Supervisory system for Onboard Checkout and Data Management System, /OCDMS/, Saturn/Apollo application program

Supervisory computer program for onboard checkout and data management system of Saturn/Apollo application progra

Développement sans rupture de systèmes complexes : une approche basée multi-exigences

Prouver qu'un système satisfait à ses exigences est un défi important de l'ingénierie des exigences. D'une part, les approches formelles fournissent un moyen d'exprimer les exigences mathématiquement et de prouver qu'un système satisfait ses exigences. Cependant, si la formalisation offre des possibilités supplémentaires telles que la vérification, voire la validation, elle s'avère souvent trop difficile à utiliser en pratique par les acteurs impliqués dans le développement des systèmes. D'autre part, dans la plupart des cas, les exigences sont écrites et parfois tracées en langage naturel à des fins de communication et de compréhension mutuelle. De plus, cela reste le cas tout au long du processus de développement. Ainsi, il est nécessaire de considérer le besoin de s'adresser à toutes ces parties prenantes pendant le processus de développement. L'objectif principal de cette thèse est de fournir une méthodologie sans rupture qui permet de bénéficier de la formalisation des exigences tout en étant compréhensible par toutes les parties prenantes. Nous proposons une approche qui considère les exigences comme des parties du code du système, ce qui, en tant que tel, contribue à améliorer l'évaluation de la qualité. De plus, l'intégration des exigences dans le code garantit un développement sans rupture. Ces contributions visent trois avantages principaux. Premièrement, il n'est pas nécessaire de passer d'un outil ou d'un environnement à un autre : un cadre unique prend en charge le développement de l'analyse à la mise en œuvre. Deuxièmement, les changements et la réversibilité deviennent un phénomène régulier, directement pris en charge par la méthode, le langage et les outils, ce qui facilite les allers-retours. Enfin, les différents niveaux d'abstraction restent dans le cadre du paradigme orienté objet. Nous appliquons cette vision au processus de développement lui-même avec les mêmes avantages attendus. Le cycle de vie du développement peut alors bénéficier de cette forte intégration des exigences dans le code. Ces artefacts aident au développement du logiciel en fournissant un support et des lignes directrices pour l'analyse ou l'aide à la décision et en renforçant la qualité du logiciel. En outre, la réutilisabilité, l'évolutivité et la maintenabilité sont améliorées. La traçabilité entre les exigences et le code permet une analyse d'impact facile lorsque l'un de ces artefacts évolue. Cependant, si ce paradigme est familier aux développeurs et même si nous faisons un effort d'expressivité, il ne s'adresse pas aux autres parties prenantes qui ont l'habitude de travailler avec d'autres outils. Puisque nous souhaitons également que des non-experts utilisent notre approche pour valider des systèmes dans la première phase de leur développement, nous proposons un langage spécifique au domaine : (i) proche du langage naturel et (ii) basé sur une sémantique formelle. En utilisant les techniques de l'ingénierie dirigée par les modèles, ce langage permet de combler le fossé entre les différents acteurs impliqués dans un projet (compte tenu de leurs différentes expériences) et entre les exigences et le code. Nous avons enfin consacré un effort de recherche à la définition des relations entre les exigences. Nous fournissons leurs définitions formelles et leurs propriétés sur la propagation de l'état de satisfaction. Ces définitions peuvent aider les ingénieurs à vérifier les exigences (en vérifiant la validité de la sémantique des relations entre deux exigences) et à vérifier la conformité du système (grâce à la propagation de la satisfaction). Ce travail est une étape vers l'introduction de la sémantique formelle dans la traçabilité, permettant d'analyser automatiquement les exigences et d'utiliser leurs relations pour vérifier l'implémentation correspondante du système.Proving that a system satisfies its requirements is an important challenge of Requirements Engineering. On the one hand, formal approaches provide a way to express requirements mathematically and prove that a system satisfies its requirements. However, if formalization offers additional possibilities such as verification, or even validation, it often proves to be too difficult to use in practice by the stakeholders involved in the development of systems. On the other hand, in most cases, requirements are written and sometimes traced in Natural Language for communication and mutual understanding purposes. Moreover, this remains during the whole development process. Thus, it is necessary to consider the need to address all these stakeholders during the development process. The main objective of this thesis is to provide a seamless methodology that allows benefiting from the formalization of requirements while being understandable by all stakeholders. We propose an approach that considers requirements as parts of the system's code, which, as such, contributes to improving quality assessment. In addition, integrating the requirements into the code guarantees a seamless development. The contributions target three main benefits. First, there is no need to switch from one tool or environment to another: a single framework supports the development from analysis to implementation. Second, changes and reversibility become a regular occurrence, directly supported by the method, language, and tools, facilitating round-trips. Third, the different levels of abstraction remain inside the object-oriented paradigm. We apply this vision to the development process itself with the same expected advantages. The development life-cycle can then benefit from this strong integration of requirements into the code. These artifacts help in software development by providing support and guidelines for analysis or decision support and reinforcing the software quality. Besides, reusability, evolutivity, and maintainability are enhanced. Traceability between requirements and code allows an easy impact analysis when any of these artifacts evolve. However, if this paradigm is familiar to developers and even if we put an effort in providing expressivity, they are not addressed to other stakeholders that used to work with several tools. Since we also want non-experts to use our approach to validate systems in the early stage of their development, we propose a Domain-Specific Language: (i) close to natural language and (ii) based on formal semantics. Using Model-Driven Engineering techniques, this language bridges the gap between the several stakeholders involved in a project (considering their different backgrounds) and between the requirements and the code. We finally put a research effort into defining relationships between requirements. We provide their formal definitions and properties on the propagation of the satisfaction state. These definitions can help engineers verify requirements (by checking the validity of the semantics of the relationships between two requirements) and verify the system compliance (thanks to satisfaction propagation). This work is a step towards introducing formal semantics into traceability, making it possible to automatically analyze requirements and use their relationships to verify the corresponding implementation of the system

Automation and Control Architecture for Hybrid Pipeline Robots

The aim of this research project, towards the automation of the Hybrid Pipeline Robot (HPR), is the development of a control architecture and strategy, based on reconfiguration of the control strategy for speed-controlled pipeline operations and self-recovering action, while performing energy and time management. The HPR is a turbine powered pipeline device where the flow energy is converted to mechanical energy for traction of the crawler vehicle. Thus, the device is flow dependent, compromising the autonomy, and the range of tasks it can perform. The control strategy proposes pipeline operations supervised by a speed control, while optimizing the energy, solved as a multi-objective optimization problem. The states of robot cruising and self recovering, are controlled by solving a neuro-dynamic programming algorithm for energy and time optimization, The robust operation of the robot includes a self-recovering state either after completion of the mission, or as a result of failures leading to the loss of the robot inside the pipeline, and to guaranteeing the HPR autonomy and operations even under adverse pipeline conditions Two of the proposed models, system identification and tracking system, based on Artificial Neural Networks, have been simulated with trial data. Despite the satisfactory results, it is necessary to measure a full set of robot’s parameters for simulating the complete control strategy. To solve the problem, an instrumentation system, consisting on a set of probes and a signal conditioning board, was designed and developed, customized for the HPR’s mechanical and environmental constraints. As a result, the contribution of this research project to the Hybrid Pipeline Robot is to add the capabilities of energy management, for improving the vehicle autonomy, increasing the distances the device can travel inside the pipelines; the speed control for broadening the range of operations; and the self-recovery capability for improving the reliability of the device in pipeline operations, lowering the risk of potential loss of the robot inside the pipeline, causing the degradation of pipeline performance. All that means the pipeline robot can target new market sectors that before were prohibitive

Supervisory Control Optimization with Sequential Quadratic Programming for Parallel Hybrid Vehicle with Synchronous Power Sources

abstract: The thesis covers the development and modeling of the supervisory hybrid controller using two different methods to achieve real-world optimization and power split of a parallel hybrid vehicle with a fixed shaft connecting the Internal Combustion Engine (ICE) and Electric Motor (EM). The first strategy uses a rule based controller to determine modes the vehicle should operate in. This approach is well suited for real-world applications. The second approach uses Sequential Quadratic Programming (SQP) approach in conjunction with an Equivalent Consumption Minimization Strategy (ECMS) strategy to keep the vehicle in the most efficient operating regions. This latter method is able to operate the vehicle in various drive cycles while maintaining the SOC with-in allowed charge sustaining (CS) limits. Further, the overall efficiency of the vehicle for all drive cycles is increased. The limitation here is the that process is computationally expensive; however, with advent of the low cost high performance hardware this method can be used for the hybrid vehicle control.Dissertation/ThesisMasters Thesis Engineering 201

A survey of variants and extensions of the resource-constrained project scheduling problem

The resource-constrained project scheduling problem (RCPSP) consists of activities that must be scheduled subject to precedence and resource constraints such that the makespan is minimized. It has become a well-known standard problem in the context of project scheduling which has attracted numerous researchers who developed both exact and heuristic scheduling procedures. However, it is a rather basic model with assumptions that are too restrictive for many practical applications. Consequently, various extensions of the basic RCPSP have been developed. This paper gives an overview over these extensions. The extensions are classified according to the structure of the RCPSP. We summarize generalizations of the activity concept, of the precedence relations and of the resource constraints. Alternative objectives and approaches for scheduling multiple projects are discussed as well. In addition to popular variants and extensions such as multiple modes, minimal and maximal time lags, and net present value-based objectives, the paper also provides a survey of many less known concepts. --project scheduling,modeling,resource constraints,temporal constraints,networks

Programmiersprachen und Rechenkonzepte

Seit 1984 veranstaltet die GI-Fachgruppe "Programmiersprachen und Rechenkonzepte" regelmäßig im Frühjahr einen Workshop im Physikzentrum Bad Honnef. Das Treffen dient in erster Linie dem gegenseitigen Kennenlernen, dem Erfahrungsaustausch, der Diskussion und der Vertiefung gegenseitiger Kontakte. In diesem Forum werden Vorträge und Demonstrationen sowohl bereits abgeschlossener als auch noch laufender Arbeiten vorgestellt, unter anderem (aber nicht ausschließlich) zu Themen wie - Sprachen, Sprachparadigmen, - Korrektheit von Entwurf und Implementierung, -Werkzeuge, -Software-/Hardware-Architekturen, -Spezifikation, Entwurf, - Validierung, Verifikation, - Implementierung, Integration, - Sicherheit (Safety und Security), - eingebettete Systeme, - hardware-nahe Programmierung. In diesem Technischen Bericht sind einige der präsentierten Arbeiten zusammen gestellt

Adaptive Constraint Solving for Information Flow Analysis

In program analysis, unknown properties for terms are typically represented symbolically as variables. Bound constraints on these variables can then specify multiple optimisation goals for computer programs and nd application in areas such as type theory, security, alias analysis and resource reasoning. Resolution of bound constraints is a problem steeped in graph theory; interdependencies between the variables is represented as a constraint graph. Additionally, constants are introduced into the system as concrete bounds over these variables and constants themselves are ordered over a lattice which is, once again, represented as a graph. Despite graph algorithms being central to bound constraint solving, most approaches to program optimisation that use bound constraint solving have treated their graph theoretic foundations as a black box. Little has been done to investigate the computational costs or design e cient graph algorithms for constraint resolution. Emerging examples of these lattices and bound constraint graphs, particularly from the domain of language-based security, are showing that these graphs and lattices are structurally diverse and could be arbitrarily large. Therefore, there is a pressing need to investigate the graph theoretic foundations of bound constraint solving. In this thesis, we investigate the computational costs of bound constraint solving from a graph theoretic perspective for Information Flow Analysis (IFA); IFA is a sub- eld of language-based security which veri es whether con dentiality and integrity of classified information is preserved as it is manipulated by a program. We present a novel framework based on graph decomposition for solving the (atomic) bound constraint problem for IFA. Our approach enables us to abstract away from connections between individual vertices to those between sets of vertices in both the constraint graph and an accompanying security lattice which defines ordering over constants. Thereby, we are able to achieve significant speedups compared to state-of-the-art graph algorithms applied to bound constraint solving. More importantly, our algorithms are highly adaptive in nature and seamlessly adapt to the structure of the constraint graph and the lattice. The computational costs of our approach is a function of the latent scope of decomposition in the constraint graph and the lattice; therefore, we enjoy the fastest runtime for every point in the structure-spectrum of these graphs and lattices. While the techniques in this dissertation are developed with IFA in mind, they can be extended to other application of the bound constraints problem, such as type inference and program analysis frameworks which use annotated type systems, where constants are ordered over a lattice

Modélisation probabiliste du style d'apprentissage et application à l'adaptation de contenus pédagogiques indexés par une ontologie

Cette thèse s'inscrit dans le cadre général des systèmes d'enseignement adaptatifs. La problématique traitée est l'adaptation de l'activité pédagogique au mode d'apprentissage préféré de l'élève. Les travaux réalisés ont eu pour objectifs de : modéliser les préférences d'apprentissage de l'élève ; modéliser les contenus pédagogiques du domaine à enseigner ; proposer une stratégie d'adaptation qui rapproche les préférences des contenus afin de proposer une méthode pédagogique appropriée. Pour atteindre le premier objectif, la thèse étudie le style d'apprentissage de Felder. Une étude empirique pour établir un modèle de dépendance entre style, pédagogie, et comportement de l'élève a été réalisée. Les résultats ont permis d'établir un modèle de préférences probabiliste. Une méthode en deux étapes pour apprendre ce odèle puis le renforcer est développée. Deux implantations sont proposées : un réseau bayésien et une machine à vecteurs de support. Le contenu quant à lui est modélisé en utilisant une ontologie combinant le domaine, la pédagogie, ainsi que les ressources physiques. Une stratégie d'adaptation structurée sur quatre dimensions est présentée. Celle-ci consiste à rechercher dans le contenu la séquence pédagogique sémantiquement pertinente pour les préférences de l'élève. La recherche s'appuie sur une mesure de similarité sémantique qui est établie. Ce travail a eu un impact sur deux projets européens. En effet, la méthode de production et structuration des contenus, basée sur SCORM, qui est proposée a servi pour le projet UP2UML. L'approche de modélisation de l'élève sert aux recherches sur le profilage dans le projet KPLAB. ABSTRACT : This thesis deals with adaptive teaching systems. The research question is how to adapt pedagogical activities to the prefered learning mode of a student. The scientific objectives are: modelisation of student's learning preferences ; modelisation of adaptive learning contents of a given domain ; establishing an adaptation strategy that maps preferences to contents in order to recommend an appropriate teaching method In order to reach the first objective, the thesis studies the learning style of Felder. An empirical study to derive a dependency model between the style, the pedagogy, and the student behaviour has been conducted. Results led to creating a probabilistic preference model. A two-stage method to learn and reinforce the model is developed. Two implementations are proposed: a bayesian network and an SVM classifier. The content is represented using an ontology that combines the domain, the pedagogy, and the physical resources. An adaptation strategy centered around four dimensions is presented. This consists of searching the content to retrieve the most semantically pertinent pedagogical sequence given the student preferences. The search implements an original semantic similarity measure. This work significantly impacted two European research projects. The production and structuration method designed in this thesis and based on SCORM has been applied in the Leonardo Da Vinci project called UP2UML. The student modeling approche serves currently our research on user profiling in the KPLAB projec

Code generation for RESTful APIs in HEADREST

Tese de mestrado, Engenharia Informática (Engenharia de Software) Universidade de Lisboa, Faculdade de Ciências, 2018Os serviços web com APIs que aderem ao estilo arquitetural REST, conhecidos por serviços web RESTful, são atualmente muito populares. Estes serviços seguem um estilo cliente-servidor, com interações sem estado baseadas nos verbos disponibilizados pela norma HTTP. Como meio de especificar formalmente a interação entre os clientes e fornecedores de serviços REST, várias linguagens de definição de interfaces (IDL) têm sido propostas. No entanto, na sua maioria, limitam-se ao nível sintático das interfaces que especificam e à descrição das estruturas de dados e dos pontos de interação. A linguagem HEADREST foi desenvolvida como uma IDL que permite ultrapassar estas limitações, suportando a descrição das APIs RESTful também ao nível semântico. Através de tipos e asserções é possível em HEADREST não só definir a estrutura dos dados trocados mas também correlacionar o output com input e o estado do servidor. Uma das principais vantagens de ter descrições formais de APIs RESTful é a capacidade de gerar código boilerplate tanto para clientes como fornecedores. Este trabalho endereça o problema de geração de código para as APIs RESTful descritas com HEADREST e investiga de que forma as técnicas de geração de código existentes para os aspectos sintáticos das APIs RESTful podem ser estendidas para levar em conta também as propriedades comportamentais que podem ser descritas em HEADREST. Tendo em conta que a linguagem HEADREST adota muitos conceitos da Open API Specification (OAS), o trabalho desenvolvido capitaliza nas técnicas de geração de código desenvolvidas para a OAS e envolveu o desenvolvimento de protótipos de geração de código cliente e servidor a partir de especificações HEADREST.Web services with APIs that adhere to the REST architectural style, known as RESTful web services, have become popular. These services follow a client-server style, with stateless interactions based on standard HTTP verbs. In an effort to formally specify the interaction between clients and providers of RESTful services, various interface definition languages (IDL) have been proposed. However, for the most part, they limit themselves to the syntactic level of the interfaces and the description of the data structures and the interaction points. The HEADREST language was developed as an IDL that addresses these limitations, supporting the description of the RESTful APIs also at the semantical level. Through the use of types and assertions we not only define the structure of the data transmitted but also relate output with input and the state of the server. One of the main advantages of having formal descriptions of RESTful APIs is the ability to generate a lot of boilerplate code for both clients and servers. This work addresses the problem of code generation for RESTful APIs described in HEADREST and aims to investigate how the existing code generation techniques for the syntactical aspects of RESTful APIs can be extended to take into account also the behavioural properties that can be described in HEADREST. Given that HEADREST adopts many concepts from the Open API Specification (OAS), this work capitalised on the code generation tools available for OAS and encompassed the development of a prototypical implementation of a code generator for clients and servers from HEADREST specifications