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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.
381

Inkludering av elever med ADHD : En fallstudie från åk 5 / The inclusion of students with ADHD :  A case study from the fifth grade

Sandström, Lina January 2010 (has links)
Today there are many students with behavioral and developmental disorders in schools. One of these disorders is ADHD. The medical designation ADHD stands for Attention Deficit Hyperactivity Disorder. I have chosen to research how two students with ADHD can be included in a fifth grade classroom. This research paper addresses the issues surrounding the student’s day-to-day life with a focus on the classroom. It also discusses pedagogical methods, resources, and support, as well as social relationships, and routines in relation to the students in question. In order to develop a more complete understanding of the two students and their situation, I have chosen to do a qualitative study where I’ve observed the students in their classroom for four days, and interviewed the adults that interact with the students the most on a day to day basis. The interviewees include the students’ classroom teacher, their assistant teacher, as well as the students’ mothers. I begin the paper by describing ADHD, as well as the potential causes and treatments. I also present the two predominant opinions regarding the source of ADHD that exist in Sweden today. The first is a biological perspective, which states that ADHD is passed on genetically, and the second is a sociological perspective, which states that ADHD is acquired through exposure to a range of social and environmental factors. However, I have based my research on the biological perspective because it is currently the most widely accepted, and because the biological model of explanation is the model most of the current literature is based on. As a result of my research, I have concluded that students with ADHD can have a wide range of different symptoms despite having the same diagnosis. Hellström states that teachers should be aware that all students with ADHD are unique individuals, and it is therefore difficult to prescribe a general set of guidelines to follow when working with such students. One must take each individual’s needs into consideration and decide which methods and solutions work best for each particular individual (Hellström 2007, s. 1). Hellström’s statement is consistent with the conclusions I came to after conducting my research. The classroom teacher saw the students as very different individuals and adapted their education according to their very different needs despite the fact that they have the same diagnosis.
382

Blast Retrofit of Reinforced Concrete Walls and Slabs

Jacques, Eric 01 March 2011 (has links)
Mitigation of the blast risk associated with terrorist attacks and accidental explosions threatening critical infrastructure has become a topic of great interest in the civil engineering community, both in Canada and abroad. One method of mitigating blast risk is to retrofit vulnerable structures to resist the impulsive effects of blast loading. A comprehensive re-search program has been undertaken to develop fibre reinforced polymer (FRP) retrofit methodologies for structural and non-structural elements, specifically reinforced concrete slabs and walls, subjected to blast loading. The results of this investigation are equally valid for flexure dominant reinforced concrete beams subject to blast effects. The objective of the research program was to generate a large volume of research data for the development of blast-resistant design guidelines for externally bonded FRP retrofit systems. A combined experimental and analytical investigation was performed to achieve the objectives of the program. The experimental program involved the construction and simulated blast testing of a total of thirteen reinforced concrete wall and slab specimens divided into five companion sets. These specimens were subjected to a total of sixty simulated explosions generated at the University of Ottawa Shock Tube Testing Facility. Companion sets were designed to study one- and two-way bending, as well as the performance of specimens with simply-supported and fully-fixed boundary conditions. The majority of the specimens were retrofitted with externally bonded carbon fibre reinforced polymer (CFRP) sheets to improve overall load-deformation characteristics. Specimens within each companion set were subjected to progressively increasing pressure-impulse combinations to study component behaviour from elastic response up to inelastic component failure. The blast performance of companion as-built and retrofitted specimens was quantified in terms of measured load-deformation characteristics, and observed member behaviour throughout all stages of response. The results show that externally bonded FRP retrofits are an effective retrofit technique to improve the blast resistance of reinforced concrete structures, provided that debonding of the composite from the concrete substrate is prevented. The test results also indicate that FRP retrofitted reinforced concrete structures may survive initial inbound displacements, only to failure by moment reversals during the negative displacement phase. The experimental test data was used to verify analytical techniques to model the behaviour of reinforced concrete walls and slabs subjected to blast loading. The force-deformation characteristics of one-way wall strips were established using inelastic sectional and member analyses. The force-deformation characteristics of two-way slab plates were established using commonly accepted design approximations. The response of all specimens was computed by explicit solution of the single degree of freedom dynamic equation of motion. An equivalent static force procedure was used to analyze the response of CFRP retrofitted specimens which remained elastic after testing. The predicted maximum displacements and time-to-maximum displacements were compared against experimental results. The analysis indicates that the modelling procedures accurately describe the response characteristics of both retrofitted and unretrofitted specimens observed during the experiment.
383

Svenska aktiemarknaden : Hur påverkas den svenska aktiemarknaden av makroekonomiska variabler / The Swedish Stock Market : How is the Swedish Stock Market affected by macroeconomic variables

Bodin, Oscar, Nielsen, Jenny January 2013 (has links)
Bakgrund och Problem: Aktiemarknaden påverkas både av inhemska och utländska faktorer. Därför är det av intresse att se vilka makroekonomiska variabler som påverkar den svenska aktiemarknaden. Anledningen till att Sverige har valts som den geografiska punkten är att det är av intresse att se hur ett litet land som Sverige, som har en öppen ekonomi påverkas av de utvalda makroekonomiska variablerna. Syfte: Syftet med uppsatsen är att med hjälp av information samt analys, studera hur de olika makroekonomiska variablerna påverkar den inhemska aktiemarknaden. Olika faktorer som påverkar aktiemarknaden kommer att lyftas fram för att i sin tur även se till de olika branscherna. Metod: Då data enbart består av hämtning av tidigare information fokuseras det enbart på sekundärdata i form av historiska siffror samt historiska undersökningar. De statistiska tester som tillämpas är Granger Causality test, Johansens Cointegration test, Impulse Response Function test, ADF test, KPSS test, Mulitpel regression. Slutsats: Med de resultat som presenterades i denna studie, skulle vi nog inte kunna säga att vi har ett svar över vilka aktier en investerare ska införskaffa. Dock skulle vi kunna poängtera att den potentiella investeraren bör ha dessa variabler i beaktning vid beslut. Genom att studera dessa variabler kan man få en känsla om vilket håll variablerna kommer att röra sig och på så sätt säga att de kan påverka aktieindexen. Att bara kolla på de makroekonomiska variabler som denna studie belyser räcker inte för att förstå hur aktieindex kommer att se ut i framtiden, men det är en bit på vägen till att förstå aktiemarknadens rörelse.
384

Transparent Satellite Switching using Flexible Frequency-band Reallocation

Yagüe, Edgar Cámara, Carretero, José Manuel Menéndez January 2006 (has links)
The society expects a global interconected digital communication system offering multimedia services, information on demand and interchange of information with a high data rates and low cost. All this can not be realized with the terrestrial nets used nowadays cause it is necessary a high economic inversion to get a competitive capacity to interchange information between server and user. The next generation of satellite must have characteristics which improve the current generation, one important requirement is that the same satellite could make a treatment of the different input signals. With this we can avoid a spent of lots of money and time because we do not need terrestrial stations which modify the signals before the information is sent to the satellite. For all this, we need an on board treatment of the information in the satellite. We design a frequency bank reallocation (FBR) network by using a filter bank system. This is the first step of the thesis. After we get FBR we introduce some different input signals and analyze the output, using parameters like symbol error rate and variance. One important part in the thesis is the QAM signals used to test our system. For this, we design a modulator and a demodulator of QAM4, 16 and 64, paying more attention in the QAM64, cause is the modulation where more errors can appear due to we have got more possible chances which means more precision in the recovery of the signal.
385

Blast Retrofit of Reinforced Concrete Walls and Slabs

Jacques, Eric 01 March 2011 (has links)
Mitigation of the blast risk associated with terrorist attacks and accidental explosions threatening critical infrastructure has become a topic of great interest in the civil engineering community, both in Canada and abroad. One method of mitigating blast risk is to retrofit vulnerable structures to resist the impulsive effects of blast loading. A comprehensive re-search program has been undertaken to develop fibre reinforced polymer (FRP) retrofit methodologies for structural and non-structural elements, specifically reinforced concrete slabs and walls, subjected to blast loading. The results of this investigation are equally valid for flexure dominant reinforced concrete beams subject to blast effects. The objective of the research program was to generate a large volume of research data for the development of blast-resistant design guidelines for externally bonded FRP retrofit systems. A combined experimental and analytical investigation was performed to achieve the objectives of the program. The experimental program involved the construction and simulated blast testing of a total of thirteen reinforced concrete wall and slab specimens divided into five companion sets. These specimens were subjected to a total of sixty simulated explosions generated at the University of Ottawa Shock Tube Testing Facility. Companion sets were designed to study one- and two-way bending, as well as the performance of specimens with simply-supported and fully-fixed boundary conditions. The majority of the specimens were retrofitted with externally bonded carbon fibre reinforced polymer (CFRP) sheets to improve overall load-deformation characteristics. Specimens within each companion set were subjected to progressively increasing pressure-impulse combinations to study component behaviour from elastic response up to inelastic component failure. The blast performance of companion as-built and retrofitted specimens was quantified in terms of measured load-deformation characteristics, and observed member behaviour throughout all stages of response. The results show that externally bonded FRP retrofits are an effective retrofit technique to improve the blast resistance of reinforced concrete structures, provided that debonding of the composite from the concrete substrate is prevented. The test results also indicate that FRP retrofitted reinforced concrete structures may survive initial inbound displacements, only to failure by moment reversals during the negative displacement phase. The experimental test data was used to verify analytical techniques to model the behaviour of reinforced concrete walls and slabs subjected to blast loading. The force-deformation characteristics of one-way wall strips were established using inelastic sectional and member analyses. The force-deformation characteristics of two-way slab plates were established using commonly accepted design approximations. The response of all specimens was computed by explicit solution of the single degree of freedom dynamic equation of motion. An equivalent static force procedure was used to analyze the response of CFRP retrofitted specimens which remained elastic after testing. The predicted maximum displacements and time-to-maximum displacements were compared against experimental results. The analysis indicates that the modelling procedures accurately describe the response characteristics of both retrofitted and unretrofitted specimens observed during the experiment.
386

Implementation of the LMS and NLMS algorithms for Acoustic Echo Cancellationin teleconference systemusing MATLAB

Nguyen Ngoc, Hung, Dowlatnia, Majid, Sarfraz, Azhar January 2009 (has links)
In hands-free telephony and in teleconference systems, the main aim is to provide agood free voice quality when two or more people communicate from different places.The problem often arises during the conversation is the creation of acoustic echo. Thisproblem will cause the bad quality of voice signal and thus talkers could not hearclearly the content of the conversation, even thought lost the important information.This acoustic echo is actually the noise which is created by the reflection of soundwaves by the wall of the room and the other things exist in the room. The mainobjective for engineers is the cancellation of this acoustic echo and provides an echofree environment for speakers during conversation. For this purpose, scientists designdifferent adaptive filter algorithms. Our thesis is also to study and simulate theacoustics echo cancellation by using different adaptive algorithms.
387

The Potential for Ultrasonic Image-Guided Therapy Using a Diagnostic System

Bing, Kristin Frinkley 13 November 2008 (has links)
<p>Ultrasound can be used for a variety of therapeutic purposes. High-intensity focused ultrasound (HIFU) has progressed over the past decade to become a viable therapeutic method and is valuable as a non-invasive alternative to many surgical procedures. Ultrasonic thermal therapies can also be used to release thermally sensitive liposomes encapsulating chemotherapeutic drugs. In the brain, the permeability of the blood-brain barrier to drugs, antibodies, and gene transfer can be increased with a mechanical mechanism using ultrasound and contrast agent.</p><p>The work presented in this dissertation tests the hypothesis that a diagnostic system can be used for combined imaging and therapeutic applications. In order to evaluate the effectiveness of a diagnostic system for use in therapeutic applications, a set of non-destructive tests is developed that can predict the potential for high acoustic output. A rigorous, nondestructive testing regimen for standard, diagnostic transducers to evaluate their potential for therapeutic use is formulated. Based on this work, transducer heating is identified as the largest challenge. The design and evaluation of several custom diagnostic transducers with various modifications to reduce internal heating are described. These transducers are compared with diagnostic controls using image contrast, face heating, hydrophone, and ARFI displacement measurements. From these results, we conclude that the most promising design is a passively and actively cooled, PZT-4 multilayer composite transducer, while the acoustically lossless lens and capactive micro-machined transducers evaluated herein are determined to be ineffective.</p><p>Three therapeutic applications are evaluated for the combined system. Image-guided spot ablations, such as in the treatment of early stage liver cancers, could not be successfully performed; however, the additional acoustic output requirements are determined to be on the order of 2.4 times those that can be currently produced without transducer damage in a clinically relevant amount of time (10-20 seconds per spot). The potential of a diagnostic system for a hyperthermia application is shown by producing temperatures for the duration necessary to release chemotherapeutic agents from thermally-activated liposomes without damage to the transducer. Finally, a mechanically-based therapeutic method for opening the BBB with ultrasonic contrast agent and specialized sonication regimes under ultrasonic B-mode guidance is demonstrated.</p><p>These studies indicate that a diagnostic system is capable of both moderate thermal and mechanical therapeutic applications under co-registered image-guidance.</p> / Dissertation
388

Inventory Control In A Build-To-Order Environment

Ormeci, Melda 28 June 2006 (has links)
This dissertation consists of three independent sections: In the first part, focusing on the auto industry we look at the challenges and solution strategies of employing build-to-order (BTO) with global supply. We consider some familiar tools for managing domestic supply and exploit them for managing international supply, and propose new methods. We study frequency of supply as a way to improve performance. We study the impact of forecast accuracy, and conclude that improvements there alone may not be sufficient to obtain desired savings. Within this perspective we look at a new shipping policy, 'Ship-to-Average", which prescribes sending a fixed quantity, based on the long term average forecast, with each shipment and making adjustments only if the inventory strays outside a prescribed range. In the second part we look at a Brownian control problem. When a manufacturer places repeated orders with a supplier to meet changing production requirements, he faces the challenge of finding the right balance between holding costs and the operational costs involved in adjusting the shipment sizes. Consider a storage system whose content fluctuates as a Brownian motion in the absence of control. A linear holding cost is incurred continuously. Inventory level can be adjusted by any quantity at a fixed plus proportional cost. We show control band policies are optimal for the average cost problem and calculate the optimal policy parameters. This form of policy is described by three parameters q, Q, S. When the inventory falls to 0 (rises to S), the controller expedites (curtails) shipments to return it to q (Q). Developing techniques based on Lagrangian relaxation we show that this type of policy is optimal even with constraints on the size of adjustments and on the maximum inventory level. The Brownian Control problem can be viewed as an idealization --without delivery delays, of the problem of supplying BTO operations, and provides some theoretical explanation for the Ship-to-Average policies. In fact, Ship-to-Average policies are a practical implementation of Control Band policies in the setting with delivery delays. Finally, we explore the power and applicability of the Lagrangian approach developed in the second part.
389

A Precoding Scheme for Semi-Blind Channel Estimation in Cooperative Networks

Chen, Yen-cheng 01 August 2012 (has links)
In this thesis, we proposed a precoding scheme for semi-blind channel estimation in amplify-and-forward (AF) multipath two-way relay networks (TWRN), where two terminals exchange their information through multi-relays. The precoding scheme, which diminishes computational complexity of semi-blind channel estimator, is used to distinguish received signal at both terminals from multi-relays. By applying a non-redundant linear precoding scheme at multi-relays, we proposed a semi-blind channel estimation to estimate the channel impulse response (CIR) of direct link and the cascaded source-relay-terminal links. Firstly, semi-blind channel estimation adopts least-square (LS) estimation to find the CIR of direct link between both terminals using a smaller number of training symbols. Secondly, the CIR of the cascaded source-relay-terminal links are obtained through second-order statistics (SOS) of received signals at both terminals. Consequently, the proposed scheme can effectively reduce the computational complexity and enhance the spectral efficiency in overall system. Simulation results corroborate the effectiveness of the proposed scheme.
390

Exploration of Impulse Buying Behavior on Online Group-Buying

Wu, Kai-yu 16 August 2012 (has links)
Recently, online group-buying has been a popular business model. It was observed that many characteristics of online group-buying are potential stimuli of impulse buying. Therefore, we target traditional online group-buying and e-coupon group-buying and try to explore the characteristics of online group-buying stimulating impulse buying. Based on the literature review and empirical data collection, we identified five characteristics of online group-buying which may stimulate impulse buying. They are group-buying discount, time pressure, social interaction, perceived shopping convenience and consumption deadline. The data were collected through online questionnaire. The analysis result shows that the five characteristics of online group-buying indeed cause impulse buying. Further, we also explored whether the impulse buying behavior will be moderated in different situations. These moderators include group-buying model (traditional online group-buying vs. e-coupon group-buying), transaction price level, relationship with the group-buying initiator, product type and group-buying experience. The result indicates that the impulse buying behaviors are easier to be stimulated in the following situations: traditional online group-buying, lower transaction price, familiar with the traditional online group-buying initiator, non-food product and more experienced consumers of online group-buying.

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