Reliability of integrated circuit (IC) packages is in great demand for the automotive industry, as they are used in almost every electronic components. IC packages consist of essentially molding compound (MC), lead frame (LF), adhesive and a silicon chip. The elastic mismatch between the components makes the interfaces susceptible to crack initiation, propagation and eventual failure. The main reason of the failure is the thermo-mechanical cycles during the service time. This work presents the robustness estimation and the reliability based robustness improvement of an IC package by minimization of both crack driving force and its standard deviation at the MC and the LF interface with respect to the fatigue fracture toughness. The robustness evaluation and robust design optimization were performed by taking the uncertainty in geometrical parameters into account. Evidently, there are more robust and reliable designs than the current design which have less crack driving force and show less variation. In order to quantify the reliability with respect to the variation of the crack driving force, the fatigue fracture toughness of the interface was characterized under isothermal conditions at 25 ◦C and −40 ◦C with a three point bending test apparatus. The interface characterizations at low temperatures like −40 ◦C is a main concern due to large stress generation during the reliability tests. After then, a test methodology was prepared to validate the fatigue fracture toughness of the interface in the package level. Artificial cracks were introduced at the MC-LF interface in IC packages to predict the crack growth under thermal cycling over a temperature range of −50 ◦C to 150 ◦C. A prediction quality assisted to validate, whether the fatigue fracture toughness, which was obtained mechanically under isothermal conditions, could be used to predict the crack growth in the IC package under thermo-mechanical cycles. Material characterization of the MC and the LF was performed to acquire the fatigue fracture toughness and the crack length by the compliance calibration method as accurate as possible. The mechanical modeling of both materials was accomplished with elasticity plus plasticity at the room temperature. Then the material models were verified by using the behavior of the bi-material structure under three point bending. As the numerical simulations were used to calculate the fracture toughness, this thesis also presents a comparison between the methods in the literature by using finite element simulations. The results were compared with the analytic solution according to their accuracy, ease of implementation and mesh independence. Simultaneously, various crack tip elements were analyzed in contrast considering their capability of fracture toughness calculation. The analyses were included different fracture mechanical concepts from linear elastic to elastic plastic fracture mechanics. The comparison led to a more convenient method and crack tip element preference for the interface characterization.

Mixed-Criticality Systems (MCSs) include tasks with multiple levels of criticality and different modes of operation. These systems bring benefits such as energy and resource saving while ensuring safe operation. However, management of available resources in order to achieve high utilization, low power consumption, and required reliability level is challenging in MCSs. In many cases, there is a trade-off between these goals. For instance, although using fault-tolerance techniques, such as replication, leads to improving the timing reliability, it increases power consumption and can threaten life-time reliability. In this work, we introduce an approach named Life−timePeakPower management inMixed−Criticalitysystems (LPP-MC) to guarantee reliability, along with peak power reduction. This approach maps the tasks using a novel metric called Reliability-Power Metric (RPM). The LPP-MC approach uses this metric to balance the power consumption of different processor cores and to improve the life-time of a chip. Moreover, to guarantee the timing reliability of MCSs, a fault-tolerance technique, called task re-execution, is utilized in this approach. We evaluate the proposed approach by a real avionics task set, and various synthetic task sets. The experimental results show that the proposed approach mitigates the aging rate and reduces peak power by up to 20.6% and 17.6%, respectively, compared to state-of-the-art.

Self-regulation, the ability to guide behavior according to one’s goals, plays an integral role in understanding loss of control over unwanted behaviors, for example in alcohol use disorder (AUD). Yet, experimental tasks that measure processes underlying self-regulation are not easy to deploy in contexts where such behaviors usually occur, namely outside the laboratory, and in clinical populations such as people with AUD. Moreover, lab-based tasks have been criticized for poor test–retest reliability and lack of construct validity. Smartphones can be used to deploy tasks in the field, but often require shorter versions of tasks, which may further decrease reliability. Here, we show that combining smartphone-based tasks with joint hierarchical modeling of longitudinal data can overcome at least some of these shortcomings. We test four short smartphone-based tasks outside the laboratory in a large sample (N = 488) of participants with AUD. Although task measures indeed have low reliability when data are analyzed traditionally by modeling each session separately, joint modeling of longitudinal data increases reliability to good and oftentimes excellent levels. We next test the measures’ construct validity and show that extracted latent factors are indeed in line with theoretical accounts of cognitive control and decision-making. Finally, we demonstrate that a resulting cognitive control factor relates to a real-life measure of drinking behavior and yields stronger correlations than single measures based on traditional analyses. Our findings demonstrate how short, smartphone-based task measures, when analyzed with joint hierarchical modeling and latent factor analysis, can overcome frequently reported shortcomings of experimental tasks.

To measure the speed of a vehicle, the revolution of a wheel or a rigid axle is traditionally used. Therefore non corrigible systematic errors occur which are caused by slip, spin and by the change of wheel diameter due to fretting. Train control and traction systems require new robust as well as precise methods of speed measurement. Because of their physical properties, Doppler-radar-sensors attached to the vehicle and measuring ground speed are first choice for this range of applications. Currently used sensors cannot fulfil the high demands under all operating conditions, because they are unable to completely compensate the various interferences and systematic deviations. This is the starting point of this dissertation. Two independent diverse methods with optimised reliability and accuracy must be used to meet all requirements. Limited resources of the embedded digital signal processor system under real-time conditions have to be taken into account. According to the boundary conditions, the introductory chapters critically discuss the frequency analysis methods currently used and describe starting points for further development. This leads to the design of a new, robust, wide-band spectral analysis which combines techniques of the dyadic wavelet transformation with the fast Fourier transformation. At the same time a new frame procedure and general model for the estimation of motion parameters is developed which features short delays. The disadvantages of the block-based discrete spectral analysis applied over continuous approaches are extensively compensated. The block structure of spectral data enables the selective use of new knowledge-based spectral filters for the compensation of the remaining intense interferences which are typical of this kind of application. / Die Fahrzeuggeschwindigkeitsmessung über die Drehzahl eines Rades weist in Schlupf- und Schleuderzuständen erhebliche systematische Abweichungen auf. Deshalb erfordern Zugbeeinflussungs- und Antriebssysteme neue gleichzeitig robuste und präzise Geschwindigkeitsmessmethoden. Die Mikrowellensensorik unter Nutzung des Dopplereffekts zwischen Fahrzeug und Gleisbett wird wegen ihrer physikalischen Eigenschaften für dieses Einsatzgebiet favorisiert. Bisherige Sensorapplikationen erfüllen aber die hohen Ansprüche nicht in allen Betriebszuständen. Hier setzt die in dieser Arbeit beschriebene Sensorentwicklung auf. Zwei getrennt hergeleitete und nach Zuverlässigkeit und Genauigkeit optimierte neue Verfahren können bei gleichzeitiger Anwendung die gestellten Anforderungen erfüllen. Dabei müssen auch die beschränkten Ressourcen des eingebetteten digitalen Signalverarbeitungssystems unter Echtzeitbedingungen berücksichtigt werden. Entsprechend dieser Randbedingungen findet einleitend eine kritische Betrachtung bestehender Frequenzanalysemethoden statt und Ansätze für die Weiterentwicklung werden herausgearbeitet. Einerseits führt dies zur Konstruktion einer neuen störunempfindlichen Weitbereichsspektralzerlegung, welche Ansätze der dyadischen Wavelettransformation mit der Diskreten Fourier-Transformation verbindet. Andererseits wird ein neues Rahmenverfahren für die verzögerungsarme Schätzung der Bewegungsparameter des Fahrzeuges aufgrund seines physikalischen Bewegungsmodells hergeleitet und mit einem hochgenauen Frequenzauswerteverfahren kombiniert. Beide Verfahren basieren auf blockweisen diskreten Spektralzerlegungen, deren prinzipielle Nachteile gegenüber kontinuierlichen Ansätzen weitgehend kompensiert werden können. Durch die Blockorganisation lassen sich neuartige wissensbasierte Spektralfilter selektiv zur Unterdrückung starker bahnanwendungstypischer Störeinflüsse einsetzen.

The intentions of the so-called "More Electrical Aircraft" (MEA) are higher efficiency and lower weight. A main topic here is the application of electrical instead of hydraulical, pneumatical and mechanical systems. The necessary power electronic devices have intermediate DC-links, which are typically supplied by a three-phase system with active B6 and passive B12 rectifiers. A possible alternative is the B6 diode bridge in combination with an active power filter (APF). Due to the parallel arrangement, the APF offers a higher power density and is able to compensate for harmonics from several devices. The use of the diode bridge rectifier alone is not permitted due to the highly distorted phase current. The following investigations are dealing with the development of an active power filter for a three-phase supply with variable frequency from 360 to 800 Hz. All relevant components such as inductors, EMC-filters, power modules and DC-link capacitor are designed. A particular focus is put on the customized power module with SiC-MOSFETs and SiC-diodes, which is characterized electrically and thermally. The maximum supply frequency slope has a value of 50 Hz/ms, which requires a high dynamic and robustness on the control algorithm. Furthermore, the content of 5th and 7th harmonics must be reduced to less than 2 %, which demands a high accuracy. To cope with both requirements, a two-stage filter algorithm is developed and implemented in two independent signal processors. Simulations and laboratory experiments confirm the performance and robustness of the control algorithm. This work comprehensively presents the design of aerospace rectifiers. The results were published in conferences and patents. / Hauptziele des sogenannten "More Electrical Aircraft" (MEA) sind Effizienzerhöhung und Gewichtseinsparung. Ein Schwerpunkt hierbei ist die Nutzung von elektrischen statt hydraulischen, pneumatischen und mechanischen Systemen. Die notwendigen Leistungselektroniken haben DC-Zwischenkreise, welche mittels aktiven B6 und passiven B12 Gleichrichtern aus dem Dreiphasennetz gespeist werden. Eine mögliche Alternative ist die B6 Diodenbrücke in Kombination mit einem aktiven Netzfilter, welcher aufgrund der parallelen Anordnung eine höhere Leistungsdichte aufweist und darüber hinaus mehrere Geräte gleichzeitig entstören kann. Die alleinige Nutzung einer Diodenbrücke ist aufgrund des hohen Anteils von Stromharmonischen nicht zulässig. Diese Arbeit beschäftigt sich mit der Entwicklung eines aktiven Filters für ein Dreiphasensystem mit variabler Frequenz von 360 bis 800 Hz. Es werden alle relevanten Bauteile wie Induktivitäten, EMV-Filter, Leistungsmodule und Zwischenkreiskondensator ausgelegt. Besonderes Augenmerk liegt auf dem kundenspezifischen Modul mit SiC-Dioden und SiCMOSFETs, welches vollständig elektrisch und thermisch charakterisiert wird. Die Änderung der Netzfrequenz beträgt bis zu 50 Hz/ms, was eine hohe Dynamik und Robustheit von der Filterregelung verlangt. Weiterhin ist im statischen Fall eine hohe Genauigkeit gefordert, da die 5. und 7. Harmonische auf unter 2% geregelt werden müssen. Um beiden Anforderungen gerecht zu werden, wird ein zweistufiger Regelungsalgorithmus entwickelt der auf zwei digitalen Signalprozessoren implementiert wird. Simulationen und Labormessungen bestätigen die Robustheit des Regelungskonzeptes. Diese Arbeit stellt umfassend die Entwicklung von Luftfahrtgleichrichtern dar. Die Ergebnisse wurden in Konferenzen und Patenten veröffentlicht.

We are pleased to present the conference proceedings for the 12th edition of the International Fluid Power Conference (IFK). The IFK is one of the world’s most significant scientific conferences on fluid power control technology and systems. It offers a common platform for the presentation and discussion of trends and innovations to manufacturers, users and scientists. The Chair of Fluid-Mechatronic Systems at the TU Dresden is organizing and hosting the IFK for the sixth time. Supporting hosts are the Fluid Power Association of the German Engineering Federation (VDMA), Dresdner Verein zur Förderung der Fluidtechnik e. V. (DVF) and GWT-TUD GmbH. The organization and the conference location alternates every two years between the Chair of Fluid-Mechatronic Systems in Dresden and the Institute for Fluid Power Drives and Systems in Aachen. The symposium on the first day is dedicated to presentations focused on methodology and fundamental research. The two following conference days offer a wide variety of application and technology orientated papers about the latest state of the art in fluid power. It is this combination that makes the IFK a unique and excellent forum for the exchange of academic research and industrial application experience. A simultaneously ongoing exhibition offers the possibility to get product information and to have individual talks with manufacturers. The theme of the 12th IFK is “Fluid Power – Future Technology”, covering topics that enable the development of 5G-ready, cost-efficient and demand-driven structures, as well as individual decentralized drives. Another topic is the real-time data exchange that allows the application of numerous predictive maintenance strategies, which will significantly increase the availability of fluid power systems and their elements and ensure their improved lifetime performance. We create an atmosphere for casual exchange by offering a vast frame and cultural program. This includes a get-together, a conference banquet, laboratory festivities and some physical activities such as jogging in Dresden’s old town.:Group 8: Pneumatics Group 9 | 11: Mobile applications Group 10: Special domains Group 12: Novel system architectures Group 13 | 15: Actuators & sensors Group 14: Safety & reliability

To measure the speed of a vehicle, the revolution of a wheel or a rigid axle is traditionally used. Therefore non corrigible systematic errors occur which are caused by slip, spin and by the change of wheel diameter due to fretting. Train control and traction systems require new robust as well as precise methods of speed measurement. Because of their physical properties, Doppler-radar-sensors attached to the vehicle and measuring ground speed are first choice for this range of applications. Currently used sensors cannot fulfil the high demands under all operating conditions, because they are unable to completely compensate the various interferences and systematic deviations. This is the starting point of this dissertation. Two independent diverse methods with optimised reliability and accuracy must be used to meet all requirements. Limited resources of the embedded digital signal processor system under real-time conditions have to be taken into account. According to the boundary conditions, the introductory chapters critically discuss the frequency analysis methods currently used and describe starting points for further development. This leads to the design of a new, robust, wide-band spectral analysis which combines techniques of the dyadic wavelet transformation with the fast Fourier transformation. At the same time a new frame procedure and general model for the estimation of motion parameters is developed which features short delays. The disadvantages of the block-based discrete spectral analysis applied over continuous approaches are extensively compensated. The block structure of spectral data enables the selective use of new knowledge-based spectral filters for the compensation of the remaining intense interferences which are typical of this kind of application. / Die Fahrzeuggeschwindigkeitsmessung über die Drehzahl eines Rades weist in Schlupf- und Schleuderzuständen erhebliche systematische Abweichungen auf. Deshalb erfordern Zugbeeinflussungs- und Antriebssysteme neue gleichzeitig robuste und präzise Geschwindigkeitsmessmethoden. Die Mikrowellensensorik unter Nutzung des Dopplereffekts zwischen Fahrzeug und Gleisbett wird wegen ihrer physikalischen Eigenschaften für dieses Einsatzgebiet favorisiert. Bisherige Sensorapplikationen erfüllen aber die hohen Ansprüche nicht in allen Betriebszuständen. Hier setzt die in dieser Arbeit beschriebene Sensorentwicklung auf. Zwei getrennt hergeleitete und nach Zuverlässigkeit und Genauigkeit optimierte neue Verfahren können bei gleichzeitiger Anwendung die gestellten Anforderungen erfüllen. Dabei müssen auch die beschränkten Ressourcen des eingebetteten digitalen Signalverarbeitungssystems unter Echtzeitbedingungen berücksichtigt werden. Entsprechend dieser Randbedingungen findet einleitend eine kritische Betrachtung bestehender Frequenzanalysemethoden statt und Ansätze für die Weiterentwicklung werden herausgearbeitet. Einerseits führt dies zur Konstruktion einer neuen störunempfindlichen Weitbereichsspektralzerlegung, welche Ansätze der dyadischen Wavelettransformation mit der Diskreten Fourier-Transformation verbindet. Andererseits wird ein neues Rahmenverfahren für die verzögerungsarme Schätzung der Bewegungsparameter des Fahrzeuges aufgrund seines physikalischen Bewegungsmodells hergeleitet und mit einem hochgenauen Frequenzauswerteverfahren kombiniert. Beide Verfahren basieren auf blockweisen diskreten Spektralzerlegungen, deren prinzipielle Nachteile gegenüber kontinuierlichen Ansätzen weitgehend kompensiert werden können. Durch die Blockorganisation lassen sich neuartige wissensbasierte Spektralfilter selektiv zur Unterdrückung starker bahnanwendungstypischer Störeinflüsse einsetzen.

Quality-aware management of data streams is gaining more and more importance with the amount of data produced by streams growing continuously. The resources required for data stream processing depend on different factors and are limited by the environment of the data stream management system (DSMS). Thus, with a potentially unbounded amount of stream data and limited processing resources, some of the data stream processing tasks (originating from different users) may not be satisfyingly answered, and therefore, users should be enabled to negotiate a certain quality for the execution of their stream processing tasks. After the negotiation process, it is the responsibility of the Data Stream Management System to meet the quality constraints by using adequate resource reservation and scheduling techniques. Within this paper, we consider different aspects of real-time scheduling for operations within a DSMS. We propose a scheduling concept which enables us to meet certain time-dependent quality of service requirements for user-given processing tasks. Furthermore, we describe the implementation of our scheduling concept within a real-time capable data stream management system, and we give experimental results on that.

The intentions of the so-called "More Electrical Aircraft" (MEA) are higher efficiency and lower weight. A main topic here is the application of electrical instead of hydraulical, pneumatical and mechanical systems. The necessary power electronic devices have intermediate DC-links, which are typically supplied by a three-phase system with active B6 and passive B12 rectifiers. A possible alternative is the B6 diode bridge in combination with an active power filter (APF). Due to the parallel arrangement, the APF offers a higher power density and is able to compensate for harmonics from several devices. The use of the diode bridge rectifier alone is not permitted due to the highly distorted phase current. The following investigations are dealing with the development of an active power filter for a three-phase supply with variable frequency from 360 to 800 Hz. All relevant components such as inductors, EMC-filters, power modules and DC-link capacitor are designed. A particular focus is put on the customized power module with SiC-MOSFETs and SiC-diodes, which is characterized electrically and thermally. The maximum supply frequency slope has a value of 50 Hz/ms, which requires a high dynamic and robustness on the control algorithm. Furthermore, the content of 5th and 7th harmonics must be reduced to less than 2 %, which demands a high accuracy. To cope with both requirements, a two-stage filter algorithm is developed and implemented in two independent signal processors. Simulations and laboratory experiments confirm the performance and robustness of the control algorithm. This work comprehensively presents the design of aerospace rectifiers. The results were published in conferences and patents. / Hauptziele des sogenannten "More Electrical Aircraft" (MEA) sind Effizienzerhöhung und Gewichtseinsparung. Ein Schwerpunkt hierbei ist die Nutzung von elektrischen statt hydraulischen, pneumatischen und mechanischen Systemen. Die notwendigen Leistungselektroniken haben DC-Zwischenkreise, welche mittels aktiven B6 und passiven B12 Gleichrichtern aus dem Dreiphasennetz gespeist werden. Eine mögliche Alternative ist die B6 Diodenbrücke in Kombination mit einem aktiven Netzfilter, welcher aufgrund der parallelen Anordnung eine höhere Leistungsdichte aufweist und darüber hinaus mehrere Geräte gleichzeitig entstören kann. Die alleinige Nutzung einer Diodenbrücke ist aufgrund des hohen Anteils von Stromharmonischen nicht zulässig. Diese Arbeit beschäftigt sich mit der Entwicklung eines aktiven Filters für ein Dreiphasensystem mit variabler Frequenz von 360 bis 800 Hz. Es werden alle relevanten Bauteile wie Induktivitäten, EMV-Filter, Leistungsmodule und Zwischenkreiskondensator ausgelegt. Besonderes Augenmerk liegt auf dem kundenspezifischen Modul mit SiC-Dioden und SiCMOSFETs, welches vollständig elektrisch und thermisch charakterisiert wird. Die Änderung der Netzfrequenz beträgt bis zu 50 Hz/ms, was eine hohe Dynamik und Robustheit von der Filterregelung verlangt. Weiterhin ist im statischen Fall eine hohe Genauigkeit gefordert, da die 5. und 7. Harmonische auf unter 2% geregelt werden müssen. Um beiden Anforderungen gerecht zu werden, wird ein zweistufiger Regelungsalgorithmus entwickelt der auf zwei digitalen Signalprozessoren implementiert wird. Simulationen und Labormessungen bestätigen die Robustheit des Regelungskonzeptes. Diese Arbeit stellt umfassend die Entwicklung von Luftfahrtgleichrichtern dar. Die Ergebnisse wurden in Konferenzen und Patenten veröffentlicht.

Mit der steigenden Nachfrage nach Innovationen spielt Software in verschiedenenWirtschaftsbereichen eine wichtige Rolle, wie z.B. in der Automobilindustrie, bei intelligenten Systemen als auch bei Kommunikationssystemen. Daher ist die Qualität für die Softwareentwicklung von großer Bedeutung. Allerdings ändern sich die probabilistische Modelle (die Qualitätsbewertungsmodelle) angesichts der dynamischen Natur moderner Softwaresysteme. Dies führt dazu, dass ihre Übergangswahrscheinlichkeiten im Laufe der Zeit schwanken, welches zu erheblichen Problemen führt. Dahingehend werden probabilistische Modelle im Hinblick auf ihre Laufzeit kontinuierlich aktualisiert. Eine fortdauernde Neubewertung komplexer Wahrscheinlichkeitsmodelle ist jedoch teuer. In letzter Zeit haben sich inkrementelle Ansätze als vielversprechend für die Verifikation von adaptiven Systemen erwiesen. Trotzdem wurden bei der Bewertung struktureller Änderungen im Modell noch keine wesentlichen Verbesserungen erzielt. Wahrscheinlichkeitssysteme werden als Automaten modelliert, wie bei Markov-Modellen. Solche Modelle können in Matrixform dargestellt werden, um die Gleichungen basierend auf Zuständen und Übergangswahrscheinlichkeiten zu lösen. Laufzeitmodelle wie Matrizen sind nicht signifikant, um die Auswirkungen von Modellveränderungen erkennen zu können. In dieser Arbeit wird ein Framework unter Verwendung stochastischer Bäume mit regulären Ausdrücken entwickelt, welches modular aufgebaut ist und eine aktionshaltige sowie probabilistische Logik im Kontext der Modellprüfung aufweist. Ein solches modulares Framework ermöglicht dem Menschen die Entwicklung der Änderungsoperationen für die inkrementelle Berechnung lokaler Änderungen, die im Modell auftreten können. Darüber hinaus werden probabilistische Änderungsmuster beschrieben, um eine effiziente inkrementelle Verifizierung, unter Verwendung von Bäumen mit regulären Ausdrücken, anwenden zu können. Durch die Bewertung der Ergebnisse wird der Vorgang abgeschlossen. / Software plays an innovative role in many different domains, such as car industry, autonomous and smart systems, and communication. Hence, the quality of the software is of utmost importance and needs to be properly addressed during software evolution. Several approaches have been developed to evaluate systems’ quality attributes, such as reliability, safety, and performance of software. Due to the dynamic nature of modern software systems, probabilistic models representing the quality of the software and their transition probabilities change over time and fluctuate, leading to a significant problem that needs to be solved to obtain correct evaluation results of quantitative properties. Probabilistic models need to be continually updated at run-time to solve this issue. However, continuous re-evaluation of complex probabilistic models is expensive. Recently, incremental approaches have been found to be promising for the verification of evolving and self-adaptive systems. Nevertheless, substantial improvements have not yet been achieved for evaluating structural changes in the model. Probabilistic systems are usually represented in a matrix form to solve the equations based on states and transition probabilities. On the other side, evolutionary changes can create various effects on theese models and force them to re-verify the whole system. Run-time models, such as matrices or graph representations, lack the expressiveness to identify the change effect on the model. In this thesis, we develop a framework using stochastic regular expression trees, which are modular, with action-based probabilistic logic in the model checking context. Such a modular framework enables us to develop change operations for the incremental computation of local changes that can occur in the model. Furthermore, we describe probabilistic change patterns to apply efficient incremental quantitative verification using stochastic regular expression trees and evaluate our results.