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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.
91

Quantification of the dental arch and its use in estimating ancestry

Sharpe, Megan 13 July 2017 (has links)
One role of forensic anthropologists is to create a biological profile to help identify remains. This includes estimating ancestry. Many morphological and metrical methods of ancestry estimation have been created and utilized. This study was aimed at created a simple, metrical analysis of dental arch size and shape to aid in ancestry estimation. Maximum length and width of over 700 dental casts (both maxillary and mandibular) were recorded and statistically analyzed by one-way ANOVA. Measurements were taken using points on teeth rather than on the fragile bone of the maxilla and mandible. It was found that ancestry does affect the size of the maxillary arch but not the mandibular one, but discriminant function analysis showed that ancestry estimation is not possible with the present set of data for either the maxilla or the mandible. Further research will need to be conducted with larger sample sizes of certain populations in order to improve ancestry estimation using this method.
92

Two and three dimensional cephalometric assessment of dental and skeletal changes following orthodontic treatment with Damon passive self-ligating system

Ehsani, Sayeh 06 1900 (has links)
Objectives: The aim of this study was to evaluate dental and/or skeletal changes following orthodontic treatment with Damon self-ligating (SL) brackets in non-extraction patients. Methods: Frontal and lateral cephalomteric radiographs of 20 patients before and after non-extraction treatment with Damon SL brackets were analyzed in a three-dimensional analysis computer program (3DCeph, UIC, IL., USA). Changes of intermolar and intercanine distances, incisor positions and maxillary basal bone width of Damon treated subjects were compared to corresponding untreated controls (Bolton templates). Comparisons between the two groups were made with Nonparametric (Mann-Whitney U) test. Results and Conclusions: Transverse changes in distances between crowns of upper and lower first molars and canines in Damon group were similar to untreated individuals (P >0.01). However, in Damon group distances between roots of upper molars and lower canines increased 4.59 and 3.49 mm respectively, compared with 0.8 and -0.01 mm in the Control group (P <0.001, P= 0.001). Lingual root torque of upper incisors and proclination of lower incisors were larger in the Damon group (P<0.05). Damon treatment did not result in buccal tipping of molar crowns or maxillary base width increase (P>0.05). Overall, teeth alignment with Damon system was accomplished with a combination of arch width changes and incisor proclination and/or lingual root torque.
93

Existing and future plans for the structural health monitoring of the Indian River Inlet Bridge

Weston, Daniel Frederick. January 2006 (has links)
Thesis (M.C.E.)--University of Delaware, 2006. / Principal faculty advisor: Michael J. Chajes, Dept. of Civil & Environmental Engineering. Includes bibliographical references.
94

Inference for the Quantiles of ARCH Processes/Inférence pour les Quantiles d'un Processus ARCH

Taniai, Hiroyuki 23 June 2009 (has links)
Ce travail se compose de trois parties consacrées à différents aspects des modèles ARCH (AutoRegressive Conditionally Heteroskedastic) quantiles. Dans ces modèles, l’hétéroscédasticité conditionnelle est à prendre dans un sens très large, et affecte de fa¸ con potentiellement différenciée tous les quantiles conditionnels (et donc la loi conditionnelle elle-même), et non seulement, comme dans les modèles ARCH classiques, l’échelle conditionnelle. La première partie étudie les problèmes de Value-at-Risk (VaR) dans les séries financières ainsi modélisées. Les approches traditionnelles présentent une caractéristique discutable, que nous relevons, et à laquelle nous apportons une correction fondée sur les lois résiduelles. Nous pensons que les fondements de cette nouvelle approche sont plus solides, et permettent de prendre en compte le fait que le comportement des processus empiriques résiduels (REP) des processus ARCH, contrairement à celui des REP des processus ARMA, continue à dépendre de certains des paramètres du modèle. La seconde partie approfondit l’étude générale des processus empiriques résiduels (REP) des processus ARCH dans l’optique de la régression quantile (QR) au sens de Koenker et Bassett (Econometrica 1978). La représentation de Bahadur des estimateurs QR, et dont découle la propriété de tension asymptotique des REP, est établie. Finalement, dans la troisième partie, nous mettons en évidence la nature semi-paramétrique des modèles ARCH quantiles, et l’invariance, sous l’action de certains groupes de transforma-tions, des sous-modèles obtenus en fixant la valeur des paramètres. Cette structure de groupe permet la construction de méthodes d’inférence invariantes qui, dans l’esprit des résultats de Hallin and Werker (Bernoulli 2003) préservent l’optimalité au sens semi-paramétrique. Ces méthodes sont fondées sur les rangs et les signes résiduels. Nous développons en particulier les R-estimateurs des modèles considérés et étudions leurs performances.
95

The Impact of Off-balance Sheet Activities on Taiwan's Banks Performance: An application of ARCH-M Model

HUNG, SHENG-YUAN 05 July 2012 (has links)
This paper investigates the influence of the shares of non-interest income and the diversification, which result from off-balance sheet activities, on the performance of banking in Taiwan. I also use ARCH-M model in this study. The sample period is from January 2000 to December 2011. I find that all sample banks and private banks do not benefit from off-balance sheet activities, but government banks benefit from off-balance sheet activities. In this paper, I also use CUSUM test to find the structural breakpoint and discuss the situation in accordance with it. The result shows that the structural breakpoint is at July 2002, which closes to the founded time of lots of financial holding companies. After the structural breakpoint, the positive impact of shares of non-interest income and diversification on the performance disappear.
96

ARCH-/GARCH-Modelle und deterministisches Chaos : eine empirische Analyse von Renditezeitreihen des Swiss Market Index (SMI) /

Gadient, Yves. January 2006 (has links) (PDF)
Univ., Diss.--St. Gallen, 2006.
97

Two and three dimensional cephalometric assessment of dental and skeletal changes following orthodontic treatment with Damon passive self-ligating system

Ehsani, Sayeh Unknown Date
No description available.
98

Fibre reinforced polymer (FRP) strengthened masonry arch structures

Tao, Yi January 2013 (has links)
Masonry arch bridges have played a significant role in the road and rail transportation network in the world for centuries. They are exposed to damage due to overloading and deterioration caused by environmental actions. In order to reestablish their performance and to prevent their collapse in various hazardous conditions, many of them require strengthening. Fibre reinforced polymer (FRP) systems are increasingly used for repair and strengthening of structures, with particularly widespread application to concrete structures. However, the application of FRP composites to masonry structures is less well established due to the complexity of masonry caused by the material discontinuity. FRP strengthening masonry arch bridges has been even less studied due to the additional complexity arising from the co-existence of the normal interfacial stress and the shear interfacial stress at the curved FRP-to-masonry bondline. This thesis presents an extensive study investigating the behaviour of FRP strengthened masonry bridges. The study started with a laboratory test of a two span masonry arch bridge with sand backfill. A single ring arch bridge was first tested to near failure, and then repaired by bonding FRP into their intrados and tested to failure. It was found that the FRP strengthening not only improved the loading capacity and stiffness of bridge, but also significantly restrained the opening of cracks in the masonry. Shear and peeling debonding of FRP was observed. There have been two common strategies in finite element (FE) modelling of FRP strengthened structures in meso-scale: direct model and interface model. The former is necessary when investigating the detailed bond behaviour but challenges remain due to the difficulties in concrete modelling. A new concrete damage model based on the plastic degradation theory has been developed in this study to study the bond behaviour of FRP strengthened concrete structure. This robust model can successfully capture this bond behaviour and simulate the entire debonding process. A numerical study of masonry arch bridges including the backfill was conducted to study the behaviour of masonry arch bridge. A total of four modelling strategies were examined and compared. Although they all can successfully predict the behaviour of arch, a detailed solid model newly developed in this study is more suitable for modelling both plain masonry and FRP strengthened structures. Finally, a numerical study of bond behaviour and structural response of FRP strengthened masonry arch structures with sand backfill was conducted. In addition to the masonry and backfill, the mixed mode interfacial behaviour was modelled by the aforementioned interface model strategy and investigated in detail to achieve a deeper understanding of the behaviour of FRP strengthened masonry arch structures. The results are in close agreement with test results, and highlight the influence of the key parameters in the structural response to failure and revealed the mechanisms on how the load is transmitted through this complex multi-component structural system.
99

Bayesian Analysis of Switching ARCH Models

Kaufmann, Sylvia, Frühwirth-Schnatter, Sylvia January 2000 (has links) (PDF)
We consider a time series model with autoregressive conditional heteroskedasticity that is subject to changes in regime. The regimes evolve according to a multistate latent Markov switching process with unknown transition probabilities, and it is the constant in the variance process of the innovations that is subject to regime shifts. The joint estimation of the latent process and all model parameters is performed within a Bayesian framework using the method of Markov Chain Monte Carlo simulation. We perform model selection with respect to the number of states and the number of autoregressive parameters in the variance process using Bayes factors and model likelihoods. To this aim, the model likelihood is estimated by combining the candidate's formula with importance sampling. The usefulness of the sampler is demonstrated by applying it to the dataset previously used by Hamilton and Susmel who investigated models with switching autoregressive conditional heteroskedasticity using maximum likelihood methods. The paper concludes with some issues related to maximum likelihood methods, to classical model select ion, and to potential straightforward extensions of the model presented here. (author's abstract) / Series: Forschungsberichte / Institut für Statistik
100

Nonlinear analysis of Pacoima Dam with spatially nonuniform ground motion /

Alves, Steven W. January 2005 (has links)
Thesis (Ph. D.)--California Institute of Technology, 2004. / "October 2004." Includes bibliographical references. EERL report series available at their website: http://caltecheerl.library.caltech.edu.

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