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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.
181

Data acquisition techniques for next generation wireless sensor networks

Ehsan, Samina 12 March 2012 (has links)
The meteoric rise and prevalent usage of wireless networking technologies for mobile communication applications have captured the attention of media and imagination of public in the recent decade. One such proliferation is experienced in Wireless Sensor Networks (WSNs), where multimedia enabled elements are fused with integrated sensors to empower tightly coupled interaction with the physical world. As a promising alternative to antiquated wired systems and traditional WSNs in a multitude of novel application scenarios, the newly renovated WSNs have inspired a wide range of research among which investigation on data acquisition techniques is a fundamental one. In this dissertation, we address the problem of data acquisition in next generation WSNs. As wireless sensors are powered with limited energy resources while they are expected to work in an unattended manner for a long duration, energy conservation stands as the primal concern. Also, to enable in-situ sensing in different rate-constrained applications, routing decisions should care about the medium access feasibility of achievable end-to-end data rates. Driven by the fact, we first design cross-layer medium contention aware routing schemes for rate-constrained traffic in single-channel WSNs that maximize network lifetime. Three sufficient conditions on rate feasibility, referred to as rate-based, degree-based, and mixed constraints, are incorporated into the routing formulations to guarantee the practical viability of the routing solutions. Next, with the aim to mitigate interference and hence to enhance network capacity, we extend our work by proposing energy and cross-layer aware routing schemes for multichannel access WSNs that account for radio, MAC contention, and network constraints. In that context, we first derive three new sets of sufficient conditions that ensure feasibility of data rates in multichannel access WSNs. Then, utilizing these sets, we devise three different MAC-aware routing optimization schemes, each aiming to maximize the network lifetime while meeting data rate requirements of end-to-end flows. Finally, we perform extensive simulation studies to evaluate and compare the performance of the proposed routing approaches under various network conditions. So far works are done in milieu of WSNs with both fixed access node and sensor nodes. In the subsequent part of the dissertation, we present the continuation of our work focusing on reliable data acquisition in Mobile WSNs for a promising application namely free-ranging animal tracking/monitoring. To accomplish that goal, we concentrate on providing sufficient conditions on access-point density that limit the likelihood of buffer overflow. We first derive sufficient access-point density conditions that ensure that the data loss rates are statistically guaranteed to remain below a given threshold. Then, we evaluate and validate the derived theoretical results with both synthetic and real-world data. / Graduation date: 2012
182

A study of applying Technological Frame Theory to the implement of a Product Data Management System.

Ching-YUN, Chang 30 June 2003 (has links)
­^¤åºK­n¡GInformation Technology (IT) as a competition advantage of the organization or individual has been widely welcome in the market. Orlikowski & Gash (1994) proposed the Theory of Technological Frame revealed that the organizational context affected the assumption and expectation of the technology. Furthermore, these assumption and expectation impacted the organization behavior. Thus, study the technological frame becomes a critical issue in understanding the IT development of the organization. We adopt the Theory of Technological Frame (Orlikowski & Gash, 1994) and make some reinforcement in the domain and category as the research model. This base guided us in understanding both the groups¡¦ and individual¡¦s behaviors of introduction and implementation of a groupware (Product Data Management, PDM) in the case study. In the data analyzing process, we employed the hermeneutic method to interpret and organize our finding. The research results indicated that the users hold positive perspective of PDM effectives in the following constructs¡G1. Reducing development time of new product¡F 2. Increasing the productivity of product design ¡F3. Increasing the accuracy of manufacturing and product design¡F4. Increasing and promoting the skill of working team¡F5. Assuring the data integrality and security¡F6. Building the data standard of aerospace. We believe that the consequence of research is useful for managers to understand the technological frame is important for enterprise¡¦s competitive capacity. Furthermore, understanding how to diagnosis, explanation and anticipation around information technology such change processes in organization. Keyword: information technology, Theory of Technological Frame
183

Training and system implementation impact study subtitled : "But we just got used to the old system!" /

Matey, Barbara A. January 1900 (has links)
Thesis (Ed. D.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains x, 222 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 211-222).
184

Perceived value impact as an antecedent of perceived usefulness, perceived ease of use, and attitude a perspective on the influence of values on technology acceptance /

Seligman, Larry Stuart. January 2001 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references. Available also from UMI Company.
185

Technology acceptance and organizational change an integration of theory /

Brown, Steven. Armenakis, Achilles A. January 2009 (has links)
Dissertation (Ph.D.)--Auburn University, 2009. / Abstract. Includes bibliographic references (p.260-338).
186

The puzzles of Korean technological development, 1960-97 /

Hong, Jhea-Whan, January 2000 (has links)
Thesis (Ph. D.)--University of Oregon, 2000. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 270-288). Also available for download via the World Wide Web; free to University of Oregon users.
187

An improved cross-impact model

Halverson, Troy 08 1900 (has links)
No description available.
188

The effect of opportunities provided by telecommunications on the reading and writing of adult augmentative communicators who are severely disabled /

Gandell, Terry S. January 1992 (has links)
Augmentative communicators are perceived to have difficulty with reading and writing. This research investigates the effect of increased opportunity to communicate via telecommunications on the reading and writing of adult augmentative communicators who are severely disabled. Two case studies were conducted utilizing a single subject, repeated measure design. The subject of each case study participated in on-line interactive Blissymbol telecommunications sessions with a speaking partner for nine hours per week over ten months. Reading and language tests were administered at two month intervals. Written transcripts of on-line conversations were collected and coded according to macro and micro language functions. Following the increased opportunity to communicate via telecommunications, case study two paralleled the results found in case study one displaying increased reading ability as demonstrated by the upward trends on the multiple reading measures utilized. Case study two also corroborated case study one in the written communication as demonstrated by the increased use of complex language functions, initiations, and response to statements. The findings suggest that providing augmentative communicators with meaningful and functional reading, writing, and 'speaking' opportunities, similar to those provided with the telecommunications opportunity in this research, will have a positive effect on reading and writing.
189

Technology, competitiveness and patterns of specialisation

Amendola, Giovanni B. January 1998 (has links)
No description available.
190

Technological breakthroughs and productivity growth /

Edquist, Harald, January 2006 (has links)
Diss. Stockholm : Handelshögskolan, 2006.

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