The use of security assurance cases (security cases) to provide evidence-based assurance of security properties in software is a young field in Software Engineering. A security case uses evidence to argue that a particular claim is true. For example, the highest-level claim may be that a given system is sufficiently secure, and it would include sub claims to break that general claim down into more granular, and tangible, items - such as evidence or other claims. Random negative testing (fuzz testing) is used as evidence to support security cases and the assurance they provide. Many current approaches apply fuzz testing to a target system for a given amount of time due to resource constraints. This may leave entire sections of code untouched [60]. These results may be used as evidence in a security case but their quality varies based on controllable variables, such as time, and uncontrollable variables, such as the random paths chosen by the fuzz testing engine. This thesis presents Hermes, a proof-of-concept fuzz testing framework that provides improved evidence for security cases by automatically targeting problem sections in software and selectively fuzz tests them in a repeatable and timely manner. During our experiments Hermes produced results with comparable target code coverage to a full, exhaustive, fuzz test run while significantly reducing the test execution time that is associated with an exhaustive fuzz test. These results provide a targeted piece of evidence for security cases which can be audited and refined for further assurance. Hermes' design allows it to be easily attached to continuous integration frameworks where it can be executed in addition to other frameworks in a given test suite. / Graduate / 0984 / cshortt@uvic.ca

Membrane chromatography was investigated as an alternative method to packed-bed chromatography for protein recovery. The purification of lysozyme from egg white with Natrix adseptTM weak cation-exchange membranes was investigated under two different binding configurations: (1) a non-flow, static set-up with variable pH and sodium chloride (NaCl) concentrations during the binding and elution steps, and (2) a dynamic, cross-flow set-up with recycle at pH 7.5 and no NaCl addition during binding. The weak cation-exchange membrane consisted of a carboxylic acid-based, environmentally-responsive hydrogel layer bonded to a polymer matrix. Lysozyme was chosen to illustrate protein-membrane binding interactions due to its well-characterized nature and positive surface charge over a large pH range. For the static binding set-up, two sources of lysozyme were studied: pure lysozyme and egg whites treated with 60 % (v/v) ethanol (ESEW). Elution of bound protein was performed with 1 M NaCl under two pH strategies: binding and elution at a constant pH, and binding at pH 4.5 and variable elution pH. The highest maximum total protein binding capacity for pure lysozyme and ESEW was observed at pH 4.5 with no NaCl addition; however, poor total protein and lysozyme activity recovery were achieved during separation. As well, other egg white proteins, such as ovomucoid, were observed to bind to the membrane surface at pH 4.5, despite possessing similar charge polarity to the anionic membrane surface, indicating a non-electrostatic binding mechanism during operation below the membrane’s pKa (4.7). Based on the conditions tested, the highest total protein and lysozyme activity recovery was demonstrated for the separation of lysozyme from ESEW at pH 7.5 binding and elution and no NaCl addition. In the dynamic binding study, very high pure lysozyme dynamic binding capacity was achieved at 10 % breakthrough (167.3 mg/ml membrane for a 0.35 mg/ml lysozyme solution). The lysozyme dynamic binding capacity was 2.2 times greater than the static binding capacity under similar conditions, significantly higher than published results for other cation-exchange membranes. The separation of lysozyme from four lysozyme sources was tested: pure lysozyme, ESEW, and aqueous egg whites with (ASEW) and without (AEW) 100 mM NaCl. The highest lysozyme activity recovery during separation and lysozyme purity was achieved from the ESEW feed. Lysozyme separation from aqueous egg whites was not as effective, likely due to a high concentration of negatively-charged protein impurities fouling the surface of the membrane. Competitive binding to the membrane limited lysozyme binding and reduced the purity of the recovery elution stream. The application of feed-side pressure during the separation of ESEW produced a high purity, high recovery lysozyme elution stream with a significant reduction in processing time; however, protein aggregates were observed to form on the membrane surface, limiting the applicability of high-pressure operation and reducing protein functionality in the elution stream. The weak cation-exchange membrane system was shown to successfully separate out a target protein from a low concentration protein mixture through electrostatic interactions, and may be further applied to other protein systems.

In this thesis, autopilots are developed for missiles with moderate dynamics and stationary targets. The aim is to use the designs in real applications. Since the real missile model is nonlinear, a linearization process is required to get use of systematic linear controller design techniques. In the scope of this thesis, the linear quadratic full state feedback approach is applied for developing missile autopilots. However, the limitations of measurement systems on the missiles restrict the availability of all the states required for feedback. Because of this fact, the linear quadratic design will be approximated by the use of projective control theory. This method enables the designer to use preferably static feedback or if necessary a controller plus a low order compensator combination to approximate the full state feedback reference. Autopilots are checked for the validity of linearization, robust stability against aerodynamic, mechanical and measurement uncertainties.

A materially non-linear layered beam super element is developed for the analysis of RC beams and columns strengthened by externally bonded steel/FRP plates. The elasto-plastic behavior of RC member is incorporated by its internally generated or externally supplied moment-curvature diagram. The steel plate is assumed to be elasto-plastic and the FRP laminate is assumed to behave linearly elastic up to rupture. The thin epoxy layer between the RC member and the externally bonded lamina is simulated by a special interface element which allows for the changing failure modes from steel plate yielding/FRP plate rupture to separation of the bonded plates as a result of bond failure in the epoxy layer. An empirical failure criterion based on test results is used for the epoxy material of the interface. The most critical aspect of such applications in real life frame structures is the anchorage conditions at the member ends and junctions. This has direct influence on the success and the effectiveness of the application. Therefore, a special corner piece anchorage element is also considered in the formulation of the joint super element, which establishes the fixity and continuity conditions at the member ends and the joints.

This study investigates the relevance of dynamic traffic assignment models under uncertainty. In the last years researchers have dealt with advanced traffic control systems since road provision is not regarded as a proper solution to relieve congestion. Dynamic assignment which is an essential component of investment planning is regarded as a new research area in the field of urban transportation. In this study the performance of dynamic traffic assignment method, which incorporates time dependent flow, is compared with that of static model. Research outcomes showed that dynamic assignment method provides more reliable outcomes in predicting traffic flow / therefore its solution algorithm is integrated to conventional four staged model. Literature survey showed that researches have hot provided an appropriate framework for transforming networks. This study investigates travel demand variations in a dynamic city and discuses possible strategies to respond dynamic and uncertain properties of individuals&rsquo / travel behavior. Research findings showed that both external and internal uncertainties have significant influences on reliability of the model. Recommended procedure aims reducing uncertainty in order to improve reliability of model. Finally, the relevancy of the problem and the applicability of recently developed methods are discussed in Ankara case.

This study investigates software development process improvement approaches. In particular, the static process evaluation methodology proposed by S. G&uuml / ceglioglu is applied on the requirements analysis and validation process applied in Project X in MYCOMPANY and an improved process is proposed. That methodology is an extension of the ISO/IEC 9126 approach for software quality assessment, and is based on evaluating a set of well-defined metrics on the static model of software development processes. The improved process proposed for Project X is evaluated using G&uuml / ceglioglu&rsquo / s methodology. The applied and improved process measurement results compared to determine if the improved process is successful or not.

Numerical methods of designing control systems are currently an active area of research. Convex optimization with linear matrix inequalities (LMIs) is one such method. Control objectives like minimizing the H_2, H_infinity norms, limiting the actuating effort to avoid saturation, pole-placement constraints etc., are cast as LMIs and an optimal feedback controller is found by making use of efficient interior-point algorithms. A full-state feedback controller is designed and implemented in this thesis using this method which then forms the basis for designing a static output feedback (SOF) controller. A profile was generated that relates the change in the SOF control gain matrix required to keep the same value of the generalized H_2 norm of the transfer function from the road disturbance to the actuating effort with the change in the sprung mass of the quarter-car system. The quarter-car system makes use of a linear brushless permanent magnet motor (LBPMM) as an actuator, a linear variable differential transformer (LVDT) and two accelerometers as sensors for feedback control and forms a platform to test these control methodologies. For the full-state feedback controller a performance measure (H_2 norm of the transfer function from road disturbance to sprung mass acceleration) of 2.166*10^3 m/s^2 was achieved ensuring that actuator saturation did not occur and that all poles had a minimum damping ratio of 0.2. The SOF controller achieved a performance measure of 1.707*10^3 m/s^2 ensuring that actuator saturation does not occur. Experimental and simulation results are provided which demonstrate the effectiveness of the SOF controller for various values of the sprung mass. A reduction in the peak-to-peak velocity by 73 percent, 72 percent, and 71 percent was achieved for a sprung mass of 2.4 kg, 2.8 kg, and 3.4 kg, respectively. For the same values of the sprung mass, a modified lead-lag compensator achieved a reduction of 79 percent, 77 percent and, 69 percent, respectively. A reduction of 76 percent and 54 percent in the peak-to-peak velocity was achieved for a sprung mass of 6.0 kg in simulation by the SOF controller and the modified lead-lag compensator, respectively. The gain of the modified lead-lag compensator needs to be recomputed in order to achieve a similar attenuation as that of the SOF controller when the value of the sprung mass is changed. For a sprung mass of 3.4 kg and a suspension spring stiffness of 1640 N/m the peak-to-peak velocity of the sprung mass was attenuated by 42 percent.

Many intra-tectonic plate regions are considered to have low to moderate seismic risk. However, devastating earthquakes can occur in these regions and result in high consequences in terms of casualties and damage. Non-ductile detailing practice employed in these structures make them prone to potential damage and failure during an earthquake. Furthermore, the use of infill walls is a divisive issue as on positive side dual wall-frame systems have beneficial effects related to strength, stiffness, and ductility. However, if not designed properly infill wall can also lead to undesirable structural failures of complete wall frame system. Although, there has been significant amount of international research in this area, it is worth noting that very little research exists for Australian frames. This thesis presents the experimental and analytical research conducted at The University of Adelaide to gain some insight into the behaviour of typically detailed Australian reinforced concrete frames subjected to ground motions. The main objectives of this research were (1) to investigate the behaviour of non-seismically designed reinforced concrete frames under a 500-YRP earthquake; (2) to determine the different magnitudes of earthquake (YRP) that are likely to cause excessive drifts in or collapse of gravity-load-designed reinforced concrete frames and (3) to investigate the effect of infill walls on the moment-resisting frames subjected to seismic loads. The experimental program consisted of earthquake simulation tests on a 1/5 scale model of a 3-storey reinforced concrete frame and four ½-scale reinforced concrete brick infilled frame specimens subjected to quasi-static cyclic loading. The analytical study included static pushover and non-linear dynamic analyses of the 3-, 5- and 12-storey reinforced concrete frames. From the overall performance of gravity-load-designed bare reinforced concrete frames considered in this study, it was concluded that the non-seismically designed frames appear to be capable of resisting a “design magnitude earthquake” (i.e., 500- YRP) in low earthquake hazard regions. However, their behaviour under more severe earthquakes (e.g. a 2500-YRP earthquake) is questionable. Perhaps the earthquake design requirements should consider as an alternative the ‘collapse prevention’ limit state for longer return period earthquakes, of the order of 2000–2500-YRP. The experimental research on reinforced concrete infilled frame indicated that the infill wall does not adversely effect the in plane ultimate strength, stiffness, and ductility of the bare reinforced concrete frame. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1372229 / Thesis (M.Eng.Sc.) - University of Adelaide, School of Civil, Environmental and Mining Engineering, 2009

Thesis (Ph. D.)--University of Alabama at Birmingham, 2007. / Title from first page of PDF file (viewed Feb. 17, 2009). Includes bibliographical references.

Η εργασία πραγματεύεται την απόσβεση των ταλαντώσεων ισχύος με χρήση του εξελιγμένου ελεγχόμενου αντισταθμιστή σειράς. / SSSC is used in order to improve power system oscillation stability and some useful analytical conclusions are presented.