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Complex software systems are usually developed as systems of systems (SoS’s) in which multiple constituent applications are composed and coordinated to fulfill desired system-level requirements. The constituent applications must be augmented with suitable coordination-specific interfaces, through which they can participate in coordinated interactions. Such interfaces as well as coordination rules have a crosscutting nature. Therefore, to increase the reusability of the applications and to increase the comprehensibility of SoS’s, suitable mechanisms are required to modularize the coordination rules and interfaces from the constituent applications. We introduce a new abstraction named as architectural event modules (AEMs), which facilitate defining constituent applications and desired coordination rules as modules of SoS’s. AEMs augment the constituent applications with event-based facades to let them participate in coordinated interactions. We introduce the EventArch language in which the concept of AEMs is implemented, and illustrate its suitability using a case study.

<p>Kroz istraživanja je postavljen i razvijen kompleksan model sistema<br />identifikacije procesnih parametara štampe na osnovama<br />savremenih programskih sistema i alata koji omogućuju značajno<br />ubrzanje procesa dolaska do rešenja čime su se unapredili grafički<br />proizvodni procesi i procesi sticanja i proširivanja znanja. Model<br />je baziran na integrativnim modulima koga čine, sistem<br />identifikacije procesnih parametara štampe na osnovi sistema<br />zasnovanih na algoritamskoj programskoj strukturi, sistem<br />identifikacije procesnih parametara štampe na osnovi sistema<br />zasnovanih na principima gradnje ekspernih sistema i sistem<br />identifikacije procesnih parametara štampe na osnovi sistema<br />zasnovanih na učenju na daljinu.</p> / <p>The complex model of the printing processing parameter identification<br />system is set and developed through research on the basis of modern<br />software systems and tools that enable you to significantly speed up the<br />process reaching solutions which have improved graphics production<br />processes and the processes of acquiring and expanding knowledge. The<br />model is based on the integration modules, which consist the printing<br />processing parameter identification system based on algorithmic structure,<br />the printing processing parameter identification system based on the<br />construction principles of expert systems and the printing processing<br />parameter identification system based on distance learning principles.</p>

Organisations such as governments and healthcare bodies are increasingly responsible for managing large amounts of personal information, and the increasing complexity of modern information systems is causing growing concerns about the protection of these assets from insider threats. Insider threats are very difficult to handle, because the insiders have direct access to information and are trusted by their organisations. The nature of insider privacy breaches varies with the organisation’s acceptable usage policy and the attributes of an insider. However, the level of risk that insiders pose depends on insider breach scenarios including their access patterns and contextual information, such as timing of access. Protection from insider threats is a newly emerging research area, and thus, only few approaches are available that systemise the continuous monitoring of dynamic insider usage characteristics and adaptation depending on the level of risk. The aim of this research is to develop a formal framework for an adaptive early warning and response system for insider privacy breaches within dynamic software systems. This framework will allow the specification of multiple policies at different risk levels, depending on event patterns, timing constraints, and the enforcement of adaptive response actions, to interrupt insider activity. Our framework is based on Usage Control (UCON), a comprehensive model that controls previous, ongoing, and subsequent resource usage. We extend UCON to include interrupt policy decisions, in which multiple policy decisions can be expressed at different risk levels. In particular, interrupt policy decisions can be dynamically adapted upon the occurrence of an event or over time. We propose a computational model that represents the concurrent behaviour of an adaptive early warning and response system in the form of statechart. In addition, we propose a Privacy Breach Specification Language (PBSL) based on this computational model, in which event patterns, timing constraints, and the triggered early warning level are expressed in the form of policy rules. The main features of PBSL are its expressiveness, simplicity, practicality, and formal semantics. The formal semantics of the PBSL, together with a model of the mechanisms enforcing the policies, is given in an operational style. Enforcement mechanisms, which are defined by the outcomes of the policy rules, influence the system state by mutually interacting between the policy rules and the system behaviour. We demonstrate the use of this PBSL with a case study from the e-government domain that includes some real-world insider breach scenarios. The formal framework utilises a tool that supports the animation of the enforcement and policy models. This tool also supports the model checking used to formally verify the safety and progress properties of the system over the policy and the enforcement specifications.

El objetivo principal perseguido en esta tesis consiste en proponer un catálogo de refactorings para mejorar aspectos como usabilidad, eficiencia y eficacia de los procesos de negocio de las aplicaciones web. Mientras otras publicaciones identifican posibilidades de mejorías en los modelos de las aplicaciones web, esta tesis se focaliza en identificar problemas relacionados exclusivamente con la ejecución de los procesos de negocio y sugerir cambios para optimizar la experiencia del usuario mientras este navega por los procesos embebidos en las aplicaciones. / With time, web applications changed and evolved from simple websites to complex applications that allow users to perform a wide variety of tasks and operations online. All this progress is possible due to the fact that, nowadays, web applications support Business Processes. The integration of business processes and the associated increase in complexity of web applications generally lead to underestimate its usability which affects directly the users who have to execute these business processes daily. Focused in improve the execution and the usability of business processes, a catalog of refactorings was created with suggestions of changes classified by the affected web application model. The proposed refactorings aim to improve the user experience while executing these business processes embeded in most of web application and consequently its usability.

Early this century "S-shaped" curves, sigmoids, gained popularity among demographers. However, by 1940, the approach had "fallen out of favour", being criticised for giving poor results and having no theoretical validity. It was also considered that models of total population were of little practical interest, the main forecasting procedure currently adopted being the bottom-up "cohort-component" method. In the light of poor forecasting performance from component methods, a re-assessment is given in this thesis of the use of simple trend models. A suitable means of fitting these models to census data is developed, using a non-linear least squares algorithm based on minimisation of a proportionately weighted residual sum of squares. It is demonstrated that useful models can be obtained from which, by using a top-down methodology, component populations and vital components can be derived. When these models are recast in a recursive parameterisation, it is shown that forecasts can be obtained which, it is argued, are superior to existing official projections. Regarding theoretical validity, it is argued that sigmoid models relate closely to Malthusian theory and give a mathematical statement of the demographic transition. In order to judge the suitability of extrapolating from sigmoid models, a framework using Catastrophe Theory is developed. It is found that such a framework allows one qualitatively to model population changes resulting from subtle changes in influencing variables. The use of Catastrophe Theory has advantages over conventional demographic models as it allows a more holistic approach to population modelling.

abstract: The adoption of the Service Oriented Architecture (SOA) as the foundation for developing a new generation of software systems - known as Service Based Software Systems (SBS), poses new challenges in system design. While simulation as a methodology serves a principal role in design, there is a growing recognition that simulation of SBS requires modeling capabilities beyond those that are developed for the traditional distributed software systems. In particular, while different component-based modeling approaches may lend themselves to simulating the logical process flows in Service Oriented Computing (SOC) systems, they are inadequate in terms of supporting SOA-compliant modeling. Furthermore, composite services must satisfy multiple QoS attributes under constrained service reconfigurations and hardware resources. A key desired capability, therefore, is to model and simulate not only the services consistent with SOA concepts and principles, but also the hardware and network components on which services must execute on. In this dissertation, SOC-DEVS - a novel co-design modeling methodology that enables simulation of software and hardware aspects of SBS for early architectural design evaluation is developed. A set of abstractions representing important service characteristics and service relationships are modeled. The proposed software/hardware co-design simulation capability is introduced into the DEVS-Suite simulator. Exemplar simulation models of a communication intensive Voice Communication System and a computation intensive Encryption System are developed and then validated using data from an existing real system. The applicability of the SOC-DEVS methodology is demonstrated in a simulation testbed aimed at facilitating the design & development of SBS. Furthermore, the simulation testbed is extended by integrating an existing prototype monitoring and adaptation system with the simulator to support basic experimentation towards design & development of Adaptive SBS. / Dissertation/Thesis / Ph.D. Computer Science 2011

Modern software systems are increasingly characterized by uncertainties in the operating context and user requirements. These uncertainties are difficult to predict at design time. Achieving the quality goals of such systems depends on the ability of the software to deal with these uncertainties at runtime. A self-adaptive system employs a feedback loop to continuously monitor and adapt itself to achieve particular quality goals (i.e., adaptation goals) regardless of uncertainties. Current research applies formal techniques to provide guarantees for adaptation goals, typically using exhaustive verification techniques. Although these techniques offer strong guarantees for the goals, they suffer from well-known state explosion problem. In this thesis, we take a broader perspective and focus on two types of guarantees: (1) functional correctness of the feedback loop, and (2) guaranteeing the adaptation goals in an efficient manner. To that end, we present ActivFORMS (Active FORmal Models for Self-adaptation), a formally founded model-driven approach for engineering self-adaptive systems with guarantees. ActivFORMS achieves functional correctness by direct execution of formally verified models of the feedback loop using a reusable virtual machine. To efficiently provide guarantees for the adaptation goals with a required level of confidence, ActivFORMS applies statistical model checking at runtime. ActivFORMS supports on the fly changes of adaptation goals and updates of the verified feedback loop models that meet the changed goals. To demonstrate the applicability and effectiveness of the approach, we applied ActivFORMS in several domains: warehouse transportation, oceanic surveillance, tele assistance, and IoT building security monitoring. / Marie Curie CIG, FP7-PEOPLE-2011-CIG, Project ID: 303791

Actuellement, de nombreuses entreprises ont besoin de construire des versions\variantes légèrement différentes d'un même système. Ces versions partagent des points communs et des différences, le tout pouvant être géré à l'aide d'une approche ligne de produits (SPL). L'objectif principal d'une SPL est d'exploiter la personnalisation de masse, dans laquelle les produits sont réalisés pour répondre aux besoins spécifiques de chaque client. Pour répondre à ce besoin de personnalisation, les systèmes doivent être étendus de manière efficace, ou modifiés, configurés pour être utilisé dans un contexte particulier. Une approche encourageante consiste à connecter l'approche MDE (l'ingénierie dirigée par les modèles) à l'approche SPL – les SPL basées sur les modèles (MSPL). L'espace de conception, l'environnement du système logiciel que l'on construit (i.e., l'ingénierie du domaine) d'une MSPL est extrêmement complexe à gérer pour un ingénieur. Tout d'abord, le nombre possible des produits d'une MSPL est exponentielle au nombre d'éléments ou de décisions exprimé dans le modèle de variabilité. Ensuite, les modèles de produits dérivés doivent être conformes à de nombreuses règles liées au domaine métier mais aussi aux langages de modélisation utilisés. Troisièmement, le modèle de réalisation qui relie un modèle de variabilité et un modèle de base peut être très expressif. En plus, il faut ajouter que les ingénieurs système utilisent différents langages de modélisation dédiés dans le cadre de projets pour la réalisation de systèmes critiques. Nos contributions sont basées sur le fait qu'une solution générique, pour tous les domaines, et qui dérive des modèles corrects n'est pas réaliste, surtout si on prend en considération le contexte des systèmes complexes décrits précédemment. Nous proposons une approche indépendante du domaine pour générer des contre-exemples de MSPLs, révélant des erreurs de conceptions de modèles et supportant les parties prenantes à construire de meilleures MSPLs et des mécanismes de dérivation plus efficaces. Plus précisément, la première et principale contribution de la thèse est un processus systématique et automatisé, basé sur CVL (common variability language), pour la recherche aléatoire de contre-exemples de MSPL dans un langage donné. La seconde contribution de la thèse est un étude sur les mécanismes pour étendre la sémantique des moteurs de dérivation, offrant une approche basée sur des modèles à fin de personnaliser leurs sémantique opérationnelle. Dans la troisième contribution de la thèse, nous présentons une étude empirique à large échelle sur le langage Java en utilisant notre approche générative. La quatrième et dernière contribution de la thèse est une méthodologie pour intégrer notre travail dans une organisation qui cherche à mettre en œuvre les lignes de produit logiciels basées sur des modèles pour l'ingénierie des systèmes. / Systems Engineering is a complex and expensive activity in several kinds of companies, it imposes stakeholders to deal with massive pieces of software and their integration with several hardware components. To ease the development of such systems, engineers adopt a divide and conquer approach : each concern of the system is engineered separately, with several domain specific languages (DSL) and stakeholders. The current practice for making DSLs is to rely on the Model-driven Engineering (MDE. On the other hand, systems engineering companies also need to construct slightly different versions/variants of a same system; these variants share commonalities and variabilities that can be managed using a Software Product Line (SPL) approach. A promising approach is to ally MDE with SPL – Model-based SPLs (MSPL) – in a way that the products of the SPL are expressed as models conforming to a metamodel and well-formedness rules. The Common Variability Language (CVL) has recently emerged as an effort to standardize and promote MSPLs. Engineering an MSPL is extremely complex to an engineer: the number of possible products is exponential; the derived product models have to conform to numerous well- formedness and business rules; and the realization model that connects a variability model and a set of design models can be very expressive specially in the case of CVL. Managing variability models and design models is a non-trivial activity. Connecting both parts and therefore managing all the models is a daunting and error-prone task. Added to these challenges, we have the multiple different modeling languages of systems engineering. Each time a new modeling language is used for developing an MSPL, the realization layer should be revised accordingly. The objective of this thesis is to assist the engineering of MSPLs in the systems engineering field, considering the need to support it as earlier as possible and without compromising the existing development process. To achieve this, we provide a systematic and automated process, based on CVL, to randomly search the space of MSPLs for a given language, generating counterexamples that can server as antipatterns. We then provide ways to specialize CVL’s realization layer (and derivation engine) based on the knowledge acquired from the counterexamples. We validate our approach with four modeling languages, being one acquired from industry; the approach generates counterexamples efficiently, and we could make initial progress to increase the safety of the MSPL mechanisms for those languages, by implementing antipattern detection rules. Besides, we also analyse big Java programs, assessing the adequacy of CVL to deal with complex languages; it is also a first step to assess qualitatively the counterexamples. Finally, we provide a methodology to define the processes and roles to leverage MSPL engineering in an organization.

Network science emerged as an interdisciplinary field over the last 20 years, and played a central role to address fundamental problems in other fields, e.g., epidemiology, public health, and transportation, and is now part of most university curriculums. Network dynamics is a major area within network science where researchers study different forms of processes in networked populations, such as the spread of emotions, influence, opinions, flu, ebola, and mass movements. These processes often referred to individually and collectively as contagions. Contagions are increasingly studied because of their economic, social, and political impacts. Yet, resources for studying network dynamics are largely dispersed and stand-alone. Furthermore, many researchers interested in the study of networks are not computer scientists. As a result, they do not have easy access to computing and data resources. Even with the presence of software or tools, it is challenging to install, build, and maintain software. These challenges create a barrier for researchers and domain scientists. The goal of this work is the design and implementation of a research framework for modeling contagions on large networked populations. The framework consists of various systems and services that provide support for researchers and domain scientists at different stages of their research workflow. / Ph. D.