Sistemas de software estão cada vez mais presentes na sociedade, bem como são componentes imprescindíveis no mundo contemporâneo, uma vez que facilitam e fomentam as praticidades que os cidadãos e desenvolvedores necessitam. Esses sistemas tornam-se muito mais eficientes quando conseguem interoperar com outros, de forma que troquem recursos e não necessitem implementar essas funcionalidades de maneira individual. Os stakeholders desses sistemas buscam cada vez mais métodos que facilitem essa comunicação, de um jeito prático e sem perder a independência gerencial de cada um. Desse modo, a classe emergente de Sistema de Sistemas (SoS) ganhou uma atenção considerável, por causa de suas características intrínsecas que promovem a interoperabilidade de sistemas distintos e heterogêneos. No entanto, essa comunicação não é trivial, em razão das diferentes interfaces de cada sistema, além da presença de vários stakeholders e a falta de documentação dos sistemas constituintes, dificultando assim, a busca e o uso de cada capacidade. Assim, o objetivo deste trabalho de mestrado é estabelecer uma abordagem baseada em serviços que visa auxiliar os engenheiros de SoS, principalmente na falta de ferramentas de suporte e no esforço para procurar, compreender e adaptar componentes reutilizáveis. A abordagem proposta possui elementos fundamentais que foram utilizados como base para o desenvolvimento de um repositório para engenheiros de SoS e proprietários de sistemas constituintes, de forma organizada e bem documentada, visto que pode ser usado tanto pela comunidade de pesquisa quanto por instituições privadas. / Software systems are increasingly present in society, and consist in indispensable components in the contemporary world, since they facilitate and foster the practices that citizens and developers need. These systems become much more efficient when they can interoperate with others, so that they exchange resources and do not need to implement these features individually. Stakeholders of these systems increasingly seek methods that facilitate such communication in a practical way and without losing the managerial independence of each one. Therefore, the emerging System Of System class (SoS) gained considerable attention, because of its intrinsic characteristics that promote the interoperability of distinct and heterogeneous systems. However, this communication is not trivial, due to the different interfaces of each system, besides the presence of several stakeholders and the lack of documentation of the constituent systems, making it difficult to search and to use each capacity. Thus, the aim of this masters project is to establish a service-based approach that aims to assist SoS engineers, especially in the lack of supporting tools, in the effort to search, understand and adapt reusable components. The proposed approach has fundamental elements that were used as the basis for the development of a repository for SoS engineers and owners of constituent systems, in an organized and well documented way, since it can be used by both the research community and private institutions.

System-of-Systems (SoS) refer to complex, large-scale, and sometimes critical software-intensive systems that has raised as a promising class of systems in several application domains. In parallel, software architectures play a significant role in the development of software-intensive systems, dealing with both functional and non-functional requirements. In particular, systematic processes to design SoS software architectures can tackle challenges from SoS development, including to handle collaboration of independent constituent systems with different owners, missions, and interests. Despite the relevance and necessity of software-intensive SoS for diverse application domains, most of their software architectures have been still developed in an ad hoc manner. In general, there is a lack of structured processes for architecting SoS, hindering the secure adoption of SoS, reducing possibilities of sharing common architectural solutions, and negatively impacting in the success rate for these systems. This thesis presents SOAR (\\General Process for Acknowledged SoS Software Architectures\") that supports the establishment of architectural design processes for acknowledged SoS. Conceived to provide different levels of support according to each SoS development context, it comprises a high level kernel that describes what must be done when architecting SoS and also three practices with specific activities and work products to guide how to perform architectural analysis, synthesis, and evaluation. To evaluate SOAR, three surveys, a viability study, and an experiment were conducted. Results achieved in these evaluation studies indicate that SOAR can positively support the instantiation of architecting processes for acknowledged SoS and, as a consequence, contribute to the development and evolution of these complex, software-intensive systems. / Sistemas-de-sistemas ou SoS (do inglês, \"Systems-of-Systems\"), são sistemas complexos de larga escala e, algumas vezes, críticos e intensivos a software que têm se mostrado uma classe de sistemas promissora em vários domínios de aplicação. Em paralelo, arquiteturas de software têm um papel importante no desenvolvimento de sistemas intensivos a software, tratando requisitos funcionais e não-funcionais. Processos sistemáticos para o design de arquiteturas de software de SoS podem lidar com desafios do desenvolvimento desses sistemas, incluindo a promoção da colaboração de sistemas constituintes independentes, envolvendo diferentes proprietários, missões e interesses. Embora SoS intensivos a software sejam relevantes e necessários em diversos domínios de aplicação, a maior parte de suas arquiteturas tem sido desenvolvidas de forma ad hoc. Há uma ausência de processos estruturados para arquitetar SoS, dificultando a adoção segura de SoS, reduzindo possibilidades de compartilhamento de soluções arquiteturais para problemas comuns e impactando negativamente no sucesso desses sistemas. Esta tese apresenta um processo geral para SoS reconhecidos chamado SOAR (do inglês, \"General Process for Acknowledged SoS Software Architectures\") que dá suporte ao estabelecimento de instâncias de processos para o design arquitetural desses sistemas. Concebido para prover diferentes níveis de suporte de acordo com o contexto de desenvolvimento de cada SoS, o SOAR é constituído por um kernel de alto nível que descreve o que precisa ser feito para arquitetar SoS e também por três práticas que descrevem atividades e produtos de trabalho para guiar como conduzir a análise, a síntese e a avaliação arquitetural. Na avaliação do SOAR, foram realizados três surveys, um estudo de viabilidade e um experimento. Os resultados obtidos indicam que o SOAR pode oferecer um suporte positivo na instanciação de processos para o design de SoS reconhecidos e, como consequência, contribuir para o desenvolvimento e a evolução destes sistemas complexos intensivos a software.

Many research groups have conducted the investigation into UWB imaging radar system for various applications over the last decade. Due to the demanding security requirements, it is desirable to devise a convenient and reliable imaging system for concealed weapon detection. Therefore, this thesis presents my research into a low cost and compact UWB imaging radar system for security purpose. This research consists of two major parts: building the UWB imaging system and testing the imaging algorithms. Firstly, the time-domain UWB imaging radar system is developed based on a modulating scheme, achieving a receiver sensitivity of -78dBm and a receiver dynamic range of 69dB. A rotary UWB antenna linear array, comprising one central transmitting antenna and four side-by-side receiving antennas, is adopted to form 2D array in order to achieve a better cross-range resolution of the target. In operation, the rotation of the antenna array is automatically controlled through the computerised modules in LabVIEW. Two imaging algorithms have been extensively tested in the developed UWB radar system for a number of scenarios. In simulation, the “Delay and Sum (DAS)” method has been shown to be effective at mapping out the metallic targets in free space, but prone to errors in more complicated environments. However, the “Time Reversal (TR)” method can produce better images in more complex scenarios, where traditionally unfavorable multi-path interference becomes a valuable asset. These observations were verified in experiment in different testing environments, such as penetration through wooden boards, clutters and a stuffed sport bag. The detectable size of a single target is 8×8×1 cm3 with 30cm distance in a stuffed bag, while DAS can achieve the estimation of 7cm cross-range resolution and 15cm down-range resolution for two targets with sizes of 8×8×1 cm3 and 10×10×1 cm3, which fits within the theoretical prediction. In contrast, TR can distinguish them with a superior 4cm cross range resolution.

La complexité croissante de notre environnement socio-économique se traduit en génie logiciel par une augmentation de la taille des systèmes et par conséquent de leur complexité. Les systèmes actuels sont le plus souvent concurrents, distribués à grande échelle et composés d’autre systèmes. Ils sont alors appelés Systèmes de Systèmes (SdS). La complexité des systèmes de systèmes réside dans leurs cinq caractéristiques intrinsèques qui sont : l’indépendance opérationnelle des systèmes constituants, leur indépendance managériale, la distribution géographique, l’existence de comportements émergents, et enfin un processus de développement évolutionnaire. Les SdS évoluent dans des environnements non prévisibles et intègrent constamment de nouveaux systèmes. Nous avons traité la problématique du développement évolutionnaire d’un SdS en utilisant la reconfiguration dynamique. Nous avons défini un processus pour élaborer des modèles de configurations et un processus de conception de la reconfiguration intégrant le concept de patron de reconfiguration. Pour la validité et la faisabilité de notre approche, nous avons développé un framework d’expérimentation basé sur notre cas d’étude réel d’organisation des systèmes de secours français. / The growing complexity of our socio-economic environment is reflected in software engineering by an increase of the size of systems and therefore their complexity. Current systems are mostly concurrent, widely distributed and composed of other systems. They are then called Systems of Systems (SoS). The complexity of systems of systems lies in five intrinsic characteristics: the operational independence of the constituent systems, their managerial independence, the geographical distribution, the existence of emerging behaviours, and finally an evolutionary development process.SoS evolve in unpredictable environment and are constantly integrating new systems. We deal with the problem of the evolutionary development of a SoS by using dynamic reconfiguration. We have defined a process for developing configuration models and a reconfiguration design process incorporating the concept of reconfiguration pattern. For the validity and feasibility of our approach, we have developed an experimental framework based on our real case study of organization of the French emergency service.

An entity that functions as a system of systems (SoS) is composed of multiple systems that individually provide various functions which collectively provide a holistic functional capability. It is complex in design and function and tends to become even more complex over time as it evolves and responds to both internal and external changes. These changes might be in the composition or in the interoperability among its system members. Since interoperability affects how well the members work as one system, managing it is critical to the performance of the SoS over its lifespan. In support of this goal, this dissertation, through research and analysis of small-medium hospital systems, develops a descriptive approach to assist management in determining the impact that changes in membership and interoperability of member systems might have on SoS performance. A modeling approach was used to assess SoS performance before and after changes. This model is part of an analysis framework called Tri-Ex that can be used by managers to evaluate proposed system changes. The procedures and techniques used are recommended for any future investigations into applicability for SoS performance in different domains; designing system structure with future capabilities in mind; and operational assessment during development.

Systems engineering introduces the notion of top-down design, which involves viewing an entire system comprised of its components as a whole functioning unit. This requires an understanding of how those components efficiently interact, with optimization of the process emphasized rather than solely focusing on micro-level system components. The traditional approach to the systems engineering process involves requirements decomposition and flow down across a hierarchy of decision making levels, in which needs and requirements at one level are transformed into a set of system product and process descriptions for the next lower level. This top-down requirements flow approach therefore requires an iterative process between adjacent levels to verify that the design solution satisfies the requirements, with no direct flow between nonadjacent hierarchy levels. This thesis introduces a methodology that enables decision makers anywhere across a system-of-systems hierarchy to rapidly and simultaneously manipulate the design space, however complex. A hierarchical decision making process will be developed in which a system-of-systems, or multiple operationally and managerially independent systems, interact to affect a series of top level metrics. This takes the notion of top-down requirements flow one step further to allow for simultaneous bottom-up and top-down design, enabled by the use of neural network surrogate models to represent the complex design space. Using a proof-of-concept case study of employing a guided projectile for mortar interception, this process will show how the iterative steps that are usually required when dealing with flowing requirements from one level to the next lower in the systems engineering process are eliminated, allowing for direct manipulation across nonadjacent levels in the hierarchy. For this system-of-systems environment comprised of a Monte Carlo based design space exploration employing rapid neural network surrogate models, both bottom-up and top-down design analysis may be executed simultaneously. This process enables any response to be treated as an independent variable, meaning that information can flow in either direction within the hierarchy.

The use of architectures for the design, development, and documentation of system-of-systems engineering has become a common practice in recent years. At the same time, acquisition guidance has been recently reformed to move from the bottom-up approach of the Requirements Generation System (RGS) to the top-down approach mandated by the Joint Capabilities Integration and Development System (JCIDS), which requires the use of DoDAF to support acquisition. Defense agencies have had difficulty adjusting to these new policies, and are struggling to determine how to meet new acquisition requirements. This research has developed the Architecture-based Technology Evaluation and Capability Tradeoff (ARCHITECT) Methodology to respond to these challenges and address concerns raised about the defense acquisition process. The methodology integrates existing tools and techniques for systems engineering and system of systems engineering with several new modeling and simulation tools and techniques developed as part of this research to fill gaps noted in prior CBAs. Additional criteria for the methodology were developed by leveraging lessons learned from similar fields, including management science and cognitive psychology. A suppression of enemy air defenses (SEAD) mission is used to demonstrate the application of ARCHITECT and to show the plausibility of the approach. Overall, it is shown that the ARCHITECT methodology results in an improvement over current CBAs in the criteria developed here.

The current national security environment and fiscal tightening make it necessary for the Department of Defense to transition away from a threat based acquisition mindset towards a capability based approach to acquire portfolios of systems. This requires that groups of interdependent systems must regularly interact and work together as systems of systems to deliver desired capabilities. Technological advances, especially in the areas of electronics, computing, and communications also means that these systems of systems are tightly integrated and more complex to acquire, operate, and manage. In response to this, the Department of Defense has turned to system architecting principles along with capability based analysis. However, because of the diversity of the systems, technologies, and organizations involved in creating a system of systems, the design space of architecture alternatives is discrete and highly non-linear. The design space is also very large due to the hundreds of systems that can be used, the numerous variations in the way systems can be employed and operated, and also the thousands of tasks that are often required to fulfill a capability. This makes it very difficult to fully explore the design space. As a result, capability based analysis of system of systems architectures often only considers a small number of alternatives. This places a severe limitation on the development of capabilities that are necessary to address the needs of the war fighter. The research objective for this manuscript is to develop a Rapid Architecture Alternative Modeling (RAAM) methodology to enable traceable Pre-Milestone A decision making during the conceptual phase of design of a system of systems. Rather than following current trends that place an emphasis on adding more analysis which tends to increase the complexity of the decision making problem, RAAM improves on current methods by reducing both runtime and model creation complexity. RAAM draws upon principles from computer science, system architecting, and domain specific languages to enable the automatic generation and evaluation of architecture alternatives. For example, both mission dependent and mission independent metrics are considered. Mission dependent metrics are determined by the performance of systems accomplishing a task, such as Probability of Success. In contrast, mission independent metrics, such as acquisition cost, are solely determined and influenced by the other systems in the portfolio. RAAM also leverages advances in parallel computing to significantly reduce runtime by defining executable models that are readily amendable to parallelization. This allows the use of cloud computing infrastructures such as Amazon's Elastic Compute Cloud and the PASTEC cluster operated by the Georgia Institute of Technology Research Institute (GTRI). Also, the amount of data that can be generated when fully exploring the design space can quickly exceed the typical capacity of computational resources at the analyst's disposal. To counter this, specific algorithms and techniques are employed. Streaming algorithms and recursive architecture alternative evaluation algorithms are used that reduce computer memory requirements. Lastly, a domain specific language is created to provide a reduction in the computational time of executing the system of systems models. A domain specific language is a small, usually declarative language that offers expressive power focused on a particular problem domain by establishing an effective means to communicate the semantics from the RAAM framework. These techniques make it possible to include diverse multi-metric models within the RAAM framework in addition to system and operational level trades. A canonical example was used to explore the uses of the methodology. The canonical example contains all of the features of a full system of systems architecture analysis study but uses fewer tasks and systems. Using RAAM with the canonical example it was possible to consider both system and operational level trades in the same analysis. Once the methodology had been tested with the canonical example, a Suppression of Enemy Air Defenses (SEAD) capability model was developed. Due to the sensitive nature of analyses on that subject, notional data was developed. The notional data has similar trends and properties to realistic Suppression of Enemy Air Defenses data. RAAM was shown to be traceable and provided a mechanism for a unified treatment of a variety of metrics. The SEAD capability model demonstrated lower computer runtimes and reduced model creation complexity as compared to methods currently in use. To determine the usefulness of the implementation of the methodology on current computing hardware, RAAM was tested with system of system architecture studies of different sizes. This was necessary since system of systems may be called upon to accomplish thousands of tasks. It has been clearly demonstrated that RAAM is able to enumerate and evaluate the types of large, complex design spaces usually encountered in capability based design, oftentimes providing the ability to efficiently search the entire decision space. The core algorithms for generation and evaluation of alternatives scale linearly with expected problem sizes. The SEAD capability model outputs prompted the discovery a new issue, the data storage and manipulation requirements for an analysis. Two strategies were developed to counter large data sizes, the use of portfolio views and top `n' analysis. This proved the usefulness of the RAAM framework and methodology during Pre-Milestone A capability based analysis.

Compared to the relative wealth of information surrounding design in the context of system-of-systems there has been little research surrounding policy making in system-of-systems. While the adoption of a formal approach and lexicon for system-of-systems problems has been proposed by researchers, the specific inclusion of regulatory policies in system-of-systems is still largely absent or underdeveloped. Typically, there is no distinction between internal policies of an organization and exogenous policies coming through regulatory channels. Further, researchers have yet to formally employ a standardized framework to regulatory policy problems in the context of a system-of-systems. As international regulatory bodies are calling on world States to identify and select “baskets of measures” to address CO2 emissions from civil aviation, there is a growing recognition that doing so will require a framework for policy identification and selection. Despite this recognition, such a framework has yet to be established. This research develops a formal lexicon for public policy as a part of system-of-systems, and employs a formalized process to explore multiple established, planned, and potential policies in the context of the global civil aviation system. Existing architectures and lexicons will be expanded to include regulatory policies that have often been treated as exogenous forcing functions in system-of-systems problems. Ultimately, a process for informed quantitative decision making to support concurrent CO2 regulatory policy analysis and design in the civil aviation system-of-systems is established. The developed methodology will allow policy makers to systematically identify effective policy space, while maintaining the objectivity of the analyst.

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 206-216).