navigation, the client retrieves the position estimate from the server, together with the corresponding map tiles to visualize the user's position on the smartphone display.}}, author = {{Hoang, Manh Kha and Schmitz, Sarah and Drueke, Christian and Vu, Dang Hai Tran and Schmalenstroeer, Joerg and Haeb-Umbach, Reinhold}}, booktitle = {{Positioning Navigation and Communication (WPNC), 2013 10th Workshop on}}, keywords = {{SQL, navigation, smart phones, wireless LAN, RSSI, SQL database, complete multilevel office building, inertial sensor information, inertial smartphone sensors, map renderer, received signal strength index information, relative position estimates, server based indoor navigation, step detection, wireless-LAN access points, Smartphone, fingerprint, indoor navigation, map tile}}, pages = {{1--6}}, title = {{{Server based indoor navigation using RSSI and inertial sensor information}}}, doi = {{10.1109/WPNC.2013.6533263}}, year = {{2013}}, } @inproceedings{9783, abstract = {{To optimize the ultrasound irradiation for cavitation based ultrasound applications like sonochemistry or ultrasound cleaning, the correlation between cavitation intensity and the resulting effect on the process is of interest. Furthermore, changing conditions like temperature and pressure result in varying acoustic properties of the liquid. That might necessitate an adaption of the ultrasound irradiation. To detect such changes during operation, process monitoring is desired. Labor intensive processes, that might be carried out for several hours, also require process monitoring to increase their reliability by detection of changes or malfunctions during operation. In some applications cavitation detection and monitoring can be achieved by the application of sensors in the sound field. Though the application of sensors is possible, this necessitates modifications on the system and the sensor might disturb the sound field. In other applications harsh, process conditions prohibit the application of sensors in the sound field. Therefore alternative techniques for cavitation detection and monitoring are desired. The applicability of an external microphone and a self-sensing ultrasound transducer for cavitation detection were experimentally investigated. Both methods were found to be suitable and easily applicable.}}, author = {{Bornmann, Peter and Hemsel, Tobias and Sextro, Walter and Maeda, Takafumi and Morita, Takeshi}}, booktitle = {{Ultrasonics Symposium (IUS), 2012 IEEE International}}, issn = {{1948-5719}}, keywords = {{cavitation, chemical reactors, microphones, process monitoring, reliability, ultrasonic applications, ultrasonic waves, acoustic properties, cavitation based ultrasound applications, cavitation intensity, change detection reliability, external microphone, malfunction detection reliability, nonperturbing cavitation detection, nonperturbing cavitation monitoring, process monitoring, self-sensing ultrasound transducer, sonochemical reactors, sonochemistry, ultrasound cleaning, ultrasound irradiation, Acoustics, Liquids, Monitoring, Sensors, Sonar equipment, Transducers, Ultrasonic imaging}}, pages = {{1141--1144}}, title = {{{Non-perturbing cavitation detection / monitoring in sonochemical reactors}}}, doi = {{10.1109/ULTSYM.2012.0284}}, year = {{2012}}, } @inproceedings{9788, abstract = {{A hydrothermal method utilizes a crystallization process in the solution so that the pure and high-quality powders can be realized. Sintering from the hydrothermal KNbO3 and NaNbO3 powders, a high-dense lead-free piezoelectric (K,Na)NbO3 ceramics could be obtained (density: 98.8\%). Concerning about the g33 constant, high value as large as commercial PZT ceramics was measured. Therefore, the hydrothermal (K,Na)NbO3 ceramics is usable for the sensors and the energy harvesting devices. To demonstrate the (K,Na)NbO3 ceramics, a hydrophone sensor was fabricated and evaluated.}}, author = {{Maeda, Takafumi and Bornmann, Peter and Hemsel, Tobias and Morita, Takeshi}}, booktitle = {{Ultrasonics Symposium (IUS), 2012 IEEE International}}, issn = {{1948-5719}}, keywords = {{crystallisation, hydrophones, piezoceramics, potassium compounds, powder technology, powders, sensors, sintering, sodium compounds, (K0.48Na0.52)NbO3, KNbO3 powder, NaNbO3 powder, crystallization, energy harvesting devices, g33 constant, hydrophone sensor, hydrothermal lead-free (K0.48Na0.52)NbO3 ceramics, hydrothermal method, piezoelectric applications, sintering, Materials, Transducers}}, pages = {{194--195}}, title = {{{Piezoelectric applications of hydrothermal lead-free (K0.48Na0.52)NbO3 ceramics}}}, doi = {{10.1109/ULTSYM.2012.0048}}, year = {{2012}}, } @inproceedings{11881, abstract = {{A combination of GPS (global positioning system) and INS (inertial navigation system) is known to provide high precision and highly robust vehicle localization. Notably during times when the GPS signal has a poor quality, e.g. due to the lack of a sufficiently large number of visible satellites, the INS, which may consist of a gyroscope and an odometer, will lead to improved positioning accuracy. In this paper we show how velocity information obtained from GSM (global system for mobile communications) signalling, rather than from a tachometer, can be used together with a gyroscope sensor to support localization in the presence of temporarily unavailable GPS data. We propose a sensor fusion system architecture and present simulation results that show the effectiveness of this approach.}}, author = {{Peschke, Sven and Bevermeier, Maik and Haeb-Umbach, Reinhold}}, booktitle = {{6th Workshop on Positioning Navigation and Communication (WPNC 2009)}}, keywords = {{cellular radio, distance measurement, global positioning system, Global Positioning System, global system for mobile communications, GPS positioning approach, GSM velocity, gyroscopes, gyroscope sensor, inertial navigation, inertial navigation system, odometer, sensor fusion system architecture, sensors}}, pages = {{195--202}}, title = {{{A GPS positioning approach exploiting GSM velocity estimates}}}, doi = {{10.1109/WPNC.2009.4907827}}, year = {{2009}}, } @inproceedings{9576, abstract = {{In neurosurgery, delineation of tumor boundaries during resection of brain tumors is of substantial relevance. During operation distinction between tumor and healthy tissue rely on the abilities of the surgeon based on visual and tactile differentiation. In this paper a high sensitivity actuator-sensor system using a piezoelectric bimorph is presented. Frequency shift and transfer function of the bimorphpsilas voltages are detected and evaluated. Sensorpsilas sensitivity is evaluated using two frequency controls strategies: A phase-locked loop (PLL) and a self-oscillating circuit. Results of measurements conducted on gel-phantoms are presented and discussed.}}, author = {{Uribe, David Oliva and Stroop, Ralf and Hemsel, Tobias and Wallaschek, Jörg}}, booktitle = {{Frequency Control Symposium, 2008 IEEE International}}, issn = {{1075-6787}}, keywords = {{biomedical measurement, brain, cancer, neurophysiology, phantoms, phase locked loops, piezoelectric actuators, surgery, tactile sensors, transfer functions, tumours, PLL, biomedical tissue differentiation system, brain tumor resection, frequency control, frequency shift, gel-phantom, high sensitivity actuator-sensor system, neurosurgery, phase-locked loop, piezoelectric actuators, piezoelectric bimorph, self-oscillating circuit, sensor sensitivity, tactile differentiation, tactile sensor system, transfer function, tumor boundary, visual differentiation, Biomedical measurements, Circuits, Frequency control, Neoplasms, Neurosurgery, Phase locked loops, Piezoelectric actuators, Surges, Transfer functions, Voltage}}, pages = {{91--94}}, title = {{{Development of a biomedical tissue differentiation system using piezoelectric actuators}}}, doi = {{10.1109/FREQ.2008.4622963}}, year = {{2008}}, }