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Werner, Kim Fiona [Verfasser]. "Halo bias renormalisation / Kim Fiona Werner." Bonn : Universitäts- und Landesbibliothek Bonn, 2020. http://d-nb.info/1218301570/34.
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Zheng, Zheng. "Constraining galaxy bias and cosmology using galaxy clustering data." Connect to this title online, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1092257217.
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Thesis (Ph. D.)--Ohio State University, 2004.Title from first page of PDF file. Document formatted into pages; contains xix, 302 p. : ill. (some col.). Advisor: David H. Weinberg, Department of Astronomy. Includes bibliographical references (p. 291-302).
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Lazeyras, Titouan [Verfasser], and Eiichiro [Akademischer Betreuer] Komatsu. "Investigations into dark matter halo bias / Titouan Lazeyras ; Betreuer: Eiichiro Komatsu." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2018. http://d-nb.info/1162443596/34.
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More, Surhud, Hironao Miyatake, Masahiro Takada, Benedikt Diemer, Andrey V. Kravtsov, Neal K. Dalal, Anupreeta More, et al. "DETECTION OF THE SPLASHBACK RADIUS AND HALO ASSEMBLY BIAS OF MASSIVE GALAXY CLUSTERS." IOP PUBLISHING LTD, 2016. http://hdl.handle.net/10150/621397.
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We show that the projected number density profiles of Sloan Digital Sky Survey photometric galaxies around galaxy clusters display strong evidence for the splashback radius, a sharp halo edge corresponding to the location of the first orbital apocenter of satellite galaxies after their infall. We split the clusters into two subsamples with different mean projected radial distances of their members, < R-mem >, at fixed richness and redshift. The sample with smaller < R-mem > has a smaller ratio of the splashback radius to the traditional halo boundary R-200m than the subsample with larger < R-mem >, indicative of different mass accretion rates for these subsamples. The same subsamples were recently used by Miyatake et al. to show that their large-scale clustering differs despite their similar weak lensing masses, demonstrating strong evidence for halo assembly bias. We expand on this result by presenting a 6.6 sigma difference in the clustering amplitudes of these samples using cluster-photometric galaxy cross-correlations. This measurement is a clear indication that halo clustering depends on parameters other than halo mass. If < R-mem > is related to the mass assembly history of halos, the measurement is a manifestation of the halo assembly bias. However, our measured splashback radii are smaller, while the strength of the assembly bias signal is stronger, than the predictions of collisionless. cold dark matter simulations. We show that dynamical friction, cluster mis-centering, or projection effects are not likely to be the sole source of these discrepancies. However, further investigations regarding unknown catastrophic weak lensing or cluster identification systematics are warranted.
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Matsubara, Takahiko. "Nonlinear perturbation theory with halo bias and redshift-space distortions via the Lagrangian picture." American Physical Society, 2008. http://hdl.handle.net/2237/11327.
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Beatton, Douglas A. "Trust within teams : the relative importance of ability, benevolence and integrity." Thesis, Queensland University of Technology, 2007. https://eprints.qut.edu.au/16651/1/Douglas_A._Beatton_Thesis.pdf.
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Trust between team members is important: Research has shown that teams with higher levels of trust have a propensity to be higher performers. This study built on contemporary trust theory by examining initial interpersonal trust development between a new team member and a newly formed work-team using experimental rather than correlation-based survey methods. Undergraduate students from a metropolitan Australian university participated in a vignette experiment examining the effect of teams with varying levels of Ability, Benevolence and Integrity on trust development. It was hypothesised that these antecedents of trust do not have similar effect on our Intention to Trust as is currently depicted in Mayer, Davis and Schoorman's (1995) integrative model of organisational trust. Their model is developed by hypothesising that the type and magnitude of the information we receive about a trustee moderates the relationship between our Intention to Trust and its antecedents. Initial examination of the traditional scales identified overlaps that needed clarification. This was completed by informing existing scales and the vignette manipulations with the context specific information that emerged from the thematic analysis of structured interviews. Subsequent analyses of the questionnaire data used ANOVA and Structural Equation Modelling techniques. In testing the hypotheses, Ability was found to be most salient in the development of Intention to Trust. This research contributes methodologically by developing a vignette-based experimental method that improves the reliability of existing trust scales. The study contributes theoretically by further explaining the salience of the trust antecedents and practically by identifying that the judgment and decision-making of new workteam members can be distorted by halo bias wherein they ignore the Benevolence traits of team members of a group that exhibits high levels of Ability.
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Beatton, Douglas A. "Trust within teams : the relative importance of ability, benevolence and integrity." Queensland University of Technology, 2007. http://eprints.qut.edu.au/16651/.
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Trust between team members is important: Research has shown that teams with higher levels of trust have a propensity to be higher performers. This study built on contemporary trust theory by examining initial interpersonal trust development between a new team member and a newly formed work-team using experimental rather than correlation-based survey methods. Undergraduate students from a metropolitan Australian university participated in a vignette experiment examining the effect of teams with varying levels of Ability, Benevolence and Integrity on trust development. It was hypothesised that these antecedents of trust do not have similar effect on our Intention to Trust as is currently depicted in Mayer, Davis and Schoorman's (1995) integrative model of organisational trust. Their model is developed by hypothesising that the type and magnitude of the information we receive about a trustee moderates the relationship between our Intention to Trust and its antecedents. Initial examination of the traditional scales identified overlaps that needed clarification. This was completed by informing existing scales and the vignette manipulations with the context specific information that emerged from the thematic analysis of structured interviews. Subsequent analyses of the questionnaire data used ANOVA and Structural Equation Modelling techniques. In testing the hypotheses, Ability was found to be most salient in the development of Intention to Trust. This research contributes methodologically by developing a vignette-based experimental method that improves the reliability of existing trust scales. The study contributes theoretically by further explaining the salience of the trust antecedents and practically by identifying that the judgment and decision-making of new workteam members can be distorted by halo bias wherein they ignore the Benevolence traits of team members of a group that exhibits high levels of Ability.
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Maniyar, Abhishek Sanjay. "From the CMB to CIB : dusty star formation, dark energy and kSZ." Thesis, Aix-Marseille, 2019. http://theses.univ-amu.fr.lama.univ-amu.fr/190919_MANIYAR_759uunye462vklkb421iixa572jct_TH.pdf.
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Le fond diffus infrarouge (CIB) provient de l'émission IR cumulée des galaxies sur toute l'histoire de l'Univers. Ainsi, le CIB sonde la formation et l'évolution des galaxies sur une grande gamme de décalage vers le rouge. Dans cette thèse, nous utilisons les anisotropies du CIB pour: i) Mesurer l'histoire de la formation des étoiles de l'Univers et le biais effectif des halos de matière noire hébergeant les galaxies CIB jusqu'à un décalage rouge élevé. En utilisant ces mesures, nous calculons la masse typique de ces halos de matière noire, sur une grande gamme de décalage vers le rouge. ii) En utilisant le CIB comme traceur de la structure à grande échelle, la corrélation croisée avec le CMB fournit une sonde alternative de l'énergie noire. Nous montrons que le CIB, extrait sur une grande fraction du ciel, peut fournir la meilleure mesure de l'effet ISW. En utilisant un formalisme matriciel de Fisher, nous prédisons l'amélioration des contraintes sur les paramètres cosmologiques en utilisant l'ISW mesuré avec le CIB. iii) Mesurer le spectre de puissance de l'effet Sunyaev-Zel'dovich cinétique (kSZ) caché dans les données du CMB. Nous améliorons les analyses existantes en combinant les mesures du CIB (de Planck/HFI et Herschel/SPIRE) et les observations de Planck, SPT et ACT pour étendre la gamme des échelles spatiales et des fréquences afin de faciliter la mesure du kSZ. Nous développons un nouveau modèle pour le CIB (pour pouvoir tenir compte des petites échelles spatiales), et modélisons de façon cohérente l'effet SZ thermique (tSZ) et la corrélation CIBxtSZ. Ceci est nécessaire pour séparer avec précision ces différentes composantes dans le spectre de puissanceThe CIB is the cumulative infrared emission from all the galaxies throughout cosmic history. Its distinct frequency-redshift dependence allows to probe a large span of redshifts. In this thesis, we utilise the CIB anisotropies detected by the Planck satellite to:i) Measure the star formation history of the Universe and the effective bias of the dark matter halos hosting the CIB galaxies to a high redshift. Using these measurements, we calculate the typical mass of the host dark matter halos for the CIB galaxies at different times.ii) Using the CIB as a tracer of the large scale structure, the cross-correlation with the CMB provides with an alternative probe of the dark energy. We showed that the CIB, extracted on a large fraction of the sky, may provide the best Integrated Sachs Wolf measurement (in terms of S/N ratio). Using a Fisher matrix formalism, we also predict the improvement on the constraints on the cosmological parameters using the ISW measured with this technique. We cross-correlate the best available maps of the CIB and the CMB and find that the dust residuals in the CIB maps are too high to detect the ISW through this method.iii) Measure the kinetic Sunyaev-Zel'dovich (kSZ) power spectrum hidden in the CMB power spectrum. We improve upon the existing analysis by combining the CIB measurements (from Planck/HFI and Herschel/SPIRE) and multi-frequency observations by Planck, SPT and ACT to extend the range of scales and frequencies to facilitate the kSZ measurement. We develop a power spectrum analysis based on physically motivated but simplistic and consistent models of foreground components (CIB, tSZ, tSZxCIB) to accurately separate the kSZ from the CMB
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Gomes, Matheus Gamino. "Efeito hall extraordinário em multicamadas granulares de SiO2/Co/CoO com exchange bias." Universidade Federal de Santa Maria, 2012. http://repositorio.ufsm.br/handle/1/3920.
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Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorGranular magnetic systems can be composed by magnetic particles or clusters with size of some nanometers. These magnetic nanoparticles present different magnetic order phases, as superparamagnetic, and they can be embedded in both, metallic or insulating matrix. These systems present several phenomena such as the giant magnetoresistance (GMR), extraordinary Hall effect (EHE), tunnel magnetoresistance (TMR) and Coulomb blockade. That phenomena use to disappear when a small termal fluctuation is high enough to reverse the magnetization of the clusters leading the lost the magnetic information in a very short time range. When it occurs, the particles are in superparamagnetic phase. In order to maintain the magnetic information at high values of temperature, or even to suppress the superparamagnetic limit, many works have tried to use an antiferromagnetic matrix, to induce the increase of the energy barrier among the two easy directions of magnetization by the exchange coupling in the grain(FM)/matrix(AFM) interfaces, with the purpose of stabilizing the particles magnetization. In this work, we have produced Co granular samples embedded in SiO2/CoO insulating/antifferomagnetic matrix through a sequential deposition by magnetron sputtering, in order to study the exchange bias of Co grains laterally surrounded by CoO.Were perfomed measurements of transmission eletronic microscopy (TEM), x-ray diffraction (XRD), measures low fields thermomagnetics (ZFC-FC), to obtain answers of the structural and magnétic charater of the samples. The Exchange Bias were investigated by extraordinary Hall effect, meauresments in differents temperature values in a cooling field (FC) of 5kOe. These non conventional measurements, are carried out with field cooling and the applied external field to perfomed the loop hysteresis both with perpendicular direction to the substrate. The effective anistropy, changes the magnitude up to three ordes of magnitude for different thicknesses of CoO in the limit T!0. On the other hand, the HEB linearily decreases, and goes to zero at a certain temperature. This temperature, is approximately, equal to that where the split of ZFC-FC curves occurs. This split is associated with the CoO blocking temperature, i.e. the ordering temperature of CoO. These results are reported from the finite size effect present in thin films. For the specific case of CoO, these effects lead to a nonzero net magnetization coming from uncompensed moments present on the surface that, in some cases, are responsible for the magnetic coupling governed by a local disorder and frustration, a spin-glass-like behavior. The extraodinary Hall effect and giant magnetoresistance were study of thin Fe-rich amorphous films and Fe-rich/Cu multilayers. Were investigated and compared the extraordinary Hall effect in these two types of samples and discussed it in terms of thickness and sample structure. The thicker films exhibited a strong in-plane magnetic anisotropy, and by decreasing film thickness both saturated Hall resistivity and Hall sensitivity increase. Electrical conductance increases and Hall resistivity decreases when the films are sandwiched with Cu.
Sistemas granulares magnéticos podem ser formados por grãos ou aglomerados magnéticos cujo tamanho é de alguns nanômetros. Estes grãos magnéticos apresentam diferentes fases de ordenamento magnético, como o superparamagnetismo, e podem estar envolvidos tanto por matrizes metálicas como matrizes isolantes. Estes sistemas possuem uma riqueza de fenômenos, como a magnetorresitência gigante (GMR), Efeito Hall Extraordinário (EHE), magnetorresistência túnel (TMR), bloqueio de coulomb entre outros. Estes fenômenos muitas vezes desaparecem quando à energia térmica for suficiente para inverter a magnetização dos grãos, levando-os a perder informação magnética num intervalo de tempo muito curto. Quando isto ocorre dizemos que os grãos estão na fase superparamagnética. Para reter a informação magnética a temperatura ambiente, ou até mesmo suprimir o superparamagnetismo, tem-se tentado o uso de uma matriz antiferromagnética (AFM) onde os grãos ficam imersos, e o acoplamento de troca na interface grão (FM)/matriz (AFM) pode induzir um aumento na barreira de energia entre as duas direções de fácil magnetização e com isso estabilizar a magnetização dos grãos. Neste trabalho foram produzidas amostras granulares de Co imersos em matriz isolante/antiferromagnética de SiO2/CoO pela deposição alternada do metal e dos isolantes por magnetron sputtering , com a finalidade de estudar a evolução do exchange bias entre os grãos de Co que estão lateralmente envolvidos por CoO. Foram realizadas medidas de Microscopia Eletrônica de Transmissão (TEM), Difração de raios-X (XRD), medidas termomagnéticas a baixos campos (ZFC-FC), para obter respostas quanto ao caráter estrutural e magnético das amostras. O Exchange bias foi investigado por efeito Hall extraordinário, medidas à diferentes temperaturas sob um campo de resfriamento (FC) de 5kOe. Estas medidas, diferente do convencional, são realizadas com o campo de resfriamento e o campo externo aplicado para realizar a curva de magnetização ambas na direção perpendicular ao substrato. A anisotropia efetiva, varia, na sua magnitude, até três ordens de grandeza para diferentes espessuras de CoO para o limite T !0. Por outro lado, o HEB decresce linearmente, até ir à zero numa dada temperatura. Esta temperatura onde extingue-se o HEB é, aproxiamdamente, a mesma onde ocorre à separação das curvas ZFC-FC. Esta separação nas curvas está associado com a temperatura de bloqueio de CoO, ou seja, temperatura de ordenamento dos grãos de CoO responsáveis pelo acoplamento direto com os grãos de Co. Estes resultados reportados são oriúndos dos efeitos de tamanho de grão, presentes em filmes muitos finos. Para o caso específico do CoO, estes efeitos levam há presença de uma magnetização diferente de zero oriúndos dos momentos não compensados presentes na superfície que, para alguns casos, são responsáveis pelo acoplamento magnético governado por uma desordem local e frustação, um compotamento do tipo spin-glass-like . Efeito Hall extraordinário e magnetorresistência gigante foram estudados em filmes finos amorfos de FINEMET e multicamdas FINEMET/Cu. Foi investigado e comparado o efetio Hall nos dois tipos de amostras, e discutido em termos da espessura e estrutura da amostra. Para os filmes mais espessos foi observado uma forte anisotropia no plano do filme, por outro lado, quando a espessura diminui ambos, a resistividade Hall satura e a sensibilidade Hall aumenta considerável. A condutividade elétrica aumenta e a resistividade Hall diminui para as multicamadas FINEMET/Cu.
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Dillard, Colin. "Quasiparticle Tunneling and High Bias Breakdown in the Fractional Quantum Hall Effect." Thesis, Harvard University, 2012. http://dissertations.umi.com/gsas.harvard:10334.
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The integer and fractional quantum Hall effects arise in two-dimensional electron systems subject to low temperature and high perpendicular magnetic field. The phenomenology of these two effects is rich and provides interesting insight into quantum physics. We present two experimental studies of phenomena in the fractional quantum Hall regime. The first examines the tunneling conductance of quasiparticles at filling factor 5/2. This state is of significant interest because it lies outside the traditional Jain hierarchy of fractional quantum Hall states and because it may be the first physical system found to exhibit non-abelian particle statistics. A quantum point contact is used to bring edge states on opposite sides of the system in proximity to each other, allowing quasiparticles to tunnel between the edge states. By annealing the gates forming the quantum point contact at different voltages we control the tunneling strength for fixed temperature and bias. We demonstrate a transition from strong to weak tunneling controlled in this manner. In the weak tunneling regime, the DC bias and temperature dependence of the tunneling conductance is fit to a theoretical form, resulting in values for the quasiparticle charge \(e*\) and the interaction parameter \(g\). The values of these parameters are used to help distinguish between proposed candidate states for the 5/2 wave function. Quantitative and qualitative results are most consistent with the abelian 331 state. Our second main focus is the breakdown of the fractional quantum Hall states at filling factors 4/3 and 5/3. Breakdown of integer and fractional quantum Hall states is known to occur when the Hall and longitudinal resistances deviate from their ideal values at nonzero critical currents. Although multiple studies of breakdown in the integer quantum Hall regime have been reported, corresponding results for the fractional regime are scarce. We observe breakdown over a range of integer states that is consistent with previous results. However, breakdown in the fractional regime is found to exhibit markedly different behavior. In particular, the magnitude of the critical current decreases with increased sample width. This behavior is opposite that observed for integer filling factors and does not seem to be explicable based on current theories of breakdown.Physics
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Pathak, Arjun Kumar. "EXPLORATION OF NEW MULTIFUNCTIONAL MAGNETIC MATERIALS BASED ON A VARIETY OF HEUSLER ALLOYS AND RARE-EARTH COMPOUNDS." OpenSIUC, 2011. https://opensiuc.lib.siu.edu/dissertations/353.
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Magnetic, magnetocaloric, magnetotransport and magnetoelastic properties of Ni-Mn-X (X = In, and Ga) Heusler alloys and La-Fe-Si based rare earth compounds have been synthesized and investigated by x-ray diffraction, magnetization, strain, and electrical resistivity measurements. The phase transitions, magnetic, magnetocaloric, magnetotransport and magnetoelastic properties strongly depend on the composition of these systems. In Ni50Mn50-xInx with x = 13.5, magnetocaloric and magnetotransport properties associated with the paramagnetic martensitic to paramagnetic austenitic transformation were studied. It was shown that magnetic entropy changes (SM) and magnetoresistance (MR) associated with this transformation are larger and the hysteresis effect is significantly lower when compared to that associated with paramagnetic-ferromagnetic transitions or ferromagnetic-antiferromagnetic/paramagnetic transitions in other systems. The Hall resistivity and the Hall angle shows unusual behavior in the vicinity of the martensitic phase transition for Ni50Mn50-xInx with x = 15.2. The observed Hall resistivity and Hall angle are 50 μ*cm and , respectively. It was observed that the presence of Ge, Al and Si atoms on the In sites strongly affects the crystal structure, and the electric and magnetic behaviors of Ni50Mn35In15. It was found that the partial substitution of In atoms by Si in Ni50Mn35In15 results in an increase in the magnetocaloric effect, exchange bias and shape memory effect. In Ni50Mn35In15-xSix, the peak values of positive SM for magnetic field changes H = 5 T were found to depend on composition and vary from 82 Jkg-1K-1 for x = 1 (at T = 275 K) to 124 Jkg-1K-1 for x = 3 (at T = 239 K). The partial substitution of Ni by Co in Ni50Mn35In15 significantly improves the magnetocaloric effect and MR in the vicinity of martensitic transition. In addition, significantly large inverse SM and MR were observed at the inverse martensitic phase transitions of the Ga-based magnetic shape memory Heusler alloys Ni50-xCoxMn32-yFeyGa18. The phase transition temperatures and magnetic properties were found to be correlated with the degree of tetragonal distortion in these samples. In LaFe11.57Si1.43Bx the crystal cell parameters and Curie temperatures were found to increase linearly with increasing B concentration up to ~ 0.1 % and 9 %, respectively. It was found that the characteristics of the magnetocaloric effect of LaFe11.57Si1.43 can be adjusted by a change in B concentration in the LaFe11.57Si1.43Bx system. A study of the influence of a small substitution of Ni, Cu, Cr, and V for Fe in LaFe11.4Si1.6 revealed that the magnetic, magnetocaloric, and magnetovolume coupling constant is related to an increase in the average Fe-Fe interatomic distances, leading to a change in the d-d exchange interaction.
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Li, Zehao. "Quantum Mechanics on the Möbius Ring." Digital WPI, 2013. https://digitalcommons.wpi.edu/etd-theses/186.
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Recent advances in the chemical vapor deposition method of growing graphene sheets suggest that graphene rings can grow. We may anticipate that chemical methods can be developed to construct twisted nano-ribbons to form Möbius structures in the very near future. I investigated the quantum mechanics of an electron constrained to motion on a nanoscale Möbius ring by solving the Schrdinger equation on the curved surface. The close analogy between ordinary cylindrical rings and Möbius rings is displayed by the closeness of their energy spectra. The expectation values for the angular momentum component L_z are shown to be close, but not exactly equal, to integral or half-integral multiples of hbar. The half-integer angular momentum states are present only for the nontrivial topology of Möbius rings. The effect of the curvature of the Möbius rings manifests itself in the level splitting. This can be understood in terms of representations of the discrete rotational groups C_nv. The nonzero variance of L_z will allow weak transitions between integral and half-integral angular momentum states, while preserving the unit angular momentum for photons. Again, since the topology of the system is critical for the Aharonov-Bohm effect, I investigated the AB effect on Möbius rings and found a remarkable pattern in transmission through finite-width 2D ring structures with finite-width input and output contacts attached at the periphery. The periodicity in the magnetic flux, in units of h/e, is weakly broken on 2D rings of finite width. The unusual states with half-integer values of observed on Möbius rings, investigated earlier, display a different characteristic in transmission. In view of the fascinating properties displayed by the non-trivial topology in terms of its novel two-dimensional physics, we expect that the properties of carriers on the Möbius ring that we have presented here will be relevant for practical applications.
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Hudin, Katarina. "I linje med styrdokumenten? - en fallstudie i tre läromedel i engelska." Thesis, Malmö högskola, Lärarutbildningen (LUT), 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-33771.
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This study focuses on an analysis of three text books in English, Prime Time, Second Time, and Third Time, written for Swedish pupils between grade seven and nine. The main focus of the study is to investigate to what extent the books may be considered to follow the steering principles of the Swedish education system. The theoretical backbone of the essay is centred on the construction and maintenance of stereotypes, and is written from a social constructivist point of view. In this context, I also reason around power relations and norms in the Western society – arguments which I, in the main analysis, apply to the books in question. Scrutinising the books from a social constructivist perspective, I reach the conclusion that the books are written with a Western bias, and also from a heteronormative angle. The essay finishes with a concluding remark of the most central parts from the theoretical section and the analysis respectively.
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Manera, Miret Marc. "Cosmologia i Formació d'Estructures / Cosmology and Structures Formation." Doctoral thesis, Universitat de Barcelona, 2007. http://hdl.handle.net/10803/1790.
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In this thesis we push forward techniques to learn about the large scale structure formation of the universe. The approach is from theory, observations and simulations. From theory we study the growth of four non standard cosmological models: DGP model, Cardassian model, Chaplygin gas model and Coupled Quintessence model. From observations we look at the ISW effect by means of the cross-correlation between CMB maps and galaxy survey. From a compilation of data we contrain the cosmological parameters and give new evidence of dark energy. We also introduce a new method to compute errors in configuration space and compare it with other methods in the literature. This method takes into account the geometry of the suveys and it is shown to give accurate results at large angles. In this thesis we also use large dark matter simulations to study the clustering and the local halo bias model. KEY WORDS: large scale structure, structure formation, dark energy, halo biasCATALÀ:
En aquesta tesi estudiem la formació d'estructures a gran escala de l'univers apoximant-nos-hi des de la teoria, les observacions i les simulacions. Respecte la teoria estudiem el creixement d'estructures en quatre models no estàndards: el model DGP, el model Cardassian, el model de gas de Chaplygin i el model de Quintessècia acoplada.
De les observacions estudiem la formació d'estructura a partir de correlacions entre mapes de galàxies amb mapes del CMB, les quals mesuren l'efecte ISW. A partir d'una compilació que d'aquestes mesures restringim els paràmetres cosmològics i mostrem nova evidència de l'energia fosca. També introduim un nou mètode per a calcular els errors de les correlacions en l'espai de configuració. Comparem aquest mètode amb d'altres i mostrem que estima bé els errors a angles grans, doncs tenim en compte l'area del cel observada. Finalment utilitzem simulacions de matéria fosca per estudiar el clustering i el model de bias local.
RESUMEN CASTELLANO:
En esta tesis estudiamos la formación de estructura en el universo en las vertientes teórica, observacional y con simulaciones. Respeto a la teoria estudiamos el crecimiento de estructuras en cuatro modelos no estándares: el modelo DGP, el modelo Cardassian, el modelo de gas de Chaplygin y el modelo de Quintessencia acoplado. Respecto a las observaciones estudiamos la formación de estructura a partir de las correlaciones entre el CMB y mapas de galaxias, las cuales miden el efecto ISW. A partir de una compilación de estas medidas restringimos los parámetros cosmológicos dando nueva evidencia de la energía oscura. También introducimos un nuevo método para el cálculo de errores en espacio de configuración y mostramos, al compararlo con otros, que estima bien los errores a grandes ángulos puesto que tenemos en cuenta la geometria de área observada. Finalmente, utilizando simulaciones de materia oscura, estudiamos el clustering y el modelo de bias local. PALABRAS CLAVE: Estructura a gran escala, energia oscura, bias en halos, formación de estructura.
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Yu, Yan [Verfasser], and Peter [Akademischer Betreuer] Burger. "Synthetic, Structural, Spectroscopic and Electrochemical Studies of Dinuclear bis μ-Oxo-Bridged Molybdenum(IV) and Tungsten(IV) Half-Sandwich Complexes / Yan Yu. Betreuer: Peter Burger." Hamburg : Staats- und Universitätsbibliothek Hamburg, 2014. http://d-nb.info/1052996701/34.
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Brand, Beatrice [Verfasser], Orlando [Akademischer Betreuer] Guntinas-Lichius, Hilmar [Akademischer Betreuer] Gudziol, and Dirk [Akademischer Betreuer] Eßer. "Entwicklung von Klinik und Lehrstuhl für Hals-Nasen-Ohrenheilkunde an der Universität Jena von 1957 bis 1975 / Beatrice Brand. Gutachter: Orlando Guntinas-Lichius ; Hilmar Gudziol ; Dirk Eßer." Jena : Thüringer Universitäts- und Landesbibliothek Jena, 2015. http://d-nb.info/1072072866/34.
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Rodrigues, Sampaio de Araújo Lincoln. "Propriedades magnéticas do nanocompósito (Fe1-xCox)y(MnO)1-y." Universidade Federal de Pernambuco, 2009. https://repositorio.ufpe.br/handle/123456789/6086.
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Previous issue date: 2009No presente trabalho foram investigadas propriedades magnéticas dos nanocompósitos ferromagnéticos (Fe1−xCox)y(MnO)1−y, x = 0.4 e 0.6 e y = 0.35, 0.65 e 1, produzidos pela técnica de mecano-síntese. A caracterização estrutural e morfológica das amostras foi feita usando difração de raios x fazendo uso da equação de Scherrer, de gráficos de Williamson-Hall e refinamento Rietveld. Essas análises resultaram em valores de x e y muito próximos dos valores nominais e, dentro da resolução da técnica, não foi detectada a presença de outras fases. As amostras apresentaram valores de tamanho médio dos cristalitos muito próximos (12-14 nm) e valores reduzidos de micro-deformações (1.5% para Fe1−xCox e 0.4% para o MnO). As propriedades magnéticas foram investigadas utilizando várias técnicas de medida (SQUID, magnetometria por extração e magnetometria por amostra vibrante), medidas em um grande intervalo de temperatura T (5-700 K) e em campos magnéticos de até 2 T. A partir dessas medidas foram construídos gráficos de Henkel e curvas de inversão de primeira ordem (FORCs) à temperatura ambiente e em campos de até 1.5 T. Medidas de curvas de histerese foram utilizadas para determinar a dependência da coercividade (HC), da magnetização de saturação (MS) e do campo de exchange-bias (HEB) com T. Procedimentos de medidas de magnetização feitas resfriando a amostra a campo nulo (ZFC) e na presença de campo (FC) foram feitas no intervalo de temperatura 5-300 K para valores pequenos de campo magnético (até 5 mT). Os gráficos de Henkel e FORCs indicaram que na temperatura ambiente as interações magnéticas entre as nanopartículas de Fe1−xCox são predominantemente de origem dipolar e influenciada essencialmente pela quantidade de MnO presente nas amostras. Entretanto, no caso particular da amostra sem MnO, o gráfico de Henkel indicou uma mudança de comportamento acima de 0.25 T passando a interação de dipolar para ser predominantemente de exchange. Acima de 120 K (temperatura de Néel do MnO), as medidas de HC apresentaram um dependência com T do tipo T3/4. Este comportamento é característico de arranjos de partículas tipo Stoner-Wohlfarth orientadas aleatoriamente. Já abaixo de 120 K, HC é fortemente influenciado pela presença de MnO aumentando significativamente com a diminuição da temperatura. Similar crescimento com T foi observado nos valores de HEB o qual é visto apenas em temperaturas abaixo de 120 K. As medidas de MS apresentaram uma dependência tipo Lei de Bloch T3/2 para a amostra sem MnO em todo intervalo de temperatura (5-700 K), enquanto para as demais amostras esse comportamento foi observado para T>120 K. Abaixo dessa temperatura, a adição de MnO produz um aumento em MS. Também foi observado o efeito de exchange-bias para temperaturas inferiores à temperatura de Néel do MnO (120 K), com um significante aumento do campo de exchange-bias com a diminuição da temperatura. Por fim, observamos também um comportamento irreversível nas magnetizações ZFC e FC abaixo de 120 K nas amostras com MnO. Os resultados obtidos abaixo de 120 K foram interpretados como devidos a interações de curto alcance entre as nanopartículas e pela presença de momentos magnéticos não compensados nas interfaces entre partículas
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Matern, Julia [Verfasser], and Rainald [Akademischer Betreuer] Knecht. "Retrospektive Analyse der postoperativen Antibiotikatherapie nach semisterilen Eingriffen in der Klinik für Hals-Nasen-Ohrenheilkunde des Universitätsklinikums Hamburg-Eppendorf von 2005 bis 2008 / Julia Matern. Betreuer: Rainald Knecht." Hamburg : Staats- und Universitätsbibliothek Hamburg, 2012. http://d-nb.info/1021499714/34.
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Luque, Ramos Andres [Verfasser], Falk [Akademischer Betreuer] Hoffmann, Djordje [Akademischer Betreuer] Lazovic, and Hajo [Akademischer Betreuer] Zeeb. "Zur Versorgung von Patienten mit rheumatoider Arthritis von der Jugend bis ins hohe Alter: Analysen auf Basis eines Linkage von Abrechnungs- und Befragungsdaten / Andres Luque Ramos ; Falk Hoffmann, Djordje Lazovic, Hajo Zeeb." Oldenburg : BIS der Universität Oldenburg, 2019. http://d-nb.info/1177241358/34.
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Severac, Fabrice. "Jonctions ultra-minces p+/n pour MOS "ultimes étude de l'impact des défauts sur la mobilité et l'activation du bore." Phd thesis, Université Paul Sabatier - Toulouse III, 2009. http://tel.archives-ouvertes.fr/tel-00390908.
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La réalisation des transistors MOS de taille "ultime" nécessite la fabrication de jonctions source et drain ultra-minces (quelques dizaines de nanomètres), abruptes et fortement dopées. L'optimisation du procédé de fabrication de ces jonctions nécessite la compréhension des phénomènes physiques qui interviennent lors des différentes étapes de fabrication, en particulier l'impact des défauts cristallins sur leurs paramètres électriques. Dans ce travail, nous avons étudié l'impact des précipités de bore (BICs, Boron-Interstitial Clusters) mais aussi des défauts EOR (End-Of-Range), sur la mobilité des porteurs et l'activation des dopants (principalement le bore dans le silicium). Tout d'abord, nous avons développé un modèle d'analyse mathématique basé sur le profil de concentration des dopants mesuré par SIMS et sur les valeurs " standards " de mobilité des porteurs. Ce modèle permet de déterminer par le calcul les trois paramètres électriques mesurés par effet Hall : la résistance carrée, la dose active de dopants et la mobilité des porteurs. A partir de l'utilisation de ce modèle, nous démontrons qu'en présence de BICs, il s'avère nécessaire de modifier la valeur d'un facteur correctif, le facteur de scattering, essentiel pour les mesures par effet Hall, et nous déterminons sa valeur. Nous mettons ensuite en évidence la dégradation de la mobilité des porteurs par les BICs, puis étudions de manière plus quantitative l'évolution de cette dégradation en fonction de la quantité de BICs. Par la suite, une étude sur l'activation du bore en présence de défauts EOR est menée. Enfin, nous élargissons notre étude sur ces mêmes paramètres électriques au cas de nouveaux matériaux tels que le SOI (Silicon-On-Insulator) ou le SiGe (alliage silicium/germanium), matériaux utilisés pour les dernières générations de transistors.
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Cadiou, Corentin. "L’impact des grandes structures de l’Univers sur la formation des halos de matière noire et des galaxies How does the cosmic web impact assembly bias? Accurate tracer particles of baryon dynamics in the adaptive mesh refinement code Ramses Galaxy evolution in the metric of the cosmic web Galaxies flowing in the oriented saddle frame of the cosmic web." Thesis, Sorbonne université, 2019. http://www.theses.fr/2019SORUS508.
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À grande échelle, la distribution anisotrope de la matière forme un large réseau de vides délimités par des murs qui, avec les filaments présents à leurs intersections, tissent la toile cosmique. La matière qui doit former plus tard les halos de matière noire et leurs galaxies afflue vers les nœuds compacts se situant à l’intersection des filaments et garde dans ce processus une empreinte de la toile cosmique. Dans cette thèse, je développe une extension contrainte de la théorie de l’excursion qui, à l'aide d'un modèle de filament, me permet de montrer que l'environnement anisotrope a un effet sur l'histoire de formation des halos de matière noire. La toile cosmique a donc un rôle dans la formation des halos et de leurs galaxies. Dans un second temps, je construis un modèle qui décrit l'évolution de la toile cosmique (fusion de halos, mais aussi de filaments et de murs) afin de mieux contraindre les modèles de formation de galaxies. Le modèle prédit un excès d'accrétion anisotrope dans les filaments par rapports aux nœuds, biaisant ainsi la formation des galaxies. L'effet de l'accrétion anisotrope sur la formation des galaxies est ensuite étudié à l'aide de simulations hydrodynamiques et d'une nouvelle méthode permettant le suivi précis de l'histoire d'accrétion du gaz. J'y montre que le moment angulaire est transporté efficacement des grandes échelles de la toile cosmique jusque dans les zones internes du halo, où les couples gravitationnels le redistribue au disque de la galaxies et au halo interneThe anisotropic large-scale distribution of matter is made of an extended network of voids delimited by sheets, with filaments at their intersection which together form the cosmic web. Matter that will later form dark matter halos and their galaxies flows towards compact nodes at filaments' intersections and in the process, retains the imprint of the cosmic web. In this thesis, I develop a conditional version of the excursion set theory which, using a model of a large-scale filament, enables me to show that anisotropic environment have an impact on the formation history of dark matter halos. The cosmic web then has a role in the formation of halos and their galaxies. I then build a model that is able to capture the evolution of the cosmic web (halo mergers, but also filament and wall mergers) that can be used to better constrain galaxy formation models. The model predicts that an excess of anisotropic accretion is expected in filaments compared to nodes, so that the formation history of galaxies is biased. The effect of anisotropic accretion on galaxy formation is then studied using hydrodynamical simulations and a novel numerical method tailored to accurately follow the accretion history of the gas. I show that the angular momentum is transported efficiently from the cosmic web down to the inner halo, where gravitational torques redistribute it to the disk and the inner halo
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Hürth, Teresa [Verfasser], Sven [Gutachter] Koscielny, Matthias [Gutachter] Steinert, and Peter [Gutachter] Jecker. "Evaluierung der Rolle der diagnostischen und therapeutischen starren, flexiblen und kombiniert starren und flexiblen Bronchoskopie im klinischen Alltag der Klinik für Hals-Nasen-Ohrenheilkunde des Universitätsklinikums Jena im Zeitraum von 2011 bis 2015 / Teresa Hürth ; Gutachter: Sven Koscielny, Matthias Steinert, Peter Jecker." Jena : Friedrich-Schiller-Universität Jena, 2020. http://d-nb.info/122035614X/34.
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Dogantimur, Erkan, and Daniel Johnsson. "Analysis of Accuracy for Engine and Gearbox Sensors." Thesis, Uppsala universitet, Institutionen för teknikvetenskaper, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-388346.
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This thesis provides a standardized method to measure accuracy for engine and gearbox sensors. Accuracy is defined by ISO 5725, which states that trueness and precision need to be known to provide a metric for accuracy. However, obtaining and processing the data required for this is not straight forward. In this thesis, a method is presented that consists of two main parts: data acquisition and data analysis. The data acquisition part shows how to connect all of the equipment used and how to sample and store all the raw data from the sensors. The data analysis part shows how to process that raw data into statistical data, such as trueness, repeatability and reproducibility for the sensors. Once repeatability and reproducibility are known, the total precision can be determined. Accuracy can then be obtained by using information from trueness and precision. Besides, this thesis shows that measurement error can be separated into error caused by the sensors and error caused by the measurand. This is useful information, because it can be used to assess which type of error is the greatest, whether or not it can be compensated for, and if it is economically viable to compensate for such error. The results are then shown, where it is possible to gain information about the sensors’ performance from various graphs. Between Hall and inductive sensors, there were no superior winner, since they both have their strengths and weaknesses. The thesis ends by making recommendations on how to compensate for some of the errors, and how to improve upon the method to make it more automatic in the future.
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Laubenthal, Johannes Gerhard Heribert [Verfasser], and Josef [Akademischer Betreuer] Dumbach. "Prognostische Bedeutung klinisch-therapeutischer Faktoren beim adenoidzystischen Karzinom des Kopf-Hals-Bereiches : Retrospektive Analyse am Patientengut der Klinik für Mund-, Kiefer-, Gesichtschirurgie und Plastische Operationen des Klinikums Saarbrücken, akademisches Lehrkrankenhaus der Universität des Saarlandes, mit adenoidzystischem Karzinom im Zeitraum von 1984 bis 2015 / Johannes Gerhard Heribert Laubenthal ; Betreuer: Josef Dumbach." Saarbrücken : Saarländische Universitäts- und Landesbibliothek, 2018. http://d-nb.info/1160513988/34.
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Laubenthal, Johannes [Verfasser], and Josef [Akademischer Betreuer] Dumbach. "Prognostische Bedeutung klinisch-therapeutischer Faktoren beim adenoidzystischen Karzinom des Kopf-Hals-Bereiches : Retrospektive Analyse am Patientengut der Klinik für Mund-, Kiefer-, Gesichtschirurgie und Plastische Operationen des Klinikums Saarbrücken, akademisches Lehrkrankenhaus der Universität des Saarlandes, mit adenoidzystischem Karzinom im Zeitraum von 1984 bis 2015 / Johannes Gerhard Heribert Laubenthal ; Betreuer: Josef Dumbach." Saarbrücken : Saarländische Universitäts- und Landesbibliothek, 2018. http://d-nb.info/1160513988/34.
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Simão, Sofia Alexandra Vieira. "Au Naturel: The impact of Natural Claims on Consumers’ Judgments and Shopping Behaviour of Personal Care Products." Master's thesis, 2022. http://hdl.handle.net/10362/134637.
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Dissertation presented as the partial requirement for obtaining a Master's degree in Information Management, specialization in Marketing IntelligenceNatural claims have been increasingly used by brands across a variety of product categories (e.g., personal care products) since consumers are becoming highly aware of what they consume and put into their bodies. The frequency of use of this type of claim suggests that they deliver strong competitive advantages. The main goal of this research is to investigate the influence of natural claims on consumers’ judgments and purchase intentions of personal care products and understand the impact of individual differences (health and environmental consciousness) on the natural-is-better bias and the health halos evoked by natural claims. A pre-study and an online experiment were conducted, with a total of 425 products analysed and 256 respondents. Results suggest that natural claims influence consumers’ product evaluations (perceived efficacy, perceived safety, and sensorial expectations), and perceived efficacy and sensorial expectations partially moderate the relationship between natural claims and purchase intentions. Furthermore, findings show that environmental consciousness moderates the effects of natural claims on consumers’ judgments of perceived efficacy. The findings extend previous literature in consumer behaviour and the natural-is-better bias by proving the existence of a bias for personal care products with natural claims. The implications for brands and policy makers are discussed.
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LIN, LI-HWAI, and 林俐暉. "BIAS AND MERGER OF NONSPHERICAL HALOS." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/27068071217420645261.
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碩士國立臺灣大學
物理學研究所
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We simulate the nonspherical collapse processes by six-dimensional random walks based on Zeldovich's approximation. The collapse boundary condition we adopt here is a slightly-modified version of the one proposed by Chiueh and Lee(2001). This boundary condition concerns the nonspherical collapse nature of bound objects and can produce a mass function consistent with Sheth and Tormen's fitting formula (1999) derived from N-body simulation. Among all properties of the mass distribution, we first concentrate on the large-scale bias factor. How the distribution of bound objects relates to the background density is calculated and compared with both the analytical formula and the results of N-body simulation. We also consider the merging history of large bound objects. In our Monte-Carlo simulation, we compute the mass fraction of progenitors within the present dark halos, and derive an analytical fitting formula for the conditional probability of progenitors merged in any distant past. This fitting formula compares reasonably well with the simulation result.
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Ragone, Figueroa Cinthia Judith. "Dependencia ambiental de las propiedades de halos de materia oscura /." Doctoral thesis, 2008. http://hdl.handle.net/11086/119.
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Zíka, Vojtěch. "Kognitivní chyby v procesu masové komunikace." Master's thesis, 2016. http://www.nusl.cz/ntk/nusl-350569.
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This work is based on an assumption that human decision-making process is following several approximate rules (heuristics) that causes predictable and systematic errors in judgement (cognitive biases). Although this stand point is typical for fields like behavioural economics or behavioural law and economics, there is no reason to not apply this logic also on other discipline like a mass media communication studies. This work offers an analysis of the information market where supply side is represented by producers of information (e.g. media organizations) and demand side is represented by consumers of those information (audience). The analysis is focused on factors that cause perceived description of a particular event can vastly differ from this event. One of those cognitive biases which cause different perception of the same media content is called hostile media effect. In respect to this effect, sympathizers with a socially controversial topic tend to perceive information in the mass media as hostile to their own opinion. Previous research concluded that hostile perception is mainly caused by a reach of information which is explained by the selective categorization - although individuals with different worldview can see the same content, they perceive it with a different valence. The valence of the...
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KUDRLIČKOVÁ, Zlata. "Die Jüdische Gemeinde Wiens, ihre Entwicklung von 1945 bis heute." Master's thesis, 2014. http://www.nusl.cz/ntk/nusl-173119.
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This thesis deal with the life of Jewish Community in Vienna after Second World War to the present days. This work describes most important aspects of daily and cultural Jewish life in Vienna these days. As an introduction to the topic is described the relevant political history of Austria for example Borodajkewycz affair or Causa Waldheim. Included is also the theme of overcoming the past in Austria and the theme of anti - Semitism in this country. In the first part of this work is given a historical overview of the development of the Jewish community in Vienna after the Second World War to present days. The second part of the work deal with the main Jewish institutions, organizations and associations in present Vienna. The theme of Jewish cultural life and leisure time activities are also included. A part of this thesis is also a brief summary about the possibilities of using this theme in education at Czechs schools.
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Gottschling, Birgit. "Brachytherapie (HDR-Iridium 192) bei Kopf-Hals-Tumoren : Indikation, Durchführung und Ergebnisse bei 131 Patienten in der Zeit von 1993 bis 2001 /." 2006. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=014967964&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Abu-Ayyash, Fawzi. "Das Reinke-Ödem der Stimmbänder klinische und therapeutische Aspekte. Untersuchungen am Krankengut der Universitäts-Hals-Nasen-Ohrenklinik Köln von 1962 bis 1984 (722 Fälle) /." 1987. http://catalog.hathitrust.org/api/volumes/oclc/17847928.html.
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Kaffo, Melou Maximilien. "Essays on bootstrap in econometrics." Thèse, 2014. http://hdl.handle.net/1866/11429.
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Ma thèse est composée de trois essais sur l'inférence par le bootstrap à la fois dans les modèles de données de panel et les modèles à grands nombres de variables instrumentales #VI# dont un grand nombre peut être faible. La théorie asymptotique n'étant pas toujours une bonne approximation de la distribution d'échantillonnage des estimateurs et statistiques de tests, je considère le bootstrap comme une alternative. Ces essais tentent d'étudier la validité asymptotique des procédures bootstrap existantes et quand invalides, proposent de nouvelles méthodes bootstrap valides.
Le premier chapitre #co-écrit avec Sílvia Gonçalves# étudie la validité du bootstrap pour l'inférence dans un modèle de panel de données linéaire, dynamique et stationnaire à effets fixes. Nous considérons trois méthodes bootstrap: le recursive-design bootstrap, le fixed-design bootstrap et le pairs bootstrap. Ces méthodes sont des généralisations naturelles au contexte des panels des méthodes bootstrap considérées par Gonçalves et Kilian #2004# dans les modèles autorégressifs en séries temporelles. Nous montrons que l'estimateur MCO obtenu par le recursive-design bootstrap contient un terme intégré qui imite le biais de l'estimateur original. Ceci est en contraste avec le fixed-design bootstrap et le pairs bootstrap dont les distributions sont incorrectement centrées à zéro. Cependant, le recursive-design bootstrap et le pairs bootstrap sont asymptotiquement valides quand ils sont appliqués à l'estimateur corrigé du biais, contrairement au fixed-design bootstrap. Dans les simulations, le recursive-design bootstrap est la méthode qui produit les meilleurs résultats.
Le deuxième chapitre étend les résultats du pairs bootstrap aux modèles de panel non linéaires dynamiques avec des effets fixes. Ces modèles sont souvent estimés par l'estimateur du maximum de vraisemblance #EMV# qui souffre également d'un biais. Récemment, Dhaene et Johmans #2014# ont proposé la méthode d'estimation split-jackknife. Bien que ces estimateurs ont des approximations asymptotiques normales centrées sur le vrai paramètre, de sérieuses distorsions demeurent à échantillons finis. Dhaene et Johmans #2014# ont proposé le pairs bootstrap comme alternative dans ce contexte sans aucune justification théorique. Pour combler cette lacune, je montre que cette méthode est asymptotiquement valide lorsqu'elle est utilisée pour estimer la distribution de l'estimateur split-jackknife bien qu'incapable d'estimer la distribution de l'EMV. Des simulations Monte Carlo montrent que les intervalles de confiance bootstrap basés sur l'estimateur split-jackknife aident grandement à réduire les distorsions liées à l'approximation normale en échantillons finis. En outre, j'applique cette méthode bootstrap à un modèle de participation des femmes au marché du travail pour construire des intervalles de confiance valides.
Dans le dernier chapitre #co-écrit avec Wenjie Wang#, nous étudions la validité asymptotique des procédures bootstrap pour les modèles à grands nombres de variables instrumentales #VI# dont un grand nombre peu être faible. Nous montrons analytiquement qu'un bootstrap standard basé sur les résidus et le bootstrap restreint et efficace #RE# de Davidson et MacKinnon #2008, 2010, 2014# ne peuvent pas estimer la distribution limite de l'estimateur du maximum de vraisemblance à information limitée #EMVIL#. La raison principale est qu'ils ne parviennent pas à bien imiter le paramètre qui caractérise l'intensité de l'identification dans l'échantillon. Par conséquent, nous proposons une méthode bootstrap modifiée qui estime de facon convergente cette distribution limite. Nos simulations montrent que la méthode bootstrap modifiée réduit considérablement les distorsions des tests asymptotiques de type Wald #$t$# dans les échantillons finis, en particulier lorsque le degré d'endogénéité est élevé.My dissertation consists of three essays on bootstrap inference in both large panel data models and instrumental variable (IV) models with many instruments and possibly, many weak instruments. Since the asymptotic theory is often not a good approximation to the sampling distribution of test statistics and estimators, I consider the bootstrap as an alternative. These essays try to study the asymptotic validity of existing bootstrap procedures and when they are invalid, to propose new valid bootstrap methods. The first chapter (co-authored with Sílvia Gonçalves) studies the validity of the bootstrap for inference on a stationary linear dynamic panel data model with individual fixed effects. We consider three bootstrap methods: the recursive-design wild bootstrap, the fixed-design wild bootstrap and the pairs bootstrap. These methods are natural generalizations to the panel context of the bootstrap methods considered by \citeasnoun{GK} in pure time series autoregressive models. We show that the recursive-design wild bootstrap fixed effects OLS estimator contains a built-in bias correction term that mimics the incidental parameter bias. This is in contrast with the fixed-design wild bootstrap and the pairs bootstrap whose distributions are incorrectly centered at zero. As it turns out, both the recursive-design and the pairs bootstrap are asymptotically valid when applied to the bias-corrected estimator, but the fixed-design bootstrap is not. In the simulations, the recursive-design bootstrap is the method that does best overall. The second chapter extends our pairwise bootstrap results to dynamic nonlinear panel data models with fixed effects. These models are often estimated with the Maximum Likelihood Estimator (MLE) which also suffers from an incidental parameter bias. Recently, \citeasnoun{DhaeneJochmans} have proposed the split-jackknife estimation method. Although these estimators have asymptotic normal approximations that are centered at the true parameter, important size distortions remain in finite samples. \citeasnoun{DhaeneJochmans} have proposed the pairs bootstrap as an alternative in this context without a theoretical justification. To fill this gap, I show that this method is asymptotically valid when used to estimate the distribution of the half-panel jackknife estimator although it does not consistently estimate the distribution of the MLE. A Monte Carlo experiment shows that bootstrap-based confidence intervals that rely on the half-panel jackknife estimator greatly help to reduce the distortions associated to the normal approximation in finite samples. In addition, I apply this bootstrap method to a canonical model of female-labor participation to construct valid confidence intervals. In the last chapter (co-authored with Wenjie Wang), we study the asymptotic validity of bootstrap procedures for instrumental variable (IV) models with many weak instruments. We show analytically that a standard residual-based bootstrap and the restricted efficient (RE) bootstrap of Davidson and MacKinnon (2008, 2010, 2014) cannot consistently estimate the limiting distribution of the LIML estimator. The foremost reason is that they fail to adequately mimic the identification strength in the sample. Therefore, we propose a modified bootstrap procedure which consistently estimates this limiting distribution. Our simulations show that the modified bootstrap procedure greatly reduces the distortions associated to asymptotic Wald ($t$) tests in finite samples, especially when the degree of endogeneity is high.
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Schuldt, Tobias [Verfasser]. "Die mikrobiologische Besiedlung von Stimmprothesen : eine retrospektive Analyse des Patientengutes der Klinik und Poliklinik für Hals-Nasen-Ohrenheilkunde, Kopf- und Halschirurgie "Otto Körner" der Universität Rostock von Januar 1994 bis Juli 2004 / vorgeelgt von Tobias Christian Werner Schuldt." 2009. http://nbn-resolving.de/urn:nbn:de:gbv:28-diss2010-0042-9.
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Schuldt, Tobias Christian Werner [Verfasser]. "Die mikrobiologische Besiedlung von Stimmprothesen : eine retrospektive Analyse des Patientengutes der Klinik und Poliklinik für Hals-Nasen-Ohrenheilkunde, Kopf- und Halschirurgie "Otto Körner" der Universität Rostock von Januar 1994 bis Juli 2004 / vorgeelgt von Tobias Christian Werner Schuldt." 2009. http://d-nb.info/1003031811/34.
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Löffler, Claudia [Verfasser]. "Vergleich der offenen und endoskopischen Therapie des Zenker-Divertikels im Zeitraum von 1977 bis 2008 an der Klinik für Hals-, Nasen- und Ohrenheilkunde der Universität Jena, Bewertung verschiedener Entzündungsparameter und deren Prädiktion für postoperative Komplikationen / von: Claudia Löffler." 2009. http://d-nb.info/1007864214/34.
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