Cloud Computing and Cloud Automata as A New Paradigm for Computation

Cloud computing addresses how to make right resources available to right computation to improve scaling, resiliency and efficiency of the computation. We argue that cloud computing indeed, is a new paradigm for computation with a higher order of artificial intelligence (AI), and put forward cloud automata as a new model for computation. A high-level AI requires infusing features that mimic human functioning into AI systems. One of the central features is that humans learn all the time and the learning is incremental. Consequently, for AI, we need to use computational models, which reflect incremental learning without stopping (sentience). These features are inherent in reflexive, inductive and limit Turing machines. To construct cloud automata, we use the mathematical theory of Oracles, which include Oracles of Turing machines as its special case. We develop a hierarchical approach based on Oracles with different ranks that includes Oracle AI as a special case. Discussing a named-set approach, we describe an implementation of a high-performance edge cloud using hierarchical name-oriented networking and Oracle AI-based orchestration. We demonstrate how cloud automata with a control overlay allows microservice network provisioning, monitoring and reconfiguration to address non-deterministic fluctuations affecting their behavior without interrupting the overall evolution of computation

A configuration-based domain-specific rule generation framework for process model customization

In today’s changing world, there is an ever-increasing demand and need for software reuse in applications, where the process model needs to be reused in different applications in a domain-specific environment. The process model is required to adapt and implement changes promptly at run-time, in response of the end-user configuration requirements. Furthermore, reusability is emerging strongly as a necessary underlying capability, particularly for customization of business in a dynamic environment where end-users can select their requirements to achieve a specific goal. Such adaptations are in general, performed by non-technical end-users which can lead to losing a significant number of person-days and which can also open up possibilities to introduce errors into the system. These scenarios call for - indeed cry out for - a system with a configurable and customizable business process, operable by users with limited technical expertise. Research aims to provide a framework for generating the rule language and configuring domain constraints. This framework builds upon the core idea of Software Product Lines Engineering (SPLE) and Model-Driven Architecture (MDA). The SPLE provides a platform that includes the variability model. Variability models offer features where end-users can select features and customize possible changes in the domain template, which is the container for domain and process models. The user selects their requirements as a feature from feature models and generates rules from domain models using MDA. Then, the generated rules are translated from a high-level domain model, based on the requirements of the end-user. On the other hand, the weaving model is responsible for reflecting activation and de-activation of features of variabilities in the domain template. The usability of the proposed framework is evaluated with a user study in the area of Digital Content Technology. The results demonstrate that usability improvements can be achieved by using the proposed techniques. The framework can be used to support semi-automatic configuration that is efficient, effective and satisfactory

Vérification efficace de systèmes à compteurs à l'aide de relaxations

Abstract : Counter systems are popular models used to reason about systems in various fields such as the analysis of concurrent or distributed programs and the discovery and verification of business processes. We study well-established problems on various classes of counter systems. This thesis focusses on three particular systems, namely Petri nets, which are a type of model for discrete systems with concurrent and sequential events, workflow nets, which form a subclass of Petri nets that is suited for modelling and reasoning about business processes, and continuous one-counter automata, a novel model that combines continuous semantics with one-counter automata. For Petri nets, we focus on reachability and coverability properties. We utilize directed search algorithms, using relaxations of Petri nets as heuristics, to obtain novel semi-decision algorithms for reachability and coverability, and positively evaluate a prototype implementation. For workflow nets, we focus on the problem of soundness, a well-established correctness notion for such nets. We precisely characterize the previously widely-open complexity of three variants of soundness. Based on our insights, we develop techniques to verify soundness in practice, based on reachability relaxation of Petri nets. Lastly, we introduce the novel model of continuous one-counter automata. This model is a natural variant of one-counter automata, which allows reasoning in a hybrid manner combining continuous and discrete elements. We characterize the exact complexity of the reachability problem in several variants of the model.Les systèmes à compteurs sont des modèles utilisés afin de raisonner sur les systèmes de divers domaines tels l’analyse de programmes concurrents ou distribués, et la découverte et la vérification de systèmes d’affaires. Nous étudions des problèmes bien établis de différentes classes de systèmes à compteurs. Cette thèse se penche sur trois systèmes particuliers : les réseaux de Petri, qui sont un type de modèle pour les systèmes discrets à événements concurrents et séquentiels ; les « réseaux de processus », qui forment une sous-classe des réseaux de Petri adaptée à la modélisation et au raisonnement des processus d’affaires ; les automates continus à un compteur, un nouveau modèle qui combine une sémantique continue à celles des automates à un compteur. Pour les réseaux de Petri, nous nous concentrons sur les propriétés d’accessibilité et de couverture. Nous utilisons des algorithmes de parcours de graphes, avec des relaxations de réseaux de Petri comme heuristiques, afin d’obtenir de nouveaux algorithmes de semi-décision pour l’accessibilité et la couverture, et nous évaluons positivement un prototype. Pour les «réseaux de processus», nous nous concentrons sur le problème de validité, une notion de correction bien établie pour ces réseaux. Nous caractérisions précisément la complexité calculatoire jusqu’ici largement ouverte de trois variantes du problème de validité. En nous basant sur nos résultats, nous développons des techniques pour vérifier la validité en pratique, à l’aide de relaxations d’accessibilité dans les réseaux de Petri. Enfin, nous introduisons le nouveau modèle d’automates continus à un compteur. Ce modèle est une variante naturelle des automates à un compteur, qui permet de raisonner de manière hybride en combinant des éléments continus et discrets. Nous caractérisons la complexité exacte du problème d’accessibilité dans plusieurs variantes du modèle

Verification and validation of UML and SysML based systems engineering design models

In this thesis, we address the issue of model-based verification and validation of systems engineering design models expressed using UML/SysML. The main objectives are to assess the design from its structural and behavioral perspectives and to enable a qualitative as well as a quantitative appraisal of its conformance with respect to its requirements and a set of desired properties. To this end, we elaborate a heretofore unattempted unified approach composed of three well-established techniques that are model-checking, static analysis, and software engineering metrics. These techniques are synergistically combined so that they yield a comprehensive and enhanced assessment. Furthermore, we propose to extend this approach with performance analysis and probabilistic assessment of SysML activity diagrams. Thus, we devise an algorithm that systematically maps these diagrams into their corresponding probabilistic models encoded using the specification language of the probabilistic symbolic model-checker PRISM. Moreover, we define a first of its kind probabilistic calculus, namely activity calculus, dedicated to capture the essence of SysML activity diagrams and its underlying operational semantics in terms of Markov decision processes. Furthermore, we propose a formal syntax and operational semantics for the input language of PRISM. Finally, we mathematically prove the soundness of our translation algorithm with respect to the devised operational semantics using a simulation preorder defined upon Markov decision processes