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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

A re-engineering approach for software systems complying with the utilisation of ubiquitous computing technologies

Alawairdhi, Mohammed January 2009 (has links)
The evident progression of ubiquitous technologies has put forward the introduction of new features which software systems can sustain. Several of the ubiquitous technologies available today are regarded as fundamental elements of many software applications in various domains. The utilisation of ubiquitous technologies has an apparent impact on business processes that can grant organisations a competitive advantage and improve their productivity. The change in the business processes in such organisations typically leads to a change in the underlying software systems. In addressing the need for change in the underlying software systems, this research is focused on establishing a general framework and methodology to facilitate the reengineering of software systems in order to allow the incorporation of new features which are introduced by the employment of ubiquitous technologies. Although this thesis aims to be general and not limited to a specific programming language or software development approach, the focus is on Object-Oriented software. The reengineering framework follows a systematic step-based approach, with greater focus on the reverse engineering aspect. The four stages of the framework are: program understanding, additional-requirement engineering, integration, and finally the testing and operation stage. In its first stage, the proposed reengineering framework regards the source code as the starting point to understand the system using a static-analysis based method. The second stage is concerned with the elicitation of the user functional requirements resulting from the introduction of ubiquitous technologies. In the third stage, the goal is to integrate the system’s components and hardware handlers using a developed integration algorithm and available integration techniques. In the fourth and final stage, which is discussed in a general manner only in this thesis, the reengineered system is tested and put in the operation phase. The proposed approach is demonstrated using a case study in Java to show that the proposed approach is feasible and promising in its domain. Conclusions are drawn based on analysis and further research directions are discussed at the end of the study.
82

A software testing framework for context-aware applications in pervasive computing

Lu, Heng, 陸恒 January 2008 (has links)
published_or_final_version / Computer Science / Doctoral / Doctor of Philosophy
83

Protocol for a Systematic Literature Review on Security-related Research in Ubiquitous Computing

Kusen, Ema, Strembeck, Mark 18 December 2014 (has links) (PDF)
Context: This protocol is as a supplementary document to our review paper that investigates security-related challenges and solutions that have occurred during the past decade (from January 2003 to December 2013). Objectives: The objective of this systematic review is to identify security-related challenges, security goals and defenses in ubiquitous computing by answering to three main research questions. First, demographic data and trends will be given by analyzing where, when and by whom the research has been carried out. Second, we will identify security goals that occur in ubiquitous computing, along with attacks, vulnerabilities and threats that have motivated the research. Finally, we will examine the differences in addressing security in ubiquitous computing with those in traditional distributed systems. Method: In order to provide an overview of security-related challenges, goals and solutions proposed in the literature, we will use a systematic literature review (SLR). This protocol describes the steps which are to be taken in order to identify papers relevant to the objective of our review. The first phase of the method includes planning, in which we define the scope of our review by identifying the main research questions, search procedure, as well as inclusion and exclusion criteria. Data extracted from the relevant papers are to be used in the second phase of the method, data synthesis, to answer our research questions. The review will end by reporting on the results. Results and conclusions: The expected results of the review should provide an overview of attacks, vulnerabilities and threats that occur in ubiquitous computing and that have motivated the research in the last decade. Moreover, the review will indicate which security goals are gaining on their significance in the era of ubiquitous computing and provide a categorization of the security-related countermeasures, mechanisms and techniques found in the literature. (authors' abstract)
84

Facilitating file retrieval on resource limited devices

Sadaquat, Jan January 2011 (has links)
The rapid development of mobile technologies has facilitated users to generate and store files on mobile devices. However, it has become a challenging issue for users to search efficiently and effectively for files of interest in a mobile environment that involves a large number of mobile nodes. In this thesis, file management and retrieval alternatives have been investigated to propose a feasible framework that can be employed on resource-limited devices without altering their operating systems. The file annotation and retrieval framework (FARM) proposed in the thesis automatically annotates the files with their basic file attributes by extracting them from the underlying operating system of the device. The framework is implemented in the JME platform as a case study. This framework provides a variety of features for managing the metadata and file search features on the device itself and on other devices in a networked environment. FARM not only automates the file-search process but also provides accurate results as demonstrated by the experimental analysis. In order to facilitate a file search and take advantage of the Semantic Web Technologies, the SemFARM framework is proposed which utilizes the knowledge of a generic ontology. The generic ontology defines the most common keywords that can be used as the metadata of stored files. This provides semantic-based file search capabilities on low-end devices where the search keywords are enriched with additional knowledge extracted from the defined ontology. The existing frameworks annotate image files only, while SemFARM can be used to annotate all types of files. Semantic heterogeneity is a challenging issue and necessitates extensive research to accomplish the aim of a semantic web. For this reason, significant research efforts have been made in recent years by proposing an enormous number of ontology alignment systems to deal with ontology heterogeneities. In the process of aligning different ontologies, it is essential to encompass their semantic, structural or any system-specific measures in mapping decisions to produce more accurate alignments. The proposed solution, in this thesis, for ontology alignment presents a structural matcher, which computes the similarity between the super-classes, sub-classes and properties of two entities from different ontologies that require aligning. The proposed alignment system (OARS) uses Rough Sets to aggregate the results obtained from various matchers in order to deal with uncertainties during the mapping process of entities. The OARS uses a combinational approach by using a string-based and linguistic-based matcher, in addition to structural-matcher for computing the overall similarity between two entities. The performance of the OARS is evaluated in comparison with existing state of the art alignment systems in terms of precision and recall. The performance tests are performed by using benchmark ontologies and the results show significant improvements, specifically in terms of recall on all groups of test ontologies. There is no such existing framework, which can use alignments for file search on mobile devices. The ontology alignment paradigm is integrated in the SemFARM to further enhance the file search features of the framework as it utilises the knowledge of more than one ontology in order to perform a search query. The experimental evaluations show that it performs better in terms of precision and recall where more than one ontology is available when searching for a required file.
85

Protocol for a Systematic Literature Review on Security-related Research in Ubiquitous Computing

Kusen, Ema, Strembeck, Mark 18 December 2014 (has links) (PDF)
Context: This protocol is as a supplementary document to our review paper that investigates security-related challenges and solutions that have occurred during the past decade (from January 2003 to December 2013). Objectives: The objective of this systematic review is to identify security-related challenges, security goals and defenses in ubiquitous computing by answering to three main research questions. First, demographic data and trends will be given by analyzing where, when and by whom the research has been carried out. Second, we will identify security goals that occur in ubiquitous computing, along with attacks, vulnerabilities and threats that have motivated the research. Finally, we will examine the differences in addressing security in ubiquitous computing with those in traditional distributed systems. Method: In order to provide an overview of security-related challenges, goals and solutions proposed in the literature, we will use a systematic literature review (SLR). This protocol describes the steps which are to be taken in order to identify papers relevant to the objective of our review. The first phase of the method includes planning, in which we define the scope of our review by identifying the main research questions, search procedure, as well as inclusion and exclusion criteria. Data extracted from the relevant papers are to be used in the second phase of the method, data synthesis, to answer our research questions. The review will end by reporting on the results. Results and conclusions: The expected results of the review should provide an overview of attacks, vulnerabilities and threats that occur in ubiquitous computing and that have motivated the research in the last decade. Moreover, the review will indicate which security goals are gaining on their significance in the era of ubiquitous computing and provide a categorization of the security-related countermeasures, mechanisms and techniques found in the literature. (authors' abstract) / Series: Working Papers on Information Systems, Information Business and Operations
86

Data stream mining in fog computing environment with feature selection using ensemble of swarm search algorithms

Ma, Bin Bin January 2018 (has links)
University of Macau / Faculty of Science and Technology. / Department of Computer and Information Science
87

"Construção de aplicações de captura e acesso baseada em recorrência de funcionalidades" / "Building capture and access applications based on recurrence of funcionalities"

Cattelan, Renan Gonçalves 19 April 2004 (has links)
Aplicações de captura e acesso exploram o paradigma de computação ubíqua --- que consiste em popular o ambiente com aplicações e dispositivos computacionais a fim de auxiliar transparentemente as pessoas na realização de suas atividades --- para dar apoio à captura automática de informação em experiências ``ao vivo' e à correspondente geração de documentos passíveis de armazenamento, recuperação, visualização e extensão ao longo do tempo. Devido à sua natureza distribuída, à heterogeneidade dos dispositivos computacionais envolvidos e à diversidade nas funcionalidades providas, essas aplicações são difíceis de se construir e requerem infra-estruturas e serviços de software que auxiliem o desenvolvedor nessa tarefa. Este trabalho investiga a construção e o uso de aplicações de captura e acesso por meio do desenvolvimento da xINCA, uma infra-estrutura estendida baseada em componentes de software reutilizáveis que englobam as funcionalidades recorrentes nessa classe de aplicações. A xINCA é uma extensão da infra-estrutura INCA --- uma infra-estrutura de baixo nível que provê abstrações de comunicação para aplicações de captura e acesso. Complementares, as infra-estruturas INCA e xINCA provêem um modelo simplificado para o desenvolvimento de aplicações de captura e acesso, considerando aspectos de projeto, implementação e reuso. Associada ao modelo de armazenamento do serviço StRES, a xINCA tem ainda papel na estruturação da informação capturada com o uso de XML e tecnologias correlatas. / Capture and access applications explore the ubiquitous computing paradigm --- that basically consists on populating the environment with computational devices and applications to transparently assist people on their activities --- to support the automatic capture of information on live experiences and generate corresponding documents that can be further stored, retrieved, visualized and extended. Due to their distributed nature, heterogeneity of involved devices and variety of provided functionalities, capture and access applications are hard to build and require software infrastructures and services that help the developer out on his task. This work investigates the building and use of capture and access applications through the development of xINCA, a component-based software infrastructure comprising the most common func-tio-na-li-ties present in such a class of applications. xINCA is an extension of INCA --- a low-level infrastructure that provides communication abstractions for capture and access applications. Complementary, INCA and xINCA provide a simplified model for the development of capture and access applications, concerning design, implementation and reuse aspects. Allied with the StRES storage model, xINCA also plays an important role on the structuring of captured information by using XML and corresponding technologies.
88

Uso de informações de contexto em segurança computacional / Use of context information on computer security

Milagres, Francisco Gomes 07 October 2004 (has links)
Diariamente, novos sistemas ubíquos são desenvolvidos e integrados ao nosso cotidiano, cuja presença às vezes não é percebida pelos seus usuários. O objetivo deste trabalho é investigar as questões de segurança e privacidade existentes nos paradigmas de computação ubíqua e ciente de contexto. Utilizando um protótipo de TV interativa - TV-I (Goularte, 2003) - que possui características de mobilidade e ciência de contexto, este trabalho define um conjunto de requisitos mínimos para a garantia de segurança e privacidade em sistemas ubíquos. É também objetivo deste trabalho utilizar informações contextuais para gerenciamento dinâmico de requisitos de segurança e privacidade por meio de políticas expressas em linguagem EPAL. Para validar os resultados desta pesquisa, foi implementado o Gerente de Segurança como um serviço do protótipo TV-I. A principal característica desse gerente é controlar o acesso a informações pessoais por meio de informações de contexto fornecidas pelo Gerente de Contexto, de autoria de Santos (2004) / Every day, new ubiquitous systems are being developed and integrated into our daily routines, whose presence is sometimes not even perceived by the casual user. The aim of this work is to investigate questions of security and privacy in ubiquitous and context aware computing. Using a prototype for interactive television - TV-I (Goularte, 2003) - that has characteristics of mobility and contextual-awareness, this work defines a set of basic requirements that are fundamental in order to guarantee security and privacy in ubiquitous systems. Furthermore, this work uses contextual information in order to dynamically manage security and privacy requirements according to security and privacy policies that are expressed in the EPAL language. In order to validate the experimental results, a Security Manager has been implemented as a service of the TV-I prototype. The principal characteristic of this manager is to enforce access control over the personal information using contextual information of the ubiquitous system, and which is supplied via the Context Manager, designed by Santos (2004).
89

An attitude compensation technique for a MEMS motion sensor based digital writing instrument.

January 2006 (has links)
Luo Yilun. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 87-91). / Abstracts in English and Chinese. / Chapter 1. --- Introduction --- p.1 / Chapter 1.1. --- Organization --- p.3 / Chapter 2. --- Architecture of MAG-μIMU --- p.5 / Chapter 2.1. --- Hardware for Attitude Filter --- p.5 / Chapter 2.2. --- Handwriting Recording for a Digital Writing Instrument --- p.7 / Chapter 3. --- Inertial Tracking for Handwriting --- p.9 / Chapter 3.1. --- Spatial Descriptions and Transformations --- p.9 / Chapter 3.1.1. --- Vector Description and Position of a Frame --- p.9 / Chapter 3.1.2. --- Coordinate Transformation and Orientation of a Frame --- p.10 / Chapter 3.1.3. --- Kinematics for Digital Writing Instruments --- p.12 / Chapter 3.1.4. --- Vector Rotation --- p.16 / Chapter 3.2. --- Euler Angles for Rotation in Space --- p.17 / Chapter 3.3. --- Euler Angles Attitude Kinematics --- p.19 / Chapter 3.4. --- Singular Problem --- p.19 / Chapter 4. --- Attitude in Quaternion --- p.22 / Chapter 4.1. --- Quaternion Operations --- p.22 / Chapter 4.1.1. --- Quaternion Conjugate --- p.23 / Chapter 4.1.2. --- Quaternion Norm --- p.24 / Chapter 4.1.3. --- Quaternion Inverse --- p.24 / Chapter 4.2. --- Orientation Description in Quaternion --- p.24 / Chapter 4.3. --- Attitude Kinematics in Quaternion --- p.25 / Chapter 5. --- Kalman Filter --- p.27 / Chapter 5.1. --- Time Update --- p.28 / Chapter 5.2. --- Measurement Update --- p.29 / Chapter 5.2.1. --- Maximum a Posterior Probability --- p.29 / Chapter 5.2.2. --- Batch Least-Square Estimation --- p.31 / Chapter 5.2.3. --- Measurement Update in Kalman Filter --- p.34 / Chapter 5.3. --- Kalman Filter Summary --- p.36 / Chapter 6. --- Extended Kalman Filter --- p.38 / Chapter 7. --- Attitude Extended Kalman Filter --- p.41 / Chapter 7.1. --- Time Update Model --- p.41 / Chapter 7.1.1. --- Attitude Strapdown Theory for a Quaternion --- p.41 / Chapter 7.1.2. --- Error Model for Time Update --- p.42 / Chapter 7.2. --- Measurement Update Model --- p.43 / Chapter 7.2.1. --- Error Model for the Measurement Update --- p.45 / Chapter 7.3. --- Summary --- p.46 / Chapter 8. --- Experiment Results --- p.47 / Chapter 8.1. --- Experiment for Attitude EKF based on MAG-μIMU --- p.47 / Chapter 8.1.1. --- Simulation Test --- p.48 / Chapter 8.1.2. --- Experiment Test --- p.49 / Chapter 8.2. --- Writing Application based on Attitude EKF Compensation --- p.52 / Chapter 8.2.1. --- Stroke Segment Kalman Filter --- p.54 / Chapter 8.2.2. --- Zero Velocity Compensation --- p.58 / Chapter 8.2.3. --- Complementary Attitude EKF for Writing Experiment --- p.60 / Chapter 9. --- Future Work --- p.73 / Chapter 9.1. --- Unscented Kalman Filter --- p.73 / Chapter 9.1.1. --- Least-square Estimator Structure --- p.73 / Chapter 9.1.2. --- Unscented Transform --- p.74 / Chapter 9.1.3. --- Unscented Kalman Filter --- p.76 / Chapter 9.2. --- Experiment Result --- p.81 / Chapter 10. --- Conclusion --- p.85 / Chapter 10.1. --- Attitude Extended Kalman Filter --- p.85 / Chapter 10.2. --- Complementary Attitude EKF --- p.85 / Chapter 10.3. --- Unscented Kalman Filter --- p.86 / Chapter 10.4. --- Future Work --- p.86 / Bibliography --- p.87 / Appendix A --- p.92
90

Ubiservices: um modelo para administração de serviços em ambientes ubíquos

Brand, Gustavo Bervian 28 April 2010 (has links)
Made available in DSpace on 2015-03-05T14:01:49Z (GMT). No. of bitstreams: 0 Previous issue date: 28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Com a evolução acelerada dos dispositivos computacionais, diminuição de tamanho e custo, ocorre uma imersão das pessoas no mundo digital. Com o uso de mais tecnologia, abundante e barata, surgem ambientes que tiram proveito da computação ubíqua, permitindo aos seus usuários uma interatividade e acesso a informações de forma fácil, ágil e natural. No entanto, ambientes ubíquos foram definidos em função da necessidade de uma grande infra-estrutura instalada para funcionar adequadamente, algo que não é uma realidade atualmente. Este trabalho apresenta uma alternativa aos ambientes ubíquos clássicos: um modelo para administração de serviços chamado Ubiservices. O objetivo do Ubiservices é fornecer conectividade em ambientes formados através de redes Ad Hoc não estruturadas, com aplicações como migração, replicação, publicação e busca de informações e serviços nesta rede. A interconexão das redes Ad Hoc ocorre através de uma rede overlay de forma transparente ao usuário, utilizando tecnologias existentes que, devi / With the fast evolution of the computing devices, its reduced size and cost, there is an immersion of people in the digital world. With the use of more technology, abundant and cheap, there are environments that can take advantage of the ubiquitous computing, allowing users to interact and have access to information easily, quickly and naturaly. However, ubiquitous environments were defined needing a large installed infrastructure to work properly, something that is not a reality nowadays. This work presents an alternative to the classic ubiquitous environments called Ubiservices. Its goal is to provide connectivity to environments made up of unstructured Ad Hoc networks, besides applications like migration, replication, publishing and search of information and services at the network. The interconnection of Ad Hoc networks occurs through an overlay network, user transparently, using existing technologies that, properly adapted and refined, can create a network that allows different mesh networks to interact

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