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Die Einführung der extrakorporalen Zirkulation unter Verwendung eines medikamentös induzierten Herzstillstands ermöglicht der Herzchirurgie die Herzoperationen, wie sie heute bekannt sind. Eine große Debatte besteht in der optimalen Zusammensetzung und Anwendungsweise der kardioplegischen Lösungen [6]. In der Helios Klinik für Herzchirurgie in Karlsruhe werden die kalte, kristalloide Kardioplegie nach Bretschneider und die modifizierte, kalte Blutkardioplegie nach Calafiore verwendet. Die vorliegende Arbeit beschäftigt sich mit der Frage, ob die Wahl der Kardioplegie Einwirkungen auf den intraoperativen und postoperativen Verlauf einer Bypass-Operation hat.
In der dazu angefertigten Studie wurden die Daten von 135 KHK Patienten retrospektiv erfasst und statistisch analysiert. Darunter wurden 81 Patienten mit der kalten Blutkardioplegie nach Calafiore behandelt und 53 Patienten mit der kristalloiden HTKLösung nach Bretschneider. Die demografischen Daten und Dringlichkeit der Operationen unterscheiden sich nicht signifikant voneinander. Bei den intraoperativen Parametern sind hinsichtlich der Hämoglobin-, Natrium-, und Kaliumkonzentration signifikante Unterschiede erkennbar. Weitere intraoperative Laborwerte zeigen keine Signifikanz. Die intraoperativen Parameter der Myokardprotektionsverfahren unterscheiden sich bezüglich der verabreichten Kardioplegiemenge. Bei postoperativen Parametern sind keine besonderen Signifikanzen notiert.
Die kristalloide Kardioplegie nach Bretschneider wie auch die modifizierte kalte Blutkardioplegie nach Calafiore sind sichere und effektive Verfahren. Einige Unterschiede konnten zugunsten der Blutkardioplegie nach Calafiore gefunden werden, die spezifisch für das jeweilige Verfahren sind. Zwingende Argumente für oder gegen eines dieser Verfahren konnten nicht gefunden werden.
Die Vision vom "Internet der Dinge" prägt seit Jahren Forschung und Entwicklung, wenn es um smarte Technologien und die Vernetzung von Geräten geht. In der Zukunft wird die reale Welt zunehmend mit dem Internet verknüpft, wodurch zahlreiche Gegenstände (Dinge) des normalen Alltags dazu befähigt werden, zu interagieren und sowohl online als auch autark zu kommunizieren. Viele Branchen wie Medizin, Automobilbau, Energieversorgung und Unterhaltungselektronik sind gleichermaßen betroffen, wodurch trotz Risiken auch neues wirtschaftliches Potential entsteht. Im Bereich "Connected Home" sind bereits Lösungen vorhanden, mittels intelligenter Vernetzung von Haushaltsgeräten und Sensoren, die Lebensqualität in den eigenen vier Wänden zu erhöhen. Diese Arbeit beschäftigt sich mit dem Thread Protokoll; einer neuen Technologie zur Integration mehrerer Kommunikationsschnittstellen innerhalb eines Netzwerks. Darüber hinaus wird die Implementierung auf Netzwerkebene (Network Layer) vorgestellt, sowie aufbereitete Informationen bezüglich verwendeter Technologien dargestellt.
Remote code attestation protocols are an essential building block to offer a reasonable system security for wireless embedded devices. In the work at hand we investigate in detail the trustability of a purely software-based remote code attestation based inference mechanism over the wireless when e.g. running the prominent protocol derivate SoftWare-based ATTestation for Embedded Devices (SWATT). Besides the disclosure of pitfalls of such a protocol class we also point out good parameter choices which allow at least a meaningful plausibility check with a balanced false positive and false negative ratio.
In the last decade, IPv6 over Low power Wireless Personal Area Networks (IEEE802.15.4), also known as 6LoWPAN, has well evolved as a primary contender for short range wireless communications and holds the promise of an Internet of Things, which is completely based on the Internet Protocol. The authors' team has developed a 6LoWPAN protocol stack in C language, the stack without the necessity to use a specific design environment or operating system. It is highly flexible, modular, and portable and can be enhanced by several interesting modules, like a Wake-On-Radio-(WOR) MAC layer or a TLS1.2 based security sublayer. The stack is made available as open source at https://github.com/hso-esk/emb6. It was extensively tested on the Automated Physical Testbed (APTB) for Wireless Systems, which is available in the authors' lab and allows a flexible setup and full control of arbitrary topologies. The results of the measurements demonstrate a very good stability and short-term with long-term performance also under dynamic conditions.
Serendipities in der Medizin
(2016)
Zufälle begleiten unser Leben. Auch bei wichtigen Entdeckungen und Entwicklungen in der Medizin spielt der „Zufall“ (engl. „serendipity“) eine Rolle. Hierzu gehören u. a. die Mendelschen Gesetze, die Ermittlung der menschlichen Chromosomenzahl, die Entdeckung der DNS durch Watson und Crick, der PAP-Test oder die Entdeckung der Röntgenstrahlung und der Radioaktivität. Aber auch und gerade in der Pharmakologie gibt es viele Beispiele für Serendipitäten. Einige gehen eng mit Zufällen bei der Entdeckung der Bakteriologie einher.
The interaural time difference (ITD) is an important cue for the localization of sounds. ITD changes as little as 10 μs can be detected by the human auditory system. By provision of one ear with a cochlear implant (CI) ITD are altered due to the partial replacement of the peripheral auditory system. A hearing aid (HA), in contrast, does not replace but adds a processing delay component to the peripheral auditory system extending ITD. The aim of the present study was to quantify interaural stimulation timing between these different modalities to estimate the need for central auditory temporal compensation in single sided deaf CI users or bimodal CI/HA users. For this purpose, wave V latencies of auditory brainstem responses evoked either acoustically (ABR) or electrically via the CI (EABR) have been measured. The sum of delays consisting of CI signal processing measured in the MED-EL OPUS2 audio processor and EABR wave V latencies evoked on different intracochlear sites allowed an estimation of the entire CI channel-specific delay for MED-EL MAESTRO CI systems. We compared these values with ABR wave V latencies measured in the contralateral normal hearing or HA provided ear in different frequency bands. The results showed that EABR wave V latencies were consistently shorter than those evoked acoustically in the unaided normal hearing ear. Thus, artificial delays within the audio processor can be implemented to adjust interaural stimulation timing. The currently implemented group delays in the MED-EL CI system turned out to be reasonably similar to those of the unaided ear. For adjustment of CI and contralateral HA, in contrast, an adjustable additional across-frequency delay in the range of 1–11 ms implemented in the CI would be required. Especially for bimodal CI/HA users the adjustment of interaural stimulation timing may induce improved binaural hearing, reduced need for central auditory temporal compensation and increased acceptance of the CI/HA provision.
Battery degradation is a complex physicochemical process that strongly depends on operating conditions and environment. We present a model-based analysis of lithium-ion battery degradation in smart microgrids, in particular, a single-family house and an office tract with photovoltaics generator. We use a multi-scale multi-physics model of a graphite/lithium iron phosphate (LiFePO4, LFP) cell including SEI formation as ageing mechanism. The cell-level model is dynamically coupled to a system-level model consisting of photovoltaics, inverter, power consumption profiles, grid interaction, and energy management system, fed with historic weather data. The behavior of the cell in terms of degradation propensity, performance, state of charge and other internal states is predicted over an annual operation cycle. As result, we have identified a peak in degradation rate during the battery charging process, caused by charging overpotentials. Ageing strongly depends on the load situation, where the predicted annual capacity fade is 1.9 % for the single-family house and only 1.3 % for the office tract.
IPv6 over LoRaWAN™
(2016)
Although short-range wireless communication explicitly targets local and regional applications, range continues to be a highly important issue. The range directly depends on the so-called link budget, which can be increased by the choice of modulation and coding schemes. The recent transceiver generation in particular comes with extensive and flexible support for software-defined radio (SDR). The SX127× family from Semtech Corp. is a member of this device class and promises significant benefits for range, robust performance, and battery lifetime compared to competing technologies. This contribution gives a short overview of the technologies to support Long Range (LoRa™) and the corresponding Layer 2 protocol (LoRaWAN™). It particularly describes the possibility to combine the Internet Protocol, i.e. IPv6, into LoRaWAN™, so that it can be directly integrated into a full-fledged Internet of Things (IoT). The proposed solution, which we name 6LoRaWAN, has been implemented and tested; results of the experiments are also shown in this paper.
Due to its numerous application fields and benefits, virtualization has become an interesting and attractive topic in computer and mobile systems, as it promises advantages for security and cost efficiency. However, it may bring additional performance overhead. Recently, CPU virtualization has become more popular for embedded platforms, where the performance overhead is especially critical. In this article, we present the measurements of the performance overhead of the two hypervisors Xen and Jailhouse on ARM processors in the context of the heavy load “Cpuburn-a8” application and compare it to a native Linux system running on ARM processors.
In the work at hand, we combine a Private Information Retrieval (PIR) protocol with Somewhat Homomorphic Encryption (SHE) and use Searchable Encryption (SE) with the objective to provide security and confidentiality features for a third party cloud security audit. During the auditing process, a third party auditor will act on behalf of a cloud service user to validate the security requirements performed by a cloud service provider. Our concrete contribution consists of developing a PIR protocol which is proceeding directly on a log database of encrypted data and allowing to retrieve a sum or a product of multiple encrypted elements. Subsequently, we concretely apply our new form of PIR protocol to a cloud audit use case where searchable encryption is employed to allow additional confidentiality requirements to the privacy of the user. Exemplarily we are considering and evaluating an audit of client accesses to a controlled resource provided by a cloud service provider.
Die Bachelorarbeit umfasst die Erstellung eines Printproduktes (Coffee Table Book, 30x30 cm) und eine dazugehörige digitale Version (Enriched E-Book). Inhaltlich geht es um die Geschichten & Traditionen in sechs verschiedenen Ländern Südostasiens. Die hochgeladene Dokumentation beinhaltet die einzelnen Schritte der Ausarbeitung von der Konzeption über die Reise bis zur finalen Fertigstellung der Endprodukte.
We present a videodensitometric quantification method for methadone in syrup, separated by thin-layer chromatography (TLC). The quantification is based on a derivation reaction with Dragendorf reagent. Measurements were carried out using a 16-bit flatbed scanner. The range of linearity covers two magnitudes of power using the Kubelka-Munk expression for data transformation. The separation method is inexpensive, fast, and reliable.
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.
In this work, we consider a duty-cycled wireless sensor network with the assumption that the on/off schedules are uncoordinated. In such networks, as all nodes may not be awake during the transmission of time synchronization messages, nodes will require to re-transmit the synchronization messages. Ideally a node should re-transmit for the maximum sleep duration to ensure that all nodes are synchronized. However, such a proposition will immensely increase the energy consumption of the nodes. Such a situation demands that there is an upper bound of the number of retransmissions. We refer to the time a node spends in re-transmission of the control message as broadcast duration. We ask the question, what should be the broadcast duration to ensure that a certain percentage of the available nodes are synchronized. The problem to estimate the broadcast duration is formulated so as to capture the probability threshold of the nodes being synchronized. Results show the proposed analytical model can predict the broadcast duration with a given lower error margin under real world conditions, thus demonstrating the efficiency of our solution.
In der vorliegenden Arbeit wird Augmented Reality (AR) sowohl in der Theorie als auch in der Praxis ausführlich behandelt. Die Technik, welche in den letzten Jahren stark weiterentwickelt wurde, die Entwicklungsgeschichte, sowie die Projektbegleitung (aus Sicht des Auftraggebers einer AR-Anwendung) stehen im Fokus.
Neben den einleitenden Kapiteln wurde die Ausarbeitung thematisch in zwei große Bereiche unterteilt. Der erste, eher theoretische Bereich (Kapitel 2), bildet den wissenschaftlichen Teil dieser Ausarbeitung. Er beinhaltet eine Einführung in Augmented Reality und analysiert aktuelle Techniken. Auch die Funktionsweise wird aufgezeigt, um zu verstehen, was hinter den Kulissen der Anwendungen steckt. Im zweiten, praxisnahen Bereich (Kapitel 3) wird der Entstehungsprozess der Augmented Reality Applikation (App) von Kaba begleitet. Es wurde der Entstehungsprozess der App für Android und iOS ausführlich dokumentiert. Für Leser, die Probleme mit einigen Wissensbereichen haben, gibt es im Anhang eine ausführliche Literaturliste.
This paper focuses on appropriately measuring the accuracy of forecasts of load behavior and renewable generation in micro-grid operation. Common accuracy measures like the root mean square of the error are often difficult to interpret for system design, as they describe the mean accuracy of the forecast. Micro-grid systems, however, have to be designed to handle also worst case situations. This paper therefore suggests two error measures that are based on the maximum function and that better allow understanding worst case requirements with respect to balancing power and balancing energy supply.
Diese Arbeit befasst sich mit der Konzeption und Implementierung eines Dateiimportfilters für Mess- und Kalibrierwerkzeuge. Dieser ermöglicht das Importieren von INCA-Experimenten nach CANape, indem aus Experiment-Exportdateien Konfigurationsdateien generiert werden. Im Zuge der Umsetzung wurde dazu das aus binären Daten bestehende Exportdateiformat von INCA analysiert. Das Ziel dieser Analyse bestand darin, herauszufinden, wo und wie die Informationen in den Exportdateien gespeichert sind. Die so erlangten Erkenntnisse wurden verwendet, um den Dateiimportfilter zu entwickeln. Dieser liest aus Exportdateien die notwendigen Informationen aus, überführt sie in eine CANape interne Repräsentation und generiert daraus eine entsprechende Konfigurationsdatei. Die korrekte Funktionsweise wurde anhand von selbst erstellten Experimenten sowie mithilfe von Kundenexperimenten validiert.
There is a growing trend for the use of thermo-active building systems (TABS) for the heating and cooling of buildings, because these systems are known to be very economical and efficient. However, their control is complicated due to the large thermal inertia, and their parameterization is time-consuming. With conventional TABS-control strategies, the required thermal comfort in buildings can often not be maintained, particularly if the internal heat sources are suddenly changed. This paper shows measurement results and evaluations of the operation of a novel adaptive and predictive calculation method, based on a multiple linear regression (AMLR) for the control of TABS. The measurement results are compared with the standard TABS strategy. The results show that the electrical pump energy could be reduced by more than 86%. Including the weather adjustment, it could be demonstrated that thermal energy savings of over 41% could be reached. In addition, the thermal comfort could be improved due to the possibility to specify mean room set-point temperatures. With the AMLR, comfort category I of the comfort norms ISO 7730 and DIN EN 15251 are observed in about 95% of occasions. With the standard TABS strategy, only about 24% are within category I.
Adaptive predictive control of thermo-active building systems (TABS) based on a multiple regression algorithm: First practical test. Available from: https://www.researchgate.net/publication/305903009_Adaptive_predictive_control_of_thermo-active_building_systems_TABS_based_on_a_multiple_regression_algorithm_First_practical_test [accessed Jul 7, 2017].
Die in dieser Arbeit erzielten Ergebnisse zur Optimierung der Parameter zur Registrierung elektrisch evozierter Hirnstammpotenziale mit den beiden ERA-Messsystemen Eclipse EP25 und Synergy EDX dienen als Grundlage für die eBERA Untersuchungen. Betrachtet wurden besonders hierbei die Stimulati-onsart, Filtereinstellungen und Mittelungsoptionen.
Bei allen Messungen mit beiden Systemen, Eclipse EP25 und Synergy EDX, wird eine contralaterale Ableitung nahegelegt.
Eine zu empfehlende Filtereinstellung der Hochpassfilter und Tiefpassfilter zur Potenzialregistrierung mittels eBERA ist 0,2 Hz / 3000 Hz bei der Synergy und 33 Hz / 3000 Hz bei der Eclipse EP25. Bei Vorliegen tieffrequenter Einstreuun-gen ist eine Erhöhung der Grenzfrequenz des Hochpassfilters auf 100 Hz zu empfehlen.
Bei der Wahl der Stimulationsart hat sich die alternierende als die beste her-ausgestellt. Dies belegen sowohl die in den Ergebnissen gemessenen Potentia-le als auch Messungen von Kollegen (Steffens, 2016).
Die Mittelungsoption „bayesian weighting“ bei der Eclipse EP25 hat sich bei der eBERA Messung als nicht sehr hilfreich erwiesen. Bei der Synergy EDX hat die Einstellung „Mittel“ im Vergleich zu „Gewichtet“ die besseren Ergebnisse erzielt. Daher wird diese Wahl empfohlen, falls mit diesem System gemessen wird. Weitere weniger einflussreiche Einstellungen werden im Anhang C. „Optimierte Parameter beider Messsysteme“ aufgelistet.
Mit der Messung des Wärme- und Kälteverbrauchs im Labor gelingt es, sowohl thermisch träge als auch agile Flächentemperiersysteme unter praxisnahen, dynamischen Bedingungen messtechnisch zu bewerten. Werden Nutzwärme- und Nutzkältebedarf berechnet und ins Verhältnis zu den gemessenen Verbräuchen gesetzt, können die Aufwandzahlen für die Nutzenübergabe ece für verschiedene Flächentemperiersysteme und in Kombinationen mit anderen Übergabesystemen unter verschiedenen Nutzungsbedingungen und für unterschiedliche Betriebsführungsstrategien bestimmt werden. Damit stehen Aufwandszahlen auf Basis kalorischer Messungen zur Verfügung, die je nach Aufgabenstellung entweder produkt- oder objektbezogen in der Planung komplexer Energiekonzepte verwendet werden können und die tatsächlichen Aufwandszahlen eh, ce für den Heizfall bzw. ec, ce für den Kühlfall genauer als Literaturwerte bzw. projektbezogen beschreiben
Die Namen Cormack und Hounsfield sind für den Radiologen zu einem wichtigen Synonym für die Computertomographie (CT) geworden. Der mathematische Wegbereiter für die CT, Johann Radon, kommt in der radiologischen Diskussion und den historischen Rückblicken hingegen oft zu Unrecht zu kurz. Die folgende Kurzübersicht möchte daher dem interessierten Leser die wichtigsten historischen Eckdaten zu dem in vielerlei Hinsicht bewegenden Leben und Wirken dieses großen Mathematikers näherbringen.
The industry of the agave-derived bacanora, in the northern Mexican state of Sonora, has been growing substantially in recent years. However, this higher demand still lies under the influences of a variety of social, legal, cultural, ecological and economic elements. The governmental institutions of the state have tried to encourage a sustainable development and certain levels of standardization in the production of bacanora by applying different economical and legal strategies. However, a large portion of this alcoholic beverage is still produced in a traditional and rudimentary fashion. Beyond the quality of the beverage, the lack of proper control, by using adequate instrumental methods, might represent a health risk, as in several cases traditional-distilled beverages can contain elevated levels of harmful materials. The present article describes the qualitative spectral analysis of samples of the traditional-produced distilled beverage bacanora in the range from 0 cm−1 to 3500 cm−1 by using a Fourier Transform Raman spectrometer. This particular technique has not been previously explored for the analysis of bacanora, as in the case of other beverages, including tequila. The proposed instrumental arrangement for the spectral analysis has been built by combining conventional hardware parts (Michelson interferometer, photo-diodes, visible laser, etc.) and a set of self-developed evaluation algorithms. The resulting spectral information has been compared to those of pure samples of ethanol and to the spectra from different samples of the alcoholic beverage tequila. The proposed instrumental arrangement can be used the analysis of bacanora.
Electric arc furnaces (EAF) are complex industrial plants whose actual behavior depends upon numerous factors. Due to its energy intensive operation, the EAF process has always been subject to optimization efforts. For these reasons, several models have been proposed in literature to analyze and predict different modes of operation. Most of these models focused on the processes inside the vessel itself. The present paper introduces a dynamic, physics-based model of a complete EAF plant which consists of the four subsystems vessel, electric system, electrode regulation, and off-gas system. Furthermore the solid phase is not treated to be homogenous but a simple spatial discretization is employed. Hence it is possible to simulate the energy input by electric arcs and fossil fuel burners depending on the state of the melting progress. The model is implemented in object-oriented, equation-based language Modelica. The simulation results are compared to literature data.
Wireless sensor networks have found their way into a wide range of applications among which environmental monitoring systems have attracted increasing interests of researchers. The main challenges for the applications are scalability of the network size and energy efficiency of the spatially distributed motes. These devices are mostly battery-powered and spend most of their energy budget on the radio transceiver module. A so-called Wake-On-Radio (WOR) technology can be used to achieve a reasonable balance among power consumption, range, complexity and response time. In this paper, a novel design for integration of WOR into IEEE802.1.5.4 is presented, which flexibly allows trade-offs in energy consumption between sender and receiver station, between real-time capability and energy consumption. For identical behavior, the proposed scheme is significantly more efficient than other schemes, which were proposed in recent publications, while preserving backward compatibility with standard IEEE802.15.4 transceivers.
Das Ziel meiner Bachelor-Thesis soll die selbständige Realisation eines Medienprojektes in Form eines gedruckten Buches sein. Mit Hilfe der im Studium erlernten theoretischen und praktischen Kenntnissen und den Erfahrungen, die ich bereits im Vorfeld als Mediengestalter eines Verlages sammeln konnte, soll unter Anwendung wissenschaftlicher Methoden ein humorvoller Freizeitplaner für gebürtige oder zugezogene Ortenauer entstehen. Dieser soll den Leser die 51 Gemeinden von Baden-Württembergs größtem Landkreis spielerisch (neu) entdecken lassen.
Das Buch soll jede Gemeinde kurz anhand der wichtigsten Informationen vorstellen und beispielhafte Unternehmungen aufzeigen, die ohne große Vorbereitungen von Jedermann spontan durchgeführt werden können (ohne jedoch jeglichen Anspruch der Vollständigkeit zu haben). Der Freizeitplaner soll auf den ersten Blick den Anschein eines Schulbuches vermitteln, das den Nutzer durch die Absolvierung 51 lustiger und skurriler Aufgaben
und den damit verbundenen Besuch aller Gemeinden des Landkreises zum "Ortenauer" transformiert. Eine Dokumentation nach wissenschaftlichen Kriterien soll zusätzlich die wesentlichen Aspekte des Buches und die konzeptionelle Herangehensweise erläutern.
Ultra wide band (UWB) signals are well suited both for short-range wireless communication and for high-precision localization applications. Channel impulse response (CIR) analysis in UWB systems is a major element in localization estimation. In this paper, practical aspects of CIR are presented. I.e. a technique for the construction of the accumulated echo-gram of a multipath delayed signal is proposed. Decawave hardware was used to demonstrate the technique of analysis of fine structure of signals with a sub-nanosecond resolution. Temporal stability, reliability and two-way characteristics of such echo-grams are discussed as well. The results of using two EVK1000 radio modules as a radar installation to detect a target in indoor environments prove that a low cost UWB intrusion detection and through-the-wall-vision systems might be developed using the proposed technique.
Die vorliegende Arbeit setzt sich mit dem Thema YouTube als Teil der Jugendkultur auseinander. Dabei wird der Frage nachgegangen, inwiefern sich die Nutzung der Videoplattform auf das Verhalten der Jugendlichen auswirkt. Im Zuge dessen sollen zudem Einblicke darüber gewonnen werden, welchen Einfluss YouTube auf die Lebenswelt der Jugendlichen nimmt. Diese Fragestellungen werden auf Basis aktu- eller Fachliteratur und vor dem Hintergrund der Erkenntnisse aus quantitativer und qualitativer Befragung diskutiert. So können mengenmäßig erhobene Daten durch die Einbindung subjektiver Meinungen unterstützt werden.
Laser pulses focused near the tip of an elastic wedge generate acoustic waves guided at its apex. The shapes of the acoustic wedge wave pulses depend on the energy and the profile of the exciting laser pulse and on the anisotropy of the elastic medium the wedge is made of. Expressions for the acoustic pulse shapes have been derived in terms of the modal displacement fields of wedge waves for laser excitation in the thermo-elastic regime and for excitation via a pressure pulse exerted on the surface. The physical quantity considered is the local inclination of a surface of the wedge, which is measured optically by laser-probe-beam deflection. Experimental results on pulse shapes in the thermo-elastic regime are presented and confirmed by numerical calculations. They pertain to an isotropic sharp-angle wedge with two wedge-wave branches and to a non-reciprocity phenomenon at rectangular silicon edges.
In a recent paper it has been shown that the effective nonlinear constant which is used in a P-Matrix approach to describe third-order intermodulation (IMD3) in surface acoustic wave (SAW) devices can be obtained from finite element (FEM) calculations of a periodic cell using nonlinear tensor data [1]. In this paper we extend this FEM calculation and show that the IMD3 of an infinite periodic array of electrodes on a piezoelectric substrate can be directly simulated in the sagittal plane. This direct approach opens the way for a FEM based simulation of nonlinearities for finite and generalized structures avoiding the simplifications of phenomenological approaches.
Economic dispatch is a well-known optimization problem in smart grid systems which aims at minimizing the total cost of power generation among generation units while maintaining some system constraints. Recently, some distributed consensus-based approaches have been proposed to replace traditional centralized calculation. However, existing approaches fail to protect privacy of individual units like cost function parameters, generator constraints, output power levels, etc. In this paper, we show an attack against an existing consensus-based economic dispatch algorithm from [16] assuming semi-honest non-colluding adversaries. Then we propose a simple solution by combining a secure sum protocol and the consensus-based economic dispatch algorithm that guarantees data privacy under the same attacker model. Our Privacy Preserving Economic Dispatch (PPED) protocol is information-theoretically secure.
Die Vielfalt der Protokolle, die praktisch auf allen Ebenen der Netzwerkkommunikation zu berücksichtigen ist, stellt eine der großen Herausforderungen bei der fortschreitenden Automatisierung des intelligenten Hauses dar. Unter dem Überbegriff Internet der Dinge (Internet of Things) entstehen gegenwärtig zahlreiche neue Entwicklungen, Standards, Allianzen und so genannte Ökosysteme. Diese haben die Absicht einer horizontalen Integration gewerkeübergreifender Anwendungen und verfolgen fast alle das Ziel, die Situation zu vereinfachen, die Entwicklungen zu beschleunigen und Markterfolge zu erreichen. Leider macht diese Vielfalt momentan die Welt aber eher noch komplexer und bringt damit das Risiko mit sich, genau das Gegenteil der ursprünglichen Absichten zu erreichen. Dieser Beitrag versucht, die Entwicklungen möglichst systematisch zu kategorisieren und mögliche Lösungsansätze zu beschreiben.
Diese Arbeit beschäftigt sich mit der Entwicklung einer nativen Anwendung bzw. Applikation für Mobilgeräte, wie Smartphones oder Tablets, die auf einem Android Betriebssystem basieren. Dabei liegt die Idee einer intuitiv anwendbaren Benutzeranwendung zugrunde, welche Auskünfte über bestimmte Lokale bereitstellt, die zu einer gewissen Zeit ein spezielles Produkt zu einem besonderen Preis offerieren. Dazu wählt ein Anwendungsnutzer ein oder mehrere Produkt-/e aus und legt eine Postleitzahl oder Stadt fest.
The paper recommends an approach to estimate effectively the probability of buffer overflow in high-speed communication networks, capable of carrying diverse traffic, including self-similar teletraffic, and supporting diverse levels of quality of service. Simulations with stochastic, long-range dependent self-similar traffic source models are conducted. A new efficient algorithm, based on a variant of the RESTART/LRE method, is developed and applied to accelerate the buffer overflow simulation in a finite buffer single server model under long-range dependent self-similar traffic load with different buffer sizes. Numerical examples and simulation results are shown
Planung und Inbetriebnahme der raumlufttechnischen Anlage für einen Reinraum in der Pharmazie
(2016)
To arouse the customer’s interest, enterprises insert certain methods of advertising in the context of their communications strategy. For this purpose, digital advertising channels are established beside classical forms of advertising like print campaigns or TV spots.
These work with the topic “Digital advertising and their suitability for the fashion industry in the multi-channel-retailing” gives an overview of different digital advertising media and il-lustrates the way they are inserted by fashion enterprises.
The results of this work are based on a wide range of literature and also refer to significant studies and statistics. A self-contained data acquisition, realized in a fashion shop, provides additional information about the importance of digital advertising for the fashion industry.
If it’s accomplished to generate the will to buy a fashion product by digital advertising me-dia, the customer will have the choice to buy the product on the internet or in the stationary trade. Following, the online and the offline channel of distribution will be shown and their properties will be illustrated. It is essential to detect the possible combinations of these two sales channels and relegate to the influence that effect digital advertising media to the pur-chase decision-making process.
Finally the results of the secondary research and studies as well as the data acquisition of the author are summarized. The eventual aim consists in detecting the suitability of digital advertising for the fashion industry and their meaning for the offline- and the online-sales channel.
The number of impaired persons rises -- as a result of both regular degradation with age and psychological problems like burnout. Sheltered work organizations aim to reintegrate impaired persons into work environments and prepare them for the re-entry in the regular job market.
Both for elderly and for impaired persons it is crucial to quickly assess the abilities, to identify limits and potentials and thus find work processes suitable for their skill profile.
This work focuses on the analysis and comparison of software-tools that assess the abilities of persons with impairments. We describe two established generic tools (CANTAB, Cogstate), analyze a yet unknown specialized tool (Hamet) and present a new gamified tool (GATRAS).
Finally, we present a study with 20 participants with impairments, comparing the tools against a ground truth baseline generated by a real-world assembly task.
Flexible Three-dimensional Camera-based Reconstruction and Calibration of Tracked Instruments
(2016)
Navigated instruments commonly include applied parts, e.g. burrs or saw blades, that need to be calibrated with respect to the attached or integrated tracker. Since this calibration has to be very precise, it is often performed by the manufacturer. However, due to the great variety of instruments and the option to exchange the applied parts (e.g. burrs) there is a definite demand for flexible and generic calibration techniques. Furthermore, if we look into the medical field, there is also a need for calibrating sterile instruments. We propose a new and flexible camera-based calibration technique that addresses these demands by working contactlessly, precisely, and generically for a large variety of tracked instruments. This is realized using one or more tracked cameras which are calibrated with respect to an attached or integrated tracker. The tracked instrument is rotated in front of the camera(s) and its 3D geometry and surface are reconstructed from the 2D images in the coordinate system of the attached or integrated tracker. The 3D geometry of the navigated instrument was reconstructed with an accuracy of under 0.2 mm. The radius of a sphere-shaped instrument was reconstructed with an RMS deviation of 0.015mm.
This work describes a non-parametric camera-based method for the calibration of Optical See-Through Glasses (OSTG). Existing works model the optical system through perspective projection and parametric functions. In the border areas of the displays such models are often inadequate. Moreover, rigid calibration patterns, that produce only a small amount of non-equidistant point correspondences, are used. In order to overcome these disadvantages every single display pixel is calibrated individually. The error prone user interaction is avoided by using cameras placed behind the displays of the OSTG. The displays show a shifting pattern that is used to calculate the pixels' locations. A camera mounted rigidly on the OSTG is used to find the relations between the system components. The obtained results show better accuracies than in previous works and prove that a second calibration step for user adaptation is necessary for high accuracy applications.