Generating Circuit Tests by Exploiting Designed Behavior

This thesis describes two programs for generating tests for digital circuits that exploit several kinds of expert knowledge not used by previous approaches. First, many test generation problems can be solved efficiently using operation relations, a novel representation of circuit behavior that connects internal component operations with directly executable circuit operations. Operation relations can be computed efficiently by searching traces of simulated circuit behavior. Second, experts write test programs rather than test vectors because programs are more readable and compact. Test programs can be constructed automatically by merging program fragments using expert-supplied goal-refinement rules and domain-independent planning techniques

Extended Duration Simulation and Testing of Cellular and Decellularised Heart Valve Roots

Heart valve disease can affect people of all ages, and can be treated by either valve repair or valve replacement surgery. Currently available replacement heart valves, including mechanical prostheses, bioprostheses, autografts and allografts improve patient survival and quality of life, but have limitations. Key limitations include the risk of immunological reaction and the lack of growth potential and regeneration, which is of particular importance in young patients. To address these limitations, low concentration sodium dodecyl sulphate (SDS) decellularised human aortic, human pulmonary, porcine aortic and porcine pulmonary heart valve roots have been developed. Decellularisation of allografts would potentially reduce the risk of immunological reaction, and the development of a decellularised porcine pulmonary heart valve root would potentially provide an option for right ventricular outflow reconstruction in younger patients who have undergone the Ross Procedure. Before moving to clinical trials, the functional performance of decellularised heart valve roots needs to be pre-clinically assessed appropriately to determine mechanical safety. Whilst there are recommended test methods in place for the in vitro functional performance assessment of newly manufactured and modified surgical replacement heart valves, they need to be optimised or replaced with novel methods suitable for decellularised heart valve roots, due to their time dependent viscoelastic properties. The main aim of this research was to optimise in vitro hydrodynamic and biomechanical performance test methods and develop a novel real time fatigue test method for biological heart valve roots. The secondary aim was to apply the developed in vitro test methods to cellular and decellularised (human and porcine) heart valve roots to evaluate the effect of decellularisation, prior to the decellularised heart valve roots being implanted in patients for clinical trials. In collaboration with NHS Blood and Transplant, Tissue and Eye Services, in vitro biomechanical and hydrodynamic performance of decellularised human aortic and pulmonary heart valve roots was evaluated for the first time in this research. This research determined that the hydrodynamic and functional biomechanical performance of human aortic and pulmonary heart valve roots was not affected by decellularisation treatment. Decellularisation, however, significantly altered some of the directional material properties of pulmonary and aortic heart valve root leaflets. To support clinical translation of decellularised porcine pulmonary heart valve roots, material properties of pulmonary heart valve roots was evaluated following 12 months implantation in sheep. In addition, the effect of the processing steps of cryopreservation and decellularisation on the material properties of porcine pulmonary heart valve roots was investigated. Cryopreservation was shown not to alter the material properties of cellular porcine pulmonary heart valve roots, however, decellularisation did have an effect on the material properties of the porcine pulmonary heart valve root wall. Following 12 months implantation in sheep, the decellularised porcine pulmonary heart valve root wall and leaflets showed a trend for decreasing stiffness and strength; becoming more like the cellular ovine, potentially indicating constructive remodelling. A novel method was developed to investigate the real time fatigue of biological heart valve roots, which was then applied to porcine cellular aortic heart valve roots and porcine decellularised aortic heart valve roots at 120 bpm under physiological cyclic pressures for a maximum of 1.2 million cycles. The results showed no fatigue difference between the cellular and decellularised heart valve roots. Overall, a portfolio of in vitro pre-clinical test methods were developed, optimised and applied to assess the hydrodynamic, biomechanical and fatigue performance of biological heart valve roots including decellularised human and porcine heart valve roots. The in vitro pre-clinical test methods developed in this study will lead to the refinement of in vivo large animal studies and revision of international standards; and the data will help in the development of the next generation of replacement biological heart valve roots, such as decellularised heart valve roots

An integrated approach to testing complex systems

Die steigende Komplexität heutiger Testszenarien für komplexe Systeme erfordert einen ganzheitlichen und offenen Ansatz zur Verwaltung des gesamten Testprozesses. Eine Anwendung klassischer modellbasierter Testansätze, in denen eine präzise und vollständige formale Spezifikation des Systems als Referenz zur automatischen Testfallgenerierung dient, ist in der Praxis nicht möglich.Gründe dafür liegen zum einen im Fehlen einer adäquaten formalen Spezifikation. Komplexe Systeme sind aus verschiedenen Komponenten zusammengesetzt, teils Hardware teils Software und oft auch aus Fremdkomponenten. Dadurch ist es inhärent unrealistisch anzunehmen, dass eine solche formale Spezifikation a priori existiert. Andererseits muss eine ausgereifte Testumgebung die Ausführung von verteilten Testfällen unterstützen, denn die Test-Stimuli und -Beobachtungen können an verschiedenen Teilkomponenten des Systems stattfinden.Diese Arbeit präsentiert einen neuartigen Ansatz für das ganzheitliche Testen komplexer Systeme. Der Ansatz stellt eine 'grobgranulare' Testumgebung zur Verfügung, die mittels einer komponentenbasierten Testfallbeschreibung realisiert ist. Die Basis dafür bildet eine Bibliothek von elementaren, aber intuitiv verständlichen Testfallfragmenten. Die Beziehungen zwischen den Testfallfragmenten sind orthogonal. Dies ermöglicht eine Testbeschreibung und -ausführung, die durch formale Verifikationsmethoden ergänzt wird. Hierdurch können die Testfallbeschreibungsaspekte von Experten des Systems und der verwendeten Testwerkzeuge zu Experten der Systemlogik verschoben werden. Der Ansatz wird durch verschiedene, industrielle Fallstudien in zwei verschiedenen Bereichen illustriert: Computer Telephony Integrations Lösungen und Webbasierte Applikationen. Als Erweiterung des ganzheitlichen Testansatzes wird ein Algorithmus zur a posteriori Generierung approximativer Modelle für komplexe Systeme vorgestellt. Dafür wurde ein bekannter Algorithmus aus dem Maschinellen Lernen an applikationsbedingte Charakteristika angepasst, wie Präfix-Abgeschlossenheit,Input-Determinismus, sowie Unabhängigkeit und Symmetrien zwischen Aktionen. Die resultierenden Modelle können zwar nie exakt sein, in dem Sinne, dass sie das vollständige und korrekte Systemverhalten abbilden. Dennoch können sie von hohem praktischen Nutzen sein, da sie das gesammelte Wissen über das System in einer konsistenten Beschreibungsform repräsentieren.The increasing complexity of today's testing scenarios for complex systems demands an integrated, open, and flexible approach to support the managementof the overall test process. ``Classical'' model-based testing approaches, where a complete and precise formal specification serves as a reference for automatic test generation, are often impractical. Reasons are, on the one hand, the absence of a suitable formal specification. As complex systems are composed of several components, either hardware or software, often pre-built and third party, it is unrealistic to assume that a formal specification exists a priori. On the other hand, a sophisticated test execution environment is needed that can handle distributed test cases. This is because the test actions and observations can take place on different subsystems of the overall system. This thesis presents a novel approach to the integrated testing of complex systems. Our approach offers a coarse grained test environment, realized in terms of a component-based test design on top of a library of elementary but intuitively understandable test case fragments. The relations between the fragments are treated orthogonally, delivering a test design and execution environment enhanced by means of light-weight formal verification methods. In this way we are able to shift the test design issues from total experts of the system and the used test tools to experts of the system's logic only. We illustrate the practical usability of our approach by means of industrial case studies in two different application domains: Computer Telephony Integrated solutions and Web-based applications. As an enhancement of our integrated test approach we provide an algorithm for generating approximate models for complex systems a posteriori. This is done by optimizing a standard machine learning algorithm according to domain-specific structural properties, i.e. properties like prefix-closeness, input-determinism, as well as independency and symmetries of events. The resulting models can never be exact, i.e. reflect the complete and correct behaviour of the considered system. Nevertheless they can be useful in practice, to represent the cumulative knowledge of the system in a consistent description

Computerized project management: how to use a Macintosh to improve manager productivity.

http://archive.org/details/computerizedproj00scirN

Creep behaviour of the ternary lead-free solder alloy : Sn-3.8wt.%Ag-0.7wt.%Cu

Electronic equipment is facing the challenge of both miniaturisation and the need to replace lead in interconnections. In service, interconnections generally fail by thermomechanical fatigue, and this behaviour is strongly affected by the creep process. This thesis examines the creep behaviour of a popular lead-free replacement alloy, Sn-3.8wt.%Ag-0.7wt%Cu (Sn-Ag-Cu), in joint and bulk form. Experimental work involved the determination of the creep properties of this alloy at various temperatures, over a range of stresses. Over the regions tested, the creep behaviour is best described by the Norton power law constitutive equation. The stress exponent for bulk Sn-Ag-Cu ranged between 10 and 18 (at 125 to -lOoC respectively) and indicates that a dispersion-strengthened mechanism is dominant in the creep process. The activation energy for creep in the bulk Sn-Ag-Cu is approximately 120kJ/moi and falls in the region similar to that observed for the self-diffusion of tin. In joint form the stress exponent is greater than 10 at high stresses but a change in mechanism is indicated at lower stress where the creep exponent falls to 3. The activation energy for creep in Sn-Ag-Cu when used in joint form is approximately 70kJ/moi and falls in the region similar to that observed for the short-circuit diffusion of tin. Results obtained from the ternary alloy were directly compared to those from Sn- 37wt.%Pb (Sn-Pb) and other prospective lead-free alloys in bulk form. The creep resistance of the ternary lead-free alloy at 75°C is superior to the conventional Sn-Pb alloy and the possible replacement alloys (tin-copper and tin-silver). This superiority is retained when tested at similar homologous temperatures. However, the Sn-3.8Ag- O.7Cu alloy is less ductile but generally possesses strains to failure above 10 percent in comparison to the 25 to 50 percent ductility of Sn-Pb

Characterization of Antibody Responses to Virus Infections in Humans

This book focuses on fundamental and applied research on humoral immune responses to viral infections in humans. The comprehensive study of antibody response is critical for the development of diagnostic tools, vaccines, and immunotherapeutics against life-threatening viral infections. Special attention is given to serological surveillance and characterization of virus-neutralizing antibodies

Mining Technologies Innovative Development

The present book covers the main challenges, important for future prospects of subsoils extraction as a public effective and profitable business, as well as technologically advanced industry. In the near future, the mining industry must overcome the problems of structural changes in raw materials demand and raise the productivity up to the level of high-tech industries to maintain the profits. This means the formation of a comprehensive and integral response to such challenges as the need for innovative modernization of mining equipment and an increase in its reliability, the widespread introduction of Industry 4.0 technologies in the activities of mining enterprises, the transition to "green mining" and the improvement of labor safety and avoidance of man-made accidents. The answer to these challenges is impossible without involving a wide range of scientific community in the publication of research results and exchange of views and ideas. To solve the problem, this book combines the works of researchers from the world's leading centers of mining science on the development of mining machines and mechanical systems, surface and underground geotechnology, mineral processing, digital systems in mining, mine ventilation and labor protection, and geo-ecology. A special place among them is given to post-mining technologies research