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On the estimation and application of flexible unordered spatial discrete choice modelsSidharthan, Raghuprasad 22 February 2013 (has links)
Unordered choice models are commonly used in the field of transportation and several other fields to analyze discrete choice behavior. In the past decade, there have been substantial advances in specifying and estimating such models to allow unobserved taste variations and flexible error covariance structures. However, the current estimation methods are still computationally intensive and often break down when spatial dependence structures are introduced (due to the resulting high dimensionality of integration in the likelihood function). But a recently proposed method, the Maximum Approximate Composite Marginal Likelihood (MACML) method, offers an effective approach to estimate such models. The MACML approach combines a composite marginal likelihood (CML) estimation approach with an approximation method to evaluate the multivariate standard normal cumulative distribution (MVNCD) function. The composite likelihood approach replaces the likelihood function with a surrogate likelihood function of substantially lower dimensionality, which is then subsequently evaluated using an analytic approximation method rather than simulation techniques. This combination of the CML with the specific analytic approximation for the MVNCD function is effective because it involves only univariate and bivariate cumulative normal distribution function evaluations, regardless of the dimensionality of the problem.
For my dissertation, I have four objectives. The first is to evaluate the performance of the MACML method to estimate unordered response models by undertaking a Monte Carlo simulation exercise. The second is to formulate and estimate a spatial and temporal unordered discrete choice model and apply this model to a land use change context and to the mode choice decision of school children. The third objective is to formulate a random coefficient model with non-normal mixing distributions on model parameters which can be estimated using the MACML approach. Finally, the fourth objective us to propose an improvement to the MACML method by incorporating a second order MVNCD function that is more accurate and evaluate its performance in estimating parameters for a variety of model structures. / text
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The Transformed Rejection Method for Generation Random Variables, an Alternative to the Ratio of Uniforms MethodHörmann, Wolfgang, Derflinger, Gerhard January 1994 (has links) (PDF)
Theoretical considerations and empirical results show that the one-dimensional quality of non-uniform random numbers is bad and the discrepancy is high when they are generated by the ratio of uniforms method combined with linear congruential generators. This observation motivates the suggestion to replace the ratio of uniforms method by transformed rejection (also called exact approximation or almost exact inversion), as the above problem does not occur for this method. Using the function $G(x) =\left( \frac(a)(1-x)+b\right)x $ with appropriate $a$ and $b$ as approximation of the inverse distribution function the transformed rejection method can be used for the same distributions as the ratio of uniforms method. The resulting algorithms for the normal, the exponential and the t-distribution are short and easy to implement. Looking at the number of uniform deviates required, at the code length and at the speed the suggested algorithms are superior to the ratio of uniforms method and compare well with other algorithms suggested in literature. (author's abstract) / Series: Preprint Series / Department of Applied Statistics and Data Processing
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A Compactification of the Space of Algebraic Maps from P^1 to a GrassmannianShao, Yijun January 2010 (has links)
Let Md be the moduli space of algebraic maps (morphisms) of degree d from P^1 to a fixed Grassmannian. The main purpose of this thesis is to provide an explicit construction of a compactification of Md satisfying the following property: the compactification is a smooth projective variety and the boundary is a simple normal crossing divisor. The main tool of the construction is blowing-up. We start with a smooth compactification given by Quot scheme, which we denote by Qd. The boundary Qd\Md is singular and of high codimension. Next, we give a filtration of the boundary Qd\Md by closed subschemes: Zd,0 subset Zd,1 subset ... Zd,d-1=Qd\Md. Then we blow up the Quot scheme Qd along these subschemes succesively, and prove that the final outcome is a compactification satisfying the desired properties. The proof is based on the key observation that each Zd,r has a smooth projective variety which maps birationally onto it. This smooth projective variety, denoted by Qd,r, is a relative Quot scheme over the Quot-scheme compactification Qr for Mr. The map from Qd,r to Zd,r is an isomorphism when restricted to the preimage of Zd,r\ Zd,r-1. With the help of the Qd,r's, one can show that the final outcome of the successive blowing-up is a smooth compactification whose boundary is a simple normal crossing divisor.
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Effet d'un entraînement en résistance sur le profil métabolique des femmes post-ménopausées obèses à risque ou métaboliquement saines (MHO)Filion, Marie-Eve 08 1900 (has links) (PDF)
Introduction : L'obésité est devenue une problématique prédominante dans notre société actuelle. Effectivement, en 2005, l'organisation mondiale de la santé estimait à plus de 400 millions le nombre d'individus obèses et elle estime qu'en 2015, 700 millions d'individus seront obèses. De plus, durant le processus du vieillissement et plus spécifiquement lors de la ménopause, on assiste à une modification de la composition corporelle (gain de masse grasse et perte de masse musculaire). Récemment, un sous-type d'obèse sain (MHO: Metabolically Healthy but Obese) a été mis en évidence dans la littérature. Contrairement aux obèses à risque, les MHO présentent des composantes métaboliques saines (e.g. profil insulinémique, lipidique et inflammatoire) malgré la présence excessive de masse grasse. Les interventions visant la perte de masse grasse semblent avoir des effets différents chez ces deux sous-types d'obèses. Effectivement, une diminution de la sensibilité à l'insuline a été observée chez les obèses MHO suite à une restriction calorique de 6 mois contrairement à l'amélioration observée chez les obèses à risque. Ainsi, il est primordial d'identifier une intervention qui permettra une amélioration de la composition corporelle chez les obèses MHO tout en conservant leur profil métabolique favorable. Il a été montré que l'entraînement en résistance permettait d'améliorer la composition corporelle, le contrôle de la glycémie, la masse grasse abdominale et la tension artérielle. Objectif : Ainsi, l'objectif de cette étude était de : 1) Comparer l'effet d'un entraînement en résistance de 16 semaines sur la masse grasse chez des femmes post-ménopausées obèses à risque et MHO. 2) Vérifier et comparer si ce type d'intervention à un effet sur les composantes du profil métabolique (tour de taille, glycémie, tension artérielle, triglycérides, HDL) chez des femmes post-ménopausées obèses à risque et MHO. Méthodes : Trente-six femmes post-ménopausées, obèses, sédentaires ont été recrutées. Les MHO ont été identifiés selon les critères du syndrome métabolique définis par la Fédération International de Diabète (circonférence de taille > 88 cm et 2 des 4 facteurs suivants : triglycérides > 1,7 mmol/L; HDL < 1,3 mmol/L; tension artérielle systolique > 130 mmHg ou diastolique > 85 mmHg ; glycémie à jeun > 5,6 mmol/L). À partir de cette méthode, les participantes ayant le syndrome métabolique ont été classées dans la catégorie des obèses à risque, les autres ont été classées dans la catégorie des obèses MHO. Le profil métabolique (tension artérielle, glycémie à jeun, insuline à jeun, triglycérides et cholestérol total), la composition corporelle (tour de taille, masse grasse et masse maigre) et la force musculaire (test de 1 répétition maximale (RM) au développé des jambes et développé des bras) ont été mesurés avant et après intervention. Les participantes ont suivi un programme d'entraînement en résistance supervisé d'une durée de 16 semaines (1h/3x/semaine). Résultats : Suite à l'intervention, une diminution significative de la masse grasse totale (%) ainsi qu'une augmentation significative de la masse maigre totale (kg), du 1RM au développé des jambes et du 1RM au développé des bras ont été observées chez les deux groupes. Finalement, aucune différence significative n'a été observée pour les composantes métaboliques. Conclusion : Un entraînement en résistance d'une durée de quatre mois entraine une diminution de la masse grasse totale (%), une augmentation de la masse musculaire totale (kg) et une augmentation de la force sans avoir d'effets sur les composantes métaboliques (tension artérielle, glucose à jeun, insuline à jeun, ApoB, triglycérides, cholestérol total, HDL-cholestérol, LDL-cholestérol et CRP) autant chez les femmes post-ménopausées obèses à risque que chez celles MHO. Ainsi, l'entraînement en résistance est donc à recommander chez la femme post-ménopausée obèse à risque et MHO.
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Ikimokyklinio amžiaus aklųjų ir silpnaregių kalbos raidos ypatumai (lyginamoji analizė) / The peculiarities in lingual development of the blind and poor-sighted children at preschool age (the comparative analysis)Babkauskaitė, Edita 29 June 2009 (has links)
Baigiamajame magistriniame darbe nagrinėjama tema – ikimokyklinio amžiaus aklųjų ir silpnaregių kalbos raidos ypatumai ( lyginamoji analizė). Sunku pervertinti kalbos plėtotės procese pagrindinių – regos ir klausos – analizatorių vaidmenį. Šių analizatorių sutrikimas labai stipriai įtakoja kalbinės veiklos vystymąsi ir suteikia jam tam tikrų ypatumų.
Labai dažnai aklo iš prigimties asmens turimų sąvokų turinys kardinaliai skiriasi nuo reginčiųjų. Stokodami vieno iš pasaulio pažinimo būdų aklieji dažnai neadekvačiai vartoja turimas sąvokas. Aklas vaikas gali girdėti kalbą ir mėgdžiodamas jos mokosi. Kartais jis labiau už regintįjį yra motyvuotas ją vartoti, nes tai pagrindinis kanalas komunikuojant su kitais. Ar iš tikrųjų aklųjų kalbinė raiška skiriasi nuo normaliai matančių vaikų? Į šį klausimą bandoma atsakyti šiame magistro darbe.
Tyrimo problema: ikimokyklinio amžiaus nereginčių ir silpnaregių vaikų kalbinė raida stokoja normalaus psichofiziologinio pagrindo. Šiuos trūkumus būtina kompensuoti, pasitelkus išlikusius sveikus analizatorius prieš tai tiksliai išsiaiškinus šios grupės vaikų kalbinės raidos pasiekimo skirtumus lyginant su sveikaisiais.
Tyrimo objektas: ikimokyklinio amžiaus aklųjų ir silpnaregių bei gerai matančių vaikų kalbos raida ( lyginamoji analizė).
Tyrimo tikslas: ištirti ikimokyklinio amžiaus aklųjų ir silpnaregių kalbos raidos ypatybes.
Tyrimo uždaviniai:
1. Išanalizuoti psichologinę ir pedagoginę literatūrą apie aklųjų ir silpnaregių kalbinę raidą... [toliau žr. visą tekstą] / SUMMARY
The final master‘s study deals with the peculiarities in lingual development of the blind and poor-sighted children at preschool age (the comparative analysis). It is difficult to overestimate the role of the main analyzers, i.e. sight and hearing in the process of lingual development. The disorder of these analyzers affects very strongly the development of lingual activities and renders certain peculiarities to it.
Very often the contents of concepts of a person, who is blind by nature, cardinally differ from that of people with normal sight. Lacking one technique for world cognition, the blind persons often inadequately use the concepts available. The sightless child can hear the language and learn it by imitation. Sometimes he is more motivated to use it than a seeing person, since it is the main channel for communication with others. Does really the lingual expression of the blind children differ from that of normally sighted? In this master’s study the attempts were done to answer this question.
Problem of study. The lingual development of blind and poor-sighted preschoolers lacks normal psycho-physiological substantiation. These shortcomings should be compensated with help of the remaining healthy analyzers. But before it the differences in achieved lingual development between the children of this group and healthy ones should be find out.
Object of study: lingual development in blind and poor-sighted children at preschool age (the comparative analysis).
... [to full text]
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A systems approach to community engaged integrated solid waste management in Todos Santos Cuchumatan, GuatemalaMarshall, Rachael 11 January 2013 (has links)
Solid waste management (SWM) is a growing problem in developing countries around the world. In Guatemala, indigenous communities, which are predominantly rural and remote, are particularly hard hit by a lack of basic SWM services. Todos Santos, situated in the Cuchumatanes mountain range of northwestern Guatemala, is one such community. As projects developed, planned, and implemented from 'the top down' continue to be ineffective, the literature provides little insight about remote communities' perspectives on exactly what issues SWM creates, influences, and exacerbates, and how they might respond to these concerns themselves. Using a participatory systems approach, this study investigated the systemic structures and behaviours that maintain and exacerbate SWM challenges in Todos Santos, and where key places (leverage points) to intervene in the system may exist. The study presents a wide selection of locally appropriate SWM solutions to target these leverage points in the form of four future scenarios These scenarios act as a step-wise implementation plan for gradual implementation in the community, each building upon the previous, ultimately reaching a community-defined vision for SWM.
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The McGill Normal School, a brief history, 1857-1907 /Paradissis, E. A. (Elia A.) January 1982 (has links)
No description available.
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Neišplėtotos bei nesutrikusios kalbos vaikų gebėjimas atpažinti kalbos taisyklingumą / The ability to recognize the language patterns of the children with undeveloped and normal speechŠiaulytė, Jorūnė 04 July 2012 (has links)
Bakalauro darbe analizuojami bendrieji vaikų kalbos raidos dėsningumai ir neišplėtotos kalbos samprata bei jos ugdymo gairės. Tyrimo tikslas – atskleisti, kaip vyresniojo ikimokyklinio amžiaus neišplėtotos bei nesutrikusios kalbos vaikai geba skirti kalbos leksinį, gramatinį bei fonologinį taisyklingumą. / Bachelor thesis analyzes the common patterns of children's language development and concept of underdeveloped speech and its development guidelines.The aim was to reveal how senior preschool aged children with underdeveloped and developed speech are able to distinguish language lexical, grammatical and phonological regularities of language.
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Non-inferiority hypothesis testing in two-arm trials with log-normal dataWickramasinghe, Lahiru 07 April 2015 (has links)
In health related studies, non-inferiority tests are used to demonstrate that a new treatment is not worse than a currently existing treatment by more than a pre-specified margin. In this thesis, we discuss three approaches; a Z-score approach, a generalized p-value approach and a Bayesian approach, to test the non-inferiority hypotheses in two-arm trials for ratio of log-normal means. The log-normal distribution is widely used to describe the positive random variables with positive skewness which is appealing for data arising from studies with small sample sizes. We demonstrate the approaches using data arising from an experimental aging study on cognitive penetrability of posture control. We also examine the suitability of three methods under various sample sizes via simulations. The results from the simulation studies indicate that the generalized p-value and the Bayesian approaches reach an agreement approximately and the degree of the agreement increases when the sample sizes increase. However, the Z-score approach can produce unsatisfactory results even under large sample sizes.
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Normal Faulting, Volcanism And Fluid Flow, Hikurangi Subduction Plate Boundary, New ZealandSeebeck, Hannu Christian January 2013 (has links)
This thesis investigates normal faulting and its influence on fluid flow over a wide range of spatial and temporal scales using tunnel engineering geological logs, outcrop, surface fault traces, earthquakes, gravity, and volcanic ages. These data have been used to investigate the impact of faults on fluid flow (chapter 2), the geometry and kinematics of the Taupo Rift (chapter 3), the hydration and dehydration of the subducting Pacific plate and its influence on the Taupo Volcanic Zone (chapter 4), the migration of arc volcanism across the North Island over the 16 Myr and the associated changes in slab geometry (chapter 5) and the Pacific-Australia relative plate motion vectors since 38 Ma and their implications for arc volcanism and deformation along the Hikurangi margin (chapter 6). The results for each of these five chapters are presented in
the five paragraphs below.
Tunnels excavated along the margins of the southern Taupo Rift at depths < 500 m provide data on the spatial relationships between faulting and ground water flow. The geometry and hydraulic properties of fault-zones for Mesozoic basement and Miocene strata vary by several orders of magnitude approximating power-law distributions with the dimensions of these zones dependent on many factors including displacement, hostrock type and fault geometries. Despite fault-zones accounting for a small proportion of the total sample length (≤ 15%), localised flow of ground water into the tunnels occurs almost exclusively (≥ 91%) within, and immediately adjacent to, these zones. The spatial distribution and rate of flow from fault-zones are highly variable with typically ≤ 50% of fault-zones in any given orientation flowing. The entire basement dataset shows that 81% of the flow-rate occurs from fault-zones ≥ 10 m wide, with a third of the total flow-rate originating from a single fault-zone (i.e. the golden fracture). The higher flow rates for the largest faults are interpreted to arise because these structures are the most connected to other faults and to the ground surface.
The structural geometry and kinematics of rifting is constrained by earthquake focal mechanisms and by geological slip and fault mapping. Comparison of present day geometry and kinematics of normal faulting in the Taupo Rift (α=76-84°) with intra-arc rifting in the Taranaki Basin and southern Havre Trough show, that for at least the last 4 Myr, the slab and the associated changes in its geometry have exerted a first-order control on the location, geometry, and extension direction of intra-arc rifting in the North Island. Second-order features of rifting in the central North Island include a clockwise ~20° northwards change in the strike of normal faults and trend of the extension direction. In the southern rift normal faults are parallel to, and potentially reactivate, Mesozoic basement fabric (e.g., faults and bedding). By contrast, in the northern rift faults diverge from basement fabric by up to 55° where focal mechanisms
indicate that extension is achieved by oblique to right-lateral strike-slip along basement fabric and dip-slip on rift faults.
Hydration and dehydration of the subducting Pacific plate is elucidated by earthquake densities and focal mechanisms within the slab. The hydration of the subducting plate varies spatially and is an important determinant for the location of arc volcanism in the overriding plate. The location and high volcanic productivity of the TVZ can be linked to the subduction water cycle, where hydration and subsequent dehydration of the subducting oceanic lithosphere is primarily accomplished by normal-faulting earthquakes. The anomalously high heat flow and volcanic productivity of the TVZ is spatially associated with high rates of seismicity in the underlying slab mantle at depths of 130-210 km which can be tracked back to high rates of deeply penetrating shallow intraplate seismicity at the trench in proximity to oceanic fluids. Dehydration of the slab mantle correlates with the location and productivity of active North Island volcanic centres, indicating this volcanism is controlled by fluids fluxing from the subducting plate.
The ages and locations of arc volcanoes provide constraints on the migration of volcanism across the North Island over the last 20 Myr. Arc-front volcanoes have migrated southeast by 150 km in the last 8 Ma (185 km since 16 Ma) sub-parallel to the present active arc. Migration of the arc is interpreted to mainly reflect slab steepening and rollback. The strike of the Pacific plate beneath the North Island, imaged by Benioff zone seismicity (50-200 km) and positive mantle velocity anomalies (200-600 km) is parallel to the northeast trend of arc-front volcanism. Arc parallelism since 16 Ma is consistent with the view that the subducting plate beneath the North Island has not
rotated clockwise about vertical axes which is in contrast to overriding plate vertical-axis rotations of ≥ 30º. Acceleration of arc-front migration rates (~4 mm/yr to ~18 mm/yr), eruption of high Mg# andesites, increasing eruption frequency and size, and
uplift of the over-riding plate indicate an increase in the hydration, temperature, and size of the mantle wedge beneath the central North Island from ~7 Ma.
Seafloor spreading data in conjunction with GPlates have been used to generate relative plate motion vectors across the Hikurangi margin since 38 Ma. Tracking the southern and down-dip limits of the seismically imaged Pacific slab beneath the New Zealand indicates arc volcanism in Northland from ~23 Ma and the Taranaki Basin between ~20 and 11 Ma requires Pacific plate subduction from at (or beyond) the northern North Island continental margin from at least 38 Ma to the present. Pacific plate motion in a west dipping subduction model shows a minimum horizontal transport distance of 285 km preceding the initiation of arc volcanism along the Northland-arc normal to the motion vector, a distance more than sufficient for self-sustaining
subduction to occur. Arc-normal convergence rates along the Hikurangi margin doubled from 11 to 23 mm/yr between 20 and 16 Ma, increasing again by approximately a third between 8 and 6 Ma. This latest increase in arc-normal rates coincided with changes in relative plate motions along the entire SW Pacific plate boundary and steepening/rollback of the Pacific plate.
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