In the construction of a large software system, it is inevitable that some aspects of program behavior will cut across the structure of the code. The changes that are needed to support a new feature, for example, may be spread across several different points in the original program, making them

First, I would like to thank to Dimka Karastoyanova and Mariano Cilia for all the fruitful discussions, their guidance and support through the course of this project. Thanks also to Prof. Alejandro Buchmann who sponsored my stay at Technische Universität Darmstadt during the spring of 2004. The special thanks go to my advisor, Mariano Cilia, who has made all this possible. Finally, I’d like to thank to my family for all these years of support.

. By slinging entire contact entries to others, we support secure introductions, as the contact entry includes the SafeSlinger public keys as well as other public keys that were important. As a result, SafeSlinger provides an easy-to-use and understand approach for trust establishment among people. 1.

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Abstract Supporting database schema evolution repre-sents a long-standing challenge of practical and theoretical importance for modern information systems. In this paper, we describe techniques and systems for automating the critical tasks of migrating the database and rewriting the legacy applications. In addition to labor saving, the ben-efits delivered by these advances are many and include reliable prediction of outcome, minimization of downtime, system-produced documentation, and support for archiving, historical queries, and provenance. The PRISM/PRISM++ system delivers these benefits, by solving the difficult prob-lem of automating the migration of databases and the rewrit-ing of queries and updates. In this paper, we present the PRISM/PRISM++ system and the novel technology that made it possible. In particular, we focus on the difficult and previously unsolved problem of supporting legacy queries and updates under schema and integrity constraints evolution. The PRISM/PRISM++ approach consists in providing the users with a set of SQL-based Schema Modification Opera-tors (SMOs), which describe how the tables in the old schema are modified into those in the new schema. In order to sup-port updates, SMOs are extended with integrity constraints

April 29, 2011Für UnsShe had never before seen a rabbit with either a waistcoat-pocket, or a watch to take out of it, and burning with curiosity, she ran across the field after it Lewis CarrollThe following document, written under the supervision of Dr. reviewed by:

Establishing secure communication among a group of physically collocated people is a challenge. This problem can be reduced to establishing authentic public keys among all the participants – these public keys then serve to establish a shared secret symmetric key for encryption and authentication of messages. Unfortunately, in most real-world settings, public key infrastructures (PKI) are uncommon and distributing a secret in a public space is difficult. Thus, it is a challenge to exchange authentic public keys in a scalable, secure, and easy to use fashion. In this paper, we propose GAnGS, a protocol for the secure exchange of authenticated information among a group of people. In contrast to prior work, GAnGS resists Groupin-the-Middle and Sybil attacks by malicious insiders, as well as infiltration attacks by malicious bystanders. GAnGS is designed to be robust to user errors, such as miscounting the number of participants or incorrectly comparing checksums. We have implemented and evaluated GAnGS on Nokia N70 phones. The GAnGS system is viable and achieves a good balance between scalability, security, and ease of use.

The recent discovery of dark energy has prompted an investigation of ways in which the accelerated expansion of the universe can be realized. In this dissertation, we present two separate projects related to dark energy. The first project analyzes a class of braneworld models in which multiple branes float in a five-dimensional anti-de Sitter bulk, while the second investigates a class of dark energy models from an effective field theory perspective. Investigations of models including extra dimensions have led to modifications of gravity involving a number of interesting features. In particular, the Randall-Sundrum model is well-known for achieving an amelioration of the hierarchy problem. However, the basic model relies on Minkowski branes and is subject to solar system constraints in the absence of a radion stabilization mechanism. We present a method by which a four-dimensional low-energy description can be obtained for braneworld scenarios, allowing for a number of generalizations to the original models. This method is applied to orbifolded and uncompactified N-brane models, deriving an effective four-dimensional action. The parameter space of this theory is constrained using observational evidence, and it is found that the generalizations do not weaken solar system constraints on the original model. Furthermore, we find that general

This report focuses on the evidence about the health.consequences of smoking for women, and is intended to serve.the public health and medical communities as 'a unified source of existing scientific research. The major issues about tobacco use and women's health are examined, including trends in consumption, biomedical evidence, and determinants of smoking ititiation, maintenance, and cessation. The biomedical aspects ofsmoking are presented in terms of mortality, morbiplity, cardiovasculaidiseases, cancer, pregnancy and infant,health,, Teptic ulcer disease, drug reactions and, interactions, food constituents, and responses to,diagnostic tests. The psychosocial and behavioraj. aspects, of smoking in women are discussed, along with the docffiented increases in- the risk of contracting lung cancer, heart,disease, or lung disease. The harmful effects of pregnant mothers smoking behaviors, are also docudented. Adhitionally, recent data are enumerated to indicate a trend of,decreasing tobacco usage among women in response to the warnings of the gavernMent, voluntary agencie, and physicrins. (Author /NRB)' DOCUMENT RESUME cc 015 465