The dynamic query language GraphQL is gaining popularity within the field as more and more software architects choose it as their architectural model of choice when designing an API. The dynamic nature of the GraphQL queries provide a different way of thinking about data fetching, focusing more on the experience for the API consumer. The language provides many exciting features for the field, but not much is known about the implications of implementing them. This thesis analyzes the architecture of GraphQL and explores its attributes in order to understand the tradeoffs and performance implications of implementing a GraphQL architecture in a data-fetching API, as opposed to a conventional REST architecture. The results from the architectural analysis suggests that the GraphQL architecture values the usability and supportability attributes higher than its REST counterpart. A performance experiment was performed, testing the internal performance of GraphQL versus REST in a use-case where its dynamic functionality is not utilized (returning the same static response as its REST equivalent). The results indicate that the performance of GraphQL implementations are lower than that of its REST equivalents in use-cases where the dynamic functionality is not utilized.

Este trabalho discorre sobre o estudo da utilização do método de avaliação ATAM como referência para um roteiro para evolução arquitetural. O estudo apresentado está dividido em duas partes: a elaboração de um roteiro para evolução de software e a aplicação do roteiro em um ambiente real de um sistema para automação de linhas aéreas. O objetivo é avaliar o uso do método de avaliação de arquitetura para direcionar a evolução do software. As diretrizes geradas neste trabalho orientam as ações a serem tomadas com base em evidências obtidas pela avaliação, possibilitando ao software que exiba os atributos de qualidade desejados. / This paper discusses the study of the use of ATAM evaluation method as a reference to a roadmap for architectural evolution. The present study is divided into two parts: the preparation of a roadmap for software development and implementation of the roadmap in a real environment of a system for automation of airlines. The goal is to evaluate the use of architecture evaluation method to direct the evolution of software. The guidelines generated in this work have guided the actions to be taken based on evidence obtained by the evaluation, enabling the software that displays the desired quality attributes.

Este trabalho discorre sobre o estudo da utilização do método de avaliação ATAM como referência para um roteiro para evolução arquitetural. O estudo apresentado está dividido em duas partes: a elaboração de um roteiro para evolução de software e a aplicação do roteiro em um ambiente real de um sistema para automação de linhas aéreas. O objetivo é avaliar o uso do método de avaliação de arquitetura para direcionar a evolução do software. As diretrizes geradas neste trabalho orientam as ações a serem tomadas com base em evidências obtidas pela avaliação, possibilitando ao software que exiba os atributos de qualidade desejados. / This paper discusses the study of the use of ATAM evaluation method as a reference to a roadmap for architectural evolution. The present study is divided into two parts: the preparation of a roadmap for software development and implementation of the roadmap in a real environment of a system for automation of airlines. The goal is to evaluate the use of architecture evaluation method to direct the evolution of software. The guidelines generated in this work have guided the actions to be taken based on evidence obtained by the evaluation, enabling the software that displays the desired quality attributes.

A utilização da Internet como um meio de automação de serviços de e-business tem sido adotada como estratégia por empresas em vários ramos da economia, diminuindo custos e propiciando uma melhoria no relacionamento com o cliente. Um requisito não-funcional importante a ser considerado no desenvolvimento de sistemas de software que possibilita esta automação é a disponibilidade. O nível de disponibilidade de um sistema pode ser influenciado pela arquitetura do sistema, e, em particular, pela arquitetura de software, pois as decisões arquitetônicas devem considerar aspectos relacionados à disponibilidade. No método de avaliação de arquitetura ATAM (Architecture Tradeoff Analysis Method Método de Análise de Compromissos de Arquitetura), esse requisito é analisado através da utilização de cenários de disponibilidade. Como a avaliação da disponibilidade é normalmente uma tarefa complexa, requerendo dos analistas a identificação de numerosos itens interdependentes, a geração e, conseqüentemente, a análise de cenários de disponibilidade na maioria das vezes não é uma tarefa trivial. O presente trabalho tem como objetivo elaborar uma técnica de análise de disponibilidade em sistemas de software para a Web, que auxilie a geração sistemática de cenários de disponibilidade requeridos no método ATAM. Para a elaboração da proposta, o trabalho aborda métodos para a elicitação, representação e análise de requisitos não-funcionais em uma determinada arquitetura de software, bem como conceitos e taxonomias relacionadas à dependabilidade. Ao final, a técnica é exercitada em um exemplo simplificado de sistema de software bancário na Web. / The use of Internet for e-business service automation has been adopted as a strategy by organizations in several sectors of the economy, reducing costs and providing a better relationship with the customer. Availability is an important nonfunctional requirement to be considered in the development of software systems offering this type of automation. The level of system availability may be affected by the system architecture, and, especially, by the software architecture, as architectural decisions must take availability-related aspects into account. In the ATAM (Architecture Tradeoff Analysis Method) architecture evaluation method, this requirement is analyzed by means of availability scenarios. As availability evaluation is normally a complex task, requiring analysts to identify several interdependent items, the generation and, consequently, the analysis of availability scenarios is often not a trivial task. This work aims to elaborate an availability technique analysis for web-based software systems, to aid in the systematic generation of availability scenarios required in the ATAM method. To elaborate the proposal, the work covers methods for elicitation, representation and analysis of non-functional requirements in a specific software architecture, as well as concepts and taxonomies related to dependability. In the end, the technique is applied on a simplified example of web banking software system.

A utilização da Internet como um meio de automação de serviços de e-business tem sido adotada como estratégia por empresas em vários ramos da economia, diminuindo custos e propiciando uma melhoria no relacionamento com o cliente. Um requisito não-funcional importante a ser considerado no desenvolvimento de sistemas de software que possibilita esta automação é a disponibilidade. O nível de disponibilidade de um sistema pode ser influenciado pela arquitetura do sistema, e, em particular, pela arquitetura de software, pois as decisões arquitetônicas devem considerar aspectos relacionados à disponibilidade. No método de avaliação de arquitetura ATAM (Architecture Tradeoff Analysis Method Método de Análise de Compromissos de Arquitetura), esse requisito é analisado através da utilização de cenários de disponibilidade. Como a avaliação da disponibilidade é normalmente uma tarefa complexa, requerendo dos analistas a identificação de numerosos itens interdependentes, a geração e, conseqüentemente, a análise de cenários de disponibilidade na maioria das vezes não é uma tarefa trivial. O presente trabalho tem como objetivo elaborar uma técnica de análise de disponibilidade em sistemas de software para a Web, que auxilie a geração sistemática de cenários de disponibilidade requeridos no método ATAM. Para a elaboração da proposta, o trabalho aborda métodos para a elicitação, representação e análise de requisitos não-funcionais em uma determinada arquitetura de software, bem como conceitos e taxonomias relacionadas à dependabilidade. Ao final, a técnica é exercitada em um exemplo simplificado de sistema de software bancário na Web. / The use of Internet for e-business service automation has been adopted as a strategy by organizations in several sectors of the economy, reducing costs and providing a better relationship with the customer. Availability is an important nonfunctional requirement to be considered in the development of software systems offering this type of automation. The level of system availability may be affected by the system architecture, and, especially, by the software architecture, as architectural decisions must take availability-related aspects into account. In the ATAM (Architecture Tradeoff Analysis Method) architecture evaluation method, this requirement is analyzed by means of availability scenarios. As availability evaluation is normally a complex task, requiring analysts to identify several interdependent items, the generation and, consequently, the analysis of availability scenarios is often not a trivial task. This work aims to elaborate an availability technique analysis for web-based software systems, to aid in the systematic generation of availability scenarios required in the ATAM method. To elaborate the proposal, the work covers methods for elicitation, representation and analysis of non-functional requirements in a specific software architecture, as well as concepts and taxonomies related to dependability. In the end, the technique is applied on a simplified example of web banking software system.

Algorithmic self-assembly has been an active area of research at the intersection of computer science, chemistry, and mathematics for almost two decades now, motivated by the natural self-assembly mechanism found in DNA and driven by the desire for precise control of nanoscale material manufacture and for the development of nanocomputing and nanorobotics. At the theoretical core of this research is the Abstract Tile Assembly Model (aTAM), the original abstract model of DNA tile self-assembly. Recent advancements in DNA nanotechnology have been made in developing strand displacement mechanisms that could allow DNA tiles to modify themselves during the assembly process by opening or closing certain binding sites, introducing new dynamics into tile self-assembly. We focus on one way of incorporating such signaling mechanisms for binding site activation and deactivation into the theoretical model of tile self-assembly by extending the aTAM to create the Active aTAM. We give appropriate definitions first for incorporating activation signals and then for incorporating deactivation signals and tile detachment into the aTAM. We then give a comparison of Active aTAM to related models, such as the STAM, and take a look at some theoretical results. The goal of the work presented here is to define and demonstrate the power of the Active aTAM with and without deactivation. To this end, we provide four constructions of temperature 1 (also known as "non-cooperative") active tile assembly systems that can simulate other computational systems. The first construction concerns the simulation of an arbitrary temperature 2 (also known as "cooperative") standard aTAM system in the sense of producing equivalent structures with a scaling factor of 2 in each dimension; the second construction generates the time history of a given 1D cellular automaton. The third and fourth constructions make use of tile detachment in order to dynamically simulate arbitrary 1D and 2D cellular automata with assemblies that record only the current state updates and not the entire computational history of the specified automaton.

<p>It is not unusual that software systems are redeveloped when the systems environment changes or new requirements to functionality are found. The reason for this is that system evolution is usually not considered during the initial development of a system.</p><p>In this report we propose a development process focusing on modifiability in security-safety critical systems. The process is based on the standard IEC 61508 Functional safety of electrical/electronic/programmable electronic safety-related systems and the CORAS framework for model-based risk assessment. We focus on integrating modifiability as a non-functionality and extend the development process with an architecture and design phase. Modifiability is addressed using Architecture Tradeoff Analysis Method (ATAM) and Attribute Driven Design (ADD). An evaluation of this process is given by redeveloping a prototype for an already existing security-critical system using the approaches given by the process. The main result from the evaluation showed that we where able to obtain a higher level of modifiability than the original prototype, without compromising the functionality and safety level required.</p>

It is not unusual that software systems are redeveloped when the systems environment changes or new requirements to functionality are found. The reason for this is that system evolution is usually not considered during the initial development of a system. In this report we propose a development process focusing on modifiability in security-safety critical systems. The process is based on the standard IEC 61508 Functional safety of electrical/electronic/programmable electronic safety-related systems and the CORAS framework for model-based risk assessment. We focus on integrating modifiability as a non-functionality and extend the development process with an architecture and design phase. Modifiability is addressed using Architecture Tradeoff Analysis Method (ATAM) and Attribute Driven Design (ADD). An evaluation of this process is given by redeveloping a prototype for an already existing security-critical system using the approaches given by the process. The main result from the evaluation showed that we where able to obtain a higher level of modifiability than the original prototype, without compromising the functionality and safety level required.

The thesis work intends to provide architecture for mobile local information search service using Wireless LAN and cellular integration. Search technology has been popular and driving business bodies with increasing e-commerce opportunities. The search technology has been recently brought to portable devices such as mobile phones and PDA devices by extending the research scope. Mobile search revenues are expected to surpass Internet search revenues in near future. Mobile local search on the other hand is getting much popular with growing number of mobile subscribers. Mobile phones have been chosen to provide mobile local search services because of its high possessivity and portable nature. In this thesis work, the author would like to propose a generalized architecture for mobile local information search in a new perspective by involving cellular service provider directly with a minimum co-operation from consumers and retailers. When providing mobile local search services, cellular operator has to maintain a replica of databases of all the existing retailers. Updating the replica at cellular operator at regular intervals has been leading to synchronization problems that produce out-dated results to mobile users. The aspects that have driven the author towards proposing the architecture are solving database synchronization problems and thriving for effective search results. The existing architecture of web search, mobile search and mobile local search are analyzed to identify the domain specific challenges and research gaps. Proposed architecture is designed and evaluated by using an approach called Architecture Tradeoff Analysis Method (ATAM). The architecture is evaluated against its quality attributes and the results are presented. / Sridher Rao Sidduri Lindblomsvagen, 97, Rum no 555, 372 33 Ronneby, Sweden E-mail: srsi05@student.bth.se