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The Division Industrial Chemistry of the Swiss Chemical Society organizes periodically a two-day event for the post-graduate education of its members. This event is known as the Freiburger Symposium. This year it focussed on sustainable chemical production. The twelve talks covered the following aspects: ethical needs for sustainability standards, the required, attained, and yet to be attained sustainability goals in chemical industry. Diverse case studies showed the highly developed awareness about the sustainability issue within the chemical community.
IPv6 over resource-constrained devices (6Lo) emerged as a de-facto standard for the Internet of Things (IoT) applications especially in home and building automation systems. We provide results of an investigation of the applicability of 6LoWPAN with RPL mesh networks for home and building automation use cases. The proper selection of Trickle parameters and neighbor reachable time-outs is important in the RPL protocol suite to respond efficiently to any path failure. These parameters were analyzed in the context of energy consumption w.r.t the number of control packets. The measurements were performed in an Automated Physical Testbeds (APTB). The results match the recommendation by RFC 7733 for selecting various parameters of RPL protocol suite. This paper shows the relationship between various RPL parameters and control traffic overhead during network rebuild. Comparative measurement results with Bluetooth Low Energy (BLE) in this work showed that 6Lo with RPL outperformed BLE in this use case with less control traffic overheads.
In the last decade, IPv6 over Low power Wireless Personal Area Networks, also known as 6LoWPAN, has well evolved as a primary contender for short range wireless communication and holds the promise of an Internet of Things, which is completely based on the Internet Protocol. In the meantime, various 6LoWPAN implementations are available, be it open source or commercial. One of these implementations, which was developed by the authors' team, was tested on an Automated Physical Testbed for Wireless Systems at the Laboratory Embedded Systems and Communication Electronics of Offenburg University of Applied Sciences, which allows the flexible setup and full control of arbitrary topologies. It also supports time-varying topologies and thus helps to measure performance of the RPL implementation. The results of the measurements show a very good stability and short-term and long-term performance also under dynamic conditions. In addition, it can be proven that the performance predictions from other papers are consistent with real-life implementations.
A simple measuring method for acquiring the radiation pattern of an ultrawide band Vivaldi antenna is presented. The measuring is performed by combining two identical Vivaldi antennas and some of the intrinsic properties of a stepped-frequency continue wave radar (SFCW radar) in the
range from 1.0 GHz to 6.0 GHz. A stepper-motor provided the azimuthal rotation for one of the antennas from 0 ◦ to 360 ◦. The tests have been performed within the conventional environment (laboratory / office) without using an anechoic chamber or absorbing materials. Special measuring devices have not been used either. This method has been tested with different pairs of Vivaldi antennas and it can be also used for different ones (with little or no change in the system), as long as their operational
bandwidth is within the frequency range of the SFCW radar.
Keywords — SFCW Radar, Antenna Gain Characterization,
Azimuthal Radiation Pattern
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.
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 idea of this game is to use a flashcard system to create a short story in a foreign language. The story is developed by a group of people by exchanging sentences via a flashcard system. This way, people can learn from each other without fear of making mistakes because the group members are anonymous.
This paper describes the use of the single-linkage hierarchical clustering method in outlier detection for manufactured metal work pieces. The main goal of the study is to group defects that occur 5 mm into a work piece from the edge, i.e., the border of the metal work piece. The goal is to remove defects outside the area of interest as outliers. According to the assumptions made for the performance criteria, the single-linkage method has achieved better results compared to other agglomeration methods.
Air traffic is by nature crossing borders and organizations. The supporting infrastructure represents a federative distributed system of independent Air Traffic Service Units, typically each with its own proprietary system architecture. Interaction between the centers is taking place over dedicated protocols, often organized as a mesh of 1:1 bilateral data exchanges.
This contribution gives an overview of the ongoing efforts to standardize this data exchange. At the core is a data-centric view, using a shared virtual Flight Object as the IT counterpart of a real flight. It permits a uniform way to access and update a flight’s static and dynamic attributes. A middleware is presented that implements this abstraction and maps it onto a physical level, employing DDS (Data Distribution Service) technology for the 1:N dissemination of flight data.
A platform of an electronic capsule is being developed for multi-task medical assistant application. It includes a near field telemetry unit for bidirectional communication system of 115 KHz low carrier frequency for inductive data transmission suited for human body energy transfer. The system triggers an actuator for drug delivery in various time and release forms via wireless external control, it has the ability to record temperature, measure pH of the body (additional sensors), and retrieve data to the outside. It consists of a 32bit processor, memory, external peripheries, and detection facility. The complete system is designed to fit small-size mass medical application with low power consumption, size of 7x25mm. The system is designed, simulated and emulated on FPGA. A final layout of the complete chip design is still under progress.
Multi-phase management is crucial for performance and durability of electrochemical cells such as batteries and fuel cells. In this paper we present a generic framework for describing the two-dimensional spatiotemporal evolution of gaseous, liquid and solid phases, as well as their interdependence with interfacial (electro-)chemistry and microstructure in a continuum description. The modeling domain consists of up to seven layers (current collectors, channels, electrodes, separator/membrane), each of which can consist of an arbitrary number of bulk phases (gas, liquid, solid) and connecting interfaces (two-phase or multi-phase boundaries). Bulk and interfacial chemistry is described using global or elementary kinetic reactions. Multi-phase management is coupled to chemistry and to mass and charge transport within bulk phases. The functionality and flexibility of this framework is demonstrated using four application areas in the context of post-lithium-ion batteries and fuel cells, that is, lithium-sulfur (Li-S) cells, lithium-oxygen (Li-O) cells, solid oxide fuel cells (SOFC) and polymer electrolyte membrane fuel cells (PEFC). The results are compared to models available in literature and properties of the generic framework are discussed.
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].
A highly scalable IEEE802.11p communication and localization subsystem for autonomous urban driving
(2013)
The IEEE802.11p standard describes a protocol for car-to-X and mainly for car-to-car-communication. It has found its place in hardware and firmware implementations and is currently tested in various field tests. In the research project Ko-TAG, which is part of the research initiative Ko-FAS, cooperative sensor technology is developed for the support of highly autonomous driving. A secondary radar principle based on communication signals enables localization of objects with simultaneous data transmission. It mainly concentrates on the detection of pedestrians and other vulnerable road users (VRU), but also supports pre crash safety applications. Thus it is mainly targeted for the support of traffic safety applications in intra-urban scenarios. This contribution describes the Ko-TAG part of the overall initiative, which develops a subsystem to improve the real-time characteristics of IEEE802.11p needed for precise time of flight real-time localization. In doing this, it still fits into the regulatory schemes. It discusses the approach for definition and verification of the protocol design, while maintaining the close coexistence with existing IEEE802.11p subsystems. System simulations were performed and hardware was implemented. Test results are shown in the last part of the paper.
The IEEE802.11p standard describes a protocol for car-to-X and mainly for car-to-car-communication. It has found its place in hardware and firmware implementations and is currently tested in various field tests. In the research project Ko-TAG, which is part of the research initiative Ko-FAS, cooperative sensor technology is developed and its benefit for traffic safety applications is evaluated. A secondary radar principle based on communication signals enables localization of objects with simultaneous data transmission. It mainly concentrates on the detection of pedestrians and other vulnerable road users (VRU), but also supports pre crash safety applications. The Ko-TAG proposal enriches the current IEEE802.11p real-time characteristics needed for precise time-of-flight real-time localization. This contribution describes the development of a subsystem, which extends the functionality of IEEE802.11p and fits into the regulatory schemes. It discusses the approach for definition and verification of the protocol design, while maintaining the close coexistence with existing IEEE802.11p subsystems. System simulations were performed and hardware was implemented. The next step will be field measurements to verify the simulation results.
Uncontrollable manufacturing variations in electrical hardware circuits can be exploited as Physical Unclonable Functions (PUFs). Herein, we present a Printed Electronics (PE)-based PUF system architecture. Our proposed Differential Circuit PUF (DiffC-PUF) is a hybrid system, combining silicon-based and PE-based electronic circuits. The novel approach of the DiffC-PUF architecture is to provide a specially designed real hardware system architecture, that enables the automatic readout of interchangeable printed DiffC-PUF core circuits. The silicon-based addressing and evaluation circuit supplies and controls the printed PUF core and ensures seamless integration into silicon-based smart systems. Major objectives of our work are interconnected applications for the Internet of Things (IoT).
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.
A Localization System Using Inertial Measurement Units from Wireless Commercial Handheld Devices
(2013)
This paper describes a newly developed technology for the calculation of trajectories of mobile objects, which is based on commercially available sensors being integrated into modern mobile phones and other gadgets. First, a step counting technique was implemented. Second, a novel step length estimator is proposed. These two algorithms utilize the data from accelerometer sensor only. Third, the heading information was obtained using a gyroscope with complementary filter in quaternion form. The combined algorithm was implemented on a low-power ARM processor to provide the trajectory points relative to an initial point. The proposed technique was tested by 10 subjects, in different shoes with different paces. The dependence of the performance of the technology on the attaching point of the mobile device is weak. The proposed algorithms have better balance and estimation accuracy and depend in less degree on the variety in physical parameters of people in comparison with the existing techniques. In experiments inertial measurement units were mounted in different places, i.e. in the hand, in trousers or in T-shirt pockets. The return position error did not exceed 5% of the total travelled distance for all performed tests.
A new electronic capsule with bidirectional communication system is being developed for multi-task application. The capsule is designed to be a platform for medical assistant application inside the body. The designed telemetry unit is a synchronous bidirectional communication block using continuous phase DQPSK of 115 kHz low carrier frequency for inductive data transmission suited for human body energy transfer. The communication system can assist the electronic pill to trigger an actuator for drug delivery, to record temperature, or to measure pH of the body. It consists additionally to a 32bit processor, memory, external peripheries, and detection facility. The complete system is designed to fit small-size mass medical application with low power consumption, size of 7x25mm. The system is designed, simulated and emulated on FPGA. A final layout of the complete chip design is still under progress.
To provide proper solutions to the problem of device dependant content delivery, a fine categorization of the application target devices is needed. Earlier attempts provided two different presentations for desktop and mobile platforms. The mobile platform presentation was divided into three categories, based on a general classification (PDA, Smartphone or mobile phone). In order to improve the on mobile device presentation a finer categorization is introduced. In this paper, our focus is to clarify the concept of this more flexible presentation module, in which the delivered content depends on the efficiency of the device based on a selected set of capabilities.
Electronic pills, smart capsules or miniaturized microsystems swallowed by human beings or animals for various biomedical and diagnostic applications are growing rapidly in the last years. This paper searched out the important existing electronic pills in the market and prototypes in research centers. Further objective of this research is to develop a technology platform with enhanced feature to cover the drawback of most
capsules. The designed telemetry unit is a synchronous bidirectional communication block using continuous phase DQPSK of 115 kHz low carrier frequency for inductive data transmission suited for human body energy transfer. The communication system can assist the electronic pill to trigger an actuator for drug delivery, to record temperature, or to measure pH of the body. It consists additionally to a 32bit processor, memory, external peripheries, and detection facility. The complete system is designed to fit small-size mass medical application with low power consumption, size of 7x25mm. The system is designed, simulated and emulated on FPGA.
Signal detection and bandwidth estimation, also known as channel segmentation or information channel estimation, is a perpetual topic in communication systems. In the field of radio monitoring this issue is extremely challenging, since unforeseeable effects like fading occur accidentally. In addition, most radio monitoring devices normally scan a wide frequency range of several hundred MHz and have to detect a multitude of different signals, varying in signal power, bandwidth and spectral shape. Since narrowband sensing techniques cannot be directly applied, most radio monitoring devices use Nyquist wideband sensing to discover the huge frequency range. In practice, sensing is normally conducted by an FFT sweep spectrum analyzer that delivers the power spectral density (PSD) values to the radio monitoring system. The channel segmentation is the initial step of a comprehensive signal analysis in a radio monitoring system based on the PSD values. In this paper, a novel approach for channel segmentation is presented that is based on a quantization and a histogram evaluation of the measured PSD. It will be shown that only the combination of both evaluations will lead to an successful automatic channel segmentation. The performance of the proposed algorithm is shown in a real radio monitoring szenario.
In large aircrafts the cabling is very complex and often causes reliability problems. This is specially true for modern In-flight Entertainment (IFE) systems, where every passenger can select a preferred movie, play computer games or be able to communicate with other travellers. Due to EMC problems, wireless communication systems (WiFi etc.) didn't succeed in solving these problems. In this paper an innovative communication system is proposed which perfectly supplements an aircraft IFE system. The key innovation of this system is to use structures that are essential parts of the airframe for data transfer, such as seat rails. Those rails consist of rectangular shapes and could easily be modified to fulfill the function of waveguides for microwaves. A waveguide as part of the seat rail would provide enormous benefits for aircrafts, such as a large bandwidth and consequently high data rates, no problems with EMC, unlimited flexibility of seat configuration, mechanical robustness with associated increase of reliability and a few additional advantages related to aircrafts such as reduction of weight and costs.
A novel approach of a testbed for embedded networking nodes has been conceptualized and implemented. It is based on the use of virtual nodes in a PC environment, where each node executes the original embedded code. Different nodes are running in parallel and are connected via so-called virtual interfaces. The presented approach is very efficient and allows a simple description of test cases without the need of a network simulator. Furthermore, it speeds up the process of developing new features.
In this paper, a complete passive transponder device has been discussed which is meant to monitor leakage in silicone breast implants. The passive tag operates in the HF frequency range of 13.56MHz using RFID ISO 15693 standard. The complete system consists of the transponder, reader and a PC. This paper focusses on the development of such a state of the art passive RFID transponder to monitor the wellness of the silicone breast implants periodically in order to detect leakage in the same. Keyword: RFID (Radio frequency identification device), EM (Electromagnetic) field, Passive Transponder, Silicone breast implants.
A new RFID/NFC (ISO 15693 standard) based inductively powered passive SoC (System on chip) for biomedical applications is presented here. The proposed SOC consists of an integrated 32 bit microcontroller, RFID/NFC frontend, sensor interface circuit, analog to digital converter and some peripherals such as timer, SPI interface and memory devices. An energy harvesting unit supplies the power required for the entire system for complete passive operation. The complete chip is realized on CMOS 0.18 μm technology with a chip area of 1.5 mm × 3.0 mm.
A new, small, and optimized for low power processor core named SIRIUS has been developed, simulated, synthesized to a netlist and verified. From this netlist, containing only primitives like gates and flip-flops, a mapping to an ASIC - or FPGA technology can easily be done with existing synthesizer tools, allowing very complex SOC designs with several blocks. Emulation via FPGA can be done on already simple setups and cheap hardware because of the small core size. The performance is estimated 50 MIPS on Cyclone II FPGA and about 100 MIPS on a 0.35 CMOS 5M2P technology with 4197 primitives used for the core, including a 16 x 16 multiplier. An example design of the ASIC for an electronic ePille device currently in development is shown.
A new miniaturized capsule with 32bit processor and bidirectional communication system is being developed for multitask application. The capsule is designed to be a platform for medical assistant application inside the body. The processor core SIRIUS has been developed, simulated, synthesized to a netlist and verified. The designed telemetry unit is a synchronous bidirectional communication block using continuous phase DQPSK of 115 kHz low carrier frequency for inductive data transmission suited for human body energy transfer. The communication system can assist the electronic pill to trigger an actuator for drug delivery, to record temperature, or to measure pH of the body. The complete system is designed to fit small-size mass medical application with low power consumption, size of 7x25 mm. The system is designed, simulated, emulated on FPGA, and routed in AMIS Technology.
With increasing flexible AC transmission system (FACTS) devices in operation, like the most versatile unified power flow controller (UPFC), the AC/DC transmission flexibility and power system stability have been suffering unprecedented challenge. This paper introduces the user-defined modeling (UDM) method into the UPFC dynamic modeling process, to deal with the challenging requirements of power system operation. This has also been verified using a leading-edge stability analysis software named DSATools TM in the IEEE-39 bus benchmark system. The characteristics of steady-state and dynamic responses are compared and analyzed under different conditions. Furthermore, simulation results prove the feasibility and effectiveness of the proposed UPFC in terms of both the independent regulation of power flow and the improvement of transient stability.
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.
Das fortwährende Streben nach Steigerung der Genauigkeit und Effizienz von industriellen Bearbeitungs- und Prüfprozessen führt bei elektrischen Antrieben zu immer höheren Forderungen an ihre dynamischen Eigenschaften. Hierbei kommt dem Stromregelkreis als dem am weitesten unterlagerten Regelkreis eines elektrischen Antriebs eine entscheidende Bedeutung zu. Mit zunehmender Dynamikerhöhung des Stromregelkreises treten jedoch aufgrund von Parameterunsicherheiten und von Messfehlem immer deutlicher Probleme der Regelkreisrobustheit und der Geräuschemission in den Vordergrund, die es oft nicht gestatten, die theoretisch erhaltenen Lösungen in vollem Umfang zu realisieren. Gegenüber der optimalen Lösung müssen dann Abstriche hinsichtlich der erreichbaren Dynamik gemacht werden. Wie diese Abstriche durch das Ausschöpfen verborgener Freiheitsgrade reduziert werden können, wird im vorliegenden Beitrag gezeigt. Als Lösungsansatz wird hierfür ein achsenunsymmetrischer Statorstromzustandsregler gewählt, der es erlaubt, in der d- und q-Achse eine unterschiedliche Dynamik einzustellen. Hierbei wird zunächst im Kapitel 2 ein kurzer Überblick über die Entwicklungsgeschichte und den Stand der Technik von pulsweitenmodulierten Stromregelverfahren für Drehstromantriebe in den zurückliegenden Jahrzehnten gegeben. Anschließend wird am Beispiel einer frequenzumrichtergespeisten Asynchronmaschine das zeitdiskrete Modell der Statorstromregelstrecke vorgestellt, das dem hier erläuterten Verfahren zugrunde liegt. Wegen des Zusammenhangs zwischen Dynamikerhöhung und Empfindlichkeitszunahme ist es naheliegend, die Dynamik des Statorstromregelkreises nur so weit zu steigern, wie es erforderlich ist. Diesbezüglich ist insbesondere zu gewährleisten, dass ein angefordertes Drehmoment möglichst schnellst eingeprägt wird. Die Änderungsgeschwindigkeit des Flusses spielt hingegen eine untergeordnetere Rolle. Demzufolge sollte die drehmomentbildende Statorstrom-q-Komponente in der Praxis eine höhere Dynamik aufweisen als die flussbildende Statorstrom-d-Komponente. Um hierbei die aufwändige reelle Rechnung so weit wie möglich zu vermeiden, wird der Reglerentwurf in zwei Schritten durchgeführt. Im ersten Schritt wird ein schiefsymmetrisches, komplex beschreibbares Regelgesetz entworfen, das zwar zu einer möglichst einfachen Darstellbarkeit des geschlossenen Statorstromregelkreises führt, das jedoch noch nicht die endgültige Dynamik zur Folge haben muss. Insbesondere muss nach Abschluss dieses ZwischenSchritts bereits eine vollständige Entkopplung der d- und der q-Komponente des Statorstromraumzeigers vollzogen sein. Im zweiten Schritt wird dann ein weiterer Regler entworfen, der auf der Grundlage des im ersten Schritt erhaltenen entkoppelten Systems jeder Stromkomponente eine separate Dynamik zuweisen kann. Die Verkettung beider Teilregler führt schließlich zum gesuchten Statorstromregler, der zum einen relativ einfach berechenbar ist und der zum anderen alle an ihn gestellten Dynamikanforderungen erfüllt. Im vierten Kapitel wird schließlich der Entwurf des achsenunsymmetrischen Statorstromzustandsreglers skizziert und die daraus hervorgehenden Regelalgorithmen vorgestellt. Die Leistungsfähigkeit des beschriebenen Zustandsreglers wird anhand von aufgenommenen Zeitverläufen eines Laborantriebs demonstriert, mit dem der Drehmomentverlauf von Verbrennungsmotoren nachgebildet wird.
This paper gives an overview of the implementation of an Active Noise Control system on the TMS320C6713 Digital Signal Processor from Texas Instruments in the Digital Signal Processing Lab at Hochschule Offenburg, Germany. This system is implemented considering some non-ideal environmental conditions on a real system instead of being limited to computer simulations. Changes over time on the physical acoustical path as well as reverberation and variation on the power of the reference signal can strongly degrade the performance of the system or even lead to instability. In order to try to minimize these effects, the Active Noise Control system was designed to support a fast and easy implementation and evaluation of different algorithms on the DSP in real-time. In Section 1 a brief introduction about active noise control system is given and in section 2 the basic algorithm is described. In section 3 the implementation of the system is described and in section 4 some final considerations are given.
The Institute of Applied Research Offenburg is working in the field of autonomous data loggers since many years. In collaboration with industry, a new RFID based active sensor data logger for continuous recording of temperature has been developed and is now manufactured in mass production. Compared to existing systems, an unusual large data memory is integrated, which can be used via a simplified file system in a flexible way. The system will be used to accompany and monitor temperature sensitive goods of high value. The transponder is the first member of a new class of logging devices, the smallest will be not larger than a 2 Euro-coin with a fully integrated ASIC frontend.
The iSign project started in 2000 as a web-based laboratory setting for students of electrical engineering. In the meantime it has broadened into a heterogeneous learning environment offering learning material, adaptive user settings and access to a simulation tool. All these offerings can be accessed via web and wireless by different clients, such as PCs, PDAs and mobile phones. User adaptive systems offer unique and personalised environment for every learner and therefore are a very important aspect of modern e-learning systems. The iSign project aims to personalise the content structure based on the learner's behaviour, content pattern, policies, and system environment. The second aspect of the recent research and development within this project is the generation of suitable content and presentation for different clients. This generation is based additionally on the user preferences in order to obtain the desirable presentation for a given device. New, valuable features are added to the mobile application, empowering the user not only to control the simulation process with his mobile device but also to input data, view the simulation's output and evaluate the results. Experiences with students have helped to improve functionality and look-and-feel whilst using the iSign system. Our goal is to provide unconstrained, continuous and personalised access to the laboratory settings and learning material everywhere and at anytime with different devices.
In previous work we [1] and other authors (e.g. [2]) have shown that agent-based systems are successful in optimizing delivery plans of single logistics companies and are meanwhile successfully productive in industry. In this paper we show that agent-based systems are particularly useful to also optimize transport across logistics companies. In intercompany optimization, privacy is of major importance between the otherwise competing companies. Some data has to be treated strictly private like the cost model or the constraint model. Other data like order information has to be shared. However, typically the amount of orders released to other companies has also to be limited. We show that our agent-based approach can be easily fine tuned to trade off privacy against the benefit of cooperation.
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.
This paper deals with the detection and segmentation of clouds on high-dynamic-range (HDR) images of the sky as well as the calculation of the position of the sun at any time of the year. In order to predict the movement of clouds and the radiation of the sun for a short period of time, the clouds thickness and position have to be known as precisely as possible. Consequently, the segmentation algorithm has to provide satisfactory results regardless of different weather, illumination and climatic conditions. The principle of the segmentation is based on the classification of each pixel as a cloud or as a sky. This classification is usually based on threshold methods, since these are relatively fast to implement and show a low computational burden. In order to predict if and when the sun will be covered by clouds, the position of the sun on the images has to be determined. For this purpose, the zenith and azimuth angles of the sun are determined and converted into XY coordinates.
This paper presents an enhancement on QPSK modulation technique for near field communication (NFC). The enhanced modulation is based on continuous-phase QPSK with Gaussian filtering during switch from one phase to the other. Signal processing is done digitally with minimum external discrete components for air interface. The telemetry system can be used to assist a smart capsule (slave) that can be swallowed to establish data communication with external device (master). The system is designed, simulated, and emulated on FPGA showing 20 dB attenuation on side-lobes of the spectrum.
The concept of m-learning which differs from other forms of e-learning covers a wide range of possibilities opened up by the convergence of new mobile technologies, wireless communication structure and distance learning development. This process of converging has launched some new goals to support m-learning where heterogeneity of devices, their operating systems (Linux, Windows, Symbian, Android etc) and supported markup languages (WML, XHTML etc), adaptive content, preferences or characteristics of user have become some of the major problems to be solved. To facilitate the learning process even more and to establish literally anytime anywhere learning, learning material/content should be available to the user always even if the user is in offline. Multiple devices used by the same user should also be synchronized among themselves and with server to provide updated learning content and to give a freedom to the user to choose any device as per his/her convenience. In this paper software architecture has been proposed to solve these problems and has been implemented by using a multidimensional flashcard learning system which synchronizes among all the devices that are being used by the user.
The communication system of a large-scale concentrator photovoltaic power plant is very challenging. Manufacturers are building power plants having thousands of sun tracking systems equipped with communication and distributed over a wide area. Research is necessary to build a scalable communication system enabling modern control strategies. This poster abstract describes the ongoing work on the development of a simulation model of such power plants in OMNeT++. The model uses the INET Framework to build a communication network based on Ethernet. First results and problems of timing and data transmission experiments are outlined. The model enables research on new communication and control approaches to improve functionality and efficiency of power plants based on concentrator photovoltaic technology.
Introduction: Cardiac resynchronization therapy (CRT) with biventricular (BV) pacing is an established therapy for heart failure (HF) patients with ventricular desynchronization and reduced left ventricular (LV) ejection fraction. The aim of this study was to evaluate electrical ventricular desynchronization with transthoracic and transesophageal signal averaging electrocardiography in HF, to better select patients for CRT.
Methods: 13 HF patients (age 68 ± 10 years; 2 females, 11 males) with New York Heart Association (NYHA) class 2.8 ± 0.5, 28.6 ± 12.6 % LV ejection fraction and 155 ± 24 ms QRS duration (QRSD) were analysed with transthoracic and transesophageal electrocardiogram recording and novel National Intruments LabView 2009 signal averaging software. Esophageal TO Osypka catheter was perorally applied to the esophagus and placed in the position of maximum LV de-flection. The 0.05-Hz high-pass filtered surface electrocardiogram and the 10-Hz high-pass filtered bipolar transesophageal electrocardiogram were recorded with Bard EP-System and 1000-Hz sampling rate.
Results: Transesophageal LV electrogram recording was possible in all HF patients (n=13). Transesophageal interventricular conduction delay (IVCD) was 51 ± 19 ms and measured between the earliest onset of QRS in the 12-channel surface electrocardiogram and the onset of the LV deflection in the transesophageal electrocardiogram. Transesophageal intra-left ventricular delay (LVCD) was 90 ± 16 ms and measured between the onset and offset of the LV deflection in the transesophageal electrocardiogram. QRSD to transesophageal IVCD ratio was 3.43 ± 1.31 ms, QRSD to transesophageal LVCD ratio was 1.75 ± 0.28 ms and QRSD was evaluated between onset and offset of QRS signal in the 12-channel surface electrocardiogram.
Conclusion: Determination of IVCD, LVCD, QRSD-to-IVCD-ratio and QRSD-to-LVCD-ratio by transesophageal LV electrogram recording with LabView 2009 signal averaging technique may be useful parameters of ventricular desynchronisation to improve patient selection for CRT.
Introduction: Cardiac resynchronization therapy (CRT) with biventricular (BV) pacing is an established therapy for heart failure (HF) patients with ventricular desynchronisation and reduced left ventricular (LV) function. The aim of this study was to evaluate preejection period (PEP) and left ventricular ejection time (LVET) with transthoracic signal averaging impedance and electrocardiography in HF patients with and without BV pacing.
Methods: 10 HF patients (age 68.9 ± 8 years; 2 females, 9 males) with New York Heart Association (NYHA) class 2,9 ± 0.5, 30.9 ± 10.5 % LV ejection fraction and 159.4 ± 22.9 ms QRS duration were analysed with transthoracic impedance and electrocardiography (Cardioscreen Medis, Ilmenau, Germany) and novel National Intruments LabView 2009 signal averaging software. One day after BV pacing device implantation, AV and VV delays were optimized by transthoracic impedance cardiography and stroke volume (SV) and cardiac output (CO) were gained by Cardioscreen.
Results: Transthoracic impedance and electrocardiography AV and VV delay opimization was possible in all HF patients with BV pacing devices (n= 10). PEP was 154 ± 24ms without BV pacing and measured between onset of QRS in the surface electrocardiogram and onset of ventricular deflection in the impedance cardiogram. LVET was 342 ± 65ms without BV pacing and measured between onset and offset of ventricular deflection in the impedance cardiogram. The use of optimal AV and VV delay BV pacing resulted in improvement of SV from 64.1 ± 26.5 ml to 94.1 ± 33.96 ml (P < 0.05) and CO from 4.05 ± 1.36 l/min to 6.44 ± 1.56 l/min (P < 0.05).
Conclusion: PEP and LVET may be useful parameters of ventricular Desynchronisation. AV and VV delay optimized BV pacing improve SV and CO. Impedance and electrocardiography with LabView 2009 signal averaging may be a simple and useful technique to optimize CRT.
Since cabling is very complex and often causes reliability problems in aircrafts new approaches which base on wireless technologies are highly desired. In this paper an innovative communication system is proposed that uses the essential elements of the airframe for data transfer. The communication is based on the wireless standard for Digital Video Broadcasting (DVB) and enables high data rates, which are required for the in-flight entertainment system as an example of use.
Today's network landscape consists of many different network technologies, a wide range of end-devices with a large scale of capabilities and power, and an immense quantity of information and data represented in different formats. Research on 3D imaging, virtual reality and holographic techniques will result in new user interfaces (UI) for mobile devices and will increase their diversity and variety. In this paper software architecture has been proposed to establish device and content format independent communication, implemented in Language Learning Game (LLG).
This paper investigates the maximum torque capability and torque ripple reduction using the asymmetric stator teeth for interior permanence magnet (IPM) synchronous machines. Traditional electric machines have the identical width for all stator teeth and the winding function is fixed. Using different widths for different stator teeth changes the winding function, therefore, the torque ripple components. The mathematical modeling of interior permanent magnet (IPM) synchronous machine torque ripple and finite element analysis simulation results for the characteristic properties of electric machines are presented. Compared with a similar rating IPM machine, certain combinations of the teeth widths can reduce the torque ripple by 80% with less than 4% average torque decline.
Transcatheter aortiv valve implantation is a new safe strategy treatment for patients with symptomatic severe aortic stenosis and high operative risk. The aim of the study was to compare the pre-and post- muiscatheter aortiv valve implantation procedures to determine the atrioventricuktr conduction time as a potential predictor of permanent pacemaker therapy requirement after transcatheter aortiv valve implantation. The transcatheter aortiv valve implantation patients were divided into groups without pacemaker and with dual or single chamber pacemEtker with diffent atrioventrieular conduction time disturbance before and after transcatheter aortiv valve implantation. In heart failure, patients without permanent pacemaker therapy after transcatheter aortiv valve implantation, atrioventricular conduction time was prolonged after transcatheter aortiv valve implantation. In patients with permanent dual chamber pacemaker therapy after transcatheter aortiv valve implantation, atrioventricular conduction time was normalised with dual chaniber atrioventrieuku pacing mode. Atrioventricular conduction time may be a useful parameter to evaluate the risk of post-procedural atrioventricular conduction block and permanent pacemaker therapy in transcatheter north, valve implantation patients.
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.
Automated RF Emulator for a Highly Scalable IEEE802.11p Communication and Localization Subsystem
(2014)
The IEEE802.11p standard describes a protocol for car-to-X and mainly for car-to-car-communication. In the research project Ko-TAG, which is part of the research initiative Ko-FAS, cooperative sensor technology is developed for the support of highly autonomous driving. The Ko-TAG subsystem improves the real-time characteristics of IEEE802.11p needed for precise time of flight real-time localization while still fitting into the regulatory schemes. A secondary radar principle based on communication signals enables localization of objects with simultaneous data transmission. The Ko-TAG subsystem mainly concentrates on the support of traffic safety applications in intra-urban scenarios. This paper details on the development of a fully automated RF emulator used to test the Ko-TAG subsystem.
The RF emulator includes the physical networking nodes, but models the RF environment using RF-waveguides. The RF emulator allows the controlling of path loss and connectivity between any of the nodes with the help of RF attenuators and programmable RF switches, while it is shielded against its surrounding RF environment in the lab. Therefore it is an inexpensive alternative to an RF absorber chamber, which often is not available or exceeds the project’s budget.
Details about the system definition can be found in earlier papers. Test results are shown in the last part of the paper.
BiCI users’ sensitivity to interaural phase differences for single- and multi-channel stimulation
(2016)
Das normalhörende auditorische System ist in der Lage, interaurale Zeit- bzw. Phasendifferenzen zur verbesserten Signaldetektion im Störgeräusch zu nutzen. Dieses Phänomen wird häufig als binaurale Entmaskierung bezeichnet und ist sowohl bei einfachen Signalen wie Sinustönen, als auch bei Sprachsignalen im Störgeräusch wirksam. Vorangegangene Studien haben gezeigt, dass binaurale Entmaskierung eingeschränkt auch bei bilateralen CI-Trägern beobachtbar ist (Zirn et al., 2016).
Aktuelle Ergebnisse zeigen, dass die binaurale Entmaskierung sensitiv gegenüber der bilateralen CI-Anpassung ist. So lässt sich der Effekt durch tonotopen Abgleich und Herausstellen eines apikalen Feinstrukturkanals modulieren. Steigerungen der binauralen Entmaskierung um bis zu 1,5 dB sind auf diese Weise gegenüber der konventionellen CI-Anpassung möglich. Allerdings variiert der Einfluss der CI-Anpassung interindividuell erheblich.
Termination of atrial flutter (AFL) is not possible in all AFL patients (P) with transesophageal left atrial pacing (TLAP) with undirected electrical pacing field (EPF) and high atrial pacing threshold. Purpose of the study was to evaluate bipo-lar transesophageal left atrial electrocardiography (TLAE) and TLAP with directed EPF for evaluation and termination of AFL with and without simultaneous transesophageal echocardiography (TEE).
Methods: AFL P were analysed using either a TO electrode with one cylindrical (CE) and three or seven hemispherical electrodes (HE) or TEE electrode with four HE (Osypka, Rheinfelden, Germany). Burst TLAP cycle length was between 200msand 50ms.
Results: AFL cycle length was 233±30 ms with mean ventricular cycle length of 540±149 ms. AFL could be terminated by rapid bipolar TLAP with directed EPF using HE-HE and CE-HE with induction of atrial fibrillation (AF), induction of AF and spontaneous conversion to sinus rhythm and direct conversion to sinus rhythm. Directed EPF was simulated with finite element method.
Conclusions: AFL can be evaluated by bipolar TLAE. AFL can be terminated with rapid TLAP with directed EPF with and without simultaneous TEE. Bipolar TLAE with rapid TLAP is a safe, simple and useful method for evaluation and termination of AFL.
Cardiac resynchronisation therapy (CRT) with biventricular pacing (BV) is an established therapy for heart failure (HF) patients with interventricular conduction delay (IVCD). The aim of the study was to evaluate transesophageal IVCD and left ventricular (LV) pacing with directed electrical pacing field (EPF) in HF patients.
Methods: HF patients were analysed with bipolar transesophageal LV electrocardiogram recording and LV pacing with constant voltage stimulus output, 4 ms stimulus duration, distal cylindrical electrode (CE) and seven 6 mm hemispherical electrodes (HE) with 15 mm electrode distance (TO, Dr. Osypka, Rheinfelden, Germany).
Results: LV electrocardiogram recording with HE-HE and CE-HE evaluated a mean IVCD of 79.9 ± 36.7 ms. Directed EPF with CE-HE and HE-HE allowed LV VAT (n=12) and LV D00 pacing (n=5) with a mean effective capture output of 97.35 ± 6.64 V. In 15 responders with IVCD of 87 ± 33 ms arterial pulse pressure (PP) increased from 65 ± 24 mmHg to 79 ± 27 mmHg (p < 0.001). EPF was simulated with finite element method.
Conclusions: Transesophageal LV electrocardiography and directed EPF pacing with CE and HE allowed the evaluation of IVCD and PP to select patients for BV pacing.
The following paper presents the results of a feasibility study about Bluetooth Low Energy (BLE) based wireless sensors. The development of industrial wireless sensors leads to important demands for the wireless technologies like a low energy consumption and a resource saving simple protocol stack. Bluetooth Low Energy (BLE) is a rather new wireless standard which will completely fulfill these fundamental requirements. A self-designed BLE sensor system has been used to explore the common applicability of BLE for wireless sensor systems. The evaluation results of various analyses with the BLE sensor system are now presented in this paper.
This paper treats the Brillouin backscattering in a single mode optical fiber and its implications on the Brillouin Ring Laser Gyroscope (BRLG). The BRLG consists of a fiber ring cavity in which stimulated Brillouin scattering is induced and provides two resonant counterpropagating backscattered waves. If this cavity is rotating around its axis, the backscattered waves get different resonant frequencies because of the Sagnac effect. The frequency difference is proportional to the rotation rate (Omega) by inducing a frequency offset between the counterpropagating waves. Some reported Brillouin spectra exhibit several peaks, which means that one pump wave provides at least two backscattered waves with distinguishable frequencies. In order to understand this multi-backscattering and to take advantage of it for the BRLG, we present results of a simulation of the Brillouin backscattering in a single mode optical fiber.
Der Studienbeginn wird an der Hochschule Offenburg durch Vorbereitungskurse, sogenannte Brückenkurse, unterstützt. Wir stellen vorläufige Ergebnisse beim Einsatz von Smartphones und Tablets im Rahmen des Physik-Brückenkurses vor, bei dem die Studenten Hilfen zum selbständigen Üben durch eine App erhalten. Durch die Überarbeitung des Kurses und den Einsatz der App konnte der Teilnehmerschwund verringert werden. Die Evaluationsergebnisse bestätigen eine hohe Akzeptanz der Neuerungen seitens der Studierenden. Erste Auswertungen von Ein- und Ausgangstests deuten darauf hin, dass durch den Brückenkurs eine Angleichung der Vorkenntnisse der Studienanfänger erreicht wird, da Teilnehmer mit geringeren Vorkenntnissen tendenziell einen größeren Lernfortschritt erreichen. Durch unterschiedliche Schwierigkeitsstufen und selbstregulierte Übungsphasen in individuellem Tempo können aber auch die Erfordernisse der stärkeren Teilnehmer angemessen berücksichtigt werden.
Im Projekt bwLehrpool wurde ein verteiltes System für die flexible Nutzung von Rechnerpools durch Desktop-Virtualisierung entwickelt. Auf Basis eines zentral gebooteten Linux- Grundsystems können beliebige virtualisierbare Betriebssysteme für Lehrund Prüfungszwecke zentral bereitgestellt und lokal auf den Maschinen aus-gewählt werden. Die verschiedenen Ar- beitsumgebungen müssen nicht mehr auf den PCs installiert werden und erlauben so eine multifunktionale Nutzung von PCs und Räumen für vielfältige Lehrund Lernszenarien sowie für elektronische Prüfungen. bwLehrpool abstrahiert von der PC-Hardware vor Ort und ermöglicht den Dozenten die eigene Gestaltung und Verwaltung ihrer Softwareumgebungen als Self-Service. Darüber hinaus fördert bwLehrpool den hochschulübergreifenden Austausch von Kursumgebungen.
Der Cache-Speicher für den Softprozessor SIRIUS ist ein 4-fach assoziativer Cache-Speicher, der mit einem DDR-Interface auf einen externen Speicher zugreifen kann. Er verwaltet und beschleunigt Zugriffe vom Prozessor auf diesen Speicher. Der Cache-Speicher arbeitet intern mit 32 Bit und der doppelten Prozessortaktfrequenz und ermöglicht Systeme mit größeren Speicheranforderungen ohne signifikante Performanceverluste. Der Cache-Speicher wurde mit der Hardwarebeschreibungssprache VHDL erstellt und mit dem bestehenden Mikrocontrollersystem verbunden.
Das Gesamtsystem wurde zunächst simuliert und anschließend mit dem Cyclone III FPGA Starter Kit von Altera, welches ein 32 MB DDR-RAM-Modul zur Verfügung stellt, durch Ausführen eines Testprogramms erfolgreich verifiziert. Für den kompletten Cache-Speicher werden inklusive der Pins für den externen Oszillator und des Reset-Tasters 3805 Logik-Zellen, 27 M9K-Blöcke, 44 Pins und eine PLL benötigt.
Introduction: To simplify AV delay (AVD) optimization in cardiac resynchronization therapy (CRT), we reported that the hemodynamically optimal AVD for VDD and DDD mode CRT pacing can be approximated by individually measuring implant-related interatrial conduction intervals (IACT) in oesophageal electrogram (LAE) and adding about 50ms. The programmer-based St Jude QuickOpt algorithm is utilizing this finding. By automatically measuring IACT in VDD operation, it predicts the sensed AVD by adding either 30ms or 60ms. Paced AVD is strictly 50ms longer than sensed AVD. As consequence of those variations, several studies identified distinct inaccuracies of QuickOpt. Therefore, we aimed to seek for better approaches to automate AVD optimization.
Methods: In a study of 35 heart failure patients (27m, 8f, age: 67±8y) with Insync III Marquis CRT-D systems we recorded telemetric electrograms between left ventricular electrode and superior vena cava shock coil (LVtip/SVC = LVCE) simultaneously with LAE. By LVCE we measured intervals As-Pe in VDD and Ap-Pe in DDD operation between right atrial sense-event (As) or atrial stimulus (Ap), resp., and end of the atrial activity (Pe). As-Pe and Ap-Pe were compared with As-LA an Ap-LA in LAE, respectively.
Results: End of the left atrial activity in LVCE could clearly be recognized in 35/35 patients in VDD and 29/35 patients in DDD operation. We found mean intervals As-LA of 40.2±24.5ms and Ap-LA of 124.3±20.6ms. As-Pe was 94.8±24.1ms and Ap-Pe was 181.1±17.8ms. Analyzing the sums of As-LA + 50ms with duration of As-Pe and Ap-LA + 50ms with duration of Ap-Pe, the differences were 4.7±9.2ms and 4.2±8.6ms, resp., only. Thus, hemodynamically optimal timing of the ventricular stimulus can be triggered by automatically detecting Pe in LVCE.
Conclusion: Based on minimal deviations between LAE and LVCE approach, we proposed companies to utilize the LVCE in order to automate individual AVD optimization in CRT pacing.
Real-Time Ethernet has become the major communication technology for modern automation and industrial control systems. On the one hand, this trend increases the need for an automation-friendly security solution, as such networks can no longer be considered sufficiently isolated. On the other hand, it shows that, despite diverging requirements, the domain of Operational Technology (OT) can derive advantage from high-volume technology of the Information Technology (IT) domain. Based on these two sides of the same coin, we study the challenges and prospects of approaches to communication security in real-time Ethernet automation systems. In order to capitalize the expertise aggregated in decades of research and development, we put a special focus on the reuse of well-established security technology from the IT domain. We argue that enhancing such technology to become automation-friendly is likely to result in more robust and secure designs than greenfield designs. Because of its widespread deployment and the (to this date) nonexistence of a consistent security architecture, we use PROFINET as a showcase of our considerations. Security requirements for this technology are defined and different well-known solutions are examined according their suitability for PROFINET. Based on these findings, we elaborate the necessary adaptions for the deployment on PROFINET.
Currently, QRS width and bundle branch block morphology are used as electrocardiographic guideline criterias to selectheart failure (HF) patients with interventricular desynchronization in sinus rhythm (SR) for cardiac resynchronisationtherapy (CRT). Nevertheless, up to 30% of these patients do not benefit from implantation of CRT systems. Esophagealleft ventricular electrogram (LVE) enables semi-invasive measurement of interventricular conduction delays (IVCD)even in patients with atrial fibrillation (AF). To routinely apply this method, a programmer based semi-invasiveautomatic quantification of IVCD should to be developed. Our aims were todefine interventricular conduction delaysby analyzing fractionated left ventricular (LV) deflections in the esophageal left ventricular electrogram of HF patientsin SR or AF.
In 66 HF patients (49 male,17 female, age 65 ± 10 years) a 5F TOslim electrode (Osypka AG, Germany) was perorallyapplied. Using BARD EP Lab, cardiac desynchronization was quantified as interval IVCD between onset of QRS insurface ECG and the investigator-determined onset of the left ventricular deflection in LVE. IVCD was compared withthe intervals between QRS onset and the first maximum (IVCDm1) and between QRS onset and the second maximum(IVCDm2) of the LV complex.
QRS of 173 ± 26 ms was linked with empirical IVCD of 75 ± 25 ms, at mean. First and second LV maximum could beascertained beyond doubt in all patients. Significant correlations of the p<0,01 level were found between IVCD and theIVCDm1 of 96 ± 28 ms as well as between IVCD and the IVCDm2 of 147 ± 31 ms, at mean. To standardize automatic measurement of interventricular conduction delays with respect to patients with fractionatedLV complexes, the first maximum of the LV deflection should be utilized to qualify the IVCD of HF patients with sinusrhythm and atrial fibrillation.
The ability to detect a signal masked by noise is improved in normal-hearing (NH) listeners when interaural phase differences (IPD) between the ear signals exist either in the masker or the signal. We determined the impact of different coding strategies in bilaterally implanted cochlear implant (BiCI) users with and without fine-structure coding (FSC) on masking level differences. First, binaural intelligibility level differences (BILD) were determined in NH listeners and BiCI users using their clinical speech processors. NH subjects (n=8) showed a significant mean BILD of 7.5 dB. In contrast, BiCI users (n=9) without FSC as well as with FSC revealed a barely significant mean BILD (0.4 dB respectively 0.6 dB). Second, IPD thresholds were measured in BiCI users using either their speech processors with FS4 or direct stimulation with FSC. With the latter approach, synchronized stimulation providing an interaural accuracy of stimulation timing of 1.67 µs was realized on pitch matched electrode pairs. The resulting individual IPD threshold was lower in most of the subjects with direct stimulation than with their speech processors. These outcomes indicate that some BiCI users can benefit from increased temporal precision of interaural FSC and adjusted interaural frequency-place mapping presumably resulting in improved BILD.
“Today’s network landscape consists of quite different network technologies, wide range of end-devices with large scale of capabilities and power, and immense quantity of information and data represented in different formats” [9]. A lot of efforts are being done in order to establish open, scalable and seamless integration of various technologies and content presentation for different devices including mobile considering individual situation of the end user. This is very difficult because various kinds of devices used by different users or in different times/parallel by the same user which is not predictable and have to be recognized by the system in order to know device capabilities. Not only the devices but also Content and User Interfaces are big issues because they could include different kinds of data format like text, image, audio, video, 3D Virtual Reality data and upcoming other formats. Language Learning Game (LLG) is such an example of a device independent application where different kinds of devices and data formats, as a content of a flashcard is used for a collaborative learning. The idea of this game is to create a short story in a foreign language by using mobile devices. The story is developed by a group of participants by exchanging sentences/data via a flashcard system. This way the participants can learn from each other by knowledge sharing without fear of making mistakes because the group members are anonymous. Moreover they do not need a constant support from a teacher.
The paper proposes a system architecture for charging infrastructure that serves the requirements of future fleets of shared-use electric vehicles in urban scenarios. The focus of the development is on the interfaces to central stakeholders such as mobility service providers, distribution network operators and utilities. The main concept of the proposed system is the adherence to a stringent resource-oriented design approach, following the design principles of the Representational State Transfer (REST) architectural software style for distributed systems. This design approach is used from the cloud-based services down to the implementation of the charging infrastructure's control algorithms. Focusing on the resources of the various entities simplifies the implementation of their interactions, compared to the explicit declaration of services that are available. The system design ensures that the charging infrastructure is open to all users and generates a benefit beyond basic charging operations. Integration in emerging smart markets is done via open web-based interfaces. These allow for the generation of an added value of concrete services for shared-use electric mobility. A link to the field of grid operation is proposed using the ISO/IEC 61850 telecontrol standard. The smart meter capabilities of the charging stations can be used to gain additional information on the current state of the distribution grid. As an exemplary service a load management service for a fleet of shared-use electric vehicles is going to be implemented.
This book constitutes the proceedings of the 6th International Workshop on Communication Technologies for Vehicles, Nets4Cars/Nets4Trains/Nets4Aircraft 2014, held in Offenburg, Germany in May 2014. The 10 papers presented in this volume were carefully reviewed and selected from 15 submissions. The book also contains 4 invited papers. The contributions are organized in topical sections named: automotive issues, car-to-car, aviation issues, in-car, and infrastructures.
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.
Solar irradiance prediction is vital for the power management and the cost reduction when integrating solar energy. The study is towards a ground image based solar irradiance prediction which is highly dependent on the cloud coverage. The sky images are collected by using ground based sky imager (fisheye lens). In this work, different algorithms for cloud detection being a preparation step for their segmentation are compared.
Im ASIC Design Center der Hochschule Offenburg wird ein Design Kit für die UMC 0.18μm Faraday Technologie aufbereitet. Dabei werden alle benötigten Dateien, welche für einen zunächst rein digitalen Chipentwurf unter Verwendung der Synopsys, Cadence und Mentor Tools benötigt werden, für den UMC 0.18μm Prozess zusammengestellt.
Printed Electronics (PE) is a promising technology that provides mechanical flexibility and low-cost fabrication. These features make PE the key enabler for emerging applications, such as smart sensors, wearables, and Internet of Things (IoTs). Since these applications need secure communication and/or authentication, it is vital to utilize security primitives for cryptographic key and identification. Physical Unclonable Functions (PUF) have been adopted widely to provide the secure keys. In this work, we present a weak PUF based on Electrolyte-gated FETs using inorganic inkjet printed electronics. A comprehensive analysis framework including Monte Carlo simulations based on real device measurements is developed to evaluate the proposed PE-PUF. Moreover, a multi-bit PE-PUF design is proposed to optimize area usage. The analysis results show that the PE-PUF has ideal uniqueness, good reliability, and can operates at low voltage which is critical for low-power PE applications. In addition, the proposed multi-bit PE-PUF reduces the area usage around 30%.
Efficient, low-cost, secure and reliable communication solutions are a major stepping stone for smart metering and smart grid applications. This especially holds true for the so called primary communication or local metrological network (LMN) between a local meter or actuator and a data collector or gateway, where the highest requirements with regard to cost, bandwidth, and energy efficiency have to be taken into consideration. Multiple developments and field tests are going on in this field, however, energy autarkic devices are hardly found, yet.
The efficient support of Hardwae-In-theLoop (HIL) in the design process of hardwaresoftware-co-designed systems is an ongoing challenge. This paper presents a network-based integration of hardware elements into the softwarebased image processing tool „ADTF“, based on a high-performance Gigabit Ethernet MAC and a highly-efficient TCP/IP-stack. The MAC has been designed in VHDL. It was verified in a SystemCsimulation environment and tested on several Altera FPGAs.
In this paper an RFID/NFC (ISO 15693 standard) based inductively powered passive SoC (system on chip) for biomedical applications is presented. A brief overview of the system design, layout techniques and verification method is dis-cussed here. The SoC includes an integrated 32 bit microcontroller, sensor interface circuit, analog to digital converter, integrated RAM, ROM and some other peripherals required for the complete passive operation. The entire chip is realized in CMOS 0.18 μm technology with a chip area of 1.52mm x 3.24 mm.
The design of control systems of concentrator photovoltaic power plants will be more challenging in the future. Reasons are cost pressure, the increasing size of power plants, and new applications for operation, monitoring and maintenance required by grid operators, manufacturers and plant operators. Concepts and products for fixed-mounted photovoltaic can only partly be adapted since control systems for concentrator photovoltaic are considerable more complex due to the required high accurate sun-tracking. In order to assure reliable operation during a lifetime of more than 20 years, robustness of the control system is one crucial design criteria. This work considers common engineering technics for robustness, safety and security. Potential failures of the control system are identified and their effects are analyzed. Different attack scenarios are investigated. Outcomes are design criteria that encounter both: failures of system components and malicious attacks on the control system of future concentrator photovoltaic power plants. Such design criteria are a transparent state management through all system layers, self-tests and update capabilities for security concerns. The findings enable future research to develop a more robust and secure control system for concentrator photovoltaics when implementing new functionalities in the next generation.
Mit dem Übergang zu immer komplexeren Designs an der Hochschule Offenburg werden DFT-Strukturen wie „Boundary Scan“ und „Scan“ in ASIC-Designs notwendig. Die DFT-Struktur Scan wird hierbei zukünftig bei Implementierung eines speziellen Scan Chain der Core Logic des ASIC-Designs verwendet und danach in der Boundary Scan Architektur integriert.
Zunächst werden die Strukturen im recht einfachen ASIC-Design „Rolling Dice“, entwickelt am IAF der Hochschule Offenburg, implementiert. Nach Verifizierung der Funktionalität der Strukturen durch Emulation erfolgt die Einführung in komplexere ASIC-Design wie Front-End ASIC DQPSK sowie Prozessor-ASIC PDA V.2 (beide ebenfalls entwickelt am IAF der Hochschule Offenburg).
Eine Verifizierung der mit DFT-Strukturen ausgestatteten komplexeren ASIC-Design erfolgt im Rahmen dieser Ausarbeitung nicht, Bezug genommen wird hauptsächlich auf die Einführung der DFT-Strukturen in das ASIC-Design des „Rolling Dice“.
Ein Vergleich von Aufwand gegenüber Nutzen bei Implementierung von DFT-Strukturen in „kleine“ gegenüber „große“ ASIC-Design bildet ein wichtiges Fazit.
Efficient, secure and reliable communication is a major precondition for powerful applications in smart metering and smart grid. This especially holds true for the so called primary communication in the Local Metrological Network (LMN) between meter and data collector, as the LMN comes with the most stringent requirements with regard to cost, range, as well as bandwidth and energy efficiency. Until today, LMN field tests are operated all over the world. In these installations, however, energy autarkic systems play a marginal role. This contribution describes the results of the framework 7 (FP 7) WiMBex project (“Remote wireless water meter reading solution based on the EN 13757 standard, providing high autonomy, interoperability and range”). In this project an energy autarkic water meter was developed and tested, which follows the specification of the Wireless M-Bus protocol (EN 13757). The complete system development covers the PCB with the RF transceiver and the microcontroller, the energy converter and storage, and the software with the protocol. This contribution especially concentrates on the design, the development and the verification of the routing protocol. The routing protocol is based on the Q mode of EN13757-5 (Wireless M-Bus) and was extended by an additional energy state related parameter. This extension is orthogonal to the existing protocol and considers both the charge level and the charge characteristics (rate of occurrences, intensity). The software was implemented in NesC under the operating system TinyOS. The system was verified in an automated test bed and in field tests in UK and Ireland.
Automatic Meter Reading (AMR) is a major enabler for the upcoming smart grid. Potentially, it will be one of the first really large-scale M2M-communication solutions for sensor applications.
To date, the definition of the standardized communication stacks for Local Metrological Network (LMN) in AMR is still ongoing. This holds true both for ZigBee Smart Energy Profile and for Wireless M-Bus according to EN 13757. During this process, there is the necessity for flexible, albeit optimized solutions, which support the different existing and upcoming versions of the communication protocols. In the case of Wireless M-Bus, the major contender for European and possibly Asian installations, this is valid not only for the different operation modes (C-, N-, P-, Q-, R-, S-, and T-modes), which work in different frequencies (i.e. 868 MHz, 433 MHz, and 169 MHz) but also for the application layer, where additional bodies, like EN137575, Open Metering System (OMS) Group, or national bodies follow their approaches.
This contribution describes requirements, design techniques and experiences from the development of highly efficient Wireless M-Bus protocol stacks with support of good flexibility and portability between microcontroller platforms and RF-transceivers. The presented approach is not limited to the use of modern software engineering design processes, as such, but also includes essential additional features like testing or simulation, as well as tools for commissioning and monitoring.
Flashcards are a well known and proven method to learn and memorise. Such a way of learning is perfectly suited for “learning on the way,” but carrying all the flashcards could be awkward. In this scenario, a mobile device (mobile phone) is an adequate solution. The new mobile device operating system Android from Google allows for writing multimedia-enriched applications.
Components of rocket engines as actively cooled combustion chambers must withstand high pressure as well as severe and complex thermal transients. While the thermal transients result in temperature gradients and, thus, in constraint thermal strains, the pressure load induces mean stresses. To assess the mechanical behaviour of such components during design via finite-element calculations, constitutive models are necessary that describe the time- and temperature-dependent plasticity of the material appropriately.
Advanced models account for viscoplastic deformations including isotropic and kinematic hardening, recovery and ratcheting. However, the models contain a relatively large number of temperature-dependent material properties that must be determined on the basis of data of material tests. The determination of the properties is a non-trivial task because it is not clear which loading history must be applied in the tests for a certain material to obtain stable and robust (i.e. objective) material properties. Consequently, the determined properties are depending on the underlying loading history in the tests as well as on the experience and valuation of the person that determined the properties. This results in uncertainties during the assessment of the components that must be faced with conservative designs leading to negative consequences in terms of mass and costs.
It is the aim of this work funded by the European Space Agency ESA to derive a procedure to determine stable and robust material properties of an advanced viscoplastic constitutive model for aerospace materials. To this end, a special loading history is applied in isothermal material tests conducted with copper at different temperatures in the temperature range from 300 to 700 K. To determine the material properties and to assess stability and robustness methods for numerical optimization as well as analytical and statistical methods are used. The determined material properties are validated on the basis of results of thermomechanical material tests also conducted in the temperature range from 300 to 700 K.
The research project Ko-TAG [2], as part of the research initiative Ko-FAS [1], funded by the German Ministry of Economics and Technologies (BMWi), deals with the development of a wireless cooperative sensor system that shall pro-vide a benefit to current driver assistance systems (DAS) and traffic safety applications (TSA). The system’s primary function is the localization of vulnerable road users (VRU) e.g. pedestrians and powered two-wheelers, using communication signals, but can also serve as pre-crash (surround) safety system among vehicles. The main difference of this project, compared to previous ones that dealt with this topic, e.g. the AMULETT project, is an underlying FPGA based Hardware-Software co-design. The platform drives a real-time capable communication protocol that enables highly scalable network topologies fulfilling the hard real-time requirements of the single localization processes. Additionally it allows the exchange of further data (e.g. sensor data) to support the accident pre-diction process and the channel arbitration, and thus supports true cooperative sensing. This paper gives an overview of the project’s current system design as well as of the implementations of the key HDL entities supporting the software parts of the communication protocol. Furthermore, an approach for the dynamic reconfiguration of the devices is described, which provides several topology setups using a single PCB design.
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.