In this dissertation, I present a set of novel constraint-based thread-modular abstract-interpretation techniques for static analysis of concurrent programs. Specifically, I integrate a lightweight constraint solver into a thread-modular abstract interpreter to reason about inter-thread interference more accurately. Then, I show how to extend the new analyzer from programs running on sequentially consistent memory to programs running on weak memory. Finally, I show how to perform incremental abstract interpretation, with and without the previously mentioned constraint solver, by analyzing only regions of the program impacted by a program modification. I also demonstrate, through experiments, that these new constraint-based static analyzers are significantly more accurate than prior abstract interpretation-based static analyzers, with lower runtime overhead, and that the incremental technique can drastically reduce runtime overhead in the presence of small program modifications. / Ph. D. / Software touches nearly every aspect of our lives, from smartphones, personal computers, and websites, to airplanes, cars, and medical equipment. Due to its ubiquity, we would like software in our lives to operate correctly, that is, without any unintended side effects, or freezes. This dissertation presents a new technique to automatically analyze a piece of software and determine if it runs as intended. We focus particularly on software where multiple entities run simultaneously, and thus can interact in many ways. Our automated analysis gives software developers high assurance that the software will always perform correctly, and thus never have any unexpected issues.

Integrated circuits have traveled a long way from being a general purpose microprocessor to an application specific circuit. It has become an integral part of the modern era of technology that we live in. As the applications and their complexities are increasing rapidly every day, so are the sizes of these circuits. With the increase in the design size, the associated testing effort to verify these designs is also increased. The goal of this thesis is to leverage some of the static analysis techniques to reduce the effort of testing and verification at the register transfer level. Studying a design at register transfer level gives exposure to the relational information for the design which is inaccessible at the structural level. In this thesis, we present a way to generate a Data Dependency Graph and a Control Flow Graph out of a register transfer level description of a circuit description. Next, the generated graphs are used to perform relation mining to improve the test generation process in terms of speed, branch coverage and number of test vectors generated. The generated control flow graph gives valuable information about the flow of information through the circuit design. We are using this information to create a framework to improve the branch reachability analysis mainly in terms of the speed. We show the efficiency of our methods by running them through a suite of ITC'99 benchmark circuits. / Master of Science / In this era of modern technology, digital circuits and microprocessors have become an unavoidable part of everyone’s life. The role of these circuits is becoming more and more critical as they are running a lot of critical services for us. Testing and verifying the design has been a very important aspect in the designing of these circuits. With the increasing number of its applications and the advancement of the technology, the size and complexity of the designs have also increased. It has imposed a need to test the design at a stage when it is easy to test and easy to fix also. There have been a lot of research focused on automatically generating the test pattern at an early stage of development and the work presented in this thesis is an effort to take it one step further in the process. The method proposed in this work is taking advantage of the fact that a design speaks for itself and can give a lot of information if looked at carefully. We present a way to extract important information about the data dependency and its flow through the design. With the help of this information, we are generating relations between the design elements which can aid the test generation process to achieve its goal more efficiently. We are also using this information to help in proving that some part of the design is inaccessible. We show the efficiency of our method by running them through benchmark designs.

Despite decades of research aiming to ameliorate the difficulties of creating software, programming still remains an error-prone task. Much work in Computer Science deals with the problem of specification, or writing the right program, rather than the complementary problem of implementation, or writing the program right. However, many desirable software properties (such as portability) are obtained via adherence to coding standards, and therefore fall outside the remit of formal specification and automatic verification. Moreover, code inspections and manual detection of standards violations are time consuming. To address these issues, this thesis describes Exstatic, a novel framework for the static detection of coding standards violations. Unlike many other static checkers Exstatic can be used to examine code in a variety of languages, including program code, in-line documentation, markup languages and so on. This means that checkable coding standards adhered to by a particular project or institution can be handled by a single tool. Consequently, a major challenge in the design of Exstatic has been to invent a way of representing code from a variety of source languages. Therefore, this thesis describes ICODE, which is an intermediate language suitable for representing code from a number of different programming paradigms. To substantiate the claim that ICODE is a universal intermediate language, a proof strategy has been developed: for a number of different programming paradigms (imperative, declarative, etc.), a proof is constructed to show that semantics-preserving translation exists from an exemplar language (such as IMP or PCF) to ICODE. The usefulness of Exstatic has been demonstrated by the implementation of a number of static analysers for different languages. This includes a checker for technical documentation written in Javadoc which validates documents against the Sun Microsystems (now Oracle) Coding Conventions and a checker for HTML pages against a site-specifc standard. A third system is targeted at a variant of the Python language, written by the author, called python-csp, based on Hoare's Communicating Sequential Processes.

<p>This thesis studies the effect of-floor slabs on the static and dynamic behaviour of the shear wall structure. A single component has been analysed using the 'Matrix Transfer' technique along with Vlaspv's thin walled elastic beam theory. Experimental verification was done on a small scale plexiglas eight storey model in the form of a channel section for both static and dynamic loading. The thesis also deals with the ·analysis of the nonplanar shear walls coupled through floor beams subjected to static loading. The continuum approach along with Vlasov's theory h&s been used in the analysis. Experimental verification was done on a small scale plexiglas model in the form of two equal angles connected by eight floor beams at equal spacing.</p> / Thesis / Master of Engineering (ME)

No description available.

Master of Science / Department of Computing and Information Sciences / John M. Hatcliff / There are a number of network situations where different networks have different security policies and still need to share information. While it is important to allow some data to flow between the two networks, it is just as important that they don't share any data that violates the respective security policies of the networks. Constraints on data sharing are often phrased in terms of classification levels of data (e.g. top secret, secret, public). They might also be stated in terms of the contents of the data (e.g. are there military base names, is the location correct). The software and hardware that works to solve these problems is called Cross Domain Solutions (CDS). There are a variety of hardware platforms capable of implementing CDS. These platforms are all configured in different ways and they are often proprietary. Not only are there a number of platforms on the market, many are difficult to understand, verify, or even specify. The Guardol project provides an open, non-proprietary, and domain-specific language for specifying CDS security policies and implementing CDS. Guardol is designed to be easy to understand and verify. This thesis describes the design and implementation of primary Guardol components. It includes a description of the Eclipse GUI plug-ins that have been developed for the project as well as a description of new formal analyses and translations that have been developed for the language. The translation is used to plug into external tools for model checking and the analyses help to make the translation clean and efficient. The analyses are also useful tools to help make the use of Guardol easier for developers.

Master of Science / Department of Computing and Information Sciences / Robby / Software defects cost our economy a significant amount of money. Techniques that can detect software defects before the software begins its operational life-cycle are therefore highly valuable. Unfortunately, as software is becoming more ubiquitous, it is also becoming more complex. Static analysis of software can be computationally intensive, and as software becomes more complex the computational demands of any analysis applied increase also. While increasingly complex software entails more computationally demanding analysis, the computational capabilities provided by computers have increased exponentially over the last half century of computing. Historically, the increase in computational capability has come by increasing the clock speed of the computer's central processing unit (CPU.) In the last several years, engineering limitations have made it increasingly difficult to build CPU's with progressively higher clock speeds. Instead, processor manufacturers now provide increased capability in the form of `multi-core' CPUs; where each processor package contains two or more processing units, enabling that processor to execute more than one task concurrently. This thesis describes the design and implementation of a parallel version of symbolic execution which can take advantage of modern multi-core and multi-processor systems to complete analysis of software units in a reduced amount of time.

Published Article / Service-learning is a relatively new teaching and learning method which has been implemented with success at national and international tertiary institutions. The identification and elucidation of the terms and processes that delineate the dynamic character of service-earning satisfactorily pose a particular challenge to researchers within the service-learning environment. Since a degree of confusion still exists amongst researchers and decision-makers regarding the distinguishing characteristics of service-learning as opposed to other forms of experiential learning, it is essential to indicate the specific position of service-learning within this environment.

The aim of this thesis is to explore methods to incorporate external effects on decision making of public health programmes in a UK setting, using smoking cessation as an example. The National Institute for Health and Clinical Excellence (NICE) methodological guidance for evaluating public health programmes is missing the incorporation of external effects. Therefore there is a need for considering their incorporation in such evaluations and to assess what are the appropiate methods to do so. Smoking cessation is an example where epidemiological evidence of external effects exists but has not generally been incorporated into economic evaluation. This thesis therefore focused in measuring the impact, in terms of costs and QALYs lost, of the incorporation of passive smoking, smoking during pregnancy and transmission of smoking behavior into economic evaluation of smoking cessation programmes previously developed to inform policy. A static Markov model is used to incorporate passive smoking and smoking during pregnancy, whereas transmisison of smoking behaviour is incorporated through a dynamic model. The findings show that some external effects can be incorporated without a system dynamic model, when this does occur, a static Markov model may be used to account for external effects in economic evaluation. Sometimes, to incorporate external effects, the model needs a change of population. Because smoking cessation interventions are generally highly cost-effective, the incorporation of external effects does not appear to change policy decisions, but there is a clear impact on the magnitude of the ICER. Passive smoking and smoking during pregnancy have higher impact in terms of costs and QALYs lost than transmission of smoking behaviour. Our discussion considers the validity of the methods used; how much the decision making process would be affected considering or not external effects on economic evaluation of smoking cessation interventions; and other valuation approaches for external effects, such as contingent valuation.

The objectives of this thesis comprise of overcoming the challenges in designing lightweight welded structures such as material selection, choice of fatigue design methods, and increased performance by using improvement techniques. Material selection of welded joints is dependent on the filler and base material strengths. Partially and fully penetrated cruciform and butt welded joints were designed in under-matching, matching, and over-matching filler materials. Base material steel grades were S600MC, S700MC, and S960. Current design rules are developed for welds in steel up to yield strength of 700MPa. Therefore, design rules in Eurocode3, AWS d1.1, and BSK 07 were verified and recommendations for developing design rules for designing welded joints in S960 were concluded. Numerical methodology for estimating static strength of welded joints by simulating heat affected zone was also developed. Another objective of the thesis work was to overcome the challenges in selection of fatigue design methods. The available design curves in standards are developed for uniaxial stress states, however, in real life the welds in mechanical structures are subjected to complex multiaxial stress states. Furthermore; weld toe failures are frequently investigated, weld root failures are seldom investigated. Therefore, in this work the multiaxial fatigue strength of welded joints failing at the weld root was assessed using experiments and various nominal and local stress based approaches. Butt welded joints with different weld seam inclinations with respect to applied uniaxial loading were designed to assess the root fatigue strength in higher multiaxial stress ratio regime. The fatigue strength of multi-pass tube-to-plate welded joints subjected to internal pressure only and combined internal pressure and torsion in and 90° out of phase loading was also investigated. Test data generated in this thesis was evaluated together with the test data collected from literature. Last objective of the thesis included investigation of the increased performance in fatigue strength by post weld treatment methods such as HFMI. The behavior of residual stresses induced due to HFMI treatment during fatigue loading is studied. Numerical residual stress estimations and residual stress relaxation models are developed and the effect of various HFMI treatment process parameters and steel grade on the induced residual stress state is investigated. Specimens studied were non load carrying longitudinal attachments and simple plates. Residual stresses in both test specimens were measured using X-ray diffraction technique. / <p>QC 20170206</p>