Green’s Function for Lamb’s Problem and Rayleigh Wave Propagation in General Transversely Isotropic Materials1

Composite materials have gained considerable industrial importance, being widely applied e.g. in aerospace industries. The need for their proper testing in view of delaminations, inclusions and other defects has correspondingly stimulated the interest in describing wave propagation in such anisotropic media. In this study, Lamb’s problem of determining the disturbance resulting from a point source in a half-space [1] is investigated for the case of transversely isotropic (TI) symmetry, which is characteristic for unidirectional fiber composites and extruded metal-matrix composites, but also for fiber-textured columnar-grained steels. Using the dyadic and triadic full-space Green’s functions obtained previously in their 2d-space-time spectral representations [2], a corresponding representation of Green’s dyad for the half-space has been derived exploiting the boundary condition of the stress-free surface. The resulting dyadic function is the solution of the elastic wave equation with point forces applied at the surface or within the uniform half-space, the fiber orientation being variable. First numerical evaluations have been performed with respect to Rayleigh-surface wave propagation by determining the zeroes of the corresponding Rayleigh function, which is included in the analytical expressions. Resulting slowness and wave curves are presented for several materials. The work presented can be further applied, e.g., to determine Rayleigh wave directivity patterns for point sources on the half-space as well as to model laser-generated wave propagation in composites. Application in the field of seismic wave propagation is also possible

Innovative Fortbildung der Lehrerinnen und Lehrer an beruflichen Schulen. Gutachten zum Programm

Mit der vorliegenden Expertise soll die Programmskizze für das BLK-Programm "Innovative Fortbildung der Lehrer und Lehrerinnen an beruflichen Schulen" ausdifferenziert werden. Aufgabe der Expertengruppe war es, die in der Programmskizze benannten Aufgabenfelder aufzugreifen, zu ergänzen und daraus thematische Schwerpunkte zu erarbeiten, die zugleich Empfehlungen für Maßnahmebereiche und mögliche Länderprojekte darstellen. Dabei sind die Autoren von dem Phasenmodell der KMK-Rahmenvereinbarung über die Ausbildung und Prüfung für ein Lehramt der Sekundarstufe II (berufliche Fächer) oder für berufliche Schulen vom 12. Mai 1995 ausgegangen und haben sich auftragsgemäß auf die 2. und 3. Phase beschränkt. Gliederung: 0. Konkretisierung des Auftrages. - 1. Leitbild der Entwicklung der Lehrerpersönlichkeit. - 2. Anforderungsprofil der Lehrkräfte an beruflichen Schulen. - 3. Bezugspunkte und Leitorientierungen einer innovativen Lehrerfortbildung (3.1 Berufsbiografische Phasen der Lehrerbildung. - 3.2 Gestaltungsgrundsätze in den berufsbiografischen Phasen. - 3.3 Aktuelle thematische Brennpunkte). - 4. Maßnahmebereiche für das Modellversuchsprogramm (4.1 Neue Qualifizierungs- und Lernkonzepte in der 2. Phase der Lehrerausbildung (Referendariat). - 4.2 Innovative Fortbildungsstrategien für die 3. Phase der Qualifizierung (Lernen im Beruf). - 4.3 Zusammenfassende Übersicht zu Maßnahmebereichen und Untersuchungsfeldern). - 5. Empfehlungen zur Programmorganisation, zu Projektstrukturen sowie zum Ergebnistransfer. (HoF/Text übernommen

Formal verification of pipelined microprocessors

Subject of this thesis is the formal verification of pipelined microprocessors. This includes processors with state of the art schedulers, such as the Tomasulo scheduler and speculation. In contrast to most of the literature, we verify synthesizable design at gate level. Furthermore, we prove both data consistency and liveness. We verify the proofs using the theorem proving system PVS. We verify both in-order and out-of-order machines. For verifying in-order machines, we extend the stall engine concept presented in [MP00]. We describe and implement an algorithm that does the transformation into a pipelined machine. We describe a generic machine that supports speculating on arbitraty values. We formally verify proofs for the Tomasulo scheduling algorithm with reorder buffer.Gegenstand dieser Dissertation ist die formale Verifikation von Mikroprozessoren mit Pipeline. Dies beinhaltet auch Prozessoren mit aktuellen Scheduling-Verfahren wie den Tomasulo Scheduler und spekulativer Ausfuehrung. Im Gegensatz zu weiten Teilen der bestehenden Literatur fuehren wir die Verifikation auf Gatter-Ebene durch. Des weitern beweisen wir sowohl Datenkonsistenz als auch eine obere Schranke fuer die Ausfuehrungszeit. Die Beweise werden mit dem Theorem Beweissystem PVS verifiziert. Es werden sowohl in-order Maschinen als auch out-of-order Maschinen verifiziert. Zur Verifikation der in-order Maschinen erweitern wir die Stall Engine aus [MP00]. Wir beschreiben und Implementieren ein Verfahren das die Transformation in die "pipelined machine\u27; durchfuehrt. Wir beschreiben eine generische Maschine die Spekulation auf beliebige Werte erlaubt. Wir verifizieren die Beweise fuer den Tomasulo Scheduler mit Reorder Buffer

Abschlussbericht des BLK-Programmträgers zum Modellversuchsprogramm "Innovative Fortbildung der Lehrerinnen und Lehrer an beruflichen Schulen"

Ziel des Programms war die Verbesserung der Qualifizierung der Berufsschullehrer in der 2. (Vorbereitungsdienst/Studienseminar) und 3. Phase (berufsbegleitende Fortbildung), da hierdurch notwendige Veränderungen schnell und direkt in die beruflichen Schulen eingebracht werden können. Insbesondere erprobte Innovationen aus berufsschulischen BLK-Modellversuchen wurden in die Lehrerfortbildung und in den Vorbereitungsdienst transferiert und dadurch verbreitet und umgesetzt. Programmschwerpunkte waren besondere Fragen des Vorbereitungsdienstes (z.B. Qualifizierung von "Seiteneinsteigern" für den Schuldienst, der Seminarleiter und Fachleiter, der Mentoren und Ausbildungslehrer, Bewertung von Lehrproben) und Lehrerfortbildung in Verbindung mit der Schnittstelle zum Vorbereitungsdienst (Unterrichtsgestaltung, Berufliche Schulen im Berufsbildungssystem, Organisation der Lehrerqualifizierung). Der Abschlussbericht beschreibt 1. Anliegen des Programms; 2. Steuerungsmaßnahmen des Programmträgers; 3. Innovationsbeiträge der Modellversuche und liefert 4. eine Zusammenfassende Einschätzung. (DIPF/DBS

Nanocomposites with p-and n-type conductivity controlled by type and content of nanotubes in thermosets for thermoelectric applications

In this work, composites based on epoxy resin and various carbon nanotubes (CNTs) were studied regarding their thermoelectric properties. The epoxy composites were prepared by infiltration of preformed CNT buckypapers. The influence of different types of CNTs on the Seebeck coefficient was investigated, namely lab-made and commercially available multi walled carbon nanotubes (MWCNTs), lab-made nitrogen doped MWCNTs (N-MWCNT) and commercially available single walled carbon nanotubes (SWCNTs). It was found that only by varying the lab-made MWCNT content could both n-and p-type composites be produced with Seebeck coefficients between -9.5 and 3.1 µV/K. The incorporation of N-MWCNTs resulted in negative Seebeck coefficients of -11.4 to -17.4 µV/K. Thus, the Seebeck coefficient of pure SWCNT changed from 37.4 to -25.5 µV/K in the epoxy/1 wt. % SWCNT composite. A possible explanation for the shift in the Seebeck coefficient is the change of the CNTs Fermi level depending on the number of epoxy molecules on the CNT surface. © 2020 by the authors. Licensee MDPI, Basel, Switzerland

Formale Verifikation von Mikroprozessoren mit Pipeline

Subject of this thesis is the formal verification of pipelined microprocessors. This includes processors with state of the art schedulers, such as the Tomasulo scheduler and speculation. In contrast to most of the literature, we verify synthesizable design at gate level. Furthermore, we prove both data consistency and liveness. We verify the proofs using the theorem proving system PVS. We verify both in-order and out-of-order machines. For verifying in-order machines, we extend the stall engine concept presented in [MP00]. We describe and implement an algorithm that does the transformation into a pipelined machine. We describe a generic machine that supports speculating on arbitraty values. We formally verify proofs for the Tomasulo scheduling algorithm with reorder buffer.Gegenstand dieser Dissertation ist die formale Verifikation von Mikroprozessoren mit Pipeline. Dies beinhaltet auch Prozessoren mit aktuellen Scheduling-Verfahren wie den Tomasulo Scheduler und spekulativer Ausfuehrung. Im Gegensatz zu weiten Teilen der bestehenden Literatur fuehren wir die Verifikation auf Gatter-Ebene durch. Des weitern beweisen wir sowohl Datenkonsistenz als auch eine obere Schranke fuer die Ausfuehrungszeit. Die Beweise werden mit dem Theorem Beweissystem PVS verifiziert. Es werden sowohl in-order Maschinen als auch out-of-order Maschinen verifiziert. Zur Verifikation der in-order Maschinen erweitern wir die Stall Engine aus [MP00]. Wir beschreiben und Implementieren ein Verfahren das die Transformation in die "pipelined machine'; durchfuehrt. Wir beschreiben eine generische Maschine die Spekulation auf beliebige Werte erlaubt. Wir verifizieren die Beweise fuer den Tomasulo Scheduler mit Reorder Buffer

Requirements and potentials of human kinetic energy harvesting technologies with focus on electromagnetic conversion methods

In the recent years, energy harvesting has become increasingly popular for powering low-energy devices. Therefore, human power has become a promising energy source in providing electrical energy. Thus, the general principles, structures, requirements and potentials of human kinetic energy harvesting technologies are presented. Commonly, human kinetic energy harvesting systems have to be adjusted to the human locomotion. For the purpose of maximizing the power output, results of biomechanical analyzing methods are presented to identify resonant frequencies and bandwidths. With focus on inertial electromagnetic generators, further challenges and potentials are discussed to optimize the power conversion. In doing so, mechanical and electrical characteristics of the generator structure are examined and optimization problems are derived. One major issue within power maximizing is to match the resonant frequency and achieve a suitable electromechanical coupling. Parameter dependencies are identified by using analytic and numerical representations of generic electromagnetic generators

O fazer musical dos violonistas-compositores Dyens e Bogdanovic: relações entre performance, composicão, arranjo e improvisação

Doutoramento em MúsicaA pesquisa doutoral realizada na Universidade de Aveiro sobre o “fazer musical” dos violonistas-compositores Roland Dyens (1955) e Dusan Bogdanovic (1955) através de estudo exploratório qualitativo observacional participante em masterclasses, recitais e ensembles em Festivais de Violão realizados na Europa, de outubro de 2012 a novembro de 2013, apoiado pelo estudo da totalidade da obra discográfica de Dyens e Bogdanovic entre os anos de 1979 e 2011. A investigação tem como eixo teórico os modos de ‘composição em performance’ desenvolvidos por Finnegan (1989) e as variáveis do “fazer musical” de Elliott (1995) em “performance”, “composição”, “arranjo” e “improvisação” para a análise qualitativa e quantitativa do “fazer musical” dos violonistas-compositores estudados na presente Tese. O percurso metodológico foi desenvolvido em 3 fases: Revisão de Literatura; Estudo Discográfico de Dyens e Bogdanovic e Pesquisa Empírica através de Estudo Observacional não Participante e Participante. Examino como Dyens e Bogdanovic articulam os tipos de “fazer musical” em situações presenciais, comparando-as com suas discografias. A Pesquisa Empirica foi realizada na França, Espanha, Liechtenstein e Sérvia, em 6 Festivais de Violão realizados nas cidades de Belgrado, Colmar, Paris, Sevilha e Vaduz. Dentre as principais contribuições da pesquisa: a) apresentação sistemática e inédita da totalidade das obras gravadas em discos por Dyens e Bogdanovic (perído de 33 anos) revelando as características e evolução do “fazer musical”de ambos; b) discussão e redefinição de modalidades e conceitos de “fazer musical” a partir da Revisão de Literatura, Estudo Discográfico e Pesquisa Empírica ; c) novas obras compostas, arranjadas e apresentadas no período da Pesquisa Empírica enquanto músico-participante em masterclasses com Dyens e Bogadanovic.Doctoral research conducted at the University of Aveiro about the "music-making" of guitarist-composers Roland Dyens (1955) and Dusan Bogdanovic (1955) through exploratory qualitative observational study participant in masterclasses, recitals and ensembles in Festivals of Guitar held in Europe from October 2012 to October 2013, supported by the study of the entire record of work Dyens and Bogdanovic between the years of 1979 and 2011. The research has as theoretical axis composition modes in performance ' developed by Finnegan (1989) and the variables of "music-making" of Elliott (1995) on "performance", "composition", "arrangement" and "improvisation" for the qualitative and quantitative analysis of the guitarists-composers` music-making studied in this Thesis. The methodological path was developed in 3 phases: Literature Review; Dyens and Bogdanovic Discograph Study and Empirical Research through observational study non-participant and participant. It is examined how Dyens and Bogdanovic articulate the kinds of "music-making" in face-to-face situations, comparing them with their discographies. Empirical Research was carried out in France, Spain, Liechtenstein and Serbia, in 6 Guitar Festivals held in the cities of Belgrade, Colmar, Paris, Seville and Vaduz. One of the main contributions of this research: a) systematic and unprecedented presentation of all the works recorded on discs by Dyens and Bogdanovic (period of 33 years) revealing the characteristics and evolution of the "music-making" of both; b) discussion and redefinition of terms and concepts of "make music" from the Literature Review, Discographic Study and Empirical Research; c) new works composed, arranged and presented in the Empirical Research as a musician-participant in masterclasses with Dyens and Bogdanovic

OS DESAFIOS PROPOSTOS PELO PENSAMENTO SISTÊMICO E A RESISTÊNCIA DAS INSTITUIÇÕES: UMA ANÁLISE DO CONTEXTO UNIVERSITÁRIO

Partindo da idéia de esgotamento do paradigma cartesiano, o artigo discute a importância dos desafios a serem enfrentados pela universidade frente à emergência de um novo modelo de pensamento, centrado na visão sistêmica (ou holística), que objetiva                                                                                               uma percepção acadêmica mais ampla da realidade e, ao mesmo tempo, mais  fidedigna à sua função social