A implementação das regras de negócio em sistemas de informação não é uma atividade trivial. Isso acontece porque os modelos utilizados para representá-las não determinam como elas podem ser efetivamente implementadas em situações reais. Neste trabalho é proposta um método para a transformação das regras de negócio descritas em SBVR para um modelo de implementação. Essa tradução é feita mapeando todos os elementos relevantes do modelo em SBVR em um modelo em $\\pi$-calculus baseado em eventos. Neste modelo, existe uma representação explícita de todos os eventos que precisam ser monitorados a fim de identificar quando a regra pode ter sido violada. O objetivo é facilitar o gerenciamento das regras de negócio ao permitir que elas permaneçam separadas dos outros elementos da arquitetura e com isso possam ser gerenciadas de forma independente. / The implementation of business rules in an information system is not an easy task. This happens because most of the models used to represent them capture only the meaning of the rules and do not provide means to make them to be effectively implemented. In this work we provide an approach for the translation from a SBVR semantic description of business rules into a implementation model. This was done by mapping all relevant elements of the SBVR semantic representation into a $\\pi$-calculus event-driven model. On this model will be described explicitly all the events that must be monitored in order to identify when some rule may have been violated. This makes the business rule implementation easier because there is a explicit indication of the moment when make sense to do a verification in order to see if any rule was violated. Besides that, it easier the business rule management since the rules stay separate from the others elements of the system architecture and in this way can be managed independently.

A implementação das regras de negócio em sistemas de informação não é uma atividade trivial. Isso acontece porque os modelos utilizados para representá-las não determinam como elas podem ser efetivamente implementadas em situações reais. Neste trabalho é proposta um método para a transformação das regras de negócio descritas em SBVR para um modelo de implementação. Essa tradução é feita mapeando todos os elementos relevantes do modelo em SBVR em um modelo em $\\pi$-calculus baseado em eventos. Neste modelo, existe uma representação explícita de todos os eventos que precisam ser monitorados a fim de identificar quando a regra pode ter sido violada. O objetivo é facilitar o gerenciamento das regras de negócio ao permitir que elas permaneçam separadas dos outros elementos da arquitetura e com isso possam ser gerenciadas de forma independente. / The implementation of business rules in an information system is not an easy task. This happens because most of the models used to represent them capture only the meaning of the rules and do not provide means to make them to be effectively implemented. In this work we provide an approach for the translation from a SBVR semantic description of business rules into a implementation model. This was done by mapping all relevant elements of the SBVR semantic representation into a $\\pi$-calculus event-driven model. On this model will be described explicitly all the events that must be monitored in order to identify when some rule may have been violated. This makes the business rule implementation easier because there is a explicit indication of the moment when make sense to do a verification in order to see if any rule was violated. Besides that, it easier the business rule management since the rules stay separate from the others elements of the system architecture and in this way can be managed independently.

In this thesis, we design and implement an analysis tool for a language called kiltera which is a timed extension of pi-calculus. kiltera allows the modeling of concurrent, mobile, real-time and distributed systems. Our analyzer takes a kiltera model as input and performs analyses such as detection of deadlock states, stable states etc. To improve performance, the analyzer uses some transformation techniques to simplify the input kiltera model without changing its behavior. We provide a detailed description of the design and implementation of the analyzer and discuss some performance optimizations. Finally, we present some case studies to illustrate the capabilities of our analyzer. / Thesis (Master, Computing) -- Queen's University, 2010-09-29 12:02:41.361

Diss. Uppsala : Uppsala Universitet, 2006.

京都大学 / 新制・課程博士 / 博士(理学) / 甲第23687号 / 理博第4777号 / 新制||理||1684(附属図書館) / 京都大学大学院理学研究科数学・数理解析専攻 / (主査)教授 長谷川 真人, 教授 牧野 和久, 准教授 照井 一成 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

A psi-calculus is an extension of the pi-calculus with nominal data types for data structures, logical assertions, and conditions. These can be transmitted between processes and their names can be statically scoped as in the standard pi-calculus. Expressiveness and therefore modelling convenience significantly exceed those of other formalisms: psi-calculi can capture the same phenomena as other extensions of the pi-calculus, and can be more general, e.g. by allowing structured channels, higher-order formalisms such as the lambda calculus for data structures, and predicate logic for assertions. Ample comparisons to related calculi are provided and a few significant applications are discussed. The labelled operational semantics and definition of bisimulation is straightforward, without a structural congruence. Minimal requirements on the nominal data and logic are established in order to prove general algebraic properties of psi-calculi. The purity of the semantics is on par with the pi-calculus. The theory of weak bisimulation is established, where the tau actions are unobservable. The notion of barb is defined as the output label of a communication action, and weak barbed equivalence is bisimilarity for tau actions and preservation of weak barbs in all static contexts. It is proved that weak barbed equivalence coincides with weak bisimulation equivalence. A symbolic transition system and bisimulation equivalence is presented, and shown fully abstract with respect to bisimulation congruence in the non-symbolic semantics. The symbolic semantics is necessary for an efficient implementation of the calculus in automated tools exploring state spaces, and the full abstraction property means processes are bisimilar in the symbolic setting if they are bisimilar in the original semantics. Psi-calculi remove the necessity of proving general properties every time a new mobile process calculus is defined. By properly instantiating the framework the properties are guaranteed to hold, thus removing the need to do tedious and error-prone proofs.

One of the issues when attempting to verify security properties of a protocol is how to model the protocol. We introduce a method for verifying event freshness in tools which use the applied π-calculus and are able to verify secrecy. Event freshness can be used to prove that a protocol never generates the same key twice. In this work we encode state in the applied π-calculus and perform bounded verification of freshness for MiniDC by using the ProVerif tool. MiniDC is a trivial protocol that for each iteration of a loop generates a unique key and outputs it to a private channel. When verifying freshness, the abstractions of ProVerif cause false attacks. We describe methods which can be used to avoid false attacks that appear when verifying freshness. We show how to avoid some false attacks introduced by private channels, state and protocols that disclose their secret. We conclude that the method used to verify freshness in MiniDCis impractical to use in more complicated protocols with state. / Ett av problemen som uppstår vid verifiering av säkerhetsprotokoll är hur protokoll ska modelleras. Vi introducerar en metod för att verifiera att skapde termer inte har använts förr. Denna metod kan användas i program som använder applicerad π-kalkyl som input och kan verifiera sekretess. I detta arbete visar vi hur protokoll med persistenta variabler kan modelleras i applicerad π-kalkyl. Vi verifierar även MiniDC för ett begränsat antal iterationer med hjälp av ProVerif. MiniDC är ett enkelt protokoll som för varje iteration av en loop skapar en nyckel och skickar den över en privat kanal. När man verifierar att skapade termer inte har använts förr så introducerar ProVerifs abstraktioner falska attacker. Vi beskriver metoder som kan användas för att undvika dessa falska attacker. Dessa metoder kan användas för falska attacker introducerade av privata kanaler, persistenta variabler eller protokoll som avslöjar sin krypteringsnyckel. Vår slutsats är att metoden som används för att verifiera MiniDC är opraktisk att använda i mer komplicerade protokoll med persistenta variabler.

Context. Name-bounded analysis is a type of static analysis that allows us to take a concurrent program, abstract away from it, and check for some interesting properties, such as deadlock-freedom, or watching the propagation of variables across different components or layers of the system. Objectives. In this study we investigate the difficulties of giving a representation of computer programs in a name-bounded variation of π-calculus. Methods. A preliminary literature review is conducted to assess the presence (or lack thereof) of other successful translations from real-world programming languages to π-calculus, as well for the presence of relevant prior art in the modelling of concurrent systems. Results. This thesis gives a novel translation going from a relevant subset of the Java programming language, to its corresponding name-bounded π-calculus equivalent. In particular, the strengths of our translation are being able to dispose of names representing inactive objects when there are no circular references, and a transparent handling of polymorphism and dynamic method resolution. The resulting processes can then be further transformed into their Petri-Net representation, enabling us to check for important properties, such as reachability and coverability of program states. Conclusions. We conclude that some important properties that are not, in general, easy to check for concurrent programs, can be in fact be feasibly determined by giving a more constrained model in π-calculus first, and as Petri Nets afterwards. / +49 151 52966429

abstract: Computer science education is an increasingly vital area of study with various challenges that increase the difficulty level for new students resulting in higher attrition rates. As part of an effort to resolve this issue, a new visual programming language environment was developed for this research, the Visual IoT and Robotics Programming Language Environment (VIPLE). VIPLE is based on computational thinking and flowchart, which reduces the needs of memorization of detailed syntax in text-based programming languages. VIPLE has been used at Arizona State University (ASU) in multiple years and sections of FSE100 as well as in universities worldwide. Another major issue with teaching large programming classes is the potential lack of qualified teaching assistants to grade and offer insight to a student’s programs at a level beyond output analysis. In this dissertation, I propose a novel framework for performing semantic autograding, which analyzes student programs at a semantic level to help students learn with additional and systematic help. A general autograder is not practical for general programming languages, due to the flexibility of semantics. A practical autograder is possible in VIPLE, because of its simplified syntax and restricted options of semantics. The design of this autograder is based on the concept of theorem provers. To achieve this goal, I employ a modified version of Pi-Calculus to represent VIPLE programs and Hoare Logic to formalize program requirements. By building on the inference rules of Pi-Calculus and Hoare Logic, I am able to construct a theorem prover that can perform automated semantic analysis. Furthermore, building on this theorem prover enables me to develop a self-learning algorithm that can learn the conditions for a program’s correctness according to a given solution program. / Dissertation/Thesis / Doctoral Dissertation Computer Science 2020

Thesis (MMus (Music))--University of Stellenbosch, 2005. / In this thesis, an attempt is made to create an aesthetically pleasing musical scale based on the ratio of phi. Precedents for the application of phi in aesthetic fields exist; noteworthy is Le Corbusier’s architectural works, the measurements of which are based on phi. A brief discussion of the unique mathematical properties of phi is given, followed by a discussion of the manifestations of phi in the physical ratios as they appear in animal and plant life. Specific scales which have found an application in art music are discussed, and the properties to which their success is attributable are identified. Consequently, during the design of the phi scale, these characteristics are incorporated. The design of the phi scale is facilitated by the use of the most sophisticated modern computer software in the field of psychacoustics. During the scale’s design process, particular emphasis is placed on the requirement of obtaining maximal sensory consonance. For this reason, an in-depth discussion of the theories regarding consonance perception is undertaken. During this discussion, the reader’s attention is drawn to the difference between musical and perceptual consonance, and a discussion of the developmental history of musical consonance is given. Lastly, the scale is tested to see whether it complies with the requirements for successful scales.