REDEFINE is a reconfigurable SoC architecture that provides a unique platform for high performance and low power computing by exploiting the synergistic interaction between coarse grain dynamic dataflow model of computation (to expose abundant parallelism in the applications) and runtime composition of efficient compute structures (on the reconfigurable computation resources). Computer architectures based on the dynamic dataflow model of computation have to be an infinite resource implementation to be able to exploit all available parallelism in all applications. It is not feasible for any real architectural implementation. When limited resource implementations are considered, there is a possibility of loss of performance (inability to efficiently exploit available parallelism). In this thesis, we study the throttling of execution in the REDEFINE architecture to maximize the architecture efficiency. We have formulated it as a design space exploration problem at two levels i.e. architectural configurations and throttling schemes. Reduced feature/high level simulation or feature specific analytical approaches are very useful for the selective study/exploration of early in design phase architectures/systems. Our approach is similar to that of SEASAME Framework which is used for the study of MPSoC (Multiprocessor SoC) architectures. We have used abstraction (feature reduction) at the levels of architecture and model of computation to make the problem approachable and practically feasible. A feature specific fast hybrid (mixed level) simulation framework for the early in design phase study is developed and implemented for the huge design space exploration (1284 throttling schemes, 128 architectural configurations and 10 applications i.e. 1.6 million executions). We have done performance modeling in terms of selection of important performance criteria, ranking of the explored throttling schemes and investigation of the effectiveness of the design space exploration using statistical hypothesis testing. We found some interesting obvious/intuitive and some non-obvious/counterintuitive results. The two performance criteria namely Exec.T and Avg.TU were found sufficient to represent the performance and the resource usage characteristics of the architecture independent of the throttling schemes, the architectural configurations and the applications. The ranking of the throttling schemes based on the selected performance criteria is found to be statistically very significant. The intuitive throttling schemes span the range of performance from the best to the worst. We found absence of trade-off amongst all of the performance criteria. The best throttling schemes give appreciable overall performance (25%) and resource usage (37%) gains in the throttling unit simultaneously. The design space exploration of the throttling schemes is found to be fine and uniform.

Information Technology (IT) is a cornerstone of our modern society and essential for governments' management of public services, economic growth and national security. Consequently, it is of importance that IT systems are kept in a dependable and secure state. Unfortunately, as modern IT systems typically are composed of numerous interconnected components, including personnel and processes that use or support it (often referred to as an enterprise architecture), this is not a simple endeavor. To make matters worse, there are malicious actors who seek to exploit vulnerabilities in the enterprise architecture to conduct unauthorized activity within it. Various models have been proposed by academia and industry to identify and mitigate vulnerabilities in enterprise architectures, however, so far none has provided a sufficiently comprehensive scope. The contribution of this thesis is a modeling framework and calculation engine that can be used as support by enterprise decision makers in regard to cyber security matters, e.g., chief information security officers. In summary, the contribution can be used to model and analyze the vulnerability of enterprise architectures, and provide mitigation suggestions based on the resulting estimates. The contribution has been tested in real-world cases and has been validated on both a component level and system level; the results of these studies show that it is adequate in terms of supporting enterprise decision making. This thesis is a composite thesis of eight papers. Paper 1 describes a method and dataset that can be used to validate the contribution described in this thesis and models similar to it. Paper 2 presents what statistical distributions that are best fit for modeling the time required to compromise computer systems. Paper 3 describes estimates on the effort required to discover novel web application vulnerabilities. Paper 4 describes estimates on the possibility of circumventing web application firewalls. Paper 5 describes a study of the time required by an attacker to obtain critical vulnerabilities and exploits for compiled software. Paper 6 presents the effectiveness of seven commonly used automated network vulnerability scanners. Paper 7 describes the ability of the signature-based intrusion detection system Snort at detecting attacks that are more novel, or older than its rule set. Finally, paper 8 describes a tool that can be used to estimate the vulnerability of enterprise architectures; this tool is founded upon the results presented in papers 1-7. / Informationsteknik (IT) är en grundsten i vårt moderna samhälle och grundläggande för staters hantering av samhällstjänster, ekonomisk tillväxt och nationell säkerhet. Det är därför av vikt att IT-system hålls i ett tillförlitligt och säkert tillstånd. Då moderna IT-system vanligen består av en mångfald av olika integrerade komponenter, inklusive människor och processer som nyttjar eller stödjer systemet (ofta benämnd organisationsövergripande arkitektur, eller enterprise architecture), är detta tyvärr ingen enkel uppgift. För att förvärra det hela så finns det även illvilliga aktörer som ämnar utnyttja sårbarheter i den organisationsövergripande arkitekturen för att utföra obehörig aktivitet inom den. Olika modeller har föreslagits av den akademiska världen och näringslivet för att identifiera samt behandla sårbarheter i organisationsövergripande arkitekturer, men det finns ännu ingen modell som är tillräckligt omfattande. Bidraget presenterat i denna avhandling är ett modelleringsramverk och en beräkningsmotor som kan användas som stöd av organisatoriska beslutsfattare med avseende på säkerhetsärenden. Sammanfattningsvis kan bidraget användas för att modellera och analysera sårbarheten av organisationsövergripande arkitekturer, samt ge förbättringsförslag baserat på dess uppskattningar. Bidraget har testats i fallstudier och validerats på både komponentnivå och systemnivå; resultaten från dessa studier visar att det är lämpligt för att stödja organisatoriskt beslutsfattande. Avhandlingen är en sammanläggningsavhandling med åtta artiklar. Artikel 1 beskriver en metod och ett dataset som kan användas för att validera avhandlingens bidrag och andra modeller likt detta. Artikel 2 presenterar vilka statistiska fördelningar som är bäst lämpade för att beskriva tiden som krävs för att kompromettera en dator. Artikel 3 beskriver uppskattningar av tiden som krävs för att upptäcka nya sårbarheter i webbapplikationer. Artikel 4 beskriver uppskattningar för möjligheten att kringgå webbapplikationsbrandväggar. Artikel 5 beskriver en studie av den tid som krävs för att en angripare skall kunna anskaffa kritiska sårbarheter och program för att utnyttja dessa för kompilerad programvara. Artikel 6 presenterar effektiviteten av sju vanligt nyttjade verktyg som används för att automatiskt identifiera sårbarheter i nätverk. Artikel 7 beskriver förmågan av det signatur-baserade intrångsdetekteringssystemet Snort att upptäcka attacker som är nyare, eller äldre, än dess regeluppsättning. Slutligen beskriver artikel 8 ett verktyg som kan användas för att uppskatta sårbarheten av organisationsövergripande arkitekturer; grunden för detta verktyg är de resultat som presenteras i artikel 1-7. / <p>QC 20140203</p>

Information technology has become increasingly important to individuals and organizations alike. Not only does IT allow us to do what we always did faster and more effectively, but it also allows us to do new things, organize ourselves differently, and work in ways previously unimaginable. However, these advantages come at a cost: as we become increasingly dependent upon IT services, we also demand that they are continuously and uninterruptedly available for use. Despite advances in reliability engineering, the complexity of today's increasingly integrated systems offers a non-trivial challenge in this respect. How can high availability of enterprise IT services be maintained in the face of constant additions and upgrades, decade-long life-cycles, dependencies upon third-parties and the ever-present business-imposed requirement of flexible and agile IT services? The contribution of this thesis includes (i) an enterprise architecture framework that offers a unique and action-guiding way to analyze service availability, (ii) identification of causal factors that affect the availability of enterprise IT services, (iii) a study of the use of fault trees for enterprise architecture availability analysis, and (iv) principles for how to think about availability management. This thesis is a composite thesis of five papers. Paper 1 offers a framework for thinking about enterprise IT service availability management, highlighting the importance of variance of outage costs. Paper 2 shows how enterprise architecture (EA) frameworks for dependency analysis can be extended with Fault Tree Analysis (FTA) and Bayesian networks (BN) techniques. FTA and BN are proven formal methods for reliability and availability modeling. Paper 3 describes a Bayesian prediction model for systems availability, based on expert elicitation from 50 experts. Paper 4 combines FTA and constructs from the ArchiMate EA language into a method for availability analysis on the enterprise level. The method is validated by five case studies, where annual downtime estimates were always within eight hours from the actual values. Paper 5 extends the Bayesian prediction model from paper 3 and the modeling method from paper 4 into a full-blown enterprise architecture framework, expressed in a probabilistic version of the Object Constraint Language. The resulting modeling framework is tested in nine case studies of enterprise information systems. / Informationsteknik blir allt viktigare för både enskilda individer och för organisationer. IT låter oss inte bara arbeta snabbare och effektivare med det vi redan gör, utan låter oss också göra helt nya saker, organisera oss annorlunda och arbeta på nya sätt. Tyvärr har dessa fördelar ett pris: i takt med att vi blir alltmer beroende av IT-tjänster ökar också våra krav på att de är ständigt tillgängliga för oss, utan avbrott. Trots att tillförlitlighetstekniken går framåt utgör dagens alltmer sammankopplade system en svår utmaning i detta avseende. Hur kan man säkerställa hög tillgänglighet hos IT-tjänster som ständigt byggs ut och uppgraderas, som har livscykler på tiotals år, som är beroende av tredjepartsleverantörer och som dessutom måste leva upp till verksamhetskrav på att vara flexibla och agila? Den här avhandlingen innehåller (i) ett arkitekturramverk som på ett unikt sätt kan analysera IT-tjänsters tillgänglighet och ta fram rekommenderade åtgärder, (ii) ett antal identifierade kausalfaktorer som påverkar IT-tjänsters tillgänglighet, (iii) en studie av hur felträd kan användas för arkitekturanalys av tillgänglighet samt (iv) en uppsättning principer för beslutsfattande kring tillgänglighet. Avhandlingen är en sammanläggningsavhandling med fem artiklar. Artikel 1 innehåller ett konceptuellt ramverk för beslutsfattande kring IT-tjänsters tillgänglighet som understryker vikten av variansen hos nertidskostnaderna. Artikel 2 visar hur ramverk för organisationsövergripande arkitektur (s.k. enterprise architecture -- EA) kan utvidgas med felträdsanalys (FTA) och bayesianska nätverk (BN) för analys av beroenden mellan komponenter. FTA och BN är bägge etablerade metoder för tillförlitlighets- och tillgänglighetsmodellering. Artikel 3 beskriver en bayesiansk prediktionsmodell för systemtillgänglighet, baserad på utlåtanden från 50 experter. Artikel 4 kombinerar FTA med modelleringselement från EA-ramverket ArchiMate till en metod för tillgänglighetsanalys på verksamhetsnivå. Metoden har validerats i fem fallstudier, där de estimerade årliga nertiderna alltid låg inom åtta timmar från de faktiska värdena. Artikel 5 utvidgar den bayesianska prediktionsmodellen från artikel 3 och modelleringsmetoden från artikel 4 till ett fullständigt EA-ramverk som uttrycks i en probabilistisk version av Object Constraint Language (OCL). Det resulterande modelleringsramverket har testats i nio fallstudier på verksamhetsstödjande IT-system. / <p>QC 20120912</p>

Made available in DSpace on 2016-12-23T14:33:33Z (GMT). No. of bitstreams: 1 Romulo Arpini - Parte 1.pdf: 1684521 bytes, checksum: 258db1cddcd5120d8961c4a55aa1c741 (MD5) Previous issue date: 2012-08-31 / The need to relate the various architectural domains captured in partial descriptions of an enterprise is addressed in virtually all enterprise modeling approaches. One of these domains, namely that of organizational behavior, has received significant attention in recent years in the context of business process modeling and management. Another important domain, that of organizational structure is strongly inter-related with the process domain. While the process domain focuses on how the business process activities are structured and performed, the organizational structure domain focuses on who performs these activities, i.e., which kinds of entities in an organization are capable of performing work. Given the strong connection between the organizational behavior and organizational resources, we argue that any comprehensive enterprise modeling technique should explicitly establish the relations between the modeling elements that represent organizational behavior, called here behavioral elements, and those used to represent the organizational resources (organizational actors) involved in these activities, called here active structure elements. Despite the importance of the relations between these architectural domains, many of the current enterprise architecture and business process modeling approaches lack support for the expressiveness of a number of important active structure allocation scenarios. This work aims to overcome these limitations by proposing a framework for active structure assignment that can be applied to enterprise architecture and business process modeling approaches. This framework enriches the expressiveness of existing techniques and supports the definition of precise active structure assignments. It is designed such that it should be applicable to a number of enterprise architecture and business process modeling languages, i.e., one should be able to use and apply different (enterprise and business process) modeling languages to the framework with minor changes / A necessidade de se relacionar os vários domínios arquiteturais capturados em descrições parciais de uma organização é, virtualmente, tratado em todas as abordagens de modelagem de arquiteturas organizacionais. Um destes domínios, particularmente chamado de comportamento organizacional, tem recebido atenção significativa nos últimos anos no contexto de modelagem e gerenciamento de processos de negócio. Outro domínio importante, chamado de estrutura organizacional, é fortemente inter-relacionado com o domínio de processo. Enquanto o domínio de processo foca em "como" as atividades de processos de negócio são estruturadas e executadas, o domínio de estrutura organizacional foca em "quem" executa essas atividades, i.e., quais tipos de entidades em uma organização são capazes de executar trabalho. Dada a forte conexão entre o comportamento organizacional e os recursos organizacionais, nós argumentamos que qualquer técnica de modelagem de arquitetura organizacional deve explicitamente estabelecer relações entre os elementos de modelagem que representam o comportamento organizacional, chamado aqui de elementos comportamentais e aqueles suados para representar recursos organizacionais (atores organizacionais) envolvidos nestas atividades, chamados aqui de elementos da estrutura ativa. Apesar da importância das relações entre esses domínios arquiteturais, muitas das abordagens de modelagem de processo de negócio e modelagem de arquiteturas organizacionais tem um suporte insuficiente para expressar uma quantidade importante de cenários de alocação da estrutura ativa. Este trabalho visa superar essas limitações propondo um framework para a atribuição da estrutura ativa que pode ser aplicado a abordagens de modelagem de processo de negócio e modelagem de arquitetura organizacionais. Esse framework enriquece a expressividade das técnicas existentes e dá suporte à definição de atribuições precisas da estrutura ativa. Ele é desenvolvido tal que pode ser aplicável a linguagens de modelagem de processo de negócio e linguagens de modelagem de arquiteturas organizacionais, i.e., é possível utilizar e aplicar diferentes linguagens de modelagem ao framework com mudanças mínimas

The number of application specific instruction set processors is rapidly increasing, because of increased demand for low power and small area designs. A lot of new instruction sets are born, but they are usually confidential. University of California in Berkeley took an opposite approach. The RISC-V instruction set is completely free. This master's thesis focuses on analysis of RISC-V instruction set and two programming languages used to model instruction sets and microarchitectures, CodAL and Chisel. Implementation of RISC-V base instruction set along with multiplication, division and 64-bit address space extensions and implementation of cycle accurate model of Rocket Core-like microarchitecture in CodAL are main goals of this master's thesis. The instruction set model is used to generate the C compiler and the cycle accurate model is used to generate RTL representation, all thanks to Codasip Studio. Generated compiler is compared against the one implemented manually and results are used for instruction set optimizations. RTL is synthesized to Artix 7 FPGA and compared to the Rocket Core synthesis.