Towards a Model-Centric Software Testing Life Cycle for Early and Consistent Testing Activities

The constant improvement of the available computing power nowadays enables the accomplishment of more and more complex tasks. The resulting implicit increase in the complexity of hardware and software solutions for realizing the desired functionality requires a constant improvement of the development methods used. On the one hand over the last decades the percentage of agile development practices, as well as testdriven development increases. On the other hand, this trend results in the need to reduce the complexity with suitable methods. At this point, the concept of abstraction comes into play, which manifests itself in model-based approaches such as MDSD or MBT. The thesis is motivated by the fact that the earliest possible detection and elimination of faults has a significant influence on product costs. Therefore, a holistic approach is developed in the context of model-driven development, which allows applying testing already in early phases and especially on the model artifacts, i.e. it provides a shift left of the testing activities. To comprehensively address the complexity problem, a modelcentric software testing life cycle is developed that maps the process steps and artifacts of classical testing to the model-level. Therefore, the conceptual basis is first created by putting the available model artifacts of all domains into context. In particular, structural mappings are specified across the included domain-specific model artifacts to establish a sufficient basis for all the process steps of the life cycle. Besides, a flexible metamodel including operational semantics is developed, which enables experts to carry out an abstract test execution on the modellevel. Based on this, approaches for test case management, automated test case generation, evaluation of test cases, and quality verification of test cases are developed. In the context of test case management, a mechanism is realized that enables the selection, prioritization, and reduction of Test Model artifacts usable for test case generation. I.e. a targeted set of test cases is generated satisfying quality criteria like coverage at the model-level. These quality requirements are accomplished by using a mutation-based analysis of the identified test cases, which builds on the model basis. As the last step of the model-centered software testing life cycle two approaches are presented, allowing an abstract execution of the test cases in the model context through structural analysis and a form of model interpretation concerning data flow information. All the approaches for accomplishing the problem are placed in the context of related work, as well as examined for their feasibility by of a prototypical implementation within the Architecture And Analysis Framework. Subsequently, the described approaches and their concepts are evaluated by qualitative as well as quantitative evaluation. Moreover, case studies show the practical applicability of the approach

Transcriptome analysis using RNA-Seq on response of respiratory cells infected with porcine reproductive and respiratory syndrome virus (PRRSV)

The porcine reproductive and respiratory syndrome (PRRS) is one of the most important viral diseases of the swine industry worldwide (Balasuriya 2013). Its aetiological agent is the PRRS virus (PRRSV) (Balasuriya 2013, Conzelmann et al. 1993). The understanding of the genetic elements and functions, involved in the response to PRRSV and the comprehension of the changes in the global transcriptome profile post infection, remain still unclear. Main objectives of this thesis are to characterize the global transcriptome profile of PRRSV infected lung DCs, by using the RNA-Sequencing (RNA-Seq), to improve the understanding of genetic components in the response to PRRSV as well as to determine the changes in the expression profile in different respiratory cells post PRRSV infection. Six female 30 days old piglets of two different porcine breeds (Pietrain and Duroc) were selected, PAMs, lung DCs and trachea epithelial cells were isolated and infected with the European prototype PRRSV strain Lelystad virus (LV). Non-infected (0 h) and infected (3, 6, 9, 12, 24 hpi) lung DCs, PAMs and trachea epithelial cells as well as cell culture supernatants were collected. Non-infected and infected lung DCs of both breeds were used for RNA-Seq. The sequence alignment was done with the reference genome build Suscrofa 10.2 and with the complete genome of LV strain. The transcriptome analysis of PRRSV infected lung DCs of Pietrain and Duroc resulted in an amount of 20,396 porcine predicted gene transcripts. The virus sequence alignment exhibited that the LV strain was able to infect lung DCs and to replicate there. Not only breed-differences post PRRSV infection in the virus growth, also breed-differences in the cytokine concentrations as well as in the detected mRNA expression profiles and in the differently expressed genes were identified. Beside these breed-dependent differences, cell-type dependent differences in the response to PRRSV were characterized. 37 clusters for Pietrain and 35 clusters for Duroc and important pathways were identified. This thesis is the first comprehensive study that described the transcriptome profile of two different breeds post PRRSV infection, especially of infected lung DCs. The main findings of the investigations showed that the virus-host interaction was different for the various respiratory celltypes and that the gene expression trends proceeded contrarily for both breeds during the first time points after infection. Additionally, key clusters, key pathways and specific gene transcripts were identified.Transkriptom-Analyse mittels RNA-Seq von respiratorischen Zellen nach deren Infektion mit dem Porcinen Reproduktiven und Respiratorischen Syndrom Virus (PRRSV) Das Porcine Reproduktive und Respiratorische Syndrom (PRRS) ist eine der wichtigsten viralen Erkrankungen in der weltweiten Schweineindustrie (Balasuriya 2013). Das PRRS Virus (PRRSV) ist der ätiologische Erreger (Balasuriya 2013, Conzelmann et al. 1993). Die Einflussnahme von genetischen Elementen und Funktionen auf die Reaktion auf PRRSV sowie die Veränderungen im Transkriptomprofil nach einer Infektion sind noch unklar. Hauptziele dieser Dissertation sind, das globale Transkriptomprofil von PRRSV infizierten Lungen-DCs mittels RNA-Sequenzierung (RNA-Seq) zu charakterisieren, das Verständnis über die Einflüsse von genetischen Komponenten auf die Reaktion auf PRRSV zu verbessern und die Veränderungen im Expressionsprofil von unterschiedlichen respiratorischen Zellen nach der Virusinfektion zu ermitteln. Sechs weibliche, 30 Tage alte Ferkel von zwei unterschiedlichen Schweinerassen (Piétrain und Duroc) wurden ausgewählt. Aus deren Lungen wurden PAMs und DCs sowie Epithelzellen aus deren Trachea isoliert. Anschließend wurden diese Zellen mit dem europäischen PRRSV Stamm Lelystad Virus (LV) infiziert. Nicht-infizierte (0 h) und infizierte (3, 6, 9, 12, 24 hpi) Lungen-DCs, PAMs und Trachea-Epithelzellen wie auch deren Zellkulturüberstände wurden gesammelt. Zur RNA-Seq wurden nicht-infizierte und infizierte Lungen-DCs beider Schweinerassen eingesetzt. Das Sequenzalignment erfolgte mit dem Referenzgenombild Suscrofa 10.2 und mit dem kompletten Genom des LV Stammes. Die Transkriptom-Analyse von PRRSV infizierten Piétrain und Duroc Lungen-DCs erkannte 20.396 porcine Gentranskripte. Das Virus Sequenzalignment zeigte, dass der LV Stamm sowohl Lungen-DCs infizieren als auch sich dort replizieren kann. Nach der PRRSV Infektion konnten Rassenunterschiede festgestellt werden, sowohl beim Viruswachstum als auch in den Cytokinkonzentrationen sowie in identifizierten mRNA Expressionsprofilen und bei den unterschiedlich exprimierten Genen. Zudem konnten Reaktionsunterschiede auf PRRSV in den verschiedenen respiratorischen Zelltypen charakterisiert werden. Es wurden 37 Cluster für Piétrain, 35 für Duroc sowie wichtige Pathways identifiziert. Diese Dissertation ist die erste umfassende Studie, die das Transkriptomprofil von PRRSV infizierten Lungen-DCs zweier unterschiedlicher Schweinerassen beschreibt. Als Hauptergebnisse zeigten die Untersuchungen, dass die Virus-Wirts-Interaktionen für die verschiedenen respiratorischen Zellen unterschiedlich verliefen und dass die Genexpressionstrends beider Rassen während der ersten Zeitpunkte nach der Infektion verschieden waren. Zusätzlich konnten Schlüssel-Cluster, Schlüssel-Pathways und spezifische Gentranskripte identifiziert werden

Design Requirements for Pressurized Chemical Looping Reforming

A key issue in chemical looping reforming is to operate the process under pressurized conditions. Applicability of dual fluidized bed systems, currently used in atmospheric chemical looping processes, is affected by pressure. Critical design issues were studied and experimentally verified by cold flow model experiments. It turns out that it is important to achieve sufficient global solids circulation and to keep the pressure difference between the reactors low enough for proper operation of the loop seals

Bioenergy Recovery from Cotton Stalk

Cotton stalk (CS) plant residue left in the field following harvest must be buried or burned to prevent it from serving as an overwintering site for insects such as the pink bollworm (PBW). This pest incurs economic costs and detrimental environmental effects. However, CS contains lignin and carbohydrates, like cellulose and hemicelluloses, which can be converted into a variety of usable forms of energy. Thermochemical or biochemical processes are considered technologically advantageous solutions. This chapter reviews potential energy generation from cotton stalks through combustion, hydrothermal carbonization, pyrolysis, fermentation, and anaerobic digestion technologies, focusing on the most relevant technologies and on the properties of the different products. The chapter is concluded with some comments on the future potential of these processes

Feasibility of fluidized bed reactor systems for pressurized chemical looping combustion of natural gas

Chemical looping combustion (CLC) of natural gas at atmospheric pressure has been successfully demonstrated at technical laboratory scale (120 kWth) since 2009 (1,2). Scale-up studies to 10 MWth have been presented (3,4), but no pilot or demonstration projects have been executed so far. Instead, researchers have recently concentrated their activities on CLC of solid fuels (5). One reason for this is the deployment challenge for natural gas CLC power plants. State-of-the-art gas-turbine combined cycle (GT-CC) plants reach high electric efficiencies up to 60% and are superior to steam cycle concepts even if post combustion CO2 capture is applied. On the other hand, all the early studies on CLC focused on efficiency increase for GT-CC plants through application of CLC (6,7). The present contribution therefore seeks to address this mismatch and to assess the practical potential of natural gas CLC for power production. A principal baseline is the application of atmospheric pressure CLC and steam cycle power generation reaching electric efficiencies up to 45% dependent on steam parameters and plant size. In order to reach higher electric efficiencies, pressurized CLC and gas turbine cycles would need to be implemented. Fluidized bed systems have been proposed for CLC (8) and preferred so far for they combine good heat management and continuous operation. If CLC is used in combination with gas turbines, at increased pressure, the operation of fluidized bed systems is challenging. Process configurations have been compared based on mass- and energy balances and basic design calculations have been carried out based on fluidization engineering methods. It turns out that high gas turbine efficiencies can only be reached if turbine inlet conditions are sufficiently high and relative pressure losses are within reasonable limits. Based on the results of the present work, the efficiencies of CLC based power generation cycles remainsignificantly lower than standard GT-CC efficiencies without CO2 capture. An optimal range of operating conditions can be identified for operation of a pressurized CLC plant with increased efficiency and design considerations for a dual circulating fluidized bed reactor system are reported. Such systems are characterized by solids transport ducts and loop seals of increased dimensions relative to atmospheric pressure systems. Accordingly, also the fluidization gas (steam) demand for loop seals is relatively increased for pressurized systems. The outcome of this work may serve as a general basis for techno-economic evaluation of pressurized CLC systems for power generation. Please click Additional Files below to see the full abstract

"I Keep My Cool" - Künstlerportrait Rebekka Bakken

Folgende Arbeit ist Rebekka Bakken gewidmet: ihrem umfassenden künstlerischen Wirken als Komponistin, Texterin, Sängerin, Bandleader und Produzentin. Sie umfasst Künstlerportrait und Personalstilanalyse der gebürtigen Norwegerin, mit dem Ziel herauszufinden, was das Spezifische ihrer Musik ist. Die Frage nach charakteristischen Merkmalen ist eine Frage nach immer wiederkehrenden, individuellen Mustern in der Arbeit eines Künstlers. Um diese Muster zu erklären wurde ein umfassender Blick auf die Biografie und das Umfeld der Musikerin geworfen, da die Arbeit eines Künstlers in hohem Masse aus dessen Erfahrungen resultiert. Die vorliegende Arbeit gliedert sich in zwei große Teile. Der erste basiert auf den Ergebnissen eines qualitativen Interviews mit der Künstlerin, in dem sie Einblick in ihr privates und musikalisches Leben, sowohl chronologisch (Biografie, Entwicklung) als auch punktuell ausführlich hinsichtlich ihres musikalischen Schaffens und Arbeitens gibt. Auf diesem Wege soll dem Leser ermöglicht werden, durch das Kennen lernen von Rebekkas Zugängen zur Musik, ihre Songs in einen breiteren Kontext einzubetten. Um ihr musikalisches Werk, ihre Songs im Konkreten geht es im zweiten großen Teil der Arbeit. Dieser spannt sich als Analyse quer über ihre drei bisher veröffentlichten Soloalben "The Art Of How To Fall" (2003), „Is That You?“ (2005) und „I Keep My Cool“ (2006). Intention ist es, durch die Methodik des Vergleichs herauszufinden, ob es eine Entwicklung in Rebekka Bakkens musikalischem Schaffen gibt und was das Individuelle, Besondere an ihrer Musik ist.The following work is dedicated to Rebekka Bakken and her comprehensive artistic work as a composer, songwriter, singer, band leader and producer. It covers an artistic portrait and a personal style analysis of the native Norwegian, that aims to determine what is the specific of her music. The determination of charactaristics in music is always about recurring, individual samples in the work of an artist. To explain these samples it needs a comprehensive view on the biography and the surroundings of the artist, since his or her creative work depends to a large extent on the personal experiences. The present work is divided into two parts. The first part is based on the results of a qualitative interview with the artist, in which she gives an idea of her private and musical life, both chronologically (biography and her artistic development) and punctually, explaining her artistic creations to a vast extent. This shall enable the reader to embed her songs in a broader context, as he or she is getting familiar with Rebekka’s approach to music. The second part of the thesis deals with Rebekka’s musical work, particularly her songs. Her three published solo albums "The Art Of How to Fall" (2003), „Is That You?“ (2005) and „I Keep My Cool“(2006) will be analized in this section. The intention is to find out through a methodic comparation, wheter there is a development in Rebekka Bakken’s artistic creations and what is her particular and individual style in music

Performance Characteristics of an 8 MW(th) Combined Heat and Power Plant Based on Dual Fluidized Bed Steam Gasification of Solid Biomass

The work focuses on a dual fluidized bed gasification technology for which a model has been developed and validated accompanying the operation of the 8 MWth biomass combined heat and power plant in Guessing/Austria. The reactor concept is a circulating fluidized bed system with a large steam-fluidized bubbling bed integrated into the solids return loop. The solids circulation rate is shown versus the riser exit velocity. Further, plant performance maps are presented for both electric and heat power output. The water content of the fuel is a major parameter with respect to plant performance. High fuel water content at high gas engine load means high gas velocities in the riser (erosion limit) and higher heat share in the produced energy