• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 3647
  • 914
  • 683
  • 424
  • 160
  • 93
  • 59
  • 57
  • 45
  • 38
  • 36
  • 35
  • 35
  • 34
  • 27
  • Tagged with
  • 7480
  • 1119
  • 875
  • 795
  • 715
  • 711
  • 706
  • 559
  • 528
  • 521
  • 518
  • 515
  • 495
  • 479
  • 471
  • 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.
91

On Measuring agreement for categorical data.

January 2002 (has links)
Tang Pik-Ha. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 51-54). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Agreement analysis --- p.2 / Chapter 1.2 --- Outline of the thesis --- p.6 / Chapter 2 --- Review --- p.8 / Chapter 2.1 --- Chance-corrected measures --- p.8 / Chapter 2.2 --- Statistical Modelling Approach --- p.15 / Chapter 3 --- Model-based kappa --- p.17 / Chapter 3.1 --- An agreement model with kappa as parameter --- p.17 / Chapter 3.2 --- Parameter Estimation --- p.21 / Chapter 3.3 --- Asymptotic variance-covariance matrix --- p.25 / Chapter 3.3.1 --- Fisher Information --- p.25 / Chapter 3.3.2 --- Computational detail --- p.27 / Chapter 3.4 --- Illustrative Example --- p.30 / Chapter 4 --- Simulation Study --- p.33 / Chapter 4.1 --- Design --- p.33 / Chapter 4.2 --- Results --- p.37 / Chapter 4.3 --- Discussion --- p.40 / Chapter 5 --- Conclusion --- p.42 / Tables --- p.44 / Figures --- p.49 / Bibliography --- p.51
92

Estimating the cost of engineering services using parametrics and the bathtub failure model

Huang, Xiaoxi January 2012 (has links)
In the engineering domain, customers traditionally purchase a product by paying a one-off price to the supplier. Currently, customers are increasingly demanding engineering services in different disciplines, such as in the aerospace, defence, manufacturing and construction sectors. This means that the customer may buy a product, which includes an integrated service or purchase the usage of a product/service (i.e. availability and capability) rather than the ownership of a product. To meet this demand for engineering services rather than stand-alone products, many companies have moved from providing a tangible product to offering such services. In both academia and industry, the majority of the activities have focused on estimating the cost for products with little in the area of estimating the cost of providing engineering services. There appears to be a clear knowledge gap in the field of costing models and rules for providing such services. It is this gap in knowledge, which is the focus of the research presented in this thesis. This research is focused on estimating the cost for engineering services using parametrics and the bathtub failure model. This is illustrated through the application to a Chinese manufacturing and service provider. Eight years of cost-related data such as historical bills, service charges, maintenance records, and costs for storage has been collected. Observations, questionnaires and structured meetings have been conducted within the company. A methodology and a cost model for estimating the cost for engineering services are provided. The major contribution of this research is the creation of an approach, which is to estimate the cost of engineering services using parametrics and the bathtub failure model.
93

Geometric Autoconfiguration for Precision Personnel Location

Woodacre, Benjamin W 05 May 2010 (has links)
The goal of a radio-based precision personnel location system is to determine the position of a mobile user, to within a desired accuracy, based on signals propagated between that user and fixed stations. In emergency response situations such information would assist search and rescue operations and provide improved situational awareness. Fundamentally location estimation is based upon the signal measured at, and the position of, each receiver. In the case of a location system where such receivers are installed on vehicles, such as for fire trucks, no external infrastructure or prior characterization of the area of operations can be assumed and the estimation of the (relative) positions of the receiving stations must be repeated each time the system is deployed at a new site as this results in the geometry of the receiving antennas being changed. This dissertation presents work towards an accurate and automatic method for determination of the geometric configuration of such receiving stations based on sampled frequency data using both a "classical" ranging method and a novel technique based on a singular value decomposition method for multilateralization. We also compare the performance of our approaches to the Cramer- Rao bound for total antenna location error for distance and frequency-data based estimators, and provide experimental performance results for these methods tested in real multipath environments.
94

Portfolio Optimization Based on Robust Estimation Procedures

Gao, Weiguo 30 April 2004 (has links)
Implemented robust regressio technology in portfolio optimization. Constructed optimized portfolio based on robust regression estimations. Compared the portfolio performance with optimized portfolio which is based on ordinary least square estimation.
95

Performance evaluation of techniques for time delay estimation

Scarbrough, Kent N January 2010 (has links)
Typescript (photocopy). / Digitized by Kansas Correctional Industries
96

A comparison of two estimators of the variance in the two-factor multiplicative interaction model

Wasserstein, Ronald Lee January 2010 (has links)
Typescript (photocopy). / Digitized by Kansas Correctional Industries
97

The effect of random dosages on probit analysis

Morrill, Bruce January 2010 (has links)
Typescript (photocopy). / Digitized by Kansas Correctional Industries
98

Parameter estimation for ranking data with dynamic latent variables. / CUHK electronic theses & dissertations collection

January 2004 (has links)
Lam Yuk Fai. / "May 2004." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (p. 50-52). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.
99

Estimation parcimonieuse de biais multitrajets pour les systèmes GNSS / Sparse estimation of multipath biases for GNSS

Lesouple, Julien 15 March 2019 (has links)
L’évolution des technologies électroniques (miniaturisation, diminution des coûts) a permis aux GNSS (systèmes de navigation par satellites) d’être de plus en plus accessibles et doncutilisés au quotidien, par exemple par le biais d’un smartphone, ou de récepteurs disponibles dans le commerce à des prix raisonnables (récepteurs bas-coûts). Ces récepteurs fournissent à l’utilisateur plusieurs informations, comme par exemple sa position et sa vitesse, ainsi que des mesures des temps de propagation entre le récepteur et les satellites visibles entre autres. Ces récepteurs sont donc devenus très répandus pour les utilisateurs souhaitant évaluer des techniques de positionnement sans développer tout le hardware nécessaire. Les signaux issus des satellites GNSS sont perturbés par de nombreuses sources d’erreurs entre le moment où ils sont traités par le récepteurs pour estimer la mesure correspondante. Il est donc nécessaire decompenser chacune des ces erreurs afin de fournir à l’utilisateur la meilleure position possible. Une des sources d’erreurs recevant beaucoup d’intérêt, est le phénomène de réflexion des différents signaux sur les éventuels obstacles de la scène dans laquelle se trouve l’utilisateur, appelé multitrajets. L’objectif de cette thèse est de proposer des algorithmes permettant de limiter l’effet des multitrajets sur les mesures GNSS. La première idée développée dans cette thèse est de supposer que ces signaux multitrajets donnent naissance à des biais additifs parcimonieux. Cette hypothèse de parcimonie permet d’estimer ces biais à l’aide de méthodes efficaces comme le problème LASSO. Plusieurs variantes ont été développés autour de cette hypothèse visant à contraindre le nombre de satellites ne souffrant pas de multitrajet comme non nul. La deuxième idée explorée dans cette thèse est une technique d’estimation des erreurs de mesure GNSS à partir d’une solution de référence, qui suppose que les erreurs dues aux multitrajets peuvent se modéliser à l’aide de mélanges de Gaussiennes ou de modèles de Markov cachés. Deux méthodes de positionnement adaptées à ces modèles sont étudiées pour la navigation GNSS. / The evolution of electronic technologies (miniaturization, price decreasing) allowed Global Navigation Satellite Systems (GNSS) to be used in our everyday life, through a smartphone for instance, or through receivers available in the market at reasonable prices (low cost receivers). Those receivers provide the user with many information, such as his position or velocity, but also measurements such as propagation delays of the signals emitted by the satellites and processed by the receiver. These receivers are thus widespread for users who want to challenge positioning techniques without developing the whole product. GNSS signals are affected by many error sources between the moment they are emitted and the moment they are processed by the receiver to compute the measurements. It is then necessary to mitigate each of these error sources to provide the user the most accurate solution. One of the most intense research topic in navigation is the phenomenon of reflexions on the eventual obstacles in the scene the receiver is located in, called multipath. The aim of this thesis is to propose algorithms allowing the effects of multipath on GNSS measurements to be reduced. The first idea presented in this thesis is to assume these multipath lead to sparse additive biases. This hypothesis allows us to estimate this biases thanks to efficient methods such as the LASSO problem. The second idea explored in this thesis is an estimation method of GNSS measurement errors corresponding to the proposed navigation algorithm thanks to a reference trajectory, which assumes these errors can be modelled by Gaussian mixtures or Hidden Markov Models. Two filtering methods corresponding to these two models are studied for GNSS navigation.
100

Run-time energy-driven optimisation of embedded systems: a complete solution

Peddersen, Jorgen, Computer Science & Engineering, Faculty of Engineering, UNSW January 2008 (has links)
Consumption of power and conservation of energy have become two of the biggest design challenges in construction of embedded systems. Energy is a resource in limited supply, but demands are increasing. Hence, much research is being performed to reduce power and energy usage or optimise performance under energy constraints. There are very few solutions that try to cater for the applications where the data input is not easily testable before run-time. These applications require an optimisation procedure that knows the power consumption of the system and is able to dynamically optimise operation to maximise performance while meeting energy constraints. This thesis provides a complete solution to the problem of run-time energy-driven optimisation of application performance. The complete system, from a processor that is able to provide feedback of the power consumption in parallel to execution, to applications that exploit the power feedback to provide dynamic optimisation. A processor that estimates its own power consumption is designed by the addition of small dedicated counters that tally occurrences of power consuming events which are macro modelled. The methodology is demonstrated on a standard processor achieving an average power estimation error of less than 2% while increasing area of the processor by only 5%. This enables energy-driven optimisation via application adaptation. Modification techniques and low-overhead algorithms are provided to demonstrate how energy feedback can be effectively used to maximise performance of algorithms within given constraints. Applications?? quality is maximised under given energy constraints using less than 0.02% of the execution time. Finally, the dissertation discusses the systems used to demonstrate the methodologies and techniques created throughout the research project. These implementations of the energy-driven optimisation system verify the soundness of the methods and applicability of the approaches used. This is the first time a complete solution for energy-driven optimisation has been shown, from creation of the processor to analysis of software utilising the approach. The methodologies and techniques can be applied to a variety of applications in a range of fields such as multimedia and networking that have never been possible before.

Page generated in 0.1136 seconds