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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.
531

Performance Assessment of Shear-critical Reinforced Concrete Plane Frames

Guner, Serhan 19 January 2009 (has links)
Current analysis procedures for new reinforced concrete structures are typically based on linear-elastic principles. However, under certain conditions, it may be necessary to analyze a structure to more accurately predict its structural behaviour. Such an analysis can be performed using nonlinear analysis procedures which typically require specialized software. This type of software is limited in number and most available programs do not adequately capture shear-related influences, potentially severely overestimating strength and ductility in shear-critical structures. The purpose of this study is to develop and verify an analytical procedure for the nonlinear analysis of frame structures with the aim of capturing shear-related mechanisms as well as flexural and axial effects. A previously developed analysis program, VecTor5, is further developed for this purpose. Originally formulated in the early 1980s at the University of Toronto, VecTor5 is based on the Modified Compression Field Theory (MCFT) and is capable of performing nonlinear frame analyses under temperature and monotonic loading conditions. Although providing generally satisfactory simulations, there are a number of deficiencies present in its computational algorithms. This study consists of three major parts: improvement of the original analysis procedure for monotonic loading conditions, expansion of the procedure for general loading conditions including the special cases of cyclic and reversed-cyclic loading, and further development of the procedure for dynamic loading conditions including time-varying base accelerations, impulse, impact and blast forces, initial mass velocities, and constant mass accelerations. Each part is supported by verification studies performed on a large number and variety of previously tested structures available in the literature. In addition, considerations in nonlinear modelling are discussed with the aim of providing guidelines for general modelling applications. Analyses of 63 previously tested structures, half of which are shear-critical, demonstrate that the developed analytical procedure is highly successful in simulating the experimental responses in terms of load-deflection response, reinforcement strains, crack widths, failure mode, failure displacement, total energy dissipation, displacement ductility ratio, and post-peak vibrational characteristics.
532

Från olja till bläck : En studie om medias inramning av ”Etiopiensvenskarna”

Land, Johan, Svedberg, Anders January 2013 (has links)
Syftet med denna uppsats är att försöka skapa en större förståelse för hur svenska tidningar har använt sig av framing/inramning och sociala representationer i sin nyhetsrapportering kring de två svenska journalisterna Johan Persson och Martin Schibbye som satt fängslade i Etiopien. För att skapa en större förståelse kring inramningen av "Etiopiensvenskarna" har denna uppsats använt sig av kritisk diskursanalys på svenska morgon- och kvällstidningar under två olika tidsperioder, en i inledningen och en i slutfasen av situationen med "Etiopiensvenskarna" Resultatet av vår analys visar att det har skett en framing/inramning av nyhetsrapporteringen kring Johan Persson och Martin Schibbyes situation i Etiopien. Denna inraming har bland annat skett genom att tidningarna tilldelar dem en hjältestatus där de har valt att belysa vissa delar av situationen, som till exempel deras nationalitet, yrke och frågan om yttrandefrihet. Denna inramning kan påverka mottagarens tolkning.
533

Studies in knowledge representation : modeling change - the frame problem : pictures and words

Janlert, Lars-Erik January 1985 (has links)
In two studies, the author attempts to develop a general symbol theoretical approach to knowledge representation. The first study, Modeling change - the frame problem, critically examines the - so far unsuccessful - attempts to solve the notorious frame problem. By discussing and analyzing a number of related problems - the prediction problem, the revision problem, the qualification problem, and the book-keeping problem - the frame problem is distinguished as the problem of finding a representational form permitting a changing, complex world to be efficiently and adequately represented. This form, it is argued, is dictated by the metaphysics of the problem world, the fundamental form of the symbol system we humans use in rightly characterizing the world. In the second study, Pictures and words, the symbol theoretical approach is made more explicit. The subject Is the distinction between pictorial (non-linguistic, non-propositional, analogical, "direct") representation and verbal (linguistic, propositional) representation, and the further implications of this distinction. The study focuses on pictorial representation, which has received little attention compared to verbal representation. Observations, ideas, and theories in AI, cognitive psychology, and philosophy are critically examined. The general conclusion is that there is as yet no cogent and mature theory of pictorial representation that gives good support to computer applications. The philosophical symbol theory of Nelson Goodman is found to be the most thoroughly developed and most congenial with the aims and methods of AI. Goodman's theory of pictorial representation, however, in effect excludes computers from the use of pictures. In the final chapter, an attempt is made to develop Goodman's analysis of pictures further turning it into a theory useful to AI. The theory outlined builds on Goodman's concept of exemplification. The key idea is that a picture is a model of a description that has the depicted object as its standard model. One consequence Is that pictorial and verbal forms of representation are seen less as competing alternatives than as complementary forms of representation mutually supporting and depending on each other. / digitalisering@umu
534

The Role of Civil Society Organizations in the Net Neutrality Debate in Canada and the United States

Harpham, Bruce 25 January 2010 (has links)
This thesis investigates the policy frames employed by civil society organizations (CSOs) in the network neutrality debate in Canada and the United States. Network neutrality is defined as restrictions on Internet Service Providers (ISPs) to respect freedom of expression on the Internet and not seek to prevent innovative competition nor control the services or content available to users. The primary question under investigation is the policy frames of CSOs in the debate. The second question is whether CSOs have influenced policy outcomes in either legislation or regulation. The focus of the analysis is on regulatory agencies (CRTC and FCC); proposed legislation in Parliament and Congress is also analyzed as well. By examining the arguments advanced by various policy participants (government, ISPs, and CSOs), common points can be identified that may help the participants come to agreement.
535

Efficient Frame Transmission For Scalable Video Streaming with Dependency Structure

Mehdian, Saied 22 November 2012 (has links)
Efficient transmission schemes are presented for streaming scalable video over a link with limited capacity. The objective is to select a transmission sequence of data units and their transmission schedule such that the overall video quality is maximized. For video with a single spatial layer, optimal transmission schemes are obtained for two general classes of hierarchical prediction structures, which include the popular dyadic structure. Based on a new characterization of the interdependence among frames in terms of trees, structural properties of an optimal transmission schedule are derived. These properties lead to the development of a jointly optimal frame selection and scheduling algorithm, which has computational complexity that is quadratic in the number of frames. Then, using the concept of virtual deadlines, an efficient sub-optimal scheme for the transmission of video with multiple spatial layers is proposed. Simulation results show that the proposed schemes substantially outperform two existing alternatives.
536

The Role of Civil Society Organizations in the Net Neutrality Debate in Canada and the United States

Harpham, Bruce 25 January 2010 (has links)
This thesis investigates the policy frames employed by civil society organizations (CSOs) in the network neutrality debate in Canada and the United States. Network neutrality is defined as restrictions on Internet Service Providers (ISPs) to respect freedom of expression on the Internet and not seek to prevent innovative competition nor control the services or content available to users. The primary question under investigation is the policy frames of CSOs in the debate. The second question is whether CSOs have influenced policy outcomes in either legislation or regulation. The focus of the analysis is on regulatory agencies (CRTC and FCC); proposed legislation in Parliament and Congress is also analyzed as well. By examining the arguments advanced by various policy participants (government, ISPs, and CSOs), common points can be identified that may help the participants come to agreement.
537

Efficient Frame Transmission For Scalable Video Streaming with Dependency Structure

Mehdian, Saied 22 November 2012 (has links)
Efficient transmission schemes are presented for streaming scalable video over a link with limited capacity. The objective is to select a transmission sequence of data units and their transmission schedule such that the overall video quality is maximized. For video with a single spatial layer, optimal transmission schemes are obtained for two general classes of hierarchical prediction structures, which include the popular dyadic structure. Based on a new characterization of the interdependence among frames in terms of trees, structural properties of an optimal transmission schedule are derived. These properties lead to the development of a jointly optimal frame selection and scheduling algorithm, which has computational complexity that is quadratic in the number of frames. Then, using the concept of virtual deadlines, an efficient sub-optimal scheme for the transmission of video with multiple spatial layers is proposed. Simulation results show that the proposed schemes substantially outperform two existing alternatives.
538

Contagion from Abroad: U.S. Press Framing of Immigrants and Epidemics, 1891 to 1893

Moore, Harriet 20 November 2008 (has links)
This thesis examines press framing of immigrant issues and epidemics in newspapers and periodicals, 1891 to 1893. During these years, immigration policies became more restrictive because of the Immigration Act of 1891, the opening of Ellis Island in 1892, the Chinese Exclusion Act of 1892, the New York City epidemics of 1892, the National Quarantine Act of 1893, and the nativist movement. Framing theory guided the following research questions: 1) How did articles in newspapers and periodicals frame immigrants and immigration issues in the context of epidemics from 1891 and 1893?; and 2) How did the press framing of immigrants and immigration issues in the context of epidemics from 1891 to 1893 reflect themes of nativism? This thesis contributes to the discourse about immigration because many Americans historically have learned about immigration issues from the press.
539

A Characterization of Wireless Network Interface Card Active Scanning Algorithms

Gupta, Vaibhav 04 December 2006 (has links)
In this thesis, we characterize the proprietary active scanning algorithm of several wireless network interface cards. Our experiments are the first of its kind to observe the complete scanning process as the wireless network interface cards probe all the channels in the 2.4GHz spectrum. We discuss the: 1) correlation of channel popularity during active scanning and access point channel deployment popularity; 2) number of probe request frames statistics on each channel; 3) channel probe order; and 4) dwell time. The knowledge gained from characterizing wireless network interface cards is important for the following reasons: 1) it helps one understand how active scanning is implemented in different hardware and software; 2) it can be useful in identifying a wireless rogue host; 3) it can help implement Active Scanning in network simulators; and 4) it can radically influence research in the familiar fields like link-layer handovers and effective deployment of access points.
540

A System for Building Corpus Annotated With Semantic Roles

Rahimi Rastgar, Sanaz, Razavi, Niloufar January 2013 (has links)
Semantic role labelling (SRL) is a natural language processing (NLP) technique that maps sentences to semantic representations. This can be used in different NLP tasks. The goal of this master thesis is to investigate how to support the novel method proposed by He Tan for building corpus annotated with semantic roles. The mentioned goal provides the context for developing a general framework of the work and as a result implementing a supporting system based on the framework. Implementation is followed using Java. Defined features of the system reflect the usage of frame semantics in understanding and explaining the meaning of lexical items. This prototype system has been processed by the biomedical corpus as a dataset for the evaluation. Our supporting environment has the ability to create frames with all related associations through XML, updating frames and related information including definition, elements and example sentences and at last annotating the example sentences of the frame. The output of annotation is a semi structure schema where tokens of a sentence are labelled. We evaluated our system by means of two surveys. The evaluation results showed that our framework and system have fulfilled the expectations of users and has satisfied them in a good scale. Also feedbacks from users have defined new areas of improvement regarding this supporting environment.

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