Dissertations / Theses on the topic 'Assimilation'
To see the other types of publications on this topic, follow the link: Assimilation.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Assimilation.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Le, Andrew Nguyen. "Assimilating through social networks? The importance of networks in assimilation trajectories." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/42483.
Full textAbstract:
The assimilation outcomes of second generation youths have been hotly debated amongst scholars (Alba et al. 2011, Haller et al. 2011). While the outcomes are contested, it is undeniable that ethnic organizations play a central role in the second generation’s assimilation trajectory. Zhou and Bankston (1998) suggest that participating in ethnic religious institutions promotes upward assimilation through instilling an ethnic identity onto youths. My research on the greater Seattle area Vietnamese Buddhist youth organizations uncovered similar mechanisms that led to Zhou and Bankston’s overall quantitative findings, but also uncover the importance of resource brokering and networks. Based on 43 in-depth interviews, I find that organization participation promotes upward and downward assimilation, and the friendships formed inside ethnic organizations play a crucial role in assimilation outcomes. My project shows that participation in Buddhist youth groups instills a Vietnamese-American identity on youths and, in turn, this ethnic identity can lead to upward assimilation only if the individual is part of a peer network that promotes normative values. Downward assimilation can be associated with youth group participation if the youths enter peer networks that promote deviant behaviors. These deviant peer networks can supersede the positive effects of the youth organization’s overall influence on the individual.
2
Peubey, Carole. "Assimilation of ENVISAT data in an advanced data assimilation system." Thesis, University of Reading, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.485367.
Full textAbstract:
i~to a stratosphere-troposphere version of the Met Office assimilation system, producing one of the first analyses to reproduce the September 2002 split of the Antarctic polar vortex. The aim of the project was to investigate the benefit of assimilating MIPAS retrievals and to assess the Met Office 3D-Var assimilation system by examining its different components. The ozone analysis was found to agree with independent ozone observations through most of the middle and upper stratosphere, biases above 60 hPa being within the range -20% to +10% and typically smaller. More significant positive biases were found in the lower stratosphere and inside the polar vortex. Although ozone amounts are shown to be slightly overestimated by MIPAS retrievals in these same regions, these biases are demonstrated to be caused by shortcomings in the model chemistry and transport. MIPAS data have been shown to have a limited impact on the Met Office temperature analysis, although a ' positive effect was identified at the mesopause. It is shown that MIPAScould bring larger benefits if more realistic background error statistics were used for ozone, especially in the lower stratosphere. Based on an evaluation of these statistics using independent datasets, it is suggested that background error variances should be decreased near the ozone maximum and increased below 70 hPa It is also recommended to introduce latitudedependence in vertical error correlations and height-dependence in horizontal error correlations. Improvements are also proposed to improve the ozone assimilation in the polar vortex region. Finally, analysed winds have been found to induce errOneous transport of ozone by increasing vertical diffusion of ozone and enhancing the mean zonal circulations. This especially affects the tropics, where ozone analyses reveal excessive exchanges of air parcels between the stratosphere and the troposphere.
3
Barillec, Remi Louis. "Bayesian data assimilation." Thesis, Aston University, 2008. http://publications.aston.ac.uk/15276/.
Full textAbstract:
This thesis addresses data assimilation, which typically refers to the estimation of the state of a physical system given a model and observations, and its application to short-term precipitation forecasting. A general introduction to data assimilation is given, both from a deterministic and stochastic point of view. Data assimilation algorithms are reviewed, in the static case (when no dynamics are involved), then in the dynamic case. A double experiment on two non-linear models, the Lorenz 63 and the Lorenz 96 models, is run and the comparative performance of the methods is discussed in terms of quality of the assimilation, robustness in the non-linear regime and computational time.
4
Ali, A. H. "Nitrate assimilation in yeasts." Thesis, Swansea University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.635757.
Full text
5
Torres, Javier. "Essays on immigrant assimilation." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/44777.
Full textAbstract:
This dissertation examines immigrants (to Canada) assimilation problems from a perspective of imperfect human capital transferability. Chapter 2 discusses how much of the immigrant wage gap can be explained by the undervaluation of foreign human capital (education and work experience). The identification of the human capital source (using information available in the 2006 Canadian census) can explain up to 70% of the native-immigrant wage gap. The foreign-born dummy coefficient goes from around -11% to close
to -3%. Education acquired in Asia tends to be valued less than education from South America, Africa and East Europe; which in turn is less valued than education from Oceania, the U.S. and the rest of continental Europe. Studying in the UK consistently appears more beneficial than studying in Canada. When incorporating country of origin fixed effects, the different specifications visibly reduce the heterogeneity of country coefficients. The reduction is sizeable for Pakistan, India, China and the Philippines; though their coefficients remain negative. A smaller reduction for Europe, South-East Asia, Hong Kong and the US drives their coefficients close to zero. The UK country of origin dummy has the only persistently positive coefficient. Chapter 3 describes the occupational assimilation process of 2000-2001 immigrants in their first four years. The results show that those with high levels of education experience a more significant decline in their first occupation. Education, though, has a positive and significant effect on occupational improvement; which reduces the size and significance of the negative effect of education on the second occupational gap. It, however, does not change its sign. The same pattern is observed when analyzing occupational gaps through time. Chapter 4 focuses on immigrants' English proficiency improvement. Overall, immigrants show relatively small improvements in language proficiency in the first four years in Canada. Still, those arriving under the family immigrant category with an intermediate or advanced level are less likely to improve and more likely to decrease their English proficiency. Human capital variables (age and education) are also consistently relevant for English proficiency improvement.
6
Campbell, Elizabeth M. "Nitrogen assimilation by limpets." Thesis, University of Glasgow, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.479100.
Full text
7
Gregory, Alastair. "Multilevel ensemble data assimilation." Thesis, Imperial College London, 2017. http://hdl.handle.net/10044/1/60645.
Full textAbstract:
This thesis aims to investigate and improve the efficiency of ensemble transform methods for data assimilation, using an application of multilevel Monte Carlo. Multilevel Monte Carlo is an interesting framework to estimate statistics of discretized random variables, since it uses a hierarchy of discretizations with a refinement in resolution. This is in contrast to standard Monte Carlo estimators that only use a discretization at a fine resolution. A linear combination of sub-estimators, on different levels of this hierarchy, can provide new statistical estimators to random variables at the finest level of resolution with significantly greater efficiency than a standard Monte Carlo equivalent. Therefore, the extension to computing filtering estimators for data assimilation is a natural, but challenging area of study. These challenges arise due to the fact that correlation must be imparted between ensembles on adjacent levels of resolution and maintained during the assimilation of data. The methodology proposed in this thesis, considers coupling algorithms to establish this correlation. This generates multilevel estimators that significantly reduce the computational expense of propagating ensembles of discretizations through time and space, in between stages of data assimilation. An effective benchmark of this methodology is realised by filtering data into high-dimensional spatio-temporal systems, where a high computational complexity is required to solve the underlying partial differential equations. A novel extension of an ensemble transform localisation framework to finite element approximations within random spatio-temporal systems is proposed, in addition to a multilevel equivalent.
8
Archangeli, Diana. "Keley-I Consonant Assimilation." University of Arizona Linguistics Circle, 1987. http://hdl.handle.net/10150/226555.
Full textAbstract:
Keley-i, a Philippine language, has two rules assimilating consonants across a vowel. Such rules might be taken as evidence against the Morphemic Tier Hypothesis (MTH) and against the Locality Condition (LC). The MTH states (1) Morphemic Tier Hypothesis (MTH) If and only if two segments are members of separate morphemes are those two segments aligned in separate phonological tiers. The Keley-i data suggest that the MTH does not hold universally because consonants assimilate across vowels, which has been taken as evidence for two segmental planes in order to prevent the crossing of association lines. The data also create problems for the Locality Condition: (3) Locality Condition (LC) A phonological rule is applicable only if the target and trigger are adjacent. The consonant features assimilate across an intervening vowel: the target and trigger, being skeletal slots, are not adjacent. I suggest here that adopting the feature hierarchy as proposed in Archangeli and Pulleyblank (1986) (which is a modification of Clements 1985) combined with underspecification theory (Archangeli 1984, Pulleyblank 1986, Archangeli and Pulleyblank 1986) allows an analysis of the Keley -i data which permits maintaining the MTH and the LC. A further result is that the Spreading Hypothesis is maintained as well, thus supporting the hypothesis that phonological assimilation is formally expressed in one manner only, namely by insertion of association lines, and not by feature copy rules. (See Hayes 1986, Archangeli and Pulleyblank 1986.) (4) Spreading Hypothesis Phonological assimilation is expressed only by rules adding association lines. The discussion is organized as follows. First, the feature hierarchy and the theory of underspecification are briefly outlined. I then present a partial analysis of the Keley-i data. The analysis consists of a syncope rule and some rules of consonant assimilation. Finally, I return to the problems that Keley -i presents for the MTH and the LC and propose that the relevant Keley-i data are not only in accordance with the MTH and the LC but predicted by the interaction of the two sub -theories, the Feature Hierarchy and Underspecification.
9
Fishman, Jonathan. "Young Adults' Assimilation of Parental Divorce: A Developmental Elaboration of the Assimilation Model." Miami University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=miami1240597649.
Full text
10
Fishman, Jonathan L. "Young adults' assimilation of parental divorce a developmental elaboration of the assimilation model /." Oxford, Ohio : Miami University, 2009. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=miami1240597649.
Full text
11
Shinkle, Monte L. "New member assimilation a strategy for assimilation in Concord Baptist Church, Jefferson City, Missouri /." Theological Research Exchange Network (TREN), 1994. http://www.tren.com.
Full text
12
Halm, Hannah. "Nitrogen assimilation by aquatic prokaryotes." Berlin mbv, Mensch-und-Buch-Verl, 2009. http://d-nb.info/100292491X/04.
Full text
13
Tong, Yuying Entwisle Barbara. "Three essays on immigrant assimilation." Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2007. http://dc.lib.unc.edu/u?/etd,1426.
Full textAbstract:
Thesis (Ph. D.)--University of North Carolina at Chapel Hill, 2007.Title from electronic title page (viewed Apr. 25, 2008). "... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Sociology." Discipline: Sociology; Department/School: Sociology.
14
Woodgate, Rebecca A. "Data assimilation in ocean models." Thesis, University of Oxford, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359566.
Full text
15
Moore, A. M. "Data assimilation in ocean models." Thesis, University of Oxford, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375276.
Full text
16
Percival, James R. "Displacement assimilation for ocean models." Thesis, University of Reading, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.501349.
Full textAbstract:
Advances in numerical ocean modelling have led to increasing interest in data assimilation for the purpose of ocean forecasting. The majority of current assimilation techniques ignore the integral constraints inherent in ocean dynamics, and instead locally insert information from observations in an Eulerian sense. It has been shown that such methods can generate spurious circulations by affecting balance of dynamic ocean tracers. In this thesis techniques are presented which solve a rearrangement problem to perform data assimilation under an integral constraint, effectively performing assimilation in a Lagrangian sense to correct assumed initial phase error. A descent algorithm equivalent to three dimensional variational assimilation is developed for the pure rearrangement problem, based on an advective process acting in pseudo-time. This method is shown to assimilate direct observations successfully, even when observations are only available on a limited subdomain. Two novel modifications which improve the rate of convergence are also discussed.
17
Da, Dalt Federico. "Ionospheric modelling and data assimilation." Thesis, University of Bath, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.665450.
Full textAbstract:
A New Ionospheric Model (ANIMo) based upon the physics of production, loss, and vertical transport has been developed. The model is driven by estimates of neutral composition, temperature and solar flux and is applicable to the mid-latitude regions of the Earth under quiet and moderate geomagnetic conditions. This model was designed to exhibit specific features that were not easy to find all together in other existing ionospheric models. ANIMo needed to be simple to use and interact with, relatively accurate, reliable, robust and computationally efficient. The definition of these characteristics was mostly driven by the intention to use ANIMo in a Data Assimilation (DA) scheme. DA or data ingestion can be described as a technique where observations and model realizations, called background information, are combined together to achieve a level of accuracy that is higher than the accuracy of the two elements taken separately. In this project ANIMo was developed to provide a robust and reliable background contribution. The observations are given by the Global Positioning System (GPS) ionospheric measurements, collected from several networks of GPS ground-station receivers and are available on on-line repositories. The research benefits from the Multi-Instrument Data Analysis System (MIDAS) [Mitchell and Spencer, 2003; Spencer and Mitchell, 2007], which is an established ionospheric tomography software package that produces three dimensional reconstructions of the ionosphere starting from GPS measurements. Utilizing ANIMo in support of MIDAS has therefore the potential to generate a very stable set-up for monitoring and study the ionosphere. In particular, the model is expected to compensate some of the typical limitations of ionospheric tomography techniques described by Yeh and Raymund [1991] and Raymund et al. [1994]. These are associated with the lack of data due to the uneven distribution of ground-based receivers and limitations to viewing angles. Even in regions of good receiver coverage there is a need to compensate for information on the vertical profile of ionisation. MIDAS and other tomography techniques introduce regularization factors that can assure the achievement of a unique solution in the inversion operation. These issues could be solved by aiding the operation with external information provided by a physical model, like ANIMo, through a data ingestion scheme; this ensures that the contribution is completely independent and there is an effective accuracy improvement. Previously, the limitation in vertical resolution has been solved by applying vertical orthonormal functions based upon empirical models in different ways [Fougere, 1995; Fremouw et al., 1992; Sutton and Na, 1994]. The potential for the application of a physical model, such ANIMo is that it can provide this information according to the current ionospheric conditions. During the project period ANIMo has been developed and incorporated with MIDAS. The result is A New Ionospheric Data Assimilation System (ANIDAS); its name suggests that the system is the implementation of ANIMo in MIDAS. Because ANIDAS is a data ingestion scheme, it has the potential to be used to perform not only more accurate now-casting but also forecasting. The outcomes of ANIDAS at the current time can be used to initialise ANIMo for the next time step and therefore trigger another assimilation turn. In future, it is intended that ANIMo will form the basis to a new system to predict the electron density of the ionosphere – ionospheric forecasting.
18
Saletri, Charles E. "Mobilizing God's people for assimilation." Theological Research Exchange Network (TREN), 1994. http://www.tren.com.
Full text
19
Shukla, Abhishek. "Analysis of data assimilation schemes." Thesis, University of Warwick, 2016. http://wrap.warwick.ac.uk/90880/.
Full textAbstract:
Data assimilation schemes are methods to estimate true underlying state of the physical systems of interest by combining the theoretical knowledge about the underlying system with available observations of the state. However, in most of the physical systems the observations often are noisy and only partially available. In the first part of this thesis we study the case of sequential data assimilation scheme, when the underlying system is nonlinear chaotic and the observations are partial and noisy. We produce a rigorous and quantitative analysis of data assimilation process for fixed observation modes. We also introduce a novel method of dynamically rearranging observation modes, leading to the requirement of fewer observation modes while maintaining the accuracy of the data assimilation process. In the second part of the thesis we focus on 4DVAR data assimilation scheme which is a variational method. 4DVAR data assimilation is a method that solves a variational problem; given a set of observations and a numerical model for the underlying physical system together with a priori information on the initial condition to estimate the initial condition for the underlying model. We propose a hybrid data assimilation scheme where, we consider the 3DVAR scheme for the model as the constraint on the variational form, rather than constraining the variational form with the original model. We observe that this method reduces the computational cost of the minimization of the 4DVAR variational form, however, it introduces a bias in the estimate of the initial condition. We then explore how the results can be extended to weak constraint 4DVAR.
20
Detter, Alfred L. "The assessment of newcomer assimilation and the development of an assimilation model at Grace Baptist Church." Theological Research Exchange Network (TREN), 1989. http://www.tren.com.
Full text
21
Kouki, Rafa. "Enterprise Resource Planning Post-Implementation Assimilation Challenge : An integrative Framework for a Better Post-Implementation Assimilation." Thesis, Université Laval, 2009. http://www.theses.ulaval.ca/2009/26287/26287.pdf.
Full text
22
Cuartero, Torres Néstor. "Voicing Assimilation in Catalan and English." Doctoral thesis, Universitat Autònoma de Barcelona, 2002. http://hdl.handle.net/10803/4908.
Full textAbstract:
El objetivo de este trabajo es estudiar el proceso de asimilación de sonoridad a diferentes velocidades de habla en catalán e inglés y, más concretamente observar y analizar la asimilación de sonoridad cuando dos consonantes que tienen una especificación fonológica de sonoridad distinta coocurren a través de palabras. Además, el estudio se propone evaluar modelos descriptivos actuales con el fin de determinar cómo explican los datos obtenidos en el experimento. Se realizó un experimento usando datos acústicos, electropalatográficos y electoglotográficos simultáneos. Las secuencias estudiadas son de 4 tipos:
1) Secuencias de obstruyentes donde C1 es fonológicamente sorda y C2 es fonológicamente sonora.
2) Secuencias de obstruyentes donde C1 es fonológicamente sonora y C2 es fonológicamente sorda.
3) Secuencies de sonorante seguida de obstruyente.
4) Secuencias de obstruyente seguida de sonorante.
Se observó que en las secuencias de obstruyentes en catalán los hablantes tienden a anticipar el gesto de sonoridad de C2 a C1, tanto en las secuencias de oclusivas como en las secuencias de fricativa seguida de oclusiva. Así, el proceso es regresivo y categórico, lo cual es congruente con la existencia de una regla de asimilación de sonoridad en catalán. También se observó que los hablantes catalanes pueden mostrar anticipación parcial del gesto de sonoridad de C2, lo cual muestra que la asimilación de sonoridad puede ser un proceso gradual en catalán. Así pues, parece que la regla de asimilación de sonoridad es opcional. Los datos del catalán reflejan dos procesos distintos: por un lado, la asimilación completa y regresiva de sonoridad en las secuencias de obstruyentes es el resultado de una regla que implica la reorganización a alto nivel de las instrucciones motoras. Por otro lado, los casos de asimilación parcial podrían ser debidos a factores de implementación fonética.
En inglés se observó que no existe una regla fonológica de asimilación de sonoridad en las secuencias de obstruyentes. La coordinación de los gestos orales y glotales durante la constricción máxima es un proceso gradual.
En las secuencias que combinan sonorantes y obstruyentes, el gesto de sonoridad coincide con la transición de C1 a C2 en ambas lenguas. Además, se observa que puede haber asimilación completa de sonoridad en las secuencias obstruyente - sonorante en catalán. Esto sugiere que la regla de asimilación regresiva de sonoridad podría extenderse a este tipo de secuencias, por lo menos en algunos hablantes catalanes.
Finalmente, se sugiere que los modelos conocidos como Articulatory Phonology y Windows Theory pueden dar cuenta de la coordinación de los gestos orales y glotales en catalán e inglés.
The present study intends to analyze the process of voicing assimilation across different speaking rates in Catalan and English. More specifically, it aims at observing and characterizing voicing assimilation when two consonants that have a different phonological specification for voicing co-occur across word boundaries. Furthermore, this study intends to evaluate current descriptive frameworks, in order to see how they account for the data obtained in the experiment.
An experiment was carried out using simultaneous acoustic, electroglottographic and electropalatographic data. The sequences were of 4 types:
1) Obstruent sequences where C1 was phonologically voiceless and C2 was phonologically voiced, e.g., 'fat gap', 'this doll'.
2) Obstruent sequences where C1 was phonologically voiced and C2 was phonologically voiceless, e.g., 'sad gap', 'his toll'.
3) Sequences of sonorant plus voiceless obstruent, e.g., 'full cap', 'long sip'.
4) Sequences of voiceless obstruent plus sonorant, e.g., 'thick lap', 'this nut'.
It was found that in Catalan obstruent sequences that differ in their phonological specification for voicing, speakers tend to anticipate the voicing gesture of C2 to C1, both in stop sequences and in fricative - stop sequences. Thus, the process is regressive and categorical, which is congruent with a rule of voicing assimilation in Catalan. Evidence was also found that speakers can display partial anticipation of the voicing gesture of C2, which shows that voicing assimilation may also be a gradient process in this language. Thus, the voicing assimilation rule seems to be optional. The Catalan data thus seem to reflect two different processes. On one hand, complete regressive voicing assimilation in obstruent sequences seems to be the result of a rule involving higher-level reorganization of motor commands. On the other hand, cases of partial assimilation may result from phonetic implementation factors.
In English, it was found that there is no phonological rule of voicing assimilation in obstruent sequences. Rather, the coordination of oral and glottal gestures during the maximal constriction is a gradient process that may result from anticipatory overlap - sensitive to time constraints - and inertial effects .
In sequences of consonants where nasals and laterals combine with obstruents, the voicing gesture seems to be switched at the transition from C1 to C2 in both languages. In addition, evidence was found for complete assimilation of voicing in Catalan obstruent - sonorant sequences, suggesting the extension of the regressive voicing assimilation rule for obstruents to these sequences, at least for some speakers.
Finally, it is suggested that Articulatory Phonology and Keating's Windows Theory account for the coordination of oral and glottal gestures in Catalan and English.
23
Lung, Shiu-cheung. "Assimilation of phytate-phosphorus by plants." Click to view the E-thesis via HKUTO, 2005. http://sunzi.lib.hku.hk/hkuto/record/B35710986.
Full text
24
Wackernagel, Hans. "Géostatistique et assimilation séquentielle de données." Habilitation à diriger des recherches, Université Pierre et Marie Curie - Paris VI, 2004. http://tel.archives-ouvertes.fr/tel-00542362.
Full textAbstract:
La géostatistique spatio-temporelle traditionnelle n'est pas en mesure de décrire adéquatement la dynamique, en général fortement non-linéaire, de processus spatio-temporels multivariables. Pour cela des modèles de transport physico-chimiques sont en général bien mieux adaptés. Cependant, étant donné que ces derniers ne maîtrisent pas totalement la complexité des processus qu'ils cherchent à décrire, soit parce qu'ils sont basés sur des hypothèses simplificatrices, soit parce que l'information servant à établir les conditions initiales et aux limites est imparfaite, il est opportun d'introduire des techniques statistiques servant à les guider pour assimiler un flot de mesures émanant de capteurs automatiques. Des projets récents au Centre de Géostatistique de l'Ecole des Mines de Paris ont permis d'explorer l'application de ces techniques dans le domaine de l'océanographie et en pollution de l'air. Il s'est très vite avéré que la géostatistique offrait des concepts et des approches qui pouvaient contribuer à enrichir les techniques d'Assimilation Séquentielle de Données. La thèse de Laurent Bertino et des publications ultérieures ont permis de développer cette thématique porteuse, dont la présente synthèse établit un compte-rendu.
25
Esser, Hartmut. "Ist das Konzept der Assimilation überholt?" Universität Potsdam, 2003. http://opus.kobv.de/ubp/volltexte/2009/3063/.
Full textAbstract:
Inhalt:
1 Die Assimilation und ihre Alternativen
2 Die Situationslogik der Assimilation
3 Die „Interaktion“ von ethnischer Segmentation und ethnischer Ungleichheit: Das Beispiel der ethnischen Mobilitätsfalle.
4 Perspektiven
26
Detert, Neils. "Assimilation in 2+1 brief therapy." Thesis, Open University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269842.
Full text
27
Jamal, Sheri K. Henderson James W. "Hispanic assimilation to American health insurance." Waco, Tex. : Baylor University, 2006. http://hdl.handle.net/2104/4825.
Full text
28
Lindskog, Magnus. "On errors in meteorological data assimilation." Doctoral thesis, Stockholm : Department of Meteorology, Stockholm university, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-7258.
Full text
29
Akay, Alpaslan. "Essays on microeconometrics and immigrant assimilation /." Göteborg : Dep. of Economics, School of Business, Economics and Law, Göteborg Univ, 2008. http://www.gbv.de/dms/zbw/566893517.pdf.
Full text
30
Milewski, Thomas. "Stratospheric chemical-dynamical ensemble data assimilation." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=110352.
Full textAbstract:
Ensemble data assimilation uses Monte-Carlo methods to estimate flow-dependent error covariances which allow the transfer of information from observed variables to correlated ones. As the winds are largely unobserved in the stratosphere and models have biases there, the possibility to constrain the dynamical analysis from temperature or ozone observations is attempted using ensemble data assimilation.The applicability of coupled chemical/dynamical ensemble data assimilation in the stratosphere is tested in idealized perfect model observation system simulation experiments with the IGCM-FASTOC chemistry-climate model. Covariance localization is found to be necessary for stability of the Ensemble Kalman Filter (EnKF) data assimilation system and optimal localization parameters yield a strong constraint on the global dynamical state of the model when assimilating synthetic limb-sounding stratospheric temperature or ozone observations only. The multivariate coupling between ozone, temperature and winds is investigated in the optimized EnKF system. Stratospheric temperature and ozone observations induce valuable dynamical analysis increments during the analysis step. There is additional feedback during the forecast steps in the ensemble data assimilation system, further constraining the global dynamical and ozone states. The potential impact of assimilating observations posterior to analysis time in multivariate mode was estimated with an Ensemble Kalman Smoother (EnKS). Assimilation of additional asynchronous observations up to 48 hours posterior toanalysis time provided improvements on the EnKF analysis nearly similar to the ones obtained from the assimilation of a same amount of additional synchronous observations. The EnKS assimilation showed beneficial impacts on the unobserved variables analysis state but mixed impacts on the observed variable analysis state.The capacity to constrain the unobserved stratospheric winds by assimilating ozone observations is demonstrated in the ensemble data assimilation system with the EnKF and EnKS. The chemical-dynamical error covariances are critical to reduce the wind error in the model analysis state particularly through the ozone-wind covariances effective in the upper-troposphere lower-stratosphere region. Additional tests with strongly-biased initial forecasts, within a stratospheric sudden warming experiment, confirm the ability of the EnKF to efficiently propagate information from ozone observations to the dynamical model state.L'assimilation d'ensemble utilise une méthode de Monte-Carlo pour estimer les covariances d'erreur du moment qui permettent le transfert d'information des variables observées aux variables corrélées à celles-ci. Puisque les vents sont très peu observés dans la stratosphère et que les modèles y présentent des biais, la possibilité de contraindre l'état dynamique du modèle par l'assimilation d'observations de température et d'ozone par la technique d'ensemble est tentée. L'applicabilité de l'assimilation d'ensemble dans un système chimique/dynamique couplé est testé lors d'une expérience idéalisé (modèle parfait) de simulation de système d'observation avec le modèle de chimie-climat IGCM-FASTOC. La localisation des covariances est indispensable à la stabilité du système d'assimilation avec filtre de Kalman d'ensemble (EnKF) et les paramètres optimaux offrent une forte contrainte sur l'état dynamique global du modèle lorsque l'on assimile des observations satellites synthétiques de température et d'ozone stratosphériques uniquement. Le couplage entre l'ozone, la température et les vents est étudié dans le système EnKF optimisé. Les observations de température et d'ozone stratosphériques créent des incréments dynamiques bénéfiques lors des phases d'analyses. Il y a également une rétroaction lors de la phase de prédiction du système d'assimilation de données, qui aide à contraindre davantage les états chimiques et dynamiques globaux. L'impact potentiel de l'assimilation de données postérieures au temps d'analyse en mode multivarié est estimé avec un lisseur d'ensemble de Kalman (EnKS). L'assimilation d'observations additionnelles asynchrones, ayant jusqu'à 48 heures d'écart avec le temps d'analyse, offre des améliorations aux analyses de l'EnKF presque équivalentes à celles obtenues par assimilation d'une quantité égale d'observations additionnelles synchrones. L'EnKS présente des impacts bénéfiques sur l'état d'analyse des variables non observées mais des impacts mitigés sur l'état analysé des variables observées. La capacité de contraindre les vents stratosphériques non-observés grâce à l'assimilation d'observations d'ozone est démontrée dans le système d'assimilation d'ensemble avec l'EnKF et l'EnKS. Les covariances d'erreurs chimiques- dynamiques sont essentielles à la réduction de l'erreur de vents dans l'état analysé du modèle, en particulier les covariances ozone-vent qui font effet dans la haute troposphère et basse stratosphère. Des expériences additionelles avec un état initial fortement biaisé, en l'occurence un réchauffement stratosphérique soudain, confirment l'abilité de l'EnKF à transférer de façon efficace l'information depuis les observations d'ozone vers l'état dynamique du modèle.
31
Stewart, Laura M. "Correlated observation errors in data assimilation." Thesis, University of Reading, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.553080.
Full textAbstract:
Data assimilation techniques combine observations and prior model forecasts to create initial conditions for numerical weather prediction (NWP). The relative weighting as- signed to each observation in the analysis is determined by the error associated with its measurement. Remote sensing data often have correlated errors, but the correlations are typically ignored in NWP. As operational centres move towards high-resolution fore- casting, the assumption of uncorrelated errors becomes impractical. This thesis provides new evidence that including observation error correlations in data assimilation schemes is both feasible and beneficial. We study the dual problem of quantifying and modelling observation error correlation structure. Firstly, in original work using statistics from the Met Office 4D- Var assimilation system, we diagnose strong cross-channel error eo- variances for the IASI satellite instrument. We then see how in a 3D- Var framework, information content is degraded under the assumption of uncorrelated errors, while re- tention of an approximate correlation gives clear benefits. These novel results motivate further study. We conclude by modelling observation error correlation structure in the framework of a one-dimensional shallow water model. Using an incremental 4D- Var assimilation system we observe that analysis errors are smallest when correlated error covariance matrix approximations are used over diagonal approximations. The new re- sults reinforce earlier conclusions on the benefits of including some error correlation structure.
32
Moodey, Alexander J. F. "Instability and regularization for data assimilation." Thesis, University of Reading, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.602412.
Full textAbstract:
The process of blending observations and numerical models is called in the environmental sciences community, data assimilation. Data assimilation schemes produce an analysis state, which is the best estimate to the state of the system. Error in the analysis state, which is due to errors in the observations and numerical models, is called the analysis error. In this thesis we formulate an expression for the analysis error as the data assimilation procedure is cycled in time and derive results on the boundedness of the analysis error for a number of different data assimilation schemes. Our work is focused on infinite dimensional dynamical systems where the equation which we solve is ill-posed. We present stability results for diagonal dynamical systems for a three-dimensional variational data assimilation scheme. We show that increasing the assumed uncertainty in the background state, which is an a priori estimate to the state of the system, leads to a bounded analysis error. We demonstrate for general linear dynamical systems that if there is uniform dissipation in the model dynamics with respect to the observation operator, then regularization can be used to ensure stability of many cycled data assimilation schemes. Under certain conditions we show that cycled data assimilation schemes that update the background error covariance in a general way remain stable for all time and demonstrate that many of these conditions hold for the Kalman filter. Our results are extended to dynamical system where the model dynamics are nonlinear and the observation operator is linear. Under certain Lipschitz continuous and dissipativity assumptions we demonstrate that the assumed uncertainty in the background state can be increased to ensure stability of cycled data assimilation schemes that update the background error covariance. The results are demonstrated numerically using the two-dimensional Eady model and the Lorenz 1963 model.
33
Luo, Xiaodong. "Recursive bayesian filters for data assimilation." Thesis, University of Oxford, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.509987.
Full text
34
Lung, Shiu-cheung, and 龍兆章. "Assimilation of phytate-phosphorus by plants." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2005. http://hub.hku.hk/bib/B35710986.
Full text
35
Fowler, Alison M. "Assimilation of misplaced boundary layer features." Thesis, University of Reading, 2010. http://centaur.reading.ac.uk/24800/.
Full text
36
Ades, Melanie. "Data assimilation in highly nonlinear sytems." Thesis, University of Reading, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.603528.
Full textAbstract:
Particle filters are a class of data-assimilation schemes which, unlike current operational data-assimilation methods, make no assumptions about the linearity of the model equations or observation operators. This means They can potentially represent the full, possibly multi-modal, posterior probability density function (pdf). Unfortunately, the standard Sequential Importance Resampling (SIR) particle filter requires too many pal1icles to make it a viable operational data-assimilation scheme in high dimensional systems. This thesis explores an adaptation to the SIR filter, the equivalent-weights particle filter, designed to ensure an ensemble representation of the high probability region of the posterior pdf even in high dimensional systems. The formulation of the equivalent-weights particle filter involves various tuneable parameters. The first part of this thesis focusses on a theoretical and practical examination of the effect of the parameter choices on the ability of the equivalent-weights particle filter to represent the posterior pdf. Theoretically, the importance of ensuring equivalent weights for the majority of particles is shown and consequently the need to sample from a mixture proposal density al analysis time. Practically, the potentially large influence of the parameters is demonstrated and how this can be used to establish appropriate choices for some of the parameters is discussed. The second part of the thesis considers two areas related to the potential of the equivalent-weights particle filter as a viable data-assimilation scheme: the capacity to represent the posterior pdf and the effect on any model balances that may be present in the system. The ability of the equivalent-weights particle filter to represent the high probability region of the posterior pdf with relatively few particles in high dimensional systems is demonstrated. Changes in the observation distribution, frequency or error statistics result in minimal impact to this posterior representation. More distinctive effects are seen when the model error statistics are misrepresented in the ensemble. The final section on model balances relates to the use of the equivalent-weights pa11icle filter in atmosphere and ocean numerical models. The equivalent-weights par1icle filter is shown to have little effect on the model balances present in a simple ocean model and hence there is no evidence for the introduction of spurious gravity waves
37
McLeod, Paul. "The melting and assimilation of xenoliths." Thesis, University of Bristol, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336850.
Full text
38
Jenkins, Siân. "Numerical model error in data assimilation." Thesis, University of Bath, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.665395.
Full textAbstract:
In this thesis, we produce a rigorous and quantitative analysis of the errors introduced by finite difference schemes into strong constraint 4D-Variational (4D-Var) data assimilation. Strong constraint 4D-Var data assimilation is a method that solves a particular kind of inverse problem; given a set of observations and a numerical model for a physical system together with a priori information on the initial condition, estimate an improved initial condition for the numerical model, known as the analysis vector. This method has many forms of error affecting the accuracy of the analysis vector, and is derived under the assumption that the numerical model is perfect, when in reality this is not true. Therefore it is important to assess whether this assumption is realistic and if not, how the method should be modified to account for model error. Here we analyse how the errors introduced by finite difference schemes used as the numerical model, affect the accuracy of the analysis vector. Initially the 1D linear advection equation is considered as our physical system. All forms of error, other than those introduced by finite difference schemes, are initially removed. The error introduced by `representative schemes' is considered in terms of numerical dissipation and numerical dispersion. A spectral approach is successfully implemented to analyse the impact on the analysis vector, examining the effects on unresolvable wavenumber components and the l2-norm of the error. Subsequently, a similar also successful analysis is conducted when observation errors are re-introduced to the problem. We then explore how the results can be extended to weak constraint 4D-Var. The 2D linear advection equation is then considered as our physical system, demonstrating how the results from the 1D problem extend to 2D. The linearised shallow water equations extend the problem further, highlighting the difficulties associated with analysing a coupled system of PDEs.
39
Hammarström, Ylva. "Folkhemmets parias : Debatten om romernas assimilation." Thesis, Mittuniversitetet, Institutionen för humaniora, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-19586.
Full text
40
Harris, Mary C. "Assimilation in Charles W. Chesnutt's Works." ScholarWorks@UNO, 2013. http://scholarworks.uno.edu/td/1635.
Full textAbstract:
ABSTRACT
Charles W. Chesnutt captures the essence of the Post Civil War period and gives examples of the assimilation process for African Americans into dominant white culture. In doing so, he shows the resistance of the dominant culture as well as the resilience of the African American culture. It is his belief that through literature he could encourage moral reform and eliminate racial discrimination. As an African American author who could pass for white, he is able to share his own experiences and to develop black characters who are ambitious and intelligent. As a result, he leaves behind a legacy of great works that are both informative and entertaining.
41
Astin, P. "Heat transfer in jet assimilation flows." Thesis, Keele University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292751.
Full text
42
Darcy, Isabelle. "Assimilation phonologique et reconnaissance des mots." Paris, EHESS, 2003. http://www.theses.fr/2003EHES0131.
Full textAbstract:
L'assimilation phonologique peut faire varier la forme sonore d'un mot sous l'influence des segments qui l'entourent. La reconnaissance des mots doit compenser ces variations systématiques caractéristiques du langage parlé. Trois expériences de détection de mot en français, anglais et américain montrent que les auditeurs utilisent une connaissance phonologique implicite des processus d'assimilation spécifiques à leur langue. En outre, cette connaissance intervient à un niveau indépendant de l'activation des représentations lexicales,la même compensation ayant été observée sur des mots et des non-mots. Ce mécanisme de compensation est également plastique : la comparaison d'apprenants anglophones et francophones d'une seconde langue (L2) montre qu'à un stade débutant, c'est le système phonologique de la langue maternelle qui effectue la compensation, mais que la construction d'un système spécifique dédié à la L2 est possible en l'espace de quelques années suite à une exposition suffisantePhonological assimilation may change the acoustic shape of words according to the influence of surrounding segments. Word recognition has to cope with this systematic variability which characterizes spoken language. Three word-detection experiments in French, English and American English show that listeners use implicit phonological knowledge of the assimilation processes that exist in their language. Moreover, this knowledge of the assimilation independently of the activation of a lexical form, as the same compensation patterns have been observed in words and in non-words. This compensation mechanism shows some flexibility : comparing French and American second language (L2) learners shows that beginners use the phonological system of their native language to compensate for assimilation processes that exist in L2, but that more advanced learners develop a specific system dedicated to L2 within a few years of exposure
43
McMahon, Debbie L. Driskell Robyn Bateman. "Hispanic assimilation are we there yet? /." Waco, Tex. : Baylor University, 2008. http://hdl.handle.net/2104/5175.
Full text
44
Caprio, Mark Edward. "Koreans into Japanese : Japan's assimilation policy /." Thesis, Connect to this title online; UW restricted, 2001. http://hdl.handle.net/1773/10378.
Full text
45
Souopgui, Innocent. "Assimilation d'images pour les fluides géophysiques." Grenoble, 2010. http://www.theses.fr/2010GRENM071.
Full textAbstract:
La compréhension et la prévision de l'évolution des fluides géophysiques sont d'une importance capitale et constituent un domaine de recherche scientifique aux enjeux conséquents. Une bonne prévision est basée sur la prise en compte de toutes les informations disponibles sur le système considéré. Ces informations incluent les modèles, les observations et les connaissances a priori. L'assimilation de données permet de les combiner de façon optimale pour déterminer les entrées du modèle. Les dernières décennies ont vu croître en densité et en qualité la couverture satellitaire produisant, entre autres, des séquences d'images montrant l'évolution dynamique de certains phénomènes géophysiques tels que les dépressions et les fronts. Ces séquences d'images sont jusqu'à présent sous-utilisées en assimilation de données. Cette thèse propose une extension de l'assimilation variationnelle de données aux observations de type séquence d'images. Après avoir présenté les images, leur utilisation actuelle et ses limites, nous introduisons les notions de niveau d'interprétation, d'espaces et d'opérateur image. Ces notions sont utilisées pour formuler l'assimilation directe de séquences d'images. Nous proposons également une nouvelle approche de régularisation par diffusion généralisée pour les problèmes inverses. Les résultats préliminaires en traitement d'images et en assimilation directe de séquence d'images montrent une méthode prometteuse qui résout la plupart des problèmes rencontrés avec les approches classiques de régularisationUnderstanding and forecasting the evolution of geophysical fluids is a major scientific and societal challenge. A good forecast must take into account all available information on the studied system. These informations include models, observations and a priori knowledge. Data assimilation techniques combine all these informations in a consistent way to produce model inputs. During the last decades, many satellites were launched to increase the knowledge of earth. They produce, among others, image sequences showing the dynamical evolution of geophysical processes such as depressions and fronts. These images sequences are currently under-utilized in data assimilation. This thesis presents a consistent approach for taking into account image sequences in variational data assimilation. After a presentation of images, their current use and its limitation, we introduce the concepts of interpretation level, image space and image operator used for direct image sequences assimilation. We also propose a new approach of regularization based on generalized diffusion for ill-posed inverse problems. Preliminary results on image processing and image sequences assimilation show a promising approach that solve most of the problems encountered with classical approaches of regularization
46
CHAN, Shing Tak Pedro. "Case studies on the assimilation of contemporary mainland migrant families in Hong Kong : a segmented assimilation theory perspective." Digital Commons @ Lingnan University, 1999. https://commons.ln.edu.hk/soc_etd/13.
Full text
47
Grunmann, Pablo Javier. "Variational data assimilation of soil moisture information." College Park, Md. : University of Maryland, 2005. http://hdl.handle.net/1903/2476.
Full textAbstract:
Thesis (Ph. D.) -- University of Maryland, College Park, 2005.Thesis research directed by: Meteorology. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
48
Bushnell, Andrew. "Assimilation and Nationality in the Modern State." Thesis, Linköping University, Centre for Applied Ethics, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-19236.
Full textAbstract:
This paper addresses the expectation that immigrants will assimilate into the culture of their new country, why that expectation may be legitimate and how the modern state may act upon it. The central contention made is that because a national culture provides meaning and structure to the lives of members, and because that culture must be both traditional and institutionalized by the state to fulfill that purpose, if the state’s institutions, processes and procedures through their association with the national culture create an assimilative pressure on immigrants, this is morally permissible. However, the modern state is restricted from actively pursuing assimilation in the private sphere because of its commitment to individual liberty. Implications of this argument for the nature of citizenship and public policy are also discussed.
49
Lanefelt, Lily Stroubouli. "Multiculturalism, Liberalism and the Burden of Assimilation." Doctoral thesis, Stockholms universitet, Statsvetenskapliga institutionen, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-81978.
Full textAbstract:
Should a liberal state meet claims for accommodation of cultural difference with a liberal multicultural approach that grants cultural rights to minorities? The present thesis tries to answer this question by investigating if a liberal state may adopt a multicultural approach and still remain liberal. The purpose of the thesis, more specifically, is to study whether the accommodation of multiculturalism through cultural rights can be based on liberal values or not. The inquiry focuses on three influential liberal multicultural approaches which claim that cultural rights are congruent with equality, toleration and autonomy respectively. The coherence of these models is, however, questioned in the thesis. These models may neither be claimed to promote liberal values in a coherent and unambiguous way, nor be described as the adequate response to the type of burden of assimilation that members of minority cultures experience in liberal states. The main conclusion of the study is that liberal multiculturalism does not follow consistently from liberal premises and that the possibility of a normative conjunction between multiculturalism and liberalism therefore should be characterized as an open question in political theory. From liberal premises, a liberal neutralist model of integration based on anti-discrimination and equality of opportunity, in fact, still seems to be the most promising basis for a multicultural policy. It is argued in the thesis that this model can be developed if combined with a liberal scheme for deliberation on multicultural issues based on the principle of equality of opportunity.
50
Liu, Liyan Jones C. K. R. T. "Lagrangian data assimilation into layered ocean model." Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2007. http://dc.lib.unc.edu/u?/etd,786.
Full textAbstract:
Thesis (Ph. D.)--University of North Carolina at Chapel Hill, 2007.Title from electronic title page (viewed Dec. 18, 2007). "... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Mathematics." Discipline: Mathematics; Department/School: Mathematics.