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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.
71

Dynamic Composition and Management of Virtual Devices for Ad Hoc Multimedia Service Delivery

Karmouch, Eric January 2011 (has links)
Pervasive computing implies the invisibility of the technology involved in providing ubiquity, such that technology is integrated into the environment and non-intrusive. In such a manner, computing and networking resources become diffused into physical environments, enabling users to exploit their provided functionalities such that functionality is distributed, enabling it to be controlled, monitored, managed, and extended beyond what it was initially designed to do. Moreover, computer awareness moves towards user-centricity, whereby systems seamlessly adapt to the characteristics, preferences, and current situations of users and their respective surrounding environments. Users exploit such functionalities in the form of a virtual device, whereby a collection of heterogeneous devices in the vicinity of the user are behaving as one single homogeneous device for the benefit of the user in solving some given task. This dissertation investigates the problem of dynamic composition and management of virtual devices for ad hoc multimedia service delivery and proposes an autonomous policy driven framework for virtual device management. The framework consists of a hierarchical structure of distributed elements, including autonomic elements, all working towards the self-management of virtual devices. The research presented in this dissertation addresses the functionalities of these components. More specifically, contributions are made towards the autonomous management of virtual devices, moving away from infrastructure based schemes with heavy user involvement to decentralized and zero touch (i.e., no user involvement) solutions. In doing so, the components and methodology behind a policy-driven autonomous framework for the dynamic discovery, selection, and composition of multimodal multi-device services are presented. The framework operates in an ad hoc network setting and introduces a Service Overlay Network (SON) based definition of a virtual device. Furthermore, device and service discovery, composition, integration, and adaptation schemes are designed for Mobile Ad hoc Network Environments (MANETs) enabling users to generate, on-the-fly, complex strong specific systems, embedding in a distributed manner, QoS models providing compositions that form the best possible virtual device at the time of need. Experimental studies are presented to demonstrate the performance of the proposed schemes.
72

Ubiquitous computing se zaměřením na bankovnictví a pojišťovnictví / Ubiquitous computing with focus on banking and insurance industry

Matuštík, Ondřej January 2007 (has links)
This dissertation thesis is focused on the issue of further extension of computers into the human life and its stronger influencing of human being, in the foreign literature defined as ubiquitous computing, everyware or pervasive computing. The basic goals of the thesis are follows: - Compare different views on this issues and make their assessment - Analyze possible effect, especially for banking and insurance area - Propose some specific innovation in named areas The results of this thesis should: - Serve as a basis for further studies in the ubiquitous computing area - Be usable as a basis for further scientific research - Bring some practical application, with which can we met in practice in future years Whole work place emphasis on the innovation process, with which is topic very closely linked and which is constantly emphasizing both in technical as in commercial spheres. The goals of the thesis are fulfilled in the individual chapters in the following way: - Definition of the goals and introduction of the topic -- Chapter 1 - Analysis of current status of knowledge -- Chapter 2 - Brief characteristic of main UC concepts -- Chapter 3 - Practical experience and innovation from UC -- Chapter 4 - Final evaluation -- Chapter 5 The scientific benefits of this work have been awarded by presentation of main parts of the thesis on international conferences and publication in the scientific magazines.
73

Autonomous and Intelligent Radio Switching

Duan, Quiyi 13 August 2008 (has links) (PDF)
With the proliferation of mobile applications and the abundance of wireless devices, it is increasingly common for devices to support multiple radios. When two devices are communicating they should choose the best available radio based on user preference and application requirements. This type of “radio switching” should happen automatically, so that the system optimizes performance dynamically. To achieve this objective, we design an Autonomous and Intelligent Radio Switching (AIRS) system to leverage the radio heterogeneity common in today's wireless devices. The AIRS system consists of three key components. First, we design a radio preference evaluation module to dynamically select the best radio according to users' preference, application's QoS requirements, and the device battery usage. Second, we propose a link quality measurement and prediction module to predict the radio quality under a variety of mobility and interference conditions. Third, we present a radio switching decision making module to switch to the preferred available radio intelligently, based on the preference and link quality evaluations. The AIRS system maintains connectivity, as well as improves link quality, via dynamic and intelligent radio switching, regardless of interference or collisions from the interfaces of other devices. The radio preference evaluation module is able to generate and adjust a preference list dynamically. Multiple users' requirements are satisfied in a mutually beneficial manner and the selected radio is Pareto optimal. The link prediction module is able to achieve an accuracy above 90% under a variety of mobility and interference conditions. The module can dynamically increase the link measurement interval and significantly reduce its power consumption, without sacrificing accuracy. The decision algorithm uses several parameters to avoid switching radios too frequently, and is able to provide dynamic, but stable radio switching, while balancing the competing objectives of high throughput and low power consumption. Overall, the AIRS system is able to achieve high goodput (application level throughput) and long battery life as applied to handoff management in a frequently changing mobile environment.
74

SmartWall: Novel RFID-enabled Ambient Human Activity Recognition using Machine Learning for Unobtrusive Health Monitoring

Oguntala, George A., Abd-Alhameed, Raed, Noras, James M., Hu, Yim Fun, Nnabuike, Eya N., Ali, N., Elfergani, Issa T., Rodriguez, Jonathan 05 1900 (has links)
Yes / Human activity recognition from sensor readings have proved to be an effective approach in pervasive computing for smart healthcare. Recent approaches to ambient assisted living (AAL) within a home or community setting offers people the prospect of more individually-focused care and improved quality of living. However, most of the available AAL systems are often limited by computational cost. In this paper, a simple, novel non-wearable human activity classification framework using the multivariate Gaussian is proposed. The classification framework augments prior information from the passive RFID tags to obtain more detailed activity profiling. The proposed algorithm based on multivariate Gaussian via maximum likelihood estimation is used to learn the features of the human activity model. Twelve sequential and concurrent experimental evaluations are conducted in a mock apartment environment. The sampled activities are predicted using a new dataset of the same activity and high prediction accuracy is established. The proposed framework suits well for the single and multi-dwelling environment and offers pervasive sensing environment for both patients and carers. / Tertiary Education Trust Fund of Federal Government of Nigeria and by the European Union’s Horizon 2020 research and innovation programme under Grant Agreement H2020-MSCA-ITN-2016 SECRET-722424
75

A Personal Place Awareness System

Snow, Bradford Jason 20 April 2005 (has links)
No description available.
76

Service Discovery in Pervasive Computing Environments

Thompson, Michael Stewart 17 October 2006 (has links)
Service discovery is a driving force in realizing pervasive computing. It provides a way for users and services to locate and interact with other services in a pervasive computing environment. Unfortunately, current service discovery solutions do not capture the effects of the human or physical world and do not deal well with diverse device populations; both of which are characteristics of pervasive computing environments. This research concentrates on the examination and fulfillment of the goals of two of the four components of service discovery, service description and dissemination. It begins with a review of and commentary on current service discovery solutions. Following this review, is the formulation of the problem statement, including a full explanation of the problems mentioned above. The problem formulation is followed by an explanation of the process followed to design and build solutions to these problems. These solutions include the Pervasive Service Description Language (PSDL), the Pervasive Service Query Language (PSQL), and the Multi-Assurance Delivery Protocol (MADEP). Prototype implementations of the components are used to validate feasibility and evaluate performance. Experimental results are presented and analyzed. This work concludes with a discussion of overall conclusions, directions for future work, and a list of contributions. / Ph. D.
77

The Effects of Handheld Network Service "Look" on the Acquisition of Common Ground

Kim, Kibum 27 February 2007 (has links)
Constructing common ground and the associated convergent conceptual change is critical to cooperative work and learning. Convergent conceptual change is achieved as participants in a conversation update common ground through presentations, repairs, and acceptances of utterances. People employ available techniques that utilize the least collaborative effort for current purposes. Although sharing physical co-presence of interlocutors' facial expressions doesn't make grounding more efficient even in more open-ended and less task-focused dialogues, visual co-presence of the addressee's workspace is essential to work-related tasks, such as information transmission and collaborative problem-solving. However, handheld-mediated collaborative activity makes sharing the workspace challenging, especially when we consider that handhelds possess small screens and permit activities of a distributed nature. In a handheld-mediated classroom, a teacher must be able to check students' work for various reasons (e.g., grading, checking whether they are following directions correctly or paying attention) and at various phases of the activity. Gazing into the small screen of a handheld over someone's shoulder is a tricky task at best. The teacher may misread the information on the screen and thus provide incorrect feedback. Another challenge involves the difficulty inherent in latecomers joining the collaborative activity when each student is involved with his or her individual and small screen. This exclusion from joining on-going activity can reduce the chance of student's vicarious and serendipitous learning. Although such events may occur naturally in the learning environment, they become important concerns when one attempts to focus collaborative activities with handheld devices. I therefore created a new handheld network service called "Look," which is designed to facilitate the acquisition of common ground and allow a latecomer to do meaningful monitoring of ongoing conversation about the workspace. I tested empirically the value of this shared physical/virtual context in the task of creating common ground by examining task performance and conversation quality. / Ph. D.
78

Ubiquitous Computing: By the People, For the People

Ndiwalana, Ali 21 August 2003 (has links)
Computing is moving away from the desktop, permeating into many everyday objects and the environments in which we live. Many researchers in ubiquitous computing are excited about the potential to profoundly change the way we live by revolutionizing how we interact with information. Despite the excitement, few successful applications are making the transition from the laboratories to the mass market. While this could easily be attributed to the immaturity of the research area, it is also a manifestation of a larger problem—the lack of coherent methods, processes or tools that assist designers in thinking about issues pertinent to ubiquitous computing, as they explore potential ideas and develop some of these into working prototypes. To this end, this research presents an overview of the important characteristics of ubiquitous computing systems identified by many of the leading researchers in the field. Contrasting with conventional systems, we discuss the resulting issues and challenges, and their implications on the future directions of this emerging research area. In a case study, we use scenario-based design to walkthrough the design of a community computing application. At various stages of the design process, the need to focus on more issues relevant to ubiquitous computing design became apparent, resulting in the augmentation of scenario-based design. The augmented scenario-based design process is proposed as a tool for helping designers conceptualize user activities within given usage circumstances and at various stages of the design process. New questions help to identify the most common pitfalls, enabling designers to produce systems that are more socially acceptable and provide a higher likelihood for adoption by everyday users beyond the laboratory. In initial testing, the augmented process was shown to produce better designs. The ultimate ambition of ubiquitous computing technology is to be able to serve users anywhere, at anytime. However, taking into account the dynamic nature of user needs and usage situations, is a novel and non trivial undertaking. In essence, it is a fundamental change that requires designers to rethink many of the conventional answers and processes that help guide the creation of interactive systems. We provide a promising approach. / Master of Science
79

Dynamische Verwaltung heterogener Kontextquellen in global verteilten Systemen

Hamann, Thomas 30 January 2009 (has links) (PDF)
Im Rahmen der Dissertation wurde ein Middlewaredienst entwickelt und realisiert. Es gestattet die dynamische Verwaltung heterogener Kontextquellen. Das zugrunde liegende Komponentenmodell selbstbeschreibender Context Provieder ermöglicht die lose Kopplung von Kontextquellen und -senken. Es wird durch Filter- und Konverterkomponenten zur generischen Providersselektion anhand domänenspezifischer Merkmale ergänzt. Die Kopplung der verteilten Dienstinstanzen erfolgt durch ein hybrides Peer-to-Peer-System. Dies trägt der Heterogenität der Endgeräte Rechnung, und erlaubt die skalierbare , verteilte Verwaltung von Kontextquellen in globalen Szenarien.
80

Dynamische Verwaltung heterogener Kontextquellen in global verteilten Systemen

Hamann, Thomas 05 December 2008 (has links)
Im Rahmen der Dissertation wurde ein Middlewaredienst entwickelt und realisiert. Es gestattet die dynamische Verwaltung heterogener Kontextquellen. Das zugrunde liegende Komponentenmodell selbstbeschreibender Context Provieder ermöglicht die lose Kopplung von Kontextquellen und -senken. Es wird durch Filter- und Konverterkomponenten zur generischen Providersselektion anhand domänenspezifischer Merkmale ergänzt. Die Kopplung der verteilten Dienstinstanzen erfolgt durch ein hybrides Peer-to-Peer-System. Dies trägt der Heterogenität der Endgeräte Rechnung, und erlaubt die skalierbare , verteilte Verwaltung von Kontextquellen in globalen Szenarien.

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