Modelling & Improving Flow Establishment in RSVP

RSVP has developed as a key component for the evolving Internet, and in particular for the Integrated Services Architecture. Therefore, RSVP performance is crucially important; yet this has been little studied up till now. In this paper, we target one of the most important aspects of RSVP: its ability to establish flows. We first identify the factors influencing the performance of the protocol by modelling the establishment mechanism. Then, we propose a Fast Establishment Mechanism (FEM) aimed at speeding up the set-up procedure in RSVP. We analyse FEM by means of simulation, and show that it offers improvements to the performance of RSVP over a range of likely circumstances

Transition to High-Speed Networks — SuperJANET Experience

For the time being, trials to establish the Information Superhighway are booming. In Britain, JANET has provided wide-area computer communication, and has recently been upgraded to SuperJANET, increasing the throughput by a factor of five to 10 Mb/s, with some sites having PDH access at n × 34 Mb/s. In this paper, the technological changes seen from a user perspective are addressed. A multimedia communication-based distance learning project on SuperJANET is introduced and the network performance measurements for this project are presented. These measurements suggest the employment of reservation protocol and packet scheduling. We also provide a mechanism for on-the-fly playback of continuous media

REDO RSVP: Efficient Signalling for Multimedia in the Internet

Alarming reports of performance and scalability problems associated with per-flow reservations, have led many to lose belief in RSVP and the Integrated Services Architecture that relies on it. Because we are convinced of the need for some form of resource reservation, to support multimedia communications in the Internet, we have set about trying to improve RSVP. By careful study of the protocol, we have identified areas for improvement, and propose REDO RSVP, a reduced overhead version that includes a fast establishment mechanism (FEM). In this paper we describe the rationale for REDO RSVP and present a detailed analysis of its features and operations. We also analyse REDO RSVP by means of simulations, and show that it offers improvements to the performance of RSVP

The Vulnerability Assessment and Penetration Testing of Two Networks

Vulnerability assessments and penetration testing are two approaches available for use by internet security practitioners to determine the security posture of information networks. By assessing network vulnerabilities and attempting to exploit found vulnerabilities through penetration testing security professionals are able to evaluate the effectiveness of their network defenses by identifying defense weaknesses, affirming the defense mechanisms in place, or some combination of the two. This project is a discussion of the methods and tools used during the vulnerability assessment and penetration testing, and the respective test results of two varied and unique networks. The assessment and testing of the first network occurred from an internal perspective, while the assessment and testing of the second occurred from an external perspective. While the tools and methodologies used across both networks were consistent, the test results differed significantly. The paper concludes with a series of recommendations regarding practical methods and tools that may prove useful to anyone interested in network security, and vulnerability assessments and penetration testing in particular

Effect of 2007-2009 Economic Crisis and Dodd-Frank Legislation on the U.S. Banking Industry

This correlation research study was used to investigate the impact of the Dodd-Frank legislation on the U.S. bank industry. The economic crisis of 2007-2009 had a global and significant financial impact, some of which still reverberates. In the United States, the reaction was The Dodd-Frank Wall Street Reform and Consumer Protection Act, which took effect July 21, 2010. This act has recently been the subject of academic research and remains debated in congress, with discussion focused on its repeal. The publicly available, secondary data set from banks\u27 quarterly filed regulatory reporting provided the data used in this study. Every FDIC insured bank in the United States was included in the study. The research question for the study examined the unintended consequences of Dodd-Frank legislation as posited by the theories of Bexley (2014) and Barth, Prabha, and Swagel (2012) that Dodd-Frank was a regulatory overreaction and could have a long-term impact on a substantial number of financial institutions. From 2007 through 2013, the number of banks declined by over 1,753 institutions; a 19.82% decline. The structure of the research presumed that banks that relied heavily on consumer fees for depository services would be negatively impacted by rule changes and regulation regarding such fees. There were two research questions. The first focused on the role of the new rules in the decline of the number of banks. The second explored the role of the legislation in the financial performance of banks. Regression results resulted in not being able to reject the null hypotheses. The implication of the study for social change is that policy makers who understand these relationships may construct better regulation to mitigate unfair and deceptive consumer fees for banking services

Essays on the Economics of Education

Post-secondary education is becoming increasingly more common for students around the world. As quantity of education increases, it becomes less of a distinguishing factor to be simply a college graduate. For those who want to stand out, the quality aspects of education become more salient. Moreover, as this expansion happens in the number of colleges and college students, it becomes less common for governments to generously fund the college education of a lucky few. In addition, the cost to colleges to provide an education is also increasing. Taken together, simply as a measure of cost-comparison, choosing between colleges based on the potential quality-for-money is also an important reason for college quality's increasing salience. College quality matters, and this dissertation endeavors to show how and to what extent. The following three separate chapters estimate the returns to different forms of college quality. There has been an extensive literature that shows, in general, that more schooling is better. These chapters seek to shift the margin of analysis from the extensive margin of quantity to the intensive margin of quality. Thus, I ask the question: is better schooling better or, to put it another way, how much better is better schooling? In the first chapter, I estimate the returns to college quality, operationalized mainly through peer quality, using a regression discontinuity design and exploiting the two separate rounds (early and regular) of college admissions in Taiwan. In the second chapter, focusing on college prestige, I again use a regression discontinuity design to estimate the returns to scoring just above (vs. just below) the admissions cutoff for the lowest-ranked national college. The theory of action is that national colleges are uniformly more desirable than private colleges (excluding a few elite private colleges), if for no other reason than that their tuitions are subsidized by the government and thus much lower for the individual. The final chapter looks at a set of 11 colleges that had already been meeting the minimum requirements for being labeled a university (an important distinction in Taiwan's system), but for bureacratic reasons had not been allowed to change their label/rank until a policy change in 1997. Treating this policy change as a natural experiment, I use a difference-in-differences framework to show that cohorts entering these newly upgraded 11 universities earn statistically significantly more than cohorts entering prior to the change at the same colleges. A consistent picture emerges out of these three papers: college quality matters on several dimensions. These chapters are set apart from other papers in the literature by the causal interpretation given to both choice of college AND choice of college major. My estimates show that those who attend higher quality colleges, within the same college major, end up earning between one-tenth to one-fifth of a standard deviation more in their first year of employment after graduating. Peer quality, college prestige, and college reputation all appear to provide a return. But choice of college major appears to be one of the most important dimensions through which college quality operates, with the science-track college majors receiving most of those returns to quality

Representations of the fundamental group of a surface in PU(p,q) and holomorphic triples

We count the connected components in the moduli space of PU(p,q)-representations of the fundamental group for a closed oriented surface. The components are labelled by pairs of integers which arise as topological invariants of the flat bundles associated to the representations. Our results show that for each allowed value of these invariants, which are bounded by a Milnor-Wood type inequality, there is a unique non-empty connected component. Interpreting the moduli space of representations as a moduli space of Higgs bundles, we take a Morse theoretic approach using a certain smooth proper function on the Higgs moduli space. A key step is the identification of the function's local minima as moduli spaces of holomorphic triples. We prove that these moduli spaces of triples are non-empty and irreducible.Comment: 6 pages, to appear in C. R. Acad. Sci. Paris Ser. I Mat