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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.
191

Classroom notes: A radiative reaction model

Fay, TH, Mead, L 16 November 2001 (has links)
Abstract A nonrelativistic model for the classical electrodynamic equations of motion for a radiating particle is investigated. This model is suitable for discussion in a beginning differential equations course and beginning physics course on particle dynamics. It is of interest as it is linear of third order and the third derivative acts as a damping term. Boundedness of the solution becomes of critical importance and conditions are determined for bounded solutions in the unforced and simple sinusoidal forcing cases. The sensitivity of numerical solutions is discussed and further investigations suitable for undergraduate research projects or small student group investigations are suggested.
192

THE APPLICATION OF KANO’S MODEL IN THE AIRLINE INDUSTRY / THE APPLICATION OF KANO’S MODEL IN THE AIRLINE INDUSTRY

Qureshi, Nouman Ahmed, Khan, Babar Ali, Saif, Jomah January 2017 (has links)
This paper shows how airline passenger service necessities can be scrutinized by utilizing Kano's model of quality component and examines the potential advantages that can be accomplished by applying this way to deal with marketing strategy planning. As per Kano's model, quality components can be grouped into three classifications, to be specific must-be, One-dimensional and Attractive needs, contingent upon their capacity to make consumer satisfaction or dissatisfaction. Aftereffects of this review propose that airline passenger service components could be grouped comparable with Kano's model to recognize the most critical passenger service components. Effects of the service components highlights on passenger satisfaction or dissatisfaction have been likewise figured as estimation records for development.
193

Portfolio Optimization, CAPM & Factor Modeling Project

Zhao, Zhen 25 April 2012 (has links)
In this project, we implement portfolio theory to construct our portfolio, applying the theory to real practice. There are 3 parts in this project, including portfolio optimization, Capital Asset Pricing Model (CAPM) analysis and Factor Model analysis. We implement portfolio theory in the portfolio optimization part. In the second part, we use the CAPM to analyze and improve our portfolio. In the third part we extend our CAPM to factor models to get a deeper analysis of our portfolio.
194

A simplified model for spontaneous combustion in coal stockpiles

Brooks, Kevin Seth 09 November 2009 (has links)
Ph.D., Faculty of Engineering, University of the Witwatersrand, 1985.
195

Etude de l’opérade Swiss-cheese et applications à la théorie des longs noeuds / The Swiss-Cheese operad and applications to the space of long knots

Ducoulombier, Julien 10 December 2015 (has links)
L’objectif de ce travail est l’étude de l’opérade Swiss-Cheese SCd qui est une version relative del’opérade des petits cubes Cd. On montre que les théorèmes classiques dans le cadre des opérades non colorées admettent des analogues dans le cas relatif. Il est ainsi possible d’extraire d’une opérade pointée O (i.e. un opérade colorée sous π₀(SC₁) ) un couple d’espaces semi-cosimpliciaux (Oc ; O₀) dont les semitotalisations sont faiblement équivalentes à une SC₂-algèbre explicite. En particulier, on prouve que le couple (ℒ1 ; n ; ℒm ; n), composé de l’espace des longs nœuds et de l’espace des longs entrelacs à m brins, est faiblement équivalent à une SC₂-algèbre explicite. Dans un second temps, on s’intéresse aux couples d’homologies singulières et d’homologies de Hochschild associés à une paire d’espaces semi-cosimpliciaux provenant d’une opérade pointée. Dans ce contexte, les couples (H∗ (sTot(Oc)) ; H∗ (sTot(O₀))) et (HH∗(Oc) ; HH∗(O₀)) possèdent tous deux une structure de H∗(SC₂)-algèbre explicite. On montre alors que le morphisme de Bousfield entre ces deux couples préserve les structures de H∗(SC₂)-algèbres. Cela nous permet de mieux appréhender le couple de suites spectrales de Bousfield calculant (H∗(sTot(Oc)) ; H∗(sTot(O₀))). En particulier, on énonce un critère permettant de faire le lien entre le couple d’homologies singulières issu d’une opérade symétrique multiplicative topologique et la page E² des suites spectrales de Bousfield. La dernière étape de notre étude consiste à généraliser les précédents résultats. Pour cela, on se base sur une conjecture de Dwyer et Hess qui vise à identifier une Cd₊₁-algèbre à partir d’un morphisme d’opérades Cd → O. En admettant ce résultat, on introduit une opérade colorée CCd telle que l’on peut extraire une SCd₊₁-algèbre à partir d’un morphisme d’opérades colorées CCd→ O. On montre ainsi que le couple d’espaces (ℒᵈ₁ ; n ; T∞Imm(ᴷ))(Rᵈ ; Rⁿ), composé de l’espace des longs nœuds en dimension d et de l’approximation polynomiale des (k)-immersions, est faiblement équivalent à une SCd₊₁-algèbre explicite. / The aim of this work is to study the Swiss-Cheese operad, denoted by SCd, which is a relative version of the little cubes operad Cd.We show that the classical theorems in the context of uncolored operads can begeneralized to the relative case. From a pointed operad O (i.e. a two colored operad under π0(SC₁) ), webuild two semi-cosimplicial spaces (Oc ; Oo) such that the pair of semi-totalizations is weakly equivalentto an explicit SC₂-algebra. In particular, we prove that the pair (ℒ₁ ; n ; ℒm; n), composed of the space oflong knots and the space of long links, is weakly equivalent to an explicit SC₂-algebra.We study two homology theories, namely singular and Hochschild homology, of a pair of semicosimplicialspaces arising from a pointed operad. In this context, (H∗(sTot(Oc)) ; H∗(sTot(Oo))) and (HH∗(Oc) ; HH∗(Oo)) are equipped with an explicit H∗(SC₂)-algebra structure. We show that the mapintroduced by Bousfield between these two pairs is a morphism of H∗(SC₂)-algebras. This result helps us to understand the pair of spectral sequences computing (H∗(sTot(Oc)) ; H∗(sTot(Oo))). In particular wegive some conditions on a multiplicative symmetric operad so that the E² pages of the Bousfield spectral sequences are weakly equivalent to H∗(sTot(Oc)) and H∗(sTot(Oo)) as H∗(SC₂)-algebras. Finally we generalize our previous results, relying on a conjecture by Dwyer and Hess. We define acolored operad CCd and obtain an SCd₊₁-algebra from an operad morphism CCd → O. As a consequence, we prove that the couple of topological spaces (ℒᵈ₁ ; n ; T∞Imm(ᴷ))(Rᵈ ; Rⁿ)), where Ld₁;n is the space of long knots from Rd to Rⁿ and where T∞Imm(k)(Rᵈ ; Rⁿ) is the polynomial approximation of the (k)-immersions,is weakly equivalent to an explicit SCd+₁-algebra.
196

Essays on macroeconometrics

Zhu, Chuanqi January 2013 (has links)
Thesis advisor: Zhijie Xiao / This dissertation contains three chapters in theoretical Macroeconometrics and applied Macroeconometrics. This first chapter addresses the issues related to the estimation, testing and computation of ordered structural breaks in multivariate linear regressions. Unlike common breaks, ordered structural breaks are those breaks that are related across equations but not necessarily occurring at the same dates. A likelihood ratio test assuming normal errors is proposed in this chapter in order to detect the ordered structural breaks in multivariate linear regressions. The estimation of ordered structural breaks uses quasi-maximum likelihood and adopts the efficient algorithm of Bai and Perron (2003). I also provide results about the consistency and rate of convergence when searching for ordered structural breaks. Finally, these methods are applied to one empirical example: the mean growth rate of output in three European countries and United States. This second chapter focuses on the parameter stability of dynamic stochastic general equilibrium (DSGE) models. To this end, I solve and estimate a representative New Keynesian model using both linear and nonlinear methods. I first examine how nonlinearities affect the parameter stability of the New Keynesian model. The results show that parameter instabilities still exist even using nonlinear solutions, and also highlight differences between two nonlinear solution methods: perturbation method and projection method. In addition, I propose a sequential procedure for searching for multiple structural breaks in nonlinear models, and apply it to the New Keynesian model. Two common structural breaks among these estimated parameters are identified for all the five solutions considered in this chapter. One structural break is in the early 1970s, while another one locates around the middle 1990s. In the third chapter, we investigate changes in long run productivity growth in the United States. In particular, we approach productivity growth from a sectoral perspective, and decompose the whole economy into two broad sectors: investment goods-producing sector and consumption goods-producing sector. Although the evidence of changes in the aggregate productivity growth is far from obvious at conventional test size, we find evidence of structural breaks in the sectoral productivity growth using both growth accounting and DSGE model based measures. There are two structural breaks in investment goods-producing sector using growth accounting measures, which indicates that the era of investment and productivity boom in the middle 1990s may have ended before the Great Recession. In addition, our results show there is one structural break in consumption goods-producing sector around the 1970s and attribute the aggregate productivity slowdown at that time to consumption goods-producing sector. These results are broadly consistent with Ireland and Schuh (2008). Our results offer up with a modestly pessimistic outlook on future productivity growth and, therefore, potential output. / Thesis (PhD) — Boston College, 2013. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Economics.
197

Experiment based development of a non-isothermal pore network model with secondary capillary invasion

Vorhauer, Nicole 18 September 2018 (has links) (PDF)
In this thesis, PN simulations of drying are compared with experimentally obtained data fromdrying of a representative 2D microfluidic network in SiO2 under varying thermal conditions withthe aim to identify governing physical pore scale effects. Gravity and viscous effects aredisregarded in this thesis. Instead drying with slight local temperature variation and drying withimposed thermal gradients are studied. Based on this investigation, a powerful non-isothermalPNM is developed. This model incorporates i) the phenomena associated with the temperaturedependency of pore scale invasion, namely thermally affected capillary invasion and vapor flow aswell as ii) the secondary effects induced by wetting liquid films of different morphology. This studyclearly evidences that the macroscopic drying behavior is fundamentally dictated by thetemperature gradient imposed on the PN and moreover by the secondary capillary invasion aswell. In agreement with literature, invasion patterns as in invasion percolation with progressiveevaporation of single clusters are observed in drying with negligible local temperature variation;gradients with temperature decreasing from the surface (negative temperature gradient) canstabilize the drying front, evolving between the invading gas phase and the receding liquid phase,whereas temperature increasing from the surface (positive temperature gradient) leads todestabilization of the liquid phase with early breakthrough of a gas branch and initiation of asecond invasion front migrating in opposite direction to the evaporation front receding from theopen surface of the PN. Special attention is paid on the distinct drying regimes found in thesituation of a positive gradient because they are associated with different pore scale invasionprocesses. More precisely, temperature dependency of surface tension dictates the order ofinvasion as long as the liquid phase is connected in a main liquid cluster (usually found during thefirst period of drying). In contrast to this, detailed study of the vapor transfer mechanismsemphasizes that vapor diffusion through the partially saturated region can control the pore leveldistributions of liquid and gas phase during the period of drying when the liquid phase isdisconnected into small clusters. This is also related to the cluster growth induced by partialcondensation of vapor. It is shown and discussed in detail in this thesis that this effect not onlydepends on direction and height of the temperature gradient for a given pore size distribution butthat moreover the overall evaporation rate influences the cluster growth mechanism. This indicatesthat liquid migration during drying of porous media might be controlled by the interplay of thermalgradients and drying rate. In summary, the study of thermally affected drying of the 2-dimensionalPN reveals complex pore scale mechanisms, usually also expected in drying of real porous media.This leads to the development of a strong mathematical pore scale model based on experimentalfindings. It is demonstrated how this model might be applied to understand and develop moderndrying processes based on the simulation of thermally affected pore scale mass transfer
198

Teste e verificação formal do comportamento excepcional de programas Java / Testing and formal verification of the exceptional behavior of Java programs

Martins, Alexandre Locci 09 June 2014 (has links)
Estruturas de tratamento de exceção são extremamente comuns em softwares desenvolvidos em linguagens modernas, como Java, e afetam de forma contundente o comportamento de um software quando exercitadas. Apesar destas duas características, as principais técnicas de verificação, teste de software e verificação formal, e as ferramentas a elas vinculadas, tendem a negligenciar o comportamento excepcional. Alguns dos fatores que levam a esta negligência são a não especificação do comportamento excepcional em termos de projeto e a consequente implementação das estruturas de tratamento com base no julgamento individual de cada programador. Isto resulta na não consideração de partes expressivas do código em termos de verificação e, consequentemente, a possibilidade de não serem detectados erros relativos tanto às próprias estruturas de tratamento quanto às estruturas de código vinculadas a estas. A fim de abordar este problema, propomos uma técnica, baseada em model checking, que automatiza o processo de exercício de caminhos excepcionais. Isto permite que seja observado o comportamento de um software quando da ocorrência de uma exceção. Pretendemos, com esta técnica, dar suporte para que seja aplicado aos caminhos que representam o comportamento excepcional de um software as mesmas técnicas de detecção de erros que são aplicadas aos caminhos que representam o comportamento normal e, com isso, agregar um aumento na qualidade do desenvolvimento de software. / Software developed in modern languages, such as Java, commonly present structures of exception handling. These structures, when exercised, may affect the software behavior. Despite these two characteristics, the main verification techniques, software testing and formal verification and the tools related to them, tend to neglect the exceptional behavior. The nonexistent specification of software exceptional behaviors at the design level, and, the subsequent implementation of exception handling based on the judgment of each programmer, are some factors that lead to this neglect. These factors result in the non-consideration of the expressive parts of the code in verification terms and, consequently, the impossibility of errors detection concerning either the exception treatment structures or the code structures linked to them. Taking this fact into consideration, we propose a technique based on the model checking process, which automates the process of exercising exceptional paths to address this problem. This allows the observation of the software behavior when an exception occurs. With this technique, we intend to support the application of the same error detection techniques for program normal behavior paths to the paths that represent the software exceptional behavior. Therefore, using the proposed technique, we aim to increase the software development quality.
199

Evaluation of Utility Pole Placement and the Impact on Crash Rates

Gagne, Amanda R 30 April 2008 (has links)
Each year in the United States over 1,000 fatalities occur as a result of collisions with utility poles. In addition, approximately 40% of utility pole crashes result in a non-fatal injury. Moreover, with over 88 million utility poles lining United States highways, it is not feasible to immediately remedy all poles that are potentially unsafe. Utility poles which pose a danger to motorists can, however, be identified and addressed over time in a structured, methodical manner. The goal of this project was to develop a method to identify and prioritize high risk utility poles that are good candidates for remediation as well as develop a standard operating procedure for the relocation of existing utility poles and placement of future utility poles along Massachusetts highways. This research found that the lateral offset, annual average daily traffic and density of the utility poles are major risk factors. Road geometry, however, also impacts the risk. Basic corrective measures such as delineation, placing poles as far from the edge of road as achievable, as well as placing poles a safe distance behind horizontal barriers are all suggested solutions.
200

The Comprehensive Digital Forensic Investigation Process Model (CDFIPM) for digital forensic practice

Montasari, Reza January 2016 (has links)
No description available.

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