Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 197-203).

Thesis (Ph. D.)--University of Texas at Austin, 2008. / Vita. Includes bibliographical references.

This thesis deals with the problem of interaction with context-aware mobile applications in digitally augmented physical spaces. The term "mobile application" is used as an umbrella term for any piece of software that can run on a mobile device in order to support a human task. “Context-aware” refers to the ability of such applications to use information about the environment or the user to adapt their behaviour accordingly. A "physical hyperlink" is a mechanism that associates a physical object or point in space with digital information/service(s). The term “digitally augmented physical space” refers here to a physical space where digital information relevant to points or artefacts can be accessed (e.g. by means of physical hyperlinks). In the last two decades mobile devices and applications have developed tremendously. With them, on one hand new ways appeared to support human tasks and on the other hand new research challenges emerged. A key factor is the continuous change of environment and context of use. This is very different to a classic desktop computer application, in which the external environment is hardly changing, as the user and the computer do not change location during interaction. In the world of mobile computing the environment and the context of use are changing, at a faster rate. One of the most widely spread mobile devices, the mobile phone, evolved into a powerful mobile computing device. These advanced devices are now ubiquitously spread and already billions of people carry and use them daily. New services and uses are emerging with every step of evolution of this technology. However these rapidly emerging and evolving technologies and services result in a generally heterogeneous environment that affects user experience. The advances in mobile technology permitted devices to be equipped with sensors and hardware that allow on one hand the acquisition of information from the environment and on the other hand interaction with objects like physical hyperlinks, that permit direct access to information related to physical artefacts. In the frame of this thesis a conceptual framework (MobiAct framework) and a service oriented architecture (MobiAct architecture) have been defined. The MobiAct framework deals with the interaction with context-aware mobile applications in a digitally augmented physical space. The MobiAct framework has as a goal to identify the main concepts that come into play while interacting with context-aware applications in digitally augmented physical spaces. MobiAct architecture is an innovative solution for delivering context-aware mobile services in digitally augmented physical spaces. The MobiAct architecture has MobiAct framework as the underlying base. The architecture aims at enabling a uniform and consistent user experience across spaces and contexts and at facilitating the design and development of context-aware mobile services by providing ready functionality for common tasks. Finally a set of software architectural patterns relevant to designing mobile context-aware applications have been identified. These patterns provide a set of building blocks to facilitate the design and development of similar systems. The road towards designing MobiAct conceptual architecture and framework for interacting with context-aware mobile applications included the development and evaluation of several prototypes mainly targeted at public and semi-public environments. These prototypes contributed in a great degree towards exploring and studying context-aware mobile applications and interaction with digitally augmented physical spaces using physical hyperlinks and subsequently defining the requirements for the architecture. To avoid binding the architecture to capabilities of a certain platform, the prototypes involved different devices and platforms. The prototypes and applications developed included educational games and a guide for a museum, an application to support users of a library and a shopping assistant aimed at a supermarket environment. The findings of these efforts contributed in the definition of the MobiAct architecture that has been evaluated through a software architecture analysis method based on scenarios and discussions involving representative stakeholders as well as an evaluation team / Αυτή η διατριβή πραγματεύεται το πρόβλημα της αλληλεπίδρασης μεταξύ χρηστών και εφαρμογών φορητών συσκευών με επίγνωση του πλαισίου, σε ψηφιακά επαυξημένους φυσικούς χώρους. Ο όρος "εφαρμογή φορητής συσκευής", ή “φορητή εφαρμογή”, χρησιμοποιείται ως όρος που περικλείει κάθε λογισμικό που μπορεί να εκτελεστεί σε μια φορητή συσκευή έτσι ώστε να υποστηρίξει μια ανθρώπινη εργασία (task). Ο όρος "πλαισιογνωστικός" αναφέρεται στη δυνατότητα τέτοιων εφαρμογών να χρησιμοποιήσουν πληροφορίες σχετικές με το άμεσο περιβάλλον ή με το χρήστη ώστε να προσαρμόσουν τη συμπεριφορά τους κατάλληλα. Ένας "φυσικός υπερσύνδεσμος" είναι ένας μηχανισμός που συσχετίζει ένα φυσικό αντικείμενο ή σημείο στο χώρο με ψηφιακή πληροφορία ή ψηφιακή υπηρεσία. Ο όρος "ψηφιακά επαυξημένος χώρος" αναφέρεται σε ένα φυσικό χώρο από όπου είναι προσβάσιμη ψηφιακή πληροφορία που σχετίζεται με σημεία ή αντικείμενα του χώρου (π.χ. μέσω φυσικών υπερσυνδέσμων). Τις τελευταίες δύο δεκαετίες οι φορητές συσκευές και εφαρμογές έχουν εξελιχθεί εντυπωσιακά. Μαζί τους εμφανίστηκαν νέοι τρόποι υποστήριξης ανθρώπινων εργασιών και παράλληλα παρουσιάστηκαν και νέα ερευνητικά προβλήματα. Ένας σημαντικός παράγοντας είναι η συνεχής αλλαγή του περιβάλλοντος στο οποίο γίνεται η χρήση και του πλαισίου επίγνωσης της χρήσης. Αυτό διαφέρει πολύ από τις κλασικές εφαρμογές υπολογιστών, όπου το εξωτερικό περιβάλλον αλλάζει ελάχιστα καθώς ο χρήστης και ο υπολογιστής δεν μεταβάλλουν τη θέση τους στη διάρκεια της αλληλεπίδρασης. Στον κόσμο των φορητών υπολογιστών το περιβάλλον και το πλαίσιο επίγνωσης αλλάζουν με γρηγορότερο ρυθμό. Μια από τις πιο ευρέως διαδεδομένες φορητές συσκευές, το κινητό τηλέφωνο, εξελίχθηκε σε μια ισχυρή φορητή υπολογιστική συσκευή. Αυτές οι εξελιγμένες συσκευές είναι σήμερα διάχυτες και δισεκατομμύρια ανθρώπων τις κουβαλούν και χρησιμοποιούν καθημερινά. Νέες υπηρεσίες και χρήσεις εμφανίζονται με κάθε βήμα εξέλιξης αυτής της τεχνολογίας. Ωστόσο αυτές οι ταχέως εμφανιζόμενες και εξελισσόμενες τεχνολογίες και υπηρεσίες καταλήγουν να δημιουργήσουν ένα γενικώς ετερογενές περιβάλλον, πράγμα το οποίο επηρεάζει την εμπειρία της χρήσης τους. Οι εξελίξεις στη φορητή τεχνολογία επέτρεψαν στις συσκευές αυτές να εξοπλισθούν με αισθητήρες και υλικό το οποίο επιτρέπει τη συλλογή πληροφοριών από το περιβάλλον και επίσης την αλληλεπίδραση με αντικείμενα όπως είναι οι φυσικοί υπερσύνδεσμοι, οι οποίοι επιτρέπουν την άμεση πρόσβαση σε πληροφορία που σχετίζεται με τα φυσικά αντικείμενα. Στο πλαίσιο αυτής της εργασίας ορίστηκε ένα εννοιολογικό πλαίσιο (πλαίσιο εργασίας MobiAct) και μια υπηρεσιοκεντρική αρχιτεκτονική (service oriented architecture) (αρχιτεκτονική MobiAct). Το πλαίσιο εργασίας MobiAct αφορά την αλληλεπίδραση με πλαισιογνωστικές φορητές εφαρμογές σε ψυφιακά επαυξημένους φυσικούς χώρους. Η αρχιτεκτονική MobiAct έχει ως στόχο τον εντοπισμό των βασικών σημείων της αλληλεπίδρασης με πλαισιογνωστικές εφαρμογές σε ψηφιακά επαυξημένους φυσικούς χώρους. Η αρχιτεκτονική MobiAct είναι μια πρωτοποριακή λύση για την παροχή πλαισιογνωστικών υπηρεσιών σε ψηφιακά επαυξημένους φυσικούς χώρους. Η βάση της αρχιτεκονικής MobiAct είναι το πλαίσιο εργασίας MobiAct. Η αρχιτεκτονική στοχεύει στην πραγμάτωση μιας ομοιόμορφης και συνεπούς εμπειρίας χρήστη διαμπάξ σε διάφορους φυσικούς χώρους και πλαίσια επίγνωσης και στη διευκόλυνση της ανάπτυξης πλαισιογνωστικών φορητών υπηρεσιών (μέσω της παροχής λειτουργικότητας για εργασίες που επαναλαμβάνονται συχνά). Τέλος έχει εντοπιστεί ένα σύνολο αρχιτεκτονικών προτύπων για το σχεδιασμό φορητών πλαισιογνωστικών εφαρμογών. Αυτά τα πρότυπα συγκροτούν μια ομάδα καλουπιών που διευκολύνουν το σχεδιασμό και την ανάπτυξη παρεμφερών συστημάτων. Η πορεία προς το σχεδιασμό του πλαισίου και της αρχιτεκτονικής MobiAct για την αλληλεπίδραση με φορητές πλαισιογνωστικές εφαρμογές συμπεριέλαβε το σχεδιασμό και την ανάπτυξη αρκετών πρωτοτύπων τα οποία στόχευαν κυρίως σε δημόσια ή ημι-δημόσια περιβάλλοντα. Αυτά τα πρωτότυπα συνέβαλαν σε μεγάλο βαθμό στην εξερεύνηση και στη μελέτη των πλαισιογνωστικών φορητών εφαρμογών και της αλληλεπίδρασης με ψηφιακά επαυξημένους φυσικούς χώρους μέσω φυσικών υπερσυνδέσμων και τελικά στον ορισμό των απαιτήσεων για την αρχιτεκτονική. Για την αποφυγή της υπερβολικής συσχέτισης της αρχιτεκτονικής με τις δυνατότητες μιας συγκεκριμένης πλατφόρμας, τα πρωτότυπα συμπεριέλαβαν διάφορες συσκευές και πλατφόρμες. Τα πρωτότυπα και οι εφαρμογές που αναπτύχθηκαν περιλαμβάνουν εκπαιδευτικές εφαρμογές και έναν πλοηγό για ένα μουσείο, μια εφαρμογή για την υποστήριξη των επισκεπτών μιας βιβλιοθήκης καθώς και έναν βοηθό αγορών σε περιβάλλον σούπερ μάρκετ. Τα ευρήματα αυτών των προσπαθειών συνέβαλλαν στον ορισμό της αρχιτεκτονικής MobiAct η οποία αξιολογήθηκε χρησιμοποιώντας μια μεθοδολογία ανάλυσης αρχιτεκτονικών λογισμικού που βασίζεται σε σενάρια και συζητήσεις με αντιπροσωπευτικούς συμμετόχους καθώς και με μια ομάδα αξιολόγησης.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / The present research aims to compare the different technologies that allow real-time communication between Android and iOS devices. We conducted a measurement-driven experiment to test the performance of each technology under different scenarios. We determine their functionality according to the environment for which they have been developed, showing competent information about their capabilities based on the communication channel they use, and their performance measured in milliseconds. The final results allow mobile application developers to determine which technologies suits them the best, based on the specific context of their projects. / Revisión por pares

Resilient Distributed Systems (RDS) are large-scale distributed systems that remain de-pendable despite their very dynamic, open-ended, and inherently unpredictable environ-ments. This combination of system and environment properties makes development of soft-ware architectures for RDS using contemporary architecture models and abstractions very challenging. Therefore, the thesis proposes: (1) new architecture abstractions that are tailored for building dynamic software architectures for RDS, (2) design models and processes that endorse these abstractions at design time, and (3) means for efficient implementation, execu-tion, and analysis of architectures based on these abstractions. Specifically, the thesis delivers (1) by introducing the DEECo component model, based on the concept of component ensembles. Contributing to (2), the thesis presents the Invari-ant Refinement Method, governing dependable, formally-grounded design of DEECo-based architectures, and the ARCAS method, focusing on dependable realization of open-ended dynamic component bindings typical for DEECo. Furthermore, it pursues (3) by presenting a formal operational semantics of DEECo and its mapping to Java in terms of an execution environment prototype - jDEECo. Additionally, the semantics is used as a basis for formal analysis via model...

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-05-08T17:28:24Z No. of bitstreams: 1 IZABELA VANESSA DE ALMEIDA MELO - DISSERTAÇÃO PPGCC 2015..pdf: 3198472 bytes, checksum: 824f30587ab3b750011a08d2e5d6019a (MD5) / Made available in DSpace on 2018-05-08T17:28:24Z (GMT). No. of bitstreams: 1 IZABELA VANESSA DE ALMEIDA MELO - DISSERTAÇÃO PPGCC 2015..pdf: 3198472 bytes, checksum: 824f30587ab3b750011a08d2e5d6019a (MD5) Previous issue date: 2015-09-10 / Desde os anos 90 a comunidade científica desempenha esforços para estudar e evoluir aspectos relacionados à Arquitetura de Software, aumentando seu volume de publicação a partir de 1999. O aumento significativo das publicações nos últimos anos demonstra a importância e preocupação que a academia tem com relação a essa área. Porém, a partir da troca de experiência entre pesquisadores e profissionais da área, percebe-se que a indústria não parece conhecer/utilizar o que é proposto pela academia. O contexto teórico sobre arquitetura de software, documentação arquitetural e verificação de conformidade arquitetural já é conhecido no meio acadêmico. Porém, qual é o contexto deles dentro da indústria? Como os profissionais definem o termo "arquitetura desoftware"? Como os profissionais realizam (se realizam) a documentação arquitetural? Como realizam (se realizam) a verificação de conformidade arquitetural? O que eles pensam sobre ferramentas de apoio à verificação de conformidade arquitetural? Para responder essas questões, realizamos um estudo qualitativo dividido em 3 etapas. Primeiro, aplicamos um survey exploratório com o objetivo de entender o ambiente prático para ter uma noção sobre o contexto em foco. Enviamos o questionário para 149 profissionais e 4 grupos de discussão, obtendo uma taxa de resposta de 24,1%. Na segunda etapa entrevistamos 14 profissionais voluntários que responderam o survey exploratório (taxa de resposta de 40%). O objetivo desta etapa foi nos aprofundarmos no contexto em foco. Por fim, nossa última etapa consistiu de um survey confirmatório. Enviamos o questionário para os usuários do GitHub que possuem endereços de e-mail visíveis e tem mais de 100 seguidores (obtivemos uma taxa de resposta de 7,74%). Como resultados principais, observamos que não há uma única definição para o termo "arquitetura de software", dependendo de fatores desde a experiência do profissional até a empresa em que trabalham. Além disso, existem documentações arquiteturais, mas, a sua maioria não é rigorosa, formal e não é atualizada. Nem todos realizam verificação de conformidade arquitetural, e, quando realizam, normalmente é feita de forma manual. Os principais motivos para a não documentação e/ou verificação são falta de tempo ou falta de necessidade. Porfim, as ferramentas de apoio à verificação de conformidade arquitetural não são muito utilizadas e/ou conhecidas. / Since the 90’s a big effort has been applied in the academy to study and evolve aspects related to Software Architecture, increasing the amount of publications from 1999 to the present-day. The significant rise in the number of publications in the last few years shows how much importance and concern academia gives to this particular area. However, after discussing what has been experienced by researchers and professionals of this area, it is possible to notice that the industry does not know/use what is proposed in the academy. The theoretical context about software architecture, architectural documentation and architectural conformance checking is already known. However, what about the practical/industrial context? How do the professionals define “software architecture”? How do they document (if they do) the architecture? How do they perform (if they do) architectural conformance checking? What do they think about support tools for architectural conformance checking? Aiming to answer these questions, we performed a 3-step qualitative study. Firstly, we applied an exploratory survey with the goal of understanding the practical environment and having a better notion about the context of our study. We sent the survey to 149 professionals and 4 discussion groups, getting 24.1% of response rate. In the second phase we interviewed 14 volunteered professionals who responded the exploratory survey (response rate of 40%). In this phase we wanted to deeply understand the context of your study. Finally, the last phase consisted of a confirmatory survey which goal was to confirm our findings. We sent the survey to GitHub users with public e-mails and more than 100 followers, getting 7.74% of response rate. As main results we observed that there is not a single definition of“software architecture” and that it depends on several factors, as the professional’s experience and the company in which he/she works. The architecture is sometimes documented but, most of the time, the documentation is incomplete, informal and outdated. In many cases, architectural conformance checking is not performed or it is performed manually. The main reasons for not documenting or verifying the architecture are lack of time and/or need. Finally, the support tools for architectural conformance checking are not often used and not well known.

There are limited tools to evaluate a microservice architecture and no common definition of how the architecture should be designed. Moreover, developing systems with microservices introduces additional complexity to the software architecture. That, together with the fact the systems are becoming more complex has led to a desire for architecture evaluation methods. In this thesis a set of quality attributes measured by structural metrics are used to evaluate Scania's IoT Offboard platform. By implementing a metrics evaluation program the quality of the software architecture can be improved. Also, metrics can assist developers and architects while they are becoming more efficient since they better understand how performance is measured, i.e. which quality attributes are the most important and how these are measured. For Scania's IoT Offboard platform the studied quality attributes are listed in decreasing importance: flexibility, reusability and understandability. All the microservices are loosely coupled in the platform, which results in a loosely coupled architecture. This indicates a flexible, reusable and understandable system, in terms of coupling. Furthermore, the architecture is decentralized, i.e. the system is unflexible and difficult to change. The other metrics were lacking a reference scale, hence they will act as a point of reference for future measurements as the architecture evolves. To improve the flexibility, reusability and understandability of the architecture the large microservices should be divided into several smaller microservices. Also aggregators should be utilized more to make the system more flexible.

O desenvolvimento de arquiteturas de controle para veículos submarinos é uma tarefa complexa. Estas podem ser caracterizadas pelos seguintes atributos: tempo real, multitarefa, concorrência e comunicações distribuídas em rede. Neste cenário, existem múltiplos processos sendo executados em paralelo, possivelmente distribuídos, e se comunicando uns com os outros. Neste contexto, o modelo comportamental pode levar a fenômenos como deadlocks, livelocks, disputa por recursos, entre outros. A fim de se tentar minimizar os efeitos de tais dificuldades, neste trabalho será apresentado um método para checagem de modelos de arquiteturas de controle de veículos submarinos baseado em Especificações Formais. A linguagem de especificação formal escolhida foi CSP-OZ, uma combinação de CSP e Object-Z. Object-Z é uma extensão orientada a objetos da linguagem Z para a especificação de predicados, tipicamente pré e pós condições, além de invariantes de dados. CSP (Communicating Sequential Process) é uma álgebra de processos desenvolvida para descrever modelos comportamentais de processos paralelos. A checagem de modelos especificados formalmente consiste na análise das especificações para verificar se um sistema possui certas propriedades através de uma busca exaustiva em todos os estados em que este pode entrar durante sua execução. Neste contexto, é possível checar corretude, livelocks, deadlocks, etc. Além disso, pode-se relacionar duas especificações diferentes a fim de se checar relações de refinamento. Para as especificações, o verificador de modelos FDR da Formal Systems Ltd. será utilizado. A implementação é desenvolvida utilizando um perfil da linguagem Ada denominado RavenSPARK, uma junção do perfil Ravenscar (desenvolvido na Universidade de York) com a linguagem SPARK (um subconjunto da linguagem Ada desenvolvido pela Praxis, Inc.). O Ravenscar é um perfil para desenvolvimento de processos, e portanto os processos de CSP, incluindo seus canais de comunicação, podem ser facilmente criados. Por outro lado, SPARK é uma linguagem onde podem ser inseridos predicados para os dados (originalmente especificados em Object-Z) utilizando anotações da própria linguagem. A linguagem SPARK possui uma ferramenta, o Examinador, que pode checar códigos de modelos baseado nestas anotações. Em resumo, o método proposto permite tanto a checagem de modelos em CSP quanto a checagem no nível de código. Para isso, as especificações em Object-Z devem inicialmente ser convertidas em um código na linguagem SPARK juntamente com suas respectivas anotações, para que então a checagem do modelo possa ser realizada no código. O desenvolvimento de uma arquitetura de controle reativa para um ROV denominado VSOR (Veículo Submarino Operado Remotamente) é utilizado como exemplo de uso do método proposto. Toda a arquitetura de controle é codificada utilizando a linguagem Ada com o perfil RavenSPARK e embarcada em um computador do tipo PC104 com o sistema operacional de tempo real VxWorks, da Windriver, Inc. / The development of control architectures for Underwater Vehicles is a complex task. These control architectures might be chracterised by the following attributes: real-time, multitasking, concurrency, and distributed over communication networks. In this scenario, we have multiple processes running in parallel, possibly distributed, and engaging in communication between each other. In this context, the behavioural model might lead to phenomena like deadlocks, livelocks, race conditions, among others. In order to try to minimize the effects of such difficulties, in this work a method for model checking control architectures of underwater vehicles based on formal specifications is presented. The chosen formal specification language is CSP-OZ, a combination of CSP and Object-Z. Object-Z is an object-oriented extension of Z for the specification of predicates, typically, data pre, post and invariant conditions. CSP (Communicating Sequential Process) is a process algebra developed to describe behavioural models of parallel process. The model checking of formal specifications is a task of reasoning on specifications in which a system verifies certain properties by means of an exhaustive search of all possible states that a system could enter during its execution. In this context, it is possible to check about correctness, liveness, deadlock, etc. Also, one can relate two different specifications in order to check a refinement ordering. For the specifications, the model checker FDR of Formal Systems Ltd. is utilised. The implementation is developed using an ADA language profile called RavenSPARK, a union of the Ravenscar profile (developed at the University of York) and the SPARK language (a subset of the ADA language developed by Praxis, Inc.). The Ravenscar is a profile for developing processes, so CSP processes including their message channels can be easily deployed. On the other hand, SPARK is a language where one can insert data predicates (originally specified in Object-Z) using language annotations. The SPARK language has a tool, the Examiner, that can model check code based on these annotations. In summary, the proposed method allows model checking of CSP processes but does not allow any checking in the code level. On the contrary, Object-Z specifications must first be converted into a SPARK language code, together with proper annotations, and then model checking can be realised in code. The development of a real-time reactive control architecture of an ROV named VSOR (Veiculo Submarino Operado Remotamente) is used as an example of the use of the proposed method. The whole control architecture is coded using the ADA Language with the RavenSPARK profile and deployed into a PC104 cpu system running the Vxworks real-time operating system of Windriver, Inc.

Embedded systems, including critical embedded systems (CES) are increasingly present in the modern society, providing specific solutions from small to large complex systems, such as in cars, airplanes, and healthcare equipment. Failures in these systems can result in damage to human beings, and to the environment, or can represent an unrecoverable financial loss. In this sense, it is very important to ensure they are built with quality. To provide such quality, it is necessary to consider their software architecture, which impacts on the quality of the systems. This way, the main objective of this Masters project is to propose a quality model concerning the most important quality attributes for CES, which may be used to support (but not limited to) architectural activities such as analysis and evaluation in the context of CES. / Sistemas embarcados, incluindo sistemas embarcados críticos (SEC), estão cada vez mais presentes na sociedade moderna, provendo soluções específicas que variam de sistemas pequenos até sistemas grandes e complexos, como é possível encontrar em carros, aviões e equipamentos médicos. Falhas nesses sistemas podem resultar em danos à seres humanos e ao meio ambiente, ou então em uma perda financeira irrecuperável. Sendo assim, é muito importante garantir que os SEC sejam construídos e apresentem um nível adequado de qualidade. Para garantir que esses sistemas alcancem tal qualidade, é necessário considerar sua arquitetura de software, já que esta impacta de maneira significativa na qualidade do software enquanto artefato ou produto. Deste modo, o objetivo deste projeto de mestrado é de propor um modelo de qualidade que contém os atributos de qualidade mais importantes para SEC, servindo como artefato para apoiar a execução de atividades arquiteturais (além de outras que possam se beneficiar) tais como análise e avaliação, no contexto de SEC.

Orientador: Cecilia Mary Fischer Rubira / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-08-10T07:04:57Z (GMT). No. of bitstreams: 1 LimaFilho_FernandoJoseCastorde_D.pdf: 5063998 bytes, checksum: 8bfec9185fab14cb08c2a8b2ce7391a9 (MD5) Previous issue date: 2006 / Resumo: Mecanismos de tratamento de exceções foram concebidos com o intuito de facilitar o gerenciamento da complexidade de sistemas de software tolerantes a falhas. Eles promovem uma separação textual explícita entre o código normal e o código que lida com situações anormais, afim de dar suporte a construção de programas que são mais concisos fáceis de evoluir e confáveis. Diversas linguagens de programação modernas e a maioria dos modelos de componentes implementam mecanismos de tratamento de exceções. Apesar de seus muitos benefícios, tratamento de exceções pode ser a fonte de diversas falhas de projeto se usado de maneira indisciplinada. Estudos recentes mostram que desenvolvedores de sistemas de grande escala baseados em infra-estruturas de componentes têm hábitos, no tocante ao uso de tratamento de exceções, que tornam suas aplicações vulneráveis a falhas e difíceis de se manter. Componentes de software criam novos desafios com os quais mecanismos de tratamento de exceções tradicionais não lidam, o que aumenta a probabilidade de que problemas ocorram. Alguns exemplos são indisponibilidade de código fonte e incompatibilidades arquiteturais. Neste trabalho propomos duas técnicas complementares centradas em tratamento de exceções para a construção de sistemas tolerantes a falhas baseados em componentes. Ambas têm ênfase na estrutura do sistema como um meio para se reduzir o impacto de mecanismos de tolerância a falhas em sua complexidade total e o número de falhas de projeto decorrentes dessa complexidade. A primeira é uma abordagem para o projeto arquitetural dos mecanismos de recuperação de erros de um sistema. Ela trata do problema de verificar se uma arquitetura de software satisfaz certas propriedades relativas ao fluxo de exceções entre componentes arquiteturais, por exemplo, se todas as exceções lançadas no nível arquitetural são tratadas. A abordagem proposta lança de diversas ferramentas existentes para automatizar ao máximo esse processo. A segunda consiste em aplicar programação orientada a aspectos (AOP) afim de melhorar a modularização de código de tratamento de exceções. Conduzimos um estudo aprofundado com o objetivo de melhorar o entendimento geral sobre o efeitos de AOP no código de tratamento de exceções e identificar as situações onde seu uso é vantajoso e onde não é / Abstract: Exception handling mechanisms were conceived as a means to help managing the complexity of fault-tolerant software. They promote an explicit textual separation between normal code and the code that deals with abnormal situations, in order to support the construction of programs that are more concise, evolvable, and reliable. Several mainstream programming languages and most of the existing component models implement exception handling mechanisms. In spite of its many bene?ts, exception handling can be a source of many design faults if used in an ad hoc fashion. Recent studies show that developers of large-scale software systems based on component infrastructures have habits concerning the use of exception handling that make applications vulnerable to faults and hard to maintain. Software components introduce new challenges which are not addressed by traditional exception handling mechanisms and increase the chances of problems occurring. Examples include unavailability of source code and architectural mismatches. In this work, we propose two complementary techniques centered on exception handling for the construction of fault-tolerant component-based systems. Both of them emphasize system structure as a means to reduce the impactof fault tolerance mechanisms on the overall complexity of a software system and the number of design faults that stem from complexity. The ?rst one is an approach for the architectural design of a system?s error handling capabilities. It addresses the problem of verifying whether a software architecture satis?es certain properties of interest pertaining the ?ow of exceptions between architectural components, e.g., if all the exceptions signaled at the architectural level are eventually handled. The proposed approach is based on a set of existing tools that automate this process as much as possible. The second one consists in applying aspect-oriented programming (AOP) to better modularize exception handling code. We have conducted a through study aimed at improving our understanding of the efects of AOP on exception handling code and identifying the situations where its use is advantageous and the ones where it is not / Doutorado / Doutor em Ciência da Computação