The common envelope (CE) interaction is a still poorly understood, yet critical phase of evolution in binary systems that is responsible for various astrophysical classes and phenomena. In this thesis, we use various approaches and techniques to investigate different aspects of this interaction, and compare our models to observations. We start with a semi-empirical analysis of post-CE systems to predict the outcome of a CE interaction. Using detailed stellar evolutionary models, we revise the α equation and calculate the ejection efficiency, α, both from observations and simulations consistently. We find a possible anti-correlation between α and the secondary-to- primary mass ratio, suggesting that the response of the donor star might be important for the envelope ejection. Secondly, we present a survey of three-dimensional hydrodynamical simulations of the CE evolution using two different numerical techniques, and find very good agreement overall. However, most of the envelope of the donor is still bound at the end of the simulations and the final orbital separations are larger than the ones of young observed post-CE systems. Despite these two investigations, questions remain about the nature of the extra mechanism required to eject the envelope. In order to study the dynamical response of the donor, we perform one-dimensional stellar evolution simulations of stars evolving with mass loss rates from 0.001 up to a few M⊙/yr. For mass-losing giant stars, the evolution is dynamical and not adiabatic, and we find no significant radius increase in any case. Finally, we investigate whether the substellar companions recently observed in close orbits around evolved stars could have survived the CE interaction, and whether they might have been more massive prior to their engulfment. Using an analytical prescription for the disruption of gravitationally bound objects by ram pressure stripping, we find that the Earth-mass planets around KIC 05807616 could be the remnants of a Jovian-mass planet, and that the other substellar objects are unlikely to have lost significant mass during the CE interaction. / Graduate

Dynamic binary translation allows us to analyze a program during execution without the need for a compiler or the program's source code. In this work, we present two applications of dynamic binary translation: tracematches and unread memory detection. Libraries are ubiquitous in modern software development. Each library requires that its clients follow certain conventions, depending on the domain of the library. Tracematches are a particularly expressive notation for specifying library usage conventions, but have only been implemented on top of Java. In this work, we leverage dynamic binary translation to enable the use of tracematches on executables, particularly for compiled C/C++ programs. The presence of memory that is never read, or memory writes that are never read during execution is wasteful, and may be also be indicative of bugs. In addition to tracematches, we present an unread memory detector. We built this detector using dynamic binary translation. We have implemented a tool which monitors tracematches on top of the Pin framework along with unread memory. We describe the operation of our tool using a series of motivating examples and then present our overall monitoring approach. Finally, we include benchmarks showing the overhead of our tool on 4 open source projects and report qualitative results.

This thesis presents the ASIC implementation of the RSA algorithm, which is one of the most widely used Public Key Cryptosystems (PKC) in the world. In RSA Cryptosystem, modular exponentiation of large integers is used for both encryption and decryption processes. The security of the RSA increases as the number of the bits increase. However, as the numbers become larger (1024-bit or higher) the challenge is to provide architectures, which can be implemented in hardware, operate at high clock speeds, use a minimum of resources and can be used in real-time applications. In this thesis, a semi-custom VLSI implementation of the RSA Cryptosystem is performed for both 512-bit and 1024-bit processes using 0.35&micro / m AMI Semiconductor Standard Cell Libraries. By suiting the design into a systolic and regular architecture, the broadcasting signals and routing delays are minimized in the implementation. With this regular architecture, the results of 3ns clock period (627Kbps) using 87K gates (8.7mm2 with I/O pads) for the 512-bit implementation, and 4ns clock period (237Kps) using 132K gates (10.4mm2 with I/O pads) for the 1024-bit implementation have been achieved. These results are obtained for the worst-case conditions and they include the post-layout routing delays. The design is also verified in real time using the Xilinx V2000E FPGA on the Celoxica RC1000 Hardware. The 1024-bit VLSI implementation has been sent to IMEC for fabrication as a prototype chip through Europractice Multi-Project Wafer (MPW) runs.

The research builds on and contributes to the representation in landscape, specifically the imaging of active landscapes. Current representational methodologies in landscape architecture have already defined various regimes for the mapping of landscapes. Most of these operate by portraying existing conditions that prioritize visual and formal qualities, displacing objects from their wider context and creating neutral artificialities. Although the discourse of representation has already emphasized the need for appropriate methodologies that engage more closely with the landscape, there has not been an examination and production of techniques that not only privilege the object but also encourage the imaginative conception of experiential phenomena unfolding over time. A convention such as the figure-ground plan is an idealized and dominant technique that expresses an existing condition, without references to evolution or change. This research provides additional insight into the depiction of events that develop over time by reconceptualising

Thesis (Ph.D.) -- McMaster University, 1997. / Includes bibliographical references (leaves 205-209). Also available via World Wide Web.

Thesis (M.S.)--University of Nevada, Reno, 2008. / "August 2008." Includes bibliographical references (leaves 52-55). Online version available on the World Wide Web.

Thesis (M. Sc.)--Carleton University, 2004. / Includes bibliographical references (p. 38-39). Also available in electronic format on the Internet.

Thesis (Ph.D.). / Written for the Dept. of Physics. Title from title page of PDF (viewed 2009/06/11). Includes bibliographical references.

Thesis (Ph.D.)--University of Melbourne, Dept. of Computer Science and Software Engineering, 2009. / Typescript. Includes bibliographical references (p. 209-228)

Στην εργασία αυτή προσπαθήσαμε να διερευνήσουμε τις μαθησιακές επιδράσεις κατάλληλα κατασκευασμένου λογισμικού με χώρο αναφοράς το Δυαδικό Σύστημα. Το λογισμικό κατασκευάστηκε σε HTML και για τις ασκήσεις χρησιμοποιήθηκε το λογισμικό ProProfs. Παράλληλα εξετάσαμε τις δυνατότητες που προσφέρουν σύγχρονα διαδικτυακά εργαλεία στη δημιουργία λογισμικού και ιδιαίτερα ασκήσεων συνδεδεμένων με ιστοσελίδες πληροφοριών. Τα αποτελέσματα έδειξαν ότι το λογισμικό βοήθησε το δείγμα των 31 μαθητών, που χρησιμοποιήθηκε στην έρευνα, να μάθουν καλύτερα τις έννοιες του περιεχομένου. Σε αυτό βοήθησαν διάφοροι παράγοντες, οι οποίοι αναλύονται στην εργασία. / In this study we tried to investigate the learning effects of a properly engineered software based on binary system. The software built into HTML and for the exercises ProProfs software was used. Furthermore, we examined the potential of modern online tools to create software and specially exercises linked to information pages. The results showed that the software helped the sample of 31 students that was used in the study, to learn better the concepts of the content. In this helped a number of factors that are analyzed in the study.