Graph algorithms are concerned with the algorithmic aspects of solving graph problems. The problems are motivated from and have application to diverse areas of computer science, engineering and other disciplines. Problems arising from these areas of application are good candidates for parallelization since they often have both intense computational needs and stringent response time requirements. Motivated by these concerns, this thesis investigates parallel algorithms for these kinds of graph problems that have at least one of the following properties: the problems involve some type of dynamic updates; the sparsification technique is applicable; or the problems are closely related to communications network issues. The models of parallel computation used in our studies are the Parallel Random Access Machine (PRAM) model and the practical interconnection network models such as meshes and hypercubes. ¶ Consider a communications network which can be represented by a graph G = (V;E), where V is a set of sites (processors), and E is a set of links which are used to connect the sites (processors). In some cases, we also assign weights and/or directions to the edges in E. Associated with this network, there are many problems such as (i) whether the network is k-edge (k-vertex) connected withfixed k; (ii) whether there are k-edge (k-vertex) disjoint paths between u and v for a pair of given vertices u and v after the network is dynamically updated by adding and/or deleting an edge etc; (iii) whether the sites in the network can communicate with each other when some sites and links fail; (iv) identifying the first k edges in the network whose deletion will result in the maximum increase in the routing cost in the resulting network for fixed k; (v) how to augment the network at optimal cost with a given feasible set of weighted edges such that the augmented network is k-edge (k-vertex) connected; (vi) how to route messages through the network efficiently. In this thesis we answer the problems mentioned above by presenting efficient parallel algorithms to solve them. As far as we know, most of the proposed algorithms are the first ones in the parallel setting. ¶ Even though most of the problems concerned in this thesis are related to communications networks, we also study the classic edge-coloring problem. The outstanding difficulty to solve this problem in parallel is that we do not yet know whether or not it is in NC. In this thesis we present an improved parallel algorithm for the problem which needs [bigcircle]([bigtriangleup][superscript 4.5]log [superscript 3] [bigtriangleup] log n + [bigtriangleup][superscript 4] log [superscript 4] n) time using [bigcircle](n[superscript 2][bigtriangleup] + n[bigtriangleup][superscript 3]) processors, where n is the number of vertices and [bigtriangleup] is the maximum vertex degree. Compared with a previously known result on the same model, we improved by an [bigcircle]([bigtriangleup][superscript 1.5]) factor in time. The non-trivial part is to reduce this problem to the edge-coloring update problem. We also generalize this problem to the approximate edge-coloring problem by giving a faster parallel algorithm for the latter case. ¶ Throughout the design and analysis of parallel graph algorithms, we also find a technique called the sparsification technique is very powerful in the design of efficient sequential and parallel algorithms on dense undirected graphs. We believe that this technique may be useful in its own right for guiding the design of efficient sequential and parallel algorithms for problems in other areas as well as in graph theory.

This Bachelors exam is about young adults and their use of Mobile Social Network System.The use of mobile social media has become more common in today’s society, ranging fromteenagers, the dominating internet users, to the elderly. The traditional purpose of use inmobile phones, the voice communication from one place to another, has in Sweden beendominated by text communication instead. Along with the development of Smartphones andthe mobile interface, the births of mobile social media have increased in the market. Reports have shown that of all the devices with the possibility to connect to social networks,the one kept closest to our bodies is the mobile phone. One of the advantages of using thephone for mobile social media is that you can easily and smoothly update whenever andwherever, within one arm’s reach. An update can be anything the user feel like sharing withfriends. For example the user’s location, feelings and thoughts or it could also be a picture ora video clip. Our report focuses on what factors contributes to the use of mobile social media, in whatcontexts the updates happen in as well as where, how and why they do.

Submitted by William Paiva (williampaiva17@hotmail.com) on 2015-04-17T19:05:59Z No. of bitstreams: 1 Ivane Almeida Duvoisin.pdf: 3722465 bytes, checksum: 4393fbf5a60a9275c7f574b02e63754e (MD5) / Approved for entry into archive by Vitor de Carvalho (vitor_carvalho_im@hotmail.com) on 2015-05-08T16:37:50Z (GMT) No. of bitstreams: 1 Ivane Almeida Duvoisin.pdf: 3722465 bytes, checksum: 4393fbf5a60a9275c7f574b02e63754e (MD5) / Made available in DSpace on 2015-05-08T16:37:50Z (GMT). No. of bitstreams: 1 Ivane Almeida Duvoisin.pdf: 3722465 bytes, checksum: 4393fbf5a60a9275c7f574b02e63754e (MD5) Previous issue date: 2013 / Este trabalho é resultado de uma pesquisa de doutorado, desenvolvida no Programa de Pós- Graduação Educação em Ciências: Química da Vida e da Saúde - PPGEC, da Universidade Federal do Rio Grande – FURG, na linha de pesquisa Educação científica: as tecnologias educativas no processo da aprendizagem. Situa-se essa pesquisa no caminho explicativo da objetividade entre parênteses, a qual, segundo Maturana (2009), caracteriza-se pela ausência de verdade absoluta e de verdade relativa, bem como pela existência de muitas verdades diferentes em domínios distintos. Trata-se de uma pesquisa de cunho qualitativo, cujo objetivo não é a generalização nem a busca de leis ou princípios, mas a compreensão particular do que se estuda, ou seja, o foco da atenção desloca-se da generalização para o específico, o peculiar, o individual, almejando sempre a compreensão do fenômeno estudado. A pesquisa busca identificar e analisar as virtualizações e as atualizações emergentes das Redes de Conversação que foram se constituindo no processo de discussão e elaboração do currículo do curso on-line de licenciatura em ciências da FURG. Para tanto, foi necessário explicar e compreender os fenômenos do linguajear e do emocionar nas redes de conversação: Rede Proponente (RP) e Rede de Estudantes-professores da Pós-Graduação Educação em Ciências (REPGEC), que se formaram no esforço de conversar sobre o currículo que geravam. Apostou-se no potencial do linguajear e do emocionar das redes conversação por considerar que o conversar promove o deslocar-se no tempo, por intermédio do relembrar fatos vividos e o pensar em novas soluções para problemáticas identificadas; nesse sentido, o atuar e vivenciar coletivo se tornam indispensáveis. Perseguiram-se três questionamentos: 1. Quais são os complexos problemáticos e os nós de tendências ou de forças que acompanham os processos de formação de professores e os currículos dos cursos on-Line? 2. Quais problemáticas e soluções, o linguajear e o emocionar dos participantes das Redes de Conversação revelou? 3. Qual desenho curricular melhor se adequa aos currículos móveis, característicos da modalidade on-line? O referencial teórico balizador e cujas conversações, em sua pluralidade, ajudaram a tramar a rede conceitual que sustenta essa tese foram: as teorias da Biologia do Conhecer, de Maturana e Varela e o conceito de Inteligência Coletiva, de Lévy e o dialogo com Marques no que tange à formação docente. Assume-se o potencial formativo das redes de conversação de Maturana, o conceito de educação on-line cunhado por Santos e, para a superação dos currículos prescritivos, o campo fecundo dos currículos em ação abordado por Macedo. O corpus da pesquisa foi produzido nas gravações das reuniões da RP e dos encontros da REPGEC. Utilizou-se a Análise Textual Discursiva – ATD, como ferramenta de análise associada ao software N-Nivo. Do processo de análise e síntese identificaram-se duas problemáticas para formação docente, categorias emergentes que passaram a ser denominados vetores de potencialização: Fragmentação do conhecimento e isolamento das áreas: questão cultural; e Distanciamento da instância formadora e da escola: espaço-tempo na educação on-line quem forma quem? As soluções inventivas para superar as problemáticas identificadas foi atualizando sucessivamente o currículo, esse movimento denominou-se Fluzz Currículo. O desenvolvimento e a análise da pesquisa evidenciou o potencial das redes de conversação para os processos de virtualização e de atualização na elaboração dos currículos e possibilitou o desenho de uma mandala curricular considerada mais ajustada aos currículos da educação on-line. / This work is the result of a PhD research, developed at the Graduate Program in Sciences Education: Chemistry of Life and Health- PPGEC, Federal University of Rio Grande - FURG in scientific research line of scientific Education: educational technology in the learning process. This research is located in the explanatory way of objectivity in parentheses, which, according to Maturana (2009), is characterized by the absence of absolute truth and relative truth, as well as the existence of many different truths in distinct domains. This is a qualitative research whose goal is not to generalize the search nor the laws location or principles, but the particular understanding of what is studied, that is, the focus of attention moves from generalization to specific, peculiar, individual, always aiming to understand the studied phenomenon. The research seeks to identify and analyze emerging virtualization and updates Network Conversation that were formed in the process of discussion and elaboration of the FURG’s course curriculum online of sciences degree. For this, it was necessary to explain and understand the phenomena of linguaging and emotioning in the conversation’s networks: Proponent Network (PN) and Network Student-teachers of Graduate Sciences Education (NSTGSE), which formed in the effort to talk about the curriculum they generated. It was betted on the potential and the emotioning of linguaging networks conversation considering that the talking promotes dislocate in time through to recall living’s facts and thinking of new solutions to identified problems, in this sense, act and collective experience become indispensable. It was pursuing three questions: 1. what are the complex and problematic nodes of tendencies or forces that go along with the processes of teacher training and curriculum onLine courses? 2. What problems and solutions the linguaging and the emotioning of participating in the Conversation Networks revealed? 3. What curriculum design best suited with mobile, characteristic of the online modality? he theoretical referential tagger and whose conversations, in its plurality, helped devise the conceptual network which support that thesis, were the theories of Biology of Cognition, by Maturana and Varela and the concept of Collective Intelligence, by Levy and dialogue with the Marques wiyh which have relation to teacher training. It is assumed the potential formative of networks of conversation from Maturana, the concept of online education coined by Santos and, to overcome the prescriptive curricula, the fertile area of the curriculum in action approached by Macedo. The research corpus was produced on recordings from meetings with the PN and NSTGSE. We used the Discursive Textual Analysis - DTA, as an analysis tool associated with the N-Nivo software. From the process of analysis and synthesis was identified two issues for teacher education, emerging categories which were named potentiation vectors: Fragmentation of knowledge and isolation areas: cultural issue, and distancing from instance of forming and from the school: space-time in education, who is teaching who online? The inventive solutions to overcome the problems identified was successively updating the curriculum, this movement was called Fluzz Curriculum. The development and analysis of this research showed the potential of conversation networks for the virtualization and update processes in preparing curriculums and enabled the design of a curricular mandala considered more suited to the curriculums of on line’s education.

The Internet-of-Things is an open source architecture for enabling information sharing between globally connected devices, which existing system do not offer. However, the Internet-of-Things induces the single points of failure and long communication delay. Thus, the Sensible Things platform is proposed, which is a fully distributed system. So far, it has produced components to share sensor and actuator information on the Internet. In the past, manual work was problematic since physical access could be difficult on remote locations. There were also difficulties to detect if the devices were actually working properly. Therefore, the thesis mainly focuses on the functionality which is able to check status, update software automatically and restart the devices with new software. The thesis first analyzes the mechanism of the automatic updating and describes the methods for it. The automatic updates of demonstrator is implemented in My-Eclipse. Finally, this paper describes the evaluation of the automatic updating in Sensible Things platform.

No description available.

Industrial Control Systems (ICSs) manage critical infrastructures such as water treatment facilities, petroleum refineries, and power plants. ICSs are networked through Information Technology (IT) infrastructure for remote monitoring and control of physical processes. As ICSs integrate with IT infrastructure, IT vulnerabilities are carried over to the ICS environment. Previously proposed process controller security architectures maintain safe and stable plant operation even in the presence of attacks that exploit ICS vulnerabilities. Security architectures are process control system-level solutions that leverage isolated and trusted hardware (secure enclaves) for ICS security. Upon detecting an intrusion, the secure enclave switches control of the physical process to a high assurance controller, making a fail-safe plant operation. The process control loop components have an average lifespan of several decades. During this time, electromechanical components of process control loop may undergo aging that alters their characteristics and affects control loop performance. To deal with component aging and to improve control algorithm flexibility, updates to control loop parameters are required. Plant model, process control loop system specifications, and control algorithm-based security mechanisms at the secure enclave require parameter updates. ICSs have hundreds of process control components that may need be installed in hazardous environments and distributed across hundreds of square kilometers. Updating each component physically may lead to accidents, expensive travel, and increased downtime. Some ICS have allowable downtime of only 5 minutes per year. Hence, remote updates are desirable. A proposed dedicated and isolated hardware module at the secure enclave provides authentication of the update and ensures safe storage in a non-volatile memory. A protocol designed for update transmission through an untrusted ICS network provides resilience against network integrity attacks such as replay attacks. Encryption and authentication of the updates maintain integrity and confidentiality. During the normal plant operation, the hardware module is invisible to the other modules of the process control loop. The proposed solution is implemented on Xilinx Zynq-7000 programmable System-on-Chip to provide secure enclave updates. / Master of Science / Industrial Control Systems (ICSs) manage critical infrastructures such as water treatment facilities, petroleum refineries, and power plants. ICS process controllers interpret sensor output and depending on the set point, generate input signals for the actuator to control physical processes. The process controllers receive set points and periodically send process state to the supervisory network. For remote monitoring and control of physical processes, ICSs are networked through Information Technology (IT) infrastructure. As ICSs integrate with IT infrastructure, IT vulnerabilities are carried over to the ICS environment. Previously proposed process controller security architectures maintain safe and stable plant operation even in the presence of attacks that exploit ICS vulnerabilities. Security architectures are process control system-level solutions that leverage isolated and trusted hardware (secure enclaves) for ICS security. Upon detecting an intrusion, the secure enclave switches control of the physical process to a high assurance controller, making a fail-safe plant operation. The process control loop components have an average lifespan of several decades. During this time, electromechanical components of process control loop may undergo aging that alters their characteristics and affects control loop performance. To deal with component aging and to improve control algorithm flexibility, updates to control loop parameters are required. Plant model, process control loop system specifications, and control algorithm-based security mechanisms at the secure enclave require parameter updates. ICSs have hundreds of process control components that may need be installed in hazardous environments and distributed across hundreds of square kilometers. Updating each component physically may lead to accidents, expensive travel, and increased downtime. Some ICS have allowable downtime of only 5 minutes per year. Hence, remote updates are desirable. A proposed dedicated and isolated hardware module at the secure enclave provides authentication of the update and ensures safe storage in a non-volatile memory. A protocol designed for update transmission through an untrusted ICS network provides resilience against network integrity attacks such as replay attacks. Encryption and authentication of the updates maintain integrity and confidentiality. During the normal plant operation, the hardware module is invisible to the other modules of the process control loop. The proposed solution is implemented on Xilinx Zynq-7000 programmable System-on-Chip to provide secure enclave updates.

Yes / In the last 10 years the University of Bradford Library Acquisitions Department has shrunk from 13 members of staff to 5. This has led to us embracing new technology to help streamline workflows within the department. As well as utilising EDI functionality, changing processing workflows and using shelf-ready books, we have devised innovative ways of dealing with everyday tasks. Topics included cover: PDA deduplication; spine labelling on a large scale; the weeding of discarded books; using saved global updates on incoming MARC records and using load profiles innovatively.

Made available in DSpace on 2014-07-29T14:57:51Z (GMT). No. of bitstreams: 1 dissertacao-rodrigohs.pdf: 1383844 bytes, checksum: b3fda2012ce5a20dc390677f308520e3 (MD5) Previous issue date: 2012-05-29 / Context models that describe dynamic context-aware scenarios usually need to be frequently updated. Some examples of situations that motivate these updates are the appearance of new services and context providers, the mobility of the entities described in these models, among others. Generally, updates on models imply redevelopment of the architectural components of context-aware systems based on these models. However, as these updates in dynamic scenarios tend to be more frequent, it is desirable that they occur at runtime. This dissertation presents an infrastructure for dynamic management of context models based on the fundamentals of complex event processing, or CEP. This infrastructure allows the fundamental abstractions from which a model is built to be updated at runtime. As these updates can impact systems based on the updated models, this dissertation identifies and analyzes these impacts, which are reproduced in a case study that aims to evaluate the proposed infrastructure by demonstrating how it deals with the impacts mentioned. / Modelos contextuais que descrevem cenários de computação sensível ao contexto dinâmicos normalmente precisam ser frequentemente atualizados. Alguns exemplos de situações que motivam essas atualizações são o surgimento de novos serviços e provedores de informações contextuais, a mobilidade das entidades descritas nesses modelos, dentre outros. Normalmente, atualizações em modelos implicam em redesenvolvimento dos componentes arquiteturais dos sistemas sensíveis ao contexto baseados nesses modelos. Porém, como em cenários dinâmicos essas atualizações tendem a ser mais frequentes, é desejável que elas ocorram em tempo de execução. Essa dissertação apresenta uma infraestrutura para gerenciamento dinâmico de modelos de contexto baseada nos fundamentos de processamento complexo de eventos, ou CEP. Essa infraestrutura permite que as abstrações fundamentais a partir das quais um modelo é construído sejam atualizadas em tempo de execução. Como essas atualizações podem causar impactos nos sistemas baseados nos modelos atualizados, essa dissertação identifica e analisa esses impactos, os quais são reproduzidos em um estudo de caso que tem como finalidade avaliar a infraestrutura proposta através da demonstração de como ela lida com os impactos mencionados.

Most optimisation problems in everyday life are not static in nature, have multiple objectives and at least two of the objectives are in conflict with one another. However, most research focusses on either static multi-objective optimisation (MOO) or dynamic singleobjective optimisation (DSOO). Furthermore, most research on dynamic multi-objective optimisation (DMOO) focusses on evolutionary algorithms (EAs) and only a few particle swarm optimisation (PSO) algorithms exist. This thesis proposes a multi-swarm PSO algorithm, dynamic Vector Evaluated Particle Swarm Optimisation (DVEPSO), to solve dynamic multi-objective optimisation problems (DMOOPs). In order to determine whether an algorithm solves DMOO efficiently, functions are required that resembles real world DMOOPs, called benchmark functions, as well as functions that quantify the performance of the algorithm, called performance measures. However, one major problem in the field of DMOO is a lack of standard benchmark functions and performance measures. To address this problem, an overview is provided from the current literature and shortcomings of current DMOO benchmark functions and performance measures are discussed. In addition, new DMOOPs are introduced to address the identified shortcomings of current benchmark functions. Guides guide the optimisation process of DVEPSO. Therefore, various guide update approaches are investigated. Furthermore, a sensitivity analysis of DVEPSO is conducted to determine the influence of various parameters on the performance of DVEPSO. The investigated parameters include approaches to manage boundary constraint violations, approaches to share knowledge between the sub-swarms and responses to changes in the environment that are applied to either the particles of the sub-swarms or the non-dominated solutions stored in the archive. From these experiments the best DVEPSO configuration is determined and compared against four state-of-the-art DMOO algorithms. / Thesis (PhD)--University of Pretoria, 2012. / Computer Science / unrestricted

As society becomes more digitalized, cyberattacks are increasingly common and severe. Security in the Internet of Things (IoT) is essential, and IoT devices must be updated to patch vulnerabilities. The thesis aims to investigate the question "How can the Software Updates for Internet of Things (SUIT) specification be applied to develop a technology-agnostic and interoperable update architecture for heterogeneous networks of Internet of Things devices?" The thesis project studied the SUIT specifications to gain an understanding of what such an architecture must provide. Five high-level domains were identified and further discussed:1) roles of devices, servers, and operators, 2) key management, 3) device profiles, 4) authorization, and 5) update handling. The architecture was shown to fulfill the requirements SUIT imposes on the architecture and information model, while being flexible and extensible. A prototype was developed in the Contiki-NG operating system to evaluate the feasibility of the architecture. The thesis found that applying the proposed architecture to constrained systems is feasible and would enable updates in heterogeneous IoT networks. / I takt med att samhället blir digitaliserat blir digitala attacker vanligare och får ökade konsekvenser. Säkerhet inom Internet of Things (IoT) är kritiskt och IoT-enheter måste kunna uppdateras för att laga sårbarheter. Denna uppsats ämnar att undersöka frågan "Hur kan Software Updates for Internet of Things (SUIT)-specifikationen appliceras för att utveckla en teknologiskt agnostisk och kompatibel uppdateringsarkitektur för heterogena nätverk av Internet of Things-enheter?"Uppsatsen studerade SUIT-specifikationen för att förstå vad en sådan arkitektur måste erbjuda. Fem abstrakta domänområden identifierades och diskuterades: 1) roller för enheter, uppdateringsservrar, och operatörer, 2) nyckelhantering, 3) enhetsprofiler, 4) auktorisering, och 5) lokal uppdateringshantering. Arkitekturen visades uppfylla de krav SUIT ställer på en arkitektur och informationsmodell samt var flexibel och kunde utökas. En prototyp utvecklades i Contiki-NG operativsystemet för att utvärdera genomförbarheten hos arkitekturen. Uppsatsen fann att det är rimligt att applicera den föreslagna arkitekturen på resursbegränsade enheter, vilket skulle möjliggöra uppdateringar för heterogena IoT-nätverk.