Cette thèse a pour cadre la spécification et la vérification de systèmes informatiques distribués, concurrents ou réactifs au moyen de graphes infinis associés à des spécifications de Thue et à certaines machines. Nous montrons que la classe des graphes des spécifications de Thue est fermée par produit synchronisé. Nous établissons aussi ce fait pour la classe des graphes des machines de Turing et pour certaines de ses sous-classes. Nous nous intéressons également à la conservation par produit synchronisé de la décidabilité de la théorie du premier ordre de graphes infinis. Nous montrons que le produit synchronisé de graphes de machines à pile restreint à sa partie accessible depuis un sommet donné à une théorie du premier ordre qui n'est pas décidable. Cependant, le produit synchronisé de graphes sans racine distinguée et dont la théorie du premier oordre est décidable a une théorie du premier ordre qui est décidable. Enfin nous mettons en évidence des liens qui unissent les graphes des machines de Turing à ceux des spécifications de Thue.

<p>Business and organizations use computer network in a greater extension than ever before, especially for business-critical use. That increase the demand of security for all systems, both against internal and external threats. The demand on the authentication method used today increases. Today they normally uses password or some kind of smart card. </p><p>I will performa literature study that will investigate the possibility to increase the security in authentication of users without the use of extra hardware. The method uses a server that stores all cryptographic keys for the user centrally to achieve stronger security. This report is based on a previous report which tested to implement this solution, in this report I will question the security of this system. I will then give an architecture proposal where this method is used to authenticate and allow cryptographic recourses for the user. </p><p>The conclusions you can get from this report is that the possibilities with comparable ease increase the security without investing in new hardware. But the solution will not be comparable by a ``smart card solution''in security levels. That means that the method described in this thesis is suitable for organizations that either do not need that strong security as smart card give or want a good solution without being forced to use some external hardware.</p>

The idea of automatic programming using the genetic programming paradigm is a concept that has been explored in the work of Koza and several works since. Most problems attempted using genetic programming are finite in size, meaning that the problem involved evolving a function that operates over a finite domain, or evolving a routine that will only run for a finite amount of time. For problems with a finite domain, the internal representation of each individual is typically a finite automaton that is unable to store an unbounded amount of data. This thesis will address the problem of applying genetic programming to problems that have a ``discrete unbounded domain", meaning the problem involves evolving a function that operates over an unbounded domain with discrete quantities. For problems with an discrete unbounded domain, the range of possible behaviors achievable by the evolved functions increases with more versatile internal memory schemes for each of the individuals. The specific problem that I will address in this thesis is the problem of evolving a real-time deciding program for a fixed language of strings. I will discuss two paradigms that I will use to attempt this problem. Each of the paradigms will allow each individual to store an unbounded amount of data, using an internal memory scheme with at least the capabilities of a Turing tape. As each character of an input string is being processed in real time, the individual will be able to imitate a single step of a Turing machine. While the real-time restriction will certainly limit the languages for which a decider may be evolved, the fact that the evolved deciding programs run in real-time yields possible applications for these paradigms in the discovery of new algorithms. The first paradigm that I will explore will take a naive approach that will ultimately prove to be unsuccessful. The second paradigm that I will explore will take a more careful approach that will have a much greater success, and will provide insight into the design of genetic programming paradigms for problems over a discrete unbounded domain.

One of the most significant rewards in science is peer recognition, often bestowed in the form of awards. However, little is known about what sets apart award-winning contributions, how award committees determine prize-worthy contributions, and why some scientists are more likely to be recognized than others, particularly in the field of computer science. Using a mixed method approach that includes qualitative and quantitative techniques, this study investigates the characteristics of award-winning contributions, and the education and career factors associated with recipients of the Turing Award, a Nobel equivalent award in computer science, and compares them to those of a matched group of non-winning scientists. In regard to award-winning contributions, the study finds that the Turing Committee was just as likely to recognize contributions related to practice ("applied research") as to theory ("basic research"). In regard to education and career factors, the study reveals that neither scientific productivity nor the quality of contributions differentiated winning from non-winning scientists and their contributions. However, early advantages, visibility to the awarding association, prior eminence, and affiliation with a top computer science department distinguished award winners. These findings suggest that excellence in computer science is a quality that has not been defined, explained, or communicated by the award committee to the computing community or to the public. The findings call attention to the limitations of peer reviews and the importance of improving the design of nomination, evaluation, and selection procedures as well as citations accompanying the Turing Award and other computer science awards.

Jag börjar allt mer inse vattnets betydelse för sjöfarten. Så lär kung Gustav V ha sagt en gång i samband med dop av ett fartyg. Uttalandet har senare kommit att bli ett sätt uttrycka att något är så uppenbart att det knappast ens behöver sägas. Vilken betydelse har datorer för tänkandet? Frågan är relevant att ställa i en tid när datorer gör intrång på allt fler områden och har blivit en så naturligt integrerad del av våra liv att användningen av dem sällan ifrågasätts. Svaret på frågan är dock inte lika uppenbart som den om vattnets betydelse för sjöfarten. Denna masteruppsats i yrkeskunnande och professionsutveckling rör sig i gränslandet mellan maskiner och människor och handlar om hur datorer och datoranvändning påverkar det mänskliga tänkandet och den mänskliga kunskapen. Utgångspunkten är den brittiske matematikern Alan Turings arbete och hans berömda artikel från 1950, med titeln Computing machinery and intelligens, där han definierar ett test (Turingtestet) avsett att kunna avgöra maskiners tankeförmåga. Den traditionella tolkningen av artikeln är att Turing menade att det en dag kommer att vara möjligt att bygga en maskin som kan imitera allt mänskligt beteende perfekt (Turingmaskinen), vilket har gett upphov till forskningsområdet artificiell intelligens. I praktiken har dock maskiner inte kunnat ersätta människor på det sätt som man trott och som många fortfarande tror. Närmandet mellan människor och maskiner tar sig andra uttryck. Utvecklingen går snarare i en riktning som gjort att människor genom att använda maskiner anpassar sig till och allt mer börjar likna dem. Vi förvandlas till Turingmänniskor med succesivt minskande utrymme att utöva vårt omdöme och ta ansvar, när maskinerna ställer sig i vägen för det mänskliga sinnet och känslan.

The Hypertext concept was introduced about 50 years ago. This thesis presents the development of a reference system using the Hypertext concept. HYATS (HYpertext Automata and Turing Theory Learning 5ys,em) is a system which helps users learn many topics in the area of theory of computation. The system is implemented by Guide which is a general purpose Hypertext system running on PC-Windows environment. HYATS also includes a Turing machine simulating program which was written by Dominique Atger as her Master's Thesis in 1993, so that users can actually experiment with Turing machines learned through HYATS. HYATS will be not only the reference system, but also the complete package of actual learning system. The motivation behind this project is to study basic concepts of a Hypertext system so that it will also contribute to G-Net research. HYATS can be used as a prototype for future development of versions of by using other Hypertext systems such as NoteCards. / Department of Computer Science

The idea of automatic programming using the genetic programming paradigm is a concept that has been explored in the work of Koza and several works since. Most problems attempted using genetic programming are finite in size, meaning that the problem involved evolving a function that operates over a finite domain, or evolving a routine that will only run for a finite amount of time. For problems with a finite domain, the internal representation of each individual is typically a finite automaton that is unable to store an unbounded amount of data. This thesis will address the problem of applying genetic programming to problems that have a ``discrete unbounded domain", meaning the problem involves evolving a function that operates over an unbounded domain with discrete quantities. For problems with an discrete unbounded domain, the range of possible behaviors achievable by the evolved functions increases with more versatile internal memory schemes for each of the individuals. The specific problem that I will address in this thesis is the problem of evolving a real-time deciding program for a fixed language of strings. I will discuss two paradigms that I will use to attempt this problem. Each of the paradigms will allow each individual to store an unbounded amount of data, using an internal memory scheme with at least the capabilities of a Turing tape. As each character of an input string is being processed in real time, the individual will be able to imitate a single step of a Turing machine. While the real-time restriction will certainly limit the languages for which a decider may be evolved, the fact that the evolved deciding programs run in real-time yields possible applications for these paradigms in the discovery of new algorithms. The first paradigm that I will explore will take a naive approach that will ultimately prove to be unsuccessful. The second paradigm that I will explore will take a more careful approach that will have a much greater success, and will provide insight into the design of genetic programming paradigms for problems over a discrete unbounded domain.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1980. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 409-443).

Stuttgart, Univ., Habil.-Schr., 2003.

Orientador: Luciano Barbanti / Banca: Ernandes Rocha de Oliveira / Banca: antonio Carlos Tamarozzi / Resumo: Este trabalho apresenta uma proposta relacionada ao ensino e prática do pensamento dedutivo formal em Matemática. São apresentados no âmbito do conjunto dos números Naturais três temas essencialmente interligados: indução/boa ordem, dedução e esquemas de computação representados pela máquina teórica de Turing. Os três temas se amalgamam na teoria lógica de dedução e tangem os fundamentos da Matemática, sua própria indecidibilidade e extensões / limites de tudo que pode ser deduzido utilizando a lógica de Aristóteles, caminho tão profundamente utilizado nos trabalhos de Gödel, Church, Turing, Robinson e outros. São apresentadas inúmeros esquemas de dedução referentes às "fórmulas" e Teoremas que permeiam o ensino fundamental e básico, com uma linguagem apropriada visando treinar os alunos (e professores) para um enfoque mais próprio pertinente à Matemática / Abstract: This work deals with the teaching and practice of formal deductive thinking in Mathematics. Three essentially interconnected themes are presented within the set of Natural Numbers: induction, deduction and computation schemes represented by the Turing theoretical machine. The three themes are put together into the logical theory of deduction and touch upon the foundations of Mathematics, its own undecidability and the extent / limits of what can be deduced by using Aristotle's logic, that is the subject in the works of Gödel, Church, Turing, Robinson, and others. There are a large number of deduction schemes referring to the "formulas" and Theorems that are usual subjects in elementary and basic degrees of the educational field, with an appropriate language in order to train students (and teachers) for a more pertinent approach to Mathematics / Mestre