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RINALDI, RICCARDO. "An empirical study on the relationship between technological innovation and the task structure of jobs." Doctoral thesis, Università di Siena, 2019. http://hdl.handle.net/11365/1082074.
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The thesis investigates the impact of technological innovation on employment and job characteristics. Automation - the technological driver behind the use of computers and robots - is here understood as a task-selective process of substitution of human input by (digitally enabled) machine input within production and distribution activities. Not only can automation impact on the structure of employment (cancelling the demand of certain jobs) but it can also bear consequences on the organization of work, with the net result of changing the nature of jobs.
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Guo, Yuxia. "User/group administration for RBAC." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0001/MQ42067.pdf.
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Khambhammettu, Hemanth. "Enforcing complex policies in RBAC." Thesis, Royal Holloway, University of London, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.529765.
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Buccelli, Emanuele. "Ingegnerizzazione di RBAC-MAS in TuCSoN." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amslaurea.unibo.it/8462/.
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L'obiettivo della tesi è la creazione di un'infrastruttura di tipo RBAC (Role Based Access Control), adibita al controllo degli accessi all'interno del linguaggio di coordinazione TuCSoN. Il punto di partenza si basa sull'analisi del lavoro sviluppato dall'Ing. Galassi: "Modello di sicurezza e controllo di accesso in una infrastruttura di coordinazione: architettura e implementazione". Usando questa come base teorica di partenza, si sono estrapolati i concetti chiave e si è data vita ad un'implementazione funzionante e di semplice utilizzo di RBAC in TuCSoN.
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Darwish, Wesam M. "Analysis of ANSI RBAC support in commercial middleware." Thesis, University of British Columbia, 2009. http://hdl.handle.net/2429/7147.
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This thesis analyzes the access control architectures of three middleware technologies: Common Object Request Broker Architecture (CORBA), Enterprise Java Beans (EJB), and Component Object Model (COM+). For all technologies under study, we formalize the protection state of their corresponding authorization architectures in a more precise and less ambiguous language than their respective specifications. We also suggest algorithms that define the semantics of authorization decisions in CORBA, EJB, and COM+. Using the formalized protection state configurations, we analyze the level of support for the American National Standard Institute's (ANSI) specification of Role-Based Access Control (RBAC) components and functional specification in the studied middleware technologies. This thesis establishes a framework for assessing implementations of ANSI RBAC in the analyzed middleware technologies.
Our findings indicate that all of three middleware technologies under study fall short of supporting even Core ANSI RBAC. Custom extensions are necessary in order for implementations compliant with each middleware to support ANSI RBAC required or optional components. Some of the limitations preventing support of ANSI RBAC are due to the middleware's architectural design decisions; however, fundamental limitations exist due to the impracticality of some aspects of the ANSI RBAC standard itself.
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Ma, Mingchao. "Distributed RBAC for subscription-based remote network services." Thesis, University of Greenwich, 2007. http://gala.gre.ac.uk/6232/.
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The problems of identity management inherent in distributed subscription-based resource sharing are investigated in this thesis. The thesis introduces a concept of authentication delegation and distributed RBAC (DRBAC) to support fine granular access control across multiple autonomous resource sites and subscribing sites. The DRBAC model extends the RBAC model to a distributed environment. A prototype system based on the concepts of authentication delegation and distributed role and the distributed RBAC model has been implemented and tested. Access is allowed based on the distributed roles, subject to certain constraints. Enforcing distributed role based access control policies allows organizations to ease the administrative overhead in a distributed environment. This thesis concentrates on both theoretical and practical aspects. It describes the design, implementation and performance of a prototype system that provides controlled access to subscription-based remote network services through a web browser. The prototype system is developed using Java technology and runs on a Tomcat web server. A third-party authentication protocol is designed and employed to exchange security assertions among involved parties. An XML-based policy language has been employed in the system for authorization decision. Public key cryptography and XML security technology are used to ensure the confidentiality and integrity of the system and interaction among the involved parties. The web servers use plug-ins to provide an authentication-delegation service and a policy-based authorization service. Users can use a single userID and password to access multiple subscribed resource sites.
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Báča, Petr. "RBC model - aplikace na ČR." Master's thesis, Vysoká škola ekonomická v Praze, 2009. http://www.nusl.cz/ntk/nusl-76667.
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The diploma thesis deals with the basic Real Business Cycle (RBC) model. RBC theory provides pure supply-side explanation of economic fluctuations. Generaly acknowledged contribution of RBC theory is the fact that the model is developed strictly on microeconomic basis. The thesis consists of two basic parts, theoretical and practical. First, historical background of RBC theory is mentioned. Then the basic RBC model is step-by-step derived and all equations are provided with explanations. In the last theoretical part section RBC theory critisism is discussed. In the practical part the derived basic model is applied to the Czech economy. First certain properties of the Czech business cycles are examined. Then, the basic model is calibrated, simulated and the results are commented.
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Regateiro, Diogo José Domingues. "A secure, distributed and dynamic RBAC for relational applications." Master's thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/14045.
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Mestrado em Engenharia de Computadores e TelemáticaNowadays, database application use tools like Java Database Connectivity, Hibernate or ADO.NET to access data stored in databases. These tools are designed to bring together the relational database and object-oriented programming paradigms, forsaking applied access control policies. Hence, the application developers must master the established policies as a means to develop software that is conformant with the established access control policies. Furthermore, there are situations where these policies can evolve dynamically. In these cases it becomes hard to adjust the access control mechanisms. This challenge has led to the development of an extension to the role based access control (RBAC) model where permissions are defined as a sequence of create, read, update and delete (CRUD) expressions that can be executed and the interfaces to access them. From these permissions it's possible to generate security artefacts on the client side, i.e. in a distributed manner, which allows the clients to access the stored data while satisfying the security policies defined. On top of this model extension, a security layer has also been created in order to make the access control secure and obligatory. For the RBAC model extension this work leverages a previous work that created a dynamic access control architecture for relational applications, here referred to as DACA (Dynamic Access Control Architecture). DACA uses business logic information and the defined access control policies to build dynamically the security artefacts for the applications. In situations where the access control policies can evolve dynamically, the security artefacts are adjusted automatically. This base work, however, defines as permissions CRUD expressions, which can be executed in any order, and needs an adequate security layer to authenticate users and protect the system form intruders. Hence, this work aims to create a new architecture, called “S-DRACA” (Secure, Dynamic and Distributed Role-based Access Control Architecture), which extends the work done with DACA so that it is capable of enforcing sequences of CRUD expressions that the applications can execute if the sequences are associated with their roles and the development of a security layer to make it secure. We discuss as well the performance of this system and its applicability to other environments outside of relational databases.
Atualmente, aplicações que acedem a bases de dados utilizam ferramentas como o Java Database Connectivity, Hibernate ou ADO.NET para aceder aos dados nelas armazenados. Estas ferramentas estão desenhadas para unir os paradigmas das bases de dados relacionais e da programação orientada a objetos, mas não estão preocupados com as políticas de controlo de acesso a aplicar. Portanto, os programadores de aplicações têm de dominar as políticas estabelecidas a fim de desenvolver aplicações em conformidade com as políticas de controlo de acesso estabelecidas.. Além disso, existem situações em que as políticas de controlo de acesso podem evoluir dinamicamente. Nestes casos, torna-se difícil adequar os mecanismos de controlo de acesso. Este desafio motivou o desenvolvimento de uma extensão ao modelo de controlo de acesso baseado em papeis (RBAC) que define como permissões sequências de expressões para criar, ler, atualizar e apagar (CRUD) informação e as interfaces de acesso a cada uma delas. A partir destas permissões podem ser gerados artefactos de segurança do lado dos clientes, i.e. de uma forma distribuída, que lhes permitem aceder à informação armazenada na base de dados segundo as políticas definidas. Por cima desta extenção também foi criada uma camada de segurança para tornar o controlo de acesso seguro e obrigatório. Para a extensão do modelo RBAC este trabalho baseou-se num trabalho anterior que criou uma arquitectura dinâmica de controlo de acesso para aplicações de bases de dados relacionais, aqui referida como DACA (Dynamic Access Control Architecture). DACA utiliza informação da lógica de negócio e as políticas de controlo de acesso que foram definidos para criar dinamicamente os artefactos de segurança para as aplicações. Em situações onde as políticas de controle de acesso evoluem de forma dinâmica, os artefactos de segurança são ajustados automaticamente. Este trabalho base, no entanto, define como permissões as expressões CRUD, podendo estas ser executadas em qualquer ordem, e necessita de uma camada de segurança adequada para autenticar utilizadores e proteger os dados sensíveis de intrusos. Portanto, neste trabalho, pretende-se criar uma nova arquitectura, chamada “S-DRACA” (Secure, Dynamic and Distributed Role-based Access Control Architecture), que estende o trabalho feito no âmbito do DACA para que este seja capaz de garantir que sejam cumpridas sequência de expressões CRUD que as aplicações podem executar e que estão associados aos seus papéis nas políticas RBAC e desenvolver uma camada de segurança adequada para a tornar segura. Discutimos, também, o seu desempenho e aplicabilidade em outros ambientes sem ser em bases de dados relacionais.
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Squarcina, Marco <1984>. "Granalyze: towards the automatic verification of Grsecurity RBAC policies." Master's Degree Thesis, Università Ca' Foscari Venezia, 2014. http://hdl.handle.net/10579/4729.
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Role-based Access Control (RBAC) is one of the most widespread security mechanisms in use today. Given the growing complexity of policy specifications arising from system administrators' needs, formally verifying that access control systems enforce some defined security invariants is a problem of crucial importance.
In a previous work which has been accepted for presentation at IEEE CSF 2012, we developed a framework for the formal verification of Grsecurity RBAC, an access control system developed on top of Unix/Linux systems. In this thesis we improve the framework by considering the interaction with the underlying operating system. This refinement allows for a reduction in the number of transitions within the labelled transition systems resulting from policies. Additionally, we deal with the problem of automatic verification of Grsecurity RBAC policies by defining a set of security invariants.
Based on our abstract semantics, we implement Granalyze, a model checker that accounts for the verification of real policies. We report on the results of the experimental analysis conducted using the tool on existing public servers running Grsecurity RBAC.
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Goran, Sladić. "Model kontekstno zavisne kontrole pristupa u poslovnim sistemima." Phd thesis, Univerzitet u Novom Sadu, Fakultet tehničkih nauka u Novom Sadu, 2011. http://dx.doi.org/10.2298/NS2011SLADICGORAN.
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Kontrola pristupa odnosno autorizacija, u širem smislu, razmatra na koji način korisnici mogu pristupiti resursima računarskog sistema i na koji način ih koristiti. Ova disertacija se bavi problemima kontrole pristupa u poslovnim sistemima. Tema disertacije je formalna specifkacija modela kontekstno zavisne kontrole pristupa u poslovnim sistemima koji je baziran na RBAC modelu kontrole pristupa. Uvođenjem kontekstno zavisne kontrole pristupa omogućeno je defnisanje složenijih prava pristupa koje u postojećim modelima kontrole pristupa za poslovne sisteme nije bilo moguće realizovati ili bi njihova realizacija bila komplikovana. Dati model primenljiv je u različitim poslovnim sistemima, a podržava defnisanje prava pristupa kako za jednostavne tako i za slo·zene poslovne tokove. Sistem je verifkovan na dva realna poslovna procesa pomoću razvijenog prototipa. Prikazana prototipska implementacija koja ispunjava ciljeve u pogledu funkcionalnosti postavljene pred sistem predstavlja potvrdu praktične vrednosti predloženog modela.Access control is concerned with the way in which users can access to resources in the computer system. This dissertation focuses on problems of access control for business processes. The subject of the dissertation is a formal specification of the RBAC-based context sensitive access control model for business processes. By using a context-sensitive access control it is possible to define more complex access control policies whose implementation in existing access control models for business processes is not possible or is very complicated. The given model is applicable in diferent business systems, and supports the definition of access control policies for both simple and complex business processes. The model's prototype is verified by two case studies on real business processes. The presented prototype implementation represents a proof of the proposed model's practical value.
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Law, Boon-Chuan. "UNCERTAINTY ANALYSIS FOR ROCKET-BASED COMBINED CYCLE (RBCC) SYSTEMS TESTING." MSSTATE, 2003. http://sun.library.msstate.edu/ETD-db/theses/available/etd-07152003-174339/.
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General uncertainty analysis was used to evaluate the performance of a Rocket-Based Combined Cycle (RBCC) engine system. To estimate the uncertainties of test results, uncertainties of basic measurements such as temperature, pressure, mass flow rate, and thrust were determined. The desired test results of interest included specific impulse and characteristic velocity. Various possible test facilities were reviewed to obtain background information and example test run conditions. Based on the test run conditions, five methods of determining specific impulse were evaluated. Also, theoretical and actual characteristic velocities were analyzed to evaluate C* efficiency. Initially, general uncertainty analyses were completed relative to 1% accuracy for each measured variable. Then, cases were run using more realistic uncertainty estimates. The relative contributions of the different variables? uncertainties to the overall uncertainty of the selected performance parameters were also calculated. This process helps to identify the critical measurements from an uncertainty standpoint and can be a significant guide in the cost effective use of resources to reduce the test uncertainty.
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Costa, Vanderlei Ferreira da. "Autorização integrada entre portais e Globus baseada no modelo RBAC." Universidade Católica de Santos, 2008. http://biblioteca.unisantos.br:8181/handle/tede/603.
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Previous issue date: 2008-10-03Plataformas de grade computacional têm sido adotadas para promover o compartilhamento, agregação e coordenação de grandes quantidades de recursos geograficamente distribuídos e multi-institucionais. Em tais ambientes, que envolvem grandes quantidades de recursos localizados em diversos domínios administrativos e sujeitos a uma diversidade de políticas de controle de acesso, o controle de acesso é obrigatório. Como principal contribuição, o presente trabalho estende o arcabouço (framework) de portais GridSphere com o objetivo de fornecer ferramentas de controle de acesso que podem ser utilizadas para o desenvolvimento de aplicaçõess para grades computacionais. Os mecanismos e ferramentas propostos também realizam o controle de acesso no nível de invocação de serviço, que pode ser usado por qualquer aplicação compatível com OGSA que realize invocações a serviços de grade. Nossa abordagem permite a integração e consistência entre políticas de autorização aplicadas no lado do portal e no lado do provedor de serviço.
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Damasceno, Carlos Diego Nascimento. "Evaluating finite state machine based testing methods on RBAC systems." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/55/55134/tde-11112016-101158/.
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Access Control (AC) is a major pillar in software security. In short, AC ensures that only intended users can access resources and only the required access to accomplish some task will be given. In this context, Role Based Access Control (RBAC) has been established as one of the most important paradigms of access control. In an organization, users receive responsibilities and privileges through roles and, in AC systems implementing RBAC, permissions are granted through roles assigned to users. Despite the apparent simplicity, mistakes can occur during the development of RBAC systems and lead to faults or either security breaches. Therefore, a careful verification and validation process becomes necessary. Access control testing aims at showing divergences between the actual and the intended behavior of access control mechanisms. Model Based Testing (MBT) is a variant of testing that relies on explicit models, such as Finite State Machines (FSM), for automatizing test generation. MBT has been successfully used for testing functional requirements; however, there is still lacking investigations on testing non-functional requirements, such as access control, specially in test criteria. In this Master Dissertation, two aspects of MBT of RBAC were investigated: FSM-based testing methods on RBAC; and Test prioritization in the domain of RBAC. At first, one recent (SPY) and two traditional (W and HSI) FSM-based testing methods were compared on RBAC policies specified as FSM models. The characteristics (number of resets, average test case length and test suite length) and the effectiveness of test suites generated from the W, HSI and SPY methods to five different RBAC policies were analyzed at an experiment. Later, three test prioritization methods were compared using the test suites generated in the previous investigation. A prioritization criteria based on RBAC similarity was introduced and compared to random prioritization and simple similarity. The obtained results pointed out that the SPY method outperformed W and HSI methods on RBAC domain. The RBAC similarity also achieved an Average Percentage Faults Detected (APFD) higher than the other approaches.Controle de Acesso (CA) é um dos principais pilares da segurança da informação. Em resumo, CA permite assegurar que somente usuários habilitados terão acesso aos recursos de um sistema, e somente o acesso necessário para a realização de uma dada tarefa será disponibilizado. Neste contexto, o controle de acesso baseado em papel (do inglês, Role Based Access Control - RBAC) tem se estabelecido como um dos mais importante paradigmas de controle de acesso. Em uma organização, usuários recebem responsabilidades por meio de cargos e papéis que eles exercem e, em sistemas RBAC, permissões são distribuídas por meio de papéis atribuídos aos usuários. Apesar da aparente simplicidade, enganos podem ocorrer no desenvolvimento de sistemas RBAC e gerar falhas ou até mesmo brechas de segurança. Dessa forma, processos de verificação e validação tornam-se necessários. Teste de CA visa identificar divergências entre a especificação e o comportamento apresentado por um mecanismo de CA. Teste Baseado em Modelos (TBM) é uma variante de teste de software que se baseia em modelos explícitos de especificação para automatizar a geração de casos testes. TBM tem sido aplicado com sucesso no teste funcional, entretanto, ainda existem lacunas de pesquisa no TBM de requisitos não funcionais, tais como controle de acesso, especialmente de critérios de teste. Nesta dissertação de mestrado, dois aspectos do TBM de RBAC são investigados: métodos de geração de teste baseados em Máquinas de Estados Finitos (MEF) para RBAC; e priorização de testes para RBAC. Inicialmente, dois métodos tradicionais de geração de teste, W e HSI, foram comparados ao método de teste mais recente, SPY, em um experimento usando políticas RBAC especificadas como MEFs. As características (número de resets, comprimento médio dos casos de teste e comprimento do conjunto de teste) e a efetividade dos conjuntos de teste gerados por cada método para cinco políticas RBAC foram analisadas. Posteriormente, três métodos de priorização de testes foram comparados usando os conjuntos de teste gerados no experimento anterior. Neste caso, um critério baseado em similaridade RBAC foi proposto e comparado com a priorização aleatória e baseada em similaridade simples. Os resultados obtidos mostraram que o método SPY conseguiu superar os métodos W e HSI no teste de sistemas RBAC. A similaridade RBAC também alcançou uma detecção de defeitos superior.
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Modebe, Emmanuel Obinna. "Extended Cr-51 RBC combined with Tc-99m RBC for the detection and localisation of occult GIT bleeding." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86509.
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Thesis (MMed)--Stellenbosch University, 2014.ENGLISH ABSTRACT: Background Occult blood loss from the gastrointestinal tract (GIT), causing iron deficiency often with anaemia, can be diagnostically and therapeutically challenging. This is because the endoscopic and radiologic tests may be negative due to the slow, chronic and intermittent nature of the gastrointestinal bleeding, making timing key in detection and localisation of the bleed. These limitations can be approached using two different radioactive isotopes. Firstly, we tested the sensitivity of extending Cr-51 RBC for 21 days relative to 5 days to detect GIT bleeding and its use to optimise timing of a Tc-99m RBC study for GIT blood loss localisation. Finally, we tested if the information provided by the Tc-99m RBC study aided gastroenterologic intervention for anatomical localisation of a lesion. Method In this retrospective review, after obtaining institutional and ethics committee approval, records of patients referred for evaluation of possible GIT blood loss were reviewed. In each; daily appearance of radiochromium in stool was measured in the whole body counter. In those cases exceeding 50 ml/day, a technetium-99m (Tc-99m) localization study was performed. These studies were correlated with clinical findings. Results A total of 59 Cr-51 RBC studies were carried out in 36 females and 21 males (n = 57). In 32 (54%) the radiochromium results were positive with 75% of the bleeding incidences occurring after 5 days of stool collection. Of 17 cases in whom Tc-99m RBC imaging studies were performed, 14 (82%) were positive with specific anatomical sites successfully defined in twelve. In all patients with blood loss of >100 ml/24h, Tc-99m RBC were positive and localised. Ten of the 17 Tc-99m RBC studies were further investigated and half diagnosed with small-bowel angiodysplasia. Conclusion This sequential twin isotope method is practical in revealing otherwise silent intestinal haemorrhage. Although it has good patient acceptability and clinical as well as diagnostic utility in management, further studies are required to clearly establish a cut-off level of blood loss for performing imaging studies and the impact of the findings on the overall patient management.
AFRIKAANSE OPSOMMING: Agtergrond Die evaluasie van okkulte bloedverlies uit die gastro-intestinale kanaal (GIT), met gevolglike ystertekort anemie, kan diagnosties en terapeuties uitdagend wees. Dit is omdat endoskopiese en radiologiese ondersoeke negatief mag wees as gevolg van die stadige, chroniese en intermitterende aard van die gastro-intestinale bloeding, wat die presiese tydstip van opsporing en lokalisering van die bloeding krities belangrik maak. Hierdie beperkings kan aangespreek word deur twee verskillende radioaktiewe isotope te gebruik. Eerstens is die sensitiwiteit van die verlenging van die Cr-51 RBS studie tot 21 dae in plaas van 5 dae om die GIT bloeding op te spoor, getoets, asook die gebruik daarvan om die optimale tyd vir ‘n Tc-99m RBS studie om die GIT bloedverlies te lokaliseer, vas te stel. Laastens is getoets of die inligting van die Tc-99m RBS studie wel bygedra het tot die gastroenterologiese ingreep om die letsel anatomies te lokaliseer. Metode Na institusionele en etiese komitee toestemming is inligting van pasiënte wat vir die evaluering van ‘n moontlike GI bloedverlies verwys is, in hierdie retrospektiewe oorsig nagegaan. Die daaglikse voorkoms van radioaktiewe chroom in stoelgangmonsters is in ‘n heelliggaamteller gemeet. In gevalle waar dit 50 ml/dag oorskry het, is ‘n tegnesium 99m (Tc 99m) studie gedoen. Hierdie studies is met die kliniese bevindinge gekorreleer. Resultate ‘n Totaal van 59 Cr-51 RBS studies is in 36 vroue en 21 mans (n = 57) gedoen. Die gemerkte chroomstudies was positief in 32 (54%), met 75% van die bloedings wat meer as 5 dae na versameling van die stoelgang plaasgevind het. In veertien (82%) van die 17 gevalle waar Tc-99m RBS studies gedoen is, was die studies positief. Spesifieke anatomiese gebiede van bloeding kon in 12 hiervan suksesvol bevestig word. Tc-99m RBS studies was positief in al die pasiënte met ‘n bloedverlies van >100 ml/24h, en kon gelokaliseer word. Tien van die 17 Tc-99m RBS studies is verder ondersoek en die helfte daarvan gediagnoseer met dunderm angiodisplasie. Gevolgtrekking Die opeenvolgende twee isotoopmetode om andersins asimptomatiese dermbloeding op te spoor, is prakties uitvoerbaar. Alhoewel die studies goed deur pasiënte aanvaar is, en ook van kliniese en diagnostiese waarde in die hantering van die pasiënte is, is verdere studies nodig om die afsnypunt vir die hoeveelheid bloedverlies om beeldingstudies uit te voer, sonder twyfel vas te stel, asook om die impak van die bevindings op ‘n groter pasiëntpopulasie vas te stel.
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Khayat, Etienne J. "Role-based access control (RBAC) : formal modelling and risk-based administration." Thesis, London South Bank University, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.435233.
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Lee, Chang Hee. "The competitive effects of RBOC interLATA entry on local telephone markets." Columbus, Ohio : Ohio State University, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1078943781.
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Thesis (Ph. D.)--Ohio State University, 2004.Title from first page of PDF file. Document formatted into pages; contains xiii, 274 p.; also includes graphics (some col). Includes abstract and vita. Advisor: Douglas N. Jones, Dept. of Public Policy and Management. Includes bibliographical references (p. 275-317).
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Jadidi, Mansoor. "Numerical and Experimental Model of Healthy and Damaged Red Blood Cell Trajectories in Micro-channels." Thesis, Griffith University, 2023. http://hdl.handle.net/10072/421347.
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Motivation: Red blood cells (RBCs) are the most common cells in the blood due to their high concentration. The RBC has a deformable membrane enclosing a jelly-like fluid known as the cytosol. For many years, the dynamics of RBCs has attracted growing interest both numerically and experimentally in various fields of research on biological systems. Owing to their high deformability, RBCs exhibit complex dynamic behaviours in micro-vessels where Reynolds numbers (Re) are less than unity (Re < 1). First, a healthy RBC at a low shear rate or a high viscosity contrast (λ - defined as the ratio of viscosities between RBC cytosol and external fluid), may tumble, i.e., the whole RBC rotates continuously in the original shape like a rigid body. Second, at a high shear rate or a low viscosity contrast (λ), the RBC may exhibit a tank-treading motion, i.e., its membrane rotates around the cytosol which maintains a fixed angle with respect to the flow direction. Finally, a healthy RBC migrates in the lateral direction towards the micro-vessel axis while moving in the longitudinal direction (downstream) of a micro-vessel.
Under physiological conditions, the RBC experiences a varying range of shear stresses (typically in the range of 1-10 Pa) in the circulatory system without exhibiting any physical signs of mechanical damage. Upon exposure to high shear stresses, such as those present within mechanical circulatory support, RBCs exhibit irreversible functional impairment called sub-haemolytic/sub-lethal damage. Sub-haemolytically damaged RBCs exhibit impaired mechanical properties that substantially alter bulk flow behaviour when compared with healthy RBCs. However, there has been little attention directed toward characterizing sub-haemolytic damage in literature. For better understanding, it is necessary to have a reliable model to predict the dynamics of sub-haemolytically damaged RBCs in micro-vessels in comparison with healthy RBCs.
Methods: Highly-efficient numerical approaches have been developed to investigate blood flow, with particular emphasis on the motion and deformation of RBCs under shear flow. Among these methods, the integration of the lattice Boltzmann method (LBM) and immersed boundary method (IBM) has received considerable attention. In this dissertation, a 2D in-house generated algorithm based on the LBM-IBM was utilised for the numerical simulations. Moreover, a spring-based model was applied to simulate the elastic behaviour of the RBC membrane. Finally, a microfluidic experimental system including flow control, image capture, and data acquisition was established to validate the numerical results with the experimental results.
Goal: The main focus of this dissertation was to establish a 2D LBM-IBM coupled with a spring-based model to simulate the trajectory of both healthy RBC and damaged RBC in Poiseuille flow in low Reynolds numbers (Re < 1), in which the numerical results are compared with the experimental ones to allow for model validation. The second aim of this study was to numerically simulate the tumbling and tank-treading-like motion of a single RBC (healthy and damaged) in a micro-channel. Finally, the third aim was to numerically simulate the effect of the viscosity contrast (λ) on the trajectory of an RBC in a micro-channel. λ is one of the important factors that can severely affect RBC dynamics and cell deformation in a shear flow. Because of computational complexity, little effort has been made to numerically model the effect of λ on RBC dynamics in flow in the literature, for this reason, most of the current simulation studies assume for simplicity the viscosity contrast of unity.
Results: Overall, the numerical results indicated a reasonable agreement with the observed experimental results. However, the numerical simulation predicts a larger migration (1.81 μm for the healthy RBC and 0.96 μm for the damaged RBC) compared to the experimental tests (1.20 μm for the healthy RBC and 0.41 μm for the damaged RBC). Moreover, the experimental results showed that at a certain distance from the entrance of the micro-channel, the RBCs have a rolling motion like a wheel but without lateral migration. Due to the deformability of the RBCs, this motion is unstable so that later on, the RBCs migrate laterally toward the centreline of the micro-channel. The results also showed that the distance at which rolling motion happens is greater for the damaged RBCs (~ 150 μm) compared to the healthy RBCs (~ 25 μm) because the damaged cells deform less. The numerical results confirm this result. It can be seen from the numerical results that the healthy RBC experiences the tank-treading motion compared to the damaged RBC that exhibits the tumbling motion. Furthermore, the numerical results indicated a significant impact on the RBC trajectory when λ = 5 compared to λ = 1. The higher viscosity contrast of 5 has less lift (5.06 μm) in comparison with the lower viscosity contrast of 1 (6.56 μm). In addition, for a fixed viscosity contrast λ of 10, as the rigidity of the RBC increases, its final lateral and longitudinal displacements decrease.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Eng & Built Env
Science, Environment, Engineering and Technology
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Carneiro, Dias André Eduardo. "Study of RBC shape transitions induced by nanoparticles." Doctoral thesis, Universitat Rovira i Virgili, 2019. http://hdl.handle.net/10803/668080.
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Aquesta tesi descriu l'estudi de les propietats del medi extracel·lular sobre la criopreservació de glòbuls vermells i la possible aplicació de nanopartícules de sílice com a co-agents per al lliurament intracel·lular de trehalosa, un crioprotector natural. La primera part de l™estudi es va centrar en les condicions de congelació i descongelació i en les propietats del medi extracel·lular per a la congelació. Es van analitzar diferents propietats segons la seva influència en la taxa de supervivència dels glòbuls vermells, que es va avaluar mitjançant l™assaig d™hemòlisi i es va analitzar l™efecte de la congelació mitjançant anàlisi morfològica d™imatges de glòbuls vermells. La segona part de l'estudi investiga la interacció de nanopartícules de sílice carregades de manera diferent amb els glòbuls vermells per a futures aplicacions com a co-agent per al lliurament de la trehalosa. La toxicitat de les nanopartícules de sílice es va determinar mitjançant un assaig d™hemòlisi i la seva distribució espacial es va estudiar mitjançant l™examen de glòbuls vermells que flotaven lliurement mitjançant microscòpia confocal d™escaneig làser (LSCM). Es va desenvolupar un nou mètode de visualització 3D de gran rendiment i aplicat a les imatges LSCM per tal de corregir la deriva al llarg de la z-stack permetent l'anàlisi de les imatges. Els resultats es van confirmar interactuant les nanopartícules de sílice amb vesícules gegants unilamellars (GUV) com a sistema experimental.Esta tesis describe el estudio de las propiedades del medio extracelular en la crioconservación de los glóbulos rojos y la posible aplicación de nanopartículas de sílice como coagentes para la entrega intracelular de trehalose, un crioprotector natural. La primera parte del estudio se centró en las condiciones de congelación y descongelación, y en las propiedades del medio extracelular para la congelación. Se analizaron diferentes propiedades de acuerdo con su influencia en la tasa de supervivencia de los glóbulos rojos, según se evaluó mediante el ensayo de hemólisis, y se analizó el efecto de la congelación mediante el análisis morfológico de las imágenes de los glóbulos rojos. La segunda parte del estudio investiga la interacción de nanopartículas de sílice, cargadas de manera diferente, con glóbulos rojos para su futura aplicación como coagente para la entrega de trehalose. La toxicidad de la nanopartícula de sílice se determinó mediante un ensayo de hemólisis y su distribución espacial se estudió mediante la obtención de imágenes de los glóbulos rojos que flotan libremente usando microscopía confocal (LSCM). Se desarrolló un nuevo método de visualización 3D de alto rendimiento que se aplicó a las imágenes LSCM para corregir la deriva en toda la pila z permitiendo el análisis de las imágenes. Los resultados se confirmaron mediante la interacción de las nanopartículas de sílice con vesículas unilamelares gigantes (GUV) como un sistema de modelo experimental.
This thesis describes the study of the properties of extracellular medium on the cryopreservation of red blood cells and the potential application of silica nanoparticles as co-agents for the intracellular delivery of trehalose, a natural cryoprotectant. The first part of the study focused on the freezing and thawing conditions, and on the properties of the extracellular medium for freezing. Different properties were analyzed according to their influence on the survival rate of red blood cells as assessed by hemolysis assay and the effect of freezing was analyzed by morphological analysis of images of red blood cells. The second part of the study investigates the interaction of differently charged silica nanoparticles with red blood cells for future application as co-agent for trehalose delivery. Silica nanoparticle toxicity was determined by hemolysis assay and their spatial distribution was studied by imaging freely floating red blood cells using laser scanning confocal microscopy (LSCM). A novel high-throughput 3D visualization method was developed and applied to LSCM images in order to correct the drift throughout the z-stack allowing the analysis of the images. Results were confirmed by interacting the silica nanoparticles with giant unilamellar vesicles (GUV) as an experimental model system.
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Mendes, William Corrêa. "ARQUITETURA BASEADA EM ONTOLOGIAS DE UM AGENTE RBC." Universidade Federal do Maranhão, 2013. http://tedebc.ufma.br:8080/jspui/handle/tede/506.
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Previous issue date: 2013-11-04Case-Based Reasoning (CBR) is a problem-solving paradigm where it is possible to use knowledge from past experiences to solve new situations. The CBR agent approach that combines agent autonomy with the problem-solving model of CBR has been proven adequate for the development of complex systems. This paper proposes the architecture of a CBR agent whose main differential is the use of ontologies for representing the case base along with all the mechanisms that make up a CBR system. The proposed architecture besides promoting the reuse of the case ontology, unifies the software agent approach with CBR, a typical paradigm of human reasoning. All the CBR mechanisms are present in the proposed architecture: case representation, similarity analysis for cases retrieval, adaptation and cases learning, where the last two mechanisms are still being specified. The architecture was evaluated in the Brazilian Family Law legal domain. For that, a targeted ontology for the representation CBR cases of this area was created. The results obtained in the tests showed good effectiveness in retrieving similar cases and showing the feasibility of the architecture using the semantic model of similarity for retrieval of CBR cases.
O Raciocínio Baseado em Casos (RBC) é um paradigma de resolução de problemas no qual é possível utilizar conhecimentos de experiências passadas para resolver novas situações. A abordagem de agentes RBC que combina a autonomia dos agentes e o modelo de resolução de problemas do RBC tem se mostrado adequada para o desenvolvimento de sistemas complexos. Este trabalho propõe a arquitetura de um agente RBC cujo principal diferencial é utilizar ontologias para representar a base de casos junto com todos os mecanismos que compõem um sistema RBC. A arquitetura proposta, além de promover o reúso da ontologia de representação dos casos, unifica as abordagens de agentes de software e RBC, um paradigma de raciocínio típico dos seres humanos. Estão presentes na arquitetura os mecanismos de representação dos casos, análise de similaridade para recuperação de casos, adaptação e aprendizado de casos, estes dois últimos ainda em fase de especificação. A arquitetura foi avaliada no domínio jurídico do Direito de Família brasileiro, sendo que para isso foi criada uma ontologia, representando casos RBC nesta área. Os resultados obtidos nos testes realizados demonstraram uma boa efetividade na recuperação de casos similares e a consequente viabilidade do uso da arquitetura com o modelo de similaridade semântico utilizado para recuperação de casos RBC.
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Almeida, Sara Cristina Cantarino Valente de. "An RBC model with a rich fiscal sector." Master's thesis, NSBE - UNL, 2013. http://hdl.handle.net/10362/9698.
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A Work Project, presented as part of the requirements for the Award of a Masters Degree in Economics from the NOVA – School of Business and EconomicsContributing to the general understanding of fiscal policy e ectiveness, this study consists in the reformulation and estimation of the DSGE model developed in Azevedo and Ercolani (2012), to measure the potential relations between the private sector and the consumption and investment components of government expenditures. The estimation results show that public consumption and capital have both a substitutability e ect on private factors. For the study of the dynamic e ects, the model is augmented with strict fiscal rules, whose imposition creates a "crowding-out" e ect of the simulated fiscal policy shocks on government consumption and investment.
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Morrow, Carl. "Phylogenetic investigations of the African Restionaceae using rbc." Thesis, University of Cape Town, 2017. http://hdl.handle.net/11427/26316.
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Beppler, Fabiano Duarte. "Emprego de RBC para recuperação inteligente de informações." Florianópolis, SC, 2002. http://repositorio.ufsc.br/xmlui/handle/123456789/82898.
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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia de Produção.Made available in DSpace on 2012-10-19T19:18:05Z (GMT). No. of bitstreams: 1 189259.pdf: 2369619 bytes, checksum: 6081c39e99c22484b1465b896722ff2a (MD5)
A dimensão do volume de informações disponíveis na Internet e as taxas diárias de crescimento tornam cada vez mais presentes mecanismos eficientes e eficazes de recuperação de informações. A maioria dos métodos pesquisados e aplicados tem por base o tratamento das informações disponíveis nos repositórios associados aos sites. Nesta abordagem, um elemento de conhecimento é normalmente negligenciado: a memória das interações efetuadas pelos usuários que utilizaram o site previamente a um usuário atual. A construção desta memória viabiliza o emprego de interações de busca do passado na apresentação de informações desejadas no momento das consultas. A presente dissertação propõe a construção da memória das buscas aos sites na forma de casos de consulta e a aplicação de Raciocínio Baseado em Casos para utilização destas interações passadas como subsídio em novos processos de consulta. O método proposto deu origem à ferramenta RBNet. Para demonstração de sua viabilidade, RBNet foi aplicada ao site de busca do "Diretório dos Grupos de Pesquisa no Brasil", projeto do Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq). RBNet permite que usuários interessados em grupos de pesquisa possam encontrar rapidamente o que desejam, quando se valem das interações semelhantes registradas na base de casos do RBNet.
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Simm, Robert. "Enhanced biological phosphorus removal using a sequencing batch RBC." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/28517.
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The objective of the research program was to demonstrate the technical feasibility of removing phosphorus, by the enhanced biological phosphorus removal mechanism, from domestic wastewater using a laboratory scale Sequencing Batch Rotating Biological Contactor (SBRBC). The rotating discs of the RBC were subjected to alternating anaerobic/aerobic conditions by varying the water level in the reaction vessel. At the start of the treatment cycle, the RBC reactor would be filled submerging the rotating discs and ensuring anaerobic conditions in the RBC biofilm. Acetate would be added to the reaction vessel at this time. Following the batch anaerobic react period part of the reactor contents were decanted to either the sewage feed tank or a separate holding vessel to later become part of the influent for the next treatment cycle. With the rotating: discs of the-RBC partially submerged oxygen was available to the bacteria, in the RBC biofilm.
Three operating schedules were tried with the above process. Each operating schedule
differed in the way the decanted wastewater from the anaerobic phase was handled.
Batch tests were conducted weekly to determine the nature of the biological reactions
taking place in each of the batch anaerobic and aerobic phases.
The SBRBC process showed promise for enhanced biological phosphorus removal from domestic wastewater. Carbon removal and nitrification of the wastewater were secondary benefits to this process. The success of the process was found to be dependent on the attainment of proper anaerobic conditions at the start of each treatment cycle.Applied Science, Faculty of
Civil Engineering, Department of
Graduate
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Tapon, Njamo Julien Serge. "Olive wastewater bioremediation using a rotating biological contactor (RBC)." Thesis, Cape Peninsula University of Technology, 2012. http://hdl.handle.net/20.500.11838/2023.
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Thesis (MTech (Food Technology))--Cape Peninsula University of Technology, 2012.The expansion of the South African olive processing industry has brought an increased threat to the environment. More production activities lead to more wastewater generation that requires more costly treatment. Regulatory bodies concerned with the release of effluents into the environment are imposing evermore-restrictive guidelines. With this information in mind, the South African olive industry is facing a significant challenge of maintaining economic competitiveness while becoming more environmentally benign. To begin addressing this challenge, the olive processing industry must develop and implement new, more effective, tailored treatment technologies to remediate olive wastewater prior to its release into the environment. In this study, the use of indigenous olive wastewater biofilms in combination with a rotating biological contactor (RBC) was investigated for possible bioremediation purposes. The development of microbial biofilms resulted in the breakdown of the hazardous chemical compounds present in the olive wastewater, i.e. reducing the chemical oxygen demand (COD) and polyphenol content. Results showed that indigenous microorganisms within table olive and olive mill wastewater have a strong tendency to form biofilms. Furthermore, when these biofilms are applied to a small-scale RBC system, significant lower levels of both COD (on average 55% for table olive wastewater (TOWW) and 46% for olive mill wastewater (OMWW) and total phenol (on average 51% for TOWW and 39% for OMWW) were obtained. Results from shocking the biofilms with chemicals routinely used during olive processing indicates that most have a negative effect on the biofilm population, but that the biofilms are able to survive and recover in a relatively short time. This study confirms the potential application of indigenous biofilms found in olive wastewater streams for future bioremediation technologies that form the basis for the development of an eco-friendly, easy-to-manage, low cost technologies specifically designed for the small South African olive processing industry.
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Moreira, Antão Leonir Langendolff. "PRECISÃO DO POSICIONAMENTO RTK USANDO CORREÇÕES DIFERENCIAIS TRANSMITIDAS PELO SISTEMA NTRIP (RBMC-IP)." Universidade Federal de Santa Maria, 2011. http://repositorio.ufsm.br/handle/1/9547.
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The Global Navigation Satellite System (GNSS), in the last few years, has been
supporting the development of mobile telephony and the expansion of electronic
equipments (GNSS receivers) to promote a revolution in geodetic surveys in real time.
In this context, it becomes important the technique of positioning Real Time
Kinematic (RTK) with the use of differential corrections transmitted by the protocol
named Networked Transport of RTCM via the Internet Protocol (NTRIP), from a
reference station via Internet. It is aimed, in this research, the evaluation of the
precision of this technique for different lengths of baseline, and also the use of
different numbers of trace periods. Then, three-dimensional coordinates of 10
stations (DEM) were used, they were also located in three municipalities of Rio
Grande do Sul, which were traced by the static post-processed (static PP) method,
which helped as being a reference in comparison with technique RTK / NTRIP, that
used the correlations of the Brazilian Network for Continuous Monitoring of the GNSS
Systems in real time - (RBMC-IP). The results showed that there was resolution of
the ambiguities in nine seasons at baseline greater than 54 km, and that the
precision values showed no difference greater than 0.041 m in the horizontal
component and 0.083 m in the vertical component. In addition, between the numbers
of the tested periods (5,10,30, 60 and 120 periods) for the method RTK / NTRIP, the
tested period that had the best average precision of the horizontal component was
the 120 one (0.01 m), and for the vertical component was considered the five periods
number as the most appropriated (0.02 m). Hence, it was proved the reliability of the
technique RTK / NTRIP (RBMC-IP) in baselines of until 54 km, showing that it can be
used for topographical surveys in areas with wireless Internet or cellular services
such as GPRS, GSM and 3G.O Sistema Global de Navegação por Satélite (GNSS) nos últimos anos vem se apoiando no desenvolvimento da telefonia móvel e no avanço da eletrônica dos equipamentos (receptores GNSS) para promover uma revolução nos levantamentos geodésicos em tempo real. Neste contexto, se destaca a técnica de posicionamento Real Time Kinematic (RTK) usando correções diferenciais transmitidas pelo protocolo Networked Transport of RTCM via internet Protocol (NTRIP), a partir de uma estação de referência via internet. O objetivo deste trabalho foi avaliar a precisão desta técnica para diferentes comprimentos de linha de base e com o uso de diferentes números de épocas de rastreio. Para isso, foram utilizadas as coordenadas tridimensionais de 10 estações (marcos), localizadas em três municípios do estado do Rio Grande do Sul, rastreadas pelo método relativo estático pós-processado (estático PP), o qual serviu de referência na comparação com a técnica RTK / NTRIP, que utilizou de correções da Rede Brasileira de Monitoramento contínuo dos Sistemas GNSS em tempo real (RBMC-IP). Os resultados mostraram que houve resolução das ambiguidades em nove estações numa linha de base superior a 54 km e que os valores de acurácia não apresentaram diferença superior a 0,041 m na componente horizontal e 0,083 m na componente vertical. Além disso, entre os números de épocas testados (5, 10, 30, 60 e 120 épocas) para o método RTK / NTRIP, aquele que apresentou a melhor média de acurácia horizontal foi o de 120 épocas (0,01 m) e para a componente vertical o melhor resultado foi alcançado com o número de 5 épocas rastreadas (0,02 m). Deste modo, foi comprovada a confiabilidade da técnica RTK / NTRIP (RBMC-IP) em linhas de base de até 54 km, podendo ser utilizada para levantamentos topográficos em locais providos por Internet wireless ou serviços de telefonia celular tais como, GPRS, GSM e 3G.
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Thompson, Martin John. "Investigation of the effects of HLS5 : a novel member of the RBCC family." University of Western Australia. School of Medicine and Pharmacology, 2006. http://theses.library.uwa.edu.au/adt-WU2006.0106.
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[Truncated abstract] Erythropoietin (Epo) is a glycoprotein hormone involved in the formation of erythrocytes, by controlling survival, differentiation and proliferation. The technique of cDNA Representational Difference Analysis was utilized to investigate J2E-NR cells that demonstrate a viability response to Epo, but not differentiation or proliferation. The aim of this project was to identify genes that may be upregulated in response to Epo-induced survival; however, no change in gene expression was detected. This was most probably because any changes were below the limit of detectability for the cDNA RDA technique, or the viability effect was mediated post-transcriptionally. Next, it was decided to investigate HLS5, a putative tumour suppressor that was identified in a myeloid variant of the J2E cell line and had been shown to cause apoptosis. A number of HeLa cell lines inducible for Hls5 expression using the tet-off system were produced; despite extremely low expression, Hls5 was shown to produce marked suppression of growth and proliferation, particularly in colony assays colony size and numbers were halved for one induced clone. … A number of haemopoiesis-associated genes were downregulated (viz. globin genes and the Epo receptor gene), which suggested Hls5s role in the myeloid variant of J2E cells, may be to suppress genes expressed in the erythroid lineage. In addition, several interferon-responsive genes were decreased in cells with elevated HLS5, suggesting it may play a role in negatively regulating interferon signaling. Online databases were also searched for information on HLS5, and showed that it is significantly downregulated in liver, lung and uterine cancers, supporting the proposition that HLS5 is a tumour suppressor gene. In summary, a number of approaches were taken to identify the effects of the Hls5 protein. It appears that it strongly suppresses proliferation and that this is likely mediated through an effect on mitosis. This may also result in apoptosis of overexpressing cells. It is possible that this is the mechanism through which HLS5 exerts its potential tumour suppressor function, as a number of tumour suppressors appear to be associated with mitosis/apoptosis control. Hls5 is also likely to have other functions in haemopoietic cells, which includes downregulation of erythroid-specific genes and suppression of interferon responses.
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Monniot, Céline. "Les protéines à ancre GPI de Candida albicans dans l’interaction avec l’hôte : de l’étude de domaines solubles à la caractérisation de la protéine Rbt1." Thesis, Paris, AgroParisTech, 2012. http://www.theses.fr/2012AGPT0075/document.
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Candida albicans est un pathogène opportuniste présent à l'état commensal chez 75% de la population. Il s'agit du premier pathogène d'origine fongique (4ème cause d'infections nosocomiales) responsable d'infections superficielles chez les personnes immunocompétentes ou d'infections profondes chez les personnes immunodéprimées. Les protéines à ancre GPI (Glycosyl Phosphatidyl Inositol) de C. albicans, situées à l'interface entre la levure et les cellules de l'hôte, semblent être les plus aptes à moduler la réponse immunitaire. Au cours de cette étude, une banque de surexpression et de sécrétion d'une vingtaine de domaines fonctionnels putatifs issus de protéines à ancre GPI potentiellement exposées à la surface a été construite. Le crible réalisé a permis d'identifier sept polypeptides impliqués dans la modulation de la réponse des cellules macrophages et trois polypeptides ayant des propriétés immunogènes. Dans un deuxième projet, nous avons démontré que la protéine à ancre GPI Rbt1 spécifique des hyphes de C. albicans avait des propriétés d'adhésines aux substrats abiotiques et contribuait à la formation de biofilm et d'agrégats. La caractérisation de cette protéine a permis d'apporter des données nouvelles concernant l'exposition en surface de protéines membranaires suivant la forme morphologique de C. albicansC. albicans is an opportunistic pathogen present as commensal in 75% of the population. This is the first fungal pathogen (4th cause of nosocomial infections) responsible for superficial infections in immunocompetent patients or deep infections in immunocompromised patients. C. albicans GPI-anchored proteins (Glycosyl Phosphatidyl Inositol) present at the interface between the yeast and the host cells appear to be the proteins most capable of modulating the immune response. In this study, a library overexpressing and secreting twenty fonctionnal domains from GPI-anchored proteins potentially exposed to the surface was constructed. We identified seven polypeptides involved in the modulation of the macrophage response and three polypeptides with immunogenic properties. In a second project, we demonstrated the properties of the hyphae specific GPI-anchored protein Rbt1 in adhesion, biofilm formation and aggregation. The characterization of this protein gives us new data on surface exposure of membrane proteins depending to C. albicans morphological state
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Galhardo, Pablo Henrique Souza. "Análise do posicionamento GNSS cinemático em ambiente urbano com uso da técnica RTK via Ntrip." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/3/3138/tde-24092018-073219/.
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O constante avanço do Global Navigation Satellite System (GNSS) possibilita aos seus usuários ao redor do mundo a utilização de seus produtos para os mais diversos fins. Dentre eles, a navegação veicular autônoma se caracteriza como um dos principais focos de investimentos e pesquisas em universidades e instituições privadas. Concomitantemente, a modernização dos receptores GNSS acompanha esta evolução, oferecendo equipamentos de dimensões menores e mais versáteis que antes, com a capacidade de rastreio de novas constelações e operações de precisão em tempo real. O uso de redes de celulares e conexões de internet sem fio vêm apoiando este desenvolvimento, permitindo aos profissionais da área de geomática realizar levantamentos utilizando a técnica conhecida como Real Time Kinematic (RTK). Esta pesquisa tem por finalidade avaliar a qualidade de dados coletados por meio desta técnica RTK, apoiada no uso do Networked Transport of RTCM via Internet Protocol (Ntrip) para obtenção das correções diferenciais necessárias à operação, em ambiente urbano, e utilizando a Rede Brasileira de Monitoramento Contínuo dos Sistemas GNSS em tempo real (RBMC-IP). Para isto, foram feitas coletas de dados com um receptor de dupla frequência acoplado a um veículo, o qual percorreu o mesmo trajeto por vinte e nove dias. O local de realização dos testes foi o Corredor Norte-Sul da cidade de São Paulo, com extensão aproximada de 22.700 m. A metodologia de análise dos dados foi dividida em três casos: O primeiro considerou todo o trajeto. O segundo, apenas um trecho sem interferências (como árvores de grande porte, túneis, viadutos e prédios), plano e sem curvas. Por fim, o terceiro investigou como seria o comportamento do receptor após uma situação de bloqueio total do sinal de satélites, ao passar por baixo de um viaduto. Avaliou-se as precisões horizontais e verticais dos pontos registrados, a quantidade de satélites rastreados, os valores de Positional Dilution of Precision (PDOP), as soluções para o vetor das ambiguidades durante o percurso e a qualidade da conexão móvel. Os resultados mostraram que o uso da técnica RTK via Ntrip por meio de serviço RBMC-IP constitui-se uma ferramenta confiável para o posicionamento preciso em tempo real. Entretanto, em ambientes urbanos, e somado ao modo cinemático de coleta, tais valores tornam-se mais suscetíveis à degradação da precisão.The continuous progress of the Global Navigation Satellite System (GNSS) enables its large user community around the world to use its products for a wide range of purposes. Amongst them, autonomous vehicular navigation is featured as one of the main focuses of investments and research in universities and private institutions. At the same time, the modernization of GNSS receivers follows this evolution, offering smaller and more versatile equipment than before, which are able to trace new constellations and high-precision operations in real time. The use of mobile networks and wireless Internet connections have supported this development, allowing geomatics professionals to carry out surveys using the technique known as Real Time Kinematic (RTK). This research aims at assessing the quality of the data gathered by this RTK technique, based on the use of the Networked Transport of RTCM via Internet Protocol (Ntrip) to obtain differential corrections necessary to the operation in an urban environment, and the use of Brazilian Network of Continuous Monitoring of GNSS Systems in real time (RBMC-IP). In order to do so, we gathered data with the receiver installed in a vehicle which travelled the same route for twenty-nine days. The test site was the North-South Corridor in São Paulo, which is approximately 22,700 m long. The methodology of data analysis was divided into three cases: The first one took the whole route into account. The second one, only one travel leg without interference (such as tall trees, tunnels, viaducts and skyscrapers), flat and curveless. Lastly, the third one investigated how the receiver would behave after a situation of total blockade of satellites, such as under a viaduct. We evaluated the horizontal and vertical accuracies of the recorded points, the number of satellites traced, the Positional Dilution of Precision (PDOP) values, the solutions to the vector of ambiguities during the course and the quality of the mobile connection. The results showed that the use of the RTK technique via Ntrip via the RBMC-IP service is a reliable tool for precise positioning in real time. However, in urban environments in addition to the kinematic mode of collection, such values become more susceptible to the degradation of precision.
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Chikochi, Christopher. "Ore breakage characterisation of UG2 deposits using the JK RBT." Master's thesis, University of Cape Town, 2017. http://hdl.handle.net/11427/27300.
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Ore breakage characterisation is a methodology that is used to determine the ore hardness, or resistance to breakage which can be compared across a database of different rock types. It thus develops a relationship between specific energy input and degree of breakage which can be applied to impact breakage in comminution devices. The present study is focussed on investigating the breakage properties of UG2 chromitite, pyroxenite, spotted anorthosite and mottled anorthosite grab samples from run-of-mine (RoM) ore stockpile (particle selection method) and cut drill core particles (cut core method). A mineralogical analysis of UG2 chromitite, pyroxenite, spotted anorthosite and mottled anorthosite was performed using Leica EZ4D optical microscope and QEMSCAN 650F to determine their mineral composition and texture. The presence of cracks in chromitite stockpile and cut drill core samples was also explored using a Nikon XTH 225 ST micro-focus X-ray system. RoM ore stockpile and cut drill core particles of each of these rock types were subjected to impact breakage in the JK Rotary Breakage Tester (RBT). The progeny particle size distributions and degrees of breakage of UG2 rock types obtained via the particle selection and cut core methods were compared. Standard breakage characterization models were fitted to the breakage data of different rock types and the relative hardness parameters compared. It was found that UG2 chromitite comprised mainly fine, isolated, round chromite grains in a plagioclase matrix. Pyroxenite samples were found to be made up of granular orthopyroxene, interstitial plagioclase and clinopyroxene. The mineralogical analysis also revealed that spotted anorthosite primarily contains plagioclase with orthopyroxene crystals forming isolated "spots" creating a poikilitic texture. Mottled anorthosite is made up of mainly plagioclase. Results from breakage tests showed that the progeny particle size distributions and the degrees of breakage for particles sourced from the RoM ore stockpile breaks into a finer product compared to cut drill core samples. This was attributed to the presence of cracks in the RoM ore particles as revealed by the tomographic scans. No visible cracks were found in the cut core particle. The ore hardness parameters were determined from fitting the breakage data to standard impact breakage characterisation models (t10 breakage and size dependent breakage model). Samples obtained via the particle selection method were consistently found to offer less resistance to impact breakage as shown by the higher Axb values compared to the cut drill core samples. Using the ore hardness classes presented by Napier-Munn et al (1999), UG2 chromitite, spotted anorthosite, mottled anorthosite and pyroxenite were thus classified as very soft, soft to very soft, soft to very soft and medium to soft respectively. The hardness indicator, 3600.M.fmat.x, for each size class determined using the parameters obtained from the size dependent breakage model decrease with an increase in the parent particle size. This shows that particles become more resistant to impact breakage as the initial particle size increases. However, for pyroxenite, spotted and mottled anorthosite, the indicator decreases between the particle sizes 14 to 28.6 mm but then increases for 41.1 mm.
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Peredriy, Sergiy Black Stanley W. "Endogenous credit market incompleteness RBC approach to emerging markets crises /." Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2008. http://dc.lib.unc.edu/u?/etd,1921.
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Thesis (Ph. D.)--University of North Carolina at Chapel Hill, 2008.Title from electronic title page (viewed Dec. 11, 2008). "... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Economics." Discipline: Economics; Department/School: Economics.
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Dong, Wei-Feng. "Expression and regulation of rhombotin-2 (RBTN/LMO-2) in normal hematopoiesis and leukemogenesis." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0017/NQ53807.pdf.
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Cho, John Myung-Jae. "Characterization of RBT1, a novel member of the TRIP-Br family of transcriptional modulators." Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=85062.
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Replication Protein A (RPA) is required for DNA recombination, repair and replication in all eukaryotes. RPA participation in these pathways is mediated by single-stranded DNA binding and protein interactions. We have identified a novel RPA protein interactor, Replication Protein Binding Trans-Activator (RBT1), in a yeast two-hybrid assay employing the second subunit of human RPA (RPA32) as bait. RBT1-RPA32 binding was confirmed by glutathione S-transferase pull-down and co-immunoprecipitation. Fluorescence microscopy indicates that over-expressed green fluorescence protein-tagged RBT1 is localized to the nucleus in vivo. RBT1 mRNA expression, determined by semi-quantitative RT-PCR, is significantly higher in cancer cell lines MCF-7, ZR-75, SaOS-2 and H661, compared to normal non-immortalized human mammary and bronchial epithelial cells. Further, yeast and mammalian one-hybrid analysis shows that RBT1 is a strong transcriptional co-activator. Interestingly, mammalian transactivation data are indicative of significant variance between cell lines; the GAL4-RBT1 fusion protein has significantly higher transcriptional activity in human cancer cells compared to human normal primary non-immortalized epithelial cells. NIH3T3 mouse fibroblasts stably overexpressing RBT1 meet several criteria of transformed cells, including lack of contact growth inhibition, growth of colonies in soft agar and tumor formation in nude mice; HCT116 colon carcinoma cells overexpressing RBT1 exhibit an enhanced growth rate in culture and form extremely aggressive tumors in vivo.BLAST analysis of the human genome localizes RBT1 to chromosome 19g13.1-q13.2 adjacent to the coding region for TRIP-Br1/p34SEI-1 in a region characterized by frequent amplification in ovarian carcinomas. Further analysis of amino acid homology places RBT1 in the TRIP-Br protein family consisting of at least four members (RBT1, TRIP-Br1 (p34SEI-1), TRIP-Br2, and HEPP (cdca4)). While not much is known about this protein family, TRIP-Br1 has been found to interact with the cyclin-dependent kinase, cdk4, and modulates E2F transcriptional activity (Hsu et al., 2001). In vitro binding and co-immunoprecipitation assays suggest that RBT1 interacts with at least cdk1, cdk2 and cdk4, and modulates E2F1 transcriptional activity indicative of one possible mechanism by which higher levels of RBT1 can both promote and enhance tumorigenesis.
We propose that RBT1 is a novel transcriptional co-activator that interacts with several important cellular proteins including RPA and cdk4, and that RBT1 may promote tumorigenesis when its protein product is over-expressed. Enhancement of E2F1 transcriptional activity by overexpressing RBT1 suggests that this novel protein has implications on cell cycle regulation and progression.
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Singh, Arundhati 1978. "SIREN : a SQL-based implementation of role-based access control (RBAC) for enterprise networks." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/87870.
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Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2002.Includes bibliographical references (leaves 69-71).
by Arundhati Singh.
M.Eng.
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Sabharwal, Dharmesh. "Regulatory roles of sRNAs in pathogenesis of Vibrio cholerae." Doctoral thesis, Umeå universitet, Institutionen för molekylärbiologi (Medicinska fakulteten), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-100528.
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The Gram-negative pathogen Vibrio cholerae uses variety of regulatory molecules to modulate expression of virulence factors. One important regulatory element of microorganisms is small non-coding RNAs (sRNAs), which control various cell functions such as expression of cell membrane proteins, mRNA decay and riboswitches. In this thesis studies, we demonstrated the roles of the sRNAs VrrA in regulation of outer membrane protein expression, biofilm formation and expression of ribosome binding proteins. In addition, we showed that VrrB, a newly discovered sRNA, played a role in amino acid dependent starvation survival of V. cholerae and might functioned as a riboswitch. VrrA, a 140-nt sRNAs in V. cholerae, was controlled by the alternative sigma factor σE. The outer membrane protein, OmpT is known to be regulated by environmental signals such as pH and temperature via the ToxR regulon and carbon source signals via the cAMP–CRP complex. Our studies provide new insight into the regulation of OmpT by signals received via the σE regulon through VrrA. We demonstrated that VrrA down-regulate ompT translation by base-pairing with the 5′ region of the ompT mRNA in a Hfq (RNA chaperone protein) dependent manner. V. cholerae biofilms contain three matrix proteins—RbmA, RbmC and Bap1—and exopolysaccharide. While much is known about exopolysaccharide regulation, little is known about the mechanisms by which the matrix protein components of biofilms are regulated. In our studies, we demonstrated that VrrA negatively regulated rbmC translation by pairing to the 5' untranslated region of the rbmC transcript and that this regulation was not stringently dependent on Hfq. In V. cholerae, VC0706 (Vrp) and VC2530 proteins are homologous to ribosome-associated inhibitor A (RaiA) and hibernation promoting factor (HPF) of Escherichia coli, respectively. HPF facilitates stationary phase survival through ribosome hibernation. We showed that VrrA repressed Vrp protein expression by base-pairing to the 5´ region of vrp mRNA and that this regulation required Hfq. We also showed that Vrp was highly expressed during stationary phase growth and associated with the ribosomes of V. cholerae. We further demonstrated that Vrp and VC2530 were important for V. cholerae starvation survival under nutrient-deficient conditions. While VC2530 was down-regulated in bacterial cells lacking vrrA, mutation of vrp resulted in increased expression of VC2530. Riboswitches are an important class of regulators in bacteria, which are most often located in the 5' untranslated region (5´ UTR) of bacterial mRNA. In this study, we discovered the novel non-coding sRNA, VrrB located at the 5´ UTR of a downstream gene encoding Vibrio auxotropic factor A (VafA) for phenylalanine. In V. cholerae, reduced production of VafA was observed in the presence of phenylalanine and phenylpyruvate in the culture media. Some analogs of phenylalanine and phenylpyruvate could also modulate the expression of VafA. Furthermore, bacterial cells lacking the vrrB gene exhibited high production of VafA, suggesting that VrrB might function as a riboswitch that controls VafA expression.
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Peddie, Craig Cameron. "RBC treatment of a municipal landfill leachate : a pilot scale evaluation." Thesis, University of British Columbia, 1986. http://hdl.handle.net/2429/26319.
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This study evaluated the on-site treatment of a moderately low strength municipal landfill leachate with a Rotating Biological Contactor (RBC), at pilot scale (0.9 m dia.). The leachate generally had COD and NH₃-N concentrations of less than 1000 mg/L and 50 mg/L respectively. A high treatment efficiency for both carbon removal and nitrification was achieved despite variable and intermittent loading conditions. The effluent filtrable BOD₅ was generally less than 10 mg/L and the effluent NH₃-N concentration was usually less than 1.0 mg/L. This effluent quality was achieved at mass loading levels comparable to those for sewage treatment (10.0 g BOD₅/m²*d for carbon removal and 0.8 g NH₃-N/m²*d for nitrification). The results demonstrated that long hydraulic retention times (HRT >4 hrs.) can offset the effects of lower temperatures. Nitrification efficiency in particular was shown to be HRT dependent. Limited heavy metal data indicated that heavy metals were removed at efficiencies and relative affinities comparable to those observed in activated sludge studies. An aside to this study showed that trace organics, some of which are on the EPA priority pollutant list, were present in this leachate and were effectively removed during passage through the RBC.Applied Science, Faculty of
Civil Engineering, Department of
Graduate
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Moghabghab, Rania Hounir. "External surface and porosity of RBC biofilms in leachate pre-treatment." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq28835.pdf.
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Petrauskienė, Rasa. "Prieigos prie bevielio tinklo resursų valdymas panaudojant vietos informaciją." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2011~D_20110901_140213-99282.
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Tobulėjant mobilioms technologijoms vietos informacija tapo svarbi prieigos valdymui. Šiame darbe analizuojamos vietos informacijos derinimo su autentifikacijos ir prieigos valdymo mechanizmais galimybės. Darbe išskirti vietos informacijos įvedimo į autentifikacijos, prieigos valdymo ir atskaitomybės procesus privalumai. Pristatomas vietos informacija paremtas prieigos prie tinklo resursų valdymo modelis, kuris leidžia padidinti teisingo autentifikavimo tikimybę bei išplėsti prieigos valdymo galimybes. Suprojektuota prieigos prie bevielio tinklo valdymo sistema, pritaikyta veikti kelių aukštų pastate. Modelis yra suderinamas su OGC (Open GeoSpatial Consortium) ir Geo-RBAC (RBAC modelio išplėtimu), į jį įtraukti kitų tipų vietos informacija pagrįsti požymiai. Darbe pristatomi prieigos valdymo išplėtimai: periodiškumo algoritmas ir erdvinių požymių įvertinimo algoritmas, naudojantis susiejimo funkcijas ir įvertinantis vietos nustatymo patikimumą. Pasiūlyto prieigos valdymo modelio veikimas įvertinamas eksperimentais, nurodomi jo galimi pažeidžiamumai.Location-based Access Control LBAC techniques allow taking users’ physical location into account when determining their access privileges. The analysis of possibilities of integrating location information into access control and authentication is provided. I show the advantages of using location information for authentication and access control. I present location-based access control model that can increase the probability of correct authentication. I design wireless LAN location-based access control system that is used in building of several floors. The model is compliant with OGC (Open GeoSpatial Consortium) and Geo-RBAC (the extent of RBAC model); it integrates other types of location-based features. I describe the periodicity algorithm of location-based access control and design the policy enforcement algorithm that uses location mapping functions and the evaluation of confidence. The model is evaluated by testing the speed of the system and computer resources used by the system. The vulnerabilities of location-based access control are discussed in the context of sniffing, highjacking, DoS and warmhole attacks.
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Landberg, Fredrik. "Flexible role-handling in command and control systems." Thesis, Linköping University, Department of Electrical Engineering, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-7880.
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In organizations the permissions a member has is not decided by their person, but by their functions within the organization. This is also the approach taken within military command and control systems. Military operations are often characterized by frictions and uncontrollable factors. People being absent when needed are one such problem.
This thesis has examined how roles are handled in three Swedish command and control systems. The result is a model for handling vacant roles with the possibility, in some situations, to override ordinary rules.
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Manning, Francis Jay. "A Framework for Enforcing Role Based Access Control in Open Source Software." NSUWorks, 2013. http://nsuworks.nova.edu/gscis_etd/228.
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While Role Based Access Control (RBAC) has been a popular topic of research over the last several years, there are some gaps in the literature that have been waiting to be addressed. One of these gaps involves the application of RBAC to free and open source software (FOSS). With the prevalence of FOSS in most information systems growing rapidly, there is a need to be able to provide a level of confidence that the software will not compromise the data integrity of an environment, nor will it enable the violation of established access controls. Additionally, when utilizing FOSS software it is desirable to
do so without having to modify its source code whenever an update is released in order to maintain a secure environment; this makes adding proprietary modules both time consuming and expensive. The challenges involved in maintaining proprietary changes to
FOSS generates a particular interest in an RBAC environment that could be deployed without requiring modification to the source code. Developing this type of a framework presented a significant challenge due to the software having been established prior to the
definition of any security requirements that would have to be applied by the proposed framework.
What this research paper shows are the results of the development of a software framework that allowed security requirements engineering to seamlessly meld with an application after it had already been developed. This framework provided a mechanism to measurably reduce the attack surface of the application against which the framework was implemented, while performing these tasks without requiring alterations to the source code of the application. Additionally, this research introduced a mechanism that was
utilized to measure the effectiveness of the framework. This mechanism provided a means of comparing the relative effectiveness of different frameworks against the same software, as well as the effectiveness of a framework against different pieces of software.
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Waddington, Gary. "Biedermans Recognition by Components (RBC) theory of human object recognition - an investigation." Thesis, University of Reading, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301971.
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Royes, Gleiber Fernandes. "Plataforma híbrida Fuzzy-Multicritério-RBC para o apoio à análise de políticas." Florianópolis, SC, 2003. http://repositorio.ufsc.br/xmlui/handle/123456789/84953.
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Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Ciência da Computação.Made available in DSpace on 2012-10-20T14:01:27Z (GMT). No. of bitstreams: 1 193852.pdf: 2312973 bytes, checksum: dca4abbcf0d79a1000e03e9eafcef809 (MD5)
A avaliação de cenários realizada por especialistas humanos envolve critérios cujos valores são vagos e definidos de forma imprecisa. Para exemplificar, dentro de um cenário de política de contratação de funcionários, um critério para a análise sobre a capacidade de liderança dos candidatos certamente aplicaria valores lingüísticos vagos como Grande ou Pouca para representar, de forma natural, o desempenho de cada concorrente. O especialista humano pondera e agrega os diversos critérios subjetivos de análise para chegar a uma conclusão consistente. Este trabalho propõe uma abordagem de apoio ao processo de análise de políticas através da reunião de três metodologias básicas. O objetivo principal é estabelecer um método de auxílio diferenciado que permita a direta representação e avaliação dos critérios vagos de um problema. A arquitetura híbrida Difusa - Multicritério - Raciocínio Baseado em Casos sugere uma forma integrada de tratamento do conhecimento: Conjuntos Difusos - para a representação e manipulação do conhecimento vago; Multicritério - para a agregação do conhecimento vago e avaliação do cenário e RBC - para a recuperação deste conhecimento e aperfeiçoamento do aparato de apoio. A proposta de auxílio não se limita apenas à indicação de um melhor caminho dentre as opções disponíveis, mas sim abrange mecanismos para a simulação e exploração do cenário apresentado. Um sistema protótipo mostra, através de alguns casos implementados, que a metodologia de auxílio pode ser útil como uma das ferramentas de análise de políticas. Além disto, a cooperação entre as metodologias Difusa - Multicritério - RBC expõe uma forma distinta e promissora de lidar com o conhecimento através da máquina que merece um aprofundamento posterior por intermédio de novas pesquisas.
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Bradshaw, Adrian Tyrone. "The Impact of Information Systems Consultants on Small and Medium-sized Enterprises: A Theory of the Firm Perspective." Thesis, University of Canterbury. Management, 2012. http://hdl.handle.net/10092/6933.
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This research aims to show the impact that consultants have on the creation of IS knowledge assets as well as the impact that they have on the development of IS competencies in SMEs. Exploratory case studies involving SMEs and consultants are used to investigate the impact consultants have on SMEs. IS knowledge and IS competencies are important themes that emerge from the exploratory stage of the study. This research further investigates the types of IS knowledge assets and IS competencies that consultants impact in SMEs by conducting further case studies with consultants and SMEs. Several propositions about the types of IS knowledge assets and IS competencies impacted by consultants are developed and tested using a longitudinal single-case study.
The results are analysed using resource-based theory and knowledge-based theory and reveals that consultants contribute to the development of experiential knowledge assets like know-how and experience, routine knowledge assets and systemic knowledge assets by influencing the knowledge creation processes of implementing SMEs. Consultants enhance and contribute to the development of the Management of IT competence which relates to the SME’s ability utilise IS. However, the results also show that consultants compensate for other IS competencies: strategy and vision; sourcing and alignment; and systems and infrastructure. These competencies relate to the SME’s ability to integrate IT with business processes, to source and alignment IT/IS and to engage in business and IS strategic thinking.
It is proposed that in addition to overcoming the knowledge barrier in SMEs, consultants are an essential part of the IS knowledge-creation process. Additionally, consultants compensate for IS competencies which are abilities; however, it is noted that if an on-going relationship develops between the consultants and SMEs then SMEs may, over time, develop IS competencies related to business and IS strategic thinking, management of IT and, sourcing and alignment.
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Gummidi, Srinivasa Raghavendra Bhuvan. "Smart-RBAC." Master's thesis, 2015. http://hdl.handle.net/10362/14568.
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Generally, smart campus applications do not consider the role of the user with his/her position in a university environment, consequently irrelevant information is delivered to the users. This dissertation proposes a location-based access control model, named Smart-RBAC, extending the functionality of Role-based Access Control Model (RBAC) by including user’s location as the contextual attribute, to solve the aforementioned problem. Smart-RBAC model is designed with a focus on content delivery to the user in order to offer a feasible level of flexibility, which was missing in the existing location-based access control models. An instance of the model, derived from Liferay’s RBAC, is implemented by creating a portal application to test and validate the Smart-RBAC model. Additionally, portlet-based applications are developed to assess the suitability of the model in a smart campus environment. The evaluation of the model, based on a popular theoretical framework, demonstrates the model’s capability to achieve some security goals like “Dynamic Separation of Duty” and “Accountability”. We believe that the Smart-RBAC model will improve the existing smart campus applications since it utilizes both, role and location of the user, to deliver content.
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Chang, Che-Chih, and 張哲誌. "A Study On Combining CR-RBAC And I-RBAC." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/69026994270833604481.
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碩士中原大學
資訊工程研究所
100
In a role-based access control system with context roles, when a user does not satisfy the context constraints, the user can not activate a context role to execute operation on the objects. But if there are dependencies between the operations on the objects, when an operation on an object could not be executed, subsequent operations on other objects can not be executed as well. In this thesis, we propose a method to combine context roles and isolated roles. When a user can not activate a context role, she can access the object by using an isolated role in the isolation environment temporarily. After some waiting period, depending on whether the context conditions are satisfied or not, the action will either be committed or canceled. The combined model can be used in workflow applications to avoid some delay or interruption. Finally, a document flow system was implemented to illustrate this model.
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Li, Chung-Hsuan, and 李忠璇. "An Integrated model of CR-RBAC and I-RBAC Application on Workflow System." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/m3u5uf.
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碩士中原大學
資訊工程研究所
102
Abstract In a role-based access control system with context roles (CR-RBAC), if context constraints are not satisfied, then a context role could not be activated by a user to execute operation on objects. But there are task dependencies among tasks in a workflow, if one task could not complete in time, then other tasks would be delayed. In this thesis, an approach to integrate CR-RBAC and I-RBAC, with applications to workflow systems, will be presented. In a workflow, when a user could not activate a context role to perform a task, an isolation role could be assigned to the user to execute the task temporarily, to continue execution of the workflow. However, the task still needs to be confirmed by using the context role. If the task could not be confirmed during a timeout period, the workflow must be rollbacked to an earlier state. An example document workflow was used to illustrate this model. It is assumed that the approval of documents must be performed inside the company. If there is an emergent document needs to be approved and the manager who has the permission to approve the document is not in the company, an isolation role could be assigned to the manager to approve the document temporarily. The approval must be confirmed when the context constraints are satisfied and the context role could be activated. Otherwise, the workflow has to be rollbacked. Keywords：Access Control、RBAC、CR-RBAC、I-RBAC、Workflow、Rollback
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Lo, Ying Jie. "Dielectrophoresis on Plasma/RBC Separation and RBC Manipulation." 2004. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-2607200411101400.
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Lo, Ying Jie, and 羅英傑. "Dielectrophoresis on Plasma/RBC Separation and RBC Manipulation." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/55952934965144409799.
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碩士國立臺灣大學
應用力學研究所
92
This thesis takes advantage of dielectric property of material, where a dielectrophoretic (DEP) force is induced in a sinusoidally time-variant electric field to achieve cell-plasma separation and cell manipulation. Dielectrophoretic theory is based on the distinct dielectric and conductive properties of cell and medium. This distinction will physically induce a directional force depending on frequency, spatial electric strength, and spatial electric phase distribution. Through fabrication of MEMS, devices miniaturized are to increase the influence of DEP force on separation and manipulation of cells. Additionally, with the aid of numerical simulation of electric field and cell trajectory, more effective devices are designed. The use of bio-compatible material polydimethysilloxane (PDMS) proved ease of fabrication and integration [1]. Types of cell-plasma separator tested various electrode design include stair, inclined, and gradient confuguration, and 3D channel assisting design. For cell manipulation, traveling wave, cell concentrator, and cell portioning devices are all tested and their performance quantified. Results show successful separation of red blood cell (RBC) and plasma vis DEP. for a wide range of electrode geometry configurations. Traveling wave DEP, however, was more difficult to implement. Manipulation of RBC proved viable using the non-uniform E-field at the tip of multi-electrode design.
48
"Automated Testing for RBAC Policies." Master's thesis, 2014. http://hdl.handle.net/2286/R.I.24933.
Full textAbstract:
abstract: Access control is necessary for information assurance in many of today's applications such as banking and electronic health record. Access control breaches are critical security problems that can result from unintended and improper implementation of security policies. Security testing can help identify security vulnerabilities early and avoid unexpected expensive cost in handling breaches for security architects and security engineers. The process of security testing which involves creating tests that effectively examine vulnerabilities is a challenging task. Role-Based Access Control (RBAC) has been widely adopted to support fine-grained access control. However, in practice, due to its complexity including role management, role hierarchy with hundreds of roles, and their associated privileges and users, systematically testing RBAC systems is crucial to ensure the security in various domains ranging from cyber-infrastructure to mission-critical applications. In this thesis, we introduce i) a security testing technique for RBAC systems considering the principle of maximum privileges, the structure of the role hierarchy, and a new security test coverage criterion; ii) a MTBDD (Multi-Terminal Binary Decision Diagram) based representation of RBAC security policy including RHMTBDD (Role Hierarchy MTBDD) to efficiently generate effective positive and negative security test cases; and iii) a security testing framework which takes an XACML-based RBAC security policy as an input, parses it into a RHMTBDD representation and then generates positive and negative test cases. We also demonstrate the efficacy of our approach through case studies.Dissertation/Thesis
M.S. Computer Science 2014
49
Lin, Ping-Jie, and 林品婕. "An Integrated model of CR-RBAC and I-RBAC and Its Application to Workflow System." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/43769565959443691598.
Full textAbstract:
碩士中原大學
資訊工程研究所
101
Context roles can be used to describe context constraints in an RBAC system. In a CR-RBAC system, a user cannot activate a context role to get the permissions to complete a job if the user does not satisfy the context constraints. To complete a workflow, one must execute successfully all the tasks that are defined sequentially. When the context constraints associated with some tasks of a workflow are not satisfied, those tasks cannot be executed and thus the workflow cannot proceed. This will cause delay of the workflow. In this thesis, we will introduce a model that integrated CR-RBAC and I-RBAC, and show its application to a workflow. If a user who was assigned to a task of a workflow does not satisfy the associated context constraint, the user cannot activate a context role to execute the task. But the user can use an isolation role to execute the task in an isolation environment temporarily. The workflow can still proceed without waiting. But the task must still be completed on host environment using the context role when the context constraints are satisfied. If the task cannot be completed on host environment, the task and its subsequent tasks must be rollbacked. A bank loan workflow was used as an example to illustrate our model. We assume that the task "Approve" has to be executed inside the bank. The user who was assigned to do the task "Approve" can use an isolation role to complete this task in isolated environment if he cannot meet the context constraints to activate a context role. Afterward the task can be confirmed in host environment by the task "Confirm". We used Activiti workflow engine in our implementation, where a program can be attached to a task. The system will reserve the loan amount of the workflow when the task "Approve" is executed by an isolation role. This amount will be restored if the final result of "Approve" is deny, and the system will notify other waiting workflows which need this amount to continue.
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KLÍMA, Martin. "Optimalizace tvorby rolí pomocí RBAC modelu." Master's thesis, 2017. http://www.nusl.cz/ntk/nusl-316587.
Full textAbstract:
The aim of the thesis is to develop algorithm which will be able to optimize roles using RBAC model. The intent of the theoretical part is to analyze RBAC model and present current options which are available for role optimization. The practical part deals with development of algorithm which allows to optimize roles based on defined criteria from user. This algorithm is implemented in programming language Java and builds on Role Process Optimization Model (ROPM). In the last part is showed on example set of data how this algorithm works, step by step, with explanation of each step. Result of this algorithm is new RBAC model defined by user criteria. In this thesis are also listed different approach in role optimization, possible future development and concept of mapping RBAC model to mathematical and data-mining techniques.